Alloy thin film for advanced pressure sensors was manufactured by means of ion-beam sputtering SiO2 insulation film and NiCr thin film on the 17-4PH stainless steel elastic substrate. The thin film resistance was resp...Alloy thin film for advanced pressure sensors was manufactured by means of ion-beam sputtering SiO2 insulation film and NiCr thin film on the 17-4PH stainless steel elastic substrate. The thin film resistance was respectively heat-treated by four processes. The effects on stability of thin film alloy resistance were investigated, and paramaters of heat treatment that make thin film resistance stable were obtained. The experimental result indicates that the most stable thin film resistance can be obtained when it is heat-treated under protection of SiO2 and N2 at 673 K for 1 h, and then kept at 473 K for 24 h. Pressure sensor chips of high precision for harsh environments can be manufactured by this process.展开更多
The author considers the global existence and global nonexistence of the initial-boundary value problem for some degenerate hyperbolic equation of the form utt- div(|△↓|^P-2 △↓u)=|u|^m u, (x,t)∈[0, +∞)...The author considers the global existence and global nonexistence of the initial-boundary value problem for some degenerate hyperbolic equation of the form utt- div(|△↓|^P-2 △↓u)=|u|^m u, (x,t)∈[0, +∞) ×Ω with p 〉 2 and m 〉 0. He deals with the global solutions by D.H.Sattinger's potential well ideas. At the same time, when the initial energy is positive, but appropriately bounded, the global nonexistence of solutions is verified by using the analysis method.展开更多
In this paper, we study the approximation problem on the closed convex cone, and prove that there exists a unique solution of the approximation problem, then give the algorithm to compute the unique solution.
Extension of a B-spline curve or surface is a useful function in a CAD system. This paper presents an algorithm for extending cubic B-spline curves or surfaces to one or more target points. To keep the extension curve...Extension of a B-spline curve or surface is a useful function in a CAD system. This paper presents an algorithm for extending cubic B-spline curves or surfaces to one or more target points. To keep the extension curve segment GC^2-continuous with the original one, a family of cubic polynomial interpolation curves can be constructed. One curve is chosen as the solution from a sub-class of such a family by setting one GC^2 parameter to be zero and determining the second GC^2 parameter by minimizing the strain energy. To simplify the final curve representation, the extension segment is reparameterized to achieve C-continuity with the given B-spline curve, and then knot removal from the curve is done. As a result, a sub-optimized solution subject to the given constraints and criteria is obtained. Additionally, new control points of the extension B-spline segment can be determined by solving lower triangular linear equations. Some computing examples for comparing our method and other methods are given.展开更多
Based on the nonlinearization of Lax pairs, the Korteweg-de Vries (KdV) soliton hierarchy is decomposed into a family of finite-dimensional Hamiltonian systems, whose Liouville integrability is proved by means of th...Based on the nonlinearization of Lax pairs, the Korteweg-de Vries (KdV) soliton hierarchy is decomposed into a family of finite-dimensional Hamiltonian systems, whose Liouville integrability is proved by means of the elliptic coordinates. By applying the Abel-Jacobi coordinates on a Riemann surface of hyperelliptic curve, the resulting Hamiltonian flows as well as the KdV soliton hierarchy are ultimately reduced into linear superpositions, expressed by the Abel-Jacobi variables.展开更多
Based on the multiplicity results of Benci and Fortunato [4], we consider some elliptic systems with strongly indefinite quadratic part, and establish the existence of infinitely many nontrivial solutions in a suitabl...Based on the multiplicity results of Benci and Fortunato [4], we consider some elliptic systems with strongly indefinite quadratic part, and establish the existence of infinitely many nontrivial solutions in a suitable family of products of fractional Sobolev spaces.展开更多
In this paper, we study the Cauchy problem of the inhomogeneous energy-critical Schrōdinger equation: iаtu=-△u-k(x)|u|4/N-2u,N≥3. Using the potential well method, we establish some new sharp criteria for blow...In this paper, we study the Cauchy problem of the inhomogeneous energy-critical Schrōdinger equation: iаtu=-△u-k(x)|u|4/N-2u,N≥3. Using the potential well method, we establish some new sharp criteria for blow-up of solutions in tile nonradial case. In particular, our conclusion in some sense improves on the results in [Kenig and Merle, invent. Math. 166, 645-675 (2006)], where only the radial case is considered in dimensions 3. 4. 5.展开更多
In freeform surface modelling, developable surfaces have much application value. But, in 3D space, there is not always a regular developable surface which interpolates the given boundary of an arbitrary piecewise smoo...In freeform surface modelling, developable surfaces have much application value. But, in 3D space, there is not always a regular developable surface which interpolates the given boundary of an arbitrary piecewise smooth closed curve. In this paper, tensor product Bézier surfaces interpolating the closed curves are determined and the resulting surface is a minimum of the functional defined by the L2-integral norm of the Gaussian curvature. The Gaussian curvature of the surfaces is minimized by the method of solving nonlinear optimization problems. An improved approach trust-region form method is proposed. A simple application example is also given.展开更多
In this paper we study the decay estimate of global solutions to the initial-boundary value problem for double degenerate nonlinear parabolic equation by using a dif-ference inequality.
The inhomogeneous nonlinear diffusion equation is studied by invariant subspace and condi- tional Lie=Bgcklund symmetry methods. It is shown that the equations admit a class of invariant subspaces governed by the nonl...The inhomogeneous nonlinear diffusion equation is studied by invariant subspace and condi- tional Lie=Bgcklund symmetry methods. It is shown that the equations admit a class of invariant subspaces governed by the nonlinear ordinary differential equations, which is equivalent to a kind of higher=order conditional Lie-B^icklund symmetries of the equations. As a consequence, a number of new solutions to the inhomogeneous nonlinear diffusion equations are constructed explicitly or reduced to solving finite-dimensional dynamical sys- tems.展开更多
This paper studies a prey-predator singular bioeconomic system with time delay and diffusion, which is described by differential-algebraic equations. For this system without diffusion, there exist three bifurcation ph...This paper studies a prey-predator singular bioeconomic system with time delay and diffusion, which is described by differential-algebraic equations. For this system without diffusion, there exist three bifurcation phenomena: Transcritical bifurcation, singularity induced bifurcation, and Hopf bifurcation. Compared with other biological systems described by differential equations, singularity induced bifurcation only occurs in singular system and usually links with the expansion of population. When the diffusion is present, it is shown that the positive equilibrium point loses its stability at some critical values of diffusion rate and periodic oscillations occur due to the increase of time delay. Furthermore, numerical simulations illustrate the effectiveness of results and the related biological implications are discussed.展开更多
Mitigating and adapting to climate change includes a requirement to evaluate the role of future land uses in delivering robust integrated responses that are sensitive to local landscape contexts.In practice,this empha...Mitigating and adapting to climate change includes a requirement to evaluate the role of future land uses in delivering robust integrated responses that are sensitive to local landscape contexts.In practice,this emphasises the need for community engagement,planning and inclusive decision-making.Community engagement may be potentially facilitated by the use of spatially explicit quantitative scenarios of landuse change in combination with interactive visualisation.This requires a coherent framework to integrate spatial data modelling,analytical capabilities and visualisation tools in a format that will also engage diverse public audiences.These challenges were explored with a case study of virtual landscapes from N-E Scotland that was used to test preferences for scenarios of future land use.Visualisations employed texture-based rendering rather than full photo-realistic rendering to facilitate interactivity and this provided additional scope for audiences to explore multiple future scenarios compared to the present landscape.Interactive voting in a virtual landscape theatre suggested preferences for visual diversity,good stewardship and perceived naturalness that should be considered in developing planned responses to change.Further investigation of preferences was conducted using interactive 3D features located within the landscape.Study findings are reviewed against objectives for inclusive engagement in the Digital Earth agenda and used to make further recommendations on the use of scenarios and visualisation tools.In particular,technical advances in user engagement need to be developed in conjunction with emerging good practice that addresses ethical,behavioural and inclusion issues so that the content is presented in as transparent and unbiased format as possible.展开更多
The authors investigate the tail probability of the supremum of a random walk with independent increments and obtain some equivalent assertions in the case that the increments are independent and identically distribut...The authors investigate the tail probability of the supremum of a random walk with independent increments and obtain some equivalent assertions in the case that the increments are independent and identically distributed random variables with Osubexponential integrated distributions.A uniform upper bound is derived for the distribution of the supremum of a random walk with independent but non-identically distributed increments,whose tail distributions are dominated by a common tail distribution with an O-subexponential integrated distribution.展开更多
In this paper, the dimension of invariant subspaces admitted by nonlinear sys- tems is estimated under certain conditions. It is shown that if the two-component nonlinear vector differential operator F = (F1, F2) wi...In this paper, the dimension of invariant subspaces admitted by nonlinear sys- tems is estimated under certain conditions. It is shown that if the two-component nonlinear vector differential operator F = (F1, F2) with orders {k1, k2} (k1≥ k2) preserves the invariant subspace Wn1^1× Wn2^2 (n1 ≥ n2), then n1 - n2 ≤ k2, n1 ≤2(k1 + k2) + 1, where Wnq^q is the space generated by solutions of a linear ordinary differential equation of order nq (q = 1, 2). Several examples including the (1+1)-dimensional diffusion system and Ito's type, Drinfel'd-Sokolov-Wilson's type and Whitham-Broer-Kaup's type equations are presented to illustrate the result. Furthermore, the estimate of dimension for m-component nonlinear systems is also given.展开更多
The large time Ll-behavior of the strong solution (including the first and second order spacial derivatives) to the incompressible magneto-hydrodynamic (MHD) equations is given in a half-space. The main tool emplo...The large time Ll-behavior of the strong solution (including the first and second order spacial derivatives) to the incompressible magneto-hydrodynamic (MHD) equations is given in a half-space. The main tool employed in this article is a new weighted estimate for the Stokes flow in L1(Rn+), such a study is of independent interest.展开更多
Let Ω∈← 0 be an open bounded domain in RN (N 〉 3) and 2*(s) = 2(N-8) =2(N-s)N-22. We consider the following elliptic system of two equations in where A, μ 〉 0 and α, β 〉 1 satisfy α + β = 2*(s...Let Ω∈← 0 be an open bounded domain in RN (N 〉 3) and 2*(s) = 2(N-8) =2(N-s)N-22. We consider the following elliptic system of two equations in where A, μ 〉 0 and α, β 〉 1 satisfy α + β = 2*(s). Using the Moser iteration, we prove the asymptotic behavior of solutions at the origin. In addition, by exploiting the Mountain-Pass theorem, we establish the existence of solutions.展开更多
文摘Alloy thin film for advanced pressure sensors was manufactured by means of ion-beam sputtering SiO2 insulation film and NiCr thin film on the 17-4PH stainless steel elastic substrate. The thin film resistance was respectively heat-treated by four processes. The effects on stability of thin film alloy resistance were investigated, and paramaters of heat treatment that make thin film resistance stable were obtained. The experimental result indicates that the most stable thin film resistance can be obtained when it is heat-treated under protection of SiO2 and N2 at 673 K for 1 h, and then kept at 473 K for 24 h. Pressure sensor chips of high precision for harsh environments can be manufactured by this process.
文摘The author considers the global existence and global nonexistence of the initial-boundary value problem for some degenerate hyperbolic equation of the form utt- div(|△↓|^P-2 △↓u)=|u|^m u, (x,t)∈[0, +∞) ×Ω with p 〉 2 and m 〉 0. He deals with the global solutions by D.H.Sattinger's potential well ideas. At the same time, when the initial energy is positive, but appropriately bounded, the global nonexistence of solutions is verified by using the analysis method.
基金Research supported by National Natural Science Foundation of China(10171031).
文摘In this paper, we study the approximation problem on the closed convex cone, and prove that there exists a unique solution of the approximation problem, then give the algorithm to compute the unique solution.
文摘Extension of a B-spline curve or surface is a useful function in a CAD system. This paper presents an algorithm for extending cubic B-spline curves or surfaces to one or more target points. To keep the extension curve segment GC^2-continuous with the original one, a family of cubic polynomial interpolation curves can be constructed. One curve is chosen as the solution from a sub-class of such a family by setting one GC^2 parameter to be zero and determining the second GC^2 parameter by minimizing the strain energy. To simplify the final curve representation, the extension segment is reparameterized to achieve C-continuity with the given B-spline curve, and then knot removal from the curve is done. As a result, a sub-optimized solution subject to the given constraints and criteria is obtained. Additionally, new control points of the extension B-spline segment can be determined by solving lower triangular linear equations. Some computing examples for comparing our method and other methods are given.
基金The project supported by National Natural Science Foundation of China under Grant No. 10471132 and the Special Foundation for.the State Key Basic Research Project "Nonlinear Science"
文摘Based on the nonlinearization of Lax pairs, the Korteweg-de Vries (KdV) soliton hierarchy is decomposed into a family of finite-dimensional Hamiltonian systems, whose Liouville integrability is proved by means of the elliptic coordinates. By applying the Abel-Jacobi coordinates on a Riemann surface of hyperelliptic curve, the resulting Hamiltonian flows as well as the KdV soliton hierarchy are ultimately reduced into linear superpositions, expressed by the Abel-Jacobi variables.
文摘Based on the multiplicity results of Benci and Fortunato [4], we consider some elliptic systems with strongly indefinite quadratic part, and establish the existence of infinitely many nontrivial solutions in a suitable family of products of fractional Sobolev spaces.
文摘In this paper, we study the Cauchy problem of the inhomogeneous energy-critical Schrōdinger equation: iаtu=-△u-k(x)|u|4/N-2u,N≥3. Using the potential well method, we establish some new sharp criteria for blow-up of solutions in tile nonradial case. In particular, our conclusion in some sense improves on the results in [Kenig and Merle, invent. Math. 166, 645-675 (2006)], where only the radial case is considered in dimensions 3. 4. 5.
文摘In freeform surface modelling, developable surfaces have much application value. But, in 3D space, there is not always a regular developable surface which interpolates the given boundary of an arbitrary piecewise smooth closed curve. In this paper, tensor product Bézier surfaces interpolating the closed curves are determined and the resulting surface is a minimum of the functional defined by the L2-integral norm of the Gaussian curvature. The Gaussian curvature of the surfaces is minimized by the method of solving nonlinear optimization problems. An improved approach trust-region form method is proposed. A simple application example is also given.
基金Supported by the NNSF of China(10441002)Supported by NNSF of Henan Province(200510466011)
文摘In this paper we study the decay estimate of global solutions to the initial-boundary value problem for double degenerate nonlinear parabolic equation by using a dif-ference inequality.
基金supported by National Natural Science Foundation of China for Distinguished Young Scholars(Grant No.10925104)the PhD Programs Foundation of Ministry of Education of China(Grant No.20106101110008)the United Funds of NSFC and Henan for Talent Training(Grant No.U1204104)
文摘The inhomogeneous nonlinear diffusion equation is studied by invariant subspace and condi- tional Lie=Bgcklund symmetry methods. It is shown that the equations admit a class of invariant subspaces governed by the nonlinear ordinary differential equations, which is equivalent to a kind of higher=order conditional Lie-B^icklund symmetries of the equations. As a consequence, a number of new solutions to the inhomogeneous nonlinear diffusion equations are constructed explicitly or reduced to solving finite-dimensional dynamical sys- tems.
基金This work was supported by the National Science Foundation of China under Grant No. 60974004 and Natural Science Foundation of China under Grant No. 60904009.
文摘This paper studies a prey-predator singular bioeconomic system with time delay and diffusion, which is described by differential-algebraic equations. For this system without diffusion, there exist three bifurcation phenomena: Transcritical bifurcation, singularity induced bifurcation, and Hopf bifurcation. Compared with other biological systems described by differential equations, singularity induced bifurcation only occurs in singular system and usually links with the expansion of population. When the diffusion is present, it is shown that the positive equilibrium point loses its stability at some critical values of diffusion rate and periodic oscillations occur due to the increase of time delay. Furthermore, numerical simulations illustrate the effectiveness of results and the related biological implications are discussed.
基金the Land Use Theme of the Scottish Government Strategic Research Programme on Environmental Change.
文摘Mitigating and adapting to climate change includes a requirement to evaluate the role of future land uses in delivering robust integrated responses that are sensitive to local landscape contexts.In practice,this emphasises the need for community engagement,planning and inclusive decision-making.Community engagement may be potentially facilitated by the use of spatially explicit quantitative scenarios of landuse change in combination with interactive visualisation.This requires a coherent framework to integrate spatial data modelling,analytical capabilities and visualisation tools in a format that will also engage diverse public audiences.These challenges were explored with a case study of virtual landscapes from N-E Scotland that was used to test preferences for scenarios of future land use.Visualisations employed texture-based rendering rather than full photo-realistic rendering to facilitate interactivity and this provided additional scope for audiences to explore multiple future scenarios compared to the present landscape.Interactive voting in a virtual landscape theatre suggested preferences for visual diversity,good stewardship and perceived naturalness that should be considered in developing planned responses to change.Further investigation of preferences was conducted using interactive 3D features located within the landscape.Study findings are reviewed against objectives for inclusive engagement in the Digital Earth agenda and used to make further recommendations on the use of scenarios and visualisation tools.In particular,technical advances in user engagement need to be developed in conjunction with emerging good practice that addresses ethical,behavioural and inclusion issues so that the content is presented in as transparent and unbiased format as possible.
基金supported by the National Natural Science Foundation of China (No.11001052)the Postdoctoral Science Foundation of China (No.20100471365)+3 种基金the Jiangsu Provincial Natural Science Foundation of China (No.BK2010480)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (No.10KJB110010)the Jiangsu Provincial Postdoctoral Research Program of China (No.0901029C)the Jiangsu Government Scholarship for Overseas Studies,Qing Lan Project
文摘The authors investigate the tail probability of the supremum of a random walk with independent increments and obtain some equivalent assertions in the case that the increments are independent and identically distributed random variables with Osubexponential integrated distributions.A uniform upper bound is derived for the distribution of the supremum of a random walk with independent but non-identically distributed increments,whose tail distributions are dominated by a common tail distribution with an O-subexponential integrated distribution.
基金Project supported by the National Natural Science Foundation of China for Distinguished Young Scholars (No.10925104)the National Natural Science Foundation of China (No.11001240)+1 种基金the Doctoral Program Foundation of the Ministry of Education of China (No.20106101110008)the Zhejiang Provincial Natural Science Foundation of China (Nos.Y6090359,Y6090383)
文摘In this paper, the dimension of invariant subspaces admitted by nonlinear sys- tems is estimated under certain conditions. It is shown that if the two-component nonlinear vector differential operator F = (F1, F2) with orders {k1, k2} (k1≥ k2) preserves the invariant subspace Wn1^1× Wn2^2 (n1 ≥ n2), then n1 - n2 ≤ k2, n1 ≤2(k1 + k2) + 1, where Wnq^q is the space generated by solutions of a linear ordinary differential equation of order nq (q = 1, 2). Several examples including the (1+1)-dimensional diffusion system and Ito's type, Drinfel'd-Sokolov-Wilson's type and Whitham-Broer-Kaup's type equations are presented to illustrate the result. Furthermore, the estimate of dimension for m-component nonlinear systems is also given.
基金Supported by the National Natural Science Foundation of China(Grant No.11611540331)Scientific Research Award Foundation of Minzu University of China(No.2016LXY08)
文摘The large time Ll-behavior of the strong solution (including the first and second order spacial derivatives) to the incompressible magneto-hydrodynamic (MHD) equations is given in a half-space. The main tool employed in this article is a new weighted estimate for the Stokes flow in L1(Rn+), such a study is of independent interest.
基金supported by National Natural Science Foundation of China under grant Nos. 1110145011071239
文摘Let Ω∈← 0 be an open bounded domain in RN (N 〉 3) and 2*(s) = 2(N-8) =2(N-s)N-22. We consider the following elliptic system of two equations in where A, μ 〉 0 and α, β 〉 1 satisfy α + β = 2*(s). Using the Moser iteration, we prove the asymptotic behavior of solutions at the origin. In addition, by exploiting the Mountain-Pass theorem, we establish the existence of solutions.