In this paper, we conduct research on the dynamic demand response problem in smart grid to control the energy consumption. The objective of the energy consumption control is constructed based on differential game, as ...In this paper, we conduct research on the dynamic demand response problem in smart grid to control the energy consumption. The objective of the energy consumption control is constructed based on differential game, as the dynamic of each users’ energy state in smart gird can be described based on a differential equation. Concept of electricity sharing is introduced to achieve load shift of main users from the high price hours to the low price hours. Nash equilibrium is given based on the Hamilton equation and the effectiveness of the proposed model is verified based on the numerical simulation results.展开更多
Owing to safety issue and low energy density of liquid lithium-ion batteries(LIBs),all-solid-state lithium metal batteries(ASLMBs)with unique all-solid-state electrolytes(SEs)have attracted wide attentions.This arises...Owing to safety issue and low energy density of liquid lithium-ion batteries(LIBs),all-solid-state lithium metal batteries(ASLMBs)with unique all-solid-state electrolytes(SEs)have attracted wide attentions.This arises mainly from the advantages of the SEs in the suppression of lithium dendrite growth,long cycle life,and broad working temperature range,showing huge potential applications in electronic devices,electric vehicles,smart grids,and biomedical devices.However,SEs suffer from low lithiumion conductivity and low mechanical integrity,slowing down the development of practical ASLMBs.Nanostructure engineering is of great efficiency in tuning the structure and composition of the SEs with improved lithium-ion conductivity and mechanical integrity.Among various available technologies for nanostructure engineering,electrospinning is a promising technique because of its simple operation,cost-effectiveness,and efficient integration with different components.In this review,we will first give a simple description of the electrospinning process.Then,the use of electrospinning technique in the synthesis of various SEs is summarized,for example,organic nanofibrous matrix,organic/inorganic nanofibrous matrix,and inorganic nanofibrous matrix combined with other components.The current development of the advanced architectures of SEs through electrospinning technology is also presented to provide references and ideas for designing high-performance ASLMBs.Finally,an outlook and further challenges in the preparation of advanced SEs for ASLMBs through electrospinning engineering are given.展开更多
The application of Low Density Parity Check (LDPC) code in the anti-interference systems has drawn an increasing attention, due to its admiring performance which is very close to the theory limit. This paper focuses o...The application of Low Density Parity Check (LDPC) code in the anti-interference systems has drawn an increasing attention, due to its admiring performance which is very close to the theory limit. This paper focuses on a LDPC encoded slow frequency hopping (SFH) communication system with partial-band interference. Firstly, a modified soft- decision algorithm based on the utilization of interference information is proposed, and its performance is compared with some other soft-decision methods. Secondly, with numerical simulation, the influence of code rate, code length and the number of symbols per hops on the performance of the system with partial band noise interference is illustrated and examined in detail. Considering the great influence of hops per symbol on the performance, interleaver should be used and its influence on the performance is further examined by simulation. Finally, some constructive advises for the design of LDPC coded SFH system are given. Simulation results show that, with a reasonable design, the SFH system with LDPC code could achieve a desirable performance.展开更多
The increasing demand for new energy sources has promoted the improvement of the energy storage capacity of lithium-ion batteries(LIBs)that urged the development of higher energy density cathode materials.The enhancem...The increasing demand for new energy sources has promoted the improvement of the energy storage capacity of lithium-ion batteries(LIBs)that urged the development of higher energy density cathode materials.The enhancement of the classical cathode in the last 30 years has reached a bottleneck,and then the discovery of the lithium-excess disordered materials has greatly expanded the research space of the cathode materials.Compared with the conventional layered oxides,the lithium-excess disordered rock-salt oxides(LEDRXs)with a more stable structure has higher extractable Li^(+)content,even though the inactive high-valent transition metals(TMs)were needed to compensate for the excess Li,which would reduce the total TM redox content.In addition,oxygen redox provides additional electron capacity for the materials,which also causes O loss and results in the subsequent poor cycle performance.Herein,a series of studies about LEDRXs and their targeted modification measures are summarized,including the prospect of the materials,in order to provide ideas for the design of highperformance LEDRXs.Finally,the new discoveries and outlook on future research directions of LEDRX cathode materials for LIBs with higher energy density are given.展开更多
The indiscriminate utilization of nondegradable polyethylene terephthalate(PET)-based products has triggered serious environmental pollution that has to be resolved vigorously.A simple synthesis of N-doped carbon nano...The indiscriminate utilization of nondegradable polyethylene terephthalate(PET)-based products has triggered serious environmental pollution that has to be resolved vigorously.A simple synthesis of N-doped carbon nanotubes from recycled PET(NCNTs_(r-PET))was developed by a nitric acid-assisted hydrothermal method.Experimental results and theoretical calculations show that the intrinsic defects in CNTs_(r-PET)would induce N-doping by NH_(3)generated from nitric acid during the hydrothermal process,thus producing the NCNTs_(r-PET).The life cycle assessment proves that the developed method for N-doped CNTs using r-PET as the carbon source is more environmentally friendly than the conventional chemical vapor deposition using acetylene as the carbon source.As a typical application,the NCNTs_(r-PET)delivered an impressive sodium storage capacity with an ultralong lifespan.This work not only provides a new route to upcycling waste plastics into valuable carbonaceous materials in an ecofriendly manner,but also reveals a basic understanding of the N-doping mechanism in carbonaceous materials.展开更多
Electrospun nanofibers(NFs)have shown excellent properties including high porosity,abundant active sites,controllable diameter,uniform and designable structure,high mechanical strength,and superior resistance to exter...Electrospun nanofibers(NFs)have shown excellent properties including high porosity,abundant active sites,controllable diameter,uniform and designable structure,high mechanical strength,and superior resistance to external destruction,which are ideal nanoreactors for in situ characterizations.Among various techniques,in situ transmission electron microscopy(TEM)has enabled operando observation at the atomic level due to its high temporal and spatial resolution combined with excellent sensitivity,which is of great importance for rational materials design and performance improvement.In this review,the basic knowledge of in situ TEM techniques and the advantages of electrospun nanoreactors for in situ TEM characterization are first introduced.The recent development in electrospun nanoreactors for studying the physical properties,structural evolution,phase transition,and formation mechanisms of materials using in situ TEM is then summarized.The electrochemical behaviors of carbon nanofibers(CNFs),metal/metal oxide NFs,and solidelectrolyte interphase for different rechargeable batteries are highlighted.Finally,challenges faced by electrospun nanoreactors for in situ TEM characterization are discussed and potential solutions are proposed to advance this field.展开更多
As a promising energy storage device,sodium-ion batteries(SIBs)have received continuous attention due to their low-cost and environmental friendliness.However,the sluggish kinetics of Na ion usually makes SIBs hard to...As a promising energy storage device,sodium-ion batteries(SIBs)have received continuous attention due to their low-cost and environmental friendliness.However,the sluggish kinetics of Na ion usually makes SIBs hard to realize desirable electrochemical performance when compared to lithium-ion batteries(LIBs).The key to addressing this issue is to build up nanostructured materials which enable fast Na-ion insertion/extraction.One-dimensional(1D)nanocarbons have been considered as both the anode and the matrix to support active materials for SIB electrodes owing to their high electronic conductivity and excellent mechanical property.Because of their large surface areas and short ion/electron difusion path,the synthesized electrodes can show good rate performance and cyclic stability during the charge/discharge processes.Electrospinning is a simple synthetic technology,featuring inexpensiveness,easy operation and scalable production,and has been largely used to fabricate 1D nanostructured composites.In this review,we frst give a simple description of the electrospinning principle and its capability to construct desired nanostructures with diferent compositions.Then,we discuss recent developments of carbon-based hybrids with desired structural and compositional characteristics as the electrodes by electrospinning engineering for SIBs.Finally,we identify future research directions to realize more breakthroughs on electrospun electrodes for SIBs.展开更多
A real-time ray-based hardware emulator for Unmanned Aerial Vehicle(UAV) communication channels which suits for the Three-Dimensional(3D) dynamic scenarios and considers the movements of both terminals is developed in...A real-time ray-based hardware emulator for Unmanned Aerial Vehicle(UAV) communication channels which suits for the Three-Dimensional(3D) dynamic scenarios and considers the movements of both terminals is developed in this paper. The time-variant channel parameters, i.e.,ray delay, ray gain, and ray Doppler frequency are precalculated in the host by using the Ray Tracing(RT) method. Meanwhile, RT simulation dramatically increases the number of valid rays. To address the problem of resource limitation and huge computational burden in the implementation,an efficient ray coefficients generation method based on iteration is proposed and implemented.With the advantages of low cost and high flexibility, a Software Defined Radio(SDR) hardware platform is used to emulate the ray-based UAV channels by utilizing the compact architecture including the Time-Division(TD) scheme and Tapped-Delay Line(TDL) for channel convolution.Finally, hardware measurement results demonstrate that the properties of emulated channel, i.e.,Power Delay Profile(PDP) and Doppler Power Spectrum Density(DPSD) consist with the simulated ones, which verifies the correctness of hardware implementation. The proposed channel emulator provides an efficient way for optimization, verification, and evaluation of UAV communication systems.展开更多
基金supported by National Key R&D Program of China, No.2018YFB1003905the Fundamental Research Funds for the Central Universities, No.FRF-TP-18-008A3
文摘In this paper, we conduct research on the dynamic demand response problem in smart grid to control the energy consumption. The objective of the energy consumption control is constructed based on differential game, as the dynamic of each users’ energy state in smart gird can be described based on a differential equation. Concept of electricity sharing is introduced to achieve load shift of main users from the high price hours to the low price hours. Nash equilibrium is given based on the Hamilton equation and the effectiveness of the proposed model is verified based on the numerical simulation results.
基金financially supported by the National Key Research and Development Project of China for Demonstration of Integrated Utilization of Solid Waste in Distinctive Convergent Areas of Southeast Light Industry Building Materials(2019YFC1904500)the National Natural Science Foundation of China(Grant No.81770222)+4 种基金the Social Development Industry University Research Cooperation Project from the Department of Science and Technology in Fujian(2018Y4002)support by the Award Program for Fujian Minjiang Scholar Professorshipsupport from the Australian Research Grants Council(DP130104648)support from the NSERC Discovery Grant(NSERC RGPIN-2020-04463)McGill Start-Up Grant。
文摘Owing to safety issue and low energy density of liquid lithium-ion batteries(LIBs),all-solid-state lithium metal batteries(ASLMBs)with unique all-solid-state electrolytes(SEs)have attracted wide attentions.This arises mainly from the advantages of the SEs in the suppression of lithium dendrite growth,long cycle life,and broad working temperature range,showing huge potential applications in electronic devices,electric vehicles,smart grids,and biomedical devices.However,SEs suffer from low lithiumion conductivity and low mechanical integrity,slowing down the development of practical ASLMBs.Nanostructure engineering is of great efficiency in tuning the structure and composition of the SEs with improved lithium-ion conductivity and mechanical integrity.Among various available technologies for nanostructure engineering,electrospinning is a promising technique because of its simple operation,cost-effectiveness,and efficient integration with different components.In this review,we will first give a simple description of the electrospinning process.Then,the use of electrospinning technique in the synthesis of various SEs is summarized,for example,organic nanofibrous matrix,organic/inorganic nanofibrous matrix,and inorganic nanofibrous matrix combined with other components.The current development of the advanced architectures of SEs through electrospinning technology is also presented to provide references and ideas for designing high-performance ASLMBs.Finally,an outlook and further challenges in the preparation of advanced SEs for ASLMBs through electrospinning engineering are given.
文摘The application of Low Density Parity Check (LDPC) code in the anti-interference systems has drawn an increasing attention, due to its admiring performance which is very close to the theory limit. This paper focuses on a LDPC encoded slow frequency hopping (SFH) communication system with partial-band interference. Firstly, a modified soft- decision algorithm based on the utilization of interference information is proposed, and its performance is compared with some other soft-decision methods. Secondly, with numerical simulation, the influence of code rate, code length and the number of symbols per hops on the performance of the system with partial band noise interference is illustrated and examined in detail. Considering the great influence of hops per symbol on the performance, interleaver should be used and its influence on the performance is further examined by simulation. Finally, some constructive advises for the design of LDPC coded SFH system are given. Simulation results show that, with a reasonable design, the SFH system with LDPC code could achieve a desirable performance.
基金financially supported by the National Natural Science Foundation of China(Nos.22179022,22109023 and 22179021)the Industry-University-Research Joint Innovation Project of Fujian Province(No.2021H6006)+3 种基金the Award Program for Fujian Minjiang Scholar Professorshipthe Talent Fund Program of Fujian Normal Universitythe support from the NSERC Discovery Grant(NSERC RGPIN-2020-04463)McGill Start-Up Grant.
文摘The increasing demand for new energy sources has promoted the improvement of the energy storage capacity of lithium-ion batteries(LIBs)that urged the development of higher energy density cathode materials.The enhancement of the classical cathode in the last 30 years has reached a bottleneck,and then the discovery of the lithium-excess disordered materials has greatly expanded the research space of the cathode materials.Compared with the conventional layered oxides,the lithium-excess disordered rock-salt oxides(LEDRXs)with a more stable structure has higher extractable Li^(+)content,even though the inactive high-valent transition metals(TMs)were needed to compensate for the excess Li,which would reduce the total TM redox content.In addition,oxygen redox provides additional electron capacity for the materials,which also causes O loss and results in the subsequent poor cycle performance.Herein,a series of studies about LEDRXs and their targeted modification measures are summarized,including the prospect of the materials,in order to provide ideas for the design of highperformance LEDRXs.Finally,the new discoveries and outlook on future research directions of LEDRX cathode materials for LIBs with higher energy density are given.
基金National Natural Science Foundation of China,Grant/Award Numbers:22109023,22179022,22209027Industry-University-Research Joint Innovation Project of Fujian Province,Grant/Award Number:2021H6006+2 种基金FuXiaQuan National Independent Innovation Demonstration Zone Collaborative Innovation Platform,Grant/Award Number:2022-P-027Youth Innovation Fund of Fujian Province,Grant/Award Numbers:2021J05043,2022J05046Science and Technology。
文摘The indiscriminate utilization of nondegradable polyethylene terephthalate(PET)-based products has triggered serious environmental pollution that has to be resolved vigorously.A simple synthesis of N-doped carbon nanotubes from recycled PET(NCNTs_(r-PET))was developed by a nitric acid-assisted hydrothermal method.Experimental results and theoretical calculations show that the intrinsic defects in CNTs_(r-PET)would induce N-doping by NH_(3)generated from nitric acid during the hydrothermal process,thus producing the NCNTs_(r-PET).The life cycle assessment proves that the developed method for N-doped CNTs using r-PET as the carbon source is more environmentally friendly than the conventional chemical vapor deposition using acetylene as the carbon source.As a typical application,the NCNTs_(r-PET)delivered an impressive sodium storage capacity with an ultralong lifespan.This work not only provides a new route to upcycling waste plastics into valuable carbonaceous materials in an ecofriendly manner,but also reveals a basic understanding of the N-doping mechanism in carbonaceous materials.
基金the National Natural Science Foundation of China,Grant/Award Numbers:22179022,22109023,22209027,22209097the Industry-University-Research Joint Innovation Project of Fujian Province,Grant/Award Number:2021H6006+2 种基金the FuXiaQuan National Independent Innovation Demonstration Zone Collaborative Innovation Platform,Grant/Award Number:2022-P-027the Youth Innovation Fund of Fujian Province,Grant/Award Numbers:2021J05043,2022J05046the Award Program for Fujian Minjiang Scholar Professorship,the Talent Fund Program of Fujian Normal University and Shenzhen Science and Technology Program,Grant/Award Numbers:JCYJ20220530142806015,JCYJ20220818101008018。
文摘Electrospun nanofibers(NFs)have shown excellent properties including high porosity,abundant active sites,controllable diameter,uniform and designable structure,high mechanical strength,and superior resistance to external destruction,which are ideal nanoreactors for in situ characterizations.Among various techniques,in situ transmission electron microscopy(TEM)has enabled operando observation at the atomic level due to its high temporal and spatial resolution combined with excellent sensitivity,which is of great importance for rational materials design and performance improvement.In this review,the basic knowledge of in situ TEM techniques and the advantages of electrospun nanoreactors for in situ TEM characterization are first introduced.The recent development in electrospun nanoreactors for studying the physical properties,structural evolution,phase transition,and formation mechanisms of materials using in situ TEM is then summarized.The electrochemical behaviors of carbon nanofibers(CNFs),metal/metal oxide NFs,and solidelectrolyte interphase for different rechargeable batteries are highlighted.Finally,challenges faced by electrospun nanoreactors for in situ TEM characterization are discussed and potential solutions are proposed to advance this field.
文摘As a promising energy storage device,sodium-ion batteries(SIBs)have received continuous attention due to their low-cost and environmental friendliness.However,the sluggish kinetics of Na ion usually makes SIBs hard to realize desirable electrochemical performance when compared to lithium-ion batteries(LIBs).The key to addressing this issue is to build up nanostructured materials which enable fast Na-ion insertion/extraction.One-dimensional(1D)nanocarbons have been considered as both the anode and the matrix to support active materials for SIB electrodes owing to their high electronic conductivity and excellent mechanical property.Because of their large surface areas and short ion/electron difusion path,the synthesized electrodes can show good rate performance and cyclic stability during the charge/discharge processes.Electrospinning is a simple synthetic technology,featuring inexpensiveness,easy operation and scalable production,and has been largely used to fabricate 1D nanostructured composites.In this review,we frst give a simple description of the electrospinning principle and its capability to construct desired nanostructures with diferent compositions.Then,we discuss recent developments of carbon-based hybrids with desired structural and compositional characteristics as the electrodes by electrospinning engineering for SIBs.Finally,we identify future research directions to realize more breakthroughs on electrospun electrodes for SIBs.
基金supported in part by CEMEE State Key Laboratory Fund(No.2020Z0207B)in part by the National Key Scientific Instrument and Equipment Development Project,China(No.61827801)+1 种基金in part by the State Key Laboratory of Integrated Services Networks Fund,China(No.ISN22-11)in part by the Fundamental Research Funds for the Central Universities,China(Nos.NS2020026 and NS2020063)。
文摘A real-time ray-based hardware emulator for Unmanned Aerial Vehicle(UAV) communication channels which suits for the Three-Dimensional(3D) dynamic scenarios and considers the movements of both terminals is developed in this paper. The time-variant channel parameters, i.e.,ray delay, ray gain, and ray Doppler frequency are precalculated in the host by using the Ray Tracing(RT) method. Meanwhile, RT simulation dramatically increases the number of valid rays. To address the problem of resource limitation and huge computational burden in the implementation,an efficient ray coefficients generation method based on iteration is proposed and implemented.With the advantages of low cost and high flexibility, a Software Defined Radio(SDR) hardware platform is used to emulate the ray-based UAV channels by utilizing the compact architecture including the Time-Division(TD) scheme and Tapped-Delay Line(TDL) for channel convolution.Finally, hardware measurement results demonstrate that the properties of emulated channel, i.e.,Power Delay Profile(PDP) and Doppler Power Spectrum Density(DPSD) consist with the simulated ones, which verifies the correctness of hardware implementation. The proposed channel emulator provides an efficient way for optimization, verification, and evaluation of UAV communication systems.