A modular system of cascaded converters based on model predictive control(MPC)is proposed to meet the application requirements ofmultiple voltage levels and electrical isolation in renewable energy generation systems....A modular system of cascaded converters based on model predictive control(MPC)is proposed to meet the application requirements ofmultiple voltage levels and electrical isolation in renewable energy generation systems.The system consists of a Buck/Boost+CLLLC cascaded converter as a submodule,which is combined in series and parallel on the input and output sides to achieve direct-current(DC)voltage transformation,bidirectional energy flow,and electrical isolation.The CLLLC converter operates in DC transformer mode in the submodule,while the Buck/Boost converter participates in voltage regulation.This article establishes a suitable mathematical model for the proposed system topology,and uses MPC to control the system based on this mathematical model.Module parameters are designed and calculated,and simulation is built in MATLAB/Simulink to complete the simulation comparison experiment between MPC and traditional proportional integral(PI)control.Finally,a physical experimental platform is built to complete the physical comparison experiment.The simulation and physical experimental results prove that the control accuracy and response speed ofMPC are better than traditional PI control strategy.展开更多
In clinical practice,the irregular shapes of traumas pose a significant challenge in rapidly manufacturing personalized scaffolds.To address these challenges,inspired by LEGO■ bricks,this study proposed a novel conce...In clinical practice,the irregular shapes of traumas pose a significant challenge in rapidly manufacturing personalized scaffolds.To address these challenges,inspired by LEGO■ bricks,this study proposed a novel concept of modular scaffolds and developed an innovative system based on machine vision for their rapid and intelligent assembly tailored to defect shapes.Trapezoidal interfaces effectively connect standardized bone units based on magnesium-doped silicate calcium,ensuring high stability of the modular scaffolds,with compressive strength up to 135 MPa and bending strength up to 17 MPa.Through self-developed defect recognition and reconstruction algorithms,defect recognition and personalized assembly schemes for bone scaffolds can be achieved autonomously.Modular scaffolds seamlessly integrate with surrounding bone tissue,promoting new bone growth,with no apparent differences compared to fully 3D printed integral scaffolds in the skull and femur repair experiments.In summary,the adoption of modular scaffolds not only integrates personalization and standardization but also satisfies the optimal treatment window.展开更多
Based on the analysis and research of the airworthiness objective of integrated modular avionics system(IMA),and the characteristics of IMA system’s comprehensive and complex cross-linking with other airborne systems...Based on the analysis and research of the airworthiness objective of integrated modular avionics system(IMA),and the characteristics of IMA system’s comprehensive and complex cross-linking with other airborne systems,the extraction strategy of IMA system’s compliance flight test subjects and the selection method of IMA system’s compliance flight test parameters are proposed.The data analysis method based on the abnormal probability matrix of the IMA system is proposed for the first time,and the abnormal state information of the IMA system can be quickly identified.The compliance flight test of the IMA system is completed with limited flight test resources,which achieves the purpose of saving flight test sorties and improving flight test efficiency.This research has been successfully applied to the airworthiness certification flight test of a certain civil transport aircraft in China,and can provide technical support for the subsequent type flight test.展开更多
The intricate interplay between rock mechanics and fracture-induced fluid flow during resource extrac-tion exerts profound effects on groundwater systems,posing a pivotal challenge for promoting green and safe develop...The intricate interplay between rock mechanics and fracture-induced fluid flow during resource extrac-tion exerts profound effects on groundwater systems,posing a pivotal challenge for promoting green and safe development in underground engineering.To address this,a novel numerical model with an explicit coupling simulation strategy is presented.This model integrates distinct modules for individual physical mechanisms,ensuring second-order accuracy through shared time integration,thereby overcoming lim-itations in simulating mining-induced strata damage,water flow,and permeability dynamics.A novel mathematical model is incorporated into the mechanical simulation to characterize the abrupt increase in permeability resulting from rock fracture propagation.This increase is quantified by evaluating the plastic damage state of rocks and incorporating a damage coefficient that is intrinsically linked to rock strength.The mechanical model tracks permeability changes due to mining.The flow model simulates aquifer-mine water interactions by calculating hydraulic conductivity and using dynamic zoning,adapt-ing to mining progress.When applied to a case study of a complex mine,this approach significantly improved the accuracy of water inflow rate predictions by 57%.展开更多
Integrating wave energy converters(WECs)with offshore platforms offers numerous advantages,such as reducing wave loads,supplying energy to the platform,and cost-sharing in construction.This paper reports an experiment...Integrating wave energy converters(WECs)with offshore platforms offers numerous advantages,such as reducing wave loads,supplying energy to the platform,and cost-sharing in construction.This paper reports an experimental investigation focusing on the hydrodynamic characteristics of a proposed modular floating structure system integrated with WEC-type floating artificial reefs.The proposed system comprises several serially arranged hexagonal floating structures,anchored by tension legs,and integrated with outermost WEC-type floating artificial reefs.A simplified wave energy converter utilizing the relative pitch motion between adjacent modules for energy conversion was constructed in the scale model test.The effects of chain-type modular expansion on the multi-body motion response,mooring tension response,and WEC performance of the system have been thoroughly investigated.The experimental results indicate that increasing the number of hexagonal modules can notably reduce the system’s surge response,particularly under survival sea conditions.The connection of the outermost reef modules slightly increases the tension leg load of the adjacent module,whereas the tension leg load remains relatively consistent across the inner hexagonal modules.Furthermore,through a comparison of the dynamic responses of the hexagonal module connected and unconnected outermost reefs,the good performance in terms of energy conversion and wave attenuation of the WECtype floating artificial reef modules was effectively validated.The main results from this work can provide useful references for engineering applications involving modular floating structures integrated with WECs.展开更多
Small modular reactor(SMR)belongs to the research forefront of nuclear reactor technology.Nowadays,advancement of intelligent control technologies paves a new way to the design and build of unmanned SMR.The autonomous...Small modular reactor(SMR)belongs to the research forefront of nuclear reactor technology.Nowadays,advancement of intelligent control technologies paves a new way to the design and build of unmanned SMR.The autonomous control process of SMR can be divided into three stages,say,state diagnosis,autonomous decision-making and coordinated control.In this paper,the autonomous state recognition and task planning of unmanned SMR are investigated.An operating condition recognition method based on the knowledge base of SMR operation is proposed by using the artificial neural network(ANN)technology,which constructs a basis for the state judgment of intelligent reactor control path planning.An improved reinforcement learning path planning algorithm is utilized to implement the path transfer decision-makingThis algorithm performs condition transitions with minimal cost under specified modes.In summary,the full range control path intelligent decision-planning technology of SMR is realized,thus provides some theoretical basis for the design and build of unmanned SMR in the future.展开更多
Lignans have been established as a privileged scaffold in drug discovery,particularly in anticancer and antioxidant properties.Concise and efficient construction of lignans and their derivatives in a single operation ...Lignans have been established as a privileged scaffold in drug discovery,particularly in anticancer and antioxidant properties.Concise and efficient construction of lignans and their derivatives in a single operation holds great medicinal significance for structure-activity relationship studies yet remains challenging.Drawing inspiration from the biosynthesis of lignans,we present a general,high-step-economy palladium-catalyzed reaction that converts simple chemical feedstocks into dehydrodibenzylbutyrolactone lignans through the in-situ construction and coupling of two phenylpropanoid molecules.The diversity of organoboronic acids and the editability of enyne provide a powerful platform for the rapid construction of lignan libraries,featuring 82 lignans analogs,collective syntheses of 10 distinct lignan skeletons,and 13 hybrid molecules combining pharmacophore fragments with drug and derivatives.The subtle combination of phosphine ligands with quinones for switching chemoselectivity is vital to the success of this protocol.展开更多
A brief concept study of a modular research aircraft with potential applications to Mars exploration is conducted.Considered are dimensional and mass constraints of a launch vehicle payload compartment,mission radius ...A brief concept study of a modular research aircraft with potential applications to Mars exploration is conducted.Considered are dimensional and mass constraints of a launch vehicle payload compartment,mission radius extension applying ground mobility and overall flight envelope extension using fixed-wing aerodynamics.Also,some lessons learned from NASA Mars Ingenuity flights are considered and addressed with few solutions.The modular system includes a fixed-wing design along with a number of smaller autonomous quadcopter UAVs,encapsulated inside a geodesic spherical support through a gimbal mechanism for ground mobility.Analyzed is the feasibility of allocating to these mini drones both scout and mapping tasks of complex terrain such as crater walls,canyons and cave systems that might hold key insights into the planet's geologic history.Once docked with the mothership fixed wing,the mini drones serve as a distributed propulsion system,for vertical take-off and landing and control,completely replacing control surfaces on the flying wing itself,its engine and landing gear.CFD and structural simulations have demonstrated the flight-ability in Mars conditions of a flying wing design along with scout drone prototypes with a pentagon-hexagon geodesic shell.Also demonstrated is the great flexibility of the suggested modular approach for various research applications and mission profiles on Mars and other planets or moons,improving overall reliability and mission radius.展开更多
This paper comprehensively explores the impulsive on-orbit inspection game problem utilizing reinforcement learning and game training methods.The purpose of the spacecraft is to inspect the entire surface of a non-coo...This paper comprehensively explores the impulsive on-orbit inspection game problem utilizing reinforcement learning and game training methods.The purpose of the spacecraft is to inspect the entire surface of a non-cooperative target with active maneuverability in front lighting.First,the impulsive orbital game problem is formulated as a turn-based sequential game problem.Second,several typical relative orbit transfers are encapsulated into modules to construct a parameterized action space containing discrete modules and continuous parameters,and multi-pass deep Q-networks(MPDQN)algorithm is used to implement autonomous decision-making.Then,a curriculum learning method is used to gradually increase the difficulty of the training scenario.The backtracking proportional self-play training framework is used to enhance the agent’s ability to defeat inconsistent strategies by building a pool of opponents.The behavior variations of the agents during training indicate that the intelligent game system gradually evolves towards an equilibrium situation.The restraint relations between the agents show that the agents steadily improve the strategy.The influence of various factors on game results is tested.展开更多
Given the rapid growth of sustainable construction strategies globally and the importance of resiliency in civil infrastructure,it is crucial to adopt best practices.Modular construction is one such practice and is co...Given the rapid growth of sustainable construction strategies globally and the importance of resiliency in civil infrastructure,it is crucial to adopt best practices.Modular construction is one such practice and is considered a better alternative to conventional construction in terms of resilience,construction times,resource efficiency,and sustainability.However,the continued expansion of modular construction relies on quantifying and evaluating its sustainability and the purported benefits.This paper develops and checks feasibility through an integrated multi-level decision support framework to empirically evaluate the sustainability performances of single-family residential modular homes.Criteria and indicator development and calculation,benchmark scale establishment,quantitative and qualitative data collection from literature and surveys,and multi-criteria decision analysis are unique aspects of this framework.The results of the two case studies located in the Okanagan region,Canada showed that modular homes perform at a higher level of sustainability than their conventional counterparts across multiple metrics and levels related to environmental and economic factors.The modular homes scored eco-efficiency values of 62.5 and 56.0,respectively and fell into higher performance range.The proposed frame-work offers flexibility in examining different dimensions of sustainability,providing valuable insights into the key parameters that need to be addressed to enhance overall sustainability.This research,which integrates life cycle thinking and decision-making,helps the construction industry and,municipalities,governments,and pol-icymakers in making informed decisions on the selection of suitable construction methods in city developments and move towards a more resilient and sustainable sector.展开更多
The seismic intensity is generally high in the Qinghai-Tibet Plateau region of China.The seismic performance of the new prefabricated modular pressurized buildings used to solve the plateau response is insufficient.To...The seismic intensity is generally high in the Qinghai-Tibet Plateau region of China.The seismic performance of the new prefabricated modular pressurized buildings used to solve the plateau response is insufficient.To solve this problem,the small friction pendulum bearing(FPB)isolation design is proposed for modular pressurized buildings.Firstly,a simplified model of cross-truss support for the pressurized module is proposed to simplify the modeling and calculation of the pressurized buildings.The reasonability of the simplified model is verified by comparing the refined finite element model.Subsequently,according to the FPB design process for modular pressurized buildings,a small FPB for isolation is provided for a two-story modular pressurized building under 8-degree fortification earthquakes.Lastly,the seismic effectiveness and constructional feasibility of the isolation structure are verified compared with the non-isolated structure using dynamic time-history analysis.The study results show that the size of FPBs for modular pressurized buildings should consider both displacement and dimension requirements to weigh seismic isolation performance and installation feasibility,respectively.When adopting FPBs,the response of the structure is significantly reduced,and the seismic isolation effect is obvious.The proposed construction process can improve the seismic resilience of the prefabricated modular pressurized buildings by replacing post-earthquake damaged components quickly.It provides ideas for the seismic isolation design of the prefabricated modular pressurized buildings in high seismic intensity areas.展开更多
This article focuses on the municipal prefabricated bathroom station.It elaborates on its modular design concept,including key design points such as spatial layout,functional modules,and determination of key parameter...This article focuses on the municipal prefabricated bathroom station.It elaborates on its modular design concept,including key design points such as spatial layout,functional modules,and determination of key parameters;introduces the optimization of intelligent production processes,precision control,and integration of construction technology,and also mentions the verification of full lifecycle applications and quality control;as well as emphasizes the importance of BIM+IoT platform and looks forward to the future.展开更多
A new modular solution to the state explosion problem caused by the Markov-based modular solution of dynamic multiple-phased systems is proposed. First, the solution makes full use of the static parts of dynamic multi...A new modular solution to the state explosion problem caused by the Markov-based modular solution of dynamic multiple-phased systems is proposed. First, the solution makes full use of the static parts of dynamic multiple-phased systems and constructs cross-phase dynamic modules by combining the dynamic modules of phase fault trees. Secondly, the system binary decision diagram （BDD） from a modularized multiple- phased system （MPS）is generated by using variable ordering and BDD operations. The computational formulations of the BDD node event probability are derived for various node links and the system reliability results are figured out. Finally, a hypothetical multiple-phased system is given to demonstrate the advantages of the dynamic modular solution when the Markov state space and the size of the system BDD are reduced.展开更多
Distributed Integrated Modular Avionics(DIMA)develops from Integrated Modular Avionics(IMA)and realizes distributed integration of multiple sub-function areas.Timetriggered network provides effective support for time ...Distributed Integrated Modular Avionics(DIMA)develops from Integrated Modular Avionics(IMA)and realizes distributed integration of multiple sub-function areas.Timetriggered network provides effective support for time synchronization and information coordination in DIMA systems.However,inconsistency between processing resources and communication network destroys the time determinism benefiting from partitions and time-triggered mechanism.To ensure such time determinism and achieve guaranteed real-time performance,system design should collectively provide a global communication scheme for messages in network domain and a corresponding execution scheme for partitions in processing domain.This paper firstly establishes a general DIMA model which coordinates partitioned processing and time-triggered communication,and then proposes a hybrid scheduling algorithm using Mixed Integer Programming to produce feasible system schemes.Furthermore,incrementally integrating new functions causes upgrades or reconfigurations of DIMA systems and will generate integration cost.To control such cost,this paper further develops an optimization algorithm based on Maximum Satisfiability Problem and guarantees that the scheduling design for upgraded DIMA systems inherit their original schemes as much as possible.Finally,two typical cases,including a simple fully connected DIMA system case and an industrial DIMA system case,are constructed to illustrate our DIMA model and validate the effectiveness of our hybrid scheduling algorithms.展开更多
Recently the integrated modular avionics （IMA） architecture which introduces the concept of resource partitioning becomes popular as an alternative to the traditional federated architecture. A novel hierarchical app...Recently the integrated modular avionics （IMA） architecture which introduces the concept of resource partitioning becomes popular as an alternative to the traditional federated architecture. A novel hierarchical approach is proposed to solve the resource allocation problem for IMA systems in distributed environments. Firstly, the worst case response time of tasks with arbitrary deadlines is analyzed for the two-level scheduler. Then, the hierarchical resource allocation approach is presented in two levels. At the platform level, a task assignment algorithm based on genetic simulated annealing （GSA） is proposed to assign a set of pre-defined tasks to different processing nodes in the form of task groups, so that resources can be allocated as partitions and mapped to task groups. While yielding to all the resource con- straints, the algorithm tries to find an optimal task assignment with minimized communication costs and balanced work load. At the node level, partition parameters are optimized, so that the computational resource can be allocated further. An example is shown to illustrate the hierarchal resource allocation approach and manifest the validity. Simulation results comparing the performance of the proposed GSA with that of traditional genetic algorithms are presented in the context of task assignment in IMA systems.展开更多
4-Bromo-3-methylanisole is mainly used to synthesize black fluorane dye(2-anilino-3-methyl-6-dibutylaminofluorane, ODB-2), which is one of the most important heat and pressure-sensitive dyes in the manufacture of ther...4-Bromo-3-methylanisole is mainly used to synthesize black fluorane dye(2-anilino-3-methyl-6-dibutylaminofluorane, ODB-2), which is one of the most important heat and pressure-sensitive dyes in the manufacture of thermal papers. Compared to the industrial heterogeneous batch process, a continuous homogeneous bromination technology in a modular microreaction system has been developed, and 4-bromo-3-methylanisole has been successfully prepared through high-selective mono-bromination of 3-methylanisole with Br2 solution in CHCl3. In optimal conditions, the content of bis-brominated byproducts can be controlled less than 0.5%,which is superior to the industrial standard with 99.5% 3-methylanisole conversion at very short residence time and mild reaction temperature.展开更多
Modeling of a centrifugal compressor is of great significance to surge characteristics and fluid dynamics in the Altitude Ground Test Facilities(AGTF).Real-time Modular Dynamic System Greitzer(MDSG)modeling for dynami...Modeling of a centrifugal compressor is of great significance to surge characteristics and fluid dynamics in the Altitude Ground Test Facilities(AGTF).Real-time Modular Dynamic System Greitzer(MDSG)modeling for dynamic response and simulation of the compression system is introduced.The centrifugal compressor,pipeline network,and valve are divided into pressure output type and mass flow output type for module modeling,and the two types of components alternate when the system is established.The pressure loss and thermodynamics of the system are considered.An air supply compression system of AGTF is modeled and simulated by the MDSG model.The simulation results of mass flow,pressure,and temperature are compared with the experimental results,and the error is less than 5%,which demonstrates the reliability,practicability,and universality of the MDSG model.展开更多
Objective:To investigate the efficacy and patient satisfaction of the EarWell Infant Ear Correction System combined with modular parents'nursing education's curative effect on deformed auricle.Methods:A total ...Objective:To investigate the efficacy and patient satisfaction of the EarWell Infant Ear Correction System combined with modular parents'nursing education's curative effect on deformed auricle.Methods:A total of 42 patients(29 boys and 13 girls;73 ears;age≤3 months)with auricle deformities who had received EarWell Infant Ear Correction System's treatment and modular parents'nursing education in Guangzhou Children and Women's Medical Center between April and October 2018.The modular parents'education program is standardized by EarWell system.Physician and patients'parents compared the severity of auricle deformity separately before and after the treatment by using the auricle deformities visual analogue scales(VAS)rating system.Patient satisfaction was evaluated by using global aesthetic improvement scale(GAIS).The data collected of auricle deformities VAS and GAIS satisfaction score were applied to measure the treatment's effectiveness.Results:All the 42 patients(73 external ears)completed the treatment with EarWell Infant Ear Correction System and modular parents'nursing education.The mean age at initiation of treatment was 37.87±19.44 days and the therapeutic time span was 47.21±17.36 days.At the end of treatment,the physician's and patients'guardians rating of the severity of auricle deformity were significantly improved separately compared to the initial rating(8.33±1.27 vs.6.51±0.84;P<0.005)(5.77±1.59 vs.8.19±2.38 P<0.05).During the treatment and parents'home nursing care period,the side effect and complications were minor like skin eczema and irrigation;there were no severe complications such as necrosis of the skin and cartilage.The patient tolerance for the treatment was acceptable with the adequate parents'nursing care.Most patients'guardians were satisfied with the treatment outcomes of EarWell Infant Ear Correction System with more engagement of nursing care,the GAIS's rating were increased from pretreatment stage's 26.19%to treatment completed stage's 90.48%,and the difference was statistically significant(P<0.05).Conclusions:In this study,we proved that EarWell Infant Ear Correction System with its unique parents'modular nursing care education,as a noninvasive treatment,reasonably improved auricle morphological malformation,and patients'guardians satisfaction with few complications,which is worthy of a wildly clinical promotion.展开更多
To solve the existing problems during the ceramic mold enterprises product design and development process, the variable structure parametric design system based on modular of ceramic mold has been developed. The syste...To solve the existing problems during the ceramic mold enterprises product design and development process, the variable structure parametric design system based on modular of ceramic mold has been developed. The system uses the object-oriented technology and top-down design concept as a guide, establishes a ceramic mold parametric design process, divides the process of ceramic mold design into modules of different levels and creates a component model library based on the functional analysis. Expanding modular thinking to parts structure design level is an effective solution to the difficulty of changing the structure during the product design process. Examples show that the system can achieve a ceramic mold product design, improve design efficiency.展开更多
This paper studies a fault-tolerant control system for a space modular manipulator system mounted on space station or other spacecrafts such as satellites, located in low earth orbit. Design technologies for tradition...This paper studies a fault-tolerant control system for a space modular manipulator system mounted on space station or other spacecrafts such as satellites, located in low earth orbit. Design technologies for traditional industrial manipulator systems cannot be directly used to the space ones due to the special space environment and compactness. Considering the extremely tight constraints on mass, power consumption, volume, cost and ＂design-to-orbit＂ schedules, the fault-tolerant control system is developed mainly based on commercial-off-the-shaft components. The features of the hardware and software of the fault-tolerant control system are presented. The performance specifications are also discussed. Because many space proven design technologies and experiences are adopted, the fault-tolerant control system is characterized by high reliability and practicability.展开更多
基金supported by the National Key Research and Development Plan,Grant/Award Number:2018YFB1503005.
文摘A modular system of cascaded converters based on model predictive control(MPC)is proposed to meet the application requirements ofmultiple voltage levels and electrical isolation in renewable energy generation systems.The system consists of a Buck/Boost+CLLLC cascaded converter as a submodule,which is combined in series and parallel on the input and output sides to achieve direct-current(DC)voltage transformation,bidirectional energy flow,and electrical isolation.The CLLLC converter operates in DC transformer mode in the submodule,while the Buck/Boost converter participates in voltage regulation.This article establishes a suitable mathematical model for the proposed system topology,and uses MPC to control the system based on this mathematical model.Module parameters are designed and calculated,and simulation is built in MATLAB/Simulink to complete the simulation comparison experiment between MPC and traditional proportional integral(PI)control.Finally,a physical experimental platform is built to complete the physical comparison experiment.The simulation and physical experimental results prove that the control accuracy and response speed ofMPC are better than traditional PI control strategy.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(LY22E050011)National Natural Science Foundation of China(T2121004,51805475)。
文摘In clinical practice,the irregular shapes of traumas pose a significant challenge in rapidly manufacturing personalized scaffolds.To address these challenges,inspired by LEGO■ bricks,this study proposed a novel concept of modular scaffolds and developed an innovative system based on machine vision for their rapid and intelligent assembly tailored to defect shapes.Trapezoidal interfaces effectively connect standardized bone units based on magnesium-doped silicate calcium,ensuring high stability of the modular scaffolds,with compressive strength up to 135 MPa and bending strength up to 17 MPa.Through self-developed defect recognition and reconstruction algorithms,defect recognition and personalized assembly schemes for bone scaffolds can be achieved autonomously.Modular scaffolds seamlessly integrate with surrounding bone tissue,promoting new bone growth,with no apparent differences compared to fully 3D printed integral scaffolds in the skull and femur repair experiments.In summary,the adoption of modular scaffolds not only integrates personalization and standardization but also satisfies the optimal treatment window.
文摘Based on the analysis and research of the airworthiness objective of integrated modular avionics system(IMA),and the characteristics of IMA system’s comprehensive and complex cross-linking with other airborne systems,the extraction strategy of IMA system’s compliance flight test subjects and the selection method of IMA system’s compliance flight test parameters are proposed.The data analysis method based on the abnormal probability matrix of the IMA system is proposed for the first time,and the abnormal state information of the IMA system can be quickly identified.The compliance flight test of the IMA system is completed with limited flight test resources,which achieves the purpose of saving flight test sorties and improving flight test efficiency.This research has been successfully applied to the airworthiness certification flight test of a certain civil transport aircraft in China,and can provide technical support for the subsequent type flight test.
基金supported by the National Natural Science Foundation of China (Nos. 42027801, 42072284, and 42372297)the National Key Research and Development Program of China (Nos. 2023YFC3012102 and 2021YFC2902004)the Fundamental Research Funds for the Central Universities (No. 2023ZKPYSH01)
文摘The intricate interplay between rock mechanics and fracture-induced fluid flow during resource extrac-tion exerts profound effects on groundwater systems,posing a pivotal challenge for promoting green and safe development in underground engineering.To address this,a novel numerical model with an explicit coupling simulation strategy is presented.This model integrates distinct modules for individual physical mechanisms,ensuring second-order accuracy through shared time integration,thereby overcoming lim-itations in simulating mining-induced strata damage,water flow,and permeability dynamics.A novel mathematical model is incorporated into the mechanical simulation to characterize the abrupt increase in permeability resulting from rock fracture propagation.This increase is quantified by evaluating the plastic damage state of rocks and incorporating a damage coefficient that is intrinsically linked to rock strength.The mechanical model tracks permeability changes due to mining.The flow model simulates aquifer-mine water interactions by calculating hydraulic conductivity and using dynamic zoning,adapt-ing to mining progress.When applied to a case study of a complex mine,this approach significantly improved the accuracy of water inflow rate predictions by 57%.
基金financially supported by the National Natural Science Foundation of China(Grant No.52161041)the Natural Science Foundation of Hainan Province(Grant No.520RC552).
文摘Integrating wave energy converters(WECs)with offshore platforms offers numerous advantages,such as reducing wave loads,supplying energy to the platform,and cost-sharing in construction.This paper reports an experimental investigation focusing on the hydrodynamic characteristics of a proposed modular floating structure system integrated with WEC-type floating artificial reefs.The proposed system comprises several serially arranged hexagonal floating structures,anchored by tension legs,and integrated with outermost WEC-type floating artificial reefs.A simplified wave energy converter utilizing the relative pitch motion between adjacent modules for energy conversion was constructed in the scale model test.The effects of chain-type modular expansion on the multi-body motion response,mooring tension response,and WEC performance of the system have been thoroughly investigated.The experimental results indicate that increasing the number of hexagonal modules can notably reduce the system’s surge response,particularly under survival sea conditions.The connection of the outermost reef modules slightly increases the tension leg load of the adjacent module,whereas the tension leg load remains relatively consistent across the inner hexagonal modules.Furthermore,through a comparison of the dynamic responses of the hexagonal module connected and unconnected outermost reefs,the good performance in terms of energy conversion and wave attenuation of the WECtype floating artificial reef modules was effectively validated.The main results from this work can provide useful references for engineering applications involving modular floating structures integrated with WECs.
文摘Small modular reactor(SMR)belongs to the research forefront of nuclear reactor technology.Nowadays,advancement of intelligent control technologies paves a new way to the design and build of unmanned SMR.The autonomous control process of SMR can be divided into three stages,say,state diagnosis,autonomous decision-making and coordinated control.In this paper,the autonomous state recognition and task planning of unmanned SMR are investigated.An operating condition recognition method based on the knowledge base of SMR operation is proposed by using the artificial neural network(ANN)technology,which constructs a basis for the state judgment of intelligent reactor control path planning.An improved reinforcement learning path planning algorithm is utilized to implement the path transfer decision-makingThis algorithm performs condition transitions with minimal cost under specified modes.In summary,the full range control path intelligent decision-planning technology of SMR is realized,thus provides some theoretical basis for the design and build of unmanned SMR in the future.
基金Financial support was provided by the State Key Laboratory of Pulp and Paper Engineering(No.2022PY01)the National Natural Science Foundation of China(Nos.22231002 and 21871095)the Key-Area Research and Development Program of Guangdong Province(No.2020B010188001)。
文摘Lignans have been established as a privileged scaffold in drug discovery,particularly in anticancer and antioxidant properties.Concise and efficient construction of lignans and their derivatives in a single operation holds great medicinal significance for structure-activity relationship studies yet remains challenging.Drawing inspiration from the biosynthesis of lignans,we present a general,high-step-economy palladium-catalyzed reaction that converts simple chemical feedstocks into dehydrodibenzylbutyrolactone lignans through the in-situ construction and coupling of two phenylpropanoid molecules.The diversity of organoboronic acids and the editability of enyne provide a powerful platform for the rapid construction of lignan libraries,featuring 82 lignans analogs,collective syntheses of 10 distinct lignan skeletons,and 13 hybrid molecules combining pharmacophore fragments with drug and derivatives.The subtle combination of phosphine ligands with quinones for switching chemoselectivity is vital to the success of this protocol.
基金funded by the Russian Science Foundation(No.22–49-02047)。
文摘A brief concept study of a modular research aircraft with potential applications to Mars exploration is conducted.Considered are dimensional and mass constraints of a launch vehicle payload compartment,mission radius extension applying ground mobility and overall flight envelope extension using fixed-wing aerodynamics.Also,some lessons learned from NASA Mars Ingenuity flights are considered and addressed with few solutions.The modular system includes a fixed-wing design along with a number of smaller autonomous quadcopter UAVs,encapsulated inside a geodesic spherical support through a gimbal mechanism for ground mobility.Analyzed is the feasibility of allocating to these mini drones both scout and mapping tasks of complex terrain such as crater walls,canyons and cave systems that might hold key insights into the planet's geologic history.Once docked with the mothership fixed wing,the mini drones serve as a distributed propulsion system,for vertical take-off and landing and control,completely replacing control surfaces on the flying wing itself,its engine and landing gear.CFD and structural simulations have demonstrated the flight-ability in Mars conditions of a flying wing design along with scout drone prototypes with a pentagon-hexagon geodesic shell.Also demonstrated is the great flexibility of the suggested modular approach for various research applications and mission profiles on Mars and other planets or moons,improving overall reliability and mission radius.
文摘This paper comprehensively explores the impulsive on-orbit inspection game problem utilizing reinforcement learning and game training methods.The purpose of the spacecraft is to inspect the entire surface of a non-cooperative target with active maneuverability in front lighting.First,the impulsive orbital game problem is formulated as a turn-based sequential game problem.Second,several typical relative orbit transfers are encapsulated into modules to construct a parameterized action space containing discrete modules and continuous parameters,and multi-pass deep Q-networks(MPDQN)algorithm is used to implement autonomous decision-making.Then,a curriculum learning method is used to gradually increase the difficulty of the training scenario.The backtracking proportional self-play training framework is used to enhance the agent’s ability to defeat inconsistent strategies by building a pool of opponents.The behavior variations of the agents during training indicate that the intelligent game system gradually evolves towards an equilibrium situation.The restraint relations between the agents show that the agents steadily improve the strategy.The influence of various factors on game results is tested.
文摘Given the rapid growth of sustainable construction strategies globally and the importance of resiliency in civil infrastructure,it is crucial to adopt best practices.Modular construction is one such practice and is considered a better alternative to conventional construction in terms of resilience,construction times,resource efficiency,and sustainability.However,the continued expansion of modular construction relies on quantifying and evaluating its sustainability and the purported benefits.This paper develops and checks feasibility through an integrated multi-level decision support framework to empirically evaluate the sustainability performances of single-family residential modular homes.Criteria and indicator development and calculation,benchmark scale establishment,quantitative and qualitative data collection from literature and surveys,and multi-criteria decision analysis are unique aspects of this framework.The results of the two case studies located in the Okanagan region,Canada showed that modular homes perform at a higher level of sustainability than their conventional counterparts across multiple metrics and levels related to environmental and economic factors.The modular homes scored eco-efficiency values of 62.5 and 56.0,respectively and fell into higher performance range.The proposed frame-work offers flexibility in examining different dimensions of sustainability,providing valuable insights into the key parameters that need to be addressed to enhance overall sustainability.This research,which integrates life cycle thinking and decision-making,helps the construction industry and,municipalities,governments,and pol-icymakers in making informed decisions on the selection of suitable construction methods in city developments and move towards a more resilient and sustainable sector.
基金supported by Technology Research and Development Program of China Construction Advanced Technology Research Institute(Grant No.XJY-2024-16)。
文摘The seismic intensity is generally high in the Qinghai-Tibet Plateau region of China.The seismic performance of the new prefabricated modular pressurized buildings used to solve the plateau response is insufficient.To solve this problem,the small friction pendulum bearing(FPB)isolation design is proposed for modular pressurized buildings.Firstly,a simplified model of cross-truss support for the pressurized module is proposed to simplify the modeling and calculation of the pressurized buildings.The reasonability of the simplified model is verified by comparing the refined finite element model.Subsequently,according to the FPB design process for modular pressurized buildings,a small FPB for isolation is provided for a two-story modular pressurized building under 8-degree fortification earthquakes.Lastly,the seismic effectiveness and constructional feasibility of the isolation structure are verified compared with the non-isolated structure using dynamic time-history analysis.The study results show that the size of FPBs for modular pressurized buildings should consider both displacement and dimension requirements to weigh seismic isolation performance and installation feasibility,respectively.When adopting FPBs,the response of the structure is significantly reduced,and the seismic isolation effect is obvious.The proposed construction process can improve the seismic resilience of the prefabricated modular pressurized buildings by replacing post-earthquake damaged components quickly.It provides ideas for the seismic isolation design of the prefabricated modular pressurized buildings in high seismic intensity areas.
文摘This article focuses on the municipal prefabricated bathroom station.It elaborates on its modular design concept,including key design points such as spatial layout,functional modules,and determination of key parameters;introduces the optimization of intelligent production processes,precision control,and integration of construction technology,and also mentions the verification of full lifecycle applications and quality control;as well as emphasizes the importance of BIM+IoT platform and looks forward to the future.
基金The National Natural Science Foundation of China(No.60903011)the Natural Science Foundation of Jiangsu Province(No.BK2009267)
文摘A new modular solution to the state explosion problem caused by the Markov-based modular solution of dynamic multiple-phased systems is proposed. First, the solution makes full use of the static parts of dynamic multiple-phased systems and constructs cross-phase dynamic modules by combining the dynamic modules of phase fault trees. Secondly, the system binary decision diagram （BDD） from a modularized multiple- phased system （MPS）is generated by using variable ordering and BDD operations. The computational formulations of the BDD node event probability are derived for various node links and the system reliability results are figured out. Finally, a hypothetical multiple-phased system is given to demonstrate the advantages of the dynamic modular solution when the Markov state space and the size of the system BDD are reduced.
基金co-supported by the National Natural Science Foundation of China(No.71701020)the Defense Research Field Foundation of China(No.61403120404)the Civil Aircraft Airworthiness and Maintenance Key Laboratory Fund of Civil Aviation University of China(No.2017SW02).
文摘Distributed Integrated Modular Avionics(DIMA)develops from Integrated Modular Avionics(IMA)and realizes distributed integration of multiple sub-function areas.Timetriggered network provides effective support for time synchronization and information coordination in DIMA systems.However,inconsistency between processing resources and communication network destroys the time determinism benefiting from partitions and time-triggered mechanism.To ensure such time determinism and achieve guaranteed real-time performance,system design should collectively provide a global communication scheme for messages in network domain and a corresponding execution scheme for partitions in processing domain.This paper firstly establishes a general DIMA model which coordinates partitioned processing and time-triggered communication,and then proposes a hybrid scheduling algorithm using Mixed Integer Programming to produce feasible system schemes.Furthermore,incrementally integrating new functions causes upgrades or reconfigurations of DIMA systems and will generate integration cost.To control such cost,this paper further develops an optimization algorithm based on Maximum Satisfiability Problem and guarantees that the scheduling design for upgraded DIMA systems inherit their original schemes as much as possible.Finally,two typical cases,including a simple fully connected DIMA system case and an industrial DIMA system case,are constructed to illustrate our DIMA model and validate the effectiveness of our hybrid scheduling algorithms.
基金supported by the National Natural Science Foundation of China (60879024)
文摘Recently the integrated modular avionics （IMA） architecture which introduces the concept of resource partitioning becomes popular as an alternative to the traditional federated architecture. A novel hierarchical approach is proposed to solve the resource allocation problem for IMA systems in distributed environments. Firstly, the worst case response time of tasks with arbitrary deadlines is analyzed for the two-level scheduler. Then, the hierarchical resource allocation approach is presented in two levels. At the platform level, a task assignment algorithm based on genetic simulated annealing （GSA） is proposed to assign a set of pre-defined tasks to different processing nodes in the form of task groups, so that resources can be allocated as partitions and mapped to task groups. While yielding to all the resource con- straints, the algorithm tries to find an optimal task assignment with minimized communication costs and balanced work load. At the node level, partition parameters are optimized, so that the computational resource can be allocated further. An example is shown to illustrate the hierarchal resource allocation approach and manifest the validity. Simulation results comparing the performance of the proposed GSA with that of traditional genetic algorithms are presented in the context of task assignment in IMA systems.
基金financial support from National Key R&D Program of China(2017YFB0307102)National Natural Science Foundation of China(21991100,21991104)。
文摘4-Bromo-3-methylanisole is mainly used to synthesize black fluorane dye(2-anilino-3-methyl-6-dibutylaminofluorane, ODB-2), which is one of the most important heat and pressure-sensitive dyes in the manufacture of thermal papers. Compared to the industrial heterogeneous batch process, a continuous homogeneous bromination technology in a modular microreaction system has been developed, and 4-bromo-3-methylanisole has been successfully prepared through high-selective mono-bromination of 3-methylanisole with Br2 solution in CHCl3. In optimal conditions, the content of bis-brominated byproducts can be controlled less than 0.5%,which is superior to the industrial standard with 99.5% 3-methylanisole conversion at very short residence time and mild reaction temperature.
基金supported in part by the Stable Support Research Project of AECC Sichuan Gas Turbine Establishment,China(No.GJCZ-0013-19)the Open Foundation of State Key Laboratory of Compressor Technology,China(Compressor Technology Laboratory of Anhui Province)(No.SKL-YSJ2020007).
文摘Modeling of a centrifugal compressor is of great significance to surge characteristics and fluid dynamics in the Altitude Ground Test Facilities(AGTF).Real-time Modular Dynamic System Greitzer(MDSG)modeling for dynamic response and simulation of the compression system is introduced.The centrifugal compressor,pipeline network,and valve are divided into pressure output type and mass flow output type for module modeling,and the two types of components alternate when the system is established.The pressure loss and thermodynamics of the system are considered.An air supply compression system of AGTF is modeled and simulated by the MDSG model.The simulation results of mass flow,pressure,and temperature are compared with the experimental results,and the error is less than 5%,which demonstrates the reliability,practicability,and universality of the MDSG model.
文摘Objective:To investigate the efficacy and patient satisfaction of the EarWell Infant Ear Correction System combined with modular parents'nursing education's curative effect on deformed auricle.Methods:A total of 42 patients(29 boys and 13 girls;73 ears;age≤3 months)with auricle deformities who had received EarWell Infant Ear Correction System's treatment and modular parents'nursing education in Guangzhou Children and Women's Medical Center between April and October 2018.The modular parents'education program is standardized by EarWell system.Physician and patients'parents compared the severity of auricle deformity separately before and after the treatment by using the auricle deformities visual analogue scales(VAS)rating system.Patient satisfaction was evaluated by using global aesthetic improvement scale(GAIS).The data collected of auricle deformities VAS and GAIS satisfaction score were applied to measure the treatment's effectiveness.Results:All the 42 patients(73 external ears)completed the treatment with EarWell Infant Ear Correction System and modular parents'nursing education.The mean age at initiation of treatment was 37.87±19.44 days and the therapeutic time span was 47.21±17.36 days.At the end of treatment,the physician's and patients'guardians rating of the severity of auricle deformity were significantly improved separately compared to the initial rating(8.33±1.27 vs.6.51±0.84;P<0.005)(5.77±1.59 vs.8.19±2.38 P<0.05).During the treatment and parents'home nursing care period,the side effect and complications were minor like skin eczema and irrigation;there were no severe complications such as necrosis of the skin and cartilage.The patient tolerance for the treatment was acceptable with the adequate parents'nursing care.Most patients'guardians were satisfied with the treatment outcomes of EarWell Infant Ear Correction System with more engagement of nursing care,the GAIS's rating were increased from pretreatment stage's 26.19%to treatment completed stage's 90.48%,and the difference was statistically significant(P<0.05).Conclusions:In this study,we proved that EarWell Infant Ear Correction System with its unique parents'modular nursing care education,as a noninvasive treatment,reasonably improved auricle morphological malformation,and patients'guardians satisfaction with few complications,which is worthy of a wildly clinical promotion.
文摘To solve the existing problems during the ceramic mold enterprises product design and development process, the variable structure parametric design system based on modular of ceramic mold has been developed. The system uses the object-oriented technology and top-down design concept as a guide, establishes a ceramic mold parametric design process, divides the process of ceramic mold design into modules of different levels and creates a component model library based on the functional analysis. Expanding modular thinking to parts structure design level is an effective solution to the difficulty of changing the structure during the product design process. Examples show that the system can achieve a ceramic mold product design, improve design efficiency.
基金"863" National High Technology Foundation in Astronautics(2005AA742030)
文摘This paper studies a fault-tolerant control system for a space modular manipulator system mounted on space station or other spacecrafts such as satellites, located in low earth orbit. Design technologies for traditional industrial manipulator systems cannot be directly used to the space ones due to the special space environment and compactness. Considering the extremely tight constraints on mass, power consumption, volume, cost and ＂design-to-orbit＂ schedules, the fault-tolerant control system is developed mainly based on commercial-off-the-shaft components. The features of the hardware and software of the fault-tolerant control system are presented. The performance specifications are also discussed. Because many space proven design technologies and experiences are adopted, the fault-tolerant control system is characterized by high reliability and practicability.
