新疆天山北坡经济带持续低温指数变化特征     

郑玉萍  宫恒瑞  苗运玲  王毅  崔玉玲  蒲洁 《沙漠与绿洲气象(新疆气象)》2022,16(5):8-14

利用新疆天山北坡经济带12个国家气象站逐日最低气温和平均气温资料,研究该区域1965—2019年持续低温指数C_CDI的变化规律及其对气温变化的响应,结果表明：研究区的年、季平均气温均呈显著升高趋势,其中冬季升温幅度最大,夏季升温幅度最小;受气候变暖的影响,研究区C_CDI呈显著减少趋势,其中冬季减少幅度最大、夏季最小;研究区C_CDI和平均气温之间呈显著的反相关,年、季都经历了气温距平由负转正、同时对应C_CDI距平由正转负的过程;年、季C_CDI对平均气温的敏感系数均为负值,说明C_CDI值随着气温的升高而减少,敏感系数绝对值春、夏、秋三季均呈显著减小趋势,即C_CDI对气候变暖的响应在减弱,而冬季则呈显著增大趋势,即C_CDI对气候变暖的响应在增强。  相似文献   

Phytoplankton Assemblage of Yangtze River Estuary and the Adjacent East China Sea in Summer, 2004   总被引：6，自引：0，他引：6  

Luan Qingshan  Sun Jun  Shen Zhiliang  Song Shuqun  Wang Min 《中国海洋大学学报(英文版)》2006,5(2):123-131

A cruise was conducted from late August to early September 2004 with the intention of obtaining an interdisciplinary understanding of the Yangtze River Estuary including the biological, chemical and physical subjects. Water sample analysis indicated that total phytoplankton species richness was 137. Of them 81 were found in Bacillariophyta and 48 in Pyrrophyta, accounting for 59.1% and 35.0% respectively. The average cell abundance of surface water samples was 8.8×104 cells L-1, with the maximum, 102.9×104 cells L-1, encountered in the area (31.75°N, 122.33°E) and the minimum, 0.2×104 cells L-1, in (30.75°N, 122.17°E). The dominant species at most stations were Skeletonema costatum and Proboscia alata f. gracillima with the dominance of 0.35 and 0.27. Vertical distribution analysis indicated that obvious stratification of cell abundance and dominant species was found in the representative stations of 5, 18 and 33. Shannon-Wiener index and evenness of phytoplankton assemblage presented negative correlation with the cell abundance, with the optimum appearing in (30.75°N, 122.67°E). According to the PCA analysis of the environmental variables, elevated nutrients of nitrate, silicate and phosphate through river discharge were mainly responsible for the phytoplankton bloom in this area.  相似文献   

"长江中下游地区深部找矿研讨会"在合肥举行     

黄建平 《地质学刊》2007,31(1):29

日前,由中国地质调查局南京地质调查中心主办的“长江中下游地区深部找矿研讨会”在合肥举行。来自长江中下游地区各省地勘单位、科研院校的专家代表共计138人出席了会议,江苏省国土资源厅副厅长刘聪、江苏省地质调查研究院院长袁晓军参加了研讨。与会的专家代表就长江中下游地  相似文献   

长江滩地不同林龄杨树人工林植物群落物种多样性研究     

胡兴宜  唐万鹏  刘学全 《湿地科学与管理》2006,2(4):24-27

本文以石首、公安长江外滩不同林龄杨树人工群落为研究对象,研究了林下植物群落物种多样性的变化规律,结果表明:滩地立地条件较好,适合多种植物生长;滩地造林对土壤养分和草本植物种群数量分布的影响不大;有林地的多样性指数比无林地略有上升,不同林龄草本植物群落的丰富度指数R和多样性指数H′大于1.0、多样性指数D和均匀度指数J小于1.0,且与林龄的变化基本没有相关性,确定了物种多样性指数模型。  相似文献   

The effects of co-cultivation of pearl mussels and fishes on water pollution control in middle or small sized water     

张根芳邓闽中  方爱萍 《中国海洋湖沼学报》2004,22(4):425-430

Our field experiments showed that the cultivation of pearl mussels formed a new biocoene composed of filamentous algae, protozoa, porifera and coelenterate. It effectively reduced nitrogen, phosphorus,chemical oxygen demand and biochemical oxygen demand in the water by 67.3%, 73.2%, 38.1% and 15.5%,respectively, during May to September 1998 when the water eutrophication was developing. This could control water eutrophication and produce pearls, shellfish meat and shells. This is an economical and effective way to control water eutrophication by using the ultra strong filtering capability of freshwater pearl mussels.  相似文献   

长江河口地区第四纪古地理古环境变迁   总被引：21，自引：4，他引：17  

陈中原  杨文达 《地理学报》1991,46(4):436-448

通过对钻孔样品的粒度、层理揭片、矿物、微体古生物、孢粉、地球化学元素及古地磁等项目的实验室分析,着重探讨长江河口地区第四纪古地理、古环境变迁特征和长江三角洲的发育过程。  相似文献   

重庆—宜昌间长江沿岸崩塌滑坡的危害与防治对策探讨     

欧正东 《中国地质》1990,(11):22-24

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太阳活动与长江中下游地区旱涝的规律   总被引：8，自引：0，他引：8  

孙长安  杨本有 《天文学报》1992,33(2):179-185

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长江河源区冰缘环境沼泽的研究：献给竺可桢教授诞辰百周年   总被引：8，自引：2，他引：6  

孙广友  邓伟 《地理科学》1990,10(1):86-94

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长江三峡工程库首区重力场变化与构造活动   总被引：7，自引：6，他引：1  

孙少安  项爱民  李辉 《大地测量与地球动力学》2002,22(3):56-59

分析了近年来长江三峡工程库首区重力场变化的时空分布特征，研究了重力场升降变化与构造活动、地壳应力场变化的关系，认为长江三峡工程库首区应力场现阶段呈相对加强的趋势，应力场方向为北东东－南西西。  相似文献