新型系列准贝氏体钢

介绍了我们多年的研究成果－－新型系列准贝氏体钢，该系列钢具有独特的组织和性能，以及广阔的应用前景。     

基于LS-DYNA软件的单点渐进成形过程的模拟方法

单点渐进成形技术是基于快速原型制造技术所发展起来的新技术，本介绍了一种基于LS—DYNA软件模拟单点渐进成形过程的模拟方法，为基础理论的研究提供了一种非常有效的方法。     

论研究型大学的办学取向

研究型大学，是创办世界一流大学的必由之路。本文试图从教育的综合性、科研的前沿性、管理的科学性、环境的学术性等四个维度等来阐述大学向研究型迈进所必须作出的取向选择，以此为研究型大学的创建提供一种新的思路。     

逆变弧焊机中IGBT的防护

本文介绍了ＩＧＢＴ逆变弧焊机中的过电压、过电流保护电路，包括外部过电压、内部过电压、输出过电流和ＩＧＢＴ器件过电流的防护措施。文中还就驱动电路的应用进行了讨论，以提高ＩＧＢＴ器件的使用可靠性。     

CALCULATION OF TRANSFORMATION VOLUME FRACTION TO HQ590 HOT ROLLED STRIP STEEL DURING CONTINUOUS COOLING

On the basis of phase transformation kinetics, the transformation of γ→α,P,B have been investigated through considering the effect of deformation. The calculation methods of volume fraction have also been given. Comparing with common method, the simulated results are in more agreement with experiment results.     

ELECTROMIGRATION PHENOMENON IN TUNGSTEN

<正> 我所自制的Auger电子能谱仪的一次电子激发源是直热式电子枪发射的电子束。电子枪的热阴极是直径0.12mm,长15mm的发叉式钨丝,两端焊在1mm的Covar丝插座上。加热电流是直流2.0—2.5A。用光学高温计测量发叉尖端温度最高。仪器调试中发现灯丝使用寿命较短。图1(见图版45)是灯丝烧断后的形貌,断口出现在偏离发尖约0.7mm的一侧,另一侧有钨的堆积。断口和钨堆积区偏离发尖的距离不相等。图2     

"SINGLE GRAIN" OSCILLATING CRYSTAL METHOD FOR ULTRAMICROANALYSIS BY X-RAY

采用“单颗”回摆法,在普通的德拜相机中,对重量只有0.003μg的超微量物质进行X射线相分析。 对方法的原理、衍射角的测量及计算、衍射斑点的数目、各个斑点的相对强度与ASTM卡片上同一物质各线条的相对强度间的关系等问题,进行了详细的分析和讨论。 举例说阴这种方法在鉴定稀土夹杂物上的应用,并验证所推导的公式的正确性。     

Effect of laser fluences on the structure of carbon nitride films deposited by direct current plasma assisted pulsed laser ablation

Carbon nitride films were deposited by direct current plasma assisted pulsed laser ablation of a graphite target under a nitrogen atmosphere at room temperature. The surface morphology, composition and bonding structure of the deposited films were characterized by atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, Raman, and X-ray photoelectron spectroscopy (XPS). The effect of laser fluences in the range 0.5–3 J/cm² on the surface morphology, composition and bonding structure of the carbon nitride films were systematically studied. As laser fluence is increased, AFM results show a great decrease in the surface roughness of carbon nitride films. FTIR and XPS results indicate an increase in the N/C ratio and the content of N atoms bonded to sp³ C, as well as a decrease in the content of H atoms and the content of N atoms boned to sp² C in the deposited films, and Raman spectra indicate an increase in the content of disordered sp² C atoms and the sp² cluster size. The increase in the film density and the decrease in the particle fraction contribute to the decrease of surface roughness with increasing laser fluence.     

A STUDY OF RATE-DEPENDENCE AT ELEVATED TEMPERATURE FOR AN Al-Cu-Mg ALLOY

The hot deformation of an Al-Cu-Mg alloy was studied in the two temperature ranges (room temperature-300℃ and 400℃-480℃). The rate-independent flow curves are typical of elasto-plastic response with significant work hardening followed by strain softening below 300℃. Similar dislocation structures with high density tangled into grain interiors were observed by TEM, which suggests that the process of obstacles arresting mobile dislocations results in this macroscopically rate-independence. At 400-480℃, all rate dependent flow behaviors characterized by a continuous softening after an initial work hardening at a small plastic strain show large tensile elongations. Long dislocation segments around the second phases infer their good mobility to climb across obstacles. Grain boundary morphology observed by TEM suggests that the capacity of the grain boundaries to absorb the dislocations sensitively accounts for the rate-dependent mechanical properties.     

二辊轧机轧辊堆焊新技术应用

介绍了二辊粗轧机轧辊利用堆焊新技术开展堆焊修复试验与应用，并介绍了堆焊材料的选择、堆焊工艺以及取得的良好效果。