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Jishi Gorge Outburst Flood
The Jishi Gorge outburst flood was a natural disaster that occurred around 1920 BC in China. The water flow during the eruption was one of the largest fresh water flows to occur in our geologic epoch (Holocene) and caused large widespread flooding around the Yellow River, affecting everyone living in the river basin. The flood outbreak was triggered by the bursting of a dam caused by landslides after an earthquake. The flood is suggested to possibly be the disaster that gave rise to the Great Flood (China), Gun-Yu flood myth, which preceded the establishment of the Xia dynasty. The Lajia archaeological site, downstream of the Jishi Gorge, was first destroyed by the earthquake and later covered by sediments from the flood eruption. The course The Jishi Gorge (球石峡) leads the Yellow River from the river area around Xunhua Salar Autonomous County, Xunhua in the west through the Jishi Mountain and further east to the river area around the Guanting Reservoir, Guanting Basin. An earth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Disaster
A natural disaster is "the negative impact following an actual occurrence of natural hazard in the event that it significantly harms a community". A natural disaster can cause loss of life or damage property, and typically leaves some economic damage in its wake. The severity of the damage depends on the affected population's resilience and on the infrastructure available. Examples of natural hazards include: avalanche, coastal flooding, cold wave, drought, earthquake, hail, heat wave, hurricane (tropical cyclone), ice storm, landslide, lightning, riverine flooding, strong wind, tornado, typhoon, tsunami, volcanic activity, wildfire, winter weather. In modern times, the divide between natural, man-made and man-accelerated disasters is quite difficult to draw. Human choices and activities like architecture, fire, resource management or even climate change potentially play a role in causing "natural disasters". In fact, the term "natural disaster" has been called a misnom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lanzhou
Lanzhou (, ; ) is the capital and largest city of Gansu Province in Northwest China. Located on the banks of the Yellow River, it is a key regional transportation hub, connecting areas further west by rail to the eastern half of the country. Historically, it has been a major link on the Northern Silk Road and it stands to become a major hub on the New Eurasian Land Bridge. The city is also a center for heavy industry and petrochemical industry. Lanzhou is one of the top 70 major cities in the world by scientific research output as tracked by the Nature Index. The city hosts several research institutions, including, Lanzhou University, Lanzhou University of Technology, Northwest Normal University, Lanzhou Jiaotong University, Gansu University of Chinese Medicine, and Gansu Agricultural University. Notably, Lanzhou University is one of China's prestige universities as a member of the Project 985. History Originally in the territory of the ancient Western Qiangs, Lanzhou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Book Of Documents
The ''Book of Documents'' (''Shūjīng'', earlier ''Shu King'') or ''Classic of History'', also known as the ''Shangshu'' (“Venerated Documents”), is one of the Five Classics of ancient Chinese literature. It is a collection of rhetorical prose attributed to figures of ancient China, and served as the foundation of Chinese political philosophy for over 2,000 years. The ''Book of Documents'' was the subject of one of China's oldest literary controversies, between proponents of different versions of the text. A version was preserved from Qin Shi Huang's burning of books and burying of scholars by scholar Fu Sheng, in 29 sections (''pian'' 篇). This group of texts were referred to as "Modern Script" ''jinwen'' 今文, because written with the script in use at the beginning of the Western Han dyansty. According to Western Han dynasty documents, new textual material was discovered in the wall of Confucius' family estate in Qufu by his descendant Kong Anguo in the late 2nd c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, and language. Humans are highly social and tend to live in complex social structures composed of many cooperating and competing groups, from families and kinship networks to political states. Social interactions between humans have established a wide variety of values, social norms, and rituals, which bolster human society. Its intelligence and its desire to understand and influence the environment and to explain and manipulate phenomena have motivated humanity's development of science, philosophy, mythology, religion, and other fields of study. Although some scientists equate the term ''humans'' with all members of the genus ''Homo'', in common usage, it generally refers to ''Homo sapiens'', the only extant member. Anatomically moder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skeleton
A skeleton is the structural frame that supports the body of an animal. There are several types of skeletons, including the exoskeleton, which is the stable outer shell of an organism, the endoskeleton, which forms the support structure inside the body, and the hydroskeleton, a flexible internal skeleton supported by fluid pressure. Vertebrates are animals with a vertebral column, and their skeletons are typically composed of bone and cartilage. Invertebrates are animals that lack a vertebral column. The skeletons of invertebrates vary, including hard exoskeleton shells, plated endoskeletons, or Sponge spicule, spicules. Cartilage is a rigid connective tissue that is found in the skeletal systems of vertebrates and invertebrates. Etymology The term ''skeleton'' comes . ''Sceleton'' is an archaic form of the word. Classification Skeletons can be defined by several attributes. Solid skeletons consist of hard substances, such as bone, cartilage, or cuticle. These can be further ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiocarbon Dating
Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was developed in the late 1940s at the University of Chicago by Willard Libby. It is based on the fact that radiocarbon () is constantly being created in the Earth's atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and thereafter the amount of it contains begins to decrease as the undergoes radioactive decay. Measuring the amount of in a sample from a dead plant or animal, such as a piece of wood or a fragment of bone, provides information that can be used to calc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Qijia Culture
The Qijia culture (2200 BC – 1600 BC) was an early Bronze Age culture distributed around the upper Yellow River region of Gansu (centered in Lanzhou) and eastern Qinghai, China. It is regarded as one of the earliest bronze cultures in China. The Qijia Culture is named after the Qijiaping Site (齐家坪) in Gansu Province. Prior to Qijia culture, in the same area there existed Majiayao culture that was also familiar with metalwork. At the end of the third millennium B.C., Qijia culture succeeded Majiayao culture at sites in three main geographic zones: Eastern Gansu, Middle Gansu, and Western Gansu/Eastern Qinghai. Research Johan Gunnar Andersson discovered the initial site at ''Qijiaping'' () in 1923. Qijia culture was a sedentary culture, based on agriculture, and breeding pigs, which were also used in sacrifices. Qijia culture is distinguished by a presence of numerous domesticated horses, and practice of oracle divination, the metal knives and axes recovered apparently p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mudrock
Mudrocks are a class of fine-grained siliciclastic sedimentary rocks. The varying types of mudrocks include siltstone, claystone, mudstone, slate, and shale. Most of the particles of which the stone is composed are less than and are too small to study readily in the field. At first sight, the rock types appear quite similar; however, there are important differences in composition and nomenclature. There has been a great deal of disagreement involving the classification of mudrocks. A few important hurdles to their classification include the following: # Mudrocks are the least understood and among the most understudied sedimentary rocks to date. # Studying mudrock constituents is difficult due to their diminutive size and susceptibility to weathering on outcrops. # And most importantly, scientists accept more than one classification scheme. Mudrocks make up 50% of the sedimentary rocks in the geologic record and are easily the most widespread deposits on Earth. Fine sedi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenschist
Greenschists are metamorphic rocks that formed under the lowest temperatures and pressures usually produced by regional metamorphism, typically and 2–10 kilobars (). Greenschists commonly have an abundance of green minerals such as chlorite, serpentine, and epidote, and platy minerals such as muscovite and platy serpentine. The platiness gives the rock schistosity (a tendency to split into layers.) Other common minerals include quartz, orthoclase, talc, carbonate minerals and amphibole (actinolite). Greenschist is a general field petrologic term for metamorphic or altered mafic volcanic rock. In Europe, the term ''prasinite'' is sometimes used. A ''greenstone'' is sometimes a greenschist but can also be rock types without any schistosity, especially metabasalt (spilite). However, basalts may remain quite black if primary pyroxene does not revert to chlorite or actinolite. To qualify for the name a rock must also exhibit schistosity or some foliation or layering. The rock i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clastic Rock
Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. A clast is a fragment of geological detritus,Essentials of Geology, 3rd Ed, Stephen Marshak, p. G-3 chunks, and smaller grains of rock broken off other rocks by physical weathering.Essentials of Geology, 3rd Ed, Stephen Marshak, p. G-5 Geologists use the term clastic to refer to sedimentary rocks and particles in sediment transport, whether in suspension or as bed load, and in sediment deposits. Sedimentary clastic rocks Clastic sedimentary rocks are rocks composed predominantly of broken pieces or ''clasts'' of older weathered and eroded rocks. Clastic sediments or sedimentary rocks are classified based on grain size, clast and cementing material (matrix) composition, and texture. The classification factors are often useful in determining a sample's environment of deposition. An example of clastic environment would be a river system in which the full range of grains being transported by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second
The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each (24 × 60 × 60 = 86400). The current and formal definition in the International System of Units ( SI) is more precise:The second ..is defined by taking the fixed numerical value of the caesium frequency, Δ''ν''Cs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be when expressed in the unit Hz, which is equal to s−1. This current definition was adopted in 1967 when it became feasible to define the second based on fundamental properties of nature with caesium clocks. Because the speed of Earth's rotation varies and is slowing ever so slightly, a leap second is added at irregular intervals to civil time to keep clocks in sync with Earth's rotation. Uses Analog clocks and watches often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cubic Metre
The cubic metre (in Commonwealth English and international spelling as used by the International Bureau of Weights and Measures) or cubic meter (in American English) is the unit of volume in the International System of Units (SI). Its symbol is m3. Bureau International de Poids et Mesures.Derived units expressed in terms of base units". 2014. Accessed 7 August 2014. It is the volume of a cube with edges one metre in length. An alternative name, which allowed a different usage with metric prefixes, was the stère, still sometimes used for dry measure (for instance, in reference to wood). Another alternative name, no longer widely used, was the kilolitre. Conversions : A cubic metre of pure water at the temperature of maximum density (3.98 °C) and standard atmospheric pressure (101.325 kPa) has a mass of , or one tonne. At 0 °C, the freezing point of water, a cubic metre of water has slightly less mass, 999.972 kilograms. A cubic metre is sometimes abbreviated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
