聚焦离子束在二维多孔Si/Al2O3/SiC薄膜透射电镜截面微观结构表征中的应用

二维多孔Si/Al₂O₃/SiC薄膜材料的透射电镜截面微观结构表征中，存在薄膜易脱落、脆性大、耐磨性差，以及选区制备难度大、制样效率低、成功率低等问题。采用聚焦离子束技术，成功地进行了二维多孔Si/Al₂O₃/SiC薄膜的透射电镜截面微观形貌的表征。结果表明，聚焦离子束技术是一种可以有效减少二维多孔薄膜样品制备过程中的损伤，进行高质量进行透射电镜截面微观结构表征的方法。     

粉体颗粒微观结构的透射电镜研究

简要介绍粉体颗粒透射电镜薄膜的制备方法,选取几种粉体颗粒的薄膜对粉体颗粒的微观结构进行透射电镜研究。     

聚电解质自组装膜对聚吡咯原位沉积的影响

采用聚电解质自组装膜对其体材料进行表面化学改性，通过原位聚合在基体材料上沉积聚吡咯薄膜。采用UV－Vis和SEM对聚吡咯薄膜的结构进行了表征，结果表明基体材料经聚电解质自组装膜处理后，能改变聚吡咯薄膜的结构与性能。其中聚苯乙烯磺酸钠自组装膜不仅能明显增加聚吡咯薄膜厚度和改善薄膜均匀性及其与基体材料的附着力，而且能明显改变聚吡咯薄膜的微观结构，提高其导电性。     

非织造材料表面生长ZnO薄膜的特性研究

室温下采用射频磁控溅射技术在涤纶纺粘非织造材料表面生长ZnO薄膜。通过扫描电子显微镜及原子力显微镜对ZnO薄膜的微观结构进行表征,用分光光度计测量样品的透光率。结果表明,ZnO薄膜为纳米级,其平均晶粒大小约为30 nm~55 nm。生长了ZnO透明纳米结构的非织造材料对紫外光有较强的吸收能力,在可见光区的透光率达60%以上。     

聚酰亚胺/氧化硅-氧化铝杂化薄膜的制备

利用溶胶-凝胶法制备了一种新型的聚酰亚胺杂化材料,并采用红外光谱和扫描电镜表征了杂化材料的化学结构和微观相结构以及分析了薄膜的成分及其含量。     

ZnO薄膜结构表征的研究现状

ZnO薄膜是继GaN材料之后的另一种具有应用前景的直接宽带隙半导体材料.针对目前对ZnO薄膜结构的分析,综述了ZnO薄膜结构表征的常用方法,着重分析了XRD在ZnO薄膜结构方面的应用.     

氧化锌纳米结构的电化学控制制备及其光致发光性能

利用电化学沉积法, 通过调节电解液浓度、时间、温度等因素, 在氧化铟锡(ITO)导电玻璃上制备了形貌不同的氧化锌(ZnO)纳米薄膜. 通过X射线衍射、扫描电镜、透射电镜、光致发光谱等测试手段对不同形貌的ZnO纳米薄膜进行了表征和研究. 研究表明, 在高于阈值电压的情况下氧化锌薄膜迅速生成, 微观形貌主要受电解质溶液的浓度影响, 随着电解质浓度的升高可分别获得胞芽状、棒状、片层状结构, 结合晶体生长理论探讨了不同形貌ZnO薄膜的成因. 室温光致发光谱显示片状的ZnO纳米薄膜在近带边有较强的宽化激发峰, 而可见区的发光峰受到明显抑制, 这一结构有望应用于光电器件、传感器等领域.     

RF-PECVD法在钢衬底上沉积氮化硅薄膜的研究

采用射频等离子体增强化学气相沉积法(RF-PECVD)在钢衬底上沉积氮化硅薄膜.用台阶仪、X射线光电子能谱(XPS)、透射电镜(TEM)和扫描电镜(SEM)等手段对薄膜的厚度、成分、结构及形貌进行表征,并探讨了各工艺参数对薄膜沉积速率的影响.     

Ag-Al_2O_3金属陶瓷复合薄膜的光学特性

采用磁控溅射技术在硼硅玻璃基片上沉积具有不同填充因子的Ag-Al_2O_3金属陶瓷复合薄膜,用紫外-可见-近红外分光光度计和透射电镜(TEM)分别表征复合薄膜的光谱特性及微观结构,使用透射光谱及反射光谱数据计算其光学常数,研究了Ag-Al_2O_3复合薄膜的表面等离子体共振(SPR)吸收峰随填充因子的变化特征.结果表明,在一定范围内,随着填充因子的增大,SPR吸收峰增强、半峰全宽增大且峰位红移。     

氧离子束流密度对Ta2O5薄膜的影响

利用氧离子辅助电子束蒸发沉积Ta2O5薄膜,在dd定氧离子能量的条件下研究了氧离子束流密度对Ta2O5薄膜的微观结构、化学计量比和漏电流密度的影响.利用原子力显微镜和X射线衍射仪对Ta2O5薄膜微观结构进行表征研究,发现随着离子束流密度增大,沉积的Ta2O5薄膜致密性提高,粗糙度下降,但薄膜一直保持非晶态;同时能谱仪测试的结果表明,薄膜中O/Ta比例逐渐提高,直至呈现富氧状态.测量了不同薄膜样品的漏电流密度和击穿场强,发现随着离子束流密度增大,薄膜漏电流密度显著降低,击穿场强提高.总之,提高氧离子束流密度能够明显改善Ta2O5薄膜的微观结构和电学性能.     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.     

Estimation of potentialities of methods of summation of direct measurement errors

Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995.     

空压机轴承箱蜗壳温度探头油封改造

由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。     

Characteristics of mechanical properties of materials in studies of conditions of attainment of marginal states

It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle.     

Determination of parameters of microstructural inhomogeneity of deformation of metals by the method of modeling

The article suggests a method of evaluating the microstructural inhomogeneity of deformation of metals by modeling. The method includes the measurement of deformations of metal according to meshes of a dividing grid with small base and the calculation of the distribution parameters of microdeformations in model representation. It is shown that the modeling method makes it possible objectively to evaluate the microinhomogeneity of deformation of metals independently of the chosen mesh size of the dividing grid. New structural characteristics are introduced: the base and wave of variation expressing the degree of crumbling or amalgamation of metal grains by inhomogeneity of deformation.Translated from Problemy Prochnosti, No. 7, pp. 40–44, July, 1991.     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.     

水三相点复现的不确定度评定

水三相点是开尔文热力学温度的唯一基准点，也是ITS-90国际温标重要的定义固定点。因此，水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来，中国计量科学研究院研制出一系列高质量的水三相点容器，加强了水三相点的研究，为不确定度的分析提供了更为可靠的实验依据。同时，不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此，根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明，其扩展不确定度为0．16mK(k=2．69，P=0．99)。