过共晶Al－Si合金共生区激光表面处理

用２ｋＷ连续ＣＯ２激光对过共晶Ａｌ－１８Ｓｉ合金以不同能量密度和扫描速度进行快速熔凝处理。用扫描电镜、电子微区分析仪分析了微观结构。从计算机对Ａｌ－Ｓｉ合金ｆ－ｎｆ系统的非平衡理论计算所得的共生区及实验结果的分析可见，当能量密度和扫描速度决定的凝固条件处于共生区中部时，过共晶Ａｌ－Ｓｉ合金激光表面处理可以得到共晶间距低于２００ｎｍ的完全共晶结构。     

代数曲面的几何连续过渡及其应用

本文对代数曲面的几何连续拼接作了研究，给出了多个代数曲面的几何连续过渡方法，同时给出了一种基于分片的曲面过渡方法。     

面流消能近底紊动流速特性的研究(面流消能试验研究之一)

本文主要论述了面流消能五种典型流态近底紊动流速特性,总结出了近底时均流速和紊动强度沿程变化规律,提出了近底紊动流速可能出现的最大瞬时值及相应位置的计算公式。面流消能工程的下游防冲设计中考虑的主要水力参数之一是,消能段近底流速紊动可能出现的最大瞬时值及其相应的部位,但目前国内外研究成果较少。笔者通过水工模型试验重点研究了面流消能各典型流态近底流速及其紊动纵向分量沿程的变化规律,并提出了计算公式,为优化面流设计提供科学依据。     

优化双圆弧拟合

本文提出一种优化双圆弧拟合的新算法，它采用的方法是用改变双圆弧联结点的切线使双圆弧与样条曲线间的法向误差达到最小（或小于允许误差），与其他双圆弧拟合方法相比较，该算法计算简单，线性，并可消除拟合曲线的不稳定性，拟合效果快速，良好。可直接应用于雕塑曲面的ＣＮＣ加工中。     

食品高压装置

高压装置是研究高压食品科学、开发和生产高压食品的核心设备，能否提供性能优良、价格相对便宜的装置是高压食品产业化的关键。本文系统介绍食品高压处理装置的类型、结构、性能、特点及最新研究进展，并就如何降低高压装置造价，提高生产能力等关键问题进行探讨。     

A vibrating-tube densimeter for fluids at high pressures and temperatures

A vibrating U-tube apparatus has been developed for determining the densities of pure fluids and fluid mixtures at 10-200 MPa and 323-773 K. Measured parameters areP,T, andr (period of vibration). Fluids are injected into the U-tube at constantP andT. Three or more reference fluids are used to calibrate the response of the instrument. Fluid mixtures are produced by pumping pure fluids into T-junctions on the upstream side of the U-tube using high accuracy syringe pumps. An automated syringe pump is used to maintainP at setpoint ±0.01 MPa.T is controlled to ±0.01 K using a closed-loop, electronic signal amplification/feedback system. For mixtures, a statistically significant number of measurements of r are obtained to account for the effects of small heterogeneities in fluid composition (generally <0.005X;). Typically, density data for 15 fluids can be obtained in a 6- to 8-h period. Considering all of the potential sources of error in the experimentation, conservative estimates of uncertainty are as follows:P, ±0.02 MPa;T, ±0.05 K;p (pure fluids), ±0.0005g.cm^–3; andp (fluid mixtures), ±0.0005-0.0010g-cm^–3.Paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994, Boulder, Colorado, U.S.A.     

高强度烧结钢

为开拓粉末冶金材料新的应用领域，近年来对高强度烧结钢进行了大量的研究与开发。本文简要介绍Ｈｏｇａｎａｓ公司开发的一些高强粉末冶金材料及对一些高强度烧结材料尺寸变化的控制。     

Study on Factors Affecting the Structure of High SpeedSteel Ingot Produced by ESR

ＳｔｕｄｙｏｎＦａｃｔｏｒｓＡｆｆｅｃｔｉｎｇｔｈｅＳｔｒｕｃｔｕｒｅｏｆＨｉｇｈＳｐｅｅｄＳｔｅｅｌＩｎｇｏｔＰｒｏｄｕｃｅｄｂｙＥＳＲＬｉＺｈｅｎｇｂａｎｇ；ＣｈｅＸｉａｎｇｑｉａｎＡｂｓｔｒａｃｔ：Ｔｈｅｉｎｆｌｕｅｎｃｅｏｆｔｈｅｍｅｔａｌｐ...     

Fluidization of the active component of catalysts in catalytic formation of carbon assisted by iron and nickel carbides

A series of vanadium-tin mixed oxide catalysts have been prepared by the solid-state reaction of V₂O₅ and SnO₂ at 1250°C. The fresh and the used catalysts have been characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). High temperature oxygen chemisorption (HTOC) has been employed to titrate the coordinatively unsaturated vanadia sites. Ammoxidation of mesitylene has been carried out on these catalysts and an optimum composition of vanadium is arrived at. Better yields of tricyanobenzene (TCB) compared to literature values are obtained. A good correlation between the oxygen uptake and the TCB yield extends the applicability of HTOC to the fused oxide system.IICT Communication No. 3507.     

High-temperature,high-pressure thermophysical measurements on liquid zinc

Wire-shaped zinc samples were resistively volume heated as part of a fast-capacitor discharge circuit. Time-resolved measurements with submicrosecond resolution of the current through the specimen, the voltage drop across it, and the thermal expansion of the specimen as a function of time allow determination of the enthalpy, electrical resistivity, and density at different temperatures up to superheated liquid states of zinc far above the normal boiling point. High static pressures, up to 3800 bar of the ambient medium water, were used. An estimate of the critical pressure for zinc is given by investigations of the stability of the sample with a framing CCD camera, taking pictures of different samples varying the ambient static pressure. The critical volume and the critical temperature are obtained by means of an extrapolation of measured data at different pressures.Paper presented at the Fourth International Workshop on Subsecond Thermophysics, June 27–29, 1995, Köln, Germany.