Wind power is a kind of important green energy.Thus,wind turbines have been widely utilized around the world.Wind turbines are composed of many important components.Among these components,the failure rate of the trans...Wind power is a kind of important green energy.Thus,wind turbines have been widely utilized around the world.Wind turbines are composed of many important components.Among these components,the failure rate of the transmission system is relatively high in wind turbines.It is because the components are subjected to aerodynamic loads for a long time.In addition,its inertial load will result in fatigue fracture,wear and other problems.In this situation,wind turbines have to be repaired at a higher cost.Moreover,the traditional reliability methods are difficult to deal with the above challenges when performing the reliability analysis of the transmission system of wind turbines.To solve this problem,a stress-strength interference model based on performance degradation is introduced.Based on considering the strength degradation of each component,the improved Monte Carlomethod simulation based on the Back Propagation neural network is used to obtain the curve of system reliability over time.Finally,the Miner linear cumulative damage theory and the Carten-Dolan cumulative damage theory method are used to calculate the cumulative damage and fatigue life of the gear transmission system.展开更多
The authors regret that the printed version of the above article contained an error reference.We hope to correct it here.[14]B.J.M.Christophe Legein,Franck Fayon,Angew.Chem.Int.Ed.,132(2020)19409–19415.
Quantum light sources are the core resources for photonics-based quantum information processing.We investigate the spectral engineering of photon triplets generated by third-order spontaneous parametric down-conversio...Quantum light sources are the core resources for photonics-based quantum information processing.We investigate the spectral engineering of photon triplets generated by third-order spontaneous parametric down-conversion in micro/nanofiber.The phase mismatching at one-third pump frequency gives rise to non-degenerate photon triplets,the joint spectral intensity of which has an elliptical locus with a fixed eccentricity of√6/3.Therefore,we propose a frequency-division scheme to separate non-degenerate photon triplets into three channels with high heralding efficiency for the first time.Choosing an appropriate pump wavelength can compensate for the fabrication errors of micro/nanofiber and also generate narrowband,non-degenerate photon triplet sources with a high signal-to-noise ratio.Furthermore,the long-period micro/nanofiber grating introduces a new controllable degree of freedom to tailor phase matching,resulting from the periodic oscillation of dispersion.In this scheme,the wavelength of photon triplets can be flexibly tuned using quasi-phase matching.We study the generation of photon triplets from this novel perspective of spectrum engineering,and we believe that this work will accelerate the practical implementation of photon triplets in quantum information processing.展开更多
Concentrating solar thermal power system can provide low carbon,renewable energy resources in countries or regions with strong solar irradiation.For this kind of power plant which is likely to be located in the arid a...Concentrating solar thermal power system can provide low carbon,renewable energy resources in countries or regions with strong solar irradiation.For this kind of power plant which is likely to be located in the arid area,natural draft dry cooling tower is a promising choice.To develop the experimental studies on small cooling tower,a 20 m high natural draft dry cooling tower with fully instrumented measurement system was established by the Queensland Geothermal Energy Centre of Excellence.The performance of this cooling tower was measured with the constant heat input of 600 kW and 840 kW and with ambient temperature ranging from 20 ℃ to 32 ℃.The cooling tower numerical model was refined and validated with the experimental data.The model of 1 MW concentrating solar thermal supercritical CO2 power cycle was developed and integrated with the cooling tower model.The influences of changing ambient temperature and the performance of the cooling tower on efficiency of the power system were simulated.The differences of the mechanism of the ambient temperature effect on Rankine cycle and supercritical CO2 Brayton cycle were analysed and discussed.展开更多
Conductive polymers as one of the candidate materials with pseudocapacitor behavior have inspired wide attentions,because of their high conductivity,fexibility,low cost and excellent processability.However,the intrins...Conductive polymers as one of the candidate materials with pseudocapacitor behavior have inspired wide attentions,because of their high conductivity,fexibility,low cost and excellent processability.However,the intrinsically poor cycling stability induced by the volume change over the doping/dedoping redox process limits their practical applications.Herein,we report the exploration of electrodes with robust cycling capacity for supercapacitors(SCs),which are rationally designed by coating conductive poly(3,4-ethylenedioxythiophene)(PEDOT)around free-standing SiC nanowires using an all-dry oxidative chemical vaper deposition(oCVD)method.The as-constructed SiC@PEDOT nanowire architecture enables a specific capacitance of 26.53 m F/cm^(2)at 0.2 m A/cm^(2),which is~370%to that of SiC nanowire counterpart(7.04 m F/cm^(2)).Moreover,their aqueous-based SCs exhibit robust cycling stability with104%capacity retention after 10000 cycles,which is among the highest values achieved for PEDOTbased SCs.展开更多
Contrary to the other multi-carrier modulation systems, the coherent optical orthogonal frequency division multiplexing communication system with an offset quadrature amplitude modulation (CO-OFDM-OQAM) possesses inhe...Contrary to the other multi-carrier modulation systems, the coherent optical orthogonal frequency division multiplexing communication system with an offset quadrature amplitude modulation (CO-OFDM-OQAM) possesses inherent imaginary interference (IMI). This has an important impact on the channel estimation process. Currently, a variety of frequency-domain channel estimation methods have been proposed. However, there are various problems that still exist. For instance, in order to reduce the influence of IMI, it is necessary to insert more guard intervals between the training sequence and the payload, leading to the occupation of excessive spectrum resources. In order to address this problem, this work designs a high spectral efficient frequency-domain channel estimation method for the polarization-division-multiplexing CO-OFDM-OQAM systems. First, the working principle of the proposed method is described in detail. Then, its spectral efficiency, power peak-to-average ratio, and channel estimation performance are studied based on simulations. The simulation results show that the proposed method improves the spectral efficiency without worsening the power peak-to-average ratio. The channel estimation capability of this method is verified in three scenarios of long-distance transmissions, including back-to-back, 100 km, and 200 km transmissions. .展开更多
The shuttle effect induced by soluble lithium polysulfides(LiPSs)is known as one of the crucial issues that limit the practical applications of lithium-sulfur(Li-S)batteries.Herein,a titanium dioxide nanoparticle embe...The shuttle effect induced by soluble lithium polysulfides(LiPSs)is known as one of the crucial issues that limit the practical applications of lithium-sulfur(Li-S)batteries.Herein,a titanium dioxide nanoparticle embedded in nitrogen-doped porous carbon nanofiber(TiO_(2)@NCNF)composite is constructed via an interface-induced polymerization strategy to serve as an ideal sulfur host.Under the protection of the nanofiber walls,the uniformly dispersed TiO_(2) nanocrystalline can act as capturing centers to constantly immobilize LiPSs towards durable sulfur chemistry.Besides,the mesoporous microstructure in the fibrous framework endows the TiO_(2)@NCNF host with strong physical reservation for sulfur and LiPSs,sufficient pathways for electron/ion transfer,and excellent endurance for volume change.As expected,the sulfur-loaded TiO_(2)@NCNF composite electrode presents a fabulous rate performance and long cycle lifespan(capacity fading rate of 0.062%per cycle over 500 cycles)at 2.0 C.Furthermore,the assembled Li-S batteries harvest superb areal capacity and cycling stability even under high sulfur loading and lean electrolyte conditions.展开更多
Labor scarcity requires double-season rice to be planted by direct seeding as an alternative to transplanting. Only ultrashort-duration varieties can be used in direct-seeded, double-season rice(DSD) in central China ...Labor scarcity requires double-season rice to be planted by direct seeding as an alternative to transplanting. Only ultrashort-duration varieties can be used in direct-seeded, double-season rice(DSD) in central China where thermal time is limited. Whether ultrashort-duration varieties grown in DSD can be as productive and efficient in nitrogen(N) use as transplanted double-season rice(TPD) remains unclear. Field experiments were conducted in Hubei province, central China with two establishment methods(DSD,TPD) and three N rates in the early and late seasons of 2017 and 2018. Nitrogen treatments included zero-N control(N0), total N rate of 60 kg N ha;with equal splits at basal, midtillering, and panicle initiation(N1), and weekly N application at 15 kg ha;from seeding/transplanting to heading(N2). Both early-and late-season rice under DSD matured within 95 days, on average 9 days shorter than rice under TPD. The grain yield of DSD was comparable to or higher than that of TDP in both seasons, although the daily yield was significantly higher under DSD than under TDP. Before heading, DSD had higher leaf area,stem number, intercepted radiation, and radiation use efficiency than TPD, which compensated for the negative effect of short growth duration on biomass production. Total dry weight and harvest index under DSD were comparable to or higher than those under TDP. In general, the recovery efficiency of fertilizer-N under DSD was higher than that under TPD, but the reverse was true for physiological N use efficiency. Thus, there was no significant difference in agronomic N use efficiency between DSD and TPD. These results suggested that DSD with ultrashort-duration varieties is a promising alternative to TPD in central China for maintaining high grain yield and N fertilizer use efficiency with less labor input.展开更多
Carbohydrates,which are mostly present in sugar,starch,and fiber,are one of the main ingredients of food and the primary source of energy in the human diet.Among these three main sources,starch stands out as one of th...Carbohydrates,which are mostly present in sugar,starch,and fiber,are one of the main ingredients of food and the primary source of energy in the human diet.Among these three main sources,starch stands out as one of the most abundant reserves of carbohydrates.Investigating starch would not only enhance our understanding of the functionality of starch in the human body but also aid in the design of novel starch-based dietary foods.The present review first provides a state-of-the-art understanding of the various classifications of dietary starches,including rapidly digesting starch(RDS),slowly digesting starch(SDS),and resistant starch(RS).Moreover,both the in vivo and in vitro determination methods of the digestibility of starch-based dietary foods are discussed.Based on the current understanding,present research strategies to design novel starch-based dietary foods through either the direct addition of modified starch or the alteration of processing conditions are highlighted.Furthermore,certain perspectives related to the future research directions of starch-based foods are also included.展开更多
This paper investigates a wireless system with multi-Unmanned Aerial Vehicles(UAVs)for improving the overall throughput.In contrast to previous studies that optimize the locations of UAVs and channel assignment separa...This paper investigates a wireless system with multi-Unmanned Aerial Vehicles(UAVs)for improving the overall throughput.In contrast to previous studies that optimize the locations of UAVs and channel assignment separately,this paper considers the two issues jointly by exploiting Partially Overlapped Channels(POCs).The optimization problem of maximizing network throughput is formulated as a non-convex and non-linear problem.In order to find a practical solution,the problem is decomposed into two subproblems,which are iteratively optimized.First,the optimal locations of UAVs are determined under a fixed channel assignment scheme by solving the mixed-integer second-order cone problem.Second,an efficient POC allocation scheme is determined via the proposed channel assignment algorithm.Simulation results show that the proposed approach not only significantly improves system throughput and service reliability compared with the cases in which only orthogonal channels and stationary UAVs are considered,but also achieves similar performance using the exhaustive search algorithm with lower time complexity.展开更多
Due to the advantages of aluminum in abundance in the earth’s crust and safety,how to exploit these advantages to develop high-performance rechargeable aluminum batteries to replace traditional batteries has become a...Due to the advantages of aluminum in abundance in the earth’s crust and safety,how to exploit these advantages to develop high-performance rechargeable aluminum batteries to replace traditional batteries has become an urgent issue.The key to solving this problem is to find suitable materials as cathode for aluminum batteries.Here,we propose a strategy in which Ti_(3)C_(2)(MXene)is used as a loaded structure for the organic anthraquinone derivative Benzo[1,2-b:4,5-b’]dithiophene-4,8-dione(BDTO).This strategy enables the self-stacking of monolayer MXene into a layered structure while embedding organics into it.The unique structure enables efficient and reversible intercalation/deintercalation of Al^(3+).At the same time,it exhibits excellent electrochemical performance,and its reversible capacity reaches229.8 mAh g^(-1).Moreover,it can still maintain a capacity of 134.9 mAh g^(-1)after 500 cycles.In addition.compared with BDTO,the rate performance of MXene@BDTO has also been greatly improved.Meanwhile,this unique layered structure also brings better electro nic co nductivity and ionic diffusion coefficient.We also demonstrate that the battery mechanism is a reaction between three C=O and one Al^(3+) through multiple characterization methods and density functional calculations(DFT).The advantages of MXene@BDTO provide a better research basis for the study of rechargeable Aluminum-Organic batteries,and provide a good idea to explore the development of Aluminum-Organic batteries.展开更多
Aiming at the needs of different lighting applications, combined with the characteristics of LED dimming and color control, and using MSP430 digital control technology, a novel LED intelligent dimming and color contro...Aiming at the needs of different lighting applications, combined with the characteristics of LED dimming and color control, and using MSP430 digital control technology, a novel LED intelligent dimming and color control system was designed. The system integrated Bluetooth remote, human infrared sensor, voice/gesture control and other control modes, which could achieve LED multi-mode dimming and color intelligent control. System hardware and software were designed to develop a prototype to experimental verification. The designed method proposes new ideas and information for LED control.展开更多
Vehicle wading is a complex fluid-structure interaction(FSI) problem and has attracted great attention recently from the automotive industry, especially for electric vehicles. As a meshless Lagrangian particle method,...Vehicle wading is a complex fluid-structure interaction(FSI) problem and has attracted great attention recently from the automotive industry, especially for electric vehicles. As a meshless Lagrangian particle method, smoothed particle hydrodynamics(SPH) is one of the most suitable candidates for simulations of vehicle wading due to its inherent advantages in modeling free surface flows, splash, and moving interfaces. Nevertheless, the inevitable neighbor query for the nearest adjacent particles among the support domain leads to considerable computational cost and thus limits its application in 3D large-scale simulations. In this work, a GPU-based SPH method is developed with an adaptive spatial sort technology for simulations of vehicle wading. In addition, a fast, easy-to-implement particle generator is presented for isotropic initialization of the complex vehicle geometry with optimal interpolation properties. A comparative study of vehicle wading on a puddle between the GPUbased SPH with two pieces of commercial software is used to verify the capability of the GPU-based SPH method in terms of convergence analysis, kinematic characteristics, and computing performance. Finally, different conditions of vehicle speeds, water depths, and puddle widths are tested to investigate the vehicle wading numerically. The results demonstrate that the adaptive spatial sort technology can significantly improve the computing performance of the GPU-based SPH method and meanwhile promotes the GPU-based SPH method to be a competitive tool for the study of 3D large-scale FSI problems including vehicle wading. Some helpful findings of the critical vehicle speed, water depth as well as boundary wall effect are also reported in this work.展开更多
基金supports from the National Natural Science Foundation of China (Grant Nos.52075081 and 52175130)the Innovation Training Programme for Chengdu university Students (CDUCX2022047)The Key Laboratory of Pattern Recognition and Intelligent Information Processing,Institutions of Higher Education of Sichuan Province,Chengdu University,China (MSSB-2022-08)are gratefully acknowledged.
文摘Wind power is a kind of important green energy.Thus,wind turbines have been widely utilized around the world.Wind turbines are composed of many important components.Among these components,the failure rate of the transmission system is relatively high in wind turbines.It is because the components are subjected to aerodynamic loads for a long time.In addition,its inertial load will result in fatigue fracture,wear and other problems.In this situation,wind turbines have to be repaired at a higher cost.Moreover,the traditional reliability methods are difficult to deal with the above challenges when performing the reliability analysis of the transmission system of wind turbines.To solve this problem,a stress-strength interference model based on performance degradation is introduced.Based on considering the strength degradation of each component,the improved Monte Carlomethod simulation based on the Back Propagation neural network is used to obtain the curve of system reliability over time.Finally,the Miner linear cumulative damage theory and the Carten-Dolan cumulative damage theory method are used to calculate the cumulative damage and fatigue life of the gear transmission system.
文摘The authors regret that the printed version of the above article contained an error reference.We hope to correct it here.[14]B.J.M.Christophe Legein,Franck Fayon,Angew.Chem.Int.Ed.,132(2020)19409–19415.
基金Project supported by the National Natural Science Foundation of China(Grant No.61605249)the Science and Technology Key Project of Henan Province of China(Grant Nos.182102210577 and 232102211086).
文摘Quantum light sources are the core resources for photonics-based quantum information processing.We investigate the spectral engineering of photon triplets generated by third-order spontaneous parametric down-conversion in micro/nanofiber.The phase mismatching at one-third pump frequency gives rise to non-degenerate photon triplets,the joint spectral intensity of which has an elliptical locus with a fixed eccentricity of√6/3.Therefore,we propose a frequency-division scheme to separate non-degenerate photon triplets into three channels with high heralding efficiency for the first time.Choosing an appropriate pump wavelength can compensate for the fabrication errors of micro/nanofiber and also generate narrowband,non-degenerate photon triplet sources with a high signal-to-noise ratio.Furthermore,the long-period micro/nanofiber grating introduces a new controllable degree of freedom to tailor phase matching,resulting from the periodic oscillation of dispersion.In this scheme,the wavelength of photon triplets can be flexibly tuned using quasi-phase matching.We study the generation of photon triplets from this novel perspective of spectrum engineering,and we believe that this work will accelerate the practical implementation of photon triplets in quantum information processing.
文摘Concentrating solar thermal power system can provide low carbon,renewable energy resources in countries or regions with strong solar irradiation.For this kind of power plant which is likely to be located in the arid area,natural draft dry cooling tower is a promising choice.To develop the experimental studies on small cooling tower,a 20 m high natural draft dry cooling tower with fully instrumented measurement system was established by the Queensland Geothermal Energy Centre of Excellence.The performance of this cooling tower was measured with the constant heat input of 600 kW and 840 kW and with ambient temperature ranging from 20 ℃ to 32 ℃.The cooling tower numerical model was refined and validated with the experimental data.The model of 1 MW concentrating solar thermal supercritical CO2 power cycle was developed and integrated with the cooling tower model.The influences of changing ambient temperature and the performance of the cooling tower on efficiency of the power system were simulated.The differences of the mechanism of the ambient temperature effect on Rankine cycle and supercritical CO2 Brayton cycle were analysed and discussed.
基金supported by the National Natural Science Foundation of China(NSFC,51972178 and 52072041)the Natural Science Foundation of Zhejiang Province(ZJNSF,LY20E030003)+2 种基金the Science and Technology Project of Jiangsu Province(BE2020111)the National Key R&D Project from Minister of Science and Technology in China(2016YFA0202701)the University of Chinese Academy of Sciences(Y8540XX2D2)。
文摘Conductive polymers as one of the candidate materials with pseudocapacitor behavior have inspired wide attentions,because of their high conductivity,fexibility,low cost and excellent processability.However,the intrinsically poor cycling stability induced by the volume change over the doping/dedoping redox process limits their practical applications.Herein,we report the exploration of electrodes with robust cycling capacity for supercapacitors(SCs),which are rationally designed by coating conductive poly(3,4-ethylenedioxythiophene)(PEDOT)around free-standing SiC nanowires using an all-dry oxidative chemical vaper deposition(oCVD)method.The as-constructed SiC@PEDOT nanowire architecture enables a specific capacitance of 26.53 m F/cm^(2)at 0.2 m A/cm^(2),which is~370%to that of SiC nanowire counterpart(7.04 m F/cm^(2)).Moreover,their aqueous-based SCs exhibit robust cycling stability with104%capacity retention after 10000 cycles,which is among the highest values achieved for PEDOTbased SCs.
文摘Contrary to the other multi-carrier modulation systems, the coherent optical orthogonal frequency division multiplexing communication system with an offset quadrature amplitude modulation (CO-OFDM-OQAM) possesses inherent imaginary interference (IMI). This has an important impact on the channel estimation process. Currently, a variety of frequency-domain channel estimation methods have been proposed. However, there are various problems that still exist. For instance, in order to reduce the influence of IMI, it is necessary to insert more guard intervals between the training sequence and the payload, leading to the occupation of excessive spectrum resources. In order to address this problem, this work designs a high spectral efficient frequency-domain channel estimation method for the polarization-division-multiplexing CO-OFDM-OQAM systems. First, the working principle of the proposed method is described in detail. Then, its spectral efficiency, power peak-to-average ratio, and channel estimation performance are studied based on simulations. The simulation results show that the proposed method improves the spectral efficiency without worsening the power peak-to-average ratio. The channel estimation capability of this method is verified in three scenarios of long-distance transmissions, including back-to-back, 100 km, and 200 km transmissions. .
基金support from the National Natural Science Foundation of China(No.22075042)Shanghai Rising-Star Program(No.22QA1400300)+3 种基金the Natural Science Foundation of Shanghai(No.20ZR1401400)the Shanghai Scientific and Technological Innovation Project(No.22520710100)the Innovation Program of Shanghai Municipal Education Commission(No.2021-01-07-00-03-E00108)the Fundamental Research Funds for the Central Universities,and the Donghua University(DHU)Distinguished Young Professor Program(No.LZB2021002).
文摘The shuttle effect induced by soluble lithium polysulfides(LiPSs)is known as one of the crucial issues that limit the practical applications of lithium-sulfur(Li-S)batteries.Herein,a titanium dioxide nanoparticle embedded in nitrogen-doped porous carbon nanofiber(TiO_(2)@NCNF)composite is constructed via an interface-induced polymerization strategy to serve as an ideal sulfur host.Under the protection of the nanofiber walls,the uniformly dispersed TiO_(2) nanocrystalline can act as capturing centers to constantly immobilize LiPSs towards durable sulfur chemistry.Besides,the mesoporous microstructure in the fibrous framework endows the TiO_(2)@NCNF host with strong physical reservation for sulfur and LiPSs,sufficient pathways for electron/ion transfer,and excellent endurance for volume change.As expected,the sulfur-loaded TiO_(2)@NCNF composite electrode presents a fabulous rate performance and long cycle lifespan(capacity fading rate of 0.062%per cycle over 500 cycles)at 2.0 C.Furthermore,the assembled Li-S batteries harvest superb areal capacity and cycling stability even under high sulfur loading and lean electrolyte conditions.
基金supported by the National Natural Science Foundation of China(21707055,21567008,21607064)Program of Qingjiang Excellent Young Talents,Jiangxi University of Science and Technology,Program of 5511 Talents in Scientific and Technological Innovation of Jiangxi Province(20165BCB18014)+3 种基金Academic and Technical Leaders of the Main Disciplines in Jiangxi Province(20172BCB22018)Jiangxi Province Natural Science Foundation(20161BAB203090,20181BAB213010,20181BAB203018)Young Science Foundation of Jiangxi Province Education Office(GJJ160671)Open Project Program of the State Key Laboratory of Photocatalysis on Energy and Environment(SKLPEE-KF201712)in Fuzhou University基金来源:国家自然科学基金(21707055,21567008,21607064)~~
基金supported by the National Natural Science Foundation of China(31971845,32061143038)the China Postdoctoral Science Foundation(2021 M691179)+3 种基金the China Agriculture Research System(CARS-01-20)the Program of Introducing Talents of Discipline to Universities in China(the 111 Project no.B14032)the Program for Changjiang Scholars and Innovative Research Team in University of China(IRT1247)a grant from the Bill and Melinda Gates Foundation(OPP51587)。
文摘Labor scarcity requires double-season rice to be planted by direct seeding as an alternative to transplanting. Only ultrashort-duration varieties can be used in direct-seeded, double-season rice(DSD) in central China where thermal time is limited. Whether ultrashort-duration varieties grown in DSD can be as productive and efficient in nitrogen(N) use as transplanted double-season rice(TPD) remains unclear. Field experiments were conducted in Hubei province, central China with two establishment methods(DSD,TPD) and three N rates in the early and late seasons of 2017 and 2018. Nitrogen treatments included zero-N control(N0), total N rate of 60 kg N ha;with equal splits at basal, midtillering, and panicle initiation(N1), and weekly N application at 15 kg ha;from seeding/transplanting to heading(N2). Both early-and late-season rice under DSD matured within 95 days, on average 9 days shorter than rice under TPD. The grain yield of DSD was comparable to or higher than that of TDP in both seasons, although the daily yield was significantly higher under DSD than under TDP. Before heading, DSD had higher leaf area,stem number, intercepted radiation, and radiation use efficiency than TPD, which compensated for the negative effect of short growth duration on biomass production. Total dry weight and harvest index under DSD were comparable to or higher than those under TDP. In general, the recovery efficiency of fertilizer-N under DSD was higher than that under TPD, but the reverse was true for physiological N use efficiency. Thus, there was no significant difference in agronomic N use efficiency between DSD and TPD. These results suggested that DSD with ultrashort-duration varieties is a promising alternative to TPD in central China for maintaining high grain yield and N fertilizer use efficiency with less labor input.
基金This work was financially supported by the National Natural Science Foundation of China(31701644 and 32072268)the Science&Technology Pillar Program of Jiangsu Province(BE2018304)the National First-Class Discipline Program of Food Science and Technology(JUFSTR20180203).
文摘Carbohydrates,which are mostly present in sugar,starch,and fiber,are one of the main ingredients of food and the primary source of energy in the human diet.Among these three main sources,starch stands out as one of the most abundant reserves of carbohydrates.Investigating starch would not only enhance our understanding of the functionality of starch in the human body but also aid in the design of novel starch-based dietary foods.The present review first provides a state-of-the-art understanding of the various classifications of dietary starches,including rapidly digesting starch(RDS),slowly digesting starch(SDS),and resistant starch(RS).Moreover,both the in vivo and in vitro determination methods of the digestibility of starch-based dietary foods are discussed.Based on the current understanding,present research strategies to design novel starch-based dietary foods through either the direct addition of modified starch or the alteration of processing conditions are highlighted.Furthermore,certain perspectives related to the future research directions of starch-based foods are also included.
基金Thanks to the National Natural Science Foundation of China under Grant No.61702387 for the support of the research in this paper.
文摘This paper investigates a wireless system with multi-Unmanned Aerial Vehicles(UAVs)for improving the overall throughput.In contrast to previous studies that optimize the locations of UAVs and channel assignment separately,this paper considers the two issues jointly by exploiting Partially Overlapped Channels(POCs).The optimization problem of maximizing network throughput is formulated as a non-convex and non-linear problem.In order to find a practical solution,the problem is decomposed into two subproblems,which are iteratively optimized.First,the optimal locations of UAVs are determined under a fixed channel assignment scheme by solving the mixed-integer second-order cone problem.Second,an efficient POC allocation scheme is determined via the proposed channel assignment algorithm.Simulation results show that the proposed approach not only significantly improves system throughput and service reliability compared with the cases in which only orthogonal channels and stationary UAVs are considered,but also achieves similar performance using the exhaustive search algorithm with lower time complexity.
基金financially supported by the National Natural Science Foundation of China(52102233 and 52102095)the Nature Science Foundation of Hebei Province(E2021201006)。
文摘Due to the advantages of aluminum in abundance in the earth’s crust and safety,how to exploit these advantages to develop high-performance rechargeable aluminum batteries to replace traditional batteries has become an urgent issue.The key to solving this problem is to find suitable materials as cathode for aluminum batteries.Here,we propose a strategy in which Ti_(3)C_(2)(MXene)is used as a loaded structure for the organic anthraquinone derivative Benzo[1,2-b:4,5-b’]dithiophene-4,8-dione(BDTO).This strategy enables the self-stacking of monolayer MXene into a layered structure while embedding organics into it.The unique structure enables efficient and reversible intercalation/deintercalation of Al^(3+).At the same time,it exhibits excellent electrochemical performance,and its reversible capacity reaches229.8 mAh g^(-1).Moreover,it can still maintain a capacity of 134.9 mAh g^(-1)after 500 cycles.In addition.compared with BDTO,the rate performance of MXene@BDTO has also been greatly improved.Meanwhile,this unique layered structure also brings better electro nic co nductivity and ionic diffusion coefficient.We also demonstrate that the battery mechanism is a reaction between three C=O and one Al^(3+) through multiple characterization methods and density functional calculations(DFT).The advantages of MXene@BDTO provide a better research basis for the study of rechargeable Aluminum-Organic batteries,and provide a good idea to explore the development of Aluminum-Organic batteries.
文摘Aiming at the needs of different lighting applications, combined with the characteristics of LED dimming and color control, and using MSP430 digital control technology, a novel LED intelligent dimming and color control system was designed. The system integrated Bluetooth remote, human infrared sensor, voice/gesture control and other control modes, which could achieve LED multi-mode dimming and color intelligent control. System hardware and software were designed to develop a prototype to experimental verification. The designed method proposes new ideas and information for LED control.
基金supported by the Laoshan Laboratory(Grant No.LSKJ202202000)National Natural Science Foundation of China(Grant Nos.12032002,and U22A20256)Natural Science Foundation of Beijing(Grant No.L212023)。
文摘Vehicle wading is a complex fluid-structure interaction(FSI) problem and has attracted great attention recently from the automotive industry, especially for electric vehicles. As a meshless Lagrangian particle method, smoothed particle hydrodynamics(SPH) is one of the most suitable candidates for simulations of vehicle wading due to its inherent advantages in modeling free surface flows, splash, and moving interfaces. Nevertheless, the inevitable neighbor query for the nearest adjacent particles among the support domain leads to considerable computational cost and thus limits its application in 3D large-scale simulations. In this work, a GPU-based SPH method is developed with an adaptive spatial sort technology for simulations of vehicle wading. In addition, a fast, easy-to-implement particle generator is presented for isotropic initialization of the complex vehicle geometry with optimal interpolation properties. A comparative study of vehicle wading on a puddle between the GPUbased SPH with two pieces of commercial software is used to verify the capability of the GPU-based SPH method in terms of convergence analysis, kinematic characteristics, and computing performance. Finally, different conditions of vehicle speeds, water depths, and puddle widths are tested to investigate the vehicle wading numerically. The results demonstrate that the adaptive spatial sort technology can significantly improve the computing performance of the GPU-based SPH method and meanwhile promotes the GPU-based SPH method to be a competitive tool for the study of 3D large-scale FSI problems including vehicle wading. Some helpful findings of the critical vehicle speed, water depth as well as boundary wall effect are also reported in this work.