The compression behaviors of iridium single crystals with different crystalline orientations were investigated by micropillar compression tests and molecular dynamics(MD) simulations.The results indicated that the def...The compression behaviors of iridium single crystals with different crystalline orientations were investigated by micropillar compression tests and molecular dynamics(MD) simulations.The results indicated that the deformation process of iridium single crystals with [100]and [110] orientations was presented as the stacking faults expansion and the formation of Lomer-Cottrell locks.And the occurrence of Lomer-Cottrell locks was considered as the interaction of stacking faults on {111} planes by MD simulations.The evolution of crystal structure in compression indicated that the Lomer-Cottrell locks might contribute to the large plastic deformation of iridium single crystals.Moreover,the deformation features in MD simulations showed that the elastic modulus(E) and yield stress(σ_(s)) of iridium single crystals were significantly influenced by the temperature.The elastic modulus and yield stress gradually decreased with an increased temperature for all orientations.Meanwhile,the single crystal with a closely spaced lattice structure exhibited superior mechanical properties at a same temperature.展开更多
In this paper,we present a QP-free algorithm without a penalty function or a filter for nonlinear semidefinite programming.At each iteration,two systems of linear equations with the same coefficient matrix are solved ...In this paper,we present a QP-free algorithm without a penalty function or a filter for nonlinear semidefinite programming.At each iteration,two systems of linear equations with the same coefficient matrix are solved to determine search direction;the nonmonotone line search ensures that the objective function or constraint violation function is sufficiently reduced.There is no feasibility restoration phase in our algorithm,which is necessary for traditional filter methods.The proposed algorithm is globally convergent under some mild conditions.Preliminary numerical results indicate that the proposed algorithm is comparable.展开更多
The emerging chemical recyclable polymers,such as poly(γ-butyrolactone)(PGBL)and poly((R)-3,4-trans six-membered ring-fused GBL)(P((R)-M)),provide a good solution to the plastic pollution.However,these homopolymers s...The emerging chemical recyclable polymers,such as poly(γ-butyrolactone)(PGBL)and poly((R)-3,4-trans six-membered ring-fused GBL)(P((R)-M)),provide a good solution to the plastic pollution.However,these homopolymers suffer from limited structures and properties.Herein,we reported a fully chemical recyclable copolymer P(GBL-co-((R)-M))through ring-opening copolymerization(ROCOP)of GBL and(R)-M.By employing organomagnesium as the catalyst and regulating the reaction conditions,the chemical structures of copolymers were wellcontrolled(GBL content=13%-78%,Mn=6560-15600 g/mol,DM=1.08-1.59).The resultant P(GBL-co-((R)-M))exhibited fully chemical recyclability,which rapidly and quantitatively depolymerized into initial GBL and(R)-M monomer through chemolysis.By varying GBL content,tunable thermal properties were achieved for P(GBL-co-((R)-M)).The onset decomposition temperatures of copolymers varied from 193°C to 234°C.A linear evolution of glass transition temperature(T_(g))of P(GBL-co-((R)-M))versus GBL content was obtained as following equation of Tg=-1.06×GBL mol%×100+39.6.We hope that the reported fully chemical recyclable copolymers with tunable structures and properties would serve as the candidate material for sustainable applications.展开更多
基金financially supported by the National Key R&D Program of China (No. 2017YFB0305503)the Joint Funds of the National Natural Science Foundation of China (No. U1202273)the National Natural Science Foundation of China (No. 51501075)。
文摘The compression behaviors of iridium single crystals with different crystalline orientations were investigated by micropillar compression tests and molecular dynamics(MD) simulations.The results indicated that the deformation process of iridium single crystals with [100]and [110] orientations was presented as the stacking faults expansion and the formation of Lomer-Cottrell locks.And the occurrence of Lomer-Cottrell locks was considered as the interaction of stacking faults on {111} planes by MD simulations.The evolution of crystal structure in compression indicated that the Lomer-Cottrell locks might contribute to the large plastic deformation of iridium single crystals.Moreover,the deformation features in MD simulations showed that the elastic modulus(E) and yield stress(σ_(s)) of iridium single crystals were significantly influenced by the temperature.The elastic modulus and yield stress gradually decreased with an increased temperature for all orientations.Meanwhile,the single crystal with a closely spaced lattice structure exhibited superior mechanical properties at a same temperature.
基金Project supported by the Zhejiang Provincial Natural Science Foundation for Distinguished Young Scholars(No.LR16H040001)the Key Project of Science and Technology Department of Zhejiang Province(No.2018C03010)+2 种基金the Zhejiang Provincial&Ministry of Health Research Fund for Medical Sciences(Nos.WKJ-ZJ-1522 and WKJ-ZJ-1722)the National Key Technology R&D Program of China(No.2014BAI05B04)the Guangxi Natural Science Foundation(Nos.2015GXNSFBA139177,2017GXNSFAA198199,and 2017GXNSFAA198193),China
基金supported by the National Natural Science Foundation(No.11561005)the National Science Foundation of Guangxi(No.2016GXNSFAA380248)。
文摘In this paper,we present a QP-free algorithm without a penalty function or a filter for nonlinear semidefinite programming.At each iteration,two systems of linear equations with the same coefficient matrix are solved to determine search direction;the nonmonotone line search ensures that the objective function or constraint violation function is sufficiently reduced.There is no feasibility restoration phase in our algorithm,which is necessary for traditional filter methods.The proposed algorithm is globally convergent under some mild conditions.Preliminary numerical results indicate that the proposed algorithm is comparable.
基金financially supported by the National Natural Science Foundation of China(Nos.22078150 and 21504039)。
文摘The emerging chemical recyclable polymers,such as poly(γ-butyrolactone)(PGBL)and poly((R)-3,4-trans six-membered ring-fused GBL)(P((R)-M)),provide a good solution to the plastic pollution.However,these homopolymers suffer from limited structures and properties.Herein,we reported a fully chemical recyclable copolymer P(GBL-co-((R)-M))through ring-opening copolymerization(ROCOP)of GBL and(R)-M.By employing organomagnesium as the catalyst and regulating the reaction conditions,the chemical structures of copolymers were wellcontrolled(GBL content=13%-78%,Mn=6560-15600 g/mol,DM=1.08-1.59).The resultant P(GBL-co-((R)-M))exhibited fully chemical recyclability,which rapidly and quantitatively depolymerized into initial GBL and(R)-M monomer through chemolysis.By varying GBL content,tunable thermal properties were achieved for P(GBL-co-((R)-M)).The onset decomposition temperatures of copolymers varied from 193°C to 234°C.A linear evolution of glass transition temperature(T_(g))of P(GBL-co-((R)-M))versus GBL content was obtained as following equation of Tg=-1.06×GBL mol%×100+39.6.We hope that the reported fully chemical recyclable copolymers with tunable structures and properties would serve as the candidate material for sustainable applications.
