Safe operation of electrochemical capacitors(supercapacitors)is hindered by the flammability of commercial organic electrolytes.Non-flammable Water-in-Salt(WIS)electrolytes are promising alternatives;however,they are ...Safe operation of electrochemical capacitors(supercapacitors)is hindered by the flammability of commercial organic electrolytes.Non-flammable Water-in-Salt(WIS)electrolytes are promising alternatives;however,they are plagued by the limited operation voltage window(typically≤2.3 V)and inherent corrosion of current collectors.Herein,a novel deep eutectic solvent(DES)-based electrolyte which uses formamide(FMD)as hydrogen-bond donor and sodium nitrate(NaNO_(3))as hydrogen-bond acceptor is demonstrated.The electrolyte exhibits the wide electrochemical stability window(3.14 V),high electrical conductivity(14.01 mScm^(-1)),good flame-retardance,anticorrosive property,and ultralow cost(7%of the commercial electrolyte and 2%of WIS).Raman spectroscopy and Density Functional Theory calculations reveal that the hydrogen bonds between the FMD molecules and NO_(3)^(-)ions are primarily responsible for the superior stability and conductivity.The developed NaNO_(3)/FMD-based coin cell supercapacitor is among the best-performing state-of-art DES and WIS devices,evidenced by the high voltage window(2.6 V),outstanding energy and power densities(22.77 Wh kg^(-1)at 630 W kg^(-1)and 17.37 kW kg^(-1)at 12.55 Wh kg^(-1)),ultralong cyclic stability(86%after 30000 cycles),and negligible current collector corrosion.The NaNO_(3)/FMD industry adoption potential is demonstrated by fabricating 100 F pouch cell supercapacitors using commercial aluminum current collectors.展开更多
The polar magnetic fields of the Sun play an important role in governing solar activity and powering fast solar wind.However,because our view of the Sun is limited in the ecliptic plane,the polar regions remain largel...The polar magnetic fields of the Sun play an important role in governing solar activity and powering fast solar wind.However,because our view of the Sun is limited in the ecliptic plane,the polar regions remain largely uncharted.Using the high spatial resolution and polarimetric precision vector magnetograms observed by Hinode from 2012 to 2021,we investigate the long-term variation of the magnetic fields in polar caps at different latitudes.The Hinode magnetic measurements show that the polarity reversal processes in the north and south polar caps are non-simultaneous.The variation of the averaged radial magnetic flux density reveals that,in each polar cap,the polarity reversal is completed successively from the 70°latitude to the pole,reflecting a poleward magnetic flux migration therein.These results clarify the polar magnetic polarity reversal process at different latitudes.展开更多
HHe^(+)is considered as the strongest acid and most powerful proton donor known to human.Whether HHe^(+)exists at planetary high pressure environment is a quite important problem in physics,chemistry and planetary sci...HHe^(+)is considered as the strongest acid and most powerful proton donor known to human.Whether HHe^(+)exists at planetary high pressure environment is a quite important problem in physics,chemistry and planetary sciences.Here,using the ab initio evolutionary algorithm USPEX package,we searched HF–He system,which was reported as the most possible candidate to contain HHe^(+).The calculation proved HHe^(+)cannot form at pressure<1000 GPa,due to a conflict between the covalent component in symmetric hydrogen bond and ionic HHe^(+).Although He atoms have no chemical bonding with other elements,they can supply a chemical pressure,leading to two new phases He2(HF)4 and He(HF).With coplanar(HF)_(4)rings,He_(2)(HF)_(4)have an aromaticity-like electronic behavior while He(HF)has a new type of chiral HF chain.The formation of He_(2)(HF)_(4)and He(HF)prove that the chemical pressure from He,on par with external pressure,have ability to control the structural and electronic configuration and induce some new familiars of compounds include H and He elements which are fundamental planetary materials in giant planets.展开更多
This study was conducted to investigate and analyze Euphorbiaceae plant resources in Sanling Mountain Forest Park in Zhanjiang City,Guangdong Province.A plant resource development and utilization value evaluation syst...This study was conducted to investigate and analyze Euphorbiaceae plant resources in Sanling Mountain Forest Park in Zhanjiang City,Guangdong Province.A plant resource development and utilization value evaluation system was established by analytic hierarchy process(AHP)and used to comprehensively evaluate the development and utilization value of Euphorbiaceae plant resources in the area.The results showed that the comprehensive evaluation values of Sapium discolor,Sapium sebiferum,Flueggea virosa,Baccaurea ramiflora,Aleurites moluccana,Antidesma ghaesembilla,Phyllanthus emblica and Pedilanthus tithymaloides were greater than 2.65,performing well;the comprehensive evaluation values of Bridelia tomentosa,Glochidion puberum,Breynia fruticosa,Mallotus paniculatus,Mallotus repandus,Mallotus apelta and Alchornea trewioides were in the range of 1.9622-2.5964,performing ordinary;and the comprehensive evaluation values of Phyllanthus reticulatus,Ricinus communis,Croton crassifolius,and Sebastiania chamaelea were smaller than 1.96,which were relatively lower.S.discolor,S.sebiferum,F.virosa,B.ramiflora,A.moluccana,A.ghaesembilla,P.emblica and P.tithymaloides have great development value and can be developed and used in a planned and step-by-step manner,and Aporosa dioica and Euphorbia tirucalli with a lower comprehensive evaluation value but strong stress resistance and adaptability can be applied to the construction of ecological forests and shelter forests.展开更多
Thermal barrier coatings(TBCs)in gas turbine engines are used in expressly harsh environments;thus,assessing TBC integrity status is critical for safety and reliability.However,traditional periodic maintenance involve...Thermal barrier coatings(TBCs)in gas turbine engines are used in expressly harsh environments;thus,assessing TBC integrity status is critical for safety and reliability.However,traditional periodic maintenance involves visual inspections of the TBCs,requiring the gas turbine to be decommissioned and partially dismantled.Most importantly,tiny defects or internal damages that easily cause coating failure cannot be identified.In this work,a new nondestructive evaluation(NDE)technique of TBCs based on quantum dot(QD)anion exchange is first explored internationally.By exchanging anions between the Cl ions and the CsPbBr_(3) QDs,the degrees of salt corrosion of the TBCs are evaluated.The resultant NDE technique shows that the colour of the TBCs obviously changes from green to blue,accompanied by a large blueshift(~100 nm)of the photoluminescence(PL)peak position.In addition,the relationship between the PL peak position and coating thermophysical properties indicates that the precision of this NDE technique may easily identify theμm-level of the thermal growth oxide(TGO)changes inside the TBCs.展开更多
Double-sided microlens arrays(DSMLAs)include combinations of two single-sided MLAs to overcome positioning errors and greatly improve light transmissivity compared to other types of lenses.Precision glass molding(PGM)...Double-sided microlens arrays(DSMLAs)include combinations of two single-sided MLAs to overcome positioning errors and greatly improve light transmissivity compared to other types of lenses.Precision glass molding(PGM)is used to fabricate DSMLAs,but controlling alignment errors during this process is challenging.In this paper,a mold assembly was manufactured with a novel combination of materials to improve the alignment accuracy of mold cores during PGM by using the nonlinear thermal expansion characteristics of the various materials to improve the DSMLA alignment accuracy.By establishing a mathematical model of the DSMLA alignment error and a thermal expansion model of the mold-sleeve pair,the relationship between the maximum alignment error of the DSMLA and the mold-sleeve gap was determined.This research provides a method to optimize the mold-sleeve gap and minimize the alignment error of the DSMLA.The measured DSMLA alignment error was 10.56μm,which is similar to the predicted maximum alignment error.Optical measurements showed that the uniformity of the homogenized beam spot was 97.81%,and the effective homogeneous area accounted for 91.66%of the total area.This proposed method provides a novel strategy to improve the performance of DSMLAs.展开更多
Currently,manufacturing enterprises face increasingly fierce market competition due to the various demands of customers and the rapid development of economic globalization.Hence,they have to extend their production mo...Currently,manufacturing enterprises face increasingly fierce market competition due to the various demands of customers and the rapid development of economic globalization.Hence,they have to extend their production mode into distributed environments and establish multiple factories in various geographical locations.Nowadays,distributed manufacturing systems have been widely adopted in industrial production processes.In recent years,many studies have been done on the modeling and optimization of distributed scheduling problems.This work provides a literature review on distributed scheduling problems in intelligent manufacturing systems.By summarizing and evaluating existing studies on distributed scheduling problems,we analyze the achievements and current research status in this field and discuss ongoing studies.Insights regarding prior works are discussed to uncover future research directions,particularly swarm intelligence and evolutionary algorithms,which are used for managing distributed scheduling problems in manufacturing systems.This work focuses on journal papers discovered using Google Scholar.After reviewing the papers,in this work,we discuss the research trends of distributed scheduling problems and point out some directions for future studies.展开更多
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.LY23E060004)Royal Society Newton Advanced Fellowship(No.52061130218)
文摘Safe operation of electrochemical capacitors(supercapacitors)is hindered by the flammability of commercial organic electrolytes.Non-flammable Water-in-Salt(WIS)electrolytes are promising alternatives;however,they are plagued by the limited operation voltage window(typically≤2.3 V)and inherent corrosion of current collectors.Herein,a novel deep eutectic solvent(DES)-based electrolyte which uses formamide(FMD)as hydrogen-bond donor and sodium nitrate(NaNO_(3))as hydrogen-bond acceptor is demonstrated.The electrolyte exhibits the wide electrochemical stability window(3.14 V),high electrical conductivity(14.01 mScm^(-1)),good flame-retardance,anticorrosive property,and ultralow cost(7%of the commercial electrolyte and 2%of WIS).Raman spectroscopy and Density Functional Theory calculations reveal that the hydrogen bonds between the FMD molecules and NO_(3)^(-)ions are primarily responsible for the superior stability and conductivity.The developed NaNO_(3)/FMD-based coin cell supercapacitor is among the best-performing state-of-art DES and WIS devices,evidenced by the high voltage window(2.6 V),outstanding energy and power densities(22.77 Wh kg^(-1)at 630 W kg^(-1)and 17.37 kW kg^(-1)at 12.55 Wh kg^(-1)),ultralong cyclic stability(86%after 30000 cycles),and negligible current collector corrosion.The NaNO_(3)/FMD industry adoption potential is demonstrated by fabricating 100 F pouch cell supercapacitors using commercial aluminum current collectors.
基金supported by the National Key R&D Programs of China(2019YFA0405000,2022YFF0503800,2022YFF0503000)the Strategic Priority Research Programs of the Chinese Academy of Sciences(XDB0560000,XDB41000000)+1 种基金the National Natural Science Foundations of China(NSFC,Grant Nos.12173005,12273060,12350004,12273061,12222306,and 12073001)the Youth Innovation Promotion Association CAS,and Yunnan Academician Workstation of Wang Jingxiu(No.202005AF150025)。
文摘The polar magnetic fields of the Sun play an important role in governing solar activity and powering fast solar wind.However,because our view of the Sun is limited in the ecliptic plane,the polar regions remain largely uncharted.Using the high spatial resolution and polarimetric precision vector magnetograms observed by Hinode from 2012 to 2021,we investigate the long-term variation of the magnetic fields in polar caps at different latitudes.The Hinode magnetic measurements show that the polarity reversal processes in the north and south polar caps are non-simultaneous.The variation of the averaged radial magnetic flux density reveals that,in each polar cap,the polarity reversal is completed successively from the 70°latitude to the pole,reflecting a poleward magnetic flux migration therein.These results clarify the polar magnetic polarity reversal process at different latitudes.
基金NSFC(Grants No.21803033)Yong Elite Scientists Sponsorship Program by Tianjin(Grant No.TJSQNTJ-2018-18)the support by doctor foundation of Tianjin Normal University(52XB1911).
文摘HHe^(+)is considered as the strongest acid and most powerful proton donor known to human.Whether HHe^(+)exists at planetary high pressure environment is a quite important problem in physics,chemistry and planetary sciences.Here,using the ab initio evolutionary algorithm USPEX package,we searched HF–He system,which was reported as the most possible candidate to contain HHe^(+).The calculation proved HHe^(+)cannot form at pressure<1000 GPa,due to a conflict between the covalent component in symmetric hydrogen bond and ionic HHe^(+).Although He atoms have no chemical bonding with other elements,they can supply a chemical pressure,leading to two new phases He2(HF)4 and He(HF).With coplanar(HF)_(4)rings,He_(2)(HF)_(4)have an aromaticity-like electronic behavior while He(HF)has a new type of chiral HF chain.The formation of He_(2)(HF)_(4)and He(HF)prove that the chemical pressure from He,on par with external pressure,have ability to control the structural and electronic configuration and induce some new familiars of compounds include H and He elements which are fundamental planetary materials in giant planets.
基金Young Innovative Talents Project in Regular Institutions of Higher Learning in Guangdong Province(2016KQNCX231).
文摘This study was conducted to investigate and analyze Euphorbiaceae plant resources in Sanling Mountain Forest Park in Zhanjiang City,Guangdong Province.A plant resource development and utilization value evaluation system was established by analytic hierarchy process(AHP)and used to comprehensively evaluate the development and utilization value of Euphorbiaceae plant resources in the area.The results showed that the comprehensive evaluation values of Sapium discolor,Sapium sebiferum,Flueggea virosa,Baccaurea ramiflora,Aleurites moluccana,Antidesma ghaesembilla,Phyllanthus emblica and Pedilanthus tithymaloides were greater than 2.65,performing well;the comprehensive evaluation values of Bridelia tomentosa,Glochidion puberum,Breynia fruticosa,Mallotus paniculatus,Mallotus repandus,Mallotus apelta and Alchornea trewioides were in the range of 1.9622-2.5964,performing ordinary;and the comprehensive evaluation values of Phyllanthus reticulatus,Ricinus communis,Croton crassifolius,and Sebastiania chamaelea were smaller than 1.96,which were relatively lower.S.discolor,S.sebiferum,F.virosa,B.ramiflora,A.moluccana,A.ghaesembilla,P.emblica and P.tithymaloides have great development value and can be developed and used in a planned and step-by-step manner,and Aporosa dioica and Euphorbia tirucalli with a lower comprehensive evaluation value but strong stress resistance and adaptability can be applied to the construction of ecological forests and shelter forests.
基金support form the Science and Technology Innovation Program of Hunan Province(No.2022RC1098)the Hunan Provincial Natural Science Foundation of China(Nos.2023JJ30563,2019JJ50565)+6 种基金the Scientific Research Fund of Hunan Provincial Education Department(Nos.22A0580,18A461)the Scientific Research Start-up Fund for High-level Talents in Xiangnan Universitysupported by the National Natural Science Foundation of China(Nos.51801034,52172067)the Natural Science Foundation of Guangdong Province(Nos.2021B1515020038,2020B1515020036)the Guangdong Special Support Program(No.2019BT02C629)supported by the Scientific Research Fund of Hunan Provincial Education Department(No.19C1706)the Scientific Research Fund of Chenzhou(No.zdyf201907).
文摘Thermal barrier coatings(TBCs)in gas turbine engines are used in expressly harsh environments;thus,assessing TBC integrity status is critical for safety and reliability.However,traditional periodic maintenance involves visual inspections of the TBCs,requiring the gas turbine to be decommissioned and partially dismantled.Most importantly,tiny defects or internal damages that easily cause coating failure cannot be identified.In this work,a new nondestructive evaluation(NDE)technique of TBCs based on quantum dot(QD)anion exchange is first explored internationally.By exchanging anions between the Cl ions and the CsPbBr_(3) QDs,the degrees of salt corrosion of the TBCs are evaluated.The resultant NDE technique shows that the colour of the TBCs obviously changes from green to blue,accompanied by a large blueshift(~100 nm)of the photoluminescence(PL)peak position.In addition,the relationship between the PL peak position and coating thermophysical properties indicates that the precision of this NDE technique may easily identify theμm-level of the thermal growth oxide(TGO)changes inside the TBCs.
基金support of the National Natural Science Foundation of China(52205440)the Beijing Municipal Natural Science Foundation(JQ20014)the Science and Technology Major Project of Jiangxi Province(20212AAE01002).
文摘Double-sided microlens arrays(DSMLAs)include combinations of two single-sided MLAs to overcome positioning errors and greatly improve light transmissivity compared to other types of lenses.Precision glass molding(PGM)is used to fabricate DSMLAs,but controlling alignment errors during this process is challenging.In this paper,a mold assembly was manufactured with a novel combination of materials to improve the alignment accuracy of mold cores during PGM by using the nonlinear thermal expansion characteristics of the various materials to improve the DSMLA alignment accuracy.By establishing a mathematical model of the DSMLA alignment error and a thermal expansion model of the mold-sleeve pair,the relationship between the maximum alignment error of the DSMLA and the mold-sleeve gap was determined.This research provides a method to optimize the mold-sleeve gap and minimize the alignment error of the DSMLA.The measured DSMLA alignment error was 10.56μm,which is similar to the predicted maximum alignment error.Optical measurements showed that the uniformity of the homogenized beam spot was 97.81%,and the effective homogeneous area accounted for 91.66%of the total area.This proposed method provides a novel strategy to improve the performance of DSMLAs.
基金supported in part by the National Natural Science Foundation of China(Nos.61603169,61703220,and 61873328)China Postdoctoral Science Foundation Funded Project(No.2019T120569)+3 种基金Shandong Province Outstanding Youth Innovation Team Project of Colleges and Universities of China(No.2020RWG011)Shandong Province Colleges and Universities Youth Innovation Talent Introduction and Education Programthe Faculty Research Grants(FRG)from Macao University of Science and TechnologyShandong Provincial Key Laboratory for Novel Distributed Computer Software Technology。
文摘Currently,manufacturing enterprises face increasingly fierce market competition due to the various demands of customers and the rapid development of economic globalization.Hence,they have to extend their production mode into distributed environments and establish multiple factories in various geographical locations.Nowadays,distributed manufacturing systems have been widely adopted in industrial production processes.In recent years,many studies have been done on the modeling and optimization of distributed scheduling problems.This work provides a literature review on distributed scheduling problems in intelligent manufacturing systems.By summarizing and evaluating existing studies on distributed scheduling problems,we analyze the achievements and current research status in this field and discuss ongoing studies.Insights regarding prior works are discussed to uncover future research directions,particularly swarm intelligence and evolutionary algorithms,which are used for managing distributed scheduling problems in manufacturing systems.This work focuses on journal papers discovered using Google Scholar.After reviewing the papers,in this work,we discuss the research trends of distributed scheduling problems and point out some directions for future studies.