Xuandi was the posthumous name (shi) of the eighth emperor (reigned 74–49/48 bc) of the Han dynasty (206 bc–ad 220), who ascended the throne when the designated heir apparent behaved indecorously during mourning ceremonies for his father. The Xuandi emperor strove to abate the harshness and

Huizong: …his time, known as the Xuanhe huapu (“Catalog of Paintings of the Xuanhe Emperor”).

Xuanhua, former city, northwestern Hebei sheng (province), China. In 1963 it was incorporated into Kalgan (Zhangjiakou), becoming a district of that city. Xuanhua district is situated some 25 miles (40 km) southeast of central Kalgan, on the upper course of the Yang River. In former times the

xuanji, Chinese jade form found in the Shang (c. 1600–1046 bc) and Zhou (1046–256 bc) dynasties. It is a flat disk similar in shape to the bi, except that the outer edge is broken into an irregular serration of major and minor projecting teeth, much like a circular saw blade. It has been suggested

Puyi was the last emperor (1908–1911/12) of the Qing (Manchu) dynasty (1644–1911/12) in China and puppet emperor of the Japanese-controlled state of Manchukuo (Chinese: Manzhouguo) from 1934 to 1945. Puyi succeeded to the Manchu throne at the age of three, when his uncle, the Guangxu emperor, died

China: Urbanization and assimilation: …north during the reign of Xuanwang (827–782 bce) does not seem to have been very large in scope; both sides apparently had little ambition for territorial aggrandizement. Cultural exchange in the northern frontier region was far less than the assimilation that occurred in the south along the Yangtze valley, and…

Nanjing: City layout: …the northeast is the extensive Xuanwu (“Mystic Martial”) Lake, containing five islets linked by embankments, and on the other side of the Qinhuai River, to the southwest, is Mochou (“No Sorrow”) Lake; both lake areas are city parks. The skyline suggests spaciousness and grandeur. Blue-glazed tiles adorning the old city…

China: Confucianism and philosophical Daoism: …was known as Xuanxue (“Dark Learning”); it came to reign supreme in cultural circles, especially at Jiankang during the period of division, and represented the more abstract, unworldly, and idealistic tendency in early medieval Chinese thought.

Kangxi was the second emperor (reigned 1661–1722) of the Qing (Manchu) dynasty (1644–1911/12). To the Chinese empire he added areas north of the Amur River (Heilong Jiang) and portions of Outer Mongolia, and he extended control over Tibet. He opened four ports to foreign trade and encouraged the

Huangdi, third of ancient China’s mythological emperors, a culture hero and patron saint of Daoism. Huangdi is reputed to have been born about 2704 bc and to have begun his rule as emperor in 2697. His legendary reign is credited with the introduction of wooden houses, carts, boats, the bow and

Xuanzang was a Buddhist monk and Chinese pilgrim to India who translated the sacred scriptures of Buddhism from Sanskrit into Chinese and founded in China the Buddhist Consciousness Only school. His fame rests mainly on the volume and diversity of his translations of the Buddhist sutras and on the

Xuancheng, city, southeastern Anhui sheng (province), China. It is the natural centre of the basin north of the Huang Mountains and lies on the route from Nanjing (Jiangsu province) and Wuhu south to Shexian and to Jiangxi province. A settlement was founded on the present site in 590. In 592

Xuanzong was the temple name (miaohao) of the seventh emperor of the Tang dynasty (618–907) of China, which during his reign (712–756) achieved its greatest prosperity and power. Li Longji was the third son of the Ruizong emperor, who was himself a son of the empress Wuhou. Li Longji was born

Daoguang was the reign name (nianhao) of the sixth emperor of the Qing dynasty of China, during whose reign (1820–50) attempts to prevent governmental decline met with little success. The monarch ascended the throne in 1820, assuming the reign name Daoguang in 1821. The imperial treasury had been

Xuchang, city, central Henan sheng (province), China. It is situated along the southwestern edge of the North China Plain northeast of the Funiu Range (an eastern extension of the Qin [Tsinling] Mountains). It has since early times been a natural transportation hub—the point where the north-south

China: Foreign affairs under Yangdi: …Dou Jiande in the northeast, Xue Ju in the far northwest, and Li Yuan (who remained nominally loyal but had established a local position of great power) in Shanxi. At the beginning of 617, Li Yuan inflicted a great defeat on the eastern Turks and thus consolidated his local power…

Confucianism: Confucian learning in Jin, Yuan, and Ming: …first outstanding Ming Confucian scholar, Xue Xuan (1389–1464), already revealed the turn toward moral subjectivity. Although Xue was a devoted follower of Zhu Xi, Xue’s Records of Reading clearly shows that he considered the cultivation of “mind and nature” to be particularly important. Two other early Ming scholars, Wu Yubi…

Hunan: Relief: …Guizhou Plateau, whose extension, the Xuefeng Mountains, lies in the heart of the province. These mountains are composed mainly of slate, quartzite, and sandstone, deeply incised by river valleys. The Nan Mountains in the south run from east to west at elevations of between 500 and 3,300 feet (150 and…

Hsin-chu: The Hsüeh-shan (Xueshan) Mountains, with an average elevation of 8,200 feet (2,500 metres), traverse most of the southeastern part of the county and gradually merge with the coastal plains of the northwest. Tea, paddy rice, sweet potatoes, and oranges are grown in Hsin-chu county. Its industries…

China: The era of good government: …the Tang armies defeated the Xueyantou (Syr Tardush), former vassals of the eastern Turks, who became Tang vassals in 646. The Tuyuhun in the region around Koko Nor caused considerable trouble in the early 630s. Taizong invaded their territory in 634 and defeated them, but they remained unsubdued and invaded…

African literature: Zulu: …based on Zulu history are Muntu ’s uSimpofu (1969); L.S. Luthango’s uMohlomi (1938), a biography of Mohlomi, the adviser of the Sotho chief Moshoeshoe; and Imithi ephundliwe (1968; “Barked Trees”), an imaginative work by Moses Hlela and Christopher Nkosi based on the Zulu War. The historical trickster Chakijana, who became…

xun, Chinese vessel flute made of pottery, one of the oldest known Chinese instruments. In its most common form it is egg-shaped with a flattened bottom, and there are five finger holes—three on the front and two (for thumbs) on the back. Its range is about one octave. The player blows across a

Xunzi was a philosopher who was one of the three great Confucian philosophers of the classical period in China. He elaborated and systematized the work undertaken by Confucius and Mencius, giving a cohesiveness, comprehensiveness, and direction to Confucian thought that was all the more compelling

Xunzi was a philosopher who was one of the three great Confucian philosophers of the classical period in China. He elaborated and systematized the work undertaken by Confucius and Mencius, giving a cohesiveness, comprehensiveness, and direction to Confucian thought that was all the more compelling

Xi River system: Land: …and is then called the Xun River. The Yu River rises in southeastern Yunnan province and flows about 400 miles (750 km) eastward in Guangxi to the point at Guiping where it joins the Xian to form the Xun River. The Xun flows for about 120 miles (190 km) in…

Xunzi was a philosopher who was one of the three great Confucian philosophers of the classical period in China. He elaborated and systematized the work undertaken by Confucius and Mencius, giving a cohesiveness, comprehensiveness, and direction to Confucian thought that was all the more compelling

Xunzi: Xunzi’s importance in the development of Confucian philosophy rests on the historical influence of his major work, known today as the Xunzi. This book comprises 32 chapters, or essays, and is regarded as being in large part from his own hand, uncorrupted by later emendations…

Leizhou Peninsula: …on the east coast, and Xuwen, with its port, Hai’an, at the southern tip of the peninsula. In 2000 work was completed on a railway from the north that extends southward from Zhanjiang to Hai’an; from there, railway cars are transported by ferry across the Qiong Strait to Hainan.

Xuzhou, city, northwestern Jiangsu sheng (province), eastern China. It is located in a gap in the southern portion of the Shandong Hills that constitutes a southwestern extension of the North China Plain. Through this gap flows the Feihuang River (in a former riverbed of the Huang He [Yellow

Jiangsu: Drainage: …of the Huai is the Xuzhou-Huai plain, built of the alluvium of the Huai and Huang rivers and standing about 30 to 150 feet (9 to 45 metres) above sea level. In the northern part of the plain are low hills with heights of about 650 feet (200 metres).

Helsinki 1952 Olympic Games, athletic festival held in Helsinki that took place July 19–August 3, 1952. The Helsinki Games were the 12th occurrence of the modern Olympic Games. The 1952 Summer Games were the first Olympics in which the Soviet Union participated (a Russian team had last competed in

Calgary 1988 Olympic Winter Games, athletic festival held in Calgary, Alta., Can., that took place Feb. 13–28, 1988. The Calgary Games were the 15th occurrence of the Winter Olympic Games. The city of Calgary first organized a bidding committee for the Winter Olympics in 1957; 24 years later it was

helicopter: Fixed jet: The Ryan XV-5A Vertifan used a jet engine to drive horizontally mounted fans in the nose and wing; it was nominally successful. Another type of fixed jet used separate batteries of jet engines, some dedicated to vertical flight and some to horizontal flight, but this expensive technology…

Melbourne 1956 Olympic Games, athletic festival held in Melbourne that took place November 22–December 8, 1956. The Melbourne Games were the 13th occurrence of the modern Olympic Games. The 1956 Olympics were the first held in the Southern Hemisphere. Because of the reversal of seasons, the Games

Albertville 1992 Olympic Winter Games, athletic festival held in Albertville, France, that took place February 8–23, 1992. The Albertville Games were the 16th occurrence of the Winter Olympic Games. The 1992 Games are noted for not only a change in the modern Olympics but a change in the world as

Rome 1960 Olympic Games, athletic festival held in Rome that took place August 25–September 11, 1960. The Rome Games were the 14th occurrence of the modern Olympic Games. The 1960 Olympics were the first to be fully covered by television. Taped footage of the Games was flown to New York City at the

Lillehammer 1994 Olympic Winter Games, athletic festival held in Lillehammer, Nor., that took place Feb. 12–27, 1994. The Lillehammer Games were the 17th occurrence of the Winter Olympic Games. After only a two-year interlude, the Olympic Winter Games were held in 1994, when a 1986 amendment to the

Tokyo 1964 Olympic Games, athletic festival held in Tokyo that took place October 10–24, 1964. The Tokyo Games were the 15th occurrence of the modern Olympic Games. The 1964 Olympics introduced improved timing and scoring technologies, including the first use of computers to keep statistics. After

Nagano 1998 Olympic Winter Games, athletic festival held in Nagano, Japan, that took place Feb. 7–22, 1998. The Nagano Games were the 18th occurrence of the Winter Olympic Games. Twenty-six years after the Sapporo Games, the Winter Olympics returned to Japan. The most memorable aspect of the Nagano

Munich 1972 Olympic Games, athletic festival held in Munich that took place August 26–September 11, 1972. The Munich Games were the 17th occurrence of the modern Olympic Games. Tragedy struck the 1972 Olympics in Munich when eight Palestinian terrorists from the militant group Black September

Turin 2006 Olympic Winter Games, athletic festival held in Turin, Italy, that took place Feb. 10–26, 2006. The Turin Games were the 20th occurrence of the Winter Olympic Games. In 2006 the Winter Games returned to Italy after a 50-year absence. Unlike the 1956 Games, which were held in the small

Klinefelter syndrome: Chromosome compositions: …a chromosome variant known as XX syndrome, in which Y chromosome material is transferred to an X chromosome or a nonsex chromosome (autosome). Men with XX syndrome have a male phenotype (physical appearance), but they have changes typical of Klinefelter syndrome.

Mark Ruffalo: …leading parts in the dramas XX/XY (2002) and My Life Without Me (2003). He costarred with Meg Ryan in Jane Campion’s thriller In the Cut (2003) and took the part of a nerdy scientist in the hit movie Eternal Sunshine of the Spotless Mind (2004). Also in 2004 he was…

tuberculosis: Diagnosis and treatment: …researchers reported the emergence of extremely drug-resistant tuberculosis (XXDR-TB), also known as totally drug-resistant tuberculosis (TDR-TB), in a small subset of Iranian patients. This form of the disease, which has also been detected in Italy (in 2003) and India (in 2011), is resistant to all first- and second-line antituberculosis drugs.

Montreal 1976 Olympic Games, athletic festival held in Montreal that took place July 17–August 1, 1976. The Montreal Games were the 18th occurrence of the modern Olympic Games. Despite producing 32 world records and a host of memorable performances, the 1976 Games drew more attention to the

The XXI Olympic Winter Games opened in Vancouver, British Columbia, Canada, on February 12 and closed on February 28, 2010. To celebrate the Games, Britannica is pleased to offer a broad selection of information on Vancouver and the Olympics, including a video highlighting the city’s history and

Christopher Brennan: In 1897 XXI Poems: Towards the Source was published in an edition of only 200 copies. Poems (1914) was followed by A Chant of Doom (1915).

Moscow 1980 Olympic Games, athletic festival held in Moscow that took place July 19–August 3, 1980. The Moscow Games were the 19th occurrence of the modern Olympic Games. The Soviet Union’s invasion of Afghanistan in December 1979 led to the largest boycott in the history of the Olympic movement.

Los Angeles 1984 Olympic Games, athletic festival held in Los Angeles that took place July 28–August 12, 1984. The Los Angeles Games were the 20th occurrence of the modern Olympic Games. Many communist countries—including the Soviet Union, East Germany, and Cuba—retaliated for the U.S.-led boycott

Seoul 1988 Olympic Games, athletic festival held in Seoul that took place September 17–October 2, 1988. The Seoul Games were the 21st occurrence of the modern Olympic Games. After boycotts had marred the previous two Olympiads, political problems threatened to return to center stage at the 1988

international trade: Regional arrangements and WTO rules: GATT article XXIV allowed countries to grant special treatment to one another by establishing a customs union or free-trade association, provided that (1) duties and other trade restrictions would be “eliminated on substantially all the trade” among the participants, (2) the elimination of internal barriers occurred…

Beijing 2008 Olympic Games, athletic festival held in Beijing that took place August 8–24, 2008. The Beijing Games were the 26th occurrence of the modern Olympic Games. Some 200 Olympic committees sent almost 11,000 athletes to compete in 28 sports. The Games were auspiciously scheduled to begin at

Barcelona 1992 Olympic Games, athletic festival held in Barcelona that took place July 25–August 9, 1992. The Barcelona Games were the 22nd occurrence of the modern Olympic Games. The 1992 Games were perhaps the most-successful modern Olympics. More than 9,300 athletes representing 169 countries

Atlanta 1996 Olympic Games, athletic festival held in Atlanta that took place July 19–August 4, 1996. The Atlanta Games were the 23rd occurrence of the modern Olympic Games. Selected over Athens to host the Centennial Summer Games, Atlanta staged one of the most extravagant Games in Olympic

Sydney 2000 Olympic Games, athletic festival held in Sydney that took place September 15–October 1, 2000. The Sydney Games were the 24th occurrence of the modern Olympic Games. Sydney was narrowly chosen over Beijing as host city of the 2000 Olympics. The International Olympic Committee (IOC) was

Athens 2004 Olympic Games, athletic festival held in Athens that took place August 13–29, 2004. The Athens Games were the 25th occurrence of the modern Olympic Games. The 2004 Olympic Games returned to Greece, birthplace of the ancient Games and site of the inaugural modern Olympics. The excitement

Vin Diesel: …followed with another action movie, xXx (2002), playing extreme athlete turned secret agent Xander Cage, and the crime drama A Man Apart (2003). He turned to more humorous fare with The Pacifier (2005) and Sidney Lumet’s mob comedy Find Me Guilty (2006).

ZZ Top: …commanded a substantial audience, and XXX (1999), which commemorated 30 years of playing together, was a reminder of the group’s longevity. The trio remained a popular live act, notably performing at the inauguration of U.S. Pres. George W. Bush in 2001 and releasing the live album and DVD Live from…

London 2012 Olympic Games, athletic festival held in London that took place July 27–August 12, 2012. The London Games were the 27th occurrence of the modern Olympic Games. In 2012 London became the first city to host the modern Summer Games three times, having previously been the site of the 1908

Vin Diesel: …rejoined the xXx series in xXx: Return of Xander Cage (2017) after passing on the 2005 sequel. He took a break from franchise movies with the sci-fi feature Bloodshot (2020).

carbohydrate: Homopolysaccharides: Xylans are almost as ubiquitous as cellulose in plant cell walls and contain predominantly β-d-xylose units linked as in cellulose. Some xylans contain other sugars, such as l-arabinose, but they form branches and are not part of the main chain. Xylans are of little commercial…

Ascomycota: Xylaria contains about 100 species of cosmopolitan fungi. X. polymorpha produces a club-shaped or fingerlike fruiting body (stroma) resembling burned wood and common on decaying wood or injured trees.

Ascomycota: X. polymorpha produces a club-shaped or fingerlike fruiting body (stroma) resembling burned wood and common on decaying wood or injured trees.

fungus: Annotated classification: Order Xylariales Saprotrophic; inoperculate asci; some with white conidia; included in subclass Xylariomycetidae; examples of genera include Xylaria, Hypoxylon, Anthostomella, Diatrype, and Graphostroma. Order Lulworthiales (incertae sedis; not placed in any subclass) Saprotrophic; ascomata subglobose to

xylazine, drug used in veterinary medicine to sedate, relieve pain, and induce muscle relaxation in animals. Xylazine was discovered in 1962 by researchers at the German pharmaceutical company Farbenfabriken Bayer AG (now Bayer AG). The drug was initially investigated for its antihypertensive

plant disease: General characteristics: >Xylella. With the exception of Streptomyces species, all are small, single, rod-shaped cells approximately 0.5 to 1.0 micrometre (0.00002 to 0.00004 inch) in width and 1.0 to 3.5 micrometres in length. Streptomycetes develop branched mycelia (narrow, threadlike growth) with curled chains of conidia (spores) on…

xylem, plant vascular tissue that conveys water and dissolved minerals from the roots to the rest of the plant and also provides physical support. Xylem tissue consists of a variety of specialized, water-conducting cells known as tracheary elements. Together with phloem (tissue that conducts sugars

xylene, any of three isomeric dimethylbenzenes [which have the same chemical formula, C6H4(CH3)2, but different molecular structure], used as solvents, as components of aviation fuel, and as raw materials for the manufacture of dyes, fibres, and films. The three isomers, designated ortho (o), meta

pentosuria: …urinary excretion of the sugar xylitol. It is caused by a defect in the enzyme xylitol dehydrogenase, by which xylitol is normally metabolized. No disabilities are incurred, and no dietary or other measures are necessary. Reducing properties of the urine of affected individuals may lead to confusion with, and unnecessary…

carpenter bee: The large carpenter bee, Xylocopa, somewhat resembles the bumblebee but differs in having a nonhairy abdomen and in its habit of nesting in a tunnel excavated within solid wood. Xylocopa are often considered pests because of their tunneling in structural wood such as that of buildings and fences.

carpenter bee, (subfamily Xylocopinae), any of a group of small bees in the family Anthophoridae (order Hymenoptera) that are found in most areas of the world. The small carpenter bee, Ceratina, is about six mm (0.2 inch) long and of metallic coloration. It nests in plant stems, which the female

printing: Xylography: Xylography, the art of printing from wood carving, the existence and importance of which in China was never suspected by Marco Polo, appeared in Europe no earlier than the last quarter of the 14th century, spontaneously and presumably as a result of the use…

nitrocellulose: Composition, properties, and manufacture of nitrocellulose: …various names such as pyroxylin, xyloidin, and collodion cotton, is employed as a film-forming agent in solvent-based paints, protective coatings, and fingernail polishes.

dendrology, study of the characteristics of trees, shrubs, lianas, and other woody plants. Dendrology is generally considered to be a branch of systematic botany or forestry and is primarily concerned with the taxonomy of woody species. Historically, dendrology also encompassed the natural history

celluloid: …plastic material that he called Parkesine. Parkesine plastics were made by dissolving nitrocellulose (a flammable nitric ester of cotton or wood cellulose) in solvents such as alcohol or wood naphtha and mixing in plasticizers such as vegetable oil or camphor (a waxy substance originally derived from the oils of the…

hermit crab: …Ocean, lives in bamboo sections; Xylopargus, found in West Indian waters at depths of 180 to 360 metres (600 to 1,200 feet), lives in hollow cylinders of wood. Other species make homes in coral, sponge, or the empty tubes formed by polychaete tubeworms.

shipworm: …genera are Bankia, Xylotrya, and Xylophaga. Teredo norvegica, of the coasts of Europe, has a tube about 30 cm (1 foot) long. The common shipworm, T. navalis (20 to 45 cm [8 to 18 inches] long), has a worldwide distribution but is especially destructive on the Baltic Sea coast.

xylophone, percussion instrument consisting of a set of graduated, tuned wooden bars supported at nodal (nonvibrating) points and struck with sticks or padded mallets. The xylophone possibly originated in Southeast Asia or Oceania and today exists in forms as simple as two or three logs laid across

Magnoliales: Timber: The wood of Xylopia aethiopica is quite flexible and has some local use in west-central Africa for masts, boat paddles, and rudders. It has been described as termite-proof and, accordingly, is used for house posts and beams. The dried black fruits of this species are called guinea peppers…

marimba: …large marimbas are known as xylorimbas.

rhinoceros beetle: The American rhinoceros beetle (Xyloryctes jamaicensis) is a dark brown scarab a little more than 25 mm (1 inch) long. The male possesses a single upright horn; the female has only a small tubercle. One European species, Oryctes nasicornis, has rear-pointing horns. The eastern Hercules beetle…

coleopteran: Size range and diversity of structure: , rhinoceros beetle, Xyloryctes satyrus) and up to 75 mm (2.95 inches) in width (e.g., goliath beetle, Goliathus goliathus).

carbohydrate: Configuration: Thus, although d-xylose and d-lyxose both have five carbon atoms and are of the d-configuration, the spatial arrangement of the asymmetrical centres (at carbon atoms 2, 3, and 4) is such that they are not mirror images.

malabsorption test: The d-xylose absorption test measures the absorption ability of the jejunum. Lowered excretion indicates diminished intestinal absorption usually caused by a decreased absorptive surface, infiltrative intestinal disease, or bacterial overgrowth.

Poales: Eriocaulaceae and Xyridaceae: Eriocaulaceae and Xyridaceae are generally tufted herbs with rosettes of leaves and flowers clustered into capitate inflorescences. Eriocaulaceae, or the pipewort family, contains 10 genera of small tufted herbs with grasslike leaves that grow in aquatic and marshy habitats, mostly in tropical and subtropical…

St. Sixtus I ; feast day April 3) was the pope from approximately 115 to about 125. He succeeded St. Alexander I and ruled the church under the Roman emperor Hadrian. Although authoritative sources vary on the dates of his pontificate, they all agree that he reigned for 9 or 10 years. Sixtus’s

St. Sixtus II ; feast day August 7) was the pope from 257 to 258, and is one of the early Roman church’s most venerated martyrs. He was elected in August 257 to succeed St. Stephen I, during whose pontificate there arose a conflict with certain Eastern churches over the rebaptism of converted

Saint Sixtus III ; feast day March 28) was the pope from 432 to 440. A chief Roman priest when he succeeded Pope St. Celestine I on July 31, 432, Sixtus had previously been suspected of favouring Pelagianism (heretical doctrine that minimized the role of divine grace in man’s salvation), but on

Saint Sixtus III ; feast day March 28) was the pope from 432 to 440. A chief Roman priest when he succeeded Pope St. Celestine I on July 31, 432, Sixtus had previously been suspected of favouring Pelagianism (heretical doctrine that minimized the role of divine grace in man’s salvation), but on

XYY-trisomy, relatively common human sex chromosome anomaly in which a male has two Y chromosomes rather than one. It occurs in 1 in 500–1,000 live male births, and individuals with the anomaly are often characterized by tallness and severe acne and sometimes by skeletal malformations and mental

XYZ Affair, diplomatic incident that, when made public in 1798, nearly involved the United States and France in war. Pres. John Adams dispatched three ministers to France in 1797 to negotiate a commercial agreement to protect U.S. shipping. In Paris the ministers were approached by three French