In present study LiMn2O4-xFx were prepared by the sol-gel method. X-ray diffraction (XRD) and scanning electron microscope (SEM ) were employed to detect the microstructure of the reaction products. It were found perf...
In present study LiMn2O4-xFx were prepared by the sol-gel method. X-ray diffraction (XRD) and scanning electron microscope (SEM ) were employed to detect the microstructure of the reaction products. It were found perfect crystal particles were obtained, and its' size were uniform in 1∼2 μ m. The specific capacity and cycleability were measured basing on battery program control test system. The results shown the substitution of F for O increased the specific capacity of the material at the cost of the cycleability due to more Mn3+ and less Mn4+ existed in the material. The exist of Mn3+ would reduce cycleability of cathode material due to the Jahn-Teller effect which were caused by the deformation of the crystal structure.
In the present study electronic structures of the interface between SBT and transition metal including Au, Ag, Cu, Ni, Pt were studied by employing DV-Xα method. The calculations were performed on cluster models of t...
In the present study electronic structures of the interface between SBT and transition metal including Au, Ag, Cu, Ni, Pt were studied by employing DV-Xα method. The calculations were performed on cluster models of the interface which were SrTa8O36-M2 (M=Au, Ag, Cu, Ni, Pt, and Bi). The calculations results including Fermi level, bond order, atomic charge distribution shown that there existed significant hybridization between metal d states and the O2p–Ta3d states. The Fermi levels of the metals located in the gap of SBT and metal-induced states, and the position of the Fermi levels did not change greatly due to the different transition metals. The charge of Sr and the transition metal atom transferred to oxygen atom, so that the bonding between Sr (or metal atom) and O was almost ionic bonding. The interactions between transition metal and SBT mainly came from the Coulomb interaction.
The CaF_(2)-4LiF additive was added into SrTiO_(3)ceramics in order to decrease the sintering temperature for compact pulse power *** crystalline structure,microstructure and energy storage performance of sintered cer...
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The CaF_(2)-4LiF additive was added into SrTiO_(3)ceramics in order to decrease the sintering temperature for compact pulse power *** crystalline structure,microstructure and energy storage performance of sintered ceramics were *** CaF_(2)-4LiF additive to SrTiO_(3)ceramics contributes to a notably enhancement of the energy storage *** great enhancement in energy storage density occurred due to the notable increase in breakdown strength and the refinement of *** 2 at%additive,the samples exhibited an average breakdown strength of 31.8kV/mm,and an energy storage density of 1.212 J/cm^(3)which is about 1.4 times higher than pure SrTiO_(3).
Ceramic sintering in microwave field is a new ceramic processing method. In present paper, we detected the microstructures and boundary segregation of BaTiO3 ceramics which were sintered in microwave field. Scanning e...
Ceramic sintering in microwave field is a new ceramic processing method. In present paper, we detected the microstructures and boundary segregation of BaTiO3 ceramics which were sintered in microwave field. Scanning electron microscopy(SEM), and transmission electron microscopy(TEM), and chemical analysis methods were employed to detect the microstructure of BaTiO3, element distribution near the boundary of BaTiO3 ceramic. The results shown growth of grain of the ceramic was influenced by impurities such as acceptor, benefactor et al, and the element distribution near the grain boundary of BaTiO3 sintered in microwave field were different with that sintered in conventional method. The boundary segregations of BaTiO3 sintered in microwave field were not obvious as compared to the conventional method because the diffusion was enhanced due to the microwave field.
The new type of the hierarchically structured porous solid-acid catalysts described in this presentation possess a remarkable pore system,encompassing well-defined macrochannels,interconnected mesopores,intracrystalli...
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The new type of the hierarchically structured porous solid-acid catalysts described in this presentation possess a remarkable pore system,encompassing well-defined macrochannels,interconnected mesopores,intracrystalline mesopores,and tunable zeolite(ZMS-5,Beta,…)*** hierarchical micro-meso-macroporous zeolitic catalysts with improved stability have been synthesized via a quasi solid state chemical crystallization ***,the catalyst
Spark plasma sintering (SPS) and Self-propagating High-temperature synthesis/ quick pressing (SHS/QP) methods were used to fabricate nanotubes reinforced alumina. The difference in microstructure was discussed. In the...
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Spark plasma sintering (SPS) and Self-propagating High-temperature synthesis/ quick pressing (SHS/QP) methods were used to fabricate nanotubes reinforced alumina. The difference in microstructure was discussed. In the SHS/QP process, the maximum densification temperature is 1660°C and the heating rate is about 1600°C /min. The whole densification process in SHS/QP is very short, which is much beneficial to protect the nanotubes and restrain the growing of grains. The fracture toughness of the sample prepared by SHS/QP is up to 4.9MPam1/2 for 1mass% CNTs/Al2O3 composites, which shows excellent toughening effects of nanotubes.
作者：
Hongtao YuHua HaoHanxing LiuZhongqing Tianyuhongtao2001@***
Wuhan University of Technology State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Luoshi Road 122# Wuhan 430070 China People's Republic of 86-27-87864681 86-27-87651779 haohuayang@***
Wuhan University of Technology State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan 430070 China People's Republic of lhxhp@***
Wuhan University of Technology State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan 430070 China People's Republic of tzqmail@***
Chongqing Institute of Technology Chongqing 400050 China People's Republic of
The effect of CuO on the microstructure and microwave dielectric properties of the CaTiO3-Ca(Zn1/3Nb2/3)O3 ceramics prepared by the conventional solid-method has been investigated. Doped with the 0.5∼1.25wt% CuO powd...
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The effect of CuO on the microstructure and microwave dielectric properties of the CaTiO3-Ca(Zn1/3Nb2/3)O3 ceramics prepared by the conventional solid-method has been investigated. Doped with the 0.5∼1.25wt% CuO powder, the system of which the sintering temperatures were lowered exhibited the orthorhombic perovskite. It can effectively promote the microwave dielectric properties of the 0.3CaTiO3-0.7Ca(Zn1/3Nb2/3)O3 system at lower sintering temperature at the level of 1.0wt% CuO additive. The quality factor increases from 10860 to 13900GHz and not any significant change was observed in the TCF value with fixed CuO additive at different sintering temperature.
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