哌啶醇的NMR研究

测定了2，2，6，6-四甲基4-哌啶醇（以下简称化合物1）、1，2，2，6，6-五甲基4-哌啶醇（以下简称化合物2）的NMR谱，并对其¹H，¹³C谱峰进行了全归属，利用2D NMR技术研究了该化合物的立体结构.     

EPR theoretical study of local lattice structure in YAG:Mn system

By diagonalizing a set of complete energy matrices constructed for a d⁵ configuration ion in a trigonal ligand field, a reasonable interpretation is obtained for the EPR zero-field splitting of Mn²⁺ ions located at octahedral sites in yttrium aluminum garnet. It is shown that the local lattice structure around an octahedrally coordinated Mn²⁺ center has an expansion distortion, which may be attributed to the fact that the radius of Mn²⁺ ion is larger than that of Al³⁺ ion, and the Mn²⁺ ion will push the oxygen ligands outwards. Simultaneously, the local lattice structure distortion parameters ΔR=0.1825-0.2158 A and Δθ=1.220°-1.315° for the octahedral Mn²⁺ center in the crystal are determined, respectively. Meanwhile, we also demonstrated that the empirical impurity-ligand distance is not suitable for the YAG:Mn²⁺ system which has been approximately taken in previous works.     

掺铥硫氧化钇的特殊余辉性质

迄今为止,稀土长余辉磷光体已见文献或专利公开报道的激活离子主要有适于紫外光激发的三价铈离子(Ce³⁺)和三价镨离子(Pr³⁺)、适于可见光激发的铕离子(Eu³⁺和Eu²⁺)及钐离子(Sm³⁺,Sm²⁺),尚未涉及到铥离子Tm³⁺或Tm²⁺.我们在Tm³⁺离子激活的硫氧化钇体系Y₂O₂S:Tm³⁺中发现了长余辉荧光特性.特别是在该磷光体中还发现了一种非常特殊的余辉现象.     

NaHSO4·H2O催化合成苯甲酸甲酯

以 Na HSO4 · H2 O催化苯甲酸与甲醇的酯化反应 ,合成了苯甲酸甲酯。研究结果表明 ,Na HSO4 · H2 O具有较高的催化活性。考察了苯甲酸 /甲醇摩尔比、催化剂用量及反应时间对酯产率的影响。在优化反应条件 [n(苯甲酸 )∶n(甲醇 )∶n( Na HSO4 ·H2 O) =1∶ 2∶ 0 .2 9,回流8h]下 ,苯甲酸甲酯产率达 85.3 %。     

考虑密度与温度耦合关系的非结构网格SIMPLEC算法

提出一种新的密度压力速度和温度耦合的算法,使用静焓方程构造温度修正量与压力修正量之间的关系,类似Rhie-Chow方法用动量方程插值,网格面上的温度压力修正量插值采用能量方程的形式.CGNS API(CFD General Notation System Application Programming Interface)作为非结构化网格求解器的前处理和后处理,基于网格的FVM(Finite Volume Method)作为偏微分方程求解方法.燃烧模拟采用Arrinius-Eddy Dissipation模型.最后给出两个算例作为说明.     

猪去氧胆酸衍生物的NMR研究

对6α-羟基-3α-苯甲酰氧基-5β-胆烷酸甲酯（化合物1）及3α-羟基-6α-苯甲酰氧基-5β-胆烷酸甲酯（化合物[STHZ]2[STBZ]）进行了¹H,¹³C NMR检测,通过DEPT及DQF-COSY,¹³C-¹H COSY, COLOC等NMR技术对其¹H和¹³C NMR数据进行了全归属和详细的解析,并指出了其NMR数据特征.     

基于AP法的一类非线性机械动力系统的求解

用渐近摄动法分别一类机械系统的非线性运动控制方程1∶1、1∶2内共振主参数共振-1/2亚谐共振情况进行摄动分析,得到系统的平均方程.结果发现用渐近摄动法求得1∶2内共振的平均方程中会漏掉某些非线性项,而且内共振比值越大漏掉的项越多,由此可以看出渐近摄动法不适用于求解多模态之间内共振比值大的非线性动力学系统.     

Chelating Properties of Salicylhydroxamic Acid-functionalized Polystyrene Resins and Its Application to Efficient Removal of Heavy Metal Ions from Aqueous Solutions

Salicylhydroxamic acid(SHA) was covalently bound onto crosslinked polystyrene spheres(CPSs) via the Friedel-Crafts alkylation reaction between chloromethylated CPSs and SHA in the presence of SnCl4 as the Lewis acid catalyst. The resulted SHA-CPSs possessed very strong chelating ability for heavy metal ions. In particular, the saturated adsorption amount of SHA-CPSs for Cu²⁺ ions could reach as high as 34.2 mg/g at 318 K. The chelating capability of SHA-CPSs towards heavy metal ions was pH and temperature dependent. SHA-CPSs also showed selective metal coordination with the chelating capacity decreasing in the order of Cu²⁺>Zn²⁺>>Pb²⁺. The adsorption isotherms conformed well to the Langmuir model, and the adsorption process was found to be entropy-driven and endothermic. Besides, SHA-CPSs possessed the excellent reusability.     

基于近红外光谱技术的内燃机油鉴别研究

针对常规近红外光谱技术测试内燃机油时光谱信号响应低,对大分子基团分辨率不高,以及光谱信息与其结构组成之间存在非线性关系等难点,提出了一种基于电压为外扰方式的内燃机油二维近红外光谱测试技术,介绍了近红外光谱具有分形的特征.运用小波变换将近红外光谱分解至不同分辨尺度,然后计算各尺度分量的分形维数(盒维数),用近红外光谱的小波基分形参量替代近红外光谱的采样值.计算结果表明,在不同小波基和不同分解尺度下,内燃机油近红外光谱具有不同的盒维数,得到了近红外光谱在分形意义下的特征信息.以美孚、埃索和壳牌3种内燃机油品种鉴别分类问题为实例,比较研究了近红外光谱采样值与小波基分形参量,K近邻法的交互验证计算结果表明,小波基分形参量的分类效果优于近红外光谱采样值.采用近红外光谱技术测试内燃机油的结构组成信息是可行的.     

Experimental study on polarization holographic storage in genetic mutant BR-D96N film

The information storage is developing toward high speed access and massive stor-age capacity. Optical holographic storage has not only high speed parallel data access and high addressing speed without mechanical motion but also high storage density with multiplexed volume holographic storage[1]. In recent years, optical holographic storage is studied intensely in the field of information storage. It has been shown that the polari-zation of light could also be recorded with polarization hologra…