The Experts below are selected from a list of 111951 Experts worldwide ranked by ideXlab platform
Fujiu Ke - One of the best experts on this subject based on the ideXlab platform.
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Molecular Cluster statistical thermodynamics methods to simulate quasi static deformations at finite temperature
International Journal of Solids and Structures, 2008Co-Authors: Haiying Wang, Ming Hu, Fujiu KeAbstract:The rapid evolution of nanotechnology appeals for the understanding of global response of nanoscale systems based on atomic interactions, hence necessitates novel, sophisticated, and physically based approaches to bridge the gaps between various length and time scales. In this paper, we propose a group of statistical thermodynamics methods for the simulations of nanoscale systems under quasi-static loading at finite temperature, that is, Molecular statistical thermodynamics (MST) method, Cluster statistical thermodynamics (CST) method, and the hybrid Molecular/Cluster statistical thermodynamics (HMCST) method. These methods, by treating atoms as oscillators and particles simultaneously, as well as Clusters, comprise different spatial and temporal scales in a unified framework. One appealing feature of these methods is their "seamlessness" or consistency in the same underlying atomistic model in all regions consisting of atoms and Clusters, and hence can avoid the ghost force in the simulation. On the other hand, compared with conventional MD simulations, their high computational efficiency appears very attractive, as manifested by the simulations of uniaxial compression and nanoindenation. (C) 2008 Elsevier Ltd. All rights reserved.
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Molecular/Cluster statistical thermodynamics methods to simulate quasi-static deformations at finite temperature
International Journal of Solids and Structures, 2008Co-Authors: Haiying Wang, Ming Hu, Fujiu KeAbstract:The rapid evolution of nanotechnology appeals for the understanding of global response of nanoscale systems based on atomic interactions, hence necessitates novel, sophisticated, and physically based approaches to bridge the gaps between various length and time scales. In this paper, we propose a group of statistical thermodynamics methods for the simulations of nanoscale systems under quasi-static loading at finite temperature, that is, Molecular statistical thermodynamics (MST) method, Cluster statistical thermodynamics (CST) method, and the hybrid Molecular/Cluster statistical thermodynamics (HMCST) method. These methods, by treating atoms as oscillators and particles simultaneously, as well as Clusters, comprise different spatial and temporal scales in a unified framework. One appealing feature of these methods is their "seamlessness" or consistency in the same underlying atomistic model in all regions consisting of atoms and Clusters, and hence can avoid the ghost force in the simulation. On the other hand, compared with conventional MD simulations, their high computational efficiency appears very attractive, as manifested by the simulations of uniaxial compression and nanoindenation. (C) 2008 Elsevier Ltd. All rights reserved.
Kunio Awaga - One of the best experts on this subject based on the ideXlab platform.
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super reduced polyoxometalates excellent Molecular Cluster battery components and semipermeable Molecular capacitors
Journal of the American Chemical Society, 2014Co-Authors: Yoshio Nishimoto, Hirofumi Yoshikawa, Kunio Awaga, Daisuke Yokogawa, Stephan IrleAbstract:Theoretical investigations are presented on the Molecular and electronic structure changes that occur as α-Keggin-type polyoxometalate (POM3–) Clusters [PM12O40]3– (M = Mo, W) are converted toward their super-reduced POM27– state during the discharging process in lithium-based Molecular Cluster batteries. Density functional theory was employed in geometry optimization, and first-principles Molecular dynamics simulations were used to explore local minima on the potential energy surface of neutral POM Clusters adorned with randomly placed Li atoms as electron donors around the Cluster surface. On the basis of structural, electron density, and Molecular orbital studies, we present evidence that the super-reduction is accompanied by metal–metal bond formation, beginning from the 12th to 14th excess electron transferred to the Cluster. Afterward, the number of metal–metal bonds increases nearly linearly with the number of additionally transferred excess electrons. In α-Keggin-type POMs, metal triangles are a p...
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in operando x ray absorption fine structure studies of polyoxometalate Molecular Cluster batteries polyoxometalates as electron sponges
ChemInform, 2012Co-Authors: Heng Wang, Hirofumi Yoshikawa, Toshihiko Yokoyama, Shun Hamanaka, Yoshio Nishimoto, Stephan Irle, Kunio AwagaAbstract:Mo K-edge XAFS measurements on rechargeable Molecular Cluster batteries in which (NBu4)3[PMo12O40] is used as cathode material and Li metal as anode reveal that all 12 Mo6+ ions in [PMo12O40]3- are reduced to Mo4+ in the discharge process, leading to the formation of [PMo12O40]27-, which stores 24 electrons.
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in operando x ray absorption fine structure studies of polyoxometalate Molecular Cluster batteries polyoxometalates as electron sponges
Journal of the American Chemical Society, 2012Co-Authors: Heng Wang, Hirofumi Yoshikawa, Toshihiko Yokoyama, Shun Hamanaka, Yoshio Nishimoto, Stephan Irle, Kunio AwagaAbstract:We carried out in operando Mo K-edge X-ray absorption fine structure measurements on the rechargeable Molecular Cluster batteries (MCBs) of polyoxometalates (POMs), in which a Keggin-type POM, [PMo12O40]3–, is utilized as a cathode active material with a lithium metal anode. The POM-MCBs exhibit a large capacity of ca. 270 (A h)/kg in a voltage range between V = 4.0 V and V = 1.5 V. X-ray absorption near-edge structure analyses demonstrate that all 12 Mo6+ ions in [PMo12O40]3– are reduced to Mo4+ in the discharging process. This means the formation of a super-reduced state of the POM, namely, [PMo12O40]27–, which stores 24 electrons, and this electron number can explain the large capacity of the POM-MCBs. Furthermore, extended X-ray absorption fine structure analyses reveal the Molecular structure of [PMo12O40]27–, which is slightly reduced in size compared to the original [PMo12O40]3– and involves Mo4+ metal–metal-bonded triangles. Density functional theory calculations suggest that these triangles are f...
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nanohybridization of polyoxometalate Clusters and single wall carbon nanotubes applications in Molecular Cluster batteries
ChemInform, 2011Co-Authors: Naoya Kawasaki, Hirofumi Yoshikawa, Heng Wang, Toshihiko Yokoyama, Shun Hamanaka, Ryo Nakanishi, Ryo Kitaura, Hisanori Shinohara, Kunio AwagaAbstract:(NBu4)3[PMo12O40] molecules are grafted onto the surface of single-wall carbon nanotubes by addition of a MeCN solution of the polyoxometalate to a toluene suspension of the nanotubes under vigorous stirring at room temperature.
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Nanohybridization of Single-Wall Carbon Nanotubes and Molecular Clusters
2011Co-Authors: Hirofumi Yoshikawa, Naoya Kawasaki, Heng Wang, Toshihiko Yokoyama, Kunio AwagaAbstract:Introduction We have recently proposed Molecular Cluster batteries (MCBs) that consist of a lithium anode and cathodeactive material based on polynuclear metal complexes (Molecular Clusters), in order to achieve both high capacity and fast charging/discharging. However, the cathodes were made by simply mixing microcrystals of Molecular Clusters and conductive carbon materials, and the battery reaction was associated with frictional penetration/removal of lithium ions into/from the microcrystals and with non-smooth electron transfer between the Cluster molecules and the electrode. So these drawbacks brought about problems such as a slow charging/discharging rate and insufficient cyclability. In the present work, to achieve both smooth electron transfer through SWNTs and quick lithium-ion diffusion, we examined nanohybridization between a well-known Molecular Cluster, polyoxometalate (POM), and SWNT.
Haiying Wang - One of the best experts on this subject based on the ideXlab platform.
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Molecular Cluster statistical thermodynamics methods to simulate quasi static deformations at finite temperature
International Journal of Solids and Structures, 2008Co-Authors: Haiying Wang, Ming Hu, Fujiu KeAbstract:The rapid evolution of nanotechnology appeals for the understanding of global response of nanoscale systems based on atomic interactions, hence necessitates novel, sophisticated, and physically based approaches to bridge the gaps between various length and time scales. In this paper, we propose a group of statistical thermodynamics methods for the simulations of nanoscale systems under quasi-static loading at finite temperature, that is, Molecular statistical thermodynamics (MST) method, Cluster statistical thermodynamics (CST) method, and the hybrid Molecular/Cluster statistical thermodynamics (HMCST) method. These methods, by treating atoms as oscillators and particles simultaneously, as well as Clusters, comprise different spatial and temporal scales in a unified framework. One appealing feature of these methods is their "seamlessness" or consistency in the same underlying atomistic model in all regions consisting of atoms and Clusters, and hence can avoid the ghost force in the simulation. On the other hand, compared with conventional MD simulations, their high computational efficiency appears very attractive, as manifested by the simulations of uniaxial compression and nanoindenation. (C) 2008 Elsevier Ltd. All rights reserved.
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Molecular/Cluster statistical thermodynamics methods to simulate quasi-static deformations at finite temperature
International Journal of Solids and Structures, 2008Co-Authors: Haiying Wang, Ming Hu, Fujiu KeAbstract:The rapid evolution of nanotechnology appeals for the understanding of global response of nanoscale systems based on atomic interactions, hence necessitates novel, sophisticated, and physically based approaches to bridge the gaps between various length and time scales. In this paper, we propose a group of statistical thermodynamics methods for the simulations of nanoscale systems under quasi-static loading at finite temperature, that is, Molecular statistical thermodynamics (MST) method, Cluster statistical thermodynamics (CST) method, and the hybrid Molecular/Cluster statistical thermodynamics (HMCST) method. These methods, by treating atoms as oscillators and particles simultaneously, as well as Clusters, comprise different spatial and temporal scales in a unified framework. One appealing feature of these methods is their "seamlessness" or consistency in the same underlying atomistic model in all regions consisting of atoms and Clusters, and hence can avoid the ghost force in the simulation. On the other hand, compared with conventional MD simulations, their high computational efficiency appears very attractive, as manifested by the simulations of uniaxial compression and nanoindenation. (C) 2008 Elsevier Ltd. All rights reserved.
Hirofumi Yoshikawa - One of the best experts on this subject based on the ideXlab platform.
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super reduced polyoxometalates excellent Molecular Cluster battery components and semipermeable Molecular capacitors
Journal of the American Chemical Society, 2014Co-Authors: Yoshio Nishimoto, Hirofumi Yoshikawa, Kunio Awaga, Daisuke Yokogawa, Stephan IrleAbstract:Theoretical investigations are presented on the Molecular and electronic structure changes that occur as α-Keggin-type polyoxometalate (POM3–) Clusters [PM12O40]3– (M = Mo, W) are converted toward their super-reduced POM27– state during the discharging process in lithium-based Molecular Cluster batteries. Density functional theory was employed in geometry optimization, and first-principles Molecular dynamics simulations were used to explore local minima on the potential energy surface of neutral POM Clusters adorned with randomly placed Li atoms as electron donors around the Cluster surface. On the basis of structural, electron density, and Molecular orbital studies, we present evidence that the super-reduction is accompanied by metal–metal bond formation, beginning from the 12th to 14th excess electron transferred to the Cluster. Afterward, the number of metal–metal bonds increases nearly linearly with the number of additionally transferred excess electrons. In α-Keggin-type POMs, metal triangles are a p...
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in operando x ray absorption fine structure studies of polyoxometalate Molecular Cluster batteries polyoxometalates as electron sponges
ChemInform, 2012Co-Authors: Heng Wang, Hirofumi Yoshikawa, Toshihiko Yokoyama, Shun Hamanaka, Yoshio Nishimoto, Stephan Irle, Kunio AwagaAbstract:Mo K-edge XAFS measurements on rechargeable Molecular Cluster batteries in which (NBu4)3[PMo12O40] is used as cathode material and Li metal as anode reveal that all 12 Mo6+ ions in [PMo12O40]3- are reduced to Mo4+ in the discharge process, leading to the formation of [PMo12O40]27-, which stores 24 electrons.
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in operando x ray absorption fine structure studies of polyoxometalate Molecular Cluster batteries polyoxometalates as electron sponges
Journal of the American Chemical Society, 2012Co-Authors: Heng Wang, Hirofumi Yoshikawa, Toshihiko Yokoyama, Shun Hamanaka, Yoshio Nishimoto, Stephan Irle, Kunio AwagaAbstract:We carried out in operando Mo K-edge X-ray absorption fine structure measurements on the rechargeable Molecular Cluster batteries (MCBs) of polyoxometalates (POMs), in which a Keggin-type POM, [PMo12O40]3–, is utilized as a cathode active material with a lithium metal anode. The POM-MCBs exhibit a large capacity of ca. 270 (A h)/kg in a voltage range between V = 4.0 V and V = 1.5 V. X-ray absorption near-edge structure analyses demonstrate that all 12 Mo6+ ions in [PMo12O40]3– are reduced to Mo4+ in the discharging process. This means the formation of a super-reduced state of the POM, namely, [PMo12O40]27–, which stores 24 electrons, and this electron number can explain the large capacity of the POM-MCBs. Furthermore, extended X-ray absorption fine structure analyses reveal the Molecular structure of [PMo12O40]27–, which is slightly reduced in size compared to the original [PMo12O40]3– and involves Mo4+ metal–metal-bonded triangles. Density functional theory calculations suggest that these triangles are f...
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nanohybridization of polyoxometalate Clusters and single wall carbon nanotubes applications in Molecular Cluster batteries
ChemInform, 2011Co-Authors: Naoya Kawasaki, Hirofumi Yoshikawa, Heng Wang, Toshihiko Yokoyama, Shun Hamanaka, Ryo Nakanishi, Ryo Kitaura, Hisanori Shinohara, Kunio AwagaAbstract:(NBu4)3[PMo12O40] molecules are grafted onto the surface of single-wall carbon nanotubes by addition of a MeCN solution of the polyoxometalate to a toluene suspension of the nanotubes under vigorous stirring at room temperature.
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Nanohybridization of Single-Wall Carbon Nanotubes and Molecular Clusters
2011Co-Authors: Hirofumi Yoshikawa, Naoya Kawasaki, Heng Wang, Toshihiko Yokoyama, Kunio AwagaAbstract:Introduction We have recently proposed Molecular Cluster batteries (MCBs) that consist of a lithium anode and cathodeactive material based on polynuclear metal complexes (Molecular Clusters), in order to achieve both high capacity and fast charging/discharging. However, the cathodes were made by simply mixing microcrystals of Molecular Clusters and conductive carbon materials, and the battery reaction was associated with frictional penetration/removal of lithium ions into/from the microcrystals and with non-smooth electron transfer between the Cluster molecules and the electrode. So these drawbacks brought about problems such as a slow charging/discharging rate and insufficient cyclability. In the present work, to achieve both smooth electron transfer through SWNTs and quick lithium-ion diffusion, we examined nanohybridization between a well-known Molecular Cluster, polyoxometalate (POM), and SWNT.
Ming Hu - One of the best experts on this subject based on the ideXlab platform.
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Molecular Cluster statistical thermodynamics methods to simulate quasi static deformations at finite temperature
International Journal of Solids and Structures, 2008Co-Authors: Haiying Wang, Ming Hu, Fujiu KeAbstract:The rapid evolution of nanotechnology appeals for the understanding of global response of nanoscale systems based on atomic interactions, hence necessitates novel, sophisticated, and physically based approaches to bridge the gaps between various length and time scales. In this paper, we propose a group of statistical thermodynamics methods for the simulations of nanoscale systems under quasi-static loading at finite temperature, that is, Molecular statistical thermodynamics (MST) method, Cluster statistical thermodynamics (CST) method, and the hybrid Molecular/Cluster statistical thermodynamics (HMCST) method. These methods, by treating atoms as oscillators and particles simultaneously, as well as Clusters, comprise different spatial and temporal scales in a unified framework. One appealing feature of these methods is their "seamlessness" or consistency in the same underlying atomistic model in all regions consisting of atoms and Clusters, and hence can avoid the ghost force in the simulation. On the other hand, compared with conventional MD simulations, their high computational efficiency appears very attractive, as manifested by the simulations of uniaxial compression and nanoindenation. (C) 2008 Elsevier Ltd. All rights reserved.
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Molecular/Cluster statistical thermodynamics methods to simulate quasi-static deformations at finite temperature
International Journal of Solids and Structures, 2008Co-Authors: Haiying Wang, Ming Hu, Fujiu KeAbstract:The rapid evolution of nanotechnology appeals for the understanding of global response of nanoscale systems based on atomic interactions, hence necessitates novel, sophisticated, and physically based approaches to bridge the gaps between various length and time scales. In this paper, we propose a group of statistical thermodynamics methods for the simulations of nanoscale systems under quasi-static loading at finite temperature, that is, Molecular statistical thermodynamics (MST) method, Cluster statistical thermodynamics (CST) method, and the hybrid Molecular/Cluster statistical thermodynamics (HMCST) method. These methods, by treating atoms as oscillators and particles simultaneously, as well as Clusters, comprise different spatial and temporal scales in a unified framework. One appealing feature of these methods is their "seamlessness" or consistency in the same underlying atomistic model in all regions consisting of atoms and Clusters, and hence can avoid the ghost force in the simulation. On the other hand, compared with conventional MD simulations, their high computational efficiency appears very attractive, as manifested by the simulations of uniaxial compression and nanoindenation. (C) 2008 Elsevier Ltd. All rights reserved.