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Wave packet solutions in a bounded equatorial ocean and its interannual and decadal variabilities 被引量:2
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作者 Dongling Zhang Juan Zhu +1 位作者 Xu Lu Ming Zhang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2019年第3期45-59,共15页
Linearized shallow water perturbation equations with approximation in an equatorial β plane are used to obtain the analytical solution of wave packet anomalies in the upper bounded equatorial ocean. The main results ... Linearized shallow water perturbation equations with approximation in an equatorial β plane are used to obtain the analytical solution of wave packet anomalies in the upper bounded equatorial ocean. The main results are as follows. The wave packet is a superposition of eastward travelling Kelvin waves and westward travelling Rossby waves with the slowest speed, and satisfies the boundary conditions of eastern and western coasts, respectively.The decay coefficient of this solution to the north and south sides of the equator is inversely proportional only to the phase velocity of Kelvin waves in the upper water. The oscillation frequency of the wave packet, which is also the natural frequency of the ocean, is proportional to its mode number and the phase velocity of Kelvin waves and is inversely proportional to the length of the equatorial ocean in the east-west direction. The flow anomalies of the wave packet of Mode 1 most of the time appear as zonal flows with the same direction. They reach the maximum at the center of the equatorial ocean and decay rapidly away from the equator, manifested as equatorially trapped waves. The flow anomalies of the wave packet of Mode 2 appear as the zonal flows with the same direction most of the time in half of the ocean, and are always 0 at the center of the entire ocean which indicates stagnation, while decaying away from the equator with the same speed as that of Mode 1. The spatial structure and oscillation period of the wave packet solution of Mode 1 and Mode 2 are consistent with the changing periods of the surface spatial field and time coefficient of the first and second modes of complex empirical orthogonal function(EOF)analysis of flow anomalies in the actual equatorial ocean. This indicates that the solution does exist in the real ocean, and that El Ni?o-Southern Oscillation(ENSO) and Indian Ocean dipole(IOD) are both related to Mode 2.After considering the Indonesian throughflow, we can obtain the length of bounded equatorial ocean by taking the sum of that of the tropical Indian Ocean and the tropical Pacific Ocean, thus this wave packet can also explain the decadal variability(about 20 a) of the equatorial Pacific and Indian Oceans. 展开更多
关键词 boundED EQUATORIAL OCEAN wave packet SOLUTIONS DECADAL variability Kelvin wave Rossby wave
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BOUNDED TRAVELING WAVE SOLUTIONS OF VARIANT BOUSSINESQ EQUATION WITH A DISSIPATION TERM AND DISSIPATION EFFECT
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作者 张卫国 刘强 +1 位作者 李正明 李想 《Acta Mathematica Scientia》 SCIE CSCD 2014年第3期941-959,共19页
This article studies bounded traveling wave solutions of variant Boussinesq equation with a dissipation term and dissipation effect on them. Firstly, we make qualitative analysis to the bounded traveling wave solution... This article studies bounded traveling wave solutions of variant Boussinesq equation with a dissipation term and dissipation effect on them. Firstly, we make qualitative analysis to the bounded traveling wave solutions for the above equation by the theory and method of planar dynamical systems, and obtain their existent conditions, number, and general shape. Secondly, we investigate the dissipation effect on the shape evolution of bounded traveling wave solutions. We find out a critical value r^* which can characterize the scale of dissipation effect, and prove that the bounded traveling wave solutions appear as kink profile waves if |r|≥ r^*; while they appear as damped oscillatory waves if |r| 〈 r^*. We also obtain kink profile solitary wave solutions with and without dissipation effect. On the basis of the above discussion, we sensibly design the structure of the approximate damped oscillatory solutions according to the orbits evolution relation corresponding to the component u(ξ) in the global phase portraits, and then obtain the approximate solutions (u(ξ), H(ξ)). Furthermore, by using homogenization principle, we give their error estimates by establishing the integral equation which reflects the relation between exact and approximate solutions. Finally, we discuss the dissipation effect on the amplitude, frequency, and energy decay of the bounded traveling wave solutions. 展开更多
关键词 Variant Boussinesq equation with dissipation term shape analysis bounded traveling wave solution error estimate dissipation effect
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均匀磁场下二维拓扑绝缘体边缘态的多重Andreev反射研究
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作者 杨雪 吕博 《现代电子技术》 北大核心 2024年第4期17-22,共6页
研究均匀磁场下的二维拓扑绝缘体在超导隧道结中的电压偏置约瑟夫森结的输运性质,电流-电压特性显示了马约拉纳束缚态的存在。在亚谐隙结构中,也可以观察到磁场对超导能隙的影响。研究结果表明,在S波超导体/正常金属/S波超导结的隧道谱... 研究均匀磁场下的二维拓扑绝缘体在超导隧道结中的电压偏置约瑟夫森结的输运性质,电流-电压特性显示了马约拉纳束缚态的存在。在亚谐隙结构中,也可以观察到磁场对超导能隙的影响。研究结果表明,在S波超导体/正常金属/S波超导结的隧道谱中存在亚谐隙结构。透明度只影响超导结的零偏压电导值的大小,而不影响亚谐隙结构的位置。但是在磁场作用下,亚谐隙结构会发生变化,不再固定出现在特定位置。这一结果对应于拓扑螺旋态中超导和铁磁序之间的相互作用。 展开更多
关键词 拓扑绝缘体 多重Andreev反射 超导隧道结 约瑟夫森结 亚谐隙结构 马约拉纳束缚态 S波超导体 准粒子波函数
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基于FUNWAVE-TVD模型的岸礁次重力波数值模拟 被引量:1
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作者 冯卫兵 华伟豪 张俞 《河海大学学报(自然科学版)》 CAS CSCD 北大核心 2021年第4期349-357,共9页
为了研究不规则波条件下岸礁上次重力波的传播规律,采用完全非线性的Boussinesq数值模型FUNWAVE-TVD对波浪水槽的物理模型试验进行了数值模拟。在对短波、次重力波有效波高与时均水位模拟结果验证的基础上,采用互相关分析与小波二阶谱... 为了研究不规则波条件下岸礁上次重力波的传播规律,采用完全非线性的Boussinesq数值模型FUNWAVE-TVD对波浪水槽的物理模型试验进行了数值模拟。在对短波、次重力波有效波高与时均水位模拟结果验证的基础上,采用互相关分析与小波二阶谱研究了次重力波的生成、传播过程及相关的非线性能量传递。结果表明:礁前次重力波从谱峰频段获得能量;礁前斜坡上水深变浅时,非线性作用加剧,更多波能从谱峰频段传至高频段与低频段并伴随着约束波的成长;礁坪上次重力波主要由破碎点移动产生,礁坪末端能量传递主要发生在低频段之间。 展开更多
关键词 次重力波 岸礁 约束波 破碎点移动 FUNwave-TVD 非线性能量传递
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有界波模拟器中线缆倾角对电磁耦合的影响
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作者 梁英宗 刘芳 +5 位作者 赵扬 赵东艳 陈燕宁 孟庆萌 常泽洲 齐宇 《集成电路与嵌入式系统》 2024年第4期17-22,共6页
电力设备中的断路器、隔离开关等一次设备与二次控保设备距离越来越小,由于一次设备操作而引起的电磁场环境突变,降低了二次设备的可靠性。例如变电站中的隔离开关在合闸和分闸时会产生瞬态强电磁脉冲,该脉冲所携带的部分能量与暴露在... 电力设备中的断路器、隔离开关等一次设备与二次控保设备距离越来越小,由于一次设备操作而引起的电磁场环境突变,降低了二次设备的可靠性。例如变电站中的隔离开关在合闸和分闸时会产生瞬态强电磁脉冲,该脉冲所携带的部分能量与暴露在二次设备外部的线缆耦合,流入设备内部并对其中的电子元器件造成电磁干扰,严重时器件失效并导致设备工作异常。为探明其电磁耦合机理,本文汇总整理了不同电压等级的变电站因开关操作所产生的瞬态电磁场,提取出电磁脉冲的特征波形,利用有界波模拟器在实验室环境下近似再现了特征波形,并对线缆在有界波模拟器中的摆放形态进行了全波仿真分析,揭示了线缆摆放角度对电磁耦合的影响,为电力芯片在复杂电磁场环境下开展可靠性检测提供了理论基础。 展开更多
关键词 有界波模拟器 线缆 耦合效应 隔离开关 电磁脉冲
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基于5G波束成形的变电站作业人员高精度定位技术
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作者 俞家融 杨静泊 +3 位作者 林俊杰 华梁 闵捷 饶建东 《电力信息与通信技术》 2024年第4期92-98,共7页
针对变电站室内作业人员定位精度差的问题,文章提出了多个智能反射面(intelligent reflecting surface,IRS)辅助的5G毫米波高精度室内定位系统。首先基于最大似然估计和三维室内定位模型,获得关于作业人员位置的初始估计,并推导得出克... 针对变电站室内作业人员定位精度差的问题,文章提出了多个智能反射面(intelligent reflecting surface,IRS)辅助的5G毫米波高精度室内定位系统。首先基于最大似然估计和三维室内定位模型,获得关于作业人员位置的初始估计,并推导得出克拉美罗下界(cramer-rao lower bound,CRLB)的闭式表达式;然后以最小化CRLB为目标,建立了IRS反射波束和作业人员侧终端接收波束成形的优化问题;最后基于块坐标下降(block coordinate descent,BCD)和粒子群优化(particle swarm optimization,PSO)的波束成形交替优化算法求解得到最优反射和接收波束,并据此进一步优化作业人员定位精度。仿真结果表明所提方案可以有效提高系统定位精度。 展开更多
关键词 变电站室内定位 5G毫米波 智能反射面 克拉美罗界 波束成形
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Shape analysis and damped oscillatory solutions for a class of nonlinear wave equation with quintic term
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作者 李想 张卫国 +1 位作者 李正明 Ji-bin LI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2014年第1期117-132,共16页
This paper aims at analyzing the shapes of the bounded traveling wave solu- tions for a class of nonlinear wave equation with a quintic term and obtaining its damped oscillatory solutions. The theory and method of pla... This paper aims at analyzing the shapes of the bounded traveling wave solu- tions for a class of nonlinear wave equation with a quintic term and obtaining its damped oscillatory solutions. The theory and method of planar dynamical systems are used to make a qualitative analysis to the planar dynamical system which the bounded traveling wave solutions of this equation correspond to. The shapes, existent number, and condi- tions are presented for all bounded traveling wave solutions. The bounded traveling wave solutions are obtained by the undetermined coefficients method according to their shapes, including exact expressions of bell and kink profile solitary wave solutions and approxi- mate expressions of damped oscillatory solutions. For the approximate damped oscillatory solution, using the homogenization principle, its error estimate is given by establishing the integral equation, which reflects the relation between the exact and approximate so- lutions. It can be seen that the error is infinitesimal decreasing in the exponential form. 展开更多
关键词 nonlinear wave equation bounded traveling wave solution shape analysis approximate damped oscillatory solution error estimate
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Anti-periodic traveling wave solution to a forced two-dimensional generalized KdV-Burgers equation 被引量:1
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作者 谈骏渝 《Journal of Chongqing University》 CAS 2003年第2期97-100,共4页
The anti-periodic traveling wave solutions to a forced two-dimensional generalized KdV-Burgers equation are studied. Some theorems concerning the boundness, existence and uniqueness of the solution to this equation ar... The anti-periodic traveling wave solutions to a forced two-dimensional generalized KdV-Burgers equation are studied. Some theorems concerning the boundness, existence and uniqueness of the solution to this equation are proved. 展开更多
关键词 KDV-BURGERS方程 反周期行波解 存在性 唯一性
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地震波斜入射下港珠澳大桥沉管隧道地震响应分析
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作者 杜闯 高启辉 宋帅 《河北工业大学学报》 CAS 2024年第3期76-86,共11页
斜入射地震波引起的非一致性地震动对地下管廊、沉管隧道等细长结构影响明显。在细长结构抗震中,需要考虑地震动的非一致性。针对港珠澳大桥沉管隧道,采用黏弹性人工边界的方法建立三维有限元模型,对比分析P波、SV波和SH波在不同角度斜... 斜入射地震波引起的非一致性地震动对地下管廊、沉管隧道等细长结构影响明显。在细长结构抗震中,需要考虑地震动的非一致性。针对港珠澳大桥沉管隧道,采用黏弹性人工边界的方法建立三维有限元模型,对比分析P波、SV波和SH波在不同角度斜入射下的隧道动力响应。研究结果表明:不同的入射波、不同的角度在隧道中的响应差别显著。P波、SH波作用下结构加速度随入射角的变化先增大后减小,SV波作用下结构加速度随入射角增大而减小。相较于自下而上的垂直入射,地震波斜入射下结构应力响应被明显放大且不同入射波下结构应力响应的分布特点不同,P波在隧道顶、底板的中部的应力较大,SV波作用下结构纵向非一致性表现得更明显,SH波在隧道侧墙、中隔墙与顶底板相交的角点区以及两个斜向板块应力较大。随着入射角度增大,P波、SV波应力逐渐增大,SH波应力逐渐减小。 展开更多
关键词 地震波斜入射 港珠澳大桥 沉管隧道 黏弹性边界 有限元
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Simulating Long Waves in a Coifs Harbour 3D Physical Model Using Short Wave Spectra
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作者 Indra FW Jayewardene, Ed Couriel +2 位作者 Oliver Light Mark Kulmar Malcolm Robertson 《Journal of Shipping and Ocean Engineering》 2016年第1期15-21,共7页
关键词 物理模型 三维实体 数值模拟 长波 短波 光谱 同时测量 生成技术
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A Numerical Model for Nonlinear Wave Propagation on Non-uniform Current 被引量:2
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作者 张洪生 王卫远 +2 位作者 冯文静 杨建民 卢士强 《China Ocean Engineering》 SCIE EI 2010年第1期15-28,共14页
On the basis of the new type Boussinesq equations (Madsen et al., 2002), a set of equations explicitly including the effects of currents on waves are derived. A numerical implementation of the present equations in o... On the basis of the new type Boussinesq equations (Madsen et al., 2002), a set of equations explicitly including the effects of currents on waves are derived. A numerical implementation of the present equations in one dimension is described. The numerical model is tested for wave propagation in a wave flume of uniform depth with current present. The present numerical results are compared with those of other researchers. It is validated that the present numerical model can reasonably reflect the nonlinear influences of currents on waves. Moreover, the effects of inputting different incident boundary conditions on the calculated results are studied. 展开更多
关键词 Boussirtesq-type equations numerical model wave-current interaction dispersion relation incident bound-ary cortdhion
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Approximate Bound State Solutions for Certain Molecular Potentials
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作者 Mahmoud Farout Mohammed Yasin Sameer M. Ikhdair 《Journal of Applied Mathematics and Physics》 2021年第4期736-750,共15页
We present solutions of the Schrodinger equation with superposition of Manning-Rosen plus inversely Mobius square plus quadratic Yukawa potentials using parametric Nikiforov Uvarov method along with an approximation t... We present solutions of the Schrodinger equation with superposition of Manning-Rosen plus inversely Mobius square plus quadratic Yukawa potentials using parametric Nikiforov Uvarov method along with an approximation to the centrifugal term. The bound state energy eigenvalues for any angular momentum quantum number <em>l</em> and the corresponding un-normalized wave functions are calculated. The mixed potential which in some particular cases gives the solutions for different potentials: the Manning-Rosen, the Mobius square, the inversely quadratic Yukawa and the Hulthén potentials along with their bound state energies are obtained. 展开更多
关键词 Schrödinger Equation Mobius Potential Manning-Rosen Potential Quadratic Yukawa Potential Hulthén Potential bound State Energies wave Functions
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大尺寸Split型垂直极化有界波EMP模拟器场的特性分析
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作者 朱湘琴 吴伟 谢霖燊 《现代应用物理》 2023年第1期124-138,151,共16页
采用并行时域有限差分(finite-difference time-domain, FDTD)方法对大尺寸分裂型垂直极化有界波电磁脉冲模拟器(简称“Split型模拟器”)的电场进行模拟,研究分析了该类型模拟器天线的尺寸参数对模拟器内对称剖面上监测点电场垂直分量... 采用并行时域有限差分(finite-difference time-domain, FDTD)方法对大尺寸分裂型垂直极化有界波电磁脉冲模拟器(简称“Split型模拟器”)的电场进行模拟,研究分析了该类型模拟器天线的尺寸参数对模拟器内对称剖面上监测点电场垂直分量时域特性的影响,给出了该剖面上电场的瞬态分布特性,并与常规模拟器进行了比较。模拟结果表明:模拟器架高越高,监测点处的电场垂直分量的半高宽出现异常的起始高度越高,且同一监测点电场垂直分量的峰值随模拟器最大高度的增大而减小;距离源越近且距离下极板越近的监测点,电场垂直分量的峰值随整个上极板投影长度的增加有明显的减小;同一监测点电场垂直分量的上升沿会随着模拟器梯形金属板投影长度的增加而减小,峰值随该投影长度的增加而增加;监测点电场垂直分量的半高宽随上极板最大空隙宽度的增加而减小,峰值随上极板最大空隙宽度的增加而减小;当Split型模拟器选择合适的尺寸参数及工作空间高度时,电场垂直分量的上升沿和半高宽均满足IEC61000-4-25标准,且电场垂直分量的峰值与常规模拟器差别不大。 展开更多
关键词 分裂型 有界波 垂直极化 电磁脉冲 对称剖面
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Acoustic Based Crosshole Full Waveform Slowness Inversion in the Time Domain 被引量:2
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作者 Wensheng Zhang Atish Kumar Joardar 《Journal of Applied Mathematics and Physics》 2018年第5期1086-1110,共25页
We develop a new full waveform inversion (FWI) method for slowness with the crosshole data based on the acoustic wave equation in the time domain. The method combines the total variation (TV) regularization with the c... We develop a new full waveform inversion (FWI) method for slowness with the crosshole data based on the acoustic wave equation in the time domain. The method combines the total variation (TV) regularization with the constrained optimization together which can inverse the slowness effectively. One advantage of slowness inversion is that there is no further approximation in the gradient derivation. Moreover, a new algorithm named the skip method for solving the constrained optimization problem is proposed. The TV regularization has good ability to inverse slowness at its discontinuities while the constrained optimization can keep the inversion converging in the right direction. Numerical computations both for noise free data and noisy data show the robustness and effectiveness of our method and good inversion results are yielded. 展开更多
关键词 ACOUSTIC wave Equation CROSSHOLE Full waveFORM INVERSION SLOWNESS bound Constraints TV Regularization
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Kinematic Relativity of Quantum Mechanics:Free Particle with Different Boundary Conditions
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作者 Gintautas P.Kamuntavicius G.Kamuntavicius 《Journal of Applied Mathematics and Physics》 2017年第4期853-861,共9页
An investigation of origins of the quantum mechanical momentum operator has shown that it corresponds to the nonrelativistic momentum of classical special relativity theory rather than the relativistic one, as has bee... An investigation of origins of the quantum mechanical momentum operator has shown that it corresponds to the nonrelativistic momentum of classical special relativity theory rather than the relativistic one, as has been unconditionally believed in traditional relativistic quantum mechanics until now. Taking this correspondence into account, relativistic momentum and energy operators are defined. Schr&oumldinger equations with relativistic kinematics are introduced and investigated for a free particle and a particle trapped in the deep potential well. 展开更多
关键词 Special Relativity Quantum Mechanics Relativistic wave Equations Solutions of wave Equations:bound States
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最小二乘拟合正弦参数误差阶梯式分布规律的实验研究
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作者 梁志国 《计量学报》 CSCD 北大核心 2023年第9期1429-1437,共9页
针对波形拟合法估计正弦参数时,测量条件对拟合参数带来的误差,进行了误差界的搜索研究。选取的条件变量分别是A/D位数、序列所含波形的周波数、序列长度。以仿真条件变化方式进行误差界变化规律搜索,获得了幅度、频率、相位、直流偏移... 针对波形拟合法估计正弦参数时,测量条件对拟合参数带来的误差,进行了误差界的搜索研究。选取的条件变量分别是A/D位数、序列所含波形的周波数、序列长度。以仿真条件变化方式进行误差界变化规律搜索,获得了幅度、频率、相位、直流偏移、A/D有效位数等拟合参数的误差界随不同条件变化而变化的曲线规律。并对A/D位数、序列所含波形的周波数、以及序列长度带来的影响进行了深入研究,获得了拟合参数的误差界随序列长度变化呈现量子化阶梯特征的显著规律,给出了量子化阶梯宽度及高度的变化规律。当周波数不变时,各个拟合参数误差随量子化阶梯序号m的变化呈1/m 2规律变化;当量子化误差阶梯号m相同时,拟合频率误差和拟合相位误差均随序列周波数N的变化呈1/N 2规律变化,而拟合幅度、拟合直流偏移、有效位数三个参数的误差均随序列周波数N的增大呈缓慢线性规律降低。该结果可用于拟合正弦参数的误差评价和不确定度估计,也可用于在设定拟合误差和不确定度情况下,选择测量条件。 展开更多
关键词 计量学 正弦波 误差界 量化 曲线拟合 幅度 频率 相位
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残周期正弦曲线拟合的比较研究
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作者 梁志国 《计量学报》 CSCD 北大核心 2023年第6期948-955,共8页
针对频率搜索法和组合法2种残周期正弦曲线拟合方法在实际拟合中所能达到的最短周期个数极限,分别在单精度浮点数和双精度浮点数2种采样序列条件下进行了仿真实验研究,通过分别搜索变化序列周波长度、波形初始相位、序列包含的采样点数... 针对频率搜索法和组合法2种残周期正弦曲线拟合方法在实际拟合中所能达到的最短周期个数极限,分别在单精度浮点数和双精度浮点数2种采样序列条件下进行了仿真实验研究,通过分别搜索变化序列周波长度、波形初始相位、序列包含的采样点数,考查残周期正弦参数拟合误差及其变化规律。获得的结论为:1)对于单精度浮点数序列,任意相位条件下,频率搜索法在10%的波形周期曲线下可以获得可用的结果,组合法可以在7%的波形周期曲线下获得可用的结果;过零点附近的最佳条件下,组合法可以进行1%周期曲线的残周期拟合。2)对双精度浮点数序列,任意相位条件下,频率搜索法在7%的波形周期曲线下可获得可用结果,组合法可以在4%的波形周期曲线下获得可用结果;过零点附近的最佳条件下,组合法可以进行0.03%周期曲线的残周期拟合。 展开更多
关键词 计量学 残周期 正弦波 曲线拟合 误差界
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一种强电磁脉冲模拟器的仿真及验证研究 被引量:1
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作者 王鹏飞 刘恩博 +3 位作者 李贤灵 王海星 张宗兵 田清文 《现代电子技术》 2023年第22期28-32,共5页
用于GJB 151B—2013中RS105测试项目的平面金属板有界波模拟器,其过渡段上下对称能保证产生快前沿脉冲,并使得测试系统所占空间相对较小;且该模拟器中的平行板段会使得有效测试空间相对较大。为实现GJB 151B—2013中RS105项目测试虚拟... 用于GJB 151B—2013中RS105测试项目的平面金属板有界波模拟器,其过渡段上下对称能保证产生快前沿脉冲,并使得测试系统所占空间相对较小;且该模拟器中的平行板段会使得有效测试空间相对较大。为实现GJB 151B—2013中RS105项目测试虚拟化、便捷化,文中基于有限积分技术算法(FIT)的电磁仿真软件CST,通过仿真与实测相结合的方法,对平面金属板有界波模拟器的仿真进行研究,提出一种与该脉冲模拟器等比例的仿真模型,并对该模拟器仿真模型的电场分布特性进行分析。结果表明,所提模型的仿真结果与实测结果非常接近,RS105试验设备测试空间中的电场分布基本均匀,沿传播方向电场逐渐减小,而且电场关于测试系统中心的轴线呈对称分布。该仿真建模准确度高、便捷、安全,能很大程度上满足人们对该类型强电磁脉冲发生器的需求。 展开更多
关键词 平面金属板有界波模拟器 强电磁脉冲 CST FIT GJB 151B—2013标准 RS105试验设备 电磁场仿真 电场分布特性
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基于图像特征的输电线路故障行波存续性判别 被引量:2
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作者 黄杨 张广斌 +1 位作者 王潜 束洪春 《电工技术学报》 EI CSCD 北大核心 2023年第5期1339-1352,共14页
故障行波波头的持续存在是输电线路行波测距和行波保护等得以实施的关键。实际中存在弱故障,现有行波测距与保护缺乏自动判别故障初始波头是否存在和持续,导致行波装置产生错误结果。针对该问题,该文基于初始浪涌波形图像特征及行波在... 故障行波波头的持续存在是输电线路行波测距和行波保护等得以实施的关键。实际中存在弱故障,现有行波测距与保护缺乏自动判别故障初始波头是否存在和持续,导致行波装置产生错误结果。针对该问题,该文基于初始浪涌波形图像特征及行波在输电线路往复传播规律,提出一种输电线路故障行波波头存续性的判别方法。首先分析了故障行波波头阶跃性和后续行波的产生规律,进而提出构造与初始波头具有良好紧密型的包围盒,计算包围盒内故障行波和外切线构成面积与整个包围盒面积的饱和度,由饱和度判定初始波头的存在。进而对存在初始行波波头的情况,基于后续波头到达时序、波头幅值、斜率等相对特征,实现后续行波持续性判别。大量仿真和现场实测数据表明,该方法能够可靠判定故障行波的存续性,有效避免波头不存在的情况下行波装置的误动。 展开更多
关键词 波形图像 行波 初始波头 存续性 饱和度 包围盒 输电线路
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一类非线性项加权的三维弱耦合波动方程组解的生命跨度研究
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作者 王虎生 吕凡 《应用数学》 北大核心 2023年第1期26-40,共15页
本文考虑非线性项加权的三维波动方程组的柯西问题,在初值较小且具有紧支集的前提下,借助改进的Kubo引理得到经典解的生命跨度下界;同时主要通过John迭代并使用切片方法得到解的生命跨度的上界估计.
关键词 波动方程 生命跨度 经典解 上界 下界
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