基于斜交异性板单元的斜桥有限元分析

通过推导一种新型的斜桥分析单元──斜交异性板单元，实现了斜桥的空间有限元分析；通过与实用计算方法的对比，证明了这一方法的可靠性；最后，应用这一方法，结合工程实例介绍了斜桥影响面生成、影响面加载策略和斜桥的配筋计算在桥梁工程中的具体应用     

基于属性相关性分析的子空间搜索算法

在高维子空间聚类算法中,子空间识别质量有助于改善算法性能.提出了基于属性相关性分析的子空间搜索算法,利用相对熵去除冗余属性,根据联合基尼值判断两两非冗余属性之间的相关性,形成属性关系图,并在此属性关系图上搜索相似兴趣子空间.实验结果表明算法参数容易设置,有较好的子空间识别能力.     

“无己”、“丧我”之境与“不二法门”

庄子追求的悟道境界是一种"无己"、"丧我"的境界,它需要摒弃自我意识,摆脱主体与客体二分的状态。禅宗认为觅得"无上菩提"需参悟"不二之法",它要追求的是"空"或不执著的境界。庄子的悟道境界建立在对自我否定的基础上,它无法达到真正的"天人合一"。与此相比,禅宗的"不二法门"对于"真我"之网的把握可以说是对主客不分、"天人合一"境界有着更为深层次的领悟和理解。     

高层住宅是城市住宅建设的发展方向

本文通过论述高层住宅的优势,说明高层住宅将成为城市住宅建设的发展方向.     

水热法从含钛电炉熔分渣中制备纳米片状结构二氧化钛光催化剂

采用水热法，以氢氧化钠为分离剂，从含钛电炉熔分渣中成功制备出纳米片状结构二氧化钛光催化剂，并探讨了水热反应时间、水热温度以及碱液浓度对分离提取纳米片状结构二氧化钛的影响．随着水热反应时间的延长，水热温度以及氢氧化钠溶液浓度的提高，从含钛电炉熔分渣中分离提取的二氧化钛结晶度越好，微观形貌更趋近于纳米片状结构．水热法处理含钛电炉熔分渣的最佳反应条件是：水热温度高于180℃，水热反应时间大于24h，碱液浓度达到12mol·L^-1．以制备得到的纳米片状结构二氧化钛为光催化剂，在氙灯光照90min后，甲基蓝降解率可达81．1％．     

口周肌力的测量及计算机处理

利用自行设计的微型医用传感器和动态应变仪，光线示波器，磁带机等组成口周力测量系统及高速数据分析仪，ＩＢＭ３８６微机组成的计算机数据处理系统，对１１４名受试者的口周力进行测定和计算机分析，获得了良好的测试结果，并根据测定结果提出关于口周力的新观点．     

Numerical Analysis of Moisture Influential Depth in Concrete and Its Application in Durability Design

Determining the moisture influential depth in concrete under drying-wetting cycles is of great interest for investigation of chloride ion transport and thus the initiation of reinforcement corrosion. In this paper, the moisture transport processes during drying and wetting are modeled by diffusion and absorption. A predictor-corrector implicit scheme of finite difference method is used to solve the partial differential equations. The stability of moisture influential depth is then analyzed with the available numerical tool for both initially saturate and unsaturated concretes. The concept of equilibrium time ratio is proposed for drying-wetting cycles by the balance between water loss and intake during drying and wetting. According to this time ratio, drying-wetting cycles are classified into drying-dominated, wetting-dominated, and equilibrium ones. For drying-dominated cycles, the drying front will penetrate gradually into material while the influential depth is determined by wetting; for wetting-dominated cycles, the wetting front will progress into material while the influential depth is determined by drying. This classification has strong engineering implication and can give a more rational division of convection and diffusion zones of chloride ion transport. The case of concrete in marine splash zone is investigated to illustrate the application of influential depth in durability design of concrete structures.     

冻融情况下降温速率对水泥基材料变形和损伤的影响

为了明确降温速率对水泥基材料耐久性的定量影响,研究了不同降温速率两组水泥基材料(M35、M50)的变形和损伤.应用电阻式应变片测量了砂浆试件在不同降温速率下的应变变化;应用压汞法测量了材料的孔隙分布,计算了材料受冻过程的静水压力、结晶压力和有效孔隙压力,并比较损伤.研究结果表明:降温速率低,材科处于低温状态时同长,材料塑性越强,损伤越大;降温速率高,材料处于低温试件短,脆性强材料的损伤大.     

技术与设备完美结合 加快节能型水厂建设

吉林市水务集团有限公司第三供水厂扩建工程于2002年9月开工,扩建规模为20万m^3／d,工程总投资2．7亿元,总占地面积6．84公顷。其中一期工程于2006年1月竣工投产,供水能力10万m^3／d。该工程由中国市政工程东北设计研究院设计。设计中采用了快速混合、紊流多微涡反应、小间距斜板浅池沉淀、恒水位等速过滤V型滤池、最新净水工艺和工频结合的取送水等技术;     

Numerical Analysis of Moisture Influential Depth in Concrete During Drying-Wetting Cycles

The influential depth of moisture transport in a concrete surface subject to drying-wetting cycles was analyzed numerically. The moisture transport was described by a diffusion model with different diffusivities for drying and wetting. A finite difference scheme was developed to solve the partial differential equations The influential depth was then investigated numerically for initially saturated and unsaturated concretes exposed to drying-wetting actions in marine environments using an equilibrium time ratio concept. The equilibrium time ratio was calculated numerically for a saturated condition and the moisture influential depth is shown to be a linear function of the square root of the drying time. However, this equilibrium time ratio does not exist for an unsaturated condition and the moisture influential depth depends on the initial saturation as well as the drying-wetting time ratio. The results indicate that this model gives more realistic predictions of moisture transport of in situ structural concrete and its durability.