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991.
Chee-Sung Park Jae-Wung Lee Sung-Mi Lee Shin-Hee Jun Hyoun-Ee Kim 《Journal of Electroceramics》2010,25(1):20-25
Lead zirconate titanate [PZT(60/40)] films were deposited by RF-magnetron sputtering using single oxide targets with various levels of excess PbO. The excess PbO in the film played an important role in the pyrochlore-to-perovskite transformation, nucleation and growth processes, orientation control, and crack formation. When 5% or 20% excess PbO was added to the target, pyrochlore phases were created and the films were severely cracked. However, the films had a perovskite structure without any pyrochlore phases when 10% or 15% excess PbO was added to the targets. More interestingly, the crystallographic orientation was strongly dependant on the excess PbO content. A film with a (111) preferred orientation was produced when 10% excess PbO was added to the target. On the other hand, a film with a (100) preferred orientation was deposited by the target with 15% excess PbO. The dielectric, ferroelectric and piezoelectric properties of these films with different orientations and microstructures were examined and correlated with the film structure. 相似文献
992.
用故障类型及影响分析法(FMEA),对宁夏石化公司二化肥循环水系统节能改造后的现状进行了调查分析,针对发现的问题提出了改进措施和建议。该分析方法有助于提早发现装置存在隐患,对预防事故发生、减少事故损失有重大意义。 相似文献
993.
Xuqiu Yang Lisheng Liu Qingjie Zhang Pengcheng Zhai 《Journal of Electronic Materials》2011,40(5):489-492
Molecular dynamics simulations of the structural and mechanical properties of single-crystalline CoSb3 have been carried out at room temperature. Special emphasis was given to the surface effect. Four different boundary conditions were applied to represent a wide range of surface-atom fractions. The LAMMPS program in conjunction with a multibody potential was employed. First, free relaxation was performed to obtain the corresponding stable configurations. The atomic rearrangements and energy distributions were observed. Then, uniaxial tensile deformation was simulated at a constant strain rate. The stress–strain responses and structural evolutions were examined during the process. Comparison of simulation results between different boundary conditions was carefully made. It was found that, when the scale of the single-crystalline CoSb3 model becomes nanometric and the fraction of the surface atoms increases, the mechanical performance becomes substantially worse. Nonetheless, the deformation mechanism and intrinsic mechanical nature are very similar. 相似文献
994.
Thermoelectric materials have received much attention recently from the viewpoint of global environmental issues and effective utilization of energy resources. Especially those effective at relatively low temperature, such as below 100°C, which are usually abandoned without use, have become noteworthy recently. From this point of view, organic thermoelectric materials are most attractive, because they could be prepared at low cost and applied in various locations due to their flexibility. We have investigated the thermoelectric properties of organic conducting polymers such as polyaniline, polypyrrole, and polyphenylenevinylene, and succeeded in increasing the thermoelectric performance by selecting dopants, stretching conducting films, etc. Recently we have focused on new systems of organic–inorganic hybrid thermoelectric materials. Herein we present the preparation of a novel system of hybrids of polyaniline and bismuth(III) telluride nanoparticles, starting from bismuth(III) chloride and tetrachlorotellurium by using polyvinylpyrrolidone as a protecting reagent, as well as their thermoelectric properties. The hybrids prepared by this particular method showed much higher thermoelectric performance than the starting organic conducting polymer. 相似文献
995.
Dense samples of the higher boride YB22C2N have been fabricated through the spark plasma sintering (SPS) method with different sintering aids. YB22C2N is a representative of a series of newly discovered rare-earth borocarbonitrides, which may be the long-awaited n-type counterpart of boron carbide, “B4C.” The effect of Si, SiC, Al, and TiC additions on the sintering process of YB22C2N has been studied. The best sintered bodies with densities higher than 90% of theoretical density were obtained by means of SPS at 1700°C. We show that the additive choice and pressure have an effect on grain size and density. An investigation of the effect of atmosphere on the sintering behavior has also been carried out. It was found that sinterability is enhanced under nitrogen atmosphere. Thermoelectric properties of the materials sintered with additives have been evaluated, and we discuss their dependences on the fabrication process route. 相似文献
996.
Mehrsa Raeis-Zadeh Noraica Davila Melendez Yu-Chun Chen Paul A. Kohl 《Journal of Electronic Materials》2011,40(10):2126-2138
The impact of thermal cure conditions on the mechanical and electrical properties of an epoxy cross-linked network incorporating a polynorbornene (PNB) dielectric polymer was studied. The cross-linking of the dielectric composition was achieved by an acid-catalyzed cationic cure reaction initiated by either thermal or photolytic activation of a photoacid generator. It is proposed that the observed mechanical and electrical properties of the fully cured polymer composition are the result of the development of a three-dimensional cross-linked network tying together the PNB polymer and multifunctional epoxy additives. The epoxy ring-opening reaction was measured using Fourier-transform infrared spectroscopy. The reduced modulus, internal film stress, dielectric constant, and swelling behavior of cross-linked films were studied as a function of curing temperature. Trends in the observed properties are explained by formation of a three-dimensional cross-linked network and degradation of the cross-links between the multifunctional epoxy additives at high temperature. It was also found that exposure of the film to aqueous base plays a role in the cure process and has a positive effect on the final properties. The optimum values of modulus, dielectric constant, residual stress, and moisture content were found for films cured at 160°C for 1 h. This relatively low cure temperature is potentially advantageous in device assembly and processing. 相似文献
997.
998.
999.
Ruthiano Simioni Munaretti Taisy Silva Weber Sérgio Luis Cechin Bruno Coswig Fiss 《Journal of Electronic Testing》2011,27(4):531-539
In an operational environment, the identification and reproduction of faults may be hard to be done, specially in complex systems. Use of fault injection accelerates this process, improving the test of fault tolerance mechanisms. However, there are a significant amount of fault injectors available, using several different approaches. This diversity of tools, each one with different methods to describe faultloads for fault injection campaigns, imposes severe obstacles to the efficient use of such fault injectors. In this context, this paper presents jFaultload, which applies Java for the specification of faultloads and translates them to specific formats that are appropriate to each available fault injector. Fault injectors for communication systems were integrated in the environment and completes the test scenario. The service under test used to demonstrate the usability and expressiveness of our solution is a video streaming session using RTP Protocol. 相似文献
1000.