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引入控制变量的车身噪声传递函数优化研究

汽车技术 2024年第5期 58-62页

作者：郑成龙常林王楷焱宫英伟张新敏北京交通运输职业学院北京100010 中公高远(北京)汽车检测技术有限公司北京100088 沈阳理工大学沈阳110159

为解决车辆整备车身噪声传递函数优化中消除某噪声传递函数声压级峰值时易引发新的噪声声压级峰值的问题,提出引入控制变量的车身噪声传递函数优化方法。以某车型驾驶室为研究对象,构建优化模型,以驾驶室结构板件厚度为变量,利用所提出... 详细信息

为解决车辆整备车身噪声传递函数优化中消除某噪声传递函数声压级峰值时易引发新的噪声声压级峰值的问题,提出引入控制变量的车身噪声传递函数优化方法。以某车型驾驶室为研究对象,构建优化模型,以驾驶室结构板件厚度为变量,利用所提出的算法对涉及的参数进行迭代优化。结果表明,该方法有效降低了目标频带内的噪声传递函数声压级峰值。

关键词：噪声传递函数控制变量贡献量

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5G多路冗余传输技术综述

电信科学 2024年第5期40卷 1-22页

作者：马帅杨博涵羊峰波韦安妮郑成龙中国移动通信有限公司研究院北京100053

当前社会正处在科技高速发展的时代,无线通信技术的迅猛发展不仅推动了工业、交通、医疗等领域的数字化转型,也在不断升级无线通信网络,试图从有线向无线化迈进。随着计算机技术和无线通信技术的不断演进,许多应用场景要求在无线环境下... 详细信息

当前社会正处在科技高速发展的时代,无线通信技术的迅猛发展不仅推动了工业、交通、医疗等领域的数字化转型,也在不断升级无线通信网络,试图从有线向无线化迈进。随着计算机技术和无线通信技术的不断演进,许多应用场景要求在无线环境下实现高可靠传输。特别是面向现代工业自动化、自动驾驶等领域,对高可靠传输的需求更为迫切。深入研究了作为当前业界最先进的无线传输技术之一的5G技术,重点关注了5G系统内多路冗余传输技术。综述了该技术在应用背景、技术原理和技术路线方面的关键要点。在应用背景方面,突出了5G冗余传输在现代工业自动化、自动驾驶等无线场景中的实际应用需求。在技术原理方面,有针对性地从业务端到端多路冗余传输对有关研究进行归纳和梳理,重点分析5G多路冗余传输的技术原理,解释了其在提高传输可靠性方面的独特优势。在技术路线方面,综合考虑了5G多路冗余传输技术的发展方向和各种可能的实施路径。最后,指出5G多路冗余传输技术未来发展的困难和挑战,并探讨其未来发展趋势,以更好地理解5G冗余传输技术在无线通信领域的关键作用和前景。

关键词： 5G URLLC 多路冗余传输复制和消除确定性

Diverse terahertz wavefront manipulations empowered by the spatially interleaved metasurfaces

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Science China(Information Sciences) 2023年第3期66卷 230-238页

作者： Jitao LI Zhen YUE Jie LI chenglong zheng Silei WANG Mengyao LI Yating ZHANG Yan ZHANG Jianquan YAO School of Precision Instruments and Opto-Electronics Engineering Tianjin University College of Optoelectronic Engineering Chengdu University of Information Technology Department of Physics Capital Normal University

Optical metasurfaces have advanced approaches for manipulating light information in the spatial domain, in which the spatially interleaved metasurfaces demonstrate the ability to manipulate a more complex wavefront of light than metasurfaces without the spatial interleaving. The potential of the spatially interleaved metasurfaces has not been fully exploited. In this paper, we design the spatially interleaved terahertz(THz) metasurfaces based on the ingenious spatial interleaving principles to develop the diverse THz wavefront manipulations. Four functions are performed, including the orbital angular momentum(OAM)superposition of single-frequency vortex beams, the separate vortex focusing of single-frequency dual beams,the different OAM manipulations of bifrequency beams in different planes, and achromatic focusing. The demonstrated functions prove that the spatially interleaved metasurface can manipulate THz wavefront at both single frequency and bifrequency, which traditional metasurfaces cannot. This work paves the way for diverse THz wavefront manipulations.

关键词： terahertz wavefront manipulations metasurfaces spatial interleaving onformation optics

Performance analysis of single-focus phase singularity based on elliptical reflective annulus quadrangle-element coded spiral zone plates

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Chinese Physics B 2024年第1期33卷 441-448页

作者：臧华平王宝珍郑程龙魏来范全平王少义杨祖华周维民曹磊峰郭海中 Key Laboratory of Material Physics Ministry of EducationSchool of Physics and MicroelectronicsZhengzhou UniversityZhengzhou 450052China National Key Laboratory for Laser Fusion Research Center of Laser FusionChina Academy of Engineering PhysicsMianyang 621900China School of Engineering Physics Shenzhen Technology UniversityShenzhen 518118China

Optical vortices generated by the conventional vortex lens are usually disturbed by the undesired higher-order foci,which may lead to additional artifacts and thus degrade the contrast sensitivity. In this work, we propose an efficient methodology to combine the merit of elliptical reflective zone plates(ERZPs) and the advantage of spiral zone plates(SZPs) in establishing a specific single optical element, termed elliptical reflective annulus quadrangle-element coded spiral zone plates(ERAQSZPs) to generate single-focus phase singularity. Differing from the abrupt reflectance of the ERZPs, a series of randomly distributed nanometer apertures are adopted to realize the sinusoidal reflectance. Typically, according to our physical design, the ERAQSZPs are fabricated on a bulk substrate;therefore, the new idea can significantly reduce the difficulty in the fabrication process. Based on the Kirchhoff diffraction theory and convolution theorem, the focusing performance of ERAQSZPs is calculated. The results reveal that apart from the capability of generating optical vortices,ERAQSZPs can also integrate the function of focusing, energy selection, higher-order foci elimination, as well as high spectral resolution together. In addition, the focusing properties can be further improved by appropriately adjusting the parameters, such as zone number and the size of the consisted primitives. These findings are expected to direct a new direction toward improving the performance of optical capture, x-ray fluorescence spectra, and forbidden transition.

关键词： optical vortex single-focus spiral zone plate topological charges

Dynamic phase assembled terahertz metalens for reversible conversion between linear polarization and arbitrary circular polarization

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Opto-Electronic Advances 2022年第1期5卷 24-34页

作者： Jitao Li Guocui Wang Zhen Yue Jingyu Liu Jie Li chenglong zheng Yating Zhang Yan Zhang Jianquan Yao Key Laboratory of Opto-Electronics Information Technology(Tianjin University) Ministry of EducationSchool of Precision Instruments and Opto-Electronics EngineeringTianjin UniversityTianjin 300072China Beijing Engineering Research Center for Mixed Reality and Advanced Display School of Optics and PhotonicsBeijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory for Metamaterials and Devices Key Laboratory of Terahertz OptoelectronicsMinistry of Educationand Beijing Advanced Innovation Center for Imaging TechnologyDepartment of PhysicsCapital Normal UniversityBeijing 100048China

If a metalens integrates the circular polarization(CP)conversion function,the focusing lens together with circular-polariz-ing lens(CPL)in traditional cameras may be replaced by a ***,in terahertz(THz)band,the reported metalenses still do not obtain the perfect and strict single-handed CP,because they were constructed via Pancharatnam-Berry phase so that CP conversion contained both left-handed CP(LCP)and right-handed CP(RCP)*** this paper,a silicon based THz metalens is constructed using dynamic phase to obtain single-handed CP ***,we can rotate the whole metalens at a certain angle to control the conversion of multi-polarization states,which can simply manipulate the focusing for incident linear polarization(LP)THz wave in three polarization conversion states,in-cluding LP without conversion,LCP and ***,the polarization conversion behavior is reversible,that is,the THz metalens can convert not only the LP into arbitrary single-handed CP,but also the LCP and RCP into two perpen-dicular LP,*** metalens is expected to be used in advanced THz camera,as a great candidate for tradi-tional CPL and focusing lens group,and also shows potential application in polarization imaging with discriminating LCP and RCP.

关键词： terahertz metalens metamaterials metasurfaces dynamic phase single-handed circular polarization reversible conversion

Application of S-transform threshold filtering in Anhui experiment airgun sounding data de-noising

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Geodesy and Geodynamics 2018年第4期9卷 320-327页

作者： chenglong zheng Xiaofeng Tian Zhuoxin Yang Shuaijun Wang Zhenyu Fan Geophysical Exploration Center China Earthquake Administration

As a relatively new method of processing non-stationary signal with high time-frequency resolution, S transform can be used to analyze the time-frequency characteristics of seismic signals. It has the following characteristics: its time-frequency resolution corresponding to the signal frequency, reversible inverse transform, basic wavelet that does not have to meet the permit conditions. We combined the threshold method, proposed the S-transform threshold filtering on the basis of S transform timefrequency filtering, and processed airgun seismic records from temporary stations in "Yangtze Program"(the Anhui experiment). Compared with the results of the bandpass filtering, the S transform threshold filtering can improve the signal to noise ratio(SNR) of seismic waves and provide effective help for first arrival pickup and accurate travel time. The first arrival wave seismic phase can be traced farther continuously, and the Pm seismic phase in the subsequent zone is also highlighted.

关键词： S transform Time-frequency filtering Airgun data Threshold filtering De-noising

All-silicon chiral metasurfaces and wavefront shaping assisted by interference

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Science China(Physics,Mechanics & Astronomy) 2021年第11期64卷 69-77页

作者： chenglong zheng Jie Li Jitao Li Zhen Yue Silei Wang Mengyao Li Hongliang Zhao Xuanruo Hao Huaping Zang Yating Zhang Jianquan Yao Key Laboratory of Opto-Electronics Information Technology(Tianjin University) Ministry of EducationSchool of Precision Instruments and Opto-Electronics EngineeringTianjin UniversityTianjin 300072China School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China

Chiral metasurfaces have different electromagnetic responses with circularly polarized lights,showing as circular dichroism and optical ***,a novel kind of all-silicon chiral metasurface is proposed by introducing destructive interference between achiral *** maximum value of circular dichroism spectra can reach *** adding an antireflective layer at the side of the silicon substrate,the maximum circular dichroism reaches *** is more,the bandwidth of circular dichroism greater than 0.4 reaches 0.15 *** samples are fabricated to verify the feasibility of this scheme,and the experimental results are in good agreement with the *** addition,the proposed scheme can also be used to generate various interesting functions,such as beam control and vortex *** flexible and efficient implementation solution of chiral metasurface can bring new ideas to the development of chiral devices in the future.

关键词： metasurface chiral terahertz decoupling

Broadband and tunable terahertz absorption via photogenerated carriers in undoped silicon

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Science China(Physics,Mechanics & Astronomy) 2022年第1期65卷 14-21页

作者： Jie Li Jitao Li chenglong zheng Longhai Liu Zhen Yue Hang Xu Xuanruo Hao Fuyu Li Tingting Tang Yating Zhang Jianquan Yao Key Laboratory of Opto-Electronics Information Technology(Tianjin University) Ministry of EducationSchool of Precision Instruments and Opto-Electronics EngineeringTianjin UniversityTianjin 300072China Advantest(China)Co. Ltd.Shanghai 201203China Information Materials and Device Applications Key Laboratory of Sichuan Provincial Universities Chengdu University of Information TechnologyChengdu 610225China

Terahertz absorbers based on doped silicon have achieved broadband and high-efficiency absorption due to their high concentration of ***,their tunable performance is obviously ***,we propose a new scheme for active terahertz absorption based on undoped silicon with a metamaterial antireflection layer,which realizes both strong absorption and ultrahigh modulation *** from the weak absorption and high transmission of undoped silicon for 1064-nm continuous wave,uniformly distributed carriers across the entire thickness of the absorber are excited,and efficient free carrier absorption of the terahertz wave is *** use only a 500-μm thick absorber and achieve absorption greater than 90%in the range of 0.58 to 1.92 THz,with a peak value of 99%.More important,the absorber can be switched between two working states of nonabsorption and high-efficiency absorption by changing the pump power,which means the modulation depth reaches 100%.This simple and high-performance implementation scheme provides a new idea for the design of terahertz tunable absorbers.

关键词： terahertz carriers silicon metamaterials

Nonlinear Flap-Wise Vibration Characteristics ofWind Turbine Blades Based onMulti-Scale AnalysisMethod

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Energy Engineering 2024年第2期121卷 483-498页

作者： Qifa Lang Yuqiao zheng Tiancai Cui chenglong Shi Heyu Zhang School of Mechanical and Electrical Engineering Lanzhou University of TechnologyLanzhou730050China

This work presents a novel approach to achieve nonlinear vibration response based on the Hamilton *** chose the 5-MW reference wind turbine which was established by the National Renewable Energy Laboratory(NREL),to research the effects of the nonlinear flap-wise vibration *** turbine wheel is simplified by treating the blade of a wind turbine as an Euler-Bernoulli beam,and the nonlinear flap-wise vibration characteristics of the wind turbine blades are discussed based on the simplification ***,the blade’s large-deflection flap-wise vibration governing equation is established by considering the nonlinear term involving the centrifugal ***,it is truncated by the Galerkin method and analyzed semi-analytically using the multi-scale analysis method,and numerical simulations are carried out to compare the simulation results of finite elements with the numerical simulation results using Campbell diagram analysis of blade *** results indicated that the rotational speed of the impeller has a significant impact on blade *** the wheel speed of 12.1 rpm and excitation amplitude of 1.23 the maximum displacement amplitude of the blade has increased from 0.72 to *** the amplitude-frequency curve,it can be seen that the multi-peak characteristic of blade amplitude frequency is under centrifugal *** phase trajectories in blade nonlinear vibration,exhibiting periodic motion characteristics,are found through phase diagrams and Poincare section diagrams.

关键词： Wind turbine blades nonlinear vibration Galerkin method multi-scales method