Definition.

There is no commonly accepted modern definition of feudalism, at least among scholars. The adjective "feudal" was coined in the 17th century, and the noun "feudalism", often used in a political and propaganda context, was not coined until the 19th century, from the French "féodalité" ("feudality"), itself an 18th-century creation.  According to a classic definition by François-Louis Ganshof (1944), "feudalism" describes a set of reciprocal legal and military obligations which existed among the warrior nobility and revolved around the three key concepts of lords, vassals and fiefs, though Ganshof himself noted that his treatment was only related to the "narrow, technical, legal sense of the word".  A broader definition, as described in Marc Bloch's "Feudal Society" (1939), includes not only the obligations of the warrior nobility but the obligations of all three estates of the realm: the nobility, the clergy, and those who lived off their labor, most directly the peasantry which was bound by a system of manorialism; this order is often referred to as a "feudal society", echoing Bloch's usage.  Outside its European context, the concept of feudalism is often used by analogy, most often in discussions of feudal Japan under the "shoguns", and sometimes in discussions of the Zagwe dynasty in medieval Ethiopia, which had some feudal characteristics (sometimes called "semifeudal"). Some have taken the feudalism analogy further, seeing feudalism (or traces of it) in places as diverse as China during the Spring and Autumn period, ancient Egypt, the Parthian empire, the Indian subcontinent and the Antebellum and Jim Crow American South. Wu Ta-k'un argued that China's fengjian, being kinship-based and tied to land which was controlled by a king, was entirely distinct from feudalism. This despite the fact that in translation "fengjian" is frequently paired in both directions with "feudal".  The term "feudalism" has also been applied—often inappropriately or pejoratively—to non-Western societies where institutions and attitudes which are similar to those which existed in medieval Europe are perceived to prevail. Some historians and political theorists believe that the term "feudalism" has been deprived of specific meaning by the many ways it has been used, leading them to reject it as a useful concept for understanding society.

Etymology.

The term "féodal" was used in 17th-century French legal treatises (1614) and translated into English legal treatises as an adjective, such as "feodal government".  In the 18th century, Adam Smith, seeking to describe economic systems, effectively coined the forms "feudal government" and "feudal system" in his book "Wealth of Nations" (1776). In the 19th century the adjective "feudal" evolved into a noun: "feudalism". The term "feudalism" is recent, first appearing in French in 1823, Italian in 1827, English in 1839, and in German in the second half of the 19th century.  The term "feudal" or "feodal" is derived from the medieval Latin word "feodum". The etymology of "feodum" is complex with multiple theories, some suggesting a Germanic origin (the most widely held view) and others suggesting an Arabic origin. Initially in medieval Latin European documents, a land grant in exchange for service was called a "beneficium" (Latin). Later, the term "feudum", or "feodum", began to replace "beneficium" in the documents. The first attested instance of this is from 984, although more primitive forms were seen up to one-hundred years earlier. The origin of the "feudum" and why it replaced "beneficium" has not been well established, but there are multiple theories, described below.  The most widely held theory was proposed by Johan Hendrik Caspar Kern in 1870, being supported by, amongst others, William Stubbs and Marc Bloch. Kern derived the word from a putative Frankish term "*fehu-ôd", in which "*fehu" means "cattle" and "-ôd" means "goods", implying "a moveable object of value". Bloch explains that by the beginning of the 10th century it was common to value land in monetary terms but to pay for it with moveable objects of equivalent value, such as arms, clothing, horses or food. This was known as "feos", a term that took on the general meaning of paying for something in lieu of money. This meaning was then applied to land itself, in which land was used to pay for fealty, such as to a vassal. Thus the old word "feos" meaning movable property changed little by little to "feus" meaning the exact opposite: landed property.  Another theory was put forward by Archibald R. Lewis. Lewis said the origin of 'fief' is not "feudum" (or "feodum"), but rather "foderum", the earliest attested use being in Astronomus's "Vita Hludovici" (840). In that text is a passage about Louis the Pious that says "annona militaris quas vulgo foderum vocant", which can be translated as "Louis forbade that military provender (which they popularly call "fodder") be furnished.."  Another theory by Alauddin Samarrai suggests an Arabic origin, from "fuyū" (the plural of "fay", which literally means "the returned", and was used especially for 'land that has been conquered from enemies that did not fight'). Samarrai's theory is that early forms of 'fief' include "feo", "feu", "feuz", "feuum" and others, the plurality of forms strongly suggesting origins from a loanword. The first use of these terms is in Languedoc, one of the least Germanic areas of Europe and bordering Muslim Spain. Further, the earliest use of "feuum" (as a replacement for "beneficium") can be dated to 899, the same year a Muslim base at Fraxinetum (La Garde-Freinet) in Provence was established. It is possible, Samarrai says, that French scribes, writing in Latin, attempted to transliterate the Arabic word "fuyū" (the plural of "fay"), which was being used by the Muslim invaders and occupiers at the time, resulting in a plurality of forms – "feo, feu, feuz, feuum" and others – from which eventually "feudum" derived. Samarrai, however, also advises to handle this theory with care, as Medieval and Early Modern Muslim scribes often used etymologically "fanciful roots" in order to claim the most outlandish things to be of Arabian or Muslim origin.

History.

Feudalism, in its various forms, usually emerged as a result of the decentralization of an empire: especially in the Carolingian Empire in 8th century AD/CE, which lacked the bureaucratic infrastructure necessary to support cavalry without allocating land to these mounted troops. Mounted soldiers began to secure a system of hereditary rule over their allocated land and their power over the territory came to encompass the social, political, judicial, and economic spheres.  These acquired powers significantly diminished unitary power in these empires. Only when the infrastructure existed to maintain unitary power—as with the European monarchies—did feudalism begin to yield to this new power structure and eventually disappear.

Classic feudalism.

The classic François-Louis Ganshof version of feudalism describes a set of reciprocal legal and military obligations which existed among the warrior nobility, revolving around the three key concepts of lords, vassals and fiefs. In broad terms a lord was a noble who held land, a vassal was a person who was granted possession of the land by the lord, and the land was known as a fief. In exchange for the use of the fief and protection by the lord, the vassal would provide some sort of service to the lord. There were many varieties of feudal land tenure, consisting of military and non-military service. The obligations and corresponding rights between lord and vassal concerning the fief form the basis of the feudal relationship.

Vassalage.

Before a lord could grant land (a fief) to someone, he had to make that person a vassal. This was done at a formal and symbolic ceremony called a commendation ceremony, which was composed of the two-part act of homage and oath of fealty. During homage, the lord and vassal entered into a contract in which the vassal promised to fight for the lord at his command, whilst the lord agreed to protect the vassal from external forces. "Fealty" comes from the Latin "fidelitas" and denotes the fidelity owed by a vassal to his feudal lord. "Fealty" also refers to an oath that more explicitly reinforces the commitments of the vassal made during homage. Such an oath follows homage.  Once the commendation ceremony was complete, the lord and vassal were in a feudal relationship with agreed obligations to one another. The vassal's principal obligation to the lord was to "aid", or military service. Using whatever equipment the vassal could obtain by virtue of the revenues from the fief, the vassal was responsible to answer calls to military service on behalf of the lord. This security of military help was the primary reason the lord entered into the feudal relationship. In addition, the vassal could have other obligations to his lord, such as attendance at his court, whether manorial, baronial, both termed court baron, or at the king's court. It could also involve the vassal providing "counsel", so that if the lord faced a major decision he would summon all his vassals and hold a council. At the level of the manor this might be a fairly mundane matter of agricultural policy, but also included sentencing by the lord for criminal offences, including capital punishment in some cases. Concerning the king's feudal court, such deliberation could include the question of declaring war. These are examples; depending on the period of time and location in Europe, feudal customs and practices varied; see examples of feudalism.

The "Feudal Revolution" in France.

In its origin, the feudal grant of land had been seen in terms of a personal bond between lord and vassal, but with time and the transformation of fiefs into hereditary holdings, the nature of the system came to be seen as a form of "politics of land" (an expression used by the historian Marc Bloch). The 11th century in France saw what has been called by historians a "feudal revolution" or "mutation" and a "fragmentation of powers" (Bloch) that was unlike the development of feudalism in England or Italy or Germany in the same period or later: Counties and duchies began to break down into smaller holdings as castellans and lesser seigneurs took control of local lands, and (as comital families had done before them) lesser lords usurped/privatized a wide range of prerogatives and rights of the state, most importantly the highly profitable rights of justice, but also travel dues, market dues, fees for using woodlands, obligations to use the lord's mill, etc. (what Georges Duby called collectively the ""seigneurie banale""). Power in this period became more personal.  This "fragmentation of powers" was not, however, systematic throughout France, and in certain counties (such as Flanders, Normandy, Anjou, Toulouse), counts were able to maintain control of their lands into the 12th century or later. Thus, in some regions (like Normandy and Flanders), the vassal/feudal system was an effective tool for ducal and comital control, linking vassals to their lords; but in other regions, the system led to significant confusion, all the more so as vassals could and frequently did pledge themselves to two or more lords. In response to this, the idea of a "liege lord" was developed (where the obligations to one lord are regarded as superior) in the 12th century.

End of European feudalism (1500–1850s).

Most of the military aspects of feudalism effectively ended by about 1500. This was partly since the military shifted from armies consisting of the nobility to professional fighters thus reducing the nobility's claim on power, but also because the Black Death reduced the nobility's hold over the lower classes. Vestiges of the feudal system hung on in France until the French Revolution of the 1790s, and the system lingered on in parts of Central and Eastern Europe as late as the 1850s. Slavery in Romania was abolished in 1856. Russia finally abolished serfdom in 1861.  Even when the original feudal relationships had disappeared, there were many institutional remnants of feudalism left in place. Historian Georges Lefebvre explains how at an early stage of the French Revolution, on just one night of August 4, 1789, France abolished the long-lasting remnants of the feudal order. It announced, "The National Assembly abolishes the feudal system entirely." Lefebvre explains:  Originally the peasants were supposed to pay for the release of seigneurial dues; these dues affected more than a quarter of the farmland in France and provided most of the income of the large landowners. The majority refused to pay and in 1793 the obligation was cancelled. Thus the peasants got their land free, and also no longer paid the tithe to the church.

Feudal society.

The phrase "feudal society" as defined by Marc Bloch offers a wider definition than Ganshof's and includes within the feudal structure not only the warrior aristocracy bound by vassalage, but also the peasantry bound by manorialism, and the estates of the Church. Thus the feudal order embraces society from top to bottom, though the "powerful and well-differentiated social group of the urban classes" came to occupy a distinct position to some extent outside the classic feudal hierarchy.

Historiography.

The idea of "feudalism" was unknown and the system it describes was not conceived of as a formal political system by the people living in the Medieval Period. This section describes the history of the idea of feudalism, how the concept originated among scholars and thinkers, how it changed over time, and modern debates about its use.

Evolution of the concept.

The concept of a feudal state or period, in the sense of either a regime or a period dominated by lords who possess financial or social power and prestige, became widely held in the middle of the 18th century, as a result of works such as Montesquieu's "De L'Esprit des Lois" (1748; published in English as "The Spirit of the Laws"), and Henri de Boulainvilliers’s "Histoire des anciens Parlements de France" (1737; published in English as "An Historical Account of the Ancient Parliaments of France or States-General of the Kingdom", 1739). In the 18th century, writers of the Enlightenment wrote about feudalism to denigrate the antiquated system of the "Ancien Régime", or French monarchy. This was the Age of Enlightenment when writers valued reason and the Middle Ages were viewed as the "Dark Ages". Enlightenment authors generally mocked and ridiculed anything from the "Dark Ages" including feudalism, projecting its negative characteristics on the current French monarchy as a means of political gain. For them "feudalism" meant seigneurial privileges and prerogatives. When the French Constituent Assembly abolished the "feudal regime" in August 1789 this is what was meant.  Adam Smith used the term "feudal system" to describe a social and economic system defined by inherited social ranks, each of which possessed inherent social and economic privileges and obligations. In such a system wealth derived from agriculture, which was arranged not according to market forces but on the basis of customary labour services owed by serfs to landowning nobles.

Karl Marx.

Karl Marx also used the term in the 19th century in his analysis of society's economic and political development, describing feudalism (or more usually feudal society or the feudal mode of production) as the order coming before capitalism. For Marx, what defined feudalism was the power of the ruling class (the aristocracy) in their control of arable land, leading to a class society based upon the exploitation of the peasants who farm these lands, typically under serfdom and principally by means of labour, produce and money rents. Marx thus defined feudalism primarily by its economic characteristics.  He also took it as a paradigm for understanding the power-relationships between capitalists and wage-labourers in his own time: "in pre-capitalist systems it was obvious that most people did not control their own destiny—under feudalism, for instance, serfs had to work for their lords. Capitalism seems different because people are in theory free to work for themselves or for others as they choose. Yet most workers have as little control over their lives as feudal serfs." Some later Marxist theorists (e.g. Eric Wolf) have applied this label to include non-European societies, grouping feudalism together with Imperial Chinese and pre-Columbian Incan societies as 'tributary'.

Later studies.

In the late 19th and early 20th centuries, John Horace Round and Frederic William Maitland, both historians of medieval Britain, arrived at different conclusions as to the character of English society before the Norman Conquest in 1066. Round argued that the Normans had brought feudalism with them to England, while Maitland contended that its fundamentals were already in place in Britain before 1066. The debate continues today, but a consensus viewpoint is that England before the Conquest had commendation (which embodied some of the personal elements in feudalism) while William the Conqueror introduced a modified and stricter northern French feudalism to England incorporating (1086) oaths of loyalty to the king by all who held by feudal tenure, even the vassals of his principal vassals (holding by feudal tenure meant that vassals must provide the quota of knights required by the king or a money payment in substitution).  In the 20th century, two outstanding historians offered still more widely differing perspectives. The French historian Marc Bloch, arguably the most influential 20th-century medieval historian, approached feudalism not so much from a legal and military point of view but from a sociological one, presenting in "Feudal Society" (1939; English 1961) a feudal order not limited solely to the nobility. It is his radical notion that peasants were part of the feudal relationship that sets Bloch apart from his peers: while the vassal performed military service in exchange for the fief, the peasant performed physical labour in return for protection – both are a form of feudal relationship. According to Bloch, other elements of society can be seen in feudal terms; all the aspects of life were centered on "lordship", and so we can speak usefully of a feudal church structure, a feudal courtly (and anti-courtly) literature, and a feudal economy.  In contradistinction to Bloch, the Belgian historian François-Louis Ganshof defined feudalism from a narrow legal and military perspective, arguing that feudal relationships existed only within the medieval nobility itself. Ganshof articulated this concept in "Qu'est-ce que la féodalité?" ("What is feudalism?", 1944; translated in English as "Feudalism"). His classic definition of feudalism is widely accepted today among medieval scholars, though questioned both by those who view the concept in wider terms and by those who find insufficient uniformity in noble exchanges to support such a model.  Although he was never formally a student in the circle of scholars around Marc Bloch and Lucien Febvre that came to be known as the Annales School, Georges Duby was an exponent of the "Annaliste" tradition. In a published version of his 1952 doctoral thesis entitled "La société aux XIe et XIIe siècles dans la région mâconnaise" ("Society in the 11th and 12th centuries in the Mâconnais region"), and working from the extensive documentary sources surviving from the Burgundian monastery of Cluny, as well as the dioceses of Mâcon and Dijon, Duby excavated the complex social and economic relationships among the individuals and institutions of the Mâconnais region and charted a profound shift in the social structures of medieval society around the year 1000. He argued that in early 11th century, governing institutions—particularly comital courts established under the Carolingian monarchy—that had represented public justice and order in Burgundy during the 9th and 10th centuries receded and gave way to a new feudal order wherein independent aristocratic knights wielded power over peasant communities through strong-arm tactics and threats of violence.  In 1939 the Austrian historian subordinated the feudal state as secondary to his concept of a persons association state (""), understanding it in contrast to the territorial state. This form of statehood, identified with the Holy Roman Empire, is described as the most complete form of medieval rule, completing conventional feudal structure of lordship and vassalage with the personal association between the nobility. But the applicability of this concept to cases outside of the Holy Roman Empire has been questioned, as by Susan Reynolds. The concept has also been questioned and superseded in German histography because of its bias and reductionism towards legitimating the Führerprinzip.

Challenges to the feudal model.

In 1974, the American historian Elizabeth A. R. Brown rejected the label "feudalism" as an anachronism that imparts a false sense of uniformity to the concept. Having noted the current use of many, often contradictory, definitions of "feudalism", she argued that the word is only a construct with no basis in medieval reality, an invention of modern historians read back "tyrannically" into the historical record. Supporters of Brown have suggested that the term should be expunged from history textbooks and lectures on medieval history entirely. In "Fiefs and Vassals: The Medieval Evidence Reinterpreted" (1994), Susan Reynolds expanded upon Brown's original thesis. Although some contemporaries questioned Reynolds's methodology, other historians have supported it and her argument. Reynolds argues: Too many models of feudalism used for comparisons, even by Marxists, are still either constructed on the 16th-century basis or incorporate what, in a Marxist view, must surely be superficial or irrelevant features from it. Even when one restricts oneself to Europe and to feudalism in its narrow sense it is extremely doubtful whether feudo-vassalic institutions formed a coherent bundle of institutions or concepts that were structurally separate from other institutions and concepts of the time.  The term "feudal" has also been applied to non-Western societies in which institutions and attitudes similar to those of medieval Europe are perceived to have prevailed (See Examples of feudalism). Japan has been extensively studied in this regard. Friday notes that in the 21st century historians of Japan rarely invoke feudalism; instead of looking at similarities, specialists attempting comparative analysis concentrate on fundamental differences. Ultimately, critics say, the many ways the term "feudalism" has been used have deprived it of specific meaning, leading some historians and political theorists to reject it as a useful concept for understanding society.  Richard Abels notes that "Western Civilization and World Civilization textbooks now shy away from the term 'feudalism'."  Military:  Non-European:

Feudalism was a combination of legal, economic, military and cultural customs that flourished in Medieval Europe between the 9th and 15th centuries. Broadly defined, it was a way of structuring society around relationships that were derived from the holding of land in exchange for service or labour. Although it is derived from the Latin word "feodum" or "feudum" (fief), which was used during the Medieval period, the term "feudalism" and the system which it describes were not conceived of as a formal political system by the people who lived during the Middle Ages. The classic definition, by François-Louis Ganshof (1944), describes a set of reciprocal legal and military obligations which existed among the warrior nobility and revolved around the three key concepts of lords, vassals and fiefs.

欧洲封建制度又称为封建等级制、封建君主制,指的是欧洲中世纪与贵族骑士相对应的法律地位及军事责任制度。主要围绕着三个中心:领主、封臣及领地。


Etymology.

The term "metropolitan France" dates from the country's colonial period (from the 16th to the 20th centuries), when France was referred to as "la Métropole" (literally "the Metropolis"), as distinguished from its colonies and protectorates, known as "les colonies" or "l'Empire". Similar terms existed to describe other European colonial powers (e.g. "metropolitan Britain", "España metropolitana"). This application of the words "metropolis" and "metropolitan" came from Ancient Greek "metropolis" (from μήτηρ "mētēr" "mother" and πόλις "pólis" "city, town"), which was the name for a city-state that created colonies across the Mediterranean (e.g. Marseille was a colony of the city-state of Phocaea; therefore Phocaea was the "metropolis" of Marseille). By extension "metropolis" and "metropolitan" came to mean "motherland", a nation or country as opposed to its colonies overseas.  Today, some people in Overseas France object to the use of the term "la France métropolitaine" due to its colonial history. They prefer to call it "the European territory of France" (le territoire européen de la France), as the Treaties of the European Union do. Likewise, they oppose treating overseas France and metropolitan France as separate entities. For example, INSEE used to calculate its statistics (demography, economy, etc.) for metropolitan France only, and to analyze separate statistics for the overseas departments and territories. People in the overseas departments have opposed this separate treatment, arguing that the then four overseas departments were fully part of France.  As a result, since the end of the 1990s INSEE has included the four overseas departments in its figures for France (such as total population or GDP). The fifth overseas department, Mayotte, has been included in the figures for France since the mid-2010s too. INSEE refers to metropolitan France and the five overseas departments as "la France entière" ("the whole of France"). "The whole of France" includes the five overseas departments, but does not include the other overseas collectivities and territories that have more autonomy than the departments. Other branches of the French administration may have different definitions of what "la France entière" is. For example, in contrast to INSEE, when the Ministry of the Interior releases election results, they use the term "la France entière" to refer to the entire French Republic, including all of overseas France, and not just the five overseas departments.  Note that since INSEE now calculates statistics for "la France entière", this practice has spread to international institutions. For instance, the French GDP published by the World Bank includes metropolitan France and the five overseas departments. The World Bank refers to this total as "France"; it does not use the phrase "the whole of France", as INSEE does.

Statistics.

Metropolitan France covers a land area of, while Overseas France covers a land area of, for a total of in the French Republic (excluding Adélie Land in Antarctica where sovereignty is suspended since the signing of the Antarctic Treaty in 1959). Thus, metropolitan France accounts for 82.0% of the French Republic's land territory.  At sea, the exclusive economic zone (EEZ) of metropolitan France covers, while the EEZ of Overseas France covers, for a total of in the French Republic (excluding Adélie Land). Thus, metropolitan France accounts for 3.3% of the French Republic's EEZ.  According to INSEE, 65,018,000 people lived in metropolitan France as of January 2018, while 2,790,000 lived in overseas France, for a total of 67,808,000 inhabitants in the French Republic. Thus, metropolitan France accounts for 95.9% of the French Republic's population.  In the second round of the 2017 French presidential election, 35,467,327 French people cast a ballot (meaning a turnout of 74.56%). 33,883,463 of these (95.53% of the total voters) cast their ballots in metropolitan France (turnout: 76.26%), 1,003,910 (2.83% of the total voters) cast their ballots in overseas France (turnout: 53.59%), and 579,954 (1.64% of the total voters) cast their ballots in foreign countries (French people living abroad; turnout: 45.84%).  The French National Assembly is made up of 577 deputies, 539 of whom (93.4% of the total) are elected in metropolitan France, 27 (4.7% of the total) in overseas France, and 11 (1.9% of the total) by French citizens living in foreign countries.

Mainland France.

Mainland France (French: "la France continentale"), or just "the mainland" (French: "le continent"), does not include the French islands in the Atlantic Ocean, English Channel or Mediterranean Sea, the largest of which is Corsica.  In Corsica, people from the mainland part of metropolitan France are referred to as "les continentaux".  A casual synonym for the mainland part of metropolitan France is "l'Hexagone" ("the Hexagon"), for its approximate shape, and the adjective "hexagonal" may be a casual synonym of French (usually understood as metropolitan only, except in topics related to the foreign affairs and national politics of France as a whole).

Metropolitan France ( or "la Métropole"), also known as European France, is the area of the French Republic which is geographically in Europe. It comprises mainland France and Corsica, as well as other islands in the Atlantic Ocean, the English Channel () and the Mediterranean Sea.

法国本土(法语:France métropolitaine),或者国际法上称法国欧洲领土(Territoire européen de la France),是指法兰西共和国位于欧洲的部分。其包括了欧洲大陆部分以及如科西嘉岛的位于大西洋、地中海、英吉利海峡的岛屿,总面积达543,965平方公里。法国本土语言为法语,文字为法文,前三大城市分别为位居北部的首都巴黎、南部的马赛、以及东部的里昂。地区最高点为勃朗峰(4817米),而最长河流为卢瓦尔河,长1020公里。


Connections.

An AP connects directly to a wired local area network, typically Ethernet, and the AP then provides wireless connections using wireless LAN technology, typically Wi-Fi, for other devices to use that wired connection. APs support the connection of multiple wireless devices through their one wired connection.

Wireless data standards.

There are many wireless data standards that have been introduced for wireless access point and wireless router technology. New standards have been created to accommodate the increasing need for faster wireless connections. Some wireless routers provide backward compatibility with older Wi-Fi technologies as many devices were manufactured for use with older standards.

Wireless access point vs. ad hoc network.

Some people confuse wireless access points with wireless ad hoc networks. An ad hoc network uses a connection between two or more devices "without" using a wireless access point; The devices communicate directly when in range. Because setup is easy and does not require an access point, an ad hoc network is used in situations such as a quick data exchange or a multiplayer video game. Due to its peer-to-peer layout, ad hoc Wi-Fi connections are similar to connections available using Bluetooth.  Ad hoc connections are generally not recommended for a permanent installation. Internet access via ad hoc networks, using features like Windows' Internet Connection Sharing, may work well with a small number of devices that are close to each other, but ad hoc networks do not scale well. Internet traffic will converge to the nodes with direct internet connection, potentially congesting these nodes. For internet-enabled nodes, access points have a clear advantage, with the possibility of having a wired LAN.

Limitations.

It is generally recommended that one IEEE 802.11 AP should have, at a maximum, 10-25 clients. However, the actual maximum number of clients that can be supported can vary significantly depending on several factors, such as type of APs in use, density of client environment, desired client throughput, etc. The range of communication can also vary significantly, depending on such variables as indoor or outdoor placement, height above ground, nearby obstructions, other electronic devices that might actively interfere with the signal by broadcasting on the same frequency, type of antenna, the current weather, operating radio frequency, and the power output of devices. Network designers can extend the range of APs through the use of repeaters, which amplify a radio signal, and reflectors, which only bounce it. In experimental conditions, wireless networking has operated over distances of several hundred kilometers.  Most jurisdictions have only a limited number of frequencies legally available for use by wireless networks. Usually, adjacent APs will use different frequencies (Channels) to communicate with their clients in order to avoid interference between the two nearby systems. Wireless devices can "listen" for data traffic on other frequencies, and can rapidly switch from one frequency to another to achieve better reception. However, the limited number of frequencies becomes problematic in crowded downtown areas with tall buildings using multiple APs. In such an environment, signal overlap becomes an issue causing interference, which results in signal droppage and data errors.  Wireless networking lags wired networking in terms of increasing bandwidth and throughput. While (as of 2013) high-density 256-QAM (TurboQAM) modulation, 3-antenna wireless devices for the consumer market can reach sustained real-world speeds of some 240 Mbit/s at 13 m behind two standing walls (NLOS) depending on their nature or 360 Mbit/s at 10 m line of sight or 380 Mbit/s at 2 m line of sight (IEEE 802.11ac) or 20 to 25 Mbit/s at 2 m line of sight (IEEE 802.11g), wired hardware of similar cost reaches closer to 1000 Mbit/s up to specified distance of 100 m with twisted-pair cabling in optimal conditions (Category 5 (known as Cat-5) or better cabling with Gigabit Ethernet). One impediment to increasing the speed of wireless communications comes from Wi-Fi's use of a shared communications medium: Thus, two stations in infrastructure mode that are communicating with each other even over the same AP must have each and every frame transmitted twice: from the sender to the AP, then from the AP to the receiver. This approximately halves the effective bandwidth, so an AP is only able to use somewhat less than half the actual over-the-air rate for data throughput. Thus a typical 54 Mbit/s wireless connection actually carries TCP/IP data at 20 to 25 Mbit/s. Users of legacy wired networks expect faster speeds, and people using wireless connections keenly want to see the wireless networks catch up.  By 2012, 802.11n based access points and client devices have already taken a fair share of the marketplace and with the finalization of the 802.11n standard in 2009 inherent problems integrating products from different vendors are less prevalent.

Security.

Wireless access has special security considerations. Many wired networks base the security on physical access control, trusting all the users on the local network, but if wireless access points are connected to the network, anybody within range of the AP (which typically extends farther than the intended area) can attach to the network.  The most common solution is wireless traffic encryption. Modern access points come with built-in encryption. The first generation encryption scheme, WEP, proved easy to crack; the second and third generation schemes, WPA and WPA2, are considered secure if a strong enough password or passphrase is used.  Some APs support hotspot style authentication using RADIUS and other authentication servers.  Opinions about wireless network security vary widely. For example, in a 2008 article for "Wired" magazine, Bruce Schneier asserted the net benefits of open Wi-Fi without passwords outweigh the risks, a position supported in 2014 by Peter Eckersley of the Electronic Frontier Foundation. The opposite position was taken by Nick Mediati in an article for "PC World", in which he advocates that every wireless access point should be protected with a password.

In computer networking, a wireless access point (WAP), or more generally just access point (AP), is a networking hardware device that allows other Wi-Fi devices to connect to a wired network. The AP usually connects to a router (via a wired network) as a standalone device, but it can also be an integral component of the router itself. An AP is differentiated from a hotspot which is a physical location where Wi-Fi access is available.

无线存取点(英语:Wireless Access Point,缩写WAP)是电脑网络中一种连接无线网络至有线网络(以太网)的装置,又称为无线基地台。它通常作为一个单独装置,并通过有线网络连接到路由器,也能与路由器整合在一起。无线接入点和热点不同,后者是指称能够连接无线局域网的物理地点。漫游则是数个无线接入点运行,将传送的数据由一个接入点连至到另一接入点使该无线网络扩大;反之整个无线网络若没有任何接入点就会成为一个点对点的ad-hoc网络。无线接入点亦具有DHCP之动态配置IP地址功能。


Purpose.

Allocation (also called Initiation).

On OS/360 and derived mainframe systems, most programs never specify files (usually called datasets) directly, but instead reference them indirectly through the Job Control Language (JCL) statements that invoke the programs. These data definition (or "codice_1") statements can include a "disposition" (codice_2) parameter that indicates how the file is to be managed — whether a new file is to be created or an old one re-used; and whether the file should be deleted upon completion or retained; "etc".  IEFBR14 was created because while codice_1 statements can create or delete files easily, they cannot do so without a program to be run due to a certain peculiarity of the Job Management system, which always requires that the Initiator actually execute a program, even if that program is effectively a null statement. The program used in the JCL does not actually need to use the files to cause their creation or deletion — the codice_4 specification does all the work. Thus a very simple do-nothing program was needed to fill that role.  IEFBR14 can thus be used to create or delete a data set using JCL.

Deallocation (also called Termination).

A secondary reason to run IEFBR14 was to unmount devices (usually tapes or disks) that had been left mounted from a previous job, perhaps because of an error in that job's JCL or because the job ended in error. In either event, the system operators would often need to demount the devices, and a started task – codice_5 – was often provided for this purpose.  Simply entering the command at the system console would run the started task, which consisted of just one step. However, due to the design of Job Management, DEALLOC must actually exist in the system's procedure library, SYS1.PROCLIB, lest the start command fail.  Also, all such started tasks "must" be a single jobstep as the "Started Task Control" (STC) module within the Job Management component of the operating system only accepts single-step jobs, and it fails all multi-step jobs, without exception.

Parsing and validation.

At least on z/OS, branching off to execute another program would cause the calling program to be evaluated for syntax errors at that point.

Naming.

The "IEF" derives from a convention on mainframe computers that programs supplied by IBM were grouped together by function or creator and that each group shared a three-letter prefix. In OS/360, the first letter was almost always "I", and the programs produced by the Job Management group (including IEFBR14) all used the prefix "IEF". Other common prefixes included "IEB" for dataset utility programs, "IEH" for system utility programs, and "IEW" for program linkage and loading. Other major components were (and still are) "IEA" (Operating System Supervisor) and "IEC" (Input/Output Supervisor).  As explained below, "BR 14" was the essential function of the program, to simply return to the operating system. This portion of a program name was often mnemonic — for example, IEBUPDTE was the dataset utility (IEB) that applied updates (UPDTE) to source code files, and IEHINITT was the system utility (IEH) that initialized (INIT) magnetic tape labels (T).  As explained further in "Usage" below, the name "BR14" comes from the IBM assembler-language instruction "Branch (to the address in) Register 14", which by convention is used to "return from a subroutine". Most early users of OS/360 were familiar with IBM Assembler Language and would have recognized this at once.

Usage.

Example JCL would be :  //IEFBR14 JOB ACCT,'DELETE DATASET',MSGCLASS=J,CLASS=A //STEP0001 EXEC PGM=IEFBR14 //DELDD DD DSN=xxxxx.yyyyy.zzzzz, // DISP=(MOD,DELETE,DELETE),UNIT=DASD  To create a Partitioned Data Set:  //TZZZ84R JOB NOTIFY=&SYSUID,MSGCLASS=X //STEP01 EXEC PGM=IEFBR14 //DD1 DD DSN=TKOL084.DEMO,DISP=(NEW,CATLG,DELETE), // DCB=(RECFM=FB,LRECL=80,BLKSIZE=80,DSORG=PO), // SPACE=(TRK,(1,1,1),RLSE), // UNIT=SYSDA

Implementation.

IEFBR14 consisted initially of a single instruction a "Branch to Register" 14. The mnemonic used in the IBM Assembler was BR and hence the name: IEF BR 14. BR 14 is identically equivalent to BCR 15,14 (Branch Always [ mask = 15 = always ] to the address contained in general purpose register 14). BR is a pseudo instruction for BCR 15. The system assembler accepts many cases of such pseudo-instructions, as logical equivalents to the canonical System/360 instructions. The canonical instance of BR 14 is BCR 15,14.  The linkage convention for OS/360 and its descendants requires that a program be invoked with register 14 containing the address to return control to when complete, and register 15 containing the address at which the called program is loaded into memory; at completion, the program loads a return code in register 15, and then branches to the address contained in register 14. But, initially IEFBR14 was "not" coded with these characteristics in mind, as IEFBR14 was initially used as a dummy control section, one which simply returned to the caller, not as an executable module.  The original version of the program did not alter register 15 at all as its original application was as a placeholder in certain load modules which were generated during "Sysgen" (system generation), not as an executable program, per se. Since IEFBR14 was always invoked by the functional equivalent of the canonical BALR 14,15 instruction, the return code in register 15 was always non-zero. Later, a second instruction was to be added to clear the return code so that it would exit with a determinate status, namely zero. Initially, programmers were not using all properties of the Job Control Language, anyway, so an indeterminate return code was not a problem. However, subsequently programmers were indeed using these properties, so a determinate status became mandatory. This modification to IEFBR14 did not in any way impact its original use as a placeholder.  The machine code for the modified program is:  The equivalent machine code, eliminating the BR for clarity, is:  This makes perfect sense as the OS/360 Initiator initially "attaches" the job-step task using the ATTACH macro-instruction (SVC 42), and "unwinding" the effect of this ATTACH macro (it being a Type 2 SVC instruction) "must" be a complementary instruction, namely an EXIT macro (necessarily a Type 1 SVC instruction, SVC 3).

References.

Trombetta, Michael & Finkelstein Sue Carolyn (1985). "OS JCL and utilities". Addison Wesley. page 152.

IEFBR14 is an IBM mainframe utility program. It runs in all IBM mainframe environments derived from OS/360, including z/OS. It is a placeholder that returns the exit status zero, similar to the true command on UNIX-like systems.

IEFBR14是IBM大型计算机的应用程序。运行于OS/360的所有后继操作系统中,包括z/OS等。该程序是一个仅会返回返回码0的占位程序,类似于类Unix系统中的true命令。


Etymology.

The term refers to the white dress shirts of male office workers common through most of the nineteenth and twentieth centuries in Western countries, as opposed to the blue overalls worn by many manual laborers.  The term "white collar" is credited to Upton Sinclair, an American writer, in relation to contemporary clerical, administrative, and management workers during the 1930s, though references to white-collar work appear as early as 1935. White collar employees are considered highly educated as compared to blue collar.

Demographics.

Formerly a minority in the agrarian and early industrial societies, white-collar workers have become a majority in industrialized countries due to modernization and outsourcing of manufacturing jobs.  The blue-collar and white-collar descriptors as it pertains to work dress may no longer be an accurate descriptor as office attire has broadened beyond a white shirt and tie. Employees in office environments may wear a variety of colors, may dress in business casuals or wear casual clothes altogether. In addition, the work tasks have blurred. "White-collar" employees may perform "blue-collar" tasks (or vice versa). An example would be a restaurant manager who may wear more formal clothing yet still assist with cooking food or taking customers' orders or a construction worker who also performs desk work.

Health effects.

Less physical activity among white-collar workers has been thought to be a key factor in increased life-style related health conditions such as fatigue, obesity, diabetes, hypertension, cancer, and heart disease. Also, working at a computer spoils eyesight and leads to diseases associated with monotonous data entry such as carpal tunnel syndrome. Workplace interventions such as alternative activity workstations, sit-stand desks, promotion of stair use are among measures being implemented to counter the harms of sedentary workplace environments. The quality of evidence used to determine the effectiveness and potential health benefits of many of these interventions is weak. More research is needed to determine which interventions may be effective in the long-term. Low quality evidence indicates that sit-stand desks may reduce sitting in the workplace during the first year of their use, however, it is not clear if sit-stand desks may be effective at reducing sitting in the longer-term.

A white-collar worker is a person who performs professional, desk, managerial, or administrative work. White-collar work may be performed in an office or other administrative setting. White-collar workers include works related to Government, academia, accountancy, business and executive management, management consulting, customer support, market research, finance, human resources, operations research, marketing, information technology, networking, attorneys, medical professionals, architects, research and development and contracting. Other types of work are those of a grey-collar worker, who has more specialized knowledge than those of a blue-collar worker, whose job requires manual labor and a pink-collar worker, whose labor is related to customer interaction, entertainment, sales, or other service-oriented work. Many occupations blend blue, white and pink (service) industry categorizations.

白领族(英语:white-collar worker)是一个从西方传来的生活型态定义,经常拿来代表领较多薪水的专业人士。这个词可能最早是从1928年启用的,当时是代表非体力劳动的工作者,如公务员、教职人员等。是与蓝领族互作为对比的族群。白领族较少从事劳力工作,在公司里的职业阶层也往往是行政或是正式职员,并有专业的工作能力,如医生或律师等专业人员。在一些社会学的研究里,经理阶级的有时也被归为白领族之一。


History.

The origins of AOC date to the year 1411, when Roquefort was regulated by a parliamentary decree. The first French law on viticultural designations of origin dates to August 1, 1905, whereas the first modern law was set on May 6, 1919, when the Law for the Protection of the Place of Origin was passed, specifying the region and commune in which a given product must be manufactured, and has been revised on many occasions since then. On July 30, 1935, the "Comité National des appellations d'origine" (CNAO), with representatives of the government and the major winegrowers, was created to manage the administration of the process for wines at the initiative of deputy Joseph Capus. In the Rhône wine region Baron Pierre Le Roy Boiseaumarié, a trained lawyer and winegrower from Châteauneuf-du-Pape, successfully obtained legal recognition of the "Côtes du Rhône" appellation of origin in 1936. After World War II the committee became the public-private "Institut National des Appellations d'Origine" (INAO). The AOC seal was created and mandated by French laws in the 1950s, 1960s and 1970s. On July 2, 1990, the scope of work of the INAO was extended beyond wines to cover other agricultural products.  AOCs vary dramatically in size. Some cover vast expanses with a variety of climatic and soil characteristics, while others are small and highly uniform. For example, the Côtes du Rhône AOC "covers some, but within its area lies one of the smallest AOCs, Château-Grillet, which occupies less than of land."

Enforcement.

The INAO guarantees that all AOC products will hold to a rigorous set of clearly defined standards. The organization stresses that AOC products will be produced in a consistent and traditional manner with ingredients from specifically classified producers in designated geographical areas. The products must further be aged at least partially in the respective designated area.  Under French law, it is illegal to manufacture and sell a product under one of the AOC-controlled geographical indications if it does not comply with the criteria of the AOC. AOC products can be identified by a seal, which is printed on the label in wines, and with cheeses, on the rind. To prevent any possible misrepresentation, no part of an AOC name may be used on a label of a product not qualifying for that AOC.  This strict label policy can lead to confusion, especially in cases where towns share names with appellations. If the town of origin of a product contains a controlled appellation in its name, the producer (who is legally required to identify the place of origin on the product label but legally prohibited from using the full town's name unless the product is an approved AOC product) is enjoined from listing anything more than a cryptic postal code. For example, there are a dozen townships in l'Aude that have Cabardès in their names, several of which are not even within the geographical boundaries of the Cabardès AOC. Any vineyard that produces wine in one of those towns must not mention the name of the town of origin on the product labels.

Wine.

There are currently over 300 French wines entitled to the designation AOC on their label.  Legislation concerning the way vineyards are identified makes recognizing the various AOCs very challenging for wine drinkers not accustomed to the system. Often, distinguishing classifications requires knowledge of esoteric label laws such as "Unless the wine is from a "Premier Cru" vineyard, the vineyard name must be printed in characters no more than half the height of the ones used for the village name"  On the other hand, while the process of label approval is enforced to the millimetre, the quality control for the wine in the bottle is much less strict. While a blind taster must approve the wine for it to receive AOC classification, this tasting often occurs before the product is even bottled, and by a local expert who may well have ties to the local vintners. Even if the taster is objective, the wine sample may not be representative of the actual product, and there is almost no way to verify that the finished bottled product is the same as the original AOC sample.

Cheese.

In 1925, Roquefort became the first cheese to be awarded an AOC label, and since then over 40 cheeses have been assigned AOC status.

Meat.

On August 15, 1957, the National Assembly gave AOC status to the poultry of Bresse (Poulet de Bresse). In 2006, it awarded AOC status to salt marsh lamb raised in the Bay of the Somme.

Lavender.

In 1981, the AOC label was given to Haute-Provence Lavender Essential Oil. It refers to a very high-quality production and concerns only the essential oil of fine lavender - "Lavandula angustifolia". The fields must be located within a specific territory at a minimum altitude of 800 meters. This geographic area covers 284 communities in the Alpes-de-Haute-Provence, Hautes-Alpes, Drôme and Vaucluse regions.

Lentils.

Lentils from Le Puy-en-Velay have AOC status. (See: Le Puy Green lentil.)

Honey.

Honey from the island of Corsica has been given AOC status. There are six certified varietals of Corsican honey: Printemps, Maquis de printemps, Miellats du maquis, Châtaigneraie, Maquis d'été, and Maquis d'automne.

Butter.

France recognizes the Charente, Charente-Maritime, Vienne, Deux-Sèvres and Vendée AOC regions for butter.<br> The Beurre Charentes-Poitou has been assigned AOC status in 1979.

Spirits.

Armagnac, Calvados, Cognac and Martinique Rhum Agricole all have AOC status.

Other countries.

Europe.

Many other countries have based their controlled place name systems on the French AOC classification. Italy's Denominazione di Origine Controllata and Denominazione di Origine Controllata e Garantita followed the model set by the French AOC, and the EU standard for Quality Wines Produced in Specified Regions (QWpsr) also corresponds closely.  While Spain's denominación de origen is very similar, the classification of Rioja in 1925 and Sherry in 1933 preceded the French AOC system by a few years and show that Spain's DdO system developed parallel to France's AOC system to some extent. Similarly, Germany's Qualitätswein bestimmter Anbaugebiete is a wine classification system based on geographic region, but it differs from the AOC in important ways. Qualitätswein bestimmter Anbaugebiete wines are commonly seen as less prestigious than Qualitätswein mit Prädikat, making it more similar to the Vin de Pays or Vin Délimité de Qualité Supérieure systems.  Portugal's Denominação de Origem Controlada, Austria's Districtus Austria Controllatus, South Africa's Wine of Origin, and Switzerland's AOC-IGP are all similar to the French AOC system as well.  It appears also that AOC influenced the development of the European Union's protected designation of origin (PDO) system.

Switzerland.

Switzerland has an "appellation d'origine contrôlée" certification for wines and an "appellation d'origine protégée" certification for other food products. Before 2013, the "appellation d'origine contrôlée" was used for all products.

United States.

The United States' American Viticultural Areas also follows the model set by the French AOC. The United States Department of the Treasury's Alcohol and Tobacco Tax and Trade Bureau even uses the legal terminology "Appellation of Wine Origin" to describe a vintage wine's location of origin. The AVA indication on a label indicates that 85% of the grapes for wine are grown in the designated AVA. Overall, the appellation of a wine simply says where the grapes are from, although there are some particularities. If the appellation is a state, 100% of the grapes which go into the wine must come from the specific state. If a winery gets grapes from a neighboring state (for example, a California vintner getting Pinot noir from Oregon), it may label the wine "Oregon", but if the state is not a neighboring one (for example, a California vintner getting Cabernet from Washington state), the only permitted appellation is "American."

Canada.

In Canada, there is a government-sanctioned wine standard called Vintners Quality Alliance (VQA). It only applies to Canadian wines, and only the provinces of Ontario and British Columbia regulate it.

International trade issues.

Outside their home country, protecting the AOC status of certain products can face challenges, notably from a legal perspective. Some countries do not uphold a geographical indication system for their own products and thus, products which are labelled AOC in France, for instance, can be confronted on the international stage with foreign products claiming a similar geographical origin, even though it has not been recognized as such by the AOC system. In such a case, France (or another country) may enter into bilateral agreements with other countries, whereupon the signatories accept to recognize a special status to a list of designated products, or it can also seek the development of rules or agreements at the World Trade Organization level.  Since each country has its own legal and agricultural framework, the specifics of each trade relationship are likely to vary. Also, there are often conflicts between trademarks and geographical indications. For instance, in Canada, only Canadian wines can be VQA approved but other certification trademarks can be registered under the intellectual property legal regime. The owner of a certification trademark is then allowed to sell licences to be used for certain products meeting the owner's criteria. Thus in the case of wines, one AOC certification trademark is owned by the French Republic, while another is owned by "Maison des Futailles", a wine producer, of which the publicly owned Société des alcools du Québec is a partner.

The appellation d'origine contrôlée (AOC; ; "controlled designation of origin") is French certification granted to certain French geographical indications for wines, cheeses, butters, and other agricultural products, all under the auspices of the government bureau "Institut national des appellations d'origine", now called Institut national de l'origine et de la qualité (INAO). It is based on the concept of "terroir" and a form of geographic protectionism.

原产地命名控制(缩写:AOC,法文:)是法国的一个产品地理标志,用于标明生产、加工在同一地理区域、使用受认可技术进行的产品。


History.

In 1654 the settlers of the Dutch Cape Colony placed all their ewes and a few rams on Robben Island, the men built a large shed and a shelter. The isolation offered better protection against wild animals than on the mainland. The settlers also collected seal skins and boiled oil to supply the needs of the settlement.  Since the end of the 17th century, Robben Island has been used for the incarceration of chiefly political prisoners. The Dutch settlers were the first to use Robben Island as a prison. Its first prisoner was probably Autshumato in the mid-17th century. Among its early permanent inhabitants were political leaders imprisoned from other Dutch colonies, including Indonesia, and the leader of the mutiny on the slave ship "Meermin".  After the British Royal Navy captured several Dutch East Indiamen at the battle of Saldanha Bay in 1781, a boat rowed out to meet the British warships. On board were the "kings of Ternate and Tidore, and the princes of the respective families". The Dutch had long held them on "Isle Robin", but then had moved them to Saldanha Bay.  In 1806 the Scottish whaler John Murray opened a whaling station at a sheltered bay on the north-eastern shore of the island, which became known as Murray's Bay. It was adjacent to the site of the present-day harbour named Murray's Bay Harbour, which was constructed in 1939–40.  After a failed uprising at Grahamstown in 1819, the fifth of the Xhosa Wars, the British colonial government sentenced African leader Makanda Nxele to life imprisonment on the island. He drowned on the shores of Table Bay after escaping the prison.  The island was also used as a leper colony and animal quarantine station. Starting in 1845, lepers from the "Hemel-en-Aarde" (heaven and earth) leper colony near Caledon were moved to Robben Island when "Hemel-en-Aarde" was found unsuitable as a leper colony. Initially this was done on a voluntary basis and the lepers were free to leave the island if they so wished. In April 1891 the cornerstones for 11 new buildings to house lepers were laid. After passage of the Leprosy Repression Act in May 1892, admission was no longer voluntary, and the movement of the lepers was restricted. Doctors and scientists did not understand the disease and thought isolation was the only way to prevent other people from contracting it. Prior to 1892 an average of about 25 lepers a year were admitted to Robben Island, but in 1892 that number rose to 338, and in 1893 a further 250 were admitted.  During the Second World War, the island was fortified. BL 9.2-inch guns and 6-inch guns were installed as part of the defences for Cape Town. From 1961, Robben Island was used by the South African government as a prison for political prisoners and convicted criminals. In 1969 the "Moturu Kramat," now a sacred site for Muslim pilgrimage on Robben Island, was built to commemorate Sayed Abdurahman Moturu, the Prince of Madura. Moturu, one of Cape Town's first imams, had been exiled in the mid-1740s to the island. He died there in 1754. Muslim political prisoners would pay homage at the shrine before leaving the island.  In 1982, former inmate Indres Naidoo's book "Island in Chains" became the first published account of prison life on the island.  The maximum security prison for political prisoners closed in 1991. The medium security prison for criminal prisoners was closed five years later.  With the end of apartheid, the island has become a popular tourist destination. It is managed by Robben Island Museum (RIM); which operates the site as a living museum. In 1999 the island was declared a World Heritage Site for its importance to South Africa's political history and development of a democratic society. Every year thousands of visitors take the ferry from the Victoria & Alfred Waterfront in Cape Town for tours of the island and its former prison. Many of the guides are former prisoners. All land on the island is owned by the nation of South Africa, with the exception of the island church. Administratively, Robben Island is a suburb of the City of Cape Town. It is open all year around, weather permitting.

Access to the island.

Robben Island is accessible to visitors through tours that depart from Cape Town's waterfront. Tours depart three times a day and take about 3.5 hours, consisting of a ferry trip to and from the island, and a tour of the various historical sites on the island that form part of the Robben Island Museum. These include the island graveyard, the disused lime quarry, Robert Sobukwe's house, the Bluestone quarry, the army and navy bunkers, and the maximum security prison. Nelson Mandela's cell is shown.

Maritime hazard.

Seagoing vessels must take great care navigating near Robben Island and nearby Whale Rock (it does not break the surface) as these pose a danger to shipping. A prevailing rough Atlantic swell surrounds the offshore reefs and the island's jagged coastline. Stricken vessels driven onto rocks are quickly broken up by the powerful surf. A total of 31 vessels are known to have been wrecked around the island.  In 1990, a marine archaeology team from the University of Cape Town began Operation "Sea Eagle". It was an underwater survey that scanned of seabed around Robben Island. The task was made particularly difficult by the strong currents and high waves of these waters. The group found 24 vessels that had sunk around Robben Island. Most wrecks were found in waters less than deep. The team concluded that poor weather, darkness and fog were the cause of the sinkings. Maritime wrecks around Robben Island and its surrounding waters include the 17th-century Dutch East Indiaman ships, the "Yeanger van Horne" (1611), the "Shaapejacht" (1660), and the "Dageraad" (1694). Later 19th-century wrecks include several British brigs, including the "Gondolier" (1836), and the United States clipper, "A.H. Stevens" (1866). In 1901 the mail steamer SS "Tantallon Castle" struck rocks off Robben Island in dense fog shortly after leaving Cape Town. After distress cannons were fired from the island, nearby vessels rushed to the rescue. All 120 passengers and crew were taken off the ship before it was broken apart in the relentless swell. A further 17 ships have been wrecked in the 20th century, including British, Spanish, Norwegian and Taiwanese vessels.

Robben Island lighthouse.

Due to the maritime danger of Robben Island and its near waters, Jan van Riebeeck, the first Dutch colonial administrator in Cape Town in the 1650s, ordered that huge bonfires were to be lit at night on top of Fire Hill, the highest point on the island (now Minto Hill). These were to warn VOC ships that they were approaching the island.  In 1865 Robben Island lighthouse was completed on Minto Hill. The cylindrical masonry tower, which has an attached lightkeeper's house at its base, is high with a lantern gallery at the top. In 1938 the lamp was converted to electricity. The lighthouse uses a flashing lantern instead of a revolving lamp; it shines for a duration of 5 seconds every seven seconds. The 46,000 candela beam flashes white light away from Table Bay. It is visible up to. A secondary red light acts as a navigation aid for vessels sailing south-southeast.

Wildlife and conservation.

When the Dutch arrived in the area in 1652, the only large animals on the island were seals and birds, principally penguins. In 1654, the settlers released rabbits on the island to provide a ready source of meat for passing ships.  The original colony of African penguins on the island was completely exterminated by 1800. But since 1983 a new colony has been established there, and the modern island is again an important breeding area for the species. The colony grew to a size of ~16,000 individuals in 2004, before starting to decline in size again., this decline has been continuous (to a colony size of ~3,000 individuals). Such a decline has been found at almost all other African penguin colonies. Its causes are still largely unclear and likely to vary between colonies, but at Robben Island are probably related to a diminishing of the food supply (sardines and anchovies) through competition by fisheries. Easy to see in their natural habitat, the penguins have been a popular tourist attraction.  Around 1958, Lieutenant Peter Klerck, a naval officer serving on the island, introduced various animals. The following extract of an article, written by his son Michael Klerck, who lived on the island from an early age, describes the local fauna:  My father, a naval officer at the time, with the sanction of Doctor Hey, director of Nature Conservation, turned an area into a nature reserve. A 'Noah's Ark' berthed in the harbour sometime in 1958. They stocked the island with tortoise, duck, geese, buck (which included Springbok, Eland, Steenbok, Bontebok and Fallow Deer), Ostrich and a few Wildebeest which did not last long. All except the fallow deer are indigenous to the Cape. Many animals are still there including three species of tortoise—the most recently discovered in 1998—two Parrot Beaked specimens that have remained undetected until now. The leopard or mountain tortoises might have suspected the past terror; perhaps they had no intention of being a part of a future infamy, but they often attempted the swim back to the mainland (they are the only species in the world that can swim). Boats would lift them out of the sea in Table Bay and return them to us. None of the original 12 shipped over remain, and in 1995, four more were introduced—they seem to have more easily accepted their home as they are still residents. One resident brought across a large leopard tortoise discovered in a friend's garden in Newlands, Cape Town. He lived in our garden and grew big enough to climb over the wall and roam the island much like the sheep in Van Riebeeck's time. As children we were able to ride his great frame comfortably, as did some grown men. The buck and ostriches seemed equally happy and the ducks and Egyptian Geese were assigned a home in the old quarry, which had, some three hundred years before, supplied the dressed stone for the foundations of the Castle; at the time of my residence it bristled with fish.  Recent reports in Cape Town newspapers show that a lack of upkeep, a lack of culling, and the proliferation of rabbits on the island has led to the total devastation of the wildlife; there remains today almost none of the animals my father brought over all those years ago; the rabbits themselves have laid the island waste, stripping it of almost all ground vegetation. It looks almost like a desert. A reporter from the broadcasting corporation told me recently that they found the carcass of the last Bontebok.  In the early 21st century, the rabbit population had reached an estimated 25,000, which had become an invasive species, endangering others. Humans are hunting and culling the rabbits to reduce their number.

Robben Island () is an island in Table Bay, west of the coast of Bloubergstrand, Cape Town, South Africa. It takes its name from the Dutch word for seals ("robben"), hence the Dutch/Afrikaans name "Robbeneiland" which translates to "Seal(s) Island". Robben Island is roughly oval in shape, long north-south, and wide, with an area of. It is flat and only a few metres above sea level, as a result of an ancient erosion event. It was fortified and used as a prison from the late 17th century to 1996, after the end of apartheid. Many of its prisoners were political.

罗本岛(南非荷兰语:Robbeneiland;英语:Robben Island),南非开普敦桌湾中一小岛,面积5.07平方公里,岛名在荷兰语中意为“海豹岛”。


Theories.

The simplest theory to predict the behaviour of detonations in gases is known as Chapman-Jouguet (CJ) theory, developed around the turn of the 20th century. This theory, described by a relatively simple set of algebraic equations, models the detonation as a propagating shock wave accompanied by exothermic heat release. Such a theory confines the chemistry and diffusive transport processes to an infinitesimally thin zone.  A more complex theory was advanced during World War II independently by Zel'dovich, von Neumann, and W. Doering. This theory, now known as ZND theory, admits finite-rate chemical reactions and thus describes a detonation as an infinitesimally thin shock wave followed by a zone of exothermic chemical reaction. With a reference frame of a stationary shock, the following flow is subsonic, so that an acoustic reaction zone follows immediately behind the lead front, the Chapman-Jouguet condition. There is also some evidence that the reaction zone is semi-metallic in some explosives.  Both theories describe one-dimensional and steady wave fronts. However, in the 1960s, experiments revealed that gas-phase detonations were most often characterized by unsteady, three-dimensional structures, which can only in an averaged sense be predicted by one-dimensional steady theories. Indeed, such waves are quenched as their structure is destroyed. The Wood-Kirkwood detonation theory can correct for some of these limitations.  Experimental studies have revealed some of the conditions needed for the propagation of such fronts. In confinement, the range of composition of mixes of fuel and oxidant and self-decomposing substances with inerts are slightly below the flammability limits and for spherically expanding fronts well below them. The influence of increasing the concentration of diluent on expanding individual detonation cells has been elegantly demonstrated. Similarly their size grows as the initial pressure falls. Since cell widths must be matched with minimum dimension of containment, any wave overdriven by the initiator will be quenched.  Mathematical modeling has steadily advanced to predicting the complex flow fields behind shocks inducing reactions. To date, none has adequately described how structure is formed and sustained behind unconfined waves.

Applications.

When used in explosive devices, the main cause of damage from a detonation is the supersonic blast front (a powerful shock wave) in the surrounding area. This is a significant distinction from deflagrations where the exothermic wave is subsonic and maximum pressures are at most one eighth as great. Therefore, detonation is a feature for destructive purpose while deflagration is favored for the acceleration of firearms' projectiles. However, detonation waves may also be used for less destructive purposes, including deposition of coatings to a surface or cleaning of equipment (e.g. slag removal) and even explosively welding together metals that would otherwise fail to fuse. Pulse detonation engines use the detonation wave for aerospace propulsion. The first flight of an aircraft powered by a pulse detonation engine took place at the Mojave Air & Space Port on January 31, 2008.

In engines and firearms.

Unintentional detonation when deflagration is desired is a problem in some devices. In internal combustion engines it is called engine knocking or pinging or pinking, and it causes a loss of power, excessive heating, and eventual engine failure in some cases. In firearms, it may cause catastrophic and potentially lethal failure.

Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations occur in both conventional solid and liquid explosives, as well as in reactive gases. The velocity of detonation in solid and liquid explosives is much higher than that in gaseous ones, which allows the wave system to be observed with greater detail (higher resolution).

爆轰(Detonation)是火释放能量的两种之一。爆轰是超声速的急烈燃烧,当超声速的放热锋加速通过介质并形成冲击波锋。超音速的爆炸亦属爆轰。火另一种释放能量的方式称缓燃,两种方式都有俗称「爆燃」造成混淆。


Nomenclature.

The word, "Mannerism" derives from the Italian "maniera", meaning "style" or "manner". Like the English word "style", "maniera" can either indicate a specific type of style (a beautiful style, an abrasive style) or indicate an absolute that needs no qualification (someone "has style"). In the second edition of his "Lives of the Most Excellent Painters, Sculptors, and Architects" (1568), Giorgio Vasari used "maniera" in three different contexts: to discuss an artist's manner or method of working; to describe a personal or group style, such as the term "maniera greca" to refer to the Byzantine style or simply to the "maniera" of Michelangelo; and to affirm a positive judgment of artistic quality. Vasari was also a Mannerist artist, and he described the period in which he worked as "la maniera moderna", or the "modern style". James V. Mirollo describes how "bella maniera" poets attempted to surpass in virtuosity the sonnets of Petrarch. This notion of "bella maniera" suggests that artists who were thus inspired looked to

Origin and development.

By the end of the High Renaissance, young artists experienced a crisis: it seemed that everything that could be achieved was already achieved. No more difficulties, technical or otherwise, remained to be solved. The detailed knowledge of anatomy, light, physiognomy and the way in which humans register emotion in expression and gesture, the innovative use of the human form in figurative composition, the use of the subtle gradation of tone, all had reached near perfection. The young artists needed to find a new goal, and they sought new approaches. At this point Mannerism started to emerge. The new style developed between 1510 and 1520 either in Florence, or in Rome, or in both cities simultaneously.

Origins and role models.

This period has been described as a "natural extension" of the art of Andrea del Sarto, Michelangelo, and Raphael. Michelangelo developed his own style at an early age, a deeply original one which was greatly admired at first, then often copied and imitated by other artists of the era. One of the qualities most admired by his contemporaries was his "terribilità", a sense of awe-inspiring grandeur, and subsequent artists attempted to imitate it. Other artists learned Michelangelo's impassioned and highly personal style by copying the works of the master, a standard way that students learned to paint and sculpt. His Sistine Chapel ceiling provided examples for them to follow, in particular his representation of collected figures often called "ignudi" and of the Libyan Sibyl, his vestibule to the Laurentian Library, the figures on his Medici tombs, and above all his "Last Judgment". The later Michelangelo was one of the great role models of Mannerism. Young artists broke into his house and stole drawings from him. In his book "Lives of the Most Eminent Painters, Sculptors, and Architects", Giorgio Vasari noted that Michelangelo stated once: "Those who are followers can never pass by whom they follow".

The competitive spirit.

The competitive spirit was cultivated by patrons who encouraged sponsored artists to emphasize virtuosic technique and to compete with one another for commissions. It drove artists to look for new approaches and dramatically illuminated scenes, elaborate clothes and compositions, elongated proportions, highly stylized poses, and a lack of clear perspective. Leonardo da Vinci and Michelangelo were each given a commission by Gonfaloniere Piero Soderini to decorate a wall in the Hall of Five Hundred in Florence. These two artists were set to paint side by side and compete against each other, fueling the incentive to be as innovative as possible.

Early mannerism.

The early Mannerists in Florence—especially the students of Andrea del Sarto such as Jacopo da Pontormo and Rosso Fiorentino who are notable for elongated forms, precariously balanced poses, a collapsed perspective, irrational settings, and theatrical lighting. Parmigianino (a student of Correggio) and Giulio Romano (Raphael's head assistant) were moving in similarly stylized aesthetic directions in Rome. These artists had matured under the influence of the High Renaissance, and their style has been characterized as a reaction to or exaggerated extension of it. Instead of studying nature directly, younger artists began studying Hellenistic sculpture and paintings of masters past. Therefore, this style is often identified as "anti-classical", yet at the time it was considered a

High maniera.

The second period of Mannerism is commonly differentiated from the earlier, so-called "anti-classical" phase. Subsequent mannerists stressed intellectual conceits and artistic virtuosity, features that have led later critics to accuse them of working in an unnatural and affected "manner" ("maniera"). Maniera artists looked to their older contemporary Michelangelo as their principal model; theirs was an art imitating art, rather than an art imitating nature. Art historian Sydney Joseph Freedberg argues that the intellectualizing aspect of maniera art involves expecting its audience to notice and

Spread of Mannerism.

The cities Rome, Florence, and Mantua were Mannerist centers in Italy. Venetian painting pursued a different course, represented by Titian in his long career. A number of the earliest Mannerist artists who had been working in Rome during the 1520s fled the city after the Sack of Rome in 1527. As they spread out across the continent in search of employment, their style was disseminated throughout Italy and Northern Europe. The result was the first international artistic style since the Gothic. Other parts of Northern Europe did not have the advantage of such direct contact with Italian artists, but the Mannerist style made its presence felt through prints and illustrated books. European rulers, among others, purchased Italian works, while northern European artists continued to travel to Italy, helping to spread the Mannerist style. Individual Italian artists working in the North gave birth to a movement known as the Northern Mannerism. Francis I of France, for example, was presented with Bronzino's "Venus, Cupid,

Sculpture.

As in painting, early Italian Mannerist sculpture was very largely an attempt to find an original style that would top the achievement of the High Renaissance, which in sculpture essentially meant Michelangelo, and much of the struggle to achieve this was played out in commissions to fill other places in the Piazza della Signoria in Florence, next to Michelangelo's "David". Baccio Bandinelli took over the project of "Hercules and Cacus" from the master himself, but it was little more popular then than it is now, and maliciously compared by Benvenuto Cellini to "a sack of melons", though it had a long-lasting effect in apparently

Early theorists.

Giorgio Vasari.

Giorgio Vasari's opinions about the art of painting emerge in the praise he bestows on fellow artists in his multi-volume "Lives of the Artists": he believed that excellence in painting demanded refinement, richness of invention ("invenzione"), expressed through virtuoso technique ("maniera"), and wit and study that appeared in the finished work, all criteria that emphasized the artist's intellect and the patron's sensibility. The artist was now no longer just a

Gian Paolo Lomazzo.

Another literary figure from the period is Gian Paolo Lomazzo, who produced two works—one practical and one metaphysical—that helped define the Mannerist artist's self-conscious relation to his art. His "Trattato dell'arte della pittura, scoltura et architettura" (Milan, 1584) is in part a guide to contemporary concepts of decorum, which the Renaissance inherited in part from Antiquity but Mannerism elaborated upon. Lomazzo's systematic codification

Characteristics of artworks created during the Mannerist period.

Mannerism was an anti-classical movement which differed greatly from the aesthetic ideologies of the Renaissance. Though Mannerism was initially accepted with positivity based on the writings of Vasari, it was later regarded in a negative light

Mannerist artists and examples of their works.

Jacopo da Pontormo.

Jacopo da Pontormo's work has been known as some of the most important contributions to Mannerism. Much of his subject matter drew upon religious narratives as well as the influence of the works of Michelangelo and referencing sculpture for composing human forms. A well-known element of his work is the rendering of gazes by various figures which often pierce out at the viewer in various directions. Dedicated to his work, Pontormo, often expressed anxiety about the quality of his work and was known to work slow and methodically. His legacy is highly regarded, as he influenced artists such as Agnolo Bronzino and the aesthetic ideals of late Mannerism.  Pontomoro's "Joseph in Egypt", painted in 1517, portrays

Rosso Fiorentino and the School of Fontainebleau.

Rosso Fiorentino, who had been a fellow pupil of Pontormo in the studio of Andrea del Sarto, in 1530 brought Florentine Mannerism to Fontainebleau, where he became one of the founders of French 16th-century Mannerism, popularly known as the School of Fontainebleau.  The examples of

Agnolo Bronzino.

Agnolo Bronzino was a pupil of Pontormo, whose style was very influential and often confusing in terms of figuring out the attribution of many artworks. During his career, Bronzino also collaborated with Vasari as a set designer for the production "Comedy of Magicians", where he painted many portraits. Bronzino's work was sought after, and he enjoyed great success when he became a court painter for the Medici family in 1539. A unique Mannerist characteristic of Bronzino's work was the rendering of milky complexions.  In the painting, "Venus, Cupid, Folly and Time", Bronzino portrays an erotic scene that leaves the viewer with more questions than answers. In the foreground, Cupid and Venus are nearly engaged in a kiss, but pause as if caught in the act. Above the pair are mythological figures, Father

Alessandro Allori.

Alessandro Allori's (1535–1607) "Susanna and the Elders" ("below") is distinguished

Jacopo Tintoretto.

Jacopo Tintoretto has been known for his vastly different contributions to Venetian painting after the legacy of Titian. His work, which differed greatly from his predecessors, had been criticized by Vasari for its, "fantastical, extravagant, bizarre style." Within his work, Tinitoretto adopted Mannerist elements that have distanced him from the classical notion of Venetian painting, as he often created artworks which contained elements of fantasy and retained naturalism. Other unique elements of Tintoretto's work include his attention to color through the regular utilization of rough brushstrokes and experimentation with pigment to create illusion.  An artwork that is associated with Mannerist characteristics is the "Last Supper"; it was commissioned by Michele Alabardi for

El Greco.

El Greco attempted to express religious emotion with exaggerated traits. After the realistic depiction of the human form and the mastery of perspective achieved in High Renaissance, some artists started to deliberately distort proportions in disjointed, irrational space for emotional and artistic effect. El Greco still is a deeply original artist. He has been characterized by modern scholars as an artist so individual that he belongs to no conventional school. Key aspects of Mannerism in El Greco include the jarring "acid" palette, elongated and tortured anatomy, irrational perspective and light, and obscure and troubling iconography. El Greco's style was a culmination of unique developments based on his Greek heritage and travels to Spain and Italy.  El Greco's work reflects a multitude of styles including Byzantine elements as well as the influence of Caravaggio and Parmigianino in addition to Venetian coloring. An important

Benvenuto Cellini.

Benvenuto Cellini created the "Cellini Salt Cellar" of gold and enamel in 1540 featuring

Lavinia Fontana.

Lavinia Fontana (1552–1614) was a Mannerist portraitist often acknowledged to be the first female career artist in Western Europe. She was appointed to be the Portraitist in Ordinary at the

Taddeo Zuccaro (or Zuccari).

Taddeo Zuccaro was born in Sant'Angelo in Vado, near Urbino, the son

Federico Zuccaro (or Zuccari).

Federico Zuccaro’s documented career as a painter began in 1550, when he moved to Rome to work under Taddeo, his elder brother. He went on to complete decorations

Joachim Wtewael.

Joachim Wtewael (1566–1638) continued to paint in a Northern Mannerist style until the end of his life, ignoring the arrival of the Baroque art, and making

Giuseppe Arcimboldo.

Giuseppe Arcimboldo is most readily known for his artworks that incorporate still life and portraiture. His style is viewed as Mannerist with the assemblage style of fruits and vegetables in which its composition can be depicted in various ways—right side up and upside down. Arcimboldo's artworks have also applied to Mannerism in terms of humor that it conveys to viewers, because it does not hold the same degree of seriousness as Renaissance works. Stylistically, Arcimboldo's paintings are known for their attention to nature and concept of a "monstrous appearance."  One of Arcimboldo's paintings which contains various Mannerist characteristics is, "Vertumnus". Painted against a black background is a portrait of Rudolf II, whose body

Mannerist architecture.

Mannerist architecture was characterized by visual trickery and unexpected elements that challenged the Renaissance norms. Flemish artists, many of whom had traveled to Italy and were influenced by Mannerist developments there, were responsible for the spread of Mannerist trends into Europe north of the Alps, including into the realm of architecture. During the period, architects experimented with using architectural forms to emphasize solid and spatial relationships. The Renaissance ideal of harmony gave way to freer and more imaginative rhythms. The best known architect associated with the Mannerist style, and a pioneer at the Laurentian Library, was Michelangelo (1475–1564). He is credited with inventing the giant order, a large pilaster that stretches from the bottom to the top of a façade. He used this in his design for the Piazza del Campidoglio in Rome.  Prior to the 20th century, the term "Mannerism" had negative connotations, but it is now used to describe the historical period in more general, non-judgmental terms. Mannerist architecture has also been used to describe a trend in the 1960s and 1970s that involved breaking the norms of modernist architecture while at the same time recognizing their existence. Defining Mannerism in this context, architect and author Robert Venturi wrote "Mannerism for architecture of our time that acknowledges conventional order rather than original expression but breaks the conventional order to accommodate complexity and contradiction and thereby engages ambiguity unambiguously."

Renaissance examples.

An example of Mannerist architecture is the Villa Farnese at Caprarola, in the rugged country side outside of Rome. The proliferation of engravers during the 16th century spread Mannerist styles more quickly than any previous styles.  Dense with ornament of "Roman" detailing, the display doorway at Colditz Castle exemplifies the northern style, characteristically applied as an

Mannerism in literature and music.

In English literature, Mannerism is commonly identified with the qualities of the "Metaphysical" poets of whom the most famous is John Donne. The witty sally of a Baroque writer, John Dryden, against the verse of Donne in the previous generation, affords a concise contrast between Baroque and Mannerist aims in the arts:  The rich musical possibilities in the poetry of the late 16th and early 17th centuries provided an attractive basis for the madrigal, which quickly rose to prominence as the pre-eminent musical form in Italian musical culture, as discussed by Tim Carter:  The word Mannerism has also been used to describe the style of highly florid and contrapuntally complex polyphonic music made in France in the late 14th century. This period is now usually referred to as the "ars subtilior".

Mannerism and theatre.

"The Early Commedia dell'Arte (1550–1621): The Mannerist Context" by Paul Castagno discusses Mannerism's effect on the contemporary professional theatre. Castagno's was the first study to define a theatrical form as Mannerist, employing the vocabulary of Mannerism and maniera to discuss the typification, exaggerated, and "effetto meraviglioso" of the "comici dell'arte". See Part II of the above book for a full discussion of Mannerist characteristics in the commedia dell'arte. The study is largely iconographic, presenting a pictorial evidence that many of the artists who painted or printed commedia images were in fact, coming from the workshops of the day, heavily ensconced in the maniera tradition.  The preciosity in Jacques Callot's minute engravings seem to belie a much larger scale of action. Callot's "Balli di Sfessania" (literally, dance of the buttocks) celebrates the commedia's blatant eroticism, with protruding phalli, spears posed with the anticipation of a comic ream, and grossly exaggerated masks that mix the bestial with human. The eroticism of the "innamorate" (lovers) including the baring of breasts, or excessive veiling, was quite in vogue in the paintings and engravings from the second School of Fontainebleau, particularly those that detect a Franco-Flemish influence. Castagno demonstrates iconographic linkages between genre painting and the figures of the commedia dell'arte that demonstrate how this theatrical form was embedded within the cultural traditions of the late cinquecento.

Commedia dell'arte, "disegno interno", and the "discordia concors".

Important corollaries exist between the "disegno interno", which substituted for the "disegno esterno" (external design) in Mannerist painting. This notion of projecting a deeply subjective view as superseding nature or established principles (perspective, for example), in essence, the emphasis away from the object to its subject, now emphasizing execution, displays of virtuosity, or unique techniques. This inner vision is at the heart of commedia performance. For example, in the moment of improvisation the actor expresses his virtuosity without heed to formal boundaries, decorum, unity, or text. Arlecchino became emblematic of the mannerist "discordia concors" (the union of opposites), at one moment he would be gentle and kind, then, on a dime, become a thief violently acting out with his battle. Arlecchino could be graceful in movement, only in the next beat, to clumsily trip over his feet. Freed from the external rules, the actor celebrated the evanescence of the moment; much the way Benvenuto Cellini would dazzle his patrons by draping his sculptures, unveiling them with lighting effects and a sense of the marvelous. The presentation of the object became as important as the object itself.

Neo-Mannerism.

According to art critic Jerry Saltz, "Neo-Mannerism" (new Mannerism) is among several clichés that are "squeezing the life out of the art world". Neo-Mannerism describes art of

Mannerism, also known as Late Renaissance, is a style in European art that emerged in the later years of the Italian High Renaissance around 1520, spreading by about 1530 and lasting until about the end of the 16th century in Italy, when the Baroque style largely replaced it. Northern Mannerism continued into the early 17th century.

矫饰主义,又有译为风格主义、手法主义,有时也被过于简单化地称为形式主义。是一种在16世纪出现的艺术风格。最早缘于瓦萨里的著作《艺苑名人传》,他用“grande maniera”等词来描述文艺复兴时期三位大家米开朗基罗、达芬奇和拉斐尔的风格。认为他们超越了希腊古罗马时期的前人在艺术领域的研究。后来风格主义则慢慢带有贬义,指将文艺复兴时期的宗旨: 和谐,理想美,对称比例这三点本质撇弃,模仿这三大家,或是刻意炫耀技能的一种风格。1517年,马丁·路德发表《九十五条论纲》成为宗教改革的导火索,改革如火如荼进行着,天主教也从这个不可逆的改革事件得到教训进行反省和检讨,之后组织了一轮1545-1563年反宗教大会--特伦托大会,在这次大会上规范了艺术领域里的设计手法,或是绘画领域或是建筑领域进行一系列的规范措施。


Early life.

Powell was born in Tonbridge, Kent, England, the son of a local gunsmith, and educated at a local primary school before gaining a scholarship to the Judd School, Tonbridge, which had one of its four houses named after Powell (the house colour is green), from 2008-2017. To this day the school awards the Powell Physics and Mathematics Prize to an upper sixth form student every year in his honour (in addition Powell is honoured by the local branch of Pizza Express, which is dedicated to him and a portrait of Powell hangs in the restaurant). Following this he attended Sidney Sussex College, Cambridge, graduating in 1925 in Natural Sciences. After completing his bachelor's degree he worked at the Cavendish Laboratory, Cambridge, under C.T.R. Wilson and Lord Rutherford, conducting research into condensation phenomena, and gaining his PhD in Physics in 1929.

Professional life.

In 1928 he took up a post as Research Assistant to A.M. Tyndall in the H.H. Wills Physical Laboratory at the University of Bristol, later being appointed lecturer, and in 1948 appointed Melville Wills Professor of Physics. In 1932 Powell married Isobel Artner (1907-1995), and the couple had two daughters. In 1936 he took part in an expedition to the West Indies as part of a study of volcanic activity, and where he appears on a stamp issued in Grenada.  During his time at Bristol University, Powell applied himself to the development of techniques for measuring the mobility of positive ions, to establishing the nature of the ions in common gases, and to the construction and use of a Cockcroft generator to study the scattering of atomic nuclei. He also began to develop methods employing specialised photographic emulsions to facilitate the recording of the tracks of elementary particles, and in 1938 began applying this technique to the study of cosmic radiation, exposing photographic plates at high-altitude, at the tops of mountains and using specially designed balloons, collaborating in the study with Giuseppe Occhialini, H. Muirhead and young Brazilian physicist César Lattes. This work led in 1946 to the discovery of the pion (pi-meson), which proved to be the hypothetical particle proposed in 1935 by Yukawa Hideki in his theory of nuclear physics.  In 1949 Powell became a Fellow of the Royal Society and received the society's Hughes Medal the same year. In 1950 he was awarded the Nobel Prize for Physics "for his development of the photographic method of studying nuclear processes and his discoveries regarding mesons made with this method" although the Brazilian Cesar Lattes be the first author and the real responsible of the discovery. Debendra Mohan (DM) Bose [nephew of Sir J.C. Bose] and Chowdhuri published three consecutive papers in Nature, but could not continue further investigation on account of "non-availability of more sensitive emulsion plates during the war years. Seven years after this discovery of mesons by DM Bose and Bibha Chowdhuri, C.F. Powell made the same discovery of pions and muons and further decay of muons to electrons... using the same technique". He acknowledged in his book, "In 1941, Bose and Chaudhuri (sic) had pointed it out that it is possible, in principle, to distinguish between the tracks of protons and mesons in an emulsion... They concluded that many of the charged particles arrested in their plates were lighter than protons, their mean mass being... the physical basis of their method was correct and their work represents the first approach to the scattering method of determining momenta of charged particles by observation of their tracks in emulsion". In fact, the measured mass of the particle by Bose and Chowdhuri was very close to the accepted value measured by Powell who used improved "full-tone" plates. From 1952 Powell was appointed director of several expeditions to Sardinia and the Po Valley, Italy, utilizing high-altitude balloon flights.  In 1955, Powell, also a member of the World Federation of Scientific Workers, added his signature to the Russell-Einstein Manifesto put forward by Bertrand Russell, Albert Einstein and scientist Joseph Rotblat, and was involved in preparations for the first Pugwash Conference on Science and World Affairs. As Rotblat put it, "Cecil Powell has been the backbone of the Pugwash Movement. He gave it coherence, endurance and vitality." Powell chaired the meetings of the Pugwash Continuing Committee, often standing in for Bertrand Russell, and attended meetings until 1968.  In 1961 Powell received the Royal Medal, and served on the Scientific Policy Committee of the European Organization for Nuclear Research (CERN) that year, and in 1967 he was awarded the Lomonosov Gold Medal by the Academy of Sciences of the USSR (now Russian Academy of Sciences) "for outstanding achievements in the physics of elementary particles".  Powell died on 9 August 1969, whilst out walking in the foothills of the Alps near the Valsassina region of Italy, where he had been staying with friends. A bench with commemorative plaque was erected near the site of his death.

Cecil Frank Powell, FRS (5 December 1903 – 9 August 1969) was an English physicist, and Nobel Prize in Physics laureate for his development of the photographic method of studying nuclear processes and for the resulting discovery of the pion (pi-meson), a subatomic particle.

塞西尔·鲍威尔(英语:Cecil Powell,1903年-12月5日-1969年-8月9日),英国物理学家。