双柱式钻孔灌注桩桥盖梁荷载内力计算

盖梁作为桥梁重要的组成部分,其主要作用是支撑上部结构的荷载作用,进而将这部分荷载作用传递到桥墩。对双柱式钻孔灌注桩桥梁盖梁进行内力计算。     

中国人口老龄化趋势下老年人科学健身发展策略

进入21世纪,中国人口老龄化趋势日渐明显,作为世界上唯一的老年人口过亿的国家,老年人的健康问题自然成为社会大众关注的热点。通过分析中国社会日渐凸显的老龄化特点,针对老年人的健康状况,研究制定适合老年人体育健身的方法,以促进老年体育朝着科学健康的方向发展。     

Degradation characteristic of 4-bromdiphenyl ether in mixed solutions by electron beam irradiation

The degradation characteristic of 4-bromdiphenyl ether （BDE-4） was investigated in different solutions.The study indicates that the process of direct degradation of this compound is dependent upon the bromine and the ether bond connected to diphenyl by electron beam.laser flash photolysis was employed to determine the degradation of each species （cationic,neutral,and anionic）.From these data,intermediate products of BDE-4 degradation were shown for direct irradiationdegradation.The neutral radical was formed during the photolysis of these compounds.For all the compounds,diphenyl ether and hydroxybiphenyl were observed as common products.Reaction of the BDE-4 under electron beam was debromide.The debromide rate of BDE-4 at pH=5.5 is somewhat lower than that of BDE-4 at pH=10.0.The decomposition rate for BDE-4 is 99.8% at pH=10.0 on the dose of 14 kGy.BDE-4 from its radical could provide bromine ion into water and the cation radical of BDE-4 formed quickly recombine with hydrogen radical and formed phenyl ether.     

高性能聚焦离子束(FIB)系统及其在材料科学领域的应用

采用液态镓作为离子源的FIB系统在材料科学研究领域可以起非常重要的作用。离子束聚焦于样品表面，在不同大小、束流及通入不同辅助气体的情况下，可分别实现图形刻蚀、绝缘和金属膜的沉淀，扫描离子成像等功能。该系统有三大用途：形貌观察，分辨率高达5nm；微刻蚀以及微沉淀。本文介绍了FIB技术的应用。     

高架桥连续梁盖梁混凝土冬季施工

介绍了高架现浇梁预应力混凝土冬季施工技术,对混凝土冬期施工质量因素进行了研究并采取了相应的措施,从而确保工程质量与安全。     

590MPa级高强度汽车大梁钢的组织与性能研究

通过在碳锰钢基础上添加铌钛微合金化元素,成功开发出铁素体+珠光体组织的高强度大梁用钢,该钢钢质纯净、晶粒细小、强度高、耐疲劳性好,已成功应用于重型载重车纵梁制造。     

谐振腔长对薄板不锈钢焊接工艺的影响

通过研究YAG激光器谐振腔腔长与光束质量的关系,优化设计谐振腔腔长,得到了良好的激光光束质量。当激光器腔长L=766mm时,激光的光束质量最好,高斯分布均匀,对薄板不锈钢进行穿透焊接工艺试验,此腔长的焊接效果最好。     

Performance measurement of broadband, wide-angle polarizing beam splitter

INTRODUCTION A polarizing beam splitter (PBS) cube is an op- tical element used in projection display systems where light must be spatially separated into or- thogonal linear polarizations. PBS is a key component in any liquid crystal projectors, whether they are transmitting or reflective. In reflective mode liquid crystal light valve projector, PBS is often used as both polarizer and analyzer. PBS transmits p-polarized light and reflects s-polarized light (You et al., 2005). The im…     

麝毛被扫描电镜观察和机能意义探讨

麝毛被由长针毛和短针毛组成,无绒毛。长针毛的髓部和皮部由致密纵横膈分隔成气室,气室连续贯穿毛干,毛小皮呈菱形。短针毛髓部为气室,皮部为致密角质物,毛小皮呈扁平形。毛干气室发达充盈体表温度,毛被层形成体表保温层,具保温御寒功能。     

超限剪力墙连梁的设计

自2000年开始执行的结构专业新规范,关于剪力墙结构的设计有若干新的规定,给设计人员带来了新的课题。其中,连梁超筋超限是高层剪力墙结构设计中一种常遏问题。结合一具体高层剪力墙结构住宅项目,探讨了由概念设计入手的处理措施,可供类似工程设计借鉴。