Zinc ion batteries are considered as potential energy storage devices due to their advantages of low-cost,high-safety,and high theoretical capacity.However,dendrite growth and chemical corrosion occurring on Zn anode ...Zinc ion batteries are considered as potential energy storage devices due to their advantages of low-cost,high-safety,and high theoretical capacity.However,dendrite growth and chemical corrosion occurring on Zn anode limit their commercialization.These problems can be tackled through the optimization of the electrolyte.However,the screening of electrolyte additives using normal electrochemical methods is time-consuming and labor-intensive.Herein,a fast and simple method based on the digital holography is developed.It can realize the in situ monitoring of electrode/electrolyte interface and provide direct information concerning ion concentration evolution of the diffusion layer.It is effective and time-saving in estimating the homogeneity of the deposition layer and predicting the tendency of dendrite growth,thus able to value the applicability of electrolyte additives.The feasibility of this method is further validated by the forecast and evaluation of thioacetamide additive.Based on systematic characterization,it is proved that the introduction of thioacetamide can not only regulate the interficial ion flux to induce dendrite-free Zn deposition,but also construct adsorption molecule layers to inhibit side reactions of Zn anode.Being easy to operate,capable of in situ observation,and able to endure harsh conditions,digital holography method will be a promising approach for the interfacial investigation of other battery systems.展开更多
The creep characteristics of rock under high crustal stress are of important influence on the long‐term stability of deep rock engineering.To study the creep characteristics and engineering application of sandstone u...The creep characteristics of rock under high crustal stress are of important influence on the long‐term stability of deep rock engineering.To study the creep characteristics and engineering application of sandstone under high crustal stress,this study constructed nonlinear creep damage(NCD)constitutive mode based on the triaxial graded loading‒unloading creep test of sandstone in the Yuezhishan Tunnel.A numerical NCD constitutive model and a breakable lining(BL)model were developed based on FLAC3D and then applied to the stability analysis of the Yuezhishan Tunnel.Based on the creep test results of sandstone,a power function of creep rate and stress level was constructed,by which the long‐term strength was solved.The results show that the long‐term strength of the red sandstone based on the related function of the steady‐state creep rate and stress level is close to the measured stress value in engineering.The NCD model considering damage factors reflects the instantaneous and viscoelastic plasticity deformation characteristics of the red sandstone.The numerical NCD constitutive model and the BL model can reflect surrounding rock deformation characteristics and lining failure characteristics in practical engineering.The research results provide theoretical references for long‐term stability analysis of rock engineering and the deformation control of surrounding rock under high crustal stress.展开更多
Prognostics and Health Management(PHM),including monitoring,diagnosis,prognosis,and health management,occupies an increasingly important position in reducing costly breakdowns and avoiding catastrophic accidents in mo...Prognostics and Health Management(PHM),including monitoring,diagnosis,prognosis,and health management,occupies an increasingly important position in reducing costly breakdowns and avoiding catastrophic accidents in modern industry.With the development of artificial intelligence(AI),especially deep learning(DL)approaches,the application of AI-enabled methods to monitor,diagnose and predict potential equipment malfunctions has gone through tremendous progress with verified success in both academia and industry.However,there is still a gap to cover monitoring,diagnosis,and prognosis based on AI-enabled methods,simultaneously,and the importance of an open source community,including open source datasets and codes,has not been fully emphasized.To fill this gap,this paper provides a systematic overview of the current development,common technologies,open source datasets,codes,and challenges of AI-enabled PHM methods from three aspects of monitoring,diagnosis,and prognosis.展开更多
hypoxicischemic brain injury;however,the therapeutic efficacy of bone marrow-derived mesenchymal stem cells largely depends on the number of cells that are successfully transferred to the target.Magnet-targeted drug d...hypoxicischemic brain injury;however,the therapeutic efficacy of bone marrow-derived mesenchymal stem cells largely depends on the number of cells that are successfully transferred to the target.Magnet-targeted drug delivery systems can use a specific magnetic field to attract the drug to the target site,increasing the drug concentration.In this study,we found that the double-labeling using superparamagnetic iron oxide nanoparticle and poly-L-lysine(SPIO-PLL)of bone marrow-derived mesenchymal stem cells had no effect on cell survival but decreased cell proliferation 48 hours after labeling.Rat models of hypoxic-ischemic brain injury were established by ligating the left common carotid artery.One day after modeling,intraventricular and caudal vein injections of 1×105 SPIO-PLL-labeled bone marrow-derived mesenchymal stem cells were performed.Twenty-four hours after the intraventricular injection,magnets were fixed to the left side of the rats’heads for 2 hours.Intravoxel incoherent motion magnetic resonance imaging revealed that the perfusion fraction and the diffusion coefficient of rat brain tissue were significantly increased in rats treated with SPIO-PLL-labeled cells through intraventricular injection combined with magnetic guidance,compared with those treated with SPIO-PLL-labeled cells through intraventricular or tail vein injections without magnetic guidance.Hematoxylin-eosin and terminal deoxynucleotidyl transferase dUTP nick-end labeling(TUNEL)staining revealed that in rats treated with SPIO-PLL-labeled cells through intraventricular injection under magnetic guidance,cerebral edema was alleviated,and apoptosis was decreased.These findings suggest that targeted magnetic guidance can be used to improve the therapeutic efficacy of bone marrow-derived mesenchymal stem cell transplantation for hypoxic-ischemic brain injury.This study was approved by the Animal Care and Use Committee of The Second Hospital of Dalian Medical University,China(approval No.2016-060)on March 2,2016.展开更多
Zinc metal batteries have been considered as a promising candidate for next-generation batteries due to their high safety and low cost.However,their practical applications are severely hampered by the poor cyclability...Zinc metal batteries have been considered as a promising candidate for next-generation batteries due to their high safety and low cost.However,their practical applications are severely hampered by the poor cyclability that caused by the undesired dendrite growth of metallic Zn.Herein,Ti_(3)C_(2)T_(x) MXene was first used as electrolyte additive to facilitate the uniform Zn deposition by controlling the nucleation and growth process of Zn.Such MXene additives can not only be absorbed on Zn foil to induce uniform initial Zn deposition via providing abundant zincophilic-O groups and subsequently participate in the formation of robust solid-electrolyte interface film,but also accelerate ion transportation by reducing the Zn^(2+) concentration gradient at the electrode/electrolyte interface.Consequently,MXene-containing electrolyte realizes dendrite-free Zn plating/striping with high Coulombic efficiency(99.7%)and superior reversibility(stably up to 1180 cycles).When applied in full cell,the Zn-V_(2)O_(5)cell also delivers significantly improved cycling performances.This work provides a facile yet effective method for developing reversible zinc metal batteries.展开更多
Aqueous zinc-ion batteries(AZIBs)can be one of the most promising electrochemical energy storage devices for being non-flammable,low-cost,and sustainable.However,the challenges of AZIBs,including dendrite growth,hydro...Aqueous zinc-ion batteries(AZIBs)can be one of the most promising electrochemical energy storage devices for being non-flammable,low-cost,and sustainable.However,the challenges of AZIBs,including dendrite growth,hydrogen evolution,corrosion,and passivation of zinc anode during charging and discharging processes,must be overcome to achieve high cycling performance and stability in practical applications.In this work,we utilize a dual-func-tional organic additive cyclohexanedodecol(CHD)to firstly establish[Zn(H2O)5(CHD)]2+complex ion in an aqueous Zn electrolyte and secondly build a robust protection layer on the Zn surface to overcome these dilemmas.Systematic experiments and theoretical calculations are carried out to interpret the working mechanism of CHD.At a very low concentration of 0.1 mg mL^(−1) CHD,long-term reversible Zn plating/stripping could be achieved up to 2200 h at 2 mA cm^(−2),1000 h at 5 mA cm^(−2),and 650 h at 10 mA cm^(−2) at the fixed capacity of 1 mAh cm^(−2).When matched with V_(2)O_(5) cathode,the resultant AZIBs full cell with the CHD-modified electrolyte presents a high capacity of 175 mAh g^(−1) with the capacity retention of 92%after 2000 cycles under 2 A g^(−1).Such a performance could enable the commercialization of AZIBs for applications in grid energy storage and industrial energy storage.展开更多
As an integrated application of modern information technologies and artificial intelligence,Prognostic and Health Management(PHM)is important for machine health monitoring.Prediction of tool wear is one of the symboli...As an integrated application of modern information technologies and artificial intelligence,Prognostic and Health Management(PHM)is important for machine health monitoring.Prediction of tool wear is one of the symbolic applications of PHM technology in modern manufacturing systems and industry.In this paper,a multi-scale Convolutional Gated Recurrent Unit network(MCGRU)is proposed to address raw sensory data for tool wear prediction.At the bottom of MCGRU,six parallel and independent branches with different kernel sizes are designed to form a multi-scale convolutional neural network,which augments the adaptability to features of different time scales.These features of different scales extracted from raw data are then fed into a Deep Gated Recurrent Unit network to capture long-term dependencies and learn significant representations.At the top of the MCGRU,a fully connected layer and a regression layer are built for cutting tool wear prediction.Two case studies are performed to verify the capability and effectiveness of the proposed MCGRU network and results show that MCGRU outperforms several state-of-the-art baseline models.展开更多
Three-dimensional(3D)printing has gained popularity in a variety of applications,particularly in the manufacture of wearable devices.Aided by the large degree of freedom in customizable fabrication,3D printing can cat...Three-dimensional(3D)printing has gained popularity in a variety of applications,particularly in the manufacture of wearable devices.Aided by the large degree of freedom in customizable fabrication,3D printing can cater towards the practical requirements of wearable devices in terms of light weight and flexibility.In particular,this focus review aims to cover the important aspect of wearable energy storage devices(WESDs),which is an essential component of most wearable devices.Herein,the topics discussed are the fundamentals of 3D printing inks used,the optimizing strategies in improving the mechanical and electrochemical properties of wearable devices and the recent developments and challenges of wearable electrochemical systems such as batteries and supercapacitors.It can be expected that,with the development of 3D printing technology,realization of the full potential of WESDs and seamless integration into smart devices also needs further in-depth investigations.展开更多
Organic–inorganic halide perovskite(OIHP)solar cells have garnered great attention in the last decade since they continuously approach the Shockley–Queisser Limit.Compared with conventional organic and inorganic sem...Organic–inorganic halide perovskite(OIHP)solar cells have garnered great attention in the last decade since they continuously approach the Shockley–Queisser Limit.Compared with conventional organic and inorganic semiconductors,OIHPs possess the high tolerance on defects due to the dominated intrinsically shallow-level carrier-trapping centers.However,the existence of defects still causes the ion migration,produces the hysteresis effect,and accelerates the film degradation,eventually suppressing the device efficiency and stability.In this Review Article,we summarize recent impressive advance on passivating OIHP defects and discuss the future horizon of exploiting high-efficiency and long-stability OIHP solar cells in terms of defect managements.展开更多
Linear vibration table can provide harmonic accelerations to excite the nonlinear error terms of Pendulous Integrating Gyro Accelerometer(PIGA).Integral precession calibration method is proposed to calibrate PIGA on a...Linear vibration table can provide harmonic accelerations to excite the nonlinear error terms of Pendulous Integrating Gyro Accelerometer(PIGA).Integral precession calibration method is proposed to calibrate PIGA on a linear vibration table in this paper.Based on the precise expressions of PIGA’s inputs,the error calibration model of PIGA is established.Precession angular velocity errors of PIGA are suppressed by integer periodic precession and the errors caused by non-integer periods vibrating are compensated.The complete calibration process,including planning,preparation,PIGA testing,and coefficient identification,is designed to optimize the test operations and evaluate the calibration results.The effect of the main errors on calibration uncertainty is analyzed and the relative sensitivity function is proposed to further optimize the test positions.Experimental and simulation results verify that the proposed 10-position calibration method can improve calibration uncertainties after compensating for the related errors.The order of calibration uncertainties of the second-and third-order coefficients are decreased to 10^(-8)(rad.s^(-1))/g^(2)and 10^(-8)(rad.s^(-1))/g3,respectively.Compared with the other two classical calibration methods,the calibration uncertainties of PIGA’s nonlinear error coefficients can be effectively reduced and the proportional residual errors are decreased less than 3×10-6(rad.s^(-1))/g by using the proposed calibration method.展开更多
With their excellent reliability and environmental friendliness,zinc-ion batteries(ZIBs)are regarded as potential energy storage technologies.Unfortunately,their poor cycling durability and low Coulombic effectiveness...With their excellent reliability and environmental friendliness,zinc-ion batteries(ZIBs)are regarded as potential energy storage technologies.Unfortunately,their poor cycling durability and low Coulombic effectiveness(CE),driven by dendritic growth and surface passivation on the Zn anode,severely restrict their commercialization.Herein,we describe the in situ construction of a Zn-rich polymeric solid–electrolyte interface(SEI)using poly-acrylic acid(PAA)as an electrolyte additive.On the one hand,the PAA SEI layer offers evenly distributed nucleation sites and promotes ion transport,hence suppressing dendrite growth.On the other hand,the SEI layer prevents direct contact between the Zn foil and the electrolyte,thus inhibiting side reactions.Additionally,the robust coordination of PAA with Zn^(2+)and the SEI layer's good adherence to the Zn foil provide long-term pro-tection to the Zn anode.As a result,symmetric cells and Zn/V_(2)O_(5)cells all deliver prolonged cycle life and superior electrochemical efficiency.展开更多
In this Letter, a 116-actuator deformable mirror (DM) was used to correct the wavefront distortion in a 10.7 J, 10 Hz neodymium-doped yttrium aluminum gamet (Nd:YAG) slab amplifier. By applying a pump-light homogenize...In this Letter, a 116-actuator deformable mirror (DM) was used to correct the wavefront distortion in a 10.7 J, 10 Hz neodymium-doped yttrium aluminum gamet (Nd:YAG) slab amplifier. By applying a pump-light homogenizer to transform the 3x1 near-field beam array into an integrated beam, the beam quality was greatly improved from 5.54 times diffraction limit (TDL) to 1.57 TDL after being corrected by the DM. To the best of our knowledge, this is the first investigation on beam quality control of an arrayed near-field beam in high-energy diode-pumped solid-state lasers.展开更多
In this paper,numerical investigation of hypersonic gas flow over two typical gap-cavity structures is carried out using all-speed preconditioned density-based solver.Such structures filled with porous seal in the gap...In this paper,numerical investigation of hypersonic gas flow over two typical gap-cavity structures is carried out using all-speed preconditioned density-based solver.Such structures filled with porous seal in the gap are often present at the joint locations of control surfaces of the hypersonic vehicles.Single-domain approach is adopted to integrate the governing equations for both porous and fluid regions.The basic thermal invasion characteristic is first illustrated using the maze gap-cavity structure without sealing.Then,the influence of seal filling depth on the thermal invasion characteristic is investigated for the structure with sealing.Finally,a comparison of thermal invasion characteristics between maze and straight gap-cavity structures is performed to examine the influence of gap bending.Results show that the main source of hot airflow invading into the gap is from the millimeter scale gas layer within the boundary layer.And the invasion characteristic presents approximate stationary behavior.A primary vortex occurs in the gap adjacent to the leeward wall,which is ascribed to the impinging effect between the separate boundary flow and the windward wall.This effect is also the main driving force of thermal invasion.A treatment of filling the seal in certain depth inside the gap can significantly reduce the thermal load of seal and maintain an acceptable level of the invading mass flow rate.Additionally,it is found that the gap bending exerts a limited block effect on the thermal invasion without sealing,and this effect can be ignored with sealing.These results can provide a reference for optimizing the seal gap-cavity structure configuration.展开更多
A 21.2 kW,1.94 times the diffraction-limit quasi-continuous-wave laser is presented in this Letter based on a multi-stage,power-scalable Yb:YAG master-oscillator-power-amplifier(MOPA)system under adaptive optics(AO)co...A 21.2 kW,1.94 times the diffraction-limit quasi-continuous-wave laser is presented in this Letter based on a multi-stage,power-scalable Yb:YAG master-oscillator-power-amplifier(MOPA)system under adaptive optics(AO)control.The output laser of the MOPA system is a rectangular beam with a length-width ratio of 2:1,a 200μs pulse duration,and a 1000 Hz repetition rate.With the AO control system,the beam quality of the laser is improved from 4.20 to 1.94 times the diffraction limit.To our knowledge,this is the best quality laser in the 20 kW class except for combined lasers.展开更多
To improve the robustness and discrimination power of the triangle-area representation,a novel shape matching method based on multi-scale angle representation is proposed in this study.By analysing the configurations ...To improve the robustness and discrimination power of the triangle-area representation,a novel shape matching method based on multi-scale angle representation is proposed in this study.By analysing the configurations of different sample points from each shape contour,shape descriptors are constructed by using space angles at different scale levels.With the proposed shape representation,the multi-scale information of shape contours is efficiently described,and the dynamic programming is further used to determine the correspondence between samples from different shapes and calculate the shape distance in the feature matching step.Moreover,to improve the shape retrieval results based on pairwise shape distances,the dynamic label propagation is introduced as the post-processing step.Unlike previous distance learning methods learning the database manifold implicitly,the authors method retrieves relative objects on the shortest paths from near to far explicitly,and the underlying structure can be effectively captured.The proposed method tested on different shape databases provides the performances superior to many other methods,and it can be applied to visual data processing and understanding of the internet of things.展开更多
基金supported by the National Natural Science Foundation of China(No.22075115)Natural Science Foundation of Jiangsu Province(No.BK20211352)+2 种基金Joint Funds of the National Natural Science Foundation of China(No.U2141201)Natural Science Foundation(No.22KJA430005)of Jiangsu Education Committee of ChinaPostgraduate Research and Practice Innovation Program of Jiangsu Normal University(No.2021XKT0296).
文摘Zinc ion batteries are considered as potential energy storage devices due to their advantages of low-cost,high-safety,and high theoretical capacity.However,dendrite growth and chemical corrosion occurring on Zn anode limit their commercialization.These problems can be tackled through the optimization of the electrolyte.However,the screening of electrolyte additives using normal electrochemical methods is time-consuming and labor-intensive.Herein,a fast and simple method based on the digital holography is developed.It can realize the in situ monitoring of electrode/electrolyte interface and provide direct information concerning ion concentration evolution of the diffusion layer.It is effective and time-saving in estimating the homogeneity of the deposition layer and predicting the tendency of dendrite growth,thus able to value the applicability of electrolyte additives.The feasibility of this method is further validated by the forecast and evaluation of thioacetamide additive.Based on systematic characterization,it is proved that the introduction of thioacetamide can not only regulate the interficial ion flux to induce dendrite-free Zn deposition,but also construct adsorption molecule layers to inhibit side reactions of Zn anode.Being easy to operate,capable of in situ observation,and able to endure harsh conditions,digital holography method will be a promising approach for the interfacial investigation of other battery systems.
基金National Science and Technology Major Project,Grant/Award Number:2017YFC1503102National Natural Science Foundation of China,Grant/Award Number:51704144。
文摘The creep characteristics of rock under high crustal stress are of important influence on the long‐term stability of deep rock engineering.To study the creep characteristics and engineering application of sandstone under high crustal stress,this study constructed nonlinear creep damage(NCD)constitutive mode based on the triaxial graded loading‒unloading creep test of sandstone in the Yuezhishan Tunnel.A numerical NCD constitutive model and a breakable lining(BL)model were developed based on FLAC3D and then applied to the stability analysis of the Yuezhishan Tunnel.Based on the creep test results of sandstone,a power function of creep rate and stress level was constructed,by which the long‐term strength was solved.The results show that the long‐term strength of the red sandstone based on the related function of the steady‐state creep rate and stress level is close to the measured stress value in engineering.The NCD model considering damage factors reflects the instantaneous and viscoelastic plasticity deformation characteristics of the red sandstone.The numerical NCD constitutive model and the BL model can reflect surrounding rock deformation characteristics and lining failure characteristics in practical engineering.The research results provide theoretical references for long‐term stability analysis of rock engineering and the deformation control of surrounding rock under high crustal stress.
基金Supported by National Key Research and Development Program of China(Grant No.2018YFB1702400)National Natural Science Foundation of China(Grant Nos.51835009,51705398).
文摘Prognostics and Health Management(PHM),including monitoring,diagnosis,prognosis,and health management,occupies an increasingly important position in reducing costly breakdowns and avoiding catastrophic accidents in modern industry.With the development of artificial intelligence(AI),especially deep learning(DL)approaches,the application of AI-enabled methods to monitor,diagnose and predict potential equipment malfunctions has gone through tremendous progress with verified success in both academia and industry.However,there is still a gap to cover monitoring,diagnosis,and prognosis based on AI-enabled methods,simultaneously,and the importance of an open source community,including open source datasets and codes,has not been fully emphasized.To fill this gap,this paper provides a systematic overview of the current development,common technologies,open source datasets,codes,and challenges of AI-enabled PHM methods from three aspects of monitoring,diagnosis,and prognosis.
文摘hypoxicischemic brain injury;however,the therapeutic efficacy of bone marrow-derived mesenchymal stem cells largely depends on the number of cells that are successfully transferred to the target.Magnet-targeted drug delivery systems can use a specific magnetic field to attract the drug to the target site,increasing the drug concentration.In this study,we found that the double-labeling using superparamagnetic iron oxide nanoparticle and poly-L-lysine(SPIO-PLL)of bone marrow-derived mesenchymal stem cells had no effect on cell survival but decreased cell proliferation 48 hours after labeling.Rat models of hypoxic-ischemic brain injury were established by ligating the left common carotid artery.One day after modeling,intraventricular and caudal vein injections of 1×105 SPIO-PLL-labeled bone marrow-derived mesenchymal stem cells were performed.Twenty-four hours after the intraventricular injection,magnets were fixed to the left side of the rats’heads for 2 hours.Intravoxel incoherent motion magnetic resonance imaging revealed that the perfusion fraction and the diffusion coefficient of rat brain tissue were significantly increased in rats treated with SPIO-PLL-labeled cells through intraventricular injection combined with magnetic guidance,compared with those treated with SPIO-PLL-labeled cells through intraventricular or tail vein injections without magnetic guidance.Hematoxylin-eosin and terminal deoxynucleotidyl transferase dUTP nick-end labeling(TUNEL)staining revealed that in rats treated with SPIO-PLL-labeled cells through intraventricular injection under magnetic guidance,cerebral edema was alleviated,and apoptosis was decreased.These findings suggest that targeted magnetic guidance can be used to improve the therapeutic efficacy of bone marrow-derived mesenchymal stem cell transplantation for hypoxic-ischemic brain injury.This study was approved by the Animal Care and Use Committee of The Second Hospital of Dalian Medical University,China(approval No.2016-060)on March 2,2016.
基金the National Natural Science Foundation of China(No.51902036,51702138,22075115)Natural Science Foundation of Chongqing Science&Technology Commission(No.cstc2019jcyj-msxm1407)+4 种基金Natural Science Foundation of Chongqing Technology and Business University(No.1952009)the Venture&Innovation Support Program for Chongqing Overseas Returnees(Grant No.CX2018129)the Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN201900826 and KJQN201800808)the Innovation Group of New Technologies for Industrial Pollution Control of Chongqing Education Commission(Grant No.CXQT19023)Key Disciplines of Chemical Engineering and Technology in Chongqing Colleges and Universities during the 13th Five Year Plan provided the financial support.
文摘Zinc metal batteries have been considered as a promising candidate for next-generation batteries due to their high safety and low cost.However,their practical applications are severely hampered by the poor cyclability that caused by the undesired dendrite growth of metallic Zn.Herein,Ti_(3)C_(2)T_(x) MXene was first used as electrolyte additive to facilitate the uniform Zn deposition by controlling the nucleation and growth process of Zn.Such MXene additives can not only be absorbed on Zn foil to induce uniform initial Zn deposition via providing abundant zincophilic-O groups and subsequently participate in the formation of robust solid-electrolyte interface film,but also accelerate ion transportation by reducing the Zn^(2+) concentration gradient at the electrode/electrolyte interface.Consequently,MXene-containing electrolyte realizes dendrite-free Zn plating/striping with high Coulombic efficiency(99.7%)and superior reversibility(stably up to 1180 cycles).When applied in full cell,the Zn-V_(2)O_(5)cell also delivers significantly improved cycling performances.This work provides a facile yet effective method for developing reversible zinc metal batteries.
基金financial support from the Australia Research Council Discovery Projects(DP210103266)of Australiasupported by computational resources provided by the Australian Government through the National Computational Infrastructure(NCI)under the National Computational Merit Allocation Scheme and the Pawsey Supercomputing Centre with funding from the Australian Government and the Government of Western Australia。
文摘Aqueous zinc-ion batteries(AZIBs)can be one of the most promising electrochemical energy storage devices for being non-flammable,low-cost,and sustainable.However,the challenges of AZIBs,including dendrite growth,hydrogen evolution,corrosion,and passivation of zinc anode during charging and discharging processes,must be overcome to achieve high cycling performance and stability in practical applications.In this work,we utilize a dual-func-tional organic additive cyclohexanedodecol(CHD)to firstly establish[Zn(H2O)5(CHD)]2+complex ion in an aqueous Zn electrolyte and secondly build a robust protection layer on the Zn surface to overcome these dilemmas.Systematic experiments and theoretical calculations are carried out to interpret the working mechanism of CHD.At a very low concentration of 0.1 mg mL^(−1) CHD,long-term reversible Zn plating/stripping could be achieved up to 2200 h at 2 mA cm^(−2),1000 h at 5 mA cm^(−2),and 650 h at 10 mA cm^(−2) at the fixed capacity of 1 mAh cm^(−2).When matched with V_(2)O_(5) cathode,the resultant AZIBs full cell with the CHD-modified electrolyte presents a high capacity of 175 mAh g^(−1) with the capacity retention of 92%after 2000 cycles under 2 A g^(−1).Such a performance could enable the commercialization of AZIBs for applications in grid energy storage and industrial energy storage.
基金Supported in part by Natural Science Foundation of China(Grant Nos.51835009,51705398)Shaanxi Province 2020 Natural Science Basic Research Plan(Grant No.2020JQ-042)Aeronautical Science Foundation(Grant No.2019ZB070001).
文摘As an integrated application of modern information technologies and artificial intelligence,Prognostic and Health Management(PHM)is important for machine health monitoring.Prediction of tool wear is one of the symbolic applications of PHM technology in modern manufacturing systems and industry.In this paper,a multi-scale Convolutional Gated Recurrent Unit network(MCGRU)is proposed to address raw sensory data for tool wear prediction.At the bottom of MCGRU,six parallel and independent branches with different kernel sizes are designed to form a multi-scale convolutional neural network,which augments the adaptability to features of different time scales.These features of different scales extracted from raw data are then fed into a Deep Gated Recurrent Unit network to capture long-term dependencies and learn significant representations.At the top of the MCGRU,a fully connected layer and a regression layer are built for cutting tool wear prediction.Two case studies are performed to verify the capability and effectiveness of the proposed MCGRU network and results show that MCGRU outperforms several state-of-the-art baseline models.
基金Australian Research Council,Grant/Award Numbers:DP190100120,FT200100015。
文摘Three-dimensional(3D)printing has gained popularity in a variety of applications,particularly in the manufacture of wearable devices.Aided by the large degree of freedom in customizable fabrication,3D printing can cater towards the practical requirements of wearable devices in terms of light weight and flexibility.In particular,this focus review aims to cover the important aspect of wearable energy storage devices(WESDs),which is an essential component of most wearable devices.Herein,the topics discussed are the fundamentals of 3D printing inks used,the optimizing strategies in improving the mechanical and electrochemical properties of wearable devices and the recent developments and challenges of wearable electrochemical systems such as batteries and supercapacitors.It can be expected that,with the development of 3D printing technology,realization of the full potential of WESDs and seamless integration into smart devices also needs further in-depth investigations.
文摘Organic–inorganic halide perovskite(OIHP)solar cells have garnered great attention in the last decade since they continuously approach the Shockley–Queisser Limit.Compared with conventional organic and inorganic semiconductors,OIHPs possess the high tolerance on defects due to the dominated intrinsically shallow-level carrier-trapping centers.However,the existence of defects still causes the ion migration,produces the hysteresis effect,and accelerates the film degradation,eventually suppressing the device efficiency and stability.In this Review Article,we summarize recent impressive advance on passivating OIHP defects and discuss the future horizon of exploiting high-efficiency and long-stability OIHP solar cells in terms of defect managements.
文摘Linear vibration table can provide harmonic accelerations to excite the nonlinear error terms of Pendulous Integrating Gyro Accelerometer(PIGA).Integral precession calibration method is proposed to calibrate PIGA on a linear vibration table in this paper.Based on the precise expressions of PIGA’s inputs,the error calibration model of PIGA is established.Precession angular velocity errors of PIGA are suppressed by integer periodic precession and the errors caused by non-integer periods vibrating are compensated.The complete calibration process,including planning,preparation,PIGA testing,and coefficient identification,is designed to optimize the test operations and evaluate the calibration results.The effect of the main errors on calibration uncertainty is analyzed and the relative sensitivity function is proposed to further optimize the test positions.Experimental and simulation results verify that the proposed 10-position calibration method can improve calibration uncertainties after compensating for the related errors.The order of calibration uncertainties of the second-and third-order coefficients are decreased to 10^(-8)(rad.s^(-1))/g^(2)and 10^(-8)(rad.s^(-1))/g3,respectively.Compared with the other two classical calibration methods,the calibration uncertainties of PIGA’s nonlinear error coefficients can be effectively reduced and the proportional residual errors are decreased less than 3×10-6(rad.s^(-1))/g by using the proposed calibration method.
基金supported by grants from the National Natural Science Foundation of China(Grant No.22222902,52202245)Natural Science Foundation of Jiangsu Province(Grant No.BK20211352)+1 种基金Natural Science Foundation of Jiangsu Education Committee of China(Grant No.22KJA430005,22KJB430004)Postgraduate Research and Practice Innovation Program of Jiangsu Normal University(No.2021XKT0296).
文摘With their excellent reliability and environmental friendliness,zinc-ion batteries(ZIBs)are regarded as potential energy storage technologies.Unfortunately,their poor cycling durability and low Coulombic effectiveness(CE),driven by dendritic growth and surface passivation on the Zn anode,severely restrict their commercialization.Herein,we describe the in situ construction of a Zn-rich polymeric solid–electrolyte interface(SEI)using poly-acrylic acid(PAA)as an electrolyte additive.On the one hand,the PAA SEI layer offers evenly distributed nucleation sites and promotes ion transport,hence suppressing dendrite growth.On the other hand,the SEI layer prevents direct contact between the Zn foil and the electrolyte,thus inhibiting side reactions.Additionally,the robust coordination of PAA with Zn^(2+)and the SEI layer's good adherence to the Zn foil provide long-term pro-tection to the Zn anode.As a result,symmetric cells and Zn/V_(2)O_(5)cells all deliver prolonged cycle life and superior electrochemical efficiency.
基金supported by the National Natural Science Foundation of China(22222902,52027801,51871113,and 52111530236)the National Key R&D Program of China(2022YFA1203902 and 2022YFA1200093)the Natural Science Foundation of Jiangsu Province(BK20200047)。
基金supported by the National Natural Science Foundation of China(No.61775112)the Natural Science Foundation of Beijing Municipality(No.4172030)the Beijing Young Talents Support Project(No.2017000020124G044)
文摘In this Letter, a 116-actuator deformable mirror (DM) was used to correct the wavefront distortion in a 10.7 J, 10 Hz neodymium-doped yttrium aluminum gamet (Nd:YAG) slab amplifier. By applying a pump-light homogenizer to transform the 3x1 near-field beam array into an integrated beam, the beam quality was greatly improved from 5.54 times diffraction limit (TDL) to 1.57 TDL after being corrected by the DM. To the best of our knowledge, this is the first investigation on beam quality control of an arrayed near-field beam in high-energy diode-pumped solid-state lasers.
基金supported by the National Natural Science Foundation of China(No.51536001 and No.51776053)。
文摘In this paper,numerical investigation of hypersonic gas flow over two typical gap-cavity structures is carried out using all-speed preconditioned density-based solver.Such structures filled with porous seal in the gap are often present at the joint locations of control surfaces of the hypersonic vehicles.Single-domain approach is adopted to integrate the governing equations for both porous and fluid regions.The basic thermal invasion characteristic is first illustrated using the maze gap-cavity structure without sealing.Then,the influence of seal filling depth on the thermal invasion characteristic is investigated for the structure with sealing.Finally,a comparison of thermal invasion characteristics between maze and straight gap-cavity structures is performed to examine the influence of gap bending.Results show that the main source of hot airflow invading into the gap is from the millimeter scale gas layer within the boundary layer.And the invasion characteristic presents approximate stationary behavior.A primary vortex occurs in the gap adjacent to the leeward wall,which is ascribed to the impinging effect between the separate boundary flow and the windward wall.This effect is also the main driving force of thermal invasion.A treatment of filling the seal in certain depth inside the gap can significantly reduce the thermal load of seal and maintain an acceptable level of the invading mass flow rate.Additionally,it is found that the gap bending exerts a limited block effect on the thermal invasion without sealing,and this effect can be ignored with sealing.These results can provide a reference for optimizing the seal gap-cavity structure configuration.
基金This work was supported by the National Natural Science Foundation of China(No.61775112).
文摘A 21.2 kW,1.94 times the diffraction-limit quasi-continuous-wave laser is presented in this Letter based on a multi-stage,power-scalable Yb:YAG master-oscillator-power-amplifier(MOPA)system under adaptive optics(AO)control.The output laser of the MOPA system is a rectangular beam with a length-width ratio of 2:1,a 200μs pulse duration,and a 1000 Hz repetition rate.With the AO control system,the beam quality of the laser is improved from 4.20 to 1.94 times the diffraction limit.To our knowledge,this is the best quality laser in the 20 kW class except for combined lasers.
文摘To improve the robustness and discrimination power of the triangle-area representation,a novel shape matching method based on multi-scale angle representation is proposed in this study.By analysing the configurations of different sample points from each shape contour,shape descriptors are constructed by using space angles at different scale levels.With the proposed shape representation,the multi-scale information of shape contours is efficiently described,and the dynamic programming is further used to determine the correspondence between samples from different shapes and calculate the shape distance in the feature matching step.Moreover,to improve the shape retrieval results based on pairwise shape distances,the dynamic label propagation is introduced as the post-processing step.Unlike previous distance learning methods learning the database manifold implicitly,the authors method retrieves relative objects on the shortest paths from near to far explicitly,and the underlying structure can be effectively captured.The proposed method tested on different shape databases provides the performances superior to many other methods,and it can be applied to visual data processing and understanding of the internet of things.
