المؤلفون: Gu, Ke, Wang, Shiqi, Zhai, Guangtao, Ma, Siwei, Yang, Xiaokang, Lin, Weisi, Zhang, Wenjun, Gao, Wen

المساهمون: Gu, K, Lin, WS (reprint author), Nanyang Technol Univ, Sch Comp Engn, Singapore 639798, Singapore., Zhai, GT, Yang, XK, Zhang, WJ (reprint author), Shanghai Jiao Tong Univ, Inst Image Commun & Informat Proc, Shanghai 200240, Peoples R China., Wang, SQ, Ma, SW, Gao, W (reprint author), Peking Univ, Sch Elect Engn & Comp Sci, Inst Digital Media, Beijing 100871, Peoples R China., Nanyang Technol Univ, Sch Comp Engn, Singapore 639798, Singapore., Shanghai Jiao Tong Univ, Shanghai 200240, Peoples R China., Shanghai Jiao Tong Univ, Inst Image Commun & Informat Proc, Shanghai 200240, Peoples R China., Peking Univ, Sch Elect Engn & Comp Sci, Inst Digital Media, Beijing 100871, Peoples R China.

المصدر: EI ; SCI

مصطلحات موضوعية: High dynamic range, image quality assessment (IQA), information entropy, no-reference (NR), statistical naturalness, structural preservation, tone mapping, DYNAMIC-RANGE IMAGES, CONTRAST, SCENES, PRESERVATION, SIMILARITY, STATISTICS, VISIBILITY, DOMAIN, MODEL

الوصف: High dynamic range (HDR) imaging techniques have been working constantly, actively, and validly in the fault detection and disease diagnosis in the astronomical and medical fields, and currently they have also gained much more attention from digital image processing and computer vision communities. While HDR imaging devices are starting to have friendly prices, HDR display devices are still out of reach of typical consumers. Due to the limited availability of HDR display devices, in most cases tone mapping operators (TMOs) are used to convert HDR images to standard low dynamic range (LDR) images for visualization. But existing TMOs cannot work effectively for all kinds of HDR images, with their performance largely depending on brightness, contrast, and structure properties of a scene. To accurately measure and compare the performance of distinct TMOs, in this paper develop an effective and efficient no-reference objective quality metric which can automatically assess LDR images created by different TMOs without access to the original HDR images. Our model is shown to be statistically superior to recent full-and no-reference quality measures on the existing tone-mapped image database and a new relevant database built in this work. ; Singapore MoE Tier 1 Project [M4011379, RG141/14]; National Science Foundation of China [61025005, 61371146, 61221001, 61390514] ; SCI(E) ; EI ; ARTICLE ; guke.doctor@gmail.com; sqwang1986@pku.edu.cn; zhaiguangtao@sjtu.edu.cn; swma@pku.edu.cn; xkyang@sjtu.edu.cn; wslin@ntu.edu.sg; zhangwenjun@sjtu.edu.cn; wgao@pku.edu.cn ; 3 ; 432-443 ; 18

العلاقة: IEEE TRANSACTIONS ON MULTIMEDIA.2016,18,(3),432-443.; 1395026; http://hdl.handle.net/20.500.11897/437573Test; WOS:000371931600010

الإتاحة: https://doi.org/20.500.11897/437573Test
https://doi.org/10.1109/TMM.2016.2518868Test
https://hdl.handle.net/20.500.11897/437573Test

المؤلفون: Wang, Linjuan, Xu, Jifeng, Wang, Jianxiang

المساهمون: Wang, JX (reprint author), Peking Univ, Dept Mech & Engn Sci, Coll Engn, State Key Lab Turbulence & Complex Syst, Beijing 100871, Peoples R China., Wang, JX (reprint author), Peking Univ, CAPT, HEDPS, Beijing 100871, Peoples R China., Wang, JX (reprint author), Peking Univ, IFSA Collaborat Innovat Ctr, MoE, Beijing 100871, Peoples R China., Peking Univ, Dept Mech & Engn Sci, Coll Engn, State Key Lab Turbulence & Complex Syst, Beijing 100871, Peoples R China., Beijing Aeronaut Sci & Technol Res Inst, Beijing 100083, Peoples R China., Peking Univ, CAPT, HEDPS, Beijing 100871, Peoples R China., Peking Univ, IFSA Collaborat Innovat Ctr, MoE, Beijing 100871, Peoples R China.

المصدر: SCI

مصطلحات موضوعية: Green's function, Peridynamics, Nonlocality, Integro-differential equation, NONLOCAL VECTOR CALCULUS, LONG-RANGE FORCES, LINEAR ELASTICITY, COMPOSITE, DAMAGE, APPROXIMATION, DIFFUSION, EQUATION, MODEL, BAR

الوصف: We derive the static and dynamic Green's functions for one-, two- and three-dimensional infinite domains within the formalism of peridynamics, making use of Fourier transforms and Laplace transforms. Noting that the one-dimensional and three-dimensional cases have been previously studied by other researchers, in this paper, we develop a method to obtain convergent solutions from the divergent integrals, so that the Green's functions can be uniformly expressed as conventional solutions plus Dirac functions, and convergent nonlocal integrals. Thus, the Green's functions for the two-dimensional domain are newly obtained, and those for the one and three dimensions are expressed in forms different from the previous expressions in the literature. We also prove that the peridynamic Green's functions always degenerate into the corresponding classical counterparts of linear elasticity as the nonlocal length tends to zero. The static solutions for a single point load and the dynamic solutions for a time-dependent point load are analyzed. It is analytically shown that for static loading, the nonlocal effect is limited to the neighborhood of the loading point, and the displacement field far away from the loading point approaches the classical solution. For dynamic loading, due to peridynamic nonlinear dispersion relations, the propagation of waves given by the peridynamic solutions is dispersive. The Green's functions may be used to solve other more complicated problems, and applied to systems that have long-range interactions between material points. ; SCI(E) ; CORRECTION ; 1 ; 95-127 ; 126

العلاقة: JOURNAL OF ELASTICITY.2017,126(1),95-127.; 1911271; http://hdl.handle.net/20.500.11897/476526Test; WOS:000390026600005

الإتاحة: https://doi.org/20.500.11897/476526Test
https://doi.org/10.1007/s10659-016-9602-5Test
https://hdl.handle.net/20.500.11897/476526Test

المؤلفون: Wang, Linjuan, Chen, Yongshuai, Xu, Jifeng, Wang, Jianxiang

المساهمون: Wang, JX (reprint author), Peking Univ, Dept Mech & Engn Sci, Coll Engn, State Key Lab Turbulence & Complex Syst, Beijing 100871, Peoples R China., Peking Univ, Dept Mech & Engn Sci, Coll Engn, State Key Lab Turbulence & Complex Syst, Beijing 100871, Peoples R China., Beijing Aeronaut Sci & Technol Res Inst, Beijing 100083, Peoples R China., Peking Univ, Coll Engn, CAPT HEDPS, MoE, Beijing 100871, Peoples R China., Peking Univ, Coll Engn, IFSA Collaborat Innovat Ctr, MoE, Beijing 100871, Peoples R China.

المصدر: SCI

مصطلحات موضوعية: peridynamics, transmitting boundary conditions, nonlocality, meshfree methods, PERFECTLY MATCHED LAYER, LONG-RANGE FORCES, SIMULATIONS, DYNAMICS, MODEL, ELASTICITY, CONTINUUM, COMPOSITE, FRACTURE, BAR

الوصف: The peridynamic theory reformulates the equations of continuum mechanics in terms of integro-differential equations instead of partial differential equations. It is not straightforward to apply the available artificial boundary conditions for continua to peridynamic modeling. We therefore develop peridynamic transmitting boundary conditions (PTBCs) for 1D wave propagation. Differently from the previous method where the matching boundary condition is constructed for only one boundary material point, the PTBCs are established by considering the interaction and exchange of information between a group of boundary material points and another group of inner material points. The motion of the boundary material points is recursively constructed in terms of their locations and is determined through matching the peridynamic dispersion relation. The effectiveness of the PTBCs is examined by reflection analyses, numerical tests, and numerical convergent conditions. Furthermore, two-way interfacial conditions are proposed. The PTBCs are then applied to simulations of wave propagation in a bar with a defect, a composite bar with interfaces, and a domain with a seismic source. All the analyses and applications demonstrate that the PTBCs can effectively remove undesired numerical reflections at artificial boundaries. The methodology may be applied to modeling of wave propagation by other nonlocal theories. Copyright (C) 2016 John Wiley & Sons, Ltd. ; National Natural Science Foundation of China [11521202, 11232001]; China Postdoctoral Science Foundation [2014M561539]; Technology Foundation Grant for Selected Overseas Chinese Scholars ; SCI(E) ; ARTICLE ; 4 ; 379-400 ; 110

العلاقة: INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING.2017,110(4),379-400.; 1908200; http://hdl.handle.net/20.500.11897/473879Test; WOS:000398799900004

الإتاحة: https://doi.org/20.500.11897/473879Test
https://doi.org/10.1002/nme.5373Test
https://hdl.handle.net/20.500.11897/473879Test

المؤلفون: 武振伟, 李茂枝, 徐莉梅, 汪卫华

المساهمون: Wu, ZW (reprint author), Peking Univ, Sch Phys, Int Ctr Quantum Mat, Beijing 100871, Peoples R China., 北京大学物理学院, 量子材料科学中心, 北京 100871, 中国人民大学物理系,北京,100872, 中国科学院物理研究所,北京,100190

المصدر: SCI ; 万方 ; 知网 ; http://d.g.wanfangdata.com.cn/Periodical_wlxb201717018.aspxTest

مصطلحات موضوعية: 非晶态物质, 金属玻璃, 结构遗传性, amorphous solid, metallic glass, inherited structure, BULK METALLIC GLASSES, MATERIALS SCIENCE, RANGE ORDER, TRANSITION, ALLOYS, FRUSTRATION, PLASTICITY, ADDITIONS, MODEL

الوصف: 非晶态物质广泛存在于人们的日常生活和工业生产活动中,但人们对其原子结构及其结构与性能关系的认识还远不如对晶体材料那样充分.非晶态物质的原子结构不具备空间平移对称性,这使得传统针对晶体材料的实验技术和手段无法直接有效地应用到非晶态物质的结构分析中.用常规的衍射实验数据分析方法并不能直接地观察到非晶态物质的本征结构特征,但这些实验衍射数据往往隐含有极其重要的微观结构信息.本文简要综述了这些衍射数据背后所隐含的与金属玻璃中程序相关的结构信息.研究发现,非晶态物质中的一类隐含序与晶体结构中的球周期序紧密相关,意味着非晶态物质与晶体材料之间在原子结构上存在着非凡的同源性.进一步的研究结果还表明,不同隐含拓扑序之间纠缠的强弱与体系本身的玻璃形成能力存在明显的对应关系,这为衡量金属合金玻璃形成能力强弱的经验规律——混乱原理提供了微观结构上的理解,同时为进一步深入认识和理解非晶态材料衍射数据所隐含的微观结构信息提供了新的分析思路和方法. ; The inherent atomic packing mode of glassy solid is still one of the most interesting and fundamental problems in condensed-matter physics and material science. Although significant progress has been made and provided insights into the atomic-level structure and short-to-medium-range order in glass, the way of leading to the medium-range order is still unclear. Does a universal rule exist in nature to construct a glass structure as what has been discovered for crystals? Is there any connection between glassy and crystalline structures? If so, what does the connection look like and how is the connection related to the properties of the glassy solids? A glassy state is usually obtained through supercooling a liquid fast enough to avoid crystallization. The amorphous nature of glassy solid is experimentally ascertained by X-ray diffraction (XRD), transmission electron microscopy or selected area electron diffraction (SAED). Almost all kinds of glassy solids exhibit similar maze-like SAED patterns without any local lattice fringes and broad diffraction maximum characteristics in XRD data. However, the glassy solids are inherently different in atomic-level structure, demonstrated by their different response behaviors under certain conditions, for example, the diverse annealing-precipitated crystalline-phases, the distinct mechanical strengths and ductilities, and the different thermal stabilities against crystallization. Unfortunately, such a difference in inherent structure among glassy solids cannot be easily differentiated from a trivial analysis of the experimental diffraction data. However, the ...

العلاقة: 物理学报. 2017, 66(17), 261-272.; 1897748; http://hdl.handle.net/20.500.11897/464184Test; WOS:000412842000018

الإتاحة: https://doi.org/20.500.11897/464184Test
https://doi.org/10.7498/aps.66.176405Test
https://hdl.handle.net/20.500.11897/464184Test

المؤلفون: Sun, ZhongHao, Wu, Qiang, Xu, FuRong

المساهمون: Xu, FR (reprint author), Peking Univ, Sch Phys, Beijing 100871, Peoples R China., Peking Univ, Sch Phys, Beijing 100871, Peoples R China.

المصدر: EI ; SCI

مصطلحات موضوعية: RANGE CORRELATIONS, MODEL, ENERGY

الوصف: The influence of short-range correlations in nuclei was investigated with realistic nuclear force. The nucleon-nucleon interaction was renormalized with Vlowk technique and applied to the Green's function calculations. The Dyson equation was reformulated with algebraic diagrammatic constructions. We also analyzed the binding energy of He-4, calculated with chiral potential and CD-Bonn potential. The properties of Green's function with realistic nuclear forces are also discussed. ; National Key Basic Research Program of China [2013CB834402]; National Natural Science Foundation of China [11235001, 11320101004, 11575007] ; SCI(E) ; EI ; ARTICLE ; frxu@pku.edu.cn ; 9 ; 59

العلاقة: SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY.2016,59(9).; 1429330; http://hdl.handle.net/20.500.11897/491456Test; WOS:000381089500006

الإتاحة: https://doi.org/20.500.11897/491456Test
https://doi.org/10.1007/s11433-016-0128-1Test
https://hdl.handle.net/20.500.11897/491456Test

المؤلفون: Shen, Miaogen, Piao, Shilong, Jeong, Su-Jong, Zhou, Liming, Zeng, Zhenzhong, Ciais, Philippe, Chen, Deliang, Huang, Mengtian, Jin, Chun-Sil, Li, Laurent Z. X., Li, Yue, Myneni, Ranga B., Yang, Kun, Zhang, Gengxin, Zhang, Yangjian, Yao, Tandong

المساهمون: Shen, MG (reprint author), Chinese Acad Sci, Inst Tibetan Plateau Res, Beijing 100101, Peoples R China., Chinese Acad Sci, Inst Tibetan Plateau Res, Beijing 100101, Peoples R China., Chinese Acad Sci, Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China., Peking Univ, Coll Urban & Environm Sci, Dept Ecol, Beijing 100871, Peoples R China., CALTECH, Jet Prop Lab, Pasadena, CA 91011 USA., SUNY Albany, Dept Atmospher & Environm Sci, Albany, NY 12222 USA., Univ Versailles St Quentin En Yvelines, Lab Sci Climat & Environm, UMR Commissariat Energie Atom CNRS 1572, F-91191 Gif Sur Yvette, France., Univ Gothenberg, Dept Earth Sci, S-40530 Gothenburg, Sweden., Seoul Natl Univ, Sch Earth & Environm Sci, Seoul 151747, South Korea., Univ Paris 06, CNRS, Lab Meteorol Dynam, F-75252 Paris, France., Boston Univ, Dept Earth & Environm, Boston, MA 02215 USA., Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modeling, Beijing 100101, Peoples R China.

المصدر: SCI ; PubMed

مصطلحات موضوعية: climate change, feedback, evapotranspiration, vegetation, Tibetan Plateau, DIURNAL TEMPERATURE-RANGE, CLIMATE-CHANGE, CONVECTIVE PARAMETERIZATION, ALPINE MEADOW, IMPACTS, MODIS, RADIATION, MODEL, PRECIPITATION, SENSITIVITY

الوصف: In the Arctic, climate warming enhances vegetation activity by extending the length of the growing season and intensifying maximum rates of productivity. In turn, increased vegetation productivity reduces albedo, which causes a positive feedback on temperature. Over the Tibetan Plateau (TP), regional vegetation greening has also been observed in response to recent warming. Here, we show that in contrast to arctic regions, increased growing season vegetation activity over the TP may have attenuated surface warming. This negative feedback on growing season vegetation temperature is attributed to enhanced evapotranspiration (ET). The extra energy available at the surface, which results from lower albedo, is efficiently dissipated by evaporative cooling. The net effect is a decrease in daily maximum temperature and the diurnal temperature range, which is supported by statistical analyses of in situ observations and by decomposition of the surface energy budget. A daytime cooling effect from increased vegetation activity is also modeled from a set of regional weather research and forecasting (WRF) mesoscale model simulations, but with a magnitude smaller than observed, likely because the WRF model simulates a weaker ET enhancement. Our results suggest that actions to restore native grasslands in degraded areas, roughly one-third of the plateau, will both facilitate a sustainable ecological development in this region and have local climate cobenefits. More accurate simulations of the biophysical coupling between the land surface and the atmosphere are needed to help understand regional climate change over the TP, and possible larger scale feedbacks between climate in the TP and the Asian monsoon system. ; Chinese Academy of Sciences [XDB03030404]; National Basic Research Program of China [2013CB956303]; National Natural Science Foundation of China [41125004]; Youth Innovation Promotion Association of the Chinese Academy of Sciences [2015055] ; SCI(E) ; PubMed ; ARTICLE ; shen.miaogen@gmail.com; slpiao@pku.edu.cn ; 30 ...

العلاقة: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA.2015,112,(30),9299-9304.; 1297348; http://hdl.handle.net/20.500.11897/418078Test; WOS:000358656500056

الإتاحة: https://doi.org/20.500.11897/418078Test
https://doi.org/10.1073/pnas.1504418112Test
https://hdl.handle.net/20.500.11897/418078Test

المؤلفون: Shen, Jin, Zhang, Yuanhang, Wang, Xuesong, Li, Jinfeng, Chen, Hao, Liu, Run, Zhong, Liuju, Jiang, Ming, Yue, Dingli, Chen, Duohong, Lv, Wei

المساهمون: Zhang, YH (reprint author), Peking Univ, Coll Environm Sci & Engn, Beijing 100871, Peoples R China., Guangdong Environm Monitoring Ctr, State Environm Protect Key Lab Reg Air Qual Monit, Guangzhou, Guangdong, Peoples R China., Peking Univ, Coll Environm Sci & Engn, Beijing 100871, Peoples R China., China Inst Atom Energy, Dept Radiat Safety, Beijing, Peoples R China.

المصدر: EI ; SCI

مصطلحات موضوعية: Ozone episode, Pearl River Delta, Ozone source apportionment, Ozone sensitivity, Process analysis, LONG-RANGE TRANSPORT, GROUND-LEVEL OZONE, AIR-POLLUTION, HONG-KONG, SENSITIVITY-ANALYSIS, CAMPAIGN, CHINA, MODEL, PRIDE-PRD2004, EMISSIONS

الوصف: The north and east Pearl River Delta (PRD) is usually a clean, upwind area in autumn. Serious ozone pollution there in mid-late October 2008 was first discovered and then analyzed. Trajectory analysis, process analysis, ozone source apportionment technology, and sensitivity analysis were used to study this episode. Under the influence of a weak south wind, the precursors emitted in Guangzhou and Foshan were transported to the north and northeast PRD and formed ozone there, which resulted in high ozone concentration (>100 ppb). As the wind direction later transited to northerly, the precursors in the northeast PRD that originated from the central and west PRD were transported to the south, and caused severe ozone pollution in the southeast PRD. The,ozone contributed by chemical processes reached >20 ppb/h in Jinguowan. More than 40 ppb ozone was contributed by the precursor emission in the central and west PRD during the episode. The ozone concentration was highly sensitive to the precursor emission in the PRD region in the high-ozone situations. This episode showed the complexity of regional pollution in the PRD. When the PRD is controlled by a low air pressure system and then cold air moves from northern China to the south, the risk of ozone pollution in the north and southeast PRD increases. (C) 2015 Elsevier Ltd. All rights reserved. ; Strategic Leading Science & Technology Programme of the Chinese Academy of Sciences [XDB05010500, XDB05020205]; Natural Science Foundation of China [41175102, 41303075, 21190052]; Project on Characteristics of PM2.5 Pollution in Dongguan City and Prevention and Cure Countermeasures; National High Technology Research and Development Program of China [2006AA06A306] ; SCI(E) ; EI ; ARTICLE ; yhzhang@pku.edu.cn ; 852-863 ; 122

العلاقة: ATMOSPHERIC ENVIRONMENT.2015,122,852-863.; 1391781; http://hdl.handle.net/20.500.11897/435751Test; WOS:000367413600089

الإتاحة: https://doi.org/20.500.11897/435751Test
https://doi.org/10.1016/j.atmosenv.2015.03.036Test
https://hdl.handle.net/20.500.11897/435751Test

المؤلفون: Li Na, Ren Heng-Xin, Huang Qing-Hua, Chen Xiao-Fei

المساهمون: Li, N (reprint author), Univ Sci & Technol China, Sch Earth & Space Sci, Hefei 230026, Peoples R China., Univ Sci & Technol China, Sch Earth & Space Sci, Hefei 230026, Peoples R China., Schlumberger China, WesternGeco, Beijing 100015, Peoples R China., Univ Sci & Technol China, Lab Seismol & Phys Earths Interior, Hefei 230026, Peoples R China., Peking Univ, Sch Earth & Space Sci, Beijing 100871, Peoples R China.

المصدر: SCI ; EI

مصطلحات موضوعية: Stratified porous media, Elastic waves, Half-analytical solution, Generalized reflection and transmission method, 2-PHASE SATURATED MEDIUM, GREEN-FUNCTION, DYNAMIC POROELASTICITY, IRREGULAR INTERFACES, MULTILAYERED MEDIA, FREQUENCY RANGE, HALF-SPACE, PROPAGATION, EQUATIONS, MODEL

الوصف: Theory of propagation of elastic waves in porous media has extensive application in many important areas, e. g. geophysical exploration, earthquake engineering, and geotechnical dynamics. Elastic waves in porous media are affected by medium properties e. g. porosity, permeability, and fluid viscosity, therefore, research of propagation characteristics of wave fields could be helpful to the analysis and determination of media properties. The Luco-Apsel-Chen (LAC) generalized reflection and transmission method has already affirmed its stability, efficiency, and wide application scope in the research of synthesis of theoretical seismogram. Based on Biot theory and aiming at three-dimensional (3D) stratified porous media, we use the LAC generalized reflection and transmission method to derive an integral expression of half-analytical solution for elastic waves, which could be used to efficiently and accurately compute the theoretical elastic wave fields in porous media by numerical method. This integral expression provides an alternative way for the theoretical research and numerical simulation of propagation characteristics of wave fields in 3D stratified porous media. ; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000338396900020&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Test ; Geochemistry & Geophysics ; SCI(E) ; EI ; 中文核心期刊要目总览(PKU) ; 中国科技核心期刊(ISTIC) ; 中国科学引文数据库(CSCD) ; 2 ; angelinaer0922@gmail.com; renhx@ustc.edu.cn ; 6 ; 1891-1899 ; 57

العلاقة: CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION.2014,57,(6),1891-1899.; 774932; http://hdl.handle.net/20.500.11897/389229Test; WOS:000338396900020

الإتاحة: https://doi.org/20.500.11897/389229Test
https://doi.org/10.6038/cjg20140620Test
https://hdl.handle.net/20.500.11897/389229Test

المؤلفون: Mo, Zhong Jun, Bin Zhao, Yan, Wang, Li Zhen, Sun, Yu, Zhang, Ming, Fan, Yu Bo

المساهمون: Fan, YB (reprint author), Beihang Univ, Sch Biol Sci & Med Engn, Minist Sci & Technol, Int Joint Res Ctr Aerosp Biotechnol & Med Engn, XueYuan Rd 37, Beijing 100191, Peoples R China., Beihang Univ, Sch Biol Sci & Med Engn, Minist Sci & Technol, Int Joint Res Ctr Aerosp Biotechnol & Med Engn, Beijing 100191, Peoples R China., Hong Kong Polytech Univ, Interdisciplinary Div Biomed Engn, Hong Kong, Hong Kong, Peoples R China., Peking Univ, Hosp 3, Dept Orthoped Surg, Beijing 100191, Peoples R China., Beihang Univ, Sch Biol Sci & Med Engn, Minist Sci & Technol, Int Joint Res Ctr Aerosp Biotechnol & Med Engn, XueYuan Rd 37, Beijing 100191, Peoples R China.

المصدر: SCI

مصطلحات موضوعية: Cervical disc arthroplasty, U-shaped implant, Finite element method, Range of motion, Intradiscal pressure, Ligament strain, SPINE, FUSION, FLEXIBILITY, REPLACEMENT, DISKECTOMY, MODEL

الوصف: Various design concepts have been adopted in cervical disc prostheses, including sliding articulation and standalone configuration. This study aimed to evaluate the biomechanical effects of the standalone U-shaped configuration on the cervical spine. Based on an intact finite element model of C3-C7, a standalone U-shaped implant (DCI) was installed at C5-C6 and compared with a sliding articulation design (Prodisc-C) and an anterior fusion system. The range of motion (ROM), adjacent intradiscal pressure (IDP) and capsular ligament strain were calculated under different spinal motions. Compared to the intact configuration, the ROM at C5-C6 was reduced by 90 % after fusion, but increased by 70 % in the Prodisc-C model, while the maximum percentage change in the DCI model was 30 % decrease. At the adjacent segments, up to 32 % increase in ROM happened after fusion, while up to 34 % decrease occurred in Prodisc-C model and 17 % decrease in DCI model. The IDP increased by 11.6 % after fusion, but decreased by 5.6 and 6.3 % in the DCI and Prodisc-C model, respectively. The capsular ligament strain increased by 147 % in Prodisc-C and by 13 % in the DCI model. The DCI implant exhibited a high stress distribution. Spinal fusion resulted in compensatory increase of ROM at the adjacent sites, thereby elevating the IDP. Prodisc-C resulted in hyper-mobility at the operative site that led to an increase of ligament force and strain. The U-shaped implant could maintain the spinal kinematics and impose minimum influence on the adjacent soft tissues, despite the standalone configuration encountering the disadvantages of high stress distribution. ; Clinical Neurology ; Orthopedics ; SCI(E) ; 3 ; ARTICLE ; sunyuor@vip.sina.com; yubofan@buaa.edu.cn ; 3 ; 613-621 ; 23

العلاقة: EUROPEAN SPINE JOURNAL.2014,23,(3),613-621.; 785896; http://hdl.handle.net/20.500.11897/215114Test; WOS:000332604600020

الإتاحة: https://doi.org/20.500.11897/215114Test
https://doi.org/10.1007/s00586-013-3070-4Test
https://hdl.handle.net/20.500.11897/215114Test

المؤلفون: Moriizumi, Jun, Ohkura, Takehisa, Hirao, Shigekazu, Nono, Yuki, Yamazawa, Hiromi, Kim, Yoon-Shin, Gu, Qiuju, Mukai, Hitoshi, Tohjima, Yasunori, Iida, Takao

المساهمون: Moriizumi, J (reprint author), Nagoya Univ, Grad Sch Engn, Nagoya, Aichi 4648603, Japan., Nagoya Univ, Grad Sch Engn, Nagoya, Aichi 4648603, Japan., Hanyang Univ, Inst Environm & Ind Med, Seoul 133791, South Korea., Peking Univ, Dept Tech Phys, Beijing 100871, Peoples R China., Natl Inst Environm Studies, Tsukuba, Ibaraki 3050061, Japan.

المصدر: SCI

مصطلحات موضوعية: radon-222, Rn-222, atmospheric transport, long range transport, tracer, environmental monitoring, monsoon, BOUNDARY-LAYER, VERTICAL-DISTRIBUTION, DECAY PRODUCTS, RADON 222, MODEL, POLLUTANTS, PACIFIC

الوصف: The observation network of atmospheric radon-222 (Rn-222) concentration established in East Asia region is introduced, and the characteristics of the observations at two continental sites Beijing and Seoul and three remote sites Cape Ochiishi, Hachijo Is. and Hateruma Is. are discussed in this paper. Higher levels of Rn-222 concentrations with typical diurnal variation with early morning maxima were observed on the continent, and lower levels with no diurnal variation at remote islands. Seasonal variations with Summer minima and winter maxima were commonly obtained at all five observatories, and they suggested contribution of Rn-222 originated froth the continent to atmospheric Rn-222 over the remote islands isolated in the ocean. A backward trajectory analysis showed clear relationship between variation in wind field and in Rn-222 concentration at Hachijo Is., and proved availability of the observation for analysis of atmospheric transport in East Asia. ; Nuclear Science & Technology ; SCI(E) ; CPCI-S(ISTP) ; 0

العلاقة: JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY.2008/9/1.; 1059366; http://hdl.handle.net/20.500.11897/406604Test; WOS:000269380500036

الإتاحة: https://doi.org/20.500.11897/406604Test
https://hdl.handle.net/20.500.11897/406604Test