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Effects of salinity on methane gas hydrate system

science china {2. sciences 2007年第11期50卷 1733-1745页

作者： YANG DingHui1 & XU WenYue2.1 department of Mathematical sciences, Tsinghua {2., Beijing 100084, china 2.School of earth & Atmospheric sciences, Georgia Institute of technology, Atlanta, GA 30332. USA 1. department of Mathematical sciences Tsinghua University Beijing 100084 China 2. School of earth & Atmospheric sciences Georgia Institute of Technology Atlanta GA 30332 USA

Using an approximately analytical formation, we extend the steady state model of the pure methane hydrate system to include the salinity based on the dynamic model of the methane hydrate system. The top and bottom boundaries of the methane hydrate stability zone (MHSZ) and the actual methane hy-drate zone (MHZ), and the top of free gas occurrence are determined by using numerical methods and the new steady state model developed in this paper. Numerical results show that the MHZ thickness becomes thinner with increasing the salinity, and the stability is lowered and the base of the MHSZ is shifted toward the seafloor in the presence of salts. As a result, the thickness of actual hydrate occur-rence becomes thinner compared with that of the pure water case. On the other hand, since lower solubility reduces the amount of gas needed to form methane hydrate, the existence of salts in sea-water can actually promote methane gas hydrate formation in the hydrate stability zone. Numerical modeling also demonstrates that for the salt-water case the presence of methane within the field of methane hydrate stability is not sufficient to ensure the occurrence of gas hydrate, which can only form when the methane concentration dissolved in solution with salts exceeds the local methane solubility in salt water and if the methane flux exceeds a critical value corresponding to the rate of diffusive methane transport. In order to maintain gas hydrate or to form methane gas hydrate in marine sedi-ments, a persistent supplied methane probably from biogenic or thermogenic processes, is required to overcome losses due to diffusion and advection.

关键词： methane gas hydrate,solubility,stability of hydrate,salinity,phase equilibrium

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MONOTONE COUPLING AND STOCHASTIC ORDERING OF ORDER STATISTICS

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Systems science and Mathematical sciences 1995年第3期8卷 209-214页

作者： HU Taizhong(department of Mathematics, university of science and technology of china,{2., china) 中国科学技术大学数学系安徽合肥

ＭＯＮＯＴＯＮＥＣＯＵＰＬＩＮＧＡＮＤＳＴＯＣＨＡＳＴＩＣＯＲＤＥＲＩＮＧＯＦＯＲＤＥＲＳＴＡＴＩＳＴＩＣＳ￥ＨＵＴａｉｚｈｏｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＵｎｉｖｅｒｓｉｔｙｏｆＳｃｉｅｎｃ... 详细信息

ＭＯＮＯＴＯＮＥＣＯＵＰＬＩＮＧＡＮＤＳＴＯＣＨＡＳＴＩＣＯＲＤＥＲＩＮＧＯＦＯＲＤＥＲＳＴＡＴＩＳＴＩＣＳ￥ＨＵＴａｉｚｈｏｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＵｎｉｖｅｒｓｉｔｙｏｆＳｃｉｅｎｃｅａｎｄＴｅｃｈｎｏｌｏｇｙｏｆＣ...

关键词： Monotone coupling order statistics epidemic.

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Distribution characteristics of terrestrial heat flow density in Jiyang depression of Shengli Oilfield, East china

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science china {2. sciences 2004年第9期47卷 804-812页

作者： GONG Yuling1,2. WANG Liangshu1, LIU Shaowen1, LI Cheng1, HAN Yongbing1, LI Hua1, LIU Bo1 & CAI Jingong3 1. department of earth {2., Nanjing university, Nanjing 2.0093, china 2. department of Exploration and Information technology of East china Institute of technology, Fuzhou 344000, china 3. earth science Institution of Shengli Oilfield, Dongying 2.7015, china department of earth {2. Nanjing University Nanjing 210093 China department of Exploration and Information technology of East{2. Institute of technology Fuzhou 344000 China earth science Institution of Shengli Oilfield Dongying 257015 China

Based on the geo-temperature data of 13 systematically continuous temperature log curves and 700 testing oil boreholes in Jiyang depression, Shengli Oilfield, and the measured thermal conductivities of 47 rock samples, the terrestrial heat flow densities of 114 boreholes of Jiyang depression and its surrounding areas are determined, including 13 of those data derived from systemically continuous temperature logging. The results show that Jiyang depression has a relatively high background heat flow with an average value (65.8 5.4) mW/m2. The lateral variation of heat flow in basin has negative correlation with basement depth. Moreover, heat flow of uplift areas with shallower basement is high, so are those of regions with volcanic rocks, and those of depression areas with deep basement are relatively low. The heat flow densities of different structural units of Jiyang depression can be summarized as follows: The average heat flow value of Zhanhua sag is (67.4 5.3) mW/m2. higher than that of the whole basin, that of Dongying sag is (66.0 6.1) mW/m2. and that of Chezhen sag is (65.1 3.7) mW/m2. It is apparent that these latter two values are approximate to the average value of the whole Jiyang depression, while the average value of Huimin sag is (63.65.0) mW/m2. lower than that of the whole basin. In fact, the basement depth and the distribution framework of uplift and depression areas are all controlled by the process of lithosphere extension. In addition, the distribution of volcanic rocks in basin is also relatively close to this extension geodynamic process. In summary, the distribution characteristics of terrestrial heat flow of Jiyang depression is determined by the Cenozoic tectono-thermal events of this region.

关键词： Jiyang depression, terrestrial heat flow, thermal conductivity.

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On three-dimensional geological modeling and visualization

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science china {2. sciences 2004年第8期47卷 739-748页

作者： WU Qiang1 & XU Hua2.1. department of Resource Exploitation Engineering, china {2. of Mining and technology, Beijing 100083, china 2. Beijing Institute of Petrochemical technology, Beijing 102.17, china 1. department of Resource Exploitation Engineering China University of Mining and Technology 100083 Beijing China 2. Beijing Institute of Petrochemical technology 102617 Beijing China

The technology of 3D geological modeling will bring about great changes in the methods of geological data acquiring, storing, processing and displaying. However, no perfect or convenient software systems have been developed up to now since the geologic data which re-flect geological entities bear the feature of diversity, uncertainty and complexity. Some supervoxel models, mathematical models of fault and geometrical models of fold have been contrived so as to show the space geometric configuration of the complicated geologic structures. The application-oriented system architecture for 3D geological modeling is established; and a novel design concept based on spatial data processing is also proposed with the technology of solid modeling as its core and the application of models as its objective. Theories and methods for 3D geological modeling will hopefully be enriched and developed. In the light of these theories and methods, a feature-based navigation visualization technique is also put forward in the paper. By integrating geo-database, graphics libraries and KBS with 3D dynamic simulation systems, geologists will be able to capture the partial characteristics and whole structure embodied in the geological data in a direct-viewing, figurative and accurate manner.

关键词： 3D geological modeling,geometrical model,system architecture,visualization

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Stratigraphy and TL Dating of Paleolithic Sites in the Luonan Basin,china

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人类学学报 2002年第S1期21卷 67-77页

作者： WANG She jiang(Shaanxi Provincial Institute of Archaeology, Xi’an, P. R. china 710054) HUANG Pei hua(department of {2. and space science, university of science and technology of china, hefei 2.002.)

Between 1995 and 1999 the Longyadong cave site and 50 open air Paleolithic sites were investigated and excavated in the Luonan Basin of china. A total of 1?751 stone artifacts were collected from open air sites, and fossils from about 2. animal species as well as 65?000 lithic artifacts were excavated from the cave site. This paper provides a preliminary study of site lithic stratigraphics in their geological context as well as the results of thermoluminescence (TL) dating. The TL dates of five soil samples place the sites into the middle to late period of the Middle Pleistocene (Q 2.2.3 ). Upon further taking into account strata relationships, three cultural periods were identified in Longyadong cave. When compared with the TL dates and stratigraphy from Zhoukoudian Locality 1, loess deposits in Shaanxi Luochuan, red earth in Anhui and deep sea records, Longyadong is in the range of 500—2.0 kyr, approximately the same timeframe as Zhoukoudian Locality 1.

关键词： Stratigraphy TL dating Paleolithic Longyadong Cave Open air Sites Luonan Basin

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Advanced information feedback strategy in intelligent two-route traffic flow systems

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science china(Information {2.) 2010年第11期53卷 2265-2271页

作者： DONG ChuanFei1,2. MA Xu1,3 & WANG BingHong1,4 1department of Modern Physics and Nonlinear science Center,{2. (USTC), hefei 2.002., china 2.chool of earth and Atmospheric sciences, Georgia Institute of technology, Atlanta, GA 30332. USA 3 department of Physics, Syracuse university, Syracuse, NY 132.4, USA 4The Research Center for Complex System science, university of Shanghai for science and technology and Shanghai Academy of System science, Shanghai 2.0093, china 1. department of Modern Physics and Nonlinear science Center University of Science and Technology of China (USTC) Hefei 230026 China2. School of Earth and Atmospheric Sciences Georgia Institute of Technology Atlanta GA 30332 USA3. Department of Physics Syracuse University Syracuse NY 13244 USA4. The Research Center for Complex System Science University of Shanghai for Science and Technology and Shanghai Academy of System Science Shanghai 200093 China

The optimal information feedback has a significant effect on many socioeconomic systems like stock market and traffic systems aiming to make full use of resources. In this paper, we study dynamics of traffic flow with real-time information. The influence of a feedback strategy named vehicle number feedback strategy (VNFS) is introduced, in which we only calculate the vehicle number of first 500 route sites from the entrance. Moreover, the two-route traffic system has only one entrance and one exit, which is different from those in the previous work. Our model incorporates the effects of adaptability into the cellular automaton models of traffic flow, and simulation results by adopting this optimal information feedback strategy have demonstrated higher efficiency in controlling spatial distribution of traffic patterns than the other three information feedback strategies, i.e., TTFS, MVFS and CCFS.

关键词： vehicle number feedback strategy two-route selecting traffic flow intelligent vehicle cellular automaton model

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Development of environmental monitoring satellite systems in china

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science china {2. sciences 2010年第S1期53卷 1-7页

作者： LI GuoPing1 & CAO ChunXiang2.1 School of earth and space {2.,Peking university,Beijing 100871,china 2.State Key Laboratory of Remote Sensing science,Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of {2. and Beijing Normal university,Beijing 100101,china 1. School of earth and space {2. Peking University Beijing 100871 China2. State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China

With the increase in global environmental problems,the necessity and urgency of remote sensing technology being applied to environmental monitoring has been widely recognized around the *** has launched the environment and disaster monitoring and forecasting small satellite constellation HJ-1A/B and the FY3 atmosphere and environmental satellite,but they still cannot fully satisfy requirements for environmental *** paper summarizes the current status of satellite environmental monitoring in china and the existing problems of inadequate load design and low data utilization efficiency,and discusses the demand for environmental monitoring *** on the development of foreign satellite systems for environmental monitoring,the future development and key tasks of the environmental monitoring satellite system in china is discussed,as are some related initiatives.

关键词： environmental satellite environmental monitoring global climate change specialty load satellite system

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Discovery of a pterodactylid pterosaur from the Yixian Formation of western Liaoning,china

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Chinese science Bulletin 2001年第13期46卷 1112-1117页

作者： WANG Xiaolin & LU Junchang1. Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of sciences, Beijing 100044, china 2. College of {2. sciences and Resources, china university of Geo-sciences, Beijing 100083, china 3. department of Geological sciences, Southern Methodist university, Dallas, TX 752.5, USA Institute of Vertebrate Paleontology Chinese Academy of Sciences Beijing 100044 China

A well-preserved pterosaur with nearly complete skull is described from the Lower Cretaceous Yixian Formation at Sihetun in western Liaoning. It is characterized by a low and long crestless skull, slender and pointed teeth, long metacarpal, nearly equal length of metatarsals I -III and short pedal digit V. It is referred to a new genus and species of the family Pterodactylidae: Haopterus gracilis gen. et sp. nov. This is the first pterosaur with a nearly complete skull from the Jehol Biota; it also represents the first non-controversial fossil record of Pterodactylidae in Asia. Haopterus is more derived than Pterodactylus from the Late Jurassic Solnhofen in Germany. This discovery extends the distribution of the family Pterodactylidae from Europe and Africa to Asia and its latest occurrence from the Late Jurassic to the Early Cretaceous. The discovery of Haopterus gracilis provides further evidence for the study of the originand radiation of the Jehol Biota; it also sheds new light on the evolution and

关键词： western Liaoning Early Cretaceous Yixian Formation Pterodactylidae.

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K-uniformly rotund spaces and k-uniformly smooth spaces

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Chinese science Bulletin 1998年第2期43卷 92-95页

作者： Suyalatu 1 and WU Congxin 2.1. department of Mathematics,Inner Mongolia Normal university, Huhhot 01002.,{2. 2. department of Mathematics, Harbin Institute of technology, Harbin 150006,{2. department of Mathematics Inner Mongolia Normal University Huhhot China department of Mathematics Harbin Institute of Technology Harbin China

The conception of k_uniform smoothness (KUS) is introduced. It is the extension of the conception of uniform smoothness. It is proved that the k_uniform smoothness and Sullivan’s K_uniform rotundity (KUR) are the daul notions. X+* is a KUR space if and only if X is a KUS space, X+* is a KUS space if and only if X is a KUR space. If X is a KUS space, then X is a (K+1)US space. It is also proved that the KUS space includes the Nan’s k_strongly smooth space.

关键词： K_uniform smoothness K_uniform convexity.

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Geodynamic significance of the A-type granites in the Sawuer region in west Junggar, Xinjiang: Rock geochemistry and SHRIMP zircon age evidence

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science china {2. sciences 2006年第2期49卷 113-123页

作者： ZHOU Taofa1, YUAN Feng1, TAN Lugui1,2. FAN Yu1 & YUE Shucang1 1. School of Resources and Environmental Engineering, hefei university of {2., hefei 2.0009, china 2. department of Geography and Environment science, Wanxi College, Liuan 2.7012. china 1. School of Resources and Environmental Engineering Hefei University of Technology Hefei 230009 China 2. department of Geography and Environment science Wanxi College Liuan 237012 China

Sawuer region is located in west Junggar, Jimunai County of Altay district and Hefeng County of Tacheng district, Xinjiang. The region is along the north margin of Kazakstan-Junggar plate. The intrusions (mainly acid) are widespread. Qiaqihai and Kuoyitasi intrusions are important in the region, with the characteristics of A-type granite. Further investigations indicate that they belong to A2.type granite that formed in extension tectonic setting of post collision. The REE chon-drite-normalized patterns of the intrusions show LREE enrichment and the δ Eu values are lower. The Nd, Sr, Pb isotope compositions of the intrusions indicate a mantle source, while the low δ 18O values resulted from the isotope exchange between intrusion and meteoric water. According to SHRIMP U-Pb age analysis results, the crystallization age of Qiaqihai intrusion is 2.0.7 ± 9.3 Ma (1σ ), and that of Kuoyitasi intrusion is 2.7.9 ± 4.6 Ma (1σ ), corresponding to the beginning of early Permian. The A2.type granites indicate that the region was in the extension period of the post-collisional stage at the beginning of early Permian in the Sawuer region. The A-type granites in the Sawuer region in west Junggar discovered from this work is analogous to the A-type granites found in east Junggar of the Ulungur alkali granites belt. The confirmation of post-collisional A-type granites of early Permian in the Sawuer region provides new evidence for the regional vertical continental crust growth in early Per-mian. The former proposed Ulungur alkali granites belt can extend from east Ulungur through west Ulungur and to Zhaisang in Kazakstan westwards.

关键词： A-type granite, zircon, SHRIMP age, post-collision, Junggar, Xinjiang.

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