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结构主义视角下的中国高等教育“过度”问题研究 被引量:3
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作者 王文龙 《江苏高教》 CSSCI 北大核心 2012年第6期17-19,共3页
与发达国家的教育过度不同,中国高等教育"过度"的根本原因在于中国二元体制的强化以及体制内外不断扩大的收入、地位差距,以及特殊利益集团对资源与权力日益加强的垄断造成的社会闭锁。只有尽快推动中国政治体制改革,打破二... 与发达国家的教育过度不同,中国高等教育"过度"的根本原因在于中国二元体制的强化以及体制内外不断扩大的收入、地位差距,以及特殊利益集团对资源与权力日益加强的垄断造成的社会闭锁。只有尽快推动中国政治体制改革,打破二元体制分割,逐步拉平体制内外的收入差距,进一步推动市场化改革,完善市场体系,重建开放社会,我们才能从根源上化解教育"过度",缓解社会危机。 展开更多
关键词 中国高等教育 社会闭锁 二元强化 机会垄断 教育“过度” 开放社会
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Single-row laser beam with energy strengthened ends for continuous scanning laser surface hardening of large metal components 被引量:3
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作者 LI ShaoXia YU Gang +4 位作者 ZHANG JingChuan TAN QiaoFeng XU NingHan SUN PeiPei ZHENG CaiYun 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第6期1074-1078,共5页
For laser surface hardening of metal components with large superficies,a binary grating is proposed to generate single-row laser beam with proportional-intensity diffractive orders.To obtain a uniform hardened band di... For laser surface hardening of metal components with large superficies,a binary grating is proposed to generate single-row laser beam with proportional-intensity diffractive orders.To obtain a uniform hardened band distribution and improve the wear resistance of the sample surface,the binary grating is designed to produce single-row laser beam with energy strengthened at the two ends.The profile of the laser beam spot was designed to be strip with high length-width ratio to improve the machining efficiency of the hardening of large surfaces.A new advantage is suggested to obtain proportional intensity spots with evenness.The design results show that the diffractive efficiency of the binary grating is more than 70%,and the uniformity is less than 3%.The surface profile of the grating fabricated was measured,which shows that the fabrication error is less than 2%.The application of the binary grating in the laser surface hardening of metal components with large superficies is experimentally investigated,and the results show that the hardness distribution of the modified layer is more uniform than that hardened by Gaussian laser beam or array spots with equal intensity distribution. 展开更多
关键词 binary grating beam shaping laser surface hardening DIFFRACTION
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