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961.
在我国地震预报的经验性基础上,引入发生地震机理。只要地震、地质、地球物理、力学等专家齐心共同努力,搞清地壳、天气、天体等的一些物理化学参数后,完全可以实现科学数字地震预报。  相似文献   
962.
青藏铁路唐古拉山-拉萨段全新世控震断裂研究   总被引:8,自引:0,他引:8  
地表调查表明,沿青藏铁路唐古拉山-拉萨段存在5条重要的全新世控震断裂带,从北到南分别是温泉盆地西缘断裂带、安多盆地北缘断裂带、崩错断裂带、谷露西缘断裂带和当雄-羊八井断裂带.构造-地貌和年代学分析结果表明,北部的温泉盆地西缘断裂和安多盆地北缘断裂带的活动强度相对比较小,平均垂直活动速率约为0.2~0.5mm/a.南侧的谷露西缘断裂带和当雄-羊八井断裂带的全新世垂直活动速率为约(15±0.5)mm/a.而中部的崩错走滑断裂带的活动强度最大,晚第四纪期间的走滑速率可达(11±4.5)mm/a.全新世断裂活动和古地震研究表明,其中温泉盆地西缘断裂带、安多盆地北缘断裂带、崩错断裂带的西北分支、当雄-羊八井断裂带的当雄段等区域未来发生强震的概率相对更大.  相似文献   
963.
以同济逸夫楼等四个项目为例,就建筑设计要兼顾社会效益和经济效益,要考虑一专多能,要勇于创新、敢于创新,要充分利用环境、改造环境等方面作了阐述和随想.  相似文献   
964.
应用大容量、大道数地震仪,改变传统二维地震排列方式,由单线排列接收改为多线排列接收。根据勘探精度的要求、测线网度的不同分二种方式:一是适合于大网度概查普查的单条测线多线排列接收;二是适合于精查和采区二维地震的多条测线多线排列接收方式。  相似文献   
965.
Recent Progress in the Impact of the Tibetan Plateau on Climate in China   总被引:14,自引:0,他引:14  
Studies of the impacts of the Tibetan Plateau (TP) on climate in China in the last four years are reviewed. It is reported that temperature and precipitation over the TP have increased during recent decades. From satellite data analysis, it is demonstrated that most of the precipitation over the TP is from deep convection clouds. Moreover, the huge TP mechanical forcing and extraordinary elevated thermal forcing impose remarkable impacts upon local circulation and global climate. In winter and spring, stream flow is deflected by a large obstacle and appears as an asymmetric dipole, making East Asia much colder than mid Asia in winter and forming persistent rainfall in late winter and early spring over South China. In late spring, TP heating contributes to the establishment and intensification of the South Asian high and the abrupt seasonal transition of the surrounding circulations. In summer, TP heating in conjunction with the TP air pump cause the deviating stream field to resemble a cyclonic spiral, converging towards and rising over the TP. Therefore, the prominent Asian monsoon climate over East Asia and the dry climate over mid Asia in summer are forced by both TP local forcing and Eurasian continental forcing.
Due to the longer memory of snow and soil moisture, the TP thermal status both in summer and in late winter and spring can influence the variation of Eastern Asian summer rainfall. A combined index using both snow cover over the TP and the ENSO index in winter shows a better seasonal forecast.
On the other hand, strong sensible heating over the Tibetan Plateau in spring contributes significantly to anchor the earliest Asian monsoon being over the eastern Bay of Bengal (BOB) and the western Indochina peninsula. Qualitative prediction of the BOB monsoon onset was attempted by using the sign of meridional temperature gradient in March in the upper troposphere, or at 400 hPa over the TP. It is also demonstrated by a numerical experiment and theoretical study that the heating over the TP lea  相似文献   
966.
A simple method based on high-performance size-exclusion chromatography (HPSEC) has been developed for rapid quantification of humic and fulvic acids (HA and FA) in stream waters. A Tsk-gel column was used to separate natural dissolved organic matter (DOM) into two components: peak A and B. In terms of HPSEC chromatograms and fluorescence patterns, peak A and B were similar to the corresponding XAD-extracted HA and FA, respectively. It is suggested that peak A fraction mainly consisted of HA, and peak B fraction FA. The similar separation of HA and FA using HPSEC and a conventional XAD method suggests the consistency of molecular size distribution and physical–chemical properties of DOM. HPSEC offers a simple and rapid method for the quantification of HA and FA instead of tedious extractions of humic substances. Analyses of natural water samples show that the calculation of HA/FA based on UV absorbance was under- or over-estimated, the calibration using the extracted HS allows a more accurate quantification. The fast screening of HA and FA provides useful quantitative and qualitative information that can be used in environmental or monitoring studies.  相似文献   
967.
Fulong Wu 《Geoforum》2007,38(2):379-392
Rather than being abandoned along with the demise of the centrally planned economy, city planning as a profession is flourishing in China. New hybrid plans such as strategic development plans (concept plans) have been invented, and the planning procedure has become more flexible. Design competition and planning consultancy are widespread. This paper examines the development of new strategic development plans and design competition. It is argued that city planning has been re-orientated from a technical rationale, i.e. allocating state development projects to the city, to the imperative derived from market-oriented development, i.e. consolidating competitiveness during inter-city competition. The contradiction between market and planning is that while the status of city planning has been raised and its approach is becoming more strategic, the actual functionality of city planning has become more instrumental.  相似文献   
968.
安哥拉下刚果盆地吉拉索尔深水油田   总被引:4,自引:2,他引:4  
吉拉索尔油田位于西非安哥拉17号深水区块,水深1200~1400m,距安哥拉海岸150km。1996年发现,2001年产油,是安哥拉投入开发的第一个深水油田。油田面积约140km2,地质储量约为15.5×108bbl,可采储量约7.25×108bbl,为轻质油。油田所在的下刚果盆地主要经历了裂谷期、过渡期和热沉降期三个阶段的构造演化,相应沉积了裂谷期陆相地层、过渡期蒸发岩层和热沉降期海相地层。主要烃源岩为下白垩统Bucomazi组湖相页岩,有机质丰度高,类型好,成熟度适中,为很好的烃源岩。盆地深水区主要储层为上渐新统—中新统河道充填浊积砂岩复合体,砂岩固结差,物性良好。吉拉索尔油田主要由几个河道浊积砂岩复合体叠置组成,其中夹几个薄层席状砂岩,复合体之间被海相泥页岩分隔。上覆第三系泥岩为其主要盖层。  相似文献   
969.
Based on data of earthquake sequences with MS≥5.0 in Chinese mainland from 1970 to 2004,for different se-quence types and different rupture modes of the main shock,the relationship between aftershock distribution size Rand the magnitude of the main shock M0 has been studied statistically.Considering the rupture mode of the mainshock,we give the quantitative statistical relationships between R and M0 under 95%confidence level for differentsequence types.Qualitatively,lgR,the logarithm of the aftershock distribution size,is positively correlative to theM0,but the data distribution is dispersed.Viewing from different sequence types,the correlation between R and M0is very weak for isolated earthquake type(IET)sequence,R distributes in the range from 5 to 60 km;For main-shock-aftershock type(MAT),lgR is positively correlative to M0;For multiple main shock type(MMT),the core-lation between lgR and M0 is not very obvious when M0≤6.2 and R distributes in the range from 5 to 70 km,whileit shows a linear correlation when M0≥6.3.The statistical results also show that the occupational ratios of differentsequence types for strike-slip and oblique slip are almost the same.But for dip-slip(mostly are thrust mechanisms),the ratio of MAT is higher than that of IET and MMT.Comparing with previous results,it indicates that,when M0is large enough,R is mainly determined by M0 and there is almost no relationship with the rupture mode of themain shock.  相似文献   
970.
Analyses of rock-magnetic properties of Neogene sediments of the Taxihe section, northern Tianshan Mountains, show that the section can be classified into three categories including lacustrine facies, fluvial facies and alluvial facies, which correspond to the lower, middle and upper of the Taxihe section respectively. The magnetic minerals of the lacustrine facies may be affected by the process of weath- ering, lithogenesis and biolithogenesis besides the source of the sediments. The natural remanence intensities are between 10-3 A/m and 10-2 A/m. The minerals are dominated by magnetite and the high coercive magnetic mineral may be goethite. The magnetic grains are the mixture of PSD SD or SD SP. The natural remanence intensities of the strata of fluvial facies are between 10-2 A/m and 10-1 A/m, about ten times that of the lacustrine facies. The magnetic minerals are mainly magnetite and hematite, and the magnetic grains are mainly PSD. The characteristic remanence (ChRM) carriers are magnetites. In the alluvial facies, the natural remanence intensities are mostly less than 1×10-2 A/m. The magnetic minerals of the series are dominated by magnetite and hematite, almost the same as the fluvial facies. But the difference is that most of the stepwise demagnetization can reveal two components and the ChRM carriers are hematites. The magnetic grains are PSD in terms of the hysteresis parameters.  相似文献   
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