Throughout the supply chain,there is interest in conserving resources and reducing the textile industry's environmental footprint.Every stage of a textile product's life cycle has environmental impacts-from fi...Throughout the supply chain,there is interest in conserving resources and reducing the textile industry's environmental footprint.Every stage of a textile product's life cycle has environmental impacts-from fiber production through manufacturing and retailing to laundering and disposal by consumers.Of particular concern is the use of water,energy,and chemicals(WEC) in textile processing-an area where technological advances offer significant savings in resources and environmental benefits.In cotton textile processing, dyeing and finishing have the largest WEC requirements and therefore offer the greatest scope for reductions.展开更多
The advancement of renewable energy(RE)represents a pivotal strategy in mitigating climate change and advancing energy transition efforts.A current of research pertains to strategies for fostering RE growth.Among the ...The advancement of renewable energy(RE)represents a pivotal strategy in mitigating climate change and advancing energy transition efforts.A current of research pertains to strategies for fostering RE growth.Among the frequently proposed approaches,employing optimization models to facilitate decision-making stands out prominently.Drawing from an extensive dataset comprising 32806 literature entries encompassing the optimization of renewable energy systems(RES)from 1990 to 2023 within the Web of Science database,this study reviews the decision-making optimization problems,models,and solution methods thereof throughout the renewable energy development and utilization chain(REDUC)process.This review also endeavors to structure and assess the contextual landscape of RES optimization modeling research.As evidenced by the literature review,optimization modeling effectively resolves decisionmaking predicaments spanning RE investment,construction,operation and maintenance,and scheduling.Predominantly,a hybrid model that combines prediction,optimization,simulation,and assessment methodologies emerges as the favored approach for optimizing RES-related decisions.The primary framework prevalent in extant research solutions entails the dissection and linearization of established models,in combination with hybrid analytical strategies and artificial intelligence algorithms.Noteworthy advancements within modeling encompass domains such as uncertainty,multienergy carrier considerations,and the refinement of spatiotemporal resolution.In the realm of algorithmic solutions for RES optimization models,a pronounced focus is anticipated on the convergence of analytical techniques with artificial intelligence-driven optimization.Furthermore,this study serves to facilitate a comprehensive understanding of research trajectories and existing gaps,expediting the identification of pertinent optimization models conducive to enhancing the efficiency of REDUC development endeavors.展开更多
On the basis of the concept of finite element methods, the rigorous analytical solutions of structural response in terms of the design variables are researched in this paper. The spatial trusses are taken as an exampl...On the basis of the concept of finite element methods, the rigorous analytical solutions of structural response in terms of the design variables are researched in this paper. The spatial trusses are taken as an example for the solution of the analytical expressions of the explicit displacements which are proved mathematically; then some conclusions are reached that are useful to structural sensitivity analysis and optimization. In the third part of the paper, a generalized geometric programming method is sugguested for the optimal model with the explicit displacement. Finally, the analytical solutions of the displacements of three trusses are given as examples.展开更多
The computational efficiency of numerical solution of linearalgebraic equations in finite elements can be improved in two ways.One is to decrease the fill-in numbers, which are new non-ze- ronumbers in the matrix of g...The computational efficiency of numerical solution of linearalgebraic equations in finite elements can be improved in two ways.One is to decrease the fill-in numbers, which are new non-ze- ronumbers in the matrix of global stiffness generated during theprocess of elimination. The other is to reduce the computationaloperation of multiplying a real number by zero. Based on the factthat the order of elimination can determine how many fill-in numbersshould be generated, we present a new method for optimization ofnumbering nodes. This method is quite different from bandwidthoptimiza- tion. Fill-in numbers can be decreased in a large scale bythe use of this method. The bi-factorization method is adopted toavoid multiplying real numbers by zero. For large scale finiteelement analysis, the method presented in this paper is moreefficient than the traditional LDLT method.展开更多
In this work,flexible photothermal PVA/Ti_(2)O_(3) composite films with different amount(0 wt%,5 wt%,10 wt%,15 wt%)of Ti_(2)O_(3) particles modified by steric acid were prepared by a simple solution casting method.The...In this work,flexible photothermal PVA/Ti_(2)O_(3) composite films with different amount(0 wt%,5 wt%,10 wt%,15 wt%)of Ti_(2)O_(3) particles modified by steric acid were prepared by a simple solution casting method.The microstructures,XRD patterns,FTIR spectra,UV-Vis-NIR spectra thermo-conductivity,thermo-stability and photothermal effects of these composite films were all characterized.These results indicated that Ti_(2)O_(3) particles were well dispersed throughout the polyvinyl alcohol(PVA)matrix in the PVA/Ti_(2)O_(3) composite films.And Ti_(2)O_(3) particles could also effectively improve the photothermal properties of the composite films which exhibited high light absorption and generated a high temperature(about 57.4℃for film with 15 wt%Ti_(2)O_(3) amount)on the surface when it was irradiated by a simulated sunlight source(1 kW/m^(2)).展开更多
In this article the travelling wave solution for a class of nonlinear reaction diffusion problems are considered. Using the homotopic method and the theory of travelling wave transform, the approximate solution for th...In this article the travelling wave solution for a class of nonlinear reaction diffusion problems are considered. Using the homotopic method and the theory of travelling wave transform, the approximate solution for the corresponding problem is obtained.展开更多
The present work describes the application of the method of fundamental solutions (MFS) along with the analog equation method (AEM) and radial basis function (RBF) approximation for solving the 2D isotropic and ...The present work describes the application of the method of fundamental solutions (MFS) along with the analog equation method (AEM) and radial basis function (RBF) approximation for solving the 2D isotropic and anisotropic Helmholtz problems with different wave numbers. The AEM is used to convert the original governing equation into the classical Poisson's equation, and the MFS and RBF approximations are used to derive the homogeneous and particular solutions, respectively. Finally, the satisfaction of the solution consisting of the homogeneous and particular parts to the related governing equation and boundary conditions can produce a system of linear equations, which can be solved with the singular value decomposition (SVD) technique. In the computation, such crucial factors related to the MFS-RBF as the location of the virtual boundary, the differential and integrating strategies, and the variation of shape parameters in multi-quadric (MQ) are fully analyzed to provide useful reference.展开更多
The paper deals with a development of the discrete-analytical method for the solution of the dynamical problems of a hollow sphere with inhomogeneous initial stresses.The examinations are made with respect to the prob...The paper deals with a development of the discrete-analytical method for the solution of the dynamical problems of a hollow sphere with inhomogeneous initial stresses.The examinations are made with respect to the problem on the natural vibration of the hollow sphere the initial stresses in which is caused by internal and external uniformly distributed pressure.The initial stresses in the sphere are determined within the scope of the exact equations of elastostatics.It is assumed that after appearing this static initial stresses the sphere gets a dynamical excitation and mechanical behavior of the sphere caused by this excitation is described with the so-called three-dimensional linearized equations of elastic wave propagation in initially stressed bodies.For the solution of these equations,which have variable coefficients,the discrete analytical solution method is developed and applied.In particular,it is established that the convergence of the numerical results with respect to the number of discretization is very acceptable and applicable for the considered type dynamical problems.Numerical results on the influence of the initial stresses on the values of the natural frequencies of the hollow sphere are also presented and these results are discussed.展开更多
Ordered zinc oxide (ZnO) rod arrays with very high orientation were fabricated on Si substrates by using a solution method. The substrate surfaces were functionalized by Self-Assembly Monolayers (SAMs). In the ver...Ordered zinc oxide (ZnO) rod arrays with very high orientation were fabricated on Si substrates by using a solution method. The substrate surfaces were functionalized by Self-Assembly Monolayers (SAMs). In the very early growth stage, the oriented ZnO crystals had already grown, which appeared to be the main reason why ZnO nanorods showed very high orientation. The un-dense and un-uniform SAMs provided a surface that was heterogeneous to ZnO nucleation. Consequently, highly oriented ZnO rods were selectively grown on the "coin-like" SAM-uncovered regions. The route developed here can provide some helpful information to control the nucleation and orientation of ZnO in aqueous solution. Also, the site-selective growth mechanisms can indicate a clue to grow patterned highly oriented ZnO nanorod arrays by the organic template.展开更多
New exact solutions, expressed in terms of the Jacobi elliptic functions, to the nonlinear Klein-Gordon equation are obtained by using a modified mapping method. The solutions include the conditions for equation's pa...New exact solutions, expressed in terms of the Jacobi elliptic functions, to the nonlinear Klein-Gordon equation are obtained by using a modified mapping method. The solutions include the conditions for equation's parameters and travelling wave transformation parameters. Some figures for a specific kind of solution are also presented.展开更多
For Time Difference Of Arrival(TDOA) location based on multi-ground stations scene,two direct solution methods are proposed to solve the target position in TDOA location.Therein,the solving methods are realized in the...For Time Difference Of Arrival(TDOA) location based on multi-ground stations scene,two direct solution methods are proposed to solve the target position in TDOA location.Therein,the solving methods are realized in the rectangular and polar coordinates.On the condition of rectangular coordinates,first of all,it solves the radial range between the target and reference station,then cal-culates the location of the target.In the case of polar coordinates,the azimuth between the target and reference station is solved first,then the radial range between the target and reference station is figured out,finally the location of the target is obtained.Simultaneously,the simulation and comparison analysis are given in detail,and show that the polar solving method has the better fuzzy performance than that of rectangular coordinate.展开更多
The theoretic solution for rectangular thin plate on foundation with four edges free is derived by symplectic geometry method. In the analysis proceeding, the elastic foundation is presented by the Winkler model. Firs...The theoretic solution for rectangular thin plate on foundation with four edges free is derived by symplectic geometry method. In the analysis proceeding, the elastic foundation is presented by the Winkler model. Firstly, the basic equations for elastic thin plate are transferred into Hamilton canonical equations. The symplectic geometry method is used to separate the whole variables and eigenvalues are obtained simultaneously. Finally, according to the method of eigen function expansion, the explicit solution for rectangular thin plate on foundation with the boundary conditions of four edges frees are developed. Since the basic elasticity equations of thin plate are only used and it is not need to select the deformation function arbitrarily. Therefore, the solution is theoretical and reasonable. In order to show the correction of formulations derived, a numerical example is given to demonstrate the accuracy and convergence of the current solution.展开更多
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
For lower dimensional Fermi–Pasta–Ulam(FPU) chains, the α-chain is completely integrable and the Hamiltonian of the β-chain can be identified with the H′enon–Heiles Hamiltonian. When the strengths α, β of th...For lower dimensional Fermi–Pasta–Ulam(FPU) chains, the α-chain is completely integrable and the Hamiltonian of the β-chain can be identified with the H′enon–Heiles Hamiltonian. When the strengths α, β of the nonlinearities depend on time periodically with the same frequencies as the natural angular frequencies, the resonance phenomenon is inevitable. In this paper, for certain periodic functions α(t) and β(t) with resonance frequencies, we give the existence and stability of some nontrivial exact periodic solutions for a one-dimensional αβ-FPU model composed of three particles with periodic boundary conditions.展开更多
Nanocrystals of Ce1-xMnxO2-δ(x=0.00,0.05,0.10,0.15,and 0.20) were synthesized by a hydrothermal reaction route.The solid solutions crystallized in a cubic fluorite structure with a particle size in the range of 11...Nanocrystals of Ce1-xMnxO2-δ(x=0.00,0.05,0.10,0.15,and 0.20) were synthesized by a hydrothermal reaction route.The solid solutions crystallized in a cubic fluorite structure with a particle size in the range of 11~15 nm.The incorporation of Mn ions in CeO2 resulted in a lattice volume reduction.Mn ions showed a mixed valence state of +2,+3 and +4 in CeO2 lattice.An obvious red-shift of the absorption threshold edge was observed from the UV-visible spectrum.Compared with the bulk CeO2,Ce1-xMnxO2-δ nanocrystals exhibited a lower releasing oxygen temperature as indicated by TPR technique.展开更多
In this work, ZnO, Ce<sup>3+</sup> doped ZnO (ZnO/Ce<sup>3+</sup>) and Cu<sup>2+</sup> + Ce<sup>3+</sup> co-doped ZnO (ZnO/Cu<sup>2+</sup> + Ce<sup>3+&...In this work, ZnO, Ce<sup>3+</sup> doped ZnO (ZnO/Ce<sup>3+</sup>) and Cu<sup>2+</sup> + Ce<sup>3+</sup> co-doped ZnO (ZnO/Cu<sup>2+</sup> + Ce<sup>3+</sup> ) solid solutions powders were synthesized by a solution combustion method maintaining the Ce<sup>3+</sup> ion concentration constant in 3%Wt while the Cu<sup>2+</sup> ion concentration was varied in 1, 2, 3, 10 and 20%Wt. After its synthesis, all the samples were annealed at 900?C by 24 h. The ZnO, ZnO/Ce<sup>3+</sup> and ZnO/Cu<sup>2+</sup> + Ce<sup>3+</sup> powders were structurally characterized using X-ray diffraction (XRD) technique, and the XRD patterns showed that for pure ZnO, Cu<sup>2+</sup> undoped ZnO/Ce<sup>3</sup><sup>+</sup> and ZnO/Ce<sup>3+</sup> doped with the Cu<sup>2+</sup> ion, the three samples exhibited the hexagonal wurtzite ZnO crystalline structure. However, the morphology and particle size of both samples were observed by means of a scanning electron microscopy (SEM);from SEM image, it is observed that the crystallites of both samples are agglomerated forming bigger amorphous particles with an approximate average size of 1 μm. In addition, the photoluminescence of the ZnO, Ce<sup>3+</sup> doped ZnO and Cu<sup>2+</sup> + Ce<sup>3+</sup> doped ZnO samples was measurement under an illumination of 209 nm wavelength (UV region): for the ZnO/Ce<sup>3+</sup> sample, your emission spectrum is in the visible region from blue color until red color;the UV band of the ZnO is suppressed. The multicolor emission visible is attributed to the Ce<sup>3+</sup> ion photoluminescence, while for the ZnO/Cu<sup>2+</sup> + Ce<sup>3+</sup>, its emission PL spectrum is quenching by the Cu<sup>2+</sup> ion, present in the ZnO crystalline.展开更多
A small amount of mineralizer MgO was added into Al2TiO5 synthesized from the sludge of aluminum factory to form Al(2-x)Mg(x+y)Ti(1-y)O(5-0.5x-y) solid solution and inhibit the decomposition of Al2TiO5 solid ...A small amount of mineralizer MgO was added into Al2TiO5 synthesized from the sludge of aluminum factory to form Al(2-x)Mg(x+y)Ti(1-y)O(5-0.5x-y) solid solution and inhibit the decomposition of Al2TiO5 solid solution. It increased the content of Al2TiO5 solid solution and improved the thermal stability of materials. In this work,XRD and SEM methods were adopted to characterize the crystalline structure and microstructure of each kind of sample. Rietveld Quantification method was used to determine the content of crystalline phases in each sample. Results show as follows: the optimal addition concentration of MgO was 2.0%,and the corresponding content of Al2TiO5 solid solution which displayed irregular bulk shape was 100%; the addition of mineralizer MgO could enhance the flexural strength and thermal stability of Al2TiO5 solid solution materials. The optimal addition concentration of MgO determined by performance analysis was 2.0%,and its corresponding retention rate of thermal-shock flexural strength was 86.4%. Structure analysis and performance analysis resulted in good accordance.展开更多
Ultralong titanyl phthalocyanine (TiOPc) sub-micron wires have been synthesized by a novel solution-based self- assembly method. By using different solvents, changing the mass concentration and the solvent vapor pre...Ultralong titanyl phthalocyanine (TiOPc) sub-micron wires have been synthesized by a novel solution-based self- assembly method. By using different solvents, changing the mass concentration and the solvent vapor pressure, the length and the shape of the wires can be adjusted. The mixed-phase properties of the TiOPc sub-micron wires were investigated by the ultraviolet-visible (UV-vis) absorption spectrum and X-ray diffraction. Organic transistors based on these wires were studied, which show the typical p-channel characteristics.展开更多
The elastic plate vibration model is studied under the external force. The size of the source term by the given mode of the source and some observations from the body of the plate is determined over a time interval, w...The elastic plate vibration model is studied under the external force. The size of the source term by the given mode of the source and some observations from the body of the plate is determined over a time interval, which is referred to be an inverse source problem of a plate equation. The uniqueness theorem for this problem is stated, and the fundamental solution to the plate equation is derived. In the case that the plate is driven by the harmonic load, the fundamental solution method (FSM) and the Tikhonov regularization technique axe used to calculate the source term. Numerical experiments of the Euler-Bernoulli beam and the Kirchhoff-Love plate show that the FSM can work well for practical use, no matter the source term is smooth or piecewise.展开更多
文摘Throughout the supply chain,there is interest in conserving resources and reducing the textile industry's environmental footprint.Every stage of a textile product's life cycle has environmental impacts-from fiber production through manufacturing and retailing to laundering and disposal by consumers.Of particular concern is the use of water,energy,and chemicals(WEC) in textile processing-an area where technological advances offer significant savings in resources and environmental benefits.In cotton textile processing, dyeing and finishing have the largest WEC requirements and therefore offer the greatest scope for reductions.
文摘The advancement of renewable energy(RE)represents a pivotal strategy in mitigating climate change and advancing energy transition efforts.A current of research pertains to strategies for fostering RE growth.Among the frequently proposed approaches,employing optimization models to facilitate decision-making stands out prominently.Drawing from an extensive dataset comprising 32806 literature entries encompassing the optimization of renewable energy systems(RES)from 1990 to 2023 within the Web of Science database,this study reviews the decision-making optimization problems,models,and solution methods thereof throughout the renewable energy development and utilization chain(REDUC)process.This review also endeavors to structure and assess the contextual landscape of RES optimization modeling research.As evidenced by the literature review,optimization modeling effectively resolves decisionmaking predicaments spanning RE investment,construction,operation and maintenance,and scheduling.Predominantly,a hybrid model that combines prediction,optimization,simulation,and assessment methodologies emerges as the favored approach for optimizing RES-related decisions.The primary framework prevalent in extant research solutions entails the dissection and linearization of established models,in combination with hybrid analytical strategies and artificial intelligence algorithms.Noteworthy advancements within modeling encompass domains such as uncertainty,multienergy carrier considerations,and the refinement of spatiotemporal resolution.In the realm of algorithmic solutions for RES optimization models,a pronounced focus is anticipated on the convergence of analytical techniques with artificial intelligence-driven optimization.Furthermore,this study serves to facilitate a comprehensive understanding of research trajectories and existing gaps,expediting the identification of pertinent optimization models conducive to enhancing the efficiency of REDUC development endeavors.
文摘On the basis of the concept of finite element methods, the rigorous analytical solutions of structural response in terms of the design variables are researched in this paper. The spatial trusses are taken as an example for the solution of the analytical expressions of the explicit displacements which are proved mathematically; then some conclusions are reached that are useful to structural sensitivity analysis and optimization. In the third part of the paper, a generalized geometric programming method is sugguested for the optimal model with the explicit displacement. Finally, the analytical solutions of the displacements of three trusses are given as examples.
文摘The computational efficiency of numerical solution of linearalgebraic equations in finite elements can be improved in two ways.One is to decrease the fill-in numbers, which are new non-ze- ronumbers in the matrix of global stiffness generated during theprocess of elimination. The other is to reduce the computationaloperation of multiplying a real number by zero. Based on the factthat the order of elimination can determine how many fill-in numbersshould be generated, we present a new method for optimization ofnumbering nodes. This method is quite different from bandwidthoptimiza- tion. Fill-in numbers can be decreased in a large scale bythe use of this method. The bi-factorization method is adopted toavoid multiplying real numbers by zero. For large scale finiteelement analysis, the method presented in this paper is moreefficient than the traditional LDLT method.
基金Funded by the Youth Backbone Teacher Training Plan in University of Henan Province(No.21220028)Science and Technology Research Project of Henan Province(No.242102321066)+2 种基金Natural Science Foundation of Henan Province(No.232300420312)Henan University of Technology Young Backbone Teacher Training Plan(No.21421260)the Innovation Training Program for College Students in Henan Province(No.202310463046)。
文摘In this work,flexible photothermal PVA/Ti_(2)O_(3) composite films with different amount(0 wt%,5 wt%,10 wt%,15 wt%)of Ti_(2)O_(3) particles modified by steric acid were prepared by a simple solution casting method.The microstructures,XRD patterns,FTIR spectra,UV-Vis-NIR spectra thermo-conductivity,thermo-stability and photothermal effects of these composite films were all characterized.These results indicated that Ti_(2)O_(3) particles were well dispersed throughout the polyvinyl alcohol(PVA)matrix in the PVA/Ti_(2)O_(3) composite films.And Ti_(2)O_(3) particles could also effectively improve the photothermal properties of the composite films which exhibited high light absorption and generated a high temperature(about 57.4℃for film with 15 wt%Ti_(2)O_(3) amount)on the surface when it was irradiated by a simulated sunlight source(1 kW/m^(2)).
基金Supported by the National Natural Sciences Foundation of China(40676016 and 10471039)the National Key Project for Basic Research(2003CB415101-03 and 2004CB418304)+2 种基金the Key Project of the Chinese Academy of Sciences(KZCX3-SW-221)in part by E-Institutes of Shanghai Municipal Education Commission(N.E03004)the Natural Science Foundation of Zeijiang,China(Y606268).
文摘In this article the travelling wave solution for a class of nonlinear reaction diffusion problems are considered. Using the homotopic method and the theory of travelling wave transform, the approximate solution for the corresponding problem is obtained.
文摘The present work describes the application of the method of fundamental solutions (MFS) along with the analog equation method (AEM) and radial basis function (RBF) approximation for solving the 2D isotropic and anisotropic Helmholtz problems with different wave numbers. The AEM is used to convert the original governing equation into the classical Poisson's equation, and the MFS and RBF approximations are used to derive the homogeneous and particular solutions, respectively. Finally, the satisfaction of the solution consisting of the homogeneous and particular parts to the related governing equation and boundary conditions can produce a system of linear equations, which can be solved with the singular value decomposition (SVD) technique. In the computation, such crucial factors related to the MFS-RBF as the location of the virtual boundary, the differential and integrating strategies, and the variation of shape parameters in multi-quadric (MQ) are fully analyzed to provide useful reference.
文摘The paper deals with a development of the discrete-analytical method for the solution of the dynamical problems of a hollow sphere with inhomogeneous initial stresses.The examinations are made with respect to the problem on the natural vibration of the hollow sphere the initial stresses in which is caused by internal and external uniformly distributed pressure.The initial stresses in the sphere are determined within the scope of the exact equations of elastostatics.It is assumed that after appearing this static initial stresses the sphere gets a dynamical excitation and mechanical behavior of the sphere caused by this excitation is described with the so-called three-dimensional linearized equations of elastic wave propagation in initially stressed bodies.For the solution of these equations,which have variable coefficients,the discrete analytical solution method is developed and applied.In particular,it is established that the convergence of the numerical results with respect to the number of discretization is very acceptable and applicable for the considered type dynamical problems.Numerical results on the influence of the initial stresses on the values of the natural frequencies of the hollow sphere are also presented and these results are discussed.
基金the National Natural Science Foundation of China(No.50702029)Shandong Provincial Education Department(No.J05D08)Natural Science Foundation of Qingdao(No.05-1-JC-89)
文摘Ordered zinc oxide (ZnO) rod arrays with very high orientation were fabricated on Si substrates by using a solution method. The substrate surfaces were functionalized by Self-Assembly Monolayers (SAMs). In the very early growth stage, the oriented ZnO crystals had already grown, which appeared to be the main reason why ZnO nanorods showed very high orientation. The un-dense and un-uniform SAMs provided a surface that was heterogeneous to ZnO nucleation. Consequently, highly oriented ZnO rods were selectively grown on the "coin-like" SAM-uncovered regions. The route developed here can provide some helpful information to control the nucleation and orientation of ZnO in aqueous solution. Also, the site-selective growth mechanisms can indicate a clue to grow patterned highly oriented ZnO nanorod arrays by the organic template.
文摘New exact solutions, expressed in terms of the Jacobi elliptic functions, to the nonlinear Klein-Gordon equation are obtained by using a modified mapping method. The solutions include the conditions for equation's parameters and travelling wave transformation parameters. Some figures for a specific kind of solution are also presented.
基金Supported by the National Natural Science Foundation of China (No. 60825104,61072107)the National Postdoctor Fundation (No. 20090451251)+1 种基金the Shaanxi Industry Surmount Foundation (2009K08-31)the Fundamental Research Funds for the Central Universities(JY10000-902025) of China
文摘For Time Difference Of Arrival(TDOA) location based on multi-ground stations scene,two direct solution methods are proposed to solve the target position in TDOA location.Therein,the solving methods are realized in the rectangular and polar coordinates.On the condition of rectangular coordinates,first of all,it solves the radial range between the target and reference station,then cal-culates the location of the target.In the case of polar coordinates,the azimuth between the target and reference station is solved first,then the radial range between the target and reference station is figured out,finally the location of the target is obtained.Simultaneously,the simulation and comparison analysis are given in detail,and show that the polar solving method has the better fuzzy performance than that of rectangular coordinate.
文摘The theoretic solution for rectangular thin plate on foundation with four edges free is derived by symplectic geometry method. In the analysis proceeding, the elastic foundation is presented by the Winkler model. Firstly, the basic equations for elastic thin plate are transferred into Hamilton canonical equations. The symplectic geometry method is used to separate the whole variables and eigenvalues are obtained simultaneously. Finally, according to the method of eigen function expansion, the explicit solution for rectangular thin plate on foundation with the boundary conditions of four edges frees are developed. Since the basic elasticity equations of thin plate are only used and it is not need to select the deformation function arbitrarily. Therefore, the solution is theoretical and reasonable. In order to show the correction of formulations derived, a numerical example is given to demonstrate the accuracy and convergence of the current solution.
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.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.1130110611201288+6 种基金and 11261013)the Natural Science Foundation of Guangxi Zhuang Autonomous RegionChina(Grant No.2014GXNSFBA118017)the Innovation Project of Graduate Education of Guangxi Zhuang Autonomous RegionChina(Grant No.YCSZ2014143)the Guangxi Experiment Center of Information Science(Grant No.YB1410)
文摘For lower dimensional Fermi–Pasta–Ulam(FPU) chains, the α-chain is completely integrable and the Hamiltonian of the β-chain can be identified with the H′enon–Heiles Hamiltonian. When the strengths α, β of the nonlinearities depend on time periodically with the same frequencies as the natural angular frequencies, the resonance phenomenon is inevitable. In this paper, for certain periodic functions α(t) and β(t) with resonance frequencies, we give the existence and stability of some nontrivial exact periodic solutions for a one-dimensional αβ-FPU model composed of three particles with periodic boundary conditions.
基金Supported by NNSFC (Nos 20671092, 20773132, 20771101)National Basic Research Program of China (No 2007BAE08B01, 2009 CB613306)
文摘Nanocrystals of Ce1-xMnxO2-δ(x=0.00,0.05,0.10,0.15,and 0.20) were synthesized by a hydrothermal reaction route.The solid solutions crystallized in a cubic fluorite structure with a particle size in the range of 11~15 nm.The incorporation of Mn ions in CeO2 resulted in a lattice volume reduction.Mn ions showed a mixed valence state of +2,+3 and +4 in CeO2 lattice.An obvious red-shift of the absorption threshold edge was observed from the UV-visible spectrum.Compared with the bulk CeO2,Ce1-xMnxO2-δ nanocrystals exhibited a lower releasing oxygen temperature as indicated by TPR technique.
文摘In this work, ZnO, Ce<sup>3+</sup> doped ZnO (ZnO/Ce<sup>3+</sup>) and Cu<sup>2+</sup> + Ce<sup>3+</sup> co-doped ZnO (ZnO/Cu<sup>2+</sup> + Ce<sup>3+</sup> ) solid solutions powders were synthesized by a solution combustion method maintaining the Ce<sup>3+</sup> ion concentration constant in 3%Wt while the Cu<sup>2+</sup> ion concentration was varied in 1, 2, 3, 10 and 20%Wt. After its synthesis, all the samples were annealed at 900?C by 24 h. The ZnO, ZnO/Ce<sup>3+</sup> and ZnO/Cu<sup>2+</sup> + Ce<sup>3+</sup> powders were structurally characterized using X-ray diffraction (XRD) technique, and the XRD patterns showed that for pure ZnO, Cu<sup>2+</sup> undoped ZnO/Ce<sup>3</sup><sup>+</sup> and ZnO/Ce<sup>3+</sup> doped with the Cu<sup>2+</sup> ion, the three samples exhibited the hexagonal wurtzite ZnO crystalline structure. However, the morphology and particle size of both samples were observed by means of a scanning electron microscopy (SEM);from SEM image, it is observed that the crystallites of both samples are agglomerated forming bigger amorphous particles with an approximate average size of 1 μm. In addition, the photoluminescence of the ZnO, Ce<sup>3+</sup> doped ZnO and Cu<sup>2+</sup> + Ce<sup>3+</sup> doped ZnO samples was measurement under an illumination of 209 nm wavelength (UV region): for the ZnO/Ce<sup>3+</sup> sample, your emission spectrum is in the visible region from blue color until red color;the UV band of the ZnO is suppressed. The multicolor emission visible is attributed to the Ce<sup>3+</sup> ion photoluminescence, while for the ZnO/Cu<sup>2+</sup> + Ce<sup>3+</sup>, its emission PL spectrum is quenching by the Cu<sup>2+</sup> ion, present in the ZnO crystalline.
基金supported by the Natural Science Foundation of Fujian Province (No. T08J0129)the Science and Technology Developing Foundation of Fuzhou University (No. 2008-XQ-001)2007-year New Century Talents Supporting Program of Fujian Province (No. XSJRC2007-17)
文摘A small amount of mineralizer MgO was added into Al2TiO5 synthesized from the sludge of aluminum factory to form Al(2-x)Mg(x+y)Ti(1-y)O(5-0.5x-y) solid solution and inhibit the decomposition of Al2TiO5 solid solution. It increased the content of Al2TiO5 solid solution and improved the thermal stability of materials. In this work,XRD and SEM methods were adopted to characterize the crystalline structure and microstructure of each kind of sample. Rietveld Quantification method was used to determine the content of crystalline phases in each sample. Results show as follows: the optimal addition concentration of MgO was 2.0%,and the corresponding content of Al2TiO5 solid solution which displayed irregular bulk shape was 100%; the addition of mineralizer MgO could enhance the flexural strength and thermal stability of Al2TiO5 solid solution materials. The optimal addition concentration of MgO determined by performance analysis was 2.0%,and its corresponding retention rate of thermal-shock flexural strength was 86.4%. Structure analysis and performance analysis resulted in good accordance.
基金supported by the National Natural Science Foundation of China(Grant No.61176021)the Innovation Group Project from Shanghai EducationCommission,China
文摘Ultralong titanyl phthalocyanine (TiOPc) sub-micron wires have been synthesized by a novel solution-based self- assembly method. By using different solvents, changing the mass concentration and the solvent vapor pressure, the length and the shape of the wires can be adjusted. The mixed-phase properties of the TiOPc sub-micron wires were investigated by the ultraviolet-visible (UV-vis) absorption spectrum and X-ray diffraction. Organic transistors based on these wires were studied, which show the typical p-channel characteristics.
文摘The elastic plate vibration model is studied under the external force. The size of the source term by the given mode of the source and some observations from the body of the plate is determined over a time interval, which is referred to be an inverse source problem of a plate equation. The uniqueness theorem for this problem is stated, and the fundamental solution to the plate equation is derived. In the case that the plate is driven by the harmonic load, the fundamental solution method (FSM) and the Tikhonov regularization technique axe used to calculate the source term. Numerical experiments of the Euler-Bernoulli beam and the Kirchhoff-Love plate show that the FSM can work well for practical use, no matter the source term is smooth or piecewise.