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KDP晶体生长过程中溶液稳定性的研究 被引量:6
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作者 李云南 房昌水 +5 位作者 顾庆天 孙洵 王圣来 李义平 王坤鹏 王波 《人工晶体学报》 EI CAS CSCD 北大核心 2004年第1期63-66,共4页
在KDP晶体生长过程中,溶液的稳定性对KDP晶体的光学质量影响较大。溶液的稳定性是多种因素共同作用的结果。本文主要研究了过饱和KDP溶液中晶胚的分布情况、降温过程中晶体生长驱动力与降温速度之间的关系,并分析了KDP晶体实际生长过程... 在KDP晶体生长过程中,溶液的稳定性对KDP晶体的光学质量影响较大。溶液的稳定性是多种因素共同作用的结果。本文主要研究了过饱和KDP溶液中晶胚的分布情况、降温过程中晶体生长驱动力与降温速度之间的关系,并分析了KDP晶体实际生长过程中影响溶液稳定性的主要因素。我们认为,通过改善KDP晶体生长过程中溶液的稳定性,并与其它措施和技术相结合,是提高KDP晶体光学质量的有效途径。 展开更多
关键词 KDP晶体 生长过程 溶液 稳定性 晶胚 生长驱动力 生长条件 光学质量
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高导热氮化硅陶瓷基板影响因素研究现状
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作者 朱允瑞 贺云鹏 +6 位作者 杨鑑 周国相 林坤鹏 张砚召 杨治华 贾德昌 周玉 《硅酸盐通报》 CAS 北大核心 2024年第7期2649-2660,共12页
电子电力技术的高度集成化对承载电子元器件的脆性陶瓷基板提出了更高的散热和强度要求。氮化硅陶瓷兼备优异的本征热导率和力学性能,在大功率半导体器件封装领域有广阔的发展前景。然而,目前商业及实验中可实现的氮化硅热导率远低于其... 电子电力技术的高度集成化对承载电子元器件的脆性陶瓷基板提出了更高的散热和强度要求。氮化硅陶瓷兼备优异的本征热导率和力学性能,在大功率半导体器件封装领域有广阔的发展前景。然而,目前商业及实验中可实现的氮化硅热导率远低于其本征热导率,如何在保证氮化硅优异力学性能的基础上提高热导率仍然是一个难题。本文概述了高热导氮化硅的发展近况,着重论述氮化硅实际热导率的影响因素和提高方法。同时对比了几种氮化硅烧结工艺的优劣情况,并简要介绍目前主流商业化的氮化硅陶瓷基板成型工艺,最后对氮化硅陶瓷基板发展方向作出展望。 展开更多
关键词 氮化硅 高导热 陶瓷基板 晶格氧 致密度 晶粒生长驱动力 晶粒生长形貌 烧结工艺
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Driving force and changing trends of vegetation phenology in the Loess Plateau of China from 2000 to 2010 被引量:10
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作者 WANG Hao LIU Guo-hua +3 位作者 LI Zong-shan YE Xin WANG Meng GONG Li 《Journal of Mountain Science》 SCIE CSCD 2016年第5期844-856,共13页
Changes in vegetation phenology are key indicators of the response of ecosystems to climate change.Therefore,knowledge of growing seasons is essential to predict ecosystem changes,especially for regions with a fragile... Changes in vegetation phenology are key indicators of the response of ecosystems to climate change.Therefore,knowledge of growing seasons is essential to predict ecosystem changes,especially for regions with a fragile ecosystem such as the Loess Plateau.In this study,based on the normalized difference vegetation index(NDVI) data,we estimated and analyzed the vegetation phenology in the Loess Plateau from 2000 to 2010 for the beginning,length,and end of the growing season,measuring changes in trends and their relationship to climatic factors.The results show that for 54.84% of the vegetation,the trend was an advancement of the beginning of the growing season(BGS),while for 67.64% the trend was a delay in the end of the growing season(EGS).The length of the growing season(LGS) was extended for 66.28% of the vegetation in the plateau.While the temperature is important for the vegetation to begin the growing season in this region,warmer climate may lead to drought and can become a limiting factor for vegetation growth.We found that increasedprecipitation benefits the advancement of the BGS in this area.Areas with a delayed EGS indicated that the appropriate temperature and rainfall in autumn or winter enhanced photosynthesis and extended the growth process.A positive correlation with precipitation was found for 76.53% of the areas with an extended LGS,indicating that precipitation is one of the key factors in changes in the vegetation phenology in this water-limited region.Precipitation plays an important role in determining the phenological activities of the vegetation in arid and semiarid areas,such as the Loess Plateau.The extended growing season will significantly influence both the vegetation productivity and the carbon fixation capacity in this region. 展开更多
关键词 The Loess Plateau Trend analysis PHENOLOGY NDVI Vegetation green-up date
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Five characteristics of China textile industry performance in 2017 Former and present driving forces transferred significantly
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作者 Zhao Zihan 《China Textile》 2018年第2期8-11,共4页
According to the 2017 Summary Conference of China National Textile and Apparel Council(CNTAC)held on January 22nd to 23rd,in the first 11 months of 2017,the overall operation of China’s textile industry showed a stea... According to the 2017 Summary Conference of China National Textile and Apparel Council(CNTAC)held on January 22nd to 23rd,in the first 11 months of 2017,the overall operation of China’s textile industry showed a steady growth rate,stable domestic demand growth。 展开更多
关键词 Five characteristics of China textile industry performance in 2017 Former and present driving forces transferred significantly
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