共查询到19条相似文献,搜索用时 187 毫秒
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利用同伦分析方法, 研究了一类由柱形杂质随机嵌入基质所形成的、电场和电流密度满足J = σ E + χ |E|2E + η|E|4E 形式本构关系的高阶弱非线性复合介质在外加直流电场作用下的电势分布问题. 首先利用模函数展开法, 将本构方程及边界条件化成了一系列非线性常微分方程的边值问题; 再利用同伦分析方法进行求解, 给出了电势在基质和杂质区域的渐近解析解.
关键词:
高阶弱非线性复合介质
模函数展开法
同伦分析方法
电势分布 相似文献
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Effects of an electromagnetic field on intracellular calcium oscillations in a cell with external noise 下载免费PDF全文
Intracellular calcium ion concentration oscillation in a cell subjected to external noise and irradiated by an electromagnetic field is considered. The effects of the intensity E0, the polar angle θ and the frequency omega of the external electric field on steady-state probability distribution and the mean Ca2+ concentration, respectively, are investigated by a numerical calculation method. The results indicate that (i) variation of ω cannot affect the intracellular calcium oscillation; (ii) the steady-state probability distribution presents a meaningful modification due to the variations of E0 and θ, while variation of θ does not affect the steady-state probability distribution under the condition of a small E0, and E0 cannot affect the steady-state probability distribution either when θ = π/2; (iii) the mean Ca2+ concentration increases as E0 increases when θ < π/2 and, as θ increases, it first increases and then decreases. However, it does not vary with E0 increasing when θ = π/2, but it increases with θ increasing when E0 is small. 相似文献
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用Vlasov-Poisson方程对相对论电子束在单板、双板间的传播过程进行了数值模拟,给出了单板模型空间电荷积累最大的位置,不同位置上的电流J、电子数密度n、电场E的振荡频率随入射电子数密度n0、入射速度v0的变化关系,双板模型空间电荷积累最大的位置,J、n、E的振荡频率随入射流J0及两板间距离的变化关系。虚阴极位置的数值结果与稳态理论给出的结果相近,它的振荡频率符合经验公式(1~√2π)ωpeb。单板时入射电子数密度按速度服从高斯分布,能散△En/En < 10%时的数值结果给出与单能情况基本相同的结论。 相似文献
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用数值方法证实了亮、暗屏蔽光伏孤子在有外加电场的LiNbO3晶体中都可以发生大自偏转,并验证了这种自偏转现象不但与晶体中受主浓度NA有关而且还与外加电场E0有关. 在E0相同的条件下,NA越小这种自偏转现象越明显,在NA相同的条件下,E0越大自偏转现象越明显. 还发现亮、暗屏蔽光伏孤子的自偏转现象不同:亮屏蔽光伏孤子整体都发生明显偏转,暗屏蔽光伏孤子的偏转只是发生在一侧,其极值位置和另一侧几乎不发生偏转.
关键词:
自偏转
空间孤子
光折变效应 相似文献
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Effective response in nonlinear spherical coated composites under external AC and DC electric field 下载免费PDF全文
By using the perturbation method, effective nonlinear direct current (DC) and alternating current (AC) responses of nonlinear composites with spherical coated inclusions randomly embedded in a host medium are studied under the action of external electric field Ea =E0 +E1 sin ωt+E3 sin 3ωt with different amplitudes and frequencies. The local potentials of composites at all harmonics are given in the inclusion particles and the host regions. All effective nonlinear responses to composites and the relationship between the effective nonlinear responses at all harmonics are also deduced for the spherical coated inclusions in a dilute limit. 相似文献
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Effective response in nonlinear spherical coated composites under external AC and DC electric fields 下载免费PDF全文
By using the perturbation method,effective nonlinear direct current(DC) and alternating current(AC) responses of nonlinear composites with spherical coated inclusions randomly embedded in a host medium are studied under the action of an external electric field E a = E 0 + E 1 sin ωt + E 3 sin 3ωt with different amplitudes and frequencies.The local potentials of composites at all harmonics are given in the inclusion particles and the host regions.All effective nonlinear responses to composites and the relationship between the effective nonlinear responses at all harmonics are also deduced for the spherical coated inclusions in a dilute limit. 相似文献
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Electric field distribution and effective nonlinear AC and DC responses of graded cylindrical composites 下载免费PDF全文
The perturbation method is used to study the localization of electric field distribution and the effective nonlinear response of graded composites under an external alternating-current (AC) and direct-current (DC) electric field Eapp = E0 (1+sin ωt). The dielectric profile of the cylindrical inclusions is modeled by function εi (r) = Ck rk (r ≤ a), where r is the radius of the cylindrical inclusion, and Ck, k, a are parameters. In the dilute limit, the local potentials and the effective nonlinear responses at all harmonics are derived. Meanwhile, the general effective nonlinear responses are also derived and compared with the effective nonlinear responses at harmonics under the AC and DC external field. It is found that the effective nonlinear AC and DC responses at harmonics can be calculated by those of the general effective nonlinear of the graded composites under the external DC electric field. Moreover, the obtained local electrical fields show that the electrical field distribution in the cylindrical inclusions is controllable, and the maximum of the electric field inside the cylinder is at its center. 相似文献
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A method for determining effective dielectric responses of Kerr-like coated nonlinear composites under the alternating current (AC) electric field is proposed by using perturbation approach. As an example, we have investigated the composite with coated cylindrical inclusions randomly embedded in a host under an external sinusoidal field with finite frequency ω. The local field and potential of composites in general consists of components with all harmonic frequencies. The effective nonlinear AC responses at all harmonics are induced by the coated nonlinear composites because of the nonlinear constitutive relation. Moreover, we have derived the formulae of effective nonlinear AC responses at the fundamental frequency and the third harmonic in the dilute limit. 相似文献
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Effective response of nonlinear cylindrical coated composites under external AC and DC electric field 下载免费PDF全文
This paper uses the perturbation method to study effective response
of nonlinear cylindrical coated composites. Under the external AC
and DC electric field Ea(1 + sinωt), the
local potentials of composites at all harmonic frequencies are
induced. An effective nonlinear response to composite is given for
the cylindrical coated inclusions in the dilute limit. 相似文献
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The perturbation method is used to study the effective nonlinear response of graded cylindrical composites with power-law gradient inclusions under a sinusoidal alternating current (AC) external field of finite frequency ω. In dilute limit, the local potentials and the formulae of effective nonlinear AC responses are derived at the fundamental frequency and the third harmonics. Furthermore, the general effective nonlinear responses are given and compared with the effective nonlinear AC responses of fundamental frequency and the third harmonics, and the relationships between the nonlinear effective AC response and the general effective nonlinear response are also determined. 相似文献
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Effective AC Response of Nonlinear Spherical Coated Composites 总被引:2,自引:0,他引:2
Under alternating current electric field, effective response of granular nonlinear composites with spherical coated inclusions is investigated in the dilute limit by using the perturbation approach. For an external sinusoidal applied field with finite
frequency ω, the local fields and potentials of composites in
general consist of components at all harmonics for cubic nonlinear
constitutive relationships. We derive the local potentials
of spherical coated composites at harmonics. Moreover, we
give the formulae of the nonlinear effective AC susceptibility
at the third harmonic frequency. 相似文献
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An effective nonlinear response of a nonlinear composite
with spherical coated inclusions randomly embedded in a host medium
under the action of an external AC electric field, {{\bm E}}_a =
{{\bm E}}_1 \sin (\omega t) + {{\bm E}}_3 \sin (3\omega t), is
investigated using a perturbation method. The local potentials of the
composite at higher harmonics are given both in the region of local
inclusion particles and in the local host region under the external
AC electric field. All effective nonlinear responses of the composite
and the relationship between the effective nonlinear responses at
the fundamental frequency and third harmonics are also studied for
spherical coated inclusion in a dilute limit. 相似文献
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SHEN Yu-Yan CHEN Xiao-Gang LI Qian-Qian CUI Wei HAO Yan-Hua 《理论物理通讯》2009,51(4):743-747
Under the external AC and DC electric field, the effective response of nonlinear spherical coated composites, which obey the constitutive relation of electric displacement and electric field, is investigated in the dilute limit by using the perturbation method. The local potentials in inclusion and host regions are derived at all harmonics. Moreover, the formulae of the effective linear and nonlinear responses are given in the dilute limit. 相似文献