【作者】 邓茂林； 朱位秋；

【Author】 DENG Mao-line ZHU Wei-qiu WU Yu ZHU Wei-qiu (School of Aeronautics and Astronautics,Zhejiang University,Hangzhou 310027,China)

【机构】 浙江大学航空航天学院应用力学所；

【摘要】 尽管DNA分子的研究主要是在生物学领域内进行的,但是目前也有力学理论用于对它的动力学行为研究。从力学的角度来看,DNA是一个复杂的多自由度非线性振动系统,一些力学模型可用来理解或研究DNA分子的生物学行为。在本文中, Hamilton系统理论框架内的非线性随机动力学理论与方法被用来研究DNA分子的热变性。首先,介绍了一种基于DNA分子二级结构的Peyrard-Bishop-Dauxois力学模型。通过观察DNA模型的动力学行为来理解DNA的热变性;其次,用所提出的理论和方法得到DNA模型动力学行为的统计量,包括平均能量的分布和首次穿越时间。最后,通过与来自Monte Carlo数字模拟实验得到的结果相比较,证实了所得理论结果的正确性。由于能量在DNA热变性中起着重要的作用,因此,本文分析能量的理论方法将有助于理解和预测DNA分子的动力学行为。更多还原

【Abstract】 Although the behavior of DNA is an essential object of study for biologists,its dynamics were also investigated by using the mechanical theory.From the physical point of view,DNA is usually regarded as a complex nonlinear vibrational system with many thousands degrees of freedom.Many corresponding physical models are built for using to investigate or understand the biological behavior of DNA.In this paper,the DNA thermal denaturation is theoretically analyzed by using the nonlinear stochastic dynamics theory for quasi Hamiltonian systems.Firstly,a kind of second hierarchy model for DNA structure,i.e.,the model of Peyrard-Bishop-Dauxois,is introduced.And then the dynamical behavior of the DNA model is briefly observed for understanding the thermal denaturation of DNA.Secondly,the proposed theoretical method is used to obtain the statistical properties for the behavior of the DNA model including stationary distribution of average energy and the mean first passage time. Finally,the validity of some obtained theoretical solutions are verified by comparing with those results obtained from the Monte Carlo simulation.For the important role of energy in the process of DNA thermal denaturation,the applied theory and those corresponding theoretical results are promising for predicting and understanding the dynamical behavior of the DNA.更多还原