Co-seismic ground deformation and source parameters of Mani M7.9 earthquake inferred from spaceborne D-InSAR observation data   总被引：4，自引：0，他引：4  

SHAN Xinjian  MA Jin  WANG Changlin  LIU Jiahang  SONG Xiaoyu & ZHANG Guifang .Institute of Geology  Laboratory of Tectonophysics  China Seismological Bureau  Beijing  China  .Institute of Remote Sensing Application  Chinese Academy of Sciences  Beijing  China 《中国科学D辑(英文版)》2004,47(6):481-488

In recent ten years, Differential Interferometric Synthetic Aperture Radar (D-InSAR) has become a major technique of space-based geodesy together with GPS, VLBI and SLR. Interferometric Synthetic Aper-ture Radar (InSAR) has many advantages, such as all-weather, all-time, strong stability and dynamic survey property, and no requirements for ground sta-tions. In particular, the surveying results by InSAR can cover a large range of the ground deformation field in succession and has gr…  相似文献   

Wind tunnel simulation experiment and investigation on the electrification of sandstorms     

QU Jianjun  YAN Muhong  DONG Guangrong  ZHANG Hongfa  ZU Ruiping  TUO Wanquan  ZHAO Aiguo  XlAO Zhenghua  LI Fang & YANG Bao Key Laboratory of Desert  Desertification  Cold  Arid Regions Environmental  Engineering Research Institute  Shapotou Desert Research  Experiment Station  Chinese Academy of Sciences  Lanzhou  China 《中国科学D辑(英文版)》2004,47(6):529-539

~~Wind tunnel simulation experiment and investigation on the electrification of sandstorms~~  相似文献   

Comparison of the dynamic response of a saturated soil between two models     

LIN Mian Institute of Mechanics  Chinese Academy of Sciences  Beijing  China 《中国科学D辑(英文版)》2004,47(6):551-558

The dynamic response of marine sediment to ocean surface waves is treated extremely by marine geotechnical and coastal engineers. In the area of conventional hydrodynamics, the assumption of im-permeable rigid seabed has been used as the boundary of water waves theories and the waves parameters de-duced from the theory have not referred to the interac-tion of water waves and seabed. In the area of soil mechanics, many engineers regard the response as slow loading according to the Zienkewiczs[1…  相似文献   

Palynological record during the Pleistocene (between 1.05 Ma and 0.36 Ma) from ODP1144, northern South China Sea     

HUANG Fei & SUN XiangjunInstitute of Geology  Paleontology  Chinese Academy of Sciences  Nanjing  China  Institute of Botany  Chinese Academy of Sciences  Beijing  China  Key Laboratory of Marine Geology  Ministry of Education  Tongji University  Shanghai  China Correspondence should be addressed to Huang Fei 《中国科学D辑(英文版)》2004,47(1):30-36

This paper presents the pollen record from the lower section of ODP1144 (depth 501.3-225.7 m, ca. 1.05-0.36 Ma). Two pollen zones (PA and PB) and eleven pollen subzones are recognized. Within zone PB, the 11 pollen subzones (PB21-11) are defined according to the pine, fern and herb variations, and are equivalent to the marine isotope stages 21-11 (MISs 21-11). The interglacial periods are typified by an increase in pine pollen and fern spores, and a decrease in herbaceous pollen, while the patterning during the glacial periods is just the opposite. During the interglacial periods, pollen assemblages were dominated by pine similar to those of the present day, suggesting that the paleoenvironment of the interglacial periods was similar to that of the present day, whereas the glacial periods are marked by an increase in herbaceous pollen, mainly Gramineae and Cyperaceae, indicating that grassland covered the exposed continental shelf when sea level declined. Increased Artemisia percentages and the highest  相似文献   

Synthesis of todorokite by refluxing process and its primary characteristics     

FENG Xionghan  LIU Fan  TAN Wenfeng  LIU Xiangwen & HU Hongqing . College of Resources  Environment  Huazhong Agricultural University  Wuhan  China  . Testing Center  China University of Geosciences  Wuhan  China 《中国科学D辑(英文版)》2004,47(8):760-768

Todorokite is one of the common manganese ox-ides in manganese ore deposits, weathering product of manganese-bearing rocks, soils and sediments. It is also an important component in the abundant marine manganese nodules. Since todorokite was firstly found in Japanese Todoroki mine in 1934, its properties and origination have appeared to be very interesting to many researchers[1—3]. It has a stable structure similar to porous molecular sieves, constructed of triple MnO6 octahedral chains. Th…  相似文献   

Land cover change over the last three centuries due to human activities: The availability of new global data sets   总被引：15，自引：0，他引：15  

Kees?Klein GoldewijkEmail author  Navin?Ramankutty 《GeoJournal》2004,61(4):335-344

Land use and land cover change is an important driver of global change (Turner et al., 1993). It is recognized that land use change has important consequences for global and regional climates, the global biogeochemical cycles such as carbon, nitrogen, and water, biodiversity, etc. Nevertheless, there have been relatively few comprehensive studies of global, long-term historical changes in land cover due to land use. In this paper, we review the development of global scale data sets of land use and land cover change. Furthermore, we assess the differences between two recently developed global data sets of historical land cover change due to land use. Based on historical statistical inventories (e.g. census data, tax records, land surveys, historical geography estimates, etc) and applying different spatial analysis techniques, changes in agricultural land cover (croplands, pastures) were reconstructed for the last 300 years. The two data sets indicate that cropland areas expanded from 3–4 million km² in 1700 to 15–18 million km² in 1990 (mostly at the expense of forests), while grazing land area expanded from 5 million km² in 1700 to 31 million km² in 1990 (mostly at the expense of natural grasslands). The data sets disagree most over Latin America and Oceania, and agree best over North America. Major differences in the two data sets can be explained by the use of a fractional versus Boolean approach, different modelling assumptions, and inventory data sets.  相似文献   

The land-use projections and resulting emissions in the IPCC SRES scenarios scenarios as simulated by the IMAGE 2.2 model   总被引：1，自引：0，他引：1  

Bart?StrengersEmail author  Rik?Leemans  Bas?Eickhout  Bert?de?Vries  Lex?Bouwman 《GeoJournal》2004,61(4):381-393

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Understanding land-use change to reconstruct,describe or predict changes in land cover     

Rik?LeemansEmail author  Suzanne?Serneels 《GeoJournal》2004,61(4):305-307

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Release of heavy metals during weathering of the Lower Cambrian Black Shales in western Hunan,China   总被引：8，自引：0，他引：8  

Bo?PengEmail author  Zhaoliang?Song  Xiangling?Tu  Meilian?Xiao  Fucheng?Wu  Huanzhe?Lv 《Environmental Geology》2004,45(8):1137-1147

Weathering of heavy metal enriched black shales may be one of the most important sources of environmental contamination in areas where black shales are distributed. Heavy metal release during weathering of the Lower Cambrian Black Shales (LCBS) in western Hunan, China, was investigated using traditional geochemical methods and the ICP-MS analytical technique. Concentrations of 16 heavy metals, 8 trace elements and P were measured for samples from selected weathering profiles at the Taiping vanadium ore mine (TP), the Matian phosphorous ore mine (MT), and Taojiang stone-coal mine (TJ). The results show that the bedrock at these three profiles is enriched with Sc, V, Cr, Co, Ni, Cu, Zn, Pb, Th, U, Mo, Cd, Sb, Tl, and P. Based on mass-balance calculation, the percentages of heavy metals released (in % loss) relative to immobile element Nb were estimated. The results show significant rates of release during weathering of: V, Cr, Co, Ni, Cu, Zn, U, Mo, Cd, Sn, Sb, and Tl for the TP profile; Sc, Cr, Mn, Co, Ni, Cu, Zn, Pb, Th, Cd, and Sn for the MT profile; and Sc, Mn, Co, Ni, Zn, Th, Cd, Sn, and Tl for the TJ profile. Among these heavy metals, Co, Ni, Zn, Cd, and Sn show very similar features of release from each of the three weathering profiles. The heavy metals released during weathering may affect the environment (especially topsoil and surface waters) and are possibly related to an observed high incidence of endemic diseases in the area.  相似文献   

Analysis of Wedge Stability Using Different Methods   总被引：1，自引：0，他引：1  

Y.-J. Wang  J.-H. Yin  Z. Chen  C. F. Lee 《Rock Mechanics and Rock Engineering》2004,37(2):127-150

Summary The stability problem of a rock slope containing a wedge resting on two intersecting discontinuities is of great interest in rock slope engineering. It is a statistically indeterminate problem with two extra unknowns according to the force (stress) equilibrium analysis. The widely used limit equilibrium methods in practice assume that the directions of the shear forces acting on the two discontinuities are parallel to their line of intersection. The validity of this assumption, however, has not been verified theoretically. This paper presents a general limit equilibrium method that determines the directions of the shear forces by using Pans Maximum principle and an upper bound method that applies the classic upper bound theorem of limit analysis to avoid making extra assumptions. The formulations of the two methods are derived. A non-symmetric wedge and a symmetric wedge are analyzed using the two derived methods. To further explore the influence on stability due to the direction of the shear force acting on the two discontinuities, three-dimensional finite-element analyses are also conducted. The results are compared and discussed.  相似文献