检索结果-南通市图书馆

Chronology of Holocene lacustrine sediments in Co Ngoin, central Tibetan Plateau

Science china Earth sciences 2006年第9期49卷 991-1001页

作者： wu yanhong1, wang sumin1& hou xinhua1,{2., nanjing institute of geography and limnology, chinese Academy of sciences, nanjing 2.0008, china 2. institute of Tibetan Plateau Research, chinese Academy of sciences, Beijing 10085, china 3. Graduate University of chinese Academy of sciences, Beijing 100039, china 1. key laboratory of {2. sedimentation and environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China 2. institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 10085 China 3. Graduate University of chinese Academy of sciences Beijing 100039 China

Chronology is the basis for using lacustrine sediments to reconstruct the history of en-vironmental change. Radioactive-nuclides such as 14C, 2.0Pb and 137Cs dating are mainly used to establish the chronology for recent several ten thousand years. Because of being mixed with “dead carbon”, the measured 14C age is always older than the actual age which is recognized as “reservoir effect”. Cs is a kind of active metal element, and easy to migrate vertically in the sediment that leads to the error of the time marker. 2.0Pb dating should make sure to select CIC model or CRS model. On the Tibetan Plateau, most of the {2.s are alkaline closed {2. where Cs is more moveable in the sediment and the reservoir effect caused by “dead carbon” on 14C dating is stronger. Based on the analysis on results of 14C, 2.0Pb and 137Cs of the lacustrine sediments from Co Ngoin, central Tibetan Plateau, we use the simple regression method to re-calculate the 14C calendar ages, and establish the time sequence for cores CE-1 and CE-2.with result of 2.0Pb CRS model for the upper 35 cm and re-calculated 14C calendar age for sediments bellow 35 cm. Since 1400 cal. a BP, sedimentation inter-rupted for more than 1000 years. According to this time sequence, variations of environmental proxies confidently reflect the major climatic events in Holocene.

关键词： 14C, 2.0Pb and 137Cs, chronology, lacustrine sediments, climatic event, Co Ngoin, central Tibetan Plateau.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Status of aquatic organisms resources and their environments in Yangtze River system(2.17-2.2.)⋆

引用

Aquaculture and Fisheries 2024年第5期9卷 833-850页

作者： Haile Yang Li Shen Yongfeng He Huiwu Tian Lei Gao Jinming wu Zhigang Mei Nian Wei Lin {2. Tingbing Zhu Feifei Hu Jinling Gong Hongchun Du Xinbin Duan Huatang Deng Daoqun {2. Fengyue Zhu Yunfeng Li Fan wu Huijun Ru Yan Zhang Junyi Li Junlin Yang Yuntao Zhou Dongdong Fang Yinping {2. Danqing Lin Yanping Yang Peijie Li Silei Liu Jian Yang Ping Zhuang Sikai {2. Tao Zhang Gang Yang Wenbo Yang Lilai Yuan Kun Cao Shuo Xu Huiyuan Liu Zhiqiang Liang Chongrui {2. Hong Li Xiping Yuan Xin Yang Yilong Fu Yanping Zhang Haixin Zhang Zhiying Tao Sheng {2. Xiaoping Gao Binsong Jin Kemao Li Guojie {2. Shenglong Jian Yingqin Li Chenjiang Xue Chunyun Lei Shaowei Xue Yi Sun Bin Zhu Ke Shao Xingkun Hu Meihua Xiong Jun Du Bin He Tao Yan Yingying Huang Yuanchao Zou Biwen Xie Yongming {2. Bin Li Fei Liu Yaoyao Zhang Fei Fan Zhijian {2. Jing Huang Haoran Gu Hailong Ge Yan Dan Yan Li Shuqiao {2. Chuang Zhang Lu Zhou Xue {2. Sheng Zeng Yan Xiang Xugang He Jianhui Qin Chengxing Xia Jie hou Yifu Shi Lifang Gao Zhiqiang Zhu Hongbao Shen Yun Du Xuejun Duan Jiawu Xiong Deguo Yang Shaoping Liu Zhaohui Ni Hui Zhang Kai Liu Feng Zhao Yingren Li Jianwei {2. Qiwei Wei Yangtze River Fisheries Research institute Chinese Academy of Fishery SciencesWuhan430223China institute of Hydrobiology Chinese Academy of SciencesWuhan430072China Fishery Resource and environment Research Center Chinese Academy of Fishery SciencesBeijing100141China key laboratory of Freshwater Fisheries and Germplasm Resources Utilization Ministry of Agriculture and Rural AffairsFreshwater Fisheries Research CenterChinese Academy of Fishery SciencesWuxi214081China East china Sea Fisheries Research institute Chinese Academy of Fishery SciencesShanghai200090China institute of Fisheries Engineering Chinese Academy of Fishery SciencesBeijing100141China Hunan Fisheries Science institute Changsha410153China Jiangxi Fisheries Research institute Nanchang330039China Jiujiang Academy of Fishery sciences Jiujiang332000China School of Life sciences Nanchang UniversityNanchang330031China Qinghai Provincial Fishery Technology Extension Center Xining810012China Yunnan Academy of Fishery sciences Kunming650111China institute of Hydroecology Ministry of Water Resources and Chinese Academy of SciencesWuhan430079China Fisheries institute Sichuan Academy of Agricultural SciencesChengdu611731China School of Life sciences Neijiang Normal UniversityNeijiang641100China School of Life sciences Southwest UniversityChongqing400715China Chongqing Fishery sciences Research institute Chongqing401120China Guizhou Fisheries Research institute Guiyang550025China College of Fisheries Huazhong Agricultural UniversityWuhan430072China Hubei Fisheries Science Research institute Wuhan430070China Shaanxi Fisheries Research institute Xi’an710086China Innovation Academy for Precision Measurement Science and Technology Chinese Academy of SciencesWuhan430077China nanjing institute of {2. and limnology Chinese Academy of SciencesNanjing210008China Central South Inventory and Planning institute of State Forestry and Grassland Administration Changsha410014China

The Yangtze River is the mother river of *** promote the aquatic ecosystem protection of the great river,the Project of Yangtze Fisheries Resources and environment Investigation(2.17-2.2.)supported by the Ministry of Agriculture and Rural Affairs,*** carried out by 2. institutes and universities that located in the Yangtze River basin surveys the status of(1)fish species composition and spatial distribution,(2.current fish abundance,(3)endangered fishes,(4)Yangtze finless porpoise,(5)aquatic eco-environments,(6)water-level fluctuation areas,(7)capture fisheries and recreational fisheries of the Yangtze River mainstream and 10 of its main tributaries,including Yalong River,Heng River,Min River(including Dadu River),Chishui River,Tuo River,Jialing River,wu River,Han River,Dongting lake and Poyang *** results showed that there were 443 fish species(belonging to 163 genus,37 families,and 18 orders)before 2.17,but only 32. fish species(including 15 new recorded exotic species)were recorded in the project of *** them,Cyprinus carpio,Carassius auratus,Hypophthalmichthys molitrix,Pelteobagrus fulvidraco,Coilia brachygnathus,Silurus asotus,Saurogobio dabryi,Ctenopharyngodon idellus,Pelteobagrus nitidus,Hemiculter leucisculus,Siniperca chuatsi,Coreius heterodon,Culter alburnus,Parabramis pekinensis,and Aristichthys nobilis were the dominant species across the whole Yangtze River *** is estimated that there were 886 million individuals weighing 12..8 million kg,merely equivalent to 2..3%of the resources in 1950s,30.9%of the resources in 1960s,or 58.7%of the resources in *** the new list of protected fishes that recorded in the Yangtze River system,only 15 of 2. were collected in this project of *** gladius has been affirmed to be Extinct by International Union for Conservation of Nature(IUCN).The wild individuals of Tenualosa reevesii and Luciobrama macrocephalus have disappeared for many years and maybe have been extinct

关键词： Fishes Yangtze finless porpoise Resources Aquatic ecosystem Fisheries Background investigation Yangtze river system

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geochronology of recent lake sediments from Longgan lake,middle reach of the Yangtze River,influenced by disturbance of human activities

引用

Science china Earth sciences 2010年第8期53卷 1188-1194页

作者： wu yanhong LIU EnFeng BING HaiJian YANG XiangDong XUE Bin XIA WeiLan State key laboratory of {2. Science and environment Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China institute of Mountain Hazards and environment Chinese Academy of SciencesChengdu 610041China Graduate University of chinese Academy of sciences Beijing 100049China

The impacts of human activities in Longgan lake region on the distribution of 2.0Pb in lake sediment made it difficult to establish geochronological sequence. However, {2.al proxies recorded these human activities and could be used as time marker to check 2.0Pb dating results. Based on the analysis of 2.0Pbexc distribution in cores LS-1 and LGL-1, and in combination with the human activities records in grain-size and element concentration, the sedimentation rates in the upper layers of these two cores were determined to be 0.19 and 0.2. cm/a respectively. The MAR (mass accumulation rates) of these two cores demonstrated that natural condition, such as precipitation and runoffs, led to the variation of MAR before human disturbance, and human activities controlled the sedimentary processes afterwards, which obviously reduced the particles influx into the lakes. During 1940s when human activity had not changed the water system within the catchment, 2.0Pb activity was abnormally strong in lakes along middle to lower reaches of the Yangtze River, which might be attributed to less precipitation and can be used as a time marker for geochronological research.

关键词： 2.0Pb geochronology environmental index human activity Longgan lake

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

洞庭湖湿地短尖薹草(Carex brevicuspis)种群克隆生长对泥沙淤积的适应

引用

湖泊科学 2024年第5期36卷 1470-1478,I0015页

作者：潘柏含邹雅邓正苗谢永宏侯志勇李旭曾静吴滔谢洪涛黎慧娟湖南师范大学生命科学学院长沙410081 中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室洞庭湖湿地生态系统观测研究站长沙410125 湖南省益阳市林业局益阳413000 湖南鑫远环境科技股份有限公司湖南省环境保护入河湖湿地生态修复工程技术中心长沙410008

泥沙淤积是影响湿地植物生存和生长的重要因素。克隆植物是湿地生态系统的主要植物类型之一。在自然水文条件下,湿地克隆植物种群对不同淤积速率的响应研究相对较少。本研究以洞庭湖湿地优势克隆植物短尖薹草(Carex brevicuspis)为对象... 详细信息

泥沙淤积是影响湿地植物生存和生长的重要因素。克隆植物是湿地生态系统的主要植物类型之一。在自然水文条件下,湿地克隆植物种群对不同淤积速率的响应研究相对较少。本研究以洞庭湖湿地优势克隆植物短尖薹草(Carex brevicuspis)为对象,通过连续3年的野外控制实验,研究了不同淤积速率(0、2.4、6 cm/a,分别对应对照组,低、中和高淤积速率组)对湿地克隆植物种群的影响。结果表明:淤积速率对短尖薹草的种群密度影响显著,淤积处理的密度显著低于对照处理。随着淤积速率的增加,密度下降,地下/地上生物量比增加,高淤积速率下种群的密度最低,地下/地上生物量比最高。与对照处理相比,泥沙淤积促进了更多的短根(10 cm)、长根茎(≥1 cm)和游击型克隆分株的形成,长根茎的长度随淤积速率的增加而增加。高淤积速率下的长根茎数量较低,但其根长最长,表明其克隆生长策略由密集型向游击型转变。由此可见,短尖薹草种群可通过对密度、生物量分配、根系长度和克隆生长策略的调节,有效地应对不同泥沙淤积速率的影响。

关键词：淤积速率湿地植物种群特征根系克隆生长

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

巴丹吉林沙漠南缘高台盐湖记录的中晚全新世气候变化

引用

海洋地质与第四纪地质 2020年第4期40卷 192-203页

作者：伏梦璇于世永吴金甲陈诗越侯战方周瑞文李政魏本杰聊城大学环境与规划学院聊城252000 江苏师范大学地理测绘与城乡规划学院徐州221116 聊城大学运河学研究院聊城252000 中国科学院地球环境研究所黄土与第四纪地质国家重点实验室西安710061

位于季风边缘区和受西风环流显著影响的巴丹吉林沙漠南缘的高台盐湖提供了中晚全新世亚洲干旱区气候变化的可靠记录.在OSL测年的基础上,通过对高台盐湖剖面CaCO3含量、色度(L*、a*、b*)、粒度端元组分(EM)等环境代用指标的综合分析,重... 详细信息

位于季风边缘区和受西风环流显著影响的巴丹吉林沙漠南缘的高台盐湖提供了中晚全新世亚洲干旱区气候变化的可靠记录.在OSL测年的基础上,通过对高台盐湖剖面CaCO3含量、色度(L*、a*、b*)、粒度端元组分(EM)等环境代用指标的综合分析,重建了我国西北地区中晚全新世的气候变化.结果表明,中晚全新世高台盐湖地区气候变化经历了4个阶段:约7.1~5.3 ka,代表河流作用的EM2.主导,为浅湖/滨湖相沉积环境,气候相对干旱;5.3.1.2.ka期间,代表悬移作用的EM1占主导,指示深湖相沉积环境,CaCO3含量和a*和b*指示流域降水增多,地表侵蚀加强,近源物质输入较多,为中晚全新世以来的最湿润期;1.2.0.2.ka期间,EM2.示沉积环境转为滨湖/浅湖相沉积,气候变干;0.2.ka以来,气候进一步变干,湖泊消亡,演变为现代沙丘堆积.区域古气候替代记录的对比表明,高台地区中晚全新世以来演化过程与中亚干旱区湖泊记录具有一致性,气候变化主要受西风环流与高纬度北大西洋共同影响.

关键词：粒度端元气候变化中晚全新世高台盐湖

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

新安江水库悬浮颗粒物时空分布、沉降通量及其营养盐效应

引用

环境科学 2020年第5期41卷 2137-2148页

作者：史鹏程朱广伟杨文斌许海朱梦圆刘明亮虞左明吴志旭郑文婷王裕成笪文怡胡林娜中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室南京210008 安徽师范大学环境科学与工程学院芜湖241003 杭州市环境保护科学研究院杭州310000 杭州市生态环境局淳安分局杭州311700

为分析降雨入流影响下水库悬浮颗粒物的时空分布及沉降特征,在华东地区最大水库新安江水库(千岛湖)的河流区、过渡区和湖泊区(分别对应街口、小金山和大坝这3个水质断面)布设水体沉降物自动捕获器和水质高频自动监测浮标,结合定期水样... 详细信息

为分析降雨入流影响下水库悬浮颗粒物的时空分布及沉降特征,在华东地区最大水库新安江水库(千岛湖)的河流区、过渡区和湖泊区(分别对应街口、小金山和大坝这3个水质断面)布设水体沉降物自动捕获器和水质高频自动监测浮标,结合定期水样采集分析,开展了为期1 a的水体颗粒物沉降通量及其营养盐效应观测研究.结果发现,水库水体浊度、悬浮颗粒物浓度(SS)、颗粒物沉降通量与降雨量、入库流量极显著相关(P1),其中浊度与SS的相关性最好(R2.0.86);在降雨较多的春夏季,SS空间差异明显(河流区>过渡区>湖泊区),而秋冬空间差异不大;颗粒物沉降通量具有明显的时空异质性,空间上河流区>过渡区>湖泊区[分别为2..82. 4.34和0.2. g·(m^2.d)^-1],时间上春夏季>秋冬季;结合全湖60个点位四季悬浮物浓度调查估算,全库颗粒物沉降通量为2.57×10^6 t·a^-1,其中春夏季沉降通量高于秋冬季;街口、小金山和大坝捕获沉降物中颗粒态氮含量(PN)分别为6 812. 15 886和2. 986 mg·kg^-1,磷含量(PP)分别为2.545、 3 2.9和3 077 mg·kg^-1,自上游向下递增.统计分析表明,中雨以上降雨过程与河流区浊度增量呈指数相关(R2.0.81),持续强降雨则对浊度有累加效应,但对过渡区影响不大;SS浓度自河流入库区至下游大坝随距离增加呈较好的指数下降特征(R2.0.84),降雨较多的春夏季更为明显.结果还表明,新安江水库年均库容淤损率为0.07%,与全国其它大型水库相比较低,但是坝前沉降物营养盐含量较高,具有一定的内源释放风险;管理上应加强流域水土保持治理,降低降雨冲刷对水质的影响;同时关注坝前高营养沉积物的内源释放对水质的影响.

关键词：悬浮颗粒物沉降物捕获器高频监测浮标沉降通量新安江水库

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：