聚乙二醇存在下钯催化氯代芳烃氢转移脱氯的研究

研究了以甲酸钠为氢源，聚乙烯吡咯烷酮锚定的ＰｄＣｌ２（ＰＶＰ－ＰｄＣｌ２）催化氯代芳烃脱氯．结果表明：ＰＶＰ－ＰｄＣｌ２是使氯代芳烃有效脱氯的催化剂，加入聚乙二醇可明显提高脱氯效果．该方法催化剂用量少，反应条件温和，操作简便     

聚乙二醇相转移催化法制备氯代烷

本文报道以聚乙二醇为催化剂,采用固液相转移催化法合成氯代烷,结果较好.     

Catalytic conversion of alcohol to corresponding alkyl chlorides

1-chloro-octane, 1-chloro-dedocane and 1-chloro-hexadecane are synthesized from the corresponding alcohols. The reactions are catalyzed by N, N-dimethyl formamide and dodecyltrimethyl animonium chloride, not only the reaction time has been reduced, but also the yield improved from 10%∼20%.     

邻取代苯基氯化汞质子分解反应的量子化学研究

本文优化了汞的CND0/2参数井用CND0/2和EHM0法研究了邻取代苯基氯化汞o-XC_3H_4HgCl(×=CH_3,H,Cl,Br,COOC_2H_5,NO_2)的质子分解反应。提出了分步反应历程,计算了反应的活化能,计算值变化趋势与实验观测值相符合,即反应速度顺序为:CH_2>H>Cl>Br～COOC_2H_5>NO_2。     

氯化铝电解时铝的析出反应速度的测定

提要在975K和氧化铝浓度为(2—8)×10~(-5)mol·cm~(-3)的条件下,应用计时库仑法、计时电流法和电位扫描法测定了铝从AlCl_3-NaCl-KCl熔体中电解析出的反应速度.测定结果表明铝的析出为快速反应.     

氢氧化铯催化下三甲硅基乙炔与二芳基二硒醚反应研究

氢氧化铯催化下,以THF作溶剂,在低温(-20℃)、空气中,三甲硅基乙炔与二芳基二硒醚反应20 h,给出摩尔比为70∶30的二苯硒基乙炔和三苯硒基乙烯的混合物,产率为96%;而在室温进行,反应速度大大加快,仅需1 h,得到摩尔比为5∶55∶45的二苯硒基乙炔、三苯硒基乙烯和(Z)-1,2-二苯硒基乙烯的混合物,产率为92%;在氮气保护及室温下反应1 h,以95%的产率生成唯一的产物(Z)-1,2-二苯硒基乙烯.溶剂对反应速度和反应结果也有较大的影响.以DMF作溶剂,即使在-20℃,也能使反应有效发生,高产率的生成唯一的产物(Z)-1,2-二苯硒基乙烯.讨论了反应机理.     

Cesium accumulation by bacterium Thermus sp. TibetanG7:hints for biomineralization of cesium-bearing geyserite in hot springs in Tibet,China

The bacterium Thermus sp. TibetanG7, isolated from hot springs in Tibet, China, was examined for the ability to accumulate cesium from solutions. Environmental conditions were simulated and the effects of pH, K , Na and K -regimes were then studied to determine the possible role of the bacterium in the formation of cesium-bearing geyserite around these hot springs. In despite of the inhibition of K and Na , the bacterium Thermus sp. TibetanG7 revealed noticeable accumulation of cesium from solutions, with maximum accumulations of 53.49 and 40.41 μmol Cesium/g cell dry weight in Na and K inhibition experiments, respectively. The accumulation of cesium by this microorganism is rapid, with 40%―50% accumulated within the first 5 min. K -deficient cells showed a much higher capacity of cesium accu- mulation compared with K -sufficient cells. It is evident that the bacteria within the genus thermus play a significant role in the cesium assembly. The formation of cesium-bearing geyserite is also considered.     

阴离子加聚对聚合氯化铝铁形态和絮凝性能的影响

采用 (Al Fe) - Ferron逐时络合比色法研究了三种阴离子 (SO42 - 、PO43 - 、Si O3 2 - )加聚对聚合氯化铝铁(CPAFC)形态分布、转化和稳定性的影响 ,探讨了三种阴离子加聚 CPAFC的机理 ,通过混凝实验观察并测定了各絮凝剂的絮凝性能。结果表明 ,以上三种阴离子具有不同程度的增聚、增效作用 ,尤以硅酸根的作用效果最为显著 ,对 35 .7μg/ L 低浊度水的去浊率达到 99.9%。     

浸铯钽阴极热发射性能的研究

通过实验分析,验证了浸铯的钽阴极在低于700℃时也有比较理想的发射,并有发射峰出现。同时对产生这种现象的原因进行了分析 与探索。     

氯盐溶液中Pb(Ⅱ)离子在汞电极上阴极还原的机理

本文采用多种电化学研究方法探讨了酸性氯盐水溶液中Pb(Ⅱ)离子在汞电极上阴极还原的电极过程。酸性氯盐水溶液中Pb(Ⅱ)离子在汞电极上阴极还原的两电荷传递一步完成,电极过程具有扩散传质步骤控制的动力学规律。Pb(Ⅱ)离子在酸性氯盐水溶液中主要以PbCl_3~-和PbCl_4~(2-)络合离子形式存在时,其电极反应表现为PbCl_3~-和PbCl_4~(2-)络合离子直接放电还原。