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21.
史培军  汪明  胡小兵  叶涛 《地理学报》2014,69(6):863-876
在综合风险防范“凝聚力”概念的基础上,从社会—生态系统综合风险防范的“凝聚力”基本原理、凝聚力形成中的协同效能、凝聚力实现手段、凝聚力优化对提高系统抗打击能力的作用等方面系统研究了“凝聚力”的科学内涵,并初步建立了“凝聚力”的模式,以期完善现有综合风险防范理论体系。结果表明:协同宽容、协同约束、协同放大和协同分散四个基本原理阐述了社会—生态系统综合风险凝聚力在协同运作上的四种表现,同时也是凝聚力在“凝心”和“聚力”具体问题上的4 种优化目标的阐释;凝聚力模式将四个协同原理及其优化目标转化为社会认知普及化、成本分摊合理化、组合优化智能化、费用效益最大化等一系列手段,实现了社会—生态系统综合风险防范产生的共识最高化、成本最低化、福利最大化以及风险最小化;运用复杂系统建模和仿真的方法,通过设计社会—生态系统结构和功能的表达,验证了随着系统凝聚力的提高,系统抵抗局部和全局打击的能力均得以增强,而且,可通过优化社会—生态系统中节点的结构和功能,以达到提升系统凝聚力的目的;凝聚力模式补充了灾害系统中脆弱性、恢复性、适应性等概念在阐释社会—生态系统综合风险防范问题上存在的缺陷。  相似文献   
22.
Based on the theory of formation dynamics of oil/gas pools, the Dongying sag can be divided into three dynamic systems regarding the accumulation of oil and gas: the superpressure closed system, the semi-closed system and the normal pressure open system. Based on the analysis of genesis of superpressure in the superpressure closed system and the rule of hydrocarbon expulsion, it is found that hydrocarbon generation is related to superpressure, which is the main driving factor of hydrocarbon migration. Micro fractures formed by superpressure are the main channels for hydrocarbon migration. There are three dynamic patterns for hydrocarbon expulsion: free water drainage, hydrocarbon accumulation and drainage through micro fissures. In the superpressure closed system, the oil-driving-water process and oil/gas accumulation were completed in lithologic traps by way of such two dynamic patterns as episodic evolution of superpressure systems and episodic pressure release of faults. The oil-bearing capacity of lithologic traps is intimately related to reservoir-forming dynamic force. Quantitative evaluation of dynamic conditions for pool formation can effectively predict the oil-bearing capability of traps.  相似文献   
23.
<正>The Beiya gold polymetallic ore district covers an area of 22.06 km2 and is located 47.5 km away in the direction 172°from Heqing county seat of northwestern Yunnan.Its geographical coordinates are 100°11′15″–100°13′00″E and6°07′30″–26°10′30″N.Since its discovery in 1999 until November 31st 2013,it has had accumulative proven(111b+122b+331+332+333)gold metal amounts of 258.475t at an average grade of 2.61 g/t.This deposit contains 88.98million tons of paragenetic and associated iron ores,with TFe grade varying from 9%to 36%;metal amounts are:gold  相似文献   
24.
The Sichuan Basin,also known as the‘Red Basin’,is famous for its abundance of Mesozoic dinosaur fossils,especially in the Zigong area during the Jurassic era;the Middle Jurassic Shunosaurus and the Late Jurassic Mamenchisaurus faunal assemblages are the most representative.The Qinglongshan dinosaur fossil site is located in Fuxing,to the northwest of Rong County,Zigong City.This new site is situated within the Middle Jurassic Xiashaximiao Formation,and geologically is roughly equivalent to the well-known Dashanpu dinosaur fossil site.More than 600 dinosaur fossils were found concentrated in the excavation area,including teeth;cervical,dorsal and caudal vertebrae;and various parts of appendicular skeletons.This fossil site is also most significant as it provides new information on non-avian dinosaur life during the poorly understood Middle Jurassic.  相似文献   
25.
基于多年实地调研考察和近20年的文献资料,对云南纳西族和汉族地区农村典型民居的抗震性能进行了研究。结合传统工艺中的抗震构造措施,分析了这种典型民居建筑形式的震害特征及原因,探讨了云南典型民居建筑在社会变迁中出现的抗震新问题和实施抗震加固工程中的问题,提出了提升区域整体抗震防灾能力的思考。  相似文献   
26.
Enclaves in intermediate-acid plutons from Tongling can be divided into three types: xenoliths, relics and magmatogenic enclaves. The magmatogenic enclaves consist of cumulates, micrograined dioritite mixtite and dioritic chilled border enclaves. Petrologically, relics with eyed and meta-poikilitic texture are characterized by high content of biotite (>80%) and low content of cordierite and grossular. The cumulates with accumulate texture consist of a great amount of pyroxene, hornblende and minor spinel and phlogopite. The micrograined dioritic mixtite is composed of more hornblendes and feldspar and less needle apatites and an ellipsoid basic core included in plagio-clase. The chilled border enclaves have the same mineral association, but more dark minerals than the host rocks consisting of plagioclase, quartz, alkaline feldspar, hornblende and biotite. Geochemically, the relics exhibit high REE content (455.8×10-6) and high ratio of LREE/HREE, more obvious Eu negative anomaly and are rich in Cr and  相似文献   
27.
There are two production areas for vanadium-titanium magnetite deposits in China:the Panzhihua area in Sichuan Province and the Chengde area in Hebei Province. The Panzhihua vanadium titanomagnetite iron ore deposits are hosted by a mafic-ultramafic intrusive complex,and belong to late magmatic differentiation condensation of crystalline iron deposits.The rock mass is characterized by good differentiation,clear and differentiated facies zones and rhythm.The rock assemblage can be divided into the following rock facies combination:gabbro,gabbro-norite,gabbro troctolite,gabbro-plagioclase,gabbro-eclogite-olivine pyroxenite,and diabase types.The orebodies occur mostly as close-bedded,distributed in the dark facies zone in the bottom layers of the middle or lower part of the stratiform rock mass.The main ore minerals are granular ilmenite,magnetite,ilmenite spar,and magnesium aluminum spinel,with small amounts of pyrrhotite,pyrite and cobalt,nickel and copper sulfide.The ores have siderite and mosaic textures and occur as compact massive,banded and disseminated structures;they consist of TFeO 20%-45%,TiO2 3%-16%,V2O50.15%-0.5%,Cr2O30.1%-0.38%,associated with trace amounts of Cu,Co,Ni,Ga,Mn,P,Se,Te,Sc and Pt group elements.  相似文献   
28.
正For thousands of years,a large number of peripheral rivers have been flowing into deserts,the water from which then will infiltrate underground or evaporate into the air.When desert sand engulfs and humans retreat,precious freshwater resources lie dormant all the year round,making almost no contribution to human progress.  相似文献   
29.
利用小波变换和集合经验模态分解(EEMD)的方法对广州市1908—2010年103 a的温度、降水资料进行多尺度分析,并对比EEMD和小波分析的差异。结果表明:(1) 小波分解基于先验的小波基函数和分解层次有较大的人为选择性,易产生虚假波动;(2) EEMD具有自适性,分解结果更稳定和一致,处理非线性、非平稳数据更准确;(3) EEMD分解显示,广州的温度、降水均存在2~6.8 a的年际尺度波动,年代际尺度上,温度表现为13.6 a、34 a、68 a的波动周期,降水存在22.6 a的波动周期。   相似文献   
30.
In the East China Sea (ECS), there are some mud areas, including the south coastal mud area, the north coastal mud area, and the mud area to the southwest of Cheju Island. X-ray fluorescence (XRF) techniques and Thermal Ionization Mass Spectrometry (TIMS) were used to study the high-resolution sedimentary record of Pb concentrations and Pb stable isotopic compositions in the past one hundred and fifty years in the coastal mud of the ECS. Pb concentrations of a ^210Pb dating S5 core in the study area have increased rapidly since 1980, and reached the maximal value with 65.08 μg/g in 2000, corresponding to the fast economic development of China since the implementation of the "Reform and Open Policy" in 1978; ^206Pb/^207Pb ratios generally had stabilized at 1.195 from 1860 to 1966, and decreased gradually from 1966 to 2000, indicating that the anthropogenic source Pb contribution to the ECS has increased gradually since 1966, especially since 1980. Pb concentrations decreased distinctly from 2000 to 2003 and ^206Pb/^207Pb ratios increased from 2001 to 2003, corresponding closely to the ban of lead gasoline from 2000 in China. From 1950 to 2003, there occurred four distinct decrease events of ^206Pb/^207Pb, possibly responding to the Changjiang River (Yangtze River) catastrophic floods in 1998, 1991, 1981 and 1954; from 1860 to 1966, there were two decrease periods of ^206Pb/^207Pb, which may respond to the catastrophic floods of Changjiang River in 1931 and 1935, and 1870. As a result of the erosion and drowning by the catastrophic floods, the anthropogenic lead accumulated in soil and water environments over a long period of time was brought into the Changjiang River, then part of them was finally transported into the ECS, which leads to changes in Pb stable isotopic composition.  相似文献   
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