The spontaneous emission property ofΛ-type three-level atom driven by the bichromatic field in the anisotropic double-band photonic crystal is calculated by n-times iteration method.The influence of different paramet...The spontaneous emission property ofΛ-type three-level atom driven by the bichromatic field in the anisotropic double-band photonic crystal is calculated by n-times iteration method.The influence of different parameters on atomic spontaneous emission is studied,and the phenomena of atomic spontaneous emission are explained in the dressed state representation.It is found that the spontaneous emission spectra of the atom driven by the bichromatic field presents a multi-peak comb structure.The position of the emission peak is determined by the initial state of the atom,and the interval between the neighboring emission peaks is the detuningδof the bichromatic field.When the ratio between Rabi frequency intensity and the detuningδof the bichromatic field remains unchanged,the intensity of each emitted peak remains invariant.The spontaneously emitted peak can be annihilated in the band gap and enhanced near the band edge in the anisotropic photonic crystals.Meanwhile,we also observe the fluorescence quenching phenomenon in the spontaneous emission spectra.The research in this paper provides the theoretical guidance for the control of atomic spontaneous emission.展开更多
Strain sensors with good stability are vital to the development of wearable healthcare monitoring systems.However,the design of strain sensor with both duration stability and environmental stability is still a challen...Strain sensors with good stability are vital to the development of wearable healthcare monitoring systems.However,the design of strain sensor with both duration stability and environmental stability is still a challenge.In this work,we propose an ultra-stable and washable strain sensor by embedding a coupled composite film of carbon nanotube(CNT)and Ti_(3)C_(2)T_(x) MXene into polydimethylsiloxane(PDMS)matrix.The composite strain sensor with embedded microstructure and uneven surface makes it conformal to skin,while the CNT/MXene sensing layer exhibits a resistance sensitive to strain.This sensor shows reliable responses at different frequencies and with long-term cycling durability(over 1,000 cycles).Meanwhile,the CNT/MXene/PDMS composite strain sensor provides the advantages of superior anti-interference to temperature change and water washing.The results demonstrate less than 10%resistance changes as the temperature rises from-20 to 80℃or after sonication in water for 120 min,respectively.The composite sensor is applied to monitor human joint motions,such as bending of finger,wrist and elbow.Moreover,the simultaneous monitoring of the electrocardiogram(ECG)signal and joint movement while riding a sports bicycle is demonstrated,enabling the great potential of the as-fabricated sensor in real-time human healthcare monitoring.展开更多
基金Project supported by the Natural Science Foundation of Jilin Province of China(Grant No.20220101031JC)。
文摘The spontaneous emission property ofΛ-type three-level atom driven by the bichromatic field in the anisotropic double-band photonic crystal is calculated by n-times iteration method.The influence of different parameters on atomic spontaneous emission is studied,and the phenomena of atomic spontaneous emission are explained in the dressed state representation.It is found that the spontaneous emission spectra of the atom driven by the bichromatic field presents a multi-peak comb structure.The position of the emission peak is determined by the initial state of the atom,and the interval between the neighboring emission peaks is the detuningδof the bichromatic field.When the ratio between Rabi frequency intensity and the detuningδof the bichromatic field remains unchanged,the intensity of each emitted peak remains invariant.The spontaneously emitted peak can be annihilated in the band gap and enhanced near the band edge in the anisotropic photonic crystals.Meanwhile,we also observe the fluorescence quenching phenomenon in the spontaneous emission spectra.The research in this paper provides the theoretical guidance for the control of atomic spontaneous emission.
基金supported by the National Natural Science Foundation of China(No.61804185)the National Key Research and Development Program of China(No.2017YFA0206600)+3 种基金the Natural Science Foundation of Hunan Province(No.2019JJ50804)the Science and Technology Innovation Program of Hunan Province(No.2020RC4004)the Special Funding for the Construction of Innovative Provinces in Hunan Province(No.2020GK2024)Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing(No.GXKL06200208).
文摘Strain sensors with good stability are vital to the development of wearable healthcare monitoring systems.However,the design of strain sensor with both duration stability and environmental stability is still a challenge.In this work,we propose an ultra-stable and washable strain sensor by embedding a coupled composite film of carbon nanotube(CNT)and Ti_(3)C_(2)T_(x) MXene into polydimethylsiloxane(PDMS)matrix.The composite strain sensor with embedded microstructure and uneven surface makes it conformal to skin,while the CNT/MXene sensing layer exhibits a resistance sensitive to strain.This sensor shows reliable responses at different frequencies and with long-term cycling durability(over 1,000 cycles).Meanwhile,the CNT/MXene/PDMS composite strain sensor provides the advantages of superior anti-interference to temperature change and water washing.The results demonstrate less than 10%resistance changes as the temperature rises from-20 to 80℃or after sonication in water for 120 min,respectively.The composite sensor is applied to monitor human joint motions,such as bending of finger,wrist and elbow.Moreover,the simultaneous monitoring of the electrocardiogram(ECG)signal and joint movement while riding a sports bicycle is demonstrated,enabling the great potential of the as-fabricated sensor in real-time human healthcare monitoring.
