Internal tides generated upon two-dimensional Gaussian topographies of different sizes and steepness are investigated theoretically in a numerical methodology.Compared with previous theoretical works,this model is not...Internal tides generated upon two-dimensional Gaussian topographies of different sizes and steepness are investigated theoretically in a numerical methodology.Compared with previous theoretical works,this model is not restricted by weak topography,but provides an opportunity to examine the influence of topography.Ten typical cases are studied using different values of height and/or width of topography.By analyzing the baroclinic velocity fields,as well as their first eight baroclinic modes,it is found that the magnitude of baroclinic velocity increases and the vertical structure becomes increasingly complex as height increases or width decreases.However,when both height and width vary,while parameter s(the ratio of the topographic slope to the characteristic slope of the internal wave ray) remains invariant,the final pattern is influenced primarily by width.The conversion rate is studied and the results indicate that width determines where the conversion rate reaches a peak,and where it is positive or negative,whereas height affects only the magnitude.High and narrow topography is considerably more beneficial to converting energy from barotropic to baroclinic fields than low and wide topography.Furthermore,parameter s,which is an important non-dimensional parameter for internal tide generation,is not the sole parameter by which the baroclinic velocity fields and conversion rate are determined.展开更多
This paper describes the characteristics of the supply chain e-commerce era, understands the concept,content and objectives of supply chain management,and raises supply chain management model,and also analyzes e-comme...This paper describes the characteristics of the supply chain e-commerce era, understands the concept,content and objectives of supply chain management,and raises supply chain management model,and also analyzes e-commerce supply chain architecture.On the existing architecture,elaborates the build about e-commerce supply chain management system, along with proposing strategic directions of e-commerce supply chain management,including JIT, quick response, efficient customer response, enterprise resource planning and electronic ordering system,and discusses in detail the effects of various policy for the entire e-commerce supply chain management.展开更多
Triplicate waveform modeling is used to resolve SH （Vs） and P （Vp） wave velocity structures in the upper mantle transition zone （TZ） beneath northwestern （NW） Tibet. Focal depth move out stacking is proposed t...Triplicate waveform modeling is used to resolve SH （Vs） and P （Vp） wave velocity structures in the upper mantle transition zone （TZ） beneath northwestern （NW） Tibet. Focal depth move out stacking is proposed to enhance the identification of triplicate phases, and can be used to test consistency of our data. Our results show that the Vs and Vp structures are decorrelated, and that a large Vs jump occurred across the 660-km discontinuity, with a small Vs gradient above it. Conversely, the Vp model is characterized by a relatively small contrast across the discontinuity, accompanied by a high Vp gradient in the TZ. There seem no significant depth anomalies of the 660-kin discontinuity in both models. The seismic structures in TZ beneath NW Tibet are similar to recent studies beneath the central Qiangtang and western Lhasa terrains. Taking the lower TZ structures under India as references, Vs is normal but Vp appears slightly high, and thus a high ratio of Vp/Vs was indicated beneath NW Tibet. Combined results with experiment information from mineral studies, we suggest that the differential anomalies of Vp and Vs can be attributed to a chemical heterogeneity, such as increased A1 content in the lower TZ. Considering the tectonic evolution of Tibet, the chemical heterogeneity may be associated with subduction or detachment of the Tethys oceanic slab.展开更多
基金Supported by the National Natural Science Foundation of China(No.41371496)the National High Technology Research and Development Program of China(863 Program)(No.2013AA122803)the Fundamental Research Funds for the Central Universities(Nos.201262007,201362033)
文摘Internal tides generated upon two-dimensional Gaussian topographies of different sizes and steepness are investigated theoretically in a numerical methodology.Compared with previous theoretical works,this model is not restricted by weak topography,but provides an opportunity to examine the influence of topography.Ten typical cases are studied using different values of height and/or width of topography.By analyzing the baroclinic velocity fields,as well as their first eight baroclinic modes,it is found that the magnitude of baroclinic velocity increases and the vertical structure becomes increasingly complex as height increases or width decreases.However,when both height and width vary,while parameter s(the ratio of the topographic slope to the characteristic slope of the internal wave ray) remains invariant,the final pattern is influenced primarily by width.The conversion rate is studied and the results indicate that width determines where the conversion rate reaches a peak,and where it is positive or negative,whereas height affects only the magnitude.High and narrow topography is considerably more beneficial to converting energy from barotropic to baroclinic fields than low and wide topography.Furthermore,parameter s,which is an important non-dimensional parameter for internal tide generation,is not the sole parameter by which the baroclinic velocity fields and conversion rate are determined.
文摘This paper describes the characteristics of the supply chain e-commerce era, understands the concept,content and objectives of supply chain management,and raises supply chain management model,and also analyzes e-commerce supply chain architecture.On the existing architecture,elaborates the build about e-commerce supply chain management system, along with proposing strategic directions of e-commerce supply chain management,including JIT, quick response, efficient customer response, enterprise resource planning and electronic ordering system,and discusses in detail the effects of various policy for the entire e-commerce supply chain management.
基金supported by the National Natural Science Foundation of China (Grant Nos. 40604009, 40574040, 40704011 and 40974061)
文摘Triplicate waveform modeling is used to resolve SH （Vs） and P （Vp） wave velocity structures in the upper mantle transition zone （TZ） beneath northwestern （NW） Tibet. Focal depth move out stacking is proposed to enhance the identification of triplicate phases, and can be used to test consistency of our data. Our results show that the Vs and Vp structures are decorrelated, and that a large Vs jump occurred across the 660-km discontinuity, with a small Vs gradient above it. Conversely, the Vp model is characterized by a relatively small contrast across the discontinuity, accompanied by a high Vp gradient in the TZ. There seem no significant depth anomalies of the 660-kin discontinuity in both models. The seismic structures in TZ beneath NW Tibet are similar to recent studies beneath the central Qiangtang and western Lhasa terrains. Taking the lower TZ structures under India as references, Vs is normal but Vp appears slightly high, and thus a high ratio of Vp/Vs was indicated beneath NW Tibet. Combined results with experiment information from mineral studies, we suggest that the differential anomalies of Vp and Vs can be attributed to a chemical heterogeneity, such as increased A1 content in the lower TZ. Considering the tectonic evolution of Tibet, the chemical heterogeneity may be associated with subduction or detachment of the Tethys oceanic slab.
