Delphinid spatial distribution and abundance estimates over the shelf of the Bay of Biscay     

Certain  G.; Ridoux  V.; van Canneyt  O.; Bretagnolle  V. 《ICES Journal of Marine Science》2008,65(4):656-666

  相似文献   

台湾-阿尔泰地学断面阿尔金-龙门山剖面的地壳纵波速度结构   总被引：28，自引：12，他引：16       下载免费PDF全文

王有学  W D Mooney  韩果花  袁学诚  姜枚 《地球物理学报》2005,48(1):98-106

通过分析阿尔金—龙门山地学断面的地震资料,建立了该剖面的地壳纵波速度结构。研究结果表明,阿尔金北侧的塔里木盆地地区莫霍面为50km,而在其南侧的祁连地块莫霍面突然加深至73km,在柴达木盆地莫霍面又抬升至58km左右,然后,在松潘甘孜地块莫霍面降至70km,并呈现为台阶状向龙门山方向抬升到60km左右,最低速层,而在其南部地区则没有低速层出现,推测低速层为地壳中部的局部熔融物质,阿尔金—龙门山剖面上的两个莫霍面坳陷区分别与祁连地块和松潘—甘孜地块上的两个莫霍面坳陷区相对应,指示出这个两个地块具有较深的山根,青藏高原北部的巨厚地壳很可能是由于中生代以来发生的印度板块与亚洲板块碰撞时受到来自东西及南北方向的挤压,使地壳缩短所致。  相似文献   

华南地球化学走廊带碎屑沉积岩W、Sn时空分布特征及其指示意义     

赵起超  迟清华  王学求 《物探与化探》2014,(2):211-219

通过系统的高密度采样,选取了470件来自华南走廊带的细粒碎屑沉积岩,涵盖了中元古到白垩系地层,对其主要元素、微量元素、稀土元素进行了精确分析。研究结果显示,所有样品都存在明显的稀土元素的分异和Eu的负异常,其中(La/Yb)N=10.0,Eu/Eu*=0.67。相对上地壳平均组成,样品明显亏损Ca、Na和Sr,并具有较高的化学风化指数,暗示样品受到了较为强烈的风化作用影响,并且经历了长距离的搬运过程;主要元素和微量元素图解暗示样品的源岩可能包括花岗质、安山质和长英质岩石。样品的地球化学特征显示,样品可以代表较大的源区,并且W、Sn的含量可以反映走廊带上W、Sn分布特征。在走廊带上,W、Sn的含量自东南向西北递减,在江山—绍兴断裂带附近突变,该分布特征与华南地区的钨锡成矿作用非常吻合。碎屑沉积岩中W、Sn的含量明显高于上地壳平均含量,其中W、Sn含量的峰值存在于中元古代—奥陶系地层,而华夏地块从中元古代开始便具有高钨锡含量,可能是该地区形成全世界最大的钨锡成矿省的重要原因。  相似文献   

中国地质学会印发地学科普研学基地（营地）评选授牌和监督管理办法（试行）通知     

孙莉莉 《地质论评》2022,68(4):68041277-68041277

为了贯彻落实《全民科学素质行动计划纲要（2021—2035）》,普及地球科学知识,顺利开展地学科普研学基地（营地）的推荐与评选,中国地质学会秘书局制定了《中国地质学会地学科普研学基地（营地）评选授牌和监督管理办法 (试行)》,并经过中国地质学会第40届理事会第三十七次常务理事会议（通讯）审批通过,现予以印发,请遵照执行。  相似文献   

中国地质学会印发科普奖评选办法 (试行)通知     

孙莉莉 《地质论评》2022,68(4):68041529-68041529

为了充分调动广大地质科技工作者积极参与地质科普创作,顺利开展科普奖的推荐与评选,中国地质学会秘书局制定了《中国地质学会科普奖评选办法 (试行)》,并经过中国地质学会第40届理事会第十三次常务理事会议（通讯）审批通过,现予以印发,请遵照执行。  相似文献   

Silicon limitation on primary production and its destiny in Jiaozhou Bay, China Ⅳ: Study on cross-bay transect from estuary to ocean     

杨东方  陈豫  高振会  张经  王凡 《中国海洋湖沼学报》2005,(1)

1 INTRODUCTION Terrestrial matter is continuously loaded into ocean by rivers and up taken by myriad organisms who would ultimately sink to the sea bottom, whichconstitutes a complete process of transferring terrestrial matter from land to sea. Among this dynamic process, diatoms are very important in theNo.1 YANG et al.: Silicon limitation on primary production and its destiny 73material cycle. Phytoplankton is a prime mover in the conversion from inorganic matter to organic in marine…  相似文献   

生态系统响应全球变化的陆地样带研究   总被引：2，自引：0，他引：2  

周广胜  何奇瑾 《地球科学进展》2012,27(5):563-572

为从机理上理解、评估和预测陆地生态系统对全球变化的响应,国际地圈生物圈计划在全球共启动了15条全球变化陆地样带,其中2条在中国,即中国东北样带和中国东部南北样带。从植物碳氮代谢、生物多样性、生态系统功能与碳收支及样带生态系统的变化趋势等方面较系统地总结了围绕中国这2条全球变化陆地样带的最新研究进展,加深了全球变化与陆地生态系统相互作用过程与机制的理解,提出未来中国全球变化陆地样带研究应充分利用我国特殊的生态与环境及区域特色,重点针对陆地生态系统对全球变化的适应性、地球系统相互作用的生物—物理—化学—社会过程与管理、土地利用变化的动力学过程与机制、灾害性天气气候的生态效应及其调控机制和全球变化模拟预警系统开展研究,做出一些在国际上既有显示度又服务于我国社会经济可持续发展的研究成果。  相似文献   

Seasonal variation of carbon exchange of typical forest ecosystems along the eastern forest transect in China     

《中国科学D辑(英文版)》2006,(Z2)

The long-term and continuous carbon fluxes of Changbaishan temperate mixed forest (CBS), Qianyanzhou subtropical evergreen coniferous forest (QYZ), Dinghushan subtropical evergreen mixed forest (DHS) and Xishuangbana tropical rainforest (XSBN) have been measured with eddy covariance techniques. In 2003, different responses of carbon exchange to the environment appeared across the four ecosystems. At CBS, the carbon exchange was mainly determined by radiation and temperature. 0℃and 10℃were two important temperature thresholds; the former determined the length of the growing season and the latter affected the magnitude of carbon exchange. The maximum net ecosystem exchange (NEE) of CBS occurred in early summer because maximum ecosystem photosynthesis (GPP) occurred earlier than maximum ecosystem respiration (Rθ). During summer, QYZ experienced severe drought and NEE decreased significantly mainly as a result of the depression of GPP. At DHS and XSBN, NEE was higher in the drought season than the wet season, especially the conversion between carbon sink and source occurring during the transition season at XSBN. During the wet season, increased fog and humid weather resulted from the plentiful rainfall, the ecosystem GPP was dispressed. The Q10 and annual respiration of XSBN were the highest among the four ecosystems, while the average daily respiration of CBS during the growing season was the highest. Annual NEE of CBS, QYZ, DHS and XSBN were 181.5, 360.9, 536.2 and -320.0 g·C·m-2·a-1, respectively. From CBS to DHS, the temperature and precipitation increased with the decrease in latitude. The ratio of WEE/Rθincreased with latitude, while Rθ/Gpp, ecosystem light use efficiency (LUE), precipitation use efficiency and average daily GPP decreased gradually. However, XSBN usually escaped such latitude trend probably because of the influence of the south-west monsoon climate which does not affect the other ecosystems. Long-term measurement and more research were necessary to understand the adaptation of forest ecosystems to climate change and to evaluate the ecosystem carbon balance due to the complexity of structure and function of forest ecosystems.  相似文献   

中国大陆岩石GPS平台Geo TransGIS的设计与实现   总被引：2，自引：0，他引：2  

王磊  许惠平  周云轩  刘万崧 《武汉大学学报(信息科学版)》2001,26(3):239-246

在中国大陆岩石圈地理信息系统研究过程中，提出了一种工具型二维地理信息系统和二三维地理信息系统地功能模块的设计思路，探讨了了面向对象方法，面向对象数据模型，面向对象数据库、无缝集成、开放式数据库互联技术在理信息系统研制中的运用；并用实例证明了此设计方法的可行性和实用性。  相似文献   

GEOSCIENCE DATA IN THE INFORMATION AGE: ACQUISITION,DISSEMINATION AND THEIR APPLICATIONS     

HE Bo-chu 《大地构造与成矿学(英文版)》2001,25(1)

Recent dramatic advances in technologies such as computer,data management,and communication have revolutionized the way geologists collect,disseminate,and utilize geoscience data.After summarized the characteristics and fusion of geo-data,several major field data capture systems adopted in North America have been introduced.Geoscience information dissemination and distribution via the web technology and GIS package have also been discussed.In addition,multisources geo-data integration and their applications to mineral exploration,geological hazard risk assessment,and national land resources protection and utilization have been addressed by concrete examples.  相似文献