A new model for self-diffusion coefficients was proposed based oil both the concepts of molecular free volume and activation energy. The unknown parameters of this model were clearly defined and compared with the Chap...A new model for self-diffusion coefficients was proposed based oil both the concepts of molecular free volume and activation energy. The unknown parameters of this model were clearly defined and compared with the Chapman-Enskog model. At the same time a new method for calculating activation energy was devised and applied to the new model. In addition, the free volume was defined by implementing the generic van der Waals equation of state, the radial distribution function of which was obtained by using the Morsali- Goharshadi empirical formula. Under the same conditions, the new model was better than the original free volume model.展开更多
This paper deals with problems of the uniqueness of entire functions that share one pair of values with their derivatives. The results in this paper generalize and improve a result of Jank, Mues and Volkmann, a result...This paper deals with problems of the uniqueness of entire functions that share one pair of values with their derivatives. The results in this paper generalize and improve a result of Jank, Mues and Volkmann, a result of YANG L Z and a result of R Brück.展开更多
In this paper, some necessary and sufficient optimality conditions are obtained for a fractional multiple objective programming involving semilocal E-convex and related functions. Also, some dual results are establish...In this paper, some necessary and sufficient optimality conditions are obtained for a fractional multiple objective programming involving semilocal E-convex and related functions. Also, some dual results are established under this kind of generalized convex functions. Our results generalize the ones obtained by Preda[J Math Anal Appl, 288（2003） 365-382].展开更多
This study demonstrates how the volatility index （VIX） can help predict the returns for sequential trading days. Using a logit function and previous VIX information, we present an initial attempt to estimate the pro...This study demonstrates how the volatility index （VIX） can help predict the returns for sequential trading days. Using a logit function and previous VIX information, we present an initial attempt to estimate the probability of a positive market return. The estimation procedure is applied to recent data on the S＆P500 and to the 10-year U.S. Treasury Bonds yields. Our findings indicate that such a relationship does exist and is significant, especially for the bond market. We also ran an investment simulation using different VIX scores and found that from 2004 to June 2009, VIX=18 was the score that yielded the highest.展开更多
Based on the Global Color Symmetry Model, the non-perturbative Q, CD vacuum is investigated in the parameterized fully dressed quark propagator. Our theoretical predictions for various quantities characterized the QCD...Based on the Global Color Symmetry Model, the non-perturbative Q, CD vacuum is investigated in the parameterized fully dressed quark propagator. Our theoretical predictions for various quantities characterized the QCD vacuum are in agreement with those predicted by many other phenomenologieal QCD inspired models. The successful predictions clearly indicate the extensive validity of our parameterized quark propagator used here. A detailed discussion on the arbitrariness in determining the integration cut-off parameter ofμ in calculating QCD vacuum condensates and a good method, which avoided the dependence of calculating results on the cut-off parameter is also strongly recommended to readers.展开更多
Gaussian models without intermittency are extensively used in estimating the effect of turbulence,but italso brings some puzzles,for example the observed pulse shape that disagrees with the result of the standard theo...Gaussian models without intermittency are extensively used in estimating the effect of turbulence,but italso brings some puzzles,for example the observed pulse shape that disagrees with the result of the standard theoryof interstellar scintillations.Indeed the property of intermittency is inherent in turbulence,i.e.,all the quantities thatcharacterize it suffer from strong fluctuations.So it is necessary to consider turbulent intermittency in many applications.In this paper we propose a non-Gaussian phase screen,which obeys log-Poisson statistics,and also offers the correspondingpoint spread function(PSF).These results describe that intermittency leads to the more extent and different directionaldistribution of PSF.Theoretical analysis is made under the hypothesis of the phase difference satisfying log-Poissonstatistics,and the average point spread function,which accord qualitatively with the result of the above generated phasescreen,is derived.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
The Leibniz-Hopf algebra is the free associative algebra with one generator in each positive degree and coproduct given by the Cartan formula. Quasi-symmetric functions are a generalisation of symmetric functions [7],...The Leibniz-Hopf algebra is the free associative algebra with one generator in each positive degree and coproduct given by the Cartan formula. Quasi-symmetric functions are a generalisation of symmetric functions [7],and the algebra of quasi-symmetric functions appear as the dual of the Leibniz-Hopf algebra. The Leibniz-Hopf algebra and its dual are word Hopf algebras and play an important role in combinatorics, algebra and topology. We give some properties of words and consider an another view of proof for the antipode in the dual Leibniz-Hopf algebra.展开更多
In this paper.a characterizationis,obtained for those pairs of weight funetions on (0=∞) for which the Hardy operator Pf(x)=f(t)dt is bounded from (μ) to ,0<q<1<p <+∞.
Based on a simplified 3-DOF model of twin-tower structure linked by a sky-bridge,the frequency response functions,the displacement power spectral density(PSD)functions,and the time-averaged total vibration energy were...Based on a simplified 3-DOF model of twin-tower structure linked by a sky-bridge,the frequency response functions,the displacement power spectral density(PSD)functions,and the time-averaged total vibration energy were derived,by assuming the white noise as the earthquake excitation.The effects of connecting parameters,such as linking stiffness ratio and linking damping ratio,on the structural vibration responses were then studied,and the optimal connecting parameters were obtained to minimize the vibration energy of either the independent monomer tower or the integral structure.The influences of sky-bridge elevation position on the optimal connecting parameters were also discussed.Finally,the distribution characteristics of the top displacement PSD and the structural responses,excited by El Centro,Taft and artificial waves,were compared in both frequency and time domain.It is found that the connecting parameters at either end of connection interactively affect the responses of the towers.The optimal connecting parameters can greatly improve the damping connections on their seismic reduction effectiveness,but are unable to reduce the seismic responses of the towers to the best extent simultaneously.It is also indicated that the optimal connecting parameters derived from the simplified 3-DOF model are applicable for two multi-story structures linked by a sky-bridge with dampers.The seismic reduction effectiveness obtained varies from 0.3 to 1.0 with different sky-bridge mass ratio.The displacement responses of the example structures are reduced by approximately 22% with sky-bridge connections.展开更多
We propose a scheme for the effective polarization and manipulation of electron spin by using a quantum dot with both charge and spin bias. Using the equation of motion for Keldysh nonequilibrium Green function, we st...We propose a scheme for the effective polarization and manipulation of electron spin by using a quantum dot with both charge and spin bias. Using the equation of motion for Keldysh nonequilibrium Green function, we study the spin accumulation and polarization for the system. Through analytical analysis and a few numerical examples, it is demonstrated that fairly large spin accumulation and polarization can be produced due to the breaking symmetry of the chemical potential for different electron spin in the leads. Moreover, the direction and the strength of the spin polarization can be conveniently controlled and tuned by varying the charge bias or the gate voltage.展开更多
By use of a direct method, we discuss symmetries and reductions of the two-dimensional Burgers equation with variable coefficient (VCBurgers). Five types of symmetry-reducing VCBurgers to (1+1)-dimensional partial dif...By use of a direct method, we discuss symmetries and reductions of the two-dimensional Burgers equation with variable coefficient (VCBurgers). Five types of symmetry-reducing VCBurgers to (1+1)-dimensional partial differential equation and three types of symmetry reducing VCBurgers to ordinary differential equation are obtained.展开更多
The Leibniz-Hopf algebra is the free associative Z - algebra with one generator in each positive degree and coproduct is given by the Cartan formula. It has been also known as the ＇ring ofnoncommutative symmetric fun...The Leibniz-Hopf algebra is the free associative Z - algebra with one generator in each positive degree and coproduct is given by the Cartan formula. It has been also known as the ＇ring ofnoncommutative symmetric functions＇ [1], and to be isomorphic to the Solomon Descent algebra [ 12]. This Hopf algebra has links with algebra,topology and combinatorics. In this article we consider another approach of proof for the antipode formula in the Leibniz-Hopf algebra by using some properties of words in [2].展开更多
文摘A new model for self-diffusion coefficients was proposed based oil both the concepts of molecular free volume and activation energy. The unknown parameters of this model were clearly defined and compared with the Chapman-Enskog model. At the same time a new method for calculating activation energy was devised and applied to the new model. In addition, the free volume was defined by implementing the generic van der Waals equation of state, the radial distribution function of which was obtained by using the Morsali- Goharshadi empirical formula. Under the same conditions, the new model was better than the original free volume model.
文摘This paper deals with problems of the uniqueness of entire functions that share one pair of values with their derivatives. The results in this paper generalize and improve a result of Jank, Mues and Volkmann, a result of YANG L Z and a result of R Brück.
基金Foundation item： Supported by Hunan Provincial Natural Science Foundation of China（05JJ40103） Supported by Soft Science Research Fund of Hunan Province（2006ZK3028） Supported by Scientific Research Fund of Hunan Provincial Education Department（105B0707, 08C470）
文摘In this paper, some necessary and sufficient optimality conditions are obtained for a fractional multiple objective programming involving semilocal E-convex and related functions. Also, some dual results are established under this kind of generalized convex functions. Our results generalize the ones obtained by Preda[J Math Anal Appl, 288（2003） 365-382].
文摘This study demonstrates how the volatility index （VIX） can help predict the returns for sequential trading days. Using a logit function and previous VIX information, we present an initial attempt to estimate the probability of a positive market return. The estimation procedure is applied to recent data on the S＆P500 and to the 10-year U.S. Treasury Bonds yields. Our findings indicate that such a relationship does exist and is significant, especially for the bond market. We also ran an investment simulation using different VIX scores and found that from 2004 to June 2009, VIX=18 was the score that yielded the highest.
基金The project supported in part by National Natural Science Foundation of China under Grant Nos.10647002 and 10565001Natural Science Foundation of Guangxi Province under Grant Nos.0542042,0481030,and 0575020Guangxi University of Technology under Grant No.05006
文摘Based on the Global Color Symmetry Model, the non-perturbative Q, CD vacuum is investigated in the parameterized fully dressed quark propagator. Our theoretical predictions for various quantities characterized the QCD vacuum are in agreement with those predicted by many other phenomenologieal QCD inspired models. The successful predictions clearly indicate the extensive validity of our parameterized quark propagator used here. A detailed discussion on the arbitrariness in determining the integration cut-off parameter ofμ in calculating QCD vacuum condensates and a good method, which avoided the dependence of calculating results on the cut-off parameter is also strongly recommended to readers.
基金Supported by the National Natural Science Foundation Science Foundation of China Academy of Engineering Physics (NSAF) under Grant No.10576005the National Natural Science Foundation of China under Grant No.10647127+1 种基金the Science Foundation of Hebei Education Department under Grant No.2009135the Science Foundation of Hebei Normal University
文摘Gaussian models without intermittency are extensively used in estimating the effect of turbulence,but italso brings some puzzles,for example the observed pulse shape that disagrees with the result of the standard theoryof interstellar scintillations.Indeed the property of intermittency is inherent in turbulence,i.e.,all the quantities thatcharacterize it suffer from strong fluctuations.So it is necessary to consider turbulent intermittency in many applications.In this paper we propose a non-Gaussian phase screen,which obeys log-Poisson statistics,and also offers the correspondingpoint spread function(PSF).These results describe that intermittency leads to the more extent and different directionaldistribution of PSF.Theoretical analysis is made under the hypothesis of the phase difference satisfying log-Poissonstatistics,and the average point spread function,which accord qualitatively with the result of the above generated phasescreen,is derived.
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.
文摘The Leibniz-Hopf algebra is the free associative algebra with one generator in each positive degree and coproduct given by the Cartan formula. Quasi-symmetric functions are a generalisation of symmetric functions [7],and the algebra of quasi-symmetric functions appear as the dual of the Leibniz-Hopf algebra. The Leibniz-Hopf algebra and its dual are word Hopf algebras and play an important role in combinatorics, algebra and topology. We give some properties of words and consider an another view of proof for the antipode in the dual Leibniz-Hopf algebra.
文摘In this paper.a characterizationis,obtained for those pairs of weight funetions on (0=∞) for which the Hardy operator Pf(x)=f(t)dt is bounded from (μ) to ,0<q<1<p <+∞.
基金Project(51178203)supported by the National Natural Science Foundation of China
文摘Based on a simplified 3-DOF model of twin-tower structure linked by a sky-bridge,the frequency response functions,the displacement power spectral density(PSD)functions,and the time-averaged total vibration energy were derived,by assuming the white noise as the earthquake excitation.The effects of connecting parameters,such as linking stiffness ratio and linking damping ratio,on the structural vibration responses were then studied,and the optimal connecting parameters were obtained to minimize the vibration energy of either the independent monomer tower or the integral structure.The influences of sky-bridge elevation position on the optimal connecting parameters were also discussed.Finally,the distribution characteristics of the top displacement PSD and the structural responses,excited by El Centro,Taft and artificial waves,were compared in both frequency and time domain.It is found that the connecting parameters at either end of connection interactively affect the responses of the towers.The optimal connecting parameters can greatly improve the damping connections on their seismic reduction effectiveness,but are unable to reduce the seismic responses of the towers to the best extent simultaneously.It is also indicated that the optimal connecting parameters derived from the simplified 3-DOF model are applicable for two multi-story structures linked by a sky-bridge with dampers.The seismic reduction effectiveness obtained varies from 0.3 to 1.0 with different sky-bridge mass ratio.The displacement responses of the example structures are reduced by approximately 22% with sky-bridge connections.
基金Supported by the Guizhou Province Governor Foundation for Excellent Talents in Science and Education under Grant No.200847the Research Found of Qiannan Normal College for Nationalities under Grant No.2008Y19
文摘We propose a scheme for the effective polarization and manipulation of electron spin by using a quantum dot with both charge and spin bias. Using the equation of motion for Keldysh nonequilibrium Green function, we study the spin accumulation and polarization for the system. Through analytical analysis and a few numerical examples, it is demonstrated that fairly large spin accumulation and polarization can be produced due to the breaking symmetry of the chemical potential for different electron spin in the leads. Moreover, the direction and the strength of the spin polarization can be conveniently controlled and tuned by varying the charge bias or the gate voltage.
文摘By use of a direct method, we discuss symmetries and reductions of the two-dimensional Burgers equation with variable coefficient (VCBurgers). Five types of symmetry-reducing VCBurgers to (1+1)-dimensional partial differential equation and three types of symmetry reducing VCBurgers to ordinary differential equation are obtained.
文摘The Leibniz-Hopf algebra is the free associative Z - algebra with one generator in each positive degree and coproduct is given by the Cartan formula. It has been also known as the ＇ring ofnoncommutative symmetric functions＇ [1], and to be isomorphic to the Solomon Descent algebra [ 12]. This Hopf algebra has links with algebra,topology and combinatorics. In this article we consider another approach of proof for the antipode formula in the Leibniz-Hopf algebra by using some properties of words in [2].
