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991.
Song Yao Hao-Tong Zhang Hai-Long Yuan Yong-Heng Zhao Yi-Qiao Dong Zhong-Rui Bai Li-Cai Deng Ya-Juan Lei 《天文和天体物理学研究(英文版)》2013,(10):1255-1268
Using a sky brightness monitor at the Xinglong station of National Astronomical Observatories,Chinese Academy of Sciences,we collected data from22 dark clear nights and 90 moon nights.We first measured the sky brightness variation with time for dark nights and found a clear correlation between sky brightness and human activity.Then with a modified sky brightness model of moon nights and data from these nights,we derived the typical value for several important parameters in the model.With these results,we calculated the sky brightness distribution under a given moon condition for the Xinglong station.Furthermore,we simulated the sky brightness distribution of a moon night for a telescope with a 5 field of view(such as LAMOST).These simulations will be helpful for determining the limiting magnitude and exposure time,as well as planning the survey for LAMOST during moon nights. 相似文献
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993.
基于Camera Link总线的CCD高速图像采集技术 总被引:1,自引:0,他引:1
现代天文学研究越来越依赖于高质量的天文观测结果。针对天文实测的需要,对基于Camera Link总线的CCD高速图像采集技术进行了系统调研,分析对比了Camera Link总线技术及其优缺点,对基于Camera link接口的高速CCD采集技术进行了深入的研究,着重讨论了单缓存与双缓存高速采集技术和实现机制。经实际测试,所实现的技术稳定、可靠,CPU负载低,采集速度达到了厂家给出的CCD相机的最高采集速度,可以满足天文大数据量采集与准实时观测的需要。 相似文献
994.
Li-Cai Deng Heidi Jo Newberg Chao Liu Jeffrey L. Carlin Timothy C. Beers Li Chen Hsu-Tai Lee Carl J. Grillmair Puragra Guhathakurta Zhan-Wen Han Jin-Liang Hou Sebastien Lepine Jing Li Xiao-Wei Liu Kai-Ke Pan J. A. Sellwood Bo Wang Hong-Chi Wang Fan Yang Brian Yanny Hao-Tong Zhang Yue-Yang Zhang Zheng Zheng Zi Zhu 《天体物理学报》2012,(7):735-754
995.
Jeffrey L. Carlin Sebastien Lepine Heidi Jo Newberg Li-Cai Deng Timothy C. Beers Yu-Qin Chen Norbert Christlie Xiao-Ting Fu Shuang Gao Carl J. Grillmair PuragraGuhathakurta Zhan-Wen Han Jin-Liang Hou Hsu-Tai Lee Jing Li Chao Liu Xiao-Wei Liu Kai-Ke Pan J. A. Sellwood Hong-Chi Wang Fan Yang Brian Yanny Yue-Yang Zhan Zheng Zheng Zi Zhu 《天体物理学报》2012,(7):755-771
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LAMOST(Large Sky Area Multi-Object Fiber Spectroscopy Telescope)的巡天战略系统的主要功能是安排观测计划,而规划巡天星表是开展所有工作的初始步骤。天文研究人员或者巡天观测人员需要从各种类型的数据库进行选星、提取和录入。使用JDBC(Java Database Connectivity)数据库访问技术,利用面向对象的编程思想,实现了一个能访问多种类型数据库、获取星表数据、数据格式转换和星表录入的工具,支持大数据量处理,为天文研究人员以及巡天观测管理人员提供帮助。 相似文献
999.
从项目管理角度出发,介绍关键路径法在项目管理中应用的基本原则和方法,并在《地震监测设施建设标准定额体系研究》项目管理中实际应用,不仅在计划制定期间求得工期、资源、成本的优化,而且在计划的执行过程中,通过信息反馈,进行有效的监督、控制和调整,保证项目在预定期望中的目标实现,通过识别并严格执行关键路径,提高项目管理的效率,压缩项目实施进度. 相似文献
1000.
A~200 ka pollen record from Okinawa Trough:Paleoenvironment reconstruction of glacial-interglacial cycles 总被引:1,自引:0,他引:1
ZHENG Zhuo HUANG KangYou DENG Yun CAO LingLong YU ShaoHua Jean-Pierre SUC Serge BERNE Franois GUICHARD 《中国科学:地球科学(英文版)》2013,56(10):1731-1747
Pollen analysis was carried out on the Core MD982194 of 29.78 m retrieved from the Middle Okinawa Trough which was dated as old as~200 ka BP.The results revealed that pollen assemblages mainly presented an alternation of coniferous and herb pollen.The coniferous saccate pollen,principally Pinus and Tsuga,predominated in most parts of the core,especially highlighted in the interstadial stages including MIS 1,3,5 and MIS7,whereas the herb pollen significantly increased in the glacial periods.Thus the pollen flora and their percentages showed the sensitive changes under the influence of ice volume during the glacial and interglacial periods.Our record from this core has first documented that the percentage of Cyperaceae was extremely high in the glacial stages with a notable increase in Artemisia,Gramineae,Asteraceae,Chenopodiaceae,and freshwater algae,which can be used as a proxy for sea-level change at the study site because of their close negative correlation of the orbital-scale changes in sea level.The distance between the continental coastline and the Okinawa Trough has deeply shortened due to the sea-level drop in the LGM.As a result,the sediment materials from Yangtze River were extensively deposited on the flat,exposed continental shelf owing to the rapid decline of river flow speed,leading to that pollen grains from Okinawa Trough are derived mainly from the flat coastal vegetation of exposed continental shelf at glacial stages.Changes of pollen assemblage were consistent with the variation of temperature and humidity,which showed that the percentage of arboreal pollen was highly augmented at MIS 7,5 and MIS 1,corresponding to the strengthening of the East Asian summer monsoon and increasing of rainfall.Moreover,the peak of Pinus percentage in MIS 5.3,5.1 and MIS 3.3 may be closely linked by orbital and sub-orbital cycles of solar radiation and monsoonal variability.The present study of core MD981294 implied lower temperature and precipitation during the lowest sea-level stage(LGM),and more visibly testified that the vegetation of the flat plain on the exposed continental shelf was dominated by intrazonal communities such as halophyte grasslands and freshwater wetlands instead of zonal steppe or semi-arid desert.All above evidence demonstrated that the fundamental changes of pollen assemblage and their origins in Okinawa Trough since~200 ka BP were affected by combine factors including the coastline position and climate fluctuation.Moreover,the substantial shortening of distance between shoreline and the Okinawa Trough driven by orbital insolation cycles was clearly indicated by the pollen spectra,whereas the source-area climate signal of the pollen record was largely weakened. 相似文献