Matlab汽车运动控制系统设计

本课题以汽车运动控制系统的设计为应用背景,利用MATLAB语言对其进行设计与仿真。首先对汽车的运动原理进行分析,建立控制系统模型,确定期望的静态指标（稳态误差）和动态指标（超调量和上升时间）,最终应用MATLAB环境下的.m文件来实现汽车运动控制系统的设计。其中,.m文件用step（s）语句来绘制阶跃响应曲线,根据曲线中指标的变化进行PID校正。     

NONLINEAR DYNAMICS OF LATERAL MICRO-RESONATOR INCLUDING VISCOUS AIR DAMPING

The nonlinear dynamics of the lateral micro-resonator including the air damping effect is researched. The air damping force is varied periodically during the resonator oscillating, and the air damp coefficient can not be fixed as a constant. Therefore the linear dynamic analysis which used the constant air damping coefficient can not describe the actual dynamic characteristics of the mi-cro-resonator. The nonlinear dynamic model including the air damping force is established. On the base of Navier-Stokes equation and nonlinear dynamical equation, a coupled fluid-solid numerical simulation method is developed and demonstrates that damping force is a vital factor in micro-comb structures. Compared with existing experimental result, the nonlinear numerical value has quite good agreement with it. The differences of the amplitudes (peak) between the experimental data and the results by the linear model and the nonlinear model are 74.5% and 6% respectively. Nonlinear nu-merical value is more exact than linear value and the method can be applied in other mi-cro-electro-mechanical systeme (MEMS) structures to simulate the dynamic performance.     

An Integrative Technique for Predicting Cooling Performance of Tanks

The cooling process of tanks relates to various physical actions, parts or components and fluids. A predication method is presented to evaluate the effects of cooling system for tanks . A predication model that includes the heat production, heat transfer and fluid flow modules is established. The engine combustion and friction between components act as the primary heat sources. The solid components of power transmission train are partitioned into thermal nodes. The heat conductions among the thermal nodes, coolant, lubricant, powerhouse fresh air, combustion gas and exhaust gas are taken into account. The coolant flow, lubricant flow and powerhouse air flow are also considered. The prediction model is resolved by use of a multilayer iterative technique and an arithmetic of local convergence combined with global convergence for coupled modules. A calculation example shows that the model can implement predication of cooling system under different environment temperatures and running conditions quite better.     

按分支节点完全等效解耦的配电网故障定位法

提出了一种按分支节点完全等效解耦的配电网故障定位新方法。用邻接表结构体存储配电网络拓扑信息、将配网拓扑等效解耦为边不相接路径的定理进行了推广．将网络解耦成若干务单树枝支路,以首节点、次节点和末节点三节点信息组来描述单树枝支路．进而提出新的判据,初步定位故障所在支路。经对该支路进行详细故障定位,该方法对多重故障定位同样适用,从效果上可以看出该方法减小了计算量,缩小故障判定的范围,可以快速准确地实现故障定位的要求。     

Primary study on solvent effect of COCA4 by laser photolysis

Reaction of p-tert-oxocalix[4]arene in acetonitrile (CH3CN) by 308nm laser pulses was investigated to understand its mechanism as polymer stabilizer. Four main absorption bands were observed at 300nm, 400nm, 460nm and 540nm. The 300nm absorption was assigned to the absorption of phenoxy radical, and the 460nm and 540nm were triple state absorption. It was concluded that the relative stable phenoxy radical mediate was formed through intramolecular energy transition of carbonyl triplet after laser excitation in CH3CN. The formation mechanism of phenoxyl radical was quite different from that in cyclohexane (C6H12), which was cooperation of two-photon process and one-photon process.     

Energy loss caused by shielding effect of steel cage outside source tube

The energy loss, produced by shielding effect of steel cage outside the source tube, is quite considerable. With PENELOPE software package, MC results have been obtained based on the simulation of different source con- formations. The result illustrates that the naked source tubes can improve the utilization ratio of the cobalt facilities. It demonstrates the applied value of the naked source tube in engineering.