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1.
设计并搭建了一套简易的激光衍射实验装置,通过该装置作者测量了水的表面波的波长,并确定了水的表面波主要成份是毛细成分。 相似文献
2.
Effects of orientation and shape of holes on the band gaps in water waves over periodically drilled bottoms
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The complete band gaps (CBGs) of shallow water waves
propagating over bottoms with periodically drilled holes are
investigated numerically by the plane wave expansion method. Four
different patterns are considered, containing triangular, square,
hexagonal and circular cross-sectioned holes arranged into
triangular lattices. Results show that the width of CBGs can be
changed by adjusting the orientation of noncircular holes and the
effect of hole shape on the width of the maximal CBGs is discussed. 相似文献
3.
DUAN Wen-Shan DOU Fu-Quan 《理论物理通讯》2004,42(7)
By using the potential method and the perturbation method under the condition of small amplitude and shallow water waves, we analytically get the KdV-type equation for a viscous shallow water. It indicates that for one soliton-like solution, its amplitude will decrease as it propagates away due to the viscous effects of water. 相似文献
4.
通过对“静水中表面波的力学分析”一的补充讨论,得出,与波长λ相比,深度h不须很大,便能在很高的精度上将水面质元的轨迹视为正圆,在此基础上给出了水面波的波形曲线方程,并指出深槽和浅槽近似条件下水面波的传播特征。 相似文献
5.
声波测井数据是石油天然气勘探开发中最为重要的基础资料,其数据质量受井壁环境、频散等因素影响较大,且部分钻井并未采集声波。这对后续开展速度分析、储层识别和烃类检测都带来较大影响。因此需要对声波测井数据进行环境校正、补齐、预测等处理。目前,主要依据研究区域内已钻井的统计规律对声波测井数据进行评估和预测。而在深水区,因钻井距离远、地质条件差异较大等原因,不同地区的声波变化较大,依据统计方法评估数据存在较大的多解性。本文提出采用岩石物理模型来评估声波质量和预测声波数据。基于Xu&White岩石物理模型,采用密度曲线反演计算泥岩孔隙度,改善了岩石物理模拟在储层段和非储层段的拟合效果,且在多口井的适用性更好。基于新方法,本文建立了可在区域内稳定适用的岩石物理模型,可计算多口井在不同岩性、不同深度下的速度,为在不同地区和不同深度的声波质量评估和预测提供依据,指导后期储层预测和含气性检测。 相似文献
6.
DUANWen-Shan DOUFu-Quan 《理论物理通讯》2004,42(1):117-120
By using the potential method and the perturbation method under the condition of small amplitude and shallow water waves, we analytically get the KdV-type equation for a viscous shallow water. It indicates that for one soliton-like solution, its amplitude will decrease as it propagates away due to the viscous effects of water. 相似文献
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The effect of shock sterilization on marine Vibrio sp. is investigated by carrying out a bio-experiment based on a bubble-shockwave interaction. In the experiments, underwater shock waves with different strength and frequencies are produced by a high-voltage power supply in a cylindrical water chamber. The bio-experimental results show marine Vibrio sp. is completely inactivated in a short time by a 1.0-Hz electric discharge. However, a high sterilization effect requires a strong and high frequency of the bubble motion, and it also depends on the lifetime of the bubble. Subsequently, by an experiment with an air gap to prevent the underwater shock waves entering the cell suspension, it is found that the introduction of a strong shock pressure is not entirely required to obtain the effective sterilization. On the other hand, the direct effect of the sterilization by rebound shock wave resulting from the bubble-shock wave interaction is examined in the experiments. The results suggest that free radicals mainly contribute to killing marine bacteria, and direct mechanical effects of the bubble motion are not responsible. In addition, the creation of the OH radical is indirectly confirmed by measuring the H2O2 concentration. Finally, the Herring equation is solved to investigate the condition of free radical generation when considering the effect of thermal conductivity at the bubble interface. As a result, the effective sterilization conditions based on the bubble-shock wave interaction are clearly obtained. 相似文献
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10.
大尺度正压大气环流的波动特征对理解气候变化具有重要的意义,而非线性浅水波方程组是描述大尺度正压大气环流的原始控制方程.本文对线性方程的复变函数解,通过二次适当的移植,求得浅水波方程组的发展方程的扰动位势的实变函数解,该实变函数解析解由基流项和波动项两部分组成.其中基流由波数、波速、β效应、变形半径和时间的任意函数共同决定;波动项与β效应有关.分析表明,在大尺度正压大气环流中扰动位势存在曲面的周期波和孤波的现象,周期波与孤波相互调制而呈现不稳定性;当多个周期孤波同时出现时,则彼此独立传播;扰动位势波动项中的时间任意函数对曲面周期孤波的波幅有调制作用,可控制波的产生、发展和消失.所得结果对研究大气波动现象和气候变化具有一定的理论参考价值. 相似文献
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利用激光器、硅光电池等器件,采用光折射方法设计了激光测量水的振动频率与水波传播速度实验.本文介绍了实验原理和装置,测量了水的振动频率和水波向外传播的速度,观察了小块物体落水激起的水波情况. 相似文献
13.
I. Magdalena S. R. Pudjaprasetya & L. H. Wiryanto 《advances in applied mathematics and mechanics.》2014,6(5):680-692
In this paper, we study wave interaction with an emerged porous media.
The governing equation is shallow water equations with a friction
term of the linearized Dupuit-Forcheimer's formula. From the continuity of surface and
horizontal flux, we derived the wave reflection and transmission coefficient formulas.
They are similar to the corresponding formulas of the submerged solid bar
breakwater. We solve the equations numerically using finite volume method on
a staggered grid. The numerical wave reduction in the porous media confirms the
analytical wave transmission curve. 相似文献
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The determining equations for the nonclassical symmetry reductions of nonlinear partial differential equations with arbitrary order can be obtained by requiring the compatibility between the original equations and the invariant surface conditions. The (2+1)-dimensional shallow water wave equation,
Boussinesq equation, and the dispersive wave equations in shallow water serve as examples illustrating how compatibility leads quickly and easily to the determining equations for their nonclassical symmetries. 相似文献
16.
在水体表面波的扰动作用下,水下光场随深度呈现较为明显的波动现象,且水中光合作用会对水下光场波动作出响应,因而此现象引起了广泛的关注。基于太湖梅梁湾观测的水下光场数据,计算了水下光场随深度的变化,并分析了其波动特征。结果表明:表面波引起了水下光场较为明显的波动现象,波动振幅最大的深度基本小于20 cm,远小于海洋中对应的深度;水下光场波动的振幅随深度呈e的负指数衰减,漫射消光系数越大,水下光场的波动衰减得也越快;当深度大于30 cm时,水下光场的扰动现象基本消失。还计算了船舶对水下光场观测的影响,发现直射光未被遮挡的情况下,漫射比例越高,其相对误差越大。 相似文献
17.
YAN Zhi-Lian LIU Xi-Qiang 《理论物理通讯》2005,44(9)
By applying the extended homogeneous balance method, we find some new explicit solutions to two nonlinear evolution equations, which include n-resonance plane solitary wave and non-traveling wave solutions. 相似文献
18.
YAN Zhi-Lian LIU Xi-Qiang 《理论物理通讯》2005,44(3):479-482
By applying the extended homogeneous balance method, we find some new explicit solutions to two nonlinear evolution equations, which include n-resonance plane solitary wave and non-traveling wave solutions. 相似文献
19.
研究(1+1)维广义的浅水波方程的变量分离解和孤子激发模式. 该方程包括两种完全可积(IST可积)的特殊情况,分别为AKNS方程和Hirota-Satsuma方程. 首先把基于Bcklund变换的变量分离(BT-VS)方法推广到该方程,得到了含有低维任意函数的变量分离解. 对于可积的情况,含有一个空间任意函数和一个时间任意函数,而对于不可积的情况,仅含有一个时间任意函数,其空间函数需要满足附加条件. 另外,对于得到的(1+1)维普适公式,选取合适的函数,构造了丰富的孤子激发模式,包括单孤子,正-反孤子,孤子膨胀,类呼吸子,类瞬子等等. 最后,对BT-VS方法作一些讨论.
关键词:
浅水波方程
Bcklund变换
变量分离
孤子 相似文献
20.
基于一般的浅水波方程, 根据大尺度正压大气的特点, 得到无量纲的控制大尺度大气的动力学非线性方程组. 利用多尺度法, 由无量纲的动力学方程组导出了扰动位势的非线性控制方程. 采用椭圆方程构造该扰动位势控制方程的解, 获得了扰动位势和速度的多周期波与冲击波(爆炸波) 并存的解析解. 扰动位势的解表明经向和纬向具有不同周期和波长的周期波, 且都受纬向孤波的调制; 速度的解表明大尺度大气流动存在气旋和反气旋周期性分布的现象.
关键词:
浅水波方程
大尺度正压大气
解析解
非线性波 相似文献