The exploration of aqueous flexible metal-air batteries with high energy density and durability has attracted many research efforts with the demand for portable and wearable electronic devices.Aqueous flexible metal-a...The exploration of aqueous flexible metal-air batteries with high energy density and durability has attracted many research efforts with the demand for portable and wearable electronic devices.Aqueous flexible metal-air batteries feature Earth-abundant materials,environmental friendliness,and operational safety.Each part of one metal-air battery can significantly affect the overall performance.This review starts with the fundamental working principles and the basic battery configurations and then highlights on the common issues and the recent advances in designing high-performance metal electrodes,solid-state electrolytes,and air electrodes.Bifunctional oxygen electrocatalysts with high activity and long-term stability for constructing efficient air electrodes in flexible metal-air batteries are summarized including metal-free carbon-based materials and nonprecious Co/Fe-based materials(alloys,metal oxides,metal sulfites,metal phosphates,metal nitrates,single-site metal-nitrogen-carbon materials,and composites).Finally,a perspective is provided on the existing challenges and possible future research directions in optimizing the performance and lifetime of the flexible aqueous solid-state metal-air batteries.展开更多
This study predicts the characteristics of a compressible polytropic air spring model. A second-order nonlinear autonomous air spring model is presented. The proposed model is based on the assumption that polytropic p...This study predicts the characteristics of a compressible polytropic air spring model. A second-order nonlinear autonomous air spring model is presented. The proposed model is based on the assumption that polytropic processes occur. Isothermal and isentropic compression and expansion of the air within the spring chambers are the two scenarios that are taken into consideration. In these situations, the air inside the spring chambers compresses and expands, resulting in nonlinear spring restoring forces. The MATLAB/Simulink software environment is used to build a numerical simulation model for the dynamic behavior of the air spring. To quantify the values of the stiffnesses of the proposed models, a numerical solution is run over time for various values of the design parameters. The isentropic process case has a higher dynamic air spring stiffness than the isothermal process case, according to the results. The size of the air spring chamber and the area of the air spring piston influence the air spring stiffness in both situations. It is demonstrated that the stiffness of the air spring increases linearly with increasing piston area and decreases nonlinearly with increasing air chamber length. As long as the ratio of the vibration’s amplitude to the air spring’s chamber length is small, there is good agreement in both scenarios between the linearized model and the full nonlinear model. This implies that linear modeling is a reasonable approximation of the complete nonlinear model in this particular scenario.展开更多
The metal-air batteries with the largest theoretical energy densities have been paid much more attention.However,metal-air batteries including Li-air/O_(2),Li-CO_(2),Na-air/O_(2).and Zn-air/O_(2) batteries,are complex...The metal-air batteries with the largest theoretical energy densities have been paid much more attention.However,metal-air batteries including Li-air/O_(2),Li-CO_(2),Na-air/O_(2).and Zn-air/O_(2) batteries,are complex systems that have their respective scientific problems,such as metal dendrite forming/deforming,the kinetics of redox mediators for oxygen reduction/evolution reactions,high overpotentials,desolution of CO_(2),H_(2)O,etc.from the air and related side reactions on both anode and cathode.It should be the main direction to address these shortages to improve performance.Here,we summarized recently research progress in these metal-air/O_(2) batteries.Some perspectives are also provided for these research fields.展开更多
All-solid-state lithium batteries(ASSLBs),which use solid electrolytes instead of liquid ones,have become a hot research topic due to their high energy and power density,ability to solve battery safety issues,and capa...All-solid-state lithium batteries(ASSLBs),which use solid electrolytes instead of liquid ones,have become a hot research topic due to their high energy and power density,ability to solve battery safety issues,and capabilities to fulfill the increasing demand for energy storage in electric vehicles and smart grid applications.Garnet-type solid electrolytes have attracted considerable interest as they meet all the properties of an ideal solid electrolyte for ASSLBs.The garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO)has excellent environmental stability;experiments and computational analyses showed that this solid electrolyte has a high lithium(Li)ionic conductivity(10^(-4)-10^(-3) S·cm^(-1)),an electrochemical window as wide as 6 V,stability against Li metal anode,and compatibility with most of the cathode materials.In this review,we present the fundamentals of garnet-type solid electrolytes,preparation methods,air stability,some strategies for improving the conductivity based on experimental and computational results,interfacial issues,and finally applications and challenges for future developments of LLZO solid electrolytes for ASSLBs.展开更多
详细阐述了一种基于多变量状态估计(Multivariate State Estimation Techniques,MSET)的电站锅炉空气预热器状态预测的方法。在该方法中,首先建立正常工况下各监测参数之间的关联模型;然后根据系统当前观测特征向量与各建模样本特征向...详细阐述了一种基于多变量状态估计(Multivariate State Estimation Techniques,MSET)的电站锅炉空气预热器状态预测的方法。在该方法中,首先建立正常工况下各监测参数之间的关联模型;然后根据系统当前观测特征向量与各建模样本特征向量之间的相似性程度,使用MSET对当前观测向量进行估计,得到与观测向量相对应的估计残差。最终模拟计算结果表明,MSET可有效并精确的对空气预热器的运行状态进行预测,实现对空气预热器劣化趋势进行早期预测,具有很高的实用价值。展开更多
Li-air batteries have attracted extensive attention because of their ultrahigh theoretical energy density. However, the potential safety hazard of flammable organic liquid electrolytes hinders their practical applicat...Li-air batteries have attracted extensive attention because of their ultrahigh theoretical energy density. However, the potential safety hazard of flammable organic liquid electrolytes hinders their practical applications. Replacing liquid electrolytes with solidstate electrolytes(SSEs) is expected to fundamentally overcome the safety issues. In this work, we focus on the development and challenge of solid-state Li-air batteries(SSLABs). The rise of different types of SSEs, interfacial compatibility and verifiability in SSLABs are presented. The corresponding strategies and prospects of SSLABs are also proposed. In particular, combining machine learning method with experiment and in situ(or operando)techniques is imperative to accelerate the development of SSLABs.展开更多
This study examines long-term rainfall and temperature variations over a dry tropical environment in Nigeria.An assessment of the variations of these weather variables showcases the extent of climate change limits and...This study examines long-term rainfall and temperature variations over a dry tropical environment in Nigeria.An assessment of the variations of these weather variables showcases the extent of climate change limits and corresponding effects on the biotic environment.Rainfall and temperature data were obtained from Nigerian Meteorological Agency for a period of 31 years(1991-2020)for Kano and Katsina States.Descriptive statistics were used to determine the degree of variability of the weather variables across spatial domains.Results showed that there is a sharp contrast in mean annual rainfall amounts of 1154.1 mm and 569.6 mm for Kano and Katsina located in the dry continental and semi-arid climate zones of Nigeria respectively.It is revealed that the month of August had the highest mean monthly rainfall for both areas i.e.359 mm and 194 mm with little or no trace during the dry season.The sharp difference in rainfall amount across spatial domains of the near similar climate zones shows that the Inter-tropical Discontinuity(ITD)does not completely overwhelm the northern band of Nigeria in August.The least variable monthly rainfall was in August and July with coefficient variations(CV)of 40%and 47%for Kano and Katsina.The months of February and March had the highest CV of 557%and 273%for the respective areas.In the examined areas the wet and dry seasons are from June-September and October-May respectively.The index of rainfall variability and drought intensity for the areas ranged from 0.85-0.95 and 45%indicating moderate variability and drought respectively.Mean annual temperature values are 33.4℃and 33.8℃for Kano and Katsina.The study recommends a proper climate observing scheme,most especially for agrarian practices so as to ensure profitable outputs for human sustainability.展开更多
Owing to the varied mechanisms of ORR/OER,exploiting cost-effective bifunctional catalysts with robust ORR/OER activities and excellent performances in Zn-air batteries is still a challenge.In this work,the Co/CoO@NSC...Owing to the varied mechanisms of ORR/OER,exploiting cost-effective bifunctional catalysts with robust ORR/OER activities and excellent performances in Zn-air batteries is still a challenge.In this work,the Co/CoO@NSC bifunctional catalyst is obtained by using Zn-MOF@Co-MOF as self-template.The Co/CoO@NSC composite has interconnected porous architecture with in tact metal@carb on structure,exhibiting superior electrocatalytic activities toward ORR and OER that can be comparable with the Pt/C and RuO_(2) catalysts,respectively.The Co/CoO@NSC-based aqueous Zn-air battery achieves a high specific capacity(759.7 mAh/g)and energy density(990.5 Wh/kg),and ultra-long rechargeable property(more than 400 h/1200 cycles).The Co/CoO@NSC-based solid-state Zn-air battery also delivers an excellent performance with a long cycle life(more than 143 h/858 cycles).Most importantly,the newly synthesized and recharged Co/CoO@NSC-based solid-state Zn-air battery can be used to light up a 2 V LED lamp for more than 28 h,demonstrating the superior practicability as rechargeable power source.展开更多
Solid-state batteries have been considered as promising next-generation energy storage devices for potentially higher energy density and better safety compared with commercial lithium-ion batteries that are based on o...Solid-state batteries have been considered as promising next-generation energy storage devices for potentially higher energy density and better safety compared with commercial lithium-ion batteries that are based on organic liquid electrolytes.However,in terms of indispensable solid-state electrolytes,there are remaining issues to be solved before entering the market.Most solid-state electrolytes are air-sensitive,which causes a complex and expensive cell assembly and impressible interface.Therefore,the solid-state electrolytes are expected to be atmosphere-stable,which will undoubtedly bring significant benefits to solid-state battery manufacturing.This review covers air-stabilityrelated issues of different types of inorganic solid-state electrolytes and the corresponding strategies.First,we provide an overview of solid-state electrolytes and solid-state batteries,including their history and advantages/disadvantages.Then,different types of solid-state electrolytes are selected as examples to illustrate the unfavorable interactions in air and the corresponding adverse effects.Next,according to recent advances,we summarize the effective strategies of constructing different types of air-stable inorganic solid-state electrolytes.Finally,perspectives on designing accessible air-stable solid-state electrolytes are provided,aiming to achieve the assembly of high-performance solid-state batteries in the atmosphere.展开更多
In a large-volume,high-density traffic background,air traffic manifests fluid-like microscopical characteristics.The characteristics are formed by the micro tailing actions between individual aircraft.Aircraft headway...In a large-volume,high-density traffic background,air traffic manifests fluid-like microscopical characteristics.The characteristics are formed by the micro tailing actions between individual aircraft.Aircraft headway refers to the time interval between successive flying aircraft in air traffic flow,which is one of the most important characteristics of air traffic flow.The variation in aircraft headway reveals the air traffic control behaviour.In this paper,we study the characteristics of air traffic control behaviours by analyzing radar tracks in a terminal maneuvering area.The headway in arrival traffic flow is measured after the determination of aircraft trailing relationships.The headway evolutionary characteristics for different control decisions and the headway evolutionary characteristics in different phase-states are discussed,and some interesting findings are gotten.This work may be helpful for scholars and managers in understanding the intrinsic nature of air traffic flow and in the development of intelligent assistant decision systems for air traffic management.展开更多
基金Australian Research Council,Grant/Award Numbers:DP190101008,FT190100058。
文摘The exploration of aqueous flexible metal-air batteries with high energy density and durability has attracted many research efforts with the demand for portable and wearable electronic devices.Aqueous flexible metal-air batteries feature Earth-abundant materials,environmental friendliness,and operational safety.Each part of one metal-air battery can significantly affect the overall performance.This review starts with the fundamental working principles and the basic battery configurations and then highlights on the common issues and the recent advances in designing high-performance metal electrodes,solid-state electrolytes,and air electrodes.Bifunctional oxygen electrocatalysts with high activity and long-term stability for constructing efficient air electrodes in flexible metal-air batteries are summarized including metal-free carbon-based materials and nonprecious Co/Fe-based materials(alloys,metal oxides,metal sulfites,metal phosphates,metal nitrates,single-site metal-nitrogen-carbon materials,and composites).Finally,a perspective is provided on the existing challenges and possible future research directions in optimizing the performance and lifetime of the flexible aqueous solid-state metal-air batteries.
文摘This study predicts the characteristics of a compressible polytropic air spring model. A second-order nonlinear autonomous air spring model is presented. The proposed model is based on the assumption that polytropic processes occur. Isothermal and isentropic compression and expansion of the air within the spring chambers are the two scenarios that are taken into consideration. In these situations, the air inside the spring chambers compresses and expands, resulting in nonlinear spring restoring forces. The MATLAB/Simulink software environment is used to build a numerical simulation model for the dynamic behavior of the air spring. To quantify the values of the stiffnesses of the proposed models, a numerical solution is run over time for various values of the design parameters. The isentropic process case has a higher dynamic air spring stiffness than the isothermal process case, according to the results. The size of the air spring chamber and the area of the air spring piston influence the air spring stiffness in both situations. It is demonstrated that the stiffness of the air spring increases linearly with increasing piston area and decreases nonlinearly with increasing air chamber length. As long as the ratio of the vibration’s amplitude to the air spring’s chamber length is small, there is good agreement in both scenarios between the linearized model and the full nonlinear model. This implies that linear modeling is a reasonable approximation of the complete nonlinear model in this particular scenario.
基金supported by the National Basic Research Programme of China (2021YFB3800301)the National Natural Science Foundation of China (21633003 and U1801251)Science,and Technology Innovation Fund for Emission Peak and Carbon Neutrality of Jiangsu Province (BK20220034)。
文摘The metal-air batteries with the largest theoretical energy densities have been paid much more attention.However,metal-air batteries including Li-air/O_(2),Li-CO_(2),Na-air/O_(2).and Zn-air/O_(2) batteries,are complex systems that have their respective scientific problems,such as metal dendrite forming/deforming,the kinetics of redox mediators for oxygen reduction/evolution reactions,high overpotentials,desolution of CO_(2),H_(2)O,etc.from the air and related side reactions on both anode and cathode.It should be the main direction to address these shortages to improve performance.Here,we summarized recently research progress in these metal-air/O_(2) batteries.Some perspectives are also provided for these research fields.
基金supported by the National Key R&D Program of China(Nos.2018YFB0905600 and 2017YFB0310400)the National Natural Science Foundation of China(No.51972246)+2 种基金Fundamental Research Funds for the Central Universities in China,State Key Laboratory of Advanced Electromagnetic Engineering and Technology(Huazhong University of Science and Technology)the"111"project(No.B13035)the Science and Technology Project of Global Energy Interconnection Research Institute Co.,Ltd.(No.SGGR0000WLJS1801080).
文摘All-solid-state lithium batteries(ASSLBs),which use solid electrolytes instead of liquid ones,have become a hot research topic due to their high energy and power density,ability to solve battery safety issues,and capabilities to fulfill the increasing demand for energy storage in electric vehicles and smart grid applications.Garnet-type solid electrolytes have attracted considerable interest as they meet all the properties of an ideal solid electrolyte for ASSLBs.The garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO)has excellent environmental stability;experiments and computational analyses showed that this solid electrolyte has a high lithium(Li)ionic conductivity(10^(-4)-10^(-3) S·cm^(-1)),an electrochemical window as wide as 6 V,stability against Li metal anode,and compatibility with most of the cathode materials.In this review,we present the fundamentals of garnet-type solid electrolytes,preparation methods,air stability,some strategies for improving the conductivity based on experimental and computational results,interfacial issues,and finally applications and challenges for future developments of LLZO solid electrolytes for ASSLBs.
文摘详细阐述了一种基于多变量状态估计(Multivariate State Estimation Techniques,MSET)的电站锅炉空气预热器状态预测的方法。在该方法中,首先建立正常工况下各监测参数之间的关联模型;然后根据系统当前观测特征向量与各建模样本特征向量之间的相似性程度,使用MSET对当前观测向量进行估计,得到与观测向量相对应的估计残差。最终模拟计算结果表明,MSET可有效并精确的对空气预热器的运行状态进行预测,实现对空气预热器劣化趋势进行早期预测,具有很高的实用价值。
基金supported by National Key Research and Development Program of China (No.2021YFF0500600)NSFC (22279120)Key R&D projects in Henan Province (221111240100)。
文摘Li-air batteries have attracted extensive attention because of their ultrahigh theoretical energy density. However, the potential safety hazard of flammable organic liquid electrolytes hinders their practical applications. Replacing liquid electrolytes with solidstate electrolytes(SSEs) is expected to fundamentally overcome the safety issues. In this work, we focus on the development and challenge of solid-state Li-air batteries(SSLABs). The rise of different types of SSEs, interfacial compatibility and verifiability in SSLABs are presented. The corresponding strategies and prospects of SSLABs are also proposed. In particular, combining machine learning method with experiment and in situ(or operando)techniques is imperative to accelerate the development of SSLABs.
文摘This study examines long-term rainfall and temperature variations over a dry tropical environment in Nigeria.An assessment of the variations of these weather variables showcases the extent of climate change limits and corresponding effects on the biotic environment.Rainfall and temperature data were obtained from Nigerian Meteorological Agency for a period of 31 years(1991-2020)for Kano and Katsina States.Descriptive statistics were used to determine the degree of variability of the weather variables across spatial domains.Results showed that there is a sharp contrast in mean annual rainfall amounts of 1154.1 mm and 569.6 mm for Kano and Katsina located in the dry continental and semi-arid climate zones of Nigeria respectively.It is revealed that the month of August had the highest mean monthly rainfall for both areas i.e.359 mm and 194 mm with little or no trace during the dry season.The sharp difference in rainfall amount across spatial domains of the near similar climate zones shows that the Inter-tropical Discontinuity(ITD)does not completely overwhelm the northern band of Nigeria in August.The least variable monthly rainfall was in August and July with coefficient variations(CV)of 40%and 47%for Kano and Katsina.The months of February and March had the highest CV of 557%and 273%for the respective areas.In the examined areas the wet and dry seasons are from June-September and October-May respectively.The index of rainfall variability and drought intensity for the areas ranged from 0.85-0.95 and 45%indicating moderate variability and drought respectively.Mean annual temperature values are 33.4℃and 33.8℃for Kano and Katsina.The study recommends a proper climate observing scheme,most especially for agrarian practices so as to ensure profitable outputs for human sustainability.
基金supported by the National Natural Science Foundation of China (21706217)the Fundamental Research Funds of China West Normal University (CXTD2020-1,17C035)+1 种基金the Scientific Research Fund of Science & Technology of Sichuan (2021YJ0410)the Province and Scientific Research Fund of Sichuan Provincial Education Department (17ZA0382).
文摘Owing to the varied mechanisms of ORR/OER,exploiting cost-effective bifunctional catalysts with robust ORR/OER activities and excellent performances in Zn-air batteries is still a challenge.In this work,the Co/CoO@NSC bifunctional catalyst is obtained by using Zn-MOF@Co-MOF as self-template.The Co/CoO@NSC composite has interconnected porous architecture with in tact metal@carb on structure,exhibiting superior electrocatalytic activities toward ORR and OER that can be comparable with the Pt/C and RuO_(2) catalysts,respectively.The Co/CoO@NSC-based aqueous Zn-air battery achieves a high specific capacity(759.7 mAh/g)and energy density(990.5 Wh/kg),and ultra-long rechargeable property(more than 400 h/1200 cycles).The Co/CoO@NSC-based solid-state Zn-air battery also delivers an excellent performance with a long cycle life(more than 143 h/858 cycles).Most importantly,the newly synthesized and recharged Co/CoO@NSC-based solid-state Zn-air battery can be used to light up a 2 V LED lamp for more than 28 h,demonstrating the superior practicability as rechargeable power source.
基金supported by the Innovation-Driven Project of Central South University(No.2019CX033)the National Natural Science Foundation of China(Nos.51622210,51904344,51925207,U1910210 and 51872277)+1 种基金the National Synchrotron Radiation Laboratory(KY2060000173)the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(grant nos.YLU-DNL Fund 2021002).
文摘Solid-state batteries have been considered as promising next-generation energy storage devices for potentially higher energy density and better safety compared with commercial lithium-ion batteries that are based on organic liquid electrolytes.However,in terms of indispensable solid-state electrolytes,there are remaining issues to be solved before entering the market.Most solid-state electrolytes are air-sensitive,which causes a complex and expensive cell assembly and impressible interface.Therefore,the solid-state electrolytes are expected to be atmosphere-stable,which will undoubtedly bring significant benefits to solid-state battery manufacturing.This review covers air-stabilityrelated issues of different types of inorganic solid-state electrolytes and the corresponding strategies.First,we provide an overview of solid-state electrolytes and solid-state batteries,including their history and advantages/disadvantages.Then,different types of solid-state electrolytes are selected as examples to illustrate the unfavorable interactions in air and the corresponding adverse effects.Next,according to recent advances,we summarize the effective strategies of constructing different types of air-stable inorganic solid-state electrolytes.Finally,perspectives on designing accessible air-stable solid-state electrolytes are provided,aiming to achieve the assembly of high-performance solid-state batteries in the atmosphere.
基金supported by the National Nature Science Foundation of China(No.71801215)the Fundamental Research Fund for the Central Universities (No. 3122016C009).
文摘In a large-volume,high-density traffic background,air traffic manifests fluid-like microscopical characteristics.The characteristics are formed by the micro tailing actions between individual aircraft.Aircraft headway refers to the time interval between successive flying aircraft in air traffic flow,which is one of the most important characteristics of air traffic flow.The variation in aircraft headway reveals the air traffic control behaviour.In this paper,we study the characteristics of air traffic control behaviours by analyzing radar tracks in a terminal maneuvering area.The headway in arrival traffic flow is measured after the determination of aircraft trailing relationships.The headway evolutionary characteristics for different control decisions and the headway evolutionary characteristics in different phase-states are discussed,and some interesting findings are gotten.This work may be helpful for scholars and managers in understanding the intrinsic nature of air traffic flow and in the development of intelligent assistant decision systems for air traffic management.
