以Web of Science在2000-2012年间产出的电子服务研究文献为数据源,利用SPSS、NetDraw软件对其关键词进行因子分析、聚类分析、共词分析以及可视化分析。分析结果表明国际电子服务研究可分为五大主题,网络服务、电子服务质量、电子商务...以Web of Science在2000-2012年间产出的电子服务研究文献为数据源,利用SPSS、NetDraw软件对其关键词进行因子分析、聚类分析、共词分析以及可视化分析。分析结果表明国际电子服务研究可分为五大主题,网络服务、电子服务质量、电子商务与电子政府、知识管理、公共电子服务;研究热点主要集中于电子政府、电子商务、客户满意、电子服务质量、互联网、信任与忠诚等方面;从主题演化来看,电子商务、电子政府、服务质量、客户满意、网络服务等贯穿于整个研究期。展开更多
Rare earth permanent magnets Sm（Co, Fe, Cu, Zr）z with outstanding performance and high-temperature thermal stability were fabricated. Optimized by Fe content and process, Sm（Co0.72Fe0.15Cu0.1Zr0.03）7.5 magnet with...Rare earth permanent magnets Sm（Co, Fe, Cu, Zr）z with outstanding performance and high-temperature thermal stability were fabricated. Optimized by Fe content and process, Sm（Co0.72Fe0.15Cu0.1Zr0.03）7.5 magnet with B1〉0.75 T and Hci〉1300 kA/m at 300 ℃ can be obtained. According to the performance data of Sm（Co0.72Fe0.15Cu0.1Zr0.03）7.5, the magnetic field along central axis Bz in periodic permanent magnet （PPM） focusing system was simulated using electromagnetic field analysis software Maxwell 2D/3D. The Bz exhibited typical cosine curve along central axis, and the peak value of Bz was high enough to meet the demand of PPM focusing system at room temperature even at 200±20 ℃. Additionally, a kind of simple cooling structure for PPM focusing system was designed by setting cooling pipe between polepieces. Simulated results showed that smooth cosine curve of Bz was successfully achieved with good control of the thickness of cooling pipe.展开更多
文摘以Web of Science在2000-2012年间产出的电子服务研究文献为数据源,利用SPSS、NetDraw软件对其关键词进行因子分析、聚类分析、共词分析以及可视化分析。分析结果表明国际电子服务研究可分为五大主题,网络服务、电子服务质量、电子商务与电子政府、知识管理、公共电子服务;研究热点主要集中于电子政府、电子商务、客户满意、电子服务质量、互联网、信任与忠诚等方面;从主题演化来看,电子商务、电子政府、服务质量、客户满意、网络服务等贯穿于整个研究期。
基金the National Basic Research Program (973) (2007CB31407)the International S&T Cooperation Program of China (2006DFA53410)
文摘Rare earth permanent magnets Sm（Co, Fe, Cu, Zr）z with outstanding performance and high-temperature thermal stability were fabricated. Optimized by Fe content and process, Sm（Co0.72Fe0.15Cu0.1Zr0.03）7.5 magnet with B1〉0.75 T and Hci〉1300 kA/m at 300 ℃ can be obtained. According to the performance data of Sm（Co0.72Fe0.15Cu0.1Zr0.03）7.5, the magnetic field along central axis Bz in periodic permanent magnet （PPM） focusing system was simulated using electromagnetic field analysis software Maxwell 2D/3D. The Bz exhibited typical cosine curve along central axis, and the peak value of Bz was high enough to meet the demand of PPM focusing system at room temperature even at 200±20 ℃. Additionally, a kind of simple cooling structure for PPM focusing system was designed by setting cooling pipe between polepieces. Simulated results showed that smooth cosine curve of Bz was successfully achieved with good control of the thickness of cooling pipe.
