| 5 | 1/1 | 返回列表 |
| 查看: 3827 | 回復(fù): 64 | |||
| 當(dāng)前只顯示滿足指定條件的回帖,點(diǎn)擊這里查看本話題的所有回帖 | |||
[交流]
【Discussion】anyone could tell me the reasons
|
|||
» 搶金幣啦!回帖就可以得到:
+1/184
+1/183
+1/182
+2/42
+1/39
+1/38
+1/20
+1/12
+1/11
+1/7
+1/7
+1/6
+1/5
+1/4
+1/4
+1/3
+1/2
+1/2
+1/1
+1/1
銅蟲 (職業(yè)作家)
|
植物中含有纖維素、木素和色素。在造紙過程中,將植物莖桿(如稻草)經(jīng)過堿煮,木素和色素溶于堿液中,被水洗除去,但是難得除干凈,紙漿里面仍含有少量的木素和色素。這些木素和色素在 陽光和空氣的作用下,逐漸發(fā)生了變化,使得紙變 ; 黃變脆。 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. ![]() ![]() |
榮譽(yù)版主 (文壇精英)
木蟲 (職業(yè)作家)
|
It's rare and commendable that you could conserve so many cards for so long a time! I dumped them immediately after their missions. May be I should learn from you, they are really memorable! I suggest you to keep them away from air and light in a container with powerful vaccum effect |
| 最具人氣熱帖推薦 [查看全部] | 作者 | 回/看 | 最后發(fā)表 | |
|---|---|---|---|---|
|
[考研] 一志愿北京化工大學(xué)材料與化工(085600)296求調(diào)劑 +12 | 稻妻小編 2026-03-26 | 12/600 |
|
|---|---|---|---|---|
|
[考研] 數(shù)一英一271專碩(085401)求調(diào)劑,可跨 +7 | 前行必有光 2026-03-28 | 8/400 |
|
|
[考研] 一志愿北化085600材料專碩275|有文章專利|求調(diào)劑 +7 | Micky11223 2026-03-25 | 7/350 |
|
|
[考研] 304求調(diào)劑 +6 | 曼殊2266 2026-03-27 | 6/300 |
|
|
[考研] 266分,求材料冶金能源化工等調(diào)劑 +7 | 哇呼哼呼哼 2026-03-27 | 9/450 |
|
|
[有機(jī)交流]
高溫高壓反應(yīng)求助
10+4
|
chibby 2026-03-25 | 4/200 |
|
|
[考研] 285求調(diào)劑 +4 | AZMK 2026-03-27 | 7/350 |
|
|
[考研] 266分求材料化工冶金礦業(yè)等專業(yè)的調(diào)劑 +4 | 哇呼哼呼哼 2026-03-26 | 4/200 |
|
|
[考研] 348求調(diào)劑 +4 | 小懶蟲不懶了 2026-03-27 | 5/250 |
|
|
[考研] 求調(diào)劑 +6 | 林之夕 2026-03-24 | 6/300 |
|
|
[考研] 材料調(diào)劑 +8 | 匹克i 2026-03-23 | 8/400 |
|
|
[考研] 321求調(diào)劑 +6 | wasdssaa 2026-03-26 | 6/300 |
|
|
[考研] 0703化學(xué)求調(diào)劑 +3 | 丹青奶蓋 2026-03-26 | 5/250 |
|
|
[考研] 材料科學(xué)與工程 317求調(diào)劑 +4 | JKSOIID 2026-03-26 | 4/200 |
|
|
[考研] 上海電力大學(xué)材料防護(hù)與新材料重點(diǎn)實(shí)驗(yàn)室招收調(diào)劑研究生(材料、化學(xué)、電化學(xué),環(huán)境) +4 | 我愛學(xué)電池 2026-03-23 | 4/200 |
|
|
[考研] 求調(diào)劑 +6 | 研研,接電話 2026-03-24 | 7/350 |
|
|
[考研] 一志愿河北工業(yè)大學(xué)0817化工278分求調(diào)劑 +7 | jhybd 2026-03-23 | 12/600 |
|
|
[基金申請] 請教下大家 2026年國家基金申請是雙盲審嗎? +3 | lishucheng1 2026-03-22 | 5/250 |
|
|
[考研] 環(huán)境學(xué)碩288求調(diào)劑 +8 | 皮皮皮123456 2026-03-22 | 8/400 |
|
|
[考研] 269求調(diào)劑 +4 | 我想讀研11 2026-03-23 | 4/200 |
|