共查询到18条相似文献,搜索用时 62 毫秒
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日本研究人员开发出一种在真空中加热纳米碳管与金属粉末制造纳米金属丝的方法。用此法制造的纳米丝比其他方法制造的纳米丝稳定,化学活性低。这种方法最适合于在相对低的温度下可转变为气体的金属,像铕、钐、镱与锶等。以此方式,金属原子几乎可完全充满纳米碳管的空腔。研究发现 相似文献
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采用浸渍还原法制备不同比例的AuPd/C纳米粒子;分别采用X线衍射仪(XRD)和透射电镜(TEM)对催化剂进行结构和形貌分析;利用CHI660a电化学工作站对催化剂进行电化学测试,结果表明:催化剂材料均为面心立方结构,AuPd/C中纳米合金粒子的粒径为5 nm左右,比Au/C中的纳米Au粒子更小,且均匀分散在VXC-72R炭黑的表面;Au/C的峰电流密度为25.05 mA/cm2,与Au/C相比,AuPd/C明显提高NaBH4的电氧化催化活性;以纳米AuPd/C为阳极催化剂、Au/C为阴极催化剂制成直接NaBH4-H2O2燃料电池(DBHFC),发现以Au1Pd2/C为阳极催化剂的DBHFC拥有良好的电池性能;在温度为60℃、NaBH4浓度为1 mol/L时DBHFC的最大功率密度达到114.6 mW/cm2。 相似文献
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中国科学院兰州化学物理研究所固体润滑国家重点实验室刘维民、王晓波与中国石油兰州润滑油研究开发中心付兴国合作发明的“纳米铜颗粒的制备方法”于2008年9月9日获得美国专利授权,专利号为Patent No.7,422,620。 相似文献
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"培育国家梯队,尽享金属魅力;打造国际精英,迈向世界一流"是北京科技大学新金属材料国家重点实验室舞动科学前沿的动力源泉(见封面),瞄准金属材料科学的前沿问题,致力重大金属材料科学的应用基础问题,新金属材料国家重点实验室激活了新金属材料科学研究一池春水,为我国新金属材料领域的科技储备和原始创新能力带来了新气象。系列文章(1)介绍了实验室的最新科技成果:新金属结构材料发展里程碑——高温高性能高Nb-TiAl合金;FeGa合金主要科研进展;第三代先进汽车用钢研究进展;第四代单晶高温合金的基础研究进展;飞秒激光加工技术研究进展。 相似文献
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陶瓷粉末尺寸对电弧喷涂金属-陶瓷复合涂层形成及性能的影响 总被引:1,自引:0,他引:1
利用高速电弧喷涂和含有微米TiB2和纳米Al2O3陶瓷粉末的粉芯丝材在碳钢基体上制备了六组陶瓷颗粒弥散增强的Fe-TiB2复合涂层,研究微纳米陶瓷粉末对电弧喷涂Fe-TiB2复合涂层的形成和性能的影响.采用光学显微镜、WYKONT1100三维表面形貌仪对比分析了扁平粒子形貌和厚度;用SEM,EDAX及XRD分析涂层的形貌和相组成,测试了涂层的显微硬度和耐磨粒磨损性能,并用激光共聚焦显微镜观察磨损后的涂层形貌.结果表明,随着粉芯丝材中微纳米陶瓷粉末含量的增加,扁平粒子的形貌从飞溅严重的散点状逐渐转变成少量飞溅的盘状,涂层的孔隙率随之下降.对比6种涂层的组织及性能,发现当粉芯丝材中的TiB2粉末尺寸<2 μm时,Fe-TiB2复合涂层中的陶瓷硬质相分布最为细小、弥散,涂层的耐磨性能最好. 相似文献
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Cr颗粒尺寸对Ni-Cr复合镀层750℃氧化性能的影响 总被引:2,自引:0,他引:2
采用复合电镀技术,通过向普通电镀溶液中分别加入平均粒度约40nm和1~5μm Cr粉的方法,在Ni基材上制备了2种金属Ni基纳米Cr粒子弥散的Ni-Cr复合镀层(简称为ENCCs Ni-Cr)和1种微米Cr粒子弥散的Ni-Cr复合镀层(简称为EMCCsNi-Cr).750℃氧化对比实验结果表明:在相同的Cr颗粒含量条件下,Cr颗粒尺寸的减小明显提高了Ni-Cr复合镀层的抗氧化性能;在相同的Cr颗粒含量条件下,Cr颗粒越细,Ni-Cr复合镀层的氧化性能越好. 相似文献
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P. Mahi A. A. J. Smeets D. J. Fray J. A. Charles 《JOM Journal of the Minerals, Metals and Materials Society》1986,38(11):20-26
The lithium industry is expected to grow rapidly in the near future due to developments in batteries and aircraft alloys, both of which require large quantities of pure lithium metal. This expansion will transform the lithium industry from predominantly chemical to predominantly metallurgical. With this growth, a question arises as to whether the current lithium industry can cope with an increasing demand for high purity lithium metal. While the resources for lithium are abundant enough to satisfy world demand for many decades, new processes must be developed to produce both high tonnages and high purities. Toward this end, several new extractive processes have recently been proposed. 相似文献
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B. A. Pint 《JOM Journal of the Minerals, Metals and Materials Society》2013,65(8):1024-1032
Fossil fuels have historically represented two-thirds of all electricity generation in the United States and are projected to continue to play a similar role despite historically low projected growth rates in electricity demand and the recent dramatic shift from coal to more natural gas usage. Economic and environmental drivers will require more reliable and efficient fossil fuel generation systems in the future, likely with new system designs, higher operating temperatures, and more aggressive environments. Some of the current corrosion issues in power plants are reviewed along with research on materials solutions for systems envisioned for the near future, such as coal gasification and oxy-fired coal boilers. 相似文献
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现代汽车制造要求一些产品的形状要符合紧凑的空间或者特殊的功能特性,这使得现在的产品与以往的产品比较来说,造型趋向复杂化,汽车的油箱就是如此,为了降低开模风险和缩短开发周期,应用分析软件结合往的经验设计了油箱上壳的冲压工艺。 相似文献
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电极催化剂是燃料电池组件中的关键,直接影响着电池性能及燃料电池的产业化进程。综述了直接甲醇燃料电池电极催化剂中贵金属的应用。从燃料电池的阳极催化剂和阴极催化剂2个方面阐述了应用贵金属的研究进展,并对其未来发展进行了展望。 相似文献
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Mushy/Semi-Solid Metal Forming Technology - Present and Future 总被引:2,自引:0,他引:2
M. KiuchiR. Kopp 《CIRP Annals》2002,51(2):653-670
Mushy, semi-solid and/or thixo processing of metals (alloys) is becoming popular as a new potential manufacturing technology for parts and components in automobile, electronic and machine industries. Internal structures and mechanical properties of those metals that include solid and liquid fractions are quite different from those of hot or molten metals. Diversified possibilities are known today to process those metals based on die casting, hot metal forming or polymer injection technologies, each of which has its own specific advantages and disadvantages. Up to now thixocasting and thixomolding have been used in industrial applications for light metal alloys. The potentials of those processes are wider by far however. They include the processing of specially designed alloys and composites, the combination of forming and joining processes as well as reduction of production costs and energy consumption. 相似文献
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A. Grinberg Dana M. Starostin G. E. Shter A. Buk O. Dinner G. S. Grader 《Oxidation of Metals》2014,82(5-6):491-508
We report here for the first time on a metal corrosion screening study of a novel nitrogen-based fuel under high temperature and pressure continuous combustion. The fuel consists of an aqueous urea and ammonium nitrate solution. Three austenitic stainless steels (SS) 316L, 310S, 330 were tested for 200 h under 20 MPa. One coupon set was positioned in the hot reactor zone, while a second set was placed in a colder zone. The temperatures in the hot and cooler zones were 745 ± 5 and 545 ± 5 °C, respectively. Microstructure, chemical composition, depth profile, and oxide scale thickness were studied by SEM/EDS and TOF-SIMS analyses. The heaviest corrosion was observed in the hot reaction zone for 316L SS. No protective Cr-rich oxide films were found in the scales formed on all tested SS. 相似文献