Control Strategy and Simulation Study on NiMH Battery Quick Charging for Regenerative Braking of HEV

Based on the result of NiMH battery performance experiments, changing trend of maximal temperature and difference in temperature of HEV NiMH battery in different SOC and different charging current is analyzed. Considering the working situation of HEV NiMH battery and the theory of battery quick charging, a control strategy for NiMH battery quick charging is described which adapts to HEV regenerative braking system based on Mascc law. By Modeling and simulating the process of NiMH battery quick charging with this strategy, constant voltage charge method and constant current charge method, validates this control strategy.     

Analysis on Longitudinal Cracks and Deflection of the Pre-stressed V-shape Slab Roof Structure

In this paper, the finite element method is used to analyze the behavior of the prestressed V-shape Slab Roof structure, especially the effect of temperature change on the stress of slab. The calculated results indicate that when the temperature changes, the tensile stress at the lower extreme fibers of the flange plate near rib exceeds the tensile strength of concrete subjected to the combined action of triaxial stresses and results in the longitudinal cracks of the flange plate. The deflection analysis is based on the mechanical model of the prestressed V shape slab with the longitudinal cracks. The calculated results are in general agreement with the field observations.     

Artificial Neural Networks Models for Flow Stress during High Temperature Plastic Deformation of Al-Li Alloy

Using gained experimental data to develop the models of stable flow stresses at high temperature plastic deformation by statistical methods for alloy materials, precision of the models is poor and at the same time the processes of modeling are complicated with great workload. On the basis of the data obtained on Gleeble-1500 Thermal Simulator,the predicting models for the relation between stable flow stress during high temperature plastic deformation and deformation strain, strain rate and temperature for 1420 Al-Li alloy have been developed with BP Artificial Neural Network method. The results show that the model on basis of BPNN is practical and it reflects the real feature of the deforming process. It states that the difference between the real value and the output of the model is in order of 5 percent.     

Tentative Research About the Macroscopic Regulating to Blast

The paper analyzes the difference of the pathogenic varieties and the relationship of the variety composition,allording to the historic material to the varieties of the main hybid fece varieties in Southeast Sichuan during 1992 to 1998.It's the first time to advance to use the camparison on rate of pathogenic isolates between norm and refrieving to define the susceptible extent of the varity.It's an scientific base to adjust the structures of the vartieties,to reach the objective of the macroscopic regulating to rice blast.     

Numerical Simulation of Flow field and Temperature field in Combustion Chamber Widened Suddenly

The flowfield and temperature field are numerically Simulated by the mathematical model of the fluid flow and heat transfer in circular combustion chamber widened suddenly. The distributions and influence factors of the flow field and temperature field are studied in it. The results have the guiding significance for the design of combustion chamber. The mathematical models can serve as the quantitative analysis methods for design.     

Recommendations on Shrinkage and Temperature Reinforcements in Concrete Slabs

The mechanism of shrinkage cracking is discussed with a simple member, which is fully restrained and subjected only to an axial restraining force caused by shrinkage, while a simple procedure is presented for the determination of the number and spacing of the cracks and the average crack width. With the simple model, some examples are shown to compare the provisions for minimum shrinkage and temperature reinforcement in GB 50010-2002 Code, ACI 318-02 Code and AS 3600-1988 Code. The results show that the provisions in GB 50010-2002 Code are too weak in comparison with the others. Finally, some recommendations are proposed.     

EFFECT OF MICRO-GALLIUM ON THE INTERGRANULAR SEGREGATINN OF PHOSPHORUS IN CARBON STEELS

The effect of small amounts of gallium on the intergranular segregation of phosphorus in carbon steels is discussed, with the help of the impact test, fracture morphology and micro-structure analyses, combined with composition analysis on the fracture surfaces by Auger electronspectrometer. The results show that gallium in the steel with a content of gallium more than ten thou-sandth can suppress, to some extent, the intergranular segregation of phosphorus and retard the tempering process. As a result, the temper embrittlement of the steel disappears and the embrittlement transition temperature declines.