反应自生Al_3Ni－Al_2O_3－Al复合材料

通过热力学计算，选择Ｎｉ_２Ｏ_３粉末作原材料，采用反应挤压铸造方法实现了Ａｌ与Ｎｉ２Ｏ３直接压铸反应合成Ａｌ３Ｎｉ－Ａｌ２Ｏ３－Ａｌ原位复合材料。研究了压铸工艺参数和预制块中纯Ａｌ粉的含量对反应合成复合材料过程的影响，并对反应机理做了较深入的分析。结果表明，Ｎｉ２Ｏ３与Ａｌ的反应是为高放热反应，反应是爆发式的，通过调整预制块中Ａｌ粉的体积分数控制了反应的剧烈程度，并能获得不同组成和基体含量的复合材料。对反应机理的分析表明，在Ａｌ足量的情况下，Ｎｉ２Ｏ３与Ａｌ反应合成复合材料分为两个过程，一是反应过程，即Ｎｉ２Ｏ３＋Ａｌ→Ａｌ２Ｏ３＋［Ｎｉ］；二是凝固过程，即反应后多余的Ａｌ与反应生成的［Ｎｉ］在随后冷却中的凝固过程，最终形成Ａｌ３Ｎｉ＋α－Ａｌ２Ｏ３＋Ａｌ复合材料。     

Reticulated Porous Multiphase Ceramics with Improved Compressive Strength and Fracture Toughness

A multiphase reticulated porous ceramic (RPC) as Si₃N₄–Al₂O₃–SiO₂ was fabricated by replication techniques. Proper volumes of additives and twice sinter- twice immerse process endow the RPC an excellent crack healing and submerging property. The compressive strength and fracture toughness improved owing to the crack bridging behavior. The existence of pores in struts in RPC blunt the crack tip and increased the external force needed to propagate the crack. The mechanisms play a beneficial role in enhancing the compressive strength and fracture strength. Si₃N₄ RPC with additives of 5%Al and 5% Al₂O₃ yielded the compressive strength of 9.8 MPa and fracture toughness of 0.3 MPa m^1/2.     

泥沙实体模型时间变态问题的研究

运用数学模型对陈家湾~新厂河段实体模型进行数值模拟,采用该河段2002年10月~2004年7月实测水沙资料,对实体模型时间变态有关问题进行了系列研究。分别采用容重为1.38t/m3及1.15t/m3模型沙比较了沿程水位、流量、流速、含沙量等基本参数的变化过程与原型的偏差,以及由此引起模型河道冲淤量与原型河道的偏差,并对这些物理量偏差的原因进行探讨。     

阜新市细河改造工程坝基渗漏计算及处理效果分析

阜新市细河改造工程由四座橡胶坝和两岸防洪大堤组成，由于堤(坝)基第四系冲洪积层广泛发育，存在渗漏同题。合理选择施工处理方案，是工程成功的关键。作者根据场区不同的地质条件环境条件采取有针对性的不同处理方案，既解决了防渗问题又缩短了施工工期，降低工程造价，取得了很好的经济效益和社会效益。     

浅析分户供热的计量

本文介绍了国外在供热分户计量方面的测定原理、手段和设备,费用分配原则,仪表与系统的配合和安装方式,并就其与国内系统的配合提出了建议。     

Numerical Filling Simulation of Injection Molding Using Three-Dimensional Model

1 Introduction During injection moulding, the rheological response of polymer melts is generally non-Newtonian and nonisothermal with the position of the moving flow front. Because of these inherent factors, it is difficult to analyze the filling process. Therefore, simplifications usually are used. For example, in middle-plane technique and dual domain technique [1], because the most injection molded parts have the characteristic of being thin but generally of complex shape, the Hele-Shaw …     

排列互比法用于超精测角的研究

作者分析了我互比法现行的两种数据处理方法的缺点，提出了应用最小二乘法原理推导出合理的数据处理方法。本文还首次从理论上阐明了排列互比法测量结果中出现一次谐波系统误差的原因，提出了减少和消除这一些系统误差的方法，并给实验验证。     

Ornithine decarboxylase transformation of NIH/3T3 cells is mediated by altered epidermal growth factor receptor activity

Ornithine decarboxylase (ODC) has been shown to be oncogenic in transfected NIH/3T3 cells overexpressing the enzyme from a heterologous promoter. These cells, designated as NODC-2 cells, acquire proliferative properties associated with tumorigenic transformation such as loss of contact inhibition, decreased population doubling time, anchorage-independent growth, and tumor production in nude mice. At least one of these parameters, loss of contact inhibition, remains dependent on elevated ODC levels. We have used these cells to investigate the molecular mechanisms by which ODC overexpression drives cell transformation and to examine the involvement of other proto-oncogene products in this process. An interaction between ODC overexpression and the epidermal growth factor receptor (EGF-R) was suggested initially by the elevation of both basal (300%) and ligand-induced (457%) EGF-R tyrosine kinase activities in NODC-2 cells compared to similarly treated control NLK cells. Disruption of EGF-R mediated signal transduction in NODC-2 cells both by treatment with tyrphostin-25 or by transfection with a vector expressing a dominant negative EGF-R mutant resulted in reacquisition of contact-inhibited growth and suppression of anchorage-independent, clonogenic growth in soft agar. We conclude that ODC-induced transformation of NIH/3T3 cells is mediated, at least partly, by alterations in EGF-R signal transduction activity.     

FSC系统在加氢裂化—连续重整联合装置的应用

紧急停车系统对于生产过程的安全是十分重要的.以HONEYWELL公司的FSC系统为例.介绍了该系统在加氢裂化一连续重整联合装置的实际应用,对装置的长、安、稳运行起到了重要作用。