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Helium
Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling and melting point are the lowest among all the elements. It is the second lightest and second most abundant element in the observable universe (hydrogen is the lightest and most abundant). It is present at about 24% of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined. Its abundance is similar to this in both the Sun and in Jupiter, due to the very high nuclear binding energy (per nucleon) of helium-4, with respect to the next three elements after helium. This helium-4 binding energy also accounts for why it is a product of both nuclear fusion and radioactive decay. The most common isotope of helium in the universe is helium-4, the vast majority of which was formed during t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zheng He
Zheng He (; 1371–1433 or 1435) was a Chinese mariner, explorer, diplomat, fleet admiral, and court eunuch during China's early Ming dynasty. He was originally born as Ma He in a Muslim family and later adopted the surname Zheng conferred by the Yongle Emperor. Commissioned by the Yongle Emperor and later the Xuande Emperor, Zheng commanded seven expeditionary treasure voyages to Southeast Asia, South Asia, West Asia, and East Africa from 1405 to 1433. According to legend, his larger ships carried hundreds of sailors on four decks and were almost twice as long as any wooden ship ever recorded. As a favorite of the Yongle Emperor, whom Zheng assisted in the overthrow of the Jianwen Emperor, he rose to the top of the imperial hierarchy and served as commander of the southern capital Nanjing. Early life and family Zheng He was born Ma He () to a Muslim family of Kunyang, Kunming, Yunnan, during the Ming dynasty of China. He had an older brother and four sisters. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hebrew Language
Hebrew (; ; ) is a Northwest Semitic language of the Afroasiatic language family. Historically, it is one of the spoken languages of the Israelites and their longest-surviving descendants, the Jews and Samaritans. It was largely preserved throughout history as the main liturgical language of Judaism (since the Second Temple period) and Samaritanism. Hebrew is the only Canaanite language still spoken today, and serves as the only truly successful example of a dead language that has been revived. It is also one of only two Northwest Semitic languages still in use, with the other being Aramaic. The earliest examples of written Paleo-Hebrew date back to the 10th century BCE. Nearly all of the Hebrew Bible is written in Biblical Hebrew, with much of its present form in the dialect that scholars believe flourished around the 6th century BCE, during the time of the Babylonian captivity. For this reason, Hebrew has been referred to by Jews as '' Lashon Hakodesh'' (, ) since a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hesse
Hesse (, , ) or Hessia (, ; german: Hessen ), officially the State of Hessen (german: links=no, Land Hessen), is a state in Germany. Its capital city is Wiesbaden, and the largest urban area is Frankfurt. Two other major historic cities are Darmstadt and Kassel. With an area of 21,114.73 square kilometers and a population of just over six million, it ranks seventh and fifth, respectively, among the sixteen German states. Frankfurt Rhine-Main, Germany's second-largest metropolitan area (after Rhine-Ruhr), is mainly located in Hesse. As a cultural region, Hesse also includes the area known as Rhenish Hesse (Rheinhessen) in the neighbouring state of Rhineland-Palatinate. Name The German name ''Hessen'', like the names of other German regions (''Schwaben'' "Swabia", ''Franken'' "Franconia", ''Bayern'' "Bavaria", ''Sachsen'' "Saxony"), derives from the dative plural form of the name of the inhabitants or eponymous tribe, the Hessians (''Hessen'', singular ''Hesse''). The geograp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
He River
The Yellow River or Huang He (Chinese: , Standard Beijing Mandarin, Mandarin: ''Huáng hé'' ) is the second-longest river in China, after the Yangtze River, and the List of rivers by length, sixth-longest river system in the world at the estimated length of . Originating in the Bayan Har Mountains in Qinghai province of Western China, it flows through nine provinces, and it empties into the Bohai Sea near the city of Dongying in Shandong province. The Yellow River basin has an east–west extent of about and a north–south extent of about . Its total drainage area is about . The Yellow River's basin was the Yellow River civilization, birthplace of ancient Chinese, and, by extension, Far East, Far Eastern civilization, and it was the most prosperous region in early Chinese history. There are frequent devastating natural disasters in China, floods and course changes produced by the continual elevation of the river bed, sometimes above the level of its surrounding farm fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An explosive charge is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances. The potential energy stored in an explosive material may, for example, be * chemical energy, such as nitroglycerin or grain dust * pressurized gas, such as a gas cylinder, aerosol can, or BLEVE * nuclear energy, such as in the fissile isotopes uranium-235 and plutonium-239 Explosive materials may be categorized by the speed at which they expand. Materials that detonate (the front of the chemical reaction moves faster through the material than the speed of sound) are said to be "high explosives" and materials that deflagrate are said to be "low explosives". Expl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hebei
Hebei or , (; alternately Hopeh) is a northern province of China. Hebei is China's sixth most populous province, with over 75 million people. Shijiazhuang is the capital city. The province is 96% Han Chinese, 3% Manchu, 0.8% Hui, and 0.3% Mongol. Three Mandarin dialects are spoken: Jilu Mandarin, Beijing Mandarin and Jin. Hebei borders the provinces of Shanxi to the west, Henan to the south, Shandong to the southeast, Liaoning to the northeast, and the Inner Mongolia Autonomous Region to the north. Its economy is based on agriculture and manufacturing. The province is China's premier steel producer, although the steel industry creates serious air pollution. Five UNESCO World Heritage Sites can be found in the province, the: Great Wall of China, Chengde Mountain Resort, Grand Canal, Eastern Qing tombs, and Western Qing tombs. It is also home to five National Famous Historical and Cultural Cities: Handan, Baoding, Chengde, Zhengding and Shanhaiguan. Historically, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Excellency
Excellency is an honorific style given to certain high-level officers of a sovereign state, officials of an international organization, or members of an aristocracy. Once entitled to the title "Excellency", the holder usually retains the right to that courtesy throughout their lifetime, although in some cases the title is attached to a particular office, and is held only for the duration of that office. Generally people addressed as ''Excellency'' are heads of state, heads of government, governors, ambassadors, Roman Catholic bishops and high-ranking ecclesiastics and others holding equivalent rank (e.g., heads of international organizations). Members of royal families generally have distinct addresses ( Majesty, Highness, etc.) It is sometimes misinterpreted as a title of office in itself, but in fact is an honorific that precedes various titles (such as Mr. President, and so on), both in speech and in writing. In reference to such an official, it takes the form ''His'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-explosive Anti-tank
High-explosive anti-tank (HEAT) is the effect of a shaped charge explosive that uses the Munroe effect to penetrate heavy armor. The warhead functions by having an explosive charge collapse a metal liner inside the warhead into a high-velocity explosively formed penetrator (EFP) jet; this is capable of penetrating armor steel to a depth of seven or more times the diameter of the charge (charge diameters, CD). The EFPs jet effect is purely kinetic in nature; the round has no explosive or incendiary effect on the target. Because they rely on the kinetic energy of the EFP jet for their penetration performance, HEAT warheads do not have to be delivered with high velocity, as an armor-piercing round does. Thus they generate less recoil. The performance of HEAT weapons has nothing to do with thermal effects, with HEAT being simply an acronym. History HEAT warheads were developed during World War II, from extensive research and development into shaped charge warheads. Shaped c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemagglutinin Esterase
Hemagglutinin esterase (HEs) is a glycoprotein that certain enveloped viruses possess and use as an invading mechanism. HEs helps in the attachment and destruction of certain sialic acid receptors that are found on the host cell surface. Viruses that possess HEs include '' influenza C virus'', toroviruses, and coronaviruses of the subgenus ''Embecovirus'' (which does not include SARS-like coronaviruses). HEs is a dimer transmembrane protein consisting of two monomers, each monomer is made of three domains. The three domains are: membrane fusion, esterase, and receptor binding domains. The different HEs enzyme activities include: receptor binding activity, receptor hydrolysis (esterase) activity, and membrane fusion activity. The receptor binding activity involve the attachment of HEs to N-acetyl-9-O-acetylneuraminic acid (9-O-Ac- Neu5Ac) of glycolipids and glycoproteins and in turn serve as viral receptor. Receptor hydrolysis (esterase) activity allows virus part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holocene
The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1. It is considered by some to be an interglacial period within the Pleistocene Epoch, called the Flandrian interglacial.Oxford University Press – Why Geography Matters: More Than Ever (book) – "Holocene Humanity" section https://books.google.com/books?id=7P0_sWIcBNsC The Holocene corresponds with the rapid proliferation, growth and impacts of the human species worldwide, including all of its written history, technological revolutions, development of major civilizations, and overall significant transition towards urban living in the present. The human impact on modern-era Earth and its ecosystems may be considered of global ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatic Encephalopathy
Hepatic encephalopathy (HE) is an altered level of consciousness as a result of liver failure. Its onset may be gradual or sudden. Other symptoms may include movement problems, changes in mood, or changes in personality. In the advanced stages it can result in a coma. Hepatic encephalopathy can occur in those with acute or chronic liver disease. Episodes can be triggered by infections, GI bleeding, constipation, electrolyte problems, or certain medications. The underlying mechanism is believed to involve the buildup of ammonia in the blood, a substance that is normally removed by the liver. The diagnosis is typically based on symptoms after ruling out other potential causes. It may be supported by blood ammonia levels, an electroencephalogram, or a CT scan of the brain. Hepatic encephalopathy is possibly reversible with treatment. This typically involves supportive care and addressing the triggers of the event. Lactulose is frequently used to decrease ammonia levels. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
