According to the proportion of 1:1, konjac flour and mulberry leaf powder are compounded into a kind of dietary fiber source(KMCP). It is found to be good for anti-inflammation. However, its precise anti-allergic rhin...According to the proportion of 1:1, konjac flour and mulberry leaf powder are compounded into a kind of dietary fiber source(KMCP). It is found to be good for anti-inflammation. However, its precise anti-allergic rhinitis effect and mechanism remain unknown. In our work, the effect of KMCP on allergic rhinitis(AR)induced by ovalbumin(OVA)was investigated. We found that the number of nasal rubbing and sneezing, the eosinophil(EOS)count in the nasal mucosa, and the serum levels of histamine(HIS), OVA-specific immunoglobulin E(OVA-sIgE)and interleukin-4(IL-4)were decreased, and the histopathological changes of nasal mucosa were inhibited. Additionally, the experiments further proved that the KMCP treatment could exert substantial effects on short-chain fatty acids(SCFAs)metabolism in the cecum as well. Overall findings suggest that KMCP could suppress the inflammatory response in AR mice, and serve as a novel curative therapeutic for AR without side effects.展开更多
In order to improve the comprehensive utilization rate of highfines sand(HFS)produced by the mine,full solid waste shotcrete(HFS-BFRS)was prepared with HFS asfine aggregate in cooperation with basaltfiber(BF).The strengt...In order to improve the comprehensive utilization rate of highfines sand(HFS)produced by the mine,full solid waste shotcrete(HFS-BFRS)was prepared with HFS asfine aggregate in cooperation with basaltfiber(BF).The strength growth characteristics of HFS-BFRS were analyzed.And thefitting equation of compressive strength growth characteristics of HFS-BFRS under the synergistic effect of multiple factors was given.And based on the orthogonal experimental method,the effects on the compressive strength,splitting tensile strength andflex-ural strength of HFS-BFRS under the action of different levels of influencing factors were investigated.The effect of three factors on the mechanical properties of HFS-BFRS,3,and 28 d,respectively,was revealed by choosing the colloidal sand ratio(C/H),basaltfiber volume fraction(BF Vol)and naphthalene high-efficiency water reducing agent(FDN)as the design variables,combined with indoor tests and theoretical analysis.The results show that the sensitivity of the three factors on compressive strength andflexural strength is C/H>FDN>BF Vol,and split-ting tensile strength is BF Vol>FDN>C/H.Finally,thefitting ratio of HFS-BFRS was optimized by the factor index method,and the rationality was verified by thefield test.For thefluidity of HFS-BFRS,the slump can be improved by 139%under the action of 1.2%FDN,which guarantees the pump-ability of HFS-BFRS.展开更多
As-extruded Mg-Er-Ni alloys with different volume fractions of long-period stacking ordered(LPSO)phase and density of lamellar γ' phase were prepared,and the microstructure,mechanical,and degradation properties w...As-extruded Mg-Er-Ni alloys with different volume fractions of long-period stacking ordered(LPSO)phase and density of lamellar γ' phase were prepared,and the microstructure,mechanical,and degradation properties were investigated.Coupling the bulk LPSO phase and the lamellar γ' phase,and controlling the dynamic recrystallization processes during deformation by adjusting the volume fraction of LPSO and the density of the γ' phase,a synergistic increase in strength and degradation rate can be achieved.On the one hand,the increase in corrosion rate was related to the increased volume fraction of the bulk LPSO phase and the densities of the lamellar γ' phase,which provide more galvanic corrosion.Moreover,high densities of the lamellar γ' phase can provide more corrosion interface by inhibiting the recrystallization process to refine dynamic recrystallized(DRXed)grains during the hot extrusion.On the other hand,the ultimate tensile strength(UTS)and tensile yield strength(TYS)of the Mg-Er-Ni alloy increased from 345 and 265 MPa to 514 MPa and 358 MPa,respectively,which was mainly attributed to grain boundary and texture strengthening,bulk LPSO phase and lamellar γ' phase strengthening.Overall,Mg^(-1)4Er-4Ni alloy,which contains the highest volume fraction bulk LPSO phase and the densities of lamellar γ' phase,re-alized a synergistic enhancement of strength and degradation rate.The UTS,TYS,and degradation rate of Mg^(-1)4Er-4Ni were 514 MPa,358 MPa,and 142.5 mg cm^(-2)h^(-1)(3 wt%KCl solution at 93◦C),respectively.This research provides new insight into developing Mg alloys with high strength and degradation rates for fracturing tool materials in the application of oil and gas exploitation in harsh environments.展开更多
Piezoresponse force microscopy(PFM)is an indispensable tool in the investigation of local electromechanical responses and polarization switching.The acquired data provide spatial information on the local disparity of ...Piezoresponse force microscopy(PFM)is an indispensable tool in the investigation of local electromechanical responses and polarization switching.The acquired data provide spatial information on the local disparity of polarization switching and electromechanical responses,making this technique advantageous over macroscopic approaches.Despite its widespread application in ferroelectrics,it has rarely been used to investigate the ferrielectric(FiE)behaviors in antiferroelectric(AFE)materials.Herein,the PFM was utilized to study the local electromechanical behavior and distribution of FiE,and the AFE phases of PbZrO_(3)thin-film were studied,where only the FiE behavior is observable using a macroscopic approach.The FiE region resembles a ferroelectric material at low voltages but exhibits a unique on-field amplitude response at high voltages.In contrast,the AFE region only yields an observable response at high voltages.Phase-field simulations reveal the coexistence of AFE and FiE states as well as the phase-transition processes that underpin our experimental observations.Our work illustrates the usefulness of PFM as an analytical tool to characterize AFE/FiE materials and their phase-coexistence behavior,thereby providing insights to guide property modification and potential applications.展开更多
In this study,Mg-13.2Gd-4.3Ni alloys containing continuous bulk-shaped long-period stacking ordered(LPSO),lamellar LPSO,and a small amount of eutectic phase were prepared,and the evolution of microstructure at differe...In this study,Mg-13.2Gd-4.3Ni alloys containing continuous bulk-shaped long-period stacking ordered(LPSO),lamellar LPSO,and a small amount of eutectic phase were prepared,and the evolution of microstructure at different extrusion temperatures and its influence on mechanical and degradation properties as well as corrosion mechanism were investigated.Preheating before extrusion can effectively promote the precipitation of lamellar LPSO in matrix.EX400 with higher volume fraction of non-DRXed grains exhibited higher strength,which was mainly due to strong texture,high dislocation density,and high volume fraction of lamellar LPSO.The EX420 with higher volume fraction of DRXed grains showed higher degradation rate,which was mainly due to the higher density of grain boundary.The EX400 exhibited excellent comprehensive properties with tensile yield strength(TYS)of 334 MPa,ultimate tensile strength(UTS)of 484 MPa and elongation(EL)of 7.4%,ultimate compressive strength(UCS)of 638 MPa and compressive yield strength(CYS)of 443 MPa,degradation rate of 86.1 mg/cm^(2)/h at 93℃in 3 wt.%KCl solution.展开更多
Large-scale Mg-8Gd-4Y-1Zn-Mn(wt.%)alloy ingot with a diameter of 315 mm and a length of 2410 mm was prepared through semi-continuous casting.Chemical composition,microstructure and mechanical properties at different l...Large-scale Mg-8Gd-4Y-1Zn-Mn(wt.%)alloy ingot with a diameter of 315 mm and a length of 2410 mm was prepared through semi-continuous casting.Chemical composition,microstructure and mechanical properties at different locations of the samples with as-cast,T4 and T6 heat-treated states,respectively,were investigated.No obvious macro segregation has been detected in the high-quality alloy ingot.The main eutectic structures at all different locations are composed ofα-Mg,Mg3RE-type,Mg5RE-type and LPSO phases.At the edge of ingot,the unusual casting twins including 10-12 extension twins and 10-11 compression twins were observed due to the intensive internal stress.In T4 heat-treated alloy,the micro segregation was eliminated.The remained phases wereα-Mg and LPSO phase.Combined with the remarkable age-hardening response,T6 samples exhibits improved mechanical properties at ambient temperature,which derives from the dense prismaticβ'precipitates and profuse basalγ'precipitates.展开更多
Hydrological Component has been one of three essential parts of ESCAP/WMO Typhoon Committee.The Working Group on Hydrology(WGH)established at TC 33rd Session in 2000 is the first working group among three basic compon...Hydrological Component has been one of three essential parts of ESCAP/WMO Typhoon Committee.The Working Group on Hydrology(WGH)established at TC 33rd Session in 2000 is the first working group among three basic components of the Committee,which has been repeatedly recognized as the most active component in the Committee who has integrated conducted successfully a number of cooperation projects and integrated actions among Members.In the past decade,WGH has implemented wide range activities under the framework of Strategic Plan of the Committee.The achievement of those cooperation projects played very important roles in promoting the capacity building on hydrological monitoring,forecasting and early warning among Members.This paper introduced the Term of Reference for WGH and its high priorities,and summarized the activities conducted in recent decade.The paper also reviewed the progresses in TC Members on hydrological observation and monitoring network,hydrological data collection and transmission,hydrological information and forecasting,and establishment of flood forecasting system.The paper also pointed out the development direction and the area to be enhanced for hydrological component in future,including:(1)application of QPE/QPF in flood forecasting and establishment of the coupled hydro-meteorological modeling;(2)development of impact-based,risk-based and community-based flood forecasting and warning system,including storm surge,urban flood,sediment disaster(flash flood,landslide and mudflow);and(3)application of internet of things(IOT),big data,cloud computing,and mobile internet in flood monitoring,forecasting and early warning,and better response,particularly in flood inundation mapping and QPE/QPF products application.展开更多
Proton exchange membrane fuel cells(PEMFCs)are considered as one of the most effective technologies to resolve environmental problems and energy crisis for future automotive applications[1-4].The direct methanol fuel ...Proton exchange membrane fuel cells(PEMFCs)are considered as one of the most effective technologies to resolve environmental problems and energy crisis for future automotive applications[1-4].The direct methanol fuel cell(DMFC)[5-6]is a new type of PEMFC using methanol as fuel[7].Because of its higher energy density and conversion efficiency,methanol can be used as direct fuel at a relatively lower operating temperature[8]with portable great potential in equipment and transportation utilization.Therefore,developing DMFCs that use methanol aqueous solution or steam methanol as fuel is a good choice to solve energy problems[9].展开更多
Fertilizer sphericity is an important assessment index of appearance quality that affects the fertilization effect.A fertilizer sphericity measuring device based on machine vision was designed aimed at low precision a...Fertilizer sphericity is an important assessment index of appearance quality that affects the fertilization effect.A fertilizer sphericity measuring device based on machine vision was designed aimed at low precision and heavy workload of manual fertilizer measurement,and high cost and complicated operation of high precision measuring instruments.A fertilizer sphericity measuring method based on equatorial and meridian circles was proposed.The device works in an intermittent static acquisition mode to simultaneously obtain both top and side images of a single fertilizer.First,the method performs gamma correction on the top and side images of the single fertilizer,and uses the Canny operator to detect the edge of the image to obtain the equatorial and meridian circular contour images of the fertilizer.Second,based on the fertilizer equatorial and meridian circular contour,the Least Squares Circle method was used to evaluate the roundness of the single fertilizer.Finally,the average roundness value of the equatorial and meridian circles was used as the final sphericity value of the fertilizer.The sphericity measurement test was carried out on the same batch of compound,organic and biological fertilizers by using the sphericity measuring device.The fertilizer sphericity data were obtained by different measurement and evaluation methods.The variation coefficient was used to evaluate the difference in fertilizer sphericity measured by different sphericity measurement and evaluation methods.The results show that among the different measurement and evaluation methods,the coefficient of variation of fertilizer sphericity measured by the equatorial and meridian circle method was the smallest,and the coefficient of variation of sphericity measured by the Least Squares Circle method was the smallest and accurate.This study shows that the sphericity measuring device and method can accurately measure the fertilizer sphericity,and has a significant potential to facilitate fertilizer production and quality inspection.展开更多
基金financially supported by Chongqing Undergraduate Training Programs for Innovation and Entrepreneurship (S201910635126)approved by the Natural Science Foundation of Chongqing Province-Level Municipality,China (cstc2018jcyjAX0527)。
文摘According to the proportion of 1:1, konjac flour and mulberry leaf powder are compounded into a kind of dietary fiber source(KMCP). It is found to be good for anti-inflammation. However, its precise anti-allergic rhinitis effect and mechanism remain unknown. In our work, the effect of KMCP on allergic rhinitis(AR)induced by ovalbumin(OVA)was investigated. We found that the number of nasal rubbing and sneezing, the eosinophil(EOS)count in the nasal mucosa, and the serum levels of histamine(HIS), OVA-specific immunoglobulin E(OVA-sIgE)and interleukin-4(IL-4)were decreased, and the histopathological changes of nasal mucosa were inhibited. Additionally, the experiments further proved that the KMCP treatment could exert substantial effects on short-chain fatty acids(SCFAs)metabolism in the cecum as well. Overall findings suggest that KMCP could suppress the inflammatory response in AR mice, and serve as a novel curative therapeutic for AR without side effects.
基金This work was supported by the National Natural Science Foundation of China(51834001,52104129)a project supported by the China Postdoctoral Science Foundation(2020M672226,2022T150195)Key Laboratory of Mine Ecological Effects and Systematic Restoration,Ministry of Natural Resources,Open Fund(MEER-2022-09).
文摘In order to improve the comprehensive utilization rate of highfines sand(HFS)produced by the mine,full solid waste shotcrete(HFS-BFRS)was prepared with HFS asfine aggregate in cooperation with basaltfiber(BF).The strength growth characteristics of HFS-BFRS were analyzed.And thefitting equation of compressive strength growth characteristics of HFS-BFRS under the synergistic effect of multiple factors was given.And based on the orthogonal experimental method,the effects on the compressive strength,splitting tensile strength andflex-ural strength of HFS-BFRS under the action of different levels of influencing factors were investigated.The effect of three factors on the mechanical properties of HFS-BFRS,3,and 28 d,respectively,was revealed by choosing the colloidal sand ratio(C/H),basaltfiber volume fraction(BF Vol)and naphthalene high-efficiency water reducing agent(FDN)as the design variables,combined with indoor tests and theoretical analysis.The results show that the sensitivity of the three factors on compressive strength andflexural strength is C/H>FDN>BF Vol,and split-ting tensile strength is BF Vol>FDN>C/H.Finally,thefitting ratio of HFS-BFRS was optimized by the factor index method,and the rationality was verified by thefield test.For thefluidity of HFS-BFRS,the slump can be improved by 139%under the action of 1.2%FDN,which guarantees the pump-ability of HFS-BFRS.
基金support from the National Key Research and Development Program of China(No.2021YFB3701100)the Natural Science Foundation Commission of China(Grant Nos.U20A20234 and 51874062)+1 种基金the Fundamental Re-search Funds for Central Universities(No.2022CDJKYJH004C)the Science and Technology Major Project of Shanxi Province(No.20191102008).
文摘As-extruded Mg-Er-Ni alloys with different volume fractions of long-period stacking ordered(LPSO)phase and density of lamellar γ' phase were prepared,and the microstructure,mechanical,and degradation properties were investigated.Coupling the bulk LPSO phase and the lamellar γ' phase,and controlling the dynamic recrystallization processes during deformation by adjusting the volume fraction of LPSO and the density of the γ' phase,a synergistic increase in strength and degradation rate can be achieved.On the one hand,the increase in corrosion rate was related to the increased volume fraction of the bulk LPSO phase and the densities of the lamellar γ' phase,which provide more galvanic corrosion.Moreover,high densities of the lamellar γ' phase can provide more corrosion interface by inhibiting the recrystallization process to refine dynamic recrystallized(DRXed)grains during the hot extrusion.On the other hand,the ultimate tensile strength(UTS)and tensile yield strength(TYS)of the Mg-Er-Ni alloy increased from 345 and 265 MPa to 514 MPa and 358 MPa,respectively,which was mainly attributed to grain boundary and texture strengthening,bulk LPSO phase and lamellar γ' phase strengthening.Overall,Mg^(-1)4Er-4Ni alloy,which contains the highest volume fraction bulk LPSO phase and the densities of lamellar γ' phase,re-alized a synergistic enhancement of strength and degradation rate.The UTS,TYS,and degradation rate of Mg^(-1)4Er-4Ni were 514 MPa,358 MPa,and 142.5 mg cm^(-2)h^(-1)(3 wt%KCl solution at 93◦C),respectively.This research provides new insight into developing Mg alloys with high strength and degradation rates for fracturing tool materials in the application of oil and gas exploitation in harsh environments.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIP)(No.2019R1I1A1A01063888)the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.2019R1A6A1A03033215)F.P.Z.acknowledges the Alexander von Humboldt Foundation(AvH)for the fellowship with award number 1203828,and Z.L.acknowledges the LOEWE program of the State of Hesse,Germany,within the project FLAME(Fermi Level Engineering of Antiferroelectric Materials for Energy Storage and Insulation Systems).
文摘Piezoresponse force microscopy(PFM)is an indispensable tool in the investigation of local electromechanical responses and polarization switching.The acquired data provide spatial information on the local disparity of polarization switching and electromechanical responses,making this technique advantageous over macroscopic approaches.Despite its widespread application in ferroelectrics,it has rarely been used to investigate the ferrielectric(FiE)behaviors in antiferroelectric(AFE)materials.Herein,the PFM was utilized to study the local electromechanical behavior and distribution of FiE,and the AFE phases of PbZrO_(3)thin-film were studied,where only the FiE behavior is observable using a macroscopic approach.The FiE region resembles a ferroelectric material at low voltages but exhibits a unique on-field amplitude response at high voltages.In contrast,the AFE region only yields an observable response at high voltages.Phase-field simulations reveal the coexistence of AFE and FiE states as well as the phase-transition processes that underpin our experimental observations.Our work illustrates the usefulness of PFM as an analytical tool to characterize AFE/FiE materials and their phase-coexistence behavior,thereby providing insights to guide property modification and potential applications.
基金the financial support from the National Key Research and Development Program of China(No.2021YFB3701100)the Natural Science Foundation Commission of China(Grant Nos.U20A20234,51874062)+3 种基金the Chongqing Foundation and Advanced Research Project(Grant No.cstc2019jcyj-zdxm X0010)Fundamental Research Funds for the Central Universities(No.2022CDJKYJH004)the Science and Technology Major Project of Shanxi Province(No.20191102008)University Innovation Research Group of Chongqing(CXQT20023)。
文摘In this study,Mg-13.2Gd-4.3Ni alloys containing continuous bulk-shaped long-period stacking ordered(LPSO),lamellar LPSO,and a small amount of eutectic phase were prepared,and the evolution of microstructure at different extrusion temperatures and its influence on mechanical and degradation properties as well as corrosion mechanism were investigated.Preheating before extrusion can effectively promote the precipitation of lamellar LPSO in matrix.EX400 with higher volume fraction of non-DRXed grains exhibited higher strength,which was mainly due to strong texture,high dislocation density,and high volume fraction of lamellar LPSO.The EX420 with higher volume fraction of DRXed grains showed higher degradation rate,which was mainly due to the higher density of grain boundary.The EX400 exhibited excellent comprehensive properties with tensile yield strength(TYS)of 334 MPa,ultimate tensile strength(UTS)of 484 MPa and elongation(EL)of 7.4%,ultimate compressive strength(UCS)of 638 MPa and compressive yield strength(CYS)of 443 MPa,degradation rate of 86.1 mg/cm^(2)/h at 93℃in 3 wt.%KCl solution.
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0301100)the Natural Science Foundation Commission of China(Nos.51571044 and 51874062)+2 种基金the Chongqing foundation and advanced research project(No.cstc2019jcyjzdxmX0010)the Fundamental Research Funds for the Central Universities(Nos.2018CDGFCL0005 and 2019CDXYCL0031)the financial support from the China Scholarship Council(No.201906050113)。
文摘Large-scale Mg-8Gd-4Y-1Zn-Mn(wt.%)alloy ingot with a diameter of 315 mm and a length of 2410 mm was prepared through semi-continuous casting.Chemical composition,microstructure and mechanical properties at different locations of the samples with as-cast,T4 and T6 heat-treated states,respectively,were investigated.No obvious macro segregation has been detected in the high-quality alloy ingot.The main eutectic structures at all different locations are composed ofα-Mg,Mg3RE-type,Mg5RE-type and LPSO phases.At the edge of ingot,the unusual casting twins including 10-12 extension twins and 10-11 compression twins were observed due to the intensive internal stress.In T4 heat-treated alloy,the micro segregation was eliminated.The remained phases wereα-Mg and LPSO phase.Combined with the remarkable age-hardening response,T6 samples exhibits improved mechanical properties at ambient temperature,which derives from the dense prismaticβ'precipitates and profuse basalγ'precipitates.
文摘Hydrological Component has been one of three essential parts of ESCAP/WMO Typhoon Committee.The Working Group on Hydrology(WGH)established at TC 33rd Session in 2000 is the first working group among three basic components of the Committee,which has been repeatedly recognized as the most active component in the Committee who has integrated conducted successfully a number of cooperation projects and integrated actions among Members.In the past decade,WGH has implemented wide range activities under the framework of Strategic Plan of the Committee.The achievement of those cooperation projects played very important roles in promoting the capacity building on hydrological monitoring,forecasting and early warning among Members.This paper introduced the Term of Reference for WGH and its high priorities,and summarized the activities conducted in recent decade.The paper also reviewed the progresses in TC Members on hydrological observation and monitoring network,hydrological data collection and transmission,hydrological information and forecasting,and establishment of flood forecasting system.The paper also pointed out the development direction and the area to be enhanced for hydrological component in future,including:(1)application of QPE/QPF in flood forecasting and establishment of the coupled hydro-meteorological modeling;(2)development of impact-based,risk-based and community-based flood forecasting and warning system,including storm surge,urban flood,sediment disaster(flash flood,landslide and mudflow);and(3)application of internet of things(IOT),big data,cloud computing,and mobile internet in flood monitoring,forecasting and early warning,and better response,particularly in flood inundation mapping and QPE/QPF products application.
基金supported by the National Key R&D Program of China(Grant No.2016YFA0200200)the National Natural Science Foundation of China(Grant Nos.51272071,51203045 and 21401049)the Wuhan Science and Technology Bureau of China(Grant No.2018010401011280).
文摘Proton exchange membrane fuel cells(PEMFCs)are considered as one of the most effective technologies to resolve environmental problems and energy crisis for future automotive applications[1-4].The direct methanol fuel cell(DMFC)[5-6]is a new type of PEMFC using methanol as fuel[7].Because of its higher energy density and conversion efficiency,methanol can be used as direct fuel at a relatively lower operating temperature[8]with portable great potential in equipment and transportation utilization.Therefore,developing DMFCs that use methanol aqueous solution or steam methanol as fuel is a good choice to solve energy problems[9].
基金This work was supported in part by the National Key Research and Development Plan of China(2016YFD0201104),National Apple Industry Technology System Project.
文摘Fertilizer sphericity is an important assessment index of appearance quality that affects the fertilization effect.A fertilizer sphericity measuring device based on machine vision was designed aimed at low precision and heavy workload of manual fertilizer measurement,and high cost and complicated operation of high precision measuring instruments.A fertilizer sphericity measuring method based on equatorial and meridian circles was proposed.The device works in an intermittent static acquisition mode to simultaneously obtain both top and side images of a single fertilizer.First,the method performs gamma correction on the top and side images of the single fertilizer,and uses the Canny operator to detect the edge of the image to obtain the equatorial and meridian circular contour images of the fertilizer.Second,based on the fertilizer equatorial and meridian circular contour,the Least Squares Circle method was used to evaluate the roundness of the single fertilizer.Finally,the average roundness value of the equatorial and meridian circles was used as the final sphericity value of the fertilizer.The sphericity measurement test was carried out on the same batch of compound,organic and biological fertilizers by using the sphericity measuring device.The fertilizer sphericity data were obtained by different measurement and evaluation methods.The variation coefficient was used to evaluate the difference in fertilizer sphericity measured by different sphericity measurement and evaluation methods.The results show that among the different measurement and evaluation methods,the coefficient of variation of fertilizer sphericity measured by the equatorial and meridian circle method was the smallest,and the coefficient of variation of sphericity measured by the Least Squares Circle method was the smallest and accurate.This study shows that the sphericity measuring device and method can accurately measure the fertilizer sphericity,and has a significant potential to facilitate fertilizer production and quality inspection.