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Evolution of Carbon Isotope Composition in Potential Global Stratotype Section and Point at Luoyixi, South China, for the Base of the Unnamed Global Seventh Stage of Cambrian System 被引量:4
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作者 左景勋 彭善池 +3 位作者 朱学剑 祁玉平 林焕令 杨显峰 《Journal of China University of Geosciences》 SCIE CSCD 2008年第1期9-22,共14页
This work deals with the evolution of carbon isotope composition in the Luoyixi (罗依溪) Section, a candidate of the Global Standard Stratotype-section and Point (GSSP), defining the base of the as-yet-undefined s... This work deals with the evolution of carbon isotope composition in the Luoyixi (罗依溪) Section, a candidate of the Global Standard Stratotype-section and Point (GSSP), defining the base of the as-yet-undefined seventh stage of Cambrian System at the first appearance of the cosmopolitan agnostoid Lejopyge iaevigata. This level is favored in a vote of International Subcommission on Cambrian Stratigraphy (ISCS) as the biohorizon for defining the base of a global stage. Two hundred and sixty-four samples for carbon and oxygen isotope analysis have been collected from the carbonate successions at an interval of 0.25 to 0.5 m in this section. Results of the carbon isotope data exhibit a remarkable disciplinarian trend. The pattern of the carbon isotope evolution is gently undulant with a relatively long period during the underlying Drumian Stage, and then the values of δ13C fluctuate sharply with a short period in provisional seventh stage. The onset of sharp fluctuation in the δ13C values begins at the proposed GSSP level, defining the base of the global seventh stage, where δ13C values change from a gentle trend to a sharp trend. Distinct covariant-relationships among δ13C,δ18O, and sea level fluctuations suggest that a warming change in paleoclimate took place during the early global seventh stage, which led to a positive shift in δ13C values. 展开更多
关键词 carbon isotope composition global seventh stage of Cambrian System Luoyixi Section northwestern Hunan (湖南).
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Conservation Laws and Soliton Solutions for Generalized Seventh Order KdV Equation 被引量:3
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作者 YAORuo-Xia XUGui-Qiong LIZhi-Bin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第4期487-492,共6页
With the assistance of the symbolic computation system Maple,rich higher order polynomial-type conservation laws and a sixth order t/x-dependent conservation law are constructed for a generalized seventh order nonline... With the assistance of the symbolic computation system Maple,rich higher order polynomial-type conservation laws and a sixth order t/x-dependent conservation law are constructed for a generalized seventh order nonlinear evolution equation by using a direct algebraic method.From the compatibility conditions that guaranteeing the existence of conserved densities,an integrable unnamed seventh order KdV-type equation is found.By introducing some nonlinear transformations,the one-,two-,and three-solition solutions as well as the solitary wave solutions are obtained. 展开更多
关键词 seventh order evolution equation conservation law soliton solution symbolic computation
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Potential etiopathogenesis of seventh day syndrome following living donor liver transplantation:ischemia of the graft? 被引量:3
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作者 Lan, Xiang Li, Bo +3 位作者 Wang, Xiao-Fei Wei, Yong-Gang Yan, Lu-Nan Zhao, Ji-Chun 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2010年第1期22-26,共5页
BACKGROUND: Seventh-day syndrome (7DS) is an early serious complication following liver transplantation with a high mortality because of its unknown etiopathogenesis. This study aimed to analyze the potential etiopath... BACKGROUND: Seventh-day syndrome (7DS) is an early serious complication following liver transplantation with a high mortality because of its unknown etiopathogenesis. This study aimed to analyze the potential etiopathogenesis of 7DS. METHODS: A retrospective analysis of 98 consecutive living donor liver transplants performed from 2001 to 2007 at our center revealed that 5 patients had suffered from 7DS; their age, MELD score, portal vein inflow and other parameters were compared with those of the other recipients. RESULTS: The 5 patients showed common features: (a) initial uneventful recovery, and a dramatic rise of serum liver enzyme levels I to 2 weeks later; (b) decreased inflow in the portal vein accompanied by augmentation of serum creatinine and urea nitrogen level; and (c) serial liver biopsy findings of apoptosis and ischemic necrosis of hepatocytes. Four of the 5 patients died. Age, waiting time to transplantation, MELD score, operation time, cold ischemic time, portal interceptive time and diameter of the portal vein were not significantly different between the 2 groups, but a difference was found in the flow rate of the portal vein (t=3.234, P<0.001). CONCLUSIONS: The 5 patients suffered from a decreased portal vein inflow, ischemic liver necrosis, and renal failure. Hence, hypoperfusion of the liver graft was considered to be the etiopathogenesis of 7DS, for which, however sufficient evidence is lacking. More studies of 7DS are needed. 展开更多
关键词 seventh-day syndrome living donor liver transplantation ischemic hepatitis ETIOPATHOGENESIS hepatocellular necrosis
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Approximate Solution Method of the Seventh Order KdV Equations by Decomposition Method 被引量:1
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作者 Nawal Abdullah Alzaid Bashayr Ali Alrayiqi 《Journal of Applied Mathematics and Physics》 2019年第9期2148-2155,共8页
In this paper, Adomian decomposition method (ADM) is implemented to approximate the solution of the Korteweg-de Vries (KdV) equations of seventh order, which are Kaup-Kuperschmidt equation and seventh order Kawahara e... In this paper, Adomian decomposition method (ADM) is implemented to approximate the solution of the Korteweg-de Vries (KdV) equations of seventh order, which are Kaup-Kuperschmidt equation and seventh order Kawahara equation. The results obtained by the ADM are compared with the exact solutions. It is found that the ADM is very efficient and convenient and can be applied to a large class of problems. The conservation properties of solution are examined by calculating the first three invariants. 展开更多
关键词 Adomian Decomposition Method Kaup-Kuperschmidt seventh-Order KDV EQUATION seventh-Order Kawahara EQUATION Conservation LAWS
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Solutions of Seventh Order Boundary Value Problems Using Ninth Degree Spline Functions and Comparison with Eighth Degree Spline Solutions 被引量:1
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作者 Parcha Kalyani Mihretu Nigatu Lemma 《Journal of Applied Mathematics and Physics》 2016年第2期249-261,共13页
In this article, we develop numerical method by constructing ninth degree spline function using extended cubic spline Bickley’s method to find the approximate solution of seventh order linear boundary value problems ... In this article, we develop numerical method by constructing ninth degree spline function using extended cubic spline Bickley’s method to find the approximate solution of seventh order linear boundary value problems at different step lengths. The approximate solution is compared with the solution obtained by eighth degree splines and exact solution. It has been observed that the approximate solution is an excellent agreement with exact solution. Low absolute error indicates that our numerical method is effective for solving high order linear boundary value problems. 展开更多
关键词 seventh Order Boundary Value Problem Boundary Value Problem Ninth Degree Spline Function Absolute Error
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The Abstracts of Papers in Special Issue on the Seventh Five Year Project for Rare Earths of Chinese Academy of Sciences (in Chinese)
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《Journal of Rare Earths》 SCIE EI CAS CSCD 1994年第4期305-312,共8页
TheAbstractsofPapersinSpecialIssueontheSeventhFiveYearProjectforRareEarthsofChineseAcademyofSciences(inChine... TheAbstractsofPapersinSpecialIssueontheSeventhFiveYearProjectforRareEarthsofChineseAcademyofSciences(inChinese)StudyonMateria... 展开更多
关键词 Project YEAR ABSTRACTS The Earths RARE seventh the FIVE ACADEMY CHINESE 洪广言 吴兆明
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Sample Plot Change in the Seventh Review of Continuous National Forest Inventory in Zigui County
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作者 Zhongmei DENG Jiaxuan XIANG +3 位作者 Jun SONG Xueyong QIN Dongwei WANG Lei ZHOU 《Asian Agricultural Research》 2016年第2期61-63,共3页
The following qualitative conclusions of forest resources in Zigui can be drawn by the research on 73 plots and 5 vegetation plots:forest area is increasing; forest growing stock is increasing; the adjustment of fores... The following qualitative conclusions of forest resources in Zigui can be drawn by the research on 73 plots and 5 vegetation plots:forest area is increasing; forest growing stock is increasing; the adjustment of forest category structure is constantly improved; forest quality has been improving; stand structure is optimized continuously; biodiversity has initially appeared. 展开更多
关键词 NATIONAL FOREST INVENTORY The seventh review in Zigui SAMPLE PLOT CHANGE
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Design for Kernel Garden,Exhibition Garden for Landscape Architect of the Seventh China Intentional Garden & Flowers Exhibition
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作者 沈丹 刘扬 《Journal of Landscape Research》 2011年第12期8-11,15,共5页
With plants as the "kernel",based on the deliberation on the "kernel",by combining with "cultural inheritance and scientific development" as the theme of the exhibition,the paper has illu... With plants as the "kernel",based on the deliberation on the "kernel",by combining with "cultural inheritance and scientific development" as the theme of the exhibition,the paper has illustrated the design idea of Kernel Garden with plants landscaping as the dominance.On the basis of the natural condition,location and terrain of the No.6 exhibition garden,four functional spaces,seven transport nodes and a diagonal composition have been designed by adopting modern landscaping techniques.Through the illustration of seasonal plant landscapes,it has created the artistic conception of "inhaling in spring","enjoying in summer","tasting in autumn" and "listening in winter".Through the creative design of "Kernel Garden",it hopes to arouse the society's concern and pursuit of the future living environment and explore the development direction of landscaping and living environment. 展开更多
关键词 Design of EXHIBITION GARDEN of landscape ARCHITECT KERNEL GARDEN Plants LANDSCAPING Ecological concept The seventh GARDEN EXHIBITION Jinan
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The Seventh National Congress of Foundry Directors 2006 Held in Beijing
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作者 Paper/TIAN Shi-jiang , photo/GE Chen-guang 《China Foundry》 SCIE CAS 2006年第2期156-157,共2页
关键词 The seventh National Congress of Foundry Directors 2006 Held in Beijing
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Numerical Solution of the Seventh Order Boundary Value Problems Using B-Spline Method
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作者 Maryam Khazaei Yeganeh Karamipour 《Journal of Applied Mathematics and Physics》 2021年第12期3058-3066,共9页
We develop a numerical method for solving the boundary value problem of The Linear Seventh Ordinary Boundary Value Problem by using the seventh-degree B-Spline function. Formulation is based on particular terms of ord... We develop a numerical method for solving the boundary value problem of The Linear Seventh Ordinary Boundary Value Problem by using the seventh-degree B-Spline function. Formulation is based on particular terms of order of seventh order boundary value problem. We obtain Septic B-Spline formulation and the Collocation B-spline method is formulated as an approximation solution. We apply the presented method to solve an example of seventh order boundary value problem in which the result shows that there is an agreement between approximate solutions and exact solutions. Resulting in low absolute errors shows that the presented numerical method is effective for solving high order boundary value problems. Finally, a general conclusion has been included. 展开更多
关键词 Spline and B-Spline Functions seventh Order Boundary Value Problem Septic B-Spline Collocation Method
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The Seventh National Games of the People's Republic of China
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《China Today》 1994年第6期6-6,共1页
The Seveoth National Games opened on September 4,1993,in Beijing.Orer 7,000 athletes from China's different provinces,monicipalities,autonomous regions,the PLA(People's Liberation Army)and amateur sports assoc... The Seveoth National Games opened on September 4,1993,in Beijing.Orer 7,000 athletes from China's different provinces,monicipalities,autonomous regions,the PLA(People's Liberation Army)and amateur sports associations participated in 43 compet-itive events,including track-and-field events,swimming,football,basketball,'weight lifting,sboting,boxing,cyeliog,wushu,weiqi,and table tennis.A total of 328 gold medals were given out.The Ministry of Posts and Telecomounications issued one stamp to commemorate the day. 展开更多
关键词 The seventh National Games of the People’s Republic of China
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BY-LAWS ON THE CAS MEMBERSHIP (Adopted by the Sixth General Assembly of the Chinese Academy of Sciences in 1992, and Amended by the Seventh General Assembly of the Chinese Academy of Sciences in 1994)
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《Bulletin of the Chinese Academy of Sciences》 1995年第3期226-229,共4页
Article 1. The Membership of the Chinese Academy of Sciences (hereinafter referred to as the Member) is the highest academic title of life tenure and honor established by the State in the field of science and technology.
关键词 and Amended by the seventh General Assembly of the Chinese Academy of Sciences in 1994 Adopted by the Sixth General Assembly of the Chinese Academy of Sciences in 1992 BY-LAWS ON THE CAS MEMBERSHIP CAS
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中国出生性别比下降停滞进程中的结构性失衡研究——基于第七次全国人口普查的分析
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作者 果臻 董琳 +1 位作者 杨柳清 李树茁 《人口与发展》 北大核心 2025年第3期14-25,共12页
当前中国的出生性别比停滞在111附近,迟迟无法降到正常水平,表明近年来治理工作进入瓶颈期,未能进一步推动出生性别比继续下降。研究结合第七次全国人口普查数据,从城乡、省份、母亲属性等维度剖析当前出生性别比偏高的结构性失衡特征... 当前中国的出生性别比停滞在111附近,迟迟无法降到正常水平,表明近年来治理工作进入瓶颈期,未能进一步推动出生性别比继续下降。研究结合第七次全国人口普查数据,从城乡、省份、母亲属性等维度剖析当前出生性别比偏高的结构性失衡特征。研究发现:(1)利用“七普”数据对以往公布的全国出生性别比数据进行矫正,结果显示估计值略低于公布值,且演变进程趋缓。(2)部分省份至今仍居高不下,一孩、少数民族、高中及以上母亲群体中出生性别比偏高问题凸显。其中,海南和江西的出生性别比超过120,壮族、土家族、苗族、彝族、布依族出生性别比均超过汉族。(3)出生性别比偏高的重点地区和人群发生转变。对全国出生性别比偏高贡献较大的群体从农村二孩转变为城镇一孩,从初中及以下母亲变为高中及以上母亲,一孩或三孩及以上影响也高于二孩。现阶段亟需持续重视和加强治理工作,依据出生性别比偏高的重点地区和人群,因势利导、因地制宜地调整治理策略。 展开更多
关键词 出生性别比 结构性失衡 贡献率 第七次全国人口普查
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北方蚕业科研协作区第七批桑品种鉴定试验总结
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作者 陈传杰 顾寅钰 +2 位作者 张洁华 陈旗 苏超 《北方蚕业》 2025年第1期31-35,共5页
西北农林科技大学蚕桑丝绸研究所、山西省蚕业科学研究院、山东省农科院胶东创新中心(山东省蚕业研究所)3单位联合对北方蚕业科研协作区第七批鉴定桑品种陕桑908、晋选10号、沧海7、沧海12、湖桑32号(对照)等5个品种,进行了为时3年的产... 西北农林科技大学蚕桑丝绸研究所、山西省蚕业科学研究院、山东省农科院胶东创新中心(山东省蚕业研究所)3单位联合对北方蚕业科研协作区第七批鉴定桑品种陕桑908、晋选10号、沧海7、沧海12、湖桑32号(对照)等5个品种,进行了为时3年的产叶量、养蚕成绩调查鉴定和主要经济性状的统计分析,总结提出了第七批参鉴桑品种的特征特性,以及适宜推广区域。 展开更多
关键词 第七批 桑树 品种鉴定
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IPCC第七次评估报告第一工作组“气候变化科学基础”大纲解读及启示
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作者 周天军 陈晓龙 +2 位作者 张文霞 江洁 胡帅 《气候变化研究进展》 北大核心 2025年第4期477-483,共7页
2025年2月,IPCC第62次全会审议通过了第七次评估周期(AR7)第一工作组(WGI)报告大纲,为后续组织编写第七次科学评估报告奠定了基础。主报告包括框架概要、当前状况和趋势、未来变化、支持应对的信息等四部分内容共10章。文中扼要介绍了... 2025年2月,IPCC第62次全会审议通过了第七次评估周期(AR7)第一工作组(WGI)报告大纲,为后续组织编写第七次科学评估报告奠定了基础。主报告包括框架概要、当前状况和趋势、未来变化、支持应对的信息等四部分内容共10章。文中扼要介绍了该报告所关注的当前状况和趋势、未来变化、支持应对的信息这三大领域的评估内容和要点。指出与第六次评估报告(AR6)相比,AR7 WGI的大纲结构具有三方面的新特点:一是篇幅大幅压缩,特别是关于地球系统变化过程理解的内容;二是高度关注排放情景与未来全球温升的关系、地球系统的突变、小概率-高影响事件和临界点等问题;三是加强了支持应对方面的信息评估,包括评估气候干预(包括过冲路径)下的地球系统响应。基于AR7 WGI报告大纲的启发,针对我国亟需加强的研究工作进行了讨论,包括加强针对未来排放情景的设计研究,加强区域气候变化研究的方法学和数据创新,加快能够支撑基于排放驱动的气候预估的地球系统模式的研发,加强针对气候稳定性、可逆性和临界点问题的研究,以及开展关于气候干预的影响评估等。 展开更多
关键词 IPCC 第七次评估报告 第一工作组报告大纲 气候状况 未来变化 应对信息
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第七次公共图书馆评估工作“保障条件”模块指标研究
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作者 丁轶 《新世纪图书馆》 2025年第8期28-36,共9页
论文介绍了第七次评估定级工作本溪市图书馆“保障条件”模块中所涉部分指标的材料上报实践经验,并就法律政策保障、人员保障、安全保障指标上报材料反映出的公共图书馆事业发展阶段性鲜明特点加以阐释,同时结合公共文化服务高质量发展... 论文介绍了第七次评估定级工作本溪市图书馆“保障条件”模块中所涉部分指标的材料上报实践经验,并就法律政策保障、人员保障、安全保障指标上报材料反映出的公共图书馆事业发展阶段性鲜明特点加以阐释,同时结合公共文化服务高质量发展要求提出了对于未来评估体系“保障条件”模块的合理化建议,希望以此填补“保障条件”模块在国内图书馆界评估工作研究领域的专项学术空白,让“保障条件”模块以全新饱满的战略性姿态出现在第八次公共图书馆评估定级工作的指标体系框架中。 展开更多
关键词 第七次评估 保障条件 上报实践 阶段性特点 合理化建议
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少数民族人口变化新样态——基于第六次、第七次人口普查分地级数据的分析 被引量:2
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作者 王跃 严庆 郑文婧 《贵州省党校学报》 2025年第1期86-97,共12页
我国少数民族人口增长样态存在较为显著的区域性差异。北方、东北少数民族人口以低、负增长为主。在南方少数民族中,云南、湖南的少数民族人口增长相对较慢,贵州、四川的少数民族人口增长相对较快,广西的少数民族人口增速介于二者之间... 我国少数民族人口增长样态存在较为显著的区域性差异。北方、东北少数民族人口以低、负增长为主。在南方少数民族中,云南、湖南的少数民族人口增长相对较慢,贵州、四川的少数民族人口增长相对较快,广西的少数民族人口增速介于二者之间。西部的维吾尔、藏、回等民族人口增速整体较快。十年间,少数民族人口发展的宏观进程呈现“变”与“不变”的辩证统一。“变”体现为少数民族人口增长集中于发达地区,人口增量的空间重心与人口存量的空间重心明显分离。“不变”体现为少数民族小聚居、相对聚居的情况没有改变,多数少数民族人口仍居于传统分布区,西部少数民族的人口增量与存量仍集中于传统聚居区。 展开更多
关键词 第六次人口普查 第七次人口普查 少数民族 人口增量
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行政层级约束优化的人口空间大数据校准方法
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作者 项广鑫 文佳亮 +7 位作者 陈瑗瑗 张一雯 黄诗怡 汉景源 彭佳捷 易红超 李家宝 麻战洪 《地球信息科学学报》 北大核心 2025年第8期1983-1995,共13页
【目的】人口空间大数据虽具备样本量大、时空分辨率高等优势,但其准确性不足制约了定量研究的可靠性。现有方法因缺乏权威基准或依赖大数据生产商的“黑盒”算法,难以实现校准。【方法】本文提出一种基于行政层级约束优化的人口大数据... 【目的】人口空间大数据虽具备样本量大、时空分辨率高等优势,但其准确性不足制约了定量研究的可靠性。现有方法因缺乏权威基准或依赖大数据生产商的“黑盒”算法,难以实现校准。【方法】本文提出一种基于行政层级约束优化的人口大数据校准普适方法,以法定、权威的第七次人口普查数据为锚点,空间关联七普常住人口数据与2020年百度常住人口大数据,构建行政层级约束下的运筹学模型,通过求取偏差值的全局最优解,达到校准人口大数据的目的。以湖南省第七次人口普查常住人口数据为锚点,以湖南省的2020年度百度常住人口大数据为示例进行了校准。【结果】校准后的湖南全省2020年百度人口大数据常住人口与七普常住人口的偏差比降至-1.01%(降幅25.87%),市、县级偏差比分别收敛至[-2.05%,+0.92%]与[-2.06%,+1.99%],且未改变原始偏差趋势。与国家统计局城区人口数据的验证结果显示,采用该方法计算得出的城区人口总数与国家统计局数据偏差比在-2.7%~+1.7%。根据人口大数据估算的绿心地区常住人口与实地调查的常住人口数量的偏差比为+0.47%。【结论】校准结果和2次验证结果充分表明本文提出的方法有效,为依据人口大数据估算非人口普查年份的人口数量、人口空间化分布数据提供可能。 展开更多
关键词 人口 大数据 校准 行政层级约束优化 运筹学 第七次人口普查 常住人口空间分布 湖南省
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IPCC第七次评估报告第二工作组气候变化影响、适应与脆弱性大纲解读及启示
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作者 丁杰 曹左男 +4 位作者 胡国铮 干珠扎布 赵芬 王海锋 高清竹 《气候变化研究进展》 北大核心 2025年第4期484-493,共10页
2025年3月初,政府间气候变化专门委员会(IPCC)第62次全会审议通过并发布第七次评估周期第二工作组(WGII)报告大纲,为下一步编写第七次评估报告(AR7)提供了科学基础和行动指南。报告包括概要、全球评估、区域评估和领域评估四部分内容共2... 2025年3月初,政府间气候变化专门委员会(IPCC)第62次全会审议通过并发布第七次评估周期第二工作组(WGII)报告大纲,为下一步编写第七次评估报告(AR7)提供了科学基础和行动指南。报告包括概要、全球评估、区域评估和领域评估四部分内容共20章,此外,还计划对《IPCC气候变化影响和适应评估技术指南(1994年)》进行更新并新增关于适应工具、模块和推动因素的内容,旨在通过系统性风险分析、包容性框架设计及方法论创新,更加全面科学地评估气候变化影响、适应与脆弱性及其最新研究进展,为全球气候政策和行动提供科学依据。文中简述了AR7 WGII关注的全球评估、区域评估和领域评估的内容和要点。与第六次评估报告(AR6)相比,AR7 WGII在整体架构上呈现了3个新特点:(1)将全球评估置于区域和领域专题评估之前,强化对跨尺度风险的整合分析;(2)突出适应措施的有效性评估;(3)新增应对损失损害和资金章节。基于AR7 WGII报告大纲,文中在全球和区域范围、水资源管理、农业发展、公共健康与生计保障等多个领域提出了研究关键点和重要启示,为未来气候变化影响、适应与脆弱性评估的研究提供了科学框架,对推动全球范围内的气候变化应对措施和实现可持续发展目标具有重要意义。 展开更多
关键词 IPCC 第七次评估报告(AR7) 第二工作组(WGII) 报告大纲 气候变化 影响、适应与脆弱性
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