A new algorithm for iterative reconstruction is suggested.It is named simple self-correlative algebraic reconstruction technique (SSART).With numerical simulation experiments,SSART was applied in reconstructing a non-...A new algorithm for iterative reconstruction is suggested.It is named simple self-correlative algebraic reconstruction technique (SSART).With numerical simulation experiments,SSART was applied in reconstructing a non-ideal-bordered field in order to test its reconstructive effect.For contrast,three current representative algebraic reconstruction(ARTs) including basic ART,simultaneous ART (SART) and modified SART (MSART) were simulated simultaneously.The calculated results and reconstructive accuracy are discussed with three kinds of error indexes,namely mean-square error (MSE),absolute value error (AVE) and peak error (PE).As the results,the indexes of reconstructive accuracy are much improved by the proposed SSART.The MSE and PE have been decreased by 63.6% on the order of magnitude 10-4 and 88.9% on the order of magnitude 0-2,respectively,compared to that of ART.It is concluded that SSART is one of the most super iterative reconstructing techniques.展开更多
Using an exact solution of the one-dimensional quantum transverse-field Ising model, we calculate the critical exponents of the two-dimensional anisotropic classical Ising model （IM）. We verify that the exponents ar...Using an exact solution of the one-dimensional quantum transverse-field Ising model, we calculate the critical exponents of the two-dimensional anisotropic classical Ising model （IM）. We verify that the exponents are the same as those of isotropic claesical IM. Our approach provides an alternative means of obtaining and verifying these well-known results.展开更多
In this paper we consider exact solutions to the KdV equation under the Bargmann constraint. Solutions expressed through exponential polynomials and Wronskians are derived by bilinear approach through solving the Lax ...In this paper we consider exact solutions to the KdV equation under the Bargmann constraint. Solutions expressed through exponential polynomials and Wronskians are derived by bilinear approach through solving the Lax pair under the Bargmann constraint. It is also shown that the potential u in the stationary Sehrodinger equation can be a summation of squares of wave functions from bilinear point of view.展开更多
We find exact solutions to the Klein-Gordon equation in the vicinity of Schwarzschild black holes.For particles with a zero angular momentum,the convergence range of the solution is r < 4M.One of the solutions desc...We find exact solutions to the Klein-Gordon equation in the vicinity of Schwarzschild black holes.For particles with a zero angular momentum,the convergence range of the solution is r < 4M.One of the solutions describes an exponential enhancement of the density of particles in the vicinity of Schwarzschild black holes,which might be the mechanism of gamma-ray bursts.展开更多
In this paper,we consider the best EFET(entire functions of the exponential type) approximations of some convolution classes associated with Laplace operator on R d and obtain exact constants in the spaces L1(R2) and ...In this paper,we consider the best EFET(entire functions of the exponential type) approximations of some convolution classes associated with Laplace operator on R d and obtain exact constants in the spaces L1(R2) and L2(Rd).Moreover,the best constants of trigonometric approximations of their analogies on Td are also gained.展开更多
基金This project was supported by China Postdoctoral Science Foun-dation(2004036121) the National Natural Science Foundation ofChina(10404022) Education Bureau of Shandong province(J04A63)
文摘A new algorithm for iterative reconstruction is suggested.It is named simple self-correlative algebraic reconstruction technique (SSART).With numerical simulation experiments,SSART was applied in reconstructing a non-ideal-bordered field in order to test its reconstructive effect.For contrast,three current representative algebraic reconstruction(ARTs) including basic ART,simultaneous ART (SART) and modified SART (MSART) were simulated simultaneously.The calculated results and reconstructive accuracy are discussed with three kinds of error indexes,namely mean-square error (MSE),absolute value error (AVE) and peak error (PE).As the results,the indexes of reconstructive accuracy are much improved by the proposed SSART.The MSE and PE have been decreased by 63.6% on the order of magnitude 10-4 and 88.9% on the order of magnitude 0-2,respectively,compared to that of ART.It is concluded that SSART is one of the most super iterative reconstructing techniques.
基金The project supported by National Natural Science Foundation of China under Grant No. 10347101 and the grant from Beijing Normal University
文摘Using an exact solution of the one-dimensional quantum transverse-field Ising model, we calculate the critical exponents of the two-dimensional anisotropic classical Ising model （IM）. We verify that the exponents are the same as those of isotropic claesical IM. Our approach provides an alternative means of obtaining and verifying these well-known results.
基金Supported by National Natural Science Foundation of China under Grant Nos. 10871165 and 10671121
文摘In this paper we consider exact solutions to the KdV equation under the Bargmann constraint. Solutions expressed through exponential polynomials and Wronskians are derived by bilinear approach through solving the Lax pair under the Bargmann constraint. It is also shown that the potential u in the stationary Sehrodinger equation can be a summation of squares of wave functions from bilinear point of view.
基金supported by the National Natural Science Foundation of China (Grant No. 11073007)
文摘We find exact solutions to the Klein-Gordon equation in the vicinity of Schwarzschild black holes.For particles with a zero angular momentum,the convergence range of the solution is r < 4M.One of the solutions describes an exponential enhancement of the density of particles in the vicinity of Schwarzschild black holes,which might be the mechanism of gamma-ray bursts.
基金supported partly by National Natural Science Foundation of China(GrantNo.11071019)Research Fund for the Doctoral Program of Higher Education and Beijing Natural Science Foundation(Grant No.1102011)
文摘In this paper,we consider the best EFET(entire functions of the exponential type) approximations of some convolution classes associated with Laplace operator on R d and obtain exact constants in the spaces L1(R2) and L2(Rd).Moreover,the best constants of trigonometric approximations of their analogies on Td are also gained.
