利用CitesSpace软件对1997-2017年DMSP/OLS夜间灯光数据进行知识图谱分析,梳理国内外研究热点与演化历史,发掘研究难点,为后来研究者提供方向。本文选取Web of Science核心数据集数据库收录的文献,进行合著特征分析、关键词共现分析和...利用CitesSpace软件对1997-2017年DMSP/OLS夜间灯光数据进行知识图谱分析,梳理国内外研究热点与演化历史,发掘研究难点,为后来研究者提供方向。本文选取Web of Science核心数据集数据库收录的文献,进行合著特征分析、关键词共现分析和文献共被引分析。结果表明:(1)夜间灯光数据相关研究最活跃的国家、机构和作者分别是美国、中国科学院和Elvidge;(2)社会经济条件估计(人口、人口密度和电力)和城市扩展变化监测一直是国内外研究的热点和前沿;(3)目前的研究难点是如何减少灯光溢出效应以及灯光过饱和现象对研究精度的影响;(4)研究学科交叉性强,涉及地理学、测绘科学与技术、应用经济学、社会学等领域。因此,未来的研究趋势主要表现在数据处理方法的优化、研究领域的拓展以及深化已有研究成果3个方面。展开更多
In this paper, we proposed and experimentally demonstrated a route-asymmetrical light transmission scheme based on the thermal radiative effect, which means that forward and backward propagations of an optical device ...In this paper, we proposed and experimentally demonstrated a route-asymmetrical light transmission scheme based on the thermal radiative effect, which means that forward and backward propagations of an optical device have different transmittances provided they are not present simultaneously. Employing a fiber-chipfiber optomechanical system, our scheme has successfully achieved a broad operation bandwidth of at least 24 nm and an ultra-high route-asymmetrical transmission ratio （RATR） up to 63 dB. The route-asymmetrical device has been demonstrated effectively with not only the continuous-wave （CW） light but also 10 Gbit/s on-off-keying （OOK） digital signals. Above mentioned unique features can be mostly attributed to the significant characteristics of the thermal radiative effect, which could cause a fiber displacement up to tens of microns. The powerful and significant thermal radiative effect opens up a new opportunity and method for route-asymmetrical light transmission. Moreover, this research may have important applications in all-optical systems, such as the optical limiters and ultra-low loss switches.展开更多
文摘利用CitesSpace软件对1997-2017年DMSP/OLS夜间灯光数据进行知识图谱分析,梳理国内外研究热点与演化历史,发掘研究难点,为后来研究者提供方向。本文选取Web of Science核心数据集数据库收录的文献,进行合著特征分析、关键词共现分析和文献共被引分析。结果表明:(1)夜间灯光数据相关研究最活跃的国家、机构和作者分别是美国、中国科学院和Elvidge;(2)社会经济条件估计(人口、人口密度和电力)和城市扩展变化监测一直是国内外研究的热点和前沿;(3)目前的研究难点是如何减少灯光溢出效应以及灯光过饱和现象对研究精度的影响;(4)研究学科交叉性强,涉及地理学、测绘科学与技术、应用经济学、社会学等领域。因此,未来的研究趋势主要表现在数据处理方法的优化、研究领域的拓展以及深化已有研究成果3个方面。
基金Acknowledgements This work was partially supported by the National Basic Research Program of China （No. 2011CB301704）, the Program for New Century Excellent Talents in Ministry of Education of China （No. NCET-11-0168）, a Foundation for the Author of National Excellent Doctoral Dissertation of China （No. 201139）, the National Natural Science Foundation of China （Grant Nos. 11174096 and 61475052）, and the Opened Fund of the State Key Laboratory on Advanced Optical Communication System and Network （No. 2015GZKF03004）.
文摘In this paper, we proposed and experimentally demonstrated a route-asymmetrical light transmission scheme based on the thermal radiative effect, which means that forward and backward propagations of an optical device have different transmittances provided they are not present simultaneously. Employing a fiber-chipfiber optomechanical system, our scheme has successfully achieved a broad operation bandwidth of at least 24 nm and an ultra-high route-asymmetrical transmission ratio （RATR） up to 63 dB. The route-asymmetrical device has been demonstrated effectively with not only the continuous-wave （CW） light but also 10 Gbit/s on-off-keying （OOK） digital signals. Above mentioned unique features can be mostly attributed to the significant characteristics of the thermal radiative effect, which could cause a fiber displacement up to tens of microns. The powerful and significant thermal radiative effect opens up a new opportunity and method for route-asymmetrical light transmission. Moreover, this research may have important applications in all-optical systems, such as the optical limiters and ultra-low loss switches.
