We present a design of an acoustic levitator consisting of three pairs of opposite transducer arrays.Three orthogonal standing waves create a large number of acoustic traps at which the particles are levitated in mid-...We present a design of an acoustic levitator consisting of three pairs of opposite transducer arrays.Three orthogonal standing waves create a large number of acoustic traps at which the particles are levitated in mid-air.By changing the phase difference of transducer arrays,three-dimensional manipulation of particles is successfully realized.Moreover,the relationship between the translation of particles and the phase difference is experimentally investigated,and the result is in agreement with the theoretical calculation.This design can expand the application of acoustic levitation in many fields,such as biomedicine,ultrasonic motor and new materials processing.展开更多
Composite structure materials were potential sensing elements for magnetic sensors due to Giant magnetoimpedance(GMI) effect. Two kinds of composite wires with different magnetic/non-magnetic structures were fabricate...Composite structure materials were potential sensing elements for magnetic sensors due to Giant magnetoimpedance(GMI) effect. Two kinds of composite wires with different magnetic/non-magnetic structures were fabricated by using electroless deposition methods and the magnetoimpedance properties were investigated. The maximum GMI ratio of 114% was acquired at 60 MHz in the composite wires with a ferromagnetic core, whereas, 116% of maximum GMI ratio was found in the composite wires with a conductive core at low frequency of 600 k Hz. These results exhibit that the GMI ratio reaches the maximum when magnetoresistance ratio ?R/R and magnetoinductance ratio ?X/X make the comparative contributions to the total magnetoimpedance(MI). The obvious GMI effect obtained in the composite wires with conductive core frequency may provide a candidate for applications in magnetic sensors, especially at low frequencies.展开更多
Attosecond transient absorption(ATA)has been developed as an all-optical technique for probing electron dynamics in matter.Here we present a scheme that can modify the laserinduced state and the corresponding ATA spec...Attosecond transient absorption(ATA)has been developed as an all-optical technique for probing electron dynamics in matter.Here we present a scheme that can modify the laserinduced state and the corresponding ATA spectrum via excitation by a pair of XUV attosecond pulses and by a time-delayed mid-infrared(MIR)laser probe.Different from the scheme of the electronic excitation by a single XUV attosecond pulse,the application of a pair of XUV pulses provides extra degrees of freedom,such as the time delay and the intensity ratio between two XUV pulses,which make it possible to adjust the pump process,resulting in the modification of the ATA spectrum.We show that by varying the time delay between the two XUV pulses,the population of the dark state and the ATA spectrum of the laser-induced state have periodic modulations.We also demonstrate that the peak of the ATA spectrum of the laser-induced state appears at a fixed time delay between the XUV pair and the MIR laser when the intensity ratio is large,and it changes with the time delay when the intensity ratio is small,which can be related to either one of two peaks in the population of the dark state.展开更多
基金Supported by the Beijing College Students’Innovation and Entrepreneurship Training Program under Grant No BJ17040
文摘We present a design of an acoustic levitator consisting of three pairs of opposite transducer arrays.Three orthogonal standing waves create a large number of acoustic traps at which the particles are levitated in mid-air.By changing the phase difference of transducer arrays,three-dimensional manipulation of particles is successfully realized.Moreover,the relationship between the translation of particles and the phase difference is experimentally investigated,and the result is in agreement with the theoretical calculation.This design can expand the application of acoustic levitation in many fields,such as biomedicine,ultrasonic motor and new materials processing.
基金Shanghai Automotive Science and Technology Development Foundation (SAISTDF/12-06)East China Normal University Program (78210142, 78210183)Shanghai Ocean University Program (A-2600-10-0054, B-5406-12-0012)
文摘Composite structure materials were potential sensing elements for magnetic sensors due to Giant magnetoimpedance(GMI) effect. Two kinds of composite wires with different magnetic/non-magnetic structures were fabricated by using electroless deposition methods and the magnetoimpedance properties were investigated. The maximum GMI ratio of 114% was acquired at 60 MHz in the composite wires with a ferromagnetic core, whereas, 116% of maximum GMI ratio was found in the composite wires with a conductive core at low frequency of 600 k Hz. These results exhibit that the GMI ratio reaches the maximum when magnetoresistance ratio ?R/R and magnetoinductance ratio ?X/X make the comparative contributions to the total magnetoimpedance(MI). The obvious GMI effect obtained in the composite wires with conductive core frequency may provide a candidate for applications in magnetic sensors, especially at low frequencies.
基金supported by the National Natural Science Foundation of China(Grant Nos.91950102 and 11834004)the Natural Science Foundation of Jiangsu Province(Grant No.BK20220925)the Funding of Nanjing University of Science and Technology(NJUST)(Grant No.TSXK2022D005)
文摘Attosecond transient absorption(ATA)has been developed as an all-optical technique for probing electron dynamics in matter.Here we present a scheme that can modify the laserinduced state and the corresponding ATA spectrum via excitation by a pair of XUV attosecond pulses and by a time-delayed mid-infrared(MIR)laser probe.Different from the scheme of the electronic excitation by a single XUV attosecond pulse,the application of a pair of XUV pulses provides extra degrees of freedom,such as the time delay and the intensity ratio between two XUV pulses,which make it possible to adjust the pump process,resulting in the modification of the ATA spectrum.We show that by varying the time delay between the two XUV pulses,the population of the dark state and the ATA spectrum of the laser-induced state have periodic modulations.We also demonstrate that the peak of the ATA spectrum of the laser-induced state appears at a fixed time delay between the XUV pair and the MIR laser when the intensity ratio is large,and it changes with the time delay when the intensity ratio is small,which can be related to either one of two peaks in the population of the dark state.