This paper investigates the phenomenon of stochastic resonance in a single-mode laser driven by time-modulated correlated coloured noise sources. The power spectrum and signal-to-noise ratio R of the laser intensity a...This paper investigates the phenomenon of stochastic resonance in a single-mode laser driven by time-modulated correlated coloured noise sources. The power spectrum and signal-to-noise ratio R of the laser intensity are calculated by the linear approximation. The effects caused by noise self-correlation time τ1, τ2 and cross-correlated time τ3 for stochastic resonance are analysed in two ways： τ1, τ2 and τ3 are taken to be the independent variables and the parameters respectively. The effects of the gain coefficient F and loss coefficient K on the stochastic resonance are also discussed. It is found that besides the presence of the standard form and the broad sense of stochastic resonance, the number of extrema in the curve of R versus K is reduced with the increase of the gain coefficient Г.展开更多
In this paper, the effect of every parameter （including p, q, r, λ, τ） on the mean first-passage time （MFPT） is investigated in an asymmetric bistable system driven by colour-correlated noise. The expression of ...In this paper, the effect of every parameter （including p, q, r, λ, τ） on the mean first-passage time （MFPT） is investigated in an asymmetric bistable system driven by colour-correlated noise. The expression of MFPT has been obtained by applying the steepest-descent approximation. Numerical results show that （1） the intensity of multiplicative noise p and the intensity of additive noise q play different roles in the MFPT of the system, （2） suppression appears on the curve of the MFPT with small λ （e.g. λ 〈 0.5） but there is a peak on the curve of the MFPT when λ is big （e.g. λ 〉 0.5）, and （3） with different values of r （e.g. r = 0.1, 0.5, 1.5）, the effort of τ on the MFPT is diverse.展开更多
为建立一种快速高效的猪肺炎支原体(Mycoplasma hyopneumoniae,Mhp)检测方法,根据NCBI公布的Mhp保守序列设计4对特异性引物,依据4对引物的荧光定量PCR检测结果及拟合曲线进行相关性分析,筛选出最佳引物(SX4),建立了Mhp SYBR Green Ⅰ实...为建立一种快速高效的猪肺炎支原体(Mycoplasma hyopneumoniae,Mhp)检测方法,根据NCBI公布的Mhp保守序列设计4对特异性引物,依据4对引物的荧光定量PCR检测结果及拟合曲线进行相关性分析,筛选出最佳引物(SX4),建立了Mhp SYBR Green Ⅰ实时荧光定量检测方法。该方法可特异性检测Mhp,对猪圆环病毒2型、猪细小病毒、猪伪狂犬病病毒、副猪嗜血杆菌4型及链球菌2型等病原均无特异性扩增;最佳引物SX4检测的灵敏度可达4.9×10^(1) copies/μL,组内和组间变异系数均小于2%。该方法可稳定检测出工艺生产抗原和市售疫苗中的Mhp菌量。试验表明,本研究成功建立了Mhp SYBR Green Ⅰ实时荧光定量检测方法,其特异性强、灵敏度高、重复性好,可用于Mhp疫苗抗原生产和临床疫苗中的Mhp菌量检测。展开更多
The aging process of pure copper precursors and copper-zinc binary precursorswere studied by XRD, TG-DTG and TPR techniques. The catalytic activity and stability of CuO/ZnOwere tested using fixed-bed flow reactor, and...The aging process of pure copper precursors and copper-zinc binary precursorswere studied by XRD, TG-DTG and TPR techniques. The catalytic activity and stability of CuO/ZnOwere tested using fixed-bed flow reactor, and the physical properties of the catalysts and Cuspecies were characterized with N_2 adsorption and N_2O passivation method, respectively. For theCu-Zn binary system prepared at the precipitating condition of pH=8.0 and temperature=80℃, theinitial phase was a mixture of copper nitrate hydroxide Cu_2(NO_3)(OH)_3, georgeite and hydrozinciteZn_5(CO_3)_2(OH)_6. By increasing the duration of its aging time, the phase of Cu_2(NO_3)(OH)_2first transited to georgeite, and then interdiffused into Zn_5(CO_3)_2(OH)_6 and resulted in two newphases: rosasite (Cu,Zn)_2CO_3(OH)_2 and au-richalcite (Zn,Cu)_5(CO_3)_2(OH)_6. The former phasewas much easier to be formed than the latter one, while the latter phase was more responsible forthe activity of methanol synthesis than the former one. It is found that the composition andstructure of the precursors altered obviously after the colour transition point. The experimentalresults showed that methanol synthesis is a structure-sensitive catalytic reaction.展开更多
文摘This paper investigates the phenomenon of stochastic resonance in a single-mode laser driven by time-modulated correlated coloured noise sources. The power spectrum and signal-to-noise ratio R of the laser intensity are calculated by the linear approximation. The effects caused by noise self-correlation time τ1, τ2 and cross-correlated time τ3 for stochastic resonance are analysed in two ways： τ1, τ2 and τ3 are taken to be the independent variables and the parameters respectively. The effects of the gain coefficient F and loss coefficient K on the stochastic resonance are also discussed. It is found that besides the presence of the standard form and the broad sense of stochastic resonance, the number of extrema in the curve of R versus K is reduced with the increase of the gain coefficient Г.
基金Project supported by the National Natural Science Foundation of China （Grants Nos 10472091, 10332030 and 10502042） and the Graduate Starting Seed Fund of Northwestern Polytechnical University （Grant No Z200655）.
文摘In this paper, the effect of every parameter （including p, q, r, λ, τ） on the mean first-passage time （MFPT） is investigated in an asymmetric bistable system driven by colour-correlated noise. The expression of MFPT has been obtained by applying the steepest-descent approximation. Numerical results show that （1） the intensity of multiplicative noise p and the intensity of additive noise q play different roles in the MFPT of the system, （2） suppression appears on the curve of the MFPT with small λ （e.g. λ 〈 0.5） but there is a peak on the curve of the MFPT when λ is big （e.g. λ 〉 0.5）, and （3） with different values of r （e.g. r = 0.1, 0.5, 1.5）, the effort of τ on the MFPT is diverse.
文摘为建立一种快速高效的猪肺炎支原体(Mycoplasma hyopneumoniae,Mhp)检测方法,根据NCBI公布的Mhp保守序列设计4对特异性引物,依据4对引物的荧光定量PCR检测结果及拟合曲线进行相关性分析,筛选出最佳引物(SX4),建立了Mhp SYBR Green Ⅰ实时荧光定量检测方法。该方法可特异性检测Mhp,对猪圆环病毒2型、猪细小病毒、猪伪狂犬病病毒、副猪嗜血杆菌4型及链球菌2型等病原均无特异性扩增;最佳引物SX4检测的灵敏度可达4.9×10^(1) copies/μL,组内和组间变异系数均小于2%。该方法可稳定检测出工艺生产抗原和市售疫苗中的Mhp菌量。试验表明,本研究成功建立了Mhp SYBR Green Ⅰ实时荧光定量检测方法,其特异性强、灵敏度高、重复性好,可用于Mhp疫苗抗原生产和临床疫苗中的Mhp菌量检测。
文摘The aging process of pure copper precursors and copper-zinc binary precursorswere studied by XRD, TG-DTG and TPR techniques. The catalytic activity and stability of CuO/ZnOwere tested using fixed-bed flow reactor, and the physical properties of the catalysts and Cuspecies were characterized with N_2 adsorption and N_2O passivation method, respectively. For theCu-Zn binary system prepared at the precipitating condition of pH=8.0 and temperature=80℃, theinitial phase was a mixture of copper nitrate hydroxide Cu_2(NO_3)(OH)_3, georgeite and hydrozinciteZn_5(CO_3)_2(OH)_6. By increasing the duration of its aging time, the phase of Cu_2(NO_3)(OH)_2first transited to georgeite, and then interdiffused into Zn_5(CO_3)_2(OH)_6 and resulted in two newphases: rosasite (Cu,Zn)_2CO_3(OH)_2 and au-richalcite (Zn,Cu)_5(CO_3)_2(OH)_6. The former phasewas much easier to be formed than the latter one, while the latter phase was more responsible forthe activity of methanol synthesis than the former one. It is found that the composition andstructure of the precursors altered obviously after the colour transition point. The experimentalresults showed that methanol synthesis is a structure-sensitive catalytic reaction.
