谈井下矿山二次破碎裸露爆破方法

井下矿山二次破碎裸露爆破可采用聚能药包和水封聚能药包破碎大块，聚能药包能改变药柱某个方向的猛度，提高炸药能量利用率，水封爆破利用了炸药的猛度和一部分爆力作用，从而有效地利用了炸药本身的能量，降低了爆破危害。     

特种钢用结晶器铜管破裂原因分析

通过对某特钢厂破裂的结晶器铜管进行金相实验、扫描电镜和能谱分析,并结合结晶器的生产、使用及失效过程情况,综合受力分析,认为铜管破裂原因主要是环境介质硫渗入形成硫化物,在拉应力作用下,裂纹沿脆性质点扩展导致的破坏。     

The Stability of Rare Earth-Iron-Nitrides Sm_2(Fe,M)_(17)N_y,Permanent Magnets

The effects of the partial substitution of element M(M=Cr,V,Mn,x=0.05;Zr,Ga,x=0.017;Si,x=0.15;Co,x=0.10)for Fe in samarium-iron-nitride Sm_2(Fe_(1-x)M_x)_(17)N_y compounds on their stabilitiesand Curie temperatures have been studied.It is found that Co,Ga can raise the Curie temperature of thecompounds.The initial decomposition temperatures cannot be raised significantly by all the studied elementsexcept Co.The result contradicts the formation enthalpy consideration.The final decomposition tempera-tures can be raised by all of the substitution elements.The effects of atmospheres on their decomposition be-havior were also studied.The results show that oxidation is the major reason for magnetic deterioration ofthe powder heated in air.Compared with nitrogen atmosphere,argon or vacuum helps to delay the decompo-sition of the compounds.     

红外车辆分离子系统的设计和性能分析

在机动车磁卡收费系统中,红外车辆分离子系统是一种重要设备,它是由平行等距红外线族构成的平面检测系统,其性能直接影响收费系统的正常运转。本文介绍该子系统的设计并对系统性能进行分析,得出:子系统采取相关检测技术后,不仅能有效地抑制外界干扰、噪声,还具有抗相邻红外信号干扰能力。     

小波变换在手写体汉字识别中的应用

汉字识别中的结构类特征具有抗变形的优点，合适做为手写体识别过程使用，但其中笔划特征的提取非常困难。本文用小波变换这一图象分析中有力工具对汉字图象分析处理之后，再进行笔划的提取，其过程简洁、明晰。     

高能球磨AL─Cu合金固态合成反应研究

采用扫描电镜、能谱分析、Ｘ射线衍射和示差扫描量热分析研究了具有较大负混合焓的Ａｌ＿ｘＣｕ＿（１－ｘ）对称扩散系合金的高能球磨固态合成反应。高能球磨时组元晶粒细化达纳米级，造成纳米晶界亚互溶，为室温固态合成反应创造了条件，球磨强度对反应进程影响显著，在ｘ＝０．３～０．７范围内仅形成一种金属间化合物。     

Carbon fibre composites based on polyimide/silica ceramers: aspects of structure-properties relationship

Polyimide/silica ceramers, based on the products of the hydrolysis of tetraethoxysilane (TEOS) and a commercial poly(amic acid) solution, were used to fabricate unidirectional carbon fibre composites, which were subsequently evaluated with respect to thermal and mechanical properties. There is evidence to suggest that the silica component of these ceramers is present as dispersed discrete particles at low silica concentration (i.e. 7 wt%) and as fine interconnected domains trapped within the polyimide matrix at higher silica content (i.e. 14 wt%). The dimensions of the silica domains were in the region of 7–20 nm. Carbon fibre composites produced from ceramer solutions (CF/ceramers) were found to exhibit lower thermal expansion and a greater retention of flexural and interlaminar shear properties at elevated temperature than the corresponding polyimide-matrix composites (CF/polyimide). The properties of CF/ceramers were generally better for systems containing the higher amount of silica and were improved further by lowering the pH value of the precursor ceramer solution. This is believed to have resulted from the enhanced fluidity of the ceramer gel within the pre-impregnated fibres, giving rise to a higher packing density of the fibres and a more homogeneous distribution of fibres. CF/ceramers were also found to exhibit a better thermal oxidative stability at 350°C than the corresponding CF/polyimide, although a substantial amount of porosity developed in the case of ceramers with the higher silica content.     

On social computing research collaboration patterns: a social network perspective

The field of social computing emerged more than ten years ago. During the last decade, researchers from a variety of disciplines have been closely collaborating to boost the growth of social computing research. This paper aims at identifying key researchers and institutions, and examining the collaboration patterns in the field. We employ co-authorship network analysis at different levels to study the bibliographic information of 6 543 publications in social computing from 1998 to 2011. This paper gives a snapshot of the current research in social computing and can provide an initial guidance to new researchers in social computing.     

基于B/S网上教学资源管理平台的分析与设计

随着信息化技术的不断发展,网上教学资源管理平台已经成为目前高校教学中非常重要的工具,尤其是在当前信息技术和计算机网络技术飞速发展的时代,高校开始充分利用现有网络资源来进行教学资源管理。区别于传统的C/S模式,B/S开发模式使得高校内部用户通过校园网或者互联网就可访问本平台。本文就基于B/S模式的网上教学资源管理平台进行详细分析。     

网络媒体发展中的信息安全问题探讨

现代信息化的技术的进步给我们的社会生活带来的很大帮助,而网络媒体就是信息化技术的一个产物,它能迅速成为市场的一大宠儿,不仅有着他自身独有的优势和特点,还有与之相适应的外部条件,传统媒体在某些方面已经不能适应现代产业的发展,人们正在寻求一种迅速、容量大的传播方式,于是网络媒体的出现众望所归。但是由于我国的网络媒体的出现时间尚短,难免有着这样那样的问题,随着网络媒体为越来越多的人所接受,其问题也更加严重,尤其是传播不良的信息荼毒青少年的思想健康,网络受到黑客、病毒的侵袭,网上传播虚假信息、盗窃数据库资料等等,信息安全问题突出,这些问题越来越受到全世界的关注,成为全球共同注意的事情。