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过去的几十年里,人们对噪声的积极作用进行了广泛研究,其中,化学反应体系中噪声的作用引起人们的很大兴趣.人们研究了单晶表面和纳米粒子表面催化体系中内、外噪声对反应振荡的影响,发现了随机共振和相干共振现象.然而,在以往的研究中,人们总是用高斯噪声代替实际噪声.但实验研究表明,神经元和自催化反应等生物化学反应体系中可能存在非高斯噪声.本文研究非高斯噪声对纳米尺度钯粒子表面一氧化碳催化氧化反应速率振荡的影响.我们首先给出了不存在外噪声时体系振荡随粒子尺度的变化情况,得到了内噪声相干共振行为.其次,我们重点研究了在非高斯噪声作用下体系反应速率的振荡.发现,随着非高斯噪声与高斯噪声的偏离q的增大,振荡规律性经历了由差变好到再变差的演化,而且在某个最佳的q值,振荡变得最有规律性.我们分别给出了振荡时间序列、功率谱和信噪比随q值的变化,充分反映了上述振荡的演化情况.这个结果表明,适当的外噪声能够增强纳米尺度钯粒子表面一氧化碳氧化反应随机速率振荡,而且存在某个最佳的外噪声,使速率振荡得到最大程度的增强.同时表明,非高斯噪声可能比高斯噪声起到更大的增强作用.最后,我们对非高斯噪声增强一氧化碳反应速率振荡这一现象的物理机制作了简单讨论.指出,由于非高斯噪声与高斯噪声的偏离q直接影响到有效噪声强度,并通过有效噪声强度对反应振荡产生影响,因此,与高斯噪声的偏离亦能对反应振荡产生如噪声强度诱导的随机共振一样的效果.
In the past few decades, the positive effects of noise have been extensively studied, among which the role of noise in the chemical reaction system has attracted great interest.People have studied the influence of the internal and external catalytic systems on the surface of single crystal and on the surface of nanoparticles However, in the previous studies, Gaussian noise was always used to replace the actual noise, but experimental studies showed that neurochemical and autocatalytic reactions such as biochemical reaction systems There may be non-Gaussian noise.This paper studies the effect of non-Gaussian noise on the rate oscillation of the catalytic oxidation of carbon monoxide on the surface of nanoscale palladium particles.Firstly, we give the change of the system oscillation with the particle size in the absence of external noise, We find that with the increase of the deviation q between the non-Gaussian noise and the Gaussian noise, the oscillation regularity has experienced a change from poor to good Variations evolve, and at some optimal value of q, the oscillation becomes the most regular. We show the oscillation times The results show that the appropriate external noise can enhance the random rate oscillation of the oxidation reaction of carbon monoxide on the surface of nanoscale palladium particles, and there is a certain maximum The best external noise can enhance the rate oscillation to a great extent, and at the same time it shows that the non-Gaussian noise may enhance the Gaussian noise more than the Gaussian noise.Finally, we analyze the physical mechanism that the non-Gaussian noise enhances the oscillation of carbon monoxide reaction rate A simple discussion is made.It is pointed out that since the deviation of non-Gaussian noise from Gaussian noise directly affects the effective noise intensity and the effective noise intensity affects the oscillation of the reaction, the deviation from the Gaussian noise can also affect the reaction oscillation such as noise Intensity-induced random resonance with the same effect.