三种非对称Schiff碱的1H NMR谱

讨论了三种新型非对称Schiff碱3,4-二羟基苯甲叉单草酰胺肟,2-羟基苯甲叉单草酰胺肟和苯甲叉单草酰胺肟的¹H NMR谱,并给出这三种化合物的活泼氢的归属.     

硅衬底上锗硅合金光波导设计及工艺的优化考虑

报道用射频加热化学气相沉积法制备Ｓｉ／ＧｅＳｉ／Ｓｉ大断面单模脊形光波导中设计和工艺的进一步完善，ＧｅＳｉ合金层中Ｇｅ的含量Ｘ要满足脊形光波导是单模，光波导的数值，孔径接近单模光纤值，脊高小于临界厚度值等，计算表明兼顾上述三项要求应取ｘ＝１～３％，脊的高与宽受大断面及单模的制约。Ｓｉ的晶体结构使脊的二个腐蚀侧壁是斜坡，为此起始脊宽取５～６μｍ为宜；腐蚀液，抛光液的选取人保证脊则壁及波导面端的优良镜     

Spectral Convergence for Degenerating Sequences of Three Dimensional Hyperbolic Manifolds

For degenerating sequences of three dimensional hyperbolic manifolds of finite volume, we prove convergence of their eigenfunctions, heat kernel and spectral measure.

     

The research in image distinction for isodyne patterns

A new birefringent phase shift method applied in isodyne fringe pattern distinction is developed. The phase map obtained by the new method corresponds to the isodyne surface in whole fields. The theory and technique of the new method is described and a bimaterial beam under three-point bending is studied as an example.     

高吸水树脂凝胶强度的测定

高吸水树脂可用于油田调剖堵水,有机溶剂脱水及农田保水等。高吸水树脂凝胶中的水不易挤出。吸水凝胶的强度的岩芯测定法由于所取岩芯孔洞不均,测定结果重现性差。本文介绍一种测定吸水树脂凝胶抗压强度和抗压能的方法。 将凝胶置于压缩器中,用INSTRON-1121型材料试验机测定极限压强,以抗压强度σ表     

碲材料中钠,钾杂质成份的测定

本文揭示了钠、钾受基体元素碲干扰的现象和分析系统中酸度对钠、钾吸光度的影响,在理论上探讨了碲对钠、钾干扰的原因,利用加入盐酸和铝元素的方法分别排除碲对钾、钠的干扰,提出一个方便,实用的测定方法,回收率和RSD分别为95-102%和7.4%。     

Morphological changes in annealed ultrahigh molecular weight polyethylene (UHMWPE) gel-films

X-ray diffraction of the UHMWPE gel-films has shown that high heating rate annealing of the films causes deformation of the crystallites. The apparent crystal sizes change with the annealing temperature (T_a). With T_a below 110°C, the dimensions of the crystallites in c-axis (L_c) increase associated with the decreasing in a-axis (L_a) and b-axis (L_b), but the changes are small because of the higher energy barrier. When T_a is raised to 138°C, L_c is nearly doubled its value at 60°C whereas L_b increases and L_a remains unchanged. IR spectral subtraction was applied to reveal the morphological changes of the gel-films upon annealing. It has been found that bands of the same type of conformation have different sensitivities subject to the thermal treatment at different annealing temperatures. The results can be understood by assuming the changing process being completed through chain segments sliding along the (020) sectors. © 1995 John Wiley & Sons, Inc.     

Peculiar meaning of the concept of the information depth in appearance potential spectroscopy

The information depth of APS is not related to the escape depth of the Auger electrons, because all electrons escaping from the target at a threshold potential can contribute to the signal without respect to the amount of energy they have lost. Nevertheless, the definition of the information depth proposed by the E-42 Committee of the American Society for Testing and Materials is still valid. Our paper presents and discusses results of a recent experimental investigation of the information depth of AEAPS and DAPS.