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基于ProCAST的风镐缸体铸件工艺及性能分析 被引量:4
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作者 黄之德 《铸造技术》 CAS 北大核心 2015年第4期1072-1074,共3页
分析了风镐缸体铸件的结构特点及工艺要求,通过Pro CAST软件对铸造工艺、充型、凝固过程进行模拟和分析,优化铸造工艺。结果表明:铸件缩孔、缩松等缺陷减少,球化石墨的大小和数量均匀,提高了铸件质量,取得了明显的经济效益。
关键词 风镐缸体 模拟 球化石墨 PROCAST
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Preparation of uniform flower-like CuO and flower-like CuO/graphene composite and their application in lithium ion batteries 被引量:5
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作者 陈晗 冯钒 +3 位作者 胡忠良 刘富生 龚文强 向楷雄 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第10期2523-2528,共6页
Flower-like CuO and flower-like CuO/graphene composite were prepared successfully by hydrothermal method. They were characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption, temperature-pr... Flower-like CuO and flower-like CuO/graphene composite were prepared successfully by hydrothermal method. They were characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption, temperature-programmed reduction, and thermogravimetric analysis. It is found that the flower-like CuO microspheres, which are composed of CuO nanosheets, possess an average diameter of 4.2 μm and a Brunauer–Emmett–Teller surface area of 12.6 m2/g. Compared with the flower-like CuO, the obtained flower-like CuO/graphene composite shows an enhanced electrochemical performance with a higher capacity of 603 mA-h/g at 0.1 C rate and 382 mA-h/g at 1 C rate, and exhibits a better cycle stability with a high capacity retention of 95.5 % after 50 cycles even though at 1 C rate. 展开更多
关键词 lithium ion batteries anode materials CuO microsphere GRAPHENE
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Highly crystalline carbon nitride hollow spheres with enhanced photocatalytic performance 被引量:16
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作者 Yang Li Dainan Zhang +1 位作者 Jiajie Fan Quanjun Xiang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第4期627-636,共10页
Graphitic carbon nitride(g-C_(3)N_(4))has emerged as a remarkably promising photocatalyst for addressing environmental and energy issues;however,it exhibits only moderate photocatalytic activity because of its low spe... Graphitic carbon nitride(g-C_(3)N_(4))has emerged as a remarkably promising photocatalyst for addressing environmental and energy issues;however,it exhibits only moderate photocatalytic activity because of its low specific surface area and high recombination of carriers.Preparation of crystalline g-C_(3)N_(4) by the molten salt method has proven to be an effective method to improve the photocatalytic activity.However,crystalline g-C_(3)N_(4) prepared by the conventional molten salt method exhibits a less regular morphology.Herein,highly crystalline g-C_(3)N_(4) hollow spheres(CCNHS)were successfully prepared by the molten salt method using cyanuric acid-melamine as a precursor.The higher crystallization of the CCNHS samples not only repaired the structural defects at the surface of the CCNHS samples but also established a built-in electric field between heptazine-based g-C_(3)N_(4) and triazine-based g-C_(3)N_(4).The hollow structure improved the level of light energy utilization and increased the number of active sites for photocatalytic reactions.Because of the above characteristics,the as-prepared CCNHS samples simultaneously realized photocatalytic hydrogen evolution with the degradation of the plasticizer bisphenol A.This research offers a new perspective on the structural optimization of supramolecular self-assembly. 展开更多
关键词 CRYSTALLINE Hollow spheres Graphitic carbon nitride Photocatalytic hydrogen evolution Photocatalytic degradation PLASTICIZER
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Mechanochemical preparation and application of graphdiyne coupled with CdSe nanoparticles for efficient photocatalytic hydrogen production 被引量:1
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作者 Zhaobo Fan Xin Guo +1 位作者 Mengxue Yang Zhiliang Jin 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第10期2708-2719,共12页
Graphdiyne(GDY)has attracted considerable attention as a new two-dimensional(2D)carbon hybrid material because of its good conductivity,adjustable electronic structure,and special electron transfer enhancement propert... Graphdiyne(GDY)has attracted considerable attention as a new two-dimensional(2D)carbon hybrid material because of its good conductivity,adjustable electronic structure,and special electron transfer enhancement properties.GDY has great potential in the field of photocatalytic water splitting for hydrogen evolution,owing to its unique properties.In this study,GDY was successfully prepared by the mechanochemical coupling of precursors C_(6)Br_(6) and CaC_(2) using a ball-milling approach.The prepared GDY,especially its microstructure and composition,was well characterized using different techniques such as X-ray diffraction,scanning electron microscopy,transmission electron microscopy,X-ray photoelectron spectroscopy(XPS),Fourier-transform infrared,and Raman characterization techniques.By exploiting the unique two-dimensional(2D)structure and outstanding light absorption properties of GDY,GDY/CdSe 2D/0D heterojunctions were successfully established and applied to photocatalytic hydrogen evolution.The hydrogen evolution activity of GDY/CdSe-20,a type of composite material,reached 6470μmol g^(-1) h^(-1),which is 461 and 40 times higher than that of GDY and CdSe,respectively.Moreover,the fine electrical conductivity of GDY enabled rapid and effective transfer of the photogenerated electrons in CdSe into the hydrogen evolution reaction.The transfer path of the photogenerated electrons was studied through XPS with in situ irradiation,and a reasonable mechanism for the hydrogen evolution reaction was proposed.This study provides a feasible approach for the large-scale preparation of GDY and demonstrates the prospects of GDY in the field of photocatalysis. 展开更多
关键词 Graphdiyne Mechanical ball-milling CaC2 C6Br6 Hydrogen evolution
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Three-dimensional porous graphene-metal oxide composite microspheres: Preparation and application in Li-ion batteries 被引量:7
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作者 Seung Ho Choi Jung-Kul Lee Yun Chan Kang 《Nano Research》 SCIE EI CAS CSCD 2015年第5期1584-1594,共11页
The use of new three-dimensional (3D) porous graphene-metal oxide composite microspheres as an anode material for Li-ion batteries (LIBs) is first introduced here. 3D graphene microspheres are aggregates of indivi... The use of new three-dimensional (3D) porous graphene-metal oxide composite microspheres as an anode material for Li-ion batteries (LIBs) is first introduced here. 3D graphene microspheres are aggregates of individual hollow graphene nanospheres composed of graphene sheets. Metal oxide nanocrystals are uniformly distributed over the graphene surface of the microspheres. The 3D porous graphene-SnO2 microspheres are selected as the first target material for investigation because of their superior electrochemical properties. The 3D porous graphene-SnO2 and graphene microspheres and bare SnO2 powders deliver discharge capacities of 1,009, 196, and 52 mAh·g^-1, respectively, after 500 cycles at a current density of 2 A·g^-1 .The 3D porous graphene-SnO2 microspheres exhibit uniquely low charge transfer resistances and high Li-ion diffusivities before and after cycling. 展开更多
关键词 GRAPHENE metal oxide NANOSTRUCTURES electrode material BATTERIES
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Production of Graphene Nanospheres by Annealing of Graphene Oxide in Solution
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作者 Jian Zheng Hongtao Liu +5 位作者 Bin Wu Yunlong Guo Ti Wu Gui Yu Yunqi Liu Daoben Zhu 《Nano Research》 SCIE EI CAS CSCD 2011年第7期705-711,共7页
We report a simple method to produce graphene nanospheres (GNSs) by annealing graphene oxide (GO) solution at high-temperature with the assistance of sparks induced by the microwave absorption of graphite flakes d... We report a simple method to produce graphene nanospheres (GNSs) by annealing graphene oxide (GO) solution at high-temperature with the assistance of sparks induced by the microwave absorption of graphite flakes dispersed in the solution. The GNSs were formed by rolling up of the annealed GO, and the diameters were mostly in the range 300-700 nm. The GNS exhibited a hollow sphere structure surrounded by graphene walls with a basal spacing of 0.34 nm. Raman spectroscopy and X-ray photoelectron spectroscopy of the GNSs confirmed that the GO was efficiently reduced during the fabrication process. The resulting GNSs may open up new opportunities both for fundamental research and applications, and this method may be extended to the synthesis of other nanomaterials and the fabrication of related nanostructures. 展开更多
关键词 GRAPHENE NANOSPHERE SELF-ASSEMBLY microwave ANNEAL
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