Background.

The first encounters between Muslims and western European Christians occurred during the 8th-century Umayyad conquest of Hispania. Relationship between the two groups remained hostile along the common borders. The Franks' stubborn resistance to the Muslim invasion of Gaul astonished most Muslim observers, because the Christians of the Umayyad Caliphate had acquiesced in their status of as second-class "protected" citizens. European Christians regarded the regular Muslim raids as signs of the wrath of God, but did not express more animosity towards Muslim corsairs than towards Viking pirates or Magyar raiders.

Levant.

In the mid-11thcentury the Muslim world, or, included more than of land in southern Europe, northern Africa and western Asia. It was a highly urbanised society, organised into regional networks of cities and interdependent villages. State administration followed the pre-Islamic concept of "Circle of Equity": a monarch could maintain good governance only with the support of the army and only good governance provide the economic basis of military expenditure. The military finance was through the system in which the ruler authorised the officers to collect taxes in the village, region or province assigned to them. As the ruler could withdrew this authorisation, the exploitation of the local population was not alien to holders. Foot soldiers, armed with spears, swords and bows, and lightly armoured mounted archers made up the bulk of Islamic armies. Most of

Europe.

Visitors from the Byzantine Empire and the Muslim world regarded Europe as backward region—a supplier of slaves, fur, timber and other raw materials. However, Latin Europe transformed and expanded stably from the 10th century. Moderate growth in population increased the demand for food and new land was brought into cultivation. New channels of trade and communication were developed with distant regions. Kings and aristocrats waged war for new territory in borderlands from Spain to Saxony. The clergy were eager to evangelise and peasants eager for achieve personal freedom and lower taxes as colonists in newly conquered lands. Norman adventurers seized Byzantine territories in southern Italy. They also captured Sicily that was once held by the Byzantines, taking advantage of power struggles between the local Muslim rulers. Levantine commerce intensified and Italian merchants benefitted of the lucrative business. Venice, Pisa and Genoa developed into maritime powers. The Byzantines depended on Venetian naval support and rewarded Venetian merchants with extensive trading privileges. The Pisans and Genoese jointly expelled the Muslims from Sardinia and they also sacked Mahdia in northern Africa.  Medieval Catholic clerics likened an ideal society to human body, consisting of individual parts, each having their

First Crusade.

From Late Antiquity the Byzantine army utilised mercenaries. Traditionally these were hired Turkic and western European troops, but conflict with the neighbouring Turkic peoples increased the importance of the use of European soldiery. Emperor Alexios I Komnenos appealed to Pope Urban II, seeking his support in raising troops to fight against the Turks. On 27 November 1095 at the Council of Clermont, the Pope responded with a proclamation of the First Crusade, offering absolution of the participants' sins. The enterprise was probably modelled on a pilgrimage with Urban's speech addressing the poor as well as knights. This prompted a ground-swell of popular enthusiasm among poor

History.

Foundation.

The Byzantine commander Tatikios guided the crusade south through Anatolia after victory at Dorylaeum opened the path to Antioch. This large city controlled the road south to Jerusalem. The crusaders common purpose did not hide competition between leaders such as Bohemond's nephew, Tancred, and Godfrey's brother, Baldwin. They expelled Turkic garrisons from Cilician towns, before quarrelling over who would retain them. This led to armed conflict between the two sets of retainers. Antioch's governor Yağısıyan expelled all Christian men from the city and approached the Muslim rulers of Syria and Iraq for support. In October 1097 Baldwin left the crusade for the area on the west bank of the Euphrates, probably to join one side of an Armenian feud. The Armenians of two small northern Syrian towns, Turbessel and Rawandan, took advantage of his advance to expel the Turkish garrisons. The main army reached Antioch and with native Christian allies captured nearby fortifications. An English fleet secured the possession of the port of Saint Symeon. In February 1098 Tatikios left the crusade.

Consolidation.

The Franks took advantage of fragmented Muslim politics to consolidate their position. The Syrian Sunnis approached the Seljuk sultan, Barkiyaruq, for assistance in 1097 or 1098, but he was engaged in a power struggle with his brother Muhammad Tapar. The Damascene jurist Ali ibn Tahir al-Sulami was most likely the first scholar to call for the against the crusaders. In his "Book of Holy War", he introduced the First Crusade in the wider context of Frankish expansion and reminded his co-religionists that disunity had enabled the Franks to seize territories in Spain, Sicily and the Levant. The fall of Tripoli was the earliest shock inducing Sultan Muhammad to mobilize the armies of his empire's western provinces against the

Muslim revival.

In 1127 and two years after al-Bursuqi's death, Imad al-Din Zengi united Mosul and Aleppo. The Seljuk sultan Mahmud appointed him to replace al-Bursuqi's grandson as of Mosul. The next year Zengi extended his rule to include Aleppo. The Burid dynasty in Damascus were Zengi's principal Muslim rivals in Syria. Toghtekin tolerated a Nizari presence, but after his death the Damascenes suppressed them. Those that survived fled to the Nusayriyah Mountains and established a new base in the region.  Baldwin II of Jerusalem married off his younger daughter, Alice, to Bohemond II of Antioch when Bohemond reached the age of majority in 1126. Baldwin's eldest daughter and heir, Melisende, was given in marriage to the wealthy Count of Anjou, Fulk who led fresh troops to the Outremer. Reinforcements came from Antioch, Edessa and Tripoli and the united army marched against Damascus. The oversized host of soldiers could not be provided with sufficient food and the Burids' troops forced the Franks to abandon the siege. Bohemond II was killed during a raid in Cilicia in 1130. The widowed Alice wanted to assume power in his principality and appealled to Zengi for help. Her father hurried to Antioch and assumed the regency for her daughter by Bohemond, Constance.  Baldwin named Fulk, Melisende and their infant son, Baldwin III, as his co-heirs on his deathbed in 1131. Fulk ignored his father-in-law's last will and

Fall.

Saladin granted extensive -holdings to his kinsmen and consolidated his position in Egypt with their support. He ruled Egypt as Nur ad-Din's lieutenant, but mutual distrust made their relationship strain. Nur ad-Din died in May 1174 and his son, As-Salih Ismail al-Malik, was only 11. Saladin seemingly acknowledged As-Salih's suzerainty, but the boy's guardian, the eunuch Gümüshtekin, distrusted him. As-Salih moved from Damascus to Aleppo and the Damascene surrendered to Saladin without resistance. He was determined to re-unite Nur ad-Din's empire and waged war against the Zengid rulers of Syria and Iraq during the following 12 years.  Amalric of Jerusalem deceased in July 1174. His 13-year-old son, Baldwin IV, suffered from leprosy. Baldwin was crowned king and the seneschal Miles of Plancy assumed power, ignoring the claim of Amalric's cousin, Raymond III of Tripoli, to the regency. After Plancy was assassinated for unknown reason, Raymond was elected as regent. He married the richest heiress of the kingdom, Eschiva of Bures, and seized Galilee. Raymond made an assault on Homs to prevent Saladin from attacking Aleppo, but he refused the Zengids' proposal

Third Crusade.

Pope Gregory VIII publicized the call for a new crusade in the bull "Audita tremendi" in October 1187. King William II of Sicily was the first European ruler to respond. He dispatched 50 ships to the Outremer and the Sicilian fleet supported the defenders of Tyre, Tripoli and Antioch to resist. Within months, Frisian, Danish, Flemish, Breton and Italian crusaders sailed for the Holy Land. Kings Henry II of England and Philip II of France jointly took the cross at Gisors in January 1188. Prolonged negotiations to terminate their conflicts and Henry's death delayed the crusade for more than two years, although Henry's successor, Richard I

Demography and Society.

Modern research using historical geography techniques indicate that Muslims and indigenous Christian populations were less integrated than historians previously thought. Palestinian Christians lived around Jerusalem and in an arc stretching from Jericho and the Jordan to Hebron in the south. Comparisons of archaeological evidence of Byzantine churches built prior the Muslim conquest and 16thcentury Ottoman census records demonstrate that while some Greek Orthodox communities had disappeared prior the crusades, most continued during and for centuries after the crusader states. Maronites were concentrated in Tripoli; Jacobites in Antioch and Edessa. Armenians were concentrated in the north but communities existed in all major towns. Palestine's central areas had a Muslim majority population. The Muslims were mainly Sunnis, but Shi'ite communities existed in Galilee. The nonconformist Muslim Druzes were recorded living in the mountains of Tripoli. The Jewish population resided in coastal towns and some Galilean villages. Little research has been done on Islamic conversion but the limited available evidence led Ellenblum to believe that around Nablus and Jerusalem Christians remained a majority.  Peasants living off the land formed the vast majority of the indigenous population, particularly after the massacres and sieges of the early 11thcentury led to widespread death and emigration among the native city dwellers. Charters from the beginning of the 12thcentury show evidence of the donation of local villeins to nobles and religious instituitions. This may have been a method of denoting the revenues from these villeins or land where the boundaries were unclear. These are described as, for Christians or for Muslims. The term was reserved for the numerous urban, domestic slaves the Franks held in Jerusalem. The use of is thought to possibly reflect the higher status that villagers or serfs held in the near East or that the indigenous men referred to were considered to have servile land tenures rather than that they lacked personal freedom. The difference between the Western serf and Near Eastern villein was that the latter could marry outside their lords' domain, were not obliged to perform unpaid labour, could hold land and inherit property. However, because the Franks needed to maintain productivity the villagers were tied to the land. Charters evidence landholders agreeing to return any villeins from other landholders they found on their property. Peasants were required to pay the lord one quarter to a half of crop yields, the Muslim pilgrim Ibn Jubayr reported there was also a poll tax of one dinar and five qirat per head and a tax on produce from trees. 13thcentury charters indicate this increased after the loss of the first kingdom to compensate the Franks for the resulting loss of income. These are the reasons that the use of the term "indentured peasant" is considered by historian

Economy.

In addition to being economic centres themselves, the crusader states provided an obstacle to Muslim trade by sea with the west and to the land routes from Mesopotamia and Syria to the great urban economies of the Nile. Despite hostility, commerce continued, coastal cities remained maritime outlets for the Islamic hinterland and eastern wares were exported to Europe in unprecedented volumes. The Byzantine-Muslim mercantile growth in the 12thand13thcenturies may have occurred anyway, as the Western European economy was booming due to population growth; this increased wealth and created a growing social class demanding city centred products and eastern imports, but it is likely that the Crusades hastened the developments. European fleets were expanded, better ships built, navigation improved and fare paying pilgrims subsidised many voyages. Agricultural production, largely the domain of the indigenous population, flourished before the fall of the First Kingdom in 1187, but was negligible afterwards. Franks, Muslims, Jews and indigenous Christians traded crafts in the souks, teeming oriental bazaars,

Monarchy.

During the period of near constant warfare in the early decades of the 12thcentury, the king of Jerusalem's foremost role was leader of the feudal host. They very rarely awarded land or lordships, and those awarded that became vacanta frequent event due to the high mortality rate in the conflictreverted to the crown. Instead their followers' loyalty was rewarded with city incomes. As a result, the royal domain of the first five rulers including much of Judea, Samaria, the coast from Jaffa to Ascalon, the ports of Acre and Tyre, and other scattered castles and territorieswas larger that the combined holdings of the nobility. This meant that the rulers of Jerusalem had greater internal power than comparative western monarchs, although they did not have the necessary administrative systems and personnel to govern such a large realm. The situation evolved in the second quarter of the century with the establishment of baronial dynasties. Magnatessuch as Raynald of Châtillon, Lord of Oultrejordain, and Raymond III, Count of Tripoli, Prince of Galileeoften acted as autonomous rulers. Royal powers were abrogated and effectively governance was undertaken within the feudatories. What central control remained was exercised at the High Court, in English. Only the 13thcentury jurists of Jerusalem used this term, was more common in Europe. These were meetings between the king and his tenants in chief. Over time the duty of the vassal to give counsel developed into a privilege and ultimately the legitimacy of the monarch depended on the agreement of the court. In practice, the High Court consisted of the great barons and the king's direct vassals. In law a quorum was the king and three tenants in chief. The 1162 the theoretically expanded the court's membership to all 600 or more fief-holders, making them all peers. All those who paid homage directly to the king were now members of the of Jerusalem. They were joined by the heads of the military orders by the end of the 12thcentury, and the Italian communes in the 13thcentury. The leaders of the Third Crusade ignored the monarchy of Jerusalem; the kings of England and France agreed on the division of future conquests as if there was no need to take into account the nobility of the crusader states. Joshua Prawer considered that the weakness of the crown of Jerusalem was demonstrated by the rapid offering of the throne to Conrad of Montferrat in 1190 and then Henry II, Count of Champagne in 1192. This was given legal effect by Baldwin IV's will stipulating if Baldwin V died a minor the Pope, the kings of England and France, and the Holt Roman Emperor should select the successor. Before the defeat at Hattin in 1187 the laws developed by the court were documented as in "Letters of the Holy Sepulchre". After Hattin the Franks lost their cities, lands and churches. Many barons feld to Cyprus and intermarried with leading new emigres from the Lusignan, Montbéliard, Brienne and Montfort families. This created a class apart from the remnents of the old nobility with limited understanding of the Latin East including the king-consorts Guy, Conrad, Henry, Aimery, John and the absent Hohenstaufen that followed. The entire body of written law was lost in the subsequent fall of Jerusalem. From this point the legal system was largely based on custom and the memory of the lost legislation. The renowned jurist Philip of Novara lamented "We know [the laws] rather poorly, for they are known by hearsay and usage...and we think an assize is something we have seen as an assize...in the kingdom of Jerusalem [the barons] made much better use of the laws and acted on them more surely before the land was lost". Thus a myth was created of an idyllic early 12thcentury legal system. The barons used this to reinterpret the, which Almalric I intended to strengthen the crown, to instead constrain the monarch, particularly with regards to the right of the monarch to remove feudal fiefs without trial. The concomitant loss of the vast majority of rural fiefs led to the barons becoming an urban mercantile class where knowledge of the law was a valuable, well-regarded skill and a career path to higher status. The barons of Jerusalem in the 13thcentury have been poorly regarded by both contemporary and modern commentators: James of Vitry was disgusted by their superficial rhetoric; Riley-Smith writes of their pedantry and

Religion.

Indigenous Christians shared each other's churches, priests and even took the sacraments together. There is no wriiten evidence that the Franks or local Christians recognised significant religious differences until the 13thcentury when the jurists repeatedly used phrases such as "men not of the rule of Rome". Partly a result of anti-Orthodox sentiment the early crusaders filled ecclesiastical positions in the Orthodox church left vacant with Franks, including the patriarchy of Jerusalem when Simeon II died. The Greek Orthodox Church was considered part of the universal Church, which enabled the replacement of Orthodox bishops by Latin clerics in coastal towns. The first Latin patriarch of Jerusalem, Arnulf of Chocques, ejected the Greek Orthodox monks from the Holy Sepulchre but relented when the miracle of Easter Fire failed in their absence. The appointment of Latin bishops had little effect on the Arabic-speaking Orthodox Christians because the previous bishops

Communes.

One Frankish weakness was the lack of sea-power. This was addressed by the purchase of naval resources from the Italian maritime republics of Pisa, Venice and Genoa. These republics were enthusiastic crusaders from the early 11thcentury whose commercial wealth secured the financial base of the Franks. In return these cities, and others such as Amalfi, Barcelona and Marseilles, received commercial rights and access to Eastern markets. Over time this developed into colonial communities with property and jurisdictional rights.  Largely located in the ports of Acre, Tyre, Tripoli and Sidon, communes of Italians, Provençals and Catalans had distinct cultural characteristics and exerted significant political power. Separate from the Frankish nobles or burgesses,

Military orders.

The crusaders habitually followed the customs of their Western European homelands and there were very few cultural innovations in the crusader states. Three notable exceptions to this were the military orders, warfare and fortifications. The order of the Poor Fellow-Soldiers of Christ and of the Temple of Solomon, more commonly known as the Templars, was formed in 1119 with a mission to protect pilgrims in the perilous territory. The founders were a group of knights attached to the Holy Sepulchre. They were formally recognised at the council of Nablus and eventually granted the Al-Aqsa Mosque on the Temple Mount to use as the orders headquarters. This was known to the Franks as Solomon's Temple from which the order's name derives. The founding leaders, Hugues de Payens and Godfrey de Saint-Omer travelled to Europe and in 1129 the order was recognised by the Latin Church at the Council of Troyes. Unshrining this in a detail rule, support, privileges and immunities followed from the papacy. Donations of estates across Western Europe and the Levant enabled the order to provide the crusader states with troops, funding, loans and luxury

Art and architecture.

According to Joshua Prawer no major European poet, theologian, scholar or historian settled in the crusader states. Some went on pilgrimage, and this is reflected in new imagery and ideas in western poetry. Although they did not migrate east themselves, their output often encouraged others to journey on pilgrimage to the east.  Historians consider military architecturedemonstrating a synthesis of the European, Byzantine and Muslim traditionsthe most original and impressive artistic achievement of the crusades. Castles were a tangible symbol of the dominance of a Latin Christian minority over a largely hostile majority population. They also acted as centres of administration. Modern historiography rejects the 19th-century consensus that Westerners learnt the basis of military architecture from the Near East, as Europe had already experienced rapid growth in defensive technology. Direct contact with Arab fortifications originally constructed by the Byzantines did influence developments in the east. But the lack of documentary evidence means that it remains difficult to differentiate between the importance of this design culture and the constraints of situation, which led to the inclusion of oriental design features such as large water reservoirs and the exclusion of occidental features like moats. Castles acted as centres of defence and administration. stimulating the development of new settlements.  Typically, early church design was in the French Romanesque style. This can be seen in

Military.

Reports from John of Ibelin indicate that around 1170 the military force of the Kingdom of Jerusalem was based on a feudal host of about 647 to 675 heavily armoured knights. Each feudatory would also provide his own armed retainers. Non-noble light cavalry and infantry were known as "serjants". The prelates and the towns were to provide 5,025 "serjants" to the royal army, according to Ibelin's list. This force would be augmented by hired soldiery called Turcopoles. In times of emergency, the king could also call upon a general muster of the whole Christian population.  Joshua Prawer estimated that the military orders could match the king's fighting strength. This means the total military of the kingdom was approximately 1,200 knights and 10,000 "serjants". Enough for further territorial gains, but fewer than required to maintain military domination. This was also a problem defensively. Putting a major army into the field required draining castles and cities of able-bodied fighting men. In the case of a defeat, such as the Battle of

Legacy.

After the fall of Acre the Hospitallers first relocated to Cyprus. The order conquered and ruled Rhodes (1309–1522) and Malta (1530–1798). The Sovereign Military Order of Malta survives to the present-day. King Philip IV of France probably had financial and political reasons to oppose the Knights Templar, which led to him exerting pressure on Pope Clement V. The pope responded in 1312 dissolving the order on the alleged and probably false grounds of sodomy, magic and heresy.

Historiography.

Modern historians have developed a broad consensus on relationships between the Frankish and native communities in the crusader states. Joshua Prawer and others described an outnumbered Frankish elite dominating the coastal areas of southern modern Turkey, Syria, Lebanon, Israel and Palestine. In this paradigm the Frankish elite is isolated from the majority population by discrimatory laws, conditions of serfdom and exclusion from positions of authority. Recently this position has been challenged by historians such as Ronnie Ellenblum, using archeological research. These challenges have recognised weaknesses and no alternative model has been presented. Christopher Tyerman points out the challenges are not a return to older theories, the sources remain the same and the archeological materials are virtually unprovable. Denys Pringle, a specialist in Frankish architecture, notes that new architectural research does not contradict the segregationist view of Frankish society that earlier in the 20thcentury, Hans Eberhard Mayer had already written that the number of Franks living in rural settlements should not be underestimated.  It was in the 19thcentury that subject of the crusader states, rather than just the crusades themselves, become a subject of study. This was paricularly true among French historians. Joseph François Michaud's influential narratives had concentrated on topics of war, conquest and settlement. Later France's colonial ambitions in the Levant were explicitly linked with French-led crusading and the Frankish character of the states. Emmanuel Rey's described Frankish settlements in the Levant as colonies in which s, offspring of mixed marriages, adopted local traditions and values instead of those of their Frankish descent. The first American crusade historian, Dana Carleton Munro extended this analysis describing the care the Franks took to "win the goodwill of the natives". In the 20thcentury historians rejected this approach. R. C. Smail argued that Rey, and the like, had identified an integrated society which did not exist in order to justify French colonial regimes. The new consensus was that the society was segregated with limited social and cultural interchange. Prawer and Jonathan Riley-Smith focussed on the evidence of social, legal and political frameworks in the kingdom of Jerusalem to present a widely accepted view of a society that was largely urban, isolated from the indigenous peoples, with separate legal and religious systems. Prawer's 1972 work, "The Latin Kingdom of Jerusalem:European Colonialism in the Middle Ages" extended this analysis: the lack of integration was based on economics with the Franks' position depending on a subjugated, disenfranchised local population. In this arrangement the Franks' primary motivations were economic. Islamic historian Carole Hillenbrand identified that Islamic population responded with resentment, suspicion and rejection of the Franks.  This model supports the idea that the crusader states were part of the wider expansion of Western Europe in places such as Ireland, eastern Europe and Spain: driven by religious reforms and the growth of papal power. However, historians now argue that were different in that there was no vigorous church reform in the East, or resulting persecution of Jews and heretics. Some historians consider it exceptional that the 1120 Council of Nablus regulated ecclesiastical tithes, outlawed bigamy and adultery, imposed the death penalty for sodomy and a penalty of castration and mutilation for any Frank engaging in sexual relations with a Muslim. Benjamin Z. Kedar considered that Nablus followed a Byzantine, rather than western reformist, precedent. This has led historians such as Claude Cahen, Jean Richard and Christopher MacEvitt to argue that the history of the crusader states is distinct from the history of the crusades. This allows other analytical techniques to be applied placing the crusader states in the context of Near Eastern politics. These ideas are sill in the process of articulation by modern historians.

The Crusader states were four Roman Catholic polities created as a consequence of the First Crusade. In 1098 Western European crusaders usurped the city of Edessa and seized Antioch on their armed pilgrimage to Jerusalem, which was taken after a siege in 1099. Territorial consolidation followed including the taking of Tripoli. At the states' largest extent territory covered the coastal areas of southern modern Turkey, Syria, Lebanon, Israel and Palestine. These holdings later became known to historians by the term "Outremer" from the French phrase or "the land beyond the sea". Edessa fell to a Turkish warlord in 1144, but the other realms endured into the 13thcentury before falling to the Mamluk Sultanate of Egypt. Antioch was captured in 1268, Tripoli in 1289. When Acre, the capital of the rump kingdom of Jerusalem fell in 1291 the last territories were quickly lost with the survivors fleeing to Cyprus.

十字军国家指经由十字军东征而建立之拉丁国家,他们建立国家时,一般都会将法兰克人那套成熟的采邑制度移植至新征服地,而他们所征服之地区,一般都会同时设立拉丁主教,这些国家之存在,无一例外的都如狂风扫落叶,除了一些因保护殖民城市而建立的碉堡外,一般在人口结构、宗教信仰、文化等等,都无法为这些地区留下深刻影响。


曼努埃尔二世 (拜占庭帝国)

Life.

Manuel II Palaiologos was the second son of Emperor John V Palaiologos and his wife Helena Kantakouzene.  Granted the title of "despotēs" by his father, the future Manuel II traveled west to seek support for the Byzantine Empire in 1365 and in 1370, serving as governor in Thessalonica from 1369. The failed attempt at usurpation by his older brother Andronikos IV Palaiologos in 1373 led to Manuel's being proclaimed heir and co-emperor of his father. In 1376–1379 and again in 1390 they were supplanted by Andronikos IV and then his son John VII, but Manuel personally defeated his nephew with help from the Republic of Venice in 1390. Although John V had been restored, Manuel was forced to go as an honorary hostage to the court of the Ottoman Sultan Bayezid I at Prousa (Bursa). During his stay, Manuel was forced to participate in the Ottoman campaign that reduced Philadelpheia, the last Byzantine enclave in Anatolia.  Having heard of his father's death in February 1391, Manuel II Palaiologos fled the Ottoman court and secured the capital against any potential claim by his nephew John VII. Although relations with John VII improved, Sultan Bayezid I besieged Constantinople from 1394 to 1402. After some five years of siege, Manuel II entrusted the city to his nephew and embarked (along with a suite of 40 people) on a long trip abroad to seek assistance against the Ottoman Empire from the courts of western Europe, including those of Henry IV of England (making him the only Byzantine emperor ever to visit England – he was welcomed from December 1400 to January 1401 at Eltham Palace, and a joust took place in his honour), Charles VI of France, Sigismund the Holy Roman Emperor, Queen Margaret I of Denmark and king Martin of Aragon. In 1399, the French King Charles VI sent Marshal Jean Le Maingre with six ships carrying 1,200 men from Aigues-Mortes to Constantinople; later 300 men under Seigneur Jean de Chateaumorand remained to defend the city against Bayezid.  Meanwhile, an anti-Ottoman crusade led by the Hungarian King Sigismund of Luxemburg failed at the Battle of Nicopolis on 25 September 1396, but the Ottomans were themselves crushingly defeated by Timur at the Battle of Ankara in 1402. Manuel II had sent 10 ships to help in the Crusade of Nicopolis. As the sons of Bayezid I struggled with each other over the succession in the Ottoman Interregnum, John VII was able to secure the return of the European coast of the Sea of Marmara and of Thessalonica to the Byzantine Empire in the Treaty of Gallipoli. When Manuel II returned home in 1403, his nephew duly surrendered control of Constantinople and received as a reward the governorship of newly recovered Thessalonica. The treaty also regained from the Ottomans Nesebar (1403–1453), Varna (1403–1415), and the Marmara coast from Scutari to Nicomedia (between 1403–1421).  On 25 July 1414, with a fleet consisting of four galleys and two other vessels carrying contingents of infantry and cavalry, departed Constantinople for Thessalonica. The purpose of this force soon became clear when he made an unannounced stop at Thasos, a normally unimportant island which was then under threat from a son of the lord of Lesbos, Francesco Gattilusio. It took Manuel three months to reassert imperial authority on the island. Only then did he continue on to Thessalonica, where he was warmly met by his son Andronicus, who then governed the city. In the spring of 1415, he and his soldiers left for the Peloponnese, arriving at the little port of Kenchreai on Good Friday, 29 March. Manuel II Palaiologos used his time there to bolster the defences of the Despotate of Morea, where the Byzantine Empire was actually expanding at the expense of the remnants of the Latin Empire. Here Manuel supervised the building of the "Hexamilion" (six-mile wall) across the Isthmus of Corinth, intended to defend the Peloponnese from the Ottomans.  Manuel II stood on friendly terms with the victor in the Ottoman civil war, Mehmed I (1402–1421), but his attempts to meddle in the next contested succession led to a new assault on Constantinople by Murad II (1421–1451) in 1422. During the last years of his life, Manuel II relinquished most official duties to his son and heir John VIII Palaiologos, and went back to Europe searching for assistance against the Ottomans, this time to the King Sigismund of Hungary, staying for two months in his court of Buda. Sigismund (after suffering a defeat against the Turks in the Battle of Nicopolis in 1396) never rejected the possibility of fighting against the Ottoman Empire. However, with the Hussite wars in Bohemia, it was impossible to count on the Czech or German armies, and the Hungarian ones were needed to protect the Kingdom and control the religious conflicts. Unhappily Manuel returned home with empty hands from the Hungarian Kingdom, and in 1424 he and his son were forced to sign an unfavourable peace treaty with the Ottoman Turks, whereby the Byzantine Empire had to pay tribute to the sultan. Manuel II died on 21 July 1425.  Manuel II was the author of numerous works of varied character, including letters, poems, a Saint's Life, treatises on theology and rhetoric, and an epitaph for his brother Theodore I Palaiologos and a mirror of prince for his son and heir John. This mirror of prince has special value, because it is the last sample of this literary genre bequeathed to us by Byzantines.

Family.

By his wife Helena Dragas, the daughter of the Serbian prince Constantine Dragas, Manuel II Palaiologos had several children, including:

Pope Benedict XVI controversy.

In a lecture delivered on 12 September 2006, Pope Benedict XVI quoted from a dialogue believed to have occurred in 1391 between Manuel II and a Persian scholar and recorded in a book by Manuel II (Dialogue 7 of "Twenty-six Dialogues with a Persian") in which the Emperor stated: "Show me just what Muhammad brought that was new and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached."  cf. James V. Schall S.J., The Regensburg Lecture, South Bend IN: St. Augustine's Press, 2007.

Manuel II Palaiologos or Palaeologus (; 27 June 1350 – 21 July 1425) was Byzantine Emperor from 1391 to 1425. Shortly before his death he was tonsured a monk and received the name "Matthew". His wife Helena Dragaš saw to it that their sons, John VIII Palaiologos and Constantine XI Palaiologos, become emperors.

曼努埃尔二世·帕里奥洛格斯(,1350年-6月27日-1425年-7月21日)拜占庭帝国皇帝(1391年-1425年在位)。


Introduction.

Tempering is a heat treatment technique applied to ferrous alloys, such as steel or cast iron, to achieve greater toughness by decreasing the hardness of the alloy. The reduction in hardness is usually accompanied by an increase in ductility, thereby decreasing the brittleness of the metal. Tempering is usually performed after quenching, which is rapid cooling of the metal to put it in its hardest state. Tempering is accomplished by controlled heating of the quenched work-piece to a temperature below its "lower critical temperature". This is also called the lower transformation temperature or lower arrest (A) temperature; the temperature at which the crystalline phases of the alloy, called ferrite and cementite, begin combining to form a single-phase solid solution referred to as austenite. Heating above this temperature is avoided, so as not to destroy the very-hard, quenched microstructure, called martensite.  Precise control of time and temperature during the tempering process is crucial to achieve the desired balance of physical properties. Low tempering temperatures may only relieve the internal stresses, decreasing brittleness while maintaining a majority of the hardness. Higher tempering temperatures tend to produce a greater reduction in the hardness, sacrificing some yield strength and tensile strength for an increase in elasticity and plasticity. However, in some low alloy steels, containing other elements like chromium and molybdenum, tempering at low temperatures may produce an increase in hardness, while at higher temperatures the hardness will decrease. Many steels with high concentrations of these alloying elements behave like precipitation hardening alloys, which produces the opposite effects under the conditions found in quenching and tempering, and are referred to as maraging steels.  In carbon steels, tempering alters the size and distribution of carbides in the martensite, forming a microstructure called "tempered martensite". Tempering is also performed on normalized steels and cast irons, to increase ductility, machinability, and impact strength. Steel is usually tempered evenly, called "through tempering," producing a nearly uniform hardness, but it is sometimes heated unevenly, referred to as "differential tempering," producing a variation in hardness.

History.

Tempering is an ancient heat-treating technique. The oldest known example of tempered martensite is a pick axe which was found in Galilee, dating from around 1200 to 1100 BC. The process was used throughout the ancient world, from Asia to Europe and Africa. Many different methods and cooling baths for quenching have been attempted during ancient times, from quenching in urine, blood, or metals like mercury or lead, but the process of tempering has remained relatively unchanged over the ages. Tempering was often confused with quenching and, often, the term was used to describe both techniques. In 1889, Sir William Chandler Roberts-Austen wrote, "There is still so much confusion between the words "temper," "tempering," and "hardening," in the writings of even eminent authorities, that it is well to keep these old definitions carefully in mind. I shall employ the word tempering in the same sense as softening."

Terminology.

In metallurgy, one may encounter many terms that have very specific meanings within the field, but may seem rather vague when viewed from outside. Terms such as "hardness," "impact resistance," "toughness," and "strength" can carry many different connotations, making it sometimes difficult to discern the specific meaning. Some of the terms encountered, and their specific definitions are:

Carbon steel.

Very few metals react to heat treatment in the same manner, or to the same extent, that carbon steel does, and carbon-steel heat-treating behavior can vary radically depending on alloying elements. Steel can be softened to a very malleable state through annealing, or it can be hardened to a state nearly as rigid and brittle as glass by quenching. However, in its hardened state, steel is usually far too brittle, lacking the fracture toughness to be useful for most applications. Tempering is a method used to decrease the hardness, thereby increasing the ductility of the quenched steel, to impart some springiness and malleability to the metal. This allows the metal to bend before breaking. Depending on how much temper is imparted to the steel, it may bend elastically (the steel returns to its original shape once the load is removed), or it may bend plastically (the steel does not return to its original shape, resulting in permanent deformation), before fracturing. Tempering is used to precisely balance the mechanical properties of the metal, such as shear strength, yield strength, hardness, ductility and tensile strength, to achieve any number of a combination of properties, making the steel useful for a wide variety of applications. Tools such as hammers and wrenches require good resistance to abrasion, impact resistance, and resistance to deformation. Springs do not require as much wear resistance, but must deform elastically without breaking. Automotive parts tend to be a little less strong, but need to deform plastically before breaking.  Except in rare cases where maximum hardness or wear resistance is needed, such as the untempered steel used for files, quenched steel is almost always tempered to some degree. However, steel is sometimes annealed through a process called normalizing, leaving the steel only partially softened. Tempering is sometimes used on normalized steels to further soften it, increasing the malleability and machinability for easier metalworking. Tempering may also be used on welded steel, to relieve some of the stresses and excess hardness created in the heat affected zone around the weld.

Quenched-steel.

Tempering is most often performed on steel that has been heated above its upper critical (A) temperature and then quickly cooled, in a process called quenching, using methods such as immersing the hot steel in water, oil, or forced-air. The quenched-steel, being placed in or very near its hardest possible state, is then tempered to incrementally decrease the hardness to a point more suitable for the desired application. The hardness of the quenched-steel depends on both cooling speed and on the composition of the alloy. Steel with a high carbon-content will reach a much harder state than steel with a low carbon-content. Likewise, tempering high-carbon steel to a certain temperature will produce steel that is considerably harder than low-carbon steel that is tempered at the same temperature. The amount of time held at the tempering temperature also has an effect. Tempering at a slightly elevated temperature for a shorter time may produce the same effect as tempering at a lower temperature for a longer time. Tempering times vary, depending on the carbon content, size, and desired application of the steel, but typically range from a few minutes to a few hours.  Tempering quenched-steel at very low temperatures, between, will usually not have much effect other than a slight relief of some of the internal stresses and a decrease in brittleness. Tempering at higher temperatures, from, will produce a slight reduction in hardness, but will primarily relieve much of the internal stresses. In some steels with low alloy content, tempering in the range of causes a decrease in ductility and an increase in brittleness, and is referred to as the "tempered martensite embrittlement" (TME) range. Except in the case of blacksmithing, this range is usually avoided. Steel requiring more strength than toughness, such as tools, are usually not tempered above. Instead, a variation in hardness is usually produced by varying only the tempering time. When increased toughness is desired at the expense of strength, higher tempering temperatures, from, are used. Tempering at even higher temperatures, between, will produce excellent toughness, but at a serious reduction in the strength and hardness. At, the steel may experience another stage of embrittlement, called "temper embrittlement" (TE), which occurs if the steel is held within the TE temperature range for too long. When heating above this temperature, the steel will usually not be held for any amount of time, and quickly cooled to avoid temper embrittlement.

Normalized steel.

Steel that has been heated above its upper critical temperature and then cooled in standing air is called normalized steel. Normalized steel consists of pearlite, martensite and sometimes bainite grains, mixed together within the microstructure. This produces steel that is much stronger than full-annealed steel, and much tougher than tempered quenched-steel. However, added toughness is sometimes needed at a reduction in strength. Tempering provides a way to carefully decrease the hardness of the steel, thereby increasing the toughness to a more desirable point. Cast-steel is often normalized rather than annealed, to decrease the amount of distortion that can occur. Tempering can further decrease the hardness, increasing the ductility to a point more like annealed steel. Tempering is often used on carbon steels, producing much the same results. The process, called "normalize and temper", is used frequently on steels such as 1045 carbon steel, or most other steels containing 0.35 to 0.55% carbon. These steels are usually tempered after normalizing, to increase the toughness and relieve internal stresses. This can make the metal more suitable for its intended use and easier to machine.

Welded steel.

Steel that has been arc welded, gas welded, or welded in any other manner besides forge welded, is affected in a localized area by the heat from the welding process. This localized area, called the heat-affected zone (HAZ), consists of steel that varies considerably in hardness, from normalized steel to steel nearly as hard as quenched steel near the edge of this heat-affected zone. Thermal contraction from the uneven heating, solidification and cooling creates internal stresses in the metal, both within and surrounding the weld. Tempering is sometimes used in place of stress relieving (even heating and cooling of the entire object to just below the A temperature) to both reduce the internal stresses and to decrease the brittleness around the weld. Localized tempering is often used on welds when the construction is too large, intricate, or otherwise too inconvenient to heat the entire object evenly. Tempering temperatures for this purpose are generally around and.

Quench and self-temper.

Modern reinforcing bar of 500 MPa strength can be made from expensive microalloyed steel or by a quench and self-temper (QST) process. After the bar exits the final rolling pass, where the final shape of the bar is applied, the bar is then sprayed with water which quenches the outer surface of the bar. The bar speed and the amount of water are carefully controlled in order to leave the core of the bar unquenched. The hot core then tempers the already quenched outer part, leaving a bar with high strength but with a certain degree of ductility too.

Blacksmithing.

Tempering was originally a process used and developed by blacksmiths (forgers of iron). The process was most likely developed by the Hittites of Anatolia (modern-day Turkey), in the twelfth or eleventh century BC. Without knowledge of metallurgy, tempering was originally devised through a trial-and-error method.  Because few methods of precisely measuring temperature existed until modern times, temperature was usually judged by watching the tempering colors of the metal. Tempering often consisted of heating above a charcoal or coal forge, or by fire, so holding the work at exactly the right temperature for the correct amount of time was usually not possible. Tempering was usually performed by slowly, evenly overheating the metal, as judged by the color, and then immediately cooling, either in open air or by immersing in water. This produced much the same effect as heating at the proper temperature for the right amount of time, and avoided embrittlement by tempering within a short time period. However, although tempering-color guides exist, this method of tempering usually requires a good amount of practice to perfect, because the final outcome depends on many factors, including the composition of the steel, the speed at which it was heated, the type of heat source (oxidizing or carburizing), the cooling rate, oil films or impurities on the surface, and many other circumstances which vary from smith to smith or even from job to job. The thickness of the steel also plays a role. With thicker items, it becomes easier to heat only the surface to the right temperature, before the heat can penetrate through. However, very thick items may not be able to harden all the way through during quenching.

Tempering colors.

If steel has been freshly ground, sanded, or polished, it will form an oxide layer on its surface when heated. As the temperature of the steel is increased, the thickness of the iron oxide will also increase. Although iron oxide is not normally transparent, such thin layers do allow light to pass through, reflecting off both the upper and lower surfaces of the layer. This causes a phenomenon called thin-film interference, which produces colors on the surface. As the thickness of this layer increases with temperature, it causes the colors to change from a very light yellow, to brown, then purple, then blue. These colors appear at very precise temperatures, and provide the blacksmith with a very accurate gauge for measuring the temperature. The various colors, their corresponding temperatures, and some of their uses are:  Beyond the grey-blue color, the iron oxide loses its transparency, and the temperature can no longer be judged in this way. The layer will also increase in thickness as time passes, which is another reason overheating and immediate cooling is used. Steel in a tempering oven, held at for a long time, will begin to turn brown, purple or blue, even though the temperature did not exceed that needed to produce a light-straw color. Oxidizing or carburizing heat sources may also affect the final result. The iron oxide layer, unlike rust, also protects the steel from corrosion through passivation.

Differential tempering.

Differential tempering is a method of providing different amounts of temper to different parts of the steel. The method is often used in bladesmithing, for making knives and swords, to provide a very hard edge while softening the spine or center of the blade. This increased the toughness while maintaining a very hard, sharp, impact-resistant edge, helping to prevent breakage. This technique was more often found in Europe, as opposed to the differential hardening techniques more common in Asia, such as in Japanese swordsmithing.  Differential tempering consists of applying heat to only a portion of the blade, usually the spine, or the center of double-edged blades. For single-edged blades, the heat, often in the form of a flame or a red-hot bar, is applied to the spine of the blade only. The blade is then carefully watched as the tempering colors form and slowly creep toward the edge. The heat is then removed before the light-straw color reaches the edge. The colors will continue to move toward the edge for a short time after the heat is removed, so the smith typically removes the heat a little early, so that the pale-yellow just reaches the edge, and travels no farther. A similar method is used for double-edged blades, but the heat source is applied to the center of the blade, allowing the colors to creep out toward each edge.

Interrupted quenching.

Interrupted quenching methods are often referred to as tempering, although the processes are very different from traditional tempering. These methods consist of quenching to a specific temperature that is above the martensite start (M) temperature, and then holding at that temperature for extended amounts of time. Depending on the temperature and the amount of time, this allows either pure bainite to form, or holds-off forming the martensite until much of the internal stresses relax. These methods are known as austempering and martempering.

Austempering.

Austempering is a technique used to form pure bainite, a transitional microstructure found between pearlite and martensite. In normalizing, both upper and lower bainite are usually found mixed with pearlite. To avoid the formation of pearlite or martensite, the steel is quenched in a bath of molten metals or salts. This quickly cools the steel past the point where pearlite can form, and into the bainite-forming range. The steel is then held at the bainite-forming temperature, beyond the point where the temperature reaches an equilibrium, until the bainite fully forms. The steel is then removed from the bath and allowed to air-cool, without the formation of either pearlite or martensite.  Depending on the holding-temperature, austempering can produce either upper or lower bainite. Upper bainite is a laminate structure formed at temperatures typically above and is a much tougher microstructure. Lower bainite is a needle-like structure, produced at temperatures below 350 °C, and is stronger but much more brittle. In either case, austempering produces greater strength and toughness for a given hardness, which is determined mostly by composition rather than cooling speed, and reduced internal stresses which could lead to breakage. This produces steel with superior impact resistance. Modern punches and chisels are often austempered. Because austempering does not produce martensite, the steel does not require further tempering.

Martempering.

Martempering is similar to austempering, in that the steel is quenched in a bath of molten metal or salts to quickly cool it past the pearlite-forming range. However, in martempering, the goal is to create martensite rather than bainite. The steel is quenched to a much lower temperature than is used for austempering; to just above the martensite start temperature. The metal is then held at this temperature until the temperature of the steel reaches an equilibrium. The steel is then removed from the bath before any bainite can form, and then is allowed to air-cool, turning it into martensite. The interruption in cooling allows much of the internal stresses to relax before the martensite forms, decreasing the brittleness of the steel. However, the martempered steel will usually need to undergo further tempering to adjust the hardness and toughness, except in rare cases where maximum hardness is needed but the accompanying brittleness is not. Modern files are often martempered.

Physical processes.

Tempering involves a three-step process in which unstable martensite decomposes into ferrite and unstable carbides, and finally into stable cementite, forming various stages of a microstructure called tempered martensite. The martensite typically consists of laths (strips) or plates, sometimes appearing acicular (needle-like) or lenticular (lens-shaped). Depending on the carbon content, it also contains a certain amount of "retained austenite." Retained austenite are crystals which are unable to transform into martensite, even after quenching below the martensite finish (M) temperature. An increase in alloying agents or carbon content causes an increase in retained austenite. Austenite has much higher stacking-fault energy than martensite or pearlite, lowering the wear resistance and increasing the chances of galling, although some or most of the retained austenite can be transformed into martensite by cold and cryogenic treatments prior to tempering.  The martensite forms during a diffusionless transformation, in which the transformation occurs due to shear-stresses created in the crystal lattices rather than by chemical changes that occur during precipitation. The shear-stresses create many defects, or "dislocations," between the crystals, providing less-stressful areas for the carbon atoms to relocate. Upon heating, the carbon atoms first migrate to these defects, and then begin forming unstable carbides. This reduces the amount of total martensite by changing some of it to ferrite. Further heating reduces the martensite even more, transforming the unstable carbides into stable cementite.  The first stage of tempering occurs between room-temperature and. In the first stage, carbon precipitates into ε-carbon (FeC). In the second stage, occurring between and, the retained austenite transforms into a form of lower-bainite containing ε-carbon rather than cementite (archaically referred to as "troostite"). The third stage occurs at and higher. In the third stage, ε-carbon precipitates into cementite, and the carbon content in the martensite decreases. If tempered at higher temperatures, between and, or for longer amounts of time, the martensite may become fully ferritic and the cementite may become coarser or spheroidize. In spheroidized steel, the cementite network breaks apart and recedes into rods or spherical shaped globules, and the steel becomes softer than annealed steel; nearly as soft as pure iron, making it very easy to form or machine.

Embrittlement.

Embrittlement occurs during tempering when, through a specific temperature range, the steel experiences an increase in hardness and a reduction in ductility, as opposed to the normal decrease in hardness that occurs to either side of this range. The first type is called tempered martensite embrittlement (TME) or one-step embrittlement. The second is referred to as temper embrittlement (TE) or two-step embrittlement.  One-step embrittlement usually occurs in carbon steel at temperatures between and, and was historically referred to as "500 degree [Fahrenheit] embrittlement." This embrittlement occurs due to the precipitation of Widmanstatten needles or plates, made of cementite, in the interlath boundaries of the martensite. Impurities such as phosphorus, or alloying agents like manganese, may increase the embrittlement, or alter the temperature at which it occurs. This type of embrittlement is permanent, and can only be relieved by heating above the upper critical temperature and then quenching again. However, these microstructures usually require an hour or more to form, so are usually not a problem in the blacksmith-method of tempering.  Two-step embrittlement typically occurs by aging the metal within a critical temperature range, or by slowly cooling it through that range, For carbon steel, this is typically between and, although impurities like phosphorus and sulfur increase the effect dramatically. This generally occurs because the impurities are able to migrate to the grain boundaries, creating weak spots in the structure. The embrittlement can often be avoided by quickly cooling the metal after tempering. Two-step embrittlement, however, is reversible. The embrittlement can be eliminated by heating the steel above and then quickly cooling.

Alloy steels.

Many elements are often alloyed with steel. The main purpose for alloying most elements with steel is to increase its hardenability and to decrease softening under temperature. Tool steels, for example, may have elements like chromium or vanadium added to increase both toughness and strength, which is necessary for things like wrenches and screwdrivers. On the other hand, drill bits and rotary files need to retain their hardness at high temperatures. Adding cobalt or molybdenum can cause the steel to retain its hardness, even at red-hot temperatures, forming high-speed steels. Often, small amounts of many different elements are added to the steel to give the desired properties, rather than just adding one or two.  Most alloying elements (solutes) have the benefit of not only increasing hardness, but also lowering both the martensite start temperature and the temperature at which austenite transforms into ferrite and cementite. During quenching, this allows a slower cooling rate, which allows items with thicker cross-sections to be hardened to greater depths than is possible in plain carbon-steel, producing more uniformity in strength.  Tempering methods for alloy steels may vary considerably, depending on the type and amount of elements added. In general, elements like manganese, nickel, silicon, and aluminum will remain dissolved in the ferrite during tempering while the carbon precipitates. When quenched, these solutes will usually produce an increase in hardness over plain carbon-steel of the same carbon content. When hardened alloy-steels, containing moderate amounts of these elements, are tempered, the alloy will usually soften somewhat proportionately to carbon steel.  However, during tempering, elements like chromium, vanadium, and molybdenum precipitate with the carbon. If the steel contains fairly low concentrations of these elements, the softening of the steel can be retarded until much higher temperatures are reached, when compared to those needed for tempering carbon steel. This allows the steel to maintain its hardness in high temperature or high friction applications. However, this also requires very high temperatures during tempering, to achieve a reduction in hardness. If the steel contains large amounts of these elements, tempering may produce an increase in hardness until a specific temperature is reached, at which point the hardness will begin to decrease. For instance, molybdenum steels will typically reach their highest hardness around whereas vanadium steels will harden fully when tempered to around. When very large amounts of solutes are added, alloy steels may behave like precipitation hardening alloys, which do not soften at all during tempering.

Cast iron.

Cast iron comes in many types, depending on the carbon-content. However, they are usually divided into grey and white cast iron, depending on the form that the carbides take. In grey cast iron, the carbon is mainly in the form of graphite, but in white cast iron, the carbon is usually in the form of cementite. Grey cast iron consists mainly of the microstructure called pearlite, mixed with graphite and sometimes ferrite. Grey cast iron is usually used as-cast, with its properties being determined by its composition.  White cast iron is composed mostly of a microstructure called ledeburite mixed with pearlite. Ledeburite is very hard, making the cast iron very brittle. If the white cast iron has a hypoeutectic composition, it is usually tempered to produce malleable or ductile cast iron. Two methods of tempering are used, called "white tempering" and "black tempering." The purposes of both tempering methods is to cause the cementite within the ledeburite to decompose, increasing the ductility.

White tempering.

Malleable (porous) cast iron is manufactured by white tempering. White tempering is used to burn off excess carbon, by heating it for extended amounts of time in an oxidizing environment. The cast iron will usually be held at temperatures as high as for as long as 60 hours. The heating is followed by a slow cooling rate of around 10 °C (18 °F) per hour. The entire process may last 160 hours or more. This causes the cementite to decompose from the ledeburite, and then the carbon burns out through the surface of the metal, increasing the malleability of the cast iron.

Black tempering.

Ductile (non-porous) cast iron (often called "black iron") is produced by black tempering. Unlike white tempering, black tempering is done in an inert gas environment, so that the decomposing carbon does not burn off. Instead, the decomposing carbon turns into a type of graphite called "temper graphite" or "flaky graphite," increasing the malleability of the metal. Tempering is usually performed at temperatures as high as for up to 20 hours. The tempering is followed by slow-cooling through the lower critical temperature, over a period that may last from 50 to over 100 hours.

Precipitation hardening alloys.

Precipitation hardening alloys first came into use during the early 1900s. Most heat-treatable alloys fall into the category of precipitation hardening alloys, including alloys of aluminum, magnesium, titanium and nickel. Several high-alloy steels are also precipitation hardening alloys. These alloys become softer than normal when quenched, and then harden over time. For this reason, precipitation hardening is often referred to as "aging."  Although most precipitation hardening alloys will harden at room temperature, some will only harden at elevated temperatures and, in others, the process can be sped up by aging at elevated temperatures. Aging at temperatures higher than room-temperature is called "artificial aging". Although the method is similar to tempering, the term "tempering" is usually not used to describe artificial aging, because the physical processes, (i.e.: precipitation of intermetallic phases from a supersaturated alloy) the desired results, (i.e.: strengthening rather than softening), and the amount of time held at a certain temperature are very different from tempering as used in carbon-steel.

Tempering is a process of heat treating, which is used to increase the toughness of iron-based alloys. Tempering is usually performed after hardening, to reduce some of the excess hardness, and is done by heating the metal to some temperature below the critical point for a certain period of time, then allowing it to cool in still air. The exact temperature determines the amount of hardness removed, and depends on both the specific composition of the alloy and on the desired properties in the finished product. For instance, very hard tools are often tempered at low temperatures, while springs are tempered at much higher temperatures.

回火(Tempering)是在冶金学当中,一种改善金属材料性质的热处理技术。


Japan.

In Japan,, commonly simply "private railway", refers to a public transit railway owned and operated by private sector, almost always organized as a joint-stock company, or in Japanese: kabushiki gaisha (lit. stock company), but may be any type of private business entity. Although Japan Railways Group (JR Group) companies are also kabushiki gaishas, they are not classified as private railways because of their unique status as the primary successors of the Japanese National Railways (JNR). Voluntary sector railways (semi-public) are additionally not classified as "shitetsu" due to their origins as rural, money-losing JNR lines that have since been transferred to local possession, in spite of their organizational structures being corporatized.  Among "private railways" in Japan, 16 companies are categorized as "major", these same companies also utilize quadruple track and skip-stop services like varying hierarchies of express trains. They are often profitable and tend to be less expensive per passenger-kilometer than JR trains that also run less dense regional routes, and assumed a heavy burden of the former JNR debt. Private railways corporations in Japan also run and generate profits from a variety of other businesses that depend on the traffic generated through their transit systems: hotels, department stores, supermarkets, resorts, and real estate development and leasing.  Japan railways whether government run, semi-public, or private business, are regulated by the Ministry of Land, Infrastructure, Transport and Tourism. They may join unions such as National Railway Workers' Union, but their abilities to call a strike is severely limited by government legislation; there is very little tolerance for railway work stoppage. Employees of private railways may legally strike but its unheard of in Japan. There have only been two notable railroad strikes in Japanese history, both by employees of government run entities (government employees are legally barred from striking): One in 1973, and a major strike protesting the breakup (and layoffs of tens of thousands of employees) of JNR in 1985.  Though "private railways" such as industrial railways have existed in Japan they are not deemed "shitetsu" nor "mintetsu" in Japanese, as their purpose is not public transit.  Tokyo Metro is a member of Associations of Private Japanese Railways but is under special laws and its stock is owned by the Japanese Government and Tokyo Metropolis (pending privatization). Whether Tokyo Metro counts as "Shitetsu" depends on the speaker.

United States.

In the United States, a private railroad is a railroad owned by a company and serves only that company, and does not hold itself out as a "common carrier" (i.e., it does not provide rail transport services for the general public).

A private railroad is a railroad run by a private business entity (usually a corporation but not need be), as opposed to a railroad run by a public sector.

私铁,通常指私有铁路或民营铁路,又称民铁,是指由私有或民营企业经营的铁路运输系统。


Life.

Arenas was born in the countryside of Newport Beach Aguas Claras, Holguín Province, Cuba, and later moved to the city of Holguín. In 1963, he moved to Havana to enroll in the School of Planification and, later, in the Faculty of Letters at the Universidad de La Habana, where he studied philosophy and literature without completing a degree. The following year, he began working at the Biblioteca Nacional José Martí. While there, his talent was noticed and he was awarded prizes at Cirilo Villaverde National Competition held by UNEAC (National Union of Cuban Writers and Artists). His "Hallucinations" was awarded "first Honorable Mention" in 1966 although, as the judges could find no better entry, no First Prize was awarded that year.  His writings and openly gay life were, by 1967, bringing him into conflict with the communist government. He left the Biblioteca Nacional and became an editor for the Cuban Book Institute until 1968. From 1968 to 1974 he was a journalist and editor for the literary magazine "La Gaceta de Cuba". In 1974, he was sent to prison after being charged and convicted of "ideological deviation" and for publishing abroad without official consent. He escaped from prison and tried to leave Cuba by launching himself from the shore on a tire inner tube. The attempt failed and he was rearrested near Lenin Park and imprisoned at the notorious El Morro Castle alongside murderers and rapists. He survived by helping the inmates to write letters to wives and lovers. He was able to collect enough paper this way to continue his writing. However, his attempts to smuggle his work out of prison were discovered and he was severely punished. Threatened with death, he was forced to renounce his work and was released in 1976. In 1980, as part of the Mariel Boatlift, he fled to the United States. He came on the boat "San Lázaro" captained by Cuban emigré Roberto Agüero.  In 1987, Arenas was diagnosed with AIDS; he continued to write and speak out against the Cuban government. He mentored many Cuban exile writers, including John O'Donnell-Rosales. After battling AIDS, Arenas died of an intentional overdose of drugs and alcohol on December 7, 1990, in New York City. In a suicide letter written for publication, Arenas wrote: Due to my delicate state of health and to the terrible depression that causes me not to be able to continue writing and struggling for the freedom of Cuba, I am ending my life... I want to encourage the Cuban people abroad as well as on the Island to continue fighting for freedom.... Cuba will be free. I already am. In 2012 Arenas was inducted into the Legacy Walk, an outdoor public display which celebrates LGBT history and people.

Writings.

Despite his short life and the hardships imposed during his imprisonment, Arenas produced a significant body of work. In addition to significant poetic efforts ("El Central", "Leprosorio"), his "Pentagonia" is a set of five novels that comprise a "secret history" of post-revolutionary Cuba. It includes "Singing from the Well" (in Spanish also titled "Celestino before Dawn"), "Farewell to the Sea" (whose literal translation is "The Sea Once More"), "Palace of the White Skunks", the Rabelaisian "Color of Summer", and "The Assault". In these novels Arenas’ style ranges from a stark realist narrative and high modernist experimental prose to absurd, satiric humor. His second novel, "Hallucinations" ("El Mundo Alucinante"), rewrites the story of the colonial dissident priest Fray Servando Teresa de Mier.  In interviews, his autobiography, and in some of his fiction work itself, Arenas draws explicit connections between his own life experience and the identities and fates of his protagonists. As is evident and as critics such as Francisco Soto have pointed out, the "child narrator" in "Celestino", Fortunato of "The Palace...", Hector of "Farewell..", and the triply named "Gabriel/Reinaldo/Gloomy Skunk" character in "Color" appear to live progressive stages of a continuous life story that is also linked to Arenas's own. In turn, Arenas consistently links his individual narrated life to the historical experience of a generation of Cubans. A constant theme in his novels and other writing is the condemnation of the Castro government, although Arenas also critiques the Catholic Church, US culture and politics. He also critique a series of literary personalities in Havana and internationally, particularly those who he believed had betrayed him and suppressed his work (Severo Sarduy and Ángel Rama are notable examples). His "Thirty truculent tongue-twisters", which he claims circulated in Havana and which are reprinted in "The Color of Summer", mock everyone from personal friends who he suggests may have spied on him to figures such as Nicolás Guillén, Alejo Carpentier, Miguel Barnet, Sarduy and of course Castro himself.  His autobiography, "Before Night Falls" was on the "New York Times" list of the ten best books of the year in 1993. In 2000 this work was made into a film, directed by Julian Schnabel, in which Arenas was played by Javier Bardem. An opera based on the autobiography with libretto and music by Cuban-American composer Jorge Martín premiered at the Fort Worth Opera on May 29, 2010, with baritone Wes Mason singing the role of Arenas.  The Reinaldo Arenas Papers are held at Princeton University Library. “The collection consists of personal and working papers of Reinaldo Arenas” and includes typescript and typescript drafts, essays, interviews, newspaper clippings, correspondence and other documents.

Further reading.

"English"  Spanish

Reinaldo Arenas (July 16, 1943 – December 7, 1990) was a Cuban poet, novelist, and playwright known as an early sympathizer, and later critic of Fidel Castro and the Cuban Revolution, and a rebel of the Cuban government.

雷纳多·阿里纳斯(,1943年-7月16日-1990年-12月7日),古巴诗人、作家、剧作家。对于古巴革命,他早期持同情和支持态度;但随后他对古巴政府持批评和反对态度。


Early life.

Doctorow was born January 6, 1931, in the Bronx, the son of Rose (Levine) and David Richard Doctorow, second-generation Americans of Russian Jewish extraction who named him after Edgar Allan Poe. His father ran a small music shop. He attended city public grade schools and the Bronx High School of Science where, surrounded by mathematically gifted children, he fled to the office of the school literary magazine, "Dynamo," which published his first literary effort. He then enrolled in a journalism class to increase his opportunities to write.  Doctorow attended Kenyon College in Ohio, where he studied with John Crowe Ransom, acted in college theater productions and majored in philosophy. While at Kenyon College, Doctorow joined the Middle Kenyon Association, and befriended Richard H. Collin. After graduating with honors in 1952, he completed a year of graduate work in English drama at Columbia University before being drafted into the United States Army. In 1954 and 1955, he served as a corporal in the signal corps in West Germany.  Back in New York after military service, Doctorow worked as a reader for a motion picture company; reading so many Westerns inspired his first novel, "Welcome to Hard Times". Begun as a parody of western fiction, it evolved into a reclamation of the genre. It was published to positive reviews in 1960, with Wirt Williams of the "New York Times" describing it as "taut and dramatic, exciting and successfully symbolic."  When asked how he decided to become a writer, he said, "I was a child who read everything I could get my hands on. Eventually, I asked of a story not only what was to happen next, but how is this done? How am I made to live from words on a page? And so I became a writer."

Career.

To support his family, Doctorow spent nine years as a book editor, first at New American Library working with Ian Fleming and Ayn Rand among others; and from 1964, as editor-in-chief at Dial Press, publishing work by James Baldwin, Norman Mailer, Ernest J. Gaines, and William Kennedy, among others.  In 1969, Doctorow left publishing to pursue a writing career. He accepted a position as Visiting Writer at the University of California, Irvine, where he completed "The Book of Daniel" (1971), a freely fictionalized consideration of the trial and execution of Julius and Ethel Rosenberg for giving nuclear secrets to the Soviet Union during the Cold War. It was widely acclaimed, called a "masterpiece" by "The Guardian", and said by "The New York Times" to launch the author into "the first rank of American writers" according to Christopher Lehmann-Haupt.  Doctorow's next book, written in his home in New Rochelle, New York, was "Ragtime" (1975), later named one of the 100 best novels of the 20th century by the Modern Library editorial board. His subsequent work includes the award-winning novels "World's Fair" (1985), "Billy Bathgate" (1989), and "The March" (2005), as well as several volumes of essays and short fiction.  Novelist Jay Parini is impressed by Doctorow's skill at writing fictionalized history in a unique style, "a kind of detached but arresting presentation of history that mingled real characters with fictional ones in ways that became his signature manner". In "Ragtime", for example, he arranges the story to include Sigmund Freud and Carl Jung sharing a ride at Coney Island, or a setting with Henry Ford and J. P. Morgan.  Despite the immense research Doctorow needed to create stories based on real events and real characters, reviewer John Brooks notes that they were nevertheless "alive enough never to smell the research in old newspaper files that they must have required". Doctorow demonstrated in most of his novels "that the past is very much alive, but that it's not easily accessed," writes Parini. "We tell and retell stories, and these stories illuminate our daily lives. He showed us again and again that our past is our present, and that those not willing to grapple with 'what happened' will be condemned to repeat its worst errors."  Doctorow also taught at Sarah Lawrence College, the Yale School of Drama, the University of Utah, the University of California, Irvine, and Princeton University. He was the Loretta and Lewis Glucksman Professor of English and American Letters at New York University. In 2001 he donated his papers to the Fales Library of New York University. The library's director, Marvin Taylor, said Doctorow was "one of the most important American novelists of the 20th century".  Doctorow opposed unofficial Iranian translations of foreign works; Iran does not follow foreign copyright agreements.

Personal life and death.

In 1954, Doctorow married fellow Columbia University student Helen Esther Setzer while serving in the U.S. Army in West Germany. The couple had three children.  He died of lung cancer on July 21, 2015, aged 84, in Manhattan. He is interred in Woodlawn Cemetery in the Bronx.

Edgar Lawrence Doctorow (January 6, 1931 – July 21, 2015) was an American novelist, editor, and professor, best known internationally for his works of historical fiction. He has been described as one of the most important American novelists of the 20th century.

埃德加·劳伦斯·多克托罗(英语:Edgar Lawrence Doctorow,1931年-1月6日-2015年-7月21日),美国犹太裔小说家、编剧。多克托罗生于纽约、曾就读于肯庸学院、哥伦比亚大学,1968年成为纽约大学教员。1960年发表长篇小说处女作《欢迎到哈德泰姆斯来》,第三部长篇《但以理书》(1971)获1972年古根海姆奖,使他受到评论界注意。《拉格泰姆时代》(1975)讲述20世纪初期三个不同阶层的家庭的故事,获全国图书批评界奖。《鱼鹰湖》(1980)、《世界博览会》(1985)、《比利·巴思格特 (小说)》(1989)写大萧条时期的美国社会,其中《比利·巴思格特》获全国图书批评界奖和福克纳奖。


Early life.

Smith was born in Willesden in the north-west London borough of Brent to a Jamaican mother, Yvonne Bailey, and an English father, Harvey Smith, who was 30 years his wife's senior. At the age of 14, she changed her name from Sadie to Zadie.  Smith's mother grew up in Jamaica and emigrated to England in 1969. Smith's parents divorced when she was a teenager. She has a half-sister, a half-brother, and two younger brothers (one is the rapper and stand-up comedian Doc Brown, and the other is the rapper Luc Skyz). As a child, Smith was fond of tap dancing, and in her teenage years, she considered a career in musical theatre. While at university, Smith earned money as a jazz singer, and wanted to become a journalist. Despite earlier ambitions, literature emerged as her principal interest.

Education.

Smith attended the local state schools, Malorees Junior School and Hampstead Comprehensive School, and King's College, Cambridge, where she studied English literature. In an interview with "The Guardian" in 2000, Smith corrected a newspaper assertion that she left Cambridge with a double First. "Actually, I got a Third in my Part Ones", she said. She graduated with upper second-class honours.  Smith seems to have been rejected for a place in the Cambridge Footlights by the popular British comedy double act Mitchell and Webb, while all three were studying at Cambridge University in the 1990s.  At Cambridge, Smith published a number of short stories in a collection of new student writing called "The Mays Anthology". They attracted the attention of a publisher, who offered her a contract for her first novel. Smith decided to contact a literary agent and was taken on by A. P. Watt. Smith returned to guest-edit the anthology in 2001.

Career.

Smith's début novel "White Teeth" was introduced to the publishing world in 1997 before it was completed. On the basis of a partial manuscript, an auction for the rights was begun, which was won by Hamish Hamilton. Smith completed "White Teeth" during her final year at the University of Cambridge. Published in 2000, the novel immediately became a best-seller and received much acclaim. It was praised internationally and won a number of awards, among them the James Tait Black Memorial Prize, and the Betty Trask Award. The novel was adapted for television in 2002. In July 2000, Smith's debut was also the subject for discussion in a controversial essay of literary criticism by James Wood entitled "Human, All Too Inhuman", where Wood critiques the novel as part of a contemporary genre of hysterical realism where "‘[i]nformation has become the new character" and human feeling is absent from contemporary fiction. In an article for The Guardian in October 2001, Smith responded to the criticism by agreeing with the accuracy of the term and that she agreed with Wood's underlying argument that "any novel that aims at hysteria will now be effortlessly outstripped". However, she rejected her debut being categorised alongside major authors such as David Foster Wallace, Salman Rushdie, and Don DeLillo and the dismissal of their own innovations on the basis of being hysterical realism. Responding earnestly to Wood's concerns about contemporary literature and culture, Smith describes her own anxieities as a writer and argued that fiction should be "not a division of head and heart, but the useful employment of both".  Smith served as writer-in-residence at the ICA in London and subsequently published, as editor, an anthology of sex writing, "Piece of Flesh", as the culmination of this role.  Smith's second novel, "The Autograph Man", was published in 2002 and was a commercial success, although it was not as well received by critics as "White Teeth".  After the publication of "The Autograph Man", Smith visited the United States as a Fellow of the Radcliffe Institute for Advanced Study at Harvard University. She started work on a still-unreleased book of essays, "The Morality of the Novel" (a.k.a. "Fail Better"), in which she considers a selection of 20th-century writers through the lens of moral philosophy. Some portions of this book presumably appear in the essay collection "Changing My Mind", published in November 2009.  Smith's third novel, "On Beauty", was published in September 2005. It is set largely in and around Greater Boston. It attracted more acclaim than "The Autograph Man": it was shortlisted for the Man Booker Prize, and won the 2006 Orange Prize for Fiction and the Anisfield-Wolf Book Award.  Later in the same year, Smith published "Martha and Hanwell", a book that pairs two short stories about two troubled characters, originally published in "Granta" and "The New Yorker" respectively. Penguin published "Martha and Hanwell" with a new introduction by the author as part of their pocket series to celebrate their 70th birthday. The first story, "Martha, Martha", deals with Smith's familiar themes of race and postcolonial identity, while "Hanwell in Hell" is about a man struggling to cope with the death of his wife. In December 2008 she guest-edited the BBC Radio 4 "Today" programme.  After teaching fiction at Columbia University School of the Arts, Smith joined New York University as a tenured professor of fiction in 2010.  Smith's novel "NW" was published in 2012. It is set in the Kilburn area of north-west London, the title being a reference to the local postcode, NW6. "NW" was shortlisted for the Royal Society of Literature's Ondaatje Prize and the Women's Prize for Fiction. "NW" was made into a BBC television film directed by Saul Dibb and adapted by Rachel Bennette. Starring Nikki Amuka-Bird and Phoebe Fox, it was broadcast on BBC Two on 14 November 2016.  In 2015 it was announced that Smith, along with her husband Nick Laird, was writing the screenplay for a science fiction movie to be directed by French filmmaker Claire Denis. Smith later said that her involvement had been overstated and that she had simply helped to polish the English dialogue for the film.  Smith's fifth novel, "Swing Time", was published in November 2016. It was long-listed for the Man Booker Prize 2017.  Between March and October 2011, Smith was the monthly New Books reviewer for "Harper's Magazine". She is also a frequent contributor to "The New York Review of Books". In 2010, "The Guardian" newspaper asked Smith for her "10 rules for writing fiction". Among them she declared: "Tell the truth through whichever veil comes to hand – but tell it. Resign yourself to the lifelong sadness that comes from never being satisfied."  Smith's first collection of short stories, "Grand Union", was published on October 8th, 2019.

Personal life.

Smith met Nick Laird at Cambridge University. They married in 2004 in the Chapel of King's College, Cambridge. Smith dedicated "On Beauty" to "my dear Laird". She also uses his name in passing in "White Teeth": "An' all the good-lookin' men, all the "rides" like your man Nicky Laird, they're all dead."  The couple lived in Rome, Italy, from November 2006 to 2007, and are now based in New York City and Queen's Park, London. They have two children, Katherine (Kit) and Harvey (Hal).  Smith describes herself as "unreligious", and was not raised in a religion, although retains a "curiosity" about the role religion plays in others' lives. In an essay exploring humanist and existentialist views of death and dying, Smith characterises her worldview as that of a "sentimental humanist".

Awards and recognition.

She was elected a fellow of the Royal Society of Literature in 2002. In a 2004 BBC poll of cultural researchers, Smith was named among the top twenty most influential people in British culture.  In 2003, she was included on "Granta's" list of 20 best young authors, and was also included in the 2013 list. She joined New York University's Creative Writing Program as a tenured professor on 1 September 2010. Smith has won the Orange Prize for Fiction and the Anisfield-Wolf Book Award in 2006 and her novel "White Teeth" was included in "Time" magazine's list of the 100 best English-language novels from 1923 to 2005. http://bookcritics.org/blog/archive/31-books-in-30-days-charles-finch-on-zadie-smiths-feel-free-essays

Zadie Adeline Smith FRSL (born 25 October 1975) is an English novelist, essayist, and short-story writer. Her debut novel, "White Teeth" (2000), immediately became a best-seller and won a number of awards. She has been a tenured professor in the Creative Writing faculty of New York University since September 2010.

查蒂·史密斯(英语:Zadie Smith,1975年-10月25日),英国小说家。至今为止她发表了三部小说。2003年《格兰塔》杂志把她列入20名最好的年轻作家之一。2010年9月1日她成为纽约大学写作终身教授。


Description.

Vostok Research Station is around from the Geographic South Pole, at the middle of the East Antarctic Ice Sheet.  Vostok is located near the Southern Pole of Inaccessibility and the South Geomagnetic Pole, making it one of the optimal places to observe changes in the Earth's magnetosphere. Other studies include actinometry, geophysics, medicine and climatology.  The station is at above sea level and is one of the most isolated established research stations on the Antarctic continent. The station was supplied from Mirny Station on the Antarctic coast. The station normally contains 25 scientists and engineers in the summer. In winter, their number drops to 13.  The only permanent research station located farther south is the Amundsen–Scott South Pole Station, operated by the United States at the geographic South Pole. The Chinese Kunlun Station is farther south than Vostok but only occupied during summers.  Some of the challenges faced by those living on the station were described in Vladimir Sanin's books such as "Newbie in the Antarctic" (1973), "72 Degrees Below Zero" (1975), and others.

History.

Vostok Station was established on 16 December 1957 (during the International Geophysical Year) by the 2nd Soviet Antarctic Expedition and was operated year-round for more than 37 years. The station was temporarily closed from February to November 1994.  In 1959, the Vostok station was the scene of a fight between two scientists over a game of chess. When one of them lost the game, he became so enraged that he attacked the other with an ice axe. According to some sources, it was a murder, though other sources say that the attack was not fatal. Afterwards, chess games were banned at Soviet/Russian Antarctic stations.  In 1974, when British scientists in Antarctica performed an airborne ice-penetrating radar survey and detected strange radar readings at the site, the presence of a liquid, freshwater lake below the ice did not instantly spring to mind. In 1991, Jeff Ridley, a remote-sensing specialist with the Mullard Space Science Laboratory at University College London, directed a European satellite called ERS-1 to turn its high-frequency array toward the center of the Antarctic ice cap. It confirmed the 1974 discovery, but it was not until 1993 that the discovery was published in the "Journal of Glaciology". Space-based radar revealed that the sub-glacial body of fresh water was one of the largest lakes in the world – and one of some 140 subglacial lakes in Antarctica. Russian and British scientists delineated the lake in 1996 by integrating a variety of data, including airborne ice-penetrating radar imaging observations and spaceborne radar altimetry. Lake Vostok lies some below the surface of the central Antarctic ice sheet and covers an area of.

Historic monuments.

Vostok Station Tractor: Heavy tractor АТТ 11, which participated in the first traverse to the South Geomagnetic Pole, along with a plaque to commemorate the opening of the station in 1957, has been designated a Historic Site or Monument (HSM 11) following a proposal by Russia to the Antarctic Treaty Consultative Meeting.  Professor Kudryashov's Drilling Complex Building: The drilling complex building stands close to Vostok Station at an elevation of. It was built in the summer season of 1983–1984. Under the leadership of Professor Boris Kudryashov, ancient ice core samples were obtained. The building has been designated a Historic Site or Monument (HSM 88), following a proposal by Russia to the Antarctic Treaty Consultative Meeting.

Climate.

Vostok Station has an ice cap climate ("EF"), with subzero temperatures year round, typical as with much of Antarctica. Annual precipitation is only (all occurring as snow), making it one of the driest places on Earth. On average, Vostok station receives 26 days of snow per year. It is also one of the sunniest places on Earth, despite having no sunshine at all between May and August; there are more hours of sunshine per year than even the sunniest places in South Africa. Vostok has the highest sunshine total for any calendar month on Earth, at an average of 708.8 hours of sunshine in December, or 22.9 hours daily. It also has the lowest sunshine for any calendar month, with an absolute maximum of 0 hours of sunshine per month during polar night. Of official weather stations that are currently in operation, Vostok is the coldest on earth in terms of mean annual temperature. However, it has been disputed that Vostok Station is the coldest known location on earth. The now inactive Plateau Station, located on the central Antarctic plateau, is believed to have recorded an average yearly temperature that was consistently lower than that of Vostok Station during the 37-month period that it was active in the late 1960s, and satellite readings have routinely detected colder temperatures in areas between Dome A and Dome F. The most recent record set was the March record low, set on 22 March 2020.  Vostok is one of the coldest places on Earth. The average temperature of the cold season (from April to October) is about, while the average temperature of the warm season (from November to March) is about.  The lowest reliably measured temperature on Earth of was in Vostok on 21 July 1983 at 05:45 Moscow Time, which was 07:45 for Vostok's time zone, and 01:45 UTC (See "List of weather records"). This beat the station's former record of on 24 August 1960. Lower temperatures occurred higher up towards the summit of the ice sheet as temperature decreases with height along the surface.  The coldest wind chill was on 24 August 2005 with a real temperature of.  Though unconfirmed, it has been reported that Vostok reached a temperature of on 28 July 1997.  The warmest recorded temperature at Vostok is, which occurred on 5 January 1974.  The coldest month was August 1987 with a mean temperature of and the warmest month was December 1989 with a mean temperature of.  In addition to the extremely cold temperatures, other factors make Vostok one of the most difficult places on Earth for human habitation:  Acclimatization to such conditions can take from a week to two months and is accompanied by headaches, eye twitches, ear pains, nose bleeds, perceived suffocation, sudden rises in blood pressure, loss of sleep, reduced appetite, vomiting, joint and muscle pain, arthritis, and weight loss of (sometimes as high as ).

Ice core drilling.

In the 1970s the Soviet Union drilled a set of cores deep. These have been used to study the oxygen isotope composition of the ice, which showed that ice of the last glacial period was present below about 400 metres' depth. Then three more holes were drilled: in 1984, Hole 3G reached a final depth of 2202 m; in 1990, Hole 4G reached a final depth of 2546 m; and in 1993 Hole 5G reached a depth of 2755 m; after a brief closure, drilling continued during the winter of 1995. In 1996 it was stopped at depth 3623 m, by the request of the Scientific Committee on Antarctic Research that expressed worries about possible contamination of Lake Vostok. This ice core, drilled collaboratively with the French, produced a record of past environmental conditions stretching back 420,000 years and covering four previous glacial periods. For a long time it was the only core to cover several glacial cycles; but in 2004 it was exceeded by the EPICA core, which, whilst shallower, covers a longer time span. In 2003 drilling was permitted to continue, but was halted at the estimated distance to the lake of only 130 m.  The ancient lake was finally breached on 5 February 2012 when scientists stopped drilling at the depth of 3,770 metres and reached the surface of the sub-glacial lake.  The brittle zone is approximately between 250 and 750 m and corresponds to the Last Glacial Maximum, with the end of the Holocene climatic optimum at or near the 250-metre depth.  Although the Vostok core reached a depth of 3623 m the usable climatic information does not extend down this far. The very bottom of the core is ice refrozen from the waters of Lake Vostok and contains no climate information. The usual data sources give proxy information down to a depth of 3310 m or 414,000 years. Below this there is evidence of ice deformation. It has been suggested that the Vostok record may be extended down to 3345 m or 436,000 years, to include more of the interesting MIS11 period, by inverting a section of the record. This then produces a record in agreement with the newer, longer EPICA record, although it provides no new information.

Vostok Station (,, meaning "Station Vostók") is a Russian research station in inland Princess Elizabeth Land, Antarctica. Founded by the Soviet Union in 1957, the station lies at the southern Pole of Cold, with the lowest reliably measured natural temperature on Earth of. Research includes ice core drilling and magnetometry. Vostok (Russian for ""east"") was named after "Vostok", the lead ship of the First Russian Antarctic Expedition captained by Fabian von Bellingshausen. The Bellingshausen Station was named after this captain. (the second ship "Mirny" captained by Mikhail Lazarev became the namesake for Mirny Station).

沃斯托克站(),是俄罗斯位于南极大陆内陆伊丽莎白公主地的一个南极科学考察站,在南磁极附近。该站于1957年由苏联建立,位于南极高原内部,以记录到地球上最低自然温度-89.2°C而闻名。该站的研究包括冰芯钻探和磁力测量。东方站以Восток(俄语为“东方”)命名,是由别林斯高晋率领的首艘俄罗斯南极探险队的主力舰的名称。