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1.
梁远森  许红  王云昌 《河南科学》2005,23(5):699-703
从计算与实测的角度,分别介绍了获取建筑结构自振周期的几种主要方法.简述了周期计算方法适用范围;着重介绍了结构周期实测的脉动分析法,并将该方法与其它两种周期实测方法进行了比较,指出了方法所得实测结果差异的实质.最后通过计算周期与实测周期的比较分析,指出了对计算周期进行折减的必要性以及周期计算经验公式的作用.  相似文献   

2.
分析了M集混沌分形图谱中不动点和周期轨道的稳定性条件,研究了混沌周期芽苞内部及不同周期芽苞之间的变化规律.借助由MATLAB 工具开发的"M集图像周期轨道轨迹绘制"软件,绘制经典M集周期芽苞周期点的周期轨道轨迹图像.通过对周期轨道轨迹变化情况的分析,得到周期芽苞内部任意点均变现出其对应的周期性;不同周期芽苞之间的周期点其周期性相互影响,而又不失独立性.  相似文献   

3.
分析了M集混沌分形图谱中不动点和周期轨道的稳定性条件,研究了混沌周期芽苞内部及不同周期芽苞之间的变化规律。借助由MATLAB工具开发的M集图像周期轨道轨迹绘制软件,绘制经典M集周期芽苞周期点的周期轨道轨迹图像。通过对周期轨道轨迹变化情况的分析,得到周期芽苞内部任意点均变现出其对应的周期性;不同周期芽苞之间的周期点其周期性相互影响,而又不失独立性。  相似文献   

4.
目的细致展现舒斯特创建周期图方法的历史过程,为研究时间序列频域分析的发展提供线索。方法内史与外史相结合、文献考证。结果在分析太阳黑子隐藏周期的过程中,舒斯特首创了周期图方法。结论 Schuster的周期图方法,不仅考察了1750—1900年太阳黑子序列的周期,而且把150年间隔平均分成两阶段逐个调查,成功地解决了太阳黑子的周期问题:太阳黑子不仅有众所周知的11年周期,也存在其他的确定周期如4.78、8.38年,3个周期11.125、8.38和4.78年不仅都是周期33.375年的子周期,而且前2个周期频率的和与第3个周期的频率相一致。此后,周期图方法成为调查各类自然现象周期问题的基本工具,引领着时间序列频域分析的发展。  相似文献   

5.
利用周期序列的广义离散傅立叶变换,计算出了一般情形下的随机周期序列线性复杂度的方差,确定了某些重要周期的随机周期序列线性复杂度的方差,并且分析了随机周期序列线性复杂度的方差渐近性质.  相似文献   

6.
小集油田周期注水方案研究   总被引:1,自引:0,他引:1  
在分析周期注水原理的基础上,研究了影响周期注水效果的主要因素,结合小集油田实际地质特征,确定了该油田采取周期注水的注水量变化幅度以及注水周期,并且在前期周期注水的基础上,制定了新一轮的周期注水方案。  相似文献   

7.
王军平 《科技资讯》2014,(33):188-188
倍周期分支过程是一条通向混沌的典型道路,即可以认为是从周期窗口中进入混沌的一种方式。在倍周期分支到达混沌现象的过程中,会依次经过周期1,周期2,周期4,……,混沌单吸引子和混沌双吸引子。该文根据倍周期分支判别法论证了一类余弦函数迭代映射后发生倍周期分支的充分条件,并对分支走向混沌的过程进行了探讨。  相似文献   

8.
利用伪概周期函数的定义及其相关性质和不动点定理,给出了一类延迟积分方程的伪概周期解的存在性定理,并证明了伪概周期解的概周期部分恰为其对应的概周期积分方程的概周期解.在一些文献对某些延迟积分方程的概周期解和渐近概周期解研究的基础上,探讨了其伪概周期解的存在条件,这样会使得到的结论应用的更加广泛.  相似文献   

9.
用微分方程分支理论和计算机数值模拟方法研究广义CH方程的周期波解.给出了行波系统的分支相图,利用相图的周期轨构造出了周期波解,在数学软件M ap le支持下用计算机进行数值模拟,发现了周期波的两种极限情况,第一种情况是光滑周期波趋于周期尖波,第二种情况是光滑周期波趋于光滑孤立波.这些结果丰富了广义CH方程的研究内容.  相似文献   

10.
分析了一个简单的具有两种微生物和周期注入营养液的恒化器模型,得到了一个微生物和营养液共存的周期解,另外,还证明了当脉冲周期小于某个临界值时,该周期解是稳定的,当脉冲周期大于该临界值时,稳定性丧失.  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.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
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   

14.
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   

15.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

16.
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   

17.
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   

18.
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   

19.
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   

20.
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   

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