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黄金供需分析 被引量:2
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作者 孙艳芳 《黄金》 北大核心 2006年第4期5-8,共4页
目前,我国对黄金的需求主要由央行储备、工业用金、饰品消费和投资需求4部分组成。通过对黄金供需形势的分析,得出中国的黄金需求市场是一个前景广阔的市场。虽然国内的黄金产量逐年增加,但面对日益旺盛的黄金需求,国内的黄金产量难以满... 目前,我国对黄金的需求主要由央行储备、工业用金、饰品消费和投资需求4部分组成。通过对黄金供需形势的分析,得出中国的黄金需求市场是一个前景广阔的市场。虽然国内的黄金产量逐年增加,但面对日益旺盛的黄金需求,国内的黄金产量难以满足,黄金的缺口需要通过进口来满足。因此,在大量进口黄金的情况下,避免价格波动的风险成为不得不考虑的问题,这时推出黄金期货很有必要性。 展开更多
关键词 央行储备 工业用金 饰品消费 投资需求
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Porous bimetallic Pt-Fe nanocatalysts for highly efficient hydrogenation of acetone 被引量:10
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作者 Yongjun Ji Yuen Wu +4 位作者 Guofeng Zhao Dingsheng Wang Lei Liu Wei He Yadong Li 《Nano Research》 SCIE EI CAS CSCD 2015年第8期2706-2713,共8页
Porous Pt-Fe bimetallic nanocrystals have been synthesized via self-assembly and can effectively facilitate the synthesis of 2-propanol from acetone. The bimetallic catalyst has three--dimensional channels and shows t... Porous Pt-Fe bimetallic nanocrystals have been synthesized via self-assembly and can effectively facilitate the synthesis of 2-propanol from acetone. The bimetallic catalyst has three--dimensional channels and shows turnover frequencies (TOFs) of up to 972 h^-1 for a continuous process more than 50 h. Preliminary mechanistic studies suggest that the high reactivity is related to the interface consisting of a bimetallic Pt-Fe alloy and Fe2O3-x. An understanding of real catalytic behavior and the catalytic mechanism based on model systems has been shown to help fabricate an improved Pt/Fe3O4 catalyst with increased activity and lifetime which has great potential for large-scale industrial applications. 展开更多
关键词 porous Pt-Fe nanocrystals(NCs) self-assembly acetone hydrogenation highly active good stability interface effect
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Catalytic alkane dehydrogenations 被引量:6
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作者 Yuxuan Zhang Wubing Yao +2 位作者 Huaquan Fang Aiguo Hu Zheng Huang 《Science Bulletin》 SCIE EI CAS CSCD 2015年第15期1316-1331,共16页
Olefins find widespread applications in the synthesis of polyolefins and fine chemicals. With an increasing demand for olefins, the technologies for alkane dehydrogenation have drawn much attention. Several types of h... Olefins find widespread applications in the synthesis of polyolefins and fine chemicals. With an increasing demand for olefins, the technologies for alkane dehydrogenation have drawn much attention. Several types of heterogeneous catalysts have found applications in industry for the dehydrogenation of light alkanes, mainly ethane, propane, and butane. In the past three decades, a number of transition-metal complexes,particularly pincer-ligated iridium complexes, have been developed as the homogeneous catalysts for alkane dehydrogenations. The homogeneous catalyst systems operate under much milder conditions compared with the heterogeneous systems, and some systems exhibit good activity and high regioselectivity in dehydrogenation of alkanes longer than butane. 展开更多
关键词 OLEFINS Alkane dehydrogenation Heterogeneous catalysts Homogeneous catalysts Pincer ligand Iridium complexes
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FePCCu nanocrystalline alloys with excellent soft magnetic properties
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作者 JIN YunLong FAN XingDu +2 位作者 MEN He LIU XinCai SHEN BaoLong 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第12期3419-3424,共6页
The effect of Cu addition on crystallization behavior and soft magnetic properties of Fe84-xP10C6Cux (x = 0-1.15) alloys was investigated. Low-cost FePCCu nanocrystalline alloys dispersed with ct-Fe phase with an av... The effect of Cu addition on crystallization behavior and soft magnetic properties of Fe84-xP10C6Cux (x = 0-1.15) alloys was investigated. Low-cost FePCCu nanocrystalline alloys dispersed with ct-Fe phase with an average grain size of 15-35 nm were obtained by appropriately annealing the melt-spun ribbons at 683 K for 5 min. The Fe83.25P10C6Cu0.75 nanocrystalline alloy ex- hibits a high Bs of 1.65 T, low Hc of 3.3 A/m and high μc at 1 kHz of 21 100, which is superior to the traditional FePC soft magnetic alloys. The core loss is as low as 0.32 W/kg at 1.0 T and 50 Hz, which is 60% that of nonoriented Fe 6.5 mass% Si-steel. It is encouraging to synthesize this Fe-based nanocrystalline alloy with excellent soft-magnetic properties even using commercially industry-grade raw materials, which is promising for the future industrial applications. 展开更多
关键词 soft magnetic ahoy Fe-based nanocrystalline alloy soft magnetic properties low core loss
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