X射线荧光分析中谢尔曼方程逆问题的求解（理论影响系数法 …

本文首先在理论分析基础上,建立多元素样品的重量分数Ｃｉ、Ｘ射线荧光相对强度Ｒｉ与基体效应因子Ｆｉ的代数关系。然后,按照此关系导出两种求解谢尔曼方程逆问题的方法,即理论影响系数法和基本参数法。并用这两种方法分析了６个耐热钢标样,主量、常量元素的平均相对分析误差〈０．５％,对低含量轻元素Ｓｉ、Ｐ、Ｓ的分析也取得良好的结果。     

利用透射系数研究周期势的能带结构

利用一维方位势透射系数的递推公式研究了周期势的能带结构,文中考察了能 结构与垒宽、阱宽及位势个数的关系。     

回旋行波管动力学分析及数值计算

 以小回旋电子注、均匀截面光滑壁圆柱波导为例,对回旋行波管动力学色散方程作了解析分析和讨论;数值计算和分析了注波互作用耦合系数与电子注参数的相互关系,为优化选择电子注参数,提高注波互作用效率获得了依据。     

二氧化碳从它溶胀后的聚合物中的解吸

研究了经过４０℃,８．０￣１４．０ＭＰａ的超临界二氧化碳溶胀后的６种聚合物ＬＤＰＥ、ＰＰ、ＰＡ６、ＥＶＡ、ＰＵ中的ＣＯ２解吸情况,模拟了聚合物中ＣＯ２的解吸规律,即以时间的自然指数递减规律,并根据Ｆｉｃｋ扩散定理从理论上推导出ＣＯ２在聚合物中的解吸方程,由解吸方程计算解吸扩散系数,结果表明ＣＯ２的解吸扩散系数数量级达１０＾－７ｃｍ＾２／ｓ,解吸扩散系数与ＣＯ２在聚合物中的浓度和温度以及解吸前聚合物     

高增透的类金刚石碳膜的红外吸收特性研究

利用射频等离子体分解甲烷的技术在锗片上沉积了非晶结构的类金刚石碳膜,傅里叶红外光谱仪测量显示镀覆的类金刚石碳膜的锗片在红外范围内具有高增透作用,特别在１７４０～！２０４４ｃｍ＾－１其峰值透过率高达９９％,在９４５．７ｃｍ＾－１（１０．６ｕｍ）处透过率为９４．５％。利用实测的液内的吸收系数接近于０,在１０．６ｕｍ的吸收系数为２３０ｃｍ＾－１,膜主要由ｓｐ＾３的Ｃ＿Ｈ键结构组成,各吸收峰均得到了很好的     

导波法测量吸收薄膜的复介电系数和厚度

具有吸收特性的波导薄膜,其衰减全反射（ＡＴＲ）峰的位置和形状包含了薄膜诸多特征多数的信息,在同时考虑棱镜的耦合和材料的吸收的基础上,本文用一阶微扰理论推导了微扰传播常数的解析公式,并且介绍了通过分析薄膜的衰减全反射峰来计算吸收薄膜的复介电系数和厚度的方法。     

Anisotropic diffusion in a nematic liquid crystal- An electric field PFG NMR approach

The access to self-diffusion coefficients in anisotropic systems such as thermotropic liquid crystals by means of PFG NMR is complicated by strong dipolar interactions. Additionally, problems arise due to the immediate orientation of low-molar-mass nematic liquid crystals in an external field. The director orientation can be changed by the application of an additional electric field. This can be exploited in order to reduce the dipolar interaction to such an extent that the NMR linewidths change from a solid-state to a liquid-like situation enabling PFG NMR experiments.     

非均匀材料样品的霍尔系数的计算

将不均匀材料网络化用等效电源的方法根据基尔霍尔定律得到了不均匀材料样品的霍尔系数的较为一般的表达式,应用该结果可以谇地计算不均匀材料样品的霍尔系数,而双层模型和三层模型是此表达式的特例。     

Thermodynamic equilibrium of the solute distribution in size-exclusion chromatography

Our understanding of the nature of solute retention in size-exclusion chromatography (SEC) is predicated upon an equilibrium, entropy-controlled, size-exclusion mechanism. The entropic nature of the separation depends, in turn, upon the solute distribution coefficient (K(SEC) being at (or close to) thermodynamic equilibrium. Classic experiments to confirm this assumption were performed over thirty years ago. Here, we combine information obtained from both flow and static mixing SEC experiments to show that the solute distribution in SEC is in thermodynamic equilibrium over a molar mass range extending one order of magnitude higher than previously measured (from 2 x 10(3) to 1.1 x 10(6) Da) using crosslinked polystyrene packing material of identical pore size (10(4) A). The differences between our observations and previous ones conducted over three decades ago are ascribed, principally, to advances in stationary phase synthesis and column technology for SEC in particular and, secondarily, to improvements in the performance of the various instrumental components of liquid chromatographic systems in general.     

Chromatographic impulse response technique with curve fitting to measure binary diffusion coefficients and retention factors using polymer-coated capillary columns

The theoretical basis of a Gaussian-like approximate solution was applied to a chromatographic impulse response technique with curve fitting for measuring binary diffusion coefficients and retention factors using a polymer-coated capillary column. The formulae were derived for evaluating both the accuracy of the approximate solution and the sensitivity of the parameters. The validity of the solution also was confirmed experimentally for pulse injection of phenol in acetone into supercritical carbon dioxide flowing at 313.15 K and 11.6-28.6 MPa. Potential sources for experimental errors of the method are discussed.