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A numerical study on nonlinear propagation and short-term variability of the migrating diurnal and semidiurnal tides

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Chinese Science Bulletin 2005年第17期50卷 1940-1948页

作者： HUANG Chunming1,2, ZHANG Shaodong1,2 & YI Fan1,2 1. School of Electronic Information, wuhan Universiy, wuhan 43.079, china 2. Key {3. of geospace environment and geodesy, ministry of education, wuhan University, wuhan 43.079, china School of Electronic Information Wuhan Universiy Wuhan China Key laboratory of geospace environment and {3. Ministry of Education Wuhan University Wuhan China

By using a three-dimensional fully nonlinear numerical model in spherical coordinates and taking the linear steady solutions of the migrating diurnal and semidi-urnal tides in January from the Global-Scale Wave Model (GSWM) as the initial values, we simulate the linear and nonlinear propagations of the migrating diurnal and semidi-urnal tides in the atmosphere from the ground to the lower thermosphere. A comparison of our simulations with the results of GSWM is also presented. The simulation results show that affected by the nonlinearity, the migrating diurnal and semidiurnal tides propagating in the middle and upper atmosphere exhibit evident short-term variability. The nonlinear interactions between the migrating tides and the background atmosphere can obviously alter the background wind and temperature fields, which suggests that the nonlin-ear propagations of the migrating diurnal and semidiurnal tides impact significantly on the transient dynamical and thermal structures of the background middle and upper at-mosphere and the nonlinear effect is an important cause of the difference between the results of GSWM and observa-tions.

关键词：大气非线性传播数学模型可变性温度场

GRACE detection of the medium-to far-field coseismic gravity changes caused by the 2004 Mw9.3.Sumatra-Andaman earthquake

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Earthquake Science 2012年第3期25卷 235-240页

作者： Jin Li1,2,3.and Wenbin Shen1,3.4, 1 Department of Geophysics, School of geodesy and Geomatics, wuhan University, wuhan 43.079,{3. 2 Key laboratory of Geodynamic geodesy of Chinese Academy, wuhan 43.077,{3. 3.Key laboratory of geospace environment and geodesy (ministry of {13.), wuhan University, wuhan 43.079,{3. 4 State Key laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, wuhan 43.079,{3. Department of Geophysics School of Geodesy and Geomatics Wuhan University Wuhan China Key laboratory of Geodynamic geodesy of Chinese Academy Wuhan China Key laboratory of geospace environment and {3. (ministry of education) Wuhan University Wuhan China State Key laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan China

Large earthquakes cause observable changes in the Earth’s gravity field, which have been detected by the Gravity Recovery and Climate Experiment (GRACE). Since most previous studies focus on the detection of near-field gravity effects, this study provides the results from the medium- to far-field gravity changes caused by the 2004 Sumatra-Andaman earthquake that are recorded within GRACE monthly solutions. Utilizing a spherical-earth dislocation model we documented that large-scale signals predominate in the global field of the coseismic gravity changes caused by the earthquake. After removing the near-field effects, the coseismic gravity changes show a negative anomaly feature with an average magnitude of -0.18×10-8 m·s-2 in the region ranging ～40° from the epicenter, which is considered as the 'medium ffield' in this study. From the GRACE data released by Center for Space Research from August 2002 to December 2008, we retrieved the large-scale gravity changes smoothed with 3.000 km Gaussian ffilter. The results show that the coseismic gravity changes detected by GRACE in the medium field have an average of (-0.20±0.06)×10-8 m·s-2, which agrees with the model prediction. The detection confirms that GRACE is sensitive to large-scale medium-field coseismic gravitational effects of mega earthquakes, and also validates the spherical-earth dislocation model in the medium field from the perspective of satellite gravimetry.

关键词： GRACE medium-to far-field coseismic gravity change 2004 Sumatra-Andaman earthquake spherical-Earth dislocation model

Estimation on principal component of multi-collinearity Gauss-Markov model based on minimum description length

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中国有色金属学会会刊：英文版 2005年第S1期15卷 153-155页

作者： SHI Yu-feng~(1, 2) (1. Shandong University of Technology, Zibo 255049, china 2. Key laboratory of geospace {3. and geodesy, ministry of education, wuhan University, wuhan 43.079, china) Shandong Univ Technol Zibo 255049 Peoples R China wuhan Univ Minist Educ Key Lab Geospace Environm & Geodesy Wuhan 430079 Peoples R China

Gauss-Markov model is frequently used in data analysis; the analysis and estimation of its parameters is always a hot issue. Based on the information theory and from the viewpoint of optimal information on description—minimum description length, this paper discusses a case: where there is multi-collinearity in the coefficient matrix, principal component estimation is used to estimate and select the original parameters, so as to reduce its multi-collinearity and improve its credibility. From the viewpoint of minimum description length, this paper discusses the approach of selecting principal components and uses this approach to solve a practical problem.

关键词： minimum description length Gauss-Markov model multi-collinearity principal component estimation

SATELLITE GRAVITY SURVEYING TECHNOLOGY AND RESEARCH OF EARTH’S GRAVITY FIELD

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大地测量与地球动力学 2003年第B12期23卷 1-7页

作者： Ning Jinsheng (The Key laboratory of Geo Space environment and geodesy, {3. of education, wuhan University, wuhan 43.079, china) The Key laboratory of Geo-Space environment and geodesy Ministry of EducationWuhan University Wuhan 430079 China

This is a summarized paper. Two topics are discussed: Firstly, the concept, development and application of four kinds of satellite gravity surveying technology are introduced; Secondly, some problems of theory and method, which must be considered in the study of the \{Earth’s\} gravity field based on satellite gravity data, are expounded.

关键词：卫星重力测量技术地球重力场卫星轨道技术概念技术进展技术应用空中重力测量

Ce Anomalies of the Yangtze Region,South china,through the Ordovician and Silurian Transition

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Journal of Earth Science 2009年第6期20卷 941-948页

作者：严德天张丽琴李双建 Key laboratory of Tectonics and Petroleum Resources of ministry of education China University of GeosciencesWuhan Institute of Geology and Geophysics Chinese Academy of Sciences School of geodesy and Geomatics Wuhan University Key laboratory of geospace environment & {3. of ministry of education Wuhan University Petroleum Exploration and Production Institute of SINOPEC

Systematic Ce anomalies for whole-rock have been obtained from the shale-dominated, continuous, and pelagic sedimentary sequences spanning the Ordovician/Silurian （O/S） boundary at the Tieshui （铁水） of Xiushan （秀山）, Chongqing （重庆）, South china. Ce anomalies across the O/S boundary are recognized in three intervals, Wufeng （五峰）, Guanyinqiao （观音桥） and Longmaxi （龙马溪）. The calculated Ce/Ce＊ values of Wufeng Formation range from 0.84 to 0.96 （avg. 0.90）. In the Guanyinqiao Formation, the values of calculated Ce/Ce＊ range from 0.73.to 0.85 （avg. 0.79）. The Ce/Ce＊ values of uppermost Longmaxi Formation range from 0.87 to 0.96 （avg. 0.91）. All along the section, the magnitude of the Ce anomaly is always negative, but is more significant in the Guanyinqiao Formation. The relatively higher Ce/Ce＊ values in the Wufeng and Longmaxi shales are likely to be due to the sediments deposited under rather reducing conditions. The Ce anomaly apparently does play some regular roles in the anoxic events that accompany prominent mass extinctions, and this work provides new data of critical importance for constraining models on the end-Ordovician anoxic events and mass extinctions.

关键词： Ce anomaly redox mass extinction Ordovician/Silurian boundary Yangtze platform.

Atmospheric correction of HJ-1A/B CCD images over Chinese coastal waters using MODIS-Terra aerosol data

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Science china(Technological Sciences) 2010年第S1期53卷 191-195页

作者： TIAN LiQiao 1,LU JianZhong 1,CHEN XiaoLing 1,2,3.YU ZhiFeng 1,XIAO JingJing 1,QIU Feng 1 & ZHAO Xi 1 1 State Key laboratory of Information Engineering in Surveying,Mapping and Remote Sensing,wuhan University,wuhan {3.,china 2Key laboratory of Poyang Lake Wetland and Watershed Research,ministry of education,Jiangxi Normal University,Nanchang 3.0022,china 3.The Key laboratory of Poyang Lake environment and Resource Utilization,ministry of education,Nanchang University,Nanchang 3.003.,china State Key laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan China Key laboratory of Poyang Lake Wetland and Watershed Research Ministry of Education Jiangxi Normal University Nanchang China The Key laboratory of Poyang Lake environment and Resource Utilization Ministry of Education Nanchang University Nanchang China

This paper demonstrates an atmospheric correction method to process HJ-1A/B CCD images over Chinese coastal waters with the aid of MODIS-Terra aerosol *** on the assumption of zero water-leaving radiance at the two near-infrared (NIR)bands or the shortwave infrared(SWIR)bands,the atmospheric aerosol optical depth(AOD)is firstly retrieved from MODIS-Terra with a simple extension of the NIR-SWIR combined atmospheric correction approach embedded in SeaDAS (SeaWiFS data analysis system).Then the"turbid"and"non-turbid"waters are separated by the turbid water *** probability of AOD at 551 nm band is derived based on the NIR information over"non-turbid"waters and FLAASH model is selected to do the atmospheric correction of the HJ-1A/B CCD imagery using the AOD values of highest probabilities as ***,according to the histogram of the AOD distribution at 551 nm band,the studied turbid water area is divided into several blocks and HJ-1A/B CCD imagery is corrected with the corresponding AOD values displayed with the highest frequency in each *** method has been applied to several HJ-1A/B images over Chinese coastal waters and validated by synchronous in-situ *** results have shown that this method is effective in the atmospheric correction process of HJ-1A/B CCD images for ocean color remote sensing study and application in the coastal waters.

关键词： ocean color remote sensing atmospheric correction turbid coastal waters HJ-1A/B MODIS

Node ordinal encoded genetic algorithm for the optimal allocation of water resources

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Progress in Natural Science:Materials International 2005年第5期15卷 448-452页

作者： YANG Xiaohua1*, YANG Zhifeng 1,2, SHEN Zhenyao1 and LI Jianqiang3.1. State Key laboratory of Water environment Simulation, School of environment, Beijing Normal University, Beijing 100875,{3. 2. Key laboratory for Water and Sediment Sciences ministry of education, School of environment, Beijing Normal University, Beijing 100875,{3. 3. Water Resources and Hydropower Planning and Design General Institute, MWR, Beijing 100011,{3.) State Key Lab. of Water Environ. Simulation Sch. of Environ. Beijing Normal Univ. Beijing 100875 China Key Lab. for Water and Sediment Sci. Min. of Edu. Sch. of Environ. Beijing Normal Univ. Beijing 100875 China Water Resources and Hydropower Planning and Design General Inst. MWR Beijing 100011 China

A new method, node ordinal encoded genetic algorithm (NOEGA), is proposed for solving water resources optimal allocation problems, in which the capacity of water resources is split into a number of smaller parts so that successive operations can be overlapped. Our objective is to maximize the whole benefit function. To overcome the “dimensionality and algorithm complexity curse” while searching for solutions and looking for an optimal solution, the operations of one-point crossover operator, gene exchange operator, gene random operator, gene shift operator and node ordinal strings are established. It is proved to be an effective optimal method in searching for global solutions. The NOEGA does not need a diversity of initial population, and it does not have the problem of immature convergence. The results of two cases show that using NOEGA to solve the optimal allocation model is very efficient and robust. In addition, the algorithm complexity of NOEGA is discussed.

关键词： water resources optimal allocation node ordinal code genetic algorithm.

Sedimentary geochemistry of the Cambrian-Ordovician cherts: Implication on archipelagic ocean of North Qilian orogenic belt

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Science china Earth Sciences 2007年第11期50卷 1628-1644页

作者： DU YuanSheng1,2, ZHU Jie1, GU SongZhu1, 2, XU YaJun1 & YANG JiangHai1 1 Faculty of Earth Sciences, china University of Geosciences, wuhan 43.074, china 2 Key {3. of Biogeology and environment Geology of education ministry, wuhan 43.074, china Faculty of Earth Sciences China University of Geosciences Wuhan China Key laboratory of Biogeology and environment Geology of education {3. Wuhan China

The Caledonian North Qilian orogenic belt lies between the North china plate and the Qaidam mi-croplates, and resulted from the collision among the Qaidam microplate, mid-Qilian block and the North china plate. The orogen initiated from the rifting of the Late Proterozoic Rodinia, and then it experi-enced stages of Cambrian rift basin and Ordovician archipelagic oceanic basin, and foreland basin during Silurian to Early-Middle Devonian. The average ratios of Al/(Al+Fe+Mn), Al/(Al+Fe), δ Ce, Lan/Ybn and Lan/Cen from cherts of Cambrian Heicigou Formation are 0.797, 0.627, 1.114, 0.994 and 1.03. re-spectively. In the NAS standardized REE distribution pattern, the cherts from Xiangqianshan is slightly HREE enriched, and the cherts from Ganluci and Shiqingdong are plane. All of these features indicated that Cambrian cherts of the Heicigou Formation originated from a continental margin rift background. On the contrary, the average ratios of Al/(Al+Fe+Mn), Al/(Al+Fe), δ Ce, Lan/Ybn, Lan/Cen of the Ordovician chert from Dakecha, Cuijiadun, Shihuigou, Laohushan, Heicigou, Maomaoshan, Bianmagou, Da-chadaban, Baiquanmen, Jiugequan and Angzanggou, are respectively 0.72, 0.58, 0.99, 1.09 and 0.96 respectively. Their NAS standardized REE distribution patterns of most Ordovician cherts are plane mode or slightly HREE enriched. The REE distribution pattern of few samples of cherts are slightly LREE enriched. Characteristics of sedimentary geochemistry and tectonic evolution demonstrated that the Cambrian-Ordovician cherts, associated with rift, oceanic, island arc and back-arc volcanic rocks, was not formed in a typical abyssal oceanic basin or mid-oceanic ridge. On the contrary, they formed in a deepwater basin of continental margin or a archipelagic ocean tectonic setting. Several Early Paleo-zoic ophiolite belts in North Qilian and adjacent periphery Qaidam microplate imply that an archipelagic ocean during Ordovician existed in the east of Pro-Tethys.

关键词： North Qilian orogenic belt,Cambrian-Ordovician,cherts sedimentary geochemistry,archipelagic ocean

MULTISCALE MECHANICAL BEHAVIORS IN DISCRETE MATERIALS: A REVIEW

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Acta Mechanica Solida Sinica 2010年第6期23卷 579-591页

作者： Xiaojing Zheng Dengming Wang (Key laboratory of Mechanics on Western Disaster and environment,the ministry of {3. of china,Lanzhou University,Lanzhou 73.000,china) Key laboratory of Mechanics on Western Disaster and environment the Ministry of Education of China Lanzhou University Lanzhou China

The discrete material, which belongs to the category of soft materials, is one of the most prevalent forms of matter in nature and engineering fields. These materials often exhibit abundant and complex mechanical properties which are still far from being perfectly understood. From the view of multi-scale framework concentrated on the ＇bridge＇ role in the macro-micro relation, this review mainly introduces some theoretical investigations of mechanical behaviors in discrete materials, including the continuum constitutive model based on the macroscopic phenomenological approach and coupled micro-macro approach, the statistical analysis of some microscopic physical quantities involved contacted forces between particles and its transmission within the whole system, and the statistical analysis for some microscopic processes in aeolian landform systems involving the grain-bed impact, the transportation and sedimentation of wind-blown sand flux, et al. Finally, some further worthwhile challenges in these fields are suggested.

关键词： discrete material multiple space and time scales trans-scales correlation sanddune statistical analysis