双棱镜干涉实验中的参量取值研究

本文从理论上推导出双棱镜干涉实验中各参量的取值范围,并通过实验研究找到测量误差小于1%时各参量的取值,这为减小实验误差提供了理论和实验依据.     

X-ray diffraction and scanning electron microscopy of galvannealed coatings on steel

The formation of Fe–Zn intermetallic compounds, as relevant in the commercial product galvannealed steel sheet, was investigated by scanning electron microscopy and different methods of X-ray diffraction. A scanning electron microscope with high resolution was applied to investigate the layers of the galvannealed coating and its topography. Grazing incidence X-ray diffraction (GID) was preferred over conventional Bragg–Brentano geometry for analysing thin crystalline layers because of its lower incidence angle α and its lower depth of information. Furthermore, in situ experiments at an environmental scanning electron microscope (ESEM) with an internal heating plate and at an X-ray diffractometer equipped with a high-temperature chamber were carried out. Thus, it was possible to investigate the phase evolution during heat treatment by X-ray diffraction and to display the growth of the ζ crystals in the ESEM.     

STRENGTH ANALYSIS OF CLAMPING IN MICRO/NANO SCALE EXPERIMENTS

Two kinds of clamping in micro/nano scale experiments are investigated in this paper, one based on electron-beam-induced deposition, and the other on the van der Waals interaction. The clamping strength and mechanism are analyzed both theoretically and experimentally. The influence of relative humidity on the micro/nano clamping and the method of electrostatic clamping are discussed. The clamping strength and performance of different clamping methods are compared considering the size and material of the clamped objects, and the application environments.     

Chiral separations of metoprolol and some analogs with carbon dioxide on chiralcel OD and chiralpak AD stationary phases. Use of chemometrics

Summary The influence of methanol concentration, column temperature, and column back-pressure on the enantios-electivity of the separation of eighteen amino alcohols in supercritical-fluid chromatography has been investigated by use of statistical experimental design. The enantioselective retention of the amino alcohols was studied using Chiralcel OD and Chiralpak AD as the chiral stationary phases and the experimental responses obtained—retention factors (k) and selectivity factors (α)—were evaluated by use of the partial least squares algorithm. The performance of the columns was compared and the enantioselectivity of the Chiralcel OD column was found to be superior. Almost all the racemic amino alcohols tested were separated and separation factors as high as 4.5 were obtained by use of the Chiralcel OD column. Experimental results from a factorial design with three centerpoints resulted in a statistical model based on linear terms only. The first-eluted enantiomers, which, when identified, were found to be theR forms, had similar retention times, whereas the retention times of theS forms were more varied. The column temperature had a greater effect on enantioselectivity than methanol content. Changes in the system back-pressure had no significant influence on enantioselectivity. The results obtained from the factorial design were used to predictk and α. Differences between predicted and experimental data were less than 10%. The effect on enantioselectivity of protolytic mobile phase additives, e. g. dimethyloctylamine, acetic acid, and trifluoroacetic acid, and of mobile-phase flow-rate, were also studied, as was the effect of solute structure. The position of substituents on the aromatic ring, type of alkyl group attached to the nitrogen atom, and the number of methylene groups between the stereogenic center and the nitrogen atom all affected enantioselectivity. The chromatographic system developed could be used to determine enantiomeric purity even if the chiral impurity eluted after the main peak.     

以PBL法进行药学实验基本技能教学的探索与实践*

根据西部少数民族地区院校的客观条件和教学特点,提出用以问题为导向的教学法(PBL)进行药学基本技能实验教学。实践证明,实验组(PBL法)的实践基本技能操作水平和发现、分析并解决问题的能力均显著高于对照组(传统教学法)。该法对提高西部少数民族地区药学本科生的创新能力具有较大意义,对其他地区药学本科生创新能力的培养也有一定的借鉴作用。     

任意凸多面体上布点均匀性的度量

均匀性度量是构作均匀设计的基础,本文从距离概念出发,通过对称的方法,得到一种新的距离函数-势函数,并将势函数作为衡量任意凸多面体上布点均匀性好坏的准则.数值例子和多变量Kendall 协和系数检验表明,当试验区域限制在单位立方体上时,势函数与目前常用的两种偏差-中心化L_2-偏差和可卷L_2.偏差在度量布点均匀性方面结论一致.     

物理实验教学应该重视的三个方面

实施素质教育的物理实验教学，是科学性与技术性的统一，本文从技术的角度立意，阐明了当今中学物理实验教学改革中应该重视的三个方面：操作技术，故障排除与反思心理。     

模型外载与自重并存变动外载的光弹性分析法

提出一个变动模型外载，分析大模型在外载与自重共同作用时的尤弹性法。它与用离心力模拟自重试验的传统方法完全不同，只要在大模型上变动外载，就可以获得上述两种载荷共同作用下的应力分析结果。此法避免了用离心模型自重受模型尺寸限制等诸多因素影响的缺点，为自重不可的大型复杂空间工程结构模型试验应力分析提出了一条新的途径。文中给出了本方法的基本原理及其简要的实验验证和工程应用结果。     

X光CCD响应特性研究

 在北京同步辐射源上建立了X光CCD(Charge-Coupled Device)量子效率实验标定方法，获得了150eV至1500eV能区范围多个X光能点的量子效率实验结果，发展了X光CCD量子效率简化计算模型，并对X光CCD表面油沾污对量子效率的影响进行了实验研究和修正。结果表明经过油沾污修正后的简化理论模型计算结果与实验标定结果符合较好。     

旋转流体实验设备改造

论述了旋转流体实验装置改造所存在的问题及改进的措施。