无粘结预应力卵形消化池的受力分析及设计

本文采用有限元计算分析软件ANSYS对近年来出现的卵形消化池进行计算分析,着重对卵形消化池在多种荷载下的内力与变形进行分析,并采用二次曲线模拟沿高度均匀变化的壁厚。提出适合卵形消化池结构预应力钢筋等效为均布荷载的计算与配筋方法,取得较好的结果。     

Effect of load ratio on the deformation behaviour of fatigue crack tips

To investigate the change in the manner of plastic deformation at a fatigue crack tip under different loading conditions, the fresh surface area which is produced in one fatigue cycle at the crack tip was measured by an electrochemical method under various load ratios. The fresh surface area produced in each fatigue cycle is in proportion to the crack propagation rate in the Paris regime. This indicates that the crack tip geometry at K_max maintains a similar profile through the Paris regime. Furthermore, the fresh surface area is independent of load ratio at a given da/dN in the Paris regime. This suggests that the shape of the fatigue crack tip at K_max should be independent of load ratio at a given da/dN, and that the shape at K_min is also independent of load ratio, whereas the size of the deformed region at the crack tip is in proportion to da/dN.     

模块化蓝光光存储性能静态测试系统

蓝光光存储是信息存储领域发展的一个重要方向。测试系统是研究蓝光光存储材料的必备条件，为建立蓝光光存储研究平台，设计和搭建了一套模块化蓝光光存储性能静态测试系统。激光工作波长为406．7nm。系统采用调制解调技术降低系统噪声，提高测量粘度：采用光点移动模式降低对样品尺寸的要求；采用纳米平台提高记录点的反复定位性能。实验结果证明测试系统性能良好，可以满足蓝光光存储性能静态测试要求。     

分布式协作工作流技术研究

工作流是实现企业业务过程建模、优化、管理、集成和自动化的核心技术．作为分布式的应用平台，工作流管理系统任务处理能力即吞吐能力是一个重要的性能指标．目前，已有的工作流管理系统在这方面存在较大的不足，成为工作流管理系统广泛应用的严重障碍．本文研究了工作流系统的协作方式和负载平衡技术，定义了工作流系统的负载因子，给出了一个分布式协作工作流系统模型，并结合业务流程逻辑，提出了分布式协作工作流系统负载平衡调度算法．实验表明该分布式协作工作流系统有效地扩展了单个工作流系统的吞吐能力。     

Analysis of lightning surge propagation in wind farm

Wind power generation is expected to become more important in future distribution systems. Although several prospective reports such as IEC 61400‐24 and NREL SR‐500‐31115 indicate an insulation scheme and grounding design for lighting protection, there still seems to be too few investigations on the problems. This paper therefore discusses lightning surge analysis using a wind farm model with 2 or 10 ideal wind turbines. Changing parameters such as grounding resistance and lightning strike points, several cases were studied. As a result of the analysis using digital simulator ARENE, it is clear that the surge tends to propagate toward the end of a distribution line in a wind farm and there is the possibility of insulation accidents at the other wind turbines when lightning attacks a wind turbine. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(2): 30– 38, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20364     

集中载荷作用下的套管抗挤能力分析

根据油田套管损坏情况,建立了集中载荷作用下的套管抗挤能力计算模型,利用能量法和曲杆理论,分析研究了承受180°对称分布集中载荷、90°均匀分布集中载荷和120°均匀分布集中载荷下中厚壁套管抗挤能力,得出了理想圆管抗挤强度和套管屈曲临界挤毁压力的计算公式,通过分析比较理论解与有限元解,其最大相对误差不超过1%,得出了套管抵抗局部载荷的能力低于抵抗均布载荷的结论。     

用NAT技术实现负载均衡的实践

通过对路由器NAT功能配置实践,提出了使用反向NAT技术实现互联网访问负载均衡技术的一种解决方案.     

Equivalent Control of Constrained Multibody Systems

This paper investigates the title problem from the perspective ofdetermining which forcesystems, although different, will have the same dynamic effectwhen applied to a mechanical system.A procedure is presented for determining how differences incontrol force/moment input are nullifiedby constraints on the system. This in turn provides a basis foroptimal control. The theoreticaldevelopment is illustrated by a series of examples with a model ofa redundant manipulator – a constrained/controlled triple pendulum.     

Increasing the precision of a device used to determine the dynamic coefficient of friction

A theoretical evaluation of the potential application of a device with inclined plane for determining the dynamic coefficient of friction is given. Structural changes in the device that make it possible to increase its precision are proposed. Computational equations for estimating the resolution of the device are presented. __________ Translated from Izmeritel’naya Tekhnika, No. 11, pp. 24–26, November, 2007.     

A hemispheric division of labor aids mental rotation.

In the present study, we investigated whether a hemispheric division of labor is most advantageous to performance when lateralized inputs place unequal resource demands on the left and right cerebral hemispheres. In each trial, participants decided whether 2 rotated letters, presented either in the same visual field (within-field trials) or in opposite visual fields (across-field trials), were both of normal orientation, or whether one was normal and the other was mirror-reversed. To discriminate a letter's orientation, one must rotate the letter to the upright position. Therefore, we manipulated whether the two letters imposed similar or dissimilar demands on cognitive resources by varying the number of degrees that each letter needed to be rotated to reach the upright position. As predicted, in 2 experiments we found that the across-field advantage increased as the number of degrees each letter needed to be rotated became more dissimilar. These findings support a current model of hemispheric interactions, which posits that an unequal hemispheric distribution of cognitive load allows the cerebral hemispheres to take the lead for different aspects of cognitive processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)