Dynamic Mechanism of Migmatization in the Dabie Complex, Northeastern Hubei, China     

Wang Jianghai  Guangzhou Institute of New Geological Technology  Academia Sini  Guangzhou  GuangdongYang Wenhua  Wu Jinping China U niversity of Geosciences  W uhan  Hubei Jiang M inxi 《《地质学报》英文版》1995,69(2)

On the basis of the detailed field work, compositions and contents of plagioclase and K - feldspar,determination of ordering degree, statistical analysis of plagioclase elongation index, mass-balance calculation and mineral spatial distribution and geochemistry, it is concluded that the migmatites in the Dabie complex are characterized by the presence of thermocenters. There are regular changes in mineral character in the migmatites from the centers outwards. The dominant genetic mechanism is anatexis and metasomatism, whose intensities decrease from the centers outwards. Finally, according to the simulated experiment on Liesegang' s rings and non-linear dynamics (dissipative structure theory), the dynamic mechanism of migmatization is profoundly expouded as consisting of the early-stage metasomatism induced by the thermal anomaly, the cardinal-stage anatexis induced by the early-stage matasomatism and finally the last-stage post-anatexis metasomatism.  相似文献   

Spectrum Characteristics and Transfer Function of the Hydrograph of the Deep Aqueous System     

Chen Baoren  Liu Shuyun  Earth Sciences Dept.  Nanjing University  Nanjing  Jiangsu  China Jin Peikang Geological Dept.  Tulane University  New Orleans  LA  U.S.A.  Dong Shouyu Hebei Province Seismological Bureau  Shijiazhuang  Hebei  China 《《地质学报》英文版》1993,67(4)

The fluctuation of most of the hydrograph in the deep aqueous system records the fluid pulsation in lithosphere and variation of the earth's crust. Many observations have verified that groundwater is an ideal information carrier of the crust. In this paper, the series of input (precipitation, air pressure, Earth tide etc.) and output (water level, artesian flow) of the deep aqueous system are studied by using the spectrum analysis and system theory. The application concepts of transfer function and the spectral structure of the hydrograph enrich the knowledge of the deep aqueous system. Two typical spectral structures of the hydrograph of the deep aqueous system are obtained by comparing with many water-bearing systems of the Jizhong depression. One is from well Ma-17 and the other is from the well Xinze-5. Finally, the physical models of forming the spectrum of the hydrograph are constructed on the basis of the spectrum research on the deep aqueous system.  相似文献   

中国地震代表团赴新西兰访问考察     

The Chinese seismological Delegation to New Zealand 《国际地震动态》1994,(3)

应新西兰国家研究科技部邀请，以国家地震局人事教育司司长李裕彻为团长的中国地震代表团于１９９３年１０月１０－２０日访问考察了新西兰。本文介绍了这次访问考察的概况，并根据访问期间了解到的情况，较详细地介绍了新西兰的防震减灾工作、防灾减灾机构及其职能、防震减灾研究等方面的情况。  相似文献   

Further comments on the Anak Krakatau question     

I. W. B. Thornton  S. A. Ward  R. A. Zann  T. R. New 《GeoJournal》1994,33(4):493-493

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MM5 simulations of interannual change and the diurnal cycle of southern African regional climate     

M. A. Tadross  W. J. Gutowski Jr  B. C. Hewitson  C. Jack  M. New 《Theoretical and Applied Climatology》2006,86(1-4):63-80

Summary Two cumulus convection and two planetary boundary layer schemes are used to investigate the climate of southern Africa using the MM5 regional climate model. Both a wet (1988/89) and a dry (1991/92) summer (December–February, DJF) rainfall season are simulated and the results compared with three different observational sources: Climate Research Unit seasonal data (precipitation, 2 m surface temperature, number of rain days), satellite-derived diurnal precipitation and the Surface Radiation Budget diurnal short-wave fluxes and optical depth. Using the ETA model boundary layer in MM5 simulates too much incident short-wave radiation at the surface at 12 UTC, whereas the medium range forecast model boundary layer yields a diurnal cycle of short-wave radiation closer to the observed. The Betts-Miller convection scheme in MM5 simulates peak rainfall later in the day and less rain days than observed, whereas when using the Kain-Fritsch convection scheme a peak rainfall earlier in the day and more rain days than observed are simulated. The intensity of the hydrological cycle is therefore dependent on the choice of convection scheme, which in turn is further modified by the boundary layer scheme. Precipitation during the wet 1988/89 season is reasonably captured by most simulations, though using the Betts-Miller scheme more accurately simulates rainfall during the dry 1991/92 season. Mean DJF biases in the surface temperature and diurnal temperature range are consistent with biases in the number of rain days and the diurnal cycles of surface moisture and energy.  相似文献   

稳定性层状云降雨量的估算研究          下载免费PDF全文

李金辉  罗俊颉 《山西气象》2006,(2):1-4

党的十六届五中全会明确提出了建设社会主义新农村。为充分发挥气象科技业务服务在新农村建设中的作用,使推进社会主义新农村建设的部署落到实处,按照中国气象局的要求,结合山西省实际情况,山西省气象局于2006年3月下旬进行了气象为建设社会主义新农村服务的调研活动。组织机构:成立了以山西省气象局党组书记、局长张世英为组长,副局长李韬光为副组长的新农村建设调研领导小组,从山西省气象局预测减灾与科技处、山西省气候中心等有关单位抽调了一批政治素质好,业务水平高的技术骨干组成了调研组。调研方法:主要通过问卷调研、专题调研、实地…  相似文献   

Intergrain contact density indices for granular mixes——Ⅱ: Liquefaction resistance     

S. Thevanayagam 《地震工程与工程振动(英文版)》2007,(2)

Whether the presence of non-plastic silt in a granular mix soil impact its liquefaction potential and how to evaluate liquefaction resistance of sand containing different amounts of silt contents are both controversial issues. This paper presents the results of an experimental evaluation to address these issues. Two parameters, namely, equivalent intergranular void ratio (ec)eq and equivalent interfine void ratio (ef)eq, proposed in a companion paper (Thevanayagam, 2007) as indices of active grain contacts in a granular mix, are used to characterize liquefaction resistance of sands and silty sands. Results indicate that, at the same global void ratio (e), liquefaction resistance of silty sand decreases with an increase in fines content (CF) up to a threshold value (CFth). This is due to a reduction in intergrain contact density between the coarse grains. Beyond CFth, with further addition of fines, the interfine contacts become significant while the inter-coarse grain contacts diminish and coarse grains become dispersed. At the same e, the liquefaction resistance increases and the soil becomes stronger with a further increase in silt content. Beyond a limiting fines content (CFL), the liquefaction resistance is controlled by interfine contacts only. When CFCFth, at the same (ef)eq, the cyclic strength of a sandy silt is comparable to the host silt at a void ratio equal to (ef)eq.  相似文献   

Spectrum Analysis of the Binary Systems with Expanding Shell Due to Stellar Wind     

ZHAO Ding-feng HUANG Run-qiang 《天文研究与技术》2000