木质纤维素

In this dissertation, key technologies in ethanol production from lignocellulosic biomass including pretreatment, enzymatic hydrolysis of cellulose and hemicellulose, ethanol fermentation from hexose and pentose, and comprehensive utilization of lignocellulosic feedstock were investigated.

本文对木质纤维原料的预处理、纤维素和半纤维素的水解糖化、利用己糖、戊糖发酵乙醇、以及木质纤维原料的综合利用等关键技术进行了系统研究。

The degree of lignification varies from slight in protoxylem to heavy in sclerenchyma and some xylem vessels, but values of 25-30% lignin and 50% cellulose are average.

不同部位的木质化的程度不同，原生木质部中只有轻微的加厚，而在厚壁组织和一些木质部导管中则进一步加厚，平均含25％-30％的木质素和50％的纤维素。

The changes in PAL and PO activity and in cellulose and lignin contents were studied. The results indicated that the activities in PAL and PO and contents in cellulose and lignin increased by a big margin, and the course of lignification was moved forward from shoot base to top.

结果表明：PAL和PO活性以及纤维素和木质素的含量从基部向顶部逐渐降低，呈梯形分布，木质化进程是从基部向顶部推进的；竹笋离体后，PAL和PO活性大幅度增高，纤维素和木质素含量大量增加加速了老化进程。

The rate of sugar was below 20% in lignocellulose enzymatic hydrolysis directly and the sugars were mainly from hemicellulose.

从木质纤维原料预处理对微生物转化的必要性和回收利用半纤维素、木质素意义两个方面分析了木质纤维原料组分分离的必要性。

Cellulose constitutes the cell-walls of vegetable life; in very young vegetables it is possible that it can be acted upon by the digestive ferments; in older vegetables it becomes woody and completely indigestible.

纤维素构成植物生命的细胞壁，在非常幼小的植物中，消化酶对纤维素起作用是可能的，但在生大后的植物中纤维素变成木质完全不可消化。

This webpage systematically introduced Tibet's macro fungi of 45 families, 175 genera and 588 species, including 415 species of edible fugi, 135 kinds of poisonous fungi, 238 species of medicinal fungi, 168 kinds of fungi which proved to boast anti-cancer medical effect, 188 species of ectotrophic mycorrhiza, and 123 species which make trees and wood decomposed and ill.

该书收集了西藏地区的大型经济真菌45科、175属、588种。本书记述的食用菌415种，毒菌135种，药用真菌238种，其中有抗癌作用或试验抑制肿瘤的168种。树木的外生菌根菌188种。能分解纤维素、木质素并引起树木木质腐烂或树木病害的123种。

Therefore, we deduce that the formation of parchment is originated from morphological changes of cells adjacent to endodermal and it not only closely relate to cell lignificantion, but aslo consiste of sclerenchym cells which had higher contents of cellulose and hemicellulose.

因此，可以推断在内果皮细胞发育分化形成的革质膜不仅是细胞的木质化，而且是由含有大量纤维素和半纤维素并高度木质化的厚壁细胞构成。

Bamboo first crystallizes then lignifies during bamboo shoot growth and basically forms crystal structure in one month. 1-year-old bamboo culm ends growth and its height,thickness, volume almost change little, but culm tissue is small and tender and there is more water and less substance in it. Bamboo crystal proportion keeps invariable during this period.2-year-old bamboo culm begin to lignify,its cellulose proportion debases and its crystal proportion decreases. Bamboo lignin debases, crystal proportion changes a little in the end of this period.Many-old-year bamboo culm crystal proportion is almost invariable. Freaky bamboo cell wall crystal region's thickness is less than normal bamboo's. Bamboo cross section crystal area and the ratio of long axis to short axis are less than normal bamboo's,and roundness,irregular index, the fiber cap density per unit area increase more than normal bamboo's.

竹笋生长阶段是先结晶后木素化的过程，一个月内细胞壁结晶组织基本形成；2）一年生竹材的植株秆茎生长结束，秆茎的高度、粗度和体积变化不大，但秆茎的组织幼嫩，含水量高，干物质少，竹材结晶度基本不变；3）二年生竹材的植株开始木质化，纤维素比例降低，结晶度减少，到后期竹子木质化降低，竹材结晶度变化不大；4）多年生竹材的结晶度没有太大的变化，结晶度大小处于波动状态；5）畸形竹材纤维帽细胞壁结晶区的厚度比正常竹小，其横截面结晶区的面积、纤维帽长轴与短轴比有所减少，而圆形度、异型指数有所加大，单位面积纤维帽的密度增大。

Aging mechanism of wood-plastic composite was: light and heat break down the long molecular chains of wood flour and plastic; the free radicals reacted with the oxygen, which generated carbonyl groups, hydroperoxides and so on; the free radicals also had cross linking reaction, which generated alkoxy; Water destroyed the interface of wood flour and plastic, hydrolyzed ester additives, extracted the small molecule additives and degradation products; Microorganism degraded cellulose, semicellulose, lignin and ester additives; degradation product from different component accelerated the aging, which could be exampled by the fact that HCl from degradation of PVC accelerated the hydrolyzation of cellulose and semicellulose.

木塑复合材料的老化机理为：光和热引发木塑复合材料中木质组分和塑料组分大分子链断裂，产生的自由基与氧气作用，发生链支化反应生成羰基、氢过氧化物等，发生交联反应生成烷氧基等；水分破坏木-塑界面、水解酯类添加剂、抽提小分子添加剂和降解产物；微生物分解纤维素、半纤维素、木素和酯类添加剂；木塑复合材料中各组分的降解产物相互促进老化，PVC降解产生的HCl溶于水，促进了纤维素和半纤维素的水解。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。