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聚苯乙烯塑料表面化学镀铜的研究 总被引:4,自引:0,他引:4
研究了聚苯乙烯表面化学镀铜的表面预处理以及化学镀铜工艺对化学镀铜的影响。结果表明,聚苯乙烯经过硫酸和重铬酸钾处理后.表面的极性官能团如羰基、羧基等大大增加。表面处理提高了塑料表面对金属镀层的附着力。对工艺因素的研究表明.化学镀铜的速度与温度、反应时间以及还原剂浓度等相关。 相似文献
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稀土可有效改善化学镀Ni-Cu-P层的硬度、耐蚀性能,目前,对此研究还不够深入。在Ni-Cu-P化学镀液中引入不同含量的Ce4+,采用金相显微镜和电子能谱分析了所得Ni-Cu-P镀层的表面形貌和成分,利用极化曲线和交流阻抗谱考察了Ce4+对Ni-Cu-P镀层在室温海水中的耐蚀性能的影响。结果表明,加入Ce4+能减少Ni-Cu-P镀层的缺陷,使晶粒细化,镀层表面平整;镀层中不含Ce,Ce4+促进了镀层的非晶态化程度,从而提高了其耐蚀性;镀层的自腐蚀电位比紫铜基材的低,自腐蚀电流密度远小于紫铜基材,添加Ce4+能提高Ni-Cu-P镀层的耐蚀性,其自腐蚀电流密度低于未加稀土所得的镀层。 相似文献
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为了进一步提高Ni-P镀层的耐蚀性能,在Ni-P化学镀液中加入硫酸铜制备了Ni-Cu-P三元合金化学镀层,测试了镀层的沉积速度,采用扫描电镜(SEM)观察了镀层的表面形貌,测试了镀层在5.0%H2SO4,5.0%NaOH及3.5%NaCl溶液中的动电位极化曲线,并与Ni-P化学镀层进行了比较。结果表明:Ni-Cu-P镀层表面的胞状物比Ni-P镀层的更加细小,镀层致密性更好;Ni-Cu-P镀层在3种介质中均表现出更好的耐均匀腐蚀性和抗点蚀性能,主要是因为Ni-Cu-P镀层的非晶态结构减少了镀层缺陷数量,从而减少了腐蚀发生的敏感位置和腐蚀微电池的数量,同时更加细小的晶粒也使Ni-Cu-P镀层比Ni-P镀层更容易钝化和维持钝态,另外Ni-Cu-P镀层更为致密也减少了腐蚀介质渗入基体的通道。 相似文献
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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. 相似文献
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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. 相似文献
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V. T. Bublik A. I. Voronin E. A. Vygovskaya V. F. Ponomarev N. Yu. Tabachkova O. V. Toropova 《Inorganic Materials》2011,47(14):1563-1568
An analysis of anisotropy of the properties of a Bi2Se0.3Te2.7 solid solution was carried out using construction of demonstrative surfaces for thermoelectric effectiveness and thermal
expansion coefficients. It is shown that the texture is an important factor forming anisotropy of properties and technological
fitness of ingots for manufacturing modules. Anisotropy of properties based on the studies of the ingot textures obtained
using the float-zone method and Bridgman method (growing thermoelectric plates in a flat cavity) was studied. 相似文献
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Liebert A Wabnitz H Grosenick D Möller M Macdonald R Rinneberg H 《Applied optics》2003,42(28):5785-5792
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. 相似文献
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O'Brien RS 《Radiation protection dosimetry》2003,105(1-4):95-100
Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides. 相似文献
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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)。 相似文献