Changes in the water cycle on the Tibetan Plateau(TP)have a significant impact on local agricultural production and livelihoods and its downstream regions.Against the background of widely reported warming and wetting,...Changes in the water cycle on the Tibetan Plateau(TP)have a significant impact on local agricultural production and livelihoods and its downstream regions.Against the background of widely reported warming and wetting,the hydrological cycle has accelerated and the likelihood of extreme weather events and natural disasters occurring(i.e.,snowstorms,floods,landslides,mudslides,and ice avalanches)has also intensified,especially in the highelevation mountainous regions.Thus,an accurate estimation of the intensity and variation of each component of the water cycle is an urgent scientific question for the assessment of plateau environmental changes.Following the transformation and movement of water between the atmosphere,biosphere and hydrosphere,the authors highlight the urgent need to strengthen the three-dimensional comprehensive observation system(including the eddy covariance system;planetary boundary layer tower;profile measurements of temperature,humidity,and wind by microwave radiometers,wind profiler,and radiosonde system;and cloud and precipitation radars)in the TP region and propose a practical implementation plan.The construction of such a three-dimensional observation system is expected to promote the study of environmental changes and natural hazards prevention.展开更多
Any tidal defense engineering involves the collection and analysis of massive information about engineering structures and their surrounding environment. Traditional method, which is carried out mainly by means of two...Any tidal defense engineering involves the collection and analysis of massive information about engineering structures and their surrounding environment. Traditional method, which is carried out mainly by means of twodimensional drawings and textures, is not efficient and intuitive enough to analyze the whole project and reflect its spatial relationship. Three-dimensional visual simulation provides an advanced technical means of solving this problem. In this paper, triangular irregular network (TIN) model simplified by non-uniform rational B-splines (NURBS) technique was used to establish the digital terrain model (DTM) of a super large region. Simulation of dynamic water surface was realized by combining noise function with sine wave superposition method. Models of different objects were established with different modeling techniques according to their characteristics. Application of texture mapping technology remarkably improved the authenticity of the models. Taking the tidal defense engineering in the new coastal region of Tianjin as a case study, three-dimensional visual simulation and dynamic roaming of the study area were realized, providing visual analysis and visible demonstration method for the management and emergency decision-making associated with construction.展开更多
The essential for microseismic monitoring is fast and accurate calculation of seismic wave source location. The precision of most traditional microseismic monitoring processes of mines, using TDOA location method in t...The essential for microseismic monitoring is fast and accurate calculation of seismic wave source location. The precision of most traditional microseismic monitoring processes of mines, using TDOA location method in two-dimensional space to position the microseismic events, as well as the accuracy of positioning microseismic events, may be reduced by the two-dimensional model and simple method, and ill-conditioned equations produced by TDOA location method will increase the positioning error. This article, based on inversion theory, studies the mathematical model of TDOA location method, polariza- tion analysis location method, and comprehensive difference location method of adding angle factor in the traditional TDOA location method. The feasibility of three methods is verified by numerical simulation and analysis of the positioning error of them. The results show that the comprehensive location method of adding angle difference has strong positioning stability and high positioning accuracy, and it may reduce the impact effectively about ill-conditioned equations to positioning results. Comprehensive location method with the data of actual measure may get better positioning results.展开更多
The trend of climate warming and deeper globalization is adding new content to urban risks in Shanghai, resulting in the adaption of traditional comprehensive defense planning to the new environment. Based on the resi...The trend of climate warming and deeper globalization is adding new content to urban risks in Shanghai, resulting in the adaption of traditional comprehensive defense planning to the new environment. Based on the resilient city theory, this paper proposes a transition for Shanghai from an original comprehensive defense to a resilient city vision through strategic framework and approaches from the three aspects of engineering technology, spatial defense, and social governance in the New Normal age. Meanwhile, it suggests that Shanghai should use information technology to enhance the level of risk monitoring and to improve engineering design standards; strengthen the resilience from the scales of "life circle-urban circle-municipal administrative area"; and innovate as well as improve the social safety governance.展开更多
采用秩和比(Runk Sum Ration)综合评价法和相关分析法,对2005-2006赛季CBA常规赛15支球队攻防能力进行量化评价,得出以下结论:(1)CBA参赛队进攻能力分布于3个等级,防守能力分布于4个等级,攻防综合能力分布于5个等级;(2)CBA参赛队在进攻...采用秩和比(Runk Sum Ration)综合评价法和相关分析法,对2005-2006赛季CBA常规赛15支球队攻防能力进行量化评价,得出以下结论:(1)CBA参赛队进攻能力分布于3个等级,防守能力分布于4个等级,攻防综合能力分布于5个等级;(2)CBA参赛队在进攻能力等级相同下,防守能力与常规赛名次正相关;在防守能力等级相同下,进攻能力与常规赛名次不相关。(3)CBA参赛队的攻防能力决定一个队的整体实力与联赛名次;(4)CBA攻防综合能力南区球队强于北区球队;(5)CBA参赛队攻守平衡型球队成绩最好,守强于攻型球队成绩次之,攻强于守型球队成绩最差。展开更多
基金This research was jointly funded by the Second Tibetan Plateau Scientific Expedition and Research Program(Grant Nos.2019QZKK0103 and 2019QZKK0105)the National Natural Science Foundation of China(Grant Nos.91837208 and 42075085).
文摘Changes in the water cycle on the Tibetan Plateau(TP)have a significant impact on local agricultural production and livelihoods and its downstream regions.Against the background of widely reported warming and wetting,the hydrological cycle has accelerated and the likelihood of extreme weather events and natural disasters occurring(i.e.,snowstorms,floods,landslides,mudslides,and ice avalanches)has also intensified,especially in the highelevation mountainous regions.Thus,an accurate estimation of the intensity and variation of each component of the water cycle is an urgent scientific question for the assessment of plateau environmental changes.Following the transformation and movement of water between the atmosphere,biosphere and hydrosphere,the authors highlight the urgent need to strengthen the three-dimensional comprehensive observation system(including the eddy covariance system;planetary boundary layer tower;profile measurements of temperature,humidity,and wind by microwave radiometers,wind profiler,and radiosonde system;and cloud and precipitation radars)in the TP region and propose a practical implementation plan.The construction of such a three-dimensional observation system is expected to promote the study of environmental changes and natural hazards prevention.
基金Supported by Tianjin Research Program of Application Foundation and Advanced Technology (No.12JCZDJC29200)Foundation for Innovative Research Groups of National Natural Science Foundation of China (No.51021004)National Key Technology R&D Program in the 12th Five-Year Plan of China(No.2011BAB10B06)
文摘Any tidal defense engineering involves the collection and analysis of massive information about engineering structures and their surrounding environment. Traditional method, which is carried out mainly by means of twodimensional drawings and textures, is not efficient and intuitive enough to analyze the whole project and reflect its spatial relationship. Three-dimensional visual simulation provides an advanced technical means of solving this problem. In this paper, triangular irregular network (TIN) model simplified by non-uniform rational B-splines (NURBS) technique was used to establish the digital terrain model (DTM) of a super large region. Simulation of dynamic water surface was realized by combining noise function with sine wave superposition method. Models of different objects were established with different modeling techniques according to their characteristics. Application of texture mapping technology remarkably improved the authenticity of the models. Taking the tidal defense engineering in the new coastal region of Tianjin as a case study, three-dimensional visual simulation and dynamic roaming of the study area were realized, providing visual analysis and visible demonstration method for the management and emergency decision-making associated with construction.
文摘The essential for microseismic monitoring is fast and accurate calculation of seismic wave source location. The precision of most traditional microseismic monitoring processes of mines, using TDOA location method in two-dimensional space to position the microseismic events, as well as the accuracy of positioning microseismic events, may be reduced by the two-dimensional model and simple method, and ill-conditioned equations produced by TDOA location method will increase the positioning error. This article, based on inversion theory, studies the mathematical model of TDOA location method, polariza- tion analysis location method, and comprehensive difference location method of adding angle factor in the traditional TDOA location method. The feasibility of three methods is verified by numerical simulation and analysis of the positioning error of them. The results show that the comprehensive location method of adding angle difference has strong positioning stability and high positioning accuracy, and it may reduce the impact effectively about ill-conditioned equations to positioning results. Comprehensive location method with the data of actual measure may get better positioning results.
文摘The trend of climate warming and deeper globalization is adding new content to urban risks in Shanghai, resulting in the adaption of traditional comprehensive defense planning to the new environment. Based on the resilient city theory, this paper proposes a transition for Shanghai from an original comprehensive defense to a resilient city vision through strategic framework and approaches from the three aspects of engineering technology, spatial defense, and social governance in the New Normal age. Meanwhile, it suggests that Shanghai should use information technology to enhance the level of risk monitoring and to improve engineering design standards; strengthen the resilience from the scales of "life circle-urban circle-municipal administrative area"; and innovate as well as improve the social safety governance.
文摘采用秩和比(Runk Sum Ration)综合评价法和相关分析法,对2005-2006赛季CBA常规赛15支球队攻防能力进行量化评价,得出以下结论:(1)CBA参赛队进攻能力分布于3个等级,防守能力分布于4个等级,攻防综合能力分布于5个等级;(2)CBA参赛队在进攻能力等级相同下,防守能力与常规赛名次正相关;在防守能力等级相同下,进攻能力与常规赛名次不相关。(3)CBA参赛队的攻防能力决定一个队的整体实力与联赛名次;(4)CBA攻防综合能力南区球队强于北区球队;(5)CBA参赛队攻守平衡型球队成绩最好,守强于攻型球队成绩次之,攻强于守型球队成绩最差。