Anomalous small‐angle X‐ray scattering characterization of composites based on sulfonated poly(ether ether ketone), zirconium phosphates,and zirconium oxide

The morphology and distribution of zirconium oxide and zirconium phosphates in a matrix of sulfonated poly(ether ether ketone) (SPEEK) were investigated with anomalous small‐angle X‐ray scattering (ASAXS) and electron microscopy. ASAXS revealed that ZrO₂ was distributed in the SPEEK matrix in the form of nanoparticles smaller than 13 Å. A decrease in the conductivity suggested that the sulfonic groups were bound to the zirconium oxo species at the particle surface. Furthermore, two kinds of membranes containing zirconium phosphate were investigated. In one case, the phosphate was directly dispersed in the polymer solution for the casting of the membrane. In the other case, the phosphate was previously treated with n‐propyl ammonium and polybenzimidazole. From ASAXS data, the fractal dimension could be estimated. Mass‐fractal behavior was confirmed for the SPEEK membrane containing previously exfoliated zirconium phosphate, with aggregates of 6.3–165 Å. Surface‐fractal behavior was detected for membranes with untreated phosphates, with aggregates of 6.4–185 Å. The untreated phosphates caused an increase in the permeability, without changing the proton conductivity much. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 567–575, 2004     

激光频率分裂方法测角技术研究

本文的测角技术是一项新原理、新方法的科研课题，现已通过评审鉴定。这种测角技术灵敏度高，当监测一个物体有无转角变化时是一种理想的方法。     

偏心结构体在光学系统中的应用（一）：棱镜在光学系统中的局限性

本文从偏心本（棱镜）的角度来对光学系统性能指标，结构布局等的合理性进行判断，研究表明，光学系统的视场和结构布局决定了棱镜的造反范围，这种选择性与人瞳直径，渐晕系数，物镜焦距无关，而仅与棱镜本身参数，即所用材料，展开长度有关。     

关于临界角法菲涅耳公式简化理论处理的新方法

本文研究了光束入射角位于临界角附近的Ｆｒｅｓｎｅｌ公式的简化处理，并导出临界角法光学调焦误差表达式，展开了讨论与分析。     

关于临界角法菲涅耳公式简化理论处理的新方法

本文研究了光束入射角位于临界角附近的Fresnel公式的简化处理,并导出临界角法光学调焦误差表达式,展开了讨论与分析。     

Hochauflösende29Si-Festkörper-NMR-Spektroskopie: Einfluß des Si-O-Si-Bindungswinkels auf die isotrope chemische Verschiebung von t- und h-Y2Si2O7

Starting from high-resolution solid-state²⁹Si NMR spectra of two modifications of Y₂Si₂O₇ with different Si-O-Si bond angles it was verified that increasing bond angles cause high-field isotropic²⁹Si chemical shifts.

     

磁光型光盘存贮介质记录特性的研究

本文给出了激光热磁记录多层膜温度场分布求解的基本公式,由此评价了温度场分布对记录磁畴尺寸的影响,并以四层膜结构为例,得到了相应的数值解,有关的验证实验也同时完成,由此得到了降低记录激光功率的方案.     

棱镜玻璃折射率的测定

本文介绍了一种高精度测量玻璃折射率的任意偏向角法，主要说明了该方法的实验原理、测量方法及理论误差分析。     

Small‐angle Scattering Studies of Adsorption and of Capillary Condensation in Porous Solids

Small‐angle scattering (SAS) studies are reviewed of adsorption and capillary condensation of water, hydrocarbons and halogenated hydrocarbons near room temperature, and of nitrogen at 78 K in some mesoporous solids, mainly silicas. The theory needed for the interpretation of SAS data is briefly covered. Calculations of the scattered intensity I(q) for a model porous medium show that I(q) depends markedly on the film thickness t. Adsorption and capillary condensation of nitrogen at 78 K in mesoporous silicas was studied by use of in situ SANS, and t as function of the relative pressure P/P_s was estimated. Adsorption of N₂ in defects within the silica skeleton at P/P_s<0.1 lead to a significant increase in I(q). Isolated vapor bubbles in capillary condensed nitrogen in a Gelsil^® appeared on adsorption near saturation of the pore system. The kinetics of capillary condensation and of drainage were followed. Power law scattering at low q indicated the formation of ramified clusters of voids on drainage of liquid nitrogen from the xerogel Gelsil^®. Similar clusters were observed on drainage of water from Vycor^® glass. Provided the clusters indicate a percolation process, the desorption branch should not be used for the estimation of a pore size distribution for materials with networked pores. The adsorptive smoothing by benzene was observed of a rough interface in a controlled pore glass.     

Accurate measurement of grain boundary misorientation by Large Angle Convergent Beam Electron Diffraction

A new method using Large Angle Convergent Beam Electron Diffraction (LACBED) patterns is proposed to measure accurately the grain boundary misorientation. The LACBED patterns which are obtained with a defocused convergent electron beam having a convergence semi-angle in the range 1 to 5^o contain very sharp deficiency lines. Due to the good quality of the LACBED patterns, these sharp deficiency lines can be used to measure with great accuracy the grain boundary misorientation. In addition, since the LACBED method is a defocus mode method, the patterns contain at the same time information on the reciprocal space (the deficiency lines typical of the crystal orientation of the two grains on each side of the grain boundary) and on the real space (the image of the grain boundary). We describe a method which allows the identification of the misorientation from these LACBED patterns. The main point to consider is the accuracy which is about 0.05^o. It is much better than the one obtained from other conventional methods used to measure this misorientation.