深厚杂填土区灌注桩及地基加固关键施工技术

为探索深厚杂填土区采用非换填方法进行地基处理,以确保灌注桩施工质量,以兰州新区西岔园区山字墩(棚改)安置房项目7#楼为例,使用钢护筒跟进法进行灌注桩成孔施工,并对地基土进行注浆加固。桩基检测结果显示,所有灌注桩质量均达到合格,所使用的方法保证了复杂地质条件下灌注桩的施工质量,为类似工程积累了经验。     

Message redundancy removal of multi-copy routing in delay tolerant MANET

This article puts forward a new scheme to control message redundancy efficiently in delay tolerant mobile Ad-hoc networks(MANET).The class of networks generally lacks end-to-end connectivity.In order to improve the efficiency that messages are delivered successfully,multiple message copies routing protocols are usually used,but the network load is increased due to a large number of message redundancies.In the study,by using counter method,every node adds an encounter counter based on epidemic routing scheme...     

核电站周边环境中锕系元素的加速器质谱测定

为了评估位于意大利南部的Garigliano核电站对周边环境的影响,利用超灵敏的加速器质谱技术对核电站周围环境表层土壤中236U和钚同位素的含量进行了测定.测量结果表明,每克表层土壤中含236U、239Pu和240Pu的原子数分别为106～107、107～108和106～107.其中,240Pu与239Pu的原子数之比...     

ANSYS二次开发技术在锅炉钢架结构分析中的应用

以ANSYS的APDL语言为基础,利用Visual Basic为开发工具,编制了锅炉钢架计算程序。软件实现了以点和面来控制线的逆向建模方式,用户输入节点信息,选择杆件截面类型,即可快速完成有限元模型的建立;对锅炉钢架上经常作用的4类荷载的以更接近实际的方式施加,并自动调用ANSYS进行2种组合工况的计算;计算结束,实现了结果的反馈并形成计算书。     

General order principle for multi-Bennett linkages

Order analysis for multi-Bennett linkages is a difficult topic in kinematics. Traditional methods fail to obtain the order of multi-Bennett linkages due to considering the special geometric distributions among joint axes. An order principle for multi-Bennett linkages is presented. For a summated multi-Bennett linkage, three procedures are included in the order principle. Firstly, a homogeneous screw equation is obtained by taking linear superposition operations and then the maximum order is determined according to linear dependency of all screws. Secondly, two theorems are employed to determine the maximum order, where the first is used to judge the linear independency of four-system screws and the second is fit for identifying the linear independency of five-system screws. Lastly, all possible cases in the order range are considered until the valid order is screened out. For a syncopated multi-Bennett linkage, an equivalent summated model is built and then the order analysis is the same as that of summated linkages. In order to verify the effectiveness of the presented order principle, the orders of summated 5R and 6R linkages as well as a syncopated 6R linkage are analyzed. The computed orders of the former two summated linkages are both 4 and the computed order of the last syncopated 6R linkage is 5. The results coincide with the prototype data. The advantage of the proposed principle is that it can get the correct order of a multi-Bennett linkage without solving the geometric conditions of joint axes and has wide application in variety of multi-Bennett linkages.     

Effect of Thermal Shock and Oxidation on Mechanical Property of Carbon/Carbon Composites with a Silicide Coating

A SiC whisker-toughened MoSi2-SiC-Si coating was prepared on carbon/carbon (C/C) composites surface by a two-step technique of slurry and pack cementation, and the effects of thermal shock and oxidation on the mechanical property of the coated C/C were studied. The flexural strength of C/C composites was improved by 6.8% after coated by SiC whisker-toughened MoSi2-SiC-Si. After thermal cycle between 1773 K and room temperature in air for 10 times, the mass loss of the coated sample was 5.08% and the percent...     

Effect of Extrusion Forming on Compressive Strength of Al_(18)B_4O_(33)w/Mg Composites

The aluminum borate whisker reinforced magnesium matrix composites (Al18B4O33w/Mg) were fabricated by pressure infiltration technique and extrusion-vacuum infiltration technique respectively to study the effect of extrusion forming on their mechanical behaviors. The microstructure of the composites was observed by scanning electron microscopy. The compressive strength was investigated and compared with that of the matrix alloy AZ91D. The results show that the extrusion forming could cause fracture of the wh...     

卫生部司(局)文件卫法监食便发［2000］162号卫生部法监司关于“生命力脑白金” 处理意见的复函

广东省卫生厅： 　　你厅“关于如何处理消费者举报投诉‘生命力脑白金’违法”函(粤法监处函［2000］003号)收悉。以松果体素为原料的食品已被我部批准为保健食品,此类食品应按保健食品管理。 　　此复。 卫生部卫生法制与监督司 二000年九月十八日     

HOLDING PATTERN

Holding Pattern是Interboro事务所为MoMA PS12011年青年建筑师计划提交的获胜方案,它是为MoMA PS1在2011年6月19日开放的露天庭院而做的一个项目。为了设计Holding Pattern,Interboro向博物馆的邻居们调研了以下问题:有没有什么你们需要的东西我们可以设计,然后将之布置在这个庭院中展览并使用一个夏天,到秋季撤展的时候再捐赠给你们?Interboro询问了出租车公司、图书馆、高中、老年中心和日托中心、社区公园、邮局和很多其他位于纽约长岛的机构,     

Numerically controlled bending performance of medium strength TA18 titanium alloy tubes under different die sets

The rapid development of aviation and aerospace technologies has led to increased interest in the application of numerically controlled(NC) technology for bending light-weight titanium alloy tubes.In order to study and develop advanced NC bending technology,it is necessary to understand the bending performance of medium strength TA18(Ti-3Al-2.5V,ASTM Gr.9) titanium alloy tubes during NC bending under different die sets.This paper focuses on the bending performance of medium strength TA18 tubes under differe...