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2013年5月河南一次大暴雨成因分析及数值预报检验   总被引:2,自引:0,他引:2  
利用常规观测资料和NCEP再分析资料,分析了2013年5月25日08时--26日08时河南大暴雨过程的成因,对主要物理量因子的T639预报场进行检验。结果表明:强正涡度平流促使中高空低涡移动、地面低压发展成气旋,最强暴雨区与中高空低涡位置相对应。θse等值面坡度加大使气旋性涡度剧烈增长,产生强烈的上升运动。高空辐散与低空辐合叠加,有利于上升运动加强维持。低空气流带来充沛的水汽,大量水汽辐合有利于产生暴雨。运用正负符号一致率、相关系数和平均距离系数检验T639数值预报产品的结果表明,垂直速度预报最优,其次是涡度、散度、涡度平流预报。水汽通量、假相当位温2412h预报产品参考价值较大。  相似文献   
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以自建航海英语报刊语料库为基础,探讨如何在航海英语阅读教学中利用报刊英语语料库辅助教学,引导学生借助语境共现、词频表和关键词表等来进行英语学习,以达到快速掌握航海英语词汇,提高阅读速度和增强阅读理解能力,培养学生的跨文化交际意识等教学目标。  相似文献   
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张午 《吉林地质》2014,(1):11-13
在大量野外资料基础上,本文对五林洞幅中生代各地层特征进行描述,并描述各地层单元地质特征、出露地点、接触关系及划分依据。  相似文献   
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青藏高原青海湖流域环境与经济协调性评价(英文)   总被引:2,自引:0,他引:2  
Qinghai Lake Watershed (QLW) is a hot place of a series of ecological restoration and environmental remediation programs nowadays.However,little information is available on change of ecosystem service and economic practice in this area.As ecosystem service and natural capital are closely related with social and economic development,an index of concordance between environment and economy (ICEE) has been proposed to compare the annual variation rate of ecosystem service value (RESV) with that of gross domestic product (RGDP).Using this Index,we have assessed concordance between environment and economy (CEE) for the QLW in the period 1977-2004.The result showed that from 1977 to 2004,the ecosystem service value in the QLW descended from 128.81×10 8 yuan to 127.32×10 8 yuan;In contrast,the GDP increased from 0.931×10 8 yuan to 8.856×10 8 yuan.The values of the I CEE were -1.14,-0.22,and -0.14 in the stages of 1977-1987,1987-2000 and 2000-2004,respectively.The result indicated that during the first stage 1977-1987,the relationship between environment and economy in the QLW was not concordant but at a high conflict;from 1987 to 2004,there was a low conflict between environment and economy,and the CEE appeared to increase slowly.Analysis of the assessment results showed that the national policies and industrial adjustment practice play an important role in the CEE changes.  相似文献   
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The Qinghai Lake area is one of key regions in the Qinghai–Tibet Plateau for supporting a highly specific array of biodiversity. However, little is known about the composition and spatio-temporal patterns of benthic assemblages across this region. Herein, we examined how the community structure and community–environment relationships of macroinvertebrates varied over three consecutive years (2012–2014) across its three distinct water types of the saline main-body (MB) and sub-lakes (SSLs) and the freshwater bodies (FWBs). These waters harbored a poor benthic fauna, with identification of 30 taxa (6 in MB, 6 in SSLs and 23 in FWBs). There were distinct differences of assemblage composition among three water bodies, whereas weak (inter-year) or insignificant (seasons) differences at temporal scales. The CCA models indicated that there were highly naturally-driven environmental-assemblage relationships through time, with constant environmental factors of salinity, water depth and nutrients being the key environmental factors affecting macroinvertebrate variations. The currently overall benthic community composition and structure remains quite stable through years, indicating their suffering less from human activities. These results provide implications for projecting comprehensive benthic biomonitoring and conservation planning for those fragile and under-investigated lakes in the Qinghai–Tibet Plateau.  相似文献   
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