Based on the hexagonal crystallite model of graphite,the electrochemical characteristics of carbon atoms on the edge and basal plane were proposed by analyzing graphite crystal structure and bonds of carbon atoms in d...Based on the hexagonal crystallite model of graphite,the electrochemical characteristics of carbon atoms on the edge and basal plane were proposed by analyzing graphite crystal structure and bonds of carbon atoms in different sites.A spherical close-packed model for graphite particle was developed.The fractions of surface carbon atoms(SCA) and edge carbon atoms(ECA) were derived in the expression of crystallographic parameters and particle size,and the effects of ECA on the initial irreversible capacity and the mechanisms of action were analyzed and verified.The results show that the atoms on the edge are more active for electrochemical reactions,such as electrolyte decomposition and tendency to form stable bond with other atoms and groups.For the practical graphite particle,corresponding modifying factors were introduced to revise the difference in calculating results.The revised expression is suitable for the calculation of the fractions of SCA and ECA for carbon materials such as graphite,disordered carbon and modified graphite.展开更多
For the ever-growing demand of advanced lithium-ion batteries, it is highly desirable to grow self-supported micro-/nanostructured arrays on metal substrates as electrodes directly. The in-situ growth of electrode mat...For the ever-growing demand of advanced lithium-ion batteries, it is highly desirable to grow self-supported micro-/nanostructured arrays on metal substrates as electrodes directly. The in-situ growth of electrode materials on the conducting substrates greatly simplifies the electrode fabrication process without using any binders or conductive additives. Moreover, the well-ordered arrays closely connected to the current collectors can provide direct electron transport pathways and enhanced accommodation of strains arisen from lithium ion lithiation/delithiation. This article summarizes our recent work on design and construction of lithium-ion battery electrodes on metal substrates. An aqueous solution-based process and a microemulsion-mediated process have been respectively presented to control the kinetic and thermodynamic processes for the micro-/nanostructured array growth on metal substrates, with particular attention to CuO nanorod arrays and microcog arrays successfully prepared on Cu foil substrates. They can be directly used as binder-free electrodes to build advanced lithium-ion batteries with high energy, high safety and high stability.展开更多
A power management unit (PMU) chip supplying dual panel supply voltage, which has a low electro-magnetic interference (EMI) characteristic and is favorable for miniaturization, is designed. A two-phase charge pump...A power management unit (PMU) chip supplying dual panel supply voltage, which has a low electro-magnetic interference (EMI) characteristic and is favorable for miniaturization, is designed. A two-phase charge pump circuit using external pumping capacitor increases its pumping current and works out the charge-loss problem by using bulk-potential biasing circuit. A low-power start-up circuit is also proposed to reduce the power consumption of the band-gap reference voltage generator. And the ring oscillator used in the ELVSS power circuit is designed with logic devices by supplying the logic power supply to reduce the layout area. The PMU chip is designed with MagnaChip's 0.25 μ high-voltage process. The driving currents of ELVDD and ELVSS are more than 50 mA when a SPICE simulation is done.展开更多
The paper analyze the polarization of study dielectric that produced field by dipole, medium field plays an important role in electromagnetic wave radiation. The electric field expression for electric dipole electric ...The paper analyze the polarization of study dielectric that produced field by dipole, medium field plays an important role in electromagnetic wave radiation. The electric field expression for electric dipole electric field distribution in ordinary textbooks only give a special direction, This paper introduces in detail the formula of the electric dipole in the space of an arbitrary point excitation electric field, and use computer sottware to simulate the distribution pattern of electric dipole, and gives some typical figures for reference.展开更多
Configuration-constrained potential-energy-surface calculations are performed to investigate high-K isomers in97Y,130Ba,176Yb,177Lu,and178Hf that were observed to have increased electric quadrupole moments but decreas...Configuration-constrained potential-energy-surface calculations are performed to investigate high-K isomers in97Y,130Ba,176Yb,177Lu,and178Hf that were observed to have increased electric quadrupole moments but decreased charge radii relative to the states on which they are built.Taking into account the efects of deformation change and unpaired protons,our calculations can reproduce the enhancement of electric quadrupole moments for the isomers in97Y,130Ba,176Yb,177Lu and the Kπ=8 isomer in178Hf,and can reproduce the reduction of charge radii for the Kπ=27/2 isomer in97Y and the Kπ=16+isomer in178Hf.展开更多
By converting incident light into electric power,self-powered electrochromic window(SP-ECW)can achieve color change in electrochromic layer with no need for external voltage.In this work,a newly-de signed SP-ECW is pr...By converting incident light into electric power,self-powered electrochromic window(SP-ECW)can achieve color change in electrochromic layer with no need for external voltage.In this work,a newly-de signed SP-ECW is proposed for altering its color between deep blue and colorless state according to on/off state of incident light.The device consists of a working electrode with planar integration of photovoltaic(PV)and electrochromic(EC)elements on one electrode,a platinum counter electrode and a redox electrolyte comprising Br^-/Br_3^-couple.A high transmittance modulation of 41%at 582 nm is obtained.Electrical energy converted from light is not only sufficient to drive the device,but also can be outputted to the external circuit.展开更多
This paper proposes a new mechanism to explain the performance of thin dye-sensitized solar cells (DSSC). Near-stoichiometric flower-like Cu2ZnSnS4 (CZTS) microspheres with a high specific surface area was fabri- ...This paper proposes a new mechanism to explain the performance of thin dye-sensitized solar cells (DSSC). Near-stoichiometric flower-like Cu2ZnSnS4 (CZTS) microspheres with a high specific surface area was fabri- cated for use as the photocathode in a DSSC. To improve the extraction and transfer of electrons, graphene was added to the CZTS. A DSSC with a 10-gin TiO2 pho- toanode layer exhibited a slightly degraded efficiency with a CZTS-graphene photocathode, relative to a Pt counter electrode (CE). Nevertheless, when the thickness of the TiO2 photoanode was reduced to 2 lam, the efficiency of a DSSC with a CZTS-graphene photocathode was greater than that of a Pt-DSSC. It is speculated that, unlike the Pt CE, a CZTS-graphene photocathode not only collects electrons from an external circuit and catalyzes the reduction of the triiodide ions in the electrolyte, but also utilizes unabsorbed photons to produce photo-excited electrons and suppresses charge recombination, thus enhancing the performance of the cell. The use of narrowband gap p-type semiconductors as photocathodes offers a new means of fabricating thin dye-sensitized solar cells and effectively improving the cell performance.展开更多
基金Project (09001232) supported by the Doctoral Foundation of Henan University of Science and Technology,China
文摘Based on the hexagonal crystallite model of graphite,the electrochemical characteristics of carbon atoms on the edge and basal plane were proposed by analyzing graphite crystal structure and bonds of carbon atoms in different sites.A spherical close-packed model for graphite particle was developed.The fractions of surface carbon atoms(SCA) and edge carbon atoms(ECA) were derived in the expression of crystallographic parameters and particle size,and the effects of ECA on the initial irreversible capacity and the mechanisms of action were analyzed and verified.The results show that the atoms on the edge are more active for electrochemical reactions,such as electrolyte decomposition and tendency to form stable bond with other atoms and groups.For the practical graphite particle,corresponding modifying factors were introduced to revise the difference in calculating results.The revised expression is suitable for the calculation of the fractions of SCA and ECA for carbon materials such as graphite,disordered carbon and modified graphite.
基金Supported by the National Natural Science Foundation of China(NSFC Grants21176054 and 21271058)
文摘For the ever-growing demand of advanced lithium-ion batteries, it is highly desirable to grow self-supported micro-/nanostructured arrays on metal substrates as electrodes directly. The in-situ growth of electrode materials on the conducting substrates greatly simplifies the electrode fabrication process without using any binders or conductive additives. Moreover, the well-ordered arrays closely connected to the current collectors can provide direct electron transport pathways and enhanced accommodation of strains arisen from lithium ion lithiation/delithiation. This article summarizes our recent work on design and construction of lithium-ion battery electrodes on metal substrates. An aqueous solution-based process and a microemulsion-mediated process have been respectively presented to control the kinetic and thermodynamic processes for the micro-/nanostructured array growth on metal substrates, with particular attention to CuO nanorod arrays and microcog arrays successfully prepared on Cu foil substrates. They can be directly used as binder-free electrodes to build advanced lithium-ion batteries with high energy, high safety and high stability.
文摘A power management unit (PMU) chip supplying dual panel supply voltage, which has a low electro-magnetic interference (EMI) characteristic and is favorable for miniaturization, is designed. A two-phase charge pump circuit using external pumping capacitor increases its pumping current and works out the charge-loss problem by using bulk-potential biasing circuit. A low-power start-up circuit is also proposed to reduce the power consumption of the band-gap reference voltage generator. And the ring oscillator used in the ELVSS power circuit is designed with logic devices by supplying the logic power supply to reduce the layout area. The PMU chip is designed with MagnaChip's 0.25 μ high-voltage process. The driving currents of ELVDD and ELVSS are more than 50 mA when a SPICE simulation is done.
文摘The paper analyze the polarization of study dielectric that produced field by dipole, medium field plays an important role in electromagnetic wave radiation. The electric field expression for electric dipole electric field distribution in ordinary textbooks only give a special direction, This paper introduces in detail the formula of the electric dipole in the space of an arbitrary point excitation electric field, and use computer sottware to simulate the distribution pattern of electric dipole, and gives some typical figures for reference.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11205120 and 11235001)the National Key Basic Research Program of China (Grant No. 2013CB834400)
文摘Configuration-constrained potential-energy-surface calculations are performed to investigate high-K isomers in97Y,130Ba,176Yb,177Lu,and178Hf that were observed to have increased electric quadrupole moments but decreased charge radii relative to the states on which they are built.Taking into account the efects of deformation change and unpaired protons,our calculations can reproduce the enhancement of electric quadrupole moments for the isomers in97Y,130Ba,176Yb,177Lu and the Kπ=8 isomer in178Hf,and can reproduce the reduction of charge radii for the Kπ=27/2 isomer in97Y and the Kπ=16+isomer in178Hf.
基金the National Natural Science Foundation of China(21274138,21273207,21474096)the Chinese Academy of Sciences(Integrated system of high efficiency building energy saving and its application,KFZD-SW-403)
文摘By converting incident light into electric power,self-powered electrochromic window(SP-ECW)can achieve color change in electrochromic layer with no need for external voltage.In this work,a newly-de signed SP-ECW is proposed for altering its color between deep blue and colorless state according to on/off state of incident light.The device consists of a working electrode with planar integration of photovoltaic(PV)and electrochromic(EC)elements on one electrode,a platinum counter electrode and a redox electrolyte comprising Br^-/Br_3^-couple.A high transmittance modulation of 41%at 582 nm is obtained.Electrical energy converted from light is not only sufficient to drive the device,but also can be outputted to the external circuit.
基金This work was supported by the National Natural Science Foundation of China (51272033, 51572037 and 51335002), the Priority Academic Program Development of Jiangsu Higher Education Institutions and the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (14KJA430001).
文摘This paper proposes a new mechanism to explain the performance of thin dye-sensitized solar cells (DSSC). Near-stoichiometric flower-like Cu2ZnSnS4 (CZTS) microspheres with a high specific surface area was fabri- cated for use as the photocathode in a DSSC. To improve the extraction and transfer of electrons, graphene was added to the CZTS. A DSSC with a 10-gin TiO2 pho- toanode layer exhibited a slightly degraded efficiency with a CZTS-graphene photocathode, relative to a Pt counter electrode (CE). Nevertheless, when the thickness of the TiO2 photoanode was reduced to 2 lam, the efficiency of a DSSC with a CZTS-graphene photocathode was greater than that of a Pt-DSSC. It is speculated that, unlike the Pt CE, a CZTS-graphene photocathode not only collects electrons from an external circuit and catalyzes the reduction of the triiodide ions in the electrolyte, but also utilizes unabsorbed photons to produce photo-excited electrons and suppresses charge recombination, thus enhancing the performance of the cell. The use of narrowband gap p-type semiconductors as photocathodes offers a new means of fabricating thin dye-sensitized solar cells and effectively improving the cell performance.