首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
为了描述平行尾矿坝坝轴方向浸润线的演化并描述其非线性动力特性,以浸润线高度与坝体高度的比值作为状态变量,引入基于反应扩散过程的耦合单峰映象格子模型;提出了运用最小二乘法进行反演,求取模型中非线性强度a及耦合强度ε,进而确定浸润线时空模式的方法.对银山铅锌矿尾矿坝浸润线实测数据进行分析,结果表明耦合单峰映象格子模型能够较好地描述平行坝轴方向浸润线的非线性动力特性;通过反演方法可以得到浸润线的时空模式,并进而判断浸润线状态,为采取安全措施提供理论依据.  相似文献   

2.
一种基于时空延迟反馈的时空混沌控制方法   总被引:1,自引:0,他引:1       下载免费PDF全文
罗晓曙  唐国宁  刘慕仁  孔令江 《广西科学》2000,7(3):190-191,195
研究耦合映象格子中的时空混沌控制问题。根据信号的自关联度与随机度之间的关系,提出了通过时空延迟反馈控制耦合单峰格子中时空混沌行为的方法,获得了很好的控制结果。这一控制方法不需要获取时空混沌系统中不稳定周期轨道的任何信息,控制参数的选择与被控的时空混沌系统的参数和方程无关。  相似文献   

3.
一种耦合映象格子中时空混沌的级联控制法   总被引:1,自引:1,他引:0  
提出了一种级联控制耦合映象格子(CML)中时空混沌的方法。以耦合单峰格子为例验证了这种控制方法,结果表明:在不同的系统模式和不同的控制参数下可以得到各种稳定时的时空周期轨道。这一控制方法的优点是不需要获取时空混沌系统中不稳定周期轨道的任何信息,且控制参数与被控系统的参数和变量的取值无关。  相似文献   

4.
本文首次在耦合映象晶格模型中使用了反对称立方映象,研究了该映象的一般非线性现象。同时较详细地研究了耦合后分岔、周期和混沌等复杂的时空动力学行为。  相似文献   

5.
研究时空混沌的单向耦合映象格子模型,由该模型产生时空混沌序列并结合数字图像的特点及图像压缩技术,实现对数字图像的加密和解密,实验结果表明,该方案保密性好、实用性强.同时,分析了该时空混沌数字图像加密方法应用于多媒体视频通讯的前景.  相似文献   

6.
对时空混沌理论及应用现状进行了简述,研究了时空混沌的数学模型及其应用,提出了一种基于时空混沌的耦合映象格子模型的序列密码算法,并在DSP上加以实现.理论分析和安全性测试实验结果均表明,该算法较之基于低维时间混沌的序列密码算法,具有更高的安全性,应用性较好.  相似文献   

7.
用预测反馈控制方法对时空混沌系统的控制进行了研究,该方法是在耦合映象格子中的每个格点处加入局部预测反馈控制器.以单向环形Henon耦合映象格子(ORHML)为例,在理论上给出了将系统控制到不稳定不动点的充分条件,并通过数值仿真及电路仿真实验证实该方法的有效性.  相似文献   

8.
主要研究耦合映像格子中的时空混沌控制问题,提出一种非线性反馈控制方法,这种方法对耦合映像格子模型中图案选择模式和图案竞争阵发混沌模式具有很好的控制效果,并通过数值模拟证明了该非线性反馈控制方法的有效性.  相似文献   

9.
二维耦合时变映象格子模型与气象预报的改进   总被引:1,自引:0,他引:1  
将气象数据投影在年-月二维格子平面上,以文中提出二维耦合时变映象格子模型所建立的若干图案模式,对年-月二维格子平面上的气象数据进行分析,获得若干与混沌动力学演化有关的参数,这类参数是气象数据中提取的新信息,并作为新的自变量加入到气象数据多元回归预报模型中,较大幅度地提高了预报精度,为改进气象预报探索了一种新方法.  相似文献   

10.
为了描述耦合映象格子(CML)的冻结化随机图案模式,定义和计算了与格点位置相关的李雅普诺夫指数谱,并和由雅可比矩阵乘积计算的李雅普诺夫指数谱做了比较。对格点扰动传播过程的研究表明,这种李雅普诺夫指数谱能很好地描述耦合映象格子在随机化冻结图案模式下的时空动力学行为。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

13.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

14.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

15.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

16.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

17.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

18.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号