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【Discussion】anyone could tell me the reasons
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28楼2011-02-25 19:33:50
5楼2011-02-25 14:06:04
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poyoro(金币+5): :tuzi3::tuzi3::tuzi3: 2011-02-25 14:30:55
xia_chong(金币+3): I peifu you! :D 2011-02-25 18:01:05
poyoro(金币+5): :tuzi3::tuzi3::tuzi3: 2011-02-25 14:30:55
xia_chong(金币+3): I peifu you! :D 2011-02-25 18:01:05
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植物中含有纤维素、木素和色素。在造纸过程中,将植物茎杆(如稻草)经过碱煮,木素和色素溶于碱液中,被水洗除去,但是难得除干净,纸浆里面仍含有少量的木素和色素。这些木素和色素在 阳光和空气的作用下,逐渐发生了变化,使得纸变 ; 黄变脆。 Plants contain cellulose, lignin and pigment. In the papermaking process, the plant stems (such as straw) after alkaline cooking, and pigments dissolved in alkali lignin, was washed to remove, but a rare addition to clean, which still contains a small amount of pulp lignin and pigment. The lignin and pigment under the action of sunlight and air, and gradually changed, making paper, variable; yellow brittle. ![]() ![]() |
7楼2011-02-25 14:21:20
8楼2011-02-25 14:29:49









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