The cyclic hydrogenation technology in a direct coal liquefaction process relies on the dissolved hydrogen of the solvent or oil participating in the hydrogenation reaction.Thus,a theoretical basis for process optimiz...The cyclic hydrogenation technology in a direct coal liquefaction process relies on the dissolved hydrogen of the solvent or oil participating in the hydrogenation reaction.Thus,a theoretical basis for process optimization and reactor design can be established by analyzing the solubility of hydrogen in liquefaction solvents.Experimental studies of hydrogen solubility in liquefaction solvents are challenging due to harsh reaction conditions and complex solvent compositions.In this study,the composition and content of liquefied solvents were analyzed.As model compounds,hexadecane,toluene,naphthalene,tetrahydronaphthalene,and phenanthrene were chosen to represent the liquefied solvents in chain alkanes and monocyclic,bicyclic,and tricyclic aromatic hydrocarbons.The solubility of hydrogen X(mol/mol)in pure solvent components and mixed solvents(alkanes and aromatics mixed in proportion to the chain alkanes+bicyclic aromatic hydrocarbons,bicyclic saturated aromatic hydrocarbons+bicyclic aromatic hydrocarbons,and bicyclic aromatic hydrocarbons+compounds containing het-eroatoms composed of mixed components)are determined using Aspen simulation at temperature and pressure conditions of 373–523 K and 2–10 MPa.The results demonstrated that at high temperatures and pressures,the solubility of hydrogen in the solvent increases with the increase in temperature and pressure,with the pressure having a greater impact.Further-more,the results revealed that hydrogen is more soluble in straight-chain alkanes than in other solvents,and the solubility of eicosanoids reaches a maximum of 0.296.The hydrogen solubility in aromatic ring compounds decreased gradually with an increase in the aromatic ring number.The influence of chain alkanes on the solubility of hydrogen predominates in a mixture of solvents with different mixing ratios of chain alkanes and aromatic hydrocarbons.The solubility of hydrogen in mixed aromatic solvents is less than that in the corresponding single solvents.Hydrogen is less soluble in solvent compounds containing heteroatoms than in compounds without heteroatoms.展开更多
Short-range ordering(SRO)is one of the most important structural features of high entropy alloys(HEAs).However,the chemical and structural analyses of SROs are very difficult due to their small size,complexed composit...Short-range ordering(SRO)is one of the most important structural features of high entropy alloys(HEAs).However,the chemical and structural analyses of SROs are very difficult due to their small size,complexed compositions,and varied locations.Transmission electron microscopy(TEM)as well as its aberration correction techniques are powerful for characterizing SROs in these compositionally complex alloys.In this short communication,we summarized recent progresses regarding characterization of SROs using TEM in the field of HEAs.By using advanced TEM techniques,not only the existence of SROs was confirmed,but also the effect of SROs on the deformation mechanism was clarified.Moreover,the perspective related to application of TEM techniques in HEAs are also discussed.展开更多
Objective： To detect the expression of heat shock protein 70 （HSP70） in human renal carcinoma tissues and cultured ACHN cells by using quantum dots-tagged fluorescence technology and its significance. Methods： Usi...Objective： To detect the expression of heat shock protein 70 （HSP70） in human renal carcinoma tissues and cultured ACHN cells by using quantum dots-tagged fluorescence technology and its significance. Methods： Using the fluorescence property of quantum dots, indirect immunofluorescence method and immunocytochemical method were used to detect the expression of HSP70 tagged by quantum dots in renal carcinoma tissues and ACHN cells cultured in vitro. Results： Confocal fluorescence microscopy showed that HSP70 were significantly expressed in renal carcinoma tissues and ACHN cells cultured in vitro characterized by homogeneous distribution of intensive salmon pink fluorescence. Compared with FITC tagging, quantum dots tagged fluorescence had good specificity and signal to background. There was no notable quenching after excitation by quantum dots for 30 rain. Conclusion： Quantum dots can be used to label subcellular proteins and have obvious advantages compared with the traditional fluorescence methods. The quantum dots-tagged fluorescence could be applied as a new method for clinical labeling detection.展开更多
As the development of Wireless Sensor Network (WSN), software testing for WSN-based applications be-comes more and more important. Simulation testing is an important approach to WSN-based software testing, and TOSSIM ...As the development of Wireless Sensor Network (WSN), software testing for WSN-based applications be-comes more and more important. Simulation testing is an important approach to WSN-based software testing, and TOSSIM is the most widely used simulation testing tool targeted at TinyOS which is the most popular operating system nowadays. However, simulation testing tools such as TOSSIM can not reveal program er-rors about communication detail or timing, and lack accurate power consumption model and even can not support power consumption estimation. In this paper, a hybrid testbed H-TOSSIM is proposed, which ex-tends TOSSIM with physical nodes. H-TOSSIM uses three physical nodes, of which, one shares the simu-lated environment with all virtual nodes to test the WSN program, and the other two bridge the real world and the simulated environment. H-TOSSIM combines the advantages of both the simulation in physical node and the simulation testing tools in WSN software testing. Through experiments, we show that H-TOSSIM really reveals program errors which the pure simulation testing can not capture, and can support power con-sumption estimation for large WSN with high accuracy and low hardware cost.展开更多
1.Introduction High entropy alloys(HEAs),arising from the incorporation of multiple principal elements[1,2],have garnered extensive atten-tion due to their great potential to be utilized under extreme con-ditions[3-5].
Producing ultrafine-grained(UFG)microstructures with enhanced thermal stability is an important yet challenging route to further improve mechanical properties of structural materials.Here,a high-performance bulk UFG c...Producing ultrafine-grained(UFG)microstructures with enhanced thermal stability is an important yet challenging route to further improve mechanical properties of structural materials.Here,a high-performance bulk UFG copper that can stabilize even at temperatures up to 750℃(∼0.75 T m,T m is the melting point)was fabricated by manipulating its recrystallization behavior via low alloying of Co.Addition of 1 wt.%–1.5 wt.%of Co can trigger quick and copious intragranular clustering of Co atoms,which offers high Zener pinning pressure and pins the grain boundaries(GBs)of freshly recrystallized ul-trafine grains.Due to the fact that the subsequent growth of the coherent Co-enriched nanoclusters was slow,sufficient particles adjacent to GBs remained to inhibit the migration of GBs,giving rise to the UFG microstructure with prominently high thermal stability.This work manifests that the strategy for pro-ducing UFGs with coherent precipitates can be applied in many alloy systems such as Fe-and Cu-based,which paves the pathway for designing advanced strain-hardenable UFGs with plain compositions.展开更多
Dual-ion batteries(DIBs)have attracted great attention due to their affordable prices,environmentalfriendliness,and high operating voltage.However,the conventional graphite anode in DIBs has draw-backs such as unsatis...Dual-ion batteries(DIBs)have attracted great attention due to their affordable prices,environmentalfriendliness,and high operating voltage.However,the conventional graphite anode in DIBs has draw-backs such as unsatisfactory capacity and worrying safety.MoS_(2)is considered to be a competitive anodematerial that exhibits large capacity due to its unique layered structure for cation insertion/extraction.Nevertheless,the sluggish reaction kinetics of MoS_(2)does not match the cathode side,which makes theconstructed full DIBs show poor rate ability.Here,a flower-like MoS_(2)/polyaniline composite electrode(MoS_(2)-PANI)where PANI was grown in situ between layers of MoS_(2)nanosheets was designed.In thisdesign,the inserted PANI can broaden the layer distance of MoS_(2)to facilitate cation diffusion and pre-vent the restacking of nanosheets.Furthermore,PANI is also expected to increase the conductivity andrelieve the volume changes during repeated charge/discharge cycles.Benefiting from that,the MoS_(2)-PANIelectrode delivered a reversible capacity of 561.91 mA h g^(-1) at 5 A g^(-1) in half-cell test.Moreover,whencoupled with a mildly expanded graphite(MEG)cathode,the obtained MEG//MoS_(2)-PANI DIB shows ex-cellent rate ability with a reversible discharge capacity of 86.62 mA h g^(-1) and a desirable energy densityof 308.83 W h kg-1 at 20 C.These results provide some inspiration for the design of high-rate DIBs.展开更多
1.Introduction Damping alloys are considered to be the most direct and effective approach to reducing unwanted vibration and noise in industrial applications.In particular,it is urgent to develop damping alloys that h...1.Introduction Damping alloys are considered to be the most direct and effective approach to reducing unwanted vibration and noise in industrial applications.In particular,it is urgent to develop damping alloys that have highdamping capacity(tanδ)as well as high strength,and a large operating temperature range to meet the demands of extreme working conditions,such as outer space.However,the application temperature of existing damping alloys is limited,which is one of the biggest challenges for developing highperformance damping alloys.For Fe-Mn binary alloys.展开更多
Tobacco is an important economic crop worldwide.Tobacco leaves contain a large number of natural products.Therefore,the analysis of tobacco composition is crucial for the control of tobacco safety and quality assessme...Tobacco is an important economic crop worldwide.Tobacco leaves contain a large number of natural products.Therefore,the analysis of tobacco composition is crucial for the control of tobacco safety and quality assessment.Microwave plasma torch desorption ionization mass spectrometry(MPT-MS) is an emerging ambient mass spectrometry(AMS) technique that can be used for rapid real-time analysis of s amples without pretreatment.Our work focuses on the chemical composition analysis of tobacco using MPT-MS,and 14 compounds were detected in green flue-cured tobacco leaves,while 30 compounds were detected in cured flue-cured tobacco leaves,which confirms that curing can enhance the flavor of cigarettes.Furthermore,we successfully in situ identified characteristic fragment ions of α/β-CBD(α/β-cembranoids),an important aroma compound in tobacco by MPT-MS.The results demonstrate the capability of MPT-MS for in situ analysis of tobacco components and its potential for evaluating tobacco quality.展开更多
Purpose:To provide an overview of global publications on artificial intelligence(AI)in thyroid-associated oph-thalmopathy(TAO)through bibliometric analysis.Methods:Publications related to AI in TAO from inception unti...Purpose:To provide an overview of global publications on artificial intelligence(AI)in thyroid-associated oph-thalmopathy(TAO)through bibliometric analysis.Methods:Publications related to AI in TAO from inception until April 2023 were retrieved from the Web of Science database.The trends of publications and citations,publishing performance,collaboration among countries and institutions,and the funding agencies,relevant research domains,leading journals,hotspots and their evolution were identified.Results:A total of 55 publications were included for analysis.The number of publications and citations continued to grow since 1998,with a significant acceleration of growth after 2020.China is the most productive country with the highest number of productive institutions,followed by the United States.European countries have the most extensive collaboration.The most relevant research domain was radiology,nuclear medicine&medical imaging.The European Journal of Radiology was one of the most productive journals,with the most influential articles published."Thyroid-associated ophthalmopathy"and"neural network"maintain hotspots during the entire period.Studies were more focused on clinical features during 1998 and 2016,clinical features and medical data during 2017 and 2020,and medical data and AI techniques during 2021 and 2023.Conclusions:This study summarized the global research status regarding AI in TAO in terms of trends,countries,institutions,research domains,journals,and key topics.AI has shown great potential in TAO.Sponsored by funding agencies such as NSFC,China has become the most productive country in the field of AI in TAO.Our findings help researchers better understand the development of this field and provide valuable clues for future research directions.展开更多
New energy sources such as solar energy and hydrogen energy have been applied to the Unmanned Aerial Vehicle(UAV), which could be formed as the hybrid power sources due to the requirement of miniaturization, lightweig...New energy sources such as solar energy and hydrogen energy have been applied to the Unmanned Aerial Vehicle(UAV), which could be formed as the hybrid power sources due to the requirement of miniaturization, lightweight, and environmental protection issue for UAV. Hybrid electrical propulsion technology has been used in UAV and it further enforces this trend for the evolution to the Hybrid-Powered System(HPS). In order to realize long endurance flight mission and improve the energy efficiency of UAV, many researching works are focused on the Energy Management Strategy(EMS) of the HPS with digital simulation, ground demonstration platforms and a few flight tests for the UAV in recent years. energy management strategy, in which off-line or on-line control algorithms acted as the core part, could optimize dynamic electrical power distribution further and directly affect the efficiency and fuel economy of hybrid-powered system onboard.In order to give the guideline for this emerging technology for UAV, this paper presents a review of the topic highlighting energy optimal management strategies of UAV. The characteristics of typical new energy sources applied in UAV are summarized firstly, and then the classification and analysis of the architecture for hybrid power systems in UAV are presented. In the context of new energy sources and configuration of energy system, a comprehensive comparison and analysis for the state of art of EMS are presented, and the various levels of complexity and accuracy of EMS are considered in terms of real time, computational burden and optimization performance based on the optimal control and operational modes of UAV. Finally, the tendency and challenges of energy management strategy applied to the UAV have been forecasted.展开更多
Arc fault detection is desperately required in Solid State Power Controllers（SSPC） in addition to their fundamental functions because arcs will provoke growing harm and threat to aircraft safety. Experimental study ...Arc fault detection is desperately required in Solid State Power Controllers（SSPC） in addition to their fundamental functions because arcs will provoke growing harm and threat to aircraft safety. Experimental study has been done to obtain the faulted current data. In order to improve the detection speed and accuracy, two fast arc fault detection methods have been proposed in this paper with the analysis of only half cycle data. Both Fast Fourier Transform（FFT） and Wavelet Packets Decomposition（WPD） have been adopted to distinguish arc fault currents from normal operation currents. Analysis results show that Alternating Current（AC） arcs can be effectively and accurately detected with the proposed half cycle data based methods. Moreover,experimental verification results have also been provided.展开更多
Distributed Electric Propulsion(DEP)aircraft use multiple electric motors to drive the propulsors,which gives potential benefits to aerodynamic-propulsion interaction.To investigate and quantify the aerodynamic-propul...Distributed Electric Propulsion(DEP)aircraft use multiple electric motors to drive the propulsors,which gives potential benefits to aerodynamic-propulsion interaction.To investigate and quantify the aerodynamic-propulsion interaction effect of the wing section,we built a DEP demonstrator with 24"high-lift"Electric Ducted Fans(EDFs)distributed along the wing’s trailing edge.This paper explores and compares the aero-propulsion coupling characteristics under various upstream speed,throttle,and EDF mounting surface deflection angles using a series of wind tunnel tests.We compare various lift-augmentation power conditions to the clean configuration without propulsion unit under the experiment condition of 15-25 m/s freestream flow and angles of attack from-4°to 16°.The comparison of computational results to the experimental results verifies the effectiveness of the computational fluid dynamic analysis method and the modeling method for the DEP configuration.The results show that the EDFs can produce significant lift increment and drag reduction simultaneously,which is accordant with the potential benefit of Boundary Layer Ingestion(BLI)at low airspeed.展开更多
A light-promoted metal-free protocol for the amination of imidazo[1,2-a]pyridines with N-aminopyridinium salt by the assistance of surfactants in water was reported,charactering mild and environmentally benign conditi...A light-promoted metal-free protocol for the amination of imidazo[1,2-a]pyridines with N-aminopyridinium salt by the assistance of surfactants in water was reported,charactering mild and environmentally benign conditions,as well as great functional group tolerance.Micelles with negatively charged polar surface and hydrophobic core formed from sodium dodecyl sulfate serve as an ideal medium for visible-light mediated radical reaction of cationic pyridine salt and imidazo[1,2-a]pyridine in aqueous phase.The electrostatic interaction between positively charged N-aminopyridinium and negatively charged surface of micelles is of great significance in this method.展开更多
Simple synthesis of multifunctional electrocatalysts with plentiful active sites from earth-abundant materials is especially fascinating. Here, N-doped defective carbon with trace Co （1.5 wt%） was prepared via a sca...Simple synthesis of multifunctional electrocatalysts with plentiful active sites from earth-abundant materials is especially fascinating. Here, N-doped defective carbon with trace Co （1.5 wt%） was prepared via a scalable one pot solid pyrolysis process. The sample exhibits efficient bifunctional OER/ORR activiW in alkaline, mainly ascribed to the unique micro-mesoporous structure （1-3 nm）, high population of graphitic-N doping （up to 49.0%）, abundant defects and the encapsulated Co nanoparticles with graphitized carbon. The according rechargeahle liquid Zn-air batteries showed excellent performance （maximum power density of 154.0 mWcm-2： energy density of 773Wh kg -1 at 5 mAcm 2 and charging-discharging cycling stability over 100 cycles）. As a proof-of-concept, the flexible, rechargeable all-solid-state Zn-air batteries were constructed, and displayed a maximum power density as high as 45.9 mW cm 2 among the top level of those reported previously.展开更多
In this paper, we shall study the uniqueness problems on meromorphic functions sharing nonzero finite value or fixed point. We have answered some questions posed by Dyavanal. Our results improve or generalize a few of...In this paper, we shall study the uniqueness problems on meromorphic functions sharing nonzero finite value or fixed point. We have answered some questions posed by Dyavanal. Our results improve or generalize a few of known results.展开更多
Control of surface structure at the atomic level can effectively tune catalytic properties of nanomaterials.Tuning surface strain is an effective strategy for enhancing catalytic activity;however,the correlation studi...Control of surface structure at the atomic level can effectively tune catalytic properties of nanomaterials.Tuning surface strain is an effective strategy for enhancing catalytic activity;however,the correlation studies between the surface strain with catalytic performance are scant because such mechanistic studies require the precise control of surface strain on catalysts.In this work,a simple strategy of precisely tuning compressive surface strain of atomic-layer Cu2O on Cu@Ag (AL-Cu2O/Cu@Ag) nanoparticles (NPs) is demonstrated.The AL-Cu2O is synthesized by structure evolution of Cu@Ag core-shell nanoparticles,and the precise thickness-control of AL-Cu2O is achieved by tuning the molar ratio of Cu/Ag of the starting material.Aberration-corrected high-resolution transmission electron microscopy (AC-HRTEM) and EELS elemental mapping characterization showed that the compressive surface strain of AL-Cu2O along the [111] and [200] directions can be precisely tuned from 6.5% to 1.6% and 6.6% to 4.7%,respectively,by changing the number of AL-Cu2O layer from 3 to 6.The as-prepared AL-Cu2O/Cu@Ag NPs exhibited excellent catalytic property in the synthesis of azobenzene from aniline,in which the strained 4-layers Cu2O (4.5% along the [111] direction,6.1% along the [200] direction) exhibits the best catalytic performance.This work may be beneficial for the design and surface engineering of catalysts toward specific applications.展开更多
The visible light-driven C2 or C3 amination of indoles without any additives was initiated via electron donor-acceptor (EDA) complex formed by indole and N-aminopyridinium salt.This method was compatible with a wide r...The visible light-driven C2 or C3 amination of indoles without any additives was initiated via electron donor-acceptor (EDA) complex formed by indole and N-aminopyridinium salt.This method was compatible with a wide range of substrates and could proceed smoothly without the addition of any photocatalysts,transition-metal catalysts,or bases.A variety of studies were carried out to examine the presence of EDA complex.展开更多
In recent years,haze has posed a serious threat to the global climate change,ecological balance and human health.In this study,the laboratory experiments and field observations were performed and a possible charging m...In recent years,haze has posed a serious threat to the global climate change,ecological balance and human health.In this study,the laboratory experiments and field observations were performed and a possible charging mechanism was proposed to investigate the space charge properties in haze events.The laboratory experiments showed that the charge polarity of primary aerosol is determined by species of combustion fuels while the magnitude is dependent on the combustion completeness.The field observations revealed that the space charge of atmosphere aerosol in haze events differs from that of fair weather and is closely related to PM2.5 concentration when Relative Humidity(RH)<60%,with 1 to 2 orders of magnitude less than the case when RH≥60%.The analysis of equivalent chargeto-mass ratio(ECTM)suggested that in haze events the space charge is governed by primary aerosol emitted by combustion of fossil fuel in a low relative humidity,whereas it is manipulated by the secondary chemical reaction of atmosphere aerosol in a high relative humidity.And we can identify the main pollutants in haze events according to the polarity of atmosphere aerosol and quickly take measures when RH<60%.Accordingly,the dusthaze of RH<80% can be divided into dry-dust-haze when RH<60%and wet-dust-haze when 60%≤RH<80%.Our study firstly elucidated the space charge properties of atmosphere aerosol in haze events and can provide a new perspective for the prevention and control of air pollution.展开更多
基金the financial support from the National Key Research and Development Program of China(2022YFB4101302-01)the National Natural Science Foundation of China(22178243)the science and technology innovation project of China Shenhua Coal to Liquid and Chemical Company Limited(MZYHG-22–02).
文摘The cyclic hydrogenation technology in a direct coal liquefaction process relies on the dissolved hydrogen of the solvent or oil participating in the hydrogenation reaction.Thus,a theoretical basis for process optimization and reactor design can be established by analyzing the solubility of hydrogen in liquefaction solvents.Experimental studies of hydrogen solubility in liquefaction solvents are challenging due to harsh reaction conditions and complex solvent compositions.In this study,the composition and content of liquefied solvents were analyzed.As model compounds,hexadecane,toluene,naphthalene,tetrahydronaphthalene,and phenanthrene were chosen to represent the liquefied solvents in chain alkanes and monocyclic,bicyclic,and tricyclic aromatic hydrocarbons.The solubility of hydrogen X(mol/mol)in pure solvent components and mixed solvents(alkanes and aromatics mixed in proportion to the chain alkanes+bicyclic aromatic hydrocarbons,bicyclic saturated aromatic hydrocarbons+bicyclic aromatic hydrocarbons,and bicyclic aromatic hydrocarbons+compounds containing het-eroatoms composed of mixed components)are determined using Aspen simulation at temperature and pressure conditions of 373–523 K and 2–10 MPa.The results demonstrated that at high temperatures and pressures,the solubility of hydrogen in the solvent increases with the increase in temperature and pressure,with the pressure having a greater impact.Further-more,the results revealed that hydrogen is more soluble in straight-chain alkanes than in other solvents,and the solubility of eicosanoids reaches a maximum of 0.296.The hydrogen solubility in aromatic ring compounds decreased gradually with an increase in the aromatic ring number.The influence of chain alkanes on the solubility of hydrogen predominates in a mixture of solvents with different mixing ratios of chain alkanes and aromatic hydrocarbons.The solubility of hydrogen in mixed aromatic solvents is less than that in the corresponding single solvents.Hydrogen is less soluble in solvent compounds containing heteroatoms than in compounds without heteroatoms.
基金financially supported by the National Natural Science Foundation of China(Nos.51971017,52271003,52071024,52001184,and 52101188)the National Science Fund for distinguished Young Scholars,China(No.52225103)+3 种基金the Funds for Creative Research Groups of China(No.51921001)the National Key Research and Development Program of China(No.2022YFB4602101)the Projects of International Cooperation and Exchanges NSFC(No.52061135207)the Fundamental Research Funds for the Central Universities,China(No.FRF-TP-22-130A1)。
文摘Short-range ordering(SRO)is one of the most important structural features of high entropy alloys(HEAs).However,the chemical and structural analyses of SROs are very difficult due to their small size,complexed compositions,and varied locations.Transmission electron microscopy(TEM)as well as its aberration correction techniques are powerful for characterizing SROs in these compositionally complex alloys.In this short communication,we summarized recent progresses regarding characterization of SROs using TEM in the field of HEAs.By using advanced TEM techniques,not only the existence of SROs was confirmed,but also the effect of SROs on the deformation mechanism was clarified.Moreover,the perspective related to application of TEM techniques in HEAs are also discussed.
文摘Objective： To detect the expression of heat shock protein 70 （HSP70） in human renal carcinoma tissues and cultured ACHN cells by using quantum dots-tagged fluorescence technology and its significance. Methods： Using the fluorescence property of quantum dots, indirect immunofluorescence method and immunocytochemical method were used to detect the expression of HSP70 tagged by quantum dots in renal carcinoma tissues and ACHN cells cultured in vitro. Results： Confocal fluorescence microscopy showed that HSP70 were significantly expressed in renal carcinoma tissues and ACHN cells cultured in vitro characterized by homogeneous distribution of intensive salmon pink fluorescence. Compared with FITC tagging, quantum dots tagged fluorescence had good specificity and signal to background. There was no notable quenching after excitation by quantum dots for 30 rain. Conclusion： Quantum dots can be used to label subcellular proteins and have obvious advantages compared with the traditional fluorescence methods. The quantum dots-tagged fluorescence could be applied as a new method for clinical labeling detection.
文摘As the development of Wireless Sensor Network (WSN), software testing for WSN-based applications be-comes more and more important. Simulation testing is an important approach to WSN-based software testing, and TOSSIM is the most widely used simulation testing tool targeted at TinyOS which is the most popular operating system nowadays. However, simulation testing tools such as TOSSIM can not reveal program er-rors about communication detail or timing, and lack accurate power consumption model and even can not support power consumption estimation. In this paper, a hybrid testbed H-TOSSIM is proposed, which ex-tends TOSSIM with physical nodes. H-TOSSIM uses three physical nodes, of which, one shares the simu-lated environment with all virtual nodes to test the WSN program, and the other two bridge the real world and the simulated environment. H-TOSSIM combines the advantages of both the simulation in physical node and the simulation testing tools in WSN software testing. Through experiments, we show that H-TOSSIM really reveals program errors which the pure simulation testing can not capture, and can support power con-sumption estimation for large WSN with high accuracy and low hardware cost.
基金National Natural Science Foundation of China(Nos.51971017,52271003,and 52071024)National Science Fund for Distinguished Young Scholars(No.52225103)+1 种基金Funds for Creative Research Groups of China(No.51921001)National Key Research and Development Program of China(No.2022YFB4602101).
文摘1.Introduction High entropy alloys(HEAs),arising from the incorporation of multiple principal elements[1,2],have garnered extensive atten-tion due to their great potential to be utilized under extreme con-ditions[3-5].
基金supported by the National Natural Science Foundation of China(Nos.52101120,52322102 and 51971018)the National Key Research and Development Program of China(No.2022YFB3705201).
文摘Producing ultrafine-grained(UFG)microstructures with enhanced thermal stability is an important yet challenging route to further improve mechanical properties of structural materials.Here,a high-performance bulk UFG copper that can stabilize even at temperatures up to 750℃(∼0.75 T m,T m is the melting point)was fabricated by manipulating its recrystallization behavior via low alloying of Co.Addition of 1 wt.%–1.5 wt.%of Co can trigger quick and copious intragranular clustering of Co atoms,which offers high Zener pinning pressure and pins the grain boundaries(GBs)of freshly recrystallized ul-trafine grains.Due to the fact that the subsequent growth of the coherent Co-enriched nanoclusters was slow,sufficient particles adjacent to GBs remained to inhibit the migration of GBs,giving rise to the UFG microstructure with prominently high thermal stability.This work manifests that the strategy for pro-ducing UFGs with coherent precipitates can be applied in many alloy systems such as Fe-and Cu-based,which paves the pathway for designing advanced strain-hardenable UFGs with plain compositions.
基金supported by the Natural Science Foundation of Shandong Province with Grant No.ZR2020QE048the National Natural Science Foundation of China with Grant No.21905304+1 种基金the State Key Laboratory of Heavy Oil Processing with Grant No.SKLHOP202101006the National Defense Science and Technology Innovation Special Zone Project No.22-05-CXZX-04-04-29.The authors also want to thank Shiyanjia Lab(www.shiyanjia.com)for the TEM test.
文摘Dual-ion batteries(DIBs)have attracted great attention due to their affordable prices,environmentalfriendliness,and high operating voltage.However,the conventional graphite anode in DIBs has draw-backs such as unsatisfactory capacity and worrying safety.MoS_(2)is considered to be a competitive anodematerial that exhibits large capacity due to its unique layered structure for cation insertion/extraction.Nevertheless,the sluggish reaction kinetics of MoS_(2)does not match the cathode side,which makes theconstructed full DIBs show poor rate ability.Here,a flower-like MoS_(2)/polyaniline composite electrode(MoS_(2)-PANI)where PANI was grown in situ between layers of MoS_(2)nanosheets was designed.In thisdesign,the inserted PANI can broaden the layer distance of MoS_(2)to facilitate cation diffusion and pre-vent the restacking of nanosheets.Furthermore,PANI is also expected to increase the conductivity andrelieve the volume changes during repeated charge/discharge cycles.Benefiting from that,the MoS_(2)-PANIelectrode delivered a reversible capacity of 561.91 mA h g^(-1) at 5 A g^(-1) in half-cell test.Moreover,whencoupled with a mildly expanded graphite(MEG)cathode,the obtained MEG//MoS_(2)-PANI DIB shows ex-cellent rate ability with a reversible discharge capacity of 86.62 mA h g^(-1) and a desirable energy densityof 308.83 W h kg-1 at 20 C.These results provide some inspiration for the design of high-rate DIBs.
基金supported by the National Natural Science Foundation of China(Nos.52071024,52225103,51971017,52271003,and 52101188)the Funds for Creative Research Groups of NSFC(No.51921001)+6 种基金Projects of International Cooperation and Exchanges of NSFC(Nos.51961160729 and 52061135207)National Key Research and Development Program of China(Nos.2022YFB3705201 and 2022YFB4602101)111 Project(No.BP0719004)Program for Changjiang Scholars and Innovative Research Team in University of China(IRT_14R05)the Fundamental Research Funds for the Central Universities of China:FRF-TP-22-005C2,FRF-TP-22-001C2Project funded by China Postdoctoral Science Foundation(2020M680009)by Key Laboratory of Construction Hydraulic Robots of Anhui Higher Education Institutes,Tongling University(Grant No.TLXYCHR-O-21YB02).
文摘1.Introduction Damping alloys are considered to be the most direct and effective approach to reducing unwanted vibration and noise in industrial applications.In particular,it is urgent to develop damping alloys that have highdamping capacity(tanδ)as well as high strength,and a large operating temperature range to meet the demands of extreme working conditions,such as outer space.However,the application temperature of existing damping alloys is limited,which is one of the biggest challenges for developing highperformance damping alloys.For Fe-Mn binary alloys.
基金supported by the National Natural Science Foundation of China(21927810)Science and Technology Program of Zhejiang Province(LGC21B050008)。
文摘Tobacco is an important economic crop worldwide.Tobacco leaves contain a large number of natural products.Therefore,the analysis of tobacco composition is crucial for the control of tobacco safety and quality assessment.Microwave plasma torch desorption ionization mass spectrometry(MPT-MS) is an emerging ambient mass spectrometry(AMS) technique that can be used for rapid real-time analysis of s amples without pretreatment.Our work focuses on the chemical composition analysis of tobacco using MPT-MS,and 14 compounds were detected in green flue-cured tobacco leaves,while 30 compounds were detected in cured flue-cured tobacco leaves,which confirms that curing can enhance the flavor of cigarettes.Furthermore,we successfully in situ identified characteristic fragment ions of α/β-CBD(α/β-cembranoids),an important aroma compound in tobacco by MPT-MS.The results demonstrate the capability of MPT-MS for in situ analysis of tobacco components and its potential for evaluating tobacco quality.
文摘Purpose:To provide an overview of global publications on artificial intelligence(AI)in thyroid-associated oph-thalmopathy(TAO)through bibliometric analysis.Methods:Publications related to AI in TAO from inception until April 2023 were retrieved from the Web of Science database.The trends of publications and citations,publishing performance,collaboration among countries and institutions,and the funding agencies,relevant research domains,leading journals,hotspots and their evolution were identified.Results:A total of 55 publications were included for analysis.The number of publications and citations continued to grow since 1998,with a significant acceleration of growth after 2020.China is the most productive country with the highest number of productive institutions,followed by the United States.European countries have the most extensive collaboration.The most relevant research domain was radiology,nuclear medicine&medical imaging.The European Journal of Radiology was one of the most productive journals,with the most influential articles published."Thyroid-associated ophthalmopathy"and"neural network"maintain hotspots during the entire period.Studies were more focused on clinical features during 1998 and 2016,clinical features and medical data during 2017 and 2020,and medical data and AI techniques during 2021 and 2023.Conclusions:This study summarized the global research status regarding AI in TAO in terms of trends,countries,institutions,research domains,journals,and key topics.AI has shown great potential in TAO.Sponsored by funding agencies such as NSFC,China has become the most productive country in the field of AI in TAO.Our findings help researchers better understand the development of this field and provide valuable clues for future research directions.
基金upported by the Open Innovative Fund of Xi’an Aisheng Technology Group Company of China (No. ASN-IF2015-0202)
文摘New energy sources such as solar energy and hydrogen energy have been applied to the Unmanned Aerial Vehicle(UAV), which could be formed as the hybrid power sources due to the requirement of miniaturization, lightweight, and environmental protection issue for UAV. Hybrid electrical propulsion technology has been used in UAV and it further enforces this trend for the evolution to the Hybrid-Powered System(HPS). In order to realize long endurance flight mission and improve the energy efficiency of UAV, many researching works are focused on the Energy Management Strategy(EMS) of the HPS with digital simulation, ground demonstration platforms and a few flight tests for the UAV in recent years. energy management strategy, in which off-line or on-line control algorithms acted as the core part, could optimize dynamic electrical power distribution further and directly affect the efficiency and fuel economy of hybrid-powered system onboard.In order to give the guideline for this emerging technology for UAV, this paper presents a review of the topic highlighting energy optimal management strategies of UAV. The characteristics of typical new energy sources applied in UAV are summarized firstly, and then the classification and analysis of the architecture for hybrid power systems in UAV are presented. In the context of new energy sources and configuration of energy system, a comprehensive comparison and analysis for the state of art of EMS are presented, and the various levels of complexity and accuracy of EMS are considered in terms of real time, computational burden and optimization performance based on the optimal control and operational modes of UAV. Finally, the tendency and challenges of energy management strategy applied to the UAV have been forecasted.
基金co-supported by the National Natural Science Foundation of China(Nos.51407144 and 51777169)the Aviation Research Funds(No.20164053029)+1 种基金the Fundamental Research Funds for the Central Universities(Nos.3102017ZY027 and 3102017GX08001)the Young Elite Scientist Sponsorship Program by CAST
文摘Arc fault detection is desperately required in Solid State Power Controllers（SSPC） in addition to their fundamental functions because arcs will provoke growing harm and threat to aircraft safety. Experimental study has been done to obtain the faulted current data. In order to improve the detection speed and accuracy, two fast arc fault detection methods have been proposed in this paper with the analysis of only half cycle data. Both Fast Fourier Transform（FFT） and Wavelet Packets Decomposition（WPD） have been adopted to distinguish arc fault currents from normal operation currents. Analysis results show that Alternating Current（AC） arcs can be effectively and accurately detected with the proposed half cycle data based methods. Moreover,experimental verification results have also been provided.
基金supported by the National Natural Science Foundation of China(No.51877178)。
文摘Distributed Electric Propulsion(DEP)aircraft use multiple electric motors to drive the propulsors,which gives potential benefits to aerodynamic-propulsion interaction.To investigate and quantify the aerodynamic-propulsion interaction effect of the wing section,we built a DEP demonstrator with 24"high-lift"Electric Ducted Fans(EDFs)distributed along the wing’s trailing edge.This paper explores and compares the aero-propulsion coupling characteristics under various upstream speed,throttle,and EDF mounting surface deflection angles using a series of wind tunnel tests.We compare various lift-augmentation power conditions to the clean configuration without propulsion unit under the experiment condition of 15-25 m/s freestream flow and angles of attack from-4°to 16°.The comparison of computational results to the experimental results verifies the effectiveness of the computational fluid dynamic analysis method and the modeling method for the DEP configuration.The results show that the EDFs can produce significant lift increment and drag reduction simultaneously,which is accordant with the potential benefit of Boundary Layer Ingestion(BLI)at low airspeed.
基金We thank the National Natural Science Foundation of China(Grant Nos.21901216 and 21871031)the Fund of Science and Technology Agency of Chengdu(2019-YF09-00049-SN)+1 种基金the Open Project Program of Irradiation Preservation Technology Key Laboratory of Sichuan Province,Sichuan Institute of Atomic Energy(No.FZBC2020002)the Sichuan Science and Technology Program(2020YFH0061,2020YJ0222,2021JDRC0018,2021YFS0092,2021YFSY0041,2021YFH0064).
文摘A light-promoted metal-free protocol for the amination of imidazo[1,2-a]pyridines with N-aminopyridinium salt by the assistance of surfactants in water was reported,charactering mild and environmentally benign conditions,as well as great functional group tolerance.Micelles with negatively charged polar surface and hydrophobic core formed from sodium dodecyl sulfate serve as an ideal medium for visible-light mediated radical reaction of cationic pyridine salt and imidazo[1,2-a]pyridine in aqueous phase.The electrostatic interaction between positively charged N-aminopyridinium and negatively charged surface of micelles is of great significance in this method.
基金support from the Research Project of National University of Defense Technology(ZK16-03-32)National University Student Innovation Programthe support form Research Foundation of Education Bureau of Hunan Province(16K102)
文摘Simple synthesis of multifunctional electrocatalysts with plentiful active sites from earth-abundant materials is especially fascinating. Here, N-doped defective carbon with trace Co （1.5 wt%） was prepared via a scalable one pot solid pyrolysis process. The sample exhibits efficient bifunctional OER/ORR activiW in alkaline, mainly ascribed to the unique micro-mesoporous structure （1-3 nm）, high population of graphitic-N doping （up to 49.0%）, abundant defects and the encapsulated Co nanoparticles with graphitized carbon. The according rechargeahle liquid Zn-air batteries showed excellent performance （maximum power density of 154.0 mWcm-2： energy density of 773Wh kg -1 at 5 mAcm 2 and charging-discharging cycling stability over 100 cycles）. As a proof-of-concept, the flexible, rechargeable all-solid-state Zn-air batteries were constructed, and displayed a maximum power density as high as 45.9 mW cm 2 among the top level of those reported previously.
基金Acknowledgements The author would like to thank the referees for their valuable suggestions. This work was partly supported by the National Natural Science Foundation of China （Grant No. 11171184） and Scientific Research Foundation of CAUC, China （Grant No. 2011QD10X）.
文摘In this paper, we shall study the uniqueness problems on meromorphic functions sharing nonzero finite value or fixed point. We have answered some questions posed by Dyavanal. Our results improve or generalize a few of known results.
基金the National Natural Science Foundation of China (Nos.51631001,21643003,51872030,51702016,and 51501010)Fundamental Research Funds for the Central Universities, Beijing Institute of Technology Research Fund Program for Young Scholars and ZDKT18-01 from State Key Laboratory of Explosion Science and Technology (Beijing Institute of Technology).
文摘Control of surface structure at the atomic level can effectively tune catalytic properties of nanomaterials.Tuning surface strain is an effective strategy for enhancing catalytic activity;however,the correlation studies between the surface strain with catalytic performance are scant because such mechanistic studies require the precise control of surface strain on catalysts.In this work,a simple strategy of precisely tuning compressive surface strain of atomic-layer Cu2O on Cu@Ag (AL-Cu2O/Cu@Ag) nanoparticles (NPs) is demonstrated.The AL-Cu2O is synthesized by structure evolution of Cu@Ag core-shell nanoparticles,and the precise thickness-control of AL-Cu2O is achieved by tuning the molar ratio of Cu/Ag of the starting material.Aberration-corrected high-resolution transmission electron microscopy (AC-HRTEM) and EELS elemental mapping characterization showed that the compressive surface strain of AL-Cu2O along the [111] and [200] directions can be precisely tuned from 6.5% to 1.6% and 6.6% to 4.7%,respectively,by changing the number of AL-Cu2O layer from 3 to 6.The as-prepared AL-Cu2O/Cu@Ag NPs exhibited excellent catalytic property in the synthesis of azobenzene from aniline,in which the strained 4-layers Cu2O (4.5% along the [111] direction,6.1% along the [200] direction) exhibits the best catalytic performance.This work may be beneficial for the design and surface engineering of catalysts toward specific applications.
基金financial support from the National Natural Science Foundation of China(Grant Nos.21901216 and 82074003,82174083)the Funds of Sichuan Science and Technology Program(23NSFSC0862,2021YFSY0041,2021YFH0064 and 2021ZHFP0032)+3 种基金the Opening subject under KF-202204 in the State Key Laboratory of Pharmaceutical Biotechnology,Nanjing University,China,the Fund of Science and Technology Agency of Chengdu(2019-YF09-00049-SN)the research project of the Administration of Traditional Chinese Medicine of Sichuan(2021MS110)the Open Project Program of Irradiation Preservation Technology Key Laboratory of Sichuan Province,Sichuan Institute of Atomic Energy(No.FZBC2020002)the Fundamental Research Funds for the Central Universities(2682020ZT85).
文摘The visible light-driven C2 or C3 amination of indoles without any additives was initiated via electron donor-acceptor (EDA) complex formed by indole and N-aminopyridinium salt.This method was compatible with a wide range of substrates and could proceed smoothly without the addition of any photocatalysts,transition-metal catalysts,or bases.A variety of studies were carried out to examine the presence of EDA complex.
基金supported by a grant from the National Natural Science Foundation of China(Nos.11490551)
文摘In recent years,haze has posed a serious threat to the global climate change,ecological balance and human health.In this study,the laboratory experiments and field observations were performed and a possible charging mechanism was proposed to investigate the space charge properties in haze events.The laboratory experiments showed that the charge polarity of primary aerosol is determined by species of combustion fuels while the magnitude is dependent on the combustion completeness.The field observations revealed that the space charge of atmosphere aerosol in haze events differs from that of fair weather and is closely related to PM2.5 concentration when Relative Humidity(RH)<60%,with 1 to 2 orders of magnitude less than the case when RH≥60%.The analysis of equivalent chargeto-mass ratio(ECTM)suggested that in haze events the space charge is governed by primary aerosol emitted by combustion of fossil fuel in a low relative humidity,whereas it is manipulated by the secondary chemical reaction of atmosphere aerosol in a high relative humidity.And we can identify the main pollutants in haze events according to the polarity of atmosphere aerosol and quickly take measures when RH<60%.Accordingly,the dusthaze of RH<80% can be divided into dry-dust-haze when RH<60%and wet-dust-haze when 60%≤RH<80%.Our study firstly elucidated the space charge properties of atmosphere aerosol in haze events and can provide a new perspective for the prevention and control of air pollution.
