FSEC赛车电池箱结构强度有限元分析

针对FSEC赛事规则以及动力系统的需求,文章设计一种FSEC赛车电池箱体。在CATIA中建立电池箱体有限元模型,通过使用ANSYS workbench有限元仿真软件对其进行急加速、急减速、转弯、耐久等工况分析,得到电池箱体的变形云图、应力云图和疲劳交变应力云图,明确了最大应力值以及最大变形位置,为后续结构优化设计提供方向。利用ANSYS软件进行仿真驱动研发,极大提高了设计效率,促进了大赛的发展。     

清水冲刷河床调整过程试验研究

通过沙质河床清水冲刷水槽试验,对河床纵剖面的调整、沙波尺度、粗化层厚度及其与沙波运动关系、粗化层级配、推移质级配等进行了观测分析,进一步揭示了清水冲刷,河床重建平衡的机理。水槽试验表明,沙质河床清水冲刷,上游河段比降调平,床沙粗化,沙波发育,河床阻力增大,水深增大,流速减小,导致河床供沙能力削弱,输沙能力降低,冲刷向不冲刷转化。     

枢纽下游河床冲刷深度估算方法

根据沙量守恒原理,从宏观上建立了清水冲刷深度估算公式。公式涉及到床沙可悬百分数;推移质单宽率输沙量及其变化过程;冲刷过程中水流条件的变化;粗化层厚度及其级配等疑难问题。通过水槽试验和理论分析给出了这些问题的计算关系式,获得了冲刷深度估算方法。经试验资料检验,精度良好。     

液压式盾构/TBM主机平移-空推集成装置的研制

研究目的:目前,隧道掘进机平移与空推工艺多采用不同装置分步完成,装置安装耗时费力,严重影响项目施工进程,且国内外没有可同时解决掘进机主机平移和空推的工法或装置.本文研制了一种基于液压的盾构/TBM主机平移-空推集成装置,将平移与空推工序合一,可极大提高工程施工效率,实现荷载600 t盾构/TBM主机连续移位. 研究结论...     

CARDIOPULMONARY BYPASS WITH AUTOLOGOUS LUNG AS SUBSTITUTE FOR ARTIFICIAL OXYGENATOR ATTENUATES INFLAMMATORY RESPONSIVE INSPIRATORY DYSFUNCTION

Objective To study if using autologous lung as a substitute of oxygenator in cardiopulmonary bypass is better than the conventional cardiopulmonary bypass with artificial oxygenator in pulmonary preservation.Methods Twelve piglets were randomly divided into two groups ( n = 6). The isolated lung perfusion model was established. The experimental animals underwent continuous lung perfusion for about 120 min. While the control animals underwent 90 min lung ischemia followed by 30 min reperfusion. Another 12 piglets were randomly divided into two groups ( n =6). The experimental animals underwent bi-ventricular bypass with autologous lung perfusion.While control animals underwent conventional cardiopulmonary bypass with artificial oxygenator. The bypass time and aortic cross clamping time were 135 min and 60 min respectively for each animal. The lung static compliance ( Cstat), alveolus-artery oxygen difference ( PA-aO2 ), TNF-α, IL-6 and wet to dry lung weight ratio (W/D) were measured. Histological and ultra-structural changes of the lung were also observed after bypass. Results After either isolated lung perfusion or cardiopulmonary bypass, the Cstat decreased, the PA-aO2 increased and the content of TNF-α increased for both groups, but the changes of experimental group were much less than those of control group. The lower W/D ratio and mild pathological changes in experimental group than those in control group were also demonstrated. Conclusion Autologous lung is able to tolerate the nonpalsatile perfusion. It can be used as a substitute to artificial ogygenator in cardiopulmonary bypass to minimize the inflammatory pulmonary injury caused mainly by ischemic reperfusion and interaction of the blood to the non-physiological surface of artificial oxygenator.     

FINGERNAIL GROWTH RATE IN A NORMAL CHINESE POPULATION

Objective To investigate fingernail growth rate (FNGR) role in the physiological or pathological status of the fingernails in normal Chinese population. Methods The FNGR was measured with vernier caliper. The data of 1 595 fingernails from 208 normal Chinese subjects (including 96 men and 112 women; age ranging from 14 to 78 years) were analyzed. Results The average FNGR was (0.104±0.027) mm per day. Higher growth rates were observed in males than in females, in the young individuals than in the old individuals, in summer than in winter, and in the right hand than in the left hand, respectively. The FNGR differed among fingernails and decreased in order of precedence: middle fingernails, index fingernails or ring fingernails, thumb and little fingernails. Conclusion FNGR was significantly associated with age, gender and temperature. Different fingernail grew at an individual speed.     

A General Attribute and Rule Based Role-Based Access Control Model

Growing numbers of users and many access control policies which involve many different resource attributes in service-oriented environments bring various problems in protecting resource.This paper analyzes the relationships of resource attributes to user attributes in all policies, and propose a general attribute and rule based role-based access control(GAR-RBAC) model to meet the security needs. The model can dynamically assign users to roles via rules to meet the need of growing numbers of users. These rules use different attribute expression and permission as a part of authorization constraints, and are defined by analyzing relations of resource attributes to user attributes in many access policies that are defined by the enterprise. The model is a general access control model, and can support many access control policies, and also can be used to wider application for service. The paper also describes how to use the GAR-RBAC model in Web service environments.     

Design for Two-degree-of-freedom PID Regulator Based on Improved Generalized Extremal Optimization Algorithm

A kind of new design method for two-degree-of-freedom(2DOF)PID regulator was presented,in which,a new global search heuristic--improved generalized extremal optimization(GEO)algorithm is applied to the parameter optimization design of 2DOF PID regulator.The simulated results show that very good dynamic response performance of both command tracking and disturbance rejection characteristics can be achieved simultaneously.At the same time,the comparisons of simulation results with the improved GA,the basic GEO and the improved GEO were given.From the comparisons,it is shown that the improved GEO algorithm is competitive in performance with the GA and basic GEO and is an attractive tool to be used in the design of two-degree-of-freedom PID regulator.     

Adaptive Synchronization in Small-World Dynamical Networks

Adaptive synchronization in NW small-world dynamical networks was studied.Firstly,an adaptive synchronization method is presented and explained.Then,it is applied to two different classes of dynamical networks,one is a class-B network,small-world connected R o¨ssler oscillators,the other is a class-A network,small-world connected Chua's circuits.The simulation verifies the validity of the presented method.It also shows that the adaptive synchronization method is robust to the variations of the node systems parameters.So the presented method can be used in networks whose node systems have unknown or time-varying parameters.     

用微粒群算法求解多元非线性方程组

分析了将多元非线性方程组的求解问题转化为求多元函数极值的优化问题的原理和方法;利用微粒群算法在连续空间中的优化能力求得极值点,得到方程组的近似解;给出了优化算法的具体流程;通过两个算例说明算法的可行性和有效性,实验结果表明此算法具有较高的效率和精度．