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炉前快速金相球墨大小不均的影响因素
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作者 王丽萍 《哈尔滨理工大学学报》 CAS 2003年第4期123-125,130,共4页
采用金相观察法研究了球墨铸铁炉前快速金相球墨大小不均的影响因素.结果表明:碳当量高是引起炉前快速金相中球墨大小不均的主要原因,炉前快速金相球墨大小不均的出现有一个临界碳当量值(wCE),wCE值低于临界值则不出现球墨大小不均,wCE... 采用金相观察法研究了球墨铸铁炉前快速金相球墨大小不均的影响因素.结果表明:碳当量高是引起炉前快速金相中球墨大小不均的主要原因,炉前快速金相球墨大小不均的出现有一个临界碳当量值(wCE),wCE值低于临界值则不出现球墨大小不均,wCE高于临界值则出现球墨大小不均,且随wCE值增大球墨大小不均程度增加,同时降低浇注温度和加入微量元素Bi,可使炉前快速金相球墨大小不均程度降低. 展开更多
关键词 球墨铸铁 炉前快速金相 临界碳当量 大小不均问题 浇注温度 影响因素
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甲状腺两叶大小不均等对131^I治疗Graves病疗效的影响研究
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作者 张德萍 《国际检验医学杂志》 CAS 2018年第A01期440-441,共2页
目的本课题旨在探讨甲状腺两叶大小不均等的Graves病(毒性弥漫性甲状腺肿)患者使用131I治疗的疗效差异和相关影响.方法选取2015年2月至2017年6月在院治疗的120例Graves病患者作为研究对象,根据患者甲状腺两叶的计数比差值(Countrate ... 目的本课题旨在探讨甲状腺两叶大小不均等的Graves病(毒性弥漫性甲状腺肿)患者使用131I治疗的疗效差异和相关影响.方法选取2015年2月至2017年6月在院治疗的120例Graves病患者作为研究对象,根据患者甲状腺两叶的计数比差值(Countrate difference,CRD)将其分为4组.甲组30例CRD为20%及20%以上,30例乙组CRD为10%~19%,丙组30例CRD为5%~9%,30例丁组CRD为5%以下.4组均行131I治疗,对比其治疗效果.结果4组患者中丁组总有效率(96.67%)最高,显著高于甲组、乙组和丙组(P〈0.05);丁组未治愈患者和治愈患者的131I治疗计划量都少于其他三组患者(P〈0.05).结论甲状腺两叶大小不均等对毒性弥漫性甲状腺肿患者的131I治疗效果很有影响,患者两叶计数比差值〈5%疗效最佳,建议临床根据Graves病患者甲状腺两叶计数比差值选用针对性的治疗方案. 展开更多
关键词 GRAVES病 甲状腺两叶大小不均 131^I治疗 疗效分析
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产生锌花大小不均的原因分析
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作者 张向英 《中国钢铁业》 2011年第6期32-33,共2页
锌花大小不均严重影响产品美观和使用寿命,文章针对锌花大小不均的不同表现形式分析其产生原因,从而制定了解决措施。
关键词 锌花 大小不均 原因分析
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Rank-size Distributions of Chinese Cities: Macro and Micro Patterns 被引量:1
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作者 LI Shujuan 《Chinese Geographical Science》 SCIE CSCD 2016年第5期577-588,共12页
A large number of studies have been conducted to find a better fit for city rank-size distributions in different countries. Many theoretical curves have been proposed, but no consensus has been reached. This study arg... A large number of studies have been conducted to find a better fit for city rank-size distributions in different countries. Many theoretical curves have been proposed, but no consensus has been reached. This study argues for the importance of examining city rank-size distribution across different city size scales. In addition to focusing on macro patterns, this study examines the micro patterns of city rank-size distributions in China. A moving window method is developed to detect rank-size distributions of cities in different sizes incrementally. The results show that micro patterns of the actual city rank-size distributions in China are much more complex than those suggested by the three theoretical distributions examined(Pareto, quadratic, and q-exponential distributions). City size distributions present persistent discontinuities. Large cities are more evenly distributed than small cities and than that predicted by Zipf′s law. In addition, the trend is becoming more pronounced over time. Medium-sized cities became evenly distributed first and then unevenly distributed thereafter. The rank-size distributions of small cities are relatively consistent. While the three theoretical distributions examined in this study all have the ability to detect the overall dynamics of city rank-size distributions, the actual macro distribution may be composed of a combination of the three theoretical distributions. 展开更多
关键词 Pareto's law city rank-size moving window China
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