To clarify the correlation of single-crystalline structure with corrosion performance in high-strength TiAl alloys, electrochemical and surface characterization was performed by comparing Ti–45Al–8Nb dual-phase sing...To clarify the correlation of single-crystalline structure with corrosion performance in high-strength TiAl alloys, electrochemical and surface characterization was performed by comparing Ti–45Al–8Nb dual-phase single crystals with their polycrystalline counterparts in NaCl solution. Polarization curves show a lower corrosion rate and a higher pitting potential of ~280 mV for the dual-phase single crystals. Electrochemical impedance spectroscopy and potentiostatic polarization plots revealed a higher impedance of the charge transfer through the compact passive film. Surface composition analysis indicated a compact film with more content of Nb, as twice as that in the film on the polycrystals.Our results reflect that the dual-phase Ti–45Al–8Nb single crystals possess a higher corrosion resistance in NaCl solution, compared with their polycrystalline counterpart, arising from a more homogeneous microstructure and composition distribution.展开更多
Photothermal catalysis realizes the synergistic effect of solar energy and thermochemistry,which also has the potential to improve the reaction rate and optimize the selectivity.In this review,the research progress of...Photothermal catalysis realizes the synergistic effect of solar energy and thermochemistry,which also has the potential to improve the reaction rate and optimize the selectivity.In this review,the research progress of photothermal catalytic removal of volatile organic compounds(VOCs)by nano-catalysts in recent years is systematically reviewed.First,the fundamentals of photothermal catalysis and the fabrication of catalysts are described,and the design strategy of optimizing photothermal catalysis performance is proposed.Second,the performance for VOC degradation with photothermal catalysis is evaluated and compared for the batch and continuous systems.Particularly,the catalytic mechanism of VOC oxidation is systematically introduced based on experimental and theoretical study.Finally,the future limitations and challenges have been discussed,and potential research directions and priorities are highlighted.A broad view of recent photothermal catalyst fabrication,applications,challenges,and prospects can be systemically provided by this review.展开更多
A fast-rising gas temperature is due to frequent collisions of the heavy particles in an atmosphericpressure dielectric barrier discharge.In this paper,a two-dimensional fluid model is applied to investigate the influ...A fast-rising gas temperature is due to frequent collisions of the heavy particles in an atmosphericpressure dielectric barrier discharge.In this paper,a two-dimensional fluid model is applied to investigate the influences of rising gas temperature on an atmospheric-pressure helium dielectric barrier discharge.With the increase in the gas temperature,it is found that:(1)a helium discharge can evolve from the discharge column to a homogeneous discharge;(2)the breakdown time is in advance and the gas breakdown voltage decreases;(3)the spatial distribution evolution of the electron density is similar to that of the helium atom density.The most significant discrepancy between them is that the electron densities are high at some positions where the helium atom densities are nevertheless low.Furthermore,the radial reduced electric fields are obtained under different gas temperatures.The physical reasons for the gas temperature effects are discussed.The simulation results provide a better understanding of the roles of the radial reduced electric field and the heavy particle.展开更多
The simple kagome-lattice band structure possesses Dirac cones,flat band,and saddle point with van Hove singularities in the electronic density of states,facilitating the emergence of various electronic orders.Here we...The simple kagome-lattice band structure possesses Dirac cones,flat band,and saddle point with van Hove singularities in the electronic density of states,facilitating the emergence of various electronic orders.Here we report a titanium-based kagome metal CsTi_(3)Bi_(5)where titanium atoms form a kagome network,resembling its isostructural compound CsV_3Sb_5.Thermodynamic properties including the magnetization,resistance,and heat capacity reveal the conventional Fermi liquid behavior in the kagome metal CsTi_(3)Bi_(5)and no signature of superconducting or charge density wave(CDW)transition anomaly down to 85 m K.Systematic angle-resolved photoemission spectroscopy measurements reveal multiple bands crossing the Fermi level,consistent with the first-principles calculations.The flat band formed by the destructive interference of hopping in the kagome lattice is observed directly.Compared to Cs V_(3)Sb_(5),the van Hove singularities are pushed far away above the Fermi level in CsTi_(3)Bi_(5),in line with the absence of CDW.Furthermore,the first-principles calculations identify the nontrivial Z_(2)topological properties for those bands crossing the Fermi level,accompanied by several local band inversions.Our results suppose CsTi_(3)Bi_(5)as a complementary platform to explore the superconductivity and nontrivial band topology.展开更多
In our most recently published article,[1]an important reference[2]predicting CsTi_(3)Bi_(5) is missing and should be added,along with Ref.[3](originally Ref.[28]),to the introduction section.
This study empirically examines whether child characteristics mitigate the negative impact of widowhood on the elderly’s mental health using follow-up survey data from the China Health and Retirement Longitudinal Stu...This study empirically examines whether child characteristics mitigate the negative impact of widowhood on the elderly’s mental health using follow-up survey data from the China Health and Retirement Longitudinal Study(CHARLS).A total of 5,326 older adults aged 60 years and older are selected from three waves of panel data(2013,2015,and 2018).Thefindings suggest that respondents who experienced widowhood exhibit an increase in depressive symptoms.However,the higher income of children and frequent face-to-face emotional interactions improve the mental health of the widowed elderly.Moreover,heterogeneity analyses show that the buffering effect of higher child income is more significant among men and the Midwestern widowed elderly,and frequent face-to-face emotional interactions are more effective in improving the psychological status of women and the Midwes-tern widowed elderly.In the special social and cultural background of China,family members remain the main support for the elderly,and the current social pension system is still imperfect.Therefore,children should strengthen emotional communication with their parents while increasing their economic income.In that way,widowhood can achieve both material and spiritual prosperity.The government should identify the vulnerable groups among the elderly widows and introduce policies aimed at improving their mental health and reducing the disparity in mental health status.展开更多
Many studies have investigated the selective laser melting(SLM)of AlSi10Mg and AlSi7Mg alloys,but there are still lack of researches focused on Al-Si-Mg alloys specifically tailored for SLM.In this work,a novel high M...Many studies have investigated the selective laser melting(SLM)of AlSi10Mg and AlSi7Mg alloys,but there are still lack of researches focused on Al-Si-Mg alloys specifically tailored for SLM.In this work,a novel high Mg-content AlSi8Mg3 alloy was specifically designed for SLM.The results showed that this new alloy exhibited excellent SLM processability with a lowest porosity of 0.07%.Massive lattice distortion led to a high Vickers hardness in samples fabricated at a high laser power due to the precipitation of Mg_(2)Si nanoparticles from theα-Al matrix induced by high-intensity intrinsic heat treatment during SLM.The maximum microhardness and compressive yield strength of the alloy reached HV(211±4)and(526±12)MPa,respectively.After aging treatment at 150℃,the maximum microhardness and compressive yield strength of the samples were further improved to HV(221±4)and(577±5)MPa,respectively.These values are higher than those of most known aluminum alloys fabricated by SLM.This paper provides a new idea for optimizing the mechanical properties of Al-Si-Mg alloys fabricated using SLM.展开更多
Rechargeable magnesium ion batteries are potential candidates to replace the lithium ion batteries due to their high volumetric energy density,dendrite free cycling,and low costs.In present work,we have critically rev...Rechargeable magnesium ion batteries are potential candidates to replace the lithium ion batteries due to their high volumetric energy density,dendrite free cycling,and low costs.In present work,we have critically reviewed the recent advances made in the field of cathode materials development to achieve the high reversible capacities and working potentials.In first part,carbon-based cathodes such as fluorinedoped graphene nanosheets and graphite fluoride(CF0.8)are discussed in terms of compatibilities of pos让ive electrode materials and electrolyte solutions for rechargeable magnesium-ion batteries.Whereas,the second part of this review focuses on crystal structure of vanadium oxide and its capability to accommodate the Mg^2+ions.Likewise,electrochemical performance of selected vanadium oxide based cathodes including VO2(B),FeVO4.0.9H2(X Mc)2.5+yVO9+δ,RFC/V2O5 and V2O5/Graphene composite,are discussed at different temperatures.To support the future research on magnesium ion batteries,particularly positive electrode material developments,several innovative research directions are proposed.展开更多
We develop a high-performance ultraviolet(UV)frequency stabilization technique implemented directly on UV diode lasers by combining the dichroic atomic vapor laser lock and the resonant transfer cavity lock.As an exam...We develop a high-performance ultraviolet(UV)frequency stabilization technique implemented directly on UV diode lasers by combining the dichroic atomic vapor laser lock and the resonant transfer cavity lock.As an example,we demonstrate a stable locking with measured frequency standard deviations of approximately 200 kHz and 300 kHz for 399 nm and 370 nm diode lasers in 20 min.We achieve a long-term frequency drift of no more than 1 MHz for the target 370 nm laser within an hour,which is further verified with fluorescence count rates of a single trapped ^171Yb+ion.We also find strong linear correlations between lock points and environmental factors such as temperature and atmospheric pressure.Our approach provides a simple and stable solution at a relatively low cost,and features flexible control,high feedback bandwidth and minimal power consumption of the target UV laser.展开更多
Dear Editor,Prototype foamy virus(PFV)belongs to the genus Spumavirus in the Spumaretrovirinae subfamily of Retroviridae.Although PFV and HIV have much in common,research into PFV has lagged far behind that into HIV,a...Dear Editor,Prototype foamy virus(PFV)belongs to the genus Spumavirus in the Spumaretrovirinae subfamily of Retroviridae.Although PFV and HIV have much in common,research into PFV has lagged far behind that into HIV,as PFV appeared to be non-pathogenic both in accidentally infected humans and in experimentally infected animals.In recent decades,however,more attention has been focused on PFV because it seems to展开更多
Recent progresses on quantum control of cold atoms and trapped ions in both the scientific and technological aspects greatly advance the applications in precision measurement. Thanks to the exceptional controllability...Recent progresses on quantum control of cold atoms and trapped ions in both the scientific and technological aspects greatly advance the applications in precision measurement. Thanks to the exceptional controllability and versatility of these massive quantum systems, unprecedented sensitivity has been achieved in clocks, magnetometers, and interferometers based on cold atoms and ions. Besides, these systems also feature many characteristics that can be employed to facilitate the applications in different scenarios. In this review, we briefly introduce the principles of optical clocks, cold atom magnetometers, and atom interferometers used for precision measurement of time, magnetic field, and inertial forces. The main content is then devoted to summarize some recent experimental and theoretical progresses in these three applications, with special attention being paid to the new designs and possibilities towards better performance. The purpose of this review is by no means to give a complete overview of all important works in this fast developing field, but to draw a rough sketch about the frontiers and show the fascinating future lying ahead.展开更多
Several Ni-W-P-TiO_(2) nanocomposite coatings were developed by the sol-enhanced electroplating method. The phase and elemental compositions of coatings were determined, and the surface and cross-section morphology we...Several Ni-W-P-TiO_(2) nanocomposite coatings were developed by the sol-enhanced electroplating method. The phase and elemental compositions of coatings were determined, and the surface and cross-section morphology were characterized. The mechanical and corrosion performance were systematically tested. The results revealed the addition of 5 ml·L^(-1) TiO_(2) sol caused a compact coating surface,while higher concentrations of TiO_(2) reduced the coating thickness and led to the inferior surface microstructure. The comparison in physiochemical properties of prepared coatings confirmed the superior performance of the Ni-W-P-TiO_(2) nanocomposite coating at 5 ml·L^(-1) TiO_(2) sol addition. Under this condition, the best mechanical properties were achieved when abrasive wear was the dominating wearresistance mechanism, and the best corrosion resistance was obtained due to its smooth and compact surface microstructure.展开更多
Recently,transition-metal-based kagome metals have aroused much research interest as a novel platform to explore exotic topological quantum phenomena.Here we report on the synthesis,structure,and physical properties o...Recently,transition-metal-based kagome metals have aroused much research interest as a novel platform to explore exotic topological quantum phenomena.Here we report on the synthesis,structure,and physical properties of a bilayer kagome lattice compound V_(3)Sb_(2).The polycrystalline V_(3)Sb_(2) samples were synthesized by conventional solid-state-reaction method in a sealed quartz tube at temperatures below 850℃.Measurements of magnetic susceptibility and resistivity revealed consistently a density-wave-like transition at Tdw≈160 K with a large thermal hysteresis,even though some sample-dependent behaviors were observed presumably due to the different preparation conditions.Upon cooling through Tdw,no strong anomaly in lattice parameters and no indication of symmetry lowering were detected in powder x-ray diffraction measurements.This transition can be suppressed completely by applying hydrostatic pressures of about 1.8 GPa,around which no sign of superconductivity was observed down to 1.5 K.Specific-heat measurements revealed a relatively large Sommerfeld coefficientγ=18.5 mJ·mol^(-1)·K^(-2),confirming the metallic ground state with moderate electronic correlations.Density functional theory calculations indicate that V_(3)Sb_(2) shows a non-trivial topological crystalline property.Thus,our study makes V_(3)Sb_(2) a new candidate of metallic kagome compound to study the interplay between density-wave-order,nontrivial band topology,and possible superconductivity.展开更多
We investigate the techniques for velocity resonance and apply them to construct soliton molecules using two solitons of the extended Lax equation.What is more,each soliton molecule can be transformed into an asymmetr...We investigate the techniques for velocity resonance and apply them to construct soliton molecules using two solitons of the extended Lax equation.What is more,each soliton molecule can be transformed into an asymmetric soliton by changing the parameterφ.In addition,the collision between soliton molecules(or asymmetric soliton)and several soliton solutions is observed.Finally,some related pictures are presented.展开更多
Erratum to:International Journal of Minerals, Metallurgy and MaterialsVolume 29, Number 9, September 2022, Page 1770https://doi.org/10.1007/s12613-021-2287-1The original version of this article unfortunately contained...Erratum to:International Journal of Minerals, Metallurgy and MaterialsVolume 29, Number 9, September 2022, Page 1770https://doi.org/10.1007/s12613-021-2287-1The original version of this article unfortunately contained a mistake due to the PDF file conversion through different softwares. The presentation of Fig. 13 in original version was incorrect.展开更多
Exploring quantum phenomena beyond predictions of any classical model has fundamental importance to understand the boundary of classical and quantum descriptions of nature.As a typical property that a quantum system b...Exploring quantum phenomena beyond predictions of any classical model has fundamental importance to understand the boundary of classical and quantum descriptions of nature.As a typical property that a quantum system behaves distinctively from a classical counterpart,contextuality has been studied extensively and verified experimentally in systems composed of at least three levels(qutrit).Here we extend the scope of experimental test of contextuality to a minimal quantum system of only two states(qubit)by implementing the minimum error state discrimination on a single171Yb+ion.We observe a substantial violation of a no-go inequality derived by assuming non-contextuality,and firmly conclude that the measured results of state discrimination cannot be reconciled with any non-contextual description.We also quantify the contextual advantage of state discrimination and the tolerance against quantum noises.展开更多
基金financially supported by the CityU internal supports under “The Structural Material Development Funding” program (No. CityU 7004894)National Natural Science Foundation of China (Nos. 51901086 and 51731006)Natural Science Foundation of Jiangsu Province, China (Nos. BK20190977 and BK 20180984)。
文摘To clarify the correlation of single-crystalline structure with corrosion performance in high-strength TiAl alloys, electrochemical and surface characterization was performed by comparing Ti–45Al–8Nb dual-phase single crystals with their polycrystalline counterparts in NaCl solution. Polarization curves show a lower corrosion rate and a higher pitting potential of ~280 mV for the dual-phase single crystals. Electrochemical impedance spectroscopy and potentiostatic polarization plots revealed a higher impedance of the charge transfer through the compact passive film. Surface composition analysis indicated a compact film with more content of Nb, as twice as that in the film on the polycrystals.Our results reflect that the dual-phase Ti–45Al–8Nb single crystals possess a higher corrosion resistance in NaCl solution, compared with their polycrystalline counterpart, arising from a more homogeneous microstructure and composition distribution.
基金sponsored financially by the National Natural Science Foundation of China (No.21906104 and No.12175145)the Shanghai Rising-Star Program (21QA1406600).
文摘Photothermal catalysis realizes the synergistic effect of solar energy and thermochemistry,which also has the potential to improve the reaction rate and optimize the selectivity.In this review,the research progress of photothermal catalytic removal of volatile organic compounds(VOCs)by nano-catalysts in recent years is systematically reviewed.First,the fundamentals of photothermal catalysis and the fabrication of catalysts are described,and the design strategy of optimizing photothermal catalysis performance is proposed.Second,the performance for VOC degradation with photothermal catalysis is evaluated and compared for the batch and continuous systems.Particularly,the catalytic mechanism of VOC oxidation is systematically introduced based on experimental and theoretical study.Finally,the future limitations and challenges have been discussed,and potential research directions and priorities are highlighted.A broad view of recent photothermal catalyst fabrication,applications,challenges,and prospects can be systemically provided by this review.
基金supported by the Liaoning Provincial Department of Education Fund(No.LJ2020008)。
文摘A fast-rising gas temperature is due to frequent collisions of the heavy particles in an atmosphericpressure dielectric barrier discharge.In this paper,a two-dimensional fluid model is applied to investigate the influences of rising gas temperature on an atmospheric-pressure helium dielectric barrier discharge.With the increase in the gas temperature,it is found that:(1)a helium discharge can evolve from the discharge column to a homogeneous discharge;(2)the breakdown time is in advance and the gas breakdown voltage decreases;(3)the spatial distribution evolution of the electron density is similar to that of the helium atom density.The most significant discrepancy between them is that the electron densities are high at some positions where the helium atom densities are nevertheless low.Furthermore,the radial reduced electric fields are obtained under different gas temperatures.The physical reasons for the gas temperature effects are discussed.The simulation results provide a better understanding of the roles of the radial reduced electric field and the heavy particle.
基金the National Key R&D Program of China(Grant No.2022YFA1403700)the National Natural Science Foundation of China(Grant Nos.12074163 and 12004030)+5 种基金the Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2022B1515020046,2022B1515130005,2021B1515130007,and 2020B1515120100)the Guangdong Innovative and Entrepreneurial Research Team Program(Grant Nos.2017ZT07C062 and 2019ZT08C044)the Shenzhen Science and Technology Program(Grant No.KQTD20190929173815000)Shenzhen Key Laboratory of Advanced Quantum Functional Materials and Devices(Grant No.ZDSYS20190902092905285)the Shenzhen Fundamental Research Program(Grant No.JCYJ20220818100405013)China Postdoctoral Science Foundation(Grant No.2020M682780 and 2022M711495)。
文摘The simple kagome-lattice band structure possesses Dirac cones,flat band,and saddle point with van Hove singularities in the electronic density of states,facilitating the emergence of various electronic orders.Here we report a titanium-based kagome metal CsTi_(3)Bi_(5)where titanium atoms form a kagome network,resembling its isostructural compound CsV_3Sb_5.Thermodynamic properties including the magnetization,resistance,and heat capacity reveal the conventional Fermi liquid behavior in the kagome metal CsTi_(3)Bi_(5)and no signature of superconducting or charge density wave(CDW)transition anomaly down to 85 m K.Systematic angle-resolved photoemission spectroscopy measurements reveal multiple bands crossing the Fermi level,consistent with the first-principles calculations.The flat band formed by the destructive interference of hopping in the kagome lattice is observed directly.Compared to Cs V_(3)Sb_(5),the van Hove singularities are pushed far away above the Fermi level in CsTi_(3)Bi_(5),in line with the absence of CDW.Furthermore,the first-principles calculations identify the nontrivial Z_(2)topological properties for those bands crossing the Fermi level,accompanied by several local band inversions.Our results suppose CsTi_(3)Bi_(5)as a complementary platform to explore the superconductivity and nontrivial band topology.
文摘In our most recently published article,[1]an important reference[2]predicting CsTi_(3)Bi_(5) is missing and should be added,along with Ref.[3](originally Ref.[28]),to the introduction section.
基金supported by the National Social Science Fund of China under Grant No.17BJL044。
文摘This study empirically examines whether child characteristics mitigate the negative impact of widowhood on the elderly’s mental health using follow-up survey data from the China Health and Retirement Longitudinal Study(CHARLS).A total of 5,326 older adults aged 60 years and older are selected from three waves of panel data(2013,2015,and 2018).Thefindings suggest that respondents who experienced widowhood exhibit an increase in depressive symptoms.However,the higher income of children and frequent face-to-face emotional interactions improve the mental health of the widowed elderly.Moreover,heterogeneity analyses show that the buffering effect of higher child income is more significant among men and the Midwestern widowed elderly,and frequent face-to-face emotional interactions are more effective in improving the psychological status of women and the Midwes-tern widowed elderly.In the special social and cultural background of China,family members remain the main support for the elderly,and the current social pension system is still imperfect.Therefore,children should strengthen emotional communication with their parents while increasing their economic income.In that way,widowhood can achieve both material and spiritual prosperity.The government should identify the vulnerable groups among the elderly widows and introduce policies aimed at improving their mental health and reducing the disparity in mental health status.
基金financially supported by the the National Natural Science Foundation of China(Nos.51801079 and 52001140)the Natural Science Foundation for Young Scientists of Jiangsu,China(Nos.BK20180985 and BK20180987)the Open Foundation of Zhenjiang Key Laboratory for High Technology Research on Marine Functional Films(No.ZHZ2019001)。
文摘Many studies have investigated the selective laser melting(SLM)of AlSi10Mg and AlSi7Mg alloys,but there are still lack of researches focused on Al-Si-Mg alloys specifically tailored for SLM.In this work,a novel high Mg-content AlSi8Mg3 alloy was specifically designed for SLM.The results showed that this new alloy exhibited excellent SLM processability with a lowest porosity of 0.07%.Massive lattice distortion led to a high Vickers hardness in samples fabricated at a high laser power due to the precipitation of Mg_(2)Si nanoparticles from theα-Al matrix induced by high-intensity intrinsic heat treatment during SLM.The maximum microhardness and compressive yield strength of the alloy reached HV(211±4)and(526±12)MPa,respectively.After aging treatment at 150℃,the maximum microhardness and compressive yield strength of the samples were further improved to HV(221±4)and(577±5)MPa,respectively.These values are higher than those of most known aluminum alloys fabricated by SLM.This paper provides a new idea for optimizing the mechanical properties of Al-Si-Mg alloys fabricated using SLM.
基金This research was supported by National Natural Science Foundation of China(51601073)Jiangsu Distinguished Professor Project(1064901601)+1 种基金Jiangsu Provincial Six Talent Peaks Project(1062991801)Jiangsu University of Science and Technology Research Start-Up Fund(1062921905).
文摘Rechargeable magnesium ion batteries are potential candidates to replace the lithium ion batteries due to their high volumetric energy density,dendrite free cycling,and low costs.In present work,we have critically reviewed the recent advances made in the field of cathode materials development to achieve the high reversible capacities and working potentials.In first part,carbon-based cathodes such as fluorinedoped graphene nanosheets and graphite fluoride(CF0.8)are discussed in terms of compatibilities of pos让ive electrode materials and electrolyte solutions for rechargeable magnesium-ion batteries.Whereas,the second part of this review focuses on crystal structure of vanadium oxide and its capability to accommodate the Mg^2+ions.Likewise,electrochemical performance of selected vanadium oxide based cathodes including VO2(B),FeVO4.0.9H2(X Mc)2.5+yVO9+δ,RFC/V2O5 and V2O5/Graphene composite,are discussed at different temperatures.To support the future research on magnesium ion batteries,particularly positive electrode material developments,several innovative research directions are proposed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11704408 and 91836106)the Beijing Natural Science Foundation,China(Grant No.Z180013)the Joint Fund of the Ministry of Education,China(Grant No.6141A020333xx).
文摘We develop a high-performance ultraviolet(UV)frequency stabilization technique implemented directly on UV diode lasers by combining the dichroic atomic vapor laser lock and the resonant transfer cavity lock.As an example,we demonstrate a stable locking with measured frequency standard deviations of approximately 200 kHz and 300 kHz for 399 nm and 370 nm diode lasers in 20 min.We achieve a long-term frequency drift of no more than 1 MHz for the target 370 nm laser within an hour,which is further verified with fluorescence count rates of a single trapped ^171Yb+ion.We also find strong linear correlations between lock points and environmental factors such as temperature and atmospheric pressure.Our approach provides a simple and stable solution at a relatively low cost,and features flexible control,high feedback bandwidth and minimal power consumption of the target UV laser.
基金supported by grants from the National Natural Science Foundation of China(No.31000086,No.31170154,No.1371790)the Fundamental Research Funds for the Central Universities(GK201305001,GK201404003)the Innovative Experiment Projects of Educational Ministry of China for Undergraduate(201310718053,cx14069)
文摘Dear Editor,Prototype foamy virus(PFV)belongs to the genus Spumavirus in the Spumaretrovirinae subfamily of Retroviridae.Although PFV and HIV have much in common,research into PFV has lagged far behind that into HIV,as PFV appeared to be non-pathogenic both in accidentally infected humans and in experimentally infected animals.In recent decades,however,more attention has been focused on PFV because it seems to
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11522436,11774425,11704408,and 91836106)the Beijing Natural Science Foundation,China(Grant No.Z180013)+1 种基金the Joint Fund of the Ministry of Education of China(Grant No.6141A020333xx)the Research Funds of Renmin University of China(Grant Nos.16XNLQ03 and 18XNLQ15).
文摘Recent progresses on quantum control of cold atoms and trapped ions in both the scientific and technological aspects greatly advance the applications in precision measurement. Thanks to the exceptional controllability and versatility of these massive quantum systems, unprecedented sensitivity has been achieved in clocks, magnetometers, and interferometers based on cold atoms and ions. Besides, these systems also feature many characteristics that can be employed to facilitate the applications in different scenarios. In this review, we briefly introduce the principles of optical clocks, cold atom magnetometers, and atom interferometers used for precision measurement of time, magnetic field, and inertial forces. The main content is then devoted to summarize some recent experimental and theoretical progresses in these three applications, with special attention being paid to the new designs and possibilities towards better performance. The purpose of this review is by no means to give a complete overview of all important works in this fast developing field, but to draw a rough sketch about the frontiers and show the fascinating future lying ahead.
基金funded by Natural Science Foundation of Jiangsu Province (BK20201008)Key Research and Development Project of Zhenjiang (GJ2020014)National Natural Science Foundation of China (51701087)。
文摘Several Ni-W-P-TiO_(2) nanocomposite coatings were developed by the sol-enhanced electroplating method. The phase and elemental compositions of coatings were determined, and the surface and cross-section morphology were characterized. The mechanical and corrosion performance were systematically tested. The results revealed the addition of 5 ml·L^(-1) TiO_(2) sol caused a compact coating surface,while higher concentrations of TiO_(2) reduced the coating thickness and led to the inferior surface microstructure. The comparison in physiochemical properties of prepared coatings confirmed the superior performance of the Ni-W-P-TiO_(2) nanocomposite coating at 5 ml·L^(-1) TiO_(2) sol addition. Under this condition, the best mechanical properties were achieved when abrasive wear was the dominating wearresistance mechanism, and the best corrosion resistance was obtained due to its smooth and compact surface microstructure.
基金the National Key R&D Program of China(Grant Nos.2018YFA0305700 and 2018YFA0305800)the National Natural Science Foundation of China(Grant Nos.12025408,11874400,11834016,11921004,11888101,and 11904391)+3 种基金the Beijing Natural Science Foundation,China(Grant No.Z190008)the Strategic Priority Research Program and Key Research Program of Frontier Sciences of Chinese Academy of Sciences(CAS)(Grant Nos.XDB25000000,XDB33000000 and QYZDBSSW-SLH013)the CAS Interdisciplinary Innovation Team(Grant No.JCTD-201-01)supported by the U.S.Department of Energy,Office of Science,Basic Energy Sciences,Materials Sciences and Engineering Division。
文摘Recently,transition-metal-based kagome metals have aroused much research interest as a novel platform to explore exotic topological quantum phenomena.Here we report on the synthesis,structure,and physical properties of a bilayer kagome lattice compound V_(3)Sb_(2).The polycrystalline V_(3)Sb_(2) samples were synthesized by conventional solid-state-reaction method in a sealed quartz tube at temperatures below 850℃.Measurements of magnetic susceptibility and resistivity revealed consistently a density-wave-like transition at Tdw≈160 K with a large thermal hysteresis,even though some sample-dependent behaviors were observed presumably due to the different preparation conditions.Upon cooling through Tdw,no strong anomaly in lattice parameters and no indication of symmetry lowering were detected in powder x-ray diffraction measurements.This transition can be suppressed completely by applying hydrostatic pressures of about 1.8 GPa,around which no sign of superconductivity was observed down to 1.5 K.Specific-heat measurements revealed a relatively large Sommerfeld coefficientγ=18.5 mJ·mol^(-1)·K^(-2),confirming the metallic ground state with moderate electronic correlations.Density functional theory calculations indicate that V_(3)Sb_(2) shows a non-trivial topological crystalline property.Thus,our study makes V_(3)Sb_(2) a new candidate of metallic kagome compound to study the interplay between density-wave-order,nontrivial band topology,and possible superconductivity.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11371086, 11671258, and 11975145)the Fund of Science and Technology Commission of Shanghai Municipality, China (Grant No. 13ZR1400100)+1 种基金the Fund of Institute for Nonlinear Sciences, Donghua Universitythe Fundamental Research Funds for the Central Universities, China (Grant No. 2232021G-13)
文摘We investigate the techniques for velocity resonance and apply them to construct soliton molecules using two solitons of the extended Lax equation.What is more,each soliton molecule can be transformed into an asymmetric soliton by changing the parameterφ.In addition,the collision between soliton molecules(or asymmetric soliton)and several soliton solutions is observed.Finally,some related pictures are presented.
文摘Erratum to:International Journal of Minerals, Metallurgy and MaterialsVolume 29, Number 9, September 2022, Page 1770https://doi.org/10.1007/s12613-021-2287-1The original version of this article unfortunately contained a mistake due to the PDF file conversion through different softwares. The presentation of Fig. 13 in original version was incorrect.
基金support from the Beijing Natural Science Foundation(Grant No.Z180013)the National Natural Science Foundation of China(Grant Nos.12074427 and 12074428)+1 种基金the National Key R&D Program of China(Grant No.2018YFA0306501)the China Postdoctoral Science Foundation(Grant Nos.BX20200379 and 2021M693478)for support。
文摘Exploring quantum phenomena beyond predictions of any classical model has fundamental importance to understand the boundary of classical and quantum descriptions of nature.As a typical property that a quantum system behaves distinctively from a classical counterpart,contextuality has been studied extensively and verified experimentally in systems composed of at least three levels(qutrit).Here we extend the scope of experimental test of contextuality to a minimal quantum system of only two states(qubit)by implementing the minimum error state discrimination on a single171Yb+ion.We observe a substantial violation of a no-go inequality derived by assuming non-contextuality,and firmly conclude that the measured results of state discrimination cannot be reconciled with any non-contextual description.We also quantify the contextual advantage of state discrimination and the tolerance against quantum noises.
