Early life.

Toledo was born into an impoverished family of indigenous peasants of Quechua heritage. He was the eighth oldest of sixteen brothers and sisters, seven of whom died in childhood. He was born in the village of Ferrer, Bolognesi, but registered in the nearby town of Cabana, Pallasca Province, Ancash Department.  As a child he worked shining shoes and selling newspapers and lottery tickets. When, at age 11, he finished grade school, his father expected him to leave school and get a job to support the family. With his teacher's encouragement, Toledo was able to continue his schooling by working nights and weekends, becoming the first person in his family to attend high school. Toledo eventually found employment as a news

Early career.

From 1981 to 1983, Toledo directed the Institute for Economic and Labor Studies in Lima, a subdivision of the Ministry of Labor and Social Development. During the same period, he also served as chairman of the Economic Advisory Committee to the president of the Central Reserve Bank and the labor minister.  Throughout his academic and governmental career, Toledo worked as a consultant for various international organizations, including the United Nations, the

Presidential election.

Toledo entered politics as an independent candidate for the presidency (winning 3% of the vote) in the 1995 election in which Alberto Fujimori was ultimately re-elected. Despite his loss, the party he founded in 1994, "Perú Posible", gained popularity and influence over the next few years. Toledo declared his intent to run again in the 2000 election and despite a constitutional controversy about his eligibility to serve a third term, Fujimori also announced his candidacy.  Despite being a relatively low-profile politician, Toledo suddenly found himself the leader of the opposition to Fujimori's presidency. Toledo promised to uphold and strengthen the market program that had been put in place, while also mitigating inequality issues attributed to it. He promised to pursue democratic reforms and reinvigorate Peru's social infrastructure. During the campaign, he promised to raise the wages of civil servants, which had been stagnant under Fujimori, and to create 400,000 jobs a year through programs designed to encourage agriculture, tourism, and small business. Toledo repeatedly called for the expansion of investigations into government, including investigations into allegations that the Fujimori administration had stolen billions from government coffers.  Racial-ethnic themes also echoed throughout the campaign. Toledo was running to become Peru's first indigenous president. He referred to himself as throughout his campaign, and many indigenous Peruvians hoped that as president he would bring greater attention to issues of importance to them. Toledo's background, engaging manner, and informal attitude made him an attractive candidate to both indigenous and non-indigenous Peruvians.  Just minutes after the polls closed at 4:00 pm on April 9, 2000, major news networks rushed to announce that Toledo had garnered more votes than Fujimori. These announcements were based on projections from Peru's top polling firms, which base their numbers on exit polls. The prominent pollsters quickly modified projections based on samples of actual vote counts from selected polling places, better known as the "quick count". Shortly after receiving news of Toledo's encouraging performance in the initial stage of the vote count, supporters gathered in the streets around Toledo's hotel room. An enthusiastic Toledo walked out onto

Presidency.

High expectations.

During his campaign, Toledo promised Peruvians higher wages, a fight against poverty, anti-corruption measures, higher pensions, more employment, military reform, development of tourism, and industrialization. As Pedro Pablo Kuczynski noted “Toledo comes after almost 30 years of either dictatorships or governments that weren't so democratic. People expect Toledo to solve all the problems of the last 30 years, which included an enormous increase in relative poverty." Toledo's inability to fulfill many of these promises created widespread dissatisfaction. His approval ratings were consistently low throughout his presidency, sometimes

"National Accord".

In November 2001, Toledo opened talks which concluded in the National Accord of July 22, 2002. In the accord, seven political parties and seven social organizations agreed upon a framework that would guide policy for the next twenty years.

Indigenous issues.

Touting his heritage throughout his campaign, Toledo continued the efforts begun by Paniagua, who had brought together experts and indigenous leaders to discuss the needs of indigenous people throughout the country. Toledo's inauguration ceremony on Machu Picchu was attended by all the presidents of the neighboring Andean states who joined him in signing the “Declaration of Machu Picchu,” promising to protect indigenous rights.  Maria Elena García calls the years of Toledo's presidency a transition ripe with new opportunities for indigenous people, noting the “reframed state-indigenous interactions”, “increase in NGO projects and social

Labor unrest.

Despite unprecedented, strong, and consistent economic growth under his leadership, Toledo dealt with much labor unrest during his presidency as workers demanded higher wages and the fulfillment of campaign promises. The crisis underlined a basic flaw in Peru's economy as pointed out by "The Economist", which noted that "some 70% of output falls within the grey or "informal"" economy, and thus escapes tax. Tax-collections, at below 12.1% of GDP, are stagnant, with most

Social initiatives.

Toledo did implement some of his plans for investment in social infrastructure and institutions. The amount of paved roads increased by 20% during his presidency; medical attention to the poor doubled in rural areas, and public sector salaries increased (school teachers' pay rose by 87%) and over 100,000 new homes were built for poor Peruvians.  By 2004, Peru had a far-reaching social safety net that included food programs serving 35 percent of the population, and work programs offering temporary employment to unskilled workers. The Cooperative Fund for Social Development funded projects to construct and improve schools, health clinics, rural roads, water and sanitation systems, and electric grids. Toledo placed food and infrastructure programs under the Ministry for Women and Social Development and urged that municipalities implement decentralization. Social safety-net spending in Peru remained well below the Latin American average under Toledo even as it covered a larger percentage of the population, which means that outlays were insufficient to lift many people up out of poverty.

Education.

Toledo inherited an educational system which had been plagued for decades by mediocrity, low completion rates, inadequate resources, and inequality between genders, classes, and races. Toledo launched Project Huascaran, which enabled primary and secondary-school classrooms to connect a nationwide computer network of learning systems. During his campaign, Toledo had promised to double teachers’ salaries, but

Healthcare.

During his first year in office, Toledo replaced previous health-insurance programs aimed at the poor with a more comprehensive free insurance program, Seguro Integral de Salud (SIS). The program aimed to provide Peruvians without health insurance with improved access to health care. By the end of his term, SIS covered more than 11 million Peruvians living on the outskirts of cities or in rural areas. However, about a third of the country remained without health coverage.  The program has been immensely popular. President García expanded the program, which

Housing.

Peru faced a major housing deficit in 2001, with the majority of its urban population living in slums. Toledo's administration sought to improve access to affordable housing through subsidies, loans, down payments, land titling, and encouraging financial institutions to reach further down-market. Most of these efforts were grouped under the Fondo Mivivienda, which was a program started in 1999.

Decentralization.

Under Toledo's predecessor, Fujimori, the governing authority in Peru was condensed and centralized. A Fujimori-dominated congress passed a new constitution in 1993, which consolidated the bicameral legislature into a unicameral legislature with a single national district. Under Fujimori local governments retained minimal legal authority including fees for utilities, basic civil registries, and management of public spaces and markets.  Decentralization was among Toledo's most successful institutional reforms. In addition to announcing regional elections upon his inauguration, he charged a Decentralization and Regionalization Commission with developing proposals. In 2002, a constitutional amendment was approved which established three levels of government: local, regional, and national. Over the next few years, the congress gradually

Fighting terrorism and drug trafficking.

The Truth and Reconciliation Commission, which had been implemented by interim president Paniagua, was tasked with examining largescale acts of violence and atrocities committed within Peru between 1980 and 2000, to assess responsibility and pave the way for reparations. The Commission's final report to President Toledo was issued in 2003, and concluded that approximately 69,000 people had been killed by the Shining Path and other extremist groups, the bulk of the victims being innocent peasants. In January of that year, the Constitutional Court repealed several anti-terrorism measures enacted during Fujimori's administration. It was estimated that 54% of these victims were killed by the extremist guerrilla group Shining Path, 30% by the Peruvian Military and police forces, and the rest were by rural or peasant self-defense militias. These investigations were financed by a portion of the US$360 million discovered in foreign accounts which had been stolen by Fujimori officials. Toledo wasted no time in pursuing suspected terrorists, arresting 199 of them in 2002 alone.  In late 2001,

Foreign relations.

The Toledo administration was unusually active in foreign policy. Its major goals were promoting democracy outside Peru, addressing the struggle against poverty, encouraging economic development in the borderlands, reducing arms spending in the region, strengthening relations with Asia-Pacific countries, and integrating with the Andean Community of Nations. Peru also became an associate member of MERCOSUR, a free trade zone that would be established gradually. The objective was for signing nations to gradually build up an infrastructure that would ease trade with one another, to cooperate in the improvement of energy efficiency, and to commit to future agreements that would increase cross border investment by eliminating double taxation.

Asia.

The Toledo administration held freetrade agreement talks with Singapore and Thailand, came to an agreement with Thailand on air transport, and signed an extradition

Bolivia.

Toledo attended Evo Morales’ inauguration in 2006, indicating a willingness to work with his administration, but Morales joined his mentor,

Brazil.

In conducting Peru's relations with Brazil, Toledo's goal was to reorient Peru from the Andean Community, toward the more economically active Brazil and MERCOSUR. In August 2003, Toledo met with Brazilian ex-president Lula. They committed to increased political and economic

Colombia.

Concern for security and trafficking led the Toledo administration to prioritize the reinforcement of its border with Colombia and the improvement of police coordination.

Chile.

Most of the Toledo administration dealings with Chile involved concern over the latter procurement of arms. Despite

Ecuador.

While Peru and Ecuador had been at peace for years, President Toledo worked to solidify and build upon that peace. During a 2001 visit to Ecuador, Toledo expressed support for the Brasília Accords, agreed to the demilitarization of the two countries’ common border, advocated reduced military spending, and agreed

Venezuela.

Relations with Venezuela deteriorated during the latter half of the Toledo presidency owing to opposing philosophies and policies of Presidents Toledo and Chávez. The issues contributing to the tension

United States.

President Toledo worked hard throughout his presidency on what became a very productive relationship with the U.S., and what Toledo described as a personal friendship with President Bush. He received lavish praise from the American president for his economic and domestic security policies. During a visit to Peru, Bush announced the establishment of an Andean Center of Excellence for Teacher Training, with a base in Peru, and a fellowship program to give Andean professionals access to education in information technology. In June 2002, the U.S. agreed to forgive $14 million of Peru's debt in exchange for a promise to invest $12 million in conservation projects. In September, Toledo secured a $300 million commitment from Bush to fund alternative-crop development in coca-producing areas. In 2003, the Peace Corps returned to Peru. Peru opposed U.S. efforts most visibly in the War in Iraq, refusing to support the intervention in any international arena.

Economic policy.

Toledo's economic policies can be described as neoliberal or strongly pro free-trade. He inherited a national economy which in the previous decade had experienced an unstable GDP with periods of growth and shrinkage, as well as fiscal deficits frequently amounting to over 2% of GDP. Inflation had not dropped below 23% until 1995 and was still feared by many. In response, Toledo developed policies which focused on fighting poverty, generating employment, decentralizing government, and modernizing the state.  Among Toledo's initiatives designed to generate revenue and transform the economy were

Post-Presidential Nomination.

Toledo was unable to run for reelection in 2006; after he took office, the constitution was amended to restore the pre-1995 ban on immediate reelection. After his presidency, Toledo went to the United States, where he served as a Distinguished Scholar in Residence at the Center for Advanced Study in the Behavioral Sciences at Stanford University, during the 2006–2008 academic years. Toledo was named a Distinguished Visiting Fellow at the Hoover Institution at Stanford University from 2006 to 2009, and in 2007–2008 was a Payne Distinguished Visiting Lecturer at Stanford University's Freeman Spogli Institute for International Studies and a CDDRL (Center on Democracy, Development and the Rule of Law) Visiting Scholar. While at Stanford, Toledo founded and continues to serve as the President of the Global Center for Development and Democracy, based in Latin America, the United States, and the European Union which 'aims to help Peru and Latin American countries build institutional bases for greater stability, with a wide political commitment to democracy, that is decentralized and equal to all".  In 2007, following the closing of media outlet RCTV in Venezuela, Toledo published an op-ed in the New York Times condemning the action of President Hugo Chávez's government as a violation of free speech. Toledo called for intervention by the Organization of American States, citing its commitment to protecting the development of democratic institutions, including the press. He also called for "continent-wide solidarity" on the grounds that the repression of free speech in a country is felt beyond the country itself. He warned that if Venezuela were allowed to silence its press without repercussions, this would encourage similar repression in the rest of Latin America, because "[w]hen one voice is silenced, we all become mute. When one thought is eliminated, we all lose some awareness. And when a space for the expression of ideas becomes closed, we all become trapped in the dungeons of dictatorship."  In 2009, Toledo joined the Brookings Institution as a nonresident senior fellow. His works on the Latin America Initiative, a joint effort of the Global Economy and Development and Foreign Policy programs at Brookings. The initiative focuses on the most critical economic, political and social issues facing the region. Research activities are concerned with a wide range of topics, including the challenges that a changing world economy poses for Latin America, the impact of organized crime on democratic institutions and economic prosperity, trade and investment policies, strategies to tackle poverty and inequality, combating climate change, and Cuba's political transition.  Toledo is also a member of the United Nations Steering Committee on the Human Development Report for Latin America, a member of the Club of Madrid, and a member of the International Board of Governors of the Peres Center for Peace in Israel.  Toledo attended the San Francisco Freedom Forum in 2011 to discuss democracy in Latin America.  Toledo created the Global Center for Development and Democracy. The center works with low income individuals in developing countries with the goal of helping them become self-sufficient entrepreneurs, along with governments and other organizations to help combat institutionalized poverty.

2011 Election.

In December 2010, Toledo announced his candidacy in the 2011 presidential election. Telling the "Peruvian Times" that "Garcia (the incumbent) is governing for the rich and not the poor", he said that when he left office, with 1 sol (approximately $0.34) bought 10 loaves bread; now it bought you five. "President Alan García (must) realize that Peru is much greater, much deeper, more generous and more warlike than the rich friends that surround him.”  The general election, which took place on April 10, 2011, Toledo won 15.62% of the vote putting him behind leftist former army officer Ollanta Humala (with 31.75%), Keiko Fujimori, daughter of the former president (with 23.5%), and Pedro Pablo Kuczynski (with 18.52%), and ahead of Luis Castaneda (with 9.84%). After the initial round, Fujimori received the support of candidate and former president Alan García, while Toledo supported Humala, calling him the

Relationship with the press.

From the beginning of Toledo's presidency, the press took an aggressive stance, scrutinizing the personal and public lives of Toledo and his advisors. Many news outlets were determined to expose corruption in a way that had not been possible under the Fujimori administration. Others wished to prove their independence from the government,

Later career and corruption charges.

, Toledo is a visiting scholar at Stanford University in the US. In 2016, Odebrecht stated as part of a plea agreement that the company had paid approximately $800 million in bribes in several Latin American countries, including $29 million in

Awards and honors.

On May 7, 2005, he received the Order of the Athir, one of the National Order of Merits of Algeria.  In 2006, UCSD's Institute of the Americas honored President Toledo with its Award for Democracy and Peace for his efforts in promoting economic growth and strengthening democracy. "It is the force of his personality that has led this country to understand that in this globalized world, there is no alternative to regional integration, to free trade, to sane economic policies," said Jeffrey Davidow, the institute's president.  Toledo has received honorary doctorates from University of Winnipeg, Los Andes Peruvian University, and 50 other universities

Publications.

Among Toledo's publications are works on economic growth and structural reforms. His latest book, "Las Cartas sobre la Mesa" (The Cards on the Table), recounts his political career and the founding of Perú Posible.

Alejandro Celestino Toledo Manrique (; born 28 March 1946) is a Peruvian politician who served President of Peru, from 2001 to 2006. He gained international prominence after leading the opposition against president Alberto Fujimori, who held the presidency from 1990 to 2000.

亚历杭德罗·托莱多(Alejandro Toledo,1946年-3月28日)是秘鲁的前总统,于2001年当选,是前任总统藤森的反对者。他的妻子为法国人类及经济学家埃利安尼·卡普。


Early life.

Andrei Nikolayevich Tupolev was born on in Pustomazovo (), a village near the city of Kimry in Tver Governorate, Russian Empire, the sixth of seven children born to his Russian parents. Tupolev's father, Nikolai Ivanovich Tupolev (1842-1911), was a native of Surgut from a Siberian Cossack background who worked as a notary for the governorate. Nikolai had studied law at St. Petersburg University, but was expelled after the assassination of Alexander II for his ties to revolutionaries despite not being involved in their actions. Tupolev's mother, Anna Vasilievna (née Lisitsyna) (1850-1928) was born in Torzhok in the family of a judicial investigator, and graduated from the Mariinsky Gymnasium in Tver. Anna's parents purchased the small estate in Pustomazovo where Tupolev was born. After first being educated at home, Tupolev studied at the Gymnasium in Tver and finished in 1908. Tupolev then applied for courses at two Russian universities: Imperial Moscow Technical School (IMTU ) and the Emperor Nicholas II Moscow State University of Railway Engineering. Tupolev accepted at both, but ultimately chose to attend at IMTU.  In 1909, Tupolev began studying aerodynamics under the Russian aviation pioneer Nikolay Zhukovsky, and volunteered for the Aeronautical workshop ("Kruzhok") headed by Zhukovsky. In 1910, together with his workshop friends, Tupolev built and test piloted his first glider. During his workshop days, Tupolev also built a wind tunnel which led to the formation of an aerodynamic laboratory at IMTU. In 1911, Tupolev was accused of taking part in revolutionary activities, including demonstrations and distribution of subversive literature, and was arrested. Tupolev was later released on condition that he return to his family home in Pustomazovo. Tupolev was only allowed to return to IMTU in 1914, studying during World War I and the Russian Revolution. Tupolev completed his studies in 1918 and was awarded the degree of Engineer-Mechanic when he presented his thesis on the development of seaplanes. By 1920, the IMTU had been renamed the Moscow Higher Technical School (MVTU) and Tupolev was teaching a course there on the basics of aerodynamic calculations.

Aircraft design.

Central Aerohydrodynamic Institute.

Tupolev was a leading figure of the Moscow-based Central Aerohydrodynamic Institute (TsAGI; ) from 1929 until his death in 1972. The Central Design Office or TsKB () based there produced bombers for the Soviet Air Force and some airliners, which in the years before World War II and especially in his 1930s-era designs, were based partially on the all-metal aircraft design concepts pioneered by Hugo Junkers. In 1925, Tupolev designed a twin-engine bomber, the TB-1, which was considered one of the most advanced designs of the time. By 1934, Tupolev had led the design bureau that designed the largest aircraft flying in the world at the time, the 63-meter wingspan, eight-engined "Maksim Gorki", again built with the Junkers metal structure airframe concepts. In 1937, an improved version of the earlier TB-1, the four-engined TB-3, made a landing at the North Pole. As the number of qualified aircraft designers increased, Tupolev set up his own office, producing a number of designs designated with the prefix ANT () from his initials.

"Sharashka".

However, on 21 October 1937, Tupolev was arrested together with Vladimir Petlyakov and the entire directorate of the TsAGI and EDO during the Great Purge on trumped up charges of sabotage, espionage and of aiding the Russian Fascist Party. Many of his colleagues were executed but Tupolev himself was imprisoned. In 1939, Tupolev was moved from a prison to an NKVD "sharashka" for aircraft designers in Bolshevo near Moscow, where many surviving ex-TsAGI people had already been sent to work. The "sharashka" soon moved to Moscow and was dubbed "Tupolevka" after Tupolev, its most prominent inmate. In 1940, Tupolev was tried and convicted with a ten-year sentence, and during this time he developed the Tupolev Tu-2 which would become one of the most important aircraft of World War II. Tupolev was released in July 1941 around the time of the German invasion of the Soviet Union to "conduct important defence work" but was not fully rehabilitated by the Soviet state until 1955, two years after Joseph Stalin's death.

Post-war.

Tupolev headed the major project of reverse engineering the American Boeing B-29 strategic bomber, which was the world's first nuclear delivery platform. The Soviet Union had repeatedly asked for B-29s in the Lend Lease program of World War II but these requests were unsuccessful. Using three B-29s which landed in Siberia after bombing Japan in 1945, Tupolev succeeded in replicating them down to trivial detail. Moreover, Tupolev got it into volume production, with crews fully trained in time for the 1947 May Day parade. Tupolev's copy of the B-29 was designated Tu-4, with many subsequent Tu aircraft having the number 4 in their designations. The Tu-4 was initially designated B-4 because Tupolev refused to have his name attached to an aircraft his bureau did not design.  By the time of his rehabilitation on 9 April 1955, Tupolev had designed and was about to start testing his unique turboprop strategic bomber, the Tu-95. In the following years, Tupolev overcame competition from Vladimir Myasishchev and his M-4 series of jet-powered strategic bombers, introducing the Tu-16 design. This was in part thanks to Tupolev's close rapport with Nikita Khrushchev, the new leader of the Soviet Union who had denounced Stalin's terror, of which Tupolev had been a victim. At about the same time, Tupolev introduced into service the Tu-104, the world's second jet airliner and the first jet transport to stay in uninterrupted service, and the only one in service anywhere in the world for two years until late 1958.

Later years and death.

After Khruschev's removal from office in late 1964 and the rise of Leonid Brezhnev, the ageing Tupolev gradually lost positions at the centres of Soviet power to rivals in the aircraft industry. The prestigious Tu-144 programme enjoyed top level support until 1973, as did the important Tu-154 airliner, but the favored position the Tupolev Design Bureau enjoyed through Tupolev's personal political connections was largely eclipsed by the Ilyushin aircraft manufacturing and design company. To his contemporaries, Tupolev was known as a witty but crude master of obscene vocabulary who invariably and energetically insisted on fast and adequate technical fixes at the expense of scholastic ideal solutions. A hallmark of Tupolev was to get an aeroplane into service very rapidly, then began an often interminable process of improving the shortcomings of the "quick and dirty" initial design. To his competitors among the Soviet aircraft design community, he was known above all as politically astute; a shrewd and unforgiving rival.  Tupolev died on 23 December 1972 and was buried in Novodevichy Cemetery in Moscow.

Memorials.

Various streets in cities across the Eastern Bloc were named in honour of Tupolev, as well as "Tupolevlaan", a street in the Schiphol-Rijk industrial estate in Haarlemmermeer next to Amsterdam Airport Schiphol.  In 1973, the Kazan Aviation Institute was named after Tupolev, and a monument of him was erected in Kazan in a public square at the intersection of Dekabristov, Gagarin and Korolev Streets. In 1979, a bust of Tupolev was erected at a public square in Kimry, near his birthplace Pustomazovo which no longer exists. Another memorial to Tupolev was erected in the estimated location of Pustomazovo in the present-day Ustinovo, north of Kimry in Kimrsky District, Tver Oblast. The local high school in Ustinovo was renamed after Tupolev and a memorial plaque was installed. In 1988, the Soviet Union issued a postage stamp dedicated to Tupolev. The 1979 biographical film "Poema o kryl'yakh" (Поэма о крыльях) directed by Daniil Khrabrovitsky is about the life and works of Tupolev and Igor Sikorsky, the Russian-American aviation pioneer. Prospekt Tupoleva, the main avenue in the Aviatsionny microdistrict of Domodedovo located next to Domodedovo Airport, was named after Tupolev. A memorial mural of Tupolev was painted on the side of the 20 Prospekt Tupoleva apartment building. In 2018, Vnukovo International Airport in Moscow was formally renamed to Vnukovo Andrei Tupolev International Airport.

Personal life.

Tupolev was married to Yuliya Nikolaevna Tupoleva (née Zheltyakova) until her death in 1962. Tupolev's daughter Yuliya (1920–2011) was a doctor who was awarded the title of Honored Doctor of the Russian Federation. Tupolev's son Alexei (1925-2001) was a successful pioneering aircraft designer who designed the Tupolev Tu-144 supersonic passenger jet, and helped design the Buran space shuttle and the Tu-2000 long-range heavy bomber.  Tupolev was never a member of the Communist Party of the Soviet Union despite his status and being elected to several deputy positions.

Aircraft designed by Andrei Tupolev.

"List (partial) of retired or active airliners designed or made by aviation designer/engineer Andrei Tupolev; incl. both military and civilian planes, jets and other aircraft:"

Andrei Nikolayevich Tupolev (; – 23 December 1972) was a Soviet aeronautical engineer known for his pioneering aircraft designs as Director of the Tupolev Design Bureau.

安德烈·图波列夫(,1888年-11月11日<ref>儒略历1888年10月29日-1972年-12月23日)是一位苏联飞机设计师。


History.

The history of the region is linked with the history of Ulm and the Swabian Alb.  Listing of Towns and Municipalities in the former Ulm district: The district of Alb-Donau was established in 1973 by merging the former districts of Ulm and Ehingen, some municipalities of the Münsingen district and the municipalities of Oberbalzheim and Unterbalzheim of the Biberach district.

Geography.

The city of Ulm is surrounded by the district. It is the administrative seat of the Alb-Donau district, although it is not part of the district.  The district is named after the Danube River (German "Donau") and the Swabian Alb ("Schwäbische Alb") mountains. The Danube enters the district in the southwest, runs through the southern parts of the district and leaves eastwards to Ulm. North of the Danube banks the hills of the Swabian Alb rise. The hill chain extends from southwest to northeast parallel to the course of the Danube River and is continued on either side of the district. An affluent of the Danube, the Iller River, forms the southeastern border of the Alb-Donau district, before it meets the Danube in Ulm.

Coat of arms.

The coat of arms is identical to the coat of arms of the former district of Ulm. The eagle was the heraldic animal of the Free Imperial City of Ulm. The shield displays the deer antlers of Württemberg and the red and white stripes of the Austrian county of Burgau (which the southern parts of the district once belonged to).

Alb-Donau-Kreis is a "Landkreis" (district) in Baden-Württemberg, Germany. It is bounded by (from the south and clockwise) the districts of Biberach, Reutlingen, Göppingen and Heidenheim, the two Bavarian districts Günzburg and Neu-Ulm, and the city of Ulm.

山地-多瑙县(Alb-Donau-Kreis)是德国巴登-符腾堡州的一个县,隶属于蒂宾根行政区,首府乌尔姆。


Terminology.

"Flat" vs "apartment".

Both words refer to a self-contained residential unit with its own front door, kitchen, toilet, and bathroom. In some parts of the world, the word "apartment" refers to a purpose-built unit in a building, whereas the word "flat" means a converted unit in an older building, usually a big house. In other places the terms are interchangeable.  The term "apartment" is favored in North America (although in some cities "flat" is used for a unit which is part of a house containing two or three units, typically one to a floor). In the UK,

By housing tenure.

Tenement law refers to the feudal basis of permanent property such as land or rents. It may be found combined as in "Messuage or Tenement" to encompass all the land, buildings and other assets of a property.  In the United States, some apartment-dwellers own their units, either as a housing cooperative, in which the residents own shares of a corporation that owns the building or development; or in a condominium, whose residents own their apartments and share ownership of the public spaces. Most apartments are in buildings designed for the purpose, but large older

By size of the unit.

Bachelor apartment,

By size of the building.

Apartment buildings are multi-story buildings where three or more residences are contained within one structure. Such a building may be called an "apartment building", "apartment complex", "flat complex", "block of flats", "tower block", "high-rise" or, occasionally, "mansion block" (in British English), especially if it consists of many apartments for rent. A high-rise apartment building is commonly referred to as a "residential tower", "apartment tower", or "block of flats" in Australia.  A high-rise building is defined by its height differently in various jurisdictions. It may be

By country.

In American English, the distinction between rental apartments and condominiums is that while rental buildings are owned by a single entity and rented out to many, condominiums are owned individually, while their owners still pay a monthly or yearly fee for building upkeep. Condominiums are often leased by their owner as rental apartments. A third alternative, the cooperative apartment building (or "co-op"), acts as a corporation with all of the tenants as shareholders of the building. Tenants in cooperative buildings do not own their apartment, but instead own a proportional number of shares of the entire cooperative. As in condominiums, cooperators pay a monthly fee for building upkeep. Co-ops are common in cities such as New York, and have gained some popularity in other larger urban areas in the U.S.  In British English the usual word is "flat", but "apartment" is used by property developers to denote expensive 'flats' in exclusive and expensive residential areas in, for example, parts of London such as Belgravia and Hampstead. In Scotland, it is called a block of flats or, if it is a traditional sandstone building, a "tenement",

Types and characteristics.

Studio apartment.

The smallest self-contained apartments are referred to as studio, efficiency or bachelor apartments in the US and Canada, or studio flat in the UK. These units usually consist of a large single main room which acts as the living room, dining room and bedroom combined and usually also includes

Garden apartment (US).

Merriam-Webster defines a garden apartment in American English as "a multiple-unit low-rise dwelling having considerable lawn or garden space" The apartment buildings are often arranged around courtyards that are open at one end. Such a garden apartment shares some characteristics of a townhouse: each apartment has its own building entrance, or shares

Garden flat (UK).

The "Oxford English Dictionary" defines the use of "garden flat" in British English as "a basement or ground-floor flat with a view of and access to a garden or lawn", although its citations acknowledge that the reference to a garden may be illusory. "Garden flat" can serve simply as a euphemism

Basement apartment.

Generally on the

Secondary suite.

When part of a house is converted for the ostensible use of the owner's family member, the self-contained dwelling may be known as an "in-law apartment", "annexe", or "granny flat", though these (sometimes illegally)

Salon apartment.

"Salon apartment" is a term linked to the exclusive apartments built as part of multi-family houses in Belgrade and in certain towns in Yugoslavia in the first decades of the 20th century. The structure of the apartments

Maisonette.

Maisonette (a corruption of, French for "little house") has no strict definition, but the "OED" suggests "a part of a residential building which is occupied separately, usually on more than one floor and having its own outside entrance." It differs from a flat in having, usually, more than one floor, with a staircase internal to the dwelling leading from the entrance floor to the upper (or, in some

One dwelling with two storeys.

The vast majority of apartments are on one level, hence "flat". Some, however, have two storeys, joined internally by stairs, just as many houses do. One term for this is "maisonette",

Small buildings with a few one-storey dwellings.

"Duplex" refers to two separate units with a common demising wall or floor-ceiling assembly.  Duplex description can be different depending on the part of the US, but generally has two to four dwellings with a door for each and usually two front doors close together but separate—referred to as 'duplex', indicating the number of units, not the number of floors, as in some areas of the country they are often only one story. The term duplex is largely unknown in the UK; there, buildings containing two dwellings with a common vertical wall are known as "semi-detached" or

Loft apartment.

This type of apartment developed in North America during the middle of the 20th century. The term initially described a living space created within a former industrial building, usually 19th century. These large apartments found favor with artists and musicians wanting accommodation in large cities (New York for example) and is related to unused buildings in the decaying parts of such cities being occupied illegally by people squatting.  These loft

Penthouse.

An apartment located on the

Communal apartment.

In Russia, a communal apartment («коммуналка») is a room with a shared kitchen and bath. A typical arrangement is a cluster of five or

Serviced apartment.

A "serviced apartment" is any size space for residential living which includes regular maid and cleaning services provided by the rental agent. Serviced apartments or serviced flats developed in the early part of the 20th century and were briefly fashionable in the 1920s and 30s. They are intended to combine the best features of luxury and self-contained apartments, often being an adjunct of a hotel. Like guests semi-permanently installed in a luxury hotel, residents could enjoy the additional facilities such as

Facilities.

Apartments may be available for rent furnished, with furniture, or unfurnished into which a tenant moves in with their own furniture. Serviced apartments, intended to be convenient for shorter stays, include soft furnishings and kitchen utensils, and maid service.  Laundry facilities may reside in a common area accessible to all building tenants, or each apartment may have its own facilities. Depending on when the building was built and its design, utilities such as water, heating, and electricity may be common for all of the apartments, or separate for each apartment and billed separately to each tenant. (Many areas in the US have ruled it illegal to split a water bill among all the tenants, especially if a pool is on the premises.) Outlets for connection to telephones are typically included in

Various.

In more urban areas, apartments close to the downtown area have the benefits of proximity to jobs and/or public transportation. However, prices per square foot are often much higher than in suburban areas.  Moving up from studio flats are one-bedroom apartments, in which a bedroom is separate from the rest of the apartment, followed by two-bedroom, three-bedroom, etc. apartments. (Apartments with more than three bedrooms are rare.)  Small apartments often

Historical examples.

Pre-Columbian Americas.

The Puebloan peoples of what is now the Southwestern United States have constructed large, multi-room dwellings, some comprising more than 900 rooms, since the 10th century.  In the Classic Period Mesoamerican city of Teotihuacan, apartments were not only the standard means

Ancient Rome.

In ancient Rome, the insulae (singular "insula") were large apartment buildings where the lower and middle classes of Romans (the plebs) dwelled. The floor at ground level was used for tabernas, shops and businesses, with living space on the higher floors. Insulae in Rome and other imperial cities reached up to ten or

Ancient and medieval Egypt.

During the medieval Arabic-Islamic period, the Egyptian capital of Fustat (Old Cairo) housed many high-rise residential buildings, some seven stories tall that could reportedly accommodate hundreds of people. In the 10th century, Al-Muqaddasi described them as resembling minarets, and stated that the majority of Fustat's population lived in these multi-storey

Yemen.

High-rise apartment buildings were built in the Yemeni city of Shibam in the 16th century. The houses of Shibam are all made out of mud bricks, but about 500 of

Ancient China.

The Hakka people in southern China adopted communal living structures designed to be easily defensible, in the form

Current examples.

England.

In London, by the time of the 2011 census, 52 per cent of all homes were flats. Many of these were built as Georgian or Victorian houses and subsequently divided up. Many others were built as council flats. Many tower blocks were built after the Second World War. A number of these have been demolished and replaced with low-rise buildings or housing estates.  In the late 19th and early 20th centuries, the concept of the flat was slow to catch on amongst the British middle classes, which generally followed the north European standard of single-family houses dating far back into history. Those

Scotland.

In Scotland, the term "tenement" lacks the pejorative connotations it carries elsewhere and refers simply to any block of flats sharing a common central staircase and lacking an elevator, particularly those constructed before 1919. Tenements were, and continue to be, inhabited by a wide range of social classes and income groups. Tenements today are bought by a wide range of social types, including young professionals, older retirees, and by absentee landlords, often for rental to students after they leave halls of residence managed by their institution. The National Trust for Scotland Tenement House (Glasgow) is a historic house museum offering an insight into the lifestyle of tenement dwellers, as it was generations ago.  During the 19th century tenements became the predominant type of new housing in Scotland's industrial cities, although they were very common in the Old Town in Edinburgh from the 15th century, where they reached ten or eleven storeys and in one case fourteen storeys. Built of sandstone or granite, Scottish tenements are usually three to five storeys in height, with two to four flats on each floor. (In contrast, industrial cities in England tended to favour "back-to-back" terraces of brick.) Scottish tenements are constructed in terraces, and each entrance within a block is referred to as a "close" or "stair"—both referring to the shared passageway to the individual flats. Flights of stairs and landings are generally designated common areas, and residents traditionally took turns to sweep clean the floors and, in Aberdeen in particular, took turns to make use of shared laundry facilities in the "back green" (garden or yard). It is now more common for cleaning of the common ways to be contracted out through a managing agent or "factor".  In Glasgow, where Scotland's highest concentration of tenement dwellings can be found, the urban renewal projects of the 1950s, 1960s and 1970s brought an end to the city's slums, which had primarily consisted of older tenements built in the early 19th century in which large extended

United States.

In 1839, the first New York City tenement was built, and soon became breeding grounds for outlaws, juvenile delinquents, and organized crime. Tenements, or their slum landlords, were also known for their price gouging rent. "How the Other Half Lives" notes one tenement district:  Blind Man's Alley bear its name for a reason. Until little more than a year ago its dark burrows harbored a colony of blind beggars, tenants of a blind landlord, old Daniel Murphy, whom every child in the ward knows, if he never heard of the President of the United States. "Old Dan" made a big fortune--he told me once four hundred thousand dollars-- out of his alley and the surrounding tenements, only to grow blind himself in extreme old age, sharing in the end the chief hardship of the wretched beings whose lot he had stubbornly refused to better that he might increase his wealth. Even when the Board of Health at last compelled him to repair and clean up the worst of the old buildings, under threat of driving out the tenants and locking the doors behind them, the work was accomplished against the old man's angry protests. He appeared in person before the Board to argue his case, and his argument was characteristic. "I have made my will," he said. "My monument stands waiting for me in Calvary. I stand on the very brink of the grave, blind and helpless, and now (here the pathos of the appeal was swept under in a burst of angry indignation) do you want me to build and get skinned, skinned? These people are not fit to live in a nice house. Let them go where they can, and let my house stand." In spite of the genuine anguish of the appeal, it was downright amusing to find that his anger was provoked less by the anticipated waste of luxury on his tenants than by distrust of his own kind, the builder. He knew intuitively what to expect. The result showed that Mr. Murphy had gauged his tenants correctly.  Many campaigners, such as Upton Sinclair and Jacob Riis, pushed for reforms in tenement dwellings. As a result, the New York State Tenement House Act was passed in 1901 to improve the conditions. More improvements followed. In 1949, President Harry S. Truman signed the Housing Act of 1949 to clean slums and reconstruct housing units for the poor.  The Dakota (1884) was one of the first luxury apartment buildings in New York City. The majority, however, remained tenements.  Some significant developments in architectural design of apartment buildings came out of the 1950s and '60s. Among them were groundbreaking designs in the 860-880 Lake Shore Drive Apartments (1951), New Century Guild (1961), Marina City (1964) and Lake Point Tower (1968).  In the United States, "tenement" is a label usually applied to the less expensive, more basic rental apartment buildings in older sections of large cities. Many of these apartment buildings are "walk-ups" without an elevator, and some have shared bathing facilities, though this is becoming less common. The slang term "dingbat" is used to describe cheap urban apartment buildings from the 1950s and 1960s with unique and often wacky façades to differentiate themselves within a full block of apartments. They are often built on stilts, and with parking underneath.

Canada.

Apartments were popular in Canada, particularly in urban centres like Vancouver, Toronto, Ottawa, Montreal, and Hamilton in the 1950s to 1970s. By the 1980s, many multi-unit buildings were being constructed as condominiums instead of apartments—both are now very common. In Toronto and Vancouver, high-rise apartments and condominiums have been spread around the

Australia.

Apartment buildings in Australia are typically managed by a body corporate or "owners corporation" in which owners pay a monthly fee to provide for common maintenance and help cover future repair. Many apartments are owned through strata title. Due to legislation, Australian banks will either apply loan to value ratios of over 70 per cent for strata titles of less than 50 square metres, the big four Australian banks will not loan at all for strata titles of less than 30 square metres. These are usually classified as studio apartments or student accommodation. Australian legislation enforces a minimum 2.4m floor-ceiling height which differentiates apartment buildings from office buildings.  In Australia, apartment living is a popular lifestyle choice for DINKY, yuppies, university students and more recently empty nesters, however, rising land values in the big cities in recent years has seen an increase in families living in apartments. In Melbourne and Sydney apartment living is sometimes not a matter of choice for the many socially disadvantaged people who often end up in public housing towers.  Australia has a relatively recent history in apartment buildings. Terrace houses were the early response to density development, though the majority of Australians lived in fully detached houses. Apartments of any kind were legislated against in the Parliament of Queensland as part of the Undue Subdivision of Land Prevention Act 1885.  The earliest apartment buildings were in the major cities of Sydney and Melbourne as the response to fast rising land values–both cities are home to the two oldest surviving apartment buildings in the country, Kingsclere in Potts Point, and The Canterbury Flats in St Kilda. Melbourne Mansions on Collins Street, Melbourne (now demolished), built in 1906 for mostly wealthy residents is believed by many to be the earliest. Today the oldest surviving self-contained apartment buildings are in the St Kilda area including the Fawkner Mansions (1910), Majestic Mansions (1912 as a boarding house) and the Canterbury (1914—the oldest surviving buildings contained flats). Kingsclere, built in 1912 is believed to be the earliest apartment building in Sydney and still survives.  During the interwar years, apartment building continued in inner Melbourne (particularly in areas such as St Kilda and South Yarra), Sydney (particularly

Yugoslavia.

The development of residential architecture in Yugoslavia during the period of socialism had its peak in the 1960s and 1970s. Significant progress in construction was accompanied by housing research directed towards finding the optimal urbanistic solutions for the newly formed lifestyle of the socialist society. The tendency was to "pack" as many residential units as possible into each building, almost up to the limits of the functional minimum, at the same time with the aim of setting a more humane pattern of living. As a

An apartment (American English), or flat (British English, Indian English), is a self-contained housing unit (a type of residential real estate) that occupies only part of a building, generally on a single storey. There are many names for these overall buildings, see below. The housing tenure of apartments also varies considerably, from large-scale public housing, to owner occupancy within what is legally a condominium (strata title or commonhold), to tenants renting from a private landlord (see leasehold estate).

公寓(美式英文:apartment,英式英文:flat,澳大利亚英文:unit)为集合式住宅的一种,是城市特有的现象。包含多个公寓单位的大厦称为公寓大厦。


波美拉尼亚省 (普鲁士)

Etymology.

The name "Pomerania" comes from

Overview.

The province was created from the former Prussian Province of Pomerania, which consisted of Farther Pomerania and the southern Western Pomerania, and former Swedish Pomerania. It resembled the territory of the former Duchy of Pomerania, which after the Peace of Westphalia in 1648 had been split between Brandenburg-Prussia and Sweden. Also, the districts of Schivelbein and Dramburg, formerly belonging to the Neumark, were merged into the new province.  While in the Kingdom of Prussia, the province was heavily influenced by the reforms of Karl August von Hardenberg and Otto von Bismarck. The Industrial Revolution primarily affected the Stettin area and the infrastructure, while most of the province retained a rural and agricultural character. From 1850, the net migration rate was negative; Pomeranians emigrated primarily to Berlin, the West German industrial regions and overseas.  After World War I, democracy and the women's right to vote were introduced to the province. After Wilhelm II's abdication, it was part of the Free State of Prussia. The economic situation worsened due to the consequences of World War I and worldwide recession. As in the previous Kingdom of Prussia, Pomerania was a stronghold of the nationalist conservatives who continued in the Weimar Republic.  In 1933, the Nazis established a totalitarian regime, concentrating the province's administration in the hands of their, and implementing. The German invasion of Poland in

Creation and administration of the province within the Kingdom of Prussia.

Although there had been a Prussian Province of Pomerania before, the Province of Pomerania was newly constituted in 1815, based on the "decree concerning improved establishment of provincial offices" (), issued by Karl August von Hardenberg on 30 April, and the integration of Swedish Pomerania, handed over to Prussia on 23 October.  The Hardenberg decree reformed all Prussian territories, which henceforth formed ten (later eight) provinces with similar administrations. After the implementation of the reform, the new Province of Pomerania consisted basically of its predecessor and Swedish Pomerania, but also of the Dramburg and Schivelbein counties.  The province was headed by a governor (, literally "senior president") with his seat in the capital, Stettin. It was subdivided into government regions () headed by a president (). Initially, two such regions were planned (Regierungsbezirk Stettin, comprising Western Pomerania, and Regierungsbezirk Köslin, comprising Farther Pomerania). Hardenberg however, who as the Prussian chief diplomat had settled the terms of session of Swedish Pomerania with Sweden at the Congress of Vienna, had assured to leave the local constitution in place when the treaty was signed on 7 June 1815. This circumstance led to a creation of a third government region, Regierungsbezirk Stralsund, for the former Swedish Pomerania at the expense of the Stettin region.  In early 1818, Governor Johann August Sack had reformed the county () shapes, yet adopted the former shape in most cases. Köslin government region comprised nine counties, Stettin government region thirteen, and Stralsund government region four (identical with the former Swedish (districts)).  The new parliament () assembled first on October 3, 1824. Based on two laws of June 5 and July, 1823, the was constituted by 25 lords and knights, 16 representatives of the towns, and eight from the rural communities.  Subordinate to the provincial were two assemblies, one for former Swedish Pomerania (Western Pomerania north of the Peene River) and one for the former Prussian part.  The counties each assembled a, where the knights of the county had one vote each and towns also just one vote.  Throughout its existence, the province was a stronghold of the Conservative Parties.

Infrastructure.

In the 19th century, the first overland routes () and railways were introduced in Pomerania. In 1848, 126.8 Prussian miles of new streets had been built. On October 12, 1840, construction of the Berlin-Stettin railway began, which was finished on 15 August 1843. Other railways followed: Stettin–Köslin (1859), Angermünde–Stralsund and Züssow–Wolgast (1863), Stettin–Stolp (1869), and a connection with Danzig (1870).  In rural areas, many narrow-gauge railways were built for faster transport of crops. The first gas, water, and power plants were built. Streets and canalisation of the towns were modernized.  The construction of narrow-gauge railways was enhanced by a special decree of July 28, 1892, implementing Prussian financial aid programs. In 1900, the total of narrow-gauge

Agricultural reform.

Already in 1807, Prussia issued a decree () abolishing serfdom. Hardenberg issued a decree on September 14, 1811, defining the terms by which serfs were to be released (). This could either be done by monetary payment or by releasing title to the land to the former lord. These reforms were applied during the early years of the province's existence. The so-called "regulation" was applied to 10,744 peasants until 1838, who paid their former lords 724,954 taler and handed over of farmland to bail themselves out.  Tumults arose in 1847 in the towns of Stettin and Köslin due

Bismarck era administrative reforms.

Otto von Bismarck inherited from his father the Farther Pomeranian estates Külz, Jarchlin and Kniephof. Aiming at a farming career, he studied agriculture at the academy in Greifswald-Eldena. From 1867 to 1874, he bought and expanded the Varzin estates.  In 1869, Friedrich Albrecht Graf zu Eulenburg drafted a county reform () that was promoted by Bismarck. The reform passed the House of Lords on December 7, 1872. Most importantly, the reform cut the linkage between noble status and the right to vote, the latter now depended on property (one had to be above a certain tax threshold) and not on status, aiming

World War I.

During the First World War, no battles took place in the province.  Nevertheless, the war affected society, economy, and administration. During the war, the provincial administrative institutions were subordinate to the military and headed by military officials. Mobilization resulted in work force shortage affecting all non-war-related industry, construction, and agriculture. Women, minors and POWs partially replaced the drafted men. Import and fishing declined when

Province of the Free State of Prussia.

After the Kaiser was forced to resign, the province became part of the Free State of Prussia within the Weimar Republic.

German Revolution of 1918–19.

During the German Revolution of 1918–19, revolutionary councils of soldiers and workers took over the Pomeranian towns (Stralsund on November 9, Stettin, Greifswald, Pasewalk, Stargard, and Swinemünde on November 10, Barth, Bütow, Neustettin, Köslin, and Stolp on November 11). On January 5, 1919, "Workers' and Soldiers' Councils" () were in charge of most of the province (231 towns and rural municipalities). The revolution was peaceful, no riots are reported. The councils were led by Social Democrats, who

Counter-revolution.

Conservative and right-wing groups evolved in opposition to the revolutions' achievements. Landowners formed the Pommerscher Landbund in February 1919, which by 1921 had 120,000 members and from the beginning was supplied with arms by the 2nd army corps in Stettin. Paramilitias

Constitution of 1920.

In 1920 (changed in 1921 and 1924), the Free State of Prussia adopted a democratic constitution for her provinces. The constitution granted a number of civil rights to the Prussian population and enhanced the self-government of the provinces.  The provincial and county parliaments (Landtag and Kreistag) were hence elected directly by the population,

Economy.

The border changes however caused a severe decline in the province's economy. Farther Pomerania was cut off from Danzig by the corridor. Former markets and supplies in the now Polish territories became unavailable.  Farther Pomeranian farmers had sold their products primarily to the eastern provinces, that were now part of the Second Polish Republic. Due to high transport costs, the markets in the West were unavailable too. The farmers reacted by modernizing their equipment, improving the quality of their products, and applying new technical methods. As a consequence, more than half of the farmers were severely indebted in 1927. The government reacted with the Osthilfe program, and granted credits to favourable conditions.  Stettin particularly suffered from a post-war change in trade routes. Before the territorial changes, it had been on the export route from the Katowice (Kattowitz) industrial region in now Polish Upper Silesia.

Nazi era.

Pomeranian Nazi movement before 1933.

Throughout the existence of the Weimar Republic, politics in the province was dominated by the nationalist conservative DNVP (, German National People's Party); an entity composed of nationalists, monarchists, radical volkisch and anti-semitic elements, and supported by Pan-German League an old organisation believing in superiority of German people over others. The Nazi party (NSDAP) did not have any significant success at elections, nor did it have a substantial number of members. The Pomeranian Nazi party was founded by students of the University of Greifswald in 1922, when the NSDAP was officially forbidden. The university's rector Theodor Vahlen became Gauleiter (head of the provincial party) in 1924. Soon afterwards, he was fired by the university and went bankrupt. In 1924, the party had 330 members, and in December 1925, 297 members. The

Nazi government since 1933.

Immediately after their gain of power, the Nazis began arresting their opponents. In March 1933, 200 people were arrested, this number rose to 600 during the following months. In Stettin-Bredow, at the site of the bankrupt Vulcan shipyards, the Nazis set up a short-lived "wild" concentration camp from October 1933 to March 1934, where SA maltreated their victims. The Pomeranian SA in 1933 had grown to 100,000 members.  Oberpräsident von Halfern retired in 1933, and with him one third of the Landrat and Oberbürgermeister (mayor) officials.  Also in 1933, an election was held for a new provincial parliament, which then had a Nazi majority. Decrees were issued that shifted all issues formerly in responsibility of the parliament to the commission, and furthermore, shifted the power to decide on these issues from the to the

Deportation of the Pomeranian Jews.

In 1933, about 7,800 Jews lived in Pomerania, of which a third lived in Stettin. The other two thirds were living all over the province, Jewish communities numbering more than 200 people were in Stettin, Kolberg, Lauenburg in Pomerania, and Stolp.  When the Nazis started to terrorize Jews, many emigrated. Twenty weeks after the Nazis seized power, the number of Jewish Pomeranians had already dropped by eight percent.  Besides the repressions Jews had to endure in all Nazi Germany, including the destruction of the Pomeranian synagogues on November 9, 1938 (Reichskristallnacht), all male Stettin Jews were deported to Oranienburg concentration camp after this event and kept there for several weeks.  On February 12 and 13,

Repressions against Polish minority.

Grzęda (1994) says that in 1910, according to German data, 10,500 Poles lived in the Stettin (Szczecin) area, and that in his view the number was most likely reduced. Fenske (1993) and Buchholz et al. (1999) say that in 1910, 7,921 Poles lived steadily in the province; Skóra (2001) says that in 1925, according to German data, 5,914 Poles lived in the province (1,104 in the Stettin and 4,226 in the Köslin government regions), while the Polish consul "boldly assumed" that over 9000 Poles lived in the province. Wynot (1996) says that during the interwar era, between 22,500

Resistance.

Resistance groups formed in the economical centers, especially in Stettin, from where most arrests were reported.  Resistance is also reported from members of the nationalist conservative DNVP. The monarchist Herbert von Bismarck-Lasbeck was forced out of office in 1933. The newspaper Pommersche Tagespost was banned in 1935 after printing an article of monarchist Hans Joachim von Rohr (1888–1971). In 1936, four members of the DNVP were tried for founding a monarchist organization.  Other DNVP members, who had addressed their opposition already before 1933, were arrested multiple times after the Nazis had taken over. Ewald Kleist-Schmenzin, Karl Magnus von Knebel-Doberitz, and Karl von Zitzewitz were active resistants.  Within the Pomeranian provincial subsection of the

World War II and aftermath.

First war years.

The invasion of Poland by the Nazi Germany on September 1, 1939, which marked the beginning of World War II, was in part mounted from the province's soil. General Guderian's 19th army corps attacked from the Schlochau and Preußisch Friedland areas, which since 1938 belonged to the province ("Grenzmark Posen-Westpreußen").  According to Kozłowski & Krzywicki (1988), around 56,000 Polish POWs were located in Pomerania after the invasion, and soon Germany stripped them of their status(against international law) turning them into forced labourers;in April 1940 they were 82.417 of them in Pomerania, with the number reaching 116.330 Polish forced labourers in 1944 September  Because the invasion of Poland (and later the Soviet Union) was a success and the battle front moved far more east (Blitzkrieg), the province was not the

East Pomeranian Offensive.

On February 14, the remnants of German Army Group Vistula () had managed to set up a frontline roughly at the province's southern frontier, and launched a counterattack (Operation Solstice, "Sonnenwende") on February 15, that however stalled already on February 18. On February 24, the Second Belorussian Front launched the East Pomeranian Offensive and despite heavy resistance primarily in the Rummelsburg area took eastern Farther Pomerania until March 10. On March 1, the First Belorussian Front had launched an offensive from the Stargard and Märkisch Friedland area and succeeded in taking northwestern Farther Pomerania within five days. Cut off

Battle of Berlin.

On March 20, the Wehrmacht abandoned the last bridgehead on the Oder rivers eastern bank, the Altdamm area. The frontline then ran along Dievenow and lower Oder, and was held by the 3rd Panzer Army commanded by general Hasso von Manteuffel. After another four days of fighting, the Red Army managed to break through and cross the Oder between Stettin and Gartz (Oder), thus starting the northern theater of the Battle of Berlin on March 24. Stettin was abandoned the next day.  Throughout April, the Second Belorussian Front led

Dissolution of the province.

By the terms of the Potsdam Agreement, Western Pomerania east of the Oder–Neisse line became part of Poland. This line left the Oder river north of Gartz (Oder) and included the Stettin and Swinemünde area () into the Polish state. The remaining German population was expelled and the area was resettled with Poles. Western Pomerania west of the Oder-Neisse line was merged with Mecklenburg to constitute the state of Mecklenburg-Vorpommern in the Soviet occupation zone of Germany, that in 1949 became the German Democratic Republic (GDR). was soon dropped from the federal state's name, and after the GDR states were abolished, the coastal Western Pomeranian Landkreis districts became part of Bezirk Rostock

Administrative subdivisions.

Köslin government region (Farther Pomerania).

The Köslin government region () was the administrative name for the region of Farther Pomerania () along with the smaller region of Lauenburg and Bütow Land (easternmost part).  These parts of Pomerania were integrated into the Brandenburg-Prussian Province of Pomerania (1653–1815) already after the Thirty Years' War. During the war, the noble House of Pomerania ("Griffins"), ruling the Duchy of Pomerania since the 1120s, became extinct in the male line with the death of Bogislaw XIV in 1637. Throughout the existence of the Griffin duchy, Brandenburg had claimed overlordship and was asserted of Pomerania inheritance in numerous treaties. Yet, Sweden had been one of the

Stettin government region (Western Pomerania).

The Stettin government region () since 1932 comprised the region of Western Pomerania (, "Hither Pomerania"), the former Swedish Pomerania. From 1815, the Stettin government region comprised only the southern parts of Western Pomerania (Old Western Pomerania, i.e. south of the Peene

Stralsund government region (Northwest).

The Stralsund government region () comprised the Western Pomeranian region of.  The reason for creating a Regierungsbezirk as small as Stralsund was that Neuvorpommern had a somewhat different history than the rest of Pomerania. This region, consisting of the island of Rügen and the adjacted mainland between the Recknitz and Peene rivers, made up the Rani and Danish Principality of Rugia in the Middle ages. Although it was inherited by the Pomeranian dukes in 1325, the region was for some time governed as the splinter duchy of Pomerania-Barth. While a part of Swedish Pomerania, Denmark maintained her old claims and occupied the area in 1715 during the Great Northern War. Yet, the Danes were forced

Posen-West Prussia government region.

The Posen-West Prussia government region () was created of the northern part (Schneidemühl government region) of the former Prussian province Posen-West-Prussia.  Following World War I, most of the Prussian provinces Posen and West Prussia became part of the Second Polish Republic. The remainders of these provinces formed the province of Posen-West Prussia, combining small German-settled

Demographics.

According to Georg Hassel, there were 65,000 Slavic-speakers in the whole Provinz Pommern in 1817-1819. Modern estimates for just eastern parts of Pommern in early 1800s range between 40,000 (Leszek Belzyt) and 25,000 (Jan Mordawski, Zygmunt Szultka). The number declined to between 35,000 and 23,000 (Zygmunt Szultka, Leszek Belzyt) in years 1827-1831. In 1850-1860s there were an estimated 23,000 to 17,000 Slavic-speakers left in Pommern, down to 15,000 in year 1892 according to Stefan Ramułt. The number was declining due to Germanisation. The bulk of Slavic population in 19th century Pommern was concentrated in its easternmost counties: especially Bytów (Bütow), Lębork (Lauenburg) and Słupsk (Stolp).  Until 1841, immigration to the province was higher than emigration. This trend reversed since 1850. However, the population grew further due to high birth rates.  Between 1871 and 1914, the prime characteristic of the province's demography was migration from the rural areas, first to urban centers (), then to destinations in other German provinces and oversees (). Despite the emigration during this time span, the population increased by 300,000 people.  Most people emigrated from Regierungsbezirk Köslin, where the population numbers of 1880 were only reached again in 1899.  The Province of Pomerania was one of the three provinces (the other two were West Prussia and Province of Posen) responsible for most of the German emigrants who went oversees. Imperial Commissioners for emigration ("Reichskommissar für Auswanderung") organized emigration from Hamburg, Bremen, Stettin, and Swinemünde. Emigration to oversees ended in 1893, when in America the free availability of soil claims ended.  Polish seasonal workers were employed in Pomeranian agriculture since the 1890s, initially to replace the emigrants. In 1910, 7921 Poles lived steadily in the province. In 1912, 12,000 seasonal workers were employed in agriculture, in 1914 their number increased to 42,000.  On October 1, 1938, the bulk of the former Province of Posen-West Prussia was merged into the Province of Pomerania, adding an area of with a population of 251,000.  On October 15, Stettin's city limits were expanded to an area of, housing 383,000 people.  During the Soviet conquest of Farther Pomerania and the subsequent expulsions of Germans until 1950, 498,000 people from the part of the province east of the Oder-Neisse line died, making up for 26,4% of the former population. Of the 498,000 dead, 375,000 were civilians, and 123,000 were Wehrmacht soldiers. Low estimates give a million expellees from the then Polish part of the province in 1945 and the following years. Only remained with Germany, about a fourth of the province's size before 1938 and a fifth of the size thereafter.

Modern inhabitants.

During the Polish post-war census of December 1950, data about the pre-war places of residence of the inhabitants as of August 1939 was collected. In case of children born between September 1939 and December 1950, their origin was reported based on the pre-war places of residence of their mothers. Thanks to this data it is possible to reconstruct the pre-war geographical origin of the post-war population. The same territory corresponding to 1939

The Province of Pomerania (; ) was a province of Prussia from 1815 to 1945. Pomerania was established as a province of the Kingdom of Prussia in 1815, an expansion of the older Brandenburg-Prussia province of Pomerania, and then became part of the German Empire in 1871. From 1918, Pomerania was a province of the Free State of Prussia until it was dissolved in 1945 following World War II, and its territory divided between Poland and Allied-occupied Germany.

波美拉尼亚省()是1815年至1946年间普鲁士和及后的普鲁士自由邦的一个省分。此省是由1648年威斯特伐利亚和约之后分别由勃兰登堡和瑞典统治的中波美拉尼亚及瑞属波美拉尼亚(「西波美拉尼亚」)所组成。瑞典在1814年的基尔条约中曾想波美拉尼亚让给丹麦,但条约重来没有被遵守,次年维也纳会议后波美拉尼亚被转让到普鲁士。


Complete and incomplete separation.

In some cases, separations require total purification, as in the electrolysis refining of bauxite ore for aluminum metal, but a good example of an incomplete separation technique is oil refining. Crude oil occurs naturally as a mixture of various hydrocarbons and impurities. The refining process splits this mixture into other, more valuable mixtures such as natural gas, gasoline and chemical feedstocks, none of which are pure substances, but each of which must be separated from the raw crude. In both of these cases, a series of separations is necessary to obtain the desired end products. In the case of oil refining, crude is subjected to a long series of individual distillation steps, each of which produces a different product or intermediate.

Separating liquids.

Separators are used to divide liquids. Vertically supported centrifuges are built with flying bearings. A separator is a continuous sedimentation centrifuge. Both exit streams are continuously discharged, using a pump (under pressure) or pressure-free. The solid material can be discharged discontinuously (chamber drum, solid-walled disc drum), pseudo continuously (self-cleaning disc drum) or continuously (nozzle drum). The drum is the centerpiece of the separator, in which the separation process takes place. There are two types of drums: the chamber drum (known as chamber separators) and the disc drum (known as disc separators). The power transmission on the spindle and thereby on the drum can take place by using one of the three drive motors: helical gears, a belt drive or direct drive, via a special motor. The sealing of the separators is differentiated into four types: open, semi-closed, hydro-hermetic (sealing of the product space) or fully hermetic (absolute airtight).

List of separation techniques.

Chromatography.

Chromatography separates dissolved substances by different interaction with (i.e., travel through) a material.

Electrophoresis.

Electrophoresis, separates organic molecules based on their different interaction with a gel under an electric potential (i.e., different travel)

A separation process is a method that converts a mixture or solution of chemical substances into two or more distinct product mixtures. At least one of results of the separation is enriched in one or more of the source mixture's constituents. In some cases, a separation may fully divide the mixture into pure constituents. Separations exploit differences in chemical properties or physical properties (such as size, shape, mass, density, or chemical affinity) between the constituents of a mixture.

分离过程(英语:separation process)在化学与化学工程中被用于将一些物质的混合物转化为两个或多个不同的产物。被分离的产物常在化学性质或一些例如尺寸、晶体形状等的物理性质上有所改变。


Introduction.

Wave propagation and polarization.

Most sources of light are classified as incoherent and unpolarized (or only "partially polarized") because they consist of a random mixture of waves having different spatial characteristics, frequencies (wavelengths), phases, and polarization states. However, for understanding electromagnetic waves and polarization in particular, it is easier to just consider coherent plane waves; these are sinusoidal waves of one particular direction (or wavevector), frequency, phase, and polarization state. Characterizing an optical system in relation to a plane wave with those given parameters can then be used to predict its response to a more general case, since a wave with any specified spatial structure can be decomposed into a combination of plane waves (its so-called angular spectrum). Incoherent states can be modeled stochastically as a weighted combination of such uncorrelated waves with some distribution of frequencies (its "spectrum"), phases, and polarizations.

Transverse electromagnetic waves.

Electromagnetic waves (such as light), traveling in free space or another homogeneous isotropic non-attenuating medium, are properly described as transverse waves, meaning that a plane wave's electric field vector E and magnetic field H are in directions perpendicular to (or "transverse" to) the direction of wave propagation; E and H are also perpendicular to each other. By convention, the "polarization" direction of an electromagnetic wave is given by its electric field vector. Considering a monochromatic plane wave of optical frequency "f" (light of vacuum wavelength λ has a frequency of "f = c/λ" where "c" is the speed of light), let us take the

Non-transverse waves.

In addition to transverse waves, there are many wave motions where the oscillation is not limited to directions perpendicular to the direction of propagation. These cases are far beyond the scope of the current article which concentrates on transverse waves (such as most electromagnetic waves in bulk media), however one should be aware of cases where the polarization of a coherent wave cannot be described simply using a Jones vector, as we have just done.  Just considering electromagnetic waves, we note that the preceding discussion strictly applies to plane waves in a homogeneous isotropic non-attenuating medium, whereas in an anisotropic medium (such as birefringent crystals as discussed below) the electric or magnetic field may have longitudinal as well as transverse components. In those cases the electric displacement "D" and magnetic flux density "B" still obey the above geometry but due to anisotropy in the electric susceptibility (or in the magnetic permeability), now given by a tensor, the

Polarization state.

Polarization is best understood by initially considering only pure polarization states, and only a coherent sinusoidal wave at some optical frequency. The vector in the adjacent diagram might describe the oscillation of the electric field emitted by a single-mode laser (whose oscillation frequency would be typically 10 times faster). The field oscillates in the "x-y" plane, along the page, with the wave propagating in the "z" direction, perpendicular to the page. The first two diagrams below trace the electric field vector over a complete cycle for linear polarization at two different orientations; these are each considered a distinct "state of polarization" (SOP). Note that the linear polarization at 45° can also be viewed as the addition of a horizontally linearly polarized wave (as in the leftmost figure) and a vertically polarized wave of the same amplitude "in the same phase".  Now if one were to introduce a phase shift in between those horizontal and vertical polarization components, one would generally obtain elliptical polarization as is shown in the third figure. When the phase shift is exactly ±90°, then "circular polarization" is produced (fourth and fifth figures). Thus is circular polarization created in practice, starting with linearly polarized light and employing a quarter-wave plate to introduce such a phase shift. The result of two such phase-shifted components in causing a rotating electric field vector is depicted in the animation on the right. Note that circular or elliptical polarization can involve either a clockwise or counterclockwise rotation of the field. These correspond to distinct polarization states, such as the two circular polarizations shown above.  Of course the orientation of the "x" and "y" axes used in this description is arbitrary. The choice of such a coordinate system and viewing the polarization ellipse in terms of the "x" and "y" polarization components, corresponds to the definition of the Jones vector (below) in terms of those basis polarizations. One would typically choose axes to suit a particular problem such as "x" being in the plane of incidence. Since there are separate reflection coefficients for the linear polarizations in and orthogonal to the plane of incidence ("p" and "s" polarizations, see below), that choice greatly simplifies the calculation of a wave's reflection from a surface.  Moreover, one can use as basis functions "any" pair of orthogonal polarization states, not just linear polarizations. For instance, choosing right and left circular polarizations as basis functions simplifies the solution of problems involving circular birefringence (optical activity) or circular dichroism.

Implications for reflection and propagation.

Polarization in wave propagation.

In a vacuum, the components of the electric field propagate at the speed of light, so that the phase of the wave varies in space and time while the polarization state does not. That is, the electric field vector e of a plane wave in the +"z" direction follows:  where "k" is the wavenumber. As noted above, the instantaneous electric field is the real part of the product of the Jones vector times the phase factor formula_36. When an electromagnetic wave interacts with matter, its propagation is altered according to the material's (complex) index of refraction. When the real or imaginary part of that refractive index is dependent on the polarization state of a wave, properties known as birefringence and polarization dichroism (or diattenuation) respectively, then the polarization state of a wave will generally be altered.  In such media, an electromagnetic wave with any given

Birefringence.

In media termed birefringent, in which the amplitudes are unchanged but a differential phase delay occurs, the Jones matrix is a unitary matrix: |"g"| = |"g"| = 1. Media termed diattenuating (or "dichroic" in the sense of polarization), in which only the amplitudes of the two polarizations are affected differentially, may be described using a Hermitian matrix (generally multiplied by a common phase factor). In fact, since "any" matrix may be written as the product of unitary and positive Hermitian matrices, light

Dichroism.

Media in which transmission of one polarization mode is preferentially reduced are called "dichroic" or "diattenuating". Like birefringence, diattenuation can be with respect to linear polarization modes (in a crystal) or circular polarization modes (usually in a liquid).  Devices that block nearly all of the radiation in one mode are known as "polarizing filters" or simply "polarizers". This corresponds to "g"=0 in the above representation of the Jones matrix. The output of an ideal polarizer is a specific polarization

Specular reflection.

In addition to birefringence and dichroism in extended media, polarization effects describable using Jones matrices can also occur at (reflective) interface between two materials of different refractive index. These effects are treated by the Fresnel equations. Part of the wave is transmitted and part is reflected; for a given material those proportions (and also the phase of reflection) are dependent on the angle of incidence and are different for the "s" and "p" polarizations. Therefore, the polarization state of reflected light (even if initially unpolarized) is generally changed. Any light striking a surface at a special angle of incidence known as Brewster's angle, where the reflection coefficient for "p" polarization is zero, will be reflected with only the "s"-polarization remaining. This principle is employed in the so-called "pile of plates polarizer" (see figure) in which part of the "s" polarization is removed by reflection at each Brewster angle surface, leaving only the

Measurement techniques involving polarization.

Some optical measurement techniques are based on polarization. In many other optical techniques polarization is crucial or at least must be taken into account and controlled; such examples are too numerous to mention.

Measurement of stress.

In engineering, the phenomenon of stress induced birefringence allows for stresses in transparent materials to be readily observed. As noted above and seen in the accompanying photograph, the chromaticity of birefringence typically creates colored patterns when

Ellipsometry.

Ellipsometry is a powerful technique for the measurement of the optical properties of a uniform surface. It involves measuring the polarization state of light following specular reflection from such a surface. This is typically done as a function of incidence angle or wavelength (or both). Since ellipsometry relies on reflection, it is not required for the sample to be transparent to light or for its back side to be accessible.  Ellipsometry can be used to model the (complex) refractive index

Geology.

The property of (linear) birefringence is widespread in crystalline minerals, and indeed was pivotal in the initial discovery of polarization. In mineralogy, this property is frequently exploited using polarization microscopes, for the purpose of identifying minerals.

Chemistry.

We have seen (above) that the birefringence of a type of crystal is useful in identifying it, and thus detection of linear birefringence is especially useful in geology and mineralogy. Linearly polarized light generally has its polarization state altered upon transmission through such a crystal, making it stand out when viewed in between two crossed polarizers, as seen in the photograph, above. Likewise, in chemistry, rotation of polarization axes in a liquid solution can be a useful measurement. In a liquid, linear birefringence is impossible, however

Astronomy.

In many areas of astronomy, the study of polarized electromagnetic radiation from outer space is of great importance. Although not usually a factor in the thermal radiation of stars, polarization is also present in radiation from coherent astronomical sources (e.g. hydroxyl or methanol masers), and incoherent sources such as the large radio lobes in active

Applications and examples.

Polarized sunglasses.

Unpolarized light, after being reflected by a specular (shiny) surface, generally obtains a degree of polarization. This phenomenon was observed in 1808 by the mathematician Étienne-Louis Malus, after whom Malus's law is named. Polarizing sunglasses exploit this effect to reduce glare from reflections by

Sky polarization and photography.

Polarization is observed in the light of the sky, as this is due to sunlight scattered by aerosols as it passes through the earth's atmosphere. The scattered light produces the brightness and color in clear skies. This partial polarization of scattered light can be used to darken the sky in photographs, increasing the contrast. This effect is most strongly observed at points on the sky making a 90° angle to the sun. Polarizing filters use these effects to

Display technologies.

The principle of liquid-crystal display (LCD) technology relies on the rotation of the axis of linear polarization by the liquid crystal array. Light from the backlight (or the back reflective layer, in devices not including or requiring a backlight) first passes through a linear polarizing sheet. That polarized light passes through the actual liquid crystal layer which may be organized in pixels (for a TV or computer monitor) or in another format such as a seven-segment display or one with custom symbols for a particular product. The liquid crystal layer is produced with a consistent right (or left) handed chirality, essentially consisting of tiny helices. This causes circular birefringence, and is engineered so that there is a 90 degree rotation of the linear polarization state. However, when a voltage is applied across a cell, the molecules straighten out, lessening or totally losing the circular birefringence. On the viewing side of the display is another linear polarizing sheet, usually oriented at 90 degrees from the one behind the active layer. Therefore, when the circular birefringence is removed by the application of a sufficient voltage, the polarization of the transmitted light remains at right angles to the front polarizer, and the pixel appears dark. With no voltage, however, the 90 degree rotation of the polarization causes it to exactly match the axis of the front polarizer, allowing the light through. Intermediate voltages create intermediate rotation of the polarization axis and the pixel has an intermediate intensity. Displays based on this principle are widespread, and now are used in the vast majority of televisions, computer monitors and video projectors, rendering the previous CRT technology essentially obsolete. The use of polarization in the operation of LCD

Radio transmission and reception.

All radio (and microwave) antennas used for transmitting or receiving are intrinsically polarized. They transmit in (or receive signals from) a particular polarization, being totally insensitive to the opposite polarization; in certain cases that polarization is a function of direction. Most antennas are nominally linearly polarized, but elliptical and circular polarization is a possibility. As is the convention in optics, the "polarization" of a radio wave is understood to refer to the polarization of its electric field, with the magnetic field being at a 90 degree rotation with respect to it for a linearly polarized wave.  The vast majority of antennas are linearly polarized. In fact it can be shown from considerations of symmetry that an antenna that lies entirely in a plane which also includes the observer, can "only" have its polarization in the direction of that plane. This applies to many cases, allowing one to easily infer such an antenna's polarization at an intended direction of propagation. So a typical rooftop Yagi or log-periodic antenna with horizontal conductors, as viewed from a second station toward the horizon, is necessarily horizontally polarized. But a vertical "whip antenna" or AM broadcast tower used as an antenna element (again, for observers horizontally displaced from it) will transmit in the vertical polarization. A turnstile antenna with its four arms in the horizontal plane, likewise transmits horizontally polarized radiation toward the horizon. However, when that same turnstile antenna is used in the "axial mode" (upwards, for the same horizontally-oriented structure) its radiation is circularly polarized. At intermediate elevations it is elliptically polarized.  Polarization is important in radio communications because, for instance, if one attempts to use

Polarization and vision.

Many animals are capable of perceiving some of the components of the polarization of light, e.g., linear horizontally polarized light. This is generally used for navigational purposes, since the linear polarization of sky light is always perpendicular to the direction of the sun. This ability is very common among the insects, including bees, which use this information to orient their communicative dances. Polarization sensitivity has also been observed in species of octopus, squid, cuttlefish, and mantis shrimp. In the latter case, one species

Angular momentum using circular polarization.

It is well known that electromagnetic radiation carries a certain linear momentum in the direction of propagation. In addition, however, light carries a certain angular momentum if it is circularly polarized (or partially so). In comparison

Polarization (also polarisation) is a property applying to transverse waves that specifies the geometrical orientation of the oscillations. In a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the wave. A simple example of a polarized transverse wave is vibrations traveling along a taut string "(see image)"; for example, in a musical instrument like a guitar string. Depending on how the string is plucked, the vibrations can be in a vertical direction, horizontal direction, or at any angle perpendicular to the string. In contrast, in longitudinal waves, such as sound waves in a liquid or gas, the displacement of the particles in the oscillation is always in the direction of propagation, so these waves do not exhibit polarization. Transverse waves that exhibit polarization include electromagnetic waves such as light and radio waves, gravitational waves, and transverse sound waves (shear waves) in solids.

偏振(polarization)指的是横波能够朝着不同方向振荡的性质。例如电磁波、引力波都会展示出偏振现象。纵波则不会展示出偏振现象,例如传播于气体或液体的声波,其只会朝着传播方向振荡。如右图所示,紧拉的细线可以展示出线偏振现象与圆偏振现象。