An operational ocean circulation-surface wave coupled forecasting system for the seas off China and adjacent areas(OCFS-C) is developed based on parallelized circulation and wave models. It has been in operation sin...An operational ocean circulation-surface wave coupled forecasting system for the seas off China and adjacent areas(OCFS-C) is developed based on parallelized circulation and wave models. It has been in operation since November 1, 2007. In this paper we comprehensively present the simulation and verification of the system, whose distinguishing feature is that the wave-induced mixing is coupled in the circulation model. In particular, with nested technique the resolution in the China's seas has been updated to(1/24)° from the global model with(1/2)°resolution. Besides, daily remote sensing sea surface temperature(SST) data have been assimilated into the model to generate a hot restart field for OCFS-C. Moreover, inter-comparisons between forecasting and independent observational data are performed to evaluate the effectiveness of OCFS-C in upper-ocean quantities predictions, including SST, mixed layer depth(MLD) and subsurface temperature. Except in conventional statistical metrics, non-dimensional skill scores(SS) is also used to evaluate forecast skill. Observations from buoys and Argo profiles are used for lead time and real time validations, which give a large SS value(more than 0.90). Besides, prediction skill for the seasonal variation of SST is confirmed. Comparisons of subsurface temperatures with Argo profiles data indicate that OCFS-C has low skill in predicting subsurface temperatures between 100 m and 150 m. Nevertheless, inter-comparisons of MLD reveal that the MLD from model is shallower than that from Argo profiles by about 12 m, i.e., OCFS-C is successful and steady in MLD predictions. Validation of 1-d, 2-d and 3-d forecasting SST shows that our operational ocean circulation-surface wave coupled forecasting model has reasonable accuracy in the upper ocean.展开更多
Nonlinear features of electron-acoustic shock waves are studied. The Burgers equation is derived and converted to the time fractional Burgers equation by Agrawal's method. Using the Adomian decomposition method, the ...Nonlinear features of electron-acoustic shock waves are studied. The Burgers equation is derived and converted to the time fractional Burgers equation by Agrawal's method. Using the Adomian decomposition method, the shock wave solutions of the time fractional Burgers equation are constructed. The effect of time fractional parameter on the shock wave properties in auroral plasma & investigated.展开更多
Just after the occurrence of an M=5. 2 earthquake in Shimian, Sichuan, two three-component seismometerswere set up near the epicenter of, the earthquake. Field observations were made for the four-year period from1989 ...Just after the occurrence of an M=5. 2 earthquake in Shimian, Sichuan, two three-component seismometerswere set up near the epicenter of, the earthquake. Field observations were made for the four-year period from1989 to 1992. Analysis of the data recorded from either aftershocks following the M=5. 2 earthquake or fromsmall earthquakes scattered in this region indicates the presence of shear wave splitting. And shear wave splittingvaries with ti-cue. The mean direction of polarization of the faster shear waves is N18°W during the pened of aftershock activity, which is consistent with the strike of the faulting plane of the mainshock; but has turned toN46'W from 1990 to 1992, which is consistent with the regional maximum compressive stress. The time delaysbetween split shear waves measured on records from 1990 to 1992 are about half of that in 1989. The results ohtamed from observations at two temporary stations are similar. This indicates that the temporal changes may berelated to the occurrence of the M= 5.2 mainshock.展开更多
Time evaluation of wave functions for any quantum mechanical system/particle is essential nevertheless quantum mechanical counterpart of the time dependant classical wave equation does simply not appear. Epistemologic...Time evaluation of wave functions for any quantum mechanical system/particle is essential nevertheless quantum mechanical counterpart of the time dependant classical wave equation does simply not appear. Epistemologically and ontologically considered time dependant momentum operator is initially defined and an Alternative Time Dependant Schrodinger Wave Equation (ATDSWE) is plainly derived. Consequent equation is primarily solved for the free particles, in a closed system, signifying a good agreement with the outcomes of the ordinary TDSWE. Free particle solution interestingly goes further possibly tracing some signs of new pathways to resolve the mysterious quantum world.展开更多
In this article, some methods are proposed for enhancing the converging velocity of the COA (chaos optimization algorithm) based on using carrier wave two times, which can greatly increase the speed and efficiency of ...In this article, some methods are proposed for enhancing the converging velocity of the COA (chaos optimization algorithm) based on using carrier wave two times, which can greatly increase the speed and efficiency of the first carrier wave’s search for the optimal point in implementing the sophisticated searching during the second carrier wave is faster and more accurate. In addition, the concept of using the carrier wave three times is proposed and put into practice to tackle the multi-variables opti- mization problems, where the searching for the optimal point of the last several variables is frequently worse than the first several ones.展开更多
The travel time of rock compressional waves is an essential parameter used for estimating important rock properties,such as porosity,permeability,and lithology.Current methods,like wireline logging tests,provide broad...The travel time of rock compressional waves is an essential parameter used for estimating important rock properties,such as porosity,permeability,and lithology.Current methods,like wireline logging tests,provide broad measurements but lack finer resolution.Laboratory-based rock core measurements offer higher resolution but are resource-intensive.Conventionally,wireline logging and rock core measurements have been used independently.This study introduces a novel approach that integrates both data sources.The method leverages the detailed features from limited core data to enhance the resolution of wireline logging data.By combining machine learning with random field theory,the method allows for probabilistic predictions in regions with sparse data sampling.In this framework,12 parameters from wireline tests are used to predict trends in rock core data.The residuals are modeled using random field theory.The outcomes are high-resolution predictions that combine both the predicted trend and the probabilistic realizations of the residual.By utilizing unconditional and conditional random field theories,this method enables unconditional and conditional simulations of the underlying high-resolution rock compressional wave travel time profile and provides uncertainty estimates.This integrated approach optimizes the use of existing core and logging data.Its applicability is confirmed in an oil project in West China.展开更多
A fast Time Domain Integral Equation(TDIE) solver is presented for analysis of transient scattering from electrically large conducting complex objects.The numerical process of Marching-On-in-Time(MOT) method based TDI...A fast Time Domain Integral Equation(TDIE) solver is presented for analysis of transient scattering from electrically large conducting complex objects.The numerical process of Marching-On-in-Time(MOT) method based TDIE encounters high computational cost and exorbitant memory requirements.A group-style accelerated method-Plane Wave Time Domain(PWTD) algorithm,which permits rapid evaluation of transient wave field generated by temporally bandlimited sources,is employed to reduce the computational cost of MOT-based TDIE solvers.An efficient compressed storage technique for sparse matrix is adopted to decrease the enormous memory requirements of MOT.The scheme of the Multi-Level PWTD(MLPWTD)-enhanced MOT with compressed storage for sparse matrix is presented for analysis of transient scattering from electrically large complex objects in this paper.The numerical simulation results demonstrate the validity and efficiency of the presented scheme.展开更多
After the time history of seismic motion is represented by superposition of a series of narrow frequency band wave groups, we obtain a general relation between wave group arrival time and derivative of phase spectra i...After the time history of seismic motion is represented by superposition of a series of narrow frequency band wave groups, we obtain a general relation between wave group arrival time and derivative of phase spectra in the paper. On the basis of the relation, frequency number distribution function of wave group arrival time is completely equivalent to that of phase difference spectra. Under the assumption that phase angles of seismic motionobey uniform distribution ranged from 0 to ─ 2π, a quantitative relation between intensity envelope function of seismic motion and energy distribution function with wave group arrival time has been derived in this paper. The relation illuminates inner links among Fourier amplitude spectra and derivative of phase spectra and intensity envelope function. Some examples given by the paper support the conclusions mentioned above.展开更多
Blood pressure is an important physiological parameter to reflect human vital signs.In order to achieve the non-contact dynamic blood pressure acquisition based on ordinary optical camera,a theoretical understanding o...Blood pressure is an important physiological parameter to reflect human vital signs.In order to achieve the non-contact dynamic blood pressure acquisition based on ordinary optical camera,a theoretical understanding of the functional relationship between blood pressure and pulse wave signal conduction time.And through imaging photoelectric plethysmography(IPPG),pulse wave signal conduction time of forehead and hand was obtained with ordinary optical camera.First,the pulse wave conduction time was obtained by recording the video with an ordinary optical camera.Second,real-time blood pressure values were collected.Finally,based on the relationship between blood pressure and pulse wave conduction time,a non-contact blood pressure measurement prediction model was obtained through neural network fitting.So that non-contact blood pressure measurement with optical camera could be completed.The method in this paper has several advantages,such as low requirements on measuring equipment,low cost,and simple operation.It can let people get rid of the discomfort caused by measuring equipment such as cuff and can measure blood pressure at any time.The predicted blood pressure results were compared with an Omron wrist electronic sphygmomanometer.The calculated error of systolic blood pressure is-9.28%~3.16%,and the error of diastolic blood pressure is-9.84~4.35%.展开更多
By representing the Earth as a rotating spherical antenna several historic and scientific breakthroughs are achieved.Visualizing the Sun as a transmitter and the planets as receivers the solar system can be represente...By representing the Earth as a rotating spherical antenna several historic and scientific breakthroughs are achieved.Visualizing the Sun as a transmitter and the planets as receivers the solar system can be represented as a long wave radio system operating at Tremendously Low Frequency(TLF).Results again confirm that the“near-field”is Tesla’s“dynamic gravity”,better known to engineers as dynamic braking or to physicists as centripetal acceleration,or simply(g).Timewave theory is invented,and the relationship of reflected timewaves and time travel explored.A new law of the Sun is proposed as well as the merging of Einstein’s equation with acoustics and cosmic superstring theory.A new law of cosmic efficiency is also proposed that equates vibratory force and pressure with volume acceleration of the solar system.Lorentz force is broken down into centripetal and gravitational waves.Ten-dimensional cosmic superstring theory is espoused versus the aging three-dimensional Maxwellian model.Spherical antenna patterns for planets are presented and flux transfer frequency is calculated using distance to planets as wavelengths.The galactic grid operates at a Schumann Resonance of 7.83 Hz,which is derived from the science of dark energy and dark matter.The Sun and the planets are tuned to transmit and receive electrical power like resonating Tesla coils.The Earth’s stator winding has been modeled as a toroid tesla coil and the armature as a spherical armature.The equation for everything is born.展开更多
Based on the equivalent integro-differential form of the considered problem, a numerical approach to solving the two-dimensional nonlinear time fractional wave equations(NTFWEs) is considered in this paper. To this en...Based on the equivalent integro-differential form of the considered problem, a numerical approach to solving the two-dimensional nonlinear time fractional wave equations(NTFWEs) is considered in this paper. To this end, an alternating direction implicit(ADI) numerical scheme is derived. The scheme is established by combining the secondorder convolution quadrature formula and Crank–Nicolson technique in time and afourth-order difference approach in space. The convergence and unconditional stability of the proposed compact ADI scheme are strictly discussed after a concise solvabilityanalysis. A numerical example is shown to demonstrate the theoretical analysis.展开更多
This paper focuses on boundary stabilization of a one-dimensional wave equation with an unstable boundary condition,in which observations are subject to arbitrary fixed time delay.The observability inequality indicate...This paper focuses on boundary stabilization of a one-dimensional wave equation with an unstable boundary condition,in which observations are subject to arbitrary fixed time delay.The observability inequality indicates that the open-loop system is observable,based on which the observer and predictor are designed:The state of system is estimated with available observation and then predicted without observation.After that equivalently the authors transform the original system to the well-posed and exponentially stable system by backstepping method.The equivalent system together with the design of observer and predictor give the estimated output feedback.It is shown that the closed-loop system is exponentially stable.Numerical simulations are presented to illustrate the effect of the stabilizing controller.展开更多
The aim of the article is to construct exact solutions for the time fractional coupled Boussinesq-Burger and approximate long water wave equations by using the generalized Kudryashov method.The fractional differential...The aim of the article is to construct exact solutions for the time fractional coupled Boussinesq-Burger and approximate long water wave equations by using the generalized Kudryashov method.The fractional differential equation is converted into ordinary differential equations with the help of fractional complex transform and the modified Riemann-Liouville derivative sense.Applying the generalized Kudryashov method through with symbolic computer maple package,numerous new exact solutions are successfully obtained.All calculations in this study have been established and verified back with the aid of the Maple package program.The executed method is powerful,effective and straightforward for solving nonlinear partial differential equations to obtain more and new solutions with the integer and fractional order.展开更多
The finite-difference time-domain (FDTD) method is proposed for analyzing the surface acoustic wave (SAW) propagation in two-dimensional (2D) piezoelectric phononic crystals (PCs) at radio frequency (RF), an...The finite-difference time-domain (FDTD) method is proposed for analyzing the surface acoustic wave (SAW) propagation in two-dimensional (2D) piezoelectric phononic crystals (PCs) at radio frequency (RF), and also experiments are established to demonstrate its analysis result of the PCs' band gaps. The FDTD method takes the piezoelectric effect of PCs into account, in which periodic boundary conditions are used to decrease memory/time consumption and the perfectly matched layer boundary conditions are adopted as the SAW absorbers to attenuate artificial reflections. Two SAW delay lines are established with/without piezoelectric PCs located between interdigital transducers. By removing several echoes with window gating function in time domain, delay lines transmission function is achieved. The PCs' transmission functions and band gaps are obtained by comparing them in these two delay lines. When Aluminum/128°YX-LiNbO3 is adopted as scatter and substrate material, the PCs' band gap is calculated by this FDTD method and COMSOL respectively. Results show that computational results of FDTD agree well with experimental results and are better than that of COMSOL.展开更多
The interaction between an atomic beam of two-level atoms and a standing wave light field has been studied by the exact solution of a time-dependent quantum system developed recently. When the initial atomic state is ...The interaction between an atomic beam of two-level atoms and a standing wave light field has been studied by the exact solution of a time-dependent quantum system developed recently. When the initial atomic state is choosen to be ground, we find that with the limit of zero detuning the atoms will oscillate between the upper and the lower levels with a decaying amplitude. The most interesting result obtained in this paper is when the initial atomic state is a particular superposition of the two levels, now the system does not oscillate at any time.展开更多
The second Madden–Julian Oscillation(MJO)event during the field campaign of the Dynamics of the MJO/Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011(DYNAMO/CINDY2011)exhibi ted an...The second Madden–Julian Oscillation(MJO)event during the field campaign of the Dynamics of the MJO/Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011(DYNAMO/CINDY2011)exhibi ted an unusual double rainband structure.Using a wavenumber-frequency spectral filtering method,we unveil that this double rainband structure arises primarily from the Kelvin wave component.The zonal phase speed of the double rainbands is about 7.9 degree per day in the equatorial Indian Ocean,being in the range of convectively coupled Kelvin wave phase speeds.The convection and circulation anomalies associated with the Kelvin wave component are characterized by two anomalous convective cells,with low-level westerly(easterly)and high(low)pressure anomalies to the west(east)of the convective centers,and opposite wind and pressure anomalies in the upper troposphere.Such a zonal wind–pressure phase relationship is consistent with the equatorial free-wave dynamics.While the freeatmospheric circulation was dominated by the first baroclinic mode vertical structure,moisture and vertical motion in the boundary layer led the convection.The convection and circulation structures derived based on the conventional MJO filter show a different characteristic.For example,the phase speed is slower(about 5.9 degree per day),and there were no double convective branches.This suggests that MJO generally involves multi-scales and it is incomplete to extract its signals by using the conventional filtering technique.展开更多
The technique of imaging or tracking objects outside the field of view(FOV)through a reflective relay surface,usually called non-line-of-sight(NLOS)imaging,has been a popular research topic in recent years.Although NL...The technique of imaging or tracking objects outside the field of view(FOV)through a reflective relay surface,usually called non-line-of-sight(NLOS)imaging,has been a popular research topic in recent years.Although NLOS imaging can be achieved through methods such as detector design,optical path inverse operation algorithm design,or deep learning,challenges such as high costs,complex algorithms,and poor results remain.This study introduces a simple algorithm-based rapid depth imaging device,namely,the continuous-wave time-offlight range imaging camera(CW-TOF camera),to address the decoupled imaging challenge of differential scattering characteristics in an object-relay surface by quantifying the differential scattering signatures through statistical analysis of light propagation paths.A scalable scattering mapping(SSM)theory has been proposed to explain the degradation process of clear images.High-quality NLOS object 3D imaging has been achieved through a data-driven approach.To verify the effectiveness of the proposed algorithm,experiments were conducted using an optical platform and real-world scenarios.The objects on the optical platform include plaster sculptures and plastic letters,while relay surfaces consist of polypropylene(PP)plastic boards,acrylic boards,and standard Lambertian diffusers.In real-world scenarios,the object is clothing,with relay surfaces including painted doors and white plaster walls.Imaging data were collected for different combinations of objects and relay surfaces for training and testing,totaling 210,000 depth images.The reconstruction of NLOS images in the laboratory and real-world is excellent according to subjective evaluation;thus,our approach can realize NLOS imaging in harsh natural scenes and advances the practical application of NLOS imaging.展开更多
基金China-Korea Cooperation Project on the development of oceanic monitoring and prediction system on nuclear safetythe Project of the National Programme on Global Change and Air-sea Interaction under contract No.GASI-03-IPOVAI-05
文摘An operational ocean circulation-surface wave coupled forecasting system for the seas off China and adjacent areas(OCFS-C) is developed based on parallelized circulation and wave models. It has been in operation since November 1, 2007. In this paper we comprehensively present the simulation and verification of the system, whose distinguishing feature is that the wave-induced mixing is coupled in the circulation model. In particular, with nested technique the resolution in the China's seas has been updated to(1/24)° from the global model with(1/2)°resolution. Besides, daily remote sensing sea surface temperature(SST) data have been assimilated into the model to generate a hot restart field for OCFS-C. Moreover, inter-comparisons between forecasting and independent observational data are performed to evaluate the effectiveness of OCFS-C in upper-ocean quantities predictions, including SST, mixed layer depth(MLD) and subsurface temperature. Except in conventional statistical metrics, non-dimensional skill scores(SS) is also used to evaluate forecast skill. Observations from buoys and Argo profiles are used for lead time and real time validations, which give a large SS value(more than 0.90). Besides, prediction skill for the seasonal variation of SST is confirmed. Comparisons of subsurface temperatures with Argo profiles data indicate that OCFS-C has low skill in predicting subsurface temperatures between 100 m and 150 m. Nevertheless, inter-comparisons of MLD reveal that the MLD from model is shallower than that from Argo profiles by about 12 m, i.e., OCFS-C is successful and steady in MLD predictions. Validation of 1-d, 2-d and 3-d forecasting SST shows that our operational ocean circulation-surface wave coupled forecasting model has reasonable accuracy in the upper ocean.
基金Supported by the Deanship of Scientific Research at Prince Sattam Bin Abdulaziz University under Grant No 2016/01/6239
文摘Nonlinear features of electron-acoustic shock waves are studied. The Burgers equation is derived and converted to the time fractional Burgers equation by Agrawal's method. Using the Adomian decomposition method, the shock wave solutions of the time fractional Burgers equation are constructed. The effect of time fractional parameter on the shock wave properties in auroral plasma & investigated.
文摘Just after the occurrence of an M=5. 2 earthquake in Shimian, Sichuan, two three-component seismometerswere set up near the epicenter of, the earthquake. Field observations were made for the four-year period from1989 to 1992. Analysis of the data recorded from either aftershocks following the M=5. 2 earthquake or fromsmall earthquakes scattered in this region indicates the presence of shear wave splitting. And shear wave splittingvaries with ti-cue. The mean direction of polarization of the faster shear waves is N18°W during the pened of aftershock activity, which is consistent with the strike of the faulting plane of the mainshock; but has turned toN46'W from 1990 to 1992, which is consistent with the regional maximum compressive stress. The time delaysbetween split shear waves measured on records from 1990 to 1992 are about half of that in 1989. The results ohtamed from observations at two temporary stations are similar. This indicates that the temporal changes may berelated to the occurrence of the M= 5.2 mainshock.
文摘Time evaluation of wave functions for any quantum mechanical system/particle is essential nevertheless quantum mechanical counterpart of the time dependant classical wave equation does simply not appear. Epistemologically and ontologically considered time dependant momentum operator is initially defined and an Alternative Time Dependant Schrodinger Wave Equation (ATDSWE) is plainly derived. Consequent equation is primarily solved for the free particles, in a closed system, signifying a good agreement with the outcomes of the ordinary TDSWE. Free particle solution interestingly goes further possibly tracing some signs of new pathways to resolve the mysterious quantum world.
基金Project supported by the National Natural Science Foundation of China (No. 60474064), and the Natural Science Foundation of Zhejiang Province (No. Y105694), China
文摘In this article, some methods are proposed for enhancing the converging velocity of the COA (chaos optimization algorithm) based on using carrier wave two times, which can greatly increase the speed and efficiency of the first carrier wave’s search for the optimal point in implementing the sophisticated searching during the second carrier wave is faster and more accurate. In addition, the concept of using the carrier wave three times is proposed and put into practice to tackle the multi-variables opti- mization problems, where the searching for the optimal point of the last several variables is frequently worse than the first several ones.
基金the Australian Government through the Australian Research Council's Discovery Projects funding scheme(Project DP190101592)the National Natural Science Foundation of China(Grant Nos.41972280 and 52179103).
文摘The travel time of rock compressional waves is an essential parameter used for estimating important rock properties,such as porosity,permeability,and lithology.Current methods,like wireline logging tests,provide broad measurements but lack finer resolution.Laboratory-based rock core measurements offer higher resolution but are resource-intensive.Conventionally,wireline logging and rock core measurements have been used independently.This study introduces a novel approach that integrates both data sources.The method leverages the detailed features from limited core data to enhance the resolution of wireline logging data.By combining machine learning with random field theory,the method allows for probabilistic predictions in regions with sparse data sampling.In this framework,12 parameters from wireline tests are used to predict trends in rock core data.The residuals are modeled using random field theory.The outcomes are high-resolution predictions that combine both the predicted trend and the probabilistic realizations of the residual.By utilizing unconditional and conditional random field theories,this method enables unconditional and conditional simulations of the underlying high-resolution rock compressional wave travel time profile and provides uncertainty estimates.This integrated approach optimizes the use of existing core and logging data.Its applicability is confirmed in an oil project in West China.
文摘A fast Time Domain Integral Equation(TDIE) solver is presented for analysis of transient scattering from electrically large conducting complex objects.The numerical process of Marching-On-in-Time(MOT) method based TDIE encounters high computational cost and exorbitant memory requirements.A group-style accelerated method-Plane Wave Time Domain(PWTD) algorithm,which permits rapid evaluation of transient wave field generated by temporally bandlimited sources,is employed to reduce the computational cost of MOT-based TDIE solvers.An efficient compressed storage technique for sparse matrix is adopted to decrease the enormous memory requirements of MOT.The scheme of the Multi-Level PWTD(MLPWTD)-enhanced MOT with compressed storage for sparse matrix is presented for analysis of transient scattering from electrically large complex objects in this paper.The numerical simulation results demonstrate the validity and efficiency of the presented scheme.
文摘After the time history of seismic motion is represented by superposition of a series of narrow frequency band wave groups, we obtain a general relation between wave group arrival time and derivative of phase spectra in the paper. On the basis of the relation, frequency number distribution function of wave group arrival time is completely equivalent to that of phase difference spectra. Under the assumption that phase angles of seismic motionobey uniform distribution ranged from 0 to ─ 2π, a quantitative relation between intensity envelope function of seismic motion and energy distribution function with wave group arrival time has been derived in this paper. The relation illuminates inner links among Fourier amplitude spectra and derivative of phase spectra and intensity envelope function. Some examples given by the paper support the conclusions mentioned above.
基金The work of this paper is supported by the National Natural Science Foundation of China under Grant No.61572038,the Innovation Project Foundation NCUT.
文摘Blood pressure is an important physiological parameter to reflect human vital signs.In order to achieve the non-contact dynamic blood pressure acquisition based on ordinary optical camera,a theoretical understanding of the functional relationship between blood pressure and pulse wave signal conduction time.And through imaging photoelectric plethysmography(IPPG),pulse wave signal conduction time of forehead and hand was obtained with ordinary optical camera.First,the pulse wave conduction time was obtained by recording the video with an ordinary optical camera.Second,real-time blood pressure values were collected.Finally,based on the relationship between blood pressure and pulse wave conduction time,a non-contact blood pressure measurement prediction model was obtained through neural network fitting.So that non-contact blood pressure measurement with optical camera could be completed.The method in this paper has several advantages,such as low requirements on measuring equipment,low cost,and simple operation.It can let people get rid of the discomfort caused by measuring equipment such as cuff and can measure blood pressure at any time.The predicted blood pressure results were compared with an Omron wrist electronic sphygmomanometer.The calculated error of systolic blood pressure is-9.28%~3.16%,and the error of diastolic blood pressure is-9.84~4.35%.
文摘By representing the Earth as a rotating spherical antenna several historic and scientific breakthroughs are achieved.Visualizing the Sun as a transmitter and the planets as receivers the solar system can be represented as a long wave radio system operating at Tremendously Low Frequency(TLF).Results again confirm that the“near-field”is Tesla’s“dynamic gravity”,better known to engineers as dynamic braking or to physicists as centripetal acceleration,or simply(g).Timewave theory is invented,and the relationship of reflected timewaves and time travel explored.A new law of the Sun is proposed as well as the merging of Einstein’s equation with acoustics and cosmic superstring theory.A new law of cosmic efficiency is also proposed that equates vibratory force and pressure with volume acceleration of the solar system.Lorentz force is broken down into centripetal and gravitational waves.Ten-dimensional cosmic superstring theory is espoused versus the aging three-dimensional Maxwellian model.Spherical antenna patterns for planets are presented and flux transfer frequency is calculated using distance to planets as wavelengths.The galactic grid operates at a Schumann Resonance of 7.83 Hz,which is derived from the science of dark energy and dark matter.The Sun and the planets are tuned to transmit and receive electrical power like resonating Tesla coils.The Earth’s stator winding has been modeled as a toroid tesla coil and the armature as a spherical armature.The equation for everything is born.
基金This survey is supported by the National Natural Science Foundation of China(Grant No.11371029)the Quality Engineering Project of Colleges and Universities in Anhui Province(Grant No.2018kfk136).
文摘Based on the equivalent integro-differential form of the considered problem, a numerical approach to solving the two-dimensional nonlinear time fractional wave equations(NTFWEs) is considered in this paper. To this end, an alternating direction implicit(ADI) numerical scheme is derived. The scheme is established by combining the secondorder convolution quadrature formula and Crank–Nicolson technique in time and afourth-order difference approach in space. The convergence and unconditional stability of the proposed compact ADI scheme are strictly discussed after a concise solvabilityanalysis. A numerical example is shown to demonstrate the theoretical analysis.
基金supported by the National Natural Science Foundation of China under Grant No.61203058the Training Program for Outstanding Young Teachers of North China University of Technology under Grant No.XN131+1 种基金the Construction Plan for Innovative Research Team of North China University of Technology under Grant No.XN129the Laboratory construction for Mathematics Network Teaching Platform of North China University of Technology under Grant No.XN041
文摘This paper focuses on boundary stabilization of a one-dimensional wave equation with an unstable boundary condition,in which observations are subject to arbitrary fixed time delay.The observability inequality indicates that the open-loop system is observable,based on which the observer and predictor are designed:The state of system is estimated with available observation and then predicted without observation.After that equivalently the authors transform the original system to the well-posed and exponentially stable system by backstepping method.The equivalent system together with the design of observer and predictor give the estimated output feedback.It is shown that the closed-loop system is exponentially stable.Numerical simulations are presented to illustrate the effect of the stabilizing controller.
文摘The aim of the article is to construct exact solutions for the time fractional coupled Boussinesq-Burger and approximate long water wave equations by using the generalized Kudryashov method.The fractional differential equation is converted into ordinary differential equations with the help of fractional complex transform and the modified Riemann-Liouville derivative sense.Applying the generalized Kudryashov method through with symbolic computer maple package,numerous new exact solutions are successfully obtained.All calculations in this study have been established and verified back with the aid of the Maple package program.The executed method is powerful,effective and straightforward for solving nonlinear partial differential equations to obtain more and new solutions with the integer and fractional order.
基金supported by the National Natural Science Foundation of China(11174318,11304346,61106081)Chinese Postdoctoral Science Foundation(2011M501204,2013T60718)+2 种基金National High Technology Research and Development Program(863 Program)(SS2013AA041103)Beijing Municipal Science and Technology Commission Project(Z141100003814016)the Fundamental Research Funds for the Central Universities(HUST:2013QN038)
文摘The finite-difference time-domain (FDTD) method is proposed for analyzing the surface acoustic wave (SAW) propagation in two-dimensional (2D) piezoelectric phononic crystals (PCs) at radio frequency (RF), and also experiments are established to demonstrate its analysis result of the PCs' band gaps. The FDTD method takes the piezoelectric effect of PCs into account, in which periodic boundary conditions are used to decrease memory/time consumption and the perfectly matched layer boundary conditions are adopted as the SAW absorbers to attenuate artificial reflections. Two SAW delay lines are established with/without piezoelectric PCs located between interdigital transducers. By removing several echoes with window gating function in time domain, delay lines transmission function is achieved. The PCs' transmission functions and band gaps are obtained by comparing them in these two delay lines. When Aluminum/128°YX-LiNbO3 is adopted as scatter and substrate material, the PCs' band gap is calculated by this FDTD method and COMSOL respectively. Results show that computational results of FDTD agree well with experimental results and are better than that of COMSOL.
基金This work was supported by the National Natural Science Foundation of China under Grant No. 10075302.
文摘The interaction between an atomic beam of two-level atoms and a standing wave light field has been studied by the exact solution of a time-dependent quantum system developed recently. When the initial atomic state is choosen to be ground, we find that with the limit of zero detuning the atoms will oscillate between the upper and the lower levels with a decaying amplitude. The most interesting result obtained in this paper is when the initial atomic state is a particular superposition of the two levels, now the system does not oscillate at any time.
基金Supported by the National(Key)Basic Research and Development(973)Program of China(2015CB453200)National Natural Science Foundation of China(41475084,41630423,41575052,and 41375095)+7 种基金US National Science Foundation(AGS-1643297)US Office of Naval Research(N00014-16-12260)US Naval Research Laboratory(N00173-16-1-G906)Jiangsu Natural Science Foundation Key Project(BK20150062)of ChinaJiangsu Shuang-Chuang Team Fund(R2014SCT001)of ChinaSOEST contribution number 9819IPRC contribution number 1211ESMC number 126
文摘The second Madden–Julian Oscillation(MJO)event during the field campaign of the Dynamics of the MJO/Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011(DYNAMO/CINDY2011)exhibi ted an unusual double rainband structure.Using a wavenumber-frequency spectral filtering method,we unveil that this double rainband structure arises primarily from the Kelvin wave component.The zonal phase speed of the double rainbands is about 7.9 degree per day in the equatorial Indian Ocean,being in the range of convectively coupled Kelvin wave phase speeds.The convection and circulation anomalies associated with the Kelvin wave component are characterized by two anomalous convective cells,with low-level westerly(easterly)and high(low)pressure anomalies to the west(east)of the convective centers,and opposite wind and pressure anomalies in the upper troposphere.Such a zonal wind–pressure phase relationship is consistent with the equatorial free-wave dynamics.While the freeatmospheric circulation was dominated by the first baroclinic mode vertical structure,moisture and vertical motion in the boundary layer led the convection.The convection and circulation structures derived based on the conventional MJO filter show a different characteristic.For example,the phase speed is slower(about 5.9 degree per day),and there were no double convective branches.This suggests that MJO generally involves multi-scales and it is incomplete to extract its signals by using the conventional filtering technique.
基金National Key Research and Development Program of China(2023YFC3321600)Special Project for Research and Development in Key Areas of Guangdong Province(2023ZDZX1044)+1 种基金Zhuhai Multimodal Intelligent Vision Engineering Technology Research Center(2320004002292)Zhuhai Basic and Applied Basic Research Foundation(2220004002937)。
文摘The technique of imaging or tracking objects outside the field of view(FOV)through a reflective relay surface,usually called non-line-of-sight(NLOS)imaging,has been a popular research topic in recent years.Although NLOS imaging can be achieved through methods such as detector design,optical path inverse operation algorithm design,or deep learning,challenges such as high costs,complex algorithms,and poor results remain.This study introduces a simple algorithm-based rapid depth imaging device,namely,the continuous-wave time-offlight range imaging camera(CW-TOF camera),to address the decoupled imaging challenge of differential scattering characteristics in an object-relay surface by quantifying the differential scattering signatures through statistical analysis of light propagation paths.A scalable scattering mapping(SSM)theory has been proposed to explain the degradation process of clear images.High-quality NLOS object 3D imaging has been achieved through a data-driven approach.To verify the effectiveness of the proposed algorithm,experiments were conducted using an optical platform and real-world scenarios.The objects on the optical platform include plaster sculptures and plastic letters,while relay surfaces consist of polypropylene(PP)plastic boards,acrylic boards,and standard Lambertian diffusers.In real-world scenarios,the object is clothing,with relay surfaces including painted doors and white plaster walls.Imaging data were collected for different combinations of objects and relay surfaces for training and testing,totaling 210,000 depth images.The reconstruction of NLOS images in the laboratory and real-world is excellent according to subjective evaluation;thus,our approach can realize NLOS imaging in harsh natural scenes and advances the practical application of NLOS imaging.