电力系统备用容量模型

发电设备合理备用容量和备用率问题是电力系统中的一个特殊问题。本文在等效持续负荷曲线概念的基础上,利用曲线拟合的思想,得出了负荷与时间的函数关系式,进一步求得合理备用容量和备用率。     

等效剪切刚度的框架结构损伤识别方法

为研究有别于现有侧重于研究结构具体构件(梁、柱及支撑等)的建筑结构损伤识别方法,提出应直接从整体开展框架结构损伤识别方法.将框架结构转换成"等效剪切型"结构,数值分析表明,结构具体构件出现损伤(即刚度发生退化)时,会引起受影响层的等效剪切刚度发生变化,因此,可以采用层等效剪切刚度变化率与层抗侧刚度作为指标来进行结构损伤定位与损伤程度评定.通过大量的框架结构数值模拟计算,归纳出了一套能将损伤定位到结构层及从整体来评定结构损伤程度的方法.     

Zonal disintegration phenomenon in enclosing rock mass surrounding deep tunnels -- Elasto-plastic analysis of stress field of enclosing rock mass

The zonal disintegration phenomenon (ZDP) is a typical phenomenon in deep block rock masses. In order to investigate the mechanism of ZDP, an improved non-linear Hock-Brown strength criterion and a bi-linear constitutive model of rock mass were used to analyze the elasto-plastic stress field of the enclosing rock mass around a deep round tunnel. The radius of the plastic region and stress of the enclosing rock mass were obtained by introducing dimensionless parameters of radial distance. The results show that tunneling in deep rock mass causes a maximum stress zone to appear in the vicinity of the boundary of the elastic and the plas-tic zone in the surrounding rock mass. Under the compression of a large tangential force and a small radial force, the rock mass in the maximum stress zone was in an approximate uniaxial loading state, which could lead to a split failure in the rock mass.     

印度应对能源需求的生态友好能源生产（英文）

全球能源需求增长显著,并且初级化石能源消耗已经呈现出很高的正增长.讨论不同的初级能源消耗情况,以及预测未来煤炭将继续作为主要能源.讨论印度的能源需求前景,以及预测未来印度对石油、天然气、煤层气和地下煤气的需求情况,同时还讨论当今国家的石油和石化工业的情况,以及在未来几年内的新能源来取代初级化石能源的最新进展.发展经济和缓解贫困取决于能否获得廉价的能源和国家的能源安全.在石油石化行业等能源行业,有必要通过政府政策的扶持,发展最新先进技术.设计这些行业路线图,规范能源企业在印度和海外的最佳实践.文中还讨论通过现代管理手段使其有效定位环境与社会的挑战,应对经济增长,并且满足能源需求的战略,但是这样的能源应当更多关注环境退化问题.结论指出能源安全可以引导能源自主是有可能的,并且可以通过规划方式来实现.     

高职院校经济管理类专业英语教学的调查研究

专业英语教学改革是高职院校发展的必然要求。本文对南京化工职业技术学院经济管理类专业英语教学情况进行调查研究,为改善经管类专业英语教学状况提供可靠的依据。     

加强企业内部经济责任制运行之我见

企业内部经济责任制是众多企业经营管理工作的一项基本管理制度。指标合理、体系完备、主体明确是推行责任制的基础;强化过程监控是保障经济责任制有效运行的必要手段;强化目标管理、严格考核兑现是推行经济责任制的关键。只有科学确定企业总体经营目标、合理分解目标任务、考核奖励公平公正,才能保证企业经济责任制的顺利实施。     

基于MATLAB/Simulink的染料敏化太阳能电池输出特性仿真

根据染料敏化太阳能电池(DSSC)的等效电路,应用MATLAB/Simulink工具建立仿真模型,对DSSC的输出伏安特性及输出功率进行仿真,讨论串联电阻和分流电阻对DSSC性能的影响.仿真结果表明,随着串联电阻的增加,开路电压不变,短路电流密度、最大输出功率及填充因子降低;随着分流电阻的增加,开路电压、短路电流密度、...     

砌体等效断裂韧度的实用解析方法研究

根据砌体准脆性材料的断裂特性,提出了一种基于竖向灰缝模型的求解砌体等效断裂韧度的实用解析方法.首先根据复合材料力学和线弹性断裂力学的基本原理,运用修正的剪滞理论,分区引入变异层,建立了分层剪滞模型;然后根据能量法则,推导出了求解无筋砌体等效断裂韧度的解析计算模式;最后针对相关试验数据,得到了对应数值解的解析解,且与相关试验对应的数值解相比,解析解的均方差和变异系数更小,由此可以看出,本文的解析方法具有很好的鲁棒性.结果还证明了无筋砌体等效断裂韧度是与试件尺寸无关的断裂参数.该方法为砌体结构开裂机理的研究和发展,砌体结构力学性能的研究提供了新的技术路径.     

Orientation angle workspaces of planar serial three-link manipulators

This paper presents a classification on the workspaces of planar serial three-link manipulators, that is, position workspace and orientation angle workspace. Position workspace indicates the region reached by the reference point on the end-effector. Orientation angle workspace indicates a set of angle ranges by which the end-effector can reach with certain orientation for every point in the reachable position workspace. By introducing a virtual equivalent mechanism, reachable position workspace can be divided into several Grashof intervals and non-Grashof intervals. The calculation equations of orientation angle workspace are deduced in three situations according to the relationships among four link lengths in the virtual four-bar chain. Three examples are given for three kinds of relationship of link lengths. The orientation angle workspace of extended groups, that is, two of the three link lengths equal, and the orientation angle workspace when the reference point on the end-effector moves along a non-radial direction are also discussed. A program is developed to calculate orientation angle workspaces and output variation curves of orientation angle workspace and key data within the position workspace. The approach and program in this paper can be used for fast calculation and identification of the variation rule of the orientation angle workspace of any given planar serial three-link manipulator on the basis of its link parameters, and for the design of a highly dexterous serial manipulator with proposed link relations. Supported by the Natural Science Foundation of Shanxi Province (Grant No. 20041070)     

Modeling and economic analysis of CO<Subscript>2</Subscript> separation process with hollow fiber membrane modules

The main purpose of the study was to develop a model using ASPEN and Excel simulation method to establish optimum CO₂ separation process utilizing hollow fiber membrane modules to treat exhaust gas from LNG combustion. During the simulation, optimum conditions of each CO₂ separation scenario were determined while operating parameters of CO₂ separation process were varied. The characteristics of hollow fibers membrane were assigned as 60 GPU of permeability and 25 of selectivity for the simulation. The simulation results illustrated that 4 stage connection of membrane module is required in order to achieve over 99% of CO₂ purity and 90% of recovery rate. The resulted optimum design and operation parameters throughout the simulation were also correlated with the experimental data from the actual CO₂ separation facility which has a capacity of 1,000 Nm³/day located in the Korea Research Institute of Chemical Technology. Throughout the simulation, the operating parameters of minimum energy consumption were evaluated. Economic analysis of pilot scale of CO₂ separation plant was done with the comparison of energy cost of CO₂ recovery and equipment cost of the plant based on the simulation model. This work was presented at the 6 ^th Korea-China Workshop on Clean Energy Technology held at Busan, Korea, July 4–7, 2006.