Zr-based amorphous alloys have attracted extensive attention because of their large glassy formation ability, wide supercooled liquid region, high elasticity, and unique mechanical strength induced by their icosahedra...Zr-based amorphous alloys have attracted extensive attention because of their large glassy formation ability, wide supercooled liquid region, high elasticity, and unique mechanical strength induced by their icosahedral local structures.To determine the microstructures of Zr–Cu clusters, the stable and metastable geometry of Zr_(n)Cu(n=2–12) clusters are screened out via the CALYPSO method using machine-learning potentials, and then the electronic structures are investigated using density functional theory. The results show that the Zr_(n)Cu(n ≥ 3) clusters possess three-dimensional geometries, Zr_(n)Cu(n≥9) possess cage-like geometries, and the Zr_(12)Cu cluster has icosahedral geometry. The binding energy per atom gradually gets enlarged with the increase in the size of the clusters, and Zr_(n)Cu(n=5,7,9,12) have relatively better stability than their neighbors. The magnetic moment of most Zr_(n)Cu clusters is just 1μB, and the main components of the highest occupied molecular orbitals(HOMOs) in the Zr_(12)Cu cluster come from the Zr-d state. There are hardly any localized two-center bonds, and there are about 20 σ-type delocalized three-center bonds.展开更多
Iodine is widely used in aqueous zinc batteries(ZBs)due to its abundant resources,low cost,and active redox reactions.In addition to the active material in zinc-iodine batteries,iodine also plays an important role in ...Iodine is widely used in aqueous zinc batteries(ZBs)due to its abundant resources,low cost,and active redox reactions.In addition to the active material in zinc-iodine batteries,iodine also plays an important role in other ZBs,such as regulating the electrochemical behavior of zinc ions,promoting the reaction kinetic and reversibility of other redox pairs,catalytic behaviors related to iodine reactions,coupling with other halogen ions,shuttle behaviors of polyiodides,etc.However,there is currently a lack of comprehensive discussion on these aspects.Here,this review provides a comprehensive overview of the electrochemical behaviors of iodide in the aqueous ZBs.The effect of iodine ions on the Zn^(2+)desolvation behaviors and the interfacial behaviors of Zn anode was summarized.Iodine redox pairs boosting other redox pairs,such as MnO_(2)/Mn^(2+)redox pair and vanadium redox pair to obtain high reversibility and capacity was also discussed.Moreover,the catalytic behaviors related to iodine reactions in aqueous ZBs,synergistic reaction with other halogen ions and suppression of shuttle behaviors for high performance zinc-iodine batteries were systematically analyzed.Finally,future prospects for designing effective iodine electrochemical behaviors with practicability are proposed,which will provide scientific guidance for the practical application of iodine-related aqueous ZBs.展开更多
Ceramic materials with intricate structures can be efficiently fabricated using stereolithography(SLA)based 3D printing technology,offering advantages over traditional methods.Sintering temperature has primary effect ...Ceramic materials with intricate structures can be efficiently fabricated using stereolithography(SLA)based 3D printing technology,offering advantages over traditional methods.Sintering temperature has primary effect on properties of ceramics.This study investigated the crucial sintering temperature for 3D printed ceramics to ensure the desired properties.The results indicate that all samples exhibit a consistent layered structure across the experimental sintering temperatures.When the sintering temperature is increased from 1,250℃ to 1,350℃,the grain's morphology changes from spherical to plate-like.Surface morphology analysis reveals a decrease in surface roughness at sintering temperatures above 1,350℃.Mechanical tests show improved flexural strength and stiffness as the sintering temperature rises.Friction and wear experiments demonstrate that as the sintering temperature increases from 1,450℃ to 1,550℃,the wear pattern on ceramic surfaces transitions from deep pits to shallow grooves.The increase in sintering temperature effectively enhances the wear resistance of 3D printed alumina ceramics.This improvement plays a significant role in expanding the application field of these ceramics,prolonging the lifespan of parts,reducing production costs,enhancing performance,and promoting environmental protection.In this study,ceramics achieve the highest strength and best wear resistance when sintered at 1,600℃,resulting in the best overall performance.展开更多
Perovskite solar cells(PSCs)offer low costs and high power conversion efficiency.However,the lack of long-term stability,primarily stemming from the interfacial defects and the sus-ceptible metal electrodes,hinders th...Perovskite solar cells(PSCs)offer low costs and high power conversion efficiency.However,the lack of long-term stability,primarily stemming from the interfacial defects and the sus-ceptible metal electrodes,hinders their practical application.In the past few years,two-dimensional(2D)materials(e.g.,graphene and its derivatives,transitional metal dichalcogenides,MXenes,and black phosphorus)have been identified as a promising solution to solving these problems because of their dangling bond-free surfaces,layer-dependent electronic band structures,tunable functional groups,and inherent compactness.Here,recent progress of 2D material toward efficient and stable PSCs is summarized,including its role as both interface materials and electrodes.We discuss their beneficial effects on perovskite growth,energy level alignment,defect passivation,as well as blocking external stimulus.In particular,the unique properties of 2D materials to form van der Waals heterojunction at the bottom interface are emphasized.Finally,perspectives on the further development of PSCs using 2D materials are provided,such as designing high-quality van der Waals heterojunction,enhancing the uniformity and coverage of 2D nanosheets,and developing new 2D materials-based electrodes.展开更多
Fully polarized Compton scattering from a beam of spin-polarized electrons is investigated in plane-wave backgrounds in a broad intensity region from the perturbative to the nonperturbative regimes.In the perturbative...Fully polarized Compton scattering from a beam of spin-polarized electrons is investigated in plane-wave backgrounds in a broad intensity region from the perturbative to the nonperturbative regimes.In the perturbative regime,polarized linear Compton scattering is considered for investigating polarization transfer from a single laser photon to a scattered photon,and in the high-intensity region,the polarized locally monochromatic approximation and locally constant field approximation are established and are employed to study polarization transfer from an incoming electron to a scattered photon.The numerical results suggest an appreciable improvement of about 10%in the scattering probability in the intermediate-intensity region if the electron’s longitudinal spin is parallel to the laser rotation.The longitudinal spin of the incoming electron can be transferred to the scattered photon with an efficiency that increases with laser intensity and collisional energy.For collision between an optical laser with frequency1 eV and a 10 GeV electron,this polarization transfer efficiency can increase from about 20%in the perturbative regime to about 50%in the nonperturbative regime for scattered photons with relatively high energy.展开更多
The stereochemically active lone pairs around post-transition metal atoms play an important role in determining distorted lattice structure and optical response.The lone pair electrons are characterized by crystal orb...The stereochemically active lone pairs around post-transition metal atoms play an important role in determining distorted lattice structure and optical response.The lone pair electrons are characterized by crystal orbitals,electron localization function(ELF)and partial density of states(PDOS).Birefringence is evaluated by means of a Born effective charge approach based on modern polarization theory.The origin of the different responses of birefringence and second-harmonic generation(SHG)is explored,as well as the effect of spin-orbit coupling(SOC)on the band structure and optical properties is explored.The study of this paper can help to deeply understand the lone pairs and their contribution to optical property.展开更多
In this study,a water-soluble fluorescent probe based on copper nanoparticles(CuNPs)was synthesized using a hydrothermal method with bovine serum albumin(BSA)(BSA@CuNPs)as a protectant,and it was utilized to efficient...In this study,a water-soluble fluorescent probe based on copper nanoparticles(CuNPs)was synthesized using a hydrothermal method with bovine serum albumin(BSA)(BSA@CuNPs)as a protectant,and it was utilized to efficiently detect the concentration of tetracycline(TC).Upon the addition of TC to the BSA@CuNPs probe,its fluorescence intensity is obviously diminished due to the keto-enol functions C=O group in TC connects with the hydroxyl group on the BSA@CuNPs probe to form a non-fluorescent complex,which can be successfully utilized for detecting TC concentration.Linear range and detection limit for TC detection are 0.1130μM and 90 nM.Furthermore,the BSA@CuNPs probe was applied to detect TC concentrations in real meat samples,with recoveries ranging from 95.40%to 102.13%,and the relative standard deviation(RSD)was below 2.73%.Therefore,BSA@CuNPs probe exhibits high sensitivity and selectivity for TC,which will be used for the study of TC analysis in meat.展开更多
The mechanical responses and structure variations of Ta_(80)Co_(20)nanoscale metallic glass(MG)film samples upon cryogenic thermal cycling(CTC)treatment were studied.The simultaneous improvements of strength and defor...The mechanical responses and structure variations of Ta_(80)Co_(20)nanoscale metallic glass(MG)film samples upon cryogenic thermal cycling(CTC)treatment were studied.The simultaneous improvements of strength and deformation ability bring about a super-high strength of 4.5 GPa and a large plastic strain of about 80%after CTC treatment.The significant increase in inter-element bonding and hardness makes the activation and percolation of sheartransformation zones to be more difficult and delays theyielding event,leading to the ultra-high strength.展开更多
We propose a new laser-plasma-based method to generate brightγ-rays carrying large orbital angular momentum by interacting a circularly polarized Laguerre–Gaussian laser pulse with a near-critical hydrogen plasma co...We propose a new laser-plasma-based method to generate brightγ-rays carrying large orbital angular momentum by interacting a circularly polarized Laguerre–Gaussian laser pulse with a near-critical hydrogen plasma conflned in an over-dense solid tube.In the flrst stage of the interaction,it is found via fully relativistic three-dimensional particle-in-cell simulations that high-energy helical electron beams with large orbital angular momentum are generated.In the second stage,this electron beam interacts with the laser pulse reflected from the plasma disc behind the solid tube,and helicalγbeams are generated with the same topological structure as the electron beams.The results show that the electrons receive angular momentum from the drive laser,which can be further transferred to theγphotons during the interaction.Theγbeam orbital angular momentum is strongly dependent on the laser topological charge l and laser intensity a_(0),which scales as L_(γ)∝a_(0)~4.A short(duration of 5 fs)isolated helicalγbeam with an angular momentum of-3.3×10^(-14)kg m~2 s^(-1)is generated using the Laguerre–Gaussian laser pulse with l=2.The peak brightness of the helicalγbeam reaches 1.22×10^(24)photons s^(-1)mm^(-2)mrad^(-2)per 0.1%BW(at 10 Me V),and the laser-to-γ-ray angular momentum conversion rate is approximately 2.1%.展开更多
The plastic deformation of amorphous alloys is well known to be localized into shear bands(SBs),which are believed to stem from the atomic-scale flow defects,i.e.,shear transformation zones(STZs).Yet,the bridge betwee...The plastic deformation of amorphous alloys is well known to be localized into shear bands(SBs),which are believed to stem from the atomic-scale flow defects,i.e.,shear transformation zones(STZs).Yet,the bridge between the mesoscopic SBs and the atomic-scale STZs remains poorly understood.In this work,through thermally activating pronouncedβrelaxations in the well-designed crystalline-layer confined amorphous(CLCA)Ni W alloy films,we experimentally captured and observed an intermediate nanosized structure termed as“nano shear bands”(NSBs)with a typical size of 1–2 nm in thickness and5–10 nm in length.The influences of such NSB structures on the macroscale deformation behavior were systematically investigated.It was found that NSBs lead to both hardening and toughening effects for the CLCA films,as they promote multiple and controlled shear banding deformation,which results in enhanced crystallization.The intermediate NSB structure could connect the microstructural characteristics and macroscopic plasticity in amorphous alloys and may provide new insights for understanding the microscopic deformation mechanism of amorphous alloys as well as tuning/designing their properties.展开更多
In this study,using surfactant monoethanolamine(MEA),zinc oxide(Zn O)-MEA humidity sensor based on Zn O was successfully prepared by hydrothermal method.MEA makes the surface of the Zn O-MEA have more oxygen vacancy a...In this study,using surfactant monoethanolamine(MEA),zinc oxide(Zn O)-MEA humidity sensor based on Zn O was successfully prepared by hydrothermal method.MEA makes the surface of the Zn O-MEA have more oxygen vacancy and hydrophilic functional groups,which improves the performance of Zn O humidity sensor.Zn O-MEA achieved a change of 4 orders of magnitude at room temperature in the relative humidity(RH)from 11%to 95%,and it shows better linearity,shorter response/recovery time(20 s/15.9 s),smaller humidity lag and long-term stability.In addition,the distribution of Zn O-MEA particles is more uniform and provides more active sites for adsorption of water molecules to enhance humidity sensing performance.展开更多
A high-performance zinc oxide(ZnO)/polyvinylpyrrolidone(PVP)humidity sensor was prepared by simple coprecipitation method with PVP as surfactant.The coprecipitation method has low reaction temperature,little energy co...A high-performance zinc oxide(ZnO)/polyvinylpyrrolidone(PVP)humidity sensor was prepared by simple coprecipitation method with PVP as surfactant.The coprecipitation method has low reaction temperature,little energy consumption and simple preparation,which is suitable for large-scale production.The PVP makes sample’s surface with more hydroxyl and oxygen vacancies than pure ZnO,which can absorb more water molecules and promote the decomposition of water molecules into H3O+to form effective ion conduction.When the molar ratio of PVP to ZnO is 1:1,the ZnO/PVP humidity sensor has low hysteresis(~4.2%),short response/recovery time(9/10 s),excellent stability and high sensitivity with more than 4 orders of magnitude in relative humidity(RH)range from 11%to 95%.Moreover,the ZnO/PVP humidity sensor can distinguish different respiratory states of human body,which has a potential in monitoring and prevention of respiratory diseases.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.11864040,11964037,and 11664038)。
文摘Zr-based amorphous alloys have attracted extensive attention because of their large glassy formation ability, wide supercooled liquid region, high elasticity, and unique mechanical strength induced by their icosahedral local structures.To determine the microstructures of Zr–Cu clusters, the stable and metastable geometry of Zr_(n)Cu(n=2–12) clusters are screened out via the CALYPSO method using machine-learning potentials, and then the electronic structures are investigated using density functional theory. The results show that the Zr_(n)Cu(n ≥ 3) clusters possess three-dimensional geometries, Zr_(n)Cu(n≥9) possess cage-like geometries, and the Zr_(12)Cu cluster has icosahedral geometry. The binding energy per atom gradually gets enlarged with the increase in the size of the clusters, and Zr_(n)Cu(n=5,7,9,12) have relatively better stability than their neighbors. The magnetic moment of most Zr_(n)Cu clusters is just 1μB, and the main components of the highest occupied molecular orbitals(HOMOs) in the Zr_(12)Cu cluster come from the Zr-d state. There are hardly any localized two-center bonds, and there are about 20 σ-type delocalized three-center bonds.
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region(Grant No.2023D01C168)Scientific Research Program of the Higher Education Institution of Xinjiang(Grant No.XJEDU2022P001)+1 种基金Autonomous Region"Tianchi Talent"Introduction Program Youth Doctoral Program(Grant No.51052401544)Tianshan Innovation Team Program of Xinjiang Uygur Autonomous Region(Grant No.2023D14001).
文摘Iodine is widely used in aqueous zinc batteries(ZBs)due to its abundant resources,low cost,and active redox reactions.In addition to the active material in zinc-iodine batteries,iodine also plays an important role in other ZBs,such as regulating the electrochemical behavior of zinc ions,promoting the reaction kinetic and reversibility of other redox pairs,catalytic behaviors related to iodine reactions,coupling with other halogen ions,shuttle behaviors of polyiodides,etc.However,there is currently a lack of comprehensive discussion on these aspects.Here,this review provides a comprehensive overview of the electrochemical behaviors of iodide in the aqueous ZBs.The effect of iodine ions on the Zn^(2+)desolvation behaviors and the interfacial behaviors of Zn anode was summarized.Iodine redox pairs boosting other redox pairs,such as MnO_(2)/Mn^(2+)redox pair and vanadium redox pair to obtain high reversibility and capacity was also discussed.Moreover,the catalytic behaviors related to iodine reactions in aqueous ZBs,synergistic reaction with other halogen ions and suppression of shuttle behaviors for high performance zinc-iodine batteries were systematically analyzed.Finally,future prospects for designing effective iodine electrochemical behaviors with practicability are proposed,which will provide scientific guidance for the practical application of iodine-related aqueous ZBs.
基金supported by the Xinjiang Tianchi Talent Introduction Plan (51052300585)the Fundamental Research Funds for Autonomous Region Universities (XJEDU2022P002)+1 种基金the Natural science foundation project of Xinjiang Uygur Autonomous Region (2023D01C192,2023D01C33)the Tianshan Innovation Team Program of Xinjiang Uygur Autonomous Region (2023D14001)。
文摘Ceramic materials with intricate structures can be efficiently fabricated using stereolithography(SLA)based 3D printing technology,offering advantages over traditional methods.Sintering temperature has primary effect on properties of ceramics.This study investigated the crucial sintering temperature for 3D printed ceramics to ensure the desired properties.The results indicate that all samples exhibit a consistent layered structure across the experimental sintering temperatures.When the sintering temperature is increased from 1,250℃ to 1,350℃,the grain's morphology changes from spherical to plate-like.Surface morphology analysis reveals a decrease in surface roughness at sintering temperatures above 1,350℃.Mechanical tests show improved flexural strength and stiffness as the sintering temperature rises.Friction and wear experiments demonstrate that as the sintering temperature increases from 1,450℃ to 1,550℃,the wear pattern on ceramic surfaces transitions from deep pits to shallow grooves.The increase in sintering temperature effectively enhances the wear resistance of 3D printed alumina ceramics.This improvement plays a significant role in expanding the application field of these ceramics,prolonging the lifespan of parts,reducing production costs,enhancing performance,and promoting environmental protection.In this study,ceramics achieve the highest strength and best wear resistance when sintered at 1,600℃,resulting in the best overall performance.
基金the financial support of the National Natural Science Foundation of China(Nos.U21A20171,12074245,and 52102281)National Key R&D Program of China(Nos.2021YFB3800068 and 2020YFB1506400)+1 种基金Shanghai Sailing Program(No.21YF1421600)Young Elite Scientists Sponsorship Program by China Association for Science and Technology(No.2021QNRC001).
文摘Perovskite solar cells(PSCs)offer low costs and high power conversion efficiency.However,the lack of long-term stability,primarily stemming from the interfacial defects and the sus-ceptible metal electrodes,hinders their practical application.In the past few years,two-dimensional(2D)materials(e.g.,graphene and its derivatives,transitional metal dichalcogenides,MXenes,and black phosphorus)have been identified as a promising solution to solving these problems because of their dangling bond-free surfaces,layer-dependent electronic band structures,tunable functional groups,and inherent compactness.Here,recent progress of 2D material toward efficient and stable PSCs is summarized,including its role as both interface materials and electrodes.We discuss their beneficial effects on perovskite growth,energy level alignment,defect passivation,as well as blocking external stimulus.In particular,the unique properties of 2D materials to form van der Waals heterojunction at the bottom interface are emphasized.Finally,perspectives on the further development of PSCs using 2D materials are provided,such as designing high-quality van der Waals heterojunction,enhancing the uniformity and coverage of 2D nanosheets,and developing new 2D materials-based electrodes.
基金The authors are supported by the National Natural Science Foundation of China(Grant Nos.12104428,12075081,12375240,and 12265024).
文摘Fully polarized Compton scattering from a beam of spin-polarized electrons is investigated in plane-wave backgrounds in a broad intensity region from the perturbative to the nonperturbative regimes.In the perturbative regime,polarized linear Compton scattering is considered for investigating polarization transfer from a single laser photon to a scattered photon,and in the high-intensity region,the polarized locally monochromatic approximation and locally constant field approximation are established and are employed to study polarization transfer from an incoming electron to a scattered photon.The numerical results suggest an appreciable improvement of about 10%in the scattering probability in the intermediate-intensity region if the electron’s longitudinal spin is parallel to the laser rotation.The longitudinal spin of the incoming electron can be transferred to the scattered photon with an efficiency that increases with laser intensity and collisional energy.For collision between an optical laser with frequency1 eV and a 10 GeV electron,this polarization transfer efficiency can increase from about 20%in the perturbative regime to about 50%in the nonperturbative regime for scattered photons with relatively high energy.
基金supported by the National Natural Science Foundation of the People's Republic of China“Mechanistic study of the influence of ns^(2) cation intrinsic properties and coordination environment on birefringence and frequency doubling effects”(12264047),“The study of the mechanism of the influence of lead-oxygen polyhedra and their coordination environments on the gain of the frequency doubling effect”(11864040)Tianshan Talent Project of Xinjiang Uygur Autonomous Region of China“Design,synthesis and photofunctional study of novel rare earth phosphate materials”(2022TSYCJU0004)。
文摘The stereochemically active lone pairs around post-transition metal atoms play an important role in determining distorted lattice structure and optical response.The lone pair electrons are characterized by crystal orbitals,electron localization function(ELF)and partial density of states(PDOS).Birefringence is evaluated by means of a Born effective charge approach based on modern polarization theory.The origin of the different responses of birefringence and second-harmonic generation(SHG)is explored,as well as the effect of spin-orbit coupling(SOC)on the band structure and optical properties is explored.The study of this paper can help to deeply understand the lone pairs and their contribution to optical property.
基金supported by the National Science Foundation of Xinjiang Science and Technology Project(No.2023D01C05)。
文摘In this study,a water-soluble fluorescent probe based on copper nanoparticles(CuNPs)was synthesized using a hydrothermal method with bovine serum albumin(BSA)(BSA@CuNPs)as a protectant,and it was utilized to efficiently detect the concentration of tetracycline(TC).Upon the addition of TC to the BSA@CuNPs probe,its fluorescence intensity is obviously diminished due to the keto-enol functions C=O group in TC connects with the hydroxyl group on the BSA@CuNPs probe to form a non-fluorescent complex,which can be successfully utilized for detecting TC concentration.Linear range and detection limit for TC detection are 0.1130μM and 90 nM.Furthermore,the BSA@CuNPs probe was applied to detect TC concentrations in real meat samples,with recoveries ranging from 95.40%to 102.13%,and the relative standard deviation(RSD)was below 2.73%.Therefore,BSA@CuNPs probe exhibits high sensitivity and selectivity for TC,which will be used for the study of TC analysis in meat.
基金financially supported by the National Natural Science Foundation of China(Nos.52301210,52101191,52071222 and 52261033)Guangdong Major Project of Basic and Applied Basic Research,China(No.2019B030302010)the Excellent PhD Innovation Program of Xinjiang University(No.XJU2023BS029)。
文摘The mechanical responses and structure variations of Ta_(80)Co_(20)nanoscale metallic glass(MG)film samples upon cryogenic thermal cycling(CTC)treatment were studied.The simultaneous improvements of strength and deformation ability bring about a super-high strength of 4.5 GPa and a large plastic strain of about 80%after CTC treatment.The significant increase in inter-element bonding and hardness makes the activation and percolation of sheartransformation zones to be more difficult and delays theyielding event,leading to the ultra-high strength.
基金flnancially supported by National Natural Science Foundation of China(Nos.11664039,11964038,12104428,and 11875007)support from the Young Talents Project at Ocean University of China。
文摘We propose a new laser-plasma-based method to generate brightγ-rays carrying large orbital angular momentum by interacting a circularly polarized Laguerre–Gaussian laser pulse with a near-critical hydrogen plasma conflned in an over-dense solid tube.In the flrst stage of the interaction,it is found via fully relativistic three-dimensional particle-in-cell simulations that high-energy helical electron beams with large orbital angular momentum are generated.In the second stage,this electron beam interacts with the laser pulse reflected from the plasma disc behind the solid tube,and helicalγbeams are generated with the same topological structure as the electron beams.The results show that the electrons receive angular momentum from the drive laser,which can be further transferred to theγphotons during the interaction.Theγbeam orbital angular momentum is strongly dependent on the laser topological charge l and laser intensity a_(0),which scales as L_(γ)∝a_(0)~4.A short(duration of 5 fs)isolated helicalγbeam with an angular momentum of-3.3×10^(-14)kg m~2 s^(-1)is generated using the Laguerre–Gaussian laser pulse with l=2.The peak brightness of the helicalγbeam reaches 1.22×10^(24)photons s^(-1)mm^(-2)mrad^(-2)per 0.1%BW(at 10 Me V),and the laser-to-γ-ray angular momentum conversion rate is approximately 2.1%.
基金financially supported by the Guangdong Major Project of Basic and Applied Basic ResearchChina(No.2019B030302010)+8 种基金the Guangdong Basic and Applied Basic Research FoundationChina(Nos.2021A1515010756,2019B1515130005)the Natural Science Foundation of Jiangsu ProvinceChina(No.BK20180266)the National Natural Science Foundation of China(Nos.51471131,52071222,51822107,11972037,52001269,52101199,52001219)the FundamentalResearch Funds for the Central Universitiesthe National Key Research and Development Plan(No.2018YFA0703603)the Strategic Priority Research Program of Chinese Academy of Sciences with Grant No.XDB30000000the Tianshan Innovation Team Program of Xinjiang Uygur Autonomous Region(No.2020D14038)。
文摘The plastic deformation of amorphous alloys is well known to be localized into shear bands(SBs),which are believed to stem from the atomic-scale flow defects,i.e.,shear transformation zones(STZs).Yet,the bridge between the mesoscopic SBs and the atomic-scale STZs remains poorly understood.In this work,through thermally activating pronouncedβrelaxations in the well-designed crystalline-layer confined amorphous(CLCA)Ni W alloy films,we experimentally captured and observed an intermediate nanosized structure termed as“nano shear bands”(NSBs)with a typical size of 1–2 nm in thickness and5–10 nm in length.The influences of such NSB structures on the macroscale deformation behavior were systematically investigated.It was found that NSBs lead to both hardening and toughening effects for the CLCA films,as they promote multiple and controlled shear banding deformation,which results in enhanced crystallization.The intermediate NSB structure could connect the microstructural characteristics and macroscopic plasticity in amorphous alloys and may provide new insights for understanding the microscopic deformation mechanism of amorphous alloys as well as tuning/designing their properties.
基金supported by the National Science Foundation of Xinjiang Science and Technology Project(No.2019D01C036)
文摘In this study,using surfactant monoethanolamine(MEA),zinc oxide(Zn O)-MEA humidity sensor based on Zn O was successfully prepared by hydrothermal method.MEA makes the surface of the Zn O-MEA have more oxygen vacancy and hydrophilic functional groups,which improves the performance of Zn O humidity sensor.Zn O-MEA achieved a change of 4 orders of magnitude at room temperature in the relative humidity(RH)from 11%to 95%,and it shows better linearity,shorter response/recovery time(20 s/15.9 s),smaller humidity lag and long-term stability.In addition,the distribution of Zn O-MEA particles is more uniform and provides more active sites for adsorption of water molecules to enhance humidity sensing performance.
基金supported by the National Natural Science Foundation of China(No.62064011).
文摘A high-performance zinc oxide(ZnO)/polyvinylpyrrolidone(PVP)humidity sensor was prepared by simple coprecipitation method with PVP as surfactant.The coprecipitation method has low reaction temperature,little energy consumption and simple preparation,which is suitable for large-scale production.The PVP makes sample’s surface with more hydroxyl and oxygen vacancies than pure ZnO,which can absorb more water molecules and promote the decomposition of water molecules into H3O+to form effective ion conduction.When the molar ratio of PVP to ZnO is 1:1,the ZnO/PVP humidity sensor has low hysteresis(~4.2%),short response/recovery time(9/10 s),excellent stability and high sensitivity with more than 4 orders of magnitude in relative humidity(RH)range from 11%to 95%.Moreover,the ZnO/PVP humidity sensor can distinguish different respiratory states of human body,which has a potential in monitoring and prevention of respiratory diseases.
