As an earth-abundant and environmentally friendly material,tin sulfide(SnS)is not only a high-performance photovoltaic material,but also a new promising thermoelectric material.Despite extensive research on the thermo...As an earth-abundant and environmentally friendly material,tin sulfide(SnS)is not only a high-performance photovoltaic material,but also a new promising thermoelectric material.Despite extensive research on the thermoelectric properties of this material in recent years,the room-temperature thermoelectric figure of merit(ZT)of SnS has not been broke through 2[2022 Sci.China Mater.651143].In this work,based on a combination of density functional theory and non-equilibrium Green’s function method,the electronic and thermoelectric properties in SnS-nanoribbon-based heterojunctions are studied.The results show that although SnS nanoribbons(SNSNRs)with zigzag edges(ZSNSNRs)and armchair edges(ASNSNRs)both have semiconductor properties,the bandgaps of ASNSNRs are much wider than those of ZSNSNRs,which induces much wider conductance gaps of𝑁N-ASNSNR(N is the number of tin-sulfide lines across the ribbon width)).In the positive energy region,the ZT peaks of𝐿L-SNS-Au are much larger than those of𝐿L-SNS-GNR(L represents the number of longitudinal repeating units of SNSNR in the scattering region).While in the positive energy region,the ZT peaks of L-SNSGNR are larger than those of L-SNS-Au.Further calculations reveal that the figure of merit will be over 3.7 in L-SNS-Au and 2.2 in L-SNS-GNR at room temperature,and over 4 in L-SNS-Au and 2.6 in L-SNS-GNR at 500 K.展开更多
The magnetic cooling utilizing magneto-caloric effect is recognized as promising energy efficiency and environmentally friendly technology.Here we report a systematical study on the microstructures,magnetic properties...The magnetic cooling utilizing magneto-caloric effect is recognized as promising energy efficiency and environmentally friendly technology.Here we report a systematical study on the microstructures,magnetic properties and cryogenic magneto-caloric performances of the Gd_(20)Ho_(20)Tm_(20)Cu_(20)Ni_(20) amorphous ribbons.It is found that the ribbons reveal a second-order phase transition and are accompanied by a table-shaped magneto-caloric effect.The calculated magneticentropy-change maximum |ΔSM|,temperature averaged entropy change(i.e.,TEC(10)),and refrigerant capacity reach 13.9 J/kg·K,13.84 J/kg-K and 740 J/kg with magnetic field change of 0-7 T,respectively,indicating that the present Gd_(20)Ho_(20)Tm_(20)Cu_(20)Ni_(20) amorphous ribbons are good candidates for magnetic cooling.展开更多
A mathematical model of a ribbon pontoon bridge subjected to moving loads was formulated using the theory of simply supported beams.Two types of moving load models were used, the first a moving-constant-force model an...A mathematical model of a ribbon pontoon bridge subjected to moving loads was formulated using the theory of simply supported beams.Two types of moving load models were used, the first a moving-constant-force model and the second a moving-mass model.Using both types of loads, the dynamic behavior of a ribbon pontoon bridge was simulated while subjected to a single moving load and then multiple moving loads.Modeling was done with the Simulink package in MATLAB software.Results indicated that the model is correct.The two types of moving load models made little difference to the response ranges when loads moved on the bridge, but made some difference to the response phases.When loads left, the amplitude of the dynamic responses induced by the moving-constant-force model load were larger than those induced by the moving-mass model.There was a great deal more difference when there were more loads.展开更多
We theoretically and numerically demonstrate that a transmission-type electrically tunable polarizer can be realized by using graphene ribbons supported on a dielectric film with a graphene sheet behind. The polarizat...We theoretically and numerically demonstrate that a transmission-type electrically tunable polarizer can be realized by using graphene ribbons supported on a dielectric film with a graphene sheet behind. The polarization mechanism originates from the antenna plasmon resonance of graphene stripes. The results of full-wave numerical simulations reveal that transmittance of 0.70 for one polarization and 0.0073 for another polarization can be obtained at normal incidence. The transmission-type electrically tunable polarizer provides and facilitates a variety of applications, including filtering, detecting, and imaging.展开更多
The highly sensitive giant magneto-impedance effect in a solenoid containing a magnetic core of Fe36Co36Nb4Si4.sB19.2 （FeCo-based） ribbon under a weak magnetic field （WMF） is presented in this paper. The FeCo-base...The highly sensitive giant magneto-impedance effect in a solenoid containing a magnetic core of Fe36Co36Nb4Si4.sB19.2 （FeCo-based） ribbon under a weak magnetic field （WMF） is presented in this paper. The FeCo-based amorphous ribbon is prepared by single roller quenching and annealed with Joule heat in a flowing nitro- gen atmosphere. The giant magnetoimpedance effect in solenoid （GMIES） profiles are measured with an HP4294A impedance analyzer. The result shows that the CMIES responds to the WMF sensitively （as high as 1580 %/A.m-1）. The high sensitivity can be obtained in a moderate narrow range of annealing current density （30-34 A/mm2） and closely depends on the driven current frequency. The highest sensitivity （1580 %/A.m-1） is obtained when the FeCo- based amorphous ribbon is annealed at 32 A/mm2 for 10 min and then driven with an alterning current （AC） at the frequency of 350 kHz. The highly sensitive GMIES under the WMF may result from the multiple magnetic-anisotropic structure, which is induced by the temperature gradient produced during Joule-heating the ribbon.展开更多
The effects of wheel speeds and high-pressure hydrogen treatment on phase evolution,microstructure,and magnetocaloric properties in La_(0.5)Pr_(0.5)Fe_(11.4)Si_(1.6)melt-spun ribbons are studied in this work.The resul...The effects of wheel speeds and high-pressure hydrogen treatment on phase evolution,microstructure,and magnetocaloric properties in La_(0.5)Pr_(0.5)Fe_(11.4)Si_(1.6)melt-spun ribbons are studied in this work.The results reveal that the increase of wheel speed is beneficial to the formation of cubic NaZn_(13)-type phase and the grain refinement.The optimized wheel speed for microstructural and magnetocaloric properties is 30 m/s.The largest entropy change of 18.1 J/kg·K at 190 K under a magnetic field change of 0 T-5 T is obtained in La_(0.5)Pr_(0.5)Fe_(11.4)Si_(1.6)ribbons melt-spun at 30 m/s.After a high-pressure hydrogen treatment of 50 MPa,the Curie temperature of the ribbons prepared at 30 m/s is adjusted to about 314 K and the large-ΔS_(M)of 17.9 J/kg·K under a magnetic field change of 0 T-5 T is achieved at room temperature with almost none hysteresis loss.The small thermal and magnetic hysteresis and the large-ΔS_(M)make the La_(0.5)Pr_(0.5)Fe_(11.4)Si_(1.6)hydride ribbons appropriate for magnetic refrigerant applications around room temperature.展开更多
The crystal structure,martensitic transformation and magnetocaloric effect have been studied in all-d-metal Ni35Co15Mn33Fe2Ti15alloy ribbons with different wheel speeds(15 m/s(S15),30 m/s(S30),and 45 m/s(S45)).All thr...The crystal structure,martensitic transformation and magnetocaloric effect have been studied in all-d-metal Ni35Co15Mn33Fe2Ti15alloy ribbons with different wheel speeds(15 m/s(S15),30 m/s(S30),and 45 m/s(S45)).All three ribbons crystalize in B2-ordered structure at room temperature with crystal constants of 5.893(2)A,5.898(4)A,and5.898(6)A,respectively.With the increase of wheel speed,the martensitic transformation temperature decreases from230 K to 210 K,the Curie temperature increases slightly from 371 K to 378 K.At the same time,magnetic entropy change(△Sm)is also enhanced,as well as refrigeration capacity(RC).The maximum△Sm of 15.6(39.7)J/kg·K and RC of85.5(212.7)J/kg under?H=20(50)k Oe(1 Oe=79.5775 A·m^(-1))appear in S45.The results indicate that the ribbons could be the candidate for solid-state magnetic refrigeration materials.展开更多
The dipolar interactions are investigated through the asymmetric magneto-impedance in FINEMET/SiO_(2)/FePd composite ribbons.The interface between the hard(FePd layer)phase and soft(FINEMET ribbon)phase is coherent by...The dipolar interactions are investigated through the asymmetric magneto-impedance in FINEMET/SiO_(2)/FePd composite ribbons.The interface between the hard(FePd layer)phase and soft(FINEMET ribbon)phase is coherent by SiO_(2)layer in FINEMET/SiO_(2)/FePd composite ribbons,which effectively induces dipolar interactions.The contribution of dipolar interaction to the bias field(Hb)by asymmetrical giant magneto-impedance and magnetic properties is analyzed.The results show that Hb response decreases with the increase of the SiO_(2)layer thickness,indicating that the linear region near-zero field can be tuned by the thickness of SiO_(2)layer.These results allow the GMI ratio(58%)and characteristic frequency(500 kHz)to be optimized.The transverse and longitudinal magnetic domain structures of FINEMET ribbon and FePd film are confirmed,respectively.The composite ribbons with high GMI ratio and low frequency can be applied to linear magnetic sensors.展开更多
Using first-principles calculations, we study the tailoring of the electronic and magnetic properties of gallium sulfide nanoribbons（Ga2S2NRs） by mechanical strain. Hydrogen-passivated armchair-and zigzag-edged NRs...Using first-principles calculations, we study the tailoring of the electronic and magnetic properties of gallium sulfide nanoribbons（Ga2S2NRs） by mechanical strain. Hydrogen-passivated armchair-and zigzag-edged NRs（ANRs and ZNRs）with different widths are investigated. Significant effects in band gap and magnetic properties are found and analyzed. First,the band gaps and their nature of ANRs can be largely tailored by a strain. The band gaps can be markedly reduced, and show an indirect-direct（I-D） transition under a tensile strain. While under an increasing compressive strain, they undergo a series transitions of I-D-I-D. Five strain zones with distinct band structures and their boundaries are identified. In addition,the carrier effective masses of ANRs are also tunable by the strain, showing jumps at the boundaries. Second, the magnetic moments of（ferromagnetic） ZNRs show jumps under an increasing compressive strain due to spin density redistribution,but are unresponsive to tensile strains. The rich tunable properties by stain suggest potential applications of Ga2S2 NRs in nanoelectronics and optoelectronics.展开更多
U.S. Department of Commerce’s final ruling finally made one-year long "double anti-" investigation (anti-dumping and anti-subsidy) in the made-in-China narrow ribbons come to a settlement on July 13th Washi...U.S. Department of Commerce’s final ruling finally made one-year long "double anti-" investigation (anti-dumping and anti-subsidy) in the made-in-China narrow ribbons come to a settlement on July 13th Washington time.展开更多
基金supported by the key projects of Hunan Provincial Department of Education(Grant No.21A0167)the Hunan Provincial Natural Science Foundation of China(Grant No.2019JJ40532)+1 种基金the National Natural Science Foundation of China(Grant Nos.11704417,11974106,and 11247030)the Talent Introducing Foundation of Central South University of Forestry and Technology(Grant No.104-0160)。
文摘As an earth-abundant and environmentally friendly material,tin sulfide(SnS)is not only a high-performance photovoltaic material,but also a new promising thermoelectric material.Despite extensive research on the thermoelectric properties of this material in recent years,the room-temperature thermoelectric figure of merit(ZT)of SnS has not been broke through 2[2022 Sci.China Mater.651143].In this work,based on a combination of density functional theory and non-equilibrium Green’s function method,the electronic and thermoelectric properties in SnS-nanoribbon-based heterojunctions are studied.The results show that although SnS nanoribbons(SNSNRs)with zigzag edges(ZSNSNRs)and armchair edges(ASNSNRs)both have semiconductor properties,the bandgaps of ASNSNRs are much wider than those of ZSNSNRs,which induces much wider conductance gaps of𝑁N-ASNSNR(N is the number of tin-sulfide lines across the ribbon width)).In the positive energy region,the ZT peaks of𝐿L-SNS-Au are much larger than those of𝐿L-SNS-GNR(L represents the number of longitudinal repeating units of SNSNR in the scattering region).While in the positive energy region,the ZT peaks of L-SNSGNR are larger than those of L-SNS-Au.Further calculations reveal that the figure of merit will be over 3.7 in L-SNS-Au and 2.2 in L-SNS-GNR at room temperature,and over 4 in L-SNS-Au and 2.6 in L-SNS-GNR at 500 K.
基金Project supported by the National Natural Science Foundation of China(Grant No.52071197)the Science and Technology Committee of Shanghai(Grant No.19ZR1418300)+2 种基金the Independent Research and Development Project of State Key Laboratory of Advanced Special SteelShanghai Key Laboratory of Advanced Ferrometallurgy,Shanghai University(Grant No.SKLASS 2019-Z003)the Science and Technology Commission of Shanghai Municipality(Grant No.19DZ2270200)。
文摘The magnetic cooling utilizing magneto-caloric effect is recognized as promising energy efficiency and environmentally friendly technology.Here we report a systematical study on the microstructures,magnetic properties and cryogenic magneto-caloric performances of the Gd_(20)Ho_(20)Tm_(20)Cu_(20)Ni_(20) amorphous ribbons.It is found that the ribbons reveal a second-order phase transition and are accompanied by a table-shaped magneto-caloric effect.The calculated magneticentropy-change maximum |ΔSM|,temperature averaged entropy change(i.e.,TEC(10)),and refrigerant capacity reach 13.9 J/kg·K,13.84 J/kg-K and 740 J/kg with magnetic field change of 0-7 T,respectively,indicating that the present Gd_(20)Ho_(20)Tm_(20)Cu_(20)Ni_(20) amorphous ribbons are good candidates for magnetic cooling.
文摘A mathematical model of a ribbon pontoon bridge subjected to moving loads was formulated using the theory of simply supported beams.Two types of moving load models were used, the first a moving-constant-force model and the second a moving-mass model.Using both types of loads, the dynamic behavior of a ribbon pontoon bridge was simulated while subjected to a single moving load and then multiple moving loads.Modeling was done with the Simulink package in MATLAB software.Results indicated that the model is correct.The two types of moving load models made little difference to the response ranges when loads moved on the bridge, but made some difference to the response phases.When loads left, the amplitude of the dynamic responses induced by the moving-constant-force model load were larger than those induced by the moving-mass model.There was a great deal more difference when there were more loads.
基金Supported by the National Basic Research Program of China under Grant No 2012CB933501the National Natural Science Foundation of China under Grant Nos 61177051,11304389,61404174 and 61205087
文摘We theoretically and numerically demonstrate that a transmission-type electrically tunable polarizer can be realized by using graphene ribbons supported on a dielectric film with a graphene sheet behind. The polarization mechanism originates from the antenna plasmon resonance of graphene stripes. The results of full-wave numerical simulations reveal that transmittance of 0.70 for one polarization and 0.0073 for another polarization can be obtained at normal incidence. The transmission-type electrically tunable polarizer provides and facilitates a variety of applications, including filtering, detecting, and imaging.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 50871104 and 11079029)the Natural Science Foundation of Zhejiang Province,China (Grant Nos. Y4080324 and Y6110246)the Natural Science Foundation of Shanxi Province, China (Grant No. Sj08e101)
文摘The highly sensitive giant magneto-impedance effect in a solenoid containing a magnetic core of Fe36Co36Nb4Si4.sB19.2 （FeCo-based） ribbon under a weak magnetic field （WMF） is presented in this paper. The FeCo-based amorphous ribbon is prepared by single roller quenching and annealed with Joule heat in a flowing nitro- gen atmosphere. The giant magnetoimpedance effect in solenoid （GMIES） profiles are measured with an HP4294A impedance analyzer. The result shows that the CMIES responds to the WMF sensitively （as high as 1580 %/A.m-1）. The high sensitivity can be obtained in a moderate narrow range of annealing current density （30-34 A/mm2） and closely depends on the driven current frequency. The highest sensitivity （1580 %/A.m-1） is obtained when the FeCo- based amorphous ribbon is annealed at 32 A/mm2 for 10 min and then driven with an alterning current （AC） at the frequency of 350 kHz. The highly sensitive GMIES under the WMF may result from the multiple magnetic-anisotropic structure, which is induced by the temperature gradient produced during Joule-heating the ribbon.
基金Project supported by the National Natural Science Foundation of China(Grant No.51771197)the Fund from the Chinese Academy of Sciences(Grant No.KJZD-EW-M05)the Liaoning Revitalization Talents Program,China(Grant No.XLYC1807122).
文摘The effects of wheel speeds and high-pressure hydrogen treatment on phase evolution,microstructure,and magnetocaloric properties in La_(0.5)Pr_(0.5)Fe_(11.4)Si_(1.6)melt-spun ribbons are studied in this work.The results reveal that the increase of wheel speed is beneficial to the formation of cubic NaZn_(13)-type phase and the grain refinement.The optimized wheel speed for microstructural and magnetocaloric properties is 30 m/s.The largest entropy change of 18.1 J/kg·K at 190 K under a magnetic field change of 0 T-5 T is obtained in La_(0.5)Pr_(0.5)Fe_(11.4)Si_(1.6)ribbons melt-spun at 30 m/s.After a high-pressure hydrogen treatment of 50 MPa,the Curie temperature of the ribbons prepared at 30 m/s is adjusted to about 314 K and the large-ΔS_(M)of 17.9 J/kg·K under a magnetic field change of 0 T-5 T is achieved at room temperature with almost none hysteresis loss.The small thermal and magnetic hysteresis and the large-ΔS_(M)make the La_(0.5)Pr_(0.5)Fe_(11.4)Si_(1.6)hydride ribbons appropriate for magnetic refrigerant applications around room temperature.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.52001102 and 51771003)。
文摘The crystal structure,martensitic transformation and magnetocaloric effect have been studied in all-d-metal Ni35Co15Mn33Fe2Ti15alloy ribbons with different wheel speeds(15 m/s(S15),30 m/s(S30),and 45 m/s(S45)).All three ribbons crystalize in B2-ordered structure at room temperature with crystal constants of 5.893(2)A,5.898(4)A,and5.898(6)A,respectively.With the increase of wheel speed,the martensitic transformation temperature decreases from230 K to 210 K,the Curie temperature increases slightly from 371 K to 378 K.At the same time,magnetic entropy change(△Sm)is also enhanced,as well as refrigeration capacity(RC).The maximum△Sm of 15.6(39.7)J/kg·K and RC of85.5(212.7)J/kg under?H=20(50)k Oe(1 Oe=79.5775 A·m^(-1))appear in S45.The results indicate that the ribbons could be the candidate for solid-state magnetic refrigeration materials.
基金Project supported by the Natural Science Foundation of Shandong Province,China(Grant No.ZR2022MF276)the Major Innovation Fund of Qilu University of Technology(Shandong Academy of Science),China(Grant No.2022JBZ02-02)+1 种基金the Fund from Shanghai Science and Technology Commission,China(Grant No.22142200900)the Natural Science Foundation of Guangxi Zhuang Autonomous Region,China(Grant No.2019GXNSFAA245056).
文摘The dipolar interactions are investigated through the asymmetric magneto-impedance in FINEMET/SiO_(2)/FePd composite ribbons.The interface between the hard(FePd layer)phase and soft(FINEMET ribbon)phase is coherent by SiO_(2)layer in FINEMET/SiO_(2)/FePd composite ribbons,which effectively induces dipolar interactions.The contribution of dipolar interaction to the bias field(Hb)by asymmetrical giant magneto-impedance and magnetic properties is analyzed.The results show that Hb response decreases with the increase of the SiO_(2)layer thickness,indicating that the linear region near-zero field can be tuned by the thickness of SiO_(2)layer.These results allow the GMI ratio(58%)and characteristic frequency(500 kHz)to be optimized.The transverse and longitudinal magnetic domain structures of FINEMET ribbon and FePd film are confirmed,respectively.The composite ribbons with high GMI ratio and low frequency can be applied to linear magnetic sensors.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11174220 and 11374226)the Key Scientific Research Project of the Henan Institutions of Higher Learning,China(Grant No.16A140009)+2 种基金the Program for Innovative Research Team of Henan Polytechnic University,China(Grant Nos.T2015-3 and T2016-2)the Doctoral Foundation of Henan Polytechnic University,China(Grant No.B2015-46)the High-performance Grid Computing Platform of Henan Polytechnic University,China
文摘Using first-principles calculations, we study the tailoring of the electronic and magnetic properties of gallium sulfide nanoribbons（Ga2S2NRs） by mechanical strain. Hydrogen-passivated armchair-and zigzag-edged NRs（ANRs and ZNRs）with different widths are investigated. Significant effects in band gap and magnetic properties are found and analyzed. First,the band gaps and their nature of ANRs can be largely tailored by a strain. The band gaps can be markedly reduced, and show an indirect-direct（I-D） transition under a tensile strain. While under an increasing compressive strain, they undergo a series transitions of I-D-I-D. Five strain zones with distinct band structures and their boundaries are identified. In addition,the carrier effective masses of ANRs are also tunable by the strain, showing jumps at the boundaries. Second, the magnetic moments of（ferromagnetic） ZNRs show jumps under an increasing compressive strain due to spin density redistribution,but are unresponsive to tensile strains. The rich tunable properties by stain suggest potential applications of Ga2S2 NRs in nanoelectronics and optoelectronics.
文摘U.S. Department of Commerce’s final ruling finally made one-year long "double anti-" investigation (anti-dumping and anti-subsidy) in the made-in-China narrow ribbons come to a settlement on July 13th Washington time.
