NaCl溶液中重力铸造镁合金的耐腐蚀性

通过在0.6 mol/L NaCl溶液中浸泡实验,研究重力砂型铸造镁合金AZ91D的耐腐蚀性能.采用光学显微镜、扫描电镜和XRD观察和分析腐蚀后的合金与生成的氧化膜.结果表明:合金在溶液中的腐蚀以点蚀开始,而后腐蚀介质通过点蚀坑向基体内部扩展;氧化膜的成分随着腐蚀时间的延长不断变化;氧化膜的晶界或缺陷处薄弱,易开裂,成...     

刺激响应膜:用于可控传质与分离过程的灵巧工具(英文)

As emerging artificial biomimetic membranes, smart or intelligent membranes that are able to respond to environmental stimuli are attracting ever-increasing interests from various fields. Their permeation properties including hydraulic permeability and diffusional permeability can be dramatically controlled or adjusted self-regulatively in response to small chemical and/or physical stimuli in their environments. Such environmental stimuli-responsive smart membranes could find myriad applications in numerous fields ranging from controlled release to separations. Here the trans-membrane mass-transfer and membrane separation is introduced as the beginning to initiate the requirement of smart membranes, and then bio-inspired design of environmental stimuli-responsive smart membranes and four essential elements for smart membranes are introduced and discussed. Next, smart membrane types and their applications as smart tools for controllable mass-transfer in controlled release and separations are reviewed. The research topics in the near future are also suggested.     

自动换刀系统在数控加工中心中的应用及故障实例

文章分别从刀库的旋转驱动，选刀装置，机械手，系统确认等各自的功能情况来说明自动换刀系统的工作过程，并举实例解析自动换刀系统的故障。     

铝合金焊接性能及焊接接头性能

根据高速列车“八五”攻关项目要求，研究了铝合金材料的系列及焊接方法和工艺的选择，不同焊接材料焊接不同合金的裂纹倾向、气孔倾向，焊接接头各区性能变化，焊接接头的强韧性     

岩石试件沿弱面滑动的动力学分析

含有不连续面的岩石力学系统，在沿不连续面的滑动过程中，其响应结果与滑动的位移、滑动的速度密切相关。该文对此现象进行了理论分析，指出在一定的滑动速度范围内，滑体随着滑动位移的积累，滑动速度发生突变。     

Settlement of Internal Cutthroat Competition Amid IT Group Companies:Away from “Prisoners’ Dilemma” of Price Wars

1 Introduction With the rapid development of economic society, many group companies in IT industry emerge and expand, with new management problems: internal profit division, disorderly competition, and the problem that subsidiary companies do the things in their own way and beat down each other. Such cutthroat competition damages the group’s benefit and enables the company to fail to bring the advantage of 1+1>2 allocating optimized resources, nothing else than killing the hen to get the eggs…     

气浮式转子静平衡测量技术研究

为了提高立式转子的静平衡精度 ,研制了气悬浮测量装置 ,其核心部分是一个将转子稳定悬浮的气体静压球面轴承。通过测量转子的微小偏移来计算其静不平衡量。理论研究表明 :转子的静不平衡量与转子的偏移成正比 ;位移比例系数越大 ,测量精度越高。所研制的测量装置剩余不平衡度可小于 0 .8g·mm/kg ,不平衡量减少率大于 90 %。     

Comparison Between Mitigation Effects of the Finite Larmor Radius and Sheared Axial Flow on Rayleigh—Taylor Instability in Z—Pinch Implosions

A magnetohydrodynamic (MHD) formulation is derived to investigate and compare the mitigation effects of both the sheared axial flow and finite Larmor radius (FLR) on the Rayleigh-Taylor (RT) instability in Z-pinch implosions. The sheared axial flow is introduced into MHD equations in a conventional way and the FLR effect into the equations via ?/?t → -i(w+ik⊥2pi2Ωi), as proposed in our previous paper [Chin. Phys. Lett. 2002, 19:217] , where k⊥2 pi2 is referred to FLR effect from the general kinetic theory of magnetized plasma. Therefore the linearized continuity and momentum equations for the perturbed mass-density and velocity include both the sheared axial flow and the FLR effect. It is found that the effect of sheared axial flow with a lower peak velocity can mitigate RT instability in the whole wavenumber region and the effect of sheared axial flow with a higher one can mitigate RT instability only in the large wavenumber region (for normalized wavenumber k>2.4); The effect of FLR can mitigate RT     

45AgCuZn钎料中心不熔物成因分析

银铜锌钎焊丝存在中心不熔物是其主要缺陷之一，严重影响其使用效果，采用扫描电镜的方法对45银铜锌焊料进行了分析。分析结果表明，不熔物主要成分是氧化锌及部分氧化铜，主要是在熔铸时抽心夹入。     

锦西民园的建筑节能技术

“锦西民园”是建设部批准的成都市第一个建筑节能示范小区。小区由四川省建筑设计院设计,成都市公用事业房地产开发公司实施。小区的建筑节能设计完全执行建设部颁发的《夏热冬冷地区居住建筑节能设计标准》。住宅内外墙主体材料采用多排矩型孔、孔洞率大于25%的岩页多孔砖,外复合1.5cm厚的保温砂浆;住宅的外门、外窗除分户门外,其余均采用节能型塑钢双玻中空窗和塑钢夹腹安全玻璃门。一期工程经西南设计研究院测定,其建筑热工性能均达到或优于国家行业标准相关条款中的各项规定。相信该示范小区对长江流域及其周围地区执行建筑节能标准有一定的启示作用。