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ESI计量分析数据库的功能与科学评价——以中国地学研究机构的科学评价为例 总被引：2，自引：0，他引：2
ESI是国际著名的学术信息机构ISI建设的衡量科学研究绩效、跟踪科学发展趋势的计量分析数据库。在介绍ESI功能的基础上,利用ESI中10年来中国地球科学论文被引情况对国家评价、研究机构评价、科学家评价、期刊评价、论文评价等方面进行了分析。从发表论文数量看,中国已经进入地学大国的行列,但与地学强国还相距甚远。地学科学家应该在提高论文质量、提升论文引用率方面更加努力,为我国乃至世界地球科学的发展做出更大的贡献。 相似文献
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在现在的表层热流模型中,有重要地球动力学意义的热异常并不总是可以认识的。假象的出现是因为表层热流响应地幔热,地壳放射性,岩浆作用,地壳变表,埋藏和或剥露以及流体运动,其中任何一种都可能抵销其它的热效应。沉积盆地特别适合于将热流分成不同的组分,以新西兰Ｔａｒｎａｋｉ盆地为例。与构造活动的东部正好相反,该盆地西部的变形相对较弱。 相似文献
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主要是对威特沃特斯兰金矿床（南非共和国）和巴列伊成矿区（外贝加尔，俄罗斯），在区域构造位置，裂谷构造发育特征，裂谷基底特征，矿床成因矿化特征等１１个方面进行了对比分析，由此揭示了两个矿床存在的一系列共同特征。首先矿床分布的区域规律性相似，它们都受大型裂谷带和裂谷带周围与构造岩浆活化有关的断裂带控制，同时构造岩浆活化两次发育的特点相似，早期形成了由双峰喷发岩岩层充填的火山洼地，及比较晚发育并叠加在火 相似文献
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在晚始新世早期的沉积物记录中 ,至少两次地外行星对地球的强撞击产生了至少两个紧邻的冲击抛出物散布场 (含单斜辉石类球粒散布场和北美陨石雨散布场 )。两个直径为９０～１００ｋｍ的撞击坑被认为是抛出物散布场的来源 ;切萨皮克海撞击坑和Ｐｏｐｉｇａｉ撞击坑。在某些地区计算的这两个抛出物地层相差１０ -２０ｋａ。然而 ,在大多数地区 ,由于其中的一个地层缺失或者垂向混合 ,两个地层已无法辨认。北美陨石雨散布场的玻陨石４０Ａｒ／ ３９Ａｒ测年 (两个地层的上层 )为３５．５Ｍａ。生物地层学研究揭示了这些撞击碎屑层与海洋生物的… 相似文献
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Moon HB An YR Park KJ Choi SG Moon DY Choi M Choi HG 《Marine pollution bulletin》2011,62(9):1963-1968
Reports of the occurrence and accumulation patterns of polycyclic aromatic hydrocarbons (PAHs) and synthetic musk compounds (SMCs) in marine mammals are scarce. In this study, the concentrations and accumulation profiles of PAHs and SMCs were determined in blubber from finless porpoises in Korean coastal waters. Total concentrations of PAHs and SMCs ranged from 6.0 to 432 (mean: 160) ng/g lipid weight and from 17 to 144 (mean: 52) ng/g lipid weight, respectively. Residue levels of PAHs were lower than those reported from other studies, while residue levels of SMCs were relatively higher than those reported in other studies. Naphthalene was the most abundant PAH and HHCB was the dominant SMC observed in finless porpoises. The concentrations of PAHs and SMCs were not correlated with each other, but were significantly correlated within the same chemical groups. No correlations were found between body size and residue levels of PAHs and SMCs. 相似文献
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Data on the occurrence and accumulation profiles of butyltins (BTs), including tributyltin (TBT), in marine mammals are scarce. This is the first study to investigate residue levels and accumulation patterns of BTs in cetaceans from Korean coastal waters. The total concentrations of BTs (sum of mono- to tri-butyltins) in minke whales (Balaenoptera acutorostrata) and long-beaked common dolphins (Delphinus capensis) ranged from 15.7 to 297 ng/g wet weight (mean: 100 ng/g wet weight) and from 59.0 to 412 ng/g wet weight (mean: 228 ng/g wet weight), respectively. Dibutyltin (DBT) accounted for 63% of the total BTs in all cetacean samples. Significant species-specific differences in BT concentrations, possibly due to the differences in their habitat and diet, were found between the two cetacean species. The concentrations of DBT and TBT in most cetacean samples exceeded the threshold value for cytotoxic effects in cetaceans, implying potentially adverse health risks from exposure to BTs. 相似文献
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The radionuclides (210)Po and (210)Pb were examined to trace the cycling of particulate organic carbon (POC) and particulate organic nitrogen (PON) in the Zhubi coral reef lagoon. The net export flux of POC to the open sea is 14 mg Cm(-2) d(-1). However, the net exchange of PON has not yet been observed. On average, the vertical export fluxes in the lagoon of POC and PON, as derived from (210)Po/(210)Pb disequilibria, are 43 mg Cm(-2) d(-1) and 13.8 mg Nm(-2) d(-1), respectively. The deficit of (210)Po relative to (210)Pb in particulate matter provides evidence for the degradation of particulate organic matter. According to the mass balance budgets, 310 mg Cm(-2) d(-1) and 121 mg Nm(-2) d(-1) were recycled into dissolved fractions. Based on a first-order kinetics model, the degradation rate constants of POC and PON are 0.28 and 0.30 m(-1), respectively. Thus, (210)Po and (210)Pb can quantify the cycling of carbon and nitrogen in this coral lagoon. 相似文献
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