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简支梁非线性响应的三维路径积分法分析 预览
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作者 潘鑫凯 王小盾 朱海涛 《计算力学学报》 CAS CSCD 北大核心 2019年第3期395-400,共6页
采用基于Gauss-Legendre积分公式的三维路径积分法,分析了在过滤高斯白噪声激励下的简支梁非线性随机振动响应的概率密度函数;联立一阶滤波方程与简支梁一阶模态的振动模型,得到在过滤高斯白噪声激励下的简支梁随机振动模型,基于Gauss-L... 采用基于Gauss-Legendre积分公式的三维路径积分法,分析了在过滤高斯白噪声激励下的简支梁非线性随机振动响应的概率密度函数;联立一阶滤波方程与简支梁一阶模态的振动模型,得到在过滤高斯白噪声激励下的简支梁随机振动模型,基于Gauss-Legendre积分公式的积分法和短时高斯近似法求解响应的概率密度函数值。结果表明,三维路径积分法计算值与蒙特卡洛模拟值符合良好,即使在尾部区域也符合良好。三维路径积分法比等效线性化法的计算精度更高。 展开更多
关键词 三维路径积分法 过滤高斯白噪声 简支梁 非线性 非平稳
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多新息理论改进优化粒子滤波研究 预览
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作者 白晓波 邵景峰 +1 位作者 和征 田建刚 《计算机仿真》 北大核心 2019年第1期284-290,共7页
研究多新息理论改进优化粒子滤波问题,以提高粒子滤波精度。其中粒子滤波状态估计模型的改进和新息数的选择是难点题。首先,基于多新息理论,利用多新息的增益矩阵和新息向量的乘积,对标准粒子滤波的状态估计模型改进优化,提出基于多新... 研究多新息理论改进优化粒子滤波问题,以提高粒子滤波精度。其中粒子滤波状态估计模型的改进和新息数的选择是难点题。首先,基于多新息理论,利用多新息的增益矩阵和新息向量的乘积,对标准粒子滤波的状态估计模型改进优化,提出基于多新息改进优化的粒子滤波MI-PF;然后,分析了MI-PF算法的时间复杂度,从理论上论述了多新息理论改进优化粒子滤波的可行性;最后,利用仿真的方法,研究了不同新息数对MI-PF滤波性能和效率的影响,并得出了在强非线性、非高斯系统下,MI-PF新息数的取值范围。实验结果表明:若粒子数相同,与其它改进的粒子滤波相比,MI-PF滤波精度更高;若滤波精度近似,MI-PF使用的粒子数最少效率最高。从而验证了多信息理论改进粒子滤波的可行性,提高了粒子滤波精度。 展开更多
关键词 多新息理论 粒子滤波 增益矩阵 新息向量 非线性 非高斯
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Two methodological approaches to assess the seismic vulnerability of masonry bridges
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作者 Diego Maria Barbieri 《交通运输工程学报(英文版)》 CSCD 2019年第1期49-64,共16页
This work describes the seismic vulnerability assessment of a railway masonry arch bridge.Its conservation state is initially investigated by means of a thorough field and laboratory test campaign, comprising destruct... This work describes the seismic vulnerability assessment of a railway masonry arch bridge.Its conservation state is initially investigated by means of a thorough field and laboratory test campaign, comprising destructive and non-destructive tests. Two different methods are used to evaluate the bridge seismic vulnerability. The first method adopts a deterministic approach and corresponds to a single non-linear static analysis, performed as described in the Eurocodes. The second method employs a probabilistic approach and considers the variability of the involved mechanical parameters(structure geometry and properties of the building materials) and seismic parameters(intensity of the action and site conditions). This method associates the probabilistic values of ground acceleration exceedance to the estimated seismic vulnerability. This is shown by means of fragility curves, which allow to take into consideration the uncertainty of the various components involved in the definition of the seismic vulnerability and display the seismic damage scenarios. Currently no code requires to perform this calculation procedure. In addition,this work compares the values of masonry mechanical properties specified in the Eurocodes with those obtained in an extensive investigation campaign involving more than one hundred masonry bridges. Compressive strength and longitudinal elasticity modulus are the relevant mechanical parameters investigated. The outcomes of this research can contribute to the development of a more efficient maintenance system of the masonry bridges belonging to the railway network. This has an important role when it comes to establishing the priority order of assets intervention. 展开更多
关键词 Railway MASONRY ARCH BRIDGE BRIDGE maintenance and conservation MASONRY mechanical parameters NON-LINEAR static ANALYSIS Seismic FRAGILITY Finite element ANALYSIS
Study of the internal characteristics of the stall in a centrifugal pump with a cubic non-linear SGS model 预览
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作者 Xian-bei Huang Zhu-qing Liu +2 位作者 Yao-jun Li Wei Yang Qiang Guo 《水动力学研究与进展:英文版》 SCIE EI CSCD 2019年第4期788-799,共12页
The stall in a centrifugal pump impeller under a quarter-load condition is investigated by using a third-order SGS model named the DCNM, for a better understanding of the rotation effect on the stall phenomenon. The s... The stall in a centrifugal pump impeller under a quarter-load condition is investigated by using a third-order SGS model named the DCNM, for a better understanding of the rotation effect on the stall phenomenon. The study of the distributions of the Reynolds stresses, the production tei*m and the rotation term reveals that the production and the rotation jointly result in the non-uniform Reynolds stress distribution. Further study of the two components of the production and the rotation shows that they jointly transport a certain energy from the Reynolds component R、to Ruu. 展开更多
关键词 Centrifligal pump large-eddy simulation NON-LINEAR model OPENFOAM STALL
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Temporal variability of visibility and its parameterizations in Ningbo,China
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作者 Jingjing Zhang Lei Tong +4 位作者 Chenghui Peng Huiling Zhang Zhongwen Huang Jun He Hang Xiao 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第3期372-382,共11页
Simultaneous and continuous measurements of visibility, meteorological parameters and air pollutants were carried out at a suburban site in Ningbo from June 1, 2013 to May 31,2015. The characteristics of visibility an... Simultaneous and continuous measurements of visibility, meteorological parameters and air pollutants were carried out at a suburban site in Ningbo from June 1, 2013 to May 31,2015. The characteristics of visibility and their relationships with air pollutants and meteorological factors were investigated using multiple statistical methods. Daily visibility ranged from 0.6 to 34.1 km, with a mean value of 11.8 km. During the 2-year experiment,43.4% of daily visibility was found to be less than 10.0 km and only 9.2% was greater than 20.0 km. Visibility was lower in winter with a frequency of 53.4% in the range of 0.0–5.0 km.Annual visibility had an obvious diurnal variation, with the lowest and highest visibility being 7.5 km at approximately 06:00 local time and 15.6 km at approximately 14:00 local time, respectively. Multiple correspondence analysis(MCA) indicated that the different ranges of visibility were significantly affected by different levels of pollutants and meteorological conditions. Based on the analyses, visibility was found to be an exponential function of PM2.5 concentrations within a certain range of relative humidity. Thus, nonlinear models combining multiple linear regressions with exponential regression were subsequently developed using the data collected from June 2014 to May 2015, and the data from June 2013 to May 2014 was used to evaluate the performance of the model. It was demonstrated that the derived models can quantitatively describe the relationships between visibility, air quality and meteorological parameters in Ningbo. 展开更多
关键词 VISIBILITY MULTIPLE CORRESPONDENCE analysis(MCA) MULTIPLE NON-LINEAR regression
基于非线性能量收集的DF中继网络性能分析 预览
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作者 李乐乐 王天赐 +2 位作者 李波 刘继明 王彦本 《计算机工程与设计》 北大核心 2019年第8期2123-2127,2195共6页
研究基于非线性能量收集的单向解码转发多中继的能量受限网络问题。对于传统的单中继网络,结合信息和能量同传(simultaneous wireless information and power transfer,SWIPT)技术,提出一种基于粒子群算法的功率分离策略。由于单中继网... 研究基于非线性能量收集的单向解码转发多中继的能量受限网络问题。对于传统的单中继网络,结合信息和能量同传(simultaneous wireless information and power transfer,SWIPT)技术,提出一种基于粒子群算法的功率分离策略。由于单中继网络传输的局限性,进一步设计非线性多中继的系统模型,该系统模型使用非对称功率分离策略,把提高系统中断吞吐量作为优化目标,将该系统模型方案与基于线性的同级比较方案进行比较。仿真结果验证了设计算法的有效性,表明时间切换因子、传输速率等因素对系统中断吞吐性能存在影响。 展开更多
关键词 非线性 能量收集 信息和能量同传 粒子群优化 非对称功率分离
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偏差改正的Partial EIV模型方差分量估计 预览
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作者 王乐洋 温贵森 《测绘学报》 EI CSCD 北大核心 2019年第4期412-421,共10页
针对PartialEIV模型的方差分量估计中未考虑参数估值偏差所带来的影响,将PartialEIV模型视为非线性函数得到参数估值的偏差及二阶近似协方差表达式,计算得到偏差改正后的参数估值,结合方差分量估计方法,更新由参数估值影响的矩阵变量,... 针对PartialEIV模型的方差分量估计中未考虑参数估值偏差所带来的影响,将PartialEIV模型视为非线性函数得到参数估值的偏差及二阶近似协方差表达式,计算得到偏差改正后的参数估值,结合方差分量估计方法,更新由参数估值影响的矩阵变量,给出了基于偏差改正的方差分量估计迭代方法.试验结果表明,参数估值及其协方差主要受参数估值偏差大小的影响,加入偏差改正能够得到更加合理的参数估值及方差分量估值,偏差改正后的方差分量估值可更加合理地评估参数估值的精度信息. 展开更多
关键词 PartialEIV模型 非线性 偏差改正 方差分量估计
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基于Hertz弹性接触的船舶推进轴系非线性校中计算 预览
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作者 杨红军 李俊 刘镇剑 《船舶力学》 EI CSCD 北大核心 2019年第2期218-226,共9页
针对大型商船推进轴系中尾管后轴承,且尾轴在螺旋桨重量作用下存在弯曲变形,导致尾管后轴承后端存在边缘载荷的特点,研究了轴系校中计算中尾管后轴承Hertz接触模型的非线性建模方法。以第二代四十万吨矿砂船轴系为对象,采用平面梁单元,... 针对大型商船推进轴系中尾管后轴承,且尾轴在螺旋桨重量作用下存在弯曲变形,导致尾管后轴承后端存在边缘载荷的特点,研究了轴系校中计算中尾管后轴承Hertz接触模型的非线性建模方法。以第二代四十万吨矿砂船轴系为对象,采用平面梁单元,建立轴系校中有限元模型;同时将尾管后轴承分成多个轴承分段,使用Hertz接触模型模拟各个轴承段与轴的接触形态,并用迭代法求解了具有非线性边界条件的梁单元有限元模型。对根据尾管后轴承单支点模型的计算结果确定的几组尾管后轴承SLOPE值进行了计算对比。研究发现,基于Hertz弹性接触的尾管后轴承多点支承的非线性模型,可以得到尾管后轴承的最大接触压力、各个轴承段的支反力等分布情况,可以更好地优化尾管后轴承的SLOPE设置,要优于传统的单支点固定约束模型。 展开更多
关键词 Hertz弹性接触 非线性 尾管后轴承 轴系校中
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基于非线性状态估计的虚假数据注入攻击代价分析 预览
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作者 赵丽莉 刘忠喜 +1 位作者 孙国强 倪明 《电力系统保护与控制》 CSCD 北大核心 2019年第19期38-45,共8页
随着智能电网的发展,信息通信系统与物理电力系统深度融合,虚假数据注入等网络攻击可能会对电网的安全稳定造成严重影响,目前这方面研究已成热点问题。一次成功的虚假数据注入攻击涉及攻击者所掌握资源、攻击区域选择和攻击向量构建。... 随着智能电网的发展,信息通信系统与物理电力系统深度融合,虚假数据注入等网络攻击可能会对电网的安全稳定造成严重影响,目前这方面研究已成热点问题。一次成功的虚假数据注入攻击涉及攻击者所掌握资源、攻击区域选择和攻击向量构建。在有限的资源下,根据实际电网运行特征,以攻击节点为中心,构建了单节点攻击区域和多节点攻击区域,一定程度上可缩小攻击范围。基于非线性状态估计模型,分别针对单节点攻击与多节点攻击情形,提出一种掌握局部电网信息下的攻击代价分析方法。最后以IEEE-14系统和IEEE-1354系统为例,分别进行单节点攻击和多节点攻击分析,其结果验证了所提虚假数据注入攻击代价分析方法的有效性。 展开更多
关键词 虚假数据注入 攻击代价 信息安全 信息物理系统 非线性 多节点攻击
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Seismic progressive-failure analysis of tall steel structures under beam-removal scenarios
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作者 Behrouz BEHNAM Fahimeh SHOJAEI Hamid Reza RONAGH 《结构与土木工程前沿:英文版》 EI CSCD 2019年第4期904-917,共14页
Investigating progressive collapse of tall structures under beam removal scenarios after earthquake is a complex subject because the earthquake damage acts as an initial condition for the subsequent scenario. An inves... Investigating progressive collapse of tall structures under beam removal scenarios after earthquake is a complex subject because the earthquake damage acts as an initial condition for the subsequent scenario. An investigation is performed here on a 10 story steel moment resisting structure designed to meet the life safety level of performance when different beam removal scenarios after earthquake are considered. To this end, the structure is first subjected to the design earthquake simulated by Tabas earthquake acceleration. The beam removal scenarios are then considered at different locations assuming that both ends connections of the beam to columns are simultaneously detached from the columns;thus the removed beam falls on the underneath floor with an impact. This imposes considerable loads to the structure leading to a progressive collapse in all the scenarios considered. The results also show that the upper stories are much more vulnerable under such scenarios than the lower stories. Hence, more attention shall be paid to the beam-to-column connections of the upper stories during the process of design and construction. 展开更多
关键词 PROGRESSIVE COLLAPSE tall steel moment-resisting FRAMES NON-LINEAR dynamic analysis beam-removal SCENARIO impact
基于MPSO-BP神经网络的PSD误差补偿 预览
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作者 王福杰 俞恒杰 陆辉山 《仪表技术与传感器》 CSCD 北大核心 2019年第2期78-81,85共5页
针对光电位置传感器(PSD)测试系统的输出非严格线性的标定问题,提出了改进的粒子群优化BP神经网络的非线性补偿方法。采用自适应调整学习因子构造MPSO-BP神经网络分类器,建立一个2×35×2的BP神经网络。利用标定数据训练网络,... 针对光电位置传感器(PSD)测试系统的输出非严格线性的标定问题,提出了改进的粒子群优化BP神经网络的非线性补偿方法。采用自适应调整学习因子构造MPSO-BP神经网络分类器,建立一个2×35×2的BP神经网络。利用标定数据训练网络,将训练好的网络应用到输出信号。实验结果表明,相比于BP神经网络0.297%的相对误差,PSO-BP神经网络的相对误差减小到0.052%,准确度提高5倍以上,提高了PSD传感器的可靠性和测量精度。 展开更多
关键词 BP神经网络 粒子群算法 非线性 PSD 误差补偿
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流体介质对齿轮泵内部流场影响的仿真分析 预览
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作者 段志善 田庆飞 郭宝良 《机械设计与制造》 北大核心 2019年第6期132-135,共4页
为研究流体介质对齿轮泵内部流场及脉动的影响机制,运用FLUENT软件对齿轮泵的二维内部流场进行了瞬态仿真分析,对比分析了不同工况下流体介质对齿轮泵内部流场及输出特性影响。数值分析表明:考虑流体介质非线性变化较不考虑时泵出口流... 为研究流体介质对齿轮泵内部流场及脉动的影响机制,运用FLUENT软件对齿轮泵的二维内部流场进行了瞬态仿真分析,对比分析了不同工况下流体介质对齿轮泵内部流场及输出特性影响。数值分析表明:考虑流体介质非线性变化较不考虑时泵出口流量脉动系数之间的差值随着转速的增大而减小,随着负载的增大而增大;流体介质的非线性变化对泵的流量脉动系数及实际流量影响较大,对压力脉动的脉动系数及实际压力影响较小。考虑流体介质非线性变化的仿真结果更符合实际工况,为开展齿轮泵的减振降噪及故障诊断等方面的研究提供了有效的工具。 展开更多
关键词 齿轮泵 内部流场分析 非线性 流量脉动 故障诊断
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一类非线性反馈系统的自适应输出调节 预览
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作者 崔雷 李其申 储珺 《火力与指挥控制》 CSCD 北大核心 2019年第5期42-47,共6页
研究了一类不确定非线性系统的全局鲁棒性输出调节问题。通过调节器的拓展方程可解性的假设,来建立非线性的内模,估计非线性未知外部扰动系统,从而将输出调节问题转化为镇定问题;结合 Lyapunov 函数和自适应理论来设计控制器,解决一类... 研究了一类不确定非线性系统的全局鲁棒性输出调节问题。通过调节器的拓展方程可解性的假设,来建立非线性的内模,估计非线性未知外部扰动系统,从而将输出调节问题转化为镇定问题;结合 Lyapunov 函数和自适应理论来设计控制器,解决一类非线性输出反馈系统的输出调节问题。最后,仿真结果验证了所设计的控制器的有效性。 展开更多
关键词 非线性 输出调节 内模 LYAPUNOV函数 自适应
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模拟发动机驱动的变速器传动系统动态性能台架试验 预览
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作者 郑凯峰 李伟 +4 位作者 程立勇 窦红印 汪记伟 杨万里 王瑞平 《汽车零部件》 2019年第6期68-70,共3页
提出一种由传动系统动态性能试验台输入电机模拟发动机驱动变速器的动态耐久试验。该试验台驱动电机采用了一台低惯量、高动态永磁电机来模拟发动机。为了能使该电机精确地模拟发动机的动态特性,基于发动机特性曲线并模拟实车阻力结合... 提出一种由传动系统动态性能试验台输入电机模拟发动机驱动变速器的动态耐久试验。该试验台驱动电机采用了一台低惯量、高动态永磁电机来模拟发动机。为了能使该电机精确地模拟发动机的动态特性,基于发动机特性曲线并模拟实车阻力结合整车道路载荷谱的使用、控制,实现了电机模拟发动机的动态试验。 展开更多
关键词 发动机特性 滚动阻力 空气阻力 载荷 非线性
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Behavior and functional modeling methods of doubly salient electromagnetic generators for aircraft electrical power system applications
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作者 Yanwu XU Zhuoran ZHANG +1 位作者 Li YU Yuke SHI 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第2期477-488,共12页
The Doubly Salient Electromagnetic Generator(DSEG) is a promising candidate in aircraft generator application due to the simplicity, robustness and reliability. However, the field windings and the armature windings ar... The Doubly Salient Electromagnetic Generator(DSEG) is a promising candidate in aircraft generator application due to the simplicity, robustness and reliability. However, the field windings and the armature windings are strongly coupled, which makes the inductance characteristics non-linear and too complex to model. The complex model with low precision also leads to difficulties in modeling and analysis of the entire aircraft Electrical Power System(EPS). A behavior level modeling method based on modified inductance Support Vector Machine(SVM) is proposed. The Finite Element Analysis(FEA) inductance data are modified based on the experiment results to improve the precision. A functional level modeling method based on input–output characteristics SVM is also proposed. The two modeling methods are applied to a 9 kW DSEG prototype. The steady state and transient process precision of the proposed methods are proved by comparing with the experiment results. Meanwhile, the modeling time consumption, the application time consumption and the calculation resource demand are compared. The DSEG behavior and functional modeling methods provide precious results with high efficiency, which accelerates theoretical analysis and expands the application foreground of the DSEG in the aircraft EPS. 展开更多
关键词 BEHAVIOR modeling DOUBLY salient electromagnetic machine FUNCTIONAL models NON-LINEAR analysis Support vector machines
高管薪酬激励、股权激励与资本结构的非线性关系研究——来自中国制造业上市公司的经验数据 预览
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作者 罗雪婷 《金融理论探索》 2019年第4期43-52,共10页
选取制造业上市公司2010—2016年的数据,结合多元回归分析和曲线拟合对高管薪酬激励、股权激励与资本结构的非线性关系进行检验。研究表明,高管薪酬激励与资本结构呈“正U型”关系,拐点为14.34%;股权激励与资本结构呈递减的非线性关系,... 选取制造业上市公司2010—2016年的数据,结合多元回归分析和曲线拟合对高管薪酬激励、股权激励与资本结构的非线性关系进行检验。研究表明,高管薪酬激励与资本结构呈“正U型”关系,拐点为14.34%;股权激励与资本结构呈递减的非线性关系,当激励水平在(0,1%)区间时,负债率随着激励水平提高而显著下降,当激励水平在(1%,+∞)区间时,负债率随高管持股比例增加而有所提升,但总体仍呈负相关。因此,我国制造业上市公司应建立以稳定高管薪酬激励、强化股权激励为特征的高管激励体系,并通过强化高管监督约束机制等方式以优化资本结构水平。 展开更多
关键词 高管薪酬激励 股权激励 资本结构 制造业上市公司 非线性关系 区间效应
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VALUE DISTRIBUTION OF MEROMORPHIC SOLUTIONS OF CERTAIN NON-LINEAR DIFFERENCE EQUATIONS 预览
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作者 陈敏风 高宗升 张继龙 《数学物理学报:B辑英文版》 SCIE CSCD 2019年第4期1173-1184,共12页
In this article, we consider the non-linear difference equation(f(z + 1)f(z)-1)(f(z)f(z-1)-1) =P(z, f(z))/Q(z, f(z)),where P(z, f(z)) and Q(z, f(z)) are relatively prime polynomials in f(z) with rational coefficients.... In this article, we consider the non-linear difference equation(f(z + 1)f(z)-1)(f(z)f(z-1)-1) =P(z, f(z))/Q(z, f(z)),where P(z, f(z)) and Q(z, f(z)) are relatively prime polynomials in f(z) with rational coefficients. For the above equation, the order of growth, the exponents of convergence of zeros and poles of its transcendental meromorphic solution f(z), and the exponents of convergence of poles of difference △f(z) and divided difference △f(z)/f(z)are estimated. Furthermore, we study the forms of rational solutions of the above equation. 展开更多
关键词 NON-LINEAR DIFFERENCE equation MEROMORPHIC SOLUTION RATIONAL SOLUTION value dist ribution
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Free vibration analysis of a spinning piezoelectric beam with geometric nonlinearities 预览
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作者 Wei Li Xiao-Dong Yang +2 位作者 Wei Zhang Yuan Ren Tian-Zhi Yang 《力学学报:英文版》 SCIE EI CAS CSCD 2019年第4期879-893,共15页
The linear and non-linear free vibrations of a spinning piezoelectric beam are studied by considering geometric nonlinearities and electromechanical coupling effect. The non-linear differential equations of the spinni... The linear and non-linear free vibrations of a spinning piezoelectric beam are studied by considering geometric nonlinearities and electromechanical coupling effect. The non-linear differential equations of the spinning piezoelectric beam governing two transverse vibrations are derived by using two Euler angles transformation and extended Hamilton principle, wherein an additional piezoelectric coupling term and different linear terms are present in contrast to the traditional shaft model. Linear frequencies are obtained by solving the standard eigenvalues of the linearized system directly, and the non-linear frequencies and non-linear complex modes are achieved by using the method of multiple scales. For free vibrations analysis of a spinning piezoelectric beam, the non-linear modal motions are investigated as forward and backward precession with different spinning speeds. The responses to the initial conditions for such a gyroscopic system are studied,and a beat phenomenon is found, which are then validated by numerical simulation. The influences of some parameters such as electrical resistance, rotary inertia and spinning speeds to the non-linear dynamics of a spinning piezoelectric beam are investigated. 展开更多
关键词 SPINNING PIEZOELECTRIC BEAM Free vibrations NON-LINEAR frequencies Complex MODES
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Programmable time-domain digital-coding metasurface for non-linear harmonic manipulation and new wireless communication systems
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作者 Jie Zhao Xi Yang +9 位作者 Jun Yan Dai Qiang Cheng Xiang Li Ning Hua Qi Jun Chen Ke Guo Dong Bai Shuo Liu Shi Jin Andrea Alu Tie Jun Cui 《国家科学评论:英文版》 CSCD 2019年第2期231-238,共8页
Optical non-linear phenomena are typically observed in natural materials interacting with light at high intensities, and they benefit a diverse range of applications from communication to sensing. However,controlling ... Optical non-linear phenomena are typically observed in natural materials interacting with light at high intensities, and they benefit a diverse range of applications from communication to sensing. However,controlling harmonic conversion with high efficiency and flexibility remains a major issue in modern optical and radio-frequency systems. Here, we introduce a dynamic time-domain digital-coding metasurface that enables efficient manipulation of spectral harmonic distribution. By dynamically modulating the local phase of the surface reflectivity, we achieve accurate control of different harmonics in a highly programmable and dynamic fashion, enabling unusual responses, such as velocity illusion. As a relevant application, we propose and realize a novel architecture for wireless communication systems based on the time-domain digital-coding metasurface, which largely simplifies the architecture of modern communication systems, at the same time yielding excellent performance for real-time signal transmission. The presented work, from new concept to new system, opens new pathways in the application of metamaterials to practical technology. 展开更多
关键词 metasurface TIME-DOMAIN DIGITAL CODING NON-LINEAR HARMONICS control NEW architecture of communication
STABILITY OF GLOBAL MAXWELLIAN FOR NON-LINEAR VLASOV-POISSON-FOKKER-PLANCK EQUATIONS 预览
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作者 廖杰 王倩蓉 杨雄锋 《数学物理学报:B辑英文版》 SCIE CSCD 2019年第1期127-138,共12页
In this article, we establish the exponential time decay of smooth solutions around a global Maxwellian to the non-linear Vlasov–Poisson–Fokker–Planck equations in the whole space by uniform-in-time energy estimate... In this article, we establish the exponential time decay of smooth solutions around a global Maxwellian to the non-linear Vlasov–Poisson–Fokker–Planck equations in the whole space by uniform-in-time energy estimates. The non-linear coupling of macroscopic part and Fokker–Planck operator in the model brings new difficulties for the energy estimates, which is resolved by adding tailored weighted-in-v energy estimates suitable for the Fokker–Planck operator. 展开更多
关键词 NON-LINEAR Vlasov–Poisson–Fokker–Planck equation GLOBAL Maxwellian GLOBAL a priori ESTIMATES EXPONENTIAL convergence
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