The stochastic resonance phenomenon in a harmonic oscillator with fluctuating intrinsic frequency by asymmetric dichotomous noise is investigated in this paper. By using the random average method and Shapiro- Loginov ...The stochastic resonance phenomenon in a harmonic oscillator with fluctuating intrinsic frequency by asymmetric dichotomous noise is investigated in this paper. By using the random average method and Shapiro- Loginov formula, the exact solution of the average output amplitude gain （OAG） is obtained. Numerical results show that OAG depends non-monotonically on the noise characteristics： intensity, correlation time and asymmetry. The maximum OAG can be achieved by tuning the noise asymmetry and or the noise correlation time.展开更多
Fe nanochains with diameters of 50-150 nm and average length of about 1μm were synthesized by titrating NaBH_(4)solution into FeCl_(2) aqueous solution(i.e.,reduction of Fe(II)ions).The microstructures and magnetic p...Fe nanochains with diameters of 50-150 nm and average length of about 1μm were synthesized by titrating NaBH_(4)solution into FeCl_(2) aqueous solution(i.e.,reduction of Fe(II)ions).The microstructures and magnetic properties were studied by X-ray diffraction(XRD),transmission electron microscope(TEM),and vibrating sample magnetometer(VSM).The results reveal that the nanochains have a core-shell structure with a-Fe as the core and amorphous iron oxide as the shell.The Fe coreshell nanochains show the characteristic of soft magnetic materials,achieving the highest magnetization of200.74 mA-m^(2)·g^(-1).The influences of the titrating rate of NaBH_(4)aqueous solution on the morphology of the Fe nanochains were also studied.It reveals that low titrating rate is beneficial for synthesizing Fe nanochains with uniform morphology.The reduction experiments indicate that these Fe nanochains are of high reducibility.About 90%Cr(VI)ions are successfully removed after 10 min reaction of 100 mg Fe nanochains in the 100 ml K_(2)Cr_(2)O_(7) solution(100 mg·L^(-1))and more than 99%after 30 min.展开更多
文摘The stochastic resonance phenomenon in a harmonic oscillator with fluctuating intrinsic frequency by asymmetric dichotomous noise is investigated in this paper. By using the random average method and Shapiro- Loginov formula, the exact solution of the average output amplitude gain （OAG） is obtained. Numerical results show that OAG depends non-monotonically on the noise characteristics： intensity, correlation time and asymmetry. The maximum OAG can be achieved by tuning the noise asymmetry and or the noise correlation time.
基金financially supported by the National Natural Science Foundation of China(No.51201004)the Research Fund for the Doctoral Program of Higher Education of China(No.20121102120002)the Fundamental Research Funds for the Central Universities(No.YWF-13-ZY-045)。
文摘Fe nanochains with diameters of 50-150 nm and average length of about 1μm were synthesized by titrating NaBH_(4)solution into FeCl_(2) aqueous solution(i.e.,reduction of Fe(II)ions).The microstructures and magnetic properties were studied by X-ray diffraction(XRD),transmission electron microscope(TEM),and vibrating sample magnetometer(VSM).The results reveal that the nanochains have a core-shell structure with a-Fe as the core and amorphous iron oxide as the shell.The Fe coreshell nanochains show the characteristic of soft magnetic materials,achieving the highest magnetization of200.74 mA-m^(2)·g^(-1).The influences of the titrating rate of NaBH_(4)aqueous solution on the morphology of the Fe nanochains were also studied.It reveals that low titrating rate is beneficial for synthesizing Fe nanochains with uniform morphology.The reduction experiments indicate that these Fe nanochains are of high reducibility.About 90%Cr(VI)ions are successfully removed after 10 min reaction of 100 mg Fe nanochains in the 100 ml K_(2)Cr_(2)O_(7) solution(100 mg·L^(-1))and more than 99%after 30 min.
