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資料更新日期 113-05-31 10:00
5 天前 · Photosynthesis ( / ˌfoʊtəˈsɪnθəsɪs / FOH-tə-SINTH-ə-sis) [1] is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their activities.
22 小時前 · Maxwell's equations, or Maxwell–Heaviside equations, are a set of coupled partial differential equations that, together with the Lorentz force law, form the foundation of classical electromagnetism, classical optics, electric and magnetic circuits. The equations provide a mathematical model for electric, optical, and radio technologies, such ...
22 小時前 · Genghis Khan (born Temüjin; c. 1162 – 25 August 1227), also known as Chinggis Khan,[a] was the founder and first khan of the Mongol Empire, which he ruled from 1206 until his death in 1227; it later became the largest contiguous empire in history. After spending most of his life uniting the Mongol tribes, he launched a series of military ...
22 小時前 · The Mississippi River[b] is the primary river, and second-longest river, of the largest drainage basin in the United States.[c][15][16] From its traditional source of Lake Itasca in northern Minnesota, it flows generally south for 2,340 miles (3,766 km)[16] to the Mississippi River Delta in the Gulf of Mexico. With its many tributaries, the ...
5 天前 · Background Titanic on sea trials, 2 April 1912 At the time of her entry into service on 2 April 1912, the Titanic was the second of three Olympic-class ocean liners, and was the largest ship in the world.She and the earlier RMS Olympic were almost one and a half times the gross register tonnage of Cunard's RMS Lusitania and RMS Mauretania, the previous record holders, and were nearly 100 feet ...
4 天前 · Chlorine is a chemical element; it has symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a yellow-green gas at room temperature.
3 天前 · Sumer (/ ˈ s uː m ər /) is the earliest known civilization, located in the historical region of southern Mesopotamia (now south-central Iraq), emerging during the Chalcolithic and early Bronze Ages between the sixth and fifth millennium BC. Like nearby Elam, it is one of the cradles of civilization, along with Egypt, the Indus Valley, the Erligang culture of the Yellow River valley, Caral ...
