The generalized Thirring model with impurity coupling is defined on two-dimensional noncommutativespace-time,a modified propagator and free energy are derived by means of functional integrals method.Moreover,quantum f...The generalized Thirring model with impurity coupling is defined on two-dimensional noncommutativespace-time,a modified propagator and free energy are derived by means of functional integrals method.Moreover,quantum fluctuations and excitation energies are calculated on two-dimensional black hole and soliton background.展开更多
The lower slope of furrow pits has following special features: small extent of weathering destruction, short time of production blasting damage, good arching effect of lower slope with small curvature radius, and good...The lower slope of furrow pits has following special features: small extent of weathering destruction, short time of production blasting damage, good arching effect of lower slope with small curvature radius, and good bottom effect of a pit end for transferring and bearing initial horizontal stresses in lower slope. The new principles provided theoretical basis for convex slope in furrow pits to reduce stripping. Similar phenomena and examples are supplied simultaneously.展开更多
In this paper we study the higher-order differential variational principle and differential equations of motion for mechanical systems in event space. Based on the higher-order d'Alembert principle of the system, the...In this paper we study the higher-order differential variational principle and differential equations of motion for mechanical systems in event space. Based on the higher-order d'Alembert principle of the system, the higher-order velocity energy and the higher-order acceleration energy of the system in event space are defined, the higher-order d'Alembert- Lagrange principle of the system in event space is established, and the parametric forms of Euler-Lagrange, Nielsen and Appell for this principle are given. Finally, the higher-order differential equations of motion for holonomic systems in event space are obtained.展开更多
In fundamental theories of physics, the dynamical equations all have time inversion invariance. Except for the evolution of some simple system which has realistic inverse processes, but for a slightly more complicated...In fundamental theories of physics, the dynamical equations all have time inversion invariance. Except for the evolution of some simple system which has realistic inverse processes, but for a slightly more complicated system, the evolution processes are irreversible. This is the problem of arrow of time, which is always warmly debated. In different point of view, we find there may have some conceptual misunderstanding in the controversy: 1) The realization of an inverse process does not mean the time of the system goes backward. 2) The principles of relativity and covariance are the constraints to physical laws, but not constraints to specific solutions. The equations must be covariant, but the solutions are not definitely symmetric. 3) Time is a global property of the universe, which is a measurement of the evolution process of the universe. The internal time of a matter system reflecting its internal evolution speed also takes this cosmic time as a unified background and standard of measurement. 4) The universe has a unified cosmic time T and a cosmic space related to this cosmic time. They are objective and absolute. 5) The eigensolution of a spinor is a critical state losing time concept, which responses the interaction of environment with some uncertainty, then the evolution process of the world is not uniquely determined. 6) The non-uniqueness of the evolution process means that the inverse process is absent. So for a world including spinors, the evolution is essentially irreversible. In this paper, according to the widely accepted principles and direct calculations of transformation, we reveal the misunderstandings in the usual controversy, and then give more natural and reasonable explanations for structure of space-time and arrow of time.展开更多
In this paper,the forecasting equations of a 2nd-order space-time differential remainder are deduced from the Navier-Stokes primitive equations and Eulerian operator by Taylor-series expansion.Here we introduce a cubi...In this paper,the forecasting equations of a 2nd-order space-time differential remainder are deduced from the Navier-Stokes primitive equations and Eulerian operator by Taylor-series expansion.Here we introduce a cubic spline numerical model(Spline Model for short),which is with a quasi-Lagrangian time-split integration scheme of fitting cubic spline/bicubic surface to all physical variable fields in the atmospheric equations on spherical discrete latitude-longitude mesh.A new algorithm of"fitting cubic spline—time step integration—fitting cubic spline—……"is developed to determine their first-and2nd-order derivatives and their upstream points for time discrete integral to the governing equations in Spline Model.And the cubic spline function and its mathematical polarities are also discussed to understand the Spline Model’s mathematical foundation of numerical analysis.It is pointed out that the Spline Model has mathematical laws of"convergence"of the cubic spline functions contracting to the original functions as well as its 1st-order and 2nd-order derivatives.The"optimality"of the 2nd-order derivative of the cubic spline functions is optimal approximation to that of the original functions.In addition,a Hermite bicubic patch is equivalent to operate on a grid for a 2nd-order derivative variable field.Besides,the slopes and curvatures of a central difference are identified respectively,with a smoothing coefficient of 1/3,three-point smoothing of that of a cubic spline.Then the slopes and curvatures of a central difference are calculated from the smoothing coefficient 1/3 and three-point smoothing of that of a cubic spline,respectively.Furthermore,a global simulation case of adiabatic,non-frictional and"incompressible"model atmosphere is shown with the quasi-Lagrangian time integration by using a global Spline Model,whose initial condition comes from the NCEP reanalysis data,along with quasi-uniform latitude-longitude grids and the so-called"shallow atmosphere"Navier-Stokes primitive equations in the spherical coordinates.The Spline Model,which adopted the Navier-Stokes primitive equations and quasi-Lagrangian time-split integration scheme,provides an initial ideal case of global atmospheric circulation.In addition,considering the essentially non-linear atmospheric motions,the Spline Model could judge reasonably well simple points of any smoothed variable field according to its fitting spline curvatures that must conform to its physical interpretation.展开更多
Based on the Mach’s principle, black holes warp the space time in a way that geodesic for every object which is moving toward black hole starts to bend and object starts to rotate around the black hole. Even light ca...Based on the Mach’s principle, black holes warp the space time in a way that geodesic for every object which is moving toward black hole starts to bend and object starts to rotate around the black hole. Even light cannot be able to escape from the strong gravitational field of black hole and all the light like paths will warp so as to fall farther to the hole. Before arriving to the Schwarzschild’s Sphere, object faces with length extension because of the difference between amount of tidal forces on the nearest and furthest points of object that take the object apart and after passing the Schwarzschild’s sphere, based on the Special relativity of Einstein, the parts of object face with length contraction. In comparison between strange stars and black holes we conclude that core of strange stars has a temperature and pressure not sufficient for up and down quarks and they turn into strange ones. However, in core of black holes, because of massive stars and hot gases falling into it, they are always in a high temperature and pressure. So they can be made up of up and down quarks. At the Ergo sphere Region of black hole, a particle that gets into it will divide into 2 pieces, one of them falls into the black hole and another gets out of the Schwarzschild sphere very fast and it’s called the black hole radiation. According to the Diagram drawn by R. Rafini and J. Weeler, an object gets out of white hole in past space-time, it can be able to send signals to us and we can receive it but black hole which is located in future space-time, after object enters to the Schwarzschild’s Sphere, the signals it sends won’t be received. In order to reach the third space-time which is like a mirror to our universe, our speed needs to exceed the speed of light to pass the Einstein-Rosen Bridge. As a conclusion, structure of black holes can be made up of up and down quarks and everything falls into the black hole, collapses and turns into a bunch of quarks. Space-time around black holes, based on Rafini-Weeler diagram, is like a frontier between our space-time and other space-times. So it can be possible to reach past space-time and other space-times.展开更多
The paper analyzes the variation characteristics of energy fields of seismicity 2.1≤M L ≤4.5 in Jiangsu and its neighboring areas during the period between January 1970 and December 2007.It also analyzes the variati...The paper analyzes the variation characteristics of energy fields of seismicity 2.1≤M L ≤4.5 in Jiangsu and its neighboring areas during the period between January 1970 and December 2007.It also analyzes the variations of time "weight" coefficients of the major typical energy fields,using random function theory with seismic energy fields as a space-time random function field based on Empirical Orthogonal Function (EOF) expansion methods.The results show that the expansion accuracy of the first seven typical fields is 0.9244.The strength of seismic energy varies remarkably in different tectonic blocks in the study area.High value areas are in middle and southern Jiangsu,and the south Yellow Sea.The distribution of the typical fields also shows that it is an area that affects most significantly the seismic energy fields of the study region.The time "weight" coefficients of the first six typical fields vary with time,and the amplitude of the variations has strong temporal correlations with moderate-strong earthquakes in the region.展开更多
20th century physics experimentally established beyond doubt the fact that moving clocks read differently from “static” clocks. This fact is typically interpreted as support for special relativity. On the other hand...20th century physics experimentally established beyond doubt the fact that moving clocks read differently from “static” clocks. This fact is typically interpreted as support for special relativity. On the other hand, the same century produced proof that clocks at various locations in the gravitational field also read differently, and this fact is explained by general relativity, which is, in general, not Lorentz transformable. This paper establishes a common framework for the physics of clocks in these different situations.展开更多
Phase space reconstruction is the first step of recognizing the chaotic time series.On the basis of differential entropy ratio method,the embedding dimension opt m and time delay t are optimal for the state space reco...Phase space reconstruction is the first step of recognizing the chaotic time series.On the basis of differential entropy ratio method,the embedding dimension opt m and time delay t are optimal for the state space reconstruction could be determined.But they are not the optimal parameters accepted for prediction.This study proposes an improved method based on the differential entropy ratio and Radial Basis Function(RBF)neural network to estimate the embedding dimension m and the time delay t,which have both optimal characteristics of the state space reconstruction and the prediction.Simulating experiments of Lorenz system and Doffing system show that the original phase space could be reconstructed from the time series effectively,and both the prediction accuracy and prediction length are improved greatly.展开更多
We obtain a new relation between Green's functions of the time-dependent Schrōdinger equation forstationary potentials and Green's functions of the same equation for certain time-dependent potentials. The rel...We obtain a new relation between Green's functions of the time-dependent Schrōdinger equation forstationary potentials and Green's functions of the same equation for certain time-dependent potentials. The relationobtained here emerges very easily from a transformation introduced by Ray [J.R. Ray, Phys. Rev. A26 (1982) 729] andgeneralizes former work of Dodonov et al. [V.V. Dodonov, V.I. Man'ko, and D.E. Nikonov, Phys. Lett. A162 (1992)359.]展开更多
This paper, having made systematic trend analysis on the front and rear segments of Xintan landslide for space and time respectively by using matbematical statistical principles,discovered that there is obvious trend ...This paper, having made systematic trend analysis on the front and rear segments of Xintan landslide for space and time respectively by using matbematical statistical principles,discovered that there is obvious trend displacement Of the monitoring points in the rear margin area of the slope and the rates of trend displacement gradually increase with time whereas there is no trend displacement of the monitoring points in the front margin area. This result suggests that the rear margin area of segment is an area of overall sliding and is transforming towards destabilization whereas the front margin area is an area of relative stability. This analytical result well coincides with the conclusion of evaluation on dynamic stability. The analytical result mentioned above shows that the medium to short term forecast and prediction of slope stability can be made by using trend displacement analysis technique in order to achieve the goal of timely evaluation and prevention.展开更多
A non-incremental time-space algorithm is proposed for numerical. analysis of forming process with the inclusion of geometrical, material, contact-frictional nonlinearities. Unlike the widely used Newton-Raphso...A non-incremental time-space algorithm is proposed for numerical. analysis of forming process with the inclusion of geometrical, material, contact-frictional nonlinearities. Unlike the widely used Newton-Raphson counterpart, the present scheme features an iterative solution procedure on entire time and space domain. Validity and feasibility of foe present scheme are further justiced by the numerical investigation herewith presented.展开更多
Space-time coding radar has been recently proposed and investigated.It is a radar framework which can perform transmit beamforming at the receiver.However,the range resolution decreases when the number of the transmit...Space-time coding radar has been recently proposed and investigated.It is a radar framework which can perform transmit beamforming at the receiver.However,the range resolution decreases when the number of the transmit element increases.A subarray-based space-time coding(sub-STC)radar is explored to alleviate the range resolution reduction.For the proposed radar configuration,an identical waveform is transmitted and it introduces a small time offset in different subarrays.The multidimensional ambiguity function of sub-STC radar is defined by considering resolutions in multiple domains including the range,Doppler,angle and probing direction.Analyses on properties of the multi-dimensional ambiguity function of the sub-STC radar with regard to the spatial coverage,resolution performance and low sidelobes are also given.Results reveal that the range resolution and low sidelobes performance are improved with the proposed approach.展开更多
There are three parts in this article. In Section 1, we establish the model of branching chain with drift in space-time random environment (BCDSTRE), i.e., the coupling of branching chain and random walk. In Section...There are three parts in this article. In Section 1, we establish the model of branching chain with drift in space-time random environment (BCDSTRE), i.e., the coupling of branching chain and random walk. In Section 2, we prove that any BCDSTRE must be a Markov chain in time random environment when we consider the distribution of the particles in space as a random element. In Section 3, we calculate the first-order moments and the second-order moments of BCDSTRE.展开更多
Based on the space spherical symmetry of 3-dimensional and the translational symmetry of time and the uncertainty principle, a 4-dimensional space-time cylinder model of quarks and leptons is established. With this mo...Based on the space spherical symmetry of 3-dimensional and the translational symmetry of time and the uncertainty principle, a 4-dimensional space-time cylinder model of quarks and leptons is established. With this model, equations of the special relativity can be extended more perfectly, thereby achieving a unity of the special relativity and quantum mechanics in deeper level. New equations can not only interpret issues explained by old equations but also solve several important pending problems. For example, a formula to strictly calculate the coefficient ξ of Lorentz invariance violation (LIV) is derived, to above 4 × 1019 eV UHECR protons the calculated |ξ| -30, although there is the LIV effect it is too weak to change the GZK cutoff, which is consistent with observations of HiRes and Auger;Also, a relation formula between the Hubble constant and several basic constants is derived, thus theoretically calculated H0 = 70.937 km·s-1·Mpc-1, which is well consistent with the final observation result of HST Key Project. In addition, an unusual effect predicted by new equations can be experimentally tested in the electron storage ring;a preliminary experiment result has hinted its signs of existence.展开更多
When the finite difference time domain(FDTD) method is used to solve electromagnetic scattering problems in Schwarzschild space-time, the Green functions linking source/observer to every surface element on connection/...When the finite difference time domain(FDTD) method is used to solve electromagnetic scattering problems in Schwarzschild space-time, the Green functions linking source/observer to every surface element on connection/output boundary must be calculated.When the scatterer is electrically extended, a huge amount of calculation is required due to a large number of surface elements on the connection/output boundary.In this paper, a method for reducing the calculation workload of Green function is proposed.The Taylor approximation is applied for the calculation of Green function.New transport equations are deduced.The numerical results verify the effectiveness of this method.展开更多
The vacuum energy density of free scalar quantum field in a Rindler distributional space-time with distributional Levi-Cività connection is considered. It has been widely believed that, except in very extreme sit...The vacuum energy density of free scalar quantum field in a Rindler distributional space-time with distributional Levi-Cività connection is considered. It has been widely believed that, except in very extreme situations, the influence of acceleration on quantum fields should amount to just small, sub-dominant contributions. Here we argue that this belief is wrong by showing that in a Rindler distributional background space-time with distributional Levi-Cività connection the vacuum energy of free quantum fields is forced, by the very same background distributional space-time such a Rindler distributional background space-time, to become dominant over any classical energy density component. This semiclassical gravity effect finds its roots in the singular behavior of quantum fields on a Rindler distributional space-times with distributional Levi-Cività connection. In particular we obtain that the vacuum fluctuations have a singular behavior at a Rindler horizon . Therefore sufficiently strongly accelerated observer burns up near the Rindler horizon. Thus Polchinski’s account doesn’t violate the Einstein equivalence principle.展开更多
In this paper, a Wind Direction Change Index (WI), which can describe four-dimensional spatiotemporal changes of the atmospheric circulation objectively and quantitatively, is defined to study its evolution and season...In this paper, a Wind Direction Change Index (WI), which can describe four-dimensional spatiotemporal changes of the atmospheric circulation objectively and quantitatively, is defined to study its evolution and seasonal variation. The first four modes can be obtained by EOF expansion of the zonally averaged WI. The first mode reveals the basic spatial distribution of the annually averaged WI. The second mode reflects the quasi-harmonic parts of the WI deviations. Tropical, subtropical and extratropical monsoon areas can be clearly reflected by this mode. The third mode reflects the non-harmonic parts of the WI deviations. It shows the so-called February reverse in stratospheric atmosphere as well as the asymmetric seasonal changes from spring to fall and from fall to spring due to both the land-sea distribution contrast between the Northern and Southern Hemispheres and the nonlinear effect of atmospheric and ocean fluids. The fourth mode reveals the northward advancing of the global reversed wind fields from spring to summer and their southward withdrawal from summer to autumn.展开更多
基金Supported by the Natural Science Foundation of Sichuan Education Committee under Grant No.08ZA038
文摘The generalized Thirring model with impurity coupling is defined on two-dimensional noncommutativespace-time,a modified propagator and free energy are derived by means of functional integrals method.Moreover,quantum fluctuations and excitation energies are calculated on two-dimensional black hole and soliton background.
文摘The lower slope of furrow pits has following special features: small extent of weathering destruction, short time of production blasting damage, good arching effect of lower slope with small curvature radius, and good bottom effect of a pit end for transferring and bearing initial horizontal stresses in lower slope. The new principles provided theoretical basis for convex slope in furrow pits to reduce stripping. Similar phenomena and examples are supplied simultaneously.
基金Project supported by the Science and Technology Program of Xi’an City,China(Grant No.CXY1352WL34)
文摘In this paper we study the higher-order differential variational principle and differential equations of motion for mechanical systems in event space. Based on the higher-order d'Alembert principle of the system, the higher-order velocity energy and the higher-order acceleration energy of the system in event space are defined, the higher-order d'Alembert- Lagrange principle of the system in event space is established, and the parametric forms of Euler-Lagrange, Nielsen and Appell for this principle are given. Finally, the higher-order differential equations of motion for holonomic systems in event space are obtained.
文摘In fundamental theories of physics, the dynamical equations all have time inversion invariance. Except for the evolution of some simple system which has realistic inverse processes, but for a slightly more complicated system, the evolution processes are irreversible. This is the problem of arrow of time, which is always warmly debated. In different point of view, we find there may have some conceptual misunderstanding in the controversy: 1) The realization of an inverse process does not mean the time of the system goes backward. 2) The principles of relativity and covariance are the constraints to physical laws, but not constraints to specific solutions. The equations must be covariant, but the solutions are not definitely symmetric. 3) Time is a global property of the universe, which is a measurement of the evolution process of the universe. The internal time of a matter system reflecting its internal evolution speed also takes this cosmic time as a unified background and standard of measurement. 4) The universe has a unified cosmic time T and a cosmic space related to this cosmic time. They are objective and absolute. 5) The eigensolution of a spinor is a critical state losing time concept, which responses the interaction of environment with some uncertainty, then the evolution process of the world is not uniquely determined. 6) The non-uniqueness of the evolution process means that the inverse process is absent. So for a world including spinors, the evolution is essentially irreversible. In this paper, according to the widely accepted principles and direct calculations of transformation, we reveal the misunderstandings in the usual controversy, and then give more natural and reasonable explanations for structure of space-time and arrow of time.
文摘In this paper,the forecasting equations of a 2nd-order space-time differential remainder are deduced from the Navier-Stokes primitive equations and Eulerian operator by Taylor-series expansion.Here we introduce a cubic spline numerical model(Spline Model for short),which is with a quasi-Lagrangian time-split integration scheme of fitting cubic spline/bicubic surface to all physical variable fields in the atmospheric equations on spherical discrete latitude-longitude mesh.A new algorithm of"fitting cubic spline—time step integration—fitting cubic spline—……"is developed to determine their first-and2nd-order derivatives and their upstream points for time discrete integral to the governing equations in Spline Model.And the cubic spline function and its mathematical polarities are also discussed to understand the Spline Model’s mathematical foundation of numerical analysis.It is pointed out that the Spline Model has mathematical laws of"convergence"of the cubic spline functions contracting to the original functions as well as its 1st-order and 2nd-order derivatives.The"optimality"of the 2nd-order derivative of the cubic spline functions is optimal approximation to that of the original functions.In addition,a Hermite bicubic patch is equivalent to operate on a grid for a 2nd-order derivative variable field.Besides,the slopes and curvatures of a central difference are identified respectively,with a smoothing coefficient of 1/3,three-point smoothing of that of a cubic spline.Then the slopes and curvatures of a central difference are calculated from the smoothing coefficient 1/3 and three-point smoothing of that of a cubic spline,respectively.Furthermore,a global simulation case of adiabatic,non-frictional and"incompressible"model atmosphere is shown with the quasi-Lagrangian time integration by using a global Spline Model,whose initial condition comes from the NCEP reanalysis data,along with quasi-uniform latitude-longitude grids and the so-called"shallow atmosphere"Navier-Stokes primitive equations in the spherical coordinates.The Spline Model,which adopted the Navier-Stokes primitive equations and quasi-Lagrangian time-split integration scheme,provides an initial ideal case of global atmospheric circulation.In addition,considering the essentially non-linear atmospheric motions,the Spline Model could judge reasonably well simple points of any smoothed variable field according to its fitting spline curvatures that must conform to its physical interpretation.
文摘Based on the Mach’s principle, black holes warp the space time in a way that geodesic for every object which is moving toward black hole starts to bend and object starts to rotate around the black hole. Even light cannot be able to escape from the strong gravitational field of black hole and all the light like paths will warp so as to fall farther to the hole. Before arriving to the Schwarzschild’s Sphere, object faces with length extension because of the difference between amount of tidal forces on the nearest and furthest points of object that take the object apart and after passing the Schwarzschild’s sphere, based on the Special relativity of Einstein, the parts of object face with length contraction. In comparison between strange stars and black holes we conclude that core of strange stars has a temperature and pressure not sufficient for up and down quarks and they turn into strange ones. However, in core of black holes, because of massive stars and hot gases falling into it, they are always in a high temperature and pressure. So they can be made up of up and down quarks. At the Ergo sphere Region of black hole, a particle that gets into it will divide into 2 pieces, one of them falls into the black hole and another gets out of the Schwarzschild sphere very fast and it’s called the black hole radiation. According to the Diagram drawn by R. Rafini and J. Weeler, an object gets out of white hole in past space-time, it can be able to send signals to us and we can receive it but black hole which is located in future space-time, after object enters to the Schwarzschild’s Sphere, the signals it sends won’t be received. In order to reach the third space-time which is like a mirror to our universe, our speed needs to exceed the speed of light to pass the Einstein-Rosen Bridge. As a conclusion, structure of black holes can be made up of up and down quarks and everything falls into the black hole, collapses and turns into a bunch of quarks. Space-time around black holes, based on Rafini-Weeler diagram, is like a frontier between our space-time and other space-times. So it can be possible to reach past space-time and other space-times.
基金the Key Projects in the National S&T Pillar Program during the Eleventh "Five-year Plan" Period(2006BAC01B03-03-01),China Earthquake AdministrationYouth Fund of Earthquake Administration of Jiangsu Province(2009),China
文摘The paper analyzes the variation characteristics of energy fields of seismicity 2.1≤M L ≤4.5 in Jiangsu and its neighboring areas during the period between January 1970 and December 2007.It also analyzes the variations of time "weight" coefficients of the major typical energy fields,using random function theory with seismic energy fields as a space-time random function field based on Empirical Orthogonal Function (EOF) expansion methods.The results show that the expansion accuracy of the first seven typical fields is 0.9244.The strength of seismic energy varies remarkably in different tectonic blocks in the study area.High value areas are in middle and southern Jiangsu,and the south Yellow Sea.The distribution of the typical fields also shows that it is an area that affects most significantly the seismic energy fields of the study region.The time "weight" coefficients of the first six typical fields vary with time,and the amplitude of the variations has strong temporal correlations with moderate-strong earthquakes in the region.
文摘20th century physics experimentally established beyond doubt the fact that moving clocks read differently from “static” clocks. This fact is typically interpreted as support for special relativity. On the other hand, the same century produced proof that clocks at various locations in the gravitational field also read differently, and this fact is explained by general relativity, which is, in general, not Lorentz transformable. This paper establishes a common framework for the physics of clocks in these different situations.
基金Supported by the Key Program of National Natural Science Foundation of China(Nos.61077071,51075349)Program of National Natural Science Foundation of Hebei Province(Nos.F2011203207,F2010001312)
文摘Phase space reconstruction is the first step of recognizing the chaotic time series.On the basis of differential entropy ratio method,the embedding dimension opt m and time delay t are optimal for the state space reconstruction could be determined.But they are not the optimal parameters accepted for prediction.This study proposes an improved method based on the differential entropy ratio and Radial Basis Function(RBF)neural network to estimate the embedding dimension m and the time delay t,which have both optimal characteristics of the state space reconstruction and the prediction.Simulating experiments of Lorenz system and Doffing system show that the original phase space could be reconstructed from the time series effectively,and both the prediction accuracy and prediction length are improved greatly.
文摘We obtain a new relation between Green's functions of the time-dependent Schrōdinger equation forstationary potentials and Green's functions of the same equation for certain time-dependent potentials. The relationobtained here emerges very easily from a transformation introduced by Ray [J.R. Ray, Phys. Rev. A26 (1982) 729] andgeneralizes former work of Dodonov et al. [V.V. Dodonov, V.I. Man'ko, and D.E. Nikonov, Phys. Lett. A162 (1992)359.]
文摘This paper, having made systematic trend analysis on the front and rear segments of Xintan landslide for space and time respectively by using matbematical statistical principles,discovered that there is obvious trend displacement Of the monitoring points in the rear margin area of the slope and the rates of trend displacement gradually increase with time whereas there is no trend displacement of the monitoring points in the front margin area. This result suggests that the rear margin area of segment is an area of overall sliding and is transforming towards destabilization whereas the front margin area is an area of relative stability. This analytical result well coincides with the conclusion of evaluation on dynamic stability. The analytical result mentioned above shows that the medium to short term forecast and prediction of slope stability can be made by using trend displacement analysis technique in order to achieve the goal of timely evaluation and prevention.
文摘A non-incremental time-space algorithm is proposed for numerical. analysis of forming process with the inclusion of geometrical, material, contact-frictional nonlinearities. Unlike the widely used Newton-Raphson counterpart, the present scheme features an iterative solution procedure on entire time and space domain. Validity and feasibility of foe present scheme are further justiced by the numerical investigation herewith presented.
基金supported by the National Key Research and Development Program of China(2016YFE0200400)the Key R&D Program of Shaanxi Province(2017KW-ZD-12)+1 种基金the Postdoctoral Science Foundation of Shaanxi Provincethe Nature Science Foundation of Shaanxi Province
文摘Space-time coding radar has been recently proposed and investigated.It is a radar framework which can perform transmit beamforming at the receiver.However,the range resolution decreases when the number of the transmit element increases.A subarray-based space-time coding(sub-STC)radar is explored to alleviate the range resolution reduction.For the proposed radar configuration,an identical waveform is transmitted and it introduces a small time offset in different subarrays.The multidimensional ambiguity function of sub-STC radar is defined by considering resolutions in multiple domains including the range,Doppler,angle and probing direction.Analyses on properties of the multi-dimensional ambiguity function of the sub-STC radar with regard to the spatial coverage,resolution performance and low sidelobes are also given.Results reveal that the range resolution and low sidelobes performance are improved with the proposed approach.
基金Supported by the NSFC(10371092,11771185,10871200)
文摘There are three parts in this article. In Section 1, we establish the model of branching chain with drift in space-time random environment (BCDSTRE), i.e., the coupling of branching chain and random walk. In Section 2, we prove that any BCDSTRE must be a Markov chain in time random environment when we consider the distribution of the particles in space as a random element. In Section 3, we calculate the first-order moments and the second-order moments of BCDSTRE.
文摘Based on the space spherical symmetry of 3-dimensional and the translational symmetry of time and the uncertainty principle, a 4-dimensional space-time cylinder model of quarks and leptons is established. With this model, equations of the special relativity can be extended more perfectly, thereby achieving a unity of the special relativity and quantum mechanics in deeper level. New equations can not only interpret issues explained by old equations but also solve several important pending problems. For example, a formula to strictly calculate the coefficient ξ of Lorentz invariance violation (LIV) is derived, to above 4 × 1019 eV UHECR protons the calculated |ξ| -30, although there is the LIV effect it is too weak to change the GZK cutoff, which is consistent with observations of HiRes and Auger;Also, a relation formula between the Hubble constant and several basic constants is derived, thus theoretically calculated H0 = 70.937 km·s-1·Mpc-1, which is well consistent with the final observation result of HST Key Project. In addition, an unusual effect predicted by new equations can be experimentally tested in the electron storage ring;a preliminary experiment result has hinted its signs of existence.
基金Project supported by the National Natural Science Foundation of China(Grant No.61601105)
文摘When the finite difference time domain(FDTD) method is used to solve electromagnetic scattering problems in Schwarzschild space-time, the Green functions linking source/observer to every surface element on connection/output boundary must be calculated.When the scatterer is electrically extended, a huge amount of calculation is required due to a large number of surface elements on the connection/output boundary.In this paper, a method for reducing the calculation workload of Green function is proposed.The Taylor approximation is applied for the calculation of Green function.New transport equations are deduced.The numerical results verify the effectiveness of this method.
文摘The vacuum energy density of free scalar quantum field in a Rindler distributional space-time with distributional Levi-Cività connection is considered. It has been widely believed that, except in very extreme situations, the influence of acceleration on quantum fields should amount to just small, sub-dominant contributions. Here we argue that this belief is wrong by showing that in a Rindler distributional background space-time with distributional Levi-Cività connection the vacuum energy of free quantum fields is forced, by the very same background distributional space-time such a Rindler distributional background space-time, to become dominant over any classical energy density component. This semiclassical gravity effect finds its roots in the singular behavior of quantum fields on a Rindler distributional space-times with distributional Levi-Cività connection. In particular we obtain that the vacuum fluctuations have a singular behavior at a Rindler horizon . Therefore sufficiently strongly accelerated observer burns up near the Rindler horizon. Thus Polchinski’s account doesn’t violate the Einstein equivalence principle.
文摘In this paper, a Wind Direction Change Index (WI), which can describe four-dimensional spatiotemporal changes of the atmospheric circulation objectively and quantitatively, is defined to study its evolution and seasonal variation. The first four modes can be obtained by EOF expansion of the zonally averaged WI. The first mode reveals the basic spatial distribution of the annually averaged WI. The second mode reflects the quasi-harmonic parts of the WI deviations. Tropical, subtropical and extratropical monsoon areas can be clearly reflected by this mode. The third mode reflects the non-harmonic parts of the WI deviations. It shows the so-called February reverse in stratospheric atmosphere as well as the asymmetric seasonal changes from spring to fall and from fall to spring due to both the land-sea distribution contrast between the Northern and Southern Hemispheres and the nonlinear effect of atmospheric and ocean fluids. The fourth mode reveals the northward advancing of the global reversed wind fields from spring to summer and their southward withdrawal from summer to autumn.