Mg-Gd based alloys are an important class of high-performance Mg alloys.In this study,three Mg-Gd alloys with different gadolinium(Gd)contents:Mg-9.54Gd-0.40Zr(wt.%,G10 K),Mg-15.11Gd-0.35Zr(wt.%,G15 K)and Mg-19.67Gd-0...Mg-Gd based alloys are an important class of high-performance Mg alloys.In this study,three Mg-Gd alloys with different gadolinium(Gd)contents:Mg-9.54Gd-0.40Zr(wt.%,G10 K),Mg-15.11Gd-0.35Zr(wt.%,G15 K)and Mg-19.67Gd-0.33Zr(wt.%,G20 K)were prepared by semicontinuous casting and subsequent solution and aging heat treatments.The role of Gd content on microstructures and mechanical properties of the Mg-Gd-Zr alloy is studied.All three as-cast alloys exhibit eutectic phases of Mg_(5)Gd,with the amount increasing as the Gd content rises.Mg_(5)Gd disappears after the solution heat treatment(the G10 K alloy solution-treated at 480℃ for 4 h,the G15 K alloy at 500℃ for 12 h and the G20 K alloy at 520℃ for 24 h,respectively).Aging heat treatment at 200℃ for 64 h after solution introduces numerous prismatic β' precipitates,with a significant increase in their area number density corresponding to increased Gd content.Additionally,the morphology of the β' precipitates exhibits distinct variations:the G10 K alloy is characterized by an enhanced aspect ratio.Consequently,the peak-aged G10 K alloy demonstrates superior strength-ductility synergy,with a yield strength(YS)of 216±1 MPa,an ultimate tensile strength(UTS)of 363±1 MPa,and an elongation(EL)of 8.7±0.6%.This study suggests that plasticity diminishes and precipitation strengthening is limited when the gadolinium content exceeds 15 wt.%.展开更多
In this article, the authors mainly study how to obtain new semicontinuous lattices from the given semicontinuous lattices and discuss the conditions under which the image of a semicontinuous projection operator is al...In this article, the authors mainly study how to obtain new semicontinuous lattices from the given semicontinuous lattices and discuss the conditions under which the image of a semicontinuous projection operator is also semicontinuous. Moreover, the authors investigate the relation between semicontinuous lattices and completely distributive lattices. Finally, it is proved that the strongly semicontinuous lattice category is a Cartesian closed category.展开更多
In this paper, we use the well known KKM type theorem for generalized convex spaces due to Park （Elements of the KKM theory for generalized convex spaces, Korean J. Comp. Appl. Math., 7（2000）, 1-28） to obtain an a...In this paper, we use the well known KKM type theorem for generalized convex spaces due to Park （Elements of the KKM theory for generalized convex spaces, Korean J. Comp. Appl. Math., 7（2000）, 1-28） to obtain an almost fixed point theorem for upper [resp., lower] semicontinuous multimaps in locally G-convex spaces, and then give a fixed point theorem for upper semicontinuous multimap with closed Γ-convex values.展开更多
The purpose of this paper is to introduce the notions of m-asymmetric semiopen sets and M-asymmetric semicontinuous multifunctions defined between asymmetric sets satisfying certain minimal conditions in the framework...The purpose of this paper is to introduce the notions of m-asymmetric semiopen sets and M-asymmetric semicontinuous multifunctions defined between asymmetric sets satisfying certain minimal conditions in the framework of bitopological spaces. Some new characterizations of m-asymmetric semiopen sets and M-asymmetric semicontinuous multifunctions will be investigated and several fundamental properties will be obtained.展开更多
The seeded semicontinuous emulsion multi-copolymerization of butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), methyl methacrylate (MMA), 2-hydroxyl propyl acrylate (HOPA) and acrylic acid (AA) was used to prepare th...The seeded semicontinuous emulsion multi-copolymerization of butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), methyl methacrylate (MMA), 2-hydroxyl propyl acrylate (HOPA) and acrylic acid (AA) was used to prepare the acrylic latexes with high-solid content. The effects of monomer emulsion feed rates (R(a)) and (R/E)(E) values, the ratio of emulsifier amount between the initial charge (R) and the addition monomer emulsion (E), on the polymerization reaction features, the viscosities, surface tensions,particle sizes and particle sizes distributions of latexes, T-g and the insoluble fractions of films, the 180 degrees peel strength, tack and holding power of pressure-sensitive adhesive (PSA) tapes, prepared from the latexes, were studied. Experimental study shows that the grafting and crosslinking fraction in the PSA tapes must be controlled within a suitable range to keep the balance of the 180 degrees peel strength, tack and holding power.展开更多
Given a compact Hausdorff space X, U(X) denotes the compact Hausdorff space of all the upper semicontinuous functions from X to the unit interval with the dual lim inf topology. Then U is an endofunctor o...Given a compact Hausdorff space X, U(X) denotes the compact Hausdorff space of all the upper semicontinuous functions from X to the unit interval with the dual lim inf topology. Then U is an endofunctor on compact Hausdorff space. It is proved in this note that this functor preserves inverse limits.展开更多
Semicontinuous equal-channel angular extrusion（ SC-ECAE） is a novel severe plastic deformation technique that has been developed to produce ultrafine-grain steels. Instead of external forces being exerted on specime...Semicontinuous equal-channel angular extrusion（ SC-ECAE） is a novel severe plastic deformation technique that has been developed to produce ultrafine-grain steels. Instead of external forces being exerted on specimens in the conventional ECAE,driving forces are applied to dies in SC-EACE. The deformation of interstitial-free（ IF） steel w as performed at room temperature,and individual specimens w ere repeatedly processed at various passes. An overall grain size of 0. 55 μm w as achieved after 10 passes. During SC-ECAE,the main textures of IF steel included { 111} ,{ 110} ,{ 112} ,{ 110} ,and { 110} At an early stage,increasing dislocations induce new textures and increase intensity. When the deformation continues,low-angle boundaries are formed betw een dislocation cell bands,w hich cause some dislocation cell bands to change their orientation,and therefore,the intensity of the textures begins to decrease. After more passes,the intensity of textures continues to decrease w ith high-angle boundaries,and the sub-grains in dislocation cell bands continuously increase. The present study reports the evolution of textures during deformation; these w ere examined and characterized using high-resolution electron backscattered diffraction（ EBSD） in a field emission scanning electron microscope. The mechanisms of texture evolution are discussed.展开更多
In the present paper, some new almost fixed point theorems and fixed point theorems for lower semicontinuous type multivalued mappings are obtained in metrizable H-spaces.
Lattice-valued semicontinuous mappings play a basic and important role in solving the problems of L-fuzzy compactification theory,and make the previous work on weakly induced spaces and induced spaces determinatively ...Lattice-valued semicontinuous mappings play a basic and important role in solving the problems of L-fuzzy compactification theory,and make the previous work on weakly induced spaces and induced spaces determinatively generalized and strengthened.Moreover,we can describe the complete distributivity of lattices with them as well.In this paper,we give the mutually descrip- tive relation between lattice-valued semicontinuous mappings and the complete distributivity of lattices, and the construction theorems of open sets and closed sets in lattice-valued fully stratified spaces, weakly induced spaces and induced spaces(they are called S-spaces).Furthermore,we will investi- gate the structure of the co-topology of S-space,solve a series of interesting problems on product, N-compactness and metrization of S-spaces.展开更多
SINCE 1956, Michael’s continuous selection theory has been applied to functional analysis,topology, approximation theory and other mathematical fields. In this letter, the concept ofthe pseudo-lower semicontinuity is...SINCE 1956, Michael’s continuous selection theory has been applied to functional analysis,topology, approximation theory and other mathematical fields. In this letter, the concept ofthe pseudo-lower semicontinuity is introduced, and a convex structure of metric space is de-fined. A continuous selection theorem for pseudo-lower semicontinuity is given. This展开更多
Let X and Y be metrizable topological linear spaces. In this paper, the following results are proved. (1) If X and Y are complete, g: X→Y is a point closed u. s. c.,and symmetric process with F(X)=Y,then either F(X) ...Let X and Y be metrizable topological linear spaces. In this paper, the following results are proved. (1) If X and Y are complete, g: X→Y is a point closed u. s. c.,and symmetric process with F(X)=Y,then either F(X) is meager in Y,or else F is an open muRifunction with F(X)=Y. (2) If X is complete, and F: X→Y is a process with a subclosed graph, then F is I s. c.. We also discuss topological multi-homomorphisms between topological linear spaces.展开更多
A new concept of finitely continuous topological spaces （in short, FC-space） without convexity structure and linear structure was introduced. Some KKM type theorems in noncompact FC-spaces were obtained, and from wh...A new concept of finitely continuous topological spaces （in short, FC-space） without convexity structure and linear structure was introduced. Some KKM type theorems in noncompact FC-spaces were obtained, and from which, some section theorems and wriational inequality theorems were proved under much weak assumptions. Our results improve and generalize the corresponding conclusions in recent literature.展开更多
Let LSC(X) denote the set of all proper lower semicontinuous functions on X with the epi-topology. In this paper we give characterizations of the separation axioms. Baire properties and metrizability of LSC(X). We sho...Let LSC(X) denote the set of all proper lower semicontinuous functions on X with the epi-topology. In this paper we give characterizations of the separation axioms. Baire properties and metrizability of LSC(X). We show also that the continuous function space C(X) with the epi-topology is of first category when N is first countable.展开更多
A new system of vector quasi-equilibrium problems is introduced and its existence of solution is proved. As applications, some existence results of weak Pareto equilibrium for both constrained multicriteria games and ...A new system of vector quasi-equilibrium problems is introduced and its existence of solution is proved. As applications, some existence results of weak Pareto equilibrium for both constrained multicriteria games and multicriteria games without constrained correspondences are also shown.展开更多
An existence result on Ky Fan type best approximation is proved. For this pur- pose, a class of factorizable multifunctions and the other one being a demicontinuous, rela- tive almost quasi-convex, onto function on an...An existence result on Ky Fan type best approximation is proved. For this pur- pose, a class of factorizable multifunctions and the other one being a demicontinuous, rela- tive almost quasi-convex, onto function on an approximately weakly compact, convex sub- set of Hausdorff locally convex topological vector space are used. As consequence, this result extends the best approximation results of Basha and Veeramani[8] and many others.展开更多
In this paper, another form of KKM type theorem on generalized convex spaces is obtained and the problems of von Neumann-Fan type sup inf sup inequalities and variational inequalities are discussed for their applicati...In this paper, another form of KKM type theorem on generalized convex spaces is obtained and the problems of von Neumann-Fan type sup inf sup inequalities and variational inequalities are discussed for their applications.The main results improve and generalize the corresponding results in previous papers.展开更多
In this paper, we define the concepts of (η,h)-quasi pseudo-monotone operators on compact set in locally convex Hausdorff topological vector spaces and prove the existence results of solutions for a class of generali...In this paper, we define the concepts of (η,h)-quasi pseudo-monotone operators on compact set in locally convex Hausdorff topological vector spaces and prove the existence results of solutions for a class of generalized quasi variational type inequalities in locally convex Hausdorff topological vector spaces.展开更多
In this paper, we introduce and study a class of generalized vector quasivariational-like inequality problems, which includes generalized nonlinear vector variational inequality problems, generalized vector variationa...In this paper, we introduce and study a class of generalized vector quasivariational-like inequality problems, which includes generalized nonlinear vector variational inequality problems, generalized vector variational inequality problems and generalized vector variational-like inequality problems as special cases. We use the maximal element theorem with an escaping sequence to prove the existence results of a solution for generalized vector quasi-variational-like inequalities without any monotonicity conditions in the setting of locally convex topological vector space.展开更多
It is studied systematically for the level strcture of the kernel and hull on continuous-lattice- calued function.In terms of these results,the level characterixations of induced space are odtained.
In this paper,we prove existence results of soutions for the nonlinear implicit complementarity problems NICP(T,S,K) where K is a closed weakly locally compact convex cone in a reflexive Banach space E,T is a nonlinea...In this paper,we prove existence results of soutions for the nonlinear implicit complementarity problems NICP(T,S,K) where K is a closed weakly locally compact convex cone in a reflexive Banach space E,T is a nonlinear operator from K into E* (i. e.,the dual space of E) and S is a nonlinear operator from K into E. Our results are the essential improvements and extension of the results obtained previously by several authors including Thera,Ding,and Zeng.展开更多
基金supported by the National Key Research and Development Program of China (No.2021YFB3701000)the National Natural Science Foundation of China (Nos. 52401158, U21A2047, 52201129, 51821001,U2037601)+1 种基金the China Postdoctoral Science Foundation (No.2023M742219)the Postdoctoral Fellowship Program(Grade B) of CPSF (No. GZB20240419)
文摘Mg-Gd based alloys are an important class of high-performance Mg alloys.In this study,three Mg-Gd alloys with different gadolinium(Gd)contents:Mg-9.54Gd-0.40Zr(wt.%,G10 K),Mg-15.11Gd-0.35Zr(wt.%,G15 K)and Mg-19.67Gd-0.33Zr(wt.%,G20 K)were prepared by semicontinuous casting and subsequent solution and aging heat treatments.The role of Gd content on microstructures and mechanical properties of the Mg-Gd-Zr alloy is studied.All three as-cast alloys exhibit eutectic phases of Mg_(5)Gd,with the amount increasing as the Gd content rises.Mg_(5)Gd disappears after the solution heat treatment(the G10 K alloy solution-treated at 480℃ for 4 h,the G15 K alloy at 500℃ for 12 h and the G20 K alloy at 520℃ for 24 h,respectively).Aging heat treatment at 200℃ for 64 h after solution introduces numerous prismatic β' precipitates,with a significant increase in their area number density corresponding to increased Gd content.Additionally,the morphology of the β' precipitates exhibits distinct variations:the G10 K alloy is characterized by an enhanced aspect ratio.Consequently,the peak-aged G10 K alloy demonstrates superior strength-ductility synergy,with a yield strength(YS)of 216±1 MPa,an ultimate tensile strength(UTS)of 363±1 MPa,and an elongation(EL)of 8.7±0.6%.This study suggests that plasticity diminishes and precipitation strengthening is limited when the gadolinium content exceeds 15 wt.%.
文摘In this article, the authors mainly study how to obtain new semicontinuous lattices from the given semicontinuous lattices and discuss the conditions under which the image of a semicontinuous projection operator is also semicontinuous. Moreover, the authors investigate the relation between semicontinuous lattices and completely distributive lattices. Finally, it is proved that the strongly semicontinuous lattice category is a Cartesian closed category.
文摘In this paper, we use the well known KKM type theorem for generalized convex spaces due to Park （Elements of the KKM theory for generalized convex spaces, Korean J. Comp. Appl. Math., 7（2000）, 1-28） to obtain an almost fixed point theorem for upper [resp., lower] semicontinuous multimaps in locally G-convex spaces, and then give a fixed point theorem for upper semicontinuous multimap with closed Γ-convex values.
文摘The purpose of this paper is to introduce the notions of m-asymmetric semiopen sets and M-asymmetric semicontinuous multifunctions defined between asymmetric sets satisfying certain minimal conditions in the framework of bitopological spaces. Some new characterizations of m-asymmetric semiopen sets and M-asymmetric semicontinuous multifunctions will be investigated and several fundamental properties will be obtained.
基金This work was supported by the National Natural Science Foundation of China
文摘The seeded semicontinuous emulsion multi-copolymerization of butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), methyl methacrylate (MMA), 2-hydroxyl propyl acrylate (HOPA) and acrylic acid (AA) was used to prepare the acrylic latexes with high-solid content. The effects of monomer emulsion feed rates (R(a)) and (R/E)(E) values, the ratio of emulsifier amount between the initial charge (R) and the addition monomer emulsion (E), on the polymerization reaction features, the viscosities, surface tensions,particle sizes and particle sizes distributions of latexes, T-g and the insoluble fractions of films, the 180 degrees peel strength, tack and holding power of pressure-sensitive adhesive (PSA) tapes, prepared from the latexes, were studied. Experimental study shows that the grafting and crosslinking fraction in the PSA tapes must be controlled within a suitable range to keep the balance of the 180 degrees peel strength, tack and holding power.
文摘Given a compact Hausdorff space X, U(X) denotes the compact Hausdorff space of all the upper semicontinuous functions from X to the unit interval with the dual lim inf topology. Then U is an endofunctor on compact Hausdorff space. It is proved in this note that this functor preserves inverse limits.
文摘Semicontinuous equal-channel angular extrusion（ SC-ECAE） is a novel severe plastic deformation technique that has been developed to produce ultrafine-grain steels. Instead of external forces being exerted on specimens in the conventional ECAE,driving forces are applied to dies in SC-EACE. The deformation of interstitial-free（ IF） steel w as performed at room temperature,and individual specimens w ere repeatedly processed at various passes. An overall grain size of 0. 55 μm w as achieved after 10 passes. During SC-ECAE,the main textures of IF steel included { 111} ,{ 110} ,{ 112} ,{ 110} ,and { 110} At an early stage,increasing dislocations induce new textures and increase intensity. When the deformation continues,low-angle boundaries are formed betw een dislocation cell bands,w hich cause some dislocation cell bands to change their orientation,and therefore,the intensity of the textures begins to decrease. After more passes,the intensity of textures continues to decrease w ith high-angle boundaries,and the sub-grains in dislocation cell bands continuously increase. The present study reports the evolution of textures during deformation; these w ere examined and characterized using high-resolution electron backscattered diffraction（ EBSD） in a field emission scanning electron microscope. The mechanisms of texture evolution are discussed.
基金This work is supported by National Natural Science Foundation of China and Natural Science Foundation of the Yunnan Province of China
文摘In the present paper, some new almost fixed point theorems and fixed point theorems for lower semicontinuous type multivalued mappings are obtained in metrizable H-spaces.
基金The Project Supported by National Natural Science Foundation of China.
文摘Lattice-valued semicontinuous mappings play a basic and important role in solving the problems of L-fuzzy compactification theory,and make the previous work on weakly induced spaces and induced spaces determinatively generalized and strengthened.Moreover,we can describe the complete distributivity of lattices with them as well.In this paper,we give the mutually descrip- tive relation between lattice-valued semicontinuous mappings and the complete distributivity of lattices, and the construction theorems of open sets and closed sets in lattice-valued fully stratified spaces, weakly induced spaces and induced spaces(they are called S-spaces).Furthermore,we will investi- gate the structure of the co-topology of S-space,solve a series of interesting problems on product, N-compactness and metrization of S-spaces.
文摘SINCE 1956, Michael’s continuous selection theory has been applied to functional analysis,topology, approximation theory and other mathematical fields. In this letter, the concept ofthe pseudo-lower semicontinuity is introduced, and a convex structure of metric space is de-fined. A continuous selection theorem for pseudo-lower semicontinuity is given. This
基金This paper was reported at the 5th National Functional Analysis Conference held at Nanjing in Nov.,1990.
文摘Let X and Y be metrizable topological linear spaces. In this paper, the following results are proved. (1) If X and Y are complete, g: X→Y is a point closed u. s. c.,and symmetric process with F(X)=Y,then either F(X) is meager in Y,or else F is an open muRifunction with F(X)=Y. (2) If X is complete, and F: X→Y is a process with a subclosed graph, then F is I s. c.. We also discuss topological multi-homomorphisms between topological linear spaces.
文摘A new concept of finitely continuous topological spaces （in short, FC-space） without convexity structure and linear structure was introduced. Some KKM type theorems in noncompact FC-spaces were obtained, and from which, some section theorems and wriational inequality theorems were proved under much weak assumptions. Our results improve and generalize the corresponding conclusions in recent literature.
文摘Let LSC(X) denote the set of all proper lower semicontinuous functions on X with the epi-topology. In this paper we give characterizations of the separation axioms. Baire properties and metrizability of LSC(X). We show also that the continuous function space C(X) with the epi-topology is of first category when N is first countable.
基金Project supported by the National Natural Science Foundation of China (Nos.10171118 and 70432001) the Applied Basic Research Foundation of Chongqing(No.030801) the Natural Science Foundation of Chongqing(No.8409) and the Postdoctoral Science Foundation of China
文摘A new system of vector quasi-equilibrium problems is introduced and its existence of solution is proved. As applications, some existence results of weak Pareto equilibrium for both constrained multicriteria games and multicriteria games without constrained correspondences are also shown.
文摘An existence result on Ky Fan type best approximation is proved. For this pur- pose, a class of factorizable multifunctions and the other one being a demicontinuous, rela- tive almost quasi-convex, onto function on an approximately weakly compact, convex sub- set of Hausdorff locally convex topological vector space are used. As consequence, this result extends the best approximation results of Basha and Veeramani[8] and many others.
文摘In this paper, another form of KKM type theorem on generalized convex spaces is obtained and the problems of von Neumann-Fan type sup inf sup inequalities and variational inequalities are discussed for their applications.The main results improve and generalize the corresponding results in previous papers.
文摘In this paper, we define the concepts of (η,h)-quasi pseudo-monotone operators on compact set in locally convex Hausdorff topological vector spaces and prove the existence results of solutions for a class of generalized quasi variational type inequalities in locally convex Hausdorff topological vector spaces.
基金The NSF(60804065) of Chinathe Foundation(11A029,11A028) of China West Normal University+2 种基金the Fundamental Research Funds(13D016) of China West Normal Universitythe Key Project(211163) of Chinese Ministry of EducationSichuan Youth Science and Technology Foundation(2012JQ0032)
文摘In this paper, we introduce and study a class of generalized vector quasivariational-like inequality problems, which includes generalized nonlinear vector variational inequality problems, generalized vector variational inequality problems and generalized vector variational-like inequality problems as special cases. We use the maximal element theorem with an escaping sequence to prove the existence results of a solution for generalized vector quasi-variational-like inequalities without any monotonicity conditions in the setting of locally convex topological vector space.
文摘It is studied systematically for the level strcture of the kernel and hull on continuous-lattice- calued function.In terms of these results,the level characterixations of induced space are odtained.
文摘In this paper,we prove existence results of soutions for the nonlinear implicit complementarity problems NICP(T,S,K) where K is a closed weakly locally compact convex cone in a reflexive Banach space E,T is a nonlinear operator from K into E* (i. e.,the dual space of E) and S is a nonlinear operator from K into E. Our results are the essential improvements and extension of the results obtained previously by several authors including Thera,Ding,and Zeng.
