kuò sàn Verbs. Expanding spread out: ~ influence; toxins have ~ to the body. Diffusion can be classified in many different types of diffusion, which requires substantially different and status. Some diffusion requires media, while others require energy. Hence the proliferation of different types can not be generalized.
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Biology nouns
Diffusion (dispersal), individual organisms or spread body (such as spores, seeds) spread to other areas of the process. Also known as the spread. Various organisms can be expanded through different habitat extent and distribution of diffusion regions; proliferation also promote biomes succession, increasing the diversity of species; diffusion combined with a wide range of geographic isolation is an important condition for species differentiation; new environment means different mechanism of natural _select_ion can change gene frequencies populations is therefore an important factor in promoting the proliferation of biological evolution. Bio-proliferation including active (self) and passive (by force) categories. Lack of ability to act mostly by microorganisms and plants passive diffusion, active animal is a multi-line diffusion. Many insects have great dispersal ability, some species also exhibit polymorphism, one of the franchise diffusion, winged or with other pro-proliferation structure. Some of the genetic polymorphism, such as the gray line with pomonella two different genotypes, an easily understood larvae of intolerance intensive proliferation, and the other not; the two alternatives are not mutually co-exist, but the quantity proportion with the population density and change. Mainly relies on passive diffusion flow (wind), water, or other organisms to carry. Microorganisms and tiny spores, seeds easily transmitted by the wind, armyworms may vary migratory flocks in March and April in the southern Chinese prevalent southwesterly flow, diffusion from the Huaihe River Valley in southern provinces. Water diffusion through terrestrial organisms must be able to float in the water, can not easily be soaked in water, and to keep the internal osmotic balance. For example, a surface layer of coconut fiber developed, long-term drift in the water. Animals such as the malaria parasite spread when mosquitoes different host individuals taking blood falciparum infection along with a new host. Some seeds are diffused by animal feeding. Human factors are also important biological proliferation, such as major pests of cotton pink bollworm Indian origin, was introduced to China in the 1930s in coastal areas, except now all cotton in Xinjiang throughout China. Diffusion (disffusion) is the plasma membrane of nutrients through the hole, material transport from the high non-specific extracellular concentrations (within) into the environment of low extracellular concentrations (outer) carried.
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Chemical terms
Diffusion (diffusion): molecular material is transferred from the low-concentration region of high concentration area, the phenomenon until evenly distributed. Concentration diffusion rate is proportional to the gradient of the substance. Since the molecule (atom) of the heat generated by the movement of the material transport phenomena. Generally occur in one or several substances in the same physical state or between different states of matter, or the concentration difference caused by the temperature difference between different regions of the former mostly. Generally from the region of higher concentration to a lower diffusion region, in the same physical state until the concentration of each of various parts of the material reaches a uniform or between two states of the concentration of substances to reach equilibrium. Obviously, due to thermal motion of molecules, this "uniform", "balance" are "dynamic equilibrium", i.e., at the same time, the number of particles on both sides of the interface is equal to the exchange, such as red-brown nitrogen dioxide gas in still air the spread blue solution of copper sulfate and water into each other stationary carburizing steel parts and the surface of the semiconductor material that becomes embodied pure N-type or P-type semiconductor dopant diffusion process, etc. are phenomena; in Electrical formation of the semiconductor PN junction, the diffusion motion of free electrons and holes is the basis. The maximum diffusion rate, followed by the liquid, the solid in the minimum gas, and the density difference, the higher the temperature, the smaller the particle mass involved, the greater the rate of diffusion.
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Physics terms
Refers to a molecule of a substance dispersed in another substance in the molecule, is uniformly distributed
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Encyclopedia
kuosan Spread diffusion Also known as the "spread." Refers to the local lesions and normal tissue invasion process, such as cancer, can continue to grow not only in the primary site and spread, but can also spread to various parts of the body through a variety of ways, with the primary tumor to form the same type of tumor.