不同车轮结构对车轮固有频率影响的研究

本文采用三维设计软件CATIA设计了不同结构车轮,利用有限元法计算出了车轮固有频率,分析了不同轮辐厚度、轮辋厚度和法兰厚度对车轮固有频率的影响。研究结果指导产品设计,改善车轮固有频率,使的产品固有频率满足工程需求。     

轴流风机出口管道的设计与施工

在异丁烯装置中,轴流风机是关键转动设备,轴流风机的正常运转关系到整套装置的安全可靠运行,而出口管道设计又是保证整个机组正常运转的核心技术之一。本文结合异丁烯装置的工艺流程,根据轴流风机的特点,对其出口管道的设计进行了详细分析和阐述。从管系波纹管膨胀节设置,特殊支吊架设置和防喘振管线设计三个方面阐述了轴流风机出口管道的设计要点。并在此基础上,总结了管道安装施工的具体技术要求。结果表明:科学规划轴流风机及其配套设施的位置,合理安排轴流风机工艺管道及辅助管道的走向,能够减小轴流风机出口管嘴的受力,对充分利用装置占地,确保装置的可靠运行起着重要作用。目前该设计方法已在多套轴流风机机组上采用,且运行正常。由此可以证明该出口管道的设计思路对于改善轴流风机的使用效果是切实有效的。     

Nd3+:Y0.5Gd0.5VO4晶体生长和基本特性

Nd^3 :Y0.5Gd0.5VO4晶体作为一种新的激光材料，可以用中频感应加热提拉法生长。X射线粉末衍射分析表明它的结构与Nd^3 :YVO4晶体结构相同，它的晶格常数介于YVO4和NdVO4晶格常数之间。用ICP光谱法测定晶体中Nd^3 含量为0．8at％，分凝系数为0．8，与Nd^3 :GdVO4晶体中Nd^3 的分凝系数0．78相当；用称重法测定其密度为5．00g／cm^3；用稳态纵向热流法测出其室温热导率为12．5W／mK。实验表明Nd^3 :Y0.5Gd0.5VO4晶体有希望作为高功率ID泵浦激光晶体材料。     

集成道路上SoC与SiP谁主浮沉？

与昌圆双雄(台积电、联电)有着密不可分的IC设计服务公司创意与智原,于2003年8、9月接二连三的成立IP Mall,其希望透过IP(Intellectual Property)交易平台的建立,授权给IC设计业者加速重复使用IP以缩短芯片开发时间,也迫使SoC(System-on-a-Chip)与SiP(System-in-a-Package)的争夺战再一次浮上台面。     

马建民追求卓越

人在一生中能有几个顿悟的时刻?豁然开朗、茅塞顿开，仿佛冥冥中神灵的仙指点化，为人生与事业的苦旅指明一条阳光大道。这样的时刻并不多得，因为大多数人不愿忍受顿悟之前求索的忧烦苦闷。三年前，作着一个普普通通、优哉游哉的小书商的马建民，忽然发现了自己未来要走的路。     

摩托罗拉8位HC08微控制器系列

摩托罗拉微控制器(MCU)具有编程语言简单、外围设备齐全、存储器模型用户友好、选择广及供应多、性能价格比高等优点,被设计者评为最容易使用的产品之一。在全球顶级的原始设备制造厂商(OEM)的无数嵌入式系统和用户最终产品中都可找到摩托罗拉的MCU,包括键盘、传呼机、电子游戏机、洗衣机、安全系统及汽车等。     

N_2S_2或N_3S型配体的合成、~(99)Tc~m标记及生物分布研究

以MAG3为基本分子骨架，根据构效关系，分别引入合适的天然氨基酸，设计合成了4种N2S2或N3S型小分子多肽新配体，并通过了IR，^1H NMR,^13C NMR,MS谱学鉴定和元素分析表征。采用葡庚糖酸钙（GH）交换法对4个配体进行了^99Tc^m标记，研究了配合物在小鼠体内的生物分布特征。结果表明，^99Tc^m-MVGG肾摄取较高，滞留时间较长，血清除快，且肾与其它组织的活度比值高，具备成为肾功能显像剂的条件；^99Tc^m-MPGG肾初始摄取较高，R（肾／血）活度比值高，但肾清除较快，R（肾／肝）活度比值较低；^99Tc^m-MVTC和^99Tc^m－MPTC心肌初始摄取均较高，但在心肌和血中的清除速度较快。     

Nucleation Mechanism for Bainite

Based on the experimental results that solute-depleted zone was observed in Cu-28Zn-4AI (mass fraction) at 523 K, AG is calculated as a positive according to the thermodynamic criteria for the spinodal decomposition of a ternary systems. So, the solute-depleted zone cannot be formed by spinodal decomposition. Dislocation density required by the formation of solute-depleted zone is estimated greater than 7.89×109 cm-2, according to the segregation of solute atoms around dislocations, which is not consistent with the practical situation for the alloy at 523 K. Associated with the internal friction experimental fact that internal friction peaks appear within the incubation for bainitic transformation in Cu-Zn-AI alloy, the equilibrium temperature, TO, is evaluated as 433 K for solute-depleted Cu-25Zn-3.4AI, which is lower than the experimental temperature 523 K. Thus, nucleation by shear mechanism is impossible in this circumstance. Therefore, it is concluded that, like bainite in steels and Ag-Cd, bainite in     

Preparation of Laminin-apatite-polymer Composites Using Metastable Calcium Phosphate Solutions

A synthetic polymer with a laminin-apatite composite layer on its surface would be useful as a percutaneous device. The preparation of such a composite was attempted in the present study using poly（ ethylene terephthalate ） （PET） and polyethylene （PE） as the synthetic polymer. PET and PE plates and those pretreated with an oxygen plasma were alternately dipped in calcium and phosphate ion solutions, and then immersed in a metastable calcium phosphate solution supplemented with laminin （ LCP solution ）. The PET and PE plates pretreated with an oxygen plasma formed a uniform and continuous layer of a laminin-apatite composite on their surfaces. In contrast, the PET and PE plates that had not been pretreated with an oxygen plasma did not form a continuous layer of a laminin-apatite composite on their surfaces. The hydrophilic functional groups on the PET and PE surfaces introduced by the plasma treatment were responsible for the successful laminin-apatite coruposite coating.