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341.
王潇  杨锴  杨顺军 《地球物理学报》2024,67(4):1546-1569

致力于研究三维TTI介质下的qP波立体层析反演算法.将射线扰动理论应用于三维具有倾斜对称轴的横向各向同性(TTI)介质拟声波程函方程, 导出立体层析所需的三维TTI介质qP波数据空间与三维TTI介质模型空间之间的所有Frechét导数.在通过灵敏度测试验证了相应Frechét导数对于三个各向异性THOMSEN参数的正确性之后, 使用两步法反演策略——即先使用坐标分量和射线参数水平分量(不包括走时)实施初始反演而后再使用所有数据空间分量进行反演, 在三维qP波TTI介质情形下针对三个各向异性THOMSEN参数可以获得理想的反演结果, 为三维qP波TTI介质下透射立体层析的应用做好了理论准备.用一个典型的理论数据算例证实了上述观点.

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342.
A chironomid data-set calibrated to July air temperatures, based on 44 lakes in western Norway, is used to reconstruct mean July air temperatures from late-glacial and early-Holocene fossil chironomid assemblages at Kråkenes Lake. The calibration function is based on Weighted Averaging Partial Least Squares regression and has a root mean square error of prediction (RMSEP) of 1.13 °C, a r2 of 0.69, and a maximum bias of 2.66 °C. All these statistics are based on leave-one-out cross-validation. A calibration function based on summer surface-water temperatures has a poorer performance (RMSEP = 2.22 °C, r2 = 0.30, maximum bias = 5.29 °C). The reconstructed July air temperatures at Kråkenes rise to 10.5 °C soon after deglaciation, are about 11.5 °C in the Allerød, decrease to 9.5-10 °C in the Younger Dryas, and rise rapidly within 15 yrs to 11.5 °C at the onset of the Holocene. There is a two-step rise to 13 °C or more in the early-Holocene. The likely over-estimation of Younger Dryas temperatures and under-estimation of early-Holocene temperatures probably result from the limited temperature range represented by the existing calibration set. The data set is currently being expanded to include lakes with warmer air temperatures (> 14 °C) and with colder air temperatures (< 8 °C).  相似文献   
343.
郁云妹 Gamm.  CH 《地质论评》1994,40(4):354-360
在控制氧逸度和酸度的条件下测定了30℃时钯和铂氯络合物溶解度,将溶解度资料作用,求得它们的氯络合物种类分别为PdCl^2-4和PtCl^2-4,计算了相应反应式的平衡常数及推导了平衡常数与温度从属关系表达式,讨论了实验结果的地质意义。  相似文献   
344.
The Guomangco ophiolitic melange is situated in the middle part of the Shiquanhe- Yongzhu-Jiali ophiolitic melange belt (SYJMB) and possesses all the subunits of a typical Penrose- type ophiolite pseudostratigraphy. The study of the Guomangco ophiolitic melange is very important for investigating the tectonic evolution of the SYJMB. The mafic rocks of this ophiolitic melange mainly include diabases, sillite dikes, and basalts. Geochemical analysis shows that these dikes mostly have E-MORB major and trace element signatures; this is the first time that this has been observed in the SYJMB. The basalts have N-MORB and IAB affinities, and the mineral chemistry of harzburgites shows a composition similar to that of SSZ peridotites, indicating that the Guomangco ophiolitic melange probably originated in a back-arc basin. The Guomangco back-arc basin opened in the Middle Jurassic, which was caused by southward subduction of the Neo-Tethys Ocean in central Tibet. The main spreading of this back-arc basin occurred during the Late Jurassic, and the basalts were formed during this time. With the development of the back-arc basin, the subducted slab gradually retreated, and new mantle convection occurred in the mantle wedge. The recycling may have caused the metasomatized mantle to undergo a high degree of partial melting and to generate E- MORBs in the Early Cretaceous. E-MORB-type dikes probably crystallized from melts produced by about 20%-30% partial melting of a spinel mantle source, which was metasomatized by melts from low-degree partial melting of the subducted slab.  相似文献   
345.
嘎仙蛇绿混杂岩位于新林-嘎仙-吉峰蛇绿混杂岩带中段。岩石主要由镁铁-超镁铁质岩石组成,呈构造岩块的形式与变质细碎屑岩基质混杂产出。对超镁铁质岩系统的岩石学、地球化学和年代学研究结果表明,超镁铁质岩石SiO2含量平均值为44.87%,Mg#平均值为87.06,锆石U-Pb同位素年龄为649.6±4.2 Ma,时代为新元古代。稀土元素配分曲线总体呈平坦型,具有富集型洋脊玄武岩(E-MORB)向洋岛玄武岩(OIB)过渡的趋势。样品亏损Nb、Ta、Ti元素,相对富集Th、U、Zr、Hf元素,具有岛弧岩浆岩的特征。在Nb/Yb-Th/Yb构造环境判别图解中,样品点落入E-MORB和OIB交汇部位。通过与区域构造带岩石组合和地球化学特征对比,认为嘎仙超镁铁岩岩浆源区可能为受俯冲流体交代的富集地幔,属俯冲型(SSZ)蛇绿岩,其就位机制与持续洋内俯冲有关。  相似文献   
346.
西藏白朗县白岗村蛇绿混杂岩中有一罕见的尖晶石石榴子石二辉橄榄岩小岩块,被松软的蛇纹岩化尖晶石二辉橄榄岩包裹其中。岩块中发育有碎基单斜辉石、斜方辉石中出溶单斜辉石、切过出溶单斜辉石的贯入单斜辉石和外来碎粒单斜辉石及钙质辉石+铬尖晶石→钙铁石榴子石相界反应。同时,在岩块和包壳岩石的橄榄石中出现针状硅镁石出溶物。计算这些矿物的温度压力表明,它们的温度压力都处于>800℃,>1.8GPa以上的地幔石榴子石域超高压环境,而且,经历过一个上升→俯冲→上升的"N"字形历程。  相似文献   
347.
348.
349.
略阳县煎茶岭金矿矿体的空间展布规律及找矿方向   总被引:1,自引:0,他引:1  
近几年的生产实践表明,煎茶岭金矿床是属于与超基性岩有密切成因关系的浅成低温热液型矿床。主断裂F145在成矿和成岩中起主导作用;与其相关的次级断裂和羽裂构造则是最重要的容矿构造;矿体的形态、规模及矿石品位的变化与控矿构造的类型、产状和性质的变化密切相关。这一特性决定了矿体在空间的展布特点。这些特点的总结和运用,对指导矿山生产和进一步找矿都具有现实意义。  相似文献   
350.
BOOK REVIEWS     
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   
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