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基于语义扩展的医学文献检索平台的设计与实现 被引量:1
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作者 张睿 《中华医学图书情报杂志》 CAS 2012年第11期53-56,78,共5页
针对不包括语义约束的基于关键字的检索方法,提出了基于语义扩展的医学文献检索平台,介绍了平台的建设目标、理论基础及平台的总体设计与技术实现,并通过实验证明了该平台的查全率查准率较高。
关键词 语义扩展 医学文献检索 检索效率 酶本体 检索平台 领域本体 医用酶
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Modeling Regional and Local-scale Permafrost Distribution in Qinghai-Tibet Plateau Using Equivalent-elevation Method 被引量:3
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作者 LI Jing SHENG Yu +5 位作者 WU Jichun WANG Jie ZHANG Bo YE Baisheng ZHANG Xiumin QIN Xiang 《Chinese Geographical Science》 SCIE CSCD 2012年第3期278-287,共10页
This study proposes an equivalent-elevation method to evaluate the integrated effects of latitude and elevation on regional and local-scale permafrost distribution in the Qinghai-Tibet Plateau,and to model the general... This study proposes an equivalent-elevation method to evaluate the integrated effects of latitude and elevation on regional and local-scale permafrost distribution in the Qinghai-Tibet Plateau,and to model the general permafrost-distribution patterns in regional and local-scale area.It is found that the Gaussian curve―an empirical model describing the relation between variations of altitudinal permafrost lower limit (PLL) and latitude in the Northern Hemisphere―could be applied in regional-and local-scale areas in the Qinghai-Tibet Plateau in a latitude-sensitive interval of 30°-50°N.The curve was then used to evaluate the latitudinal effect on permafrost distribution through transforming the latitudinal effect into a kind of altitudinal difference of PLL.This study then calculated the local equivalent-elevation value by overlaying the altitudinal difference of PLL onto real elevation at a certain location.The equivalent-elevation method was verified in an experimental subwatershed of the Qinghai-Tibet Plateau.However,feasibility of the method should be further tested in order to extend for future studies.The use of equivalent-elevation values can build a platform for comparing the regional general permafrost distribution in the plateau,and for basing further evaluations of local factors' effects on regional permafrost distribution. 展开更多
关键词 equivalent-elevation method permafrost distribution permafrost lower limit (PLL) Gaussian curve plat- form function Qinghai-Tibet Plateau
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