This paper describes a fabrication process for the hyperboloidal concave mirror of a 46.5 nm telescope. The180 mm aperture hyperboloidal concave mirror and 70 mm aperture compensator are machined directly from chemica...This paper describes a fabrication process for the hyperboloidal concave mirror of a 46.5 nm telescope. The180 mm aperture hyperboloidal concave mirror and 70 mm aperture compensator are machined directly from chemical mechanical polishing of a spherical surface to a high-accuracy aspherical surface by ion beam figuring.The aspherical measurement method is the Dall null test. To minimize system errors in the measurement process,the rotational measurement method with six rotations is used in the null test. The results of the analysis for the ME(first solve the machined surface profile, then solve the system errors) and EM(first solve the system errors, then solve the machined surface profile) methods of calculation in the measurement are given. The ME method is a more accurate rotational test method, and the six rotations are appropriate for rotational measurements. After the figuring process, the hyperboloidal concave mirror surface profile reached 8.27 nm rms and the compensator surface profile is approximately 4 nm rms. The roughness of the hyperboloidal concave mirror is smooth to0.160 nm rms.展开更多
In this proceeding,some highlight results on the constraints of the nuclear matter equation of state(EOS)from the data of nucleus resonance and neutron-skin thickness using the Bayesian approach based on the Skyrme-Ha...In this proceeding,some highlight results on the constraints of the nuclear matter equation of state(EOS)from the data of nucleus resonance and neutron-skin thickness using the Bayesian approach based on the Skyrme-Hartree-Fock model and its extension have been presented.Typically,the anti-correlation and positive correlations between the slope parameter and the value of the symmetry energy at the saturation density under the constraint of the neutron-skin thickness and the isovector giant dipole resonance have been discussed respectively.It’s shown that the Bayesian analysis can help to find a compromise for the“PREXII puzzle”and the“soft Tin puzzle”.The possible modifications on the constraints of lower-order EOS parameters as well as the relevant correlation when higher-order EOS parameters are incorporated as independent variables have been further illustrated.For a given model and parameter space,the Bayesian approach serves as a good analysis tool suitable for multi-messengers versus multi-variables,and is helpful for constraining quantitatively the model parameters as well as their correlations.展开更多
The layered pavements usually exhibit complicated mechanical properties with the effect of complex material properties under external environment.In some cases,such as launching missiles or rockets,layered pavements a...The layered pavements usually exhibit complicated mechanical properties with the effect of complex material properties under external environment.In some cases,such as launching missiles or rockets,layered pavements are required to bear large impulse load.However,traditional methods cannot non-destructively and quickly detect the internal structural of pavements.Thus,accurate and fast prediction of the mechanical properties of layered pavements is of great importance and necessity.In recent years,machine learning has shown great superiority in solving nonlinear problems.In this work,we present a method of predicting the maximum deflection and damage factor of layered pavements under instantaneous large impact based on random forest regression with the deflection basin parameters obtained from falling weight deflection testing.The regression coefficient R^(2)of testing datasets are above 0.94 in the process of predicting the elastic moduli of structural layers and mechanical responses,which indicates that the prediction results have great consistency with finite element simulation results.This paper provides a novel method for fast and accurate prediction of pavement mechanical responses under instantaneous large impact load using partial structural parameters of pavements,and has application potential in non-destructive evaluation of pavement structure.展开更多
Chromium atom photolithography gratings are a promising technology for the development of nanoscale length standard substances due to their high accuracy,uniformity,and consistency.However,the inherent difference betw...Chromium atom photolithography gratings are a promising technology for the development of nanoscale length standard substances due to their high accuracy,uniformity,and consistency.However,the inherent difference between the interaction of positive and negative frequency detuning standing wave field and the atoms can cause a difference in the adjacent peak-to-valley heights of the grating in positive and negative frequency detuning chromium atom lithography,which greatly reduces its accuracy.In this study,we performed a controlled variable growth simulation using the semi-classical theoretical model and Monte Carlo method with trajectory tracking and ballistic deposition methods to investigate the influence of key experimental parameters on the surface growth process of positive and negative frequency detuning atomic lithography gratings.We established a theoretical model based on simulation results and summarized empirical equations to guide the selection of experimental parameters.Our simulations achieved uniform positive and negative frequency detuning atomic lithography gratings with a period of 1/4 of the wavelength corresponding to the atomic transition frequency,and adjacent peak-to-valley heights differing by no more than 2 nm,providing an important theoretical reference for the controllable fabrication of these gratings.展开更多
We investigate the structural,static magnetic and damping properties in two Mn-deficient magnetic Weyl semimetal Co-Mn-Ga(CMG) alloy films,i.e.,Co_(55)Mn_(18)Ga_(27)(CMG1) and Co_(50)Mn_(18)Ga_(32)(CMG2),which were ep...We investigate the structural,static magnetic and damping properties in two Mn-deficient magnetic Weyl semimetal Co-Mn-Ga(CMG) alloy films,i.e.,Co_(55)Mn_(18)Ga_(27)(CMG1) and Co_(50)Mn_(18)Ga_(32)(CMG2),which were epitaxially grown on MgO(001) substrates.CMG1 has a mixing phase of B2and L21,larger saturation magnetization(M_(s) ~760 emu/cm^(3)),stronger in-plane magnetic anisotropy.CMG2 has an almost pure B2phase,smaller M_(s)(~330 emu/cm^(3)),negligible in-plane magnetic anisotropy.Time-resolved magneto-optical Kerr effect results unambiguously demonstrate an obvious perpendicular standing spin wave(PSSW) mode in addition to the Kittel mode for both of the CMG films.The intrinsic damping constant is about 0.0055 and 0.015 for CMG1 and CMG2,respectively,which are both significantly larger than that of the stoichiometric CMG(i.e.,Co_(2)MnGa)film reported previously.In combination with the first-principles calculations,the intrinsic damping properties of the Mn-deficient CMG films can be well explained by considering the increase of density of states at the Fermi level,reduction of M_(s),and excitation of the PSSW mode.These findings provide a new clue to tuning the magnetic damping of the magnetic Weyl semimetal film through slight off-stoichiometry.展开更多
The Solar Upper Transition Region Imager(SUTRI)focuses on the solar transition region to achieve dynamic imaging observation of the upper transition region.In this paper,we report the optical system design,mechanical ...The Solar Upper Transition Region Imager(SUTRI)focuses on the solar transition region to achieve dynamic imaging observation of the upper transition region.In this paper,we report the optical system design,mechanical design,ultrasmooth mirror manufacture and measurement,EUV multilayer film coating,prelaunch installation and calibration for the SUTRI payload at IPOE,Tongji University.Finally,the SUTRI carried by the SATech-01 satellite was successfully set to launch.All functions of this telescope were normal,and the observation results obtained in orbit were consistent with the design.展开更多
Organic compounds have the advantages of green sustainability and high designability,but their high solubility leads to poor durability of zinc-organic batteries.Herein,a high-performance quinone-based polymer(H-PNADB...Organic compounds have the advantages of green sustainability and high designability,but their high solubility leads to poor durability of zinc-organic batteries.Herein,a high-performance quinone-based polymer(H-PNADBQ)material is designed by introducing an intramolecular hydrogen bonding(HB)strategy.The intramolecular HB(C=O⋯N-H)is formed in the reaction of 1,4-benzoquinone and 1,5-naphthalene diamine,which efficiently reduces the H-PNADBQ solubility and enhances its charge transfer in theory.In situ ultraviolet-visible analysis further reveals the insolubility of H-PNADBQ during the electrochemical cycles,enabling high durability at different current densities.Specifically,the H-PNADBQ electrode with high loading(10 mg cm^(-2))performs a long cycling life at 125 mA g^(-1)(>290 cycles).The H-PNADBQ also shows high rate capability(137.1 mAh g^(−1)at 25 A g^(−1))due to significantly improved kinetics inducted by intramolecular HB.This work provides an efficient approach toward insoluble organic electrode materials.展开更多
Using first-principles calculations, we study the tailoring of the electronic and magnetic properties of gallium sulfide nanoribbons(Ga_2S_2NRs) 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(Ga_2S_2NRs) 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 Ga_2S_2 NRs in nanoelectronics and optoelectronics.展开更多
Atom lithography with chromium can be utilized to fabricate a pitch standard,which is directly traceable to the wavelength of the laser standing waves. The result of a calibrated commercial AFM measurement demonstrate...Atom lithography with chromium can be utilized to fabricate a pitch standard,which is directly traceable to the wavelength of the laser standing waves. The result of a calibrated commercial AFM measurement demonstrates that the pitch standard is(212.8±0.1) nm with a peak-to-valley-height(PTVH) better than 20 nm. The measurement results show the high period accuracy of traceability with the standing laser wavelength(λ /2 = 212.78 nm). The Cr nano-grating covers a 1000 μm×500 μm area, with a PTVH better than 10 nm. The feature width broadening of the Cr nanostructure has been experimentally observed along the direction of the standing waves. The PTVH along the Gaussian laser direction is similar to a Gaussian distribution. Highly uniform periodic nanostructures with a big area at the millimeter scale, and the surface growth uniformity of the Cr nano-grating, show its great potential in the application of a traceable pitch standard at trans-scales.展开更多
Gold films deposited by direct current magnetron sputtering are used for synchrotron radiation optics. In this study, the microstructure and surface roughness of gold films were investigated for the purpose of develop...Gold films deposited by direct current magnetron sputtering are used for synchrotron radiation optics. In this study, the microstructure and surface roughness of gold films were investigated for the purpose of developing high-reflectivity mirrors. The deposition process was first optimized. Films were fabricated at different sputtering powers (15, 40, 80, and 120 W) and characterized using grazing incidence X-ray reflectometry, X-ray diffraction, and atomic force microscopy. The results showed that all the films were highly textured, having a dominant Au (111) orientation, and the film deposited at 80 W had the lowest surface roughness. Subsequently, post-deposition annealing from 100 to 200℃ in a vacuum was performed on the films deposited at 80 W to investigate the effect of annealing on the microstructure and surface roughness of the films. The grain size, surface roughness, and their relationship were investigated as a function of annealing temperature. AFM and XRD results revealed that at annealing temperatures of 175 ℃ and below, microstructural change of the films was mainly manifested by the elimination of voids. At annealing temperatures higher than 175℃, grain coalescence occurred in addition to the void elimination, causing the surface roughness to increase.展开更多
Dy:Lu_2O_3 was grown by the float-zone(Fz) method. According to the absorption spectrum, the Judd–Ofelt(JO) parameters ?_2, ?_4, and ?_6 were calculated to be 4.86 × 10^(-20) cm^2, 2.02 × 10^(-20) cm^2, and...Dy:Lu_2O_3 was grown by the float-zone(Fz) method. According to the absorption spectrum, the Judd–Ofelt(JO) parameters ?_2, ?_4, and ?_6 were calculated to be 4.86 × 10^(-20) cm^2, 2.02 × 10^(-20) cm^2, and 1.76 × 10^(-20) cm^2, respectively.The emission cross-section at 574 nm corresponding to the ~4F6_(9/2)→~6H_(13/2) transition was calculated to be 0.53 × 10^(-20) cm^2.The yellow(~4F_(9/2)→~6H_(13/2) transition) to blue(~4F_(9/2)→~6H_(15/2) transition) intensity ratio ranges up to 12.9. The fluorescence lifetime of the ~4F_(9/2) energy level was measured to be 112.1 μs. These results reveal that Dy:Lu_2O_3 is a promising material for use in yellow lasers.展开更多
The refining and modification effect of Ti (from GRAI), B, Sr and RE (cerium-riched mixtures of rare earth) on the mechanical properties of A356 aluminum alloys under T5 and T6 treatment condition were studied by OM, ...The refining and modification effect of Ti (from GRAI), B, Sr and RE (cerium-riched mixtures of rare earth) on the mechanical properties of A356 aluminum alloys under T5 and T6 treatment condition were studied by OM, SEM, EDAX, etc. It is found that the addition of RE to A356 alloys containing Ti and/or B and Sr makes strength and elongation increase in T6 treatment, but make elongation decrease in T5 treatment, at the same time, the long axis ofα(Al) grain structure decreases and the mean diameters of silicon particles increase with RE additions increasing. Grain refining with 0.01%Ti plus 0.03% B makes the dendriteα(Al) grain structure transform into equiaxed structure, resulting in obvious increase of elongation percentage. The mean diameters of silicon particles in T5 treatment are smaller than that in T6 treatment. Roundness of silicon particles in T5 treatment is higher than that in T6 treatment. A356 alloys modified and refined with Ti, B and Sr obtain the best mechanical properties in T5 treatment, however, the alloys with Ti, B, RE and Sr additions obtain the best mechanical properties in T6 treatment.展开更多
As one of the most attractive non-radiative power transfer mechanisms without cables,efficient magnetic resonance wireless power transfer(WPT)in the near field has been extensively developed in recent years,and promot...As one of the most attractive non-radiative power transfer mechanisms without cables,efficient magnetic resonance wireless power transfer(WPT)in the near field has been extensively developed in recent years,and promoted a variety of practical applications,such as mobile phones,medical implant devices and electric vehicles.However,the physical mechanism behind some key limitations of the resonance WPT,such as frequency splitting and size-dependent efficiency,is not very clear under the widely used circuit model.Here,we review the recently developed efficient and stable resonance WPT based on non-Hermitian physics,which starts from a completely different avenue(utilizing loss and gain)to introduce novel functionalities to the resonance WPT.From the perspective of non-Hermitian photonics,the coherent and incoherent effects compete and coexist in the WPT system,and the weak stable of energy transfer mainly comes from the broken phase associated with the phase transition of parity-time symmetry.Based on this basic physical framework,some optimization schemes are proposed,including using nonlinear effect,using bound states in the continuum,or resorting to the system with high-order parity-time symmetry.Moreover,the combination of non-Hermitian physics and topological photonics in multi-coil system also provides a versatile platform for long-range robust WPT with topological protection.Therefore,the non-Hermitian physics can not only exactly predict the main results of current WPT systems,but also provide new ways to solve the difficulties of previous designs.展开更多
Boron carbide(B4C)coatings have high reflectivity and are widely used as mirrors for free-electron lasers in the x-ray range.However,B4C coatings fabricated by direct-current magnetron sputtering show a strong compres...Boron carbide(B4C)coatings have high reflectivity and are widely used as mirrors for free-electron lasers in the x-ray range.However,B4C coatings fabricated by direct-current magnetron sputtering show a strong compressive stress of about-3 GPa.By changing the argon gas pressure and nitrogen-argon gas mixing ratio,we are able to reduce the intrinsic stress to less than-1 GPa for a 50-nm-thick B4C coating.It is found that the stress in a coating deposited at 10 m Torr is-0.69 GPa,the rms roughness of the coating surface is 0.53 nm,and the coating reflectivity is 88%,which is lower than those of coatings produced at lower working pressures.When the working gas contains 8%nitrogen and 92%argon,the B4 C coating shows not only-1.19 GPa stress but also a low rms roughness of 0.16 nm,and the measured reflectivity is 93%at the wavelength of 0.154 nm.展开更多
The crystal growth,x-ray diffraction pattern,absorption spectrum,emission spectrum,and fluorescence lifetime of a Tb:Lu_2O_3 single crystal were studied.Excited at 483 nm,the peak absorption cross-section was calculat...The crystal growth,x-ray diffraction pattern,absorption spectrum,emission spectrum,and fluorescence lifetime of a Tb:Lu_2O_3 single crystal were studied.Excited at 483 nm,the peak absorption cross-section was calculated to be 3.5×10^(-22)cm^2,and the full width at half maximum was found to be 2.85 nm.The Judd-Ofelt(J-O)intensity parameters ?_2,?_4,and ?_6 were computed to be 3.79×10^(-20)cm^2,1.30×10^(-20)cm^2,and 1.08×10^(-20)cm^2,with a spectroscopic quality factor ?_4/?_6 being 1.20.The emission cross-sections of green emission around 543 nm and yellow emission around 584 nm were calculated to be 9.43×10^(-22)cm^2 and 1.32×10^(-22)cm^2,respectively.The fluorescence lifetimeτexp of ~5D_4 was fitted to be 1.13 ms.The data suggest that the Tb:Lu_2O_3 crystal could be a potential candidate for green and yellow laser operation.展开更多
High quality 0.02 mol%,0.05 mol%,and 0.08 mol%Fe:β-Ga2O3 single crystals were grown by the floating zone method.The crystal structure,optical,electrical,and thermal properties were measured and discussed.Fe:β-Ga2O3 ...High quality 0.02 mol%,0.05 mol%,and 0.08 mol%Fe:β-Ga2O3 single crystals were grown by the floating zone method.The crystal structure,optical,electrical,and thermal properties were measured and discussed.Fe:β-Ga2O3 single crystals showed transmittance of higher than 80%in the near infrared region.With the increase of the Fe doping concentration,the optical bandgaps reduced and room temperature resistivity increased.The resistivity of 0.08 mol%Fe:β-Ga2O3 crystal reached to 3.63×1011Ω·cm.The high resistivity Fe:β-Ga2O3 single crystals could be applied as the substrate for the high-power field effect transistors(FETs).展开更多
A series of 30-nm-thick epitaxial NixCo1-x(002) alloy films are fabricated by DC magnetron sputtering. MgO(002)and SrTiO3(002) single substrates are used for x > 0.5 and x < 0.5, respectively. The magnetocrystal...A series of 30-nm-thick epitaxial NixCo1-x(002) alloy films are fabricated by DC magnetron sputtering. MgO(002)and SrTiO3(002) single substrates are used for x > 0.5 and x < 0.5, respectively. The magnetocrystalline anisotropy of Ni x Co1-x(002) alloy films is studied in the entire composition region for 0 ≤ x ≤ 1.0. When x decreases, the cubic magnetic anisotropy constant K1 changes sign from negative to positive at x = 0.96 and becomes negative again at x = 0.79.It becomes more negative as x decreases from 0.79 to 0. The uniaxial anisotropy K u is smaller than the K1 by a factor of two orders.展开更多
Recently, theoretical and experimental nano-sized fundamental devices for optical circuits have been proposed at the single-photon level. The assembly of a realistic optical circuit is now a reality. In this work, we ...Recently, theoretical and experimental nano-sized fundamental devices for optical circuits have been proposed at the single-photon level. The assembly of a realistic optical circuit is now a reality. In this work, we introduce a single-photon interconnector composed of two individual nanowires and an optical N-type four-level emitter that can turn the optical connection on and off optically. Because of dipole-induced transmission at the single-photon level, a single photon can travel between the two nanowires reciprocally, which guarantees its application as an all-optical interconnector.展开更多
Ab initio density functional theory calculations are carried out to predict the electronic properties and relative stability of gallium sulfide nanoribbons(Ga_2S_2-NRs) with either zigzag- or armchair-terminated edges...Ab initio density functional theory calculations are carried out to predict the electronic properties and relative stability of gallium sulfide nanoribbons(Ga_2S_2-NRs) with either zigzag- or armchair-terminated edges. It is found that the electronic properties of the nanoribbons are very sensitive to the edge structure. The zigzag nanoribbons(Ga_2S_2-ZNRs)are ferromagnetic(FM) metallic with spin-polarized edge states regardless of the H-passivation, whereas the bare armchair ones(Ga_2S_2-ANRs) are semiconducting with an indirect band gap. This band gap exhibits an oscillation behavior as the width increases and finally converges to a constant value. Similar behavior is also found in H-saturated Ga_2S_2-ANRs,although the band gap converges to a larger value. The relative stabilities of the bare ANRs and ZNRs are investigated by calculating their binding energies. It is found that for a similar width the ANRs are more stable than the ZNRs, and both are more stable than some Ga_2S_2 nanoclusters with stable configurations.展开更多
基金funded by the National Key R&D Program of China (2022YFF0709101)the National Natural Science Foundation of China (NSFC) under Nos. 62105244 and 61621001。
文摘This paper describes a fabrication process for the hyperboloidal concave mirror of a 46.5 nm telescope. The180 mm aperture hyperboloidal concave mirror and 70 mm aperture compensator are machined directly from chemical mechanical polishing of a spherical surface to a high-accuracy aspherical surface by ion beam figuring.The aspherical measurement method is the Dall null test. To minimize system errors in the measurement process,the rotational measurement method with six rotations is used in the null test. The results of the analysis for the ME(first solve the machined surface profile, then solve the system errors) and EM(first solve the system errors, then solve the machined surface profile) methods of calculation in the measurement are given. The ME method is a more accurate rotational test method, and the six rotations are appropriate for rotational measurements. After the figuring process, the hyperboloidal concave mirror surface profile reached 8.27 nm rms and the compensator surface profile is approximately 4 nm rms. The roughness of the hyperboloidal concave mirror is smooth to0.160 nm rms.
基金Supported by National Natural Science Foundation of China (11922514)。
文摘In this proceeding,some highlight results on the constraints of the nuclear matter equation of state(EOS)from the data of nucleus resonance and neutron-skin thickness using the Bayesian approach based on the Skyrme-Hartree-Fock model and its extension have been presented.Typically,the anti-correlation and positive correlations between the slope parameter and the value of the symmetry energy at the saturation density under the constraint of the neutron-skin thickness and the isovector giant dipole resonance have been discussed respectively.It’s shown that the Bayesian analysis can help to find a compromise for the“PREXII puzzle”and the“soft Tin puzzle”.The possible modifications on the constraints of lower-order EOS parameters as well as the relevant correlation when higher-order EOS parameters are incorporated as independent variables have been further illustrated.For a given model and parameter space,the Bayesian approach serves as a good analysis tool suitable for multi-messengers versus multi-variables,and is helpful for constraining quantitatively the model parameters as well as their correlations.
基金Project supported in part by the National Natural Science Foundation of China(Grant No.12075168)the Fund from the Science and Technology Commission of Shanghai Municipality(Grant No.21JC1405600)。
文摘The layered pavements usually exhibit complicated mechanical properties with the effect of complex material properties under external environment.In some cases,such as launching missiles or rockets,layered pavements are required to bear large impulse load.However,traditional methods cannot non-destructively and quickly detect the internal structural of pavements.Thus,accurate and fast prediction of the mechanical properties of layered pavements is of great importance and necessity.In recent years,machine learning has shown great superiority in solving nonlinear problems.In this work,we present a method of predicting the maximum deflection and damage factor of layered pavements under instantaneous large impact based on random forest regression with the deflection basin parameters obtained from falling weight deflection testing.The regression coefficient R^(2)of testing datasets are above 0.94 in the process of predicting the elastic moduli of structural layers and mechanical responses,which indicates that the prediction results have great consistency with finite element simulation results.This paper provides a novel method for fast and accurate prediction of pavement mechanical responses under instantaneous large impact load using partial structural parameters of pavements,and has application potential in non-destructive evaluation of pavement structure.
基金Project supported by the National Natural Science Foundation of China(Grant No.62075165)the National Key Research and Development Program of China(Grant Nos.2022YFF0607600 and 2022YFF0605502)+3 种基金the Special Development Funds for Major Projects of Shanghai Zhangjiang National Independent Innovation Demonstration Zone(Grant No.ZJ2021ZD008)the Shanghai Natural Science Foundation(Grant No.21ZR1483100)the Shanghai Academic/Technology Research Leader(Grant No.21XD1425000)the Opening Fund of Shanghai Key Laboratory of Online Detection and Control Technology(Grant No.ZX2020101)。
文摘Chromium atom photolithography gratings are a promising technology for the development of nanoscale length standard substances due to their high accuracy,uniformity,and consistency.However,the inherent difference between the interaction of positive and negative frequency detuning standing wave field and the atoms can cause a difference in the adjacent peak-to-valley heights of the grating in positive and negative frequency detuning chromium atom lithography,which greatly reduces its accuracy.In this study,we performed a controlled variable growth simulation using the semi-classical theoretical model and Monte Carlo method with trajectory tracking and ballistic deposition methods to investigate the influence of key experimental parameters on the surface growth process of positive and negative frequency detuning atomic lithography gratings.We established a theoretical model based on simulation results and summarized empirical equations to guide the selection of experimental parameters.Our simulations achieved uniform positive and negative frequency detuning atomic lithography gratings with a period of 1/4 of the wavelength corresponding to the atomic transition frequency,and adjacent peak-to-valley heights differing by no more than 2 nm,providing an important theoretical reference for the controllable fabrication of these gratings.
基金supported by the National Key R&D Program of China (Grant Nos.2022YFA1403602 and 2021YFB3601600)the National Natural Science Foundation of China (Grant Nos.51971109,U22A20117,51771053,52001169,11874199,12104216,and 12241403)the Natural Science Foundation of Jiangsu Province of China (Grant No.BK20200307)。
文摘We investigate the structural,static magnetic and damping properties in two Mn-deficient magnetic Weyl semimetal Co-Mn-Ga(CMG) alloy films,i.e.,Co_(55)Mn_(18)Ga_(27)(CMG1) and Co_(50)Mn_(18)Ga_(32)(CMG2),which were epitaxially grown on MgO(001) substrates.CMG1 has a mixing phase of B2and L21,larger saturation magnetization(M_(s) ~760 emu/cm^(3)),stronger in-plane magnetic anisotropy.CMG2 has an almost pure B2phase,smaller M_(s)(~330 emu/cm^(3)),negligible in-plane magnetic anisotropy.Time-resolved magneto-optical Kerr effect results unambiguously demonstrate an obvious perpendicular standing spin wave(PSSW) mode in addition to the Kittel mode for both of the CMG films.The intrinsic damping constant is about 0.0055 and 0.015 for CMG1 and CMG2,respectively,which are both significantly larger than that of the stoichiometric CMG(i.e.,Co_(2)MnGa)film reported previously.In combination with the first-principles calculations,the intrinsic damping properties of the Mn-deficient CMG films can be well explained by considering the increase of density of states at the Fermi level,reduction of M_(s),and excitation of the PSSW mode.These findings provide a new clue to tuning the magnetic damping of the magnetic Weyl semimetal film through slight off-stoichiometry.
基金the National Key R&D Program of China(2022YFF0709101)the National Natural Science Foundation of China(NSFC)under grant Nos.61621001,62105244,12003016 and 12204353.
文摘The Solar Upper Transition Region Imager(SUTRI)focuses on the solar transition region to achieve dynamic imaging observation of the upper transition region.In this paper,we report the optical system design,mechanical design,ultrasmooth mirror manufacture and measurement,EUV multilayer film coating,prelaunch installation and calibration for the SUTRI payload at IPOE,Tongji University.Finally,the SUTRI carried by the SATech-01 satellite was successfully set to launch.All functions of this telescope were normal,and the observation results obtained in orbit were consistent with the design.
基金supported by the National Natural Science Foundation of China (22279063 and 52001170)the Fundamental Research Funds for the Central Universities+2 种基金Tianjin Natural Science Foundation (No. 22JCYBJC00590)the financial support by the Ministry of Education, Singapore, under its Academic Research Fund Tier 1 Thematic (RT8/22)the Haihe Laboratory of Sustainable Chemical Transformations, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) for financial support
文摘Organic compounds have the advantages of green sustainability and high designability,but their high solubility leads to poor durability of zinc-organic batteries.Herein,a high-performance quinone-based polymer(H-PNADBQ)material is designed by introducing an intramolecular hydrogen bonding(HB)strategy.The intramolecular HB(C=O⋯N-H)is formed in the reaction of 1,4-benzoquinone and 1,5-naphthalene diamine,which efficiently reduces the H-PNADBQ solubility and enhances its charge transfer in theory.In situ ultraviolet-visible analysis further reveals the insolubility of H-PNADBQ during the electrochemical cycles,enabling high durability at different current densities.Specifically,the H-PNADBQ electrode with high loading(10 mg cm^(-2))performs a long cycling life at 125 mA g^(-1)(>290 cycles).The H-PNADBQ also shows high rate capability(137.1 mAh g^(−1)at 25 A g^(−1))due to significantly improved kinetics inducted by intramolecular HB.This work provides an efficient approach toward insoluble organic electrode materials.
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(Ga_2S_2NRs) 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 Ga_2S_2 NRs in nanoelectronics and optoelectronics.
基金supported by the Major Research Plan of the National Natural Science Foundation of China(Grant No.91123022)the Young Scientists Fund of the National Natural Science Foundation of China(Grant No.10804084)
文摘Atom lithography with chromium can be utilized to fabricate a pitch standard,which is directly traceable to the wavelength of the laser standing waves. The result of a calibrated commercial AFM measurement demonstrates that the pitch standard is(212.8±0.1) nm with a peak-to-valley-height(PTVH) better than 20 nm. The measurement results show the high period accuracy of traceability with the standing laser wavelength(λ /2 = 212.78 nm). The Cr nano-grating covers a 1000 μm×500 μm area, with a PTVH better than 10 nm. The feature width broadening of the Cr nanostructure has been experimentally observed along the direction of the standing waves. The PTVH along the Gaussian laser direction is similar to a Gaussian distribution. Highly uniform periodic nanostructures with a big area at the millimeter scale, and the surface growth uniformity of the Cr nano-grating, show its great potential in the application of a traceable pitch standard at trans-scales.
基金supported by the National Key R&D Program of China(Nos.2016YFA0401304 and 2017YFA0403302)the National Natural Science Foundation of China(NSFC)(Nos.61621001,11505129,and U1732268)
文摘Gold films deposited by direct current magnetron sputtering are used for synchrotron radiation optics. In this study, the microstructure and surface roughness of gold films were investigated for the purpose of developing high-reflectivity mirrors. The deposition process was first optimized. Films were fabricated at different sputtering powers (15, 40, 80, and 120 W) and characterized using grazing incidence X-ray reflectometry, X-ray diffraction, and atomic force microscopy. The results showed that all the films were highly textured, having a dominant Au (111) orientation, and the film deposited at 80 W had the lowest surface roughness. Subsequently, post-deposition annealing from 100 to 200℃ in a vacuum was performed on the films deposited at 80 W to investigate the effect of annealing on the microstructure and surface roughness of the films. The grain size, surface roughness, and their relationship were investigated as a function of annealing temperature. AFM and XRD results revealed that at annealing temperatures of 175 ℃ and below, microstructural change of the films was mainly manifested by the elimination of voids. At annealing temperatures higher than 175℃, grain coalescence occurred in addition to the void elimination, causing the surface roughness to increase.
基金Project supported by the Fund of Key Laboratory of Optoelectronic Materials Chemistry and Physics,Chinese Academy of Sciences(Grant No.2008DP173016)the National Key Research and Development Program of China(Grant No.2016YFB1102202)the National Key Research and Development Program of China(Grant No.2016YFB0701002)
文摘Dy:Lu_2O_3 was grown by the float-zone(Fz) method. According to the absorption spectrum, the Judd–Ofelt(JO) parameters ?_2, ?_4, and ?_6 were calculated to be 4.86 × 10^(-20) cm^2, 2.02 × 10^(-20) cm^2, and 1.76 × 10^(-20) cm^2, respectively.The emission cross-section at 574 nm corresponding to the ~4F6_(9/2)→~6H_(13/2) transition was calculated to be 0.53 × 10^(-20) cm^2.The yellow(~4F_(9/2)→~6H_(13/2) transition) to blue(~4F_(9/2)→~6H_(15/2) transition) intensity ratio ranges up to 12.9. The fluorescence lifetime of the ~4F_(9/2) energy level was measured to be 112.1 μs. These results reveal that Dy:Lu_2O_3 is a promising material for use in yellow lasers.
文摘The refining and modification effect of Ti (from GRAI), B, Sr and RE (cerium-riched mixtures of rare earth) on the mechanical properties of A356 aluminum alloys under T5 and T6 treatment condition were studied by OM, SEM, EDAX, etc. It is found that the addition of RE to A356 alloys containing Ti and/or B and Sr makes strength and elongation increase in T6 treatment, but make elongation decrease in T5 treatment, at the same time, the long axis ofα(Al) grain structure decreases and the mean diameters of silicon particles increase with RE additions increasing. Grain refining with 0.01%Ti plus 0.03% B makes the dendriteα(Al) grain structure transform into equiaxed structure, resulting in obvious increase of elongation percentage. The mean diameters of silicon particles in T5 treatment are smaller than that in T6 treatment. Roundness of silicon particles in T5 treatment is higher than that in T6 treatment. A356 alloys modified and refined with Ti, B and Sr obtain the best mechanical properties in T5 treatment, however, the alloys with Ti, B, RE and Sr additions obtain the best mechanical properties in T6 treatment.
基金supported by the National Key Research and Development Program of China (Grant No. 2016YFA0301101)the National Natural Science Foundation of China (Grant Nos. 91850206, 61621001, 2004284, 11674247, and 11974261)+3 种基金Shanghai Science and Technology Committee, China (Grant Nos. 18JC1410900 and 18ZR1442900)the China Postdoctoral Science Foundation (Grant Nos. 2019TQ0232 and 2019M661605)the Shanghai Super Postdoctoral Incentive ProgramFundamental Research Funds for the Central Universities, China
文摘As one of the most attractive non-radiative power transfer mechanisms without cables,efficient magnetic resonance wireless power transfer(WPT)in the near field has been extensively developed in recent years,and promoted a variety of practical applications,such as mobile phones,medical implant devices and electric vehicles.However,the physical mechanism behind some key limitations of the resonance WPT,such as frequency splitting and size-dependent efficiency,is not very clear under the widely used circuit model.Here,we review the recently developed efficient and stable resonance WPT based on non-Hermitian physics,which starts from a completely different avenue(utilizing loss and gain)to introduce novel functionalities to the resonance WPT.From the perspective of non-Hermitian photonics,the coherent and incoherent effects compete and coexist in the WPT system,and the weak stable of energy transfer mainly comes from the broken phase associated with the phase transition of parity-time symmetry.Based on this basic physical framework,some optimization schemes are proposed,including using nonlinear effect,using bound states in the continuum,or resorting to the system with high-order parity-time symmetry.Moreover,the combination of non-Hermitian physics and topological photonics in multi-coil system also provides a versatile platform for long-range robust WPT with topological protection.Therefore,the non-Hermitian physics can not only exactly predict the main results of current WPT systems,but also provide new ways to solve the difficulties of previous designs.
基金Supported by the National Key R&D Program of China under Grant No 2016YFA0401304the National Natural Science Foundation of China under Grant Nos 61621001,U1732268 and 11875203the Shanghai Municipal Science and Technology Major Project under Grant No 2017SHZDZX02
文摘Boron carbide(B4C)coatings have high reflectivity and are widely used as mirrors for free-electron lasers in the x-ray range.However,B4C coatings fabricated by direct-current magnetron sputtering show a strong compressive stress of about-3 GPa.By changing the argon gas pressure and nitrogen-argon gas mixing ratio,we are able to reduce the intrinsic stress to less than-1 GPa for a 50-nm-thick B4C coating.It is found that the stress in a coating deposited at 10 m Torr is-0.69 GPa,the rms roughness of the coating surface is 0.53 nm,and the coating reflectivity is 88%,which is lower than those of coatings produced at lower working pressures.When the working gas contains 8%nitrogen and 92%argon,the B4 C coating shows not only-1.19 GPa stress but also a low rms roughness of 0.16 nm,and the measured reflectivity is 93%at the wavelength of 0.154 nm.
基金Project supported by the National Natural Science Foundation of China(Grant No.61621001)the National Key Research and Development Program of China(Grant Nos.2016YFB1102202 and 2016YFB0701002)+1 种基金the Fundamental Research Funds for the Central Universities,Chinathe help of MOE Key Laboratory of Advanced Micro-Structured Materials and School of Physical Science and Technology,Guangxi University
文摘The crystal growth,x-ray diffraction pattern,absorption spectrum,emission spectrum,and fluorescence lifetime of a Tb:Lu_2O_3 single crystal were studied.Excited at 483 nm,the peak absorption cross-section was calculated to be 3.5×10^(-22)cm^2,and the full width at half maximum was found to be 2.85 nm.The Judd-Ofelt(J-O)intensity parameters ?_2,?_4,and ?_6 were computed to be 3.79×10^(-20)cm^2,1.30×10^(-20)cm^2,and 1.08×10^(-20)cm^2,with a spectroscopic quality factor ?_4/?_6 being 1.20.The emission cross-sections of green emission around 543 nm and yellow emission around 584 nm were calculated to be 9.43×10^(-22)cm^2 and 1.32×10^(-22)cm^2,respectively.The fluorescence lifetimeτexp of ~5D_4 was fitted to be 1.13 ms.The data suggest that the Tb:Lu_2O_3 crystal could be a potential candidate for green and yellow laser operation.
基金the Scientific and Innovative Action Plan of Shanghai,China(Grant No.18511110502)Equipment Pre-research Fund Key Project,China(Grant No.6140922010601).
文摘High quality 0.02 mol%,0.05 mol%,and 0.08 mol%Fe:β-Ga2O3 single crystals were grown by the floating zone method.The crystal structure,optical,electrical,and thermal properties were measured and discussed.Fe:β-Ga2O3 single crystals showed transmittance of higher than 80%in the near infrared region.With the increase of the Fe doping concentration,the optical bandgaps reduced and room temperature resistivity increased.The resistivity of 0.08 mol%Fe:β-Ga2O3 crystal reached to 3.63×1011Ω·cm.The high resistivity Fe:β-Ga2O3 single crystals could be applied as the substrate for the high-power field effect transistors(FETs).
基金supported by the National Natural Science Foundation of China(Grant Nos.11374227,51331004,51171129,and 51201114)the Shanghai Science and Technology Committee,China(Grant Nos.0252nm004,13XD1403700,and 13520722700)
文摘A series of 30-nm-thick epitaxial NixCo1-x(002) alloy films are fabricated by DC magnetron sputtering. MgO(002)and SrTiO3(002) single substrates are used for x > 0.5 and x < 0.5, respectively. The magnetocrystalline anisotropy of Ni x Co1-x(002) alloy films is studied in the entire composition region for 0 ≤ x ≤ 1.0. When x decreases, the cubic magnetic anisotropy constant K1 changes sign from negative to positive at x = 0.96 and becomes negative again at x = 0.79.It becomes more negative as x decreases from 0.79 to 0. The uniaxial anisotropy K u is smaller than the K1 by a factor of two orders.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11274242,11474221,and 11574229)the Joint Fund of the National Natural Science Foundation of China+2 种基金the China Academy of Engineering Physics(Grant No.U1330203)the National Key Basic Research Special Foundation of China(Grant Nos.2011CB922203 and 2013CB632701)the Doctor Startup Fund of the Natural Science of Jinggangshan University,China(Grant No.JZB16003)
文摘Recently, theoretical and experimental nano-sized fundamental devices for optical circuits have been proposed at the single-photon level. The assembly of a realistic optical circuit is now a reality. In this work, we introduce a single-photon interconnector composed of two individual nanowires and an optical N-type four-level emitter that can turn the optical connection on and off optically. Because of dipole-induced transmission at the single-photon level, a single photon can travel between the two nanowires reciprocally, which guarantees its application as an all-optical interconnector.
基金Supported by the Nano Special Projects of Shanghai Science and Technology Commission under Grant No 11nm0560800, and the Young Scientists Fund of the National Natural Science Foundation of China under Grant Nos 11104284 and 61107077.
基金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(Grant No.16A140009)+1 种基金the Program for Innovative Research Team of Henan Polytechnic University(Grant Nos.T2015-3 and T2016-2)the Doctoral Foundation of Henan Polytechnic University(Grant No.B2015-46)
文摘Ab initio density functional theory calculations are carried out to predict the electronic properties and relative stability of gallium sulfide nanoribbons(Ga_2S_2-NRs) with either zigzag- or armchair-terminated edges. It is found that the electronic properties of the nanoribbons are very sensitive to the edge structure. The zigzag nanoribbons(Ga_2S_2-ZNRs)are ferromagnetic(FM) metallic with spin-polarized edge states regardless of the H-passivation, whereas the bare armchair ones(Ga_2S_2-ANRs) are semiconducting with an indirect band gap. This band gap exhibits an oscillation behavior as the width increases and finally converges to a constant value. Similar behavior is also found in H-saturated Ga_2S_2-ANRs,although the band gap converges to a larger value. The relative stabilities of the bare ANRs and ZNRs are investigated by calculating their binding energies. It is found that for a similar width the ANRs are more stable than the ZNRs, and both are more stable than some Ga_2S_2 nanoclusters with stable configurations.
