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91.
The graft modification of N, N'-methylene-bisacrylamide (NNMBAA) onto silk using eerie ammonium sulfate, potassium persulfate, ammonium persulfate and 2, 2-azobis (isobutyronitrile) as the initiators has been studied in the presence of air. To establish reaction conditions for the graft modification of NNMBAA onto silk, the effect of different variables such as the initiator concentration, monomer concentration, acetic acid concentration, time of polymerization, reaction temperature and liquor ratio (fabric: liq.) have been studied. The optimum grafting conditions were found. As evidence of grafting, analyses of amino acid composition and alkali solubility have been carried out. Grafting caused changes in amino acid composition and alkali solubility of silk. The observation has been explained in relation to structural changes in the grafted silk. 相似文献
92.
时效对微晶Al—Si系合金α—Al相晶格常数的影响 总被引:1,自引:0,他引:1
研究了时效对微晶态Al-Si二元合金和Al-Si-Fe-Cu-Mg多元合金相组成、基体α-Al相晶格常数的影响。结果表明:时效初期合金中第二相质量分数明显增加,时效一定时间后,第二相质量分数不再变化,而α-Al相晶格常数一直增大,直至超过纯铝晶格常数值;两种合金时效100h后,晶格常数趋于一致。 相似文献
93.
文章导出了特解边界元与动力有限元的耦合方程,并使耦合方程的自由度缩减到有限元域及其和边界元域的耦合边界上。这样得到的耦合方程不增加原有限元方程的带宽,易于计算机编程。最后对剪力墙结构与土动力相互作用问题作了数值分析 相似文献
94.
4-tert-butylstyrene-EPDM-divinylbenzene graft terpolym-er (PBED) was prepared by graft cross-polymerization in toluene using BPO as an initiator. The gel-PBED and sol-PBED were isolated from extraction of tetrahydrofuran (THF), and then they were identified by IR spectr-oscopy. The maximum oil-absorptivity of gel-PBED produced from the optimum reaction conditions was 8420% but its swelling rate was very low. The highest oil-absorptivity of photocrosslinked sol-PBED film was 5 800%. Although its oil absorbency was not as high as gel-PBED' s, swelling rate was higher than that of gel-PBED and was suitable for commercial purpose. After swelling in oil, neither gel-PBED nor photocrosslinked sol-PBED film having high oil-absorptivity had sufficient mechanical strength to be taken out of oil wholly. As is known, composite technique is one of the useful methods for reinforcing them. Fibers, sponges and non-woven cloths were used as reinforcers or supporters in this work. Oil-absorptivities and swelling kinetics 相似文献
95.
The epoxidation reaction of propylene and hydrogen peroxide with zeolite catalyst containing titanium-silicalite (TS-1)has been studied, and the reaction in the mixed solvent of water/methanol has been discussed. It is shown that the selective of epoxidation propylene decreases while the selective of propylene glycol increases, when the water content increases in the mixed solvent of me thanol/water. 相似文献
96.
采用单电势跃——计时吸收光谱法(SPS-CA)测量了准可逆体系的电子转移速率常数。首先通过测K3Fe(CN)6—K4Fe(CN)6体系的标准速率常数ks0′,证实了理论公式、实验方法及数据处理的合理性,而后以SnO2-In2O3膜玻璃电极为工作电极,分别测定了亚甲基蓝还原和无色亚甲蓝氧化的电子转移速率常数及该体系的ks0′,结果较为理想。 相似文献
97.
98.
本文区分了晶体点缺陷的定向跳跃率与跳离跳跃率这两个概念,并且由此讨论了点缺陷的运动与复合以及晶体中原子扩散的微观机构,所得理论估算值更接近了实验值。 相似文献
99.
Ramie fibre is harsh and rigid. Ramie yarns have a hairy feel and reduced cohesion. A considerable amount of research has been done to ease the undesirable properties of ramie products through modifying conditions of knitting and finishing according to the special properties of the ramie yarn. From the comparison results, burning the hairiness is shown as one of the effective methods to bnprove the properties of the yarn. A typical finishing condition with enzyme treatment is also recommended. 相似文献
100.
二部图是哈密顿的一个充分条件 总被引:1,自引:1,他引:0
使范氏条件在二部图上得到更具体的刻画,得到以下结果:设G=(X,Y;E)是-连驼的二部图,|X|=|Y|=n≥2,u,v是G中不同两顶点,当d(u,)v=2时,有max(d(u)d(v))〉n/2,则二部图G为哈 ,并说明该结果是最好的可能。 相似文献