Theoretical Computation for Non-Equilibrium Air Plasma Electrical Conductivity at Atmospheric Pressure

Based on the Chapman-Enskog theory, we calculate the electrical conductivity of non-equilibrium air plasma in the two-temperature model. We consider different degrees of non-equilibrium, which is defined by the ratio of electronic temperature to heavy particles temperature. The method of computing the composition of air plasma is demonstrated. After calculating the electrical conductivity from electron temperature 1000 K to 15000K, the present result is compared with Murphy＇s study [Plasma Chem. Plasma Process 15 （1994） 279] for equilibrium case. All the calculation is completed at atmospheric pressure. The present results may have potential applications in numerical calculation of non-equilibrium air plasma.     

直接沉积法制备棒状ZnO

在溶液体系中90 ℃下, 以三乙醇胺与醋酸锌为反应试剂, 用直接沉积法合成了微米及纳米尺寸的棒状ZnO粒子, 并对粒子进行了透射电镜(TEM)、X射线衍射(XRD)、热重(TG)和差热扫描量热分析(DSC)等表征. 通过晶体的成核和生长理论初步解释了棒状ZnO粒子的形成过程.     

A NEW TYPE LOW SHEAR RATE VISCOMETER FOR HIGH MOLECULAR WEIGHT POLYMER

In this paper, the effects of shear rate on the intrinsic viscosity measurement of partiallyHydrolysed Polyacrylamide (HPAM) in salt solution were studied with homemade multi-bulb viscometer and low shear rate rheometer. The critical shear rate of HPAM in saltsolution for high molecular weight HPAM was determined. A low shear rate capillaryviscometer was designed in which the [η] approached to value at zero shear rate can beobtained for HPAM-salt system. The effect of molecular weight on shear rate dependenceof viscosity was also studied.     

槐果碱和氧化槐果碱与溶菌酶的作用机制及构效关系研究

在模拟人体生理条件下,采用紫外光谱、荧光光谱和同步荧光光谱法相结合,研究槐果碱(SC)和氧化槐果碱(OSC)与溶菌酶(LYSO)的相互作用机制,并探讨其构效关系。紫外光谱显示,SC和OSC可与LYSO发生相互作用;荧光光谱表明,SC和OSC对LYSO的内源荧光均有显著的猝灭作用,猝灭机制主要为静态猝灭和非辐射能量转移。SC和OSC均可与LYSO形成1∶1复合物,在温度为310K下二者与LYSO的结合常数K分别为0.922×105、2.81×105 L·mol-1,结合距离r分别为3.81、4.39nm,其作用力主要为氢键和范德华力。OSC与LYSO的结合能力明显强于SC;同步荧光光谱表明,OSC与LYSO相互作用后,LYSO的构象发生改变,而SC与LYSO相互作用后,LYSO的构象基本不变。Fe3+、Mg2+、Cu2+、Zn2+四种金属离子的存在增强了SC和OSC与LYSO的结合能力,四种金属离子均以"离子架桥"模式介导SC和OSC与LYSO的相互作用,且其强弱顺序为:Mg2+>Cu2+>Fe3+>Zn2+。     

空间相机热设计中的极端工况确定

针对具有多姿态变化特点的空间相机,提出了考虑太阳辐射的到达外热流和吸收外热流两种情况下的极端工况确定方法和计算流程。根据辐射学的基本理论,并结合相机的结构特点,推导出了相机外表面总太阳辐射流的计算公式;根据相机进出地影的情况和太阳常数分别建立了相应矩阵,并进行了有关矩阵的运算和变换;借助工具软件Matlab求解得到了投落到相机外表面的总太阳辐射外热流极值,并在此基础上确定出该相机的极端工况;将此工况输入到I-DEAS/TMG仿真环境中进行仿真分析,验证了此方法的正确性。该计算方法同样适用于其它类型的相机,具用通用价值。     

新型有机非线性光学晶体-L-苹果酸脲晶体生长的初步探讨

本文初步探讨了新型非线性光学晶体-L-苹果酸脲的晶体生长,研究结果表明,L-苹果酸脲晶体在甲醇、乙醇和水三种介质中的溶解度温度系数均较大,同温度下L-苹果酸脲晶体在水中的溶解度最大,无水甲醇次之,无水乙醇中最小.L-苹果酸脲晶体在无水甲醇中的成核自由能比在无水乙醇中的低得多,因此在无水甲醇中易于成核,晶核数多,晶体尺寸小,而在无水乙醇介质中,虽然成核相对比较困难一些,但有利于制备大的单晶,且发现低温有利于大晶体的生长.因此宜选择无水乙醇为晶体生长介质.L-苹果酸脲晶体在介质中以非均匀成核方式在试管壁成核长大,晶体呈棱柱状,生长过程中呈现台阶生长的特征.     

Li1.02Cr0.1Mn1.9O4表面包覆的热稳定性研究

Improvement of elevated-temperature performance of Li_1.02Cr_0.1Mn_1.9O₄ cathode material by silicious surface modification was studied. The Li_1.02Cr_0.1Mn_1.9O₄ cathode material was treated by silanes coupling agent and then heated at 580 ℃ to remove organic material. The structures of the modified and unmodified Li_1.02Cr_0.1Mn_1.9O₄ were characterized by SpectraPlus, SEM and XRD. The results show that the surface layer of Li_1.02Cr_0.1Mn_1.9O₄ material is found to be rich in silicious compound. X-ray diffraction show that all the samples have perfect spinel structure. The electrochemical characterization of modified Li_1.02Cr_0.1Mn_1.9O₄ cathode material was tested. The cycle stability of charge/discharge at 55℃ is improved. The results of the charge/discharge curves show that the modified Li_1.02Cr_0.1Mn_1.9O₄ has better performance than those unmodified according to the inhibition of decline of reversible capacity of spinel Li_1.02Cr_0.1Mn_1.9O₄. Therefore, cycle performance is improved so obviously that 86.03% of the initial capacity is preserved after 100 cycles.     

磁靶向纳米Fe3O4-TiO2复合物的制备及其对肝癌细胞的光催化杀伤效应

采用三种低温溶胶-凝胶法制备了具有不同Fe₃O₄掺杂量的磁靶向纳米Fe₃O₄-TiO₂复合物, 通过X射线衍射(XRD)、透射电镜(TEM)、傅里叶变换红外(FTIR)光谱、紫外-可见(UV-Vis)光谱、荧光光谱(FS)及磁性能分析等表征方法筛选出包覆均匀、分散性好、磁性能优异及光催化活性较高的纳米Fe₃O₄-TiO₂复合物. 以四甲基偶氮唑蓝(MTT)法检测肝癌细胞(HepG2)的存活率, 考察纳米Fe₃O₄-TiO₂复合物在外磁场作用下对HepG2 细胞的光催化杀伤效应. 结果表明: 采用方法三制备的5%(质量分数)Fe₃O₄-TiO₂复合物具备核-壳结构, 在混悬液中分散性较好, 平均粒径约为50 nm, 具有较强的光催化活性和良好的磁响应性, 同时将纳米TiO₂的光响应范围拓宽至444 nm; 在外磁场作用下, 紫外光和可见光激发纳米Fe₃O₄-TiO₂复合物对HepG2细胞的杀伤效应差异不大, 且均强于纳米TiO₂; 其杀伤效应在0-1.0 T范围内随着外磁场强度的增大而增强.     

凝胶色谱法定量分析污水中聚丙烯酰胺

建立了凝胶色谱分析污水中部分水解聚丙烯酰胺的方法。采用普通商品水溶性凝胶色谱往,通过变换淋洗剂的作法,消除了非体积排斥效应的影响,实现了定量分析。讨论了紫外检测波长对部分水解聚丙烯酰胺测定结果的影响,检验了油田污水、选矿污水、自来水及盐水体系对结果的影响,并与溴氧比法测定的结果作了比较,所建方法的浓度分析范围为０．１～２００ｍｇ／Ｌ,精度为±２％,检测下限为０．１ｍｇ／Ｌ。     

水溶性凝胶色谱中的非体积排除效应

讨论了水溶性凝胶色谱技术（ＧＰＣ）的分离机理和不同研究领域对ＧＰＣ数据处理上的差别。详细阐述了在分离过程中存在的一些非体积排除效应及其对分析结果的影响,论述了消除这些影响因素的方法。