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【答案】应助回帖
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zhaohaixing(金币+2): 谢谢参与 2011-10-13 08:53:21
OLED：既可以充当空穴传输材料，又可以充当电子传输材料。Bipolar molecules bearing the suitable electron-rich and -deficient moieties in the molecular structures
化合键理论：Covalent bonds may result from atoms sharing electrons, but the sharing may not be completely equal: atoms with more protons may be able to hold their own and other atoms' borrowed electrons more strongly than their partner atoms can, so that electrons spend more time around the larger atom in a covalent bond. This can create slight charge differences across whole molecules or parts of molecules - areas that electrons spend more time in are slightly more negative, while areas where they spend less time are slightly positive. Molecules with such partial charges are called polar molecules. Water, with a big oxygen toward one side and little hydrogens toward the other, tends to be slightly negative on the oxygen end and slightly positive on the hydrogen end. This makes it bipolar, but not every polar arrangement is so neatly 2-ended. In water, however, this is perhaps the most important feature of the molecule, responsible for much of makes water a unique substance. |
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