ABS控制过程中制动压力增长速率试验研究

研究制动压力增长速率对制动防抱死系统(ABS)控制效果的影响.采用PWM控制方法,在制动压力增长过程中,通过改变占空比达到改变制动压力增长速率的目的.提出了偏离度的概念.研究表明,使偏离度最小化的占空比能使制动压力增长速率达到最优,该方法显著提高了ABS控制效果.     

基于Washout滤波器的Van der Pol-Duffing系统的Hopf分岔控制

对一类Van der Pol Duffing系统进行Hopf分岔分析,  并基于Washout滤波器设计状态反馈控制器, 讨论控制增益对Hopf分岔的存在性及其极限环幅值的影响. 结果表明, 选取适当的控制增益可以控制Hopf分岔的发生并改变极限环幅值的大小.     

线性控制系统稳定性的几何判据

本文对线性控制系统提出稳定性一个新的几何判据,改进了Nyquist方法。将原来作特性曲线时要求在(-∝,+∝)内取值改为在有限区间[0,π/2][0,ρ]内取值,减少了计算量,而且绘制新的特性曲线只需查三角函数表,辅之以加减乘除运算,应用方便。     

准周期积分函数控制在双管正激变换器中的应用

总结了准周期积分函数的特点,并对其存在的问题加以改进.通过前馈补偿抑制负载扰动对输出电压产生的波动.把带前馈补偿的准周期积分函数控制应用在双管正激变换器中,分析其工作原理.通过仿真验证了该控制策略的有效性和可行性.     

Materials and sustainable development

Sustainable development is a concept, which involves social, ecological and economic objectives, and requires to sustain the integrity of resources exploitation, the direction of investments, the orientation of technological development and institutional change. Although there is still much confusion and conflict about exact meaning of sustainable development, many agree that sustainable development is about satisfying social, environmenta l, and economic goals. While th e concept is generally accepted and relatively easy to comprehend, the difficulty arises in trying to apply the principles of sustai nable development in practice. One of the difficulties is need to measure the “level of sustainability”. The desirable characteristics for sustainability indicators have to include: simple to calculate, useful for decision making, and robust in indicating progress towa rd sustainability. The exergy analysis a pproach based on full life cycle assessment (LCA) of the materials and technologies is a useful metrics to evaluate mitigation of green house gas (GHG) emissions associated with industrial eco materials and technologies. The metrics is used for reducing dimensionality on the input side by combining material and energy streams and out put side reducing different characterisation factors to a single “unsustainability” indicator in a theoretically rigorous manner. The adopted approach has been illustrated on a few examples associated with Australian aluminium industry.     

图的局部连通性与上可嵌入性

研究局部连通图中支撑树的变换. 给出L.Nebesk定理的一个新证明, 并将其推广得到一类新的上可嵌入图.     

Hamilton二部图的一个充分条件

证明了当设G=(X,Y;E)是连通二部图,｜X｜=｜Y｜=n!5,且δ(G)≥2,若NC2≥n-1,则G是Hamilton图。     

Adsorption refrigerationgreen cooling driven by low grade thermal energy

With the worldwide development of the economy,the energy consumption is quickly increasing, and theproblems of environmental pollution and energy shortageare becoming more and more serious. Green cooling (en-vironmental benign refrigeration), such as adso…