Viscous heating, adiabatic heating and energetic consistency in compressible mantle convection   总被引：1，自引：0，他引：1  

Wei Leng  Shijie Zhong 《Geophysical Journal International》2008,173(2):693-702

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Efficient numerical surface wave propagation through the optimization of discrete crustal models—a technique based on non-linear dispersion curve matching (DCM)     

Andreas Fichtner  Heiner Igel 《Geophysical Journal International》2008,173(2):519-533

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Synthetic logs of multipole sources in boreholes based on the Kelvin–Voigt stress–strain relation     

José M. Carcione  Flavio Poletto 《Geophysical Journal International》2008,174(3):808-814

We design a numerical algorithm for wave simulation in a borehole due to multipole sources. The stress–strain relation of the formation is based on the Kelvin–Voigt mechanical model to describe the attenuation. The modelling, which requires two anelastic parameters and twice the spatial derivatives of the lossless case, simulates 3-D waves in an axisymmetric medium by using the Fourier and Chebyshev methods to compute the spatial derivatives along the vertical and horizontal directions, respectively. Instabilities of the Chebyshev differential operator due to the implementation of the fluid–solid boundary conditions are solved with a characteristic approach, where the characteristic variables are evaluated at the source central frequency. The algorithm uses two meshes to model the fluid and the solid. The presence of the logging tool is modelled by imposing rigid boundary conditions at the inner surface of the fluid mesh. Examples illustrating the propagation of waves are presented, namely, by using monopoles, dipoles and a quadrupoles as sources in hard and soft formations. Moreover, the presence of casing and layers is considered. The modelling correctly simulates the features—traveltime and attenuation—of the wave modes observed in sonic logs, namely, the P and S body waves, the Stoneley wave, and the dispersive S waves in the case of multipole sources.  相似文献   

海洋沉积物中孔隙水的氯同位素测量方法研究     

李艳平  蒋少涌  杨涛  濮巍 《高校地质学报》2006,12(3):388-391

采用Ba型、H型和Cs型三步阳离子交换树脂法,对海洋沉积物中孔隙水的氯进行了分离和提纯。氯的回收率达99．6％,能满足氯同位素质谱测定的需要。氯同位素的测量采用基于Cs2Cl^＋离子的高精度正热电离质谱法,对ISL354NaCI标准物质的多次测量结果为”CI／”CI=0．319130±0．000029,对一个南海海底沉积物中孔隙水的多次测量结果为^37CI／^35CI=0．319144±0．000043,表明此方法的稳定性好,测量精度高,可用于海洋沉积物中孔隙水的氯同位素示踪研究  相似文献   

Study of Laboratory Induced Self-Reversed Thermoremanent Magnetization and the Fe-Ti Oxides of the Dacite Ash from the 1991 Pinatubo Eruption (Philippines)     

Orlický  O.  Funaki  M. 《Studia Geophysica et Geodaetica》2002,46(3):527-544

The dacite ash from the 1991 Pinatubo eruption was studied. Three Fe-Ti magnetic phases were detected within the dacite ash: the ilmenite-hematite (ilm-hem) with the Curie temperature T _C 220°C, in first heating, with a compositional parameter y 0.50; but more stable form after heating is with T _C1 260°C and y 0.46; the titanomagnetite (TM) with the T _C 455°C (more stable phase is that with T _C2 475°C and x 0.13, after an original sample was heated to 700°C); the Fe-Ti phase of T _C 512°C corresponding to the TM of lower content of Ti, which is stable against the temperature influence to 700°C. The study of the self-reversed thermoremanent magnetization (SR TRM) was arranged with the dacite ash fixed within the nonmagnetic gypsum. The dacite ash is able to acquire the SR TRM within 430-25°C. The results of the induced pTRM have shown that the dominant acquisition of SR pTRM takes place within both 430-350°C and 310-230°C intervals during inducing the pTRM, but the pTRM of very low intensity was induced also within a separate interval of 630-510°C. Only the pTRM of the positive polarity was induced within the 510-430°C and 230-70°C intervals. An interesting thing is that the SR pTRM is acquired at much higher temperatures (of about 200°C higher) than the T _C of the ilm-hem phase. The stage of the TRM or pTRM of the dacite ash is strongly dependent on the mode of temperature treatment of samples. An inverse ratio between the intensity of the SR pTRM and the content of the Fe-Ti magnetic grains has pointed out, that inter-grain interactions, probably of magnetostatic origin, are topical in the dacite ash during thermal treatment. The behaviour of the SR TRM of the dacite ash during cooling and heating in the low temperature interval (to temperature of the liquid nitrogen) is supposed to be similar to that of the hematite below its Morin transition temperature (T _M). Evidently, the Ilm-hem is the main component which takes part in producing of the SR TRM of the dacite ash. We have not presented separate own model about the mechanism and origin of SR TRM, but we have accepted the model of Ozima and Funaki, shortly described in this article.  相似文献   

油气田中油气的分异作用——以塔里木盆地牙哈凝析油气田为例   总被引：4，自引：0，他引：4  

周兴熙 《地质论评》2003,49(5):507-512

塔里木盆地牙哈油气田是我国迄今发现的最大的凝析油气田,由12个油气藏组成,油气分布具有“西油东气”、“上气下油”、“上轻下重”的特征,这种特征的形成,是油气自西北分两个高峰期注入和在重力作用下分异的结果,呈现了“中部注入的正向差异聚集”的模式。这种模式与Gussow和Schowalter所建立的模式在形成机制或油气分布方面有所不同。  相似文献   

制约我国西部县域经济发展的主要因素及解决办法   总被引：2，自引：0，他引：2  

唐楚生 《广东海洋大学学报》2005,25(2):46-49

我国西部地区资源丰富,地广人稀,但产业结构不合理,农业产业化水平低,城乡一体化进程缓慢,县域财力匮乏,从而导致其经济发展相对落后。在发展生态农业的基础上,大力发展农副特色产品的加工业,加强区域间联合,发展民营经济,加强教育和人力资源开发,是解决西部县域经济发展的基本对策。  相似文献   

BOOK REVIEWS     

《The Professional geographer》1984,36(4):498-530

Book reviewed is the article: Small-State Security in the Balkans . Aurel Braun. South American Development: A Geographical Introduction . Rosemary D. F. Bromley and Ray Bromley. Interregional Migration, National Policy and Social Justice . Gordon L. Clark. Marketing Architectural and Engineering Services . Weld Coxe. A Geography of the Third World . J. P. Dickenson, C. G. Clarke, W. T. S. Gould, R. M. Prothero, D. J. Siddle, C. T. Smith, E. M. Thomas-Hope, and A. G. Hodgkiss. Wildlife and Man in Texas: Environmental Change and Conservation . Robin W. Doughty. At the Sea's Edge . William T. Fox. Englewood Cliffs Geography and Ecology . I. P. Gerasimov. Urbanization in Contemporary Latin America. Critical Approaches to the Analysis of Urban Issues . Alan Gilbert in association with Jorge E. Hardoy and Ronaldo Ramírez, eds. The Coming of the Transactional City . Jean Gottmann. College Park Visions of City and Country: Prints and Photographs of Nineteenth-Century France . Bonnie L. Grad and Timothy A. Riggs. Worcester Soviet Geography Today: Physical Geography . N. A. Gvozdetskiy, ed. Adaptive Responses of Native Amazonians . Raymond B. Hames and William T. Vickers, eds. Urban and Regional Industrial Research: The Changing UK Data Base . Michael Healey, ed. Cuando se Acaban los Montes . Stanley Heckadon Moreno. A Panama Forest and Shore: Natural History and Amerindian Culture in Bocas del Toro . Burton L. Gordon. Pacific Grove Mozambique: From Colonialism to Revolution, 1900–1982 . Allen Isaacman and Barbara Isaacman. Soviet Natural Resources in the World Economy . Robert G. Jensen, Theodore Shabad, and Arthur W. Wright, eds. The Changing Geography of the United Kingdom . R. J. Johnston and J. C. Doornkamp, eds. Pluralism and Political Geography—People, Territory and State . Nurit Kliot and Stanley Waterman, eds. Landmarks Preservation and the Property Tax . David Listokin. Irrigation Horticulture in Highland Guatemala: The Tablón System of Panajachel . Kent Mathewson. Her Space, Her Place: A Geography of Women . Mary Ellen Mazey and David R. Lee. Man, A Geomorphological Agent . Dov Nir. Dordrecht The Book of America: Inside the 50 States Today . Neal R. Peirce and Jerry Hagstrom. Rivers . Geoffrey E. Petts. Proceedings, United States/Australia Workshop on Design and Implementation of Computer-Based Geographic Information Systems . Donna Peuquet and John O'Callaghan, eds. Outdoor Recreational and Resource Management . John Pigram. Remaking the City: Social Science Perspectives on Urban Design . John S. Pipkin, Mark La Gory and Judith R. Blau, eds. The Crust of Our Earth: An Armchair Traveler's Guide to the New Geology . Chet Raymo. Englewood Cliffs Concepts and Themes in the Regional Geography of Canada J. Lewis Robinson. Vancouver Secondary Cities in Developing Countries: Policies for Diffusing Urbanization . Dennis A. Rondinelli. Beverly Hills Legal Foundations of Environmental Planning , Vol 1. J. G. Rose. Can We Delay a Greenhouse Warming? Stephen Seidel and Dale Keyes. Mobilizing Human Resources in the Arab World . R. Paul Shaw. Prairie Mosaic: An Ethnic Atlas of Rural North Dakota . William C. Sherman. The Future of Conflict in the 1980s . William J. Taylor, Jr. and Steven A. Maaranen, eds. The Visual Display of Quantitative Information . Edward R. Tufte. U.S. 40 Today: Thirty Years of landscape Change in America . Thomas R. Vale and Geraldine R. Vale. Madison Silent Violence: Food, Famine and Peasantry in Northern Nigeria . Michael Watts. Readings in Historic Preservation: Why? What? How? Norman Williams Jr., Edmund Kellogg and Frank Gilbert, eds.  相似文献   

Volatile Organic Compounds in the Po Basin. Part A: Anthropogenic VOCs   总被引：1，自引：0，他引：1  

M.?Steinbacher  J.?Dommen  C.?Ordonez  S.?Reimann  F.?C.?Grüebler  J.?Staehelin  A.?S.?H.?PrevotEmail author 《Journal of Atmospheric Chemistry》2005,51(3):271-291

Measurements of volatile organic compounds (VOCs) were performed in the Po Basin, northern Italy in early summer 1998 within the PIPAPO project as well as in summer 2002 and autumn 2003 within the FORMAT project. During the three campaigns, trace gases and meteorological parameters were measured at a semi-rural station, around 35 km north of the city center of Milan. Low toluene and benzene concentrations and lower toluene to benzene ratios on weekends, on Sundays, and in August enabled the identification of a ‘weekend’ and a ‘vacation’ effect when anthropogenic emissions were lower due to less traffic and reduced industrial activities, respectively. Recurrent nighttime cyclohexane peaks suggested a periodical short-term release of cyclohexane close to the semi-rural sampling site. A multivariate receptor model analysis resulted in the distinction of different characteristic concentration profiles attributed to natural gas, biogenic impact, vehicle exhaust, industrial activities, and a single cyclohexane source.  相似文献   

ON MULTIPLE SOLUTIONS TO A LOW-SPECTRUM MODEL OF OCEANIC CURRENT DRIVEN BY THE BOUNDARY FORCE——THE BIMODALITY OF THE KUROSHIO SOUTH OF JAPAN     

董昌明  陈水明  张庆华  袁业立 《中国海洋湖沼学报》1996,(2)

This low-spectrun medel study on the multiple solutions to a nonlinear quasi-geostrophic ocanic cur-rent equation shows that they depend on the combination of Ro, Re, λ and ε, that the bimedaity of theKuroshio depends strongly on the nonlinear effect represented by Ro and λ, and that its occurrenceprobability is reduced by the dissipation represented by Re and ε. The stability of solutions is discussed indetail with Hurwitz's theory.  相似文献