船艇电站仿真与综合管理系统

论文介绍了船艇电站模拟器的组成和实时仿真功能,着重描述了多层次的图形管理系统及其仿真界面。课题将多媒体课件制作与模拟器有机地结合,涵盖了船舶主要电气设备的控制电路,既利于实践训练又便于原理的讲解,并在实践中取得了良好的效果。     

A load dispatch method using fractional programming and semidefinite programming

This paper describes a load dispatch method which minimizes power cost—[fuel cost]/[electric output]—for a power system with thermal plants and energy storage facilities. The proposed method employs fractional programming to convert a minimization problem with fractional objective function to a series of quadratic minimization problems, and semidefinite programming to solve converted problems. The method provides the optimum time‐dependent power output/input and storage level of energy storage facilities as well as time‐dependent power output of thermal plants. The method has been applied to a power system with five thermal plants, two energy storage facilities of various performances, and five load demands. The optimum load scheme of four time mesh points is obtained for the thermal plants and energy storage facilities. The fractional programming successfully converges the optimal scheme through a few iterations. The semidefinite programming deals with a variable matrix of 164 dimensions, and 185 inequality constraints. © 2001 Scripta Technica, Electr Eng Jpn, 138(2): 49–58, 2002     

Effect of crack-growth mechanism on the prediction of fracture load of adhesive joints

This paper presents observations regarding the cracking behavior of tensile-loaded structural adhesive joints. Experiments showed that fracture occurred by the development and propagation of a damage zone, rather than a single, sharp crack, and that the presence of the adhesive spew fillet did not affect the fracture load of the adhesive joints studied. For joints bonded with the mineral-filled epoxy Cybond 4523GB (American Cyanamid), there was approximately 5 mm of subcritical crack propagation prior to final fracture. Fracture-load predictions based on the initial uncracked geometry made in previous papers were unaffected by this small change in geometry. For joints bonded with the rubber-toughened epoxy Permabond ESP 310, approximately 50 mm of subcritical crack propagation was observed. It was again found that predictions made in previous papers on the basis of the initial geometry gave a good estimate of the final fracture load even though this subcritical crack propagation significantly altered the geometry, and thus the applied energy release rates. The effect of shear deformations of the adherends was also investigated, and it was found that shear deformations could be neglected in engineering calculations for joints subject to remote tensile loading.     

转向柱管承载能力的试验研究

在分析转向柱管花键部位应力集中情况的基础上,通过对某厂生产的转向柱管扭转破坏的试验研究,得到如下结论:①转向柱管的承载能力与其外花键齿与方向盘中心内花键齿之间的非接触区长度有关,以花键端部过渡圆弧的直径大小为宜;②安装方向盘总成时所施加在安装螺母上的拧紧力矩在70N.m左右时,转向柱管的承载能力最大。     

飞轮快速静平衡工艺

介绍了一种适应多品种小批量生产类型的飞轮快速静平衡工艺。     

多级复合布尔函数性能研究

本文研究了加法复合布尔函数和乘法复合布尔函数,在平衡性、k次项系数、K次扩散准则(PC)、相关免疫 性(CI)、Walsh谱、代数次数、小项分布等方面得到了一批新结果。     

孔型热轧时轧制力的实用计算公式

采用修正系数法,利用板材在带刻槽的冲头进行深冲与平面冲头下深冲时的接触压力的比值确定孔型影响系数,进而推导出孔型热轧时轧制力的实用计算公式.     

适用于稠油开采的游梁式抽油机设计分析

在稠油开采中,抽油杆在液体中运动时,所受到的摩擦阻尼力很大,有时高达几十千牛。上冲程时,该力有加大悬点载荷的作用;下冲程时,该力使抽油杆下行困难,甚至悬点载荷为零。为了开采稠油,必须根据其特点设计适应的游梁式抽油机。文章分析了稠油用抽油机的受力特点,提出了该类抽油机的设计要求。     

结构化P2P网络中基于流言传播的负载均衡

提出了结构化P2P网络中利用结点间周期性的拓扑维护通信来夹带、传播消息进行负载均衡的方法，具体针对Chord系统从消息传播的速度和规模两个方面分析了该方法的性能，并利用仿真进行了验证。讨论了结论在其它形式网络中的推广和实现中的消息管理问题。     

Accurate higher-order analytical approximate solutions to nonconservative nonlinear oscillators and application to van der Pol damped oscillators

In general, this paper deals with general nonlinear oscillations of a nonconservative and single degree-of-freedom system with odd nonlinearity and, in particular, it presents accurate higher-order analytical approximate solutions to van der Pol damped nonlinear oscillators having odd nonlinearity and the Rayleigh equation. By combining the linearization of the governing equation with harmonic balancing and the method of averaging, we establish accurate analytical approximate solutions for the general weakly damped nonlinear systems. Unlike the classical harmonic balance method, simple linear algebraic equations instead of nonlinear algebraic equations are obtained upon linearization prior to harmonic balancing. The combination of these two methods results in very accurate transient response of the periodic solution. In addition and for the first time, this paper also presents a method for deducing fourth-, fifth- and higher-order linearized governing equations from the lower-order equations without the requirement of formulating the problem from the first principle. Three examples including the van der Pol damped nonlinear oscillator are presented to illustrate the excellent agreement with approximate solution using the exact frequency.