大尺寸玻璃网格板制作工艺的研究

玻璃网格板是一种相互垂直的纵、横刻线的二维线纹标准器,用来检测航测仪器、遥感仪器和各类二维坐标测量仪器的精度,因此,它的精度直接影响待检仪器的精度。结合计量圆光栅的制作工艺,详细介绍了基于光刻胶的玻璃网格板新型制作工艺,检验结果表明该种工艺制作的玻璃网格板线条均匀,280mm内刻线间距精度小于1μm。     

《自我主义;或心底之蛇》的罪恶观解读

通过分析霍桑短篇小说《自我主义;或心底之蛇》中"蛇"的隐喻义,聚焦于作者的罪恶观,并阐释这种罪恶存在的根源、危害及其救赎良方。     

校园文化思想政治教育功能及其实现

校园文化是思想政治教育重要的载体,具有育人导向、渗透和熏陶、约束、规范和传承、融合、创新文化等功能,本文依据时代的特征,从"两课"进网络文化、加强对校园文化活动的思想导向;结合本院社团文化活动的实际,阐述了对校园文化思想政治功能实现问题的看法。     

Machinability of Metal Matrix Composites Reinforced by 3-D Network Structure

Metal matrix composites reinforced by three-dimensional (3-D) continuous network structure reinforcement (3DCNRMMC) are difficult to machine due to serious tool wear and poor surface roughness caused by the brittle and hard reinforcement which interpenetrate into ductile matrix. In order to achieve the approach of low cost of 3DCNRMMC, the machinability of it needs to be understood. The influences of three cutting parameters and volume fraction of reinforcement on cutting force were analyzed in detail. The results indicate that: (1) Due to the brittle phase(s) introduced into ductile matrix of composites, there is a large fluctuation of cutting force causing deterioration of machinability. The fluctuation ranges of cutting forces, initially increase rapidly with the increase of volume fraction of reinforcement and then decrease finally, are largest at the range of the volume fraction of 55–65%; (2) The influence of cutting parameters on cutting force is obvious. With the increases of cutting speed, cutting force decreases gradually unless cutting speed exceeds the value of 209 m/min. Cutting forces increase with increasing feed rate and depth of cut; (3) Owing to the large fluctuation of cutting force, there were some cratered surfaces caused by Si₃N₄ reinforcement pulling-out and flaking-off. Some brittle phase protruding from the machined surface caused the deterioration of machined surface.     

DCS系统控制逻辑与联锁的分析及改进

针对DCS系统（分散控制系统班制逻辑、联锁上出现的问题进行分析和解决，阐述了完善改进控制逻辑的方法，提高了设备稳定运行。保证了机组长周期安全经济运行。     

A Study on the Pd/a-Si/Ni Seed Layer for Metal-Induced Lateral Crystallization and Poly-Si TFTs

The effect of Pd on the growth rate of metal-induced lateral crystallization (MILC) from Ni seed and the electrical properties of thin-film transistors (TFTs) fabricated on the films crystallized by MILC were investigated. When the Pd metal is placed on the amorphous-silicon/Ni-seed layer, the MILC growth rate is two to three times faster than that of conventional Ni-MILC, without any degradation of TFTs. These results were explained by a stress that is generated by the formation of Pd₂Si     

Analysis of singular stress fields at multi‐material corners under thermal loading

The scaled boundary finite‐element method is extended to the modelling of thermal stresses. The particular solution for the non‐homogeneous term caused by thermal loading is expressed as integrals in the radial direction, which are evaluated analytically for temperature changes varying as power functions of the radial coordinate. When applied to model a multi‐material corner, only the boundary of the problem domain is discretized. The boundary conditions on the straight material interfaces and the side‐faces forming the corner are satisfied analytically without discretization. The stress field is expressed semi‐analytically as a series solution. The stress distribution along the radial direction, including both the real and complex power singularity and the power‐logarithmic singularity, is represented analytically. The stress intensity factors are determined directly from their definitions in stresses. No knowledge on asymptotic expansions is required. Numerical examples are calculated to evaluate the accuracy of the scaled boundary finite‐element method. Copyright © 2005 John Wiley & Sons, Ltd.     

Strain rate sensitivity of tensile properties in high Nb containing TiAl alloys

The effect of strain rate on the yield strength of high Nb containing TiAl alloy was studied. The results show that the strain rate sensitivity varies with the test temperature, and the yield strength is not sensitive to the strain rate at room temperature but significantly sensitive to the strain rate at high temperature. An increase of the strain rate or a decrease of the temperature results in an obvious change of fracture mode. It is found that the strain rate sensitivity of this alloy varying with temperature is due to the dislocation climb generated at high temperature.     

海洋环境下船用空调现状及发展探讨

本文介绍了海洋环境下船用空调的特殊性,指出风机的选择对于保证空调系统运行是非常重要的,从环保和节能的角度出发认为采用吸收式或吸附式制冷是船用空调发展的一个方向.