In conjunction with synchronous remotely sensed winds and sea surface temperature （SST）, the spatiotemporal features of the Zhe-Min coastal current （ZMCC）, especially responses of the ZMCC adjacent to Pingtan Isla...In conjunction with synchronous remotely sensed winds and sea surface temperature （SST）, the spatiotemporal features of the Zhe-Min coastal current （ZMCC）, especially responses of the ZMCC adjacent to Pingtan Island （PT） to the wintertime mon- soon relaxation in 2006 and corresponding mechanism are investigated based on the field observations. In situ data are ac- quired from Conductivity-Temperature-Depth （CTD） cruise and Bottom-Mounted Moorings （BMM）, which are conducted during a comprehensive survey for the Chinese Offshore Investigation and Assessment Project in winter 2006. It is revealed that the ZMCC is well mixed vertically in winter 2006. The ZMCC （〈14℃） recedes during the relaxation of the wintertime monsoon and is accompanied by the enhanced northward shift of the warm, saline Taiwan Strait Mixed Water （TSMW, higher than 14~C and is constituted by the Taiwan Strait Warm Water and the Kuroshio Branch Water）. And greatly enhanced south- ward intrusion of the ZMCC can be detected when the wintertime monsoon restores. Correspondingly, the thermal interface bounded by the ZMCC and the TSMW moves in the northwest/southeast direction, leading to periodic warm/cold reversals of the near-seabed temperature adjacent to the PT. By EOF （Empirical Orthogonal Function） analysis of the large-scale wind fields and wavelet power spectrum analysis of the water level, ocean current and the near-seabed temperature, responses of the ZMCC off the PT to wintertime monsoon relaxation are suggested to be attributed mainly to the southward propagating coast- ally trapped waves triggered by the impeding atmospheric fronts. As a result, ocean current and near-seabed temperature demonstrate significant quasi-5 d and quasi-10 d subtidal oscillations. By contrast, the onshore/offshore water accumulation resulted from Ekman advection driven by the local winds has minor contributions.展开更多
In this study, the null-field boundary integral equation method （BIEM） and the image method are used to solve the SH wave scattering problem containing semi-circular canyons and circular tunnels. To fully utilize th...In this study, the null-field boundary integral equation method （BIEM） and the image method are used to solve the SH wave scattering problem containing semi-circular canyons and circular tunnels. To fully utilize the analytical property of Circular geometry, the polar coordinates are used to expand the closed-form fundamental solution to the degenerate kernel, and the Fourier series is also introduced to represent the boundary density. By collocating boundary points to match boundary condition on the boundary, a linear algebraic system is constructed. The unknown coefficients in the algebraic system can be easily determined. In this way, a semi-analytical approach is developed. Following the experience of near-trapped modes in water wave problems of the full plane, the focusing phenomenon and near-trapped modes for the SH wave problem of the half-plane are solved, since the two problems obey the same mathematical model. In this study, it is found that the SH wave problem containing two semi-circular canyons and a circular tunnel has the near-trapped mode and the focusing phenomenon for a special incident angle and wavenumber. In this situation, the amplification factor for the amplitude of displacement is over 300.展开更多
The analytical solutions of the atmospheric internal ship waves induced by three-dimensional terrain are obtained by solving the atmospheric wave equation. The solutions show that the waves consist of the untrapped an...The analytical solutions of the atmospheric internal ship waves induced by three-dimensional terrain are obtained by solving the atmospheric wave equation. The solutions show that the waves consist of the untrapped and trapped parts. The patterns of the diverging wave and transverse wave in the untrapped parts are mainly determined by the shape and orientation of the terrain. This kind of wave may transport the wave energy to the upper atmosphere. The patterns of trapped lee waves are decided by the atmospheric conditions such as stratification, mean wind speeds and wind shear.展开更多
Long waves such as tsunamis can be trapped by islands due to wave refraction,and these trapped waves will cause huge damage even in the sheltered shoreline of the island.That all waves propagating into the topography ...Long waves such as tsunamis can be trapped by islands due to wave refraction,and these trapped waves will cause huge damage even in the sheltered shoreline of the island.That all waves propagating into the topography and finally reaching the coastline are called perfect trapped modes,while any waves escaping from the topography are called leaky modes.Whether these long waves can be trapped is dependent on the depth profile of the island.This paper presents analytic solutions of the ray path for waves propagating into the circular island with power function profiles.Wave height distributions over the island are further investigated based on the principia that crowded rays correspond to large wave height and sparse rays correspond to small wave height.The trapped mechanism for water waves over the island is revealed based on their ray paths.Furthermore,the perfectly trapped criterion is derived,that is,when the slope gradient at the topography toe is greater than twice the ratio of the water depth to the radial distances,all wave rays propagating on the island will finally reach the coastline,and the waves are perfectly trapped.展开更多
We investigate the effect of dipole-dipole interaction on the intrinsic decoherence of a system which consists of two two-level atoms and an optical cavity. The entanglement of the system is calculated by making use o...We investigate the effect of dipole-dipole interaction on the intrinsic decoherence of a system which consists of two two-level atoms and an optical cavity. The entanglement of the system is calculated by making use of concurrence. Our results show that the appropriate choice for the coupling constant Ω of dipole-dipole interaction can restrain the intrinsic deeoherenee of the system. We also find a special phenomenon. No matter what the value of γ is, the concurrence of system slowly increases and cannot exceed 0.71 when Ω= 1.展开更多
A method of solving an ultracold trapped ion at the node of the standing wave laser without rotating wave approximation is proposed and the analytical forms of the eigenfunctions and eigenenergies of the system are pr...A method of solving an ultracold trapped ion at the node of the standing wave laser without rotating wave approximation is proposed and the analytical forms of the eigenfunctions and eigenenergies of the system are presented.展开更多
The ’Trapped-Fetch Wave Model(TFWM)’, which is developed for wave prediction in north Atlantic hurricanes, is applied to typhoon cases in western North Pacific(WNP). The comparison with operational numerical ocean w...The ’Trapped-Fetch Wave Model(TFWM)’, which is developed for wave prediction in north Atlantic hurricanes, is applied to typhoon cases in western North Pacific(WNP). The comparison with operational numerical ocean wind wave prediction system at Korea Meteorological Administration(KMA) is examined. In application to WNP typhoon, the TFWM has shown some advantage against typical operational spectral wave models. Even though the full spectral 3rd generation numerical wave model can provides a reliable wave field prediction, it has little value when the atmospheric model poorly predicts the location and intensity of concerned storms or tropical cyclone. The analysis of TFWM output should lead the forecaster back to a more in-depth examination of the full spectral wave model output, resulting in an improved forecast product. As a supporting guidance tool for marine forecaster, the TFWM has shown its own uniqueness and necessity.展开更多
A switched-mode unit used in electric locomotive generates a strong high frequency conducted electromagnetic interference (EMI),which radiates electromagnetic energy through railway lines.Evaluation of magnetic field ...A switched-mode unit used in electric locomotive generates a strong high frequency conducted electromagnetic interference (EMI),which radiates electromagnetic energy through railway lines.Evaluation of magnetic field using analytical technique based on contour integral is presented,in order to assess the electromagnetic environment around a high-speed railway.Actual railway multiconductor finitely long overhead lines are represented by an infinitely long single line above two-layered earth,whose characteristic is different from homogeneous earth.Owing to the constraint of the GB/T 24338-2009 and the high frequency investigated (a few MHz),only the magnetic fields are examined.The magnetic fields consist of four components:the direct wave,the ideal reflected wave or image wave,the trapped surface wave,and the lateral wave.The calculation results proved that due to the presence of the trapped surface wave,the magnetic field of the observer point on the interface is strongly influenced,when the line is on or closed to the interface.展开更多
Fault zone trapped waves （FZTWs） mainly travel along the fractured fault zone （FZ） which is of low velocity and high attenuation. FZTWs often carry significant information about a fault＇s internal structure, so i...Fault zone trapped waves （FZTWs） mainly travel along the fractured fault zone （FZ） which is of low velocity and high attenuation. FZTWs often carry significant information about a fault＇s internal structure, so it is important to understand their wave field characteristics for FZ structure inversion. Most previous simulations are based on vertical faults, while in this paper we implement the FZTW simulations on vertical or inclined faults and compare their wave fields in both time and frequency domains. The results show that the existence of fault zone and inclined angle of fault can significantly influence the features of waves near faults. In amplitude, a fault zone can generate a larger amplitude of waves. The velocity contrast between two wails of fault may lead to amplification of amplitudes in the low velocity fault wall. In frequency, a fault zone tends to influence the waves in the low frequency range. In a pattern of particle polarization of FZTWs, it tends to be single direction for vertical faults but fork to multiple directions for inclined faults, which might provide a new way to study the fault zone with FZTWs. These conclusions may be valuable for FZ structure inversion, and will enhance the knowledge on near-fault strong ground motions.展开更多
基金supported by National Natural Science Foundation of China(Grant Nos.41176031 and 40806013)Chinese Offshore Physical Oceanography and Marine Meteorology Investigation and Assessment Project(Grant No.908-ZC-I-01)National Basic Research Program of China(Grant No:.2011CB403504).
文摘In conjunction with synchronous remotely sensed winds and sea surface temperature （SST）, the spatiotemporal features of the Zhe-Min coastal current （ZMCC）, especially responses of the ZMCC adjacent to Pingtan Island （PT） to the wintertime mon- soon relaxation in 2006 and corresponding mechanism are investigated based on the field observations. In situ data are ac- quired from Conductivity-Temperature-Depth （CTD） cruise and Bottom-Mounted Moorings （BMM）, which are conducted during a comprehensive survey for the Chinese Offshore Investigation and Assessment Project in winter 2006. It is revealed that the ZMCC is well mixed vertically in winter 2006. The ZMCC （〈14℃） recedes during the relaxation of the wintertime monsoon and is accompanied by the enhanced northward shift of the warm, saline Taiwan Strait Mixed Water （TSMW, higher than 14~C and is constituted by the Taiwan Strait Warm Water and the Kuroshio Branch Water）. And greatly enhanced south- ward intrusion of the ZMCC can be detected when the wintertime monsoon restores. Correspondingly, the thermal interface bounded by the ZMCC and the TSMW moves in the northwest/southeast direction, leading to periodic warm/cold reversals of the near-seabed temperature adjacent to the PT. By EOF （Empirical Orthogonal Function） analysis of the large-scale wind fields and wavelet power spectrum analysis of the water level, ocean current and the near-seabed temperature, responses of the ZMCC off the PT to wintertime monsoon relaxation are suggested to be attributed mainly to the southward propagating coast- ally trapped waves triggered by the impeding atmospheric fronts. As a result, ocean current and near-seabed temperature demonstrate significant quasi-5 d and quasi-10 d subtidal oscillations. By contrast, the onshore/offshore water accumulation resulted from Ekman advection driven by the local winds has minor contributions.
基金Ministry of Science and Technology under Grant No.MOST 103-2815-C-019-003-E to the undergraduate studentthe NSC under Grant No.100-2221-E-019-040-MY3
文摘In this study, the null-field boundary integral equation method （BIEM） and the image method are used to solve the SH wave scattering problem containing semi-circular canyons and circular tunnels. To fully utilize the analytical property of Circular geometry, the polar coordinates are used to expand the closed-form fundamental solution to the degenerate kernel, and the Fourier series is also introduced to represent the boundary density. By collocating boundary points to match boundary condition on the boundary, a linear algebraic system is constructed. The unknown coefficients in the algebraic system can be easily determined. In this way, a semi-analytical approach is developed. Following the experience of near-trapped modes in water wave problems of the full plane, the focusing phenomenon and near-trapped modes for the SH wave problem of the half-plane are solved, since the two problems obey the same mathematical model. In this study, it is found that the SH wave problem containing two semi-circular canyons and a circular tunnel has the near-trapped mode and the focusing phenomenon for a special incident angle and wavenumber. In this situation, the amplification factor for the amplitude of displacement is over 300.
文摘The analytical solutions of the atmospheric internal ship waves induced by three-dimensional terrain are obtained by solving the atmospheric wave equation. The solutions show that the waves consist of the untrapped and trapped parts. The patterns of the diverging wave and transverse wave in the untrapped parts are mainly determined by the shape and orientation of the terrain. This kind of wave may transport the wave energy to the upper atmosphere. The patterns of trapped lee waves are decided by the atmospheric conditions such as stratification, mean wind speeds and wind shear.
基金supported by the National Key Research and Development Program of China(No.2016YFC 1402800)the National Science Fund for Distinguished Young Scholars(No.51425901)+1 种基金the National Natural Science Foundation of China(No.51579090)Innovation Project of Colleges and Universities in Jiangsu Province(No.2015B41814)
文摘Long waves such as tsunamis can be trapped by islands due to wave refraction,and these trapped waves will cause huge damage even in the sheltered shoreline of the island.That all waves propagating into the topography and finally reaching the coastline are called perfect trapped modes,while any waves escaping from the topography are called leaky modes.Whether these long waves can be trapped is dependent on the depth profile of the island.This paper presents analytic solutions of the ray path for waves propagating into the circular island with power function profiles.Wave height distributions over the island are further investigated based on the principia that crowded rays correspond to large wave height and sparse rays correspond to small wave height.The trapped mechanism for water waves over the island is revealed based on their ray paths.Furthermore,the perfectly trapped criterion is derived,that is,when the slope gradient at the topography toe is greater than twice the ratio of the water depth to the radial distances,all wave rays propagating on the island will finally reach the coastline,and the waves are perfectly trapped.
基金Supported by the National Natural Science Foundation of China under Grant No 60667001.
文摘We investigate the effect of dipole-dipole interaction on the intrinsic decoherence of a system which consists of two two-level atoms and an optical cavity. The entanglement of the system is calculated by making use of concurrence. Our results show that the appropriate choice for the coupling constant Ω of dipole-dipole interaction can restrain the intrinsic deeoherenee of the system. We also find a special phenomenon. No matter what the value of γ is, the concurrence of system slowly increases and cannot exceed 0.71 when Ω= 1.
文摘A method of solving an ultracold trapped ion at the node of the standing wave laser without rotating wave approximation is proposed and the analytical forms of the eigenfunctions and eigenenergies of the system are presented.
文摘The ’Trapped-Fetch Wave Model(TFWM)’, which is developed for wave prediction in north Atlantic hurricanes, is applied to typhoon cases in western North Pacific(WNP). The comparison with operational numerical ocean wind wave prediction system at Korea Meteorological Administration(KMA) is examined. In application to WNP typhoon, the TFWM has shown some advantage against typical operational spectral wave models. Even though the full spectral 3rd generation numerical wave model can provides a reliable wave field prediction, it has little value when the atmospheric model poorly predicts the location and intensity of concerned storms or tropical cyclone. The analysis of TFWM output should lead the forecaster back to a more in-depth examination of the full spectral wave model output, resulting in an improved forecast product. As a supporting guidance tool for marine forecaster, the TFWM has shown its own uniqueness and necessity.
基金Project supported by the National Natural Science Foundation of China(Nos.50877070 and 51105331)the Technological Research and Development Programs of the Ministry of Chinese Railways(Nos.2009J006-L and 2010J011-E)
文摘A switched-mode unit used in electric locomotive generates a strong high frequency conducted electromagnetic interference (EMI),which radiates electromagnetic energy through railway lines.Evaluation of magnetic field using analytical technique based on contour integral is presented,in order to assess the electromagnetic environment around a high-speed railway.Actual railway multiconductor finitely long overhead lines are represented by an infinitely long single line above two-layered earth,whose characteristic is different from homogeneous earth.Owing to the constraint of the GB/T 24338-2009 and the high frequency investigated (a few MHz),only the magnetic fields are examined.The magnetic fields consist of four components:the direct wave,the ideal reflected wave or image wave,the trapped surface wave,and the lateral wave.The calculation results proved that due to the presence of the trapped surface wave,the magnetic field of the observer point on the interface is strongly influenced,when the line is on or closed to the interface.
基金sponsored by the Key Basic Scientific Research Program of Institute of Earth Science,CEA(0213241302)
文摘Fault zone trapped waves （FZTWs） mainly travel along the fractured fault zone （FZ） which is of low velocity and high attenuation. FZTWs often carry significant information about a fault＇s internal structure, so it is important to understand their wave field characteristics for FZ structure inversion. Most previous simulations are based on vertical faults, while in this paper we implement the FZTW simulations on vertical or inclined faults and compare their wave fields in both time and frequency domains. The results show that the existence of fault zone and inclined angle of fault can significantly influence the features of waves near faults. In amplitude, a fault zone can generate a larger amplitude of waves. The velocity contrast between two wails of fault may lead to amplification of amplitudes in the low velocity fault wall. In frequency, a fault zone tends to influence the waves in the low frequency range. In a pattern of particle polarization of FZTWs, it tends to be single direction for vertical faults but fork to multiple directions for inclined faults, which might provide a new way to study the fault zone with FZTWs. These conclusions may be valuable for FZ structure inversion, and will enhance the knowledge on near-fault strong ground motions.
