为进一步探究电穿孔理论机制,通过COMSOL建立单细胞电穿孔二维轴对称模型,该模型同时纳入表征微孔密度的电穿孔渐进方程和表征微孔动态演变过程的孔径变化方程,且模型的轴对称性使穿孔面积的计算更为准确,从而得到微孔的时空分布特性,...为进一步探究电穿孔理论机制,通过COMSOL建立单细胞电穿孔二维轴对称模型,该模型同时纳入表征微孔密度的电穿孔渐进方程和表征微孔动态演变过程的孔径变化方程,且模型的轴对称性使穿孔面积的计算更为准确,从而得到微孔的时空分布特性,并在此基础上探讨场强和脉宽对该特性的影响。结果表明:脉宽100μs、场强2 k V/cm的脉冲作用下,产生微孔7862个,穿孔面积达细胞表面积的6.3%,电穿孔各参量的时空分布规律与文献结果一致,从而可验证所建模型的有效性;在1~5 k V/cm范围内增大脉冲场强,微孔数与场强成正比,孔径则与场强成反比,孔面积与细胞面积之比从1.3%增至12.9%;对两组能量相同的纳秒脉冲和微秒脉冲进行比较,发现脉冲结束时前者产生的微孔数是后者的353.1倍,而在细胞膜上最靠近电极的点,后者的孔径是前者的19.3倍,说明纳秒脉冲有利于微孔数增加,而微秒脉冲有利于孔径扩大。仿真结果表明,微孔特性决定电穿孔的发生和发展过程,微孔特性的精确计算是阐释电穿孔效应的关键所在。展开更多
探讨地震频带内气水界面上的法向反射系数随频率的变化特征。分别利用新场气田和Denneman et al.(2002)模型的岩石和流体属性参数,建立了弹性孔隙介质的气水界面模型,然后,讨论了Gurevich et al.(2004)法向反射系数和Silin and Goloshub...探讨地震频带内气水界面上的法向反射系数随频率的变化特征。分别利用新场气田和Denneman et al.(2002)模型的岩石和流体属性参数,建立了弹性孔隙介质的气水界面模型,然后,讨论了Gurevich et al.(2004)法向反射系数和Silin and Goloshubin(2010)的法向反射系数的简化计算方程。利用简化方程和建立的气水界面模型进行了计算,并探索了地震频带内法向反射系数随频率变化的规律。结果表明,Silin and Goloshubin(2010)的渐进方程的方法能有效反映地震频带内气水界面上反射系数随频率的变化。渐进方程的反射系数方法可用于研究实际气水界面上反射系数随频率的变化现象。展开更多
The difference equation △xn＋ pnxn-k = f（n,xn-1,...,xn-1m）, n = 0, 1,2,.. is considered, where {pn} is a sequence of nonnegative real numbers, m ∈ {1, 2, ,... }, k,l1,..., lm ∈ {0, 1, 2,,... }. Some sufficient co...The difference equation △xn＋ pnxn-k = f（n,xn-1,...,xn-1m）, n = 0, 1,2,.. is considered, where {pn} is a sequence of nonnegative real numbers, m ∈ {1, 2, ,... }, k,l1,..., lm ∈ {0, 1, 2,,... }. Some sufficient conditions for the global asymptotic stability of zero solution of the equation are obtained.展开更多
The paper deal with the asymptotic behavior of the solutions to the initial boundary value problem for unipolar drift diffusion equations for semiconductors. Under the proper assumptions on doping profile and initial ...The paper deal with the asymptotic behavior of the solutions to the initial boundary value problem for unipolar drift diffusion equations for semiconductors. Under the proper assumptions on doping profile and initial value, we prove that the smooth solutions to these evolutionary problems tend to the unique stationary solution exponentially as time tends to infinity.展开更多
In this paper,the fixed_point theorem is used to estimated an asymptotic solution of initial value problems for a class of third nonlinear differential equations which has double initial_layer properties. We obtain th...In this paper,the fixed_point theorem is used to estimated an asymptotic solution of initial value problems for a class of third nonlinear differential equations which has double initial_layer properties. We obtain the uniformly valid asymptotic expansion of any orders including boundary layers.展开更多
In this paper, we establish a criterion of unformly asymptotic stability for finite delay difference systems in terms of two measures by employing Lyapunov functionals method.
Inertial manifolds for a class of second order in time dissipative equations are constructed.The author also proves an asymptotic completeness property for the inertial manifolds and characterizes the inertial manifol...Inertial manifolds for a class of second order in time dissipative equations are constructed.The author also proves an asymptotic completeness property for the inertial manifolds and characterizes the inertial manifolds as the set of trajectories whose growth is at most of order O(e-μt ) for some p > 0. As applications, a nonlinear wave equation and a problem of nonlinear oscillations of a shallow shell are considered.展开更多
文摘为进一步探究电穿孔理论机制,通过COMSOL建立单细胞电穿孔二维轴对称模型,该模型同时纳入表征微孔密度的电穿孔渐进方程和表征微孔动态演变过程的孔径变化方程,且模型的轴对称性使穿孔面积的计算更为准确,从而得到微孔的时空分布特性,并在此基础上探讨场强和脉宽对该特性的影响。结果表明:脉宽100μs、场强2 k V/cm的脉冲作用下,产生微孔7862个,穿孔面积达细胞表面积的6.3%,电穿孔各参量的时空分布规律与文献结果一致,从而可验证所建模型的有效性;在1~5 k V/cm范围内增大脉冲场强,微孔数与场强成正比,孔径则与场强成反比,孔面积与细胞面积之比从1.3%增至12.9%;对两组能量相同的纳秒脉冲和微秒脉冲进行比较,发现脉冲结束时前者产生的微孔数是后者的353.1倍,而在细胞膜上最靠近电极的点,后者的孔径是前者的19.3倍,说明纳秒脉冲有利于微孔数增加,而微秒脉冲有利于孔径扩大。仿真结果表明,微孔特性决定电穿孔的发生和发展过程,微孔特性的精确计算是阐释电穿孔效应的关键所在。
文摘探讨地震频带内气水界面上的法向反射系数随频率的变化特征。分别利用新场气田和Denneman et al.(2002)模型的岩石和流体属性参数,建立了弹性孔隙介质的气水界面模型,然后,讨论了Gurevich et al.(2004)法向反射系数和Silin and Goloshubin(2010)的法向反射系数的简化计算方程。利用简化方程和建立的气水界面模型进行了计算,并探索了地震频带内法向反射系数随频率变化的规律。结果表明,Silin and Goloshubin(2010)的渐进方程的方法能有效反映地震频带内气水界面上反射系数随频率的变化。渐进方程的反射系数方法可用于研究实际气水界面上反射系数随频率的变化现象。
基金Supported by Natural Science Foundaton of Henan Providence(0111051200)
文摘The difference equation △xn＋ pnxn-k = f（n,xn-1,...,xn-1m）, n = 0, 1,2,.. is considered, where {pn} is a sequence of nonnegative real numbers, m ∈ {1, 2, ,... }, k,l1,..., lm ∈ {0, 1, 2,,... }. Some sufficient conditions for the global asymptotic stability of zero solution of the equation are obtained.
文摘The paper deal with the asymptotic behavior of the solutions to the initial boundary value problem for unipolar drift diffusion equations for semiconductors. Under the proper assumptions on doping profile and initial value, we prove that the smooth solutions to these evolutionary problems tend to the unique stationary solution exponentially as time tends to infinity.
文摘In this paper,the fixed_point theorem is used to estimated an asymptotic solution of initial value problems for a class of third nonlinear differential equations which has double initial_layer properties. We obtain the uniformly valid asymptotic expansion of any orders including boundary layers.
基金This work is supported by Mathematics Tianyuan Fund (No.A0324624),NNSF of China (No.10371040),Shanghai Priority Academic Discipline.
文摘In this paper, we establish a criterion of unformly asymptotic stability for finite delay difference systems in terms of two measures by employing Lyapunov functionals method.
文摘Inertial manifolds for a class of second order in time dissipative equations are constructed.The author also proves an asymptotic completeness property for the inertial manifolds and characterizes the inertial manifolds as the set of trajectories whose growth is at most of order O(e-μt ) for some p > 0. As applications, a nonlinear wave equation and a problem of nonlinear oscillations of a shallow shell are considered.
