中国炼焦煤资源与焦炭质量的现状与展望

从我国炼焦煤资源和炼焦工业现状角度论述了二者间存在的矛盾.概述了国内外诸如提高焦炉炭化室高度、捣固炼焦、煤调湿、配型煤炼焦、干熄焦以及利用焦炉处理有机废弃物等措施扩大炼焦煤源的总体情况,以及这些措施对焦炭提质的作用效果,展望了今后焦化工业的技术发展趋势.     

空间凸轮机构分度误差分析

定量分析了空间凸轮机构中各尺寸误差对机构转动曲线和分度精度的影响,并且用概率法给出各尺寸误差的允许变化范围.     

发电投资的期权博弈决策方法

电力市场中,发电商进行发电投资决策时面临着其他发电商的竞争和项目投资价值的不确定性等因素,这些因素在传统发电规划方法中基本被忽略。为兼顾这些因素,文中运用Black—Scholes（B—S）期权定价模型,并采用非合作博弈理论对多发电商的发电项目延迟投资决策进行评估,从而便于发电商做出更合理的投资决策。实际系统算例说明了该模型和决策方法的合理性和有效性。     

唐山市古冶区工业废弃地活化与再生策略研究

在综合分析现状的基础上,提出了唐山市古冶区工业废弃地活化与再生的原理、目标及实施策略。     

Detection and analysis of weld penetration in stationary TIG arc welding — a preliminary study

Abstract

A constant voltage microcomputer controlled welding source is used for on-line detection of weld penetration. By adding an instantaneous pulse at regular intervals to the normal welding current the molten pool is excited to oscillate in stationary TIG arc welding. By analysing the signal, the relationship between the frequency of molten pool oscillation and weld penetration is studied and a mathematical model, the weld pool oscillation equation, is established. Using a finite difference equation to solve the eigenvalue problem of the molten pool oscillation, a numerical solution can be obtained. Experimental results obtained from welding 1Cr18Ni9Ti, 20 # and 16Mn steel show good agreement with the theoretical predictions.     

矿用蓄电池电机车运输大型综采设备的实践

介绍了在井下轨道运输系统采用CAY25/9P型蓄电池电机车运输大型综采设备的方法.如此,解决了架线式电机车牵引力不足的问题.     

Viscosity variations of coal-oil slurry under high temperature and high pressure during heating process

Heating coal-oil slurry (COSL) is an important step in direct coal liquefaction. Some physical and chemical properties of COSL including its viscosity will change during heating. A rotary viscometer was self-designed to measure the viscosity of COSL under high pressure and temperature. Three kinds of coal, which are Yanzhou coal (middle rank and caking), Shenhua coal (low rank and non-caking) and Shengli coal (brown coal), were mixed with anthracene oil to prepare the COSL. The COSL from Yanzhou, Shenhua and Shengli at the same experimental conditions showed different viscosity variations under high hydrogen pressure during heating. Yanzhou COSL had a higher viscosity peak, while Shenhua COSL had two small viscosity peaks and in the case of Shengli COSL, no viscosity peak was present under a high hydrogen pressure during the whole heating process. The coal nature is the important factor of viscosity variations of COSL. The higher the coal rank, the more caking coal is present, and the more obvious the viscosity variations of the COSL are.     

冲击电压校准器的实验验证

本文介绍的是用来校验冲击峰值电压表的标准仪器——冲击电压校准器的实验验证方法的原理及实用试验线路,分析了实验误差。     

中国凹版艺术的渊源与发展

阐述了凹版艺术的起源和凹版艺术的主要代表人物凯绥·珂勒惠支及其代表作,回顾了中国凹版版画的产生、发展和崛起,介绍了国内优秀凹版艺术家陈晓南、曹剑峰、王维新等人的代表作以及国内金属腐蚀版画和塑料版画的新成就。     

Grain trajectory and grain workpiece contact analyses for modeling of grinding force and energy partition

To achieve controlled stress grinding and controlled grinding of the depth of modificative layer, coupled analysis of grinding force and grinding heat is required. Therefore, this paper investigated grinding force and energy partition to lay a foundation for the coupled analysis. Firstly, a new grinding force model based on the analyses of grain trajectory and grain workpiece contact. In the modeling of grinding force, critical grain indention depths for plowing and cutting were calculated and the grinding force models of a single grain were established. This model can analyze the contributions of sliding, plowing, and cutting to total grinding forces. Secondly, an energy partition model was established based on the analyses of grain trajectory and grain workpiece contact. In the modeling of energy partition, the real contact area ratio and the grain contact radius were calculated. Finally, experiments were pursued to validate the grinding force model by comparing the experimental measurements to the theoretical results. Comparisons showed reasonable agreement quantitatively.