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P—Si上电沉积非晶Ni—W—P薄膜的耐蚀性研究 总被引:3,自引:0,他引:3
对P-Si上电沉积Ni-W-P合金薄膜在3%NaCl、0.5mol·dm^-3H2SO4、1mol·dm^-3HCl介质中的阳极溶解行为进行了研究,XPS分析了钝化膜中各元素的化学价态和存在形式。结果表明,非晶Ni-W-P合金薄膜的耐蚀性远优于晶态Ni-W-P薄膜和非晶Ni-P薄膜;高W含量的非晶Ni-W-P合金薄膜,有较强的耐蚀能力;在NaCl介质中非晶Ni-W-P合金形成了由Ni2O3、NiH 相似文献
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采用溶胶凝胶工艺,合成出纳米晶La0.7Sr0.3FeO3薄膜,薄膜为钙钛矿结构,平均粒径在40nm左右。利用该薄膜采用平面工艺制作出微米尺寸、室温工作的La0.7Sr0.3FeO3纳米薄膜栅OSFET式气敏元件,并对其气敏性能进行了测试,发现器件的漏电流在乙醇气体中增大,在氨氧化物中降低。 相似文献
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介绍氧化钨基永久性的电可重编程的可变电阻器作用于电子神经网络的模拟突触记忆联接器。该器件具有类晶体管的多层薄膜器件结构,它是依次由直流溅射和电子束蒸发工艺沉积到一个绝缘衬底,即衬底/Ni/WO3/SiO/Cr2O3/SiO/Al。用电压控制H^+离子可逆地内插和去插到WO3薄膜来调制电阻。 相似文献
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本文在掺LiClO4与碳酸丙烯酯的聚乙二醇固体电解质离子电导特性与WO3、NiO薄膜离子插入性能研究了基础上,设计并制备了互补型WO3/NiO全固态电变色器件。同时研究了该器件变色过程的循环伏安特性与不同状态的可见、近红外透过特性。结果表明,互补型的WO3/PEG-LiClO4-PC/NiO器件在可见与近红外均具有良好的电变色特性,其漂白态在波长600nm的透过率为70%,着色态为20%。 相似文献
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本文将Al2O3/SiC纳米复合陶瓷分别与Cr25Ni5合金,Co-Cr-W合金及烧结W环三种配制材料在465℃的熔融锌液中进行环-块腐蚀磨损实验。结果表明耐锌腐蚀是各种材料耐磨的前提。W(环)与Al2O3/SiC纳米复合陶瓷(块)是最佳的摩擦副。 相似文献
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纳米WO3制备方法的研究进展 总被引:2,自引:0,他引:2
将新型气敏材料WO3制成纳米级粒子,会大大提高其灵敏度。指出了纳米三氧化钨在气敏材料领域的应用前景,并着重对纳米三氧化钨的制备方法进行了评述。 相似文献
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对反应溅射沉积的WOx薄膜在电致变色反应中结晶性能的变化进行了研究。结果表明:电致变色反应增加了薄膜的晶体特性,使着退色WOx薄膜的选区电子衍射呈现明显的多晶环特性,而原始沉积态WOx薄膜为非晶光晕衍射特性。STM分析得知,电致变色反应使薄膜的表面形貌也发生了剧烈的变化。 相似文献
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本文利用透射电镜(TEM)及能量色散X射线衍射分析(EDAX)技术对激光合成的Al2O3-WO3陶瓷材料进行分析.TEM分析表明,在Al2O3-WO3材料的胞状结构中,Al2O3形成柱状单晶且Co轴平行生长轴,Al2(WO4)3及AlxWO3位于Al2O3柱状晶间界;非平衡相AlxWO3中存在畴及超晶格结构,Al3+对WO3母体网格A位占位是有序的.EDAX结果则指出合成材料Al2O3晶粒中W杂质的浓度随配料WO3含量的增加而增大;样品合成过程中激光功率从最高值连续降低至0瓦可减少Al2O3晶粒W的掺入量;高温下对合成样品长时间热处理可使W杂质从Al2O3中释放出.材料电性质测试结果表明,材料电阻率与其中Al2O3晶粒W含量紧密相关,W的含量越高,材料电导率越大. 相似文献
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缓凝剂和减水剂作用于半水石膏水化硬化的研究进展 总被引:1,自引:1,他引:0
从缓凝剂和减水剂的缓凝作用机理、缓凝作用的影响因素、缓凝剂和减水剂对半水石膏水化硬化性能的影响几个方面论述了缓凝剂和减水剂作用于半水石膏水化硬化的研究进展。归纳了缓凝剂和减水剂的缓凝作用机理,分析了缓凝作用的影响因素,总结了缓凝剂和减水剂对半水石膏水化硬化性能的影响,重点提出了缓凝剂和减水剂复合作用的原理,最后指出研究外加剂复合作用于半水石膏水化硬化的不足及其原因。 相似文献
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K. V. Frolov N. A. Makhutov G. Kh. Khurshudov M. M. Gadenin 《Strength of Materials》2000,32(5):409-416
The evolution of approaches to the solution of machine dynamics and strength problems on the basis of determining static and dynamic nominal and local stresses of the operating load is discussed. It is shown how the material strength and plasticity characteristics, the cyclic strength characteristics in the high-cycle and low-cycle fatigue regions, the high-temperature long-term strength and creep characteristics, and the linear and nonlinear characteristics of fracture mechanics were sequentially used as the basic criterial parameters of the deformability and strength of structural materials. Particular emphasis was given to the results of studies on machine safety and catastrophe mechanics. Integrated approaches to the solution of strength and safety problems of potentially dangerous facilities (nuclear power stations, spacecraft complexes, aircraft, chemical plants, etc.) by analysis of all stages of their life cycle, including design, manufacture, testing, and operation, are discussed. 相似文献
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S. D. Luo 《Materials and Manufacturing Processes》2018,33(1):35-49
Microwave (MW) radiation has attracted increasing attention in the fabrication and/or synthesis of titanium (Ti) and Ti alloys from powder since 1999 when the first study was reported by Gedevanishvili et al. This article provides a comprehensive review of MW processing of Ti and Ti alloys. It begins by discussing the critical technical issues associated with MW processing of Ti powder, including the heating response of Ti powder to MW radiation, temperature measurement by infrared pyrometry and calibration, and interstitial absorption and control. This is followed by a detailed review of the sintering of a range of powder metallurgy (PM) Ti and Ti alloys for structural, biomedical, and shape memory applications. As a new development in the field, MW heating and sintering of titanium hydride (TiH2) powder for the fabrication of PM Ti are discussed in terms of the heating response, interstitial contamination, microstructure, and tensile properties of the as-sintered Ti. The challenges that face MW sintering of PM Ti from either Ti powder or TiH2 powder are reviewed, and solutions are proposed. Based on the heating and isothermal sintering characteristics by MW radiation, recommendations are made for the applications of MW processing of Ti and Ti alloys. 相似文献
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本文是作者再次对标准和标准化的概念进行讨论。首先讨论的是标准化的目的、主体和对象。作者认为标准化的目的是控制、有序化和统一化;标准化的主体是人/机构;标准化对象可以是具体的或抽象的事物,也可以是它们的组合;任何事物都可以抽象地表达为实体(entity)。第二,作者讨论了标准和标准化的本质以及它们的作用;认为从内容角度看,标准是匹配问题解决方案,也是为标准化对象规定需要满足的要求;从实施角度看,标准是规则;标准化则是制定、实施、传播标准的过程;标准的作用是能够创建并组织现实世界,并能够为相关方建立互相交流和共同理解的基础;标准化的作用是对创新方案进行选择和简化,阻止现实世界过度无序化发展,形成复杂化和简化之间的平衡。第三,作者讨论了标准的记录形式、自愿/强制属性和时空范围,认为标准的记录形式有文件、样品、图形符号、物理表达等多种形式;标准具有选择的自愿性和实施的强制性;标准在时空范围内是有限的。文章的结尾给出了理解标准化概念的框架。 相似文献
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In this paper, the energy and exergy analysis of single effect and series flow double effect water–lithium bromide absorption systems is presented. A computational model has been developed for the parametric investigation of these systems. Newly developed computationally efficient property equations of water–lithium bromide solution have been used in the computer code. The analysis involves the determination of effects of generator, absorber and evaporator temperatures on the energetic and exergetic performance of these systems. The effects of pressure drop between evaporator and absorber, and effectiveness of heat exchangers are also investigated. The performance parameters computed are coefficient of performance, exergy destruction, efficiency defects and exergetic efficiency. The results indicate that coefficient of performance of the single effect system lies in range of 0.6–0.75 and the corresponding value of coefficient of performance for the series flow double effect system lies in the range of 1–1.28. The effect of parameters such as temperature difference between heat source and generator and evaporator and cold room have also been investigated. Irreversibility is highest in the absorber in both systems when compared to other system components. 相似文献
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基于化学发光具有灵敏度高、不受外界光源干扰的优势,研究将化学发光溶液作为射流示踪剂的可行性,并开发了一套用于射流浓度场扩散规律研究的实验装置和测试分析系统。开展了化学发光体系的选择与优化、射流扩散实验装置的设计与开发(水槽实验装置、射流实验装置、图像采集与图像处理)、动水条件下射流浓度场扩散实验3方面的研究工作。构建的实验系统的特点在于以化学发光溶液作为射流浓度场的示踪剂,利用图像采集装置和图像处理程序来捕捉、分析射流浓度场时空动态变化的扩散过程。研究结果表明,过氧草酸酯类化学发光体系可以作为射流示踪剂来定量描述和分析射流浓度场的扩散特性,设计开发的实验装置和分析系统可以完成测定和分析动水条件下射流浓度场的任务。 相似文献
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目的 探索江门世遗文化的传承、发展和转化的新思路,践行国家在《粤港澳大湾区发展规划》纲要中要求江门承担与港澳地区文化创意合作与开发任务的分工。方法 与澳门高校紧密合作,开展专业培训课程,以开平碉楼为例,从人文视角开展设计研究,梳理开平碉楼的文化脉络,把世遗文化的元素和其背后的文化融入文创产品中,提升文创产品的附加值,推动当地文创产业结构的变革。结果 两地高校构建了稳定的科研团队,开设长期有效的设计培训课程,与景区建立了研究协作关系,帮助景区构建了一套产销研的商业模式。结论 以跨区域高校合作为平台,以文创产品为抓手,依托江澳两地的资源优势,可以构建江门世遗文化全新的品牌形象,最终推动开平世遗文化的活化。 相似文献
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由于工作环境复杂多变,制动器工作不稳定而导致振动和噪声,鼓式制动器制动时的温度变化对制动不稳定性影响较大,研究制动不稳定性影响因素及其制动不稳定时变特性具有实际工程意义。基于鼓式制动器四自由度接触模型,分别在Hypermesh和ABAQUS中建立鼓式制动器制动鼓和制动蹄总成模型与摩擦制动接触模型并进行试验验证;通过热机耦合动态分析,研究制动鼓温度对制动应力的影响;分析弹性模量和热膨胀系数对鼓式制动器制动不稳定时变特性的影响。分析表明:制动不稳定性是摩擦力耦合所致;制动过程中制动鼓温度与应力相互作用且均先快速上升后缓慢下降;鼓式制动器制动不稳定时变特性主要体现在不稳定模态个数及不稳定倾向系数(tendency of instability, TOI)值的变化,制动温度变化导致弹性模量变化,引起不稳定模态个数和TOI值略有变化,弹性模量对鼓式制动器制动不稳定时变特性影响较小;制动温度变化导致热膨胀系数变化,引起不稳定模态个数和TOI值先大幅降低后略有升高,热膨胀系数对鼓式制动器制动不稳定时变特性影响较大。研究结果对改善汽车制动声品质具有一定指导意义。 相似文献
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The present study aims to offer a new methodology for consuming two industrial wastes; sulfur, from petroleum and natural gas industries, and cement kiln dust (CKD), from Portland cement industries, in construction industry. Sulfur solidified cement kiln dust material (SSCKDM) was manufactured by mixing molten sulfur, treated sulfur, CKD and sand at a controlled temperature in excess of 120 °C. The hot mixture was subsequently cast and shaped into the desired mold and was then allowed to solidify at a specified cooling rate. Solidified materials were immersed for time periods up to 28 days in distilled water at different temperatures of 25 and 60 °C, sea water, and acidic and basic universal buffer solutions of pH4 and pH9, respectively. Solidified material performance as function of time and type of aqueous solution exposed to was evaluated in view of compressive strength variations and leachability of metal and heavy metal ions.The results indicated that the solidified articles exhibit homogenous and compact internal microstructure with excellent mechanical properties. However, it showed durability problem upon exposure to aqueous solution environments due to the initial chemical composition of the CKD, whose leached test showed release of relatively high amounts of sulfates and alkali metals. Durability of SSCKDM articles in relation to strength reduction and crack formations control was improved by addition of glass fiber while, the use of anti-leaching agent such as anhydrous sodium sulfide resulted in reduction of leached heavy metals without any measurable decrease in leached amounts of alkali metals and anions from the solidified matrix. Furthermore, based on leachability index method of calculation, potential chemical mobility of metal and heavy metal ions from the solidified matrix was characterized as medium. 相似文献