用米糠合成羟基磷灰石的研究

以米糠为磷源,使用添加剂———尿素、铵盐、水杨酸等,避免一些复盐膏状物的形成,用化学沉淀法,探索出一条可行的工艺路线,从而避免了多价盐、多种复盐的生成,制取得到新型补骨材料———羟基磷灰石．     

高铁智能化接触网腕臂柔性预配平台设计开发与应用研究

高铁建设接触网施工的要求和规范越来越高,亟需自动化和智能化水平高的智能装备研发和投入使用。本文介绍了腕臂预配施工现状和腕臂零件类型,腕臂柔性预配平台的结构功能、工艺流程和控制系统的软硬件部分进行了详细的设计开发。已交付的两台腕臂柔性预配平台在高铁施工现场投入使用,提升高铁建设配套智能装备的自动化和智能化水平。     

三面固定槽形板的应力遮档效应

用电测法测量了三种股骨中段骨折内固定钢板固定后对骨的应力遮档效应。结果表明，三面固定槽形板的应力遮挡效应明显低于梯形板和天津板一类的矩形截面板。     

拓扑优化在骨结构模拟中的应用

采用了一种非线性骨再造速率方程与有限元法相结合,引入工程拓扑优化思想,讨论了初始形状、有限元网格细化对模拟得到的人椎体外形、内部结构和质量的影响。     

用食用油直接制备脂肪酸晴和甘油的新工艺研究

对甘油的物理化学性质及常规生产甘油的原理方法、用途进行了介绍,同时对食用油直接制备脂肪酸晴和甘油的新工艺的原理及方法、特点,实验情况及该技术获得成功的可能进行了分析介绍．试验结果表明,该工艺较新颖,技术上是完全可行的,经济效益与生产率有很大关系,产出率又主要取决于催化剂的选用．     

Electrical and γ-ray energy spectrum response properties of PbI2 crystal grown by physical vapor transport

Lead iodide single crystal was grown by physical vapor transport method.Two radiation detectors with different configurations were fabricated from the as-grown crystal.The electrical and y-ray response properties at room temperature of the both detectors were investigated.It is found that the dark resistivity of the detectors are respectively 3×10¹⁰Ω·cm for bias electric field parallel to crystal c-axis（E//c） and 2×10⁸Ω·cm for perpendicular to crystal c-axis（E⊥c）.The energy spectrum response measurement shows that both detectors were sensitive to ²⁴¹ Am 59.5 keVγ-rays,and achieved a good energy resolution of 16.8%for the E⊥c-axis configuration detector with a full width at half maximum of 9.996 keV.     

电子束蒸发制备PbI_2薄膜及其性能表征

采用电子束蒸发工艺在普通玻璃衬底上制备了PbI_2多晶薄膜,研究了不同衬底温度对薄膜结构、表面形貌及紫外-可见光谱的影响.XRD结构表征显示,不同衬底温度下沉积的PbI_2薄膜均属六方结构,低温下呈现(002)方向的c轴择优生长,但随着衬底温度的升高,择优生长弱化;SEM形貌分析结果表明,PbI_2薄膜的晶粒尺寸随着衬底温度的升高而增大,同时晶粒间应力造成的突起减少,薄膜表面致密度和平整度提高;UV光谱测试结果表明,不同衬底温度下制备PbI_2薄膜透过光谱的吸收限均在515nm附近,且呈现陡直的吸收边.计算发现,薄膜禁带宽度约为2.42 eV,随着衬底温度升高而略微增大,显示结晶质量提高.

Abstract：

Polycrystalline lead iodide (PbI_2) thin films were deposited on glass substrates by electron beam evaporation method.The influence of different substrate temperatures on the structure,surface morphology and optical transmittance of the films was studied.XRD analysis shows the PbI_2 films deposited at different temperatures possess hexagonal structure,with a preferred growth orientation of (002) at low temperature,but this preferred growth characteristic vanishes when the substrate temperature increases.SEM micrograph reveals the grain size of PbI_2 thin films increases with the rising substrate temperature,meanwhile,the surface bulges resulted from the strain between grains decrease,making the surface of the films more compact and uniform.UV transmittance shows the steep absorption edge is at 515 nm for all samples grown under different substrate temperatures and the corresponding band gap is about 2.42 eV.     

Photoconductive properties of lead iodide films prepared by electron beam evaporation

Lead iodide (PbI2) films have been prepared by electron beam evaporation technique, and their photoconductive response to visible light was investigated under different deposition and illumination conditions. It is found that the films’ photoconductive response speed increases and the relative sensitivity decreases with the increase of substrate temperature due to the opposite requests for photo-carrier lifetime. Further, appropriately increasing the film’s thickness and rising substrate temperature simultaneously can effectively balance the opposite demands. Under the optimized conditions of substrate temperature of 200℃, source-substrate distance of 30cm and deposition time of 10min, the prepared films exhibit best response properties. In addition, the response to illumination with different wavelengths was also measured, revealing that the decline of response performance with increasing wavelength is due to lower photon energy of incident light.     

Inconel690镍基合金材料焊接技术要点

本文介绍了Inconel690镍基合金材料的特性,以及其焊接要点和焊接缺陷控制要领,进而为如何在Inconel690镍基合金材料的焊接过程中提高焊接质量提供了参考。     

印制电路板设计与工艺对信号完整性的影响

信号完整性问题是高速数字系统的研究重点,其主要形式有反射、串扰与电磁干扰等。影响信号完整性的物理互连层包括集成电路、芯片封装、印制电路板和系统级连接四个部分,芯片和印制电路板是当前信号完整性研究的主要对象。本文主要阐述了印制电路板设计和工艺对信号完整性的影响。