为了提高纵向换能器发射响应和工作带宽,本文以压电单晶PMNT做为有源驱动材料,采用双晶堆不同尺寸反相激励的方式,同时激发出一阶、二阶纵振模态,从而提高纵向换能器发射响应,拓宽工作频带。通过四端网络法简化换能器的等效电路并计算...为了提高纵向换能器发射响应和工作带宽,本文以压电单晶PMNT做为有源驱动材料,采用双晶堆不同尺寸反相激励的方式,同时激发出一阶、二阶纵振模态,从而提高纵向换能器发射响应,拓宽工作频带。通过四端网络法简化换能器的等效电路并计算其发射性能,利用ANSYS软件对模型进行优化设计并制作了试验样机,最终测试数据显示在工作频带27~65 k Hz,最大发射电压响应值不低于150 d B,带内起伏小于12 d B。研究结果表明:理论计算、有限元仿真计算与实测结果基本吻合,利用双晶堆反相激励的方式可实现纵向换能器较宽频带工作。展开更多
To improve the performance of the traditional fault-tolerant permanent magnet(PM)motor,the design and optimal schemes of dual-winding fault-tolerant permanent magnet motor(DWFT-PMM)are proposed and investigated.In ord...To improve the performance of the traditional fault-tolerant permanent magnet(PM)motor,the design and optimal schemes of dual-winding fault-tolerant permanent magnet motor(DWFT-PMM)are proposed and investigated.In order to obtain small cogging torque ripple and inhibiting the short-circuit current,the air gap surface shape of the PM and the anti short-circuits reactance parameters are designed and optimized.According to the actual design requirements of an aircraft electrical actuation system,the parameters,finite element analysis and experimental verification of the DWFT-PMM after optimal design are presented.The research results show that the optimized DWFT-PMM owns the merits of strong magnetic isolation,physics isolation,inhibiting the short circuit current,small cogging torque ripple and high fault tolerance.展开更多
Ratiometric fluorescent detection of iron(Ⅲ)(Fe^(3+))offers inherent self-calibration and contactless analytic capabilities.However,realizing a dual-emission near-infrared(NIR)nanosensor with a low limit of detection...Ratiometric fluorescent detection of iron(Ⅲ)(Fe^(3+))offers inherent self-calibration and contactless analytic capabilities.However,realizing a dual-emission near-infrared(NIR)nanosensor with a low limit of detection(LOD)is rather challenging.In this work,we report the synthesis of water-dispersible erbium-hyperdoped silicon quantum dots(Si QDs:Er),which emit NIR light at the wavelengths of 810 and 1540 nm.A dual-emission NIR nanosensor based on water-dispersible Si QDs:Er enables ratiometric Fe^(3+)detection with a very low LOD(0.06μM).The effects of pH,recyclability,and the interplay between static and dynamic quenching mechanisms for Fe^(3+)detection have been systematically studied.In addition,we demonstrate that the nanosensor may be used to construct a sequential logic circuit with memory functions.展开更多
文摘为了提高纵向换能器发射响应和工作带宽,本文以压电单晶PMNT做为有源驱动材料,采用双晶堆不同尺寸反相激励的方式,同时激发出一阶、二阶纵振模态,从而提高纵向换能器发射响应,拓宽工作频带。通过四端网络法简化换能器的等效电路并计算其发射性能,利用ANSYS软件对模型进行优化设计并制作了试验样机,最终测试数据显示在工作频带27~65 k Hz,最大发射电压响应值不低于150 d B,带内起伏小于12 d B。研究结果表明:理论计算、有限元仿真计算与实测结果基本吻合,利用双晶堆反相激励的方式可实现纵向换能器较宽频带工作。
基金This work was supported by the National Natural Science Foundation of China(51807094)the Fundamental Research Funds for the Central Universities(No.30918011327)and the Scientific Research Foundation of Nanjing University of Science and Technology(AE89991/036).
文摘To improve the performance of the traditional fault-tolerant permanent magnet(PM)motor,the design and optimal schemes of dual-winding fault-tolerant permanent magnet motor(DWFT-PMM)are proposed and investigated.In order to obtain small cogging torque ripple and inhibiting the short-circuit current,the air gap surface shape of the PM and the anti short-circuits reactance parameters are designed and optimized.According to the actual design requirements of an aircraft electrical actuation system,the parameters,finite element analysis and experimental verification of the DWFT-PMM after optimal design are presented.The research results show that the optimized DWFT-PMM owns the merits of strong magnetic isolation,physics isolation,inhibiting the short circuit current,small cogging torque ripple and high fault tolerance.
基金supported by the National Natural Science Foundation of China(U22A2075,U20A20209)the Fundamental Research Funds for the Central Universities(226-2022-00200)the Qianjiang Distinguished Experts program of Hangzhou.
文摘Ratiometric fluorescent detection of iron(Ⅲ)(Fe^(3+))offers inherent self-calibration and contactless analytic capabilities.However,realizing a dual-emission near-infrared(NIR)nanosensor with a low limit of detection(LOD)is rather challenging.In this work,we report the synthesis of water-dispersible erbium-hyperdoped silicon quantum dots(Si QDs:Er),which emit NIR light at the wavelengths of 810 and 1540 nm.A dual-emission NIR nanosensor based on water-dispersible Si QDs:Er enables ratiometric Fe^(3+)detection with a very low LOD(0.06μM).The effects of pH,recyclability,and the interplay between static and dynamic quenching mechanisms for Fe^(3+)detection have been systematically studied.In addition,we demonstrate that the nanosensor may be used to construct a sequential logic circuit with memory functions.
