In response to the current issues in the construction of software engineering(SE)degree granting program,such as insufficient resource integration,low level of internationalization,and inadequate quality control,we pr...In response to the current issues in the construction of software engineering(SE)degree granting program,such as insufficient resource integration,low level of internationalization,and inadequate quality control,we propose the Software Engineering Degree Granting Program Construction Practice Project at Harbin Institute of Technology(HIT).This project aims to explore new models for software talent cultivation,establish a superior SE degree granting program,and ultimately cultivate outstanding internationalized composite SE professionals to support the high-quality development of the national software industry.To this end,we design a distinctive overall construction idea and plan for the SE degree granting program,which are characterized by“3I3S:three highlights for specialized cultivation and strictness in three aspects to ensure quality control”.After years of practice and validation of the project at the School of Software at HIT,this project has proven effective in optimizing talent cultivation models,enhancing students’practical abilities,promoting international exchange and cooperation,advancing industry-education integration,and meeting industrial needs.展开更多
Accelerating the development of students is the basic goal of postgraduate talent cultivation.The final research results,employment situation and satisfaction of postgraduate students with school education are more im...Accelerating the development of students is the basic goal of postgraduate talent cultivation.The final research results,employment situation and satisfaction of postgraduate students with school education are more important indicators of the quality of talent cultivation in a university.For having a deeper understanding of the satisfaction of postgraduates in Harbin Institute of Technology(Weihai)in terms of motivation,tutor situation,management service and employment situation,a questionnaire survey was conducted on postgraduates.The survey results show that the overall satisfaction of postgraduates is high.In terms of studying motivation,most postgraduates think that their majors are more related to employment;in terms of professors,most of them can get along well with their professors and learn from the advantages of their professors;in terms of school management,they respond well to the"library",but think that the"dormitory"and"canteen"need further improvement;in terms of employment,most of postgraduates choose to be employed,while a few of them choose to further their studies,most of which have applied to study in domestic or foreign universities.展开更多
Graduate student recruitment publicity is a very important link in graduate student recruitment,the quality of students directly affects the quality of graduate education.Taking Harbin Institute of Technology(Weihai)a...Graduate student recruitment publicity is a very important link in graduate student recruitment,the quality of students directly affects the quality of graduate education.Taking Harbin Institute of Technology(Weihai)as the research object,this paper analyzes the internal and external factors affecting the improvement of graduate student quality in the branch campus,and carries out the corresponding countermeasures,puts forward the propaganda strategy of all-round research and recruitment,and effectively improves the quality of graduate student in the branch campus.展开更多
Harbin Institute of Technology(HIT)was established in 1920 in Harbin,Heilongjiang,China.In 1954,HIT became one of China’s first six leading universities.Presently HIT is a member of China’s top nine University Union...Harbin Institute of Technology(HIT)was established in 1920 in Harbin,Heilongjiang,China.In 1954,HIT became one of China’s first six leading universities.Presently HIT is a member of China’s top nine University Union(C9).It is a National Key University with science and engineering as its core and has developed with management,liberal arts,economy.展开更多
This paper solves the problem of model-free dual-arm space robot maneuvering after non-cooperative target capture under high control quality requirements.The explicit system model is unavailable,and the maneuvering mi...This paper solves the problem of model-free dual-arm space robot maneuvering after non-cooperative target capture under high control quality requirements.The explicit system model is unavailable,and the maneuvering mission is disturbed by the measurement noise and the target adversarial behavior.To address these problems,a model-free Combined Adaptive-length Datadriven Predictive Controller(CADPC)is proposed.It consists of a separated subsystem identification method and a combined predictive control strategy.The subsystem identification method is composed of an adaptive data length,thereby reducing sensitivity to undetermined measurement noises and disturbances.Based on the subsystem identification,the combined predictive controller is established,reducing calculating resource.The stability of the CADPC is rigorously proven using the Input-to-State Stable(ISS)theorem and the small-gain theorem.Simulations demonstrate that CADPC effectively handles the model-free space robot post operation in the presence of significant disturbances,state measurement noise,and control input errors.It achieves improved steady-state accuracy,reduced steady-state control consumption,and minimized control input chattering.展开更多
A multi-physics approach was used to quantify the effect of process parameters (laser power, scanning speed, hatch spacing, and scanning strategy) on the thermal history and corresponding microstructure evolution of T...A multi-physics approach was used to quantify the effect of process parameters (laser power, scanning speed, hatch spacing, and scanning strategy) on the thermal history and corresponding microstructure evolution of Ti-25Nb (at%) alloy during the dual-track selective laser melting (SLM) process. Simulation results reveal that during the dual-track SLM process, increasing laser power results in greater thermal accumulation, leading to a molten pool of larger volume and coarser grains. Reducing scanning speed enhances remelting and promotes cellular growth at the top of molten pool, whereas faster scanning speed leads to rougher melt tracks and finer grains. Notably, hatch spacing significantly influences the molten pool dimensions and microstructures, and smaller hatch spacing promotes remelting. Furthermore, the orientations of grains in the second track during zigzag scanning differ markedly from those in the first track. More importantly, compared with those after the first track, both the temperature gradient and cooling rate at the boundaries of remelting molten pool are reduced after the second track scanning, resulting in slower interface velocity and significant change in solidification microstructure. This research provides a theoretical foundation for controlling non-equilibrium microstructure and offering novel insights into the optimization of SLM process parameters of titanium alloys.展开更多
With its growth in spacecraft control applications,the microcontroller(MCU)becomes increasingly sensitive to radiation and the risks of system failure.In a radiation environment,the MCU is vulnerable to impacts from h...With its growth in spacecraft control applications,the microcontroller(MCU)becomes increasingly sensitive to radiation and the risks of system failure.In a radiation environment,the MCU is vulnerable to impacts from high-energy particles,which can lead to single-event effect(SEE)that disrupt normal system operations.The pipeline of MCU,being the core structure of the system,is particularly susceptible to single-event upset(SEU)and potentially causes execution failures.However,existing radiation-hardening techniques offer limited effectiveness for pipelines.To enhance SEU resistance,this study focused on a 32-bit MCU core with eight pipeline stages,proposing a pipeline hardening approach that utilizes lockstep technology to improve fault tolerance.Signals from two processors were compared including register write data,register contents and pre-fetched instructions.Any discrepancies triggered error flags to indicate faults.When an error flag was raised,recovery was initiated through an interrupt.The interrupt handler then retrieved state information from the advanced peripheral bus(APB)slave module to restore the CPU's operational state and resume execution.By combining hardware-based state preservation with software-driven error recovery,the proposed solution demonstrated significant improvements in fault tolerance rates and performance compared to traditional checkpoint-based techniques.After completing the pipeline hardening design,a fault injection platform was utilized in this paper to simulate real-world error conditions on internal processor modules.The platform was developed based on the circuit's register-transfer-level(RTL)design and statistical results.The fault injection platform was performed by automatically finding all registers within the target design.The register values were forced to upset at the tens of nanoseconds scale in the RTL description of the circuit's design.After running the circuit's functional simulation,the statistics of the faults in registers were displayed on the platform,which evaluated the influence of SEU.The vulnerability of SEU in the circuit could be observed from the results of the soft error statistics.The post-hardening soft error rates were then measured and compared to pre-hardening data,providing a quantitative evaluation of the improvements.Using this method,the soft error rates of the modules in the MCU core such as PFU,DPU,and Cache AXIM are 40.07%,26.36%,and 27.29%respectively before hardening.The soft error rates of modules mentioned above are reduced to 0%,0.69%,and 1.11%after hardening.The hardened and non-hardened designs of the entire core were implemented in FPGA.The total resource utilization of the triple mode redundancy(TMR)is 111984,as indicated by the number of look-up tables(LUTs)and registers consumed in the FPGA.The total resource utilization of this work is 78034,and the ratio of resource utilization between this work and TMR is approximately 69.68%.The error recovery time for the hardened MCU processor was analyzed using the completion cycles of a bubble sort algorithm as a benchmark.In this paper,the average recovery cycle using the software checkpoint roll-back method is 36479.06,and the average recovery cycle using this work is 26922.5.The ratio of recovery cycles between this work and checkpoint roll-back is about 73.8%.Assessments through random fault injection and FPGA implementation indicate that this approach effectively reduces processor faults caused by soft errors while optimizing resource utilization and efficiency over triplemodular redundancy.展开更多
Photocatalysis is an important technology for using solar energy to produce hydrogen,convert CO_(2) to synthetic fuels,and decrease persistent pollutant.However,conventional photocatalysts have limitations,including p...Photocatalysis is an important technology for using solar energy to produce hydrogen,convert CO_(2) to synthetic fuels,and decrease persistent pollutant.However,conventional photocatalysts have limitations,including poor spectral absorption,inefficient charge separation,and structural instability under operational stress,which demand innovative durable materials with tailored electronic properties.Nanodiamond(ND)has recently been recognized as a suitable material because of its exceptional chemical stability,superior charge carrier mobility,and possible surface functionalization.While its intrinsic wide bandgap limits its response to visible-light,different methods have been demonstrated to activate its catalytic potential.Here,several emerging strategies for improving the catalytic performance of ND-based photocatalytic systems are summarized,including surface functionalization,plasmonic hybridization,heteroatom doping,and heterostructure design.And the structure-activity relationship and design principle are proposed to improve the light harvesting,charge transport,and redox kinetics for constructing high efficiency ND-based photocatalysts used in the renewable energy and environmental industries.展开更多
Spaceborne antennas are essential for remote sensing,deep-space communication,and Earth observation,yet their trajectory planning is complicated by nonlinear base-manipulator coupling and antenna flexibility.To addres...Spaceborne antennas are essential for remote sensing,deep-space communication,and Earth observation,yet their trajectory planning is complicated by nonlinear base-manipulator coupling and antenna flexibility.To address these challenges,this paper proposes a multi-objective trajectory optimization framework.The system dynamics capture both nonlinear rigid-flexible coupling and antenna deformation through a reduced-order formulation.To enhance discretization efficiency,a predictive-terminal hp-adaptive pseudospectral method is employed,assigning collocation density based on task-phase characteristics:finer resolution is applied to dynamic segments requiring higher accuracy,especially near the terminal phase.This enables efficient transcription of the continuous-time problem into a Nonlinear Programming Problem(NLP).The resulting NLP is then solved using a multi-objective optimization strategy based on the nondominated sorting genetic algorithm II,which explores trade-offs among antenna pointing accuracy,energy consumption,and structural vibration.Numerical results demonstrate that the proposed method achieves a reduction of approximately 14.0% in control energy and 41.8%in peak actuation compared to a GPOPS-II baseline,while significantly enhancing vibration suppression.The resulting Pareto front reveals structured trade-offs and clustered solutions,offering robust and diverse options for precision,low-disturbance mission planning.展开更多
IC10 alloy is a promising material for the applications of engine turbine blades.Fabricating and repairing of the turbine blades urgently need a sound joining technique for the IC10 alloy.The traditional transient liq...IC10 alloy is a promising material for the applications of engine turbine blades.Fabricating and repairing of the turbine blades urgently need a sound joining technique for the IC10 alloy.The traditional transient liquid phase(TLP)bonding method is difficult to achieve isothermal solidification,which tends to form brittle eutectic phases.In this study,a novel Al/BNi2 composite filler was designed.This new type of composite filler facilitates the diffusion of elements to completely dissolve or disperse the brittle eutectic structure of continuous large blocks in the TLP joint,thereby improving the room-temperature mechanical properties of the joint and increasing its average shear strength by 20%to 550 MPa.Effect of Al content and bonding temperature on microstructure and mechanical strength of the IC10/Al/BNi2/IC10 joint was investigated.Microstructure evolution mechanisms of the traditional TLP bonding method(with a pure BNi2 filler)and the novel TLP bonding method(with the Al/BNi2 composite filler)were put into comparison.The TLP joint of the new filler achieved a maximum room temperature shear strength of 570 MPa(3 wt.%Al,1100℃,2 h).展开更多
Mega low Earth orbit(LEO)satellite networks serve as effective complements to terrestrial networks.However,the dual mobility of users and LEO satellites makes inter-satellite handovers more frequent for users.Moreover...Mega low Earth orbit(LEO)satellite networks serve as effective complements to terrestrial networks.However,the dual mobility of users and LEO satellites makes inter-satellite handovers more frequent for users.Moreover,there are both ascending and descending segments in widely deployed walker-delta constellations.Even if the locations of users do not change,when the access satellites of the communicating parties are not in the same ascending or descending segment,the end-to-end latency between them will increase.To address this challenge,the self-decision handover(SDH)strategy and the joint decision handover(JDH)strategy are proposed,and they both incorporate the routing hops as a crucial handover criterion to minimize the end-to-end latency.In addition,the shortest route hop-count algorithm is designed to assist in the handover decision-making process.Simulations demonstrate that the proposed handover strategies outperform the traditional handover strategies in terms of the number of handovers and end-to-end latency.展开更多
Although the thin and cold Martian atmosphere provides the feasibility of rotorcraft flight on Mars,rotors designed for denser Earth atmosphere with small angles of attack hardly generate enough thrust for rotorcraft ...Although the thin and cold Martian atmosphere provides the feasibility of rotorcraft flight on Mars,rotors designed for denser Earth atmosphere with small angles of attack hardly generate enough thrust for rotorcraft flight at conventional rotational speeds in the Martian atmosphere.In this paper,we employ the Particle Swarm Optimization(PSO)algorithm to search for the control points of the Bezier curve,completing the parameterization of the airfoil upper and lower curves based on these control points.In order to directly enhance the lift-to-drag ratio of the airfoil at high angles of attack,the NSGA-II algorithm is utilized to optimize the lift-to-drag ratio of NACA 6904 at a=17.5°,Ma=0.43,Re=7600,and CLF 5605 at a=15°,Ma=0.7,Re=7481,respectively.The two-dimensional RANS(Reynolds Average NavierStokes)and k-ωSST turbulence models are employed in the optimization process by CFD to predict the lift and drag characteristics of the airfoil in a Martian environment.Under simulated Mars atmospheric conditions(pressure of 1380 Pa,test temperature of 24°C,equivalent Mars atmospheric density at the surface of 0.0162 g/cm~3),the airfoil after optimized is subjected to rotor lift-drag characteristic tests where a single-rotor lift-drag characteristic test bench is employed for verification.The experimental results demonstrate that the RB-TB-II blade,which is obtained by optimizing the airfoil based on the RB-SWQ-I blade,exhibits a 19.6%increase in Power Loading(PL)and a 20.4%increase in Figure of Merit(FM)compared with the RB-SWQ-I blade.Based on the results of airfoil optimization,increasing the camber at the leading edge of the airfoil under high angles of attack contributes to an improved lift-to-drag ratio.展开更多
Quasi-hemispherical magnetized collisionless shocks have been generated at the SG-II laser facility through the interaction between a laserproduced supersonic plasma flow and a magnetized ambient plasma,exhibiting an ...Quasi-hemispherical magnetized collisionless shocks have been generated at the SG-II laser facility through the interaction between a laserproduced supersonic plasma flow and a magnetized ambient plasma,exhibiting an angular asymmetric shock profile accompanied by asymmetric ion acceleration.We have conducted test particle simulations using the electromagnetic fields derived from 2D MHD simulations to investigate the asymmetry of ion acceleration.The simulations reproduce the angular asymmetry of the shock and the ion acceleration observed in experiments.The results indicate that shock drift acceleration is the primary mechanism for ion energization in the present quasiperpendicular magnetized shock.The asymmetric shock structure caused by nonuniform ambient plasma forms an asymmetric accelerated electric field,ultimately leading to angular asymmetric ion acceleration,which is consistent with space observations and our experimental results.Our study provides a plausible explanation for the discrepancies reported in previous ion acceleration experiments,and could contribute to understanding of the collisionless shock acceleration.展开更多
The water-quenched(WQ)2195 Al−Li alloy was subjected to stretching at different temperatures,from room temperature(RT)to−196℃(CT),to investigate the effect of cryogenic deformation on the aging precipitation behavior...The water-quenched(WQ)2195 Al−Li alloy was subjected to stretching at different temperatures,from room temperature(RT)to−196℃(CT),to investigate the effect of cryogenic deformation on the aging precipitation behaviors and mechanical properties.The precipitation kinetics of the T1 phase and the microstructures in peak aging state were investigated through the differential scanning calorimetric(DSC)tests and electron microscopy observation.The results show that−196℃deformation produces a high dislocation density,which promotes the precipitation of the T1 phase and refines its sizes significantly.In addition,the grain boundary precipitates(GBPs)of−196℃-stretched samples are suppressed considerably due to the high dislocation density in the grain interiors,which increases the ductility.In comparison,the strength remains nearly constant.Thus,it is indicated that cryogenic forming has the potential to provide the shape and property control for the manufacture of critical components of aluminum alloys.展开更多
Seawater electrolysis has been explored as a viable and sustainable method for green hydrogen production in regions characterized by freshwater scarcity but abundant renewable energy resources.However,the high concent...Seawater electrolysis has been explored as a viable and sustainable method for green hydrogen production in regions characterized by freshwater scarcity but abundant renewable energy resources.However,the high concentration of chlorine ions(Cl^(-))in seawater leads to severe corrosion of metallic electrodes,which significantly challenges the stability of electrode catalysts in seawater electrolysis.Owing to the Cl^(-)corrosion and the competitive oxygen/chlorine evolution reactions,the design of durable and active anode catalysts is key to achieving practical seawater electrolysis.To address this challenge,this review systematically analyzes the chlorine-induced corrosion mechanisms of anode catalysts,evaluates various anticorrosion strategies,and explores future prospects for enhancing anode durability.Three mainstream anticorrosion strategies are summarized and assessed for their effectiveness in mitigating the chlorineinduced damage to anode catalysts:the physical surface coatings,electrostatic repulsion,and Cl^(-)adsorption regulation.In addition,some emerging strategies are further introduced to highlight the future trends of state-of-the-art techniques for seawater electrolysis.This review aims to provide novel insights and practical guidance for developing more stable and efficient anode catalysts for hydrogen production via seawater electrolvsis.展开更多
Machine learning(ML)is recognized as a potent tool for the inverse design of environmental functional material,particularly for complex entities like biochar-based catalysts(BCs).Thus,the tailored BCs can have a disti...Machine learning(ML)is recognized as a potent tool for the inverse design of environmental functional material,particularly for complex entities like biochar-based catalysts(BCs).Thus,the tailored BCs can have a distinct ability to trigger the nonradical pathway in advance oxidation processes(AOPs),promising a stable,rapid and selective degradation of persistent contaminants.However,due to the inherent“black box”nature and limitations of input features,results and conclusions derived from ML may not always be intuitively understood or comprehensively validated.To tackle this challenge,we linked the front-point interpretable analysis approaches with back-point density functional theory(DFT)calculations to form a chained learning strategy for deeper sight into the intrinsic activation mechanism of BCs in AOPs.At the front point,we conducted an easy-to-interpret meta-analysis to validate two strategies for enhancing nonradical pathways by increasing oxygen content and specific surface area(SSA),and prepared oxidized biochar(OBC500)and SSA-increased biochar(SBC900)by controlling pyrolysis conditions and modification methods.Subsequently,experimental results showed that OBC500 and SBC900 had distinct dominant degradation pathways for 1O2 generation and electron transfer,respectively.Finally,at the end point,DFT calculations revealed their active sites and degradation mechanisms.This chained learning strategy elucidates fundamental principles for BC inverse design and showcases the exceptional capacity to integrate computational techniques to accelerate catalyst inverse design.展开更多
In the field of intelligent air combat,real-time and accurate recognition of within-visual-range(WVR)maneuver actions serves as the foundational cornerstone for constructing autonomous decision-making systems.However,...In the field of intelligent air combat,real-time and accurate recognition of within-visual-range(WVR)maneuver actions serves as the foundational cornerstone for constructing autonomous decision-making systems.However,existing methods face two major challenges:traditional feature engineering suffers from insufficient effective dimensionality in the feature space due to kinematic coupling,making it difficult to distinguish essential differences between maneuvers,while end-to-end deep learning models lack controllability in implicit feature learning and fail to model high-order long-range temporal dependencies.This paper proposes a trajectory feature pre-extraction method based on a Long-range Masked Autoencoder(LMAE),incorporating three key innovations:(1)Random Fragment High-ratio Masking(RFH-Mask),which enforces the model to learn long-range temporal correlations by masking 80%of trajectory data while retaining continuous fragments;(2)Kalman Filter-Guided Objective Function(KFG-OF),integrating trajectory continuity constraints to align the feature space with kinematic principles;and(3)Two-stage Decoupled Architecture,enabling efficient and controllable feature learning through unsupervised pre-training and frozen-feature transfer.Experimental results demonstrate that LMAE significantly improves the average recognition accuracy for 20-class maneuvers compared to traditional end-to-end models,while significantly accelerating convergence speed.The contributions of this work lie in:introducing high-masking-rate autoencoders into low-informationdensity trajectory analysis,proposing a feature engineering framework with enhanced controllability and efficiency,and providing a novel technical pathway for intelligent air combat decision-making systems.展开更多
This study examines the viscoelastic-plastic behavior of thermoplastic resin poly-ether-ether-ketone(PEEK)under high temperature and strain rate conditions,highlighting its potential in aerospace applications due to i...This study examines the viscoelastic-plastic behavior of thermoplastic resin poly-ether-ether-ketone(PEEK)under high temperature and strain rate conditions,highlighting its potential in aerospace applications due to its impact resistance.A dualhardening constitutive model that combines physical and phenomenological approaches is developed to simulate the mechanical behavior of PEEK.The model explicitly incorporates its marked tension-compression asymmetry in plasticity and relaxation,along with thermal softening at high strain rates,enabling accurate predictions over a wide range of temperatures and strain rates with minimal parameters.This study establishes a comprehensive workflow from experimentation to finite element(FE)simulation for thermoplastic resins.Uniaxial tensile and compression tests(23℃-180℃,0.00229s^(-1)-0,19361s^(-1))and split Hopkinson pressure bar(SHPB)tests(1094.08s^(-1)-5957.88s^(-1))are performed to capture stress-strain responses across various conditions,with small-scale specimens enhancing fracture strain measurement accuracy,and quantify the Taylor-Quinney factor of the PEEK material during the adiabatic heating process.The findings demonstrate that the proposed constitutive model effectively predicts yield points across different strain rates and temperatures,with parameters easily obtainable through simple experimental methods,enhancing its practical applications.展开更多
The failure mechanisms and structural damage of SiC MOSFETs induced by heavy ion irradiation were demonstrated.The findings reveal three degradation modes,depending on the drain voltage.At a relatively low voltage,the...The failure mechanisms and structural damage of SiC MOSFETs induced by heavy ion irradiation were demonstrated.The findings reveal three degradation modes,depending on the drain voltage.At a relatively low voltage,the damage is triggered by the formation and activation of gate latent damage(LDs),with damage concentrated in the gate oxide.The second degradation mode involves permanent leakage current degradation,with damage progressively transitioning from the oxide to the SiC material as the drain voltage escalates.Ultimately,the device undergoes catastrophic burnout above certain voltages,characterized by the lattice temperature reaching the sublimation point of SiC,resulting in surface cavity and complete structural destruction.This paper presents a comprehensive investigation of SiC MOSFETs under heavy ion exposure,providing radiation resistance methods of SiC-based devices for aerospace applications.展开更多
In the construction and maintenance for large space equipment,it is essential to ensure the control accuracy and improve the dexterity of the space manipulator.In this paper,a FiniteTime Convergence Kinematic Control(...In the construction and maintenance for large space equipment,it is essential to ensure the control accuracy and improve the dexterity of the space manipulator.In this paper,a FiniteTime Convergence Kinematic Control(FTCKC)added with Acceleration Level Dexterity Optimization(ALDO)scheme is proposed to solve the kinematic uncertainty and dexterity optimization problems of redundant space manipulators.Concretely,distinguishing from the asymptotic convergence property of traditional adaptive Jacobian methods,the FTCKC scheme is adopted to construct the equality constraint to address the model uncertainty problem,and its error can converge within a finite time.Subsequently,the dexterity index is reconstructed at acceleration level by a multi-level target handling method.Then,the equality constraint,optimization task,and limit constraints are reformulated as a quadratic programming problem.Moreover,a Recurrent Neural Network(RNN)is engineered for the constructed FTCKC-ALDO scheme.Finally,the superiority of the FTCKC-ALDO-RNN scheme is verified by experiments.展开更多
基金supported in part by the Education Reform Key Projects of Heilongjiang Province under Grant Nos.SJGZ20220011,SJGZ20220012,and SJGZY2024008。
文摘In response to the current issues in the construction of software engineering(SE)degree granting program,such as insufficient resource integration,low level of internationalization,and inadequate quality control,we propose the Software Engineering Degree Granting Program Construction Practice Project at Harbin Institute of Technology(HIT).This project aims to explore new models for software talent cultivation,establish a superior SE degree granting program,and ultimately cultivate outstanding internationalized composite SE professionals to support the high-quality development of the national software industry.To this end,we design a distinctive overall construction idea and plan for the SE degree granting program,which are characterized by“3I3S:three highlights for specialized cultivation and strictness in three aspects to ensure quality control”.After years of practice and validation of the project at the School of Software at HIT,this project has proven effective in optimizing talent cultivation models,enhancing students’practical abilities,promoting international exchange and cooperation,advancing industry-education integration,and meeting industrial needs.
基金was supported by Postgraduate Education and Teaching Reform Project of Shandong Province(SDYJG21018)Postgraduate Education and Teaching Reform Project of Harbin Institute of Technology at Weihai(WH2019002)Postgraduate Education and Teaching Reform Project of Harbin Institute of Technology(21HX1001).
文摘Accelerating the development of students is the basic goal of postgraduate talent cultivation.The final research results,employment situation and satisfaction of postgraduate students with school education are more important indicators of the quality of talent cultivation in a university.For having a deeper understanding of the satisfaction of postgraduates in Harbin Institute of Technology(Weihai)in terms of motivation,tutor situation,management service and employment situation,a questionnaire survey was conducted on postgraduates.The survey results show that the overall satisfaction of postgraduates is high.In terms of studying motivation,most postgraduates think that their majors are more related to employment;in terms of professors,most of them can get along well with their professors and learn from the advantages of their professors;in terms of school management,they respond well to the"library",but think that the"dormitory"and"canteen"need further improvement;in terms of employment,most of postgraduates choose to be employed,while a few of them choose to further their studies,most of which have applied to study in domestic or foreign universities.
基金This research was supported by Postgraduate Education and Teaching Reform Project of Shandong Province(SDYJG21018)Postgraduate Education and Teaching Reform Project of Harbin Institute of Technology at Weihai(WH2019002)Postgraduate Education and Teaching Reform Project of Harbin Institute of Technology(21HX1001).
文摘Graduate student recruitment publicity is a very important link in graduate student recruitment,the quality of students directly affects the quality of graduate education.Taking Harbin Institute of Technology(Weihai)as the research object,this paper analyzes the internal and external factors affecting the improvement of graduate student quality in the branch campus,and carries out the corresponding countermeasures,puts forward the propaganda strategy of all-round research and recruitment,and effectively improves the quality of graduate student in the branch campus.
文摘Harbin Institute of Technology(HIT)was established in 1920 in Harbin,Heilongjiang,China.In 1954,HIT became one of China’s first six leading universities.Presently HIT is a member of China’s top nine University Union(C9).It is a National Key University with science and engineering as its core and has developed with management,liberal arts,economy.
基金supported by the National Natural Science Foundation of China(No.12372045)the National Key Research and the Development Program of China(Nos.2023YFC2205900,2023YFC2205901)。
文摘This paper solves the problem of model-free dual-arm space robot maneuvering after non-cooperative target capture under high control quality requirements.The explicit system model is unavailable,and the maneuvering mission is disturbed by the measurement noise and the target adversarial behavior.To address these problems,a model-free Combined Adaptive-length Datadriven Predictive Controller(CADPC)is proposed.It consists of a separated subsystem identification method and a combined predictive control strategy.The subsystem identification method is composed of an adaptive data length,thereby reducing sensitivity to undetermined measurement noises and disturbances.Based on the subsystem identification,the combined predictive controller is established,reducing calculating resource.The stability of the CADPC is rigorously proven using the Input-to-State Stable(ISS)theorem and the small-gain theorem.Simulations demonstrate that CADPC effectively handles the model-free space robot post operation in the presence of significant disturbances,state measurement noise,and control input errors.It achieves improved steady-state accuracy,reduced steady-state control consumption,and minimized control input chattering.
基金Guangdong Basic and Applied Basic Research Foundation (2024A1515011873)Shenzhen Basic Research Project (JCYJ20241202123504007)Shenzhen Science and Technology Innovation Commission (KJZD20240903101400001, KJZD20240903102006009)。
文摘A multi-physics approach was used to quantify the effect of process parameters (laser power, scanning speed, hatch spacing, and scanning strategy) on the thermal history and corresponding microstructure evolution of Ti-25Nb (at%) alloy during the dual-track selective laser melting (SLM) process. Simulation results reveal that during the dual-track SLM process, increasing laser power results in greater thermal accumulation, leading to a molten pool of larger volume and coarser grains. Reducing scanning speed enhances remelting and promotes cellular growth at the top of molten pool, whereas faster scanning speed leads to rougher melt tracks and finer grains. Notably, hatch spacing significantly influences the molten pool dimensions and microstructures, and smaller hatch spacing promotes remelting. Furthermore, the orientations of grains in the second track during zigzag scanning differ markedly from those in the first track. More importantly, compared with those after the first track, both the temperature gradient and cooling rate at the boundaries of remelting molten pool are reduced after the second track scanning, resulting in slower interface velocity and significant change in solidification microstructure. This research provides a theoretical foundation for controlling non-equilibrium microstructure and offering novel insights into the optimization of SLM process parameters of titanium alloys.
文摘With its growth in spacecraft control applications,the microcontroller(MCU)becomes increasingly sensitive to radiation and the risks of system failure.In a radiation environment,the MCU is vulnerable to impacts from high-energy particles,which can lead to single-event effect(SEE)that disrupt normal system operations.The pipeline of MCU,being the core structure of the system,is particularly susceptible to single-event upset(SEU)and potentially causes execution failures.However,existing radiation-hardening techniques offer limited effectiveness for pipelines.To enhance SEU resistance,this study focused on a 32-bit MCU core with eight pipeline stages,proposing a pipeline hardening approach that utilizes lockstep technology to improve fault tolerance.Signals from two processors were compared including register write data,register contents and pre-fetched instructions.Any discrepancies triggered error flags to indicate faults.When an error flag was raised,recovery was initiated through an interrupt.The interrupt handler then retrieved state information from the advanced peripheral bus(APB)slave module to restore the CPU's operational state and resume execution.By combining hardware-based state preservation with software-driven error recovery,the proposed solution demonstrated significant improvements in fault tolerance rates and performance compared to traditional checkpoint-based techniques.After completing the pipeline hardening design,a fault injection platform was utilized in this paper to simulate real-world error conditions on internal processor modules.The platform was developed based on the circuit's register-transfer-level(RTL)design and statistical results.The fault injection platform was performed by automatically finding all registers within the target design.The register values were forced to upset at the tens of nanoseconds scale in the RTL description of the circuit's design.After running the circuit's functional simulation,the statistics of the faults in registers were displayed on the platform,which evaluated the influence of SEU.The vulnerability of SEU in the circuit could be observed from the results of the soft error statistics.The post-hardening soft error rates were then measured and compared to pre-hardening data,providing a quantitative evaluation of the improvements.Using this method,the soft error rates of the modules in the MCU core such as PFU,DPU,and Cache AXIM are 40.07%,26.36%,and 27.29%respectively before hardening.The soft error rates of modules mentioned above are reduced to 0%,0.69%,and 1.11%after hardening.The hardened and non-hardened designs of the entire core were implemented in FPGA.The total resource utilization of the triple mode redundancy(TMR)is 111984,as indicated by the number of look-up tables(LUTs)and registers consumed in the FPGA.The total resource utilization of this work is 78034,and the ratio of resource utilization between this work and TMR is approximately 69.68%.The error recovery time for the hardened MCU processor was analyzed using the completion cycles of a bubble sort algorithm as a benchmark.In this paper,the average recovery cycle using the software checkpoint roll-back method is 36479.06,and the average recovery cycle using this work is 26922.5.The ratio of recovery cycles between this work and checkpoint roll-back is about 73.8%.Assessments through random fault injection and FPGA implementation indicate that this approach effectively reduces processor faults caused by soft errors while optimizing resource utilization and efficiency over triplemodular redundancy.
文摘Photocatalysis is an important technology for using solar energy to produce hydrogen,convert CO_(2) to synthetic fuels,and decrease persistent pollutant.However,conventional photocatalysts have limitations,including poor spectral absorption,inefficient charge separation,and structural instability under operational stress,which demand innovative durable materials with tailored electronic properties.Nanodiamond(ND)has recently been recognized as a suitable material because of its exceptional chemical stability,superior charge carrier mobility,and possible surface functionalization.While its intrinsic wide bandgap limits its response to visible-light,different methods have been demonstrated to activate its catalytic potential.Here,several emerging strategies for improving the catalytic performance of ND-based photocatalytic systems are summarized,including surface functionalization,plasmonic hybridization,heteroatom doping,and heterostructure design.And the structure-activity relationship and design principle are proposed to improve the light harvesting,charge transport,and redox kinetics for constructing high efficiency ND-based photocatalysts used in the renewable energy and environmental industries.
基金supported by the National Natural Science Foundation of China(No.62173107).
文摘Spaceborne antennas are essential for remote sensing,deep-space communication,and Earth observation,yet their trajectory planning is complicated by nonlinear base-manipulator coupling and antenna flexibility.To address these challenges,this paper proposes a multi-objective trajectory optimization framework.The system dynamics capture both nonlinear rigid-flexible coupling and antenna deformation through a reduced-order formulation.To enhance discretization efficiency,a predictive-terminal hp-adaptive pseudospectral method is employed,assigning collocation density based on task-phase characteristics:finer resolution is applied to dynamic segments requiring higher accuracy,especially near the terminal phase.This enables efficient transcription of the continuous-time problem into a Nonlinear Programming Problem(NLP).The resulting NLP is then solved using a multi-objective optimization strategy based on the nondominated sorting genetic algorithm II,which explores trade-offs among antenna pointing accuracy,energy consumption,and structural vibration.Numerical results demonstrate that the proposed method achieves a reduction of approximately 14.0% in control energy and 41.8%in peak actuation compared to a GPOPS-II baseline,while significantly enhancing vibration suppression.The resulting Pareto front reveals structured trade-offs and clustered solutions,offering robust and diverse options for precision,low-disturbance mission planning.
基金funded by the National Natural Science Foundation of China(Grant No.U2167216,52504408,52475335)China Postdoctoral Science Foundation Funded Project(Grant No.2024M754181).
文摘IC10 alloy is a promising material for the applications of engine turbine blades.Fabricating and repairing of the turbine blades urgently need a sound joining technique for the IC10 alloy.The traditional transient liquid phase(TLP)bonding method is difficult to achieve isothermal solidification,which tends to form brittle eutectic phases.In this study,a novel Al/BNi2 composite filler was designed.This new type of composite filler facilitates the diffusion of elements to completely dissolve or disperse the brittle eutectic structure of continuous large blocks in the TLP joint,thereby improving the room-temperature mechanical properties of the joint and increasing its average shear strength by 20%to 550 MPa.Effect of Al content and bonding temperature on microstructure and mechanical strength of the IC10/Al/BNi2/IC10 joint was investigated.Microstructure evolution mechanisms of the traditional TLP bonding method(with a pure BNi2 filler)and the novel TLP bonding method(with the Al/BNi2 composite filler)were put into comparison.The TLP joint of the new filler achieved a maximum room temperature shear strength of 570 MPa(3 wt.%Al,1100℃,2 h).
基金supported by the State Key Laboratory of Micro-Spacecraft Rapid Design and Intelligent Cluster(MS01240103)the National Natural Science Foundation of China(62071146,62431009)+2 种基金the National 2011 Collaborative Innovation Center of Wireless Communication Technologies(2242022k60006)the Research Project Fund of Songjiang Laboratory(SL20230104)Heilongjiang Province Postdoctoral General Foundation(LBH-Z22133)。
文摘Mega low Earth orbit(LEO)satellite networks serve as effective complements to terrestrial networks.However,the dual mobility of users and LEO satellites makes inter-satellite handovers more frequent for users.Moreover,there are both ascending and descending segments in widely deployed walker-delta constellations.Even if the locations of users do not change,when the access satellites of the communicating parties are not in the same ascending or descending segment,the end-to-end latency between them will increase.To address this challenge,the self-decision handover(SDH)strategy and the joint decision handover(JDH)strategy are proposed,and they both incorporate the routing hops as a crucial handover criterion to minimize the end-to-end latency.In addition,the shortest route hop-count algorithm is designed to assist in the handover decision-making process.Simulations demonstrate that the proposed handover strategies outperform the traditional handover strategies in terms of the number of handovers and end-to-end latency.
基金supported by the National Key R&D Program of China(No.2024YFC3015804)the Basic Science Center Program for“Space Robot Intelligent Manipulation”,China(No.T2388101)。
文摘Although the thin and cold Martian atmosphere provides the feasibility of rotorcraft flight on Mars,rotors designed for denser Earth atmosphere with small angles of attack hardly generate enough thrust for rotorcraft flight at conventional rotational speeds in the Martian atmosphere.In this paper,we employ the Particle Swarm Optimization(PSO)algorithm to search for the control points of the Bezier curve,completing the parameterization of the airfoil upper and lower curves based on these control points.In order to directly enhance the lift-to-drag ratio of the airfoil at high angles of attack,the NSGA-II algorithm is utilized to optimize the lift-to-drag ratio of NACA 6904 at a=17.5°,Ma=0.43,Re=7600,and CLF 5605 at a=15°,Ma=0.7,Re=7481,respectively.The two-dimensional RANS(Reynolds Average NavierStokes)and k-ωSST turbulence models are employed in the optimization process by CFD to predict the lift and drag characteristics of the airfoil in a Martian environment.Under simulated Mars atmospheric conditions(pressure of 1380 Pa,test temperature of 24°C,equivalent Mars atmospheric density at the surface of 0.0162 g/cm~3),the airfoil after optimized is subjected to rotor lift-drag characteristic tests where a single-rotor lift-drag characteristic test bench is employed for verification.The experimental results demonstrate that the RB-TB-II blade,which is obtained by optimizing the airfoil based on the RB-SWQ-I blade,exhibits a 19.6%increase in Power Loading(PL)and a 20.4%increase in Figure of Merit(FM)compared with the RB-SWQ-I blade.Based on the results of airfoil optimization,increasing the camber at the leading edge of the airfoil under high angles of attack contributes to an improved lift-to-drag ratio.
基金supported by the National Natural Science Foundation of China(Grant Nos.12205298 and 12175230)the Natural Science Foundation of Heilongjiang Province of China(Grant No.LH2024A010)+1 种基金the Fundamental Research Funds for the Central Universities,Controversial and Disruptive Projects of the Chinese Academy of Sciences(Grant No.FGSDFX-0001)the USTC Research Funds of the Double First-Class Initiative(Grant No.YD2140002006).
文摘Quasi-hemispherical magnetized collisionless shocks have been generated at the SG-II laser facility through the interaction between a laserproduced supersonic plasma flow and a magnetized ambient plasma,exhibiting an angular asymmetric shock profile accompanied by asymmetric ion acceleration.We have conducted test particle simulations using the electromagnetic fields derived from 2D MHD simulations to investigate the asymmetry of ion acceleration.The simulations reproduce the angular asymmetry of the shock and the ion acceleration observed in experiments.The results indicate that shock drift acceleration is the primary mechanism for ion energization in the present quasiperpendicular magnetized shock.The asymmetric shock structure caused by nonuniform ambient plasma forms an asymmetric accelerated electric field,ultimately leading to angular asymmetric ion acceleration,which is consistent with space observations and our experimental results.Our study provides a plausible explanation for the discrepancies reported in previous ion acceleration experiments,and could contribute to understanding of the collisionless shock acceleration.
基金financially supported by the National Key Research and Development Program of China (No. 2019YFA0708801)the National Natural Science Foundation of China (No. 51875125)。
文摘The water-quenched(WQ)2195 Al−Li alloy was subjected to stretching at different temperatures,from room temperature(RT)to−196℃(CT),to investigate the effect of cryogenic deformation on the aging precipitation behaviors and mechanical properties.The precipitation kinetics of the T1 phase and the microstructures in peak aging state were investigated through the differential scanning calorimetric(DSC)tests and electron microscopy observation.The results show that−196℃deformation produces a high dislocation density,which promotes the precipitation of the T1 phase and refines its sizes significantly.In addition,the grain boundary precipitates(GBPs)of−196℃-stretched samples are suppressed considerably due to the high dislocation density in the grain interiors,which increases the ductility.In comparison,the strength remains nearly constant.Thus,it is indicated that cryogenic forming has the potential to provide the shape and property control for the manufacture of critical components of aluminum alloys.
基金sponsored by the National Natural Science Foundation of China(52302039,52301043)the Guangdong Basic and Applied Basic Research Foundation(2024A1515240056)+3 种基金the Shenzhen Science and Technology Program(GXWD20231129113217001)the Shenzhen Key Laboratory of New Materials Technology(SYSPG20241211173609003)the Postdoctoral Research Startup Expenses of Shenzhen(NA25501001)Shenzhen Introduce High-level Talents and Scientific Research Start-up Funds(NA11409005)。
文摘Seawater electrolysis has been explored as a viable and sustainable method for green hydrogen production in regions characterized by freshwater scarcity but abundant renewable energy resources.However,the high concentration of chlorine ions(Cl^(-))in seawater leads to severe corrosion of metallic electrodes,which significantly challenges the stability of electrode catalysts in seawater electrolysis.Owing to the Cl^(-)corrosion and the competitive oxygen/chlorine evolution reactions,the design of durable and active anode catalysts is key to achieving practical seawater electrolysis.To address this challenge,this review systematically analyzes the chlorine-induced corrosion mechanisms of anode catalysts,evaluates various anticorrosion strategies,and explores future prospects for enhancing anode durability.Three mainstream anticorrosion strategies are summarized and assessed for their effectiveness in mitigating the chlorineinduced damage to anode catalysts:the physical surface coatings,electrostatic repulsion,and Cl^(-)adsorption regulation.In addition,some emerging strategies are further introduced to highlight the future trends of state-of-the-art techniques for seawater electrolysis.This review aims to provide novel insights and practical guidance for developing more stable and efficient anode catalysts for hydrogen production via seawater electrolvsis.
基金supported by Project of National and Local Joint Engineering Research Center for Biomass Energy Development and Utilization(Harbin Institute of Technology,No.2021A004).
文摘Machine learning(ML)is recognized as a potent tool for the inverse design of environmental functional material,particularly for complex entities like biochar-based catalysts(BCs).Thus,the tailored BCs can have a distinct ability to trigger the nonradical pathway in advance oxidation processes(AOPs),promising a stable,rapid and selective degradation of persistent contaminants.However,due to the inherent“black box”nature and limitations of input features,results and conclusions derived from ML may not always be intuitively understood or comprehensively validated.To tackle this challenge,we linked the front-point interpretable analysis approaches with back-point density functional theory(DFT)calculations to form a chained learning strategy for deeper sight into the intrinsic activation mechanism of BCs in AOPs.At the front point,we conducted an easy-to-interpret meta-analysis to validate two strategies for enhancing nonradical pathways by increasing oxygen content and specific surface area(SSA),and prepared oxidized biochar(OBC500)and SSA-increased biochar(SBC900)by controlling pyrolysis conditions and modification methods.Subsequently,experimental results showed that OBC500 and SBC900 had distinct dominant degradation pathways for 1O2 generation and electron transfer,respectively.Finally,at the end point,DFT calculations revealed their active sites and degradation mechanisms.This chained learning strategy elucidates fundamental principles for BC inverse design and showcases the exceptional capacity to integrate computational techniques to accelerate catalyst inverse design.
文摘In the field of intelligent air combat,real-time and accurate recognition of within-visual-range(WVR)maneuver actions serves as the foundational cornerstone for constructing autonomous decision-making systems.However,existing methods face two major challenges:traditional feature engineering suffers from insufficient effective dimensionality in the feature space due to kinematic coupling,making it difficult to distinguish essential differences between maneuvers,while end-to-end deep learning models lack controllability in implicit feature learning and fail to model high-order long-range temporal dependencies.This paper proposes a trajectory feature pre-extraction method based on a Long-range Masked Autoencoder(LMAE),incorporating three key innovations:(1)Random Fragment High-ratio Masking(RFH-Mask),which enforces the model to learn long-range temporal correlations by masking 80%of trajectory data while retaining continuous fragments;(2)Kalman Filter-Guided Objective Function(KFG-OF),integrating trajectory continuity constraints to align the feature space with kinematic principles;and(3)Two-stage Decoupled Architecture,enabling efficient and controllable feature learning through unsupervised pre-training and frozen-feature transfer.Experimental results demonstrate that LMAE significantly improves the average recognition accuracy for 20-class maneuvers compared to traditional end-to-end models,while significantly accelerating convergence speed.The contributions of this work lie in:introducing high-masking-rate autoencoders into low-informationdensity trajectory analysis,proposing a feature engineering framework with enhanced controllability and efficiency,and providing a novel technical pathway for intelligent air combat decision-making systems.
文摘This study examines the viscoelastic-plastic behavior of thermoplastic resin poly-ether-ether-ketone(PEEK)under high temperature and strain rate conditions,highlighting its potential in aerospace applications due to its impact resistance.A dualhardening constitutive model that combines physical and phenomenological approaches is developed to simulate the mechanical behavior of PEEK.The model explicitly incorporates its marked tension-compression asymmetry in plasticity and relaxation,along with thermal softening at high strain rates,enabling accurate predictions over a wide range of temperatures and strain rates with minimal parameters.This study establishes a comprehensive workflow from experimentation to finite element(FE)simulation for thermoplastic resins.Uniaxial tensile and compression tests(23℃-180℃,0.00229s^(-1)-0,19361s^(-1))and split Hopkinson pressure bar(SHPB)tests(1094.08s^(-1)-5957.88s^(-1))are performed to capture stress-strain responses across various conditions,with small-scale specimens enhancing fracture strain measurement accuracy,and quantify the Taylor-Quinney factor of the PEEK material during the adiabatic heating process.The findings demonstrate that the proposed constitutive model effectively predicts yield points across different strain rates and temperatures,with parameters easily obtainable through simple experimental methods,enhancing its practical applications.
基金Project supported by the National Key Research and Development Program of China(Grant No.2023YFA1609000)the National Natural Science Foundation of China(Grant Nos.U2341222,U2441248,12275061,and 12075069)。
文摘The failure mechanisms and structural damage of SiC MOSFETs induced by heavy ion irradiation were demonstrated.The findings reveal three degradation modes,depending on the drain voltage.At a relatively low voltage,the damage is triggered by the formation and activation of gate latent damage(LDs),with damage concentrated in the gate oxide.The second degradation mode involves permanent leakage current degradation,with damage progressively transitioning from the oxide to the SiC material as the drain voltage escalates.Ultimately,the device undergoes catastrophic burnout above certain voltages,characterized by the lattice temperature reaching the sublimation point of SiC,resulting in surface cavity and complete structural destruction.This paper presents a comprehensive investigation of SiC MOSFETs under heavy ion exposure,providing radiation resistance methods of SiC-based devices for aerospace applications.
基金supported by the National Natural Science Foundation of China(Nos.92148203 and T2388101)。
文摘In the construction and maintenance for large space equipment,it is essential to ensure the control accuracy and improve the dexterity of the space manipulator.In this paper,a FiniteTime Convergence Kinematic Control(FTCKC)added with Acceleration Level Dexterity Optimization(ALDO)scheme is proposed to solve the kinematic uncertainty and dexterity optimization problems of redundant space manipulators.Concretely,distinguishing from the asymptotic convergence property of traditional adaptive Jacobian methods,the FTCKC scheme is adopted to construct the equality constraint to address the model uncertainty problem,and its error can converge within a finite time.Subsequently,the dexterity index is reconstructed at acceleration level by a multi-level target handling method.Then,the equality constraint,optimization task,and limit constraints are reformulated as a quadratic programming problem.Moreover,a Recurrent Neural Network(RNN)is engineered for the constructed FTCKC-ALDO scheme.Finally,the superiority of the FTCKC-ALDO-RNN scheme is verified by experiments.
