This paper introduces a method for modeling the entire aggregated electric vehicle(EV)charging process and analyzing its dispatchable capabilities.The methodology involves developing a model for aggregated EV charging...This paper introduces a method for modeling the entire aggregated electric vehicle(EV)charging process and analyzing its dispatchable capabilities.The methodology involves developing a model for aggregated EV charging at the charging station level,estimating its physical dispatchable capability,determining its economic dispatchable capability under economic incentives,modeling its participation in the grid,and investigating the effects of different scenarios and EV penetration on the aggregated load dispatch and dispatchable capability.The results indicate that using economic dispatchable capability reduces charging prices by 9.7%compared to physical dispatchable capability and 9.3%compared to disorderly charging.Additionally,the peak-to-valley difference is reduced by 64.6%when applying economic dispatchable capability with 20%EV penetration and residential base load,compared to disorderly charging.展开更多
This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver capability.Firstly,we establish a lateral dynamic mo...This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver capability.Firstly,we establish a lateral dynamic model considering additional forces and moments resulting during the morphing process,and convert it into a Multiple Input Multiple Output(MIMO)virtual control system by importing virtual inputs.Secondly,a classical dynamics inversion controller is designed for the outer-loop system.A new Global Fast Terminal Incremental Sliding Mode Controller(NDO-GFTISMC)is proposed for the inner-loop system,in which an adaptive law is implemented to weaken control surface chattering,and a Nonlinear Disturbance Observer(NDO)is integrated to compensate for unknown disturbances.The whole control system is proven semiglobally uniformly ultimately bounded based on the multi-Lyapunov function method.Furthermore,we consider tracking errors and self-characteristics of actuators,a quadratic programmingbased dynamic control allocation law is designed,which allocates virtual control inputs to the asymmetrically deformed wingtip and rudder.Actuator dynamic models are incorporated to ensure physical realizability of designed allocation law.Finally,comparative experimental results validate the effectiveness of the designed control system and control allocation law.The NDO-GFTISMC features faster convergence,stronger robustness,and 81.25%and 75.0%reduction in maximum state tracking error under uncertainty compared to the Incremental Nonlinear Dynamic Inversion Controller based on NDO(NDO-INDI)and Incremental Sliding Mode Controller based on NDO(NDO-ISMC),respectively.The design of the morphing aircraft significantly enhances lateral maneuver capability,maintaining a substantial control margin during lateral maneuvering,reducing the burden of the rudder surface,and effectively solving the actuator saturation problem of traditional aircraft during lateral maneuvering.展开更多
Objective:To explore the application effect of emergency rescue capability intervention among students in a university in Beijing.Methods:A total of 900 students from a university in Beijing in 2023 were selected as t...Objective:To explore the application effect of emergency rescue capability intervention among students in a university in Beijing.Methods:A total of 900 students from a university in Beijing in 2023 were selected as the research objects.Emergency rescue capability training was conducted from March 2023 to June 2023,once a month.The students’mastery of emergency rescue before and after the intervention was analyzed.Survey questionnaires were distributed to all college students to understand their channels and willingness to acquire emergency rescue knowledge.Results:A total of 886 valid questionnaires were collected in this study.The highest proportion of knowledge about China’s general emergency telephone number and how to dial the emergency rescue hotline was 100.00%.Among the strategies for dealing with cardiac arrest in CPR,the highest proportion was 336.34%.Among the four major first aid techniques of hemostasis,bandaging,fixation,transportation,the highest proportion of knowledge about the use of rubber band signs was 31.71%.Among the first aid techniques for heatstroke,poisoning,fire,and sharp instrument injuries,the principle of emergency treatment for severe gas poisoning had the highest proportion of 41.42%,showing significant differences.College students mainly acquire knowledge of emergency rescue capability through TV programs,health education lectures,and the internet.Around 61.40%of college students hope to learn more about prevention and control knowledge.Conclusion:After the intervention of emergency rescue capability,the emergency rescue capability of college students in this university has been significantly improved,showing a strong training effect,which is worthy of promotion.展开更多
An inverse vulcanized polymer,SZIM combining Zn2+-imidazole coordination bonds and polysulfide bonds was synthesized and incorporated into bio-based Eucommia ulmoides gum (EUG) to generate EUG-SZIM-xs.The residual cry...An inverse vulcanized polymer,SZIM combining Zn2+-imidazole coordination bonds and polysulfide bonds was synthesized and incorporated into bio-based Eucommia ulmoides gum (EUG) to generate EUG-SZIM-xs.The residual crystallinity of the EUG matrix synergistically interacted with the dual cross-linking networks to establish reversible deformation domains,providing EUG-SZIM-xs with quick shape memory capability at moderate temperatures.The damping properties were also investigated,and EUG-SZIM-xs displayed high tanδ values (>0.3) when the SZIM dosage was higher than 5.5 phr,which showed a positive correlation with SZIM concentration.Such good damping performance endowed the EUG-SZIM-xs with broadband low-frequency sound absorption.In addition,the dual cross-linking networks endowed the materials with reprocessability under different catalytic systems,and the 1,8-diazobicyclic[5.4.0]undeca-7-ene (DBU)-catalyzed samples exhibited better mechanical properties than EUG-SZIM-xs.展开更多
The relationship between the neighborhood environment and well-being is attracting increasingly attention from researchers and policymakers,as the goal of development has shift from economy to well-being.However,exist...The relationship between the neighborhood environment and well-being is attracting increasingly attention from researchers and policymakers,as the goal of development has shift from economy to well-being.However,existing literature predominantly adopts the utilitarian approach,understanding well-being as people’s feelings about their lives and viewing the neighborhood environment as resources that benefit well-being.The Capability Approach,a novel approach that conceptualize well-being as the freedoms to do or to be and regard environment as conversion factors that influence well-being,can offer new lens by incorporating human development in-to these topics.This paper proposes an alternative theoretical framework:well-being is conceptualized and measured by capability;neighborhood environment affects well-being by providing spatial services,functioning as environmental conversion factors,and serving as social conversion factors.We conducted a case study of Changshu City located in eastern China,utilizing multiple resource data,applying explainable artificial intelligence(XAI),namely eXtreme Gradient Boosting(XGBoost)and SHapley Additive exPlana-tions(SHAP).Our findings highlight the significance of viewing the neighborhood environment as a set of conversion factors,as it provides more explanatory power than providing spatial services.Compared to conventional research based on linear relationship as-sumption,our results demonstrate that the effects of neighborhood environment on well-being are non-linear,characterized by threshold effects and interaction effects.These insights are crucial for informing urban planning and public policy.This research enriches our un-derstanding of well-being,neighborhood environment,and their relationship as well as provides empirical evidence for the core concept of conversion factors in the capability approach.展开更多
Purpose–To systematically characterize and objectively evaluate basic railway safety management capability,creating a closed-loop management approach which allows continuous improvement and optimization.Design/method...Purpose–To systematically characterize and objectively evaluate basic railway safety management capability,creating a closed-loop management approach which allows continuous improvement and optimization.Design/methodology/approach–A basic railway safety management capability evaluation index system based on a comprehensive analysis of national safety management standards,railway safety rules and regulations and existing safety data from railway transport enterprises is presented.The system comprises a guideline layer including safety committee formation,work safety responsibility,safety management organization and safety rules and regulations as its components,along with an index layer consisting of 12 quantifiable indexes.Game theory combination weighting is utilized to integrate subjective and objective weight values derived using AHP and CRITIC methods and further combined using the TOPSIS method in order to construct a comprehensive basic railway safety management capability evaluation model.Findings–The case study presented demonstrates that this evaluation index system and comprehensive evaluation model are capable of effectively characterizing and evaluating basic railway safety management capability and providing directional guidance for its sustained improvement.Originality/value–Construction of an evaluation index system that is quantifiable,generalizable and accessible,accurately reflects the main aspects of railway transportation enterprises’basic safety management capability and provides interoperability across various railway transportation enterprises.The application of the game theoretic combination weighting method to derive composite weights which combine experts’subjective evaluations with the objectivity of data.展开更多
Lizards are one of the most primitive reptiles in existence,with special limb structures that enable them to move quickly across diverse and complex terrains such as rock piles,shallow shoals,and deserts.A thorough ex...Lizards are one of the most primitive reptiles in existence,with special limb structures that enable them to move quickly across diverse and complex terrains such as rock piles,shallow shoals,and deserts.A thorough exploration was conducted on the biomimetic mechanism and ground-touching mechanism of lizard limbs from both micro and macro perspectives.Inspired by the intricate torso and limb configurations of lizards,a novel Torso-leg-foot biomimetic robot has been conceptualized based on the design of the Big-Foot robot.This robot integrates a Torso-leg-foot system,featuring a parallel torso biomimetic structure with a 2-SPR/UPU/UPR(P)configuration.It utilizes the theory of finite screws to articulate the instantaneous movements of the parallel torso,and the inverse kinematics of this mechanism have been calculated.The reachable workspace of the 2-SPR/UPU/UPR parallel mechanism using FIS theory,which is closely related to the climbing height of the robot.A comprehensive dimension synthesis was conducted on the leg-foot system,and the adoption of the three-pair rod drive method was determined by investigating its Variable Rotating Velocity Characteristics(VRVC).Simulation tests have shown that with an integrated torso,the robot can climb vertical obstacles up to 600 mm in height.The experimental tests of climbing steps and slopes using physical prototypes have confirmed the robot's obstacle-crossing capability.The potential applications of this Torso-leg-foot biomimetic robot is to carry heavy objects across obstacles to perform tasks such as planetary exploration and disaster relief.展开更多
The exceptional electrochemical performance of zinc anodes is frequently impeded by inadequate deposition kinetics and interfacial chemistry.Herein,we introduce the stereoisomerism to inform the balanced selection of ...The exceptional electrochemical performance of zinc anodes is frequently impeded by inadequate deposition kinetics and interfacial chemistry.Herein,we introduce the stereoisomerism to inform the balanced selection of electrolyte additives,taking into account their solvation and adsorption properties,to achieve the optimal deposition behaviors and electrochemical performance.The three-point coplanar adsorption configuration,in comparison to two-point adsorption,effectively mitigates the interference of water molecules and establishes a coplanar templating effect.This approach fosters a uniform distribution of charges,encourages the preferential orientation growth of(002)planes for uniform zinc deposition.Moreover,an appropriate level of solvation ability can modulate the solvation structure without substantially increasing the de-solvation energy barrier,thereby facilitating faster deposition kinetics than what is observed in cases of strong solvation.As a result,Zn//Zn cell can achieve an excellent performance of more than 3470 h at 2 mA cm^(-2)and 1 mAh cm^(-2),and Zn//AC full cell can work for 50000 cycles at 3 A g^(-1).Additionally,under practical conditions(N/P=4.37),the assembled Zn//I2 full cell demonstrates stable lifespan for 710 cycles at 1 A g^(-1).This work showcases the interplay between adsorption configuration of stereoisomeric additives on the cycling.展开更多
There is limited amount of research on surface plasmon resonance(SPR)sensors with self-referencing capabilities which are based on dielectric gratings.In the short-wavelength range,a metal grating sensor is capable of...There is limited amount of research on surface plasmon resonance(SPR)sensors with self-referencing capabilities which are based on dielectric gratings.In the short-wavelength range,a metal grating sensor is capable of simultaneously measuring liquid refractive index under proposed temperature.A fabricated gold grating is placed on one side of a thin gold film for refractive index measurement,while the other with polydimethylsiloxane(PDMS)is deposited on the other side for temperature measurement.We use finite element analysis to research its sensing characteristics.Due to the high refractive index sensitivity of SPR sensors and thermo-optic coefficient of PDMS,we discovered the maximum spectral sensitivity of the sensor is 564 nm/RIU and-50 pm/℃when the liquid refractive index ranges from 1.30 to 1.40 with temperature ranging from 0℃ to 100℃.Numerical results indicate that there may not be mutual interference between two channels for measuring refractive index and temperature,which reduces the complexity of sensor measurements.展开更多
To investigate the process of information technology （IT） impacts on firm competitiveness, an integrated process model of IT impacts on firm competitiveness is brought forward based on the process-oriented view, the...To investigate the process of information technology （IT） impacts on firm competitiveness, an integrated process model of IT impacts on firm competitiveness is brought forward based on the process-oriented view, the resource-based view and the complementary resource view, which is comprised of an IT conversion process, an information system （IS） adoption process, an IS use process and a competition process. The application capability of IT plays the critical role, which determines the efficiency and effectiveness of the aforementioned four processes. The process model of IT impacts on firm competitiveness can also be used to explain why, under what situations and how IT can generate positive organizational outcomes, as well as theoretical bases for further empirical study.展开更多
In order to solve the problem that the current matchmaking methods for semantic web service mainly focus on the matchmaking of IO （inputs, outputs） descriptions which may result in one-sidedness, a description-logic...In order to solve the problem that the current matchmaking methods for semantic web service mainly focus on the matchmaking of IO （inputs, outputs） descriptions which may result in one-sidedness, a description-logic-based IOPE （inputs, outputs, preconditions, effects） description and matchmaking method is proposed for semantic web service. The description logic concept is used to annotate service IO and the description logic assertion is employed to describe service PE（preconditions, effects）. TBox subsumption checking is used to measure the subsumption relationship between IO descriptions of service request and advertising; ABox consistency checking is used for checking the logical implication between PE descriptions of service request and advertising. Based upon the logical implication, four kinds of PE matching degrees are proposed to measure and compare the pros and cons of the results of matchmaking. They are the exact, perfect, side-effect and common match. Experiments show that the method has a higher precision rate under the same recall rate compared with the existing method.展开更多
Spinel LiMn2O4 microspheres with durable high rate capability were synthesized by a facile route using spherical MnCO3 precursors as the self-supported templates, combined with the calcinations of LiNO3 at 700 °C...Spinel LiMn2O4 microspheres with durable high rate capability were synthesized by a facile route using spherical MnCO3 precursors as the self-supported templates, combined with the calcinations of LiNO3 at 700 °C for 8 h. The spherical MnCO3 precursors were obtained from the control of the crystallizing process of Mn2＋ ions and NH4HCO3 in aqueous solution. The effects of the mole ratio of the raw materials, reaction time, and reaction temperature on the morphology and yield of the MnCO3 were investigated. The as-synthesized MnCO3 and LiMn2O4 microspheres were characterized by powder X-ray diffractometry （XRD） and scanning electron microscopy （SEM）. Galvanostatic charge/discharge tests indicate that the spinel LiMn2O4 microspheres deliver a discharge capacity of 90 mA-h/g at 10C rate show good capacity retention capability （75% of their initial capacity after 800 cycles at 10C rate）. The durable high rate capability suggests that the as-synthesized LiMn2O4 microspheres are promising cathode materials for high power lithium ion batteries.展开更多
The coexistence theory of slag structure and it's application to calculation of the oxidizing capabilities of slag melts is described. It is shown that the law of mass action can be widely applied to the calculati...The coexistence theory of slag structure and it's application to calculation of the oxidizing capabilities of slag melts is described. It is shown that the law of mass action can be widely applied to the calculation of oxidizing capabilities of slag melts in combination with the coexistence theory of slag structure.For slag melts containing basic oxides FeO and MnO, their oxidizing capabilities can be expressed by N Fe tO =N FeO +6N Fe 2O 3 , while for slag melts containing basic oxides CaO, MgO, etc., in addition to FeO and MnO, their oxidizing capabilities can be given as N Fe tO =N FeO +6N Fe 2O 3 +8N Fe 3O 4 .展开更多
The effect of acidity and redox capability over sulfuric acid-modified CeO_2 catalysts were studied for the selective catalytic reduction of NO_x with NH_3(NH_3-SCR). The deposition of sulfate significantly enhanced t...The effect of acidity and redox capability over sulfuric acid-modified CeO_2 catalysts were studied for the selective catalytic reduction of NO_x with NH_3(NH_3-SCR). The deposition of sulfate significantly enhanced the catalytic performance over CeO_2. NO_x conversion over4H_2SO_4/CeO_2 at 230–440 °C was higher than 90%. The strong redox capability of CeO_2 could result in unselective NH_3 oxidation and decrease high temperatures catalytic activity and N_2 selectivity. The deposition of sulfate increased the acidity and weakened the redox capability, and then increased the high temperature NO_x conversion and N_2 selectivity. An appropriate level of acidity also promoted the activity at 190–250 °C over ceria-based catalysts, and with further increase in the acidity, the SCR activity decreased slightly. Weak redox capability lowered the low-temperature catalytic activity. Excellent SCR activity requires a balance of acidity and redox capability on the catalysts.展开更多
基金State Grid Henan Power Company Science and Technology Project‘Key Technology and Demonstration Application of Multi-Domain Electric Vehicle Aggregated Charging Load Dispatch’(5217L0240003).
文摘This paper introduces a method for modeling the entire aggregated electric vehicle(EV)charging process and analyzing its dispatchable capabilities.The methodology involves developing a model for aggregated EV charging at the charging station level,estimating its physical dispatchable capability,determining its economic dispatchable capability under economic incentives,modeling its participation in the grid,and investigating the effects of different scenarios and EV penetration on the aggregated load dispatch and dispatchable capability.The results indicate that using economic dispatchable capability reduces charging prices by 9.7%compared to physical dispatchable capability and 9.3%compared to disorderly charging.Additionally,the peak-to-valley difference is reduced by 64.6%when applying economic dispatchable capability with 20%EV penetration and residential base load,compared to disorderly charging.
基金supported by the National Natural Science Foundation of China(Nos.62103052 and No.52175214)。
文摘This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver capability.Firstly,we establish a lateral dynamic model considering additional forces and moments resulting during the morphing process,and convert it into a Multiple Input Multiple Output(MIMO)virtual control system by importing virtual inputs.Secondly,a classical dynamics inversion controller is designed for the outer-loop system.A new Global Fast Terminal Incremental Sliding Mode Controller(NDO-GFTISMC)is proposed for the inner-loop system,in which an adaptive law is implemented to weaken control surface chattering,and a Nonlinear Disturbance Observer(NDO)is integrated to compensate for unknown disturbances.The whole control system is proven semiglobally uniformly ultimately bounded based on the multi-Lyapunov function method.Furthermore,we consider tracking errors and self-characteristics of actuators,a quadratic programmingbased dynamic control allocation law is designed,which allocates virtual control inputs to the asymmetrically deformed wingtip and rudder.Actuator dynamic models are incorporated to ensure physical realizability of designed allocation law.Finally,comparative experimental results validate the effectiveness of the designed control system and control allocation law.The NDO-GFTISMC features faster convergence,stronger robustness,and 81.25%and 75.0%reduction in maximum state tracking error under uncertainty compared to the Incremental Nonlinear Dynamic Inversion Controller based on NDO(NDO-INDI)and Incremental Sliding Mode Controller based on NDO(NDO-ISMC),respectively.The design of the morphing aircraft significantly enhances lateral maneuver capability,maintaining a substantial control margin during lateral maneuvering,reducing the burden of the rudder surface,and effectively solving the actuator saturation problem of traditional aircraft during lateral maneuvering.
文摘Objective:To explore the application effect of emergency rescue capability intervention among students in a university in Beijing.Methods:A total of 900 students from a university in Beijing in 2023 were selected as the research objects.Emergency rescue capability training was conducted from March 2023 to June 2023,once a month.The students’mastery of emergency rescue before and after the intervention was analyzed.Survey questionnaires were distributed to all college students to understand their channels and willingness to acquire emergency rescue knowledge.Results:A total of 886 valid questionnaires were collected in this study.The highest proportion of knowledge about China’s general emergency telephone number and how to dial the emergency rescue hotline was 100.00%.Among the strategies for dealing with cardiac arrest in CPR,the highest proportion was 336.34%.Among the four major first aid techniques of hemostasis,bandaging,fixation,transportation,the highest proportion of knowledge about the use of rubber band signs was 31.71%.Among the first aid techniques for heatstroke,poisoning,fire,and sharp instrument injuries,the principle of emergency treatment for severe gas poisoning had the highest proportion of 41.42%,showing significant differences.College students mainly acquire knowledge of emergency rescue capability through TV programs,health education lectures,and the internet.Around 61.40%of college students hope to learn more about prevention and control knowledge.Conclusion:After the intervention of emergency rescue capability,the emergency rescue capability of college students in this university has been significantly improved,showing a strong training effect,which is worthy of promotion.
基金supported by the Natural Science Foundation of Hunan Province(No.2024JJ7392)the National Natural Science Foundation of China(No.52463002)+1 种基金Educational Commission of Hunan Province(No.22A0383)Special Funds for Construction of Innovative Provinces in Hunan Province(No.2020SK2028).
文摘An inverse vulcanized polymer,SZIM combining Zn2+-imidazole coordination bonds and polysulfide bonds was synthesized and incorporated into bio-based Eucommia ulmoides gum (EUG) to generate EUG-SZIM-xs.The residual crystallinity of the EUG matrix synergistically interacted with the dual cross-linking networks to establish reversible deformation domains,providing EUG-SZIM-xs with quick shape memory capability at moderate temperatures.The damping properties were also investigated,and EUG-SZIM-xs displayed high tanδ values (>0.3) when the SZIM dosage was higher than 5.5 phr,which showed a positive correlation with SZIM concentration.Such good damping performance endowed the EUG-SZIM-xs with broadband low-frequency sound absorption.In addition,the dual cross-linking networks endowed the materials with reprocessability under different catalytic systems,and the 1,8-diazobicyclic[5.4.0]undeca-7-ene (DBU)-catalyzed samples exhibited better mechanical properties than EUG-SZIM-xs.
基金Under the auspices of National Natural Science Foundation of China(No.42271230,42330510)。
文摘The relationship between the neighborhood environment and well-being is attracting increasingly attention from researchers and policymakers,as the goal of development has shift from economy to well-being.However,existing literature predominantly adopts the utilitarian approach,understanding well-being as people’s feelings about their lives and viewing the neighborhood environment as resources that benefit well-being.The Capability Approach,a novel approach that conceptualize well-being as the freedoms to do or to be and regard environment as conversion factors that influence well-being,can offer new lens by incorporating human development in-to these topics.This paper proposes an alternative theoretical framework:well-being is conceptualized and measured by capability;neighborhood environment affects well-being by providing spatial services,functioning as environmental conversion factors,and serving as social conversion factors.We conducted a case study of Changshu City located in eastern China,utilizing multiple resource data,applying explainable artificial intelligence(XAI),namely eXtreme Gradient Boosting(XGBoost)and SHapley Additive exPlana-tions(SHAP).Our findings highlight the significance of viewing the neighborhood environment as a set of conversion factors,as it provides more explanatory power than providing spatial services.Compared to conventional research based on linear relationship as-sumption,our results demonstrate that the effects of neighborhood environment on well-being are non-linear,characterized by threshold effects and interaction effects.These insights are crucial for informing urban planning and public policy.This research enriches our un-derstanding of well-being,neighborhood environment,and their relationship as well as provides empirical evidence for the core concept of conversion factors in the capability approach.
基金supported by the China National Railway Group Co.,Ltd.Research and Development Project(P2023T002).
文摘Purpose–To systematically characterize and objectively evaluate basic railway safety management capability,creating a closed-loop management approach which allows continuous improvement and optimization.Design/methodology/approach–A basic railway safety management capability evaluation index system based on a comprehensive analysis of national safety management standards,railway safety rules and regulations and existing safety data from railway transport enterprises is presented.The system comprises a guideline layer including safety committee formation,work safety responsibility,safety management organization and safety rules and regulations as its components,along with an index layer consisting of 12 quantifiable indexes.Game theory combination weighting is utilized to integrate subjective and objective weight values derived using AHP and CRITIC methods and further combined using the TOPSIS method in order to construct a comprehensive basic railway safety management capability evaluation model.Findings–The case study presented demonstrates that this evaluation index system and comprehensive evaluation model are capable of effectively characterizing and evaluating basic railway safety management capability and providing directional guidance for its sustained improvement.Originality/value–Construction of an evaluation index system that is quantifiable,generalizable and accessible,accurately reflects the main aspects of railway transportation enterprises’basic safety management capability and provides interoperability across various railway transportation enterprises.The application of the game theoretic combination weighting method to derive composite weights which combine experts’subjective evaluations with the objectivity of data.
基金supported by the National Natural Science Foundation of China(Grant No.52205007).
文摘Lizards are one of the most primitive reptiles in existence,with special limb structures that enable them to move quickly across diverse and complex terrains such as rock piles,shallow shoals,and deserts.A thorough exploration was conducted on the biomimetic mechanism and ground-touching mechanism of lizard limbs from both micro and macro perspectives.Inspired by the intricate torso and limb configurations of lizards,a novel Torso-leg-foot biomimetic robot has been conceptualized based on the design of the Big-Foot robot.This robot integrates a Torso-leg-foot system,featuring a parallel torso biomimetic structure with a 2-SPR/UPU/UPR(P)configuration.It utilizes the theory of finite screws to articulate the instantaneous movements of the parallel torso,and the inverse kinematics of this mechanism have been calculated.The reachable workspace of the 2-SPR/UPU/UPR parallel mechanism using FIS theory,which is closely related to the climbing height of the robot.A comprehensive dimension synthesis was conducted on the leg-foot system,and the adoption of the three-pair rod drive method was determined by investigating its Variable Rotating Velocity Characteristics(VRVC).Simulation tests have shown that with an integrated torso,the robot can climb vertical obstacles up to 600 mm in height.The experimental tests of climbing steps and slopes using physical prototypes have confirmed the robot's obstacle-crossing capability.The potential applications of this Torso-leg-foot biomimetic robot is to carry heavy objects across obstacles to perform tasks such as planetary exploration and disaster relief.
基金supported by Natural Science Foundation of Hunan Province(No.2023JJ20064)the National Natural Science Foundation of China(No.52377222).
文摘The exceptional electrochemical performance of zinc anodes is frequently impeded by inadequate deposition kinetics and interfacial chemistry.Herein,we introduce the stereoisomerism to inform the balanced selection of electrolyte additives,taking into account their solvation and adsorption properties,to achieve the optimal deposition behaviors and electrochemical performance.The three-point coplanar adsorption configuration,in comparison to two-point adsorption,effectively mitigates the interference of water molecules and establishes a coplanar templating effect.This approach fosters a uniform distribution of charges,encourages the preferential orientation growth of(002)planes for uniform zinc deposition.Moreover,an appropriate level of solvation ability can modulate the solvation structure without substantially increasing the de-solvation energy barrier,thereby facilitating faster deposition kinetics than what is observed in cases of strong solvation.As a result,Zn//Zn cell can achieve an excellent performance of more than 3470 h at 2 mA cm^(-2)and 1 mAh cm^(-2),and Zn//AC full cell can work for 50000 cycles at 3 A g^(-1).Additionally,under practical conditions(N/P=4.37),the assembled Zn//I2 full cell demonstrates stable lifespan for 710 cycles at 1 A g^(-1).This work showcases the interplay between adsorption configuration of stereoisomeric additives on the cycling.
基金supported by the National Natural Science Foundation of China(No.52276094)the Education Project of Hunan Provincial Department(Nos.20B602 and 22C0112)+2 种基金the Industry University Education Cooperation Project(No.230803117185211)the Research Project on Teaching Reform in Ordinary Undergraduate Universities in Hunan Province(No.202401000142)the Natural Science Foundation of Hunan Province(No.2020JJ4935)。
文摘There is limited amount of research on surface plasmon resonance(SPR)sensors with self-referencing capabilities which are based on dielectric gratings.In the short-wavelength range,a metal grating sensor is capable of simultaneously measuring liquid refractive index under proposed temperature.A fabricated gold grating is placed on one side of a thin gold film for refractive index measurement,while the other with polydimethylsiloxane(PDMS)is deposited on the other side for temperature measurement.We use finite element analysis to research its sensing characteristics.Due to the high refractive index sensitivity of SPR sensors and thermo-optic coefficient of PDMS,we discovered the maximum spectral sensitivity of the sensor is 564 nm/RIU and-50 pm/℃when the liquid refractive index ranges from 1.30 to 1.40 with temperature ranging from 0℃ to 100℃.Numerical results indicate that there may not be mutual interference between two channels for measuring refractive index and temperature,which reduces the complexity of sensor measurements.
基金The National Natural Science Foundation of China(No.70671024).
文摘To investigate the process of information technology （IT） impacts on firm competitiveness, an integrated process model of IT impacts on firm competitiveness is brought forward based on the process-oriented view, the resource-based view and the complementary resource view, which is comprised of an IT conversion process, an information system （IS） adoption process, an IS use process and a competition process. The application capability of IT plays the critical role, which determines the efficiency and effectiveness of the aforementioned four processes. The process model of IT impacts on firm competitiveness can also be used to explain why, under what situations and how IT can generate positive organizational outcomes, as well as theoretical bases for further empirical study.
文摘In order to solve the problem that the current matchmaking methods for semantic web service mainly focus on the matchmaking of IO （inputs, outputs） descriptions which may result in one-sidedness, a description-logic-based IOPE （inputs, outputs, preconditions, effects） description and matchmaking method is proposed for semantic web service. The description logic concept is used to annotate service IO and the description logic assertion is employed to describe service PE（preconditions, effects）. TBox subsumption checking is used to measure the subsumption relationship between IO descriptions of service request and advertising; ABox consistency checking is used for checking the logical implication between PE descriptions of service request and advertising. Based upon the logical implication, four kinds of PE matching degrees are proposed to measure and compare the pros and cons of the results of matchmaking. They are the exact, perfect, side-effect and common match. Experiments show that the method has a higher precision rate under the same recall rate compared with the existing method.
基金Project(2011M501090) upported by the China Postdoctoral Science FoundationProject(SCUT2012ZZ0042) upported by the Fundamental Research Funds for the Central Universities+1 种基金Project supported by the"SPR-2011"of South China University of TechnologyProject(NRC07/08.EG01)supprted by the Fok Ying Tung Foundation
文摘Spinel LiMn2O4 microspheres with durable high rate capability were synthesized by a facile route using spherical MnCO3 precursors as the self-supported templates, combined with the calcinations of LiNO3 at 700 °C for 8 h. The spherical MnCO3 precursors were obtained from the control of the crystallizing process of Mn2＋ ions and NH4HCO3 in aqueous solution. The effects of the mole ratio of the raw materials, reaction time, and reaction temperature on the morphology and yield of the MnCO3 were investigated. The as-synthesized MnCO3 and LiMn2O4 microspheres were characterized by powder X-ray diffractometry （XRD） and scanning electron microscopy （SEM）. Galvanostatic charge/discharge tests indicate that the spinel LiMn2O4 microspheres deliver a discharge capacity of 90 mA-h/g at 10C rate show good capacity retention capability （75% of their initial capacity after 800 cycles at 10C rate）. The durable high rate capability suggests that the as-synthesized LiMn2O4 microspheres are promising cathode materials for high power lithium ion batteries.
文摘The coexistence theory of slag structure and it's application to calculation of the oxidizing capabilities of slag melts is described. It is shown that the law of mass action can be widely applied to the calculation of oxidizing capabilities of slag melts in combination with the coexistence theory of slag structure.For slag melts containing basic oxides FeO and MnO, their oxidizing capabilities can be expressed by N Fe tO =N FeO +6N Fe 2O 3 , while for slag melts containing basic oxides CaO, MgO, etc., in addition to FeO and MnO, their oxidizing capabilities can be given as N Fe tO =N FeO +6N Fe 2O 3 +8N Fe 3O 4 .
基金financially supported by National Key R&D Program of China(No.2016YFC0205301)the Key Project of National Natural Science Foundation(No.21637005)+1 种基金the National Natural Science Foundation of China(No.21607149)the Natural Science Foundation of Fujian Province,China(No.2016J05142)
文摘The effect of acidity and redox capability over sulfuric acid-modified CeO_2 catalysts were studied for the selective catalytic reduction of NO_x with NH_3(NH_3-SCR). The deposition of sulfate significantly enhanced the catalytic performance over CeO_2. NO_x conversion over4H_2SO_4/CeO_2 at 230–440 °C was higher than 90%. The strong redox capability of CeO_2 could result in unselective NH_3 oxidation and decrease high temperatures catalytic activity and N_2 selectivity. The deposition of sulfate increased the acidity and weakened the redox capability, and then increased the high temperature NO_x conversion and N_2 selectivity. An appropriate level of acidity also promoted the activity at 190–250 °C over ceria-based catalysts, and with further increase in the acidity, the SCR activity decreased slightly. Weak redox capability lowered the low-temperature catalytic activity. Excellent SCR activity requires a balance of acidity and redox capability on the catalysts.
