5－Br－PADAP作为配位滴定铅指示剂的研究

本文研究在ＰＨ５．５的六次甲基四胺缓冲体系中，以５－Ｂｒ－ＰＡＤＡＰ作为指示剂，用ＥＤＴＡ滴定铅精矿中铅含量。试验结果表明，终点变色敏锐，测定结果变异系数为０．２７％（ｎ＝５）。     

配位滴定指示剂确定终点最佳酸度的选择

文章讨论了滴定过程中,酸度对金属离子、滴定剂、滴定反应及指示剂的影响。     

在CPB存在下X.O作为配位滴定指示剂的试验

研究在演化十六烷基吡啶存在下的氨性溶液中,金属离子与二甲酚橙的显色反应。并试验了在上述体系中用X.O作为配位滴定指示剂时终点颜色变化。试验结果表明X.O能作为的Ca~(2 )、Mg~(2 )、Zn~(2 )”、Co~2”、Cd~2”、Cu~(2 )的直接配位滴定指示剂,也可用作Ca~(2 )”、Mg~(2 )、Sr~(2 )、Zn~2”、Cd~(2 )、Cu~(2 )的返滴定指示剂。用于工业用水硬度的测定,终点颜色变化敏锐。     

配位滴定中滴定条件的确定

从配位滴定终点误差公式出发．运用一种图解方法．能准确、快速地确定配位滴定的滴定条件．     

配位滴定曲线的计算

通过对配位滴定的讨论，介绍了根据物料等衡式和配位平衡式推导出的方程来处理配位滴定的滴定曲线，其结果更准确，更合乎实际。     

存在辅助配位剂时单一金属离子配位滴定曲线的绘制

本文指出了现代分析化学教科书在处理辅助配位剂存在时，游离金属离子浓度计算的不足之处，提出了精确计算金属离子浓度的方法，并绘制出滴定曲线。     

配位滴定中的水解效应

处理配位滴定中的水解效应时,应根据实际情况作配位效应处理或按溶度积计算金属离子的浓度,不能将两者混淆。     

影响配位滴定突跃范围的因素

本通过具体的数据和图形讨论了影响配位滴定突跃范围的主要因素即金属离子的起始浓度（CM）和表观形成常数(K'MY)对突跃范围的影响，CMK'MY大，突跃范围大，当CMK'MY≥10^7.4时，CM.aM影响突跃的起点，K'MY.aY影响突跃的终点。     

EDTA配位滴定金属离子最高酸度的计算

本文介绍了一种利用简便计算的手段,获得了EDTA滴定金属离子的最高酸度(最低PH值),从而避开了解高次方程的麻烦和查表时先近似处理的过程。给出了EDTA能配位滴定的金属离子的最高酸度,并与文献值进行了对照,结果满意。     

对配位滴定中的“6·5·—1”规则的异议

本文指出了配位滴定中的“6·5·-1”规则中的不当之处。通过推导,表明“6·5·-1规则可以改为“6·-1规则,其中的K'_(MY)应按条件形成常数的原定义(考虑共存离子效应)计算,从而使混合离子配位滴定的可行性判断更为严谨,更为简单。     

高硬度水质测定实验的研究与改进

文章对高硬度水质测定实验中变色不敏锐、终点拖长问题进行了研究并提出改进方法．实验结果表明：加盐酸并煮沸能有效改善高硬度且含大量HCO3水样变色不敏锐的问题,提高了测定的准确度．     

对络合滴定中滴定速度的探讨

该文选择络合滴定法,在不同滴定速度下对水硬度进行了实验测定,并就滴定结果对滴定速度的影响进行了分析和讨论．     

氧化还原滴定化学计量点电位通用计算式探讨

本文推导了一个普通适用于各类氧化还原滴定化学计量点电位通用计算式,并对该通用计算式的应用进行了讨论。     

THE VALIDITY OF HIGHER-ORDER QUESTIONS AS A PROCESS INDICATOR OF EDUCATIONAL QUALITY

One way to assess the quality of education in post-secondary institutions is through the use of performance indicators. Studies that have compared currently popular process indicators (e.g., library size, percentage of faculty with PhD) found that after controlling for incoming student ability, these process indicators tend to be weakly associated with student outcomes (Pascarella and Terenzini, 2005). In addition, while much research has found that students increase their critical thinking skills as a result of attending college, little is known about what goes on during the college experience that contributes to this. The purpose of this research was to examine the validity of higher-order questions on tests and assignments as a process indicator by comparing it with gains in critical thinking skills among college students as an outcome indicator. The present research consisted of three studies that used different designs, samples, and instruments. Overall, it was found that frequency of higher-order questions can be a valid process indicator as it is related to gains in students’ critical thinking skills.     

UNIVERSITY STUDIES AS TRAINING FOR THE INTELLECTUAL PROFESSIONS

The origins of the medieval university appear to be twofold: on the one hand, the training in the liberal arts that took place in various sorts of schools and academies that can be traced back to the classical era in European history as well as to the golden age of Arab‐Islamic civilization, and on the other hand, the need to offer possibilities for practical training for a trade. The first type of training was by its nature reserved to a social elite. The latter, that in the medieval period was associated with trade guilds and apprenticeship systems, was for the working classes. The medieval university arose from the union of these two types of training and education as embodied in an institution that began as guilds of students and teachers and/or as cathedral schools. The result was the university that offered training in certain intellectual professions (theology, medicine, and law) but that required prior mastery of the liberal arts. As the fruit of this intellectual and vocational union, the university continued to absorb and to disseminate the principal intellectual trends of succeeding periods in European history, first Aristotelianism and then later the experimental sciences, finally, in recent years, taking on a major research and development function.     

STUDIES ON METHOD FOR AQUEOUS EXTRACTION OF SOYBEAN OIL

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基于建构主义理论的研究生公共英语教学研究——以中医药院校为例

本文较全面地分析了中医药院校研究生公共英语教学中存在的诸多问题,从建构主义理论的角度研究和探讨了中医药院校研究生公共英语教学在课程体系、开放式教学形式和评价体系等方面的改革和措施     

酸碱滴定误差计算方法的再探

根据滴定终点时溶液中的物料平衡方程和电荷平衡方程,计算酸碱滴定误差,方法简单,易于理解和掌握.     

DIELECTRIC STUDIES OF UREASE AS A FUNCTION OF HYDRATION

The steady-state electrical conductivity,as well as the dielectric propertiesbetween 2×10~(-4)Hz and 100 kHz,and at 1 GHz,are reported for urease compressed powdersamples of low hydration.The results show that the large,low frequency dielectricdispersion,known as α-dispersion,is due to the build-up of a space charge of protons atthe sample-electrode interfaces.A smaller dispersion,appearing at higher frequencies,isconcluded to be associated with hindered motions of the peptide residues in the molecularstructure of urease.The extent of these polypeptide backbone motions is shown to bestrongly depended on the extent of enzyme hydration.This work is contributed to the de-velopment of conductimetric biosensors.