期刊文献+
共找到710篇文章
< 1 2 36 >
每页显示 20 50 100
Prediction of three-dimensional ocean temperature in the South China Sea based on time series gridded data and a dynamic spatiotemporal graph neural network
1
作者 Feng Nan Zhuolin Li +3 位作者 Jie Yu Suixiang Shi Xinrong Wu Lingyu Xu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第7期26-39,共14页
Ocean temperature is an important physical variable in marine ecosystems,and ocean temperature prediction is an important research objective in ocean-related fields.Currently,one of the commonly used methods for ocean... Ocean temperature is an important physical variable in marine ecosystems,and ocean temperature prediction is an important research objective in ocean-related fields.Currently,one of the commonly used methods for ocean temperature prediction is based on data-driven,but research on this method is mostly limited to the sea surface,with few studies on the prediction of internal ocean temperature.Existing graph neural network-based methods usually use predefined graphs or learned static graphs,which cannot capture the dynamic associations among data.In this study,we propose a novel dynamic spatiotemporal graph neural network(DSTGN)to predict threedimensional ocean temperature(3D-OT),which combines static graph learning and dynamic graph learning to automatically mine two unknown dependencies between sequences based on the original 3D-OT data without prior knowledge.Temporal and spatial dependencies in the time series were then captured using temporal and graph convolutions.We also integrated dynamic graph learning,static graph learning,graph convolution,and temporal convolution into an end-to-end framework for 3D-OT prediction using time-series grid data.In this study,we conducted prediction experiments using high-resolution 3D-OT from the Copernicus global ocean physical reanalysis,with data covering the vertical variation of temperature from the sea surface to 1000 m below the sea surface.We compared five mainstream models that are commonly used for ocean temperature prediction,and the results showed that the method achieved the best prediction results at all prediction scales. 展开更多
关键词 dynamic associations three-dimensional ocean temperature prediction graph neural network time series gridded data
下载PDF
Comparative Studies between Picard’s and Taylor’s Methods of Numerical Solutions of First Ordinary Order Differential Equations Arising from Real-Life Problems
2
作者 Khalid Abd Elrazig Awad Alla Elnour 《Journal of Applied Mathematics and Physics》 2024年第3期877-896,共20页
To solve the first-order differential equation derived from the problem of a free-falling object and the problem arising from Newton’s law of cooling, the study compares the numerical solutions obtained from Picard’... To solve the first-order differential equation derived from the problem of a free-falling object and the problem arising from Newton’s law of cooling, the study compares the numerical solutions obtained from Picard’s and Taylor’s series methods. We have carried out a descriptive analysis using the MATLAB software. Picard’s and Taylor’s techniques for deriving numerical solutions are both strong mathematical instruments that behave similarly. All first-order differential equations in standard form that have a constant function on the right-hand side share this similarity. As a result, we can conclude that Taylor’s approach is simpler to use, more effective, and more accurate. We will contrast Rung Kutta and Taylor’s methods in more detail in the following section. 展开更多
关键词 First-Order Differential Equations Picard Method Taylor series Method Numerical solutions Numerical Examples MATLAB Software
下载PDF
A series solution for surface motion amplification due to underground twin tunnels:incident SV waves 被引量:17
3
作者 梁建文 张浩 Vincent W Lee 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2003年第2期289-298,共10页
A series solution of displacement response of the ground surface in the presence of underground twin tunnels subjected to excitation of incident plane SV waves is derived by using Fourier-Bessel series expansion metho... A series solution of displacement response of the ground surface in the presence of underground twin tunnels subjected to excitation of incident plane SV waves is derived by using Fourier-Bessel series expansion method.The numerical parametric study shows that underground twin tunnels significantly amplify the nearby surface ground motion.It is suggested that the effect of subways on ground motion should be considered when the subways are planned and designed. 展开更多
关键词 underground twin tunnels surface motion plane SV wave SCATTERING series solution
下载PDF
A series solution for surface motion amplification due to underground group cavities:Incident P waves 被引量:3
4
作者 LIANG Jian-wen(梁建文) ZHANG Hao(张浩) Vincent W Lee 《Acta Seismologica Sinica(English Edition)》 CSCD 2004年第3期296-307,共12页
A series solution for surface motion amplification due to underground group cavities for incident plane P waves is derived by Fourier-Bessel series expansion method. It is shown that underground group cavities signifi... A series solution for surface motion amplification due to underground group cavities for incident plane P waves is derived by Fourier-Bessel series expansion method. It is shown that underground group cavities significantly am-plify the surface ground motion nearby. It is suggested that the effect of subways on ground motion should be con-sidered when the subways are planned and designed. 展开更多
关键词 underground group cavities surface motion plane P wave SCATTERING series solution CLC number: P315.3 Document code: A
下载PDF
Infinite series symmetry reduction solutions to the modified KdV-Burgers equation 被引量:3
5
作者 姚若侠 焦小玉 楼森岳 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第5期1821-1827,共7页
From the point of view of approximate symmetry, the modified Korteweg-de Vries-Burgers (mKdV-Burgers) equation with weak dissipation is investigated. The symmetry of a system of the corresponding partial differentia... From the point of view of approximate symmetry, the modified Korteweg-de Vries-Burgers (mKdV-Burgers) equation with weak dissipation is investigated. The symmetry of a system of the corresponding partial differential equations which approximate the perturbed mKdV-Burgers equation is constructed and the corresponding general approximate symmetry reduction is derived; thereby infinite series solutions and general formulae can be obtained. The obtained result shows that the zero-order similarity solution to the mKdV-Burgers equation satisfies the Painleve II equation. Also, at the level of travelling wave reduction, the general solution formulae are given for any travelling wave solution of an unperturbed mKdV equation. As an illustrative example, when the zero-order tanh profile solution is chosen as an initial approximate solution, physically approximate similarity solutions are obtained recursively under the appropriate choice of parameters occurring during computation. 展开更多
关键词 modified Korteweg-de Vries-Burgers (mKdV-Burgers) equation approximate symme-try reduction series reduction solution
下载PDF
The series solution to the metric of stationary vacuum with axisymmetry 被引量:1
6
作者 辜英求 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第3期90-100,共11页
The multipole moment method not only conduces to the understanding of the deformation of the space-time, but also serves as an effective tool to approximately solve the Einstein field equation with. However, the usual... The multipole moment method not only conduces to the understanding of the deformation of the space-time, but also serves as an effective tool to approximately solve the Einstein field equation with. However, the usual multipole moments are recursively determined by a sequence of symmetric and trace-free tensors, which is inconvenient for practical resolution. In this paper, we develop a simplified procedure to generate the series solutions to the metric of the stationary vacuum with axisymmetry, and show its validity. In order to understand the free parameters in the solution, we propose to take the Schwarzschild metric as a standard ruler, and some well- known examples are analysed and compared with the series solutions in detail. 展开更多
关键词 stationary metric multipole moments asymptotically fiat series solution
下载PDF
Approximate Symmetries and Infinite Series Symmetry Reduction Solutions to Perturbed Kuramoto-Sivashinsky Equation 被引量:2
7
作者 YAO Ruo-Xia JIAO Xiao-Yu LOU Sen-Yue 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第5期785-788,共4页
Starting from Lie symmetry theory and combining with the approximate symmetry method, and using the package LieSYMGRP proposed by us, we restudy the perturbed Kuramoto-Sivashinsky (KS) equation. The approximate symm... Starting from Lie symmetry theory and combining with the approximate symmetry method, and using the package LieSYMGRP proposed by us, we restudy the perturbed Kuramoto-Sivashinsky (KS) equation. The approximate symmetry reduction and the infinite series symmetry reduction solutions of the perturbed KS equation are constructed. Specially, if selecting the tanh-type travelling wave solution as initial approximate, we not only obtain the general formula of the physical approximate similarity solutions, but also obtain several new explicit solutions of the given equation, which are first reported here. 展开更多
关键词 perturbed Kuramoto-Sivashinsky equation approximate symmetry reduction series reduction solution
下载PDF
AN ANALYTICAL SOLUTION FOR THREE-DIMENSIONAL DIFFRACTION OF PLANE P-WAVES BY A HEMISPHERICAL ALLUVIAL VALLEY WITH SATURATED SOIL DEPOSITS 被引量:2
8
作者 Zhao Chenggang Dong Jun Gao Fuping 《Acta Mechanica Solida Sinica》 SCIE EI 2006年第2期141-151,共11页
An analytical solution for the three-dimensional scattering and diffraction of plane P-waves by a hemispherical alluvial valley with saturated soil deposits is developed by employing Fourier-Bessel series expansion te... An analytical solution for the three-dimensional scattering and diffraction of plane P-waves by a hemispherical alluvial valley with saturated soil deposits is developed by employing Fourier-Bessel series expansion technique. Unlike previous studies, in which the saturated soil deposits were simulated with the single-phase elastic theory, in this paper, they are simulated with Biot's dynamic theory for saturated porous media, and the half space is assumed as a single-phase elastic medium. The effects of the dimensionless frequency, the incidence angle of P-wave and the porosity of soil deposits on the surface displacement magnifications of the hemispherical alluvial valley are investigated. Numerical results show that the existence of a saturated hemispherical alluvial valley has much influence on the surface displacement magnifications. It is more reasonable to simulate soil deposits with Biot's dynamic theory when evaluating the displacement responses of a hemispherical alluvial valley with an incidence of P-waves. 展开更多
关键词 Biot's dynamic theory three-dimensional scattering hemispherical alluvial valley analytical solution
下载PDF
A Series Solution Approach to the Circular Restricted Gravitational Three-Body Dynamical Problem 被引量:1
9
作者 Maha Hamed Alghamdi Aisha Abdu Alshaery 《Journal of Applied Mathematics and Physics》 2020年第12期2703-2712,共10页
The present manuscript examines the circular restricted gravitational three-body problem (CRGTBP) by the introduction of a new approach through the power series method. In addition, certain computational algorithms wi... The present manuscript examines the circular restricted gravitational three-body problem (CRGTBP) by the introduction of a new approach through the power series method. In addition, certain computational algorithms with the aid of Mathematica software are specifically designed for the problem. The algorithms or rather mathematical modules are established to determine the velocity and position of the third body’s motion. In fact, the modules led to accurate results and thus proved the new approach to be efficient. 展开更多
关键词 n-Body Problems Restricted Gravitational Problems Power series Method series solution Approach
下载PDF
The Qualitative Analysis of a Solution of a Series Maintenance System with Two Components 被引量:1
10
作者 GUOWei-hua YANGMing-zeng 《Chinese Quarterly Journal of Mathematics》 CSCD 2003年第3期320-327,共8页
In this paper, firstly we study the series ma intenance system with two components, obtain its exsistence and uniqueness of a dynamic state nonnegative solution by strongly continuous semigroups of operator s theory. ... In this paper, firstly we study the series ma intenance system with two components, obtain its exsistence and uniqueness of a dynamic state nonnegative solution by strongly continuous semigroups of operator s theory. Then we prove that 0 is the eigenvalue of the system’s host operators, a nd finally we study the eigenvector of the eigenvalue 0. 展开更多
关键词 series connection maintenance system semig roups of operators nonnegative solution
下载PDF
Truncated series solutions to the(2+1)-dimensional perturbed Boussinesq equation by using the approximate symmetry method
11
作者 Xiao-Yu Jiao 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第10期123-129,共7页
In this paper, the(2+1)-dimensional perturbed Boussinesq equation is transformed into a series of two-dimensional(2 D) similarity reduction equations by using the approximate symmetry method. A step-by-step proce... In this paper, the(2+1)-dimensional perturbed Boussinesq equation is transformed into a series of two-dimensional(2 D) similarity reduction equations by using the approximate symmetry method. A step-by-step procedure is used to acquire Jacobi elliptic function solutions to these similarity equations, which generate the truncated series solutions to the original perturbed Boussinesq equation. Aside from some singular area, the series solutions are convergent when the perturbation parameter is diminished. 展开更多
关键词 approximate symmetry method (2+1)-dimensional perturbed Boussinesq equation series solutions convergence of series solutions
下载PDF
DIFFERENTIATOR SERIES SOLUTION OF LINEAR DIFFERENTIAL ORDINARY EQUATION
12
作者 柯红路 谢和熙 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1999年第8期59-66,共8页
In this paper, the principle techinique of the differentiator method, and some examples using the method to obtain the general solution and special solution of the differential equation are introduced. The essential d... In this paper, the principle techinique of the differentiator method, and some examples using the method to obtain the general solution and special solution of the differential equation are introduced. The essential difference between this method and the others is that by this method special and general solutions can be obtained directly with the operations of the differentor in the differential equation and without the enlightenment of other scientific knowledge. 展开更多
关键词 linear ordinary differential equation differentiator series method special solution general solution
下载PDF
Note on Barenblatt power series solution to Boussinesq equation
13
作者 宋志尧 李凌 David Lockington 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第6期823-828,共6页
To the serf-similar analytical solution of the Boussinesq equation of groundwater flow in a semi-infinite porous medium, when the hydraulic head at the boundary behaved like a power of time, Barenblatt obtained a powe... To the serf-similar analytical solution of the Boussinesq equation of groundwater flow in a semi-infinite porous medium, when the hydraulic head at the boundary behaved like a power of time, Barenblatt obtained a power series solution. However, he listed only the first three coefficients and did not give the recurrent formula among the coefficients. A formal proof of convergence of the series did not appear in his works. In this paper, the recurrent formula for the coefficients is obtained by using the method of power series expansion, and the convergence of the series is proven. The results can be easily understood and used by engineers in the catchment hydrology and baseflow studies as well as to solve agricultural drainage problems. 展开更多
关键词 power series expansion similarity solution recurrent formula CONVERGENCE
下载PDF
Series Solution of Non-Similarity Boundary-Layer Flow in Porous Medium
14
作者 Nabeela Kousar Rashid Mahmood 《Applied Mathematics》 2013年第8期127-136,共10页
This paper aims to present complete series solution of non-similarity boundary-layer flow of an incompressible viscous fluid over a porous wedge. The corresponding nonlinear partial differential equations are solved a... This paper aims to present complete series solution of non-similarity boundary-layer flow of an incompressible viscous fluid over a porous wedge. The corresponding nonlinear partial differential equations are solved analytically by means of the homotopy analysis method (HAM). An auxiliary parameter is introduced to ensure the convergence of solution series. As a result, series solutions valid for all physical parameters in the whole domain are given. Then, the effects of physical parameters γ and Prandtl number Pr on the local Nusselt number and momentum thickness are investigated. To the best of our knowledge, it is the first time that the series solutions of this kind of non-similarity boundary-layer flows are reported. 展开更多
关键词 Non-Similarity Boundary-Layer Flow POROUS WEDGE series solution HOMOTOPY Analysis Method
下载PDF
Existence and Uniqueness of the Dynamic Solution of a Series-Parallel Repairable System Consisting of Three-Unit with Multiple Vacations of a Repairman 被引量:2
15
作者 Abdukerim Haji Tursunjan Keyim Bilikiz Yunus 《Journal of Applied Mathematics and Physics》 2016年第8期1585-1591,共7页
We investigate a series-parallel repairable system consisting of three-unit with multiple vacations of a repairman. By using C0-semigroup theory of linear operators in the functional analysis, we prove that the system... We investigate a series-parallel repairable system consisting of three-unit with multiple vacations of a repairman. By using C0-semigroup theory of linear operators in the functional analysis, we prove that the system is well-posed and has a unique positive dynamic solution. 展开更多
关键词 series-Parallel Repairable System C_0-Semigroup Dynamic solution
下载PDF
Three-Dimensional Exact Solution for Dynamic Damped Response of Plates with Two Free Edges
16
作者 Le Wang Muchun Yu 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2019年第3期79-90,共12页
A three-dimensional state space method has been developed for the calculation of dynamic response of plates with two free edges and two simply supported edges.A complex damping model was introduced, then the exact sol... A three-dimensional state space method has been developed for the calculation of dynamic response of plates with two free edges and two simply supported edges.A complex damping model was introduced, then the exact solutions which satisfy all the governing equations and boundary conditions were obtained.In order to overcome the difficulty of satisfying all the stress conditions at free edges, the displacement functions of free edges were assumed.The boundary conditions were strictly satisfied when the convergence rate was good.The computing time was evidently less than that of finite element method.The comparison of the solution with those of finite element method show that there is an excellent agreement for displacements.When the imaginary parts of normal stress deviated, the finite element results showed existence of shear stresses at top and bottom surfaces, and the boundary conditions of FEM model were not strictly satisfied. 展开更多
关键词 three-dimensional EXACT solution state space method free edge RESPONSE
下载PDF
Series Solution for Localization and Entanglement of an Exciton in a Quantum Dot Molecule by an ac Electric Field
17
作者 LIN Chang ZHANG Xiu-Lian 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第2期357-362,共6页
The Schroedinger equation involving the phenomenon of the localization and entanglement for an exciton in a quantum dot molecule by an ac electric field is analytically investigated. New exact series solutions for the... The Schroedinger equation involving the phenomenon of the localization and entanglement for an exciton in a quantum dot molecule by an ac electric field is analytically investigated. New exact series solutions for the Schroedinger equation have been obtained for the first time. The analytical expressions can further describe the dynamical behaviors of an interacting electron-hole pair in a double coupled quantum dot molecule under an ac electric field accurately. 展开更多
关键词 Schrodinger equation quantum dot molecule LOCALIZATION ENTANGLEMENT exact series solution
下载PDF
Three-dimensional elasticity solutions for bending of generally supported thick functionally graded plates
18
作者 张鹤 蒋吉清 张治成 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2014年第11期1467-1478,共12页
Three-dimensional elasticity solutions for static bending of thick functionally graded plates are presented using a hybrid semi-analytical approach-the state-space based differential quadrature method (SSDQM). The p... Three-dimensional elasticity solutions for static bending of thick functionally graded plates are presented using a hybrid semi-analytical approach-the state-space based differential quadrature method (SSDQM). The plate is generally supported at four edges for which the two-way differential quadrature method is used to solve the in-plane variations of the stress and displacement fields numerically. An approximate laminate model (ALM) is exploited to reduce the inhomogeneous plate into a multi-layered laminate, thus applying the state space method to solve analytically in the thickness direction. Both the convergence properties of SSDQM and ALM are examined. The SSDQM is validated by comparing the numerical results with the exact solutions reported in the literature. As an example, the Mori-Tanaka model is used to predict the effective bulk and shear moduli. Effects of gradient index and aspect ratios on the bending behavior of functionally graded thick plates are investigated. 展开更多
关键词 functionally grade material thick plate three-dimensional solution semianalytical approach
下载PDF
THE THREE-DIMENSIONAL FUNDAMENTAL SOLUTION TO STOKES FLOW IN THE OBLATE SPHEROIDAL COORDINATES WITH APPLICATIONS TO MULTIPLES SPHEROID PROBLEMS
19
作者 庄宏 严宗毅 吴望一 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2002年第5期514-534,共21页
A new three-dimensional fundamental solution to the Stokes flow was proposed by transforming the solid harmonic functions in Lamb's solution into expressions in terms Of the oblate spheroidal coordinates. These fu... A new three-dimensional fundamental solution to the Stokes flow was proposed by transforming the solid harmonic functions in Lamb's solution into expressions in terms Of the oblate spheroidal coordinates. These fundamental solutions are advantageous in treating flows past an arbitrary number of arbitrarily positioned and oriented oblate spheroids. The least squares technique was adopted herein so that the convergence difficulties often encountered in solving three-dimensional problems were completely avoided. The examples demonstrate that present approach is highly accurate, consistently stable and computationally efficient. The oblate spheroid may be used to model a variety of particle shapes between a circular disk and a sphere. For the first time, the effect of various geometric factors on the forces and torques exerted on two oblate spheroids were systematically studied by using the proposed fundamental solutions. The generality of this approach was illustrated by two problems of three spheroids. 展开更多
关键词 Stokes flow fundamental solution three-dimension oblate spheroid multipole collocation least squares method low Reynolds number multiple particles
下载PDF
Exact analytical solution to three-dimensional phase change heat transfer problems in biological tissues subject to freezing
20
作者 李方方 刘静 乐恺 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2009年第1期63-72,共10页
Analytically solving a three-dimensional (3-D) bioheat transfer problem with phase change during a freezing process is extremely difficult but theoretically important. The moving heat source model and the Green func... Analytically solving a three-dimensional (3-D) bioheat transfer problem with phase change during a freezing process is extremely difficult but theoretically important. The moving heat source model and the Green function method are introduced to deal with the cryopreservation process of in vitro biomaterials. Exact solutions for the 3-D temperature transients of tissues under various boundary conditions, such as totally convective cooling, totally fixed temperature cooling and a hybrid between them on tissue surfaces, are obtained. Furthermore, the cryosurgical process in living tissues subject to freezing by a single or multiple cryoprobes is also analytically solved. A closed-form analytical solution to the bioheat phase change process is derived by considering contributions from blood perfusion heat transfer, metabolic heat generation, and heat sink of a cryoprobe. The present method is expected to have significant value for analytically solving complex bioheat transfer problems with phase change. 展开更多
关键词 three-dimensional phase change heat transfer problem CRYOSURGERY CRYOPRESERVATION moving heat source model bioheat transfer Green's function analytical solution
下载PDF
上一页 1 2 36 下一页 到第
使用帮助 返回顶部