Measurement Method of the Thickness Uniformity for Polymer Films

Several methods for investigating the thickness uniformity of polymer thin films are presented as well their measurement principles.A comparison of these experimental methods is given.The cylindrical lightwave feflection method is found to can obtain the thickness distribution along a certain direction.It is simple and suitable method to evaluate the film thickness uniformity.     

衍射法细丝直径的精密测量

分析了激光衍射法测量细丝直径技术中影响精度的几个主要因素，研究了一种微弱衍射条纹的精密处理及识别技术，有效地提高了测量精度，实测结果表明，文中讨论的技术能在１０￣５０μｍ的范围内实现正负０．１μｍ的重复精度，分辨力优于０．０１μｍ。     

锰铜基高阻尼合金中锌量的测定──硫氰酸盐萃取分离络合滴定法

基于甲基异丁基甲酮于稀盐酸介质中定量地萃取Ｚｎ￣（２＋）与ＣＮＳ￣－形成的络阴离子。从而达到与共存的锰、镍、铝、铬的完全分离。在有氟化物、硫脲存在时Ｆｅ￣（３＋）、Ｃｎ￣（２＋）和Ａｇ￣＋也不被萃取。有机相中的锌于ＰＨ５．５“六胺”缓冲介质中返萃取回水相，用ＥＤＴＡ滴定。在文中给定的条件下锌的一次被萃取率可达９９％以上，成功地解决了锰铜基高阻尼合金中共存离子对锌量测定的干扰问题。     

摩擦强度对薄膜表面形态的作用:原子力显微镜下的观察

展示了摩擦强度对聚酰亚胺薄膜表面形态的影响，原子力显微图像显示，机械摩擦会使聚酰亚胺薄膜表面上形成微沟槽，这些沟槽的表面具有丰富的表面精细构造。原子显微图像还揭示了机械摩擦可以改变被磨擦聚酰亚胺膜的表面形态。     

Structural properties of phosphorous-doped polycrystalline silicon

The structural properties and hydrogen bonding of undoped and phosphorous doped polycrystalline silicon produced by step-by-step laser dehydrogenation and crystallization technique were investigated using Raman spectroscopy and hydrogen effusion measurements. At low laser fluences, E_L, a two-layer system is created. This is accompanied by the change in hydrogen bonding. The intensity of the Si–H vibration mode at 2000 decreases faster than the one at 2100 cm⁻¹. This is even more pronounced in phosphorous-doped specimens. The laser crystallization results in an increase of the hydrogen binding energy by approximately 0.2–0.3 eV compared to the amorphous starting materials.     

Optimal Layout of Displacement Measurements for Parameter Identification Process in Geomechanics

This paper focuses on designing the optimal layout of measurements for parameter identification problems in geomechanics, which are usually based on in situ displacements. The existence, uniqueness, and stability of the solution from the parameter identification process are thoroughly discussed. Based on these understandings of the problem, two algorithms are proposed as a means of automatically generating the optimal measurements. The validity of these algorithms is first proved by some academic examples, then these algorithms are applied to the Munich subway tunnel project. Good results are observed there.     

德国联邦物理技术研究院(PTB)气体微流量计量评介

在真空技术应用中 ,高精度气体微流量计用于连续膨胀法校准系统压力的产生、漏孔漏率的测量以及真空泵抽速的测定。PTB先后研制了三代气体微流量计 ,第一代为手动型 ,第二代为半自动型 ,第三代为全自动型。本文详细介绍了PTB研制的气体微流量计的性能和特点 ,并介绍了气体微流量计在真空漏孔的漏率测量方面的应用。另外 ,还介绍了PTB最近研制的大气压力下漏孔漏率测量系统的性能和特点     

Measurement of the Timoshenko Shear Stiffness. II: Effect of Transverse Compressibility

This is the second of two papers devoted to the issue of measuring the Timoshenko shear stiffness of thin-walled composite beams. In the first paper, the effect of warping on the effective Timoshenko shear stiffness, as measured through bending tests, was studied. The bending test was simulated using finite-element analysis, and the results indicated that the warping effect was minimal. On the other hand, the evidence suggests that transverse flexibility may have a significant influence on the effective Timoshenko shear stiffness, decreasing the effective shear stiffness at shorter test spans. The purpose of the present study is to further investigate this effect and to explore the use of a sandwich theory to predict the measurement error. A higher-order sandwich theory, which captures the transverse strain at concentrated loads and supports, is applied to a commercially available thin-walled composite beam. The results indicate that the sandwich model does capture the decrease in the effective shear stiffness at short spans, and the dependence of the shear stiffness on span-to-depth ratio is similar to that calculated in the first paper, using the finite-element method.     

Improved direct bonding method of Nd:YVO4 and YVO4 laser crystals

We succeeded in the fabrication of bonded laser crystals composed of a neodymium-doped YVO₄ laser crystal (Nd:YVO₄) and its host crystals YVO₄ by a newly developed dry etching technique using an argon ion beam. The optical distortion caused by the bonded interface of size 5 mm × 6 mm was estimated to be 0.05λ at 633 nm. From the comparison of laser performance pumped by a laser diode, the bonded crystals could increase the laser output power by nearly twice that of the non-bonded crystals with the same degree of polarization of 99.2%. To analyze the mechanism of the enhanced reduction of the thermal load in the bonded crystals, numerical simulations with a finite-element method were also performed.     

PSD激光直线度测量仪

介绍了采用PSD传感器设计的激光直线度测量的工作原理，以及激光器、光靶和计算机系统的设计。