In this article, by the algebraic method, the author proves the existence of a new nontrivial family of filtration s + 5 in the stable homotopy groups of spheres πrS,which is represented by 0 ≠γ^-s+3hnhm∈Ext^s+...In this article, by the algebraic method, the author proves the existence of a new nontrivial family of filtration s + 5 in the stable homotopy groups of spheres πrS,which is represented by 0 ≠γ^-s+3hnhm∈Ext^s+5,A ^t(Zp,Zp)in the Adams spectral sequence,where r=q(p^m+p^n+(s+3)p^2+(s+2)p+(s+1))-5,t=p^mq+p^nq+(s+3)p^2q+(s+2)pq+(s+1)q+s,p≥7,m≥n+2〉5,0≤s〈p-3,q=2(p-1).展开更多
In this article, we prove the boundedness of commutators generated by BochnerRiesz operators below the critical index and BMO functions on the class of radial functions in Lp(Rn) with |1/p-1/2|〈(1+2α)/(2n).
There is little work concerning the properties of quaternionic operators acting on slice regular function spaces defined on quaternions.In this paper,we present an equivalent characterization for the boundedness of th...There is little work concerning the properties of quaternionic operators acting on slice regular function spaces defined on quaternions.In this paper,we present an equivalent characterization for the boundedness of the product operator C_(φ)D^(m) acting on Bloch-type spaces of slice regular functions.After that,an equivalent estimation for its essential norm is established,which can imply several existing results on holomorphic spaces.展开更多
In this paper,we first establish narrow region principle and decay at infinity theorems to extend the direct method of moving planes for general fractional p-Laplacian systems.By virtue of this method,we investigate t...In this paper,we first establish narrow region principle and decay at infinity theorems to extend the direct method of moving planes for general fractional p-Laplacian systems.By virtue of this method,we investigate the qualitative properties of positive solutions for the following Schrodinger system with fractional p-Laplacian{(-△)^(s)_(p)u+au^(p-1)=f(u,v),(-△)^(t)_(p)v+bv(p-1)=g(u,v),where 0<s,t<1 and 2<p<∞.We obtain the radial symmetry in the unit ball or the whole space R^(N)(N≥2),the monotonicity in the parabolic domain and the nonexistence on the half space for positive solutions to the above system under some suitable conditions on f and g,respectively.展开更多
This paper presents alternating direction finite volume element methods for three-dimensional parabolic partial differential equations and gives four computational schemes, one is analogous to Douglas finite differenc...This paper presents alternating direction finite volume element methods for three-dimensional parabolic partial differential equations and gives four computational schemes, one is analogous to Douglas finite difference scheme with second-order splitting error, the other two schemes have third-order splitting error, and the last one is an extended LOD scheme. The L2 norm and H1 semi-norm error estimates are obtained for the first scheme and second one, respectively. Finally, two numerical examples are provided to illustrate the efficiency and accuracy of the methods.展开更多
In this article, we present several equivalent conditions ensuring the disjoint supercyclicity of finite weighted pseudo-shifts acting on an arbitrary Banach sequence space. The disjoint supercyclic properties of weig...In this article, we present several equivalent conditions ensuring the disjoint supercyclicity of finite weighted pseudo-shifts acting on an arbitrary Banach sequence space. The disjoint supercyclic properties of weighted translations on locally compact discrete groups, the di rec t sums of finite classical weighted backward shifts, and the bilateral backward opera tor weighted shifts can be viewed as special cases of our main results. Furthermore, we exhibit an interesting fact that any finite bilateral weighted backward shifts on the space l^2 (Z) never satisfy the d-Supercyclicity Criterion by a simple proof.展开更多
Denote a finite dimensional Hopf C*-algebra by H, and a Hopf *-subalgebra of H by H1. In this paper, we study the construction of the field algebra in Hopf spin models determined by H1 together with its symmetry. More...Denote a finite dimensional Hopf C*-algebra by H, and a Hopf *-subalgebra of H by H1. In this paper, we study the construction of the field algebra in Hopf spin models determined by H1 together with its symmetry. More precisely, we consider the quantum double D(H, H_(1)) as the bicrossed product of the opposite dual Hopˆ of H and H1 with respect to the coadjoint representation, the latter acting on the former and vice versa, and under the non-trivial commutation relations between H1 and Ĥ we define the observable algebra AH1. Then using a comodule action of D(H, H1) on AH1, we obtain the field algebra FH1, which is the crossed product AH1⋊D(H,H_(1)), and show that the observable algebra AH1 is exactly a D(H, H1)-invariant subalgebra of FH1. Furthermore, we prove that there exists a duality between D(H, H1) and AH1, implemented by a*-homomorphism of D(H, H_(1)).展开更多
This paper builds a bridge between partial regularity theory and nonlinear potential theory for the following generalized stationary Stokes system with super-quadratic growth and continuous coefficients:-div A(x,Du)+...This paper builds a bridge between partial regularity theory and nonlinear potential theory for the following generalized stationary Stokes system with super-quadratic growth and continuous coefficients:-div A(x,Du)+■π=f,div u=0,where Du is the symmetric part of the gradient■u.We first establish anε-regularity criterion involving both the excess functional of the symmetric gradient Du and Wolff potentials of the nonhomogeneous term f to guarantee the local vanishing mean oscillation(VMO)-regularity of Du in an open subset Ω_(u) of Ω with full measure.Such anε-regularity criterion leads to a pointwise Wolff potential estimate of Du,which immediately infers that Du is partially C^(0)-regular under appropriate assumptions.Finally,we give a local continuous modulus estimate of Du.展开更多
We study the dynamics of coherence-induced state ordering under incoherent channels, particularly four specific Markovian channels: amplitude damping channel, phase damping channel, depolarizing channel and bit flit ...We study the dynamics of coherence-induced state ordering under incoherent channels, particularly four specific Markovian channels: amplitude damping channel, phase damping channel, depolarizing channel and bit flit channel for single-qnbit states. We show that the amplitude damping channel, phase damping channel, and depolarizing channel do not change the coherence-induced state ordering by l1 norm of coherence, relative entropy of coherence, geometric measure of coherence, and Tsallis relative α-entropies, while the bit flit channel does change for some special cases.展开更多
Supersaturated designs (SSDs) have been widely used in factor screening experiments. The present paper aims to prove that the maximal balanced designs are a kind of special optimal SSDs under the E(fNOD) criterion...Supersaturated designs (SSDs) have been widely used in factor screening experiments. The present paper aims to prove that the maximal balanced designs are a kind of special optimal SSDs under the E(fNOD) criterion. We also propose a new method, called the complementary design method, for constructing E(fNoD) optimal SSDs. The basic principle of this method is that for any existing E(fNOD) optimal SSD whose E(fNOD) value reaches its lower bound, its complementary design in the corresponding maximal balanced design is also E(fNOD) optimal. This method applies to both symmetrical and asymmetrical (mixed-level) cases. It provides a convenient and efl:icient way to construct many new designs with relatively large numbers of factors. Some newly constructed designs are given as examples.展开更多
Let G be a finite group and S be a subset of Irr(G).If for every prime divisor p of|G|there is a characterχin S such that p dividesχ(1),S is called a covering set of G.The covering number of G,denoted by cn(G),is de...Let G be a finite group and S be a subset of Irr(G).If for every prime divisor p of|G|there is a characterχin S such that p dividesχ(1),S is called a covering set of G.The covering number of G,denoted by cn(G),is defined as the minimal number of Card(S),where S is a covering set of G and Card(S)is the cardinality of set S.In this paper,we prove that if G is a finite group with F(G)=1,then the covering number cn(G)≤3.Especially,if PSL2(q)or J1 is not involved in G,then cn(G)≤2.展开更多
In this paper, we consider the n-widths and average widths of Besov classes in the usual Sobolev spaces. The weak asymptotic results concerning the Kolmogorov n-widths, the linear n-widths, the Gel'fand n-widths, in ...In this paper, we consider the n-widths and average widths of Besov classes in the usual Sobolev spaces. The weak asymptotic results concerning the Kolmogorov n-widths, the linear n-widths, the Gel'fand n-widths, in the Sobolev spaces on T^d, and the infinite-dimensional widths and the average widths in the Sobolev spaces on Ra are obtained, respectively.展开更多
UiO-66-NH2 is an efficient material for removing pollutants from wastewater due to its high specific surface area,high porosity and water stability.However,recycling them from wastewater is difficult.In this study,the...UiO-66-NH2 is an efficient material for removing pollutants from wastewater due to its high specific surface area,high porosity and water stability.However,recycling them from wastewater is difficult.In this study,the cellulose nanofibers mat deacetylated from cellulose acetate nanofibers were used to combine with UiO-66-NH_(2)by the method of in-situ growth to remove the toxic dye,rose bengal.Compared to previous work,the prepared composite could not only provide ease of separation of UiO-66-NH_(2)from the water after adsorption but also demonstrate better adsorption capacity(683 mg∙g‒1(T=25°C,pH=3))than that of the simple UiO-66-NH_(2)(309.6 mg∙g^(‒1)(T=25℃,pH=3)).Through the analysis of adsorption kinetics and isotherms,the adsorption for rose bengal is mainly suitable for the pseudo-second-order kinetic model and Freundlich model.Furthermore,the relevant research revealed that the main adsorption mechanism of the composite was electrostatic interaction,hydrogen bonding andπ–πinteraction.Overall,the approach depicts an efficient model for integrating metal-organic frameworks on cellulose nanofibers to improve metal-organic framework recovery performance with potentially broad applications.展开更多
This paper considers identification for the spatial variable coefficient of a vibrating string with Neumann boundary control from the measured boundary displacement. The reconstruction algorithm consists of two steps:...This paper considers identification for the spatial variable coefficient of a vibrating string with Neumann boundary control from the measured boundary displacement. The reconstruction algorithm consists of two steps: The first step is to recover the spectral data from the measured boundary displacement by showing that the system is spectral controllable; the second step is to reconstruct the coefficient from the recovered spectral data using the boundary control method, for which the required exact controllability is also verified.展开更多
This paper focuses on the higher order fractional differentiability of weak solution pairs to the following nonlinear stationary Stokes system{div A(x-Du)-■π=divF,inΩdivu=0,inΩ.In terms of the difference quotient ...This paper focuses on the higher order fractional differentiability of weak solution pairs to the following nonlinear stationary Stokes system{div A(x-Du)-■π=divF,inΩdivu=0,inΩ.In terms of the difference quotient method,our first result reveals that if F∈B_(p,q.loc)^(β)(Ω,R^(n))for p=2 and 1≤q≤2n/n-2β,then such extra Besov regularity can transfer to the symmetric gradient Du and its pressureπwith no losses under a suitable fractional differentiability assumption on x■A(x,ξ).Furthermore,when the vector field A(x,Du)is simplified to the full gradient■u,we improve the aforementioned Besov regularity for all integrability exponents p and q by establishing a new Campanato-type decay estimates for(■u,π).展开更多
For 1≤ p < ∞, firstly we prove that for an arbitrary set of distinct nodes in [-1, 1], it is impossible that the errors of the Hermite-Fejr interpolation approximation in L p -norm are weakly equivalent to the co...For 1≤ p < ∞, firstly we prove that for an arbitrary set of distinct nodes in [-1, 1], it is impossible that the errors of the Hermite-Fejr interpolation approximation in L p -norm are weakly equivalent to the corresponding errors of the best polynomial approximation for all continuous functions on [-1, 1]. Secondly, on the ground of probability theory, we discuss the p-average errors of Hermite-Fejr interpolation sequence based on the extended Chebyshev nodes of the second kind on the Wiener space. By our results we know that for 1≤ p < ∞ and 2≤ q < ∞, the p-average errors of Hermite-Fejr interpolation approximation sequence based on the extended Chebyshev nodes of the second kind are weakly equivalent to the p-average errors of the corresponding best polynomial approximation sequence for L q -norm approximation. In comparison with these results, we discuss the p-average errors of Hermite-Fejr interpolation approximation sequence based on the Chebyshev nodes of the second kind and the p-average errors of the well-known Bernstein polynomial approximation sequence on the Wiener space.展开更多
Let G be a finite group, Irra(G) be the set of nonlinear irreducible characters of G and cdl (G) the set of degrees of the characters in Irrl (G). A group G is said to be a D2-group if │cdl (G)│ = │Irrl(G...Let G be a finite group, Irra(G) be the set of nonlinear irreducible characters of G and cdl (G) the set of degrees of the characters in Irrl (G). A group G is said to be a D2-group if │cdl (G)│ = │Irrl(G)│ - 2. In this paper, we give a complete classification of solvable D2-groups.展开更多
Variational methods are an important class of methods for general image restoration.Boosting technique has been shown capable of improving many image denoising algorithms.This paper discusses a boosting technique for ...Variational methods are an important class of methods for general image restoration.Boosting technique has been shown capable of improving many image denoising algorithms.This paper discusses a boosting technique for general variation-al image restoration methods.It broadens the applications of boosting techniques to a wide range of image restoration problems,including not only denoising but also deblur-ring and inpainting.In particular,we combine the recent SOS technique with dynamic parameter to variational methods.The dynamic regularization parameter is motivated by Meyer’s analysis on the ROF model.In each iteration of the boosting scheme,the variational model is solved by augmented Lagrangian method.The convergence analy-sis of the boosting process is shown in a special case of total variation image denoising with a“disk”input data.We have implemented our boosting technique for several im-age restoration problems such as denoising,inpainting and deblurring.The numerical results demonstrate promising improvement over standard variational restoration mod-els such as total variation based models and higher order variational model as total generalized variation.展开更多
Let{T(t)}_(t≥0) be a C_(0)-semigroupon an infinite-dimensional separable Hilbert space;a suitable definition of near{T(t)^(*)}_(t≥0) invariance of a subspace is presented in this paper.A series of prototypical examp...Let{T(t)}_(t≥0) be a C_(0)-semigroupon an infinite-dimensional separable Hilbert space;a suitable definition of near{T(t)^(*)}_(t≥0) invariance of a subspace is presented in this paper.A series of prototypical examples for minimal nearly{S(t)^(*)}_(t≥0) invariant subspaces for the shift semigroup{S(t)}_(t≥0) on L^(2)(0,∞)are demonstrated,which have close links with near T_(θ)^(*)invariance on Hardy spaces of the unit disk for an inner functionθ.Especially,the corresponding subspaces on Hardy spaces of the right half-plane and the unit disk are related to model spaces.This work further includes a discussion on the structure of the closure of certain subspaces related to model spaces in Hardy spaces.展开更多
For an element A in a unital C^(*)-algebra B,the operator-valued 1-formωA(z)=(z-A)^(-1) dz is analytic on the resolvent setρ(A),which plays an important role in the functional calculus of A.This paper defines a clas...For an element A in a unital C^(*)-algebra B,the operator-valued 1-formωA(z)=(z-A)^(-1) dz is analytic on the resolvent setρ(A),which plays an important role in the functional calculus of A.This paper defines a class of Hermitian metrics onρ(A)through the coupling of the operator-valued(1,1)-formΩA=-ωA^(*)∧ωA with tracial and vector states.Its main goal is to study the connection between A and the properties of the metric concerning curvature,arc length,completeness and singularity.A particular example is when A is quasi-nilpotent,in which case the metric lives on the punctured complex plane C\{0}.The notion of the power set is defined to gauge the"blow-up"rate of the metric at 0,and examples are given to indicate a likely link with A’s hyper-invariant subspaces.展开更多
文摘In this article, by the algebraic method, the author proves the existence of a new nontrivial family of filtration s + 5 in the stable homotopy groups of spheres πrS,which is represented by 0 ≠γ^-s+3hnhm∈Ext^s+5,A ^t(Zp,Zp)in the Adams spectral sequence,where r=q(p^m+p^n+(s+3)p^2+(s+2)p+(s+1))-5,t=p^mq+p^nq+(s+3)p^2q+(s+2)pq+(s+1)q+s,p≥7,m≥n+2〉5,0≤s〈p-3,q=2(p-1).
基金supported by National Natural Science Foundation of China (10871024, 10931001, and 10971141)the Beijing Natural Science Foundation (1092004)+1 种基金Introduces Talent Fund Projects of Tianjin Normal University (5RL067)the Key Laboratory of Mathematics and Complex System (Beijing Normal University), Ministry of Education, China
文摘In this article, we prove the boundedness of commutators generated by BochnerRiesz operators below the critical index and BMO functions on the class of radial functions in Lp(Rn) with |1/p-1/2|〈(1+2α)/(2n).
基金supported by the National Natural Science Foundation of China(11701422).
文摘There is little work concerning the properties of quaternionic operators acting on slice regular function spaces defined on quaternions.In this paper,we present an equivalent characterization for the boundedness of the product operator C_(φ)D^(m) acting on Bloch-type spaces of slice regular functions.After that,an equivalent estimation for its essential norm is established,which can imply several existing results on holomorphic spaces.
基金Supported by the National Natural Science Foundation of China(12101452,12071229,11771218)。
文摘In this paper,we first establish narrow region principle and decay at infinity theorems to extend the direct method of moving planes for general fractional p-Laplacian systems.By virtue of this method,we investigate the qualitative properties of positive solutions for the following Schrodinger system with fractional p-Laplacian{(-△)^(s)_(p)u+au^(p-1)=f(u,v),(-△)^(t)_(p)v+bv(p-1)=g(u,v),where 0<s,t<1 and 2<p<∞.We obtain the radial symmetry in the unit ball or the whole space R^(N)(N≥2),the monotonicity in the parabolic domain and the nonexistence on the half space for positive solutions to the above system under some suitable conditions on f and g,respectively.
文摘This paper presents alternating direction finite volume element methods for three-dimensional parabolic partial differential equations and gives four computational schemes, one is analogous to Douglas finite difference scheme with second-order splitting error, the other two schemes have third-order splitting error, and the last one is an extended LOD scheme. The L2 norm and H1 semi-norm error estimates are obtained for the first scheme and second one, respectively. Finally, two numerical examples are provided to illustrate the efficiency and accuracy of the methods.
基金supported by the Research Project of Tianjin Municipal Education Commission(2017KJ124)
文摘In this article, we present several equivalent conditions ensuring the disjoint supercyclicity of finite weighted pseudo-shifts acting on an arbitrary Banach sequence space. The disjoint supercyclic properties of weighted translations on locally compact discrete groups, the di rec t sums of finite classical weighted backward shifts, and the bilateral backward opera tor weighted shifts can be viewed as special cases of our main results. Furthermore, we exhibit an interesting fact that any finite bilateral weighted backward shifts on the space l^2 (Z) never satisfy the d-Supercyclicity Criterion by a simple proof.
基金supported by National Nature Science Foundation of China(11871303,11701423)Nature Science Foundation of Hebei Province(A2019404009)。
文摘Denote a finite dimensional Hopf C*-algebra by H, and a Hopf *-subalgebra of H by H1. In this paper, we study the construction of the field algebra in Hopf spin models determined by H1 together with its symmetry. More precisely, we consider the quantum double D(H, H_(1)) as the bicrossed product of the opposite dual Hopˆ of H and H1 with respect to the coadjoint representation, the latter acting on the former and vice versa, and under the non-trivial commutation relations between H1 and Ĥ we define the observable algebra AH1. Then using a comodule action of D(H, H1) on AH1, we obtain the field algebra FH1, which is the crossed product AH1⋊D(H,H_(1)), and show that the observable algebra AH1 is exactly a D(H, H1)-invariant subalgebra of FH1. Furthermore, we prove that there exists a duality between D(H, H1) and AH1, implemented by a*-homomorphism of D(H, H_(1)).
基金supported by National Natural Science Foundation of China (Grant Nos. 12101452 and 12071229)。
文摘This paper builds a bridge between partial regularity theory and nonlinear potential theory for the following generalized stationary Stokes system with super-quadratic growth and continuous coefficients:-div A(x,Du)+■π=f,div u=0,where Du is the symmetric part of the gradient■u.We first establish anε-regularity criterion involving both the excess functional of the symmetric gradient Du and Wolff potentials of the nonhomogeneous term f to guarantee the local vanishing mean oscillation(VMO)-regularity of Du in an open subset Ω_(u) of Ω with full measure.Such anε-regularity criterion leads to a pointwise Wolff potential estimate of Du,which immediately infers that Du is partially C^(0)-regular under appropriate assumptions.Finally,we give a local continuous modulus estimate of Du.
文摘We study the dynamics of coherence-induced state ordering under incoherent channels, particularly four specific Markovian channels: amplitude damping channel, phase damping channel, depolarizing channel and bit flit channel for single-qnbit states. We show that the amplitude damping channel, phase damping channel, and depolarizing channel do not change the coherence-induced state ordering by l1 norm of coherence, relative entropy of coherence, geometric measure of coherence, and Tsallis relative α-entropies, while the bit flit channel does change for some special cases.
基金Supported by the National Natural Science Foundation of China (Nos. 10971107 and 11271205)the "131" Talents Program of Tianjin+1 种基金the Fundamental Research Funds for the Central Universities (No. 65030011)the Doctor Foundation of Tianjin Normal University (No. 52XB1205)
文摘Supersaturated designs (SSDs) have been widely used in factor screening experiments. The present paper aims to prove that the maximal balanced designs are a kind of special optimal SSDs under the E(fNOD) criterion. We also propose a new method, called the complementary design method, for constructing E(fNoD) optimal SSDs. The basic principle of this method is that for any existing E(fNOD) optimal SSD whose E(fNOD) value reaches its lower bound, its complementary design in the corresponding maximal balanced design is also E(fNOD) optimal. This method applies to both symmetrical and asymmetrical (mixed-level) cases. It provides a convenient and efl:icient way to construct many new designs with relatively large numbers of factors. Some newly constructed designs are given as examples.
基金Supported by the Science&Technology Development Fund of Tianjin Education Commission for Higher Education(Grant No.2020KJ010)。
文摘Let G be a finite group and S be a subset of Irr(G).If for every prime divisor p of|G|there is a characterχin S such that p dividesχ(1),S is called a covering set of G.The covering number of G,denoted by cn(G),is defined as the minimal number of Card(S),where S is a covering set of G and Card(S)is the cardinality of set S.In this paper,we prove that if G is a finite group with F(G)=1,then the covering number cn(G)≤3.Especially,if PSL2(q)or J1 is not involved in G,then cn(G)≤2.
基金Supported by Project(No.10471010)of National Natural Science Foundation of ChinaSupported by the Development Foundation of Science and Technology of Tianjin Universities(20040405)Supported by Project"Representation Theory and Related Topics"of the"985 Program"of Beijing Normal University
文摘In this paper, we consider the n-widths and average widths of Besov classes in the usual Sobolev spaces. The weak asymptotic results concerning the Kolmogorov n-widths, the linear n-widths, the Gel'fand n-widths, in the Sobolev spaces on T^d, and the infinite-dimensional widths and the average widths in the Sobolev spaces on Ra are obtained, respectively.
基金support of the Tianjin Natural Science Foundation(Grant No.18JCQNJC71900).
文摘UiO-66-NH2 is an efficient material for removing pollutants from wastewater due to its high specific surface area,high porosity and water stability.However,recycling them from wastewater is difficult.In this study,the cellulose nanofibers mat deacetylated from cellulose acetate nanofibers were used to combine with UiO-66-NH_(2)by the method of in-situ growth to remove the toxic dye,rose bengal.Compared to previous work,the prepared composite could not only provide ease of separation of UiO-66-NH_(2)from the water after adsorption but also demonstrate better adsorption capacity(683 mg∙g‒1(T=25°C,pH=3))than that of the simple UiO-66-NH_(2)(309.6 mg∙g^(‒1)(T=25℃,pH=3)).Through the analysis of adsorption kinetics and isotherms,the adsorption for rose bengal is mainly suitable for the pseudo-second-order kinetic model and Freundlich model.Furthermore,the relevant research revealed that the main adsorption mechanism of the composite was electrostatic interaction,hydrogen bonding andπ–πinteraction.Overall,the approach depicts an efficient model for integrating metal-organic frameworks on cellulose nanofibers to improve metal-organic framework recovery performance with potentially broad applications.
基金supported by the National Natural Science Foundation of China under Grant No.11326196the Doctoral Fund Program of Tianjin Normal University under Grant No.52XB1413
文摘This paper considers identification for the spatial variable coefficient of a vibrating string with Neumann boundary control from the measured boundary displacement. The reconstruction algorithm consists of two steps: The first step is to recover the spectral data from the measured boundary displacement by showing that the system is spectral controllable; the second step is to reconstruct the coefficient from the recovered spectral data using the boundary control method, for which the required exact controllability is also verified.
基金Supported by the National Natural Science Foundation of China(Grant Nos.12071229,12101452)Tianjin Normal University Doctoral Research Project(Grant No.52XB2110)。
文摘This paper focuses on the higher order fractional differentiability of weak solution pairs to the following nonlinear stationary Stokes system{div A(x-Du)-■π=divF,inΩdivu=0,inΩ.In terms of the difference quotient method,our first result reveals that if F∈B_(p,q.loc)^(β)(Ω,R^(n))for p=2 and 1≤q≤2n/n-2β,then such extra Besov regularity can transfer to the symmetric gradient Du and its pressureπwith no losses under a suitable fractional differentiability assumption on x■A(x,ξ).Furthermore,when the vector field A(x,Du)is simplified to the full gradient■u,we improve the aforementioned Besov regularity for all integrability exponents p and q by establishing a new Campanato-type decay estimates for(■u,π).
基金supported by National Natural Science Foundation of China (Grant No.10471010)
文摘For 1≤ p < ∞, firstly we prove that for an arbitrary set of distinct nodes in [-1, 1], it is impossible that the errors of the Hermite-Fejr interpolation approximation in L p -norm are weakly equivalent to the corresponding errors of the best polynomial approximation for all continuous functions on [-1, 1]. Secondly, on the ground of probability theory, we discuss the p-average errors of Hermite-Fejr interpolation sequence based on the extended Chebyshev nodes of the second kind on the Wiener space. By our results we know that for 1≤ p < ∞ and 2≤ q < ∞, the p-average errors of Hermite-Fejr interpolation approximation sequence based on the extended Chebyshev nodes of the second kind are weakly equivalent to the p-average errors of the corresponding best polynomial approximation sequence for L q -norm approximation. In comparison with these results, we discuss the p-average errors of Hermite-Fejr interpolation approximation sequence based on the Chebyshev nodes of the second kind and the p-average errors of the well-known Bernstein polynomial approximation sequence on the Wiener space.
文摘Let G be a finite group, Irra(G) be the set of nonlinear irreducible characters of G and cdl (G) the set of degrees of the characters in Irrl (G). A group G is said to be a D2-group if │cdl (G)│ = │Irrl(G)│ - 2. In this paper, we give a complete classification of solvable D2-groups.
基金The work of Dr.C.Wu was supported by National Natural Science Foundation of China(Grant No.11301289 and 11531013)Dr.H.Chang was partially supported by National Natural Science Foundation of China(Nos.11501413 and 51609259)+2 种基金China Scholarship Council(CSC),Young backbone of innovative personnel training program No.043-135205GC372017-Outstanding Young Innovation Team Cul-tivation Program No.043-135202TD1703Innovation Project No.043-135202XC1605 of Tianjin Normal University,and the Research Program of China Institute of Water Resources and Hydropower Research(Nos.JZ0145B472016 and JZ0145B862017).
文摘Variational methods are an important class of methods for general image restoration.Boosting technique has been shown capable of improving many image denoising algorithms.This paper discusses a boosting technique for general variation-al image restoration methods.It broadens the applications of boosting techniques to a wide range of image restoration problems,including not only denoising but also deblur-ring and inpainting.In particular,we combine the recent SOS technique with dynamic parameter to variational methods.The dynamic regularization parameter is motivated by Meyer’s analysis on the ROF model.In each iteration of the boosting scheme,the variational model is solved by augmented Lagrangian method.The convergence analy-sis of the boosting process is shown in a special case of total variation image denoising with a“disk”input data.We have implemented our boosting technique for several im-age restoration problems such as denoising,inpainting and deblurring.The numerical results demonstrate promising improvement over standard variational restoration mod-els such as total variation based models and higher order variational model as total generalized variation.
基金supported by National Natural Science Foundation of China(Grant No.11701422)。
文摘Let{T(t)}_(t≥0) be a C_(0)-semigroupon an infinite-dimensional separable Hilbert space;a suitable definition of near{T(t)^(*)}_(t≥0) invariance of a subspace is presented in this paper.A series of prototypical examples for minimal nearly{S(t)^(*)}_(t≥0) invariant subspaces for the shift semigroup{S(t)}_(t≥0) on L^(2)(0,∞)are demonstrated,which have close links with near T_(θ)^(*)invariance on Hardy spaces of the unit disk for an inner functionθ.Especially,the corresponding subspaces on Hardy spaces of the right half-plane and the unit disk are related to model spaces.This work further includes a discussion on the structure of the closure of certain subspaces related to model spaces in Hardy spaces.
文摘For an element A in a unital C^(*)-algebra B,the operator-valued 1-formωA(z)=(z-A)^(-1) dz is analytic on the resolvent setρ(A),which plays an important role in the functional calculus of A.This paper defines a class of Hermitian metrics onρ(A)through the coupling of the operator-valued(1,1)-formΩA=-ωA^(*)∧ωA with tracial and vector states.Its main goal is to study the connection between A and the properties of the metric concerning curvature,arc length,completeness and singularity.A particular example is when A is quasi-nilpotent,in which case the metric lives on the punctured complex plane C\{0}.The notion of the power set is defined to gauge the"blow-up"rate of the metric at 0,and examples are given to indicate a likely link with A’s hyper-invariant subspaces.