氯化钠在球形纳米氧化铈形成过程中的作用

以水合碳酸铈为原料, 以氯化钠作为助磨剂和阻聚剂, 采用机械活化法制备了球形纳米氧化铈, 用XRD法研究了水合碳酸铈与氯化钠质量比、球磨时间、煅烧温度对CeO2粉体晶粒度的影响, 用TEM对最终产物粒子进行形貌观察. 结果表明: 在碳酸铈的球磨过程及其随后的煅烧过程中, 氯化钠的存在起到了很好的助磨和阻聚作用, 所得CeO2为类球形粒子, 分散性较好, 晶粒度约为30～50 nm.     

水合醋酸铈直接热分解制备超细氧化铈及其抛光性能

Ultra fine ceria was prepared by calcining hydrate cerium acetate. The effects of pyrolysis temperature on the particle size, morphology, specific surface area and loose packing density of ceria were investigated, and the removal rate of optical glasses polishing by ceria was determined. The results show that with the increase of pyrolysis temperature, the loose deposit density and crystallinity increases and the specific surface area decreases, however, the particle size decreases firstly and then increases, the minimum medium particle size D₅₀ is 0.47 μm at pyrolysis temperature of 1 000 ℃. The SEM images of ceria prepared by the decomposition at 800 ℃ or at 1 100 ℃ show porous powders or quasi-sphere small particles with loosely agglomeration, respectively. It was found that the removal rate varied with pyrolysis temperature in preparation of ceria and the property of glass polished. The removal rate for three kinds of glasses was in the order of ZF7> F1> K9, and the maximum value appeared at around 1 000 ℃ for ZF7 and F1, and at around 1 100 ℃ for K9.     

关于左手性介质几何光学的研究(一)

根据几何光学中的费马原理和完善成像原理研究了光线经过正负折射率界面时的传播特性,推导了单负折射率完善成像的曲面方程,讨论了单块负折射率透镜成像特性的一些缺陷及改进方案,依此指出了最短时间原理的适用范围的局限性和利用左手性介质制作光学器件的优越性,为进一步研究左手性介质的光学特性和相关光学器件设计提供了理论基础.     

离子选择电极阵列土壤中硝态氮测定

土壤硝态氮反映土壤短期氮素供应水平,实时了解土壤硝态氮的含量为精准农业和农业面源污染防控提供支撑,因此,在线实时检测土壤硝态氮方法突破就显得十分迫切。土壤硝态氮中的硝酸根离子在土壤中的高水溶性和流动性为全固态硝酸根离子选择电极高敏感检测土壤中硝态氮提供了条件,固态硝态氮离子选择电极的离子选择膜反应硝酸根离子在被测溶液中的浓度。采用全固态硝酸根离子选择电极,且与温度电极和pH电极融合组成电极阵列对土壤饱和溶液中的硝态根离子进行检测。设计了高输入阻抗运算放大电路对电极信号进行采集,并通过微处理控制蠕动泵完成土壤硝态氮待测溶液连续流动测量及实时传输结果。实验结果表明,电极响应时间≤15 s,斜率-51.63 mV/decade,线性范围10-5-10-2.2 mol/L,最低检测限10-5.23 mol/L。相对标准差在0.78%-4.47%范围内,加标回收率均在90%-110%以内。与国家标准紫外可见分光光度法测试结果相比,相关系数（R2）为0.9952,为土壤硝态氮在现场检测奠定技术基础。     

波导型钯(Pd)膜氢传感器数值模拟及优化

基于离子交换波导的集成型器件是氢敏传感器中很有发展潜力的一种. 传感区域由离子交换波导及其表面的金属钯膜组成, 通过有限差分法（FDM）计算了这种波导结构中的导模及表面等离子模的模场分布, 分析了其传播特性与钯膜光学常数的关系, 并结合束传播方法（BPM）对钯膜的厚度进行了优化, 使其具有最高的灵敏度.     

用于超视距雷达的电源远程监控系统

论述了对多个电源实现远程测量与控制的一种监控系统。每一电源配上一个模块，就能对其做远距离的操作，一个监控模块监视3路输出，并可对其中一路的输出电压进行远距离调节，通过软件实现电源输出的过压、过流保护。     

Nb5+掺杂对(Ca0.97Ba0.03)Cu3Ti4O12陶瓷结构与电性能的影响

该文利用固相反应法制备了(Ca0.97Ba0.03)Cu3Ti4-xNbxO12 (x=0,0.01,0.03,0.05,0.07,0.10,0.15,0.20， 摩尔分数)陶瓷。借助X线衍射仪及扫描电子显微镜研究了Nb5+的摩尔分数对(Ca0.97Ba0.03)Cu3Ti4O12陶瓷的相结构及表面微观形貌的影响，借助高低温介电测试系统和阻抗测试仪获得了(Ca0.97Ba0.03)Cu3Ti4-xNbxO12陶瓷电性能变化规律。结果表明，各组分(Ca0.97Ba0.03)Cu3Ti4-xNbxO12陶瓷均为单相立方钙钛矿结构；Nb5+摩尔分数的增加可抑制(Ca0.97Ba0.03)Cu3Ti4-xNbxO12陶瓷晶粒的生长并消除其晶粒异常长大；适量掺杂 Nb+能够有效提高(Ca0.97Ba0.03)Cu3Ti4-xNbxO12陶瓷的晶界电阻，从而降低其介电损耗，且可提高(Ca0.97Ba0.03)Cu3Ti4-xNbxO12陶瓷相对介电常数的温度稳定性。     

粉末冶金制品激光熔覆的组织与性能研究

对常规烧结的铁基粉末冶金制品进行表面激光熔覆处理 ,用 SEM和 TEM对熔覆样品的显微组织进行了观察 ,测试并分析了其孔隙度和显微硬度 ,结果表明 :熔覆层组织为 γ M7C3 共晶 ,表层硬度显著提高而整体孔隙度降低。     

灰铸铁激光硬化组织及磨损特性的研究

本文用AMRAY—1000B型扫描电镜对灰铸铁激光处理后的显微组织及耐磨特性进行了研究。激光硬化区可分为二层。第一层由奥氏体枝晶组成,二次晶轴平均间距为1.5μm,在枝晶间存在着微小渗碳体;第二层由部分熔化的片状石墨、针状马氏体和大量的残余奥氏体组成,残余奥氏体经48小时冷处理转变成马氏体,并发现在第二层中有大量的“珠光体灵魂”,其上贯穿马氏体针。灰铸铁激光处理后的耐磨性能提高3倍,磨损表面光滑而无裂纹。     

CeO2-ZrO2复合氧化物的制备及协同抛光性能

Sub-micrometer ultra fine CeO₂-ZrO₂ mixed oxides have been prepared by milling solid cerium carbonate and zirconium oxy-chloride with ammonia and followed by filtering, drying and calcining procedures. The effects of Ce/Zr molar ratio, milling time and calcining temperature on the phase composition, particle size and morphology, surface charge, as well as the polishing property were investigated. The results show that the mixed oxide calcined at 1 000 ℃ is composed of cubic ceria doped with zirconium and tetragonal zirconia doped with cerium, and the phase composition varies with calcination temperature and the Ce/Zr molar ratio. The monoclinic zirconia is observed when decreasing calcination temperature and shortening milling time, demonstrating that milling and calcining can force the phase transformation from monoclinic zirconia to cerium stabilized tetragonal zirconia and zirconium doped cubic ceria solid solutions. The removal rate for the optical glass polishing varies with Ce/Zr molar ratio. A synergetic polishing effect is found when Ce/Zr molar ratio below 4, and the optimal Ce/Zr molar ratio is 1∶1. At the same time, the cubic ceria content, density, particle size and surface charge all increase when calcination temperature increasing from 800 ℃ to 1 100 ℃. However, the particle morphology changes from disperse quasi-sphere to irregular aggregation and the maximal removal rate for optical glass polishing lies at 1 000 ℃.These facts show that the polishing property of the synthesized ceria-zirconia mixed oxide is affected by the particle physical characteristics comprehensively.