搜索结果: 1-15 共查到“知识库 物理声学”相关记录39条 . 查询时间(4.438 秒)
声学蜂窝结构中的拓扑角态
声学蜂窝结构 二阶拓扑绝缘体 角态
2022/3/15
金属射流发散性理论分析及数值模拟
金属射流 射流发散 分叉射流 空洞射流
2014/5/15
分析经典射流理论和相关文献,给出了在汇聚点坐标系中金属Cu对碰形成射流的汇聚射流区、无射流激波封锁区、无射流强度封锁区和形成发散射流区域。对金属超声速射流形成的发散性问题进行了理论分析,诠释了Walker基于实验提出射流发散理论,证明了金属射流超声速部分可形成发散射流也可形成汇聚射流,且超过1.23倍体声速的金属射流必定是发散的。最后,应用自编的欧拉计算程序MEPH对金属Cu以不同速度、倾角对碰射...
低波数噪音严重影响了逆时偏移的成像质量,选择合适的低波数噪音压制方法是进行逆时偏移时必然涉及到的一个重要方面.本文首先详细分析了逆时偏移中低波数噪音产生的本质原因,然后根据噪音的产生机制对目前各类低波数噪音压制方法进行了分析和归类:第一类低波数噪音压制策略的核心是在构建波场中避免发生背向反射;第二类低波数噪音压制策略的核心是进行选择性成像.最后通过对压噪方法进行合理的选择和搭配,构建了在不同实现条...
传感器网络中基于节点数据相关的DOA估计
波达方向 矢量水听器 互相关 频谱
2014/3/14
波达方向(DOA)估计是水声阵列信号处理的重要研究方向.由多个矢量水听器组成的传感器网络利用各节点所在位置的声压、质点振速可以实现DOA估计,节点的协同合作能够确定目标声源的位置.本文根据矢量水听器的特点、相关性及DOA算法等理论,仿真分析相关性对DOA算法的影响,并结合实际湖试对节点数据的相关性进行分析处理.由于各节点数据包含严重的噪声,导致其频谱情况很差,处理后节点数据的频谱及节点间的互相关性...
基于单片机的声音导航定位系统的设计
单片机 声音定位 无线收发
2012/9/12
详细阐述了基于单片机的声音导航定位系统的设计过程,并给出了主要电路图。该系统是以智能小车为运动体的声音定位测控系统,控制器由主从结构的两片STC89C52单片机构成,主芯片同时对三个处于不同位置的声音接收模块的音频信号进行处理和时间差测量,从芯片控制小车上的声源发出音频信号,根据主芯片用无线信号传送过来的误差信号,引导小车往目的地运动,也可实现路线选择及较精确定位 ,使该声音导航定位小车具有智能化...
声学地层剖面探测技术在金州湾人工岛场址勘察中的应用
声学地层剖面 反射界面 沉积层序 渤海金州湾
2013/11/12
声学地层剖面探测是一种基于声学原理的连续走航式探测水下地层结构和构造的地球物理方法,由于其灵敏度和分辨率高、连续性好且能高效地探测水下地层的地质特征及其分布而在海洋工程勘察中得到了广泛应用。拟在渤海金州湾海域内建造一座人工岛,场址沉积的地层是自晚更新世以来伴随着海平面升降和海侵海退过程而逐渐形成的,自上而下依次为:浅海相淤泥或淤泥质粉质黏土、滨海相淤泥、陆相黏土、滨海相粉质黏土、海陆交互相黏土和粉...
Current and noise correlations in a double dot Cooper pair beam splitter
Current noise correlations double dot Cooper pair beam splitter
2010/11/23
We consider a double quantum dot coupled to two normal leads and one superconducting lead,
modeling the Cooper pair beam splitter studied in two recent experiments. Starting from a microscopic Hamilt...
Stationary and dynamical properties of bistable Langevin model under noise-intensity fluctuation
Superstatistics Stochastic volatility Stationary distribution
2010/11/19
In this paper, we study effects of noise-intensity fluctuations on stationary and dynamical prop-erties of a bistable Langevin model, based on concepts of stochastic volatility model and super-statist...
Noise induced state transitions, intermittency and universality in the noisy Kuramoto-Sivashinksy equation
Noise induced state transitions intermittency universality noisy Kuramoto-Sivashinksy equation
2010/11/18
We analyze the effect of pure additive noise on the long-time dynamics of the noisy Kuramoto-
Sivashinsky (KS) equation in a regime close to the instability onset. We show that when the noise is high...
Chirality-dependent phonon-limited resistivity in graphenes
Chirality-dependent phonon-limited resistivity graphenes
2010/11/17
We develop a theory for the temperature and density dependence of phonon-limited resistivity
(T ) in bilayer and multilayer graphene, and compare with the corresponding monolayer result. For the uns...
Five-minutes oscillations is one of the basic properties of solar convection. Observations show mixture of a large number of acoustic wave fronts propagating from their sources. We investigate the pr...
Two-mode Correlation of Microwave Quantum Noise Generated by Parametric Down-Conversion
Two-mode Correlation of Microwave Quantum Noise Parametric Down-Conversion
2010/11/24
In this letter, we report the observation of the correlation between two modes of microwave
radiation resulting from the amplication of quantum noise by the Josephson Parametric Converter.This proce...
The elusive nature of the Lyapunov regime in the Loschmidt echo
The elusive nature Lyapunov regime Loschmidt echo
2010/10/21
The Loschmidt echo is a measure of the stability and reversibility of quantum evolution under perturbations of the Hamiltonian. One of the expected and most relevant characteristics of this quantity f...