A magnetoelectrically permeable interface crack between two semi-infinite magnetoelectroelastic planes under the action of a heat flow and remote magnetoelectromechanical loadings is considered, where the assumption o...A magnetoelectrically permeable interface crack between two semi-infinite magnetoelectroelastic planes under the action of a heat flow and remote magnetoelectromechanical loadings is considered, where the assumption of frictionless contact between two dissimilar half-planes is adopted. Not only the solutions of the interface crack problem are presented in an explicit form, but also the general condition for the transition from a perfect thermal contact of two mag- netoelectroelastic bodies to their separation is given.展开更多
Magnetoelectric equivalent circuit analytical method is presented for laminate composites of magneto- strictive Terfenol-D (TbxDy1-xFe2) and piezoelectric Pb(Zr1-xTix)O3 (PZT) operated in longitudinal mag- netized and...Magnetoelectric equivalent circuit analytical method is presented for laminate composites of magneto- strictive Terfenol-D (TbxDy1-xFe2) and piezoelectric Pb(Zr1-xTix)O3 (PZT) operated in longitudinal mag- netized and transverse polarized (or L-T), and transverse magnetized and transverse polarized (or T-T) modes. Magnetoelectric (ME) couplings both at low-frequency and resonance-frequency have been studied, and our analysis predicts that (i) the ME voltage coefficients of both L-T and T-T modes in- crease with increasing the thickness of the piezoelectric phase whereas magnetostrictive phase thickness keeps constant, and then tend to saturation when the thickness ratio of piezoelectric phase to magnetic phases is >3; (ii) there are the optimum thickness ratios that maximize magnetoelectric (ME) voltage coefficients for the two modes, which are dependent on elastic compliances ratio of piezoelec- tric phase and magnetostrictive phase; and (iii) the ME voltage coefficients are dramatically increased by a factor of ~Qm, when operated at resonance frequency. A series of Terfenol-D/PZT laminates were fabricated, and the results were compared with the theoretical ones. Experiments confirmed that equivalent circuit method is a useful tool for optimum designs of ME laminates.展开更多
The effects of linear electromagnetic stirring (EMS) on the solidification structure of billet were investigated by experiments, and the electromagnetic field and the flow field during the stirring process were analyz...The effects of linear electromagnetic stirring (EMS) on the solidification structure of billet were investigated by experiments, and the electromagnetic field and the flow field during the stirring process were analyzed by numerical simulation. The results show that the billet of almost 100% equiaxed grains can be obtained by applying linear EMS at the maximum intensity of 1414 A·Hz1/2, while the maximum electromagnetic force and the maximum velocity in the molten steel are 6386 N·m-3 and 0.22 m·s-1 respectively. It is shown that in the pulsating electromagnetic force which is perpendicular to the movement of the molten steel is an important factor of increasing the equiaxed zone ration in the solidification structure, which further prevents the appearance of white band and internal defects.展开更多
Single-phase multiferroic BiFeO3 and Bi（0.9）（La/Nd）（0.1）FeO3（doped with rare earth ions La-（3＋） and Nd-（3＋）） films grown on（111）-Pt/Ti/SiO2/Si substrate were prepared via sol-gel method and a subsequen...Single-phase multiferroic BiFeO3 and Bi（0.9）（La/Nd）（0.1）FeO3（doped with rare earth ions La-（3＋） and Nd-（3＋）） films grown on（111）-Pt/Ti/SiO2/Si substrate were prepared via sol-gel method and a subsequent rapid thermal process. The phase composition, microstructure, ferroelectric, dielectric, ferromagnetic properties were investigated, and meanwhile, the in-plane magnetoelectric（ME） coupling effects of the films were reported and studied for the first time in this work. Structural characterization by X-ray diffraction and scanning electron microscopy showed that both BiFeO3 and Bi（0.9）（La/Nd）（0.1）FeO3 exhabited a rhombohedral structure with（111） preferred orientation. The results of the physical properties indicated that the introduction of rare earth ions improved significantly the polarization, magnetization and dielectric properties than the undoped BiFeO3 crystals, and it enhanced effectively the in-plane ME coupling（the ME coupling coefficient αE increased from 0.13 in the pure BiFeO3 to 0.21 in Bi（0.9）La（0.1）FeO3 and 0.34 V/（Oe·cm） in Bi（0.9）Nd（0.1）FeO3）. The mechanism of these phenomena was investigated systematically.展开更多
In this perspective paper, we discuss possible ways to control magnetism using electric-field. Special focus is given to interface/surface magnetoelectric effects, which will become important when the thickness of mag...In this perspective paper, we discuss possible ways to control magnetism using electric-field. Special focus is given to interface/surface magnetoelectric effects, which will become important when the thickness of magnetic films drops to nanoscale. We show that significantly different mechanisms may lead to interface/surface magnetoelectric effects, providing great flexibility to apply such effects. As a result, we propose several protype devices utilizing these novel magnetoelectric effects, and strongly advocate experimental endeavors to realize such devices.展开更多
This paper presents a new device integrating a nonlinear vibration absorber with a levitation magnetoelectric energy harvester for whole-spacecraft systems. This device effectively reduces vibration and has a stronger...This paper presents a new device integrating a nonlinear vibration absorber with a levitation magnetoelectric energy harvester for whole-spacecraft systems. This device effectively reduces vibration and has a stronger energy harvesting capability than the existing systems. It harvests energy from a wide frequency range and has a high output voltage. The harvested energy is determined by magnetic field strength, excitation frequency, and resistive load. The change in the magnetic field strength has the least impact on the output voltage. The vibration reduction effects and harvested energy of the system are analyzed with an approximate analytical method that combines the harmonic balance approach and the pseudo-arclength continuation algorithm. The results of the Runge-Kutta method are nearly consistent with those of the approximate analytical method. Moreover, the effects of the excitation frequency, resistive load, and parameters of the nonlinear energy sink on the system vibration response and energy harvesting are analyzed.展开更多
A systematic study has been carried out on the effects of interface bonding on the strain mediated magnetoelectric （ME） coupling in ferromagnetic-ferroelectric bilayers. The technique used involves the static electr...A systematic study has been carried out on the effects of interface bonding on the strain mediated magnetoelectric （ME） coupling in ferromagnetic-ferroelectric bilayers. The technique used involves the static electric field E tuning of the ferromagnetic resonance （FMR） in yttrium iron garnet （YIG） and lead zirconate titanate （PZT） or lead magnesium niobate-lead titanate （PMN-PT）. A broad band detection technique has been developed for studies over 1 40 GHz in three types of bilayers： epoxy bonded, eutectic bonded and YIG films directly grown onto piezoelectric substrate by electrophoretic deposition. The strength A of the converse ME effect （CME） defined as the ratio of the frequency shift 8f in FMR in E, A = 8f/E, varies over the range 0.8 to 4.3 MHz.cm/kV, and is the highest for eutectic bonded samples and is the weakest for epoxy bonded bilayers. The results presented here as of importance for dual electric and magnetic field tunable ferrite ferroelectric microwave resonators and filters.展开更多
BACKGROUND The prominent symptoms of chronic pelvic pain syndrome(CPPS)are urogenital pain,lower urinary tract symptoms,psychological problems,and sexual dysfunction.Traditional pharmacological treatments have poor ef...BACKGROUND The prominent symptoms of chronic pelvic pain syndrome(CPPS)are urogenital pain,lower urinary tract symptoms,psychological problems,and sexual dysfunction.Traditional pharmacological treatments have poor efficacy and more untoward reaction and complications.Magnetic vibration magnetoelectric therapy is a non-invasive form of physiotherapy.Nevertheless,its effectiveness in improving urinary discomfort and relieving pain in patients requires further exploration.AIM To investigate the clinical efficacy of the magnetic vibration magnetoelectric therapy instrument in the treatment of chronic prostatitis(CP)/CPPS.METHODS Seventy patients with CP/CPPS were collected from the outpatient clinic and ward of the Department of Male Medicine,Jiangsu Province Hospital of Traditional Chinese Medicine,and were treated with magnetic vibration magnetoelectric therapy once a day for a period of 14 d.National Institutes of healthchronic prostatitis symptom index(NIH-CPSI),international index of erectile function 5(IIEF-5),premature ejaculation diagnostic tool(PEDT),generalized anxiety disorder(GAD),patient health questionnaire,the pain catastrophizing scale(PCS)and traditional Chinese medicine syndrome(TCMS)scores were performed before and after treatment.RESULTS The total effective rate of treatment was 58.5%,and the total NIH-CPSI score,pain symptoms,voiding symptoms,quality of life,IIEF-5,PEDT,GAD,PCS and TCMS scores all decreased significantly(P<0.05).CONCLUSION Magnetic vibration magnetotherapy is effective in improving urinary discomfort,relieving pain,improving quality of life,improving sexual dysfunction and relieving negative emotions such as anxiety in patients with CP/CPPS.展开更多
Flexible electronics/spintronics attracts researchers’attention for their application potential abroad in wearable devices,healthcare,and other areas.Those devices’performance(speed,energy consumption)is highly depe...Flexible electronics/spintronics attracts researchers’attention for their application potential abroad in wearable devices,healthcare,and other areas.Those devices’performance(speed,energy consumption)is highly dependent on manipulating information bits(spin-orientation in flexible spintronics).In this work,we established an organic photovoltaic(OPV)/ZnO/Pt/Co/Pt heterostructure on flexible PET substrates with perpendicular magnetic anisotropy(PMA).Under sunlight illumination,the photoelectrons generated from the OPV layer transfer into the PMA heterostructure,then they reduce the PMA strength by enhancing the interfacial Rashba field accordingly.The coercive field(Hc)reduces from 800 Oe to 500 Oe at its maximum,and the magnetization can be switched up and down reversibly.The stability of sunlight control of magnetization reversal under various bending conditions is also tested for flexible spintronic applications.Lastly,the voltage output of sunlight-driven PMA is achieved in our prototype device,exhibiting an excellent angular dependence and opening a door towards solar-driven flexible spintronics with much lower energy consumption.展开更多
Manipulating strain mode and degree that can be applied to epitaxial complex oxide thin films have been a cornerstone of strain engineering.In recent years,lift-off and transfer technology of the epitaxial oxide thin ...Manipulating strain mode and degree that can be applied to epitaxial complex oxide thin films have been a cornerstone of strain engineering.In recent years,lift-off and transfer technology of the epitaxial oxide thin films have been developed that enabled the integration of heterostructures without the limitation of material types and crystal orientations.Moreover,twisted integration would provide a more interesting strategy in artificial magnetoelectric heterostructures.A specific twist angle between the ferroelectric and ferromagnetic oxide layers corresponds to the distinct strain regulation modes in the magnetoelectric coupling process,which could provide some insight in to the physical phenomena.In this work,the La_(0.67)Sr_(0.33)MnO_(3)(001)/0.7Pb(Mg_(1/3)Nb_(2/3))O_(3)-0.3PbTiO_(3)(011)(LSMO/PMN-PT)heterostructures with 45.and 0.twist angles were assembled via water-etching and transfer process.The transferred LSMO films exhibit a fourfold magnetic anisotropy with easy axis along LSMO<110>.A coexistence of uniaxial and fourfold magnetic anisotropy with LSMO[110]easy axis is observed for the 45°Sample by applying a 7.2 kV cm^(−1)electrical field,significantly different from a uniaxial anisotropy with LSMO[100]easy axis for the 0°Sample.The fitting of the ferromagnetic resonance field reveals that the strain coupling generated by the 45°twist angle causes different lattice distortion of LSMO,thereby enhancing both the fourfold and uniaxial anisotropy.This work confirms the twisting degrees of freedom for magnetoelectric coupling and opens opportunities for fabricating artificial magnetoelectric heterostructures.展开更多
本文提出了一种基于磁电耦合原理和MEMS加工工艺的矢量水声传感器。该矢量水声传感器的MEMS敏感检测单元包括磁电耦合材料、八悬臂梁-中心质量块MEMS元件和永磁铁。采用电荷放大信号处理电路处理敏感检测单元产生的信号。通过对磁电耦...本文提出了一种基于磁电耦合原理和MEMS加工工艺的矢量水声传感器。该矢量水声传感器的MEMS敏感检测单元包括磁电耦合材料、八悬臂梁-中心质量块MEMS元件和永磁铁。采用电荷放大信号处理电路处理敏感检测单元产生的信号。通过对磁电耦合材料、MEMS元件和信号处理电路进行设计,使矢量水声传感器在工作时具有很高的灵敏度。通过声学灌封完成矢量水声传感器的制备,并对矢量水声传感器的性能进行了测试,测试结果表明:该矢量水声传感器的接收灵敏度在1 000 Hz时达到-180 dB(0 dB re 1 V/μPa)。展开更多
Multiferroic materials with two or more types of ferroic orders have attracted a great deal of atten- tion in the last decade for their magnetoelectric coupling, and new ideas and concepts have been ex- plored recentl...Multiferroic materials with two or more types of ferroic orders have attracted a great deal of atten- tion in the last decade for their magnetoelectric coupling, and new ideas and concepts have been ex- plored recently to develop multiferroic materials at nano-scale. Motivated by theoretical analysis, we synthesized single-phase BiFeO3 （BFO） nanofibers, Pb（Zr0.52Ti0.48）O3-CoFe2O4 （PZT-CFO） and Pb（Zro.52Tio.ns）Oa-NiFe204 （PZT-NFO） composite nanofibers, and CoFe2O4-Pb（Zr0.52Ti0.48）O3 （CFO-PZT） core-shell nanofibers using sol-gel based electrospinning. These nanofibers typically have diameters in the range of a few hundred nanometers and grain size in the range of 10s nanome- ters, and exhibits both ferroelectric and ferromagnetic properties. Piezoresponse force microscopy （PFM） based techniques have also been developed to examine the magnetoelectrie coupling of the nanofibers, which is estimated to be two orders of magnitude higher than that of thin films, con- sistent with our theoretical analysis. These nanofibers are promising for a variety of multiferroic applications.展开更多
Two-dimensional （2D） equations for multiferroic （MF） laminated plates with imperfect interfaces are established in this paper. The interface between two adjacent sublayers, which are not perfectly bonded together,...Two-dimensional （2D） equations for multiferroic （MF） laminated plates with imperfect interfaces are established in this paper. The interface between two adjacent sublayers, which are not perfectly bonded together, is modeled as a general spring-type layer. The mechanical displacements, and the electric and magnetic potentials of the two adjacent layers are assumed to be discontinuous at the interface. As an example, the influences of imperfect interfaces on the magnetoelectric （ME） coupling effects in an MF sandwich plate are investigated with the established 2D governing equations. Numerical results show that the imperfect interfaces have a significant impact on the ME coupling effects in MF laminated structures.展开更多
Magnetic tunnel junctions with ferroelectric barriers, often referred to as multiferroic tunnel junc- tions, have been proposed recently to display new functionalities and new device concepts. One of the notable predi...Magnetic tunnel junctions with ferroelectric barriers, often referred to as multiferroic tunnel junc- tions, have been proposed recently to display new functionalities and new device concepts. One of the notable predictions is that the combination of two charge polarizing states and the parallel and antiparallel magnetic states could make it a four resistance state device. We have recently studied the ferroelectric tunneling using a scanning probe technique and multiferroic tunnel junctions using ferromagnetic Lao.7Cao.3MnO3 and Lao.TSro.3MnO3 as the electrodes and ferroelectric （Ba, Sr）TiO3 as the barrier in trilayer planner junctions. We show that very thin （Ba, Sr）TiO3 films can sustain ferroelectricity up till room temperature. The multiferroic tunnel junctions show four resistance states as predicted and can operate at room temperatures.展开更多
It is theoretically considered the propagation (first evidence) of new dispersive shear-horizontal (SH) acoustic waves in the piezoelectromagnetic (magnetoelectroelastic) composite plates. The studied two-phase compos...It is theoretically considered the propagation (first evidence) of new dispersive shear-horizontal (SH) acoustic waves in the piezoelectromagnetic (magnetoelectroelastic) composite plates. The studied two-phase composites (BaTiO3-CoFe2O4 and PZT-5H-Terfenol-D) possess the piezoelectric phase (BaTiO3, PZT-5H) and the piezomagnetic phase (CoFe2O4, Terfenol-D). The mechanical, electrical, and magnetic boundary conditions applied to both the upper and lower free surfaces of the plate are as follows: the mechanically free, electrically closed, and magnetically closed surfaces. As a result, the fundamental modes of two new dispersive SH-waves recently discovered in book [Zakharenko, A.A. (2012) ISBN: 978-3-659-30943-4] were numerically calculated. It was found that for large values of normalized plate thickness kd (k and d are the wavenumber and plate half-thickness, respectively) the velocities of both the new dispersive SH-waves can approach the nondispersive SH-SAW velocity of the piezoelectric exchange surface Melkumyan (PEESM) wave. It was also discussed that for small values of kd, the experimental study of the new dispersive SH-waves can be preferable in comparison with the nondispersive PEESM wave. The obtained results can be constructive for creation of various technical devices based on (non)dispersive SH-waves and two-phase smart materials. The new dispersive SH-waves propagating in the plates can be also employed for nondestructive testing and evaluation. Also, it is obvious that the plates can be used in technical devices instead of the corresponding bulk samples for further miniaturization.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 10772123 and 11072160)the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT0971)the Natural Science Fund for Outstanding Younger of Hebei Province (A2009001624), China
文摘A magnetoelectrically permeable interface crack between two semi-infinite magnetoelectroelastic planes under the action of a heat flow and remote magnetoelectromechanical loadings is considered, where the assumption of frictionless contact between two dissimilar half-planes is adopted. Not only the solutions of the interface crack problem are presented in an explicit form, but also the general condition for the transition from a perfect thermal contact of two mag- netoelectroelastic bodies to their separation is given.
基金Supported by the Office of Naval Research in USA
文摘Magnetoelectric equivalent circuit analytical method is presented for laminate composites of magneto- strictive Terfenol-D (TbxDy1-xFe2) and piezoelectric Pb(Zr1-xTix)O3 (PZT) operated in longitudinal mag- netized and transverse polarized (or L-T), and transverse magnetized and transverse polarized (or T-T) modes. Magnetoelectric (ME) couplings both at low-frequency and resonance-frequency have been studied, and our analysis predicts that (i) the ME voltage coefficients of both L-T and T-T modes in- crease with increasing the thickness of the piezoelectric phase whereas magnetostrictive phase thickness keeps constant, and then tend to saturation when the thickness ratio of piezoelectric phase to magnetic phases is >3; (ii) there are the optimum thickness ratios that maximize magnetoelectric (ME) voltage coefficients for the two modes, which are dependent on elastic compliances ratio of piezoelec- tric phase and magnetostrictive phase; and (iii) the ME voltage coefficients are dramatically increased by a factor of ~Qm, when operated at resonance frequency. A series of Terfenol-D/PZT laminates were fabricated, and the results were compared with the theoretical ones. Experiments confirmed that equivalent circuit method is a useful tool for optimum designs of ME laminates.
文摘The effects of linear electromagnetic stirring (EMS) on the solidification structure of billet were investigated by experiments, and the electromagnetic field and the flow field during the stirring process were analyzed by numerical simulation. The results show that the billet of almost 100% equiaxed grains can be obtained by applying linear EMS at the maximum intensity of 1414 A·Hz1/2, while the maximum electromagnetic force and the maximum velocity in the molten steel are 6386 N·m-3 and 0.22 m·s-1 respectively. It is shown that in the pulsating electromagnetic force which is perpendicular to the movement of the molten steel is an important factor of increasing the equiaxed zone ration in the solidification structure, which further prevents the appearance of white band and internal defects.
基金Project supported by National Natural Science Foundation of China(51462003)Science Research Fund of Guizhou Province,China(2015-4006,2014-001,2014-7612)+1 种基金the Introduced Talents Funds of Guizhou University(2014-30)Master’s Innovation Funds of Guizhou University(2016065)
文摘Single-phase multiferroic BiFeO3 and Bi（0.9）（La/Nd）（0.1）FeO3（doped with rare earth ions La-（3＋） and Nd-（3＋）） films grown on（111）-Pt/Ti/SiO2/Si substrate were prepared via sol-gel method and a subsequent rapid thermal process. The phase composition, microstructure, ferroelectric, dielectric, ferromagnetic properties were investigated, and meanwhile, the in-plane magnetoelectric（ME） coupling effects of the films were reported and studied for the first time in this work. Structural characterization by X-ray diffraction and scanning electron microscopy showed that both BiFeO3 and Bi（0.9）（La/Nd）（0.1）FeO3 exhabited a rhombohedral structure with（111） preferred orientation. The results of the physical properties indicated that the introduction of rare earth ions improved significantly the polarization, magnetization and dielectric properties than the undoped BiFeO3 crystals, and it enhanced effectively the in-plane ME coupling（the ME coupling coefficient αE increased from 0.13 in the pure BiFeO3 to 0.21 in Bi（0.9）La（0.1）FeO3 and 0.34 V/（Oe·cm） in Bi（0.9）Nd（0.1）FeO3）. The mechanism of these phenomena was investigated systematically.
文摘In this perspective paper, we discuss possible ways to control magnetism using electric-field. Special focus is given to interface/surface magnetoelectric effects, which will become important when the thickness of magnetic films drops to nanoscale. We show that significantly different mechanisms may lead to interface/surface magnetoelectric effects, providing great flexibility to apply such effects. As a result, we propose several protype devices utilizing these novel magnetoelectric effects, and strongly advocate experimental endeavors to realize such devices.
基金the National Natural Science Foundation of China (Project No. 11772205)the Training Project of Liaoning Provincial Higher Education Institutions in Domestic and Overseas (Project No. 2018LNGXGJWPY-YB008)the Scientific Research Fund of Liaoning Provincial Education Department (Project No. L201703).
文摘This paper presents a new device integrating a nonlinear vibration absorber with a levitation magnetoelectric energy harvester for whole-spacecraft systems. This device effectively reduces vibration and has a stronger energy harvesting capability than the existing systems. It harvests energy from a wide frequency range and has a high output voltage. The harvested energy is determined by magnetic field strength, excitation frequency, and resistive load. The change in the magnetic field strength has the least impact on the output voltage. The vibration reduction effects and harvested energy of the system are analyzed with an approximate analytical method that combines the harmonic balance approach and the pseudo-arclength continuation algorithm. The results of the Runge-Kutta method are nearly consistent with those of the approximate analytical method. Moreover, the effects of the excitation frequency, resistive load, and parameters of the nonlinear energy sink on the system vibration response and energy harvesting are analyzed.
文摘A systematic study has been carried out on the effects of interface bonding on the strain mediated magnetoelectric （ME） coupling in ferromagnetic-ferroelectric bilayers. The technique used involves the static electric field E tuning of the ferromagnetic resonance （FMR） in yttrium iron garnet （YIG） and lead zirconate titanate （PZT） or lead magnesium niobate-lead titanate （PMN-PT）. A broad band detection technique has been developed for studies over 1 40 GHz in three types of bilayers： epoxy bonded, eutectic bonded and YIG films directly grown onto piezoelectric substrate by electrophoretic deposition. The strength A of the converse ME effect （CME） defined as the ratio of the frequency shift 8f in FMR in E, A = 8f/E, varies over the range 0.8 to 4.3 MHz.cm/kV, and is the highest for eutectic bonded samples and is the weakest for epoxy bonded bilayers. The results presented here as of importance for dual electric and magnetic field tunable ferrite ferroelectric microwave resonators and filters.
文摘BACKGROUND The prominent symptoms of chronic pelvic pain syndrome(CPPS)are urogenital pain,lower urinary tract symptoms,psychological problems,and sexual dysfunction.Traditional pharmacological treatments have poor efficacy and more untoward reaction and complications.Magnetic vibration magnetoelectric therapy is a non-invasive form of physiotherapy.Nevertheless,its effectiveness in improving urinary discomfort and relieving pain in patients requires further exploration.AIM To investigate the clinical efficacy of the magnetic vibration magnetoelectric therapy instrument in the treatment of chronic prostatitis(CP)/CPPS.METHODS Seventy patients with CP/CPPS were collected from the outpatient clinic and ward of the Department of Male Medicine,Jiangsu Province Hospital of Traditional Chinese Medicine,and were treated with magnetic vibration magnetoelectric therapy once a day for a period of 14 d.National Institutes of healthchronic prostatitis symptom index(NIH-CPSI),international index of erectile function 5(IIEF-5),premature ejaculation diagnostic tool(PEDT),generalized anxiety disorder(GAD),patient health questionnaire,the pain catastrophizing scale(PCS)and traditional Chinese medicine syndrome(TCMS)scores were performed before and after treatment.RESULTS The total effective rate of treatment was 58.5%,and the total NIH-CPSI score,pain symptoms,voiding symptoms,quality of life,IIEF-5,PEDT,GAD,PCS and TCMS scores all decreased significantly(P<0.05).CONCLUSION Magnetic vibration magnetotherapy is effective in improving urinary discomfort,relieving pain,improving quality of life,improving sexual dysfunction and relieving negative emotions such as anxiety in patients with CP/CPPS.
基金The work was supported by the National Key R&D Program of China(Grant No.2022YFB3203903)the National Natural Science Foundation of China(Grant Nos.52172126 and 62001366)the China Postdoctoral Science Foundation(Grant No.2022M722509).
文摘Flexible electronics/spintronics attracts researchers’attention for their application potential abroad in wearable devices,healthcare,and other areas.Those devices’performance(speed,energy consumption)is highly dependent on manipulating information bits(spin-orientation in flexible spintronics).In this work,we established an organic photovoltaic(OPV)/ZnO/Pt/Co/Pt heterostructure on flexible PET substrates with perpendicular magnetic anisotropy(PMA).Under sunlight illumination,the photoelectrons generated from the OPV layer transfer into the PMA heterostructure,then they reduce the PMA strength by enhancing the interfacial Rashba field accordingly.The coercive field(Hc)reduces from 800 Oe to 500 Oe at its maximum,and the magnetization can be switched up and down reversibly.The stability of sunlight control of magnetization reversal under various bending conditions is also tested for flexible spintronic applications.Lastly,the voltage output of sunlight-driven PMA is achieved in our prototype device,exhibiting an excellent angular dependence and opening a door towards solar-driven flexible spintronics with much lower energy consumption.
基金supported by the National Key Research and Development Program of China (Grant No. 2021YFB3201800)Natural Science Foundation of China (Grant Nos. U22A2019, 91964109, 52372123)+3 种基金State Key Laboratory for Mechanical Behavior of Materials (No. 20222405)Innovation Capability Support Program of Shaanxi (Grant No. 2021TD-12)National 111 Project of China (B14040)support from the Instrumental Analysis Center of Xi’an Jiaotong University
文摘Manipulating strain mode and degree that can be applied to epitaxial complex oxide thin films have been a cornerstone of strain engineering.In recent years,lift-off and transfer technology of the epitaxial oxide thin films have been developed that enabled the integration of heterostructures without the limitation of material types and crystal orientations.Moreover,twisted integration would provide a more interesting strategy in artificial magnetoelectric heterostructures.A specific twist angle between the ferroelectric and ferromagnetic oxide layers corresponds to the distinct strain regulation modes in the magnetoelectric coupling process,which could provide some insight in to the physical phenomena.In this work,the La_(0.67)Sr_(0.33)MnO_(3)(001)/0.7Pb(Mg_(1/3)Nb_(2/3))O_(3)-0.3PbTiO_(3)(011)(LSMO/PMN-PT)heterostructures with 45.and 0.twist angles were assembled via water-etching and transfer process.The transferred LSMO films exhibit a fourfold magnetic anisotropy with easy axis along LSMO<110>.A coexistence of uniaxial and fourfold magnetic anisotropy with LSMO[110]easy axis is observed for the 45°Sample by applying a 7.2 kV cm^(−1)electrical field,significantly different from a uniaxial anisotropy with LSMO[100]easy axis for the 0°Sample.The fitting of the ferromagnetic resonance field reveals that the strain coupling generated by the 45°twist angle causes different lattice distortion of LSMO,thereby enhancing both the fourfold and uniaxial anisotropy.This work confirms the twisting degrees of freedom for magnetoelectric coupling and opens opportunities for fabricating artificial magnetoelectric heterostructures.
文摘本文提出了一种基于磁电耦合原理和MEMS加工工艺的矢量水声传感器。该矢量水声传感器的MEMS敏感检测单元包括磁电耦合材料、八悬臂梁-中心质量块MEMS元件和永磁铁。采用电荷放大信号处理电路处理敏感检测单元产生的信号。通过对磁电耦合材料、MEMS元件和信号处理电路进行设计,使矢量水声传感器在工作时具有很高的灵敏度。通过声学灌封完成矢量水声传感器的制备,并对矢量水声传感器的性能进行了测试,测试结果表明:该矢量水声传感器的接收灵敏度在1 000 Hz时达到-180 dB(0 dB re 1 V/μPa)。
文摘Multiferroic materials with two or more types of ferroic orders have attracted a great deal of atten- tion in the last decade for their magnetoelectric coupling, and new ideas and concepts have been ex- plored recently to develop multiferroic materials at nano-scale. Motivated by theoretical analysis, we synthesized single-phase BiFeO3 （BFO） nanofibers, Pb（Zr0.52Ti0.48）O3-CoFe2O4 （PZT-CFO） and Pb（Zro.52Tio.ns）Oa-NiFe204 （PZT-NFO） composite nanofibers, and CoFe2O4-Pb（Zr0.52Ti0.48）O3 （CFO-PZT） core-shell nanofibers using sol-gel based electrospinning. These nanofibers typically have diameters in the range of a few hundred nanometers and grain size in the range of 10s nanome- ters, and exhibits both ferroelectric and ferromagnetic properties. Piezoresponse force microscopy （PFM） based techniques have also been developed to examine the magnetoelectrie coupling of the nanofibers, which is estimated to be two orders of magnitude higher than that of thin films, con- sistent with our theoretical analysis. These nanofibers are promising for a variety of multiferroic applications.
基金supported by the National Natural Science Foundation of China(11672265,11202182,11272281,11621062,and 11321202)the Fundamental Research Funds for the Central Universities(2016QNA4026 and 2016XZZX001-05)the open foundation of Zhejiang Provincial Top Key Discipline of Mechanical Engineering
文摘Two-dimensional （2D） equations for multiferroic （MF） laminated plates with imperfect interfaces are established in this paper. The interface between two adjacent sublayers, which are not perfectly bonded together, is modeled as a general spring-type layer. The mechanical displacements, and the electric and magnetic potentials of the two adjacent layers are assumed to be discontinuous at the interface. As an example, the influences of imperfect interfaces on the magnetoelectric （ME） coupling effects in an MF sandwich plate are investigated with the established 2D governing equations. Numerical results show that the imperfect interfaces have a significant impact on the ME coupling effects in MF laminated structures.
文摘Magnetic tunnel junctions with ferroelectric barriers, often referred to as multiferroic tunnel junc- tions, have been proposed recently to display new functionalities and new device concepts. One of the notable predictions is that the combination of two charge polarizing states and the parallel and antiparallel magnetic states could make it a four resistance state device. We have recently studied the ferroelectric tunneling using a scanning probe technique and multiferroic tunnel junctions using ferromagnetic Lao.7Cao.3MnO3 and Lao.TSro.3MnO3 as the electrodes and ferroelectric （Ba, Sr）TiO3 as the barrier in trilayer planner junctions. We show that very thin （Ba, Sr）TiO3 films can sustain ferroelectricity up till room temperature. The multiferroic tunnel junctions show four resistance states as predicted and can operate at room temperatures.
文摘It is theoretically considered the propagation (first evidence) of new dispersive shear-horizontal (SH) acoustic waves in the piezoelectromagnetic (magnetoelectroelastic) composite plates. The studied two-phase composites (BaTiO3-CoFe2O4 and PZT-5H-Terfenol-D) possess the piezoelectric phase (BaTiO3, PZT-5H) and the piezomagnetic phase (CoFe2O4, Terfenol-D). The mechanical, electrical, and magnetic boundary conditions applied to both the upper and lower free surfaces of the plate are as follows: the mechanically free, electrically closed, and magnetically closed surfaces. As a result, the fundamental modes of two new dispersive SH-waves recently discovered in book [Zakharenko, A.A. (2012) ISBN: 978-3-659-30943-4] were numerically calculated. It was found that for large values of normalized plate thickness kd (k and d are the wavenumber and plate half-thickness, respectively) the velocities of both the new dispersive SH-waves can approach the nondispersive SH-SAW velocity of the piezoelectric exchange surface Melkumyan (PEESM) wave. It was also discussed that for small values of kd, the experimental study of the new dispersive SH-waves can be preferable in comparison with the nondispersive PEESM wave. The obtained results can be constructive for creation of various technical devices based on (non)dispersive SH-waves and two-phase smart materials. The new dispersive SH-waves propagating in the plates can be also employed for nondestructive testing and evaluation. Also, it is obvious that the plates can be used in technical devices instead of the corresponding bulk samples for further miniaturization.
