It has been successfully demonstrated can be widely used in nano-photonics applications owing to their flexible wavefront manipulation in a limited physical profile.However,how to improve the efficiency for the transm...It has been successfully demonstrated can be widely used in nano-photonics applications owing to their flexible wavefront manipulation in a limited physical profile.However,how to improve the efficiency for the transmission light is still a challenge.We experimentally demonstrate that the sine-shaped metallic meanderline fabricated by focus ion beam technology converts circularly polarized(CP)light to its opposite handedness and sends them into different propagation directions depending on the polarization states in near-infrared and visible frequency regions.The beam splitting behavior is well characterized by a simple geometry relation,following the rule concluded from other works on the wavefront manipulation of metasurface with phase discontinuity.Importantly,the meanderline is demonstrated to be more efficient in realizing the same functions due to the suppressed high order diffractions resulted from the absence of interruption in phase profile.The theoretical efficiency reaches 67%.Particularly,potential improvements are feasible by changing or optimizing shape of the meanderline,offering high flexibility in applications for optical imaging,communications and other phase-relative techniques.Additionally,since the continuous phase provided by the meanderline can improve the sampling efficiency of the phase function,it is helpful in realizing high quality hologram.展开更多
The two-dimensional electron gas at SrTiO3-based heterointerfaces has received a great deal of attention in recent years owing to their potential for the exploration of emergent physics and the next generation of elec...The two-dimensional electron gas at SrTiO3-based heterointerfaces has received a great deal of attention in recent years owing to their potential for the exploration of emergent physics and the next generation of electronics. One of the most fascinating aspects in this system is that the light, as a powerful external perturbation, can modify its transport properties. Recent studies have reported that SrTiO3-based heterointerfaces exhibit the persistent photoconductivity and can be tuned by the surface and interface engineering. These researches not only reveal the intrinsic physical mechanisms in the photoresponsive process, but also highlight the ability to be used as a tool for novel all-oxide optical devices. This review mainly contraposes the studies of photoresponse at SrTiO3-based heterointerfaces.展开更多
In the previous study of longitudinal spin Seebeck effect(LSSE), the thermal gradient was often generated by inserting the sample between the cool bath and the hot bath. For practical use, this method is too cumbers...In the previous study of longitudinal spin Seebeck effect(LSSE), the thermal gradient was often generated by inserting the sample between the cool bath and the hot bath. For practical use, this method is too cumbersome to be easily integrated into modern electrical circuits. Since the laser can be easily focused into a small region, it will be more convenient and friendly to the integrated circuit. In this paper, we systematically investigate the LSSE and spin Hall magnetoresistance(SMR) of the Pt/Y_3 Fe_5 O_(12) heterostructure under focused laser-heating. We find that the extremely large voltage of inverse spin Hall effect(VISHE) can be obtained by reducing the diameter of laser or increasing the number of light spots.Meanwhile, even under the illumination of the ultraviolet light which will excite the electron from the valence band to the conduction band in yttrium iron garnet(YIG), the magnitude of SMR is nearly constant. It indicates that the spin transport behavior of the adjacent Pt is independent of the electron configuration of YIG. The laser-heating method to generate LSSE will be very promising for modern integrated electronic circuits and will promote the application of spin caloritronics in practice.展开更多
The La0.85Sr0.015MnO3/Fe heterostructure deposited on Si (100) substrate was prepared by the magnetron sputtering. The laser-induced voltage in the sample and the difference in the voltage signals between the curre...The La0.85Sr0.015MnO3/Fe heterostructure deposited on Si (100) substrate was prepared by the magnetron sputtering. The laser-induced voltage in the sample and the difference in the voltage signals between the current-in-plane geometry and current-perpendicular-to-plane geometry at 77 K were investigated. This difference can be attributed to the different transport mechanisms.展开更多
The transport properties in the La2/3(Ca(1-x)Sr(x))1/3MnO3 (x=0.1/3, 2/3) films prepared using the RF magnetron sputtering method were investigated, The effect of the Ca, Sr double-doping at the A position in ...The transport properties in the La2/3(Ca(1-x)Sr(x))1/3MnO3 (x=0.1/3, 2/3) films prepared using the RF magnetron sputtering method were investigated, The effect of the Ca, Sr double-doping at the A position in the La(2/3)A(1/3)MnO3 on the structure of the targets and transport of the films has been studied. With the increase of x, the structures of the targets transform from the rhombohedral phase to the cubic phase; the metal-insulator phase transition temperature (Tp) of the films increases; and the corresponding peak resistivity decreases. All the phenomena can be qualitatively explained by the lattice effect.展开更多
The phase-field model for cell migration is used to study the effect of elasticity mismatch on the migration dynamics of multiple cells in a confluent monolayer, where one tagged cell is embedded by a number of normal...The phase-field model for cell migration is used to study the effect of elasticity mismatch on the migration dynamics of multiple cells in a confluent monolayer, where one tagged cell is embedded by a number of normal cells and both types of cells are supposed to have the same properties except elasticity. Our results show that a larger elasticity mismatch leads to a larger difference in shape change between the tagged cell and the normal cells. We find that the bursts of velocity always fall behind the peak of the perimeter, and the shape change of the tagged cell results in the accelerated motion of the tagged cell in the whole process. Moreover, the variation of the averaging cell perimeter ratio ˉLtag/ˉLnormalwith the increase of the elasticity ratio γtag/γnormal for different active velocities |a| is analyzed. We find thatˉLtag/ˉLnormaldecreases with the increase of γtag/γnormal, following a simple power law function. Our results highlight the important role played by the cell elasticity mismatch in cell deformation and migration.展开更多
By analyzing the process of soil salt accumulation in irrigation area, and discussing the change of irrigation and drainage methods for drought transformed into water, the control scheme of soil secondary salinization...By analyzing the process of soil salt accumulation in irrigation area, and discussing the change of irrigation and drainage methods for drought transformed into water, the control scheme of soil secondary salinization in Wujiazi Irrigation Area was analyzed concretely, and the experience was summarized. After in-depth discussion, the importance of irrigation and drainage methods in the prevention and control of soil secondary salinization in irrigation areas was analyzed.展开更多
Carbon hollow microspheres as microwave absorption materials(MAMs)are of great significance in the research focuses owing to their lightweight,good impedance matching,and modifiable dielectric proper-ties.However,it i...Carbon hollow microspheres as microwave absorption materials(MAMs)are of great significance in the research focuses owing to their lightweight,good impedance matching,and modifiable dielectric proper-ties.However,it is still a huge challenge to distinguish the contribution of dielectric attenuation between carbon intrinsic feature and hollow structure due to the lack of appropriate model materials.Then,the inadequate analysis of effective dielectric attenuation resulted in the construction of carbon hollow mi-crospheres semiempirical and often lacked precise modification of microstructure.Herein,a series of car-bon hollow microspheres with controllable graphitization and thickness of shell derived from phenolic resin coated on polystyrene microspheres that fully decomposed were synthesized,which is free of the impact of template residue.The carbon fragments ground from hollow microspheres exhibit the same broadband response as hollow microspheres,with effective bandwidth(RL<-10 dB)of 7.6 GHz,while their electromagnetic wave loss mechanisms are distinct.The high dielectric loss of carbon fragments with the same intrinsic characteristics as carbon hollow microspheres is mainly caused by dipole po-larization relaxation and enhancement of electrical conductivity ascribed to overlapping between carbon sheets.For the hollow structure,in addition to dipole polarization relaxation attributed to carbon intrin-sic feature,the effective dielectric loss is also comprised of the interfacial polarization in advantage due to the effective heterogeneous interface between air and carbon shell.This work provides a simplified model to clarify the effect of carbon intrinsic feature and microstructure on the dielectric loss of carbon hollow microspheres.展开更多
基金supported by National Natural Science Funds (61601367, 61601375)the Fundamental Research Funds for the Central Universities (3102016 ZY028)
文摘It has been successfully demonstrated can be widely used in nano-photonics applications owing to their flexible wavefront manipulation in a limited physical profile.However,how to improve the efficiency for the transmission light is still a challenge.We experimentally demonstrate that the sine-shaped metallic meanderline fabricated by focus ion beam technology converts circularly polarized(CP)light to its opposite handedness and sends them into different propagation directions depending on the polarization states in near-infrared and visible frequency regions.The beam splitting behavior is well characterized by a simple geometry relation,following the rule concluded from other works on the wavefront manipulation of metasurface with phase discontinuity.Importantly,the meanderline is demonstrated to be more efficient in realizing the same functions due to the suppressed high order diffractions resulted from the absence of interruption in phase profile.The theoretical efficiency reaches 67%.Particularly,potential improvements are feasible by changing or optimizing shape of the meanderline,offering high flexibility in applications for optical imaging,communications and other phase-relative techniques.Additionally,since the continuous phase provided by the meanderline can improve the sampling efficiency of the phase function,it is helpful in realizing high quality hologram.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51572222 and 11604265)Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University,China(Grant No.CX201836)
文摘The two-dimensional electron gas at SrTiO3-based heterointerfaces has received a great deal of attention in recent years owing to their potential for the exploration of emergent physics and the next generation of electronics. One of the most fascinating aspects in this system is that the light, as a powerful external perturbation, can modify its transport properties. Recent studies have reported that SrTiO3-based heterointerfaces exhibit the persistent photoconductivity and can be tuned by the surface and interface engineering. These researches not only reveal the intrinsic physical mechanisms in the photoresponsive process, but also highlight the ability to be used as a tool for novel all-oxide optical devices. This review mainly contraposes the studies of photoresponse at SrTiO3-based heterointerfaces.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11604265,51471134,51572222,and 11704386)the Fundamental Research Funds for the Central Universities,China(Grant Nos.3102018zy044 and 3102017jc01001)
文摘In the previous study of longitudinal spin Seebeck effect(LSSE), the thermal gradient was often generated by inserting the sample between the cool bath and the hot bath. For practical use, this method is too cumbersome to be easily integrated into modern electrical circuits. Since the laser can be easily focused into a small region, it will be more convenient and friendly to the integrated circuit. In this paper, we systematically investigate the LSSE and spin Hall magnetoresistance(SMR) of the Pt/Y_3 Fe_5 O_(12) heterostructure under focused laser-heating. We find that the extremely large voltage of inverse spin Hall effect(VISHE) can be obtained by reducing the diameter of laser or increasing the number of light spots.Meanwhile, even under the illumination of the ultraviolet light which will excite the electron from the valence band to the conduction band in yttrium iron garnet(YIG), the magnitude of SMR is nearly constant. It indicates that the spin transport behavior of the adjacent Pt is independent of the electron configuration of YIG. The laser-heating method to generate LSSE will be very promising for modern integrated electronic circuits and will promote the application of spin caloritronics in practice.
基金The authors are thankful to the National Natural Science Foundation of China (Grant No. 50331040)NWPU Doctor Foundation for supporting this work.
文摘The La0.85Sr0.015MnO3/Fe heterostructure deposited on Si (100) substrate was prepared by the magnetron sputtering. The laser-induced voltage in the sample and the difference in the voltage signals between the current-in-plane geometry and current-perpendicular-to-plane geometry at 77 K were investigated. This difference can be attributed to the different transport mechanisms.
基金supported by the National Natural Science Foundation of China(No.50331040)the National Natural Science Foundation of Shaanxi Provice(No.2001C21)NWPU Doctor Foundation(cx200323)
文摘The transport properties in the La2/3(Ca(1-x)Sr(x))1/3MnO3 (x=0.1/3, 2/3) films prepared using the RF magnetron sputtering method were investigated, The effect of the Ca, Sr double-doping at the A position in the La(2/3)A(1/3)MnO3 on the structure of the targets and transport of the films has been studied. With the increase of x, the structures of the targets transform from the rhombohedral phase to the cubic phase; the metal-insulator phase transition temperature (Tp) of the films increases; and the corresponding peak resistivity decreases. All the phenomena can be qualitatively explained by the lattice effect.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51701160 and U1732129)the Fundamental Research Funds for the Central Universities,China(Grant No.3102018zy046)
文摘The phase-field model for cell migration is used to study the effect of elasticity mismatch on the migration dynamics of multiple cells in a confluent monolayer, where one tagged cell is embedded by a number of normal cells and both types of cells are supposed to have the same properties except elasticity. Our results show that a larger elasticity mismatch leads to a larger difference in shape change between the tagged cell and the normal cells. We find that the bursts of velocity always fall behind the peak of the perimeter, and the shape change of the tagged cell results in the accelerated motion of the tagged cell in the whole process. Moreover, the variation of the averaging cell perimeter ratio ˉLtag/ˉLnormalwith the increase of the elasticity ratio γtag/γnormal for different active velocities |a| is analyzed. We find thatˉLtag/ˉLnormaldecreases with the increase of γtag/γnormal, following a simple power law function. Our results highlight the important role played by the cell elasticity mismatch in cell deformation and migration.
文摘By analyzing the process of soil salt accumulation in irrigation area, and discussing the change of irrigation and drainage methods for drought transformed into water, the control scheme of soil secondary salinization in Wujiazi Irrigation Area was analyzed concretely, and the experience was summarized. After in-depth discussion, the importance of irrigation and drainage methods in the prevention and control of soil secondary salinization in irrigation areas was analyzed.
基金National Natural Science Foundation of China(grant No.51802278)Natural Science Foundation of Hebei Province(grant Nos.B2021203012,E2022203082)Department of Education of Hebei Province(grant No.QN2021140).
文摘Carbon hollow microspheres as microwave absorption materials(MAMs)are of great significance in the research focuses owing to their lightweight,good impedance matching,and modifiable dielectric proper-ties.However,it is still a huge challenge to distinguish the contribution of dielectric attenuation between carbon intrinsic feature and hollow structure due to the lack of appropriate model materials.Then,the inadequate analysis of effective dielectric attenuation resulted in the construction of carbon hollow mi-crospheres semiempirical and often lacked precise modification of microstructure.Herein,a series of car-bon hollow microspheres with controllable graphitization and thickness of shell derived from phenolic resin coated on polystyrene microspheres that fully decomposed were synthesized,which is free of the impact of template residue.The carbon fragments ground from hollow microspheres exhibit the same broadband response as hollow microspheres,with effective bandwidth(RL<-10 dB)of 7.6 GHz,while their electromagnetic wave loss mechanisms are distinct.The high dielectric loss of carbon fragments with the same intrinsic characteristics as carbon hollow microspheres is mainly caused by dipole po-larization relaxation and enhancement of electrical conductivity ascribed to overlapping between carbon sheets.For the hollow structure,in addition to dipole polarization relaxation attributed to carbon intrin-sic feature,the effective dielectric loss is also comprised of the interfacial polarization in advantage due to the effective heterogeneous interface between air and carbon shell.This work provides a simplified model to clarify the effect of carbon intrinsic feature and microstructure on the dielectric loss of carbon hollow microspheres.