The us of stochastic resonance （SR） can effectively achieve the detection of weak signal in white noise and colored noise. However, SR in chaotic interference is seldom involved. In view of the requirements for the ...The us of stochastic resonance （SR） can effectively achieve the detection of weak signal in white noise and colored noise. However, SR in chaotic interference is seldom involved. In view of the requirements for the detection of weak signal in the actual project and the relationship between the signal, chaotic interference, and nonlinear system in the bistable system, a self-adaptive SR system based on genetic algorithm is designed in this paper. It regards the output signal-to-noise ratio （SNR） as a fitness function and the system parameters are jointly encoded to gain optimal bistable system parameters, then the input signal is processed in the SR system with the optimal system parameters. Experimental results show that the system can keep the best state of SR under the condition of low input SNR, which ensures the effective detection and process of weak signal in low input SNR.展开更多
We show that it is possible to localize a three-level cascade atom under the resonance condition when it passes through a standing-wave field. The localization peaks appear at the nodes of the standing-wave field, the...We show that it is possible to localize a three-level cascade atom under the resonance condition when it passes through a standing-wave field. The localization peaks appear at the nodes of the standing-wave field, the detecting probability is 50% in the subwavelength domain, and the peaks are narrower on the resonance than the off- resonance. The absorption is the same as that in the usual two-level medium at the nodes and is greatly suppressed outside the nodes due to the Autler-Townes splitting. This is in sharp contrast to the lambda scheme, in which the localization is impossible under the same resonance condition due to the depletion of population of the initial state by the probe field at the nodes and the electromagnetically induced transparency outside the nodes.展开更多
NBI作为最有效地等离子体加热手段之一,在世界各托卡马克装置上有广泛的应用。由于中性束注入装置的流强大,功率高的特点,为了保证设备的安全,须对其中的热承载部件进行实时温度监测。但是由于NBI装置的工作电压高达80 k V,且处于EAST...NBI作为最有效地等离子体加热手段之一,在世界各托卡马克装置上有广泛的应用。由于中性束注入装置的流强大,功率高的特点,为了保证设备的安全,须对其中的热承载部件进行实时温度监测。但是由于NBI装置的工作电压高达80 k V,且处于EAST复杂的电磁环境下,给温度的测量带来了很大的干扰。为了解决强电磁干扰对温度采集的影响,本文在分析干扰来源的基础上,提出了取样—存贮—判断—反馈的解决思路,利用Labview语言进行程序编写从而实现对干扰信号的滤波。实验结果表明,该方法能有效解决高压打火和等离子体破裂时对温度信号采集的影响,提高了实验数据采集的精确度。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61271011)
文摘The us of stochastic resonance （SR） can effectively achieve the detection of weak signal in white noise and colored noise. However, SR in chaotic interference is seldom involved. In view of the requirements for the detection of weak signal in the actual project and the relationship between the signal, chaotic interference, and nonlinear system in the bistable system, a self-adaptive SR system based on genetic algorithm is designed in this paper. It regards the output signal-to-noise ratio （SNR） as a fitness function and the system parameters are jointly encoded to gain optimal bistable system parameters, then the input signal is processed in the SR system with the optimal system parameters. Experimental results show that the system can keep the best state of SR under the condition of low input SNR, which ensures the effective detection and process of weak signal in low input SNR.
基金Supported by the National Natural Science Foundation of China under Grant No 10574052.
文摘We show that it is possible to localize a three-level cascade atom under the resonance condition when it passes through a standing-wave field. The localization peaks appear at the nodes of the standing-wave field, the detecting probability is 50% in the subwavelength domain, and the peaks are narrower on the resonance than the off- resonance. The absorption is the same as that in the usual two-level medium at the nodes and is greatly suppressed outside the nodes due to the Autler-Townes splitting. This is in sharp contrast to the lambda scheme, in which the localization is impossible under the same resonance condition due to the depletion of population of the initial state by the probe field at the nodes and the electromagnetically induced transparency outside the nodes.
文摘NBI作为最有效地等离子体加热手段之一,在世界各托卡马克装置上有广泛的应用。由于中性束注入装置的流强大,功率高的特点,为了保证设备的安全,须对其中的热承载部件进行实时温度监测。但是由于NBI装置的工作电压高达80 k V,且处于EAST复杂的电磁环境下,给温度的测量带来了很大的干扰。为了解决强电磁干扰对温度采集的影响,本文在分析干扰来源的基础上,提出了取样—存贮—判断—反馈的解决思路,利用Labview语言进行程序编写从而实现对干扰信号的滤波。实验结果表明,该方法能有效解决高压打火和等离子体破裂时对温度信号采集的影响,提高了实验数据采集的精确度。
