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.     

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。     

建筑围护结构与节能

针对我国夏热冬冷地区的建筑气候特点,对建筑围护结构节能在设计中的要点和意义进行了讨论。     

建筑结构爆破震动效应及安全分析研究

从现代爆破作用原理出发。对岩体爆破的振动特性，影响因素及最新研究进展作了综合评述。并通过大量科研观测资料分析。结合我国某些工程实践经验。着重介绍了岩土爆破对闸坝工程，水工隧洞的作用特性。破坏机制和安全准则。     

住宅建筑带钢副框铝合金门窗防渗漏施工技术

使用自粘性防水卷材对带钢副框的铝合金门窗窗边进行粘接,以防止雨水通过副框与墙体之间的缝隙渗漏到室内,重点介绍了详细的施工措施。     

Time‐dependent heat transfer coefficient of a wall

A time‐dependent coefficient of heat transfer is proposed for the computation of thermal power required, so that a room temperature reaches a desired value within a given time. A mathematical formulation of the room heating transient phenomenon is constructed in a dimensionless form. Using an integral approximate solution an analytical expression for this coefficient is provided and it is verified by diagrams adopted by DIN 4701. Copyright © 2003 John Wiley & Sons, Ltd.     

论智能化建筑

详细地阐述了智能化建筑的概念及其产生和发展、智能住宅的产生和发展，针对我国智能建筑发展存在的问题提出了建议，同时对未来的智能化建筑进行了展望，从而促进我国智能化建筑的发展。     

Empirical modelling of shear strength of RC deep beams by genetic programming

This paper investigates the feasibility of using genetic programming (GP) to create an empirical model for the complicated non-linear relationship between various input parameters associated with reinforced concrete (RC) deep beams and their ultimate shear strength. GP is a relatively new form of artificial intelligence, and is based on the ideas of Darwinian theory of evolution and genetics. The size and structural complexity of the empirical model are not specified in advance, but these characteristics evolve as part of the prediction. The engineering knowledge on RC deep beams is also included in the search process through the use of appropriate mathematical functions.The model produced by GP is constructed directly from a set of experimental results available in the literature. The validity of the obtained model is examined by comparing its response with the shear strength of the training and other additional datasets. The developed model is then used to study the relationships between the shear strength and different influencing parameters. The predictions obtained from GP agree well with experimental observations.     

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.