无资料地区结合数值模拟分析计算径流的方法研究

为分析计算无资料地区的径流量,以云南省瑞丽市帕色河水库上游流域为例,进行参考站的选取及资料分析,采用水文比拟法、径流等值线法、Mike11 NAM径流模拟方法计算帕色河水库上游流域的径流量,并综合分析各方法计算结果的影响因素、流域内各时段的径流变化及邻近流域水文统计参数。结果表明采用径流等值线法在该流域更为合理、可靠。

包铜钢线热浸镀过程的简化模型

在钢线热镀 Ｃｕ实验基础上，建立简化的动态数学模型，模拟反向凝固的工艺过程，研究主要工艺参数影响的规律，以模拟参数的形式描述界面处的接触热阻，合理地反映了铜液和钢芯之间的热交换过程区域的离散采用内接点法，相变潜热的描述采用热焓法，温度和焓的增加都作为求解变量。

SOI MOSFET Model Parameter Extraction via a Compound Genetic Algorithm

We improve the genetic algorithm by combining it with a simulated annealing algorithm. The improved algorithm is used to extract model parameters of SOI MOSFETs, which are fabricated with standard 1.2μm CMOS/SOI technology developed by the Institute of Microelectronics of the Chinese Academy of Sciences. The simulation results using this model are in excellent agreement with experimental results. The precision is improved noticeably compared to commercial software. This method requires neither a deeper understanding of SOl MOSFETs model nor more complex computations than conventional algorithms used by commercial software. Comprehensive verification shows that this model is applicable to a very large range of device sizes.

Adaptive polarization i mage fusion based on regional energy dynamic weighted average

According to the principle of polarization imaging and the relation between Stokes parameters and the degree of linear polarization, there are much redundant and complementary information in polarized images. Since man-made objects and natural objects can be easily distinguished in images of degree of linear polarization and images of Stokes parameters contain rich detailed information of the scene, the clutters in the images can be removed efficiently while the detailed information can be maintained by combining these images. An algorithm of adaptive polarization image fusion based on regional energy dynamic weighted average is proposed in this paper to combine these images. Through an experiment and simulations,most clutters are removed by this algorithm. The fusion method is used for different light conditions in simulation, and the influence of lighting conditions on the fusion results is analyzed.

A systematic approach for synthesizing a low-temperature distillation system

In this paper, by combining a stochastic optimization method with a refrigeration shaft work targeting method,an approach for the synthesis of a heat integrated complex distillation system in a low-temperature process is presented. The synthesis problem is formulated as a mixed-integer nonlinear programming(MINLP) problem,which is solved by simulated annealing algorithm under a random procedure to explore the optimal operating parameters and the distillation sequence structure. The shaft work targeting method is used to evaluate the minimum energy cost of the corresponding separation system during the optimization without any need for a detailed design for the heat exchanger network(HEN) and the refrigeration system(RS). The method presented in the paper can dramatically reduce the scale and complexity of the problem. A case study of ethylene cold-end separation is used to illustrate the application of the approach. Compared with the original industrial scheme, the result is encouraging.

Parametric optimization and performance comparison of organic Rankine cycle with simulated annealing algorithm

Taking the ratio of heat transfer area to net power and heat recovery efficiency into account, a multi-objective mathematical model was developed for organic Rankine cycle （ORC）. Working fluids considered were R123, R134a, R141b, R227ea and R245fa. Under the given conditions, the parameters including evaporating and condensing pressures, working fluid and cooling water velocities were optimized by simulated annealing algorithm. The results show that the optimal evaporating pressure increases with the heat source temperature increasing. Compared with other working fluids, R123 is the best choice for the temperature range of 100--180℃ and R141 b shows better performance when the temperature is higher than 180 ℃. Economic characteristic of system decreases rapidly with the decrease of heat source temperature. ORC system is uneconomical for the heat source temperature lower than 100℃.

Numerical and experimental evaluation on methods for parameter identification of thermal response tests

Several parameter identification methods of thermal response test were evaluated through numerical and experimental study.A three-dimensional finite-volume numerical model was established under the assumption that the soil thermal conductivity had been known in the simulation of thermal response test.The thermal response curve was firstly obtained through numerical calculation.Then,the accuracy of the numerical model was verified with measured data obtained through a thermal response test.Based on the numerical and experimental thermal response curves,the thermal conductivity of the soil was calculated by different parameter identification methods.The calculated results were compared with the assumed value and then the accuracy of these methods was evaluated.Furthermore,the effects of test time,variable data quality,borehole radius,initial ground temperature,and heat injection rate were analyzed.The results show that the method based on cylinder-source model has a low precision and the identified thermal conductivity decreases with an increase in borehole radius.For parameter estimation,the measuring accuracy of the initial temperature of the deep ground soil has greater effect on identified thermal conductivity.

Torsional Vibration Analysis of an FR Driveline System

Towing tractor drivelines are lightly damped non-linear systems. Interactions between components can cause dynamic behavors such as gear gap impact in gear transmissions, shuffle and clonk phenomena in driveline. The torsional vibration of driveline has an important effect on grand engineering vehicle vibration and noise. Through analyzing torsional vibration equations of driveline, torsional vibration model of driveline is developed by using Matlab/Simulink software, Shuffle and clonk phenomena are observed in torsional vibration. The modeling method of analysizing driveline torsional vibration can be used to research and improve similar engineering vehicle driveline behavors.

Research on Preventive Maintenance Strategy of Simulator Based on Reliability Theory

Based on the theory of reliability, this paper studies the preventive maintenance strategy of the simulator with incomplete maintenance, and establishes the preventive maintenance model with the aim of simulating the maintenance cost and simulating machine availability. The main contents of this paper are as follows： Firstly, this paper introduces the background and significance of this paper, expatiates the relevant concepts and mathematical foundation of simulator maintenance related theory and reliability maintenance thought, simulator performance degradation law, Weibull parameter estimation method, As the center of the maintenance （RCM） theory of system maintenance decision analysis.