检索结果-南通市图书馆

The gravitational gradient tensor’s invariants and the related boundary conditions

在线全文

学校读者我要写书评

暂无评论

Science china Earth sciences 2010年第5期53卷 781-790页

作者： YU JinHai1,2,3.& ZHAO DongMing4 1 College of Earth Science, Graduate University of Chinese academy of sciences, beijing 100049,{3. 2 institute of Geodesy and geophysics, Chinese academy of sciences, Wuhan 43.077,{3. 3.State Key Laboratory of Astronautic Dynamics, Xi’an 710043.{3. 4 Zhengzhou institute of Surveying and Mapping, Zhengzhou 450052,{3. 1. College of Earth Science Graduate University of Chinese Academy of Sciences Beijing 100049 China2. Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China3. State Key Laboratory of Astronautic Dynamics Xi’an 710043 China4. Zhengzhou Institute of Surveying and Mapping Zhengzhou 450052 China

Here we report new approaches of recovering the Earth gravitational field from GOCE (Gravity field and steady-state Ocean Circulation Explorer) gradiometric data with the help of the gradient tensor’s invariants. Our results only depend on GOCE satellite’s position and gradiometry, in other words, they are completely independent of the satellite attitude. First, starting from the invariants, linearization models are established, which can be referred as the general boundary conditions on the satellite’s orbit. Then, the spherical approximation expressions for the models are derived, and the corresponding solving methods for them are discussed. Furthermore, considering effects of J2-term, the spherical approximation models are improved so that the accuracies of the boundary conditions can be theoretically raised to O ( J 2/2 T), which is approximately equivalent to O(T2). Finally, some arithmetic examples are constructed from EGM96 model based on the derived theories, and the computational results illustrate that the spherical models have accuracies of 10-7 and the order recovering the gravitational field can reach up to 200, and the models with regard to effect of J2-term have accuracies of 10-8 and the order can reach up to 280.

关键词： the Earth’s gravitational field gravitational gravidiometry tensor’s invariant

Integrated precise orbit determination of Shenzhou IV unmanned spacecraft

在线全文

学校读者我要写书评

暂无评论

Science china(Technological sciences) 2004年第5期47卷 518-525页

作者： L Congmin1,2, GU Yidong3. LIN Baojun3.& GUO Jiong3.1. Center for Space Science and Applied Research, Chinese academy of sciences, beijing 100080,{3. 2. Graduate School of the Chinese academy of sciences, beijing 10003.,{3. 3. General Establishment of Space Science and Application, Chinese academy of sciences, beijing 100080,{3. Correspondence should be addressed to L Congmin 1. Center for Space Science and Applied Research Chinese Academy of Sciences 100080 Beijing China 2. Graduate School of the Chinese academy of sciences 100039 Beijing China 3. General Establishment of Space Science and Application Chinese Academy of Sciences 100080 Beijing China

Considering the characteristic orbit of Shenzhou IV spacecraft and the advantages and disadvantages of several types of domestic orbit measurements, a scheme of IPOD is determined, which uses GPS, SLR and USB observation data jointly plus precise ionosphere corrections to GPS observation data. IPOD system and mathematic models of OD are introduced. The results of different joint OD are analyzed using true observation data, and show that radial accuracy is better than 2 m.

关键词： Shenzhou IV unmanned spacecraft integrated precise orbit determination GPS SLR USB.

Monitoring Crustal Movement of the Coastal Zone in Eastern china with GPS Technique

在线全文

学校读者我要写书评

暂无评论

地球科学进展 2004年第S1期19卷 21-29页

作者： DING Ji-xin, YANG Zhi-fa, SHANG Yan-jun (institute of geology and geophysics, Chinese {3. of sciences, beijing 100029, china)

In this paper, various dominating factors affecting crustal movement of the coastal zone in eastern china are analyzed, and major characteristics of crustal movement are summarized. Subduction of the pacific plate and Philippine plate and southeastward "escape" of Qinghai-Tibet plateau are believed to be dominating factors affecting crustal movement of that zone. Undoubtedly, it is a best way to monitor this kind of large-scale crustal movement with GPS technique. The feasibility of monitoring crustal m...

关键词： GPS Coastal zone Eastern china Crustal movement.

Modern microbialites and their environmental signifi-cance,Meiji reef atoll,Nansha (Spratly) Islands,South china Sea

在线全文

学校读者我要写书评

暂无评论

Science china Earth sciences 2008年第4期51卷 608-617页

作者： SHEN JianWei1 & WANG Yue1,2 1 Department of Marine geology, South china Sea institute of Oceanology Key Laboratory of Marginal Sea geology, South china Sea institute of Oceanology and Guangzhou institute of Geochemistry, Chinese academy of sciences, Guangzhou 5103.1, china 2 Graduate University of the Chinese academy of sciences, beijing 100049, china Department of Marine geology South China Sea Institute of Oceanology Guangzhou China Key Laboratory of Marginal Sea geology South China Sea Institute of Oceanology and Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou

Meiji (Mischief) coral atoll, in Nansha (Spratly) Islands, South china Sea, consists of an annular reef rim surrounding a central lagoon. On the atoll rim there are either protuberant 'motu' (small coral patch reefs on the rim of atoll) islets or lower sandy cays that contain modern microbialite deposits on the corals in pinnacles and surrounding bottoms of the atoll. Microbialites, including villiform, hairy, and thin spine growth forms, as well as gelatinous masses, mats and encrustation, developed on coral colonies and atoll rim sediments between 0 and 15 m deep-water settings. The microbialites were produced by natural populations of filamentous cyanobacteria and grew on (1) bulbous corals together with Acropora sp., (2) on massive colonies of Galaxea fascicularis, (3. on dead Montipora digitata, and (4) on dead Acropora teres, some hairy microbialite growing around broken coral branches. This study demonstrates that microbial carbonates are developed in coral reefs of South china Sea and indicates that microbial processes may be important in the construction of modern reef systems. The results have significance in the determination of nature and composition in microorganisms implied in the formation ancient microbialites, and permit evaluation of the importance of microbial deposits in mo-dern coral reefs and of 'microbialites' in biogeochemical cycles of modern coral reef systems. The re-sults also provide evidence of modern analogues for ancient microbialites in shallow-water settings, and combine with sedimentological studies of ancient microbialites to understand their controls.

关键词： Microbialite Meiji reef Nansha Island South china Sea

Effects of the Biot and the squirt-flow coupling interaction on anisotropic elastic waves

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2000年第23期45卷 2130-2138页

作者： YANG Dinghui & ZHANG Zhongjie Department of Mathematical sciences, Tsinghua University, beijing 100084, china {3. of geophysics, Chinese academy of sciences, beijing 100101, china Department of Mathematical sciences Tsinghua University Beijing China institute of geophysics Chinese Academy of Sciences Beijing China

Considering the velocity anisotropy of the solid/fluid relative motion and employment of the BISQ theory based on the one-dimensional porous isotropic case, we establish a two-phase anisotropic elastic wave equation to simultaneously include the Biot and the squirt mechanisms in terms of both the basic principles of the fluid’s mass conservation and the elastic-wave dynamical equations in the two-phase anisotropic rock. Numerical results, while the Biot-flow and the squirt-flow effects are simultaneously considered in the transversely isotropic (Tl) poroelastic medium, show that the attenuation of the quasi P-wave and the quasi SV-wave strongly depend on the permeability anisotropy, and the attenuation behavior at low and high frequencies is contrary. Meanwhile, the attenuation and dispersion of the quasi P-wave are also affected seriously by the anisotropic solid/fluid coupling additional density.

关键词： two-phase anisotropy Biot flow squirt-flow elastic wave attenuation and dispersion BISQ model.

在线全文

学校读者我要写书评

暂无评论

东濮凹陷油气资源评价问题探讨

石油学报 2003年第4期24卷 17-20,25页

作者：肖斌中国科学院地质与地球物理研究所北京100029

东濮凹陷是一个典型的盐湖沉积盆地 ,特殊的沉积特征决定了其油气资源评价方法的特殊性。根据东濮凹陷生油岩的高温、高压模拟试验资料 ,在一定的温压条件下 ,生油岩的液态窗可能会延长 ,使深部地层的油气资源 ,尤其是液态石油的资源供... 详细信息

东濮凹陷是一个典型的盐湖沉积盆地 ,特殊的沉积特征决定了其油气资源评价方法的特殊性。根据东濮凹陷生油岩的高温、高压模拟试验资料 ,在一定的温压条件下 ,生油岩的液态窗可能会延长 ,使深部地层的油气资源 ,尤其是液态石油的资源供给量增加。模拟试验资料还表明 ,在高温、高压条件下 ,生油岩的总生烃量会增加 ,其有机碳的转化率最高可达 41%。因此 ,用常规方法计算的资源量偏低 ,应重新测试在高温、高压条件下生油岩的产烃资源 ,准确计算东濮凹陷的资源量。

关键词：东濮凹陷盐湖沉积盆地烃源岩油气资源评价模型

^(40)Ar-^(3.)Ar thermochronology of two ductile shear zones from Yiwulüshan,West Liaoning Region: Age constraints on the Mesozoic tectonic events

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2002年第13期47卷 1113-1118页

作者： ZHANG Xiaohui, LI Tiesheng & PU ZhipingResearch Center of Mineral Resources Exploration, institute of geology and geophysics, Chinese {3. of sciences, beijing 100101, china Guangzhou institute of Geochemistry, Chinese {3. of sciences, Guangzhou 51 Research Center of Mineral Resources Exploration Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China Guangzhou institute of Geochemistry Chinese Academy of Sciences Guangzhou China

Two ductile shear zones trending EW and NNE respectively not only controlled the tectonic framework of the northern North china, but also constrained the geody-namic background for gold mineralization in this region. Field observations and microstructural analyses reveal that the EW trending ductile shear zones are mainly contributed to dextral compressional deformation resulting from top-to-the-southeast oblique thrust shearing, whereas the NNE trending ones are genetically related to sinistral strike-slip and extensional faulting. One sample from the former yielded an 40Ar-3.Ar plateau age of (219±4) Ma (Bi) and two samples from the latter gave 40Ar-3.Ar plateau ages of (116± 2) Ma (Bi) and (127±3. Ma (Bi). These ages provide constraints on the top-to-the-southeast oblique thrusting event occurring in Late Triassic and the sinistral extensional and strike-slip faulting event which occurred in Early Cretaceous.

关键词： 40Ar-3.Ar age biotite ductile shear zone West Liaoning Region.

Genesis of excess argon in phengite and significance of ^(40)Ar-^(3.)Ar age spectra for omphacite:A case study on UHP eclogite of South Dabie Terrain,china

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2000年第15期45卷 1345-1351页

作者： WANG Songshan, GE Ningjie, SANG Haiqing & QIU Ji1. institute of geology and geophysics, Chinese {3. of sciences, beijing 100029, china 2. Department of Earth and Space Science, University of Science and Technology of china, Hefei 23.026, china Correspondence should be addressed to Wang Songshan institute of geology and geophysics Chinese Academy of Sciences Beijing China Department of Earth and Space Science University of Science and Technology of China Hefei China

The Ar-Ar dating of phengite and omphacite in ultrahigh-pressure (UHP) eclogite of Bixiling and Hengchong in the South Dabie Terrain shows that the content range of excess argon is as high as (0.4-1.3.×10 8 mol· g 1. The genesis of the excess argon is discussed. The Ar-Ar age spectra of omphacite could not support the opinion that the UHP metamorphism occurred in Caledon epoch and pre-Caledon epoch.

关键词： South Dabie Terrain ultrahigh-pressure metamorphics phengite omphacite excess argon.

A New SHRIMP Age of the Xiamaling Formation in the North china Plate and Its Geological Significance

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2007年第6期81卷 1103-1109页

作者： GAO Linzhi~(1,*)ZHANG Chuanheng~2 SHI Xiaoying~2 ZHOU Hongrui~2 WANG Ziqiang~2 SONG Biao~(1,3. 1 institute of geology,Chinese academy of Geological {3.,beijing 10003.,china 2 china University of Geo{3.(beijing),beijing 100083.china 3.beijing SHRIMP Central,10003. beijing,china institute of geology Chinese Academy of Geological Sciences Beijing 100037 China

Setting up the hypostratotype of late Precambrian is the main aim of the research on the Meso-and Neoproterozoic in North *** chronostratigraphic position is the key in this study. However,many key horizons have not been calibrated with the high-quality isotopic *** the reported new U-Pb age with the Sensitive High-Resolution Ion Microprobe（SHRIMPⅡ）,a zircon U- Pb age was obtained of the ash bed in the Xiamaling Formation in North china Plate,yielding a weighted mean;Pb/;U age of 13.8±12 *** is the first SHRIMP U-Pb age from the Xiamaling Formation in the North china Plate,and represents the depositing time of the middle part of the Xiamaling *** zircon age plays an important role to understanding geological evolution of the North china Plate during Meso-and Neoproterozoic.

关键词： SHRIMP U-Pb Dating Mesoproterozoic Xiamaling Formation North china Plate