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5 天前 · The ocean is the body of salt water that covers approx. 70.8% of Earth.[8] In English, the term ocean also refers to any of the large bodies of water into which the world ocean is conventionally divided.[9] The following names describe five different areas of the ocean: Pacific, Atlantic, Indian, Antarctic/Southern, and Arctic.[10][11] The ...
2 天前 · t. e. The viscosity of a fluid is a measure of its resistance to deformation at a given rate. [1] For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. [2] Viscosity is defined scientifically as a force multiplied by a time divided by an area.
2 天前 · Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the formula N H 3.A stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pungent smell. Biologically, it is a common nitrogenous waste, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to fertilisers.
2 天前 · Dymaxion map of the world with the 30 largest countries and territories by area This is a list of the world's countries and their dependencies by land, water, and total area, ranked by total area.The entries in this list include, but are not limited to, those in the ISO 3166-1 standard, which includes sovereign states and dependent territories.
2 天前 · The koala ( Phascolarctos cinereus ), sometimes called the koala bear, is an arboreal herbivorous marsupial native to Australia. It is the only extant representative of the family Phascolarctidae and its closest living relatives are the wombats. The koala is found in coastal areas of the mainland's eastern and southern regions, inhabiting ...
2 天前 · Mercury is the first planet from the Sun and the smallest in the Solar System. In English, it is named after the ancient Roman god Mercurius (Mercury), god of commerce and communication, and the messenger of the gods. Mercury is classified as a terrestrial planet, with roughly the same surface gravity as Mars. The surface of Mercury is heavily ...
2 天前 · A protein is a polyamide. Secondary structure: regularly repeating local structures stabilized by hydrogen bonds. The most common examples are the α-helix, β-sheet and turns. Because secondary structures are local, many regions of different secondary structure can be present in the same protein molecule.
