Reticulated polyurethane was chosen as the preceramic material for preparing the porous preform using the replication process. The immersing and sintering processes were each performed twice for fabricating a high-por...Reticulated polyurethane was chosen as the preceramic material for preparing the porous preform using the replication process. The immersing and sintering processes were each performed twice for fabricating a high-porosity and super-strong skeleton. The aluminum magnesium matrix composites reinforced with three-dimensional network structure were prepared using the infiltration technique by pressure assisting and vacuum driving. Light interfacial reactions have played a profitable role in most of the ceramic-metal systems. The metal matrix composites interpenetrated with the ceramic phase have a higher wear resistance than the metal matrix phase. The volume fraction of ceramic reinforcement has a significant effect on the abrasive wear, and the wear rate can be decreased with the increase of the volume fraction of reinforcement.展开更多
A novel three dimensional network complex polymer [Cu_4(oxen)_2(N_3)_3]_n(ClO_4)_n·2nH_2O, where oxen is N,N' -bis(2-aminoethyl)oxamide dianion, has been synthesized. It crystallizes in triclinic system, spac...A novel three dimensional network complex polymer [Cu_4(oxen)_2(N_3)_3]_n(ClO_4)_n·2nH_2O, where oxen is N,N' -bis(2-aminoethyl)oxamide dianion, has been synthesized. It crystallizes in triclinic system, space group P, with a=11.486(2), b=11.706(3), c=12.291(3) , α=77.42(2), β=67.59(2), γ=77.96(2)°, and z=2. The least-square refinements converged at R=0.047, with 3416 observed unique reflections. The complex has a pronounced three-dimensional character and can be viewed as the tetranuclear asymmetric repeating units through inversion and translation operations to extend a three-dimensional network. The structure of Cu_4 asymmetric unit consists of two square planar and two square pyramidal Cu central atoms linked by both azide ligands in end-on and end-to-end bonding modes, and oxamidate bridge in trans conformation.展开更多
The demands for better energy storage devices due to fast development of electric vehicles(EVs) have raised increasing attention on lithium ion batteries(LIBs) with high power and energy densities. In this paper, we p...The demands for better energy storage devices due to fast development of electric vehicles(EVs) have raised increasing attention on lithium ion batteries(LIBs) with high power and energy densities. In this paper, we provide an overview of recent progress in graphene-based electrode materials. Graphene with its great electrical conductivity and mechanical properties have apparently improved the performance of traditional electrode materials. The methods and electrochemical properties of advanced graphene composite as cathode and anode for LIBs are reviewed. Two novel kinds of graphene hybrid materials are specially highlighted: three-dimensional porous and flexible binder-free graphene-based materials. Challenges for LIBs and future research trend in the development of high-performance electrode materials are further discussed.展开更多
基金This work was financially supported by the Natural Science Foundation of Shandong Province, China (Y2006F03).
文摘Reticulated polyurethane was chosen as the preceramic material for preparing the porous preform using the replication process. The immersing and sintering processes were each performed twice for fabricating a high-porosity and super-strong skeleton. The aluminum magnesium matrix composites reinforced with three-dimensional network structure were prepared using the infiltration technique by pressure assisting and vacuum driving. Light interfacial reactions have played a profitable role in most of the ceramic-metal systems. The metal matrix composites interpenetrated with the ceramic phase have a higher wear resistance than the metal matrix phase. The volume fraction of ceramic reinforcement has a significant effect on the abrasive wear, and the wear rate can be decreased with the increase of the volume fraction of reinforcement.
文摘A novel three dimensional network complex polymer [Cu_4(oxen)_2(N_3)_3]_n(ClO_4)_n·2nH_2O, where oxen is N,N' -bis(2-aminoethyl)oxamide dianion, has been synthesized. It crystallizes in triclinic system, space group P, with a=11.486(2), b=11.706(3), c=12.291(3) , α=77.42(2), β=67.59(2), γ=77.96(2)°, and z=2. The least-square refinements converged at R=0.047, with 3416 observed unique reflections. The complex has a pronounced three-dimensional character and can be viewed as the tetranuclear asymmetric repeating units through inversion and translation operations to extend a three-dimensional network. The structure of Cu_4 asymmetric unit consists of two square planar and two square pyramidal Cu central atoms linked by both azide ligands in end-on and end-to-end bonding modes, and oxamidate bridge in trans conformation.
基金supported by the National Hi-Tech Research and Development Program of China("863"Project)(Grant No.2012CB932303)Shanghai Municipal Natural Science Foundation(Grant Nos.13ZR1463600&13XD1403900)
文摘The demands for better energy storage devices due to fast development of electric vehicles(EVs) have raised increasing attention on lithium ion batteries(LIBs) with high power and energy densities. In this paper, we provide an overview of recent progress in graphene-based electrode materials. Graphene with its great electrical conductivity and mechanical properties have apparently improved the performance of traditional electrode materials. The methods and electrochemical properties of advanced graphene composite as cathode and anode for LIBs are reviewed. Two novel kinds of graphene hybrid materials are specially highlighted: three-dimensional porous and flexible binder-free graphene-based materials. Challenges for LIBs and future research trend in the development of high-performance electrode materials are further discussed.
