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31.
SnS is a promising Ⅳ-Ⅵ semiconductor,which is very less explored for diluted magnetic semiconducting and dielectric applications.In this study,the Ni doping(x_(Ni)=0-10mol%) effects on SnS host lattice were investigated.A simple and low cost co-precipitation technique was employed to grow Ni doped SnS powders.The X-ray diffraction confirmed single phase orthorhombic structure with a nano-crystalline nature that was further verified through the surface structure observed by scanning electron microscopy.Near edge x-ray absorption fine structure spectroscopy revealed a shift in the Ni absorption edge towards higher energy,depicting the formation of Ni~(+3) oxidation state.The impedance measurements,in the frequency range 1 kHz to 20 MHz,depict that owing to the excellent sensitivity to the electromagnetic radiations at the low energy,the Ni doped SnS finds potential applications in various energy related devices.Vibrating sample magnetometer measurements have elucidated room temperature ferromagnetism,which depicts potential memory device applications.  相似文献   
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本文记述了伊朗不同地区鞘翅目吉丁虫科昆虫(Buprestidae)的一些种类和分布.共采集和鉴定吉丁虫科昆虫18种,隶属4亚科(Buprestinae,Chrysochroinae,Julodinae,Polycestinae)6属(Agrilus,Anthaxia,Psiloptera,Julodis,Acmaeodera,Acmaeoderella),并报道了部分种类的寄主植物.  相似文献   
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步行虫(鞘翅目:步甲科)作为强劲的捕食者,对农业害虫和森林害虫的生态学控制起着举足轻重的作用.本文研究了伊朗中部伊斯法罕地区的有益步行虫,共收集确定了42个种与亚种,来自7个亚科Broscinae、Carabinae、Cicindelinae、Harpalinae、Nebriinae和Pterostichinae.这其中有6种是伊朗区系的新记录种,分别是〖WTBX〗Cephalota 〖WTBZ〗(〖WTBX〗Taenidia〖WTBZ〗) 〖WTBX〗circumdata cappadocica 〖WTBZ〗Franzen,〖WTBX〗Lophyridia concolor concolor 〖WTBZ〗Dejean,〖WTBX〗Lophyridia littoralis mandli 〖WTBZ〗Mandl,〖WTBX〗Ophonus 〖WTBZ〗(s.str.) 〖WTBX〗cribricollis 〖WTBZ〗(Dejean),〖WTBX〗Pachycarus 〖WTBZ〗(〖WTBX〗Paramystropterus〖WTBZ〗)〖WTBX〗 bravipennis 〖WTBZ〗Chaudoir和 〖WTBX〗Cymindis 〖WTBZ〗(s.str.) 〖WTBX〗scapularis 〖WTBZ〗Schaum.  相似文献   
35.
激光喷丸成形作为一种基于单脉冲激光冲击累积效应的无模柔性成形技术,成形中几何效应对于弯曲变形量的影响直接关系到成形精度控制.轴线几何效应是复杂型面成形几何效应的重要组成部分,其对弯曲变形的影响缺乏有效的分析方法.基于圆弧轴线梁变形假设,通过激光喷丸成形等效弯曲分析方法,建立轴线几何效应分析解析模型,实现弯曲方向轴线几何效应的分析.通过激光喷丸成形固有应变数值模型验证表明,该模型能够有效反映轴线初始几何特征对于激光喷丸弯曲变形的影响;计算结果准确性与初始轴线圆弧半径有关;初始轴线圆弧半径较小时,误差相对较大.轴线初始半径对于激光喷丸弯曲变形影响较大,不同轴线初始半径分析结果表明,轴线初始半径增大时,轴线初始半径的几何效应逐渐减小.  相似文献   
36.
Galling is one of the most familiar failure forms for tubing and casing connections. It has been regarded as a key problem by metallurgy and petroleum systems all over the world. The theory of tribology and contact mechanics was used to analyze the contact force, plastic strain, and other parameters of API 10-round tubing connections in the process of makeup and breakout using the nonlinear finite element method. The stress states of the tubing thread connections were also analyzed for combined makeup and axial tensile loads. The results show that the main factors for tubing thread galling failure with thread grease are the normal contact force of the pin and box and the rigidity of the thread surface. The distribution of the contact force can be improved and the high contact force of the local thread can be reduced by optimizing the geometric parameters of the thread or using a small or varied pitch. The thread surface rigidity can be increased by improving the thread surface machining quality and by heat treatment. The chance of tubing thread galling failure can be reduced by designing hydraulic pressure tongs to avoid high speed and high torque makeup and by standardizing the operations of oilfield makeup and breakout.  相似文献   
37.
为了评价密封条在车门关闭过程中的压缩特征,应用数值模拟技术求解非线性连续介质力学问题.以桑塔纳2000(S2000)车门密封条为例,介绍了对密封条进行有限元分析的方法和步骤.通过计算可得S2000车门密封条的压缩载荷与压缩量的关系为非线性关系,密封条垂直压缩7mm时,压缩力为33.7 N.根据大众汽车企业标准4S/J.CG09.6.2-01,S2000密封条在标准压缩7mm时的压缩力应为(25 3/-5)N,因此,S2000密封条的压缩负荷超出标准范围,需要进行优化设计.同时,与使用中的S2000密封条测试结果对比,其误差在11%以内.表明应用数值模拟技术求解非线性连续介质力学问题是行之有效的.  相似文献   
38.
Prolactin inducible protein (PIP) is a 17- kDa single polypeptide chain, known by various names due to its versatile nature and function in human reproductive and immunological systems. It is expressed in several exocrine tissues such as the lacrimal, salivary, and sweat glands. Its expression is up regulated by prolactin and androgens, and estrogens down regulate it. Due to its over-expression in metastatic breast and prostate cancer, presently PIP is considered as a prognostic biomarker. Moreover, its aspartyl-proteinase nature suggests its role in tumor progression. PIP has unique features because it is small in size and plays multiple important functions. Its ability to bind potentially with CD4-T cell receptor, immunoglobulin G (IgG), actin, zinc α2-glycoprotein (ZAG), fibronectin and enamel pellicle, reveals its important biological functions. This is the first comprehensive review on the structure and functional analysis of PIP and its clinical applications. Received 04 August 2008; received after revision 09 September 2008; accepted 15 September 2008  相似文献   
39.
介绍了一种同时利用患者股骨的X线片和CT片图象进行了关节假体设计的新方法。利用该方法已成功地设计了一种新型人工髋关节假体,并完成了假体的三维造型及加工出假体铝合金模型。结合有限元分析,完成了从几何到力学的完整设计。  相似文献   
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EXISTENCEOFSOLUTIONSFORACLASSOFSYSTEMSGOVERNEDBYNONLINEARDIFFERENTIALINCLUSIONS¥XIANGXiaoling;WANGYuandi(DepartmentofMathemat...  相似文献   
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