We present a theoretic model to calculate skin depths and eddy-current power losses for a magnetic position sensor. Eddy-current, arised from the operation of an alternating-current excitation, induces secondary curre...We present a theoretic model to calculate skin depths and eddy-current power losses for a magnetic position sensor. Eddy-current, arised from the operation of an alternating-current excitation, induces secondary currents and fields between magnetic material and magnetic position sensor. In this paper, a magnetic position sensor system is simplified to be an outer-winding coil along the axial direction of a low carbon steel bar. The analytical model is derived from basic field and circuit theory considering a linear approximation for a nonlinear permeability. Thus the skin depths and eddy-current power losses from the model in eddy-current modeling techniques at various frequencies of an excited current source can be calculated. The proposed configuration is capable of predicting the skin depths and eddy-current power losses for a magnetic position sensor and has a consistence with experiments.展开更多
Various new conductive materials with exceptional properties are utilized for the preparation of electronic devices.Achieving ultra-high conductivity is crucial to attain excellent electrical performance.However,there...Various new conductive materials with exceptional properties are utilized for the preparation of electronic devices.Achieving ultra-high conductivity is crucial to attain excellent electrical performance.However,there is a lack of systematic research on the impact of conductor material thickness on device performance.Here,we investigate the effect of conductor thickness on power transmission and radiation in radio-frequency(RF)and microwave electronics based on MXene nanosheets material transmission lines and antennas.The MXene transmission line with thickness above the skin depth exhibits a good transmission coefficient of approximately-3 dB,and the realized gain of MXene antennas exceeds 2 dBi.Additionally,the signal transmission strength of MXene antenna with thickness above the skin depth is higher than 5-μm MXene antenna approximately 5.5 dB.Transmission lines and antennas made from MXene materials with thickness above the skin depth exhibit stable and reliable performance,which has significant implications for obtaining high-performance RF and microwave electronics based on new conductive materials.展开更多
Previously we introduced a concise dose-response model for the heat-induced withdrawal reflex caused by millimeter wave radiation. The model predicts the occurrence of withdrawal reflex from the given spatial temperat...Previously we introduced a concise dose-response model for the heat-induced withdrawal reflex caused by millimeter wave radiation. The model predicts the occurrence of withdrawal reflex from the given spatial temperature profile. It was formulated on the assumption that the density of nociceptors in skin is uniform, independent of the depth. The model has only two parameters: the activation temperature of heat-sensitive nociceptors and the critical threshold on the activated volume for triggering withdrawal reflex. In this study, we consider the case of depth-dependent nociceptor density in skin. We use a general parametric form with a scaling parameter in the depth direction to represent the nociceptor density. We analyze system behaviors for four density types of this form. Based on the theoretical results, we develop a methodology for 1) identifying from test data the density form of nociceptors distribution, 2) finding from test data the scaling parameter in the density form, and 3) determining from test data the activation temperature of nociceptors.展开更多
文摘We present a theoretic model to calculate skin depths and eddy-current power losses for a magnetic position sensor. Eddy-current, arised from the operation of an alternating-current excitation, induces secondary currents and fields between magnetic material and magnetic position sensor. In this paper, a magnetic position sensor system is simplified to be an outer-winding coil along the axial direction of a low carbon steel bar. The analytical model is derived from basic field and circuit theory considering a linear approximation for a nonlinear permeability. Thus the skin depths and eddy-current power losses from the model in eddy-current modeling techniques at various frequencies of an excited current source can be calculated. The proposed configuration is capable of predicting the skin depths and eddy-current power losses for a magnetic position sensor and has a consistence with experiments.
基金supported by the National Natural Science Foundation of China(No.51672204).
文摘Various new conductive materials with exceptional properties are utilized for the preparation of electronic devices.Achieving ultra-high conductivity is crucial to attain excellent electrical performance.However,there is a lack of systematic research on the impact of conductor material thickness on device performance.Here,we investigate the effect of conductor thickness on power transmission and radiation in radio-frequency(RF)and microwave electronics based on MXene nanosheets material transmission lines and antennas.The MXene transmission line with thickness above the skin depth exhibits a good transmission coefficient of approximately-3 dB,and the realized gain of MXene antennas exceeds 2 dBi.Additionally,the signal transmission strength of MXene antenna with thickness above the skin depth is higher than 5-μm MXene antenna approximately 5.5 dB.Transmission lines and antennas made from MXene materials with thickness above the skin depth exhibit stable and reliable performance,which has significant implications for obtaining high-performance RF and microwave electronics based on new conductive materials.
文摘Previously we introduced a concise dose-response model for the heat-induced withdrawal reflex caused by millimeter wave radiation. The model predicts the occurrence of withdrawal reflex from the given spatial temperature profile. It was formulated on the assumption that the density of nociceptors in skin is uniform, independent of the depth. The model has only two parameters: the activation temperature of heat-sensitive nociceptors and the critical threshold on the activated volume for triggering withdrawal reflex. In this study, we consider the case of depth-dependent nociceptor density in skin. We use a general parametric form with a scaling parameter in the depth direction to represent the nociceptor density. We analyze system behaviors for four density types of this form. Based on the theoretical results, we develop a methodology for 1) identifying from test data the density form of nociceptors distribution, 2) finding from test data the scaling parameter in the density form, and 3) determining from test data the activation temperature of nociceptors.
