The （G＇/G, 1/G）-expansion method for finding exact travelling wave solutions of nonlinear evolution equations, which can be thought of as an extension of the （G＇/G）-expansion method proposed recently, is present...The （G＇/G, 1/G）-expansion method for finding exact travelling wave solutions of nonlinear evolution equations, which can be thought of as an extension of the （G＇/G）-expansion method proposed recently, is presented. By using this method abundant travelling wave so- lutions with arbitrary parameters of the Zakharov equations are successfully obtained. When the parameters are replaced by special values, the well-known solitary wave solutions of the equations are rediscovered from the travelling waves.展开更多
A LiC1/DMAC solvent system was used to dissolve wood-cellulose with aims to broaden its application in preparing functional materials of modified wood-cellulose. We studied the dissolubility complexion of wood-cellulo...A LiC1/DMAC solvent system was used to dissolve wood-cellulose with aims to broaden its application in preparing functional materials of modified wood-cellulose. We studied the dissolubility complexion of wood-cellulose in a LiC1/DMAC solvent system, made sure of the important function of LiC1 in a cellulose solvent, and further confirmed its dissolution mechanism via the measurement of infrared spectra of soluble products. The study results are as follows： first, LiC1 salts, which can form intermediate complexes with cellulose, have played an important role in the LiC1/DMAC solvent system, and their solubility performance is en- hanced by reducing the hydrogen bond effect between cellulose molecules; second, the non-aqueous solvent system is a better method for dissolving wood-cellulose in homogenous phase. As found in infrared spectra, the absorption intensity of hydroxyl groups （broad peaks： 3,400 cm^-1） decreased greatly in cellulose macromolecules. This is because the degree of association between the hydroxyl groups of cellulose macromolecules is reduced, due to the destruction of the hydrogen bonds. Lastly, wood-cellulose can be dissolved in a LiC1/DMAC solvent thoroughly and efficiently, and can provide a better solvent system for homogeneous synthesis in the preparation of new functional materials via modified wood-cellulose.展开更多
The present paper is a further development of our previous work in solving the wholeproblem of the homogeneous isotropic turbulence from the nitial period to the final period ofdecay. An expansion method is developed ...The present paper is a further development of our previous work in solving the wholeproblem of the homogeneous isotropic turbulence from the nitial period to the final period ofdecay. An expansion method is developed to obtain the axinlly symmetrical solution of theNavier-Stokes equations of motion in the form of an infinite set of nonlinear partial differen-tial equations of the second order. For the present we solve the zeroth order approximation.By using the method of Fourier transform, we get a nonlinear nitegro-differential equationfor the amplitude function in the wave number space.It is also the dynamical equation forthe energy spectrum. By choosing a suitable initial condition, we solve this equation numerically. The energyspectrum function and the energy transfer spectrum function thus calculated satisfy the spec-trum form of the karman-Howarth equation exactly. We Lave computed the energy spectrumfunction, the energy transfer function the decay of turbulent energy, the integral scale, Taylormicroscale, the double and triple velocity correlations on the whole range from the initialperiod to the final period of decay. As a whole all these calculated statistical physicalquantities agree with experiments very wall except a few cases with small discrepancies at largeseparations.展开更多
Fourier transform method is used to obtain an approximate solution of Green's tensor to homogeneous and transversely isotropic media like unidirectional fiber re-inforced composites and austenitic stainless steel...Fourier transform method is used to obtain an approximate solution of Green's tensor to homogeneous and transversely isotropic media like unidirectional fiber re-inforced composites and austenitic stainless steel materials in order to provide the theoretical basis for the scattering problems. A comparison to homogeneously isotropic media is presented and a brief discussion of the main features of the solution is given展开更多
In this paper,several new constant-amplitude and variable-amplitude wave solutions（namely,traveling wave solutions） of a generalized nonlinear Schrdinger equation are investigated by using the extended homogeneous b...In this paper,several new constant-amplitude and variable-amplitude wave solutions（namely,traveling wave solutions） of a generalized nonlinear Schrdinger equation are investigated by using the extended homogeneous balance method,where the balance method is applied to solve the Riccati equation and the reduced nonlinear ordinary differential equation,respectively.In addition,stability analysis of those solutions are also conducted by regular phase plane technique.展开更多
Cerium and cerium-based oxides are found to be an important element in three-way catalytic converter(TWC).The effective utilization of TWC is found to be reduced due to thermal loading which results in structural defo...Cerium and cerium-based oxides are found to be an important element in three-way catalytic converter(TWC).The effective utilization of TWC is found to be reduced due to thermal loading which results in structural deformation of ceria,Doping Zr^(4+)into the rare earth element can increase the oxygen storage capacity and thermal stability.Hence,an attempt was made to study the oxygen storage capacity and thermal stability of ceria by doping Zr^(4+)and Nd^(3+).Cerium-based nanocrystallite in the composition of Ce_(0.6)Zr_(0.4-x)Nd_(1.3)xO_(2)(0≤x≤0.4)was prepared by sol-gel synthesize technique with citric acid as a gel-forming agent.X-ray diffraction(XRD)result shows that doping Nd^(3+)into ceria lattice forms homogenous solid solution of cubic fluorite structure up to 25%of substitute only.Doping higher amount of Nd^(3+)into ceria lattice leads to the formation of Nd_(2)O_(3).Raman spectrum study confirms that oxygen storage capacity band is present in Ce_(0.6)Zr_(0.4)O2 and Ce_(0.6)Zr_(0.3)Nd_(0.13)O_(2).The oxygen storage capacity was calculated through weight loss of the sample during the second heating cycle with cyclic heating from30 to 800℃in thermogravimetric analysis(TGA).The TGA study reveals that the oxygen storage capacity of Ce_(0.6)Zr_(0.4)O2 decreases after the substitution of Nd^(3+),which is due to the larger ionic radius of Nd^(3+)compared with that of Zr4+and CeO2.展开更多
基金Supported by the International Cooperation and Exchanges Foundation of Henan Province (084300510060)the Youth Science Foundation of Henan University of Science and Technology of China (2008QN026)
文摘The （G＇/G, 1/G）-expansion method for finding exact travelling wave solutions of nonlinear evolution equations, which can be thought of as an extension of the （G＇/G）-expansion method proposed recently, is presented. By using this method abundant travelling wave so- lutions with arbitrary parameters of the Zakharov equations are successfully obtained. When the parameters are replaced by special values, the well-known solitary wave solutions of the equations are rediscovered from the travelling waves.
文摘A LiC1/DMAC solvent system was used to dissolve wood-cellulose with aims to broaden its application in preparing functional materials of modified wood-cellulose. We studied the dissolubility complexion of wood-cellulose in a LiC1/DMAC solvent system, made sure of the important function of LiC1 in a cellulose solvent, and further confirmed its dissolution mechanism via the measurement of infrared spectra of soluble products. The study results are as follows： first, LiC1 salts, which can form intermediate complexes with cellulose, have played an important role in the LiC1/DMAC solvent system, and their solubility performance is en- hanced by reducing the hydrogen bond effect between cellulose molecules; second, the non-aqueous solvent system is a better method for dissolving wood-cellulose in homogenous phase. As found in infrared spectra, the absorption intensity of hydroxyl groups （broad peaks： 3,400 cm^-1） decreased greatly in cellulose macromolecules. This is because the degree of association between the hydroxyl groups of cellulose macromolecules is reduced, due to the destruction of the hydrogen bonds. Lastly, wood-cellulose can be dissolved in a LiC1/DMAC solvent thoroughly and efficiently, and can provide a better solvent system for homogeneous synthesis in the preparation of new functional materials via modified wood-cellulose.
文摘The present paper is a further development of our previous work in solving the wholeproblem of the homogeneous isotropic turbulence from the nitial period to the final period ofdecay. An expansion method is developed to obtain the axinlly symmetrical solution of theNavier-Stokes equations of motion in the form of an infinite set of nonlinear partial differen-tial equations of the second order. For the present we solve the zeroth order approximation.By using the method of Fourier transform, we get a nonlinear nitegro-differential equationfor the amplitude function in the wave number space.It is also the dynamical equation forthe energy spectrum. By choosing a suitable initial condition, we solve this equation numerically. The energyspectrum function and the energy transfer spectrum function thus calculated satisfy the spec-trum form of the karman-Howarth equation exactly. We Lave computed the energy spectrumfunction, the energy transfer function the decay of turbulent energy, the integral scale, Taylormicroscale, the double and triple velocity correlations on the whole range from the initialperiod to the final period of decay. As a whole all these calculated statistical physicalquantities agree with experiments very wall except a few cases with small discrepancies at largeseparations.
文摘Fourier transform method is used to obtain an approximate solution of Green's tensor to homogeneous and transversely isotropic media like unidirectional fiber re-inforced composites and austenitic stainless steel materials in order to provide the theoretical basis for the scattering problems. A comparison to homogeneously isotropic media is presented and a brief discussion of the main features of the solution is given
基金supported by the National NSF of China(11571088)NSF of Zhejiang Province(LY13A010020)Program(HNUEYT2013)
文摘In this paper,several new constant-amplitude and variable-amplitude wave solutions（namely,traveling wave solutions） of a generalized nonlinear Schrdinger equation are investigated by using the extended homogeneous balance method,where the balance method is applied to solve the Riccati equation and the reduced nonlinear ordinary differential equation,respectively.In addition,stability analysis of those solutions are also conducted by regular phase plane technique.
文摘Cerium and cerium-based oxides are found to be an important element in three-way catalytic converter(TWC).The effective utilization of TWC is found to be reduced due to thermal loading which results in structural deformation of ceria,Doping Zr^(4+)into the rare earth element can increase the oxygen storage capacity and thermal stability.Hence,an attempt was made to study the oxygen storage capacity and thermal stability of ceria by doping Zr^(4+)and Nd^(3+).Cerium-based nanocrystallite in the composition of Ce_(0.6)Zr_(0.4-x)Nd_(1.3)xO_(2)(0≤x≤0.4)was prepared by sol-gel synthesize technique with citric acid as a gel-forming agent.X-ray diffraction(XRD)result shows that doping Nd^(3+)into ceria lattice forms homogenous solid solution of cubic fluorite structure up to 25%of substitute only.Doping higher amount of Nd^(3+)into ceria lattice leads to the formation of Nd_(2)O_(3).Raman spectrum study confirms that oxygen storage capacity band is present in Ce_(0.6)Zr_(0.4)O2 and Ce_(0.6)Zr_(0.3)Nd_(0.13)O_(2).The oxygen storage capacity was calculated through weight loss of the sample during the second heating cycle with cyclic heating from30 to 800℃in thermogravimetric analysis(TGA).The TGA study reveals that the oxygen storage capacity of Ce_(0.6)Zr_(0.4)O2 decreases after the substitution of Nd^(3+),which is due to the larger ionic radius of Nd^(3+)compared with that of Zr4+and CeO2.
