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241.
应用钾离子选择性电极和Ag-AgCl电极组成可逆电池,通过测定电池的电动势,应用Debye-Hückel极限公式,求得不同温度下KCl在1,2-丙二醇非水溶剂中的活度系数(±),计算了KCl在1,2-丙二醇非水溶剂中的相对偏摩尔自由能(-GB,R),并据电解质溶液的溶剂化理论对KCl的活度系数及相对偏摩尔自由能的变化规律进行了初步的讨论.  相似文献   
242.
The histopathological features and the associated clinical findings of ulcerative colitis (UC) are due to persistent inflammatory response in the colon mucosa. Interventions that suppress this response benefit UC patients. We tested whether sodium arsenite (SA) benefits rats with dextran sulfate sodium (DSS)-colitis. The DSS-colitis was induced by 5% DSS in drinking water. SA (10 mg/kg; intraperitoneally) was given 8 h before DSS treatment and then every 48 h for 3 cycles of 7,14 or 21 d. At the end of each cycle rats were sacrificed and colon sections processed for histological examination. DSS induced diarrhea, loose stools, hemoccult positive stools, gross bleeding, loss of body weight, loss of epithelium, crypt damage, depletion of goblet cells and infiltration of inflammatory cells. The severity of these changes increased ir the order of Cycles 1,2 and 3. Treatment of rats with SA significantly reduced this severity and improved the weight gain.  相似文献   
243.
A series of Li_(1-x)Na_xV_3O_8 materials was prepared by solution reaction followed by calcination method and their electrochemical performances in 2 M Li_2SO_4-water-ethanol solution as negative electrodes for aqueous electrolyte lithium ion battery were studied and compared each other.X-ray diffraction analysis revealed that partially substituting sodium for lithium in LiV_3O_8 could increase the interlayer distances of (100) plane.Cyclic voltammetric experiments have demonstrated that the Li~ insertion and extraction kinetics of Li_(0.7)Na_(0.3)V_3O_8 is superior to that of LiV_3O_8.Charge/discharge results showed that the discharge specific capacity of Li_(0.7)Na_(0.3)V_3O_8 electrode is higher than that of LiV_3O_8 electrode.  相似文献   
244.
以正丁酸和戊醇为原料,硫酸氢钠为催化剂合成了丁酸戊酯.最佳合成条件:以0.1mol正丁酸为基准,醇酸摩尔比为1.2:1,催化剂用量0.2克,甲苯5毫升,反应时间30min,丁酸的酯化率可达99.3%,在无甲苯存在下,合成食品级丁酸戊酯,酯化率可达99.7%.  相似文献   
245.
酸枣仁皂甙的镇静作用研究   总被引:16,自引:0,他引:16  
酸枣仁皂忒(JBSD)20mg/kg,40mg/kg可明显抑制小鼠的自发活动,延长异戊巴比妥钠对小鼠的睡眠时间,对阈下催眠剂的异戊巴比妥钠有协同作用,显著降低戊四氮引起的惊厥率.实验证明了酸枣仁皂甙对中枢神经系统的镇静作用.  相似文献   
246.
A laboratory-scale trickling biofilter column,filled with Raschig rings and inoculated with Pseudomonas putida (ATCC 1785)was used to purify chlorobenzene contained waste gases.Sodium dodecyl sulfonate(SDS)was used to enhance the performance of trickling biofllter.Purification performance of the trickling biofilter was examined for chlorobenzene inlet concentration of 1.20~5.04 g/m~3 at different EBRTs between 76~153 s.Without SDS addition,with simultaneous increase in chlorobenzene inlet loading rate and gas flow rate,100% removal efficiency was achieved at EBRT of 109 s and inlet loadings below 5120 mg/m~3.Addition of SDS to nutrient solution led to improvement of trickling biofilter purification performance. By introducing 25 mg/L SDS,the removal efficiency was increased by 21% and elimination capacity up to 234 g/(m~3.h)was achieved at chlorobenzene inlet loading of 241 g/(m~3.h).Although SDS concentration experienced a low rate reduction after continuous nutrient solution recirculation,this result has little influence on trickling biofilter's removal efficiency in monitoring period.  相似文献   
247.
郭戈  谢海泉  刘珊珊 《科技通报》2007,23(2):225-228
将废旧泡沫磺化制备聚苯乙烯磺酸及其钠盐,目标产品可以用来作为水处理剂和土壤改良剂。在CHJ-05催化作用和适当的温度下,废旧聚苯乙烯泡沫与浓硫酸进行反应,经分离提纯得到聚苯乙烯磺酸,聚苯乙烯磺酸经中和反应可得聚苯乙烯磺酸钠。反应时间短,磺化效率高。为废旧聚苯乙烯泡沫的再利用及生产低成本的聚苯乙烯磺酸及其钠盐提供了依据。  相似文献   
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