共查询到20条相似文献，搜索用时 171 毫秒
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为研究和认识多种储层中弹性波的波场特征,以利于多波地震资料解释,高精度数值模拟是有效的方法之一.本文在弹性波方程基础上,采用高阶交错网格有限差分技术模拟地震波在各向同性介质和各向异性介质中的传播,可得到不同类型介质的弹性波场.同时,文中也分析了各向异性系数对多波波场特征的影响.通过对高精度数值模拟得到的波场快照对比研究表明,该方法可有效获得高精度弹性波正演结果,为研究各种复杂介质中弹性波的波场特征和传播规律奠定了基础. 相似文献
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刘强 《科技成果管理与研究》2016,(12):86-87
涡旋光束在湍流大气中的传播特征受到了众多学者的关注,已显现出十分良好的应用前景.另一方面,越来越多的研究人员开展复杂系统和随机介质波束散射特征研究,利用高斯波束在随机介质中的传播与散射特征,推动了相应的技术在工业、民用等领域中的应用.
西安理工大学光电工程技术研究中心柯熙政教授科研团队长期从事无线激光通信中的光信道特性、信道编码、调制技术、信号处理以及随机介质中光波的传播与散射特征等研究,在自由空间光通信中的关键技术及系统设计和开发能力等方面具有很强的科研实力,拥有多项具有自主知识产权的研发成果,掌握了无线激光通信设备核心技术.特别是从涡旋光束、高斯光束在大气湍流介质中的传播与散射特征的基础理论出发,深入研究了具有轨道角动量的涡旋光场在大气湍流随机介质中的传播及对光束轨道角动量态的影响,建立了轨道角动量涡旋光场在大气湍流中的理论传播模型,开展了大气湍流环境下高斯波束与目标、粒子的散射特征研究. 相似文献
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岩土介质爆破地震波的传播特性分析 总被引：1，自引：0，他引：1
爆破震动波在岩土介质中的传播行为较为复杂;通过理论分析并将爆破地震的影响因素分为产生和传播过程两个方面,研究了爆破震动波的传递规律及其影响因素,为工程实践提供指导. 相似文献
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《Journal of The Franklin Institute》2019,356(14):7731-7753
Since being postulated more than a decade ago, inerters have been successfully employed to enhance the dynamic performance of mechanical systems in several applications. Their ability to lend a high dynamic mass presence to systems that employ them with only a relatively small static device mass makes them unique among mechanical elements. This study explores the mechanical wave manipulation characteristics of nonlinear inertant acoustic metamaterial (NLIAM) configurations using analysis and simulations for their one-dimensional discrete element lattice representations. Firstly, based on notional concepts for nonlinear inertant devices, potential frequency-dependent and acceleration-dependent nonlinear inertant models are identified. Using an effective mass model for the NLIAM with frequency-dependent inertance in the local resonator attachment, the dispersion characteristics of inverse square law and power law inertance models are examined and contrasted with those for an acoustic metamaterial with frequency invariant inertance. While a tuned inverse square law inertance model ensures the existence of a band gap over almost the entire frequency bandwidth of interest even encompassing the extremely low frequency regime, the low and high frequency limits for this inertance law would not be realizable in practice. A potentially more practical power law approximation is proposed and shown to deliver a widening of the band gap by more than 100% towards frequencies below the lower bound of the band gap for the acoustic metamaterial with frequency invariant inertance. Further, drawing inspiration from the Duffing-type stiffness, an acceleration-dependent cubically nonlinear inertance model is proposed. First order corrections to the dispersion characteristics are obtained for an NLIAM with acceleration-dependent inertance using a perturbation approach. For weakly nonlinear cases, excitation amplitude-activated shifts in the dispersion curves are found to enable this NLIAM to act as a passive adaptive filter for mechanical waves based solely on their excitation amplitude. Practical manifestations of such NLIAM could therefore provide a means to realize extraordinary wave manipulation capabilities especially suitable for low frequency structural dynamic applications. 相似文献
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浅谈太赫兹波技术及其应用 总被引：1，自引：0，他引：1
太赫兹(THz)波是指频率在0.1T—10THz(波长为3000—30μm)范围内的电磁波。本文简单介绍了太赫兹波的主要特征及其在成像、军事安全、生物医学、天文物理等方面的应用。 相似文献
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In this paper, we utilize transmission-line matrix simulations to study the electromagnetic properties of hyperbolic metamaterial grids, which are synthesized by arranging unloaded transmission lines over electrical ground planes, such that the unit cells are rectangular in shape. The hyperbolic grids support Bragg and Hyperbolic resonant modes that have rectangular and hyperbolic dispersion surfaces, respectively. We demonstrate the formation of these resonant modes in the hyperbolic grids and their refraction, and spatial scanning properties via circuit simulations. The simulation results are compared with experimental results of a two-layer anisotropic hyperbolic metamaterial. 相似文献
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D. Schieber 《Journal of The Franklin Institute》1979,308(2):163-169
The paper considers the effect of radiation pressure acting upon a moving, resistive sheet; the analysis is specifically concerned with the drag and levitation forces resulting when the sheet attains velocities approaching the velocity of a plane wave of light in vacuum. Relevant graphical results are presented. 相似文献
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由于电子密度分布、激励功率、气压等因素的影响，等离子体天线参数（增益、方向图等）通常难以求解。本文利用时域差分建立电磁波沿等离子体天线激励和传播的模型，得到不同参数（如激励功率、碰撞频率、等离子体迟豫时间、每个电子对所需能量）对等离子体轴向电子密度分布的影响，解释了不同激励情况下电子密度的线性和非线性分布，并解决了信号沿等离子体天线传播的波矢分布、辐射方向图的求解问题。 相似文献
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日本福岛核电站的核泄漏事件使全国陷入一片恐慌之中,许多谣言相继产生。2011年3月16日,我国爆发食盐抢购风潮,这场风潮是由关于核辐射将污染我国海域和食盐可以防辐射的谣言导致的。本文以我国"抢盐"谣言为研究对象,对"抢盐"谣言传播的始末进行梳理,分析此次"抢盐"谣言的传播特点,并探讨预防和应对重大灾难性事件谣言的方法。 相似文献
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Yao Wang Chong Sheng Yong-Heng Lu Jun Gao Yi-Jun Chang Xiao-Ling Pang Tian-Huai Yang Shi-Ning Zhu Hui Liu Xian-Min Jin 《国家科学评论(英文版)》2020,7(9):1476
Though it is still a big challenge to unify general relativity and quantum mechanics in modern physics, the theory of quantum field related with the gravitational effect has been well developed and some striking phenomena are predicted, such as Hawking radiation. However, the direct measurement of these quantum effects under general relativity is far beyond present experiment techniques. Fortunately, the emulation of general relativity phenomena in the laboratory has become accessible in recent years. However, up to now, these simulations are limited either in classical regime or in flat space whereas quantum simulation related with general relativity is rarely involved. Here we propose and experimentally demonstrate a quantum evolution of fermions in close proximity to an artificial black hole on a photonic chip. We successfully observe the acceleration behavior, quantum creation, and evolution of a fermion pair near the event horizon: a single-photon wave packet with positive energy escapes from the black hole while negative energy is captured. Our extensible platform not only provides a route to access quantum effects related with general relativity, but also has the potentiality to investigate quantum gravity in future. 相似文献