基于JSP的教材查询系统设计与实现

以教材查询系统为例,介绍了利用Java技术实现基于web的教材管理系统的所有步骤,包括数据库管理、系统设置、程序实现等,并在设计过程中采用了JSP+Tomcat5.5相结合的技术,此方法对于创建基于web的应用系统具有很好的借鉴作用.     

悬浇箱梁节段张拉后腹板裂纹成因分析与防治

对某悬浇预应力连续箱梁纵向预应力下弯钢束张拉后,腹板沿着波纹管出现裂纹的现象进行了分析,并分别用拉-压杆模型、三维实体有限元模型和钢筋混凝土非线性有限元模型进行了计算,总结了腹板开裂的主要原因,提出了裂纹控制措施的建议,可为预应力连续箱梁的合理设计和同类问题的处理提供参考。     

箱梁腹板竖向预应力设置新方法研究

从箱梁腹板斜裂缝对竖向预应力的敏感性分析出发,阐明竖向预应力有效削减腹板主拉应力的力学机理,探讨现阶段国内外竖向预应力设置方法及其优缺点,提出用碳纤维力筋CFRP取代传统的精轧螺纹钢建立有效预应力的新方法,尝试设计其专用锚具及施工工艺。     

变压器漏抗取代并联整流器平衡电抗器的分析

在分析了变压器漏抗对多脉波整流器影响的基础上，提出利用变压器漏抗取代平衡电抗器的设计思想，从而消除了平衡电抗器所带来的负面影响。这一思想在广州地铁2号线的二十四脉波整流器中的理论分析中得以实现。     

Topological constraints on the dynamics of wasp-waist ecosystems

Small pelagic fish species like anchovy or sardines are of high ecological and economical importance. As marine food webs are fished down, these small pelagics tend to be more exploited and overfished. It is not yet very well known what the possible effects of their collapse can be, therefore there is an urgent need to outline a theoretical framework for understanding their dynamics. These fish occupy very special position in food webs, ensuring energy transfer between species lower and higher levels, while forming narrow “wasp-waists” poor in number of species (but very abundant). Our purpose was to quantify the interaction structure of model food webs of equal complexity but different levels of “wasp-waistedness”. We analysed the topological properties of the webs by characterising every direct and indirect interactions between individual species, as well as by assessing the relative positional importance of each species in each web. We found that (1) the shorter the interaction pathways considered, the weaker the predictive power of node degree for positional importance, (2) the importance of species varies more in wasp-waist food webs, (3) if longer indirect chain effects are considered, indirect effects can well be stronger than direct ones, (4) interactions between coexisting wasp-waist species are stronger than the average, and (5) the “self-regulatory” looping effects are also stronger for wasp-waist species. Based on the topological properties of the networks, our results describe constraints acting on the dynamical behaviour of wasp-waist ecosystems. We give explanations, from this viewpoint, for regime shifts in which one WW species replaces another, and for the unpredictable dynamics of these fish stocks. From a marine conservation viewpoint, we illustrate that as the abundance of wasp-waist species decreases, the architecture of energy flows becomes highly vulnerable and unreliable. We provide an approach for quantifying these structural changes.     

对多路数组聚集方法的研究及其优化

为了解决针对MOLAP服务器中的数据立方体的有效计算问题，对立方体全物化的多路数组聚集方法进行了研究与分析。在此基础上，提出了一种寻找最优聚集次序的方法，该方法克服了传统多路数组聚集需要计算所有扫描次序的缺陷，通过对各维数据的比较，找到一种特定的扫描方式，以方便、快捷地对以数据立方体形式存储于MOLAP服务器中的多维数据进行聚集操作，进而优化数据立方体的有效计算。     

东营银座人行桥的设计

介绍了我国第一座变截面波形钢腹板PC组合箱梁桥——东营银座人行桥的设计要点,为波形钢腹板PC组合箱梁结构在我国桥梁工程中的推广应用提供了有益的参考。     

基于web的电机保护器的原理及应用研究

通过对新型电机保护器产品的基本原理及基于web应用的介绍,使人们对该产品有了一个更全面的认识和了解.