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1.
XDA-1树脂对茶多酚的吸附及吸附柱放大研究   总被引:5,自引:0,他引:5  
研究了XDA-1树脂对茶多酚的吸附及吸附柱放大规律。建立了XDA-1树脂柱吸附茶多酚过程的传质模型,并根据该模型分别计算了不同操作条件下相应的物质总传质系数及传质区长度.结果表明,在实验操作的流速范围内,过程属于外扩散控制.按照操作线速度相等的原则进行固定床设备的放大,传质区长度的放大误差在10%左右,实验所得传质区长度的结果可作为吸附柱设计的基础.  相似文献   

2.
This paper introduced briefly the research results on lichenometry of the Holoceneglacial fluctuations in the headwater of the Urumqi River, in the central TianshanMountains and discussed the histories of the Holocene glaciers and the climate. It isconsidered that lichenometry is one applicable method for dating the mid- and late-Holocene deposits in the cold and mountainous regions. Rhizocarpon geographicum (L.)DCand Xanthoria elegans (Link.) Th. Fr. could be used for dating the deposits of about 4500and 500 a B.P. respectively. There existed at least four periods of glacial advances whichoccurred before about 5700, 4100, 2800 and 403- 74 a B. P. respectively with the firstperiod the longest. Little Ice Age includes three stages of glacial advances which endedbefore about 403, 208 and 74 a B. P. respectively with the second stage the maximum.During the general Holocene warming processes, there existed at least four cold peri-ods which ended before about 5700, 4100, 2800 and 420- 91 a B.P. respectively,  相似文献   

3.
关于Liesegang环形成机理的研究   总被引:1,自引:0,他引:1  
本文研究了Liesegang环的形成,受到两扩散电解质溶液的浓度比、离子浓度积及光照等条件影响。侧重对成环的微观汇聚过程进行了探讨。  相似文献   

4.
硅氮聚合物交联剂交联的室温硫化硅橡胶的热稳定性   总被引:19,自引:0,他引:19  
利用硅氮聚合物作交联剂使双组分缩合型室温硫化硅橡胶在不需要催化剂存在下硫化,通过对硫化胶老化后的热失重、交联密度和力学性能的测定,表明这种硫化胶的耐温性能由200℃提高到350℃.对硫化胶的降解动力学研究表明:降解反应活化能由70KJ/mol提高到330KJ/mol,这是由于消除了端基引发的主链降解.  相似文献   

5.
以甲基紫精(MV2+)作电子受体进行了纳米CdS光生电荷转移的ESR研究。实验表明,纳米CdS悬浮在1.1×10-smol/LMV2+的乙醇溶液中,光照时,MV2+的光还原速率恒定;还原产物MV二聚的速率服从二级反应动力学公式。乙醇溶液中的溶解氧和纳米CdS表面的离子及附氧对MV2+的还原过程有抑制作用。  相似文献   

6.
By comparing the different developmental characteristics of two types of sperm nucleiwhich were from gynogenetic fish (crucian carp) and amphimictic fishes (red carp, redgoldfish and sex--reversal red carp) respectively in the eggs of gynogenetic crucian carp, itwas preliminarily revealed that there existed selective inhibiting actions of the primarycontrol in the eggs of crucian carp for inhibiting the development of the two types of spermnuclei. To homologous sperms, the primary control showed weak effect, thus leading tothe decondensation of homologous sperm nuclei at different degrees in the eggs of cruciancarp. But to heterologous sperms, the primary control showed strong effects, resulting in thetotal inhibition of the development of heterologous sperm nuclei. Moreover, our experimentalresults also showed that the different developmental behavior of the two types of spermnuclei might have a great relationship to the changes or the sex ratio in the population ofgynogenetic crucian carp. The infiltr  相似文献   

7.
The effects of the root system of trees, shrubs and grasses on the hydraulic andphysical properties of soil and their interrelation with increasing soil anti--scouribility byroots are quantitatively demonstrated in this paper for the first time. Based on the analysisof the leading factors of roots to increase the soil anti--scouribility, a mathematical modelon increasing soil anti-scouribility by roots is established. The value in application of themodel is to explain the mechanism of roots to increase the soil anti-scouribility and toevaluate the increasing effects of soil anti-scouribility by roots in different layers of soilThe calculated results of the values in soil anti--scouribility intensified by roots at variousintensities of rainfall and slopes of the model have higher precision, all of the meanmaximum deviations between the estimated and observed values being less than 1.417 s/g.  相似文献   

8.
电缆用无纺布堵水带高吸水树脂的研究   总被引:1,自引:0,他引:1  
电缆用无纺布堵水带高吸水树脂的研究钟安永,陈德本,周宗华,姚文(四川联合大学(东区)化学系成都610064)关键词高吸水树脂,无纺布堵水带,丙烯酸甲酯-醋酸乙烯共聚物塑料绝缘电力电缆、通讯电缆、光纤电缆等在使用中常常因为护套破损而导致水的纵向渗透,使...  相似文献   

9.
用红外光谱法研究了Ni(naph)_2-TIBA·DBMP-BF_3·OEt_2催化丁二烯聚合中催化剂组分之间的反应。发现TIBA与DBMP反应主要产生iBu_2AlOAr,它可延缓Ni(I)的继续被还原,从而提高了活性中心Ni(Ⅰ)的稳定性,使产物分子量大大提高,而凝胶含量降低。还根据DBMP与TIBA、Ni(naph)_2与TIBA·DBMP及BF_3·OEt_2反应产物的分析数据,推测了活性中心的结构。  相似文献   

10.
<正> 二乙烯基苯(DVB)用于树脂的合成时,并非所有的乙烯基都参与交联反应,共聚物中总存在一些悬挂双键。用红外及拉曼光谱对聚合过程中DVB悬挂双键含量变化的动力学研究已有报道。作者用Nicolet 170 SX:付里叶变换红外光谱仪(FT-IR),以积分强度法测定及研究了大孔型丙烯腈-苯乙烯-二乙烯基苯共聚物(大孔AS树脂)中悬  相似文献   

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