邻苯二酚紫—溴化十六烷基吡啶测定镧的光度分析

用光度法研究了镧－邻苯二酚紫（ＰＶ）－溴化十六烷基吡啶（ＣＰＢ）的显色反应。在硼砂－盐酸缓冲体系中，Ｌａ￣（３＋）ＰＶ－ＣＰＢ形成配位比为１∶２∶３的蓝色三元配合物。其最大吸收波长λ＿（ｍａｘ）＝６７３．２ｎｍ，表观摩尔吸光系数：ε＇＝４．３×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）．当Ｌａ￣（３＋）的浓度在０～２０μｇ／１０ｍＬ范围内时符合比尔定律。在碱性条件下该显色反应可测定银合金中的微量镧。     

防风（Saposchnikovia divaricata）体细胞在继代培养过程中的染色体变异

对防风（Ｓａｐｏｓｃｈｉｋｏｖｉａｄｉｖａｒｉｃａｔａ）体细胞在组织培养过程中遗传物质的稳定性进行了研究，结果发现防风体细胞在继代培养过程中染色体变异显著，有亚倍体、超倍体、单倍体、多倍体和微核细胞出现，并发生染色体的形态变异。培养半年以上亚倍体和微核细胞出现并开始增多，超倍体和多倍体细胞极少；随着培养时间的延长，亚倍体和微核细胞消失，而多倍体和超倍体细胞显著增多。对于这种规律性的变化，认为是培养基成分对不同的变异类型加以选择的结果，推测培养后期超倍体的大量出现与微核细胞的消失可能有着某种因果联系。微核可能有其它的形成途径。     

奥氏体形变对GCr15钢珠光体片间距的影响

探讨了奥氏体形变对GCr15钢连续冷却下珠光体产物片间距的影响。片间距的测定方法是采用加权统计平均值。实验结果表明,在相同的冷却速度下,奥氏体形变后所得珠光体产物片间距增大,并在一定形变温度下,随着奥氏休变形量的增大,珠光体产物片间距的变化有一极大值。     

一个改进Visual Basic响应用户操作能力的方法

对VB事件驱动过程的分析着手，进而说明了VB响应用户操作能力的不足之处，最后给出了解决问题的有效策略和一个简单的实例．     

中国水利博物馆数值模拟分析

中国水利博物馆的结构体系比较复杂，属于沿竖向不规则结构，既存在结构大底盘的竖向收进，也存在塔体体形上的层层内收，而且沿竖向整个结构由不同抗侧力体系组合而成．本文通过对中国水利博物馆不规则高层钢结构工程的数值模拟分析，得出一些结论和建议，为其他类似工程的设计提供借鉴．     

芳香族羧酸银(Ⅰ)配合物的合成及其抑制脲酶的研究

合成并表征了4种羧酸银(I)配合物:[Ag2(L1)2(A1)2]2·H2O(1),[Ag2(L2)2(A2)3]·H2O(2),[Ag(A3)2]2(L3)·10H2O(3)和[Ag2(A4)2](L4)·4H2O(4)(HL1=3-吡啶甲酸;HL2=3,5-二硝基苯甲酸;H2L3=对苯二甲酸;H2L4=4,4’-联苯二甲酸;A1=2-氨基吡啶;A2=2-氨基嘧啶;A3=4-氨基吡啶;A4=1,6-己二胺).测定了这4种羧酸银(I)配合物抑制脲酶(urease)的效果.实验结果表明4种羧酸银(I)配合物均具有抑制脲酶的生物活性,其中配合物3的抑制活性最强.研究发现它们抑制脲酶的能力随着羧酸银(I)配合物分子聚合程度的增大而减弱.     

Developing stages and causes of desertification in the Mu Us sandland

Based on historical aerial photography of three periods and together with field investigation, the status of desertification development after the 1950s in the Mu Us sandland was analyzed, the difference of the desertification developing speed at two stages was compared, and its possible causes were explored. The results show that the developing speed of desertification from the late 1970s to the early 1990s is apparently slowed down, compared with that from the late 1950s to the late 1970s and there exists an obvious recovery trend at the second stage. The difference between the two stages accounts for severely over-reclaiming, over-grazing and unrestricted cutting during the first stage, which are the main causes of desertification development in the semi-arid steppe and arid desert steppe areas.     

基于瞬时无功理论的检测方法中低通滤波器的优化设计

针对瞬时无功理论的检测方法中Butterworth低通滤波器存在动、静态特性难以兼顾的弱点,选用Butterworth滤波器和均值滤波器串联的形式作为优化低通滤波器,通过均值滤波器抑制Butterworth滤波器的输出纹波,选用2阶Butterworth滤波器以加快检测速度.实验表明,该优化低通滤波器既可以保证畸变电流的检测精度,又具有较快的响应速度.     

Effects of structure and surface properties on carbon nanotubes’ hydrogen storage characteristics

Hydrogen adsorption experiments were carried out in special stainless steel vessels at room temperature (298K) and under 10 MPa using self-synthesized multi-walled carbon nanotubes. In the experiments, carbon nanotubessynthesized by the seeded catalyst method were pretreatedby being soaked in chemical reagents or annealed at hightemperature before they were used to adsorb hydrogen, but their capacity for hydrogen storage was still poor. Carbonnanotubes synthesized by the floating catalyst method were found to be able to adsorb more hydrogen. They have ahydrogen storage capacity of over 4% after they wereannealed at high temperatures, which suggested that theycould be used as a promising material for hydrogen storage.     

幂律能谱分布电子的同步—曲率辐射谱

根据张家铝等近年提出的同步－曲率辐射新理论,在非均匀磁场中电子的辐射已不是同步辐射,而是同步－曲率辐射。论文计算了弯曲磁场中相对论性电子在几种情况下的集体谱,发现具有幂律能谱分布的电子,其辐射谱并非幂律形式。因此过去认为是幂律谱的传统的观念似有重新考虑的必要。