Cu对304奥氏体不锈钢应变诱发马氏体相变的影响

借助 X-射线衍射分析法研究了 0.45% ~1.44%Cu 对(%)：0.068 ~ 0.072C 18.72~19.06Cr 、9.40~ 9.46Ni的304不锈钢-196 ℃低温拉伸应变诱发马氏体相变的影响。结果表明,Cu对304不锈钢-196 ℃应变诱 发e马氏体相变有明显的抑制作用;当Cu含量增至1.44%时,在经低温变形的钢中未检测到ε马氏体相变。随钢中Cu含量增加,-196℃ 应变诱发α'马氏体相变倾向降低,致使应变累积到一定程度后,流变应力低于低Cu钢。     

矿井主通风机系统改造的分析及研究

矿井通风系统由于受矿井整体开拓布局的影响原设计已经不能满足矿井中后期生产的需要。如何以最经济的方式既能满足生产需要又能充分节约现有的资源,成为我们面临的主要问题。该文通过对矿井主通风机系统改造的分析及研究,阐述了做好矿井主通风机改造的必要性与可行性。     

Differential Transformation Method to determine fin efficiency of convective straight fins with temperature dependent thermal conductivity

In this study, fin efficiency of convective straight fins with temperature-dependent thermal conductivity is solved using a simulation method called the Differential Transformation Method (DTM). The concept of differential transformation is briefly introduced, and then we employed it to derive solutions of nonlinear equation. The obtained results from DTM are compared with those from the exact and numerical solution to verify the accuracy of the proposed method. The results reveal that the Differential Transformation Method can achieve suitable results in predicting the solution of such problems. After this verification, we analyze the effects of some physical applicable parameters in this problem such as thermo-geometric fin parameter and thermal conductivity parameter.     

基于Block-SVD的小波域彩色图像数字水印算法

提出了一种基于Arnold变换和分块奇异值分解（Block-SVD）的小波域彩色图像数字水印算法。该算法采用彩色图像作为载体,灰度图像作为水印,增加了嵌入的信息量。仿真结果表明,该算法具有时间效率高、水印不可见性好、抗攻击能力强等特点,在版权保护方面具有一定的应用价值。     

长轧辊卷板机改造设计研究

作者利用已取得的研究成果，深入探索及研究了实际工况下长轧辊卷板机滚卷长圆柱形金属板产生直线度误差的机理，并提出长轧辊卷板机改造设计的新方法。研究表明，按本文推荐方法改造卷绕机可使长圆柱板直线度误差大幅度下降。     

罗德洛基公司拉赫焦化分厂

介绍了芬兰罗德洛基公司拉赫焦化分厂的工艺概况，重点论述了该厂对干熄焦的改造过程。     

Reduction of NOx over Fe/ZSM-5 catalysts: mechanistic causes of activity differences between alkanes

Fe/ZSM-5 catalysts prepared by sublimation of FeCl₃ onto H/ZSM-5 catalyze the selective reduction of NO_x by hydrocarbons to N₂. The order of the relative rates and N₂ yields obtained with different alkanes reveals a non-trivial chemistry. The maximum yield is lower for propane than for n-butane but about the same for n- and iso-butane. However, at temperatures below this maximum, the N₂ yield is higher for propane and n-butane than for iso-butane. Deposits are formed on the catalyst that contain N atoms in a low-oxidation state which are able to react with NO₂ to form N₂. TPO and FTIR results show that the amount and also the character of the deposits depend on the nature of alkanes. The change of the oxidation state of nitrogen from a high value in NO or NO₂ to a lower value in nitrile and amino groups of the deposit is rationalized by applying mechanistic concepts of organic chemistry, including the Beckmann rearrangement and fragmentation. FTIR spectra and the observed oxygen- and nitrogen-containing compounds by GC-MS are potential clues to the reaction mechanism.     

A non-linear masonry infill macro-model to represent the global behaviour of buildings under cyclic loading

The presence of masonry infill walls in RC buildings is very common. However, and even today, in the design of new buildings and in the assessment of existing ones, these infill walls are usually considered as non-structural elements and their influence in the structural response is generally ignored. For horizontal loading, infill panels can drastically modify the response, attracting forces to parts of the structure that have not been designed to resist them. This paper presents an improved non-linear numerical simulation model for the influence of the masonry infill walls in the seismic behavior of structure. The model is implemented in the PORANL program. After the implementation and calibration of the proposed masonry model, a series of non-linear dynamic analyses of a building representative of Modern Architecture in Europe were carried out. The main objective was to investigate the behavior of this type of building, and any weakness under seismic loading. The building geometry and the dimensions of the RC elements and infill walls were set in the original project, and confirmed in the technical visits. The building under study has nine storeys and the structure is mainly composed of 12 plane frames oriented in the transversal direction. The building was analyzed with a simplified plane model, for each direction, and the existing infill panels were looked at in accordance with their dimensions and location. The earthquake action adopted in this study was simulated through three series of artificially generated earthquakes, for a medium/high seismic risk scenario in Europe.     

Two way shape memory loss in Cu---Zn---Al alloy

Investigation is carried out to understand the reasons behind the degradation of two way shape memory effect in Cu---Zn---Al alloy which exhibits a complete loss in its two way memory effect after a finite number of transformation cycles. It is observed that the two-way memory loss is attributable to a chemical effect viz. the precipitation of intermetallics at the martensite plate boundaries. Since repetitive thermal cycling is related to some kind of ageing effects, the present investigation also includes the study on the ageing behaviour of the alloys. The ageing effects are finally co-related with the observed two-way shape memory loss to describe the transformation fatigue found in the Cu---Zn---Al alloy.     

华威商住大厦厚板转换结构设计

介绍四川华威商住大厦工程概况、结构选型、计算及主要技术措施。着重介绍合理调整转换结构竖向刚度满足底部大空间使用要求以及上部短肢剪力墙设计措施。