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971.
就如何利用数据库,结合Java、XML等手段对震源参数管理进行了一些探索,并给出了一些在一个实际系统中实现了的例子。 相似文献
972.
973.
国际地球科学与资源环境科学发展战略分析 总被引:4,自引:5,他引:4
介绍了国际主要地学机构(NASA、USGS、NOAA、NERC、BGS)、主要组织(ICSU、EU、OECD、UNESCO)、国际主要基金机构(NSF、ESF)21世纪初10~20年有关地球科学与资源环境科学的研究与发展战略的目标、研究计划、主要研究内容与优先研究领域。这些机构与组织的地学与资源环境科学发展战略,反映了国际上地球科学与资源环境科学的研究重点和发展趋势,对把握国际地球科学与资源环境科学发展方向、明确我国地球科学与资源环境科学的战略重点和优先领域具有重要的参考价值。同时,依据美国科学信息研究所(ISI)的基本科学指标数据库(ESI),分析了过去20年国际地学(geosciences)、环境/生态学(environment/ec ology)领域著名科学家的国别和机构分布状况,分析了国际地学、环境/生态学过去10年成果产出最多、论文被引频次最多、篇均被引频次最高的前10个研究机构,反映了过去10年国际地学、环境/生态学研究的影响力。最后,简要分析了国际地球科学与资源环境科学的优先研究领域与主要特点。 相似文献
974.
2-D crustal velocity structure and vp/vs are obtained by processing and interpretation of S-wave data from Maqen-Jingbian deep seismic sounding(DSS)profile.The result shows that there exist obvious differences in 2-D S-wave velocity structure and vp/vs ratio structure along the profile.The S-wave velocities are low and vp/vs ration is high for the westem section of the profile and Haiyuan region,while they are normal for the middle and eastern sections.The changes in lithologic characters of two major anomalous zones are discussed according to lateral variation of S-wave velocity structure and vp/vs ratio structure.It is concluded that the development and occurrence of the Haiyuan strong earthquake is not only related to tectonic activities,but also to lithologic characters of the region. 相似文献
975.
Introduction Receiver function has been extensively applied in studying S wave velocity of crust and up-per mantle for about 20 years (Owens, et al, 1987; LIU, et al, 1996), which is a time series ob-tained by the deconvolution of vertical component from horizontal component for teleseismic P waveform. Receiver function represents the teleseismic P plane wave response of crust and upper mantle beneath seismic station, from which the source and propagation effects are removed. Receiver funct… 相似文献
976.
Depth profiles of fluorescence at several excitation and emission wavelengths were measured along with CTD data during the
cruise So119 of RV Sonne in the Arabian Sea from 12 May to 10 June 1997. In addition to chlorophyll fluorescence from phytoplankton in the near-surface
layer, the profiles in the oxygen minimum region well below the euphotic zone show enhanced red fluorescence. Red fluorescence
intensity is inversely related to the oxygen concentration in intermediate and deep waters. A relationship to characteristic
water masses of the region cannot be found in the data, and this holds also with chemical data such as DOC. Absorbance spectra
of water samples taken in the oxygen minimum zone show an absorption band at 420 nm wavelength with about 50 nm bandwidth,
much weaker than gelbstoff absorbance in the same wavelength range. The absorption band remains stable after sample filtration
with 0.45 μm glass fibre filters. Hence, the size of the absorbing matter is in the range of dissolved molecules or particles
much smaller than 1 μm. Fluorescence spectra of unfiltered samples with 420 nm excitation show a weak emission band at 600
nm and a more pronounced one at 660 nm wavelength. The trailing edge of the 660 nm band falls into the range of chlorophyll
emission, thus giving rise to the observed depth profiles of red fluorescence in the oxygen minimum zone. Red fluorescence
measured on samples remain stable during a few hours after sampling even in the presence of oxygen. It is not detectable after
several weeks of sample storage in the dark and cannot be reproduced even after depletion of dissolved oxygen.
Received: 22 May 2002 / Accepted: 18 February 2003
Responsible Editor: Andreas Oschlies
Acknowledgements. This work was supported by a grant from the Federal Minister of Education and Technology, Bonn, within the frame work of
the JGOFS Arabian Sea program. We are grateful to the captain and the crew of RV Sonne for their support. We are indebted to Mrs. Kirsten Neumann from the Institute of Marine Chemistry and Biogeochemistry of
the University of Hamburg for providing the oxygen data, and to Mr. Nikolai Delling from the same institute for making the
DOC and chlorophyll data available to us. 相似文献
977.
978.
A method of visualizing structures in closed chaotic flows out of homogenous particle distributions is presented in the example of models of a meandering jet. To this end, the system will be leaked or opened up by defining a region of the flow, so that a particle is considered to be escaped if it leaves this region. By applying this method to an ensemble of nonescaped tracers, we are able to characterize mixing processes by visualizing the converging and stretching filamentations (stable and unstable manifolds) in the flow without using additional mathematical tools. The possibility of applying the algorithm to analyze buoy data, and a comparison with the finite time manifolds are discussed. 相似文献
979.
Zhao Jinren Zhang Xiankang Zhang Chengke Ren Qingfang Cheng Shuangxi Zhang Jianshi Nie Wenying PAN Shuzhen 《中国地震研究》2003,17(2):103-112
The data from two deep seismic sounding profiles was processed and studied comprehensively. The results show that crnst-mantle structures in the investigated region obviously display layered characteristics and velocity structures and tectonic features have larger distinction in different geological structure blocks. The boundary interface C between the upper and lower crust and Moho fluctuate greatly. The shallowest depths of C (30.0km) and Moho (45.5km) under Jiashi deepen sharply from Jiashi to the western Kunlun mountain areas, where the depths of C and Moho are 44.0km and 70.0km, respectively. The higher velocity structures in the Tarim massif determine its relatively “stable“ characteristics in crust tectonics. The phenomenon in the Jiashi region, where the distribution of earthquake foci mostly range from 20kin to 40kin in depth, may infer that the local uplift of C and Moho interface, anomalonsly lower velocity bodies and deep large faults control earthquake occurrence and seismogenic processes in the Jiashi strong earthquake swarm. 相似文献
980.
The regional stress field and seismic dynamics along the border zone between Fujian, Guangdong and Jiangxi Provinces are studied based on the seismo-geological data, GPS measurement, and seismicity. The results show that: (1) the principal compressional stress of the stress field is oriented in NW-SE direction and the principal extensional stress is in NE-SW direction; (2) the WNW-ward compression and collision of the Philippine Sea Plate to the eastern coast of Taiwan Island are the most direct and most important dynamic source for preparation and occurrence of strong earthquakes in the Taiwan area and along the border zone between Fujian, Guangdong and Jiangxi Provinces. 相似文献