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1.
国际全球变化研究计划综览   总被引:10,自引:2,他引:10  
全球变化研究是80年代兴起的跨学科、综合性的迄今规模最大的国际合作研究活动,其目的是研究人类所面临的一系列重大而紧迫的全球环境问题,即研究造成这些全球环境问题的物理过程、化学过程和生物过程之间复杂的相互作用,以解释当今日益显见的变化的意义,从而提出措施以减缓或适应全球变化的结果。国际全球变化研究计划由世界气候研究计划(WCRP)、国际地圈生物圈计划(IGBP)和全球环境变化中的人类因素计划(HDP或HDGECP)组成。本文浓缩介绍了这三个计划及其核心计划的科学目标、研究内容、实施期限、预期成果等关键内容。  相似文献   

2.
2006年11月9~12日,ESSP在北京召开了全球环境变化科学大会--ESSP OSC,即"2006年地球系统科学联盟全球环境变化科学大会".此次会议是继2001年ESSP在阿姆斯特丹召开第一次全球变化大会之后的第二次重大会议,由于正值世界气候研究计划(WCRP)成立25周年,由WCRP牵头组织,中国国家气候委员会和中国气象局承办.来自世界各地的900多位地球系统科学的专家(包括1位诺贝尔奖获得者和青年科学家)、资助机构的代表以及国内外政府和相关机构的官员(其中国外代表近700人)参加了大会.  相似文献   

3.
关于中国全球环境变化人文因素研究发展方向的思考   总被引:19,自引:4,他引:19  
人类如何合理地管理"地球生命支撑系统",以满足人类对可持续发展的追求,是全球环境变化GlobalEnvironmentalChange ,GEC)研究必须回答的问题。国际全球环境变化人文因素计划(Interna t ionalHumanDimensionsProgramm eonGlobalEnvironmentalChange,IHDP)侧重于全球环境变化的人文因素(HumanDimensionsofGlobalEnvironmentalChange,HDGEC)研究方面。在对国际HDGEC研究发展大势进行科学判断的基础上,概述了中国HDGEC研究进展,分析了中国HDGEC研究面临的挑战和机遇,探讨了我国HDGEC研究的未来发展走势。展望未来,我国HDGEC研究应立足国情,着眼全球,把握趋势与时机,在重大研究问题、能力建设等方面有所发展、突破。  相似文献   

4.
“地球工程学 (Geotechnologie)”是德国联邦政府教育与研究部 (BMBF)和德国科学基金会 (DFG )共同策划的未来 15年超大型地学研究计划 ,于2 0 0 0年 3月正式公布并开始招标实施 ,德国政府准备对该计划的实施投入约 5亿马克的研究经费。在经济和科学技术全球化进程不断加快的 2 1世纪之初 ,在我国自然科学基础研究已经开始实施“十五”规划 ,即将开始考虑下一个五年规划的重要时期 ,了解和掌握世界各国的科学研究动态 ,对于把握科学前沿问题、跻身世界领先行列、保证我国基础科学研究与世界同步发展及开拓创新性研究领…  相似文献   

5.
4月的辽宁,大地渐染春绿,若隐若现间散发着勃勃的生机。一年一度的"4·22世界地球日"(以下简称"地球日")又踏着春的脚步走进了我们的生活。今年"地球日"国土资源部确定的主题为"珍惜地球资源转变发展方式倡导低碳生活"。旨在借助"地球日"这个平台,提高公众对国土资源国情的认识,普及有关科学技术知识,  相似文献   

6.
《地学前缘(英文版)》2020,11(3):855-870
The global tectonics of Mercury is dominated by contractional features mainly represented by lobate scarps,high relief ridges,and wrinkle ridges.These structures are the expression of thrust faults and are linear or arcuate features widely distributed on Mercury.Locally,these structures are arranged in long systems characterized by a preferential orientation and non-random spatial distribution.In this work we identified five thrust systems,generally longer than 1000 km.They were named after the main structure or crater encompassed by the system as:Thakur,Victoria,Villa Lobos,Al-Hamadhani,and Enterprise.In order to gain clues about their formation,we dated them using the buffered crater counting technique,which can be applied to derive the ages of linear landforms such as faults,ridges and channels.To estimate the absolute age for the end of the thrust system's activity,we applied both Le Feuvre and Wieczorek Production Function and Neukum Production Functions.Moreover,to further confirm the results obtained with the buffered crater counting method,the classic stratigraphic approach has been adopted,in which a faulted and an unfaulted craters were dated for each system.The results gave consistent ages and suggested that the most movements along major structures all over Mercury most likely ended at about 3.6-3.8 Ga.This gives new clues to better understand the tectonics of the planet and,therefore,its thermal evolution.Indeed,the early occurrence of tectonic activity in the planet's history,well before than predicted by the thermophysical models,coupled with the orientation and spatial distribution of the thrust systems,suggests that other processes beside global contraction,like mantle downwelling or tidal despinning,could have contributed to the first stage of the planet's history.  相似文献   

7.
Lawrence D. Berg 《Geoforum》2004,35(5):553-558
This paper provides an analysis of the scale politics involved in the production of social-scientific geographic knowledge. I argue that critical Geographers need to acknowledge that ideas do not circulate unfettered or limited solely by their intellectual value. Instead, we must understand that some ideas are `attached' intimately to the places in which they originate while others circulate freely without attachment to specific places. Through such simple (dis)locations, geographic ideas get inserted into spaces of academic knowledge production that are shot through with scale politics. Ironically, such scalar processes produce a simple, transparent, abstract and hierarchical space of knowledge production that elides the complex spatial relations that we as geographers are supposed to be so interested in understanding.  相似文献   

8.
This excursion report describes briefly the ecclesiastical geology of seven localities in West London. It reveals that building stones related to local geology were particularly important in the construction of early churches. For this reason wall building fabric analyses of churches are also able to indicate an enormous amount of local geological information. Where London Basin rocks were unsuitable for structural aspects of these churches it was sometimes necessary to use rock types from more distant sources.  相似文献   

9.
鲍玛序列的多解性   总被引:1,自引:0,他引:1       下载免费PDF全文
鲍玛序列作为浊积岩的识别标志被广泛认可,但随着对深水沉积过程认识的深入,鲍玛序列逐渐被重新认识。近年来对深水沉积物重力流的研究发现:鲍玛序列不是浊流的唯一产物,深水环境中其它沉积过程也可形成鲍玛序列。因此,在野外识别浊积岩的过程中,要慎重使用鲍玛序列进行判别。  相似文献   

10.
London lies mainly within an area of long-term tectonic stability known as the London Platform. This is characterised by relatively thin Cretaceous and Palaeogene sequences overlying Palaeozoic basement at shallow depths, less seismic activity than surrounding areas and, according to published geological maps, little faulting.  相似文献   

11.
Planning and organization of large-scale events such as Olympic Games are accomplished by several specialized project organizations, in charge of securing finances, completing the infrastructures, negotiating with multiple stake-holders and the day-to-day management of the actual event. These organizations have to cope with a key challenge. Due to their inherently temporary nature they cannot provide the specialized knowledge and specific “project capabilities” (Davies and Brady) on their own, but have to mobilize them from the past and from outside their boundaries, e.g. from previous events or other mega-projects in the host city. Rather than in permanent organizations, then, the knowledge on preparing and performing mega-events is primarily sedimented and embodied in professionals.Drawing on the planning and organization of the London Olympics 2012 as empirical case, the paper addresses, on the one hand, this particular mobilization process. On the other, it looks at how this process is intertwined with three different trajectories that both affect and are affected by the mega-event: the trajectory of the project that aims to recruit necessary skills; the trajectory of individual persons who perceive working for the Olympics as a rewarding episode in their careers; the trajectory of professional communities that expect learning benefits for the construction and project management industry in the UK.  相似文献   

12.
Uvarovite (Ca3Cr2Si3O12) forms a complete solid solution series with andradite (Ca3Fe 2 +3 Si3O12) below 1,137±5 ° C at a total pressure of 1 atm. Pure uvarovite decomposes to pseudowollastonite (CaSiO3)+eskolaite (Cr2O3) at 1,385 ± 10 ° C. The incorporation of Ca3Fe 2 +3 Si3O12 component in the uvarovite structure lowers the thermal stability of the garnet. The breakdown assemblage is garnetss (Ca3(Cr,Fe+3 2)Si3O12)+pseudowollastonite (CaSiO3)+hemeskolaitess(Cr,Fe+3O3). Pure andradite decomposes to pseudowollastonite (CaSiO3)+hematite (Fe2O3) at 1,137±5 °C. Andradite thermal stability is increased by incorporation of Ca3Cr2Si3O12 component by 248 °C.At 1,264±5 °C pseudowollastonite+hematite react to liquid defining a thermal minimum of the CaSiO3-Cr2O3-Fe2O3 ternary system. This minimum is located at about 64.5 wt.-% CaSiO3, 0.5 wt.-% Cr2O3, and 35.0 wt.-% Fe2O3. Uvarovite and andradite bulk compositions start to melt at 1,420 °C and 1,265 ±5 °C, respectively.The unit-cell parameter for uvarovite is 11.999 (2) Å, the refractive index 1.866 (2). The substitution of Cr+3 by Fe+3 increases a and n almost linearly toward the andradite end member which displays a unit-cell parameter of 12.059 (3) Å and a refractive index of 1.887 (2).  相似文献   

13.
Quartz and rutile were synthesized from silica-saturated aqueous fluids between 5 and 20 kbar and from 700 to 940°C in a piston-cylinder apparatus to explore the potential pressure effect on Ti solubility in quartz. A systematic decrease in Ti-in-quartz solubility occurs between 5 and 20 kbar. Titanium K-edge X-ray absorption near-edge structure (XANES) measurements demonstrate that Ti4+ substitutes for Si4+ on fourfold tetrahedral sites in quartz at all conditions studied. Molecular dynamic simulations support XANES measurements and demonstrate that Ti incorporation onto fourfold sites is favored over interstitial solubility mechanisms. To account for the PT dependence of Ti-in-quartz solubility, a least-squares method was used to fit Ti concentrations in quartz from all experiments to the simple expression
RTlnX\textTiO 2 \textquartz = - 60952 + 1.520 ·T(K) - 1741 ·P(kbar) + RTlna\textTiO 2 RT\ln X_{{{\text{TiO}}_{ 2} }}^{\text{quartz}} = - 60952 + 1.520 \cdot T(K) - 1741 \cdot P(kbar) + RT\ln a_{{{\text{TiO}}_{ 2} }}  相似文献   

14.
The paper examines the pressures being exerted by cultural and economic processes upon African cultures in the intermediate zone of the Sudan. It examines in particular the experience of the Ingessana and Uduk peoples living between the White and Blue Niles. The Uduk have experienced the greater degree of disruption from Sudan's civil war, and many Uduk have sought refuge in Ethiopia. The Ingessana are in the frontline facing cultural and economic pressures from the north. To pressures for Islamisation and Arabicisation have been added the development of chromite mining, mechanised agriculture and increased nomadic activity around their hills.The paper points out the advantages of cultural adaptation and survival, rather than acculturation, to both these peoples and the Sudan and concludes that the Ingessana seem particularly likely to adapt and survive as a cultural entity.  相似文献   

15.
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