排序方式: 共有31条查询结果,搜索用时 0 毫秒
1.
The first thermodynamic dissociation constants of o-phthalic acid were determined at five temperatures from 278.15 to 318.15 K in 10, 14.93 and 20 wt% isopropanol-water solvent mixtures, by precise e. m. f. measurements of hydrogen-silver chlorld electrodes in cells without liquid junction. On the basis of Pitzer's theory, the method of polynomial approximation was used to determine the dissociation constants of H_2P and the results obtained were compared with traditional extrapolation according to the extended Debye-Huckel equation Results obtained from both methods agree within experimental error. The dependence of the first thermodynamic dissociation constant on temperature was given as a function of the thermodynamic temperature T by the empirical equation: pK_1=A_0+A_1/T+A_2/T. The thermodynamic quantities of dissociation in the mixed solvents have been calculated, and the results have been discussed. 相似文献
2.
人参中总皂甙的超声波快速提取方法研究 总被引:7,自引:0,他引:7
建立了人参中总皂甙超声波半微量快速提取方法,与索氏提取法相比,此法提取时间由索氏法的1-2个工作日缩短到30min,节省大量试剂,综合提取效率提高数十倍,与索氏提取法对照分析表明,此法可完全满足人参中总皂甙的快速测定要求。 相似文献
3.
测量电池Pt,H_2(g,1atm)|HCl(I_A),CoCl_2(I_B)|AgCl-Ag的电动势,确定了HCl(A) CoCl_2(B) H_2O体系中HCl在总离子强度I=0.5到5.0mole kg~(-1)和温度5—45℃下的活度系数γ_A,其中I_A和I_B分别是HCl和CoCl_2的离子强度。本体系中HCl活度系数为 lgγ_A=(E~0-E)/2k-0.5lg[(1-y_B)(1-y_B/3)I~2] (1)式中k=(RTln10/F),E和E~0分别是电池电动势和标准电动势,y_B是CoCl_2的离子强度分数。测定每种溶液电池在不同温度的电动势顺序,首先测定25℃,然后依次测定15° 相似文献
4.
5.
基于VirtualLab虚拟仿真软件建立了粒径在几十到几百微米内不同大小和形状的气泡模型。对其在平面光照射下的散射进行了仿真模拟,得到了气泡的前向、后向光散射特征分布,将结果与水粒的光散射特征进行比较分析,发现:同一气泡前向散射远大于后向散射,但两者拥有十分相近的变化趋势。光源和气泡大小影响气泡远场散射幅值的大小、振荡频率、角宽度及次极大与主极大的比值。气泡结构的对称性影响着气泡远场散射的对称性。气泡与水粒的远场散射特性既联系又区别。该研究的结果可以为气泡的分析检测提供了一定的理论依据。 相似文献
6.
7.
8.
9.
10.