On the corrosion fatigue crack initiation model and expression of metallic notched elements

In the present study, attempts are made to extend the application of the mechanical model for the fatigue crack initiation (FCI) and the FCI life formula of metallic notched elements in laboratory air to those in the corrosive environment. The test results and analysis of the corrosion FCI (CFCI) life of aluminum alloys and Ti---6A1---4V show that the expression of the CFCI life obtained by modifying the FCI life formula in laboratory air can give a good fit to the test results of the CFCI life. The salt water (3.5% NaCl) environment has no effects on the CFCI resistant coefficient compared with the FCI resistant coefficient in laboratory air. However, 3.5% NaCl environment greatly decreases the CFCI threshold of aluminum alloy, but has little effect on the CFCI threshold of Ti---6A1---4V. The loading frequency ranging from 1 Hz to 10 Hz has no appreciable effect on the CFCI life, and thus, the CFCI threshold of aluminum alloys investigated. Hence, the expression for the CFCI life of metallic notched elements proposed in this study is a better one, which reveals a correlation between the CFCI life and the governing parameters, such as, the geometry of the notched elements, the nominal stress range, the stress ratio, the tensile properties and the CFCI threshold. However, this new expression of the CFCI life needs to be verified by more test results.     

一种多晶硅高温压力传感器

制作压力传感器时，在二氧化硅层上淀积多晶硅膜，既可利用优良的机械特性，又可保证压敏电阻与衬底间具有良好的绝缘性，由此可大大提高器件的温度特性。介绍了一种多晶硅压力传感器的原理和设计。实验结果表明，这类传感器具有灵敏度好，精度高等特点，电路工作范围为０－２５０℃，且具有良好的温度稳定性。     

18Ni（350）马氏体时效钢的磁滞特性

采用双时效处理工艺研究了热轧１８Ｎｉ（３５０）马氏体时效钢的磁滞特性。结果表明，８２０℃·　ｈＡＣ＋（５９－６１０）·。ｈＡＣ＋５１０℃·。ｈＡＣ和８２０℃·　ｈＡＣ＋（６９０－７１０℃）·３ｈＡＣ＋１５０℃·３ｈＡＣ处理具有较高的磁滞性能，在对大量数据进行二元线性回归的基础上得出了１８Ｎｉ（３５０）马氏体时效钢磁滞特性的分段关系式。     

地壳应力场和密度场资料在油气检测中的应用

依据卫星轨道摄动测量结果反演的地壳区域构造应力场和密度场资料，可圈定油气区域构造圈闭和储集油气的低密度层。计算绘制了闽江口扇形洲区域构造应力场和密度卫星遥感图，图上显示出东海近海闽浙中拗陷含油气带与温东丽水油气构造带相接，敖江口官岭与闽江口川石储岛沥青苗等迹象都在此范围内，在闽江口扇形洲东部沿海沙泥沉积区，邻区东海宽长带深厚海沙软泥沉积区及本区北部罗源湾，用大地电磁CSAMT检测到1000－3000m深度范围内的低阻率地层，与本区卫星遥感图图低密度场相符。     

高质量ZnO薄膜的退火性质研究

在LP－MOCVD中，我们利用Zn(C2H5)2作Zn源，CO2作氧源，在（0002）蓝宝石衬底上成功制备出皮c轴取向高度一致的ZnO薄膜，并对其进行500℃-800℃四个不同温度的退火。利用XRD、吸收谱、光致发光谱和AFM等手段研究了退火对ZnO晶体质量和光学性质的影响。退火后，（0002）ZnO的XRD衍射峰强度显著增强，c轴晶格常数变小，同时（0002）ZnOX射红衍射峰半高宽不断减小表明晶粒逐渐增大，这与AFM观察结果较一致。由透射谱拟合得到的光学带隙退火后变小，PL谱的带边发射则加强，并出现红移，蓝带发光被有效抑制，表明ZnO薄膜的质量得到提高。     

用化学腐蚀制备多孔硅太阳电池减反射膜的研究

采用HF HNO3溶液化学腐蚀 ,在硅片上制备减反射效果优良的多孔硅太阳电池减反射膜 ,借助原子力显微镜 (AFM)和X光电子谱 (XPS)对其表面形貌和成分进行观察 ,发现该膜与电化学阳极腐蚀得到的多孔硅具有相似性 ,其主要成分为非化学配比的硅的氧化物SiOx(X <2 )。采用带积分球的光度分光计 ,测得形成多孔硅减反射膜后 ,硅片表面反射率大大下降 ,,在波长 330～ 80 0nm范围反射率只有 1 5～ 2 9%。研究指出这种强减反射作用 ,与多孔硅具有合适的折射率及其多孔特性的光陷阱作用有关     

橡胶卷材挤出连续硫化生产线的结构特色与工作原理

介绍了橡胶防水防腐卷材挤出连续硫化生产线的结构、特点和工作原理;指出在目前国内同类设备中,该生产设备具有先进性,并可替代引进设备。     

大长径比自旋弹箭横向自振特性的有限元计算方法与结果分析

本文研究大长径比自旋弹箭在飞行时横向振动的自振特性。本文将转子动力学应用于弹道学 ,采用有限元法 ,建立自旋弹箭横向振动自振特性方程。同时给出了计算方法。利用该方程和该方法 ,开发了相应的计算程序。通过数值计算 ,可给出细长旋转弹箭飞行时的进动转速和临界转速 ,以及相应的位移和角度振型。利用该程序 ,进行了实例计算和分析。     

An experimental study of carrier heating on channel noise in deep-submicrometer NMOSFETs via body bias

In this paper, RF noise in 0.18-mum NMOSFETs concerning the contribution of carrier heating and hot carrier effect is characterized and analyzed in detail via a novel approach that modulates the channel carrier heating and number of hot carriers using body bias. We confirm qualitatively a negligible role of hot carrier effect on the channel noise in deep-submicrometer MOSFETs. For a device under reverse body bias (V_b), even though the increase in hot carrier population is clearly characterized by dc measurements, the device high-frequency noise is found to be irrelevant to the increase in the channel hot carriers. Experimental results show that the high-frequency noise is slightly reduced with the increase in |V_b|, and can be qualitatively explained by secondary effects such as the suppression of nonequilibrium channel noise and substrate induced noise. The reduction of NF_min and R_n with the increase in |V_b| may provide a possible methodology to finely adjust the device high-frequency noise performance for circuit design     

Influence of CYP3A5 polymorphism on tacrolimus blood concentrations in renal transplant patients

Objective Tacrolimus is an immunosuppressive drug with narrow therapeutic range and wide interindividual variation in its pharmacokinetics. Tacrolimus is a substrate of cytochrome P450(CYP)3A5. The aim of this study was to evaluate whether the A6986G polymorphism is associated with tacrolimus concentration /dose ratio. Methods Fifty-two Chinese renal transplant patients were enrolled in this study. Their body weight, dosage and concentration of tacrolimus were observed. CYP3A5 genotype was determined by polymerase chain reaction followed by restriction fragment length polymorphism analysis. Results A significant association was found between tacrolimus levels per dose/kg/d and CYP3A5 gene A6986G polymorphism (P<0.001). The CYP3A5 * 3 * 3 patients have a significantly higher tacrolimus level/dose than CYP3A5 * 1 * 1 and CYP3A5 * 1 * 3. Conclusions CYP3A5 gene A6986G polymorphism is associated with tacrolimus pharmacokinetics and dose requirements. Pharmacogenetic methods could be employed prospectively to help the dose selection and to individualize immunosuppressive therapy according to the result. Foundation item: Project (03GZ3072) supported by the Science and Technology Department of Hunan Province; project (2004035206) supported by the China Postdoctoral Foundation and project (30300383) supported by the National Natural Sciences Foundation of China