作者：
Zou, Bin;Wilson, J. Gaines;Zhan, F. Benjamin;Zeng, Yongnian
期刊：
Journal of environmental monitoring : JEM,2009年11(3):475-490 ISSN：1464-0325
通讯作者：
Zou, B
作者机构：
[Zeng, Yongnian; Zou, Bin] Cent S Univ, Sch Infophys & Geomat Engn, Changsha 410086, Hunan, Peoples R China.;[Wilson, J. Gaines] Univ Texas Brownsville, Dept Chem & Environm Sci, Brownsville, TX 78520 USA.;[Zou, Bin; Zhan, F. Benjamin] Texas State Univ, Texas Ctr Geog Informat Sci, Dept Geog, San Marcos, TX 78666 USA.;[Zhan, F. Benjamin] Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Zou, B] Cent S Univ, Sch Infophys & Geomat Engn, Changsha 410086, Hunan, Peoples R China.
摘要：
The assessment of personal exposure to air pollution is a critical component of epidemiological studies associating air pollution and health effects. This paper critically reviewed 157 studies over 29 years that utilized one of five categories of exposure methods (proximity, air dispersion, hybrid, human inhalation, and biomarkers). Proximity models were found to be a questionable technique as they assume that closer proximity equates to greater exposure. Inhalation models and biomarker estimates were the most effective in assessing personal exposure, but are often cost prohibitive for large study populations. This review suggests that: (i) factors such as uncertainty, validity, data availability, and transferability related to exposure assessment methods should be considered when selecting a model; and (ii) although an entirely discreet new class of approach is not necessary, significant progress could be made through the development of a 'hybrid' model utilizing the strengths of several existing methods. Future work should systematically evaluate the performance of hybrid models compared to other individual exposure assessment methods utilizing geospatial information technologies (e.g. geographic information systems (GIS) and remote sensing (RS)) to more robustly refine estimates of ambient exposure and quantify the linkages and differences between outdoor, indoor and personal exposure estimates.
作者：
Zhao, Chongbin;Hobbs, B. E.;Hornby, P.;Ord, A.;Peng, Shenglin;Liu, Liangming
期刊：
International Journal for Numerical and Analytical Methods in Geomechanics,2008年32(9):1107-1130 ISSN：0363-9061
通讯作者：
Zhao, CB
作者机构：
[Liu, Liangming; Zhao, Chongbin; Peng, Shenglin] Computational Geosciences Research Centre, Central South University, Changsha 410083, China;[Zhao, Chongbin; Hornby, P.; Hobbs, B. E.; Ord, A.] CSIRO Division of Exploration and Mining, P.O. Box 1130, Bentley, WA 6102, Australia
通讯机构：
[Zhao, CB] Cent S Univ, Computat Geosci Res Ctr, Changsha 410083, Peoples R China.
关键词：
chemical-dissolution;front propagation;porosity feedback effect;reactive transport;numerical simulation;porous media
作者机构：
[ Zhang, Dongliang ; Peng, Jiantang ] School of Geoscience and Info-physics, Central South University, Changsha 410083, China;[ Zhang, Dongliang ; Peng, Jiantang ; Yuan, Shunda ] State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, CAS, Guiyang 550002, China;[ Li, Huimin ; Hao, Shuang ; Geng, Jianzhen ] Tianjin Institute of Geology and Mineral Resources, Tianjin 300170, China;[Yuan, Shunda ] MLR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, CAGS, Beijing 100037, China;[Yuan, Shunda ] State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China
通讯机构：
[Yuan, SD] CAGS, Inst Mineral Resources, MLR Key Lab Metallogeny & Mineral Assessment, Beijing 100037, Peoples R China.
关键词：
Age constraints - Cassiterite - Confidence levels - Hunan province - Hunan province , China - ID-TIMS - In-situ - Isochron age - LA-MC-ICP-MS - South China - U-Pb ages - U-Pb dating - U-Pb geochronology - Weighted mean
摘要：
Interferometric Synthetic Aperture Radar (InSAR) is a powerful technology for observing the Earth surface, especially for mapping the Earth's topography and deformations. InSAR measurements are however often significantly affected by the atmosphere as the radar signals propagate through the atmosphere whose state varies both in space and in time. Great efforts have been made in recent years to better understand the properties of the atmospheric effects and to develop methods for mitigating the effects. This paper provides a systematic review of the work carried out in this area. The basic principles of atmospheric effects on repeat-pass InSAR are first introduced. The studies on the properties of the atmospheric effects, including the magnitudes of the effects determined in the various parts of the world, the spectra of the atmospheric effects, the isotropic properties and the statistical distributions of the effects, are then discussed. The various methods developed for mitigating the atmospheric effects are then reviewed, including the methods that are based on PSInSAR processing, the methods that are based on interferogram modeling, and those that are based on external data such as GPS observations, ground meteorological data, and satellite data including those from the MODIS and MERIS. Two examples that use MODIS and MERIS data respectively to calibrate atmospheric effects on InSAR are also given.
期刊：
GEOCHIMICA ET COSMOCHIMICA ACTA,1991年55(10):2911-2920 ISSN：0016-7037
通讯作者：
GAO, GQ
作者机构：
[LAND, LS; GAO, GQ] CENT S UNIV TECHNOL,DEPT GEOL,CHANGSA 410012,PEOPLES R CHINA.
通讯机构：
[GAO, GQ] UNIV TEXAS,DEPT GEOL SCI,AUSTIN,TX 78713, USA.
摘要：
Isotopic analyses of 227 limestone samples from the Cambro-Ordovician Arbuckle Group, Oklahoma, document slow secular changes in the chemistry of the limestones. From late Cambrian to early Ordovician, the delta-O-18 values of the limestones increase from -10 parts per thousand to -7 parts per thousand (PDB); delta-C-13 values decrease from 0 parts per thousand to -2 parts per thousand (PDB); and Sr-87/Sr-86 ratios decrease from 0.7091 to 0.7088. The light delta-O-18 values suggest that all Arbuckle limestones underwent diagenetic alteration, probably caused by meteoric water recharged during the development of the overlying, pre-middle Ordovician unconformity. The gradual delta-O-18 increase from late Cambrian to early Ordovician reflects reduced O-18 depletion with decreasing burial temperature during alteration, although the presence of additional primary secular delta-O-18 variation cannot be ruled out. The delta-C-13 and Sr-87/Sr-86 variations, in accord with delta-C-13 and Sr-87/Sr-86 variations in the literature, represent primary secular variations. The variations indicate that the delta-C-13 value and Sr-87/Sr-86 ratio of early Paleozoic surface seawater decreased from late Cambrian to early Ordovician. The delta-C-13 variation during this time period seems to correlate with sea-level variation. Specifically, during sea-level fall, an increase in the rate of oxidation of organic matter caused C-13 depletion of inorganic bicarbonate in seawater. As a result, early Ordovician carbonates, probably deposited during the regression stage of the latest Precambrian to latest early Ordovician cycle, became C-13 depleted, relative to late Cambrian carbonates. The decrease of seawater Sr-87/Sr-86 ratio from late Cambrian to early Ordovician may have resulted from decreased riverine Sr input caused by decreased rate of continental weathering.
作者机构：
[Yang Gao] Department of Geomatics Engineering, University of Calgary, Calgary, T2N 1N4, Canada;[Yang Gao] School of Geomatics, Liaoning Technical University, Fuxin, 123000, China;[Changsheng Cai] Department of Surveying and Geo-informatics, Central South University, Changsha, 410083, China
摘要：
A combination of GPS and GLONASS observations can offer improved reliability, availability and accuracy for precise point positioning (PPP). We present and analyze a combined GPS/GLONASS PPP model, including both functional and stochastic components. Numerical comparison and analysis are conducted with respect to PPP based on only GPS or GLONASS observations to demonstrate the benefits of the combined GPS/GLONASS PPP. The observation residuals are analyzed for more appropriate stochastic modeling for observations from different navigation systems. An analysis is also made using different precise orbit and clock products. The performance of the combined GPS/GLONASS PPP is assessed using both static and kinematic data. The results indicate that the convergence time can be significantly reduced with the addition of GLONASS data. The positioning accuracy, however, is not significantly improved by adding GLONASS data if there is a sufficient number of GPS satellites with good geometry.
摘要：
A novel Li3V2(PO4)(3)/C nanofibers composite has been first prepared by a facile and environmentally friendly electrospinning method using NH4VO3, CH3COOLi, poly (4-vinyl) pyridine (PVP) and citric acid aqueous solution as raw materials. The composite is investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and electrochemical tests. The Li3V2(PO4)(3)/C nanofibers composite exhibits excellent cycle performance and good rate capability in the voltage range of 3.0-4.8 V. The composite displays a high discharge capacity of 190 mAh g(-1) (close to theoretical capacity of 197 mAh g(-1)) at 0.1 C (19.7 mA g(-1)). Even at a high-rate of 20 C, the composite presents the discharge capacity of 132 mAh g(-1) and good cycle performance. The outstanding electrochemical performance is attributed to the particular morphology and microstructure of Li3V2(PO4)(3)/C nanofibers composite that dispersive Li3V2(PO4)(3) nanofibers and carbon nanofibers aggregate to form nanofibers composite with mesopores and large surface area. (c) 2013 Elsevier B.V. All rights reserved.
期刊：
Geoscience and Remote Sensing Letters, IEEE,2013年10(3):495-499 ISSN：1545-598X
通讯作者：
Qi, SX
作者机构：
[Tao, Chao] School of Geosciences and Info-Physics, Central South University, Changsha, 410083, China;[Yang, Changcai; Tian, Jinwen; Qi, Shengxiang; Ma, Jie] Institute for Pattern Recognition and Artificial Intelligence, Huazhong University of Science and Technology, Wuhan, 430074, China
摘要：
Infrared small-target detection plays an important role in image processing for infrared remote sensing. In this letter, different from traditional algorithms, we formulate this problem as salient region detection, which is inspired by the fact that a small target can often attract attention of human eyes in infrared images. This visual effect arises from the discrepancy that a small target resembles isotropic Gaussian-like shape due to the optics point spread function of the thermal imaging system at a long distance, whereas background clutters are generally local orientational. Based on this observation, a new robust directional saliency-based method is proposed incorporating with visual attention theory for infrared small-target detection. Experimental results demonstrate that the proposed algorithm outperforms the state-of-the-art methods for real infrared images with various typical complex backgrounds.
作者机构：
[Xu, Cheng-Dong; Wang, Jin-Feng; Hu, Mao-Gui; Zhao, Yu] Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, State Key Lab Resources & Environm Informat Syst, Beijing, Peoples R China.;[Christakos, George] San Diego State Univ, Dept Geog, San Diego, CA 92182 USA.;[Zhao, Yu] Cent S Univ, Sch Geosci & Infophys, Changsha, Hunan, Peoples R China.
通讯机构：
[Wang, JF] Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, State Key Lab Resources & Environm Informat Syst, Beijing, Peoples R China.
摘要：
There has been discrepancies between the daily air quality reports of the Beijing municipal government, observations recorded at the U.S. Embassy in Beijing, and Beijing residents' perceptions of air quality. This study estimates Beijing's daily area PM(2.5) mass concentration by means of a novel technique SPA (Single Point Areal Estimation) that uses data from the single PM(2.5) observation station of the U.S Embassy and the 18 PM(10) observation stations of the Beijing Municipal Environmental Protection Bureau. The proposed technique accounts for empirical relationships between different types of observations, and generates best linear unbiased pollution estimates (in a statistical sense). The technique extends the daily PM(2.5) mass concentrations obtained at a single station (U.S. Embassy) to a citywide scale using physical relations between pollutant concentrations at the embassy PM(2.5) monitoring station and at the 18 official PM(10) stations that are evenly distributed across the city. Insight about the technique's spatial estimation accuracy (uncertainty) is gained by means of theoretical considerations and numerical validations involving real data. The technique was used to study citywide PM(2.5) pollution during the 423-day period of interest (May 10, 2010 to December 6, 2011). Finally, a freely downloadable software library is provided that performs all relevant calculations of pollution estimation.
期刊：
JOURNAL OF SEDIMENTARY PETROLOGY,1991年61(2):161-173 ISSN：0022-4472
通讯作者：
GAO, GQ
作者机构：
[LAND, LS; GAO, GQ] CENT S UNIV TECHNOL,DEPT GEOL,CHANGSHA 410012,PEOPLES R CHINA.
通讯机构：
[GAO, GQ] UNIV TEXAS,DEPT GEOL SCI,AUSTIN,TX 78713, USA.
摘要：
Dolomite in the Early Ordovician Cool Creek Formation of the Arbuckle Group, Slick Hills, SW Oklahoma, occurs as massive bodies in sabkha-like sequences. Petrographically, the dolomite displays euhedral to anhedral (and xenotopic), fine- to coarse-crystalline textures. Chemically, it is characterized by nearly stoichiometric composition (Ca1.01Mg0.99[CO3]2) and low delta-O-18 values (-7.6 to -9.9 parts per thousand, PDB), and has a large range of Sr-87/Sr-86 ratios (0.70843 to 0.70894) relative to associated limestone (0.70879 to 0.70897) and coeval Early Ordovician seawater. The Sr-87/Sr-86 ratios of most (65%) dolomite samples fall in the Sr-87/Sr-86 range of coeval seawater. The distribution of Cool Creek dolomite in sabkha-like sequences, coupled with dominant Sr-87/Sr-86 ratios similar to coeval seawater, suggests that the dolomite probably formed initially in a marine environment during early diagenesis. The low delta-O-18 values of the dolomite, however, indicate considerable burial modification. Correlations between texture and geochemistry, as well as among various parameters (Sr, Fe, delta-O-18, and Sr-87/Sr-86), demonstrate that dolomite samples with increased modification are characterized by coarser textures, lower Sr and higher Fe concentrations, and lower delta-O-18 values and Sr-87/Sr-86 ratios. These correlations, along with geochemical comparison with associated limestone, not only suggest that the dolomite was modified by fluids depleted in O-18, but also indicate that the lower Sr-87/Sr-86 ratios of many (35%) dolomite samples relative to Early Ordovician seawater resulted from diagenetic modification. On this basis, we conclude that 1) modification of the dolomite by basin-derived brines can be ruled out, 2) modification by younger seawater, seawater-meteoric mixtures, and fluids derived from early compaction of younger shales is possible, but 3) the dolomite seems most likely to have undergone long-lasting modification by meteoric water which gained low Sr-87/Sr-86 ratios by infiltrating younger carbonates, probably during emergence of the carbonate platform coincident with regional Paleozoic unconformities.
作者：
Feng, GuangCai;Hetland, Eric A.;Ding, XiaoLi;Li, ZhiWei;Zhang, Lei
期刊：
Geophysical Research Letters,2010年37(1) ISSN：0094-8276
通讯作者：
Feng, GC
作者机构：
[Ding, XiaoLi; Feng, GuangCai; Zhang, Lei] Department of Land Surveying and Geo-Informatics, Hong Kong Polytechnic University, Kowloon, Hong Kong;[Li, ZhiWei] Department of Geomatics, Central South University, Changsha 410083, China;[Hetland, Eric A.] Department of Geological Sciences, University of Michigan, Ann Arbor, MI 48109, United States
通讯机构：
[Feng, GC] Hong Kong Polytech Univ, Dept Land Surveying & Geoinformat, Kowloon, Hong Kong, Peoples R China.
摘要：
We infer co-seismic fault slip during the 2008 M-w 7.9 Wenchuan earthquake from interferometric synthetic aperture radar (InSAR) and GPS observations of ground deformation. We use ALOS/PALSAR data from ascending orbits on six tracks, and we do not use data that are strongly affected by ionospheric perturbations. We use a fault model composed of three planar fault segments of the Beichuan fault, and one planar segment representing the parallel Pengguan fault. Maximum thrust-slip is up to 6.7 m near the surface, and occurs in two locations, near Yingxiu in the south and Beichuan in the center of the rupture. Maximum strike-slip is over 4 m, and occurs near Pingtong and Nanba along the northern end of the rupture. We find that the ratio of coseismic thrust-to strike-slip on the Beichuan fault decreases from 1.5 to 0.7 from the SW to the NE. Citation: Feng, G., E. A. Hetland, X. Ding, Z. Li, and L. Zhang (2010), Coseismic fault slip of the 2008 Mw 7.9 Wenchuan earthquake estimated from InSAR and GPS measurements, Geophys. Res. Lett., 37, L01302, doi:10.1029/2009GL041213.
作者机构：
[Zhang, L.; Ding, X. L.] Hong Kong Polytech Univ, Dept Land Surveying & Geoinformat, Kowloon, Hong Kong, Peoples R China.;[Zhu, J. J.; Hu, J.; Sun, Q.; Li, Z. W.] Cent S Univ, Sch Geosci & Infophys, Changsha 410083, Hunan, Peoples R China.
通讯机构：
[Li, ZW] Cent S Univ, Sch Geosci & Infophys, Changsha 410083, Hunan, Peoples R China.
摘要：
One-dimensional measurement along the Line-Of-Sight (LOS) direction has greatly limited the capability of InSAR technique in the investigation of surface displacements and their dynamics. In recent years, great efforts have been made to resolve complete three-dimensional (3-D) displacements from InSAR measurements. This contribution is intended to provide a systematic review of the progress achieved in this field. Based on an analysis of the InSAR LOS measurements, we first cover two commonly used techniques, i.e., Offset-Tracking and multi-aperture InSAR (MAI), with which the surface displacement in the azimuth direction can be measured together with the LOS displacement. Several methods for mapping 3-D displacements using InSAR measurements are subsequently presented and categorized into three groups: (i) combination of multi-pass LOS and azimuth measurements; (ii) integration of InSAR and GPS data; and (iii) prior information assisted approaches. The strengths and weaknesses of each method are analyzed to show the applicability of each method to specific 3-D displacement mapping cases, in hope to provide a useful guidance in choosing a suitable approach accordingly. Finally, suggestions for resolving the challenging issues and outlook of future research are given. (c) 2014 Elsevier B.V. All rights reserved.
期刊：
International Journal for Numerical and Analytical Methods in Geomechanics,2010年34(17):1767-1796 ISSN：0363-9061
通讯作者：
Zhao, C.(chongbin.zhao@iinet.net.au)
作者机构：
[Zhao, Chongbin] Computational Geosciences Research Centre, Central South University, Changsha 410083, China;[Hobbs, B. E.; Ord, A.] CSIRO Division of Exploration and Mining, P. O. Box 1130, Bentley, WA 6102, Australia;[Hobbs, B. E.; Ord, A.] School of Earth and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
通讯机构：
[Zhao, CB] Cent S Univ, Computat Geosci Res Ctr, Changsha 410083, Peoples R China.
关键词：
nonaqueous phase liquid;residual saturation;NAPL dissolution;front instability;reactive mass transport;porous media
摘要：
This paper deals with the theoretical aspects of nonaqueous phase liquid (NAPL)-dissolution-induced instability in two-dimensional fluid-saturated porous media including solute dispersion effects. After some weaknesses associated with the previous work are analyzed and overcome, a comprehensive dimensionless number, known as the Zhao number, is proposed to represent the main driving force and three controlling mechanisms of an NAPL-dissolution system that has a finite domain. The linear stability analysis is carried out to derive the critical value of the comprehensive dimensionless number of the NAPL-dissolution system in a limit case as the ratio of the equilibrium concentration to the density of the NAPL approaches zero. As a result, a theoretical criterion that can be used to assess the instability of planar NAPL-dissolution fronts in two-dimensional fluid-saturated porous media of finite domains has been established. Not only can the present theoretical results be used for the theoretical understanding of the effect of solute dispersion on the instability of an NAPL-dissolution front in the fluid-saturated porous medium of either a finite domain or an infinite domain, but also they can be used as benchmark solutions for verifying numerical methods employed to simulate detailed morphological evolution processes of NAPL-dissolution fronts in two-dimensional fluid-saturated porous media. Copyright (C) 2009 John Wiley & Sons, Ltd.
期刊：
CHEMICAL REVIEWS,2009年109(6):2829-2858 ISSN：0009-2665
通讯作者：
Zhou, SQ
作者机构：
[Solana, J. R.] Applied Physics Department, University of Cantabria, 39005 Santander, Spain;[Zhou, Shiqi] State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083, China;[Zhou, Shiqi] School of Physics Science and Technology, Central South University, Changsha, Hunan 410083, China
通讯机构：
[Zhou, SQ] Cent S Univ, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.
关键词：
Energy systems - Free-energy expansion - Inverse temperatures - Perturbation approach - Perturbation energy - Perturbation theory - Reference systems - Second orders - Simple fluids - Simulation data
摘要：
Significant progress made in the perturbation approach in fluid and fluid-related theories are discussed. Some of the latest advancements in perturbation theories for simple fluids were related to the λ-expansion. The free energy system was expressed as an inverse temperature expansion in one of the equations whose terms were related to fluctuations around the mean perturbation energy calculation in the reference system. Another expression was the basis of the calculation of several of the low-order perturbative terms through computer simulation. A number of researchers also derived one of the most accurate expressions for the second-order term in the free energy expansion. This approximation was found to provide better agreement with the simulation data of F<inf>2</inf>/NkT for the SW fluid.
期刊：
INTERNATIONAL JOURNAL OF GEOGRAPHICAL INFORMATION SCIENCE,2012年26(06):1073-1089 ISSN：1365-8816
通讯作者：
Zou, B
作者机构：
[Troy Sternberg] Univ Oxford, Sch Geog & Environm, Oxford OX1 2JD, England.;[Neng Wan] Univ Nebraska Med Ctr, Dept Hlth Serv Res & Adm, Omaha, NE USA.;[Bin Zou] Cent S Univ, Dept Survey Engn & Geomat, Sch Geosci & Infophys, Changsha, Peoples R China.
通讯机构：
[Zou, B] Cent S Univ, Dept Survey Engn & Geomat, Sch Geosci & Infophys, Changsha, Peoples R China.
关键词：
spatial access;health professional shortage area;health service;GIS;E2SFCA;Gravity model
摘要：
Gravity-based spatial access models have been widely used to estimate spatial access to healthcare services in an attempt to capture the interaction of various factors. However, these models are inadequate in informing health resource allocation work due to their inappropriate assumption of healthcare demand. For the purpose of effective healthcare resource planning, this article proposes a three-step floating catchment area (3SFCA) method to minimize the healthcare-demand overestimation problem. Specifically, a spatial impedance-based competition scheme is incorporated into the enhanced two-step floating catchment area (E2SFCA) method to account for a reasonable model of healthcare supply and demand. A case study of spatial access to primary care physicians along the Austin–San Antonio corridor area in central Texas showed that the proposed method effectively minimizes the overestimation of healthcare demand and reflects a more balanced geographic pattern of spatial access than E2SFCA. In addition, by using an adjusted spatial access index, the 3SFCA method indicates strong potential for identifying health professional shortage areas. The study concludes that 3SFCA is a promising method to provide health professionals and decision makers with useful healthcare accessibility information.
摘要：
The usefulness of gravity-based spatial access models is limited because of the uncertainty introduced by the range of values of the impedance coefficient. To solve this problem, this paper proposes the concept of spatial access ratio (SPAR) derived from the enhanced 2-step floating catchment area (E2SFCA) method - a recent extension of the gravity model - to assess potential spatial access. First, a sensitivity assessment is conducted to verify the effectiveness of SPAR and its advantages in overcoming the uncertainty problem. Then, the E2SFCA method and the shortest travel time method are employed to measure potential spatial access to colorectal cancer (CRC) prevention and treatment services in Texas based on data at the census tract level. The socio-demographic and geographic distributions of potential spatial access to CRC services are also examined. The sensitivity assessment reveals substantial fluctuations in the values of the spatial access index calculated directly by the E2SFCA method under different values of the impedance coefficient. However, the values of SPAR remain stable under different values of the coefficient. A comparative analysis indicates that potential spatial access to primary care physicians (PCPs), CRC screening facilities, and oncologists varied among different racial/ethnic and socioeconomic population groups as well as in different geographic regions in Texas. Non-Hispanic blacks, Asians, and people in affluent areas had a geographical advantage in accessing CRC services than other groups. The urban/rural difference was more obvious and serious than those of different racial/ethnic groups and groups with different socio-economic statuses, as metropolitan residents had more than three times the potential spatial access than isolated rural residents. (C) 2011 Elsevier Ltd. All rights reserved.
作者机构：
[ Fang Wang, Xiao ] Ecole Centrale de Lyon, ICJ, UMR5205, F-69134, France;[ Shih, Frank Y. ] College of Computing Sciences, New Jersey Institute of Technology, Newark, NJ 07102, United States;[ Hong Wang, Xiao ; Qian Zhao, Yu ] School of Geosciences and Info-physics, Central South University, Changsha, Hunan 410083, China
通讯机构：
[Zhao, YQ] Cent S Univ, Sch Geosci & Infophys, Changsha 410083, Hunan, Peoples R China.
关键词：
Adaptive histogram equalization - Anisotropic diffusion filters - Gabor wavelets - Level Set - Region based active contours - Region growing - Retinal vessel segmentations - Retinal vessels segmentations
期刊：
Earth and Planetary Science Letters,2012年349(00):186-197 ISSN：0012-821X
通讯作者：
Sun, Y
作者机构：
[Liu, Jianxin; Sun, Ya] School of Geosciences and Info-Physics, Central South University, Changsha, China;[Niu, Fenglin; Sun, Ya; Liu, Huafeng] Department of Earth Science, Rice University, Houston, TX, United States;[Chen, Youlin] Array Information Technology, Greenbelt, MD, United States
通讯机构：
[Sun, Y] Cent S Univ, Sch Geosci & Infophys, Changsha, Hunan, Peoples R China.
关键词：
SE Tibetan plateau;crustal anisotropy;lower crustal flow;depth varying deformation
摘要：
We analyze a large amount of receiver function data recorded by regional seismic networks of the China Earthquake Administration to estimate crustal structure and deformation beneath the southeast margin of the Tibetan plateau and its surrounding areas. We develop a comprehensive analysis method that facilitates robust extraction of azimuthal seismic anisotropy from receiver function data. The method includes an estimate of fast polarization direction and splitting time by a joint analysis of radial and transverse receiver function data, and an evaluation of measurement reliability by statistical and harmonic analysis. We find significant seismic anisotropy with a splitting time of 0.5-0.9 s beneath the SE margin of the Tibetan plateau. Both the splitting time and fast polarization direction are comparable to those estimated from SKS/SKKS data, suggesting that crustal anisotropy is the main cause of shear wave splitting of the SKS/SKKS wave. This also suggests that deformation in the upper mantle is either weak or predominantly vertical, and is obviously different from the one in the crust. A vertical flow in the upper mantle, combined with the observation of a thin lithosphere beneath the study area, leads to the inference that part of the mantle lithosphere may have been removed and is descending into deep mantle. Stations located in the surrounding areas, on the other hand, exhibit very little to no crustal anisotropy. The estimated Moho depth and Vp/Vs ratio also show a distinct difference between the SE Tibetan plateau and the surrounding regions. Stations on the Tibetan plateau have a Vp/Vs ratio of similar to 1.79, which is substantially higher than those measured at the Yunnan-Guizhou (Yungui) plateau (similar to 1.69). Our observations here are consistent with the scenario that the SE Tibet has been built by lower crustal flow. They also suggest that the mantle lithosphere beneath the margin may have been mechanically decoupled from the upper crust. (C) 2012 Elsevier B.V. All rights reserved.
