Zeroing neural dynamic(ZND)model is widely deployed for time-variant non-linear equations(TVNE).Various element-wise non-linear activation functions and integration operations are investigated to enhance the convergen...Zeroing neural dynamic(ZND)model is widely deployed for time-variant non-linear equations(TVNE).Various element-wise non-linear activation functions and integration operations are investigated to enhance the convergence performance and robustness in most proposed ZND models for solving TVNE,leading to a huge cost of hardware implementation and model complexity.To overcome these problems,the authors develop a new norm-based ZND(NBZND)model with strong robustness for solving TVNE,not applying element-wise non-linear activated functions but introducing a two-norm operation to achieve finite-time convergence.Moreover,the authors develop a discretetime NBZND model for the potential deployment of the model on digital computers.Rigorous theoretical analysis for the NBZND is provided.Simulation results substantiate the advantages of the NBZND model for solving TVNE.展开更多
The problem of multi-robot formation is prevalent in scientific and engineering applications,where robots must adapt to uncertain and dynamic behaviors due to real-time environmental or task changes.Traditional method...The problem of multi-robot formation is prevalent in scientific and engineering applications,where robots must adapt to uncertain and dynamic behaviors due to real-time environmental or task changes.Traditional methods struggle to meet the demand for high-precision solutions within finite time frames.Zeroing Neural Networks(ZNNs),which utilize the time derivatives of time-varying coefficients,outperform other networks in handling dynamic system behaviors.This paper marks the first attempt to extend the ZNN approach to address finite-time multi-robot through optimization modeling.We introduce an innovative strategy that employs complex number structures to map robot coordinates,simplifying the computation needed for dynamic formation tasks.Additionally,we present a multi-robot formation strategy that minimizes the distance between neighboring robots while adhering to bias-type center constraint.This is effectively reformulated as a complex-valued time-varying matrix equation.Based on this,two complex-type Finite-Time Zeroing Dynamic Controllers(FTZDC)are designed,with their stability and convergence time bounds rigorously analyzed.Finally,in two specific formation tasks,the proposed strategy and FTZDC models achieve precise multi-robot formation,independent of the robots’initial positions,all within finite time.展开更多
While desalination is a key solution for global freshwater scarcity,its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems.Solar interfa...While desalination is a key solution for global freshwater scarcity,its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems.Solar interfacial evaporation offers sustainable management potential,yet inevitable salt nucleation at evaporation interfaces degrades photothermal conversion and operational stability via light scattering and pathway blockage.Inspired by the mangrove leaf,we propose a photothermal 3D polydopamine and polypyrrole polymerized spacer fabric(PPSF)-based upward hanging model evaporation configuration with a reverse water feeding mechanism.This design enables zero-liquiddischarge(ZLD)desalination through phase-separation crystallization.The interconnected porous architecture and the rough surface of the PPSF enable superior water transport,achieving excellent solar-absorbing efficiency of 97.8%.By adjusting the tilt angle(θ),the evaporator separates the evaporation and salt crystallization zones via controlled capillary-driven brine transport,minimizing heat dissipation from brine discharge.At an optimal tilt angle of 52°,the evaporator reaches an evaporation rate of 2.81 kg m^(−2) h^(−1) with minimal heat loss(0.366 W)under 1-sun illumination while treating a 7 wt%waste brine solution.Furthermore,it sustains an evaporation rate of 2.71 kg m^(−2) h^(−1) over 72 h while ensuring efficient salt recovery.These results highlight a scalable,energy-efficient approach for sustainable ZLD desalination.展开更多
With more and more IoT terminals being deployed in various power grid business scenarios,terminal reliability has become a practical challenge that threatens the current security protection architecture.Most IoT termi...With more and more IoT terminals being deployed in various power grid business scenarios,terminal reliability has become a practical challenge that threatens the current security protection architecture.Most IoT terminals have security risks and vulnerabilities,and limited resources make it impossible to deploy costly security protection methods on the terminal.In order to cope with these problems,this paper proposes a lightweight trust evaluation model TCL,which combines three network models,TCN,CNN,and LSTM,with stronger feature extraction capability and can score the reliability of the device by periodically analyzing the traffic behavior and activity logs generated by the terminal device,and the trust evaluation of the terminal’s continuous behavior can be achieved by combining the scores of different periods.After experiments,it is proved that TCL can effectively use the traffic behaviors and activity logs of terminal devices for trust evaluation and achieves F1-score of 95.763,94.456,99.923,and 99.195 on HDFS,BGL,N-BaIoT,and KDD99 datasets,respectively,and the size of TCL is only 91KB,which can achieve similar or better performance than CNN-LSTM,RobustLog and other methods with less computational resources and storage space.展开更多
The United Nations Sustainable Development Goal(SDG) 2 aims to achieve Zero Hunger by 2030.However,global hunger and food insecurity have continued to rise at an alarming rate(UN 2023).Subtropical regions are home to ...The United Nations Sustainable Development Goal(SDG) 2 aims to achieve Zero Hunger by 2030.However,global hunger and food insecurity have continued to rise at an alarming rate(UN 2023).Subtropical regions are home to more than 30% of the world's population,predominantly in developing countries where per capita farmland and food supply are only 40% of those in developed nations(FAO 2018).Meeting the Zero Hunger target amid ongoing population growth in these regions requires a substantial increase in agricultural production while minimizing soil degradation and adverse ecological impacts.This challenge is shared by many countries across South Asia,Africa,and Central and South America.展开更多
Hainan Province in south China is the country’s second-largest island and the largest free trade port by area.It has entered a historic phase in China’s drive to promote high-level institutional opening up.On 18 Dec...Hainan Province in south China is the country’s second-largest island and the largest free trade port by area.It has entered a historic phase in China’s drive to promote high-level institutional opening up.On 18 December 2025,Hainan officially launched island-wide special customs operations,commonly referred to as“customs closure.”From that date,goods entering or leaving the island,except those traded with the Chinese mainland,are subject to simplified customs procedures and potentially reduced or zero tariffs.展开更多
2026年1月31日-2月4日,美国供热、制冷与空调工程师学会(ASHRAE)2026年冬季会议在美国拉斯维加斯隆重召开。来自全球数十个国家的行业专家、学者及工程师齐聚一堂,共同探讨建筑环境系统与能源工程领域的前沿技术与发展趋势。会议期间,AS...2026年1月31日-2月4日,美国供热、制冷与空调工程师学会(ASHRAE)2026年冬季会议在美国拉斯维加斯隆重召开。来自全球数十个国家的行业专家、学者及工程师齐聚一堂,共同探讨建筑环境系统与能源工程领域的前沿技术与发展趋势。会议期间,ASHRAE学会正式颁发了2026年度“Engineering Global Net Zero”创新奖。“Engineering Global Net Zero”创新奖(Innovation Award 2026)旨在表彰全球范围内在推动建筑环境领域可持续发展与技术创新方面作出卓越贡献的杰出个人,该奖项由美国供热、制冷与空调工程师学会(ASHRAE)组织评议。展开更多
This work presents a nonlinear integral-ameliorated model for handling dynamic optimization problems with affine constraints.They pose a challenge as their optimal solutions evolve with time.Traditional iteration-base...This work presents a nonlinear integral-ameliorated model for handling dynamic optimization problems with affine constraints.They pose a challenge as their optimal solutions evolve with time.Traditional iteration-based methods that exactly solve the problem at each time instant,fail to precisely and realtime track the solution due to computational and communication bottlenecks.Our model,through rigorous theoretical analyses,is able to reduce the optimality gap(i.e.,the difference between the model state and optimal solution)to zero in a finite time,and thus,track the solution online.Besides,perturbance is taken into account.We prove that under certain conditions,our model can totally tolerate an important kind of noise that we call“errorrelated noise”.In numerical experiments,compared with six existing methods,our model exhibits superior robustness when contaminated by the error-related noise.The key techniques in the model design involve employing the zeroing neural network to leverage time-derivative information,and introducing an integral term as well as the class C_(L)^(0)functions to enhance convergence and noise resistance.Finally,we establish a model-free control framework for a surgical manipulator with the remote-center-of-motion constraint and compare the performances of the framework based on different models in simulations.The results indicate that our model achieves the best performance among various models employed within the framework.展开更多
Dear Editor,Aiming at the consensus tracking problem of a class of unknown heterogeneous nonlinear multiagent systems(MASs)with input constraints,a novel data-driven iterative learning consensus control(ILCC)protocol ...Dear Editor,Aiming at the consensus tracking problem of a class of unknown heterogeneous nonlinear multiagent systems(MASs)with input constraints,a novel data-driven iterative learning consensus control(ILCC)protocol based on zeroing neural networks(ZNNs)is proposed.First,a dynamic linearization data model(DLDM)is acquired via dynamic linearization technology(DLT).展开更多
Hilly terrain pipeline is a common form of pipeline in oil and gas storage and transportation industry.Due to the hilly terrain influence, the liquid at the elbow of the gathering pipeline is easy to flow back and acc...Hilly terrain pipeline is a common form of pipeline in oil and gas storage and transportation industry.Due to the hilly terrain influence, the liquid at the elbow of the gathering pipeline is easy to flow back and accumulate to form slug flow, so it is necessary to remove the accumulated liquid by gas purging. In this paper, experiment is carried out in hilly terrain pipelines. Three flow patterns of stratified flow, slug flow and stratified entrained flow are observed. The process of gas purging accumulated liquid is divided into four stages, namely liquid accumulation, liquid rising, continuous outflow and tail outflow. At the same time, the flow pattern maps of each stage are drawn. The pressure drop signal is analyzed in time domain and frequency domain, and the contour map of pressure drop distribution is drawn. It is found that the ratio of range to average value can well distinguish the occurrence range of each flow pattern.Based on visualization, the transition process of slug flow to stratified flow and stratified entrained flow is studied, and the transition boundary prediction model is established. An image processing method is proposed to convert the image signal into a similarity curve, and PSD analysis is performed to calculate the slug frequency. The normal distribution is used to fit the slug frequency, and the predicted correlation is in good agreement with the experimental data.展开更多
One of the pathways to attain NET ZERO is CO_(2)injection into deep saline aquifers(DSAs),which alters the saturation and pore pressure of the reservoir rocks,hence the effective stress,sʹ.This,in turn,would change th...One of the pathways to attain NET ZERO is CO_(2)injection into deep saline aquifers(DSAs),which alters the saturation and pore pressure of the reservoir rocks,hence the effective stress,sʹ.This,in turn,would change their geomechanical(i.e.peak deviatoric stress,elastic modulus,Poisson's ratio)and petrophysical(porosity and permeability)properties.Such a situation might trigger geo-hazards,like induced seismicity,ground deformation,caprock failure.Hence,reducing the risk of such hazards necessitates quantifying the spatial and temporal changes in sʹ,under specific CO_(2)and/or brine saturation,designated as S_(CO2)and S_(b),respectively,and resultant pore pressure.With this in view,a conceptual model depicting the reservoir,demarcated by five zones based on variations in saturation,pore-pressure,temperature,etc.,and the corresponding effective stress equations have been proposed based on the available literature.Furthermore,a critical review of literature has been carried out to decipher the limitations and contradictions associated with the findings from(i)laboratory studies to estimate S_(CO2)employing pwave velocity and electrical resistivity,(ii)analytical and numerical approaches for estimating the variation of pore-pressure in the reservoir rocks,and(iii)laboratory studies on variation in geomechanical and petrophysical properties under the conditions representative of the above-mentioned zones of the conceptual model.The authors consider that extensive experiments should be conducted on the rocks from different sources and tested under various conditions of the CO_(2)injection to validate the proposed model for the execution of risk-free CO_(2)storage in DSAs.展开更多
We study the two-dimensional(2D)Cauchy problem of nonhomogeneous Boussinesq system for magnetohydrodynamics convection without heat diffusion in the whole plane.Based on delicate weighted estimates,we derive the globa...We study the two-dimensional(2D)Cauchy problem of nonhomogeneous Boussinesq system for magnetohydrodynamics convection without heat diffusion in the whole plane.Based on delicate weighted estimates,we derive the global existence and uniqueness of strong solutions.In particular,the initial data can be arbitrarily large and the initial density may contain vacuum states and even have compact support.展开更多
When the proton exchange membrane fuel cell(PEMFC)system is running,there will be a condition that does not require power output for a short time.In order to achieve zero power output under low power consumption,it is...When the proton exchange membrane fuel cell(PEMFC)system is running,there will be a condition that does not require power output for a short time.In order to achieve zero power output under low power consumption,it is necessary to consider the diversity of control targets and the complexity of dynamic models,which brings the challenge of high-precision tracking control of the stack output power and cathode intake flow.For system idle speed control,a modelbased nonlinear control framework is constructed in this paper.Firstly,the nonlinear dynamic model of output power and cathode intake flow is derived.Secondly,a control scheme combining nonlinear extended Kalman filter observer and state feedback controller is designed.Finally,the control scheme is verified on the PEMFC experimental platform and compared with the proportion-integration-differentiation(PID)controller.The experimental results show that the control strategy proposed in this paper can realize the idle speed control of the fuel cell system and achieve the purpose of zero power output.Compared with PID controller,it has faster response speed and better system dynamics.展开更多
Dear Editor,This letter focuses on how an attacker can design suitable improved zero-dynamics (ZD) attack signal based on state estimates of target system. Improved ZD attack is to change zero dynamic gain matrix of a...Dear Editor,This letter focuses on how an attacker can design suitable improved zero-dynamics (ZD) attack signal based on state estimates of target system. Improved ZD attack is to change zero dynamic gain matrix of attack signal to a matrix with determinant greater than 1.展开更多
The concept of Net Zero Carbon Buildings,which aims to reduce greenhouse gas emissions,is essential in addressing climate change.However,the development of such buildings in Thailand faces significant challenges,inclu...The concept of Net Zero Carbon Buildings,which aims to reduce greenhouse gas emissions,is essential in addressing climate change.However,the development of such buildings in Thailand faces significant challenges,including high construction costs,uncertain returns,and limited investment incentives.This study explores the factors influencing real estate developers’decisions to pursue Net Zero Carbon Buildings in Thailand,with a focus on physical,financial,and policy-related elements.Data collection was done with 388 respondents who are stakeholders,including developers,consultants,designers,and sustainability experts,through an online questionnaire,and analyzed using Multiple Regression Analysis.The independent variables in the analytical model consist of three groups of factors:physical buildings,climate finance,and climate policy.The results indicate that physical building factors,including building age,engineering systems,and design;climate finance factors,such as project cost increases,financial returns,and investment incentives;and climate policy factors,including government policies,international climate agreements,and carbon taxes,significantly influence development decisions.Government policies,building engineering systems,and financial incentives were identified as key positive drivers for investment,while carbon taxes and energy efficiency-focused designs were found to potentially discourage investment due to higher costs.The study concludes that substantial government support such as tax incentives,grants,and low-interest financing is critical to fostering investment in Net Zero Carbon Buildings.Additionally,raising awareness among developers and the private sector about the long-term benefits of these projects is essential to strengthening investment incentives.展开更多
In the context of an increasingly severe cybersecurity landscape and the growing complexity of offensive and defen-sive techniques,Zero Trust Networks(ZTN)have emerged as a widely recognized technology.Zero Trust not ...In the context of an increasingly severe cybersecurity landscape and the growing complexity of offensive and defen-sive techniques,Zero Trust Networks(ZTN)have emerged as a widely recognized technology.Zero Trust not only addresses the shortcomings of traditional perimeter security models but also consistently follows the fundamental principle of“never trust,always verify.”Initially proposed by John Cortez in 2010 and subsequently promoted by Google,the Zero Trust model has become a key approach to addressing the ever-growing security threats in complex network environments.This paper systematically compares the current mainstream cybersecurity models,thoroughly explores the advantages and limitations of the Zero Trust model,and provides an in-depth review of its components and key technologies.Additionally,it analyzes the latest research achievements in the application of Zero Trust technology across various fields,including network security,6G networks,the Internet of Things(IoT),and cloud computing,in the context of specific use cases.The paper also discusses the innovative contributions of the Zero Trust model in these fields,the challenges it faces,and proposes corresponding solutions and future research directions.展开更多
Understanding crash contributing factors is essential in safety management and improvement. These factors drive investment decisions, policies, regulations, and other safety-related initiatives. This paper analyzes fa...Understanding crash contributing factors is essential in safety management and improvement. These factors drive investment decisions, policies, regulations, and other safety-related initiatives. This paper analyzes factors that contribute to crash occurrence based on two national datasets in the United States (CISS and NASS-CDS) for the years 2017-2022 and 2010-2015, respectively. Three taxonomies were applied to enhance understanding of the various crash contributing factors. These taxonomies were developed based on previous research and practice and involved different groupings of human factors, vehicle factors, and roadway and environmental factors. Statistics for grouping the different types of factors and statistics for specific factors are provided. The results indicate that human factors are present in over 95% of crashes, roadway and environmental factors are present in over 45% of crashes, and vehicle factors are present in less than 2% of crashes. Regarding factors related to human error and vehicle maintenance, speeding is involved in over 25% of crashes, distraction is involved in over 20% of crashes, alcohol and drugs are involved in over 9% of crashes, and vehicle maintenance is involved in approximately 0.45% of crashes. Approximately 4.4% of crashes involve a driver who “looked but did not see.” Weather is involved in over 13% of crashes. Conclusions: The findings indicate that, consistent with previous research, human factors or human error are present in around 95% of crashes. Infrastructure and environmental factors contribute to about 45% of crashes. Vehicle factors contribute to only 1.67% - 1.71% of crashes. The results from this study could potentially be used to inform future safety management and improvement activities, including policy-making, regulation development, safe systems and systemic safety approaches to safety management, and other engineering, education, emergency response, enforcement, evaluation, and encouragement activities. The findings could also be used in the development of future Driver Assistance Technologies (DAT) systems and in enhancing existing technologies.展开更多
Psychoneuroimmunology is a scientific discipline exploring the interconnectedness of the nervous system,emotion state,and immune system.The current review examines the distinct mechanisms through which the mind and bo...Psychoneuroimmunology is a scientific discipline exploring the interconnectedness of the nervous system,emotion state,and immune system.The current review examines the distinct mechanisms through which the mind and body interact when subjected to stress.Manifestations of psychoneuroimmunological stress encompass symptoms such as depression,aggression,fear,and social withdrawal,which can exert a profound impact on physiological well-being.Some observations suggest that humans and nonhuman animals exhibit similar stress-related symptoms,aiding in the identification of pharmacological pathways and potential clinical implications of therapeutic interventions.Animal stress models are predicated on varying approaches aimed at eliciting a motivational state to navigate and confront aversive circumstances.The current review describes the diverse stress induction models that have been investigated internationally,incorporating an ethological perspective that involves evaluating innate and unpunished behaviors through methodologies like the elevated plus maze,elevated zero maze,light-dark box,and open field test.Additionally,conditioned operant conflict tests,such as the Vogel conflict test,fall under the purview of learning and punishment models.This category encompasses classic conditioning models like fear conditioning,psychosocial models such as social defeat,and physical and chronic unpredictable stress paradigms.In this review,we critically evaluate existing cognitive and behavioral frameworks underpinning the development and perpetuation of stress-related disorders,while also elucidating the impact of immune system responses on the mental and physical health of animals.The primary objective of this review is to elucidate the array of animal models employed in previous research and the testing protocols used to assess animal performance in stress induction scenarios,with the ultimate aim of reducing mortality rates among research animals.展开更多
基金Natural Science Foundation of China,Grant/Award Number:62206109Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2022A1515010976+1 种基金Young Scholar Program of Pazhou Lab,Grant/Award Number:PZL2021KF0022National College Student Innovation and Entrepreneurship Training Program,Grant/Award Number:202410559070。
文摘Zeroing neural dynamic(ZND)model is widely deployed for time-variant non-linear equations(TVNE).Various element-wise non-linear activation functions and integration operations are investigated to enhance the convergence performance and robustness in most proposed ZND models for solving TVNE,leading to a huge cost of hardware implementation and model complexity.To overcome these problems,the authors develop a new norm-based ZND(NBZND)model with strong robustness for solving TVNE,not applying element-wise non-linear activated functions but introducing a two-norm operation to achieve finite-time convergence.Moreover,the authors develop a discretetime NBZND model for the potential deployment of the model on digital computers.Rigorous theoretical analysis for the NBZND is provided.Simulation results substantiate the advantages of the NBZND model for solving TVNE.
基金supported by the National Natural Science Foundation of China(No.62466019)。
文摘The problem of multi-robot formation is prevalent in scientific and engineering applications,where robots must adapt to uncertain and dynamic behaviors due to real-time environmental or task changes.Traditional methods struggle to meet the demand for high-precision solutions within finite time frames.Zeroing Neural Networks(ZNNs),which utilize the time derivatives of time-varying coefficients,outperform other networks in handling dynamic system behaviors.This paper marks the first attempt to extend the ZNN approach to address finite-time multi-robot through optimization modeling.We introduce an innovative strategy that employs complex number structures to map robot coordinates,simplifying the computation needed for dynamic formation tasks.Additionally,we present a multi-robot formation strategy that minimizes the distance between neighboring robots while adhering to bias-type center constraint.This is effectively reformulated as a complex-valued time-varying matrix equation.Based on this,two complex-type Finite-Time Zeroing Dynamic Controllers(FTZDC)are designed,with their stability and convergence time bounds rigorously analyzed.Finally,in two specific formation tasks,the proposed strategy and FTZDC models achieve precise multi-robot formation,independent of the robots’initial positions,all within finite time.
基金supported by National Key Research and Development Program of China(2022YFB3804902,2022YFB3804900)the National Natural Science Foundation of China(52203226,52161145406,42376045)the Fundamental Research Funds for the Central Universities(2232024Y-01,2232025D-02).
文摘While desalination is a key solution for global freshwater scarcity,its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems.Solar interfacial evaporation offers sustainable management potential,yet inevitable salt nucleation at evaporation interfaces degrades photothermal conversion and operational stability via light scattering and pathway blockage.Inspired by the mangrove leaf,we propose a photothermal 3D polydopamine and polypyrrole polymerized spacer fabric(PPSF)-based upward hanging model evaporation configuration with a reverse water feeding mechanism.This design enables zero-liquiddischarge(ZLD)desalination through phase-separation crystallization.The interconnected porous architecture and the rough surface of the PPSF enable superior water transport,achieving excellent solar-absorbing efficiency of 97.8%.By adjusting the tilt angle(θ),the evaporator separates the evaporation and salt crystallization zones via controlled capillary-driven brine transport,minimizing heat dissipation from brine discharge.At an optimal tilt angle of 52°,the evaporator reaches an evaporation rate of 2.81 kg m^(−2) h^(−1) with minimal heat loss(0.366 W)under 1-sun illumination while treating a 7 wt%waste brine solution.Furthermore,it sustains an evaporation rate of 2.71 kg m^(−2) h^(−1) over 72 h while ensuring efficient salt recovery.These results highlight a scalable,energy-efficient approach for sustainable ZLD desalination.
基金supported by National Key R&D Program of China(No.2022YFB3105101).
文摘With more and more IoT terminals being deployed in various power grid business scenarios,terminal reliability has become a practical challenge that threatens the current security protection architecture.Most IoT terminals have security risks and vulnerabilities,and limited resources make it impossible to deploy costly security protection methods on the terminal.In order to cope with these problems,this paper proposes a lightweight trust evaluation model TCL,which combines three network models,TCN,CNN,and LSTM,with stronger feature extraction capability and can score the reliability of the device by periodically analyzing the traffic behavior and activity logs generated by the terminal device,and the trust evaluation of the terminal’s continuous behavior can be achieved by combining the scores of different periods.After experiments,it is proved that TCL can effectively use the traffic behaviors and activity logs of terminal devices for trust evaluation and achieves F1-score of 95.763,94.456,99.923,and 99.195 on HDFS,BGL,N-BaIoT,and KDD99 datasets,respectively,and the size of TCL is only 91KB,which can achieve similar or better performance than CNN-LSTM,RobustLog and other methods with less computational resources and storage space.
文摘The United Nations Sustainable Development Goal(SDG) 2 aims to achieve Zero Hunger by 2030.However,global hunger and food insecurity have continued to rise at an alarming rate(UN 2023).Subtropical regions are home to more than 30% of the world's population,predominantly in developing countries where per capita farmland and food supply are only 40% of those in developed nations(FAO 2018).Meeting the Zero Hunger target amid ongoing population growth in these regions requires a substantial increase in agricultural production while minimizing soil degradation and adverse ecological impacts.This challenge is shared by many countries across South Asia,Africa,and Central and South America.
文摘Hainan Province in south China is the country’s second-largest island and the largest free trade port by area.It has entered a historic phase in China’s drive to promote high-level institutional opening up.On 18 December 2025,Hainan officially launched island-wide special customs operations,commonly referred to as“customs closure.”From that date,goods entering or leaving the island,except those traded with the Chinese mainland,are subject to simplified customs procedures and potentially reduced or zero tariffs.
文摘2026年1月31日-2月4日,美国供热、制冷与空调工程师学会(ASHRAE)2026年冬季会议在美国拉斯维加斯隆重召开。来自全球数十个国家的行业专家、学者及工程师齐聚一堂,共同探讨建筑环境系统与能源工程领域的前沿技术与发展趋势。会议期间,ASHRAE学会正式颁发了2026年度“Engineering Global Net Zero”创新奖。“Engineering Global Net Zero”创新奖(Innovation Award 2026)旨在表彰全球范围内在推动建筑环境领域可持续发展与技术创新方面作出卓越贡献的杰出个人,该奖项由美国供热、制冷与空调工程师学会(ASHRAE)组织评议。
基金supported by the National Natural Science Foundation of China(62376290).
文摘This work presents a nonlinear integral-ameliorated model for handling dynamic optimization problems with affine constraints.They pose a challenge as their optimal solutions evolve with time.Traditional iteration-based methods that exactly solve the problem at each time instant,fail to precisely and realtime track the solution due to computational and communication bottlenecks.Our model,through rigorous theoretical analyses,is able to reduce the optimality gap(i.e.,the difference between the model state and optimal solution)to zero in a finite time,and thus,track the solution online.Besides,perturbance is taken into account.We prove that under certain conditions,our model can totally tolerate an important kind of noise that we call“errorrelated noise”.In numerical experiments,compared with six existing methods,our model exhibits superior robustness when contaminated by the error-related noise.The key techniques in the model design involve employing the zeroing neural network to leverage time-derivative information,and introducing an integral term as well as the class C_(L)^(0)functions to enhance convergence and noise resistance.Finally,we establish a model-free control framework for a surgical manipulator with the remote-center-of-motion constraint and compare the performances of the framework based on different models in simulations.The results indicate that our model achieves the best performance among various models employed within the framework.
基金supported by the National Nature Science Foundation of China(U21A20166)the Science and Technology Development Foundation of Jilin Province(20230508095RC)+2 种基金the Major Science and Technology Projects of Jilin Province and Changchun City(20220301033GX)the Development and Reform Commission Foundation of Jilin Province(2023C034-3)the Interdisciplinary Integration and Innovation Project of JLU(JLUXKJC2020202).
文摘Dear Editor,Aiming at the consensus tracking problem of a class of unknown heterogeneous nonlinear multiagent systems(MASs)with input constraints,a novel data-driven iterative learning consensus control(ILCC)protocol based on zeroing neural networks(ZNNs)is proposed.First,a dynamic linearization data model(DLDM)is acquired via dynamic linearization technology(DLT).
基金supported by the Basic Science Center Program for Ordered Energy Conversion of the National Natural Science Foundation of China(No.52488201)the National Natural Science Foundation of China(No.52422606).
文摘Hilly terrain pipeline is a common form of pipeline in oil and gas storage and transportation industry.Due to the hilly terrain influence, the liquid at the elbow of the gathering pipeline is easy to flow back and accumulate to form slug flow, so it is necessary to remove the accumulated liquid by gas purging. In this paper, experiment is carried out in hilly terrain pipelines. Three flow patterns of stratified flow, slug flow and stratified entrained flow are observed. The process of gas purging accumulated liquid is divided into four stages, namely liquid accumulation, liquid rising, continuous outflow and tail outflow. At the same time, the flow pattern maps of each stage are drawn. The pressure drop signal is analyzed in time domain and frequency domain, and the contour map of pressure drop distribution is drawn. It is found that the ratio of range to average value can well distinguish the occurrence range of each flow pattern.Based on visualization, the transition process of slug flow to stratified flow and stratified entrained flow is studied, and the transition boundary prediction model is established. An image processing method is proposed to convert the image signal into a similarity curve, and PSD analysis is performed to calculate the slug frequency. The normal distribution is used to fit the slug frequency, and the predicted correlation is in good agreement with the experimental data.
基金The authors would like to acknowledge the grant of fellowship(DST/TMD/EWO/2K21/ACT/2021/02(G))under Project SHARP,received from the Department of Science and Technology,Government of India.
文摘One of the pathways to attain NET ZERO is CO_(2)injection into deep saline aquifers(DSAs),which alters the saturation and pore pressure of the reservoir rocks,hence the effective stress,sʹ.This,in turn,would change their geomechanical(i.e.peak deviatoric stress,elastic modulus,Poisson's ratio)and petrophysical(porosity and permeability)properties.Such a situation might trigger geo-hazards,like induced seismicity,ground deformation,caprock failure.Hence,reducing the risk of such hazards necessitates quantifying the spatial and temporal changes in sʹ,under specific CO_(2)and/or brine saturation,designated as S_(CO2)and S_(b),respectively,and resultant pore pressure.With this in view,a conceptual model depicting the reservoir,demarcated by five zones based on variations in saturation,pore-pressure,temperature,etc.,and the corresponding effective stress equations have been proposed based on the available literature.Furthermore,a critical review of literature has been carried out to decipher the limitations and contradictions associated with the findings from(i)laboratory studies to estimate S_(CO2)employing pwave velocity and electrical resistivity,(ii)analytical and numerical approaches for estimating the variation of pore-pressure in the reservoir rocks,and(iii)laboratory studies on variation in geomechanical and petrophysical properties under the conditions representative of the above-mentioned zones of the conceptual model.The authors consider that extensive experiments should be conducted on the rocks from different sources and tested under various conditions of the CO_(2)injection to validate the proposed model for the execution of risk-free CO_(2)storage in DSAs.
文摘We study the two-dimensional(2D)Cauchy problem of nonhomogeneous Boussinesq system for magnetohydrodynamics convection without heat diffusion in the whole plane.Based on delicate weighted estimates,we derive the global existence and uniqueness of strong solutions.In particular,the initial data can be arbitrarily large and the initial density may contain vacuum states and even have compact support.
基金Supported by the Major Science and Technology Projects in Jilin Province and Changchun City(20220301010GX).
文摘When the proton exchange membrane fuel cell(PEMFC)system is running,there will be a condition that does not require power output for a short time.In order to achieve zero power output under low power consumption,it is necessary to consider the diversity of control targets and the complexity of dynamic models,which brings the challenge of high-precision tracking control of the stack output power and cathode intake flow.For system idle speed control,a modelbased nonlinear control framework is constructed in this paper.Firstly,the nonlinear dynamic model of output power and cathode intake flow is derived.Secondly,a control scheme combining nonlinear extended Kalman filter observer and state feedback controller is designed.Finally,the control scheme is verified on the PEMFC experimental platform and compared with the proportion-integration-differentiation(PID)controller.The experimental results show that the control strategy proposed in this paper can realize the idle speed control of the fuel cell system and achieve the purpose of zero power output.Compared with PID controller,it has faster response speed and better system dynamics.
基金supported in part by the National Natural Science Foundation of China(61873106,62303109)Start-Up Research Fund of Southeast University(RF1028623002)Shenzhen Science and Technology Program(JCYJ20230807114609019)
文摘Dear Editor,This letter focuses on how an attacker can design suitable improved zero-dynamics (ZD) attack signal based on state estimates of target system. Improved ZD attack is to change zero dynamic gain matrix of attack signal to a matrix with determinant greater than 1.
文摘The concept of Net Zero Carbon Buildings,which aims to reduce greenhouse gas emissions,is essential in addressing climate change.However,the development of such buildings in Thailand faces significant challenges,including high construction costs,uncertain returns,and limited investment incentives.This study explores the factors influencing real estate developers’decisions to pursue Net Zero Carbon Buildings in Thailand,with a focus on physical,financial,and policy-related elements.Data collection was done with 388 respondents who are stakeholders,including developers,consultants,designers,and sustainability experts,through an online questionnaire,and analyzed using Multiple Regression Analysis.The independent variables in the analytical model consist of three groups of factors:physical buildings,climate finance,and climate policy.The results indicate that physical building factors,including building age,engineering systems,and design;climate finance factors,such as project cost increases,financial returns,and investment incentives;and climate policy factors,including government policies,international climate agreements,and carbon taxes,significantly influence development decisions.Government policies,building engineering systems,and financial incentives were identified as key positive drivers for investment,while carbon taxes and energy efficiency-focused designs were found to potentially discourage investment due to higher costs.The study concludes that substantial government support such as tax incentives,grants,and low-interest financing is critical to fostering investment in Net Zero Carbon Buildings.Additionally,raising awareness among developers and the private sector about the long-term benefits of these projects is essential to strengthening investment incentives.
基金supported by the National Natural Science Foundation of China(Grants Nos.62473146,62072249 and 62072056)the National Science Foundation of Hunan Province(Grant No.2024JJ3017)+1 种基金the Hunan Provincial Key Research and Development Program(Grant No.2022GK2019)by the Researchers Supporting Project Number(RSP2024R509),King Saud University,Riyadh,Saudi Arabia.
文摘In the context of an increasingly severe cybersecurity landscape and the growing complexity of offensive and defen-sive techniques,Zero Trust Networks(ZTN)have emerged as a widely recognized technology.Zero Trust not only addresses the shortcomings of traditional perimeter security models but also consistently follows the fundamental principle of“never trust,always verify.”Initially proposed by John Cortez in 2010 and subsequently promoted by Google,the Zero Trust model has become a key approach to addressing the ever-growing security threats in complex network environments.This paper systematically compares the current mainstream cybersecurity models,thoroughly explores the advantages and limitations of the Zero Trust model,and provides an in-depth review of its components and key technologies.Additionally,it analyzes the latest research achievements in the application of Zero Trust technology across various fields,including network security,6G networks,the Internet of Things(IoT),and cloud computing,in the context of specific use cases.The paper also discusses the innovative contributions of the Zero Trust model in these fields,the challenges it faces,and proposes corresponding solutions and future research directions.
文摘Understanding crash contributing factors is essential in safety management and improvement. These factors drive investment decisions, policies, regulations, and other safety-related initiatives. This paper analyzes factors that contribute to crash occurrence based on two national datasets in the United States (CISS and NASS-CDS) for the years 2017-2022 and 2010-2015, respectively. Three taxonomies were applied to enhance understanding of the various crash contributing factors. These taxonomies were developed based on previous research and practice and involved different groupings of human factors, vehicle factors, and roadway and environmental factors. Statistics for grouping the different types of factors and statistics for specific factors are provided. The results indicate that human factors are present in over 95% of crashes, roadway and environmental factors are present in over 45% of crashes, and vehicle factors are present in less than 2% of crashes. Regarding factors related to human error and vehicle maintenance, speeding is involved in over 25% of crashes, distraction is involved in over 20% of crashes, alcohol and drugs are involved in over 9% of crashes, and vehicle maintenance is involved in approximately 0.45% of crashes. Approximately 4.4% of crashes involve a driver who “looked but did not see.” Weather is involved in over 13% of crashes. Conclusions: The findings indicate that, consistent with previous research, human factors or human error are present in around 95% of crashes. Infrastructure and environmental factors contribute to about 45% of crashes. Vehicle factors contribute to only 1.67% - 1.71% of crashes. The results from this study could potentially be used to inform future safety management and improvement activities, including policy-making, regulation development, safe systems and systemic safety approaches to safety management, and other engineering, education, emergency response, enforcement, evaluation, and encouragement activities. The findings could also be used in the development of future Driver Assistance Technologies (DAT) systems and in enhancing existing technologies.
文摘Psychoneuroimmunology is a scientific discipline exploring the interconnectedness of the nervous system,emotion state,and immune system.The current review examines the distinct mechanisms through which the mind and body interact when subjected to stress.Manifestations of psychoneuroimmunological stress encompass symptoms such as depression,aggression,fear,and social withdrawal,which can exert a profound impact on physiological well-being.Some observations suggest that humans and nonhuman animals exhibit similar stress-related symptoms,aiding in the identification of pharmacological pathways and potential clinical implications of therapeutic interventions.Animal stress models are predicated on varying approaches aimed at eliciting a motivational state to navigate and confront aversive circumstances.The current review describes the diverse stress induction models that have been investigated internationally,incorporating an ethological perspective that involves evaluating innate and unpunished behaviors through methodologies like the elevated plus maze,elevated zero maze,light-dark box,and open field test.Additionally,conditioned operant conflict tests,such as the Vogel conflict test,fall under the purview of learning and punishment models.This category encompasses classic conditioning models like fear conditioning,psychosocial models such as social defeat,and physical and chronic unpredictable stress paradigms.In this review,we critically evaluate existing cognitive and behavioral frameworks underpinning the development and perpetuation of stress-related disorders,while also elucidating the impact of immune system responses on the mental and physical health of animals.The primary objective of this review is to elucidate the array of animal models employed in previous research and the testing protocols used to assess animal performance in stress induction scenarios,with the ultimate aim of reducing mortality rates among research animals.
