Stretched polyethylene(PE)fibers are found to have super high thermal conductivity,while the bulk of polyethylene is usually thermal insulating even for those with high crystalline degree.A molecular dynamic simulatio...Stretched polyethylene(PE)fibers are found to have super high thermal conductivity,while the bulk of polyethylene is usually thermal insulating even for those with high crystalline degree.A molecular dynamic simulation is deliberately carried out to examine the relationship between chain configuration and thermal conductivity of polyethylene.In this simulation study,independent and interacting PE chains being stretched are compared with the aim to find out the effect of stretching on thermal conductivity of PE.Various crystallization conditions for PE bulk are considered.It is found that heat transports predominately along the covalent chain rather than across chains in PE crystals.Our simulation study helps to understand experimental findings on thermal conductivity of PE at different states.W e also predict that amorphous PE may be super thermally conductive if chains are strictly stretched along heat flux.展开更多
The utilization of 2,6-bis(imidazo[1,5-a]pyridin-3-yl)pyridine(bipp)and 3-(pyridin-2-yl)imidazo[1,5-a]pyridine(pip)in the compounds of manganese(Ⅱ)and copper(Ⅰ)ions is presented.Two complexes,[Mn(bipp)(SO_(4))(H_(2)...The utilization of 2,6-bis(imidazo[1,5-a]pyridin-3-yl)pyridine(bipp)and 3-(pyridin-2-yl)imidazo[1,5-a]pyridine(pip)in the compounds of manganese(Ⅱ)and copper(Ⅰ)ions is presented.Two complexes,[Mn(bipp)(SO_(4))(H_(2)O)]n(1)and[Cu(pip)_(2)]ClO_(4)(2),were prepared with different characteristics in structure.Compound 1 exhibits a one-dimensional chain topology,and 2 is a homoleptic Cu(Ⅰ)complex.The dc magnetic susceptibility investigations reveal the antiferromagnetic(AF)MnⅡ···MnⅡinteractions in complex 1.The catalytic activity of compound 2 toward ketalization reactions was studied.Complex 2 exhibits high activity for the ketalization transformations of aliphatic ketones.展开更多
基金supported by the National Key R&D Program of China(No.2017YFB0406204)the National Natural Science Foundation of China(No.51973002)University Institution of High Performance Rubber Materials of Anhui Province.
文摘Stretched polyethylene(PE)fibers are found to have super high thermal conductivity,while the bulk of polyethylene is usually thermal insulating even for those with high crystalline degree.A molecular dynamic simulation is deliberately carried out to examine the relationship between chain configuration and thermal conductivity of polyethylene.In this simulation study,independent and interacting PE chains being stretched are compared with the aim to find out the effect of stretching on thermal conductivity of PE.Various crystallization conditions for PE bulk are considered.It is found that heat transports predominately along the covalent chain rather than across chains in PE crystals.Our simulation study helps to understand experimental findings on thermal conductivity of PE at different states.W e also predict that amorphous PE may be super thermally conductive if chains are strictly stretched along heat flux.
基金supported by the National Natural Science Foundation of China (21772140, 21771136)Natural Science Foundation of Jiangsu Province (BK20171213)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionthe Project of Scientific and Technologic Infrastructure of Suzhou (SZS201905)
文摘The utilization of 2,6-bis(imidazo[1,5-a]pyridin-3-yl)pyridine(bipp)and 3-(pyridin-2-yl)imidazo[1,5-a]pyridine(pip)in the compounds of manganese(Ⅱ)and copper(Ⅰ)ions is presented.Two complexes,[Mn(bipp)(SO_(4))(H_(2)O)]n(1)and[Cu(pip)_(2)]ClO_(4)(2),were prepared with different characteristics in structure.Compound 1 exhibits a one-dimensional chain topology,and 2 is a homoleptic Cu(Ⅰ)complex.The dc magnetic susceptibility investigations reveal the antiferromagnetic(AF)MnⅡ···MnⅡinteractions in complex 1.The catalytic activity of compound 2 toward ketalization reactions was studied.Complex 2 exhibits high activity for the ketalization transformations of aliphatic ketones.
