Considering the fractal structure of space-time, the scale relativity theory in the topological dimension DT = 2 is built. In such a conjecture, the geodesics of this space-time imply the hydrodynamic model of the qua...Considering the fractal structure of space-time, the scale relativity theory in the topological dimension DT = 2 is built. In such a conjecture, the geodesics of this space-time imply the hydrodynamic model of the quantum mechanics. Subsequently, the gauge gravitational field on a fractal space-time is given. Then, the gauge group, the gauge-covariant derivative, the strength tensor of the gauge field, the gauge-invariant Lagrangean, the field equations of the gauge potentials and the gauge energy-momentum tensor are determined. Finally, using this model, a Reissner- Nordstrom type metric is obtained.展开更多
In this paper,the Symbol Error Rate(SER)performance for Orthogonal Space-Time Block Coded(OSTBC)Orthogonal Frequency Division Multiplexing(OFDM)systems over Nakagami-m fading channels is analysed.A novel closed-form S...In this paper,the Symbol Error Rate(SER)performance for Orthogonal Space-Time Block Coded(OSTBC)Orthogonal Frequency Division Multiplexing(OFDM)systems over Nakagami-m fading channels is analysed.A novel closed-form SER expression is proposed,which incorporates the Gauss hypergeometric function and Appell hypergeometric function into the conventional Probability Density Function(PDF)approach.The proposed exact closed-form SER expression is a generalised solution since it perfectly captures OSTBCOFDM systems’performances when having different antenna configurations that employ various modulation schemes and which experience various fading conditions.Finally,Monte Carlo simulation results are provided to demonstrate the exact match between the simulation results and the proposed analytical expressions.展开更多
Oceanic front, especially Kuroshio front, is an important phenomenon that is of great significance for scientific research, national economy and military uses. However, Kuroshio front to the east of Taiwan （KFETW in ...Oceanic front, especially Kuroshio front, is an important phenomenon that is of great significance for scientific research, national economy and military uses. However, Kuroshio front to the east of Taiwan （KFETW in brief） was rare investigated. In this study, reanalysis method is used to study the KFETW＇s temporal and spatial variability and frontogenesis mechanism. It is found that although surface thermal front to the east of Taiwan is not obvious, there is an all-year strong Kuroshio thermal front called KFETW under the surface. The KFETW is connected to the south section of Kuroshio front in the East China Sea （KFECS in brief） and distributes along the east coastline of Taiwan. The KFETW has multi-scale variation feature. It has significant seasonal signal, and its intensity and width reach their maximum in summer. By using the reanalysis results obtained from this study, frontogenesis and changing mechanisms of the KFETW are discussed. It is found that both the Kuroshio and up-welling to the east of Taiwan can affect this front, and the up-welling may be the predominant factor in KFETW＇s frontogenesis and maintenance mechanism.展开更多
The tritium quantity stored in a steel pressure vessel decreases with time because of helium-3 decay and permeation of tritium into the steel wall of the pressure vessel.Meanwhile,the tritium quantity permeating into ...The tritium quantity stored in a steel pressure vessel decreases with time because of helium-3 decay and permeation of tritium into the steel wall of the pressure vessel.Meanwhile,the tritium quantity permeating into the steel wall also decreases with time due to helium-3 decay and diffusion in and out of the wall of tritium.Tritium and helium-3 in the steel wall will cause hydrogen and helium embrittlement of the wall material,respectively,and thereby change the carrying capacity of the vessel.Taking contemporarily both decay and permeation of tritium within the vessel and decay and diffusion of tritium having permeated into the wall into consideration,the governing equations of tritium and helium-3 contents in the wall were established and solved,and relevant formulas were deduced.Through analytical calculations,curves of tritium and helium-3 contents versus radius and time were theoretically plotted,the contents spatio-temporal distributions laws were obtained,and a law about helium-3 contents distribution in steel wall of a spherical pressure vessel was discovered which was called the law of double helium-3 content.展开更多
Sea ice deformation parameters are important for elucidation of the properties and characteristics of ice-ocean models.Observations of sea ice motion over 11.5 year period(November 1996–April 2008) are used to calcul...Sea ice deformation parameters are important for elucidation of the properties and characteristics of ice-ocean models.Observations of sea ice motion over 11.5 year period(November 1996–April 2008) are used to calculate ice motion divergence and shear rates, and thus, to construct total deformation rate(TDR) estimates with respect to spatial and temporal variability in the Arctic Ocean. Strong sea ice deformation signal(SDS) rates are identified when TDR>0.01 day^(-1), and very strong SDS events,when TDR>0.05 day^(-1). These calculations are based on measurements made by the RADARSAT-1 Geophysical Processer System(RGPS). Statistical analysis of the SDS data suggest the following features:(1) Mean SDS and the SDS probability distributions are larger in "low latitudes" of the Arctic Ocean(less than 80°N) than in "high latitudes"(above 80°N), in both summer and winter;(2) very high SDS probabilities distributions and mean SDS values occur in coastal areas, e.g. the East Siberian Sea, Chukchi Sea and Beaufort Sea;(3) areas with relatively low TDR values, in the range from 0.01 day^(-1) to 0.05 day^(-1), cover much of the Arctic Ocean, in summer and winter;(4) of the entire TDR dataset, 45.89% belong to SDS, with summer the SDS percentage, 59.06%,and the winter SDS percentage, 40.50%. Statistically, the summer mean SDS, SDS percentage and very strong SDS are larger than corresponding values in the winter for each year, and show slight increasing tendencies during the years from 1997 to 2007.These results suggest important constraints for accurate simulations of very strong SDS in ice-ocean models.展开更多
We define the total energy-momenta for(4+1)-dimensional asymptotically anti-de Sitter spacetimes,which comes from the boundary terms at infinity in the integral form of the Weitzenbck formula.Then we prove the positiv...We define the total energy-momenta for(4+1)-dimensional asymptotically anti-de Sitter spacetimes,which comes from the boundary terms at infinity in the integral form of the Weitzenbck formula.Then we prove the positive energy theorem for such spacetimes,following Witten’s original argumentsfor the positive energy theorem in asymptotically flat spacetimes.展开更多
文摘Considering the fractal structure of space-time, the scale relativity theory in the topological dimension DT = 2 is built. In such a conjecture, the geodesics of this space-time imply the hydrodynamic model of the quantum mechanics. Subsequently, the gauge gravitational field on a fractal space-time is given. Then, the gauge group, the gauge-covariant derivative, the strength tensor of the gauge field, the gauge-invariant Lagrangean, the field equations of the gauge potentials and the gauge energy-momentum tensor are determined. Finally, using this model, a Reissner- Nordstrom type metric is obtained.
基金supported by the Fundamental Research Funds for the Central Universities(Dalian Maritime University)under Grants No.2012QN043,No.2011QN116
文摘In this paper,the Symbol Error Rate(SER)performance for Orthogonal Space-Time Block Coded(OSTBC)Orthogonal Frequency Division Multiplexing(OFDM)systems over Nakagami-m fading channels is analysed.A novel closed-form SER expression is proposed,which incorporates the Gauss hypergeometric function and Appell hypergeometric function into the conventional Probability Density Function(PDF)approach.The proposed exact closed-form SER expression is a generalised solution since it perfectly captures OSTBCOFDM systems’performances when having different antenna configurations that employ various modulation schemes and which experience various fading conditions.Finally,Monte Carlo simulation results are provided to demonstrate the exact match between the simulation results and the proposed analytical expressions.
基金supported by grants of the National Basic Research Program of China(No.2007CB816001)the National Natural Science Foundation of China (No.41030854,40906016 and 40906015)
文摘Oceanic front, especially Kuroshio front, is an important phenomenon that is of great significance for scientific research, national economy and military uses. However, Kuroshio front to the east of Taiwan （KFETW in brief） was rare investigated. In this study, reanalysis method is used to study the KFETW＇s temporal and spatial variability and frontogenesis mechanism. It is found that although surface thermal front to the east of Taiwan is not obvious, there is an all-year strong Kuroshio thermal front called KFETW under the surface. The KFETW is connected to the south section of Kuroshio front in the East China Sea （KFECS in brief） and distributes along the east coastline of Taiwan. The KFETW has multi-scale variation feature. It has significant seasonal signal, and its intensity and width reach their maximum in summer. By using the reanalysis results obtained from this study, frontogenesis and changing mechanisms of the KFETW are discussed. It is found that both the Kuroshio and up-welling to the east of Taiwan can affect this front, and the up-welling may be the predominant factor in KFETW＇s frontogenesis and maintenance mechanism.
基金supported by Science and Technology Development Fundation of Academy of Engineering Physics (Grant No2008A0301010)
文摘The tritium quantity stored in a steel pressure vessel decreases with time because of helium-3 decay and permeation of tritium into the steel wall of the pressure vessel.Meanwhile,the tritium quantity permeating into the steel wall also decreases with time due to helium-3 decay and diffusion in and out of the wall of tritium.Tritium and helium-3 in the steel wall will cause hydrogen and helium embrittlement of the wall material,respectively,and thereby change the carrying capacity of the vessel.Taking contemporarily both decay and permeation of tritium within the vessel and decay and diffusion of tritium having permeated into the wall into consideration,the governing equations of tritium and helium-3 contents in the wall were established and solved,and relevant formulas were deduced.Through analytical calculations,curves of tritium and helium-3 contents versus radius and time were theoretically plotted,the contents spatio-temporal distributions laws were obtained,and a law about helium-3 contents distribution in steel wall of a spherical pressure vessel was discovered which was called the law of double helium-3 content.
基金supported by the Global Change Research Program of China (Grant No. 2015CB953901)the National Key Research and Development Program of China (Grant No. 2016YFC1401007)the Canadian Program on Energy Research and Development (OERD), the Office of Naval Research (Code 322, “Arctic and Global Prediction”, Grant Number and Principal Investigator: William Perrie, Grant No. N00014-15-1-2611)
文摘Sea ice deformation parameters are important for elucidation of the properties and characteristics of ice-ocean models.Observations of sea ice motion over 11.5 year period(November 1996–April 2008) are used to calculate ice motion divergence and shear rates, and thus, to construct total deformation rate(TDR) estimates with respect to spatial and temporal variability in the Arctic Ocean. Strong sea ice deformation signal(SDS) rates are identified when TDR>0.01 day^(-1), and very strong SDS events,when TDR>0.05 day^(-1). These calculations are based on measurements made by the RADARSAT-1 Geophysical Processer System(RGPS). Statistical analysis of the SDS data suggest the following features:(1) Mean SDS and the SDS probability distributions are larger in "low latitudes" of the Arctic Ocean(less than 80°N) than in "high latitudes"(above 80°N), in both summer and winter;(2) very high SDS probabilities distributions and mean SDS values occur in coastal areas, e.g. the East Siberian Sea, Chukchi Sea and Beaufort Sea;(3) areas with relatively low TDR values, in the range from 0.01 day^(-1) to 0.05 day^(-1), cover much of the Arctic Ocean, in summer and winter;(4) of the entire TDR dataset, 45.89% belong to SDS, with summer the SDS percentage, 59.06%,and the winter SDS percentage, 40.50%. Statistically, the summer mean SDS, SDS percentage and very strong SDS are larger than corresponding values in the winter for each year, and show slight increasing tendencies during the years from 1997 to 2007.These results suggest important constraints for accurate simulations of very strong SDS in ice-ocean models.
基金supported by National Natural Science Foundation of China(Grant No.11171328)Fundamental Research Funds for the Central Universities of China(Grant No.210274087)
文摘We define the total energy-momenta for(4+1)-dimensional asymptotically anti-de Sitter spacetimes,which comes from the boundary terms at infinity in the integral form of the Weitzenbck formula.Then we prove the positive energy theorem for such spacetimes,following Witten’s original argumentsfor the positive energy theorem in asymptotically flat spacetimes.
