The Experts below are selected from a list of 106800 Experts worldwide ranked by ideXlab platform
Cewen Nan - One of the best experts on this subject based on the ideXlab platform.
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high energy density of polymer nanocomposites at a low electric field induced by modulation of their Topological Structure
Journal of Materials Chemistry, 2016Co-Authors: Yang Shen, Xin Zhang, Yuanhua Lin, Dashan Shen, Jianyong Jiang, Zhenkang Dan, Yu Song, Cewen NanAbstract:Polymer nanocomposite dielectrics are of critical importance for a number of electrical and electronic applications. It is highly desirable to achieve high energy density at a low electric field. In this contribution, PVDF-based (or PVDF–TrFE–CFE based) nanocomposite films filled with BaTiO3@TiO2 nanofibers are cast from solutions. Topological-Structure modulated polymer nanocomposites are assembled layer-by-layer with the as-cast films via a hot-pressing process. Modulation of the Topological-Structure induces substantial redistribution of the local electric field among the constituent layers, giving rise to enhanced electric polarization at a low electric field and increased breakdown strength. These synergistic effects lead to an ultrahigh energy density of ∼12.5 J cm−3 and a high discharge efficiency of ∼70% at 350 kV mm−1. High energy density at a low electric field is thus achieved by modulating the Topological Structure of polymer dielectric nanocomposites, which is of critical significance to make dielectric nanocomposites viable energy storage devices.
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modulation of Topological Structure induces ultrahigh energy density of graphene ba0 6sr0 4tio3 nanofiber polymer nanocomposites
Nano Energy, 2015Co-Authors: Yang Shen, Longqing Chen, Xin Zhang, Weiwei Chen, Jianjun Wang, Yuhan Guan, Yuanhua Lin, Cewen NanAbstract:Abstract Dielectric capacitors have been the major enabler for a number of applications in advanced electronic and electrical power systems due to their capability of ultrafast charging–discharging and ultrahigh power density. High energy density dielectrics are highly desirable in order to reduce the size and cost of dielectric capacitors, which is critical for electrical pulse-power systems and power electronics in electric vehicles. Polymer nanocomposites are promising in raising the low energy density of neat polymer dielectrics of current use. In this study, a class of sandwich-Structured nanocomposites are prepared by a facile hot-pressing method. Polyvinylidene fluoride nanomcomposite layers filled with graphene oxide nanosheets coated with TiO2 nanoparticles (G-layers) or Ba0.6Sr0.4TiO3 nanofibers (B-layers) are cast from solution and assembled into sandwich-Structured nanocomposites with reversed Topological strcuture (BGB & GBG). An ultrahigh energy density of ~14.6 J/cm3 is achieved in the BGB nanocomposites. Phase-field simulations reveal the significant implications of Topological Structure on the dielectric performance of the nanocomposites. By rational design of Topological Structure and the dielectric property of the individual layers, favorable distribution of local electrical field could be achieved among the constituent layers of the sandwich-Structured nanocomposites, giving rise to the concomitant enhancement of electrical polarization and dielectric breakdown strength, and hence ultrahigh energy density.
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Topological Structure modulated polymer nanocomposites exhibiting highly enhanced dielectric strength and energy density
Advanced Functional Materials, 2014Co-Authors: Yang Shen, Yuhan Guan, Yuanhua Lin, Xuehui Zhang, Q M Zhang, Cewen NanAbstract:Dielectric materials with high electric energy densities and low dielectric losses are of critical importance in a number of applications in modern electronic and electrical power systems. An organic–inorganic 0–3 nanocomposite, in which nanoparticles (0-dimensional) are embedded in a 3-dimensionally connected polymer matrix, has the potential to combine the high breakdown strength and low dielectric loss of the polymer with the high dielectric constant of the ceramic fillers, representing a promising approach to realize high energy densities. However, one significant drawback of the composites explored up to now is that the increased dielectric constant of the composites is at the expense of the breakdown strength, limiting the energy density and dielectric reliability. In this study, by expanding the traditional 0–3 nanocomposite approach to a multilayered Structure which combines the complementary properties of the constituent layers, one can realize both greater dielectric displacement and a higher breakdown field than that of the polymer matrix. In a typical 3-layer Structure, for example, a central nanocomposite layer of higher breakdown strength is introduced to substantially improve the overall breakdown strength of the multilayer-Structured composite film, and the outer composite layers filled with large amount of high dielectric constant nanofillers can then be polarized up to higher electric fields, hence enhancing the electric displacement. As a result, the Topological-Structure modulated nanocomposites, with an optimally tailored nanomorphology and composite Structure, yield a discharged energy density of 10 J/cm3 with a dielectric breakdown strength of 450 kV mm–1, much higher than those reported from all earlier studies of nanocomposites.
Xinghua Zhu - One of the best experts on this subject based on the ideXlab platform.
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On linearly Topological Structure and property of fuzzy normed linear space
Fuzzy Sets and Systems, 2002Co-Authors: Jianzhong Xiao, Xinghua ZhuAbstract:In this paper, the simplified definition of fuzzy normed linear space is introduced; the different Structure of fuzzy normed linear space with variable right norm R is discussed in terms of Topological vector space, and its properties such as compactness, completeness and density are studied under more general left norm L and right norm R; as application, the linearly Topological Structure of Menger PN space is obtained.
Yang Shen - One of the best experts on this subject based on the ideXlab platform.
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high energy density of polymer nanocomposites at a low electric field induced by modulation of their Topological Structure
Journal of Materials Chemistry, 2016Co-Authors: Yang Shen, Xin Zhang, Yuanhua Lin, Dashan Shen, Jianyong Jiang, Zhenkang Dan, Yu Song, Cewen NanAbstract:Polymer nanocomposite dielectrics are of critical importance for a number of electrical and electronic applications. It is highly desirable to achieve high energy density at a low electric field. In this contribution, PVDF-based (or PVDF–TrFE–CFE based) nanocomposite films filled with BaTiO3@TiO2 nanofibers are cast from solutions. Topological-Structure modulated polymer nanocomposites are assembled layer-by-layer with the as-cast films via a hot-pressing process. Modulation of the Topological-Structure induces substantial redistribution of the local electric field among the constituent layers, giving rise to enhanced electric polarization at a low electric field and increased breakdown strength. These synergistic effects lead to an ultrahigh energy density of ∼12.5 J cm−3 and a high discharge efficiency of ∼70% at 350 kV mm−1. High energy density at a low electric field is thus achieved by modulating the Topological Structure of polymer dielectric nanocomposites, which is of critical significance to make dielectric nanocomposites viable energy storage devices.
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modulation of Topological Structure induces ultrahigh energy density of graphene ba0 6sr0 4tio3 nanofiber polymer nanocomposites
Nano Energy, 2015Co-Authors: Yang Shen, Longqing Chen, Xin Zhang, Weiwei Chen, Jianjun Wang, Yuhan Guan, Yuanhua Lin, Cewen NanAbstract:Abstract Dielectric capacitors have been the major enabler for a number of applications in advanced electronic and electrical power systems due to their capability of ultrafast charging–discharging and ultrahigh power density. High energy density dielectrics are highly desirable in order to reduce the size and cost of dielectric capacitors, which is critical for electrical pulse-power systems and power electronics in electric vehicles. Polymer nanocomposites are promising in raising the low energy density of neat polymer dielectrics of current use. In this study, a class of sandwich-Structured nanocomposites are prepared by a facile hot-pressing method. Polyvinylidene fluoride nanomcomposite layers filled with graphene oxide nanosheets coated with TiO2 nanoparticles (G-layers) or Ba0.6Sr0.4TiO3 nanofibers (B-layers) are cast from solution and assembled into sandwich-Structured nanocomposites with reversed Topological strcuture (BGB & GBG). An ultrahigh energy density of ~14.6 J/cm3 is achieved in the BGB nanocomposites. Phase-field simulations reveal the significant implications of Topological Structure on the dielectric performance of the nanocomposites. By rational design of Topological Structure and the dielectric property of the individual layers, favorable distribution of local electrical field could be achieved among the constituent layers of the sandwich-Structured nanocomposites, giving rise to the concomitant enhancement of electrical polarization and dielectric breakdown strength, and hence ultrahigh energy density.
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Topological Structure modulated polymer nanocomposites exhibiting highly enhanced dielectric strength and energy density
Advanced Functional Materials, 2014Co-Authors: Yang Shen, Yuhan Guan, Yuanhua Lin, Xuehui Zhang, Q M Zhang, Cewen NanAbstract:Dielectric materials with high electric energy densities and low dielectric losses are of critical importance in a number of applications in modern electronic and electrical power systems. An organic–inorganic 0–3 nanocomposite, in which nanoparticles (0-dimensional) are embedded in a 3-dimensionally connected polymer matrix, has the potential to combine the high breakdown strength and low dielectric loss of the polymer with the high dielectric constant of the ceramic fillers, representing a promising approach to realize high energy densities. However, one significant drawback of the composites explored up to now is that the increased dielectric constant of the composites is at the expense of the breakdown strength, limiting the energy density and dielectric reliability. In this study, by expanding the traditional 0–3 nanocomposite approach to a multilayered Structure which combines the complementary properties of the constituent layers, one can realize both greater dielectric displacement and a higher breakdown field than that of the polymer matrix. In a typical 3-layer Structure, for example, a central nanocomposite layer of higher breakdown strength is introduced to substantially improve the overall breakdown strength of the multilayer-Structured composite film, and the outer composite layers filled with large amount of high dielectric constant nanofillers can then be polarized up to higher electric fields, hence enhancing the electric displacement. As a result, the Topological-Structure modulated nanocomposites, with an optimally tailored nanomorphology and composite Structure, yield a discharged energy density of 10 J/cm3 with a dielectric breakdown strength of 450 kV mm–1, much higher than those reported from all earlier studies of nanocomposites.
Jianzhong Xiao - One of the best experts on this subject based on the ideXlab platform.
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On linearly Topological Structure and property of fuzzy normed linear space
Fuzzy Sets and Systems, 2002Co-Authors: Jianzhong Xiao, Xinghua ZhuAbstract:In this paper, the simplified definition of fuzzy normed linear space is introduced; the different Structure of fuzzy normed linear space with variable right norm R is discussed in terms of Topological vector space, and its properties such as compactness, completeness and density are studied under more general left norm L and right norm R; as application, the linearly Topological Structure of Menger PN space is obtained.
Xiaqing Shi - One of the best experts on this subject based on the ideXlab platform.
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Topological Structure dynamics revealing collective evolution in active nematics
Nature Communications, 2013Co-Authors: Xiaqing ShiAbstract:Topological defects frequently emerge in active matter like bacterial colonies, cytoskeleton extracts on substrates, self-propelled granular or colloidal layers and so on, but their dynamical properties and the relations to large-scale organization and fluctuations in these active systems are seldom touched. Here we reveal, through a simple model for active nematics using self-driven hard elliptic rods, that the excitation, annihilation and transportation of Topological defects differ markedly from those in non-active media. These dynamical processes exhibit strong irreversibility in active nematics in the absence of detailed balance. Moreover, Topological defects are the key factors in organizing large-scale dynamic Structures and collective flows, resulting in multi-spatial temporal effects. These findings allow us to control the self-organization of active matter through Topological Structures.
