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长江中下游地区铜金(钼)矿Re-Os年龄测定及其对成矿作用的指示 被引量:279
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作者 毛景文 Holly STEIN +5 位作者 杜安道 周涛发 梅燕雄 李永峰 藏文栓 李进文 《地质学报》 EI CAS CSCD 北大核心 2004年第1期121-131,共11页
长江中下游是中国东部一个重要的Cu-Au-Fe-Mo矿成矿带。笔者等在5个夕卡岩-斑岩Cu-Au-Mo矿区采集了11件辉钼矿样品,在铜陵地区大团山层控夕卡岩Cu-Au-Mo矿体采集了5件辉钼矿样品进行Re-Os同位素年龄测定。在对16件样品进行ICP-MS方法测... 长江中下游是中国东部一个重要的Cu-Au-Fe-Mo矿成矿带。笔者等在5个夕卡岩-斑岩Cu-Au-Mo矿区采集了11件辉钼矿样品,在铜陵地区大团山层控夕卡岩Cu-Au-Mo矿体采集了5件辉钼矿样品进行Re-Os同位素年龄测定。在对16件样品进行ICP-MS方法测定的同时,还利用NTIMS方法对其中9件样品进行了精测,两种方法测定的结果基本吻合。16件辉钼矿的Re-Os同位素模式年龄为134.7±2.3~143.7±1.6Ma(2σ)。其中大团山铜矿区的5件样品的模式年龄更为接近,分布范围为 138.0± 3.2~140.8±2.0 Ma,平均 139.3±2.6Ma,其等时线年龄为 139.1±2.7Ma,初始Os为0.7±8.1(MSWD=0.29)。这些结果清楚地反映出夕卡岩-斑岩Cu-Au-Fe-Mo矿床与层控夕卡岩Cu-Au-Mo矿床为同一时代形成,属于同一成矿系统。作为中国东部大规模成矿作用的组成部分,长江中下游地区铜钼金矿床的形成与岩石圈构造体制大转换之地球动力学事件相耦合,为中生代第二期大规模成矿作用的产物。 展开更多
关键词 Re-Os年龄测定 铜矿 金矿 长江中下游地区
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青藏高原东北部的库仑应力积累演化对大地震发生的影响 被引量:110
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作者 万永革 沈正康 +1 位作者 曾跃华 盛书中 《地震学报》 CSCD 北大核心 2007年第2期115-129,共15页
假定地震可以模拟为多层弹粘性介质中的位错,考虑大地震(M≥7.0)和GPS数据得出的长期构造加载为形变源,依据多层麦克斯韦弹粘性介质中位错产生的应力变化,计算得到了地震产生的应力变化,给出了青藏高原东北部1920年以来积累库仑破裂应... 假定地震可以模拟为多层弹粘性介质中的位错,考虑大地震(M≥7.0)和GPS数据得出的长期构造加载为形变源,依据多层麦克斯韦弹粘性介质中位错产生的应力变化,计算得到了地震产生的应力变化,给出了青藏高原东北部1920年以来积累库仑破裂应力演化.地震破裂的断层长度、宽度和滑动量根据前人统计公式和野外地质调查得到.研究表明,20次M≥7.0地震中,除1990年共和地震、1952年当雄地震和1976年松潘双震的后一个事件外,17次大地震均发生在库仑破裂应力变化为正的区域,触发率达85%.本研究为中长期地震危险性估计在一定程度上提供了基础数据. 展开更多
关键词 地震触发 青藏高原东北部 积累库仑应力变化
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中国农村医疗消费行为变化及其政策含义 被引量:69
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作者 封进 秦蓓 《世界经济文汇》 北大核心 2006年第1期75-88,共14页
收入对医疗消费的直接效应表现为医疗消费随收入水平提高而增加;收入的间接效应是指收入下降导致了健康水平下降,从而医疗支出增加。本文采用中国健康和营养调查(CHNS)数据,用一个医疗决策模型和医疗支出模型估计了中国农村医疗支出和... 收入对医疗消费的直接效应表现为医疗消费随收入水平提高而增加;收入的间接效应是指收入下降导致了健康水平下降,从而医疗支出增加。本文采用中国健康和营养调查(CHNS)数据,用一个医疗决策模型和医疗支出模型估计了中国农村医疗支出和收入水平之间的关系。结果表明在1989年,收入的间接效应大于直接效应。到1997年,收入水平对医疗支出的影响变得不显著。究其原因,这一时期的收入的直接效应和间接效应均发生作用且作用相当,由此可见低收入农民面临收入的直接效应和间接效应的双重影响,其结果可能是低收入的农民贫困程度进一步加深和健康水平进一步下降。因此,随着市场化程度的提高,增加对低收入农民的转移支付,建立医疗保障制度的必要性更加突出。 展开更多
关键词 医疗消费 收入效应 健康水平
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Mapping essential urban land use categories in China(EULUC-China):preliminary results for 2018 被引量:56
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作者 Peng Gong Bin Chen +67 位作者 Xuecao Li Han Liu Jie Wang Yuqi Bai Jingming Chen Xi Chen Lei Fang Shuailong Feng Yongjiu Feng Yali Gong Hao Gu Huabing Huang Xiaochun Huang Hongzan Jiao Yingdong Kang Guangbin Lei Ainong Li Xiaoting Li Xun Li Yuechen Li Zhilin Li Zhongde Li Chong Liu Chunxia Liu Maochou Liu Shuguang Liu Wanliu Mao Changhong Miao Hao Ni Qisheng Pan Shuhua Qi Zhehao Ren Zhuoran Shan Shaoqing Shen Minjun Shi Yimeng Song Mo Su Hoi Ping Suen Bo Sun Fangdi Sun Jian Sun Lin Sun Wenyao Sun Tian Tian Xiaohua Tong Yihsing Tseng Ying Tu Hong Wang Lan Wang Xi Wan Zongming Wang Tinghai Wu Yaowen Xie Jian Yang Jun Yang Man Yuan Wenze Yue Hongda Zeng Kuo Zhang Neng Zhang Tao Zhang Yu Zhang Feng Zhao Yichen Zheng Qiming Zhou Nicholas Clinton Zhiliang Zhu Bing Xu 《Science Bulletin》 SCIE EI CAS CSCD 2020年第3期182-187,共6页
Land use reflects human activities on land.Urban land use is the highest level human alteration on Earth,and it is rapidly changing due to population increase and urbanization.Urban areas have widespread effects on lo... Land use reflects human activities on land.Urban land use is the highest level human alteration on Earth,and it is rapidly changing due to population increase and urbanization.Urban areas have widespread effects on local hydrology,climate,biodiversity,and food production[1,2].However,maps,that contain knowledge on the distribution,pattern and composition of various land use types in urban areas,are limited to city level.The mapping standard on data sources,methods,land use classification schemes varies from city to city,due to differences in financial input and skills of mapping personnel.To address various national and global environmental challenges caused by urbanization,it is important to have urban land uses at the national and global scales that are derived from the same or consistent data sources with the same or compatible classification systems and mapping methods.This is because,only with urban land use maps produced with similar criteria,consistent environmental policies can be made,and action efforts can be compared and assessed for large scale environmental administration.However,despite of the fact that a number of urban-extent maps exist at global scales[3,4],more detailed urban land use maps do not exist at the same scale.Even at big country or regional levels such as for the United States,China and European Union,consistent land use mapping efforts are rare[5,6](e.g.,https://sdi4apps.eu/open_land_use/). 展开更多
关键词 EULUC-China 土地利用类型
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Astragalus polysaccharide enhances immunity and inhibits H9N2 avian influenza virus in vitro and in vivo 被引量:50
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作者 Sanpha Kallon Xiaorong Li +7 位作者 Jun Ji Cuiying Chen Qianyun Xi Shuang Chang Chunyi Xue Jingyun Ma Qingmei Xie Youngliang Zhang 《Journal of Animal Science and Biotechnology》 SCIE CAS 2013年第4期325-335,共11页
This study investigated the humoral immunization of Astragalus polysaccharide (APS) against HgN2 avian influenza virus (H9N2 AIV) infection in chickens. The effects of APS treatment on H9N2 infection was evaluated... This study investigated the humoral immunization of Astragalus polysaccharide (APS) against HgN2 avian influenza virus (H9N2 AIV) infection in chickens. The effects of APS treatment on H9N2 infection was evaluated by an Mqq- [3(4, 5-dimethylthiazol-2-yl)-2, 3-diphenyl tetrazolium bromide] assay and analysis of MFIC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to H9N2 AIV wet enhanced in the first week after APS treatment. The results indicated that APS treatment reduces H9N2 AIV replication and promotes early humoral immune responses in young chickens.This study investigated the humoral immunization of Astragalus polysaccharide (APS) against HgN2 avian influenza virus (H9N2 AIV) infection in chickens. The effects of APS treatment on HgN2 infection was evaluated by an M]q- [3(4, 5-dimethylthiazol-2-yl)-2, 3-diphenyl tetrazolium bromide] assay and analysis of MHC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to PIgN2 AIV were enhanced in the first week after APS treatment. The results indicated that APS treatment reduces HgN2 AIV replication and promotes early humoral immune responses in young chickens. 展开更多
关键词 Astrogalus polysaccharide HgN2 avian influenza virus Immune effect
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中文句子阅读中语义信息对眼动预视效应的影响 被引量:43
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作者 王穗苹 佟秀红 +1 位作者 杨锦绵 冷英 《心理学报》 CSSCI CSCD 北大核心 2009年第3期220-232,共13页
采用句子为阅读材料,变化句子中一个单字词形成语义连贯与语义违背两种实验条件,通过两个眼动实验探讨中文句子阅读中预视效应的产生是否受语义信息的影响。实验一运用自然阅读范式,考察当语义连贯与违背两类信息被读者直接注视时,读者... 采用句子为阅读材料,变化句子中一个单字词形成语义连贯与语义违背两种实验条件,通过两个眼动实验探讨中文句子阅读中预视效应的产生是否受语义信息的影响。实验一运用自然阅读范式,考察当语义连贯与违背两类信息被读者直接注视时,读者眼动模式的变化。结果发现,在语义连贯与违背两种条件下,读者的眼动模式在目标位置立即产生差异,违背条件下首次注视时间更长,说明中文句子理解中语义加工可以进行得十分即时。实验二运用边界技术,使实验一的语义连贯与违背两类关键字只呈现在预视位置上,当读者的注视点越过边界时,两类预视字均变为另一个与句子意义连贯的目标字。结果发现,语义违背预视条件下,读者对预视位置将进行更长时间的加工。上述结果表明,中文句子阅读过程中,语义信息可以对预视效应产生影响。 展开更多
关键词 边界技术 预视效应 语义信息 即时性 眼动
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丙型肝炎病毒Simmonds基因分型法酶切分型的研究 被引量:45
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作者 孙南雄 张永祥 +1 位作者 杜绍财 范晓峰 《江苏医药》 CAS CSCD 1999年第7期481-483,共3页
丙型肝炎病毒(HCV)的基因分型在临床和流行病学的研究方面有重要意义。以多聚酶链反应的方法扩增HCV的5’-非编码区第28至284区段(HCV-J株),并以复合限制性内切酶水解的方法按Simmonds基因分型的标准,将HCV分为6型和若干亚型。... 丙型肝炎病毒(HCV)的基因分型在临床和流行病学的研究方面有重要意义。以多聚酶链反应的方法扩增HCV的5’-非编码区第28至284区段(HCV-J株),并以复合限制性内切酶水解的方法按Simmonds基因分型的标准,将HCV分为6型和若干亚型。结果:检测标本38份,均为1b型,与以往的检测结果类似。 展开更多
关键词 丙型肝炎病毒 基因分型 Simmond基因 酶切分型
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The Plant Vascular System: Evolution, Development and Functions 被引量:40
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作者 William J. Lucas Andrew Groover +13 位作者 Raffael Lichtenberger Kaori Furuta Shri-Ram Yadav Yk Helariutta Xin-Qiang He Hiroo Fukuda Julie Kang Siobhan M. Brady John W. Patrick John Sperry Akiko Yoshida Ana-Flor López-Millan Michael A. Grusak Pradeep Kachroo 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2013年第4期294-388,共95页
The emergence of the tracheophyte-based vascular system of land plants had major impacts on the evolution of terrestrial biology, in general, through its role in facilitating the development of plants with increased s... The emergence of the tracheophyte-based vascular system of land plants had major impacts on the evolution of terrestrial biology, in general, through its role in facilitating the development of plants with increased stature, photosynthetic output, and ability to colonize a greatly expanded range of environmental habitats. Recently, considerable progress has been made in terms of our understanding of the developmental and physiological programs involved in the formation and function of the plant vascular system. In this review, we first examine the evolutionary events that gave rise to the tracheophytes, followed by analysis of the genetic and hormonal networks that cooperate to orchestrate vascular development in the gymnosperms and angiosperms. The two essentialfunctions performed by the vascular system, namely the delivery of resources (water, essential mineral nutrients, sugars and amino acids) to the various plant organs and provision of mechanical support are next discussed. Here, we focus on critical questions relating to structural and physiological properties controlling the delivery of material through the xylem and phloem. Recent discoveries into the role of the vascular system as an effective long-distance communication system are next assessed in terms of the coordination of developmental, physiological and defense-related processes, at the whole-plant level. A concerted effort has been made to integrate all these new findings into a comprehensive picture of the state-of-the-art in the area of plant vascular biology. Finally, areas important for future research are highlighted in terms of their likely contribution both to basic knowledge and applications to primary industry. 展开更多
关键词 EVOLUTION vascular development PHLOEM XYLEM nutrient delivery long-distance communication systemic signaling.
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Carotenoid Metabolism:Biosynthesis,Regulation,and Beyond 被引量:35
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作者 Shan Lu Li Li 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2008年第7期778-785,共8页
Carotenoids are indispensable to plants and play a critical role in human nutrition and health. Significant progress has been made in our understanding of carotenoid metabolism in plants. The biosynthetic pathway has ... Carotenoids are indispensable to plants and play a critical role in human nutrition and health. Significant progress has been made in our understanding of carotenoid metabolism in plants. The biosynthetic pathway has been extensively studied. Nearly all the genes encoding the biosynthetic enzymes have been isolated and characterized from various organisms. In recent years, there is an increasing body of work on the signaling pathways and plastid development, which might provide global control of carotenoid biosynthesis and accumulation. Herein, we will highlight recent progress on the biosynthesis, regulation, and metabolic engineering of carotenoids in plants, as well as the future research towards elucidating the regulatory mechanisms and metabolic network that control carotenoid metabolism. 展开更多
关键词 carotenoids ISOPRENOIDS METABOLISM metabolic engineering PLASTID regulation.
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Advances in InGaAs/InP single-photon detector systems for quantum communication 被引量:32
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作者 Jun Zhang Mark A Itzler +1 位作者 Hugo Zbinden Jian-Wei Pan 《Light(Science & Applications)》 SCIE EI CAS CSCD 2015年第1期381-393,共13页
Single-photon detectors(SPDs)are the most sensitive instruments for light detection.In the near-infrared range,SPDs based on III–V compound semiconductor avalanche photodiodes have been extensively used during the pa... Single-photon detectors(SPDs)are the most sensitive instruments for light detection.In the near-infrared range,SPDs based on III–V compound semiconductor avalanche photodiodes have been extensively used during the past two decades for diverse applications due to their advantages in practicality including small size,low cost and easy operation.In the past decade,the rapid developments and increasing demands in quantum information science have served as key drivers to improve the device performance of single-photon avalanche diodes and to invent new avalanche quenching techniques.This Review aims to introduce the technology advances of InGaAs/InP single-photon detector systems in the telecom wavelengths and the relevant quantum communication applications,and particularly to highlight recent emerging techniques such as high-frequency gating at GHz rates and free-running operation using negative-feedback avalanche diodes.Future perspectives of both the devices and quenching techniques are summarized. 展开更多
关键词 avalanche photodiode DETECTOR INGAAS/INP quantum communication single-photon avalanche diode single-photon detection
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时空数据语义理解:技术与应用 被引量:31
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作者 姚迪 张超 +2 位作者 黄建辉 陈越新 毕经平 《软件学报》 EI CSCD 北大核心 2018年第7期2018-2045,共28页
随着移动互联网的发展与手持智能终端的普及,海量带有用户时空属性的数据被生成.理解这些数据表达的语义信息对推测用户需求,分析用户偏好,进而提供精准时空推荐和预测服务具有重要作用.因此,近些年来,时空数据语义理解正成为时空数据... 随着移动互联网的发展与手持智能终端的普及,海量带有用户时空属性的数据被生成.理解这些数据表达的语义信息对推测用户需求,分析用户偏好,进而提供精准时空推荐和预测服务具有重要作用.因此,近些年来,时空数据语义理解正成为时空数据挖掘领域的研究热点.从技术和应用两个层面,对近些年来国内外研究者在该领域的研究成果进行了系统的归类和总结.技术层面上,依据语义理解的不同任务,提出了时空数据语义理解的研究框架;并依次从地理位置语义理解、用户行为语义理解、热点事件语义理解3个主要任务,归纳了时空数据语义理解所包含的相关研究成果和关键技术.应用层面上,分别总结了时空数据语义理解在时空推荐和时空预测中的应用.最后,从数据质量、算法模型和计算模式3个方面,归纳了时空数据语义理解面临的主要挑战以及未来的研究方向. 展开更多
关键词 时空数据挖掘 语义理解 语义偏好 用户画像 机器学习
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FAIR Principles:Interpretations and Implementation Considerations 被引量:30
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作者 Annika Jacobsen Ricardo de Miranda Azevedo +41 位作者 Nick Juty Dominique Batista Simon Coles Ronald Cornet Melanie Courtot Merce Crosas Michel Dumontier Chris T.Evelo Carole Goble Giancarlo Guizzardi Karsten Kryger Hansen Ali Hasnain Kristina Hettne Jaap Heringa Rob W.W.Hooft Melanie Imming Keith G.Jeffery Rajaram Kaliyaperumal Martijn GKersloot Christine R.Kirkpatrick Tobias Kuhn Ignasi Labastida Barbara Magagna PeterMcQuilton Natalie Meyers Annalisa Montesanti Mirjam van Reisen Philippe Rocca-Serra Robert Pergl Susanna-Assunta Sansone Luiz Olavo Bonino da Silva Santos Juliane Schneider George Strawn Mark Thompson Andra Waagmeester Tobias Weigel Mark D.Wilkinson Egon L.Willighagen Peter Wittenburg Marco Roos Barend Mons Erik Schultes 《Data Intelligence》 2020年第1期10-29,293-302,322,共31页
The FAIR principles have been widely cited,endorsed and adopted by a broad range of stakeholders since their publication in 2016.By intention,the 15 FAIR guiding principles do not dictate specific technological implem... The FAIR principles have been widely cited,endorsed and adopted by a broad range of stakeholders since their publication in 2016.By intention,the 15 FAIR guiding principles do not dictate specific technological implementations,but provide guidance for improving Findability,Accessibility,Interoperability and Reusability of digital resources.This has likely contributed to the broad adoption of the FAIR principles,because individual stakeholder communities can implement their own FAIR solutions.However,it has also resulted in inconsistent interpretations that carry the risk of leading to incompatible implementations.Thus,while the FAIR principles are formulated on a high level and may be interpreted and implemented in different ways,for true interoperability we need to support convergence in implementation choices that are widely accessible and(re)-usable.We introduce the concept of FAIR implementation considerations to assist accelerated global participation and convergence towards accessible,robust,widespread and consistent FAIR implementations.Any self-identified stakeholder community may either choose to reuse solutions from existing implementations,or when they spot a gap,accept the challenge to create the needed solution,which,ideally,can be used again by other communities in the future.Here,we provide interpretations and implementation considerations(choices and challenges)for each FAIR principle. 展开更多
关键词 FAIR guiding principles FAIR implementation FAIR convergence FAIR communities choices and challenges
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贵阳市大气颗粒物(PM_(2.5))污染特征及气象参数的影响 被引量:30
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作者 刘娜 冯新斌 +2 位作者 Landis Matthew 陈卓 仇广乐 《地球与环境》 CAS CSCD 北大核心 2014年第3期311-315,共5页
运用连续颗粒物采样仪(URG Model 2000-01J)对贵阳市城区大气颗粒物PM2.5进行了连续3个月(9-11月)的采集与分析,探讨了PM2.5的浓度分布特征、气象条件的影响。结果显示,贵阳市大气颗粒物PM2.5的平均质量浓度为53±27μg/m^3,变... 运用连续颗粒物采样仪(URG Model 2000-01J)对贵阳市城区大气颗粒物PM2.5进行了连续3个月(9-11月)的采集与分析,探讨了PM2.5的浓度分布特征、气象条件的影响。结果显示,贵阳市大气颗粒物PM2.5的平均质量浓度为53±27μg/m^3,变化范围为3.7-186μg/m^3;初步推断大气颗粒物PM2.5的污染来源主要是燃料燃烧、生物质燃烧、汽车尾气等人为源;相对湿度、风速、风向、温度等气象条件是影响大气颗粒物浓度及分布的重要因素。 展开更多
关键词 大气颗粒物(PM2 5) 分布特征 影响因素 贵阳市
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滇西北兰坪金顶可能的古油气藏及对铅锌大规模成矿的作用 被引量:28
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作者 薛春纪 高永宝 +1 位作者 CHI Guo-xiang David L Leach 《地球科学与环境学报》 CAS 2009年第3期221-229,共9页
滇西北兰坪中—新生代沉积盆地产有中国最大的铅锌矿床,巨量铅锌矿石集中产在金顶穹窿内,矿石中不同产状的干酪根、轻质原油、重油、烃类气、沥青等多种成熟形式的有机物质丰富。对矿区有机物质进行了岩相学、生物标志化合物、碳同位素... 滇西北兰坪中—新生代沉积盆地产有中国最大的铅锌矿床,巨量铅锌矿石集中产在金顶穹窿内,矿石中不同产状的干酪根、轻质原油、重油、烃类气、沥青等多种成熟形式的有机物质丰富。对矿区有机物质进行了岩相学、生物标志化合物、碳同位素及铅同位素分析,结果显示:有机物质中氯仿沥青“A”的质量分数为(72~395 415.42)×10^-6,w(饱和烃)/w(芳香烃)普遍大于1,饱和烃中检测出丰度较高的正构烷烃、Pr、Ph和iC18等生物标志化合物,烃源母质为藻类生物Ⅰ型有机质;相对于区域岩石,矿石中有机物质的有机转化率较低(0.5%~7.2%,平均为3.05%),已明显受热而成熟;透射全色光和紫外光显微镜在矿石光薄片样品中鉴别出较多原油和烃类气体包裹体。研究表明:金顶穹窿具有油气成藏“生、运、储、盖、闭”等配套发育的良好条件,矿区油气显示和古油气藏遗迹明显,铅锌成矿前或成矿中可能已形成油气藏;这个可能的油气藏以富含原油、烃类和H2S等还原性气体为成分特征;金顶古油气藏中H2S等还原性气体的聚集及其导致铅锌硫化物快速集中沉淀是大规模成矿的关键,成藏—成矿是金顶穹窿中一个连续发生、发展的动力学过程,成藏是成矿的前提。 展开更多
关键词 油气显示 原油包裹体 古油气藏 超大型铅锌矿 兰坪金顶
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Targeting the PI3K-AKT-mTOR signaling network in cancer 被引量:27
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作者 Khurum H. Khan Timothy A. Yap +1 位作者 Li Yan David Cunningham 《Chinese Journal of Cancer》 SCIE CAS CSCD 2013年第5期253-265,共13页
The phosphoinositide 3-kinase-AKT-mammalian target of rapamycin (PI3K-AKT-mTOR) pathway is a frequently hyperactivated pathway in cancer and is important for tumor cell growth and survival. The development of targeted... The phosphoinositide 3-kinase-AKT-mammalian target of rapamycin (PI3K-AKT-mTOR) pathway is a frequently hyperactivated pathway in cancer and is important for tumor cell growth and survival. The development of targeted therapies against mTOR, a vital substrate along this pathway, led to the approval of allosteric inhibitors, including everolimus and temsirolimus, for the treatment of breast, renal, and pancreatic cancers. However, the suboptimal duration of response in unselected patients remains an unresolved issue. Numerous novel therapies against critical nodes of this pathway are therefore being actively investigated in the clinic in multiple tumour types. In this review, we focus on the progress of these agents in clinical development along with their biological rationale, the need of predictive biomarkers and various combination strategies, which will be useful in counteracting the mechanisms of resistance to this class of drugs. 展开更多
关键词 信号网络 癌症 靶向治疗 生物标志物 磷酸肌醇 细胞生长 雷帕霉素 哺乳动物
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宽窄行栽植下三倍体毛白杨根系生物量分布及其对土壤养分因子的响应 被引量:24
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作者 邸楠 席本野 +3 位作者 Jeremiah R.PINTO 王烨 李广德 贾黎明 《植物生态学报》 CAS CSCD 北大核心 2013年第10期961-971,共11页
三倍体毛白杨(triploid Populus tomentosa)是我国华北地区主要纸浆林品种,在该地区多采用宽窄行模式栽植。为基于根系结构特征制定该模式下毛白杨人工林高效水肥管理策略和明确影响其根系空间分布的主要因子,在5年生林分中于8株样树周... 三倍体毛白杨(triploid Populus tomentosa)是我国华北地区主要纸浆林品种,在该地区多采用宽窄行模式栽植。为基于根系结构特征制定该模式下毛白杨人工林高效水肥管理策略和明确影响其根系空间分布的主要因子,在5年生林分中于8株样树周围挖取2 106个土柱,研究该栽植模式下毛白杨根系生物量的空间分布特征,并分析了细根垂直分布对土壤有机质、速效磷和碱解氮等的响应。结果表明,一维垂向上,宽行内细根根重密度(FRBD)在0–30 cm土层中随深度增加而递减,但在30cm以下土层呈均匀分布(p=0.079);窄行内FRBD呈"双峰"分布,即在0–20 cm(22%)和70–110 cm(31%)土层均有较多细根分布;10–150 cm各土层中,窄行FRBD较宽行高17%–148%。宽、窄行内,随深度增加,粗根根重密度(CRBD)均呈先增后减变化,而细根粗根比(F/C)无显著变化(p>0.05),窄行平均F/C较宽行高60%。一维径向上,宽、窄行内FRBD均呈近均匀分布,而CRBD和F/C均随距离增加分别显著递减和增大。二维尺度上,FRBD在窄行内分布相对均匀,但在宽行内主要集中在表土层且随距离增加细根浅层化程度增强;CRBD在树干两侧呈"不对称"分布;垂向0–20 cm、径向160–300 cm范围是宽行内平均FRBD和F/C较高区域,分别为宽行相应指标总平均的2.8和1.1倍。FRBD在0–30 cm土层中随土壤有机质、速效磷和碱解氮含量的增加而逐渐增大,但在30 cm以下土层中无明显变化趋势。研究结果表明,宽、窄行间毛白杨根系分布的差异性主要体现在细根一维垂直分布和细根、粗根二维分布上。土壤有机质、速效磷和碱解氮是0–30 cm土层中毛白杨细根垂直分布的重要影响因子,但对下层土壤中根系分布无影响。对宽窄行栽植的毛白杨林分灌溉时,灌溉水应供给到窄行区域;施肥时,缓释肥和速效肥应分别浅施在宽行中央附近和窄行内。 展开更多
关键词 根系生物量 土壤养分 三倍体毛白杨 宽窄行栽植模式
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Efectiveness of national air pollution control policies on the air quality in metropolitan areas of China 被引量:24
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作者 Shuxiao Wang Jia Xing +2 位作者 Bin Zhao Carey Jang Jiming Hao 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2014年第1期13-22,共10页
Understanding the effectiveness of national air pollution controls is important for control policy design to improve the future air quality in China. This study evaluated the effectiveness of major national control po... Understanding the effectiveness of national air pollution controls is important for control policy design to improve the future air quality in China. This study evaluated the effectiveness of major national control policies implemented recently in China through a modeling analysis. The sulfur dioxide (SO2) control policy during the llth Five Year Plan period (2006-2010) had succeeded in reducing the national SO2 emission in 2010 by 14% from its 2005 level, which correspondingly reduced ambient SO2 and sulfate (SO42-) concentrations by 13%-15% and 8%-10% respectively over east China. The nitrogen oxides (NOx) control policy during the 12th Five Year Plan period (2011-2015) targets the reduction of the national NOx emission in 2015 by 10% on the basis of 2010. The simulation results suggest that such a reduction in NOx emission will reduce the ambient nitrogen dioxide (NO2), nitrate (NO3-), 1-hr maxima ozone (03) concentrations and total nitrogen deposition by 8%, 3%-14%, 2% and 2%--4%, respectively over east China. The application of new emission standards for power plants will further reduce the NO2, NO3-, 1-hr maxima 03 concentrations and total nitrogen deposition by 2%-4%, 1%-%, 0-2% and 1%-2%, respectively. Sensitivity analysis was conducted to evaluate the inter-provincial impacts of emission reduction in Beijing-Tianjin-Hebei and the Yangtze River Delta, which indicated the need to implement joint regional air pollution control. 展开更多
关键词 air pollution control sulfur dioxide nitrogen oxides power plant
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Recent Development of SOFC Metallic Interconnect 被引量:19
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作者 Junwei Wu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2010年第4期293-305,共13页
Interest in solid oxide fuel cells (SOFC) stems from their higher efficiencies and lower levels of emitted pollutants, compared to traditional power production methods. Interconnects are a critical part in SOFC stac... Interest in solid oxide fuel cells (SOFC) stems from their higher efficiencies and lower levels of emitted pollutants, compared to traditional power production methods. Interconnects are a critical part in SOFC stacks, which connect cells in series electrically, and also separate air or oxygen at the cathode side from fuel at the anode side. Therefore, the requirements of interconnects are the most demanding, i.e., to maintain high electrical conductivity, good stability in both reducing and oxidizing atmospheres, and close coefficient of thermal expansion (CTE) match and good compatibility with other SOFC ceramic components. The paper reviewed the interconnect materials, and coatings for metallic interconnect materials. 展开更多
关键词 Solid oxide fuel cells (SOFC) INTERCONNECT SPINEL COATING
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Management and prevention of acute and chronic lateral ankle instability in athletic patient populations 被引量:21
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作者 Brendan J Mc Criskin Kenneth L Cameron +1 位作者 Justin D Orr Brian R Waterman 《World Journal of Orthopedics》 2015年第2期161-171,共11页
Acute and chronic lateral ankle instability are common in high-demand patient populations. If not managed appropriately, patients may experience recurrent instability, chronic pain, osteochondral lesions of the talus,... Acute and chronic lateral ankle instability are common in high-demand patient populations. If not managed appropriately, patients may experience recurrent instability, chronic pain, osteochondral lesions of the talus, premature osteoarthritis, and other significantlong-term disability. Certain populations, including young athletes, military personnel and those involved in frequent running, jumping, and cutting motions, are at increased risk. Proposed risk factors include prior ankle sprain, elevated body weight or body mass index, female gender, neuromuscular deficits, postural imbalance, foot/ankle malalignment, and exposure to at-risk athletic activity. Prompt, accurate diagnosis is crucial, and evidence-based, functional rehabilitation regimens have a proven track record in returning active patients to work and sport. When patients fail to improve with physical therapy and external bracing, multiple surgical techniques have been described with reliable results, including both anatomic and nonanatomic reconstructive methods. Anatomic repair of the lateral ligamentous complex remains the gold standard for recurrent ankle instability, and it effectively restores native ankle anatomy and joint kinematics while preserving physiologic ankle and subtalar motion. Further preventative measures may minimize the risk of ankle instability in athletic cohorts, including prophylactic bracing and combined neuromuscular and proprioceptive training programs. These interventions have demonstrated benefit in patients at heightened risk for lateral ankle sprain and allow active cohorts to return to full activity without adversely affecting athletic performance. 展开更多
关键词 ANKLE instability ATHLETE Treatment Epidemiology PREVENTION LATERAL SPRAIN
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Network Pharmacology for Traditional Chinese Medicine Research: Methodologies and Applications 被引量:21
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作者 Yu-feng Liu Ni Ai +2 位作者 Anthony Keys Xiao-hui Fan Min-jun Chen 《Chinese Herbal Medicines》 CAS 2015年第1期18-26,共9页
The inception of network pharmacology comes from the advance in "multi-target, multi-drug" paradigm and opens up a new field for pharmaceutical science. Traditional Chinese medicine (TCM) is well-known for its use... The inception of network pharmacology comes from the advance in "multi-target, multi-drug" paradigm and opens up a new field for pharmaceutical science. Traditional Chinese medicine (TCM) is well-known for its use of medicinal herb combinations to treat the functional disorders induced by diseases through a holistic view, which naturally followed the principal of network pharmacology. In this review, the methodologies of network pharmacology in TCM studies were summarized. Specifically, the methodologies for network construction and network analysis were discussed in detail by following several TCM study cases. The perspectives for TCM network pharmacology were also provided. 展开更多
关键词 network pharmacology network toxicology traditional Chinese medicine
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