高分子导电聚合物PEDT化学聚合过程及结构性能研究

分析了3,4-乙烯二氧噻吩(EDT)单体聚合过程,系统地研究了聚合条件对PEDT薄膜性能的影响,并对PEDT薄膜电学性能和热稳定性进行分析。结果表明聚合过程的起始温度、聚合时间、导电增强剂的含量、反应过程的溶液体系等因素对导电聚合物PEDT的结构及性能有显著的影响。将所制得的PEDT作为固体电解质用以制造片式钽电解电容器,电容器性能得到了明显的改善,其ESR值低于50mΩ。     

化学聚合条件对导电聚合物作阴极钽电解电容器性能的影响

研究了在多孔Ta/Ta2O5阳极表面原位聚合PEDT导电聚合物膜的制备方法,重点讨论了化学聚合的组成、聚合温度、驱溶温度等对所制电容器性能的影响.研究结果表明,所用氧化剂与单体EDT的比例保持在3～6范围内有益于提高电容器高频性能即降低ESR值;随着聚合温度的升高,对电容器的损耗有一定的影响;驱溶温度对被覆的薄膜导电性有较大影响,表现为电容器的ESR值变大.     

聚乙烯二氧噻吩热分解性能对其作阴极片式钽电解电容器自愈性能的影响

以化学原位聚合制备的导电聚合物聚乙烯二氧噻吩(3,4-polyethylene dioxythio phene,简称PEDT)薄膜在固体钽电解电容器上的应用为背景,采用TG研究了化学聚合中单体/氧化剂配比对PEDT热分解温度的影响,并以此为基础,分析了材料热性能对PEDT作阴极的固体钽电解电容器自愈特性的影响.实验结果表明,随着单体/氧化剂配比的增大,材料的热分解温度有较大变化.而以PEDT作阴极的固体钽电解电容器的自愈速度则随材料热分解温度的增大有所下降.     

浸渍条件对PEDOT型固体铝电解电容器容量引出率的影响

利用化学氧化法在电容器芯包中形成导电高分子固体阴极层,制备出固体铝电解电容器样品,考察了单体浓度、浸渍次数、氧化剂／单体浓度比例等浸渍条件对固体铝电解电容器容量引出率的影响。结果表明,在按理论化学计量比配置浸渍液的前提下,随着单体浓度和浸渍次数的增加,电容器的容量引出率呈递增趋势,最高达到标称容量的93．3％。氧化剂相对于单体的浓度比例对电容器的容量引出率有显著影响,随着氧化剂浓度的提高,电容器的容量引出率显著增加,当氧化剂相对于单体的摩尔比增加到略高于理论化学计量比,达到2．5：1时,电容器的容量引出率达到峰值,继续增大氧化剂的浓度,电容器的容量引出率下降。     

有机片式固体钽电解电容器制备工艺研究

研究了导电聚合物PEDT作为阴极材料的有机片式固体钽电解电容器的制备工艺,通过调整隔离材料、掺杂剂等参数有效改善了有机片式固体钽电容器的性能.重点研究了阻隔剂、掺杂剂含量等参数对有机片式固体钽电容器电容、等效串联电阻、漏电流等性能的影响.结果表明,当隔离材料体积分数为0.5%～1.5%时,薄膜具有较好的耐压性能,电容器的漏电流较小(<5μA);当掺杂剂质量分数为1.5%～2%时,掺杂剂可以有效地进入PEDT主链进行掺杂,PEDT薄膜的电导率较高,从而使电容器获得较低的等效串联电阻.     

聚合物阴极钽电解电容器被膜技术研究

研究了以导电聚合物PEDOT作为阴极材料的高频低ESR有机片式固体钽电解电容器的被膜技术,重点讨论不同的聚合温度、掺杂浓度和驱溶温度对降低片式固体钽电解电容器ESR的影响.研究结果表明当聚合温度为0～10℃、掺杂浓度为3%(W),驱溶温度80℃时,将得到致密的主链掺杂有效的PE-DOT膜层,从而得到较低的ESR,并表现...     

在钽电解电容器多孔阳极体表面化学原位被覆聚乙烯二氧噻吩(PEDT)薄膜研究

研究在传统固体钽电解电容器多孔阳极体微孔内表面原位化学聚合制备PEDT导电聚合物薄膜的方法,通过对比所制有机固体钽电解电容器等效串联电阻(ESR)值的变化,讨论了采用化学原位聚合被膜过程中,受限空间里高分子链形成机理以及在受限条件和开放平面条件下被覆的聚合物薄膜导电性能的变化,采用SEM、AFM、X射线能谱对所制样品表面形貌变化以及多孔阳极体内部聚合物薄膜的被覆情况进行了研究。结果表明,在受限的空间里化学聚合反应生成的聚合物薄膜电导率会由于受限能的影响而降低,其影响程度相似于聚合溶液浓度的变化对聚合物薄膜电导率的影响。     

互穿网络结构导电高分子复合固态电解质的研制与应用

采用聚四氟乙烯(PTEF)溶液对已形成钽氧化膜(Ta2O5)的Ta多孔体阳极表面进行预处理,在钽阳极微孔内形成具有许多通孔的非导电性高分子互穿网络结构,然后采用化学氧化聚合法,在互穿网络结构的通孔中原位聚合聚3,4-亚乙基二氧噻吩(PEDT)导电高分子聚合物,从而在Ta阳极体表面形成导电性高分子复合柔性固态电解质层。实验结果表明,采用20%体积浓度的PTEF水性分散液,原位聚合PEDT可以在钽阳极表面形成高机械强度的复合固态电解质层,用其制作的钽电解电容器,平均漏电流15μA,产品的平均等效串联电阻(ESR)值50mΩ。     

基于高比容钽粉的聚合物片式电容器制备工艺研究

针对比容为50000～70000μF.V/g的较高比容钽粉,研究了导电聚合物聚3,4-乙烯基二氧噻吩(PE-DOT)作为阴极材料的有机片式固体钽电解电容器的制备工艺,通过调整阳极体制备及阴极被覆工艺等参数实现了PEDOT在高比容钽块表面的有效被覆,获得了各项性能参数良好的聚合物片式钽电解电容器。重点研究了压制密度、形成电流密度等参数及分段被膜工艺对聚合物片式固体钽电容器容量引出、等效串联电阻、漏电流等性能的影响,并讨论了相应的电容器工作机理。     

改善有机片式固体钽电解电容器性能工艺研究

研究了在被膜过程中表面活性处理及掺杂对聚合物片式钽电容器容量、耐压、等效串联电阻(ESR)等特性的影响。研究结果表明表面活性处理后可以有效改善Ta2O5/PEDOT界面间的匹配,提高电容器容量引出效率;通过添加中间阻隔层(硅烷偶联剂)可以有效地阻挡杂质氧化性离子进入介质膜Ta2O5层,降低聚合物片式钽电容器的漏电流,提高耐压特性;实验结果表明在掺杂剂溶液的浓度为3%,补形成电压为赋能电压的70%时,能有效降低电容器ESR及漏电流。     

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)。