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The magnetic properties and X-ray photoelectron spectroscopy (XPS) spectra in the Dy100-xYx and Dy100-zNdz rare-earth alloys are studied.The magnetism measurements show that the dhcp crystal-field influence in the Dy-Nd alloys,which tends to destroy the orbital moment,does not vanish even though a field of 6T is applied.With increasing Y (or Nd) content the temperature region corresponding to helical phase becomes wider (or narrower).The XPS records suggest that the property of the valence fluctuation in neodymium tends to increase the Fermi wave vector kF of the Dy-Nd alloys.This testifies that the abrupt dropping of the Neel temperature,as Nd is introduced,is not only due to a dilution effect of Nd.The introduction of light rare earths into heavy ones is favorable for suppressing the helical phase in the alloys and overcoming the negative magnetocaloric effect.This result will play a guiding role in designing composite magnetic refrigeration working substances. 相似文献
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1978年初我所承接了“粉末冶金高速钢刀具”科研任务,这是一项技术复杂、工作量大的综合性研究课题。我们选定的试验工艺流程是: 熔炼→水雾化制粉→脱水、干燥与筛分→粉末检测→成份→真空退火→冷压型→真空预烧结→热模锻→调整→真空脱氧→装包套→包套封口→热挤压→刀具毛坯→刀具制造棒材→刀具制造 相似文献
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交流异步电动机无功功率就地补偿是近几年国外普遍采用的电动机节电技术措施之一。无功就地补偿是补偿在用电设备的最终端,它比集中补偿或分散补偿有更明显的节电效果。本文参考日本、美国近几年发表的文章、论文,以及我国一些企业开展无功就地补偿的经验,较详细地介绍了交流异步电动机就地补偿原理、计算及节电经济效益分析等方法。 相似文献
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交叉滚子导轨与螺栓结合面动态特性实验研究 总被引:1,自引:0,他引:1
对交叉滚子导轨和螺栓联接两种具有代表性的运动结合面及固定结合面做了动态特性测试实验,辨识出其动态特性参数,并定量研究不同结合条件下对结合面的接触刚度K和接触阻尼C的影响,提出了改善结合面接触刚度和接触阻尼的途径. 相似文献