砖砌墙体裂缝的成因与防治

本文从形成墙体裂缝的4个主要原因,并就一般砖墙体裂缝的现象特征、成因、防治和补强措施作一初步的探讨、分析和研究。     

对目前市内电话资费若干问题的探讨

文中对目前国内自动电话业务中市内电话的资费问题作了较详细的分析探讨 ,指出所存在的问题 ,并提出了新的解决方案。     

浅析机电设备安装工程成本管理

当前随着我国城市化进程持续推进,建设中机电设备的投资不断加大。而机电设备基本没有信息价,多为市场价,机电设备的价格悬差很大,很难辨别,所以急需加强机电设备的成本管理。本文就机电设备安装工程成本及控制做了深入浅出的阐述。对机电设备安装工程造价、成本管理有很好的借鉴作用。     

巧定位装夹钻削压板类工件

在方圆集团公司的产品中,有些压板类工件(如图1),年需求均在8000件以上,工件四周及端面不要求加工,保持原剪切或铸造毛坯表面,但需在中间钻孔(一个或两个以上)。按常规加工工艺,必须经划线后再钻削。为省去划线工序,我们多     

基于微观结构分形表征的钼-氧化锆材料导电导热性能研究

金属陶瓷物理性能与材料组分和空间组织结构密切相关,其组成相的形态分布具有分形特征。基于渗流理论和分形理论,通过对材料微观结构图像的二值化处理进行导通相分形维数计算,建立分形维数与导通相微观形貌、渗流临界指数之间的定量表征,研究Mo-ZrO2金属陶瓷全组分范围内材料微观结构与电导率和热导率之间的关系。结果表明：导通相面积分形维数随着Mo体积分数的增加而增加,电导率与分形维数遵循渗流转变特征。采用通用有效介质(GEM)方程建立基于导通相分形维数的金属陶瓷电导率和热导率模型,实现材料微观组织定量分析结果与金属陶瓷的渗流模型相结合,有效预测材料宏观物理性质的梯度变化。     

Polyurethane coating for ductile iron pipes

Polyurethane coating has been widely used in pipe protection because of its perfectly mechano-chemistry properties and convenient application. But, being a solvent coating, a thick coat can not be obtained by spraying once with a common polyurethane coating. Moreover, the common polyurethane coating cures slowly as a result of being a secondary hydroxy polyether polyol. Therefore, it does not meet the requirements of rapid current production nor is it suitable for spraying on the surface of du…     

Microstructure and properties of Mg-Li-Al alloys with Mn addition

M agnesium isone ofthe lowestdensity m aterialsand has high specific strength and rigidity and has widespread application (Fig.1).Itisaclose-packed hexagonalm etaland has poorform ability.H owever,itis wellknown thataddition of lithium to m agnesium can produce workable and body-centered cubicstructurealloys [1-5].M agnesium -lithium alloysexhibittwophasestructuresbetween 5.7 % and 10.3 % by wtLicontent,consisting ofthe α-M g (hcp)and β-Li (bcc) phases at room tem perature (Fig.2). The sin…     

Advances in the research of nitrogen containing stainless steels

The current status of nitrogen containing stainless steels at home and aboard has been introduced. The function and existing forms of nitrogen in the stainless steels, influence of nitrogen on mechanical properties and anti-corrosion properties as well as the application of nitrogen containing cast stainless steels were discussed in this paper. It is clear that nitrogen will be a potential and important alloying element in stainless steels. And Argon Oxygen Decarbonization (AOD) refining can provide an advanced manufacture process for nitrogen containing stainless steels with ultra-low- carbon and high cleanliness.