In this paper,a stable and adaptive sliding mode control(SMC)method for induction motors is introduced.Determining the parameters of this system has been one of the existing challenges.To solve this challenge,a new se...In this paper,a stable and adaptive sliding mode control(SMC)method for induction motors is introduced.Determining the parameters of this system has been one of the existing challenges.To solve this challenge,a new self-tuning type-2 fuzzy neural network calculates and updates the control system parameters with a fast mechanism.According to the dynamic changes of the system,in addition to the parameters of the SMC,the parameters of the type-2 fuzzy neural network are also updated online.The conditions for guaranteeing the convergence and stability of the control system are provided.In the simulation part,in order to test the proposed method,several uncertain models and load torque have been applied.Also,the results have been compared to the SMC based on the type-1 fuzzy system,the traditional SMC,and the PI controller.The average RMSE in different scenarios,for type-2 fuzzy SMC,is 0.0311,for type-1 fuzzy SMC is 0.0497,for traditional SMC is 0.0778,and finally for PI controller is 0.0997.展开更多
In this study, two full-size concrete wails were tested and analyzed to demonstrate the effectiveness of a chemically reactive enamel （CRE） coating in improving their mechanical behavior under blast loading： one wi...In this study, two full-size concrete wails were tested and analyzed to demonstrate the effectiveness of a chemically reactive enamel （CRE） coating in improving their mechanical behavior under blast loading： one with CRE-coated rebar and the other with uncoated rebar. Each wall was subjected in sequence to four explosive loads with equivalent 2, 4, 6-trinitrotoluene （TNT） charge weights of 1.82, 4.54, 13.6, and 20.4 kg. A finite element model of each wall under a close-in blast load was developed and validated with pressure and strain measurements, and used to predict rebar stresses and concrete surface sWain distributions of the wall. The test results and visual inspections consistently indicated that, compared with the barrier wall with uncoated reinforcement, the wall with CRE-coated rebar has fewer concrete cracks on the front and back faces, more effective stress transfers from concrete to steel rebar, and stronger connections with its concrete base. The concrete surface strain distributions predicted by the model under various loading conditions are in good agreement with the crack patterns observed during the tests.展开更多
In many problems,to analyze the process/metabolism behavior,a mod-el of the system is identified.The main gap is the weakness of current methods vs.noisy environments.The primary objective of this study is to present a...In many problems,to analyze the process/metabolism behavior,a mod-el of the system is identified.The main gap is the weakness of current methods vs.noisy environments.The primary objective of this study is to present a more robust method against uncertainties.This paper proposes a new deep learning scheme for modeling and identification applications.The suggested approach is based on non-singleton type-3 fuzzy logic systems(NT3-FLSs)that can support measurement errors and high-level uncertainties.Besides the rule optimization,the antecedent parameters and the level of secondary memberships are also adjusted by the suggested square root cubature Kalmanfilter(SCKF).In the learn-ing algorithm,the presented NT3-FLSs are deeply learned,and their nonlinear structure is preserved.The designed scheme is applied for modeling carbon cap-ture and sequestration problem using real-world data sets.Through various ana-lyses and comparisons,the better efficiency of the proposed fuzzy modeling scheme is verified.The main advantages of the suggested approach include better resistance against uncertainties,deep learning,and good convergence.展开更多
Dragline excavators are closed-loop mining manipulators that operate using a rigid multilink framework and rope and rigging system,which constitute its front-end assembly.The arrangements of dragline front-end assembl...Dragline excavators are closed-loop mining manipulators that operate using a rigid multilink framework and rope and rigging system,which constitute its front-end assembly.The arrangements of dragline front-end assembly provide the necessary motion of the dragline bucket within its operating radius.The assembly resembles a five-link closed kinematic chain that has two independent generalized coordinates of drag and hoist ropes and one dependent generalized coordinate of dump rope.Previous models failed to represent the actual closed loop of dragline front-end assembly,nor did they describe the maneuverability of dragline ropes under imposed geometric constraints.Therefore,a three degrees of freedom kinematic model of the dragline front-end is developed using the concept of generalized speeds.It contains all relevant configuration and kinematic constraint conditions to perform complete digging and swinging cycles.The model also uses three inputs of hoist and drag ropes linear and a rotational displacement of swinging along their trajectories.The inverse kinematics is resolved using a feedforward displacement algorithm coupled with the Newton-Raphson method to accurately estimate the trajectories of the ropes.The trajectories are solved only during the digging phase and the singularity was eliminated using Baumgarte's stabilization technique(BST),with appropriate inequality constraint equations.It is shown that the feedforward displacement algorithm can produce accurate trajectories without the need to manually solve the inverse kinematics from the geometry.The research findings are well in agreement with the dragline real operational limits and they contribute to the efficiency and the reduction in machine downtime due to better control strategies of the dragline cycles.展开更多
Alkaline water electrolysis provides a promising route for"green hydrogen"generation,where anodic oxygen evolution reaction(OER)plays a crucial role in coupling with cathodic hydrogen evolution reaction.To d...Alkaline water electrolysis provides a promising route for"green hydrogen"generation,where anodic oxygen evolution reaction(OER)plays a crucial role in coupling with cathodic hydrogen evolution reaction.To date,the development of highly active and durable OER catalysts based on earth-abundant elements has drawn wide attention;nevertheless,their performance under high current densities(HCDs≥1000 mA cm^(-2))has been less emphasized.This situation has seriously impeded large-scale electrolysis industrialization.In this review,in order to provide a guideline for designing high-performance OER electrocatalysts,the effects of HCD on catalytic performance involving electron transfer,mass transfer,and physical/chemical stability are summarized.Furthermore,the design principles were pointed out for obtaining efficient and robust OER electrocatalysts in light of recent progress of OER electrocatalysts working above 1000 mA cm^(-2).These include the aspects of developing self-supported catalytic electrodes,enhancing intrinsic activity,enhancing the catalyst-support interaction,engineering surface wettability,and introducing protective layer.Finally,summaries and outlooks in achieving OER at industrially relevant HCDs are proposed.展开更多
Active control technology has been investigated and applied in numerous building structures and infrastructures since 1972 when it was firstly introduced into the civil engineering field by Professor JTP Yao.Now,half ...Active control technology has been investigated and applied in numerous building structures and infrastructures since 1972 when it was firstly introduced into the civil engineering field by Professor JTP Yao.Now,half a century has passed,a variety of control systems have been invented and implemented by researchers and engineers from all over the world.The recent years have witnessed remarkable research attempts and progress devoted to the development in this area based on modern control theory.However,there are still some unknown areas which are worthy of being explored in depth.One of such examples is the application of tuned mass dampers(TMD)to the flutter vibration control of long span bridges.Although applications of TMDs to bridges have been sighted in practice,their genuine effectiveness remains a serious question.The issues relating to how the coupled effect of TMD’s linear force being restricted by the rotational velocity of bridge’s deck during wind excitations which may eventually leads to flutter vibrations,remains unanswered.Such unusual phenomena and limitations were initially discovered and reported by the author sixteen years ago when investigating the barge ship crane hook’s swing motion control.In recent years,the author has invented the active rotary inertia driver(ARID)system which now has been granted patents in China,the US,Europe(including the UK,France,and Germany),Russia,Brazil,India,South Africa,Canada,Australia,Japan and Korean,etc.The ARID is an active control system which could exert direct control torque or moment to the target structures with rotational motions or vibrations natures,including and not limited to buildings,bridges or offshore platforms subjected to winds,earthquakes,and waves excitations.Furthermore,the ARID control system and its methodology can also be applicable to various mechanical systems including but not limited to cranes,vehicles,trains,ships,aircrafts,space crafts,satellites,and robotics.In this paper,the theory,modelling,comprehensive parametric analysis and case study of the ARID system for flutter vibration control of bridges will be discussed,as well as its promising applications in other various occasions.展开更多
Short-circuiting flow is an important secondary flow in gas cyclones, which has a negative impact on the separation performance. To improve the understanding of the short-circuiting flow and guide the optimization of ...Short-circuiting flow is an important secondary flow in gas cyclones, which has a negative impact on the separation performance. To improve the understanding of the short-circuiting flow and guide the optimization of gas cyclones, this paper presents a numerical study of a cyclone using computational fluid dynamics. Based on the steady flow field, three methods were adopted to investigate the formation mechanism and characteristics of the short-circuiting flow and particles. The temporal variation of the tracer species concentration distribution reveals that the formation mechanism of the short-circuiting flow is the squeeze between the airflows entering the annular space of the gas cyclone at different times. The short-circuiting flow region, distinguished through the spatial distribution of the moments of age, is characterized by a small mean age and a large coefficient of variation. The proportion of the short-circuiting particles increases with the increase of the inlet velocity only for small particles. But with the increase of particle size, the proportion of the short-circuiting particles decreases faster at higher inlet velocities, resulting in significant differences in collection efficiency curves.展开更多
Nanodiamonds represent an attractive potential carrier for anticancer drugs.The main advantages of nanodiamond particles with respect to medical applications are their high compatibility with non-cancerous cells,feasi...Nanodiamonds represent an attractive potential carrier for anticancer drugs.The main advantages of nanodiamond particles with respect to medical applications are their high compatibility with non-cancerous cells,feasible surface decoration with therapeutic and cancer-cell targeting molecules,and their relatively low manufacturing cost.Additionally,nanodiamond carriers significantly increase treatment efficacy of the loaded drug,so anticancer drugs execute more effectively at a lower dose.Subsequently,lower drug dose results in less extensive side effects.The carriers decorated with a targeting molecule accumulate primarily in the tumor tissue,and those nanodiamond particles impair efflux of the drug from cancer cells.Therapeutic approaches considering nanodiamond carriers were already tested in vitro,as well as in vivo.Now,researchers focus particularly on the possible side effects of nanodiamond carriers applied systemically in vivo.The behavior of nanodiamond carriers depends heavily on their surface coatings,so each therapeutic complex must be evaluated separately.Generally,it seems that site-specific application of nanodiamond carriers is a rather safe therapeutic approach,but intravenous application needs further study.The benefits of nanodiamond carriers are remarkable and represent a potent approach to overcome the drug resistance of many cancers.展开更多
基金This research is financially supported by the Ministry of Science and Technology of China(Grant No.2019YFE0112400)the Department of Science and Technology of Shandong Province(Grant No.2021CXGC011204).
文摘In this paper,a stable and adaptive sliding mode control(SMC)method for induction motors is introduced.Determining the parameters of this system has been one of the existing challenges.To solve this challenge,a new self-tuning type-2 fuzzy neural network calculates and updates the control system parameters with a fast mechanism.According to the dynamic changes of the system,in addition to the parameters of the SMC,the parameters of the type-2 fuzzy neural network are also updated online.The conditions for guaranteeing the convergence and stability of the control system are provided.In the simulation part,in order to test the proposed method,several uncertain models and load torque have been applied.Also,the results have been compared to the SMC based on the type-1 fuzzy system,the traditional SMC,and the PI controller.The average RMSE in different scenarios,for type-2 fuzzy SMC,is 0.0311,for type-1 fuzzy SMC is 0.0497,for traditional SMC is 0.0778,and finally for PI controller is 0.0997.
基金Project supported by the National Natural Science Foundation of China （Nos. 51379186 and 51522905）, the Zhejiang Provincial Natural Science Foundation of China （No. LR15E090001）, and the Leonard Wood Institute under Award （No. LWI61009）, USA
文摘In this study, two full-size concrete wails were tested and analyzed to demonstrate the effectiveness of a chemically reactive enamel （CRE） coating in improving their mechanical behavior under blast loading： one with CRE-coated rebar and the other with uncoated rebar. Each wall was subjected in sequence to four explosive loads with equivalent 2, 4, 6-trinitrotoluene （TNT） charge weights of 1.82, 4.54, 13.6, and 20.4 kg. A finite element model of each wall under a close-in blast load was developed and validated with pressure and strain measurements, and used to predict rebar stresses and concrete surface sWain distributions of the wall. The test results and visual inspections consistently indicated that, compared with the barrier wall with uncoated reinforcement, the wall with CRE-coated rebar has fewer concrete cracks on the front and back faces, more effective stress transfers from concrete to steel rebar, and stronger connections with its concrete base. The concrete surface strain distributions predicted by the model under various loading conditions are in good agreement with the crack patterns observed during the tests.
基金supported by the project of the National Social Science Fundation(21BJL052,20BJY020,20BJL127,19BJY090)the 2018 Fujian Social Science Planning Project(FJ2018B067)The Planning Fund Project of Humanities and Social Sciences Research of the Ministry of Education in 2019(19YJA790102),The grant has been received by Aoqi Xu.
文摘In many problems,to analyze the process/metabolism behavior,a mod-el of the system is identified.The main gap is the weakness of current methods vs.noisy environments.The primary objective of this study is to present a more robust method against uncertainties.This paper proposes a new deep learning scheme for modeling and identification applications.The suggested approach is based on non-singleton type-3 fuzzy logic systems(NT3-FLSs)that can support measurement errors and high-level uncertainties.Besides the rule optimization,the antecedent parameters and the level of secondary memberships are also adjusted by the suggested square root cubature Kalmanfilter(SCKF).In the learn-ing algorithm,the presented NT3-FLSs are deeply learned,and their nonlinear structure is preserved.The designed scheme is applied for modeling carbon cap-ture and sequestration problem using real-world data sets.Through various ana-lyses and comparisons,the better efficiency of the proposed fuzzy modeling scheme is verified.The main advantages of the suggested approach include better resistance against uncertainties,deep learning,and good convergence.
基金The funding from the Robert H.Quenon Endowment at Missouri S&T for this research is also greatly acknowledged.
文摘Dragline excavators are closed-loop mining manipulators that operate using a rigid multilink framework and rope and rigging system,which constitute its front-end assembly.The arrangements of dragline front-end assembly provide the necessary motion of the dragline bucket within its operating radius.The assembly resembles a five-link closed kinematic chain that has two independent generalized coordinates of drag and hoist ropes and one dependent generalized coordinate of dump rope.Previous models failed to represent the actual closed loop of dragline front-end assembly,nor did they describe the maneuverability of dragline ropes under imposed geometric constraints.Therefore,a three degrees of freedom kinematic model of the dragline front-end is developed using the concept of generalized speeds.It contains all relevant configuration and kinematic constraint conditions to perform complete digging and swinging cycles.The model also uses three inputs of hoist and drag ropes linear and a rotational displacement of swinging along their trajectories.The inverse kinematics is resolved using a feedforward displacement algorithm coupled with the Newton-Raphson method to accurately estimate the trajectories of the ropes.The trajectories are solved only during the digging phase and the singularity was eliminated using Baumgarte's stabilization technique(BST),with appropriate inequality constraint equations.It is shown that the feedforward displacement algorithm can produce accurate trajectories without the need to manually solve the inverse kinematics from the geometry.The research findings are well in agreement with the dragline real operational limits and they contribute to the efficiency and the reduction in machine downtime due to better control strategies of the dragline cycles.
基金supported by the National Natural Science Foundation of China(Grant nos.91963129 and 51776094)the Guangdong Provincial Key Laboratory of Energy Materials for Electric Power(Grant no.2018B030322001)the Basic Research Project of Science and Technology Plan of Shenzhen(Grant no.JCYJ20180504165655180).
文摘Alkaline water electrolysis provides a promising route for"green hydrogen"generation,where anodic oxygen evolution reaction(OER)plays a crucial role in coupling with cathodic hydrogen evolution reaction.To date,the development of highly active and durable OER catalysts based on earth-abundant elements has drawn wide attention;nevertheless,their performance under high current densities(HCDs≥1000 mA cm^(-2))has been less emphasized.This situation has seriously impeded large-scale electrolysis industrialization.In this review,in order to provide a guideline for designing high-performance OER electrocatalysts,the effects of HCD on catalytic performance involving electron transfer,mass transfer,and physical/chemical stability are summarized.Furthermore,the design principles were pointed out for obtaining efficient and robust OER electrocatalysts in light of recent progress of OER electrocatalysts working above 1000 mA cm^(-2).These include the aspects of developing self-supported catalytic electrodes,enhancing intrinsic activity,enhancing the catalyst-support interaction,engineering surface wettability,and introducing protective layer.Finally,summaries and outlooks in achieving OER at industrially relevant HCDs are proposed.
基金supported by the Ministry of Science and Technology of China (Grant No.2019YFE0112400)the Department of Science and Technology of Shandong Province (Grant No.2021CXGC011204)Liaoning Provincial Key Laboratory of Safety and Protection for Infrastructure Engineering。
文摘Active control technology has been investigated and applied in numerous building structures and infrastructures since 1972 when it was firstly introduced into the civil engineering field by Professor JTP Yao.Now,half a century has passed,a variety of control systems have been invented and implemented by researchers and engineers from all over the world.The recent years have witnessed remarkable research attempts and progress devoted to the development in this area based on modern control theory.However,there are still some unknown areas which are worthy of being explored in depth.One of such examples is the application of tuned mass dampers(TMD)to the flutter vibration control of long span bridges.Although applications of TMDs to bridges have been sighted in practice,their genuine effectiveness remains a serious question.The issues relating to how the coupled effect of TMD’s linear force being restricted by the rotational velocity of bridge’s deck during wind excitations which may eventually leads to flutter vibrations,remains unanswered.Such unusual phenomena and limitations were initially discovered and reported by the author sixteen years ago when investigating the barge ship crane hook’s swing motion control.In recent years,the author has invented the active rotary inertia driver(ARID)system which now has been granted patents in China,the US,Europe(including the UK,France,and Germany),Russia,Brazil,India,South Africa,Canada,Australia,Japan and Korean,etc.The ARID is an active control system which could exert direct control torque or moment to the target structures with rotational motions or vibrations natures,including and not limited to buildings,bridges or offshore platforms subjected to winds,earthquakes,and waves excitations.Furthermore,the ARID control system and its methodology can also be applicable to various mechanical systems including but not limited to cranes,vehicles,trains,ships,aircrafts,space crafts,satellites,and robotics.In this paper,the theory,modelling,comprehensive parametric analysis and case study of the ARID system for flutter vibration control of bridges will be discussed,as well as its promising applications in other various occasions.
基金supported by the National Key Research and Development Project,China(Grant No.2018YFC1903701)the Key Consulting Research Projects of the Chinese Academy of Engineer-ing(Grant No.2021-XZ-7)Fundamental Research Funds for the Central Universities(Grant No.lzujbky-2021-71).
文摘Short-circuiting flow is an important secondary flow in gas cyclones, which has a negative impact on the separation performance. To improve the understanding of the short-circuiting flow and guide the optimization of gas cyclones, this paper presents a numerical study of a cyclone using computational fluid dynamics. Based on the steady flow field, three methods were adopted to investigate the formation mechanism and characteristics of the short-circuiting flow and particles. The temporal variation of the tracer species concentration distribution reveals that the formation mechanism of the short-circuiting flow is the squeeze between the airflows entering the annular space of the gas cyclone at different times. The short-circuiting flow region, distinguished through the spatial distribution of the moments of age, is characterized by a small mean age and a large coefficient of variation. The proportion of the short-circuiting particles increases with the increase of the inlet velocity only for small particles. But with the increase of particle size, the proportion of the short-circuiting particles decreases faster at higher inlet velocities, resulting in significant differences in collection efficiency curves.
文摘Nanodiamonds represent an attractive potential carrier for anticancer drugs.The main advantages of nanodiamond particles with respect to medical applications are their high compatibility with non-cancerous cells,feasible surface decoration with therapeutic and cancer-cell targeting molecules,and their relatively low manufacturing cost.Additionally,nanodiamond carriers significantly increase treatment efficacy of the loaded drug,so anticancer drugs execute more effectively at a lower dose.Subsequently,lower drug dose results in less extensive side effects.The carriers decorated with a targeting molecule accumulate primarily in the tumor tissue,and those nanodiamond particles impair efflux of the drug from cancer cells.Therapeutic approaches considering nanodiamond carriers were already tested in vitro,as well as in vivo.Now,researchers focus particularly on the possible side effects of nanodiamond carriers applied systemically in vivo.The behavior of nanodiamond carriers depends heavily on their surface coatings,so each therapeutic complex must be evaluated separately.Generally,it seems that site-specific application of nanodiamond carriers is a rather safe therapeutic approach,but intravenous application needs further study.The benefits of nanodiamond carriers are remarkable and represent a potent approach to overcome the drug resistance of many cancers.
