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Photonics Research 2024年第4期12卷 804-812页

作者： XIAOYU NIE HAOTIAN SONG WENHAN REN ZHEDONG ZHANG TAO PENG MARLAN O.SCULLY Institute for Quantum Science and engineering Texas A&M UniversityCollege StationTexas 77843USA School of Physics Xi’an Jiaotong UniversityXi’an 710049China department of Physics City University of Hong KongHong KongChina Baylor University WacoTexas 76706USA

The generation of speckle patterns via random matrices, statistical definitions, or apertures may not always result in optimal outcomes. Issues such as correlation fluctuations in low ensemble numbers and diffraction in long-distance propagation can arise. Instead of improving results of specific applications, our solution is catching deep correlations of patterns with the framework, Speckle-Net, which is fundamental and universally applicable to various systems. We demonstrate this in computational ghost imaging(CGI) and structured illumination microscopy(SIM). In CGI with extremely low ensemble number, it customizes correlation width and minimizes correlation fluctuations in illuminating patterns to achieve higher-quality images. It also creates non-Rayleigh nondiffracting speckle patterns only through a phase mask modulation, which overcomes the power loss in the traditional ring-aperture method. Our approach provides new insights into the nontrivial speckle patterns and has great potential for a variety of applications including dynamic SIM, X-ray and photo-acoustic imaging, and disorder physics.

关键词： CGI Deep ghost

Price prediction of power transformer materials based on CEEMD and GRU

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Global energy Interconnection 2024年第2期7卷 217-227页

作者： Yan Huang Yufeng Hu Liangzheng Wu Shangyong Wen Zhengdong Wan energy Development Research Institute China Southern Power GridGuangzhou 510623P.R.China China Southern Power Grid Guangzhou 510623P.R.China

The rapid growth of the Chinese economy has fueled the expansion of power *** transformers are key equipment in power grid projects,and their price changes have a significant impact on cost ***,the prices of power transformer materials manifest as nonsmooth and nonlinear ***,estimating the acquisition costs of power grid projects is difficult,hindering the normal operation of power engineering *** more accurately predict the price of power transformer materials,this study proposes a method based on complementary ensemble empirical mode decomposition(CEEMD)and gated recurrent unit(GRU)***,the CEEMD decomposed the price series into multiple intrinsic mode functions(IMFs).Multiple IMFs were clustered to obtain several aggregated sequences based on the sample entropy of each ***,an empirical wavelet transform(EWT)was applied to the aggregation sequence with a large sample entropy,and the multiple subsequences obtained from the decomposition were predicted by the GRU *** GRU model was used to directly predict the aggregation sequences with a small sample *** this study,we used authentic historical pricing data for power transformer materials to validate the proposed *** empirical findings demonstrated the efficacy of our method across both datasets,with mean absolute percentage errors(MAPEs)of less than 1%and 3%.This approach holds a significant reference value for future research in the field of power transformer material price prediction.

关键词： Power transformer material Price prediction Complementary ensemble empirical mode decomposition Gated recurrent unit Empirical wavelet transform

Optimization Algorithms for Sidelobes SSL Reduction: A Comparative Study

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Journal of Computer and Communications 2024年第7期12卷 120-132页

作者： Mohsen Denden Aymen Alhamdan department of Computer Science Higher Institute of Applied Sciences of Sousse Sousse University Sousse Tunisia department of Electrical Computer engineering Faculty of Engineering King Abdulaziz University Jeddah Saudi Arabia

The development of new technologies in smart cities is often hailed as it becomes a necessity to solve many problems like energy consumption and transportation. Wireless networks are part of these technologies but implementation of several antennas, using different frequency bandwidths for many applications might introduce a negative effect on human health security. In wireless networks, most antennas generate sidelobes SSL. SSL causes interference and can be an additional resource for RF power that can affect human being health. This paper aims to study algorithms that can reduce SSL. The study concerns typical uniform linear antenna arrays. Different optimum side lobe level reduction algorithms are presented. Genetic algorithm GA, Chebyshev, and Particle Swarm Optimization algorithm are used in the optimization process. A comparative study between the indicated algorithms in terms of stability, precision, and running time is shown. Results show that using these algorithms in optimizing antenna parameters can reduce SSL. A comparison of these algorithms is carried out and results show the difference between them in terms of running time and SSL reduction Level.

关键词： SSL Radio Wave Interference SAR Linear Antenna Arrays Genetic Algorithm Chebyshev Particle Swarm Optimization

Highly Aligned Graphene Aerogels for Multifunctional Composites

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Nano-Micro Letters 2024年第6期16卷 276-342页

作者： Ying Wu Chao An Yaru Guo Yangyang Zong Naisheng Jiang Qingbin Zheng Zhong‑Zhen Yu Beijing Advanced Innovation Center for Materials Genome engineering School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004People’s Republic of China School of Science and engineering The Chinese University of Hong KongShenzhenShenzhenGuangdong 518172People’s Republic of China State Key Laboratory of Organic‑Inorganic Composites College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029People’s Republic of China

Stemming from the unique in-plane honeycomb lattice structure and the sp^(2)hybridized carbon atoms bonded by exceptionally strong carbon–carbon bonds,graphene exhibits remarkable anisotropic electrical,mechanical,and thermal *** maximize the utilization of graphene’s in-plane properties,pre-constructed and aligned structures,such as oriented aerogels,films,and fibers,have been *** unique combination of aligned structure,high surface area,excellent electrical conductivity,mechanical stability,thermal conductivity,and porous nature of highly aligned graphene aerogels allows for tailored and enhanced performance in specific directions,enabling advancements in diverse *** review provides a comprehensive overview of recent advances in highly aligned graphene aerogels and their *** highlights the fabrication methods of aligned graphene aerogels and the optimization of alignment which can be estimated both qualitatively and *** oriented scaffolds endow graphene aerogels and their composites with anisotropic properties,showing enhanced electrical,mechanical,and thermal properties along the alignment at the sacrifice of the perpendicular *** review showcases remarkable properties and applications of aligned graphene aerogels and their composites,such as their suitability for electronics,environmental applications,thermal management,and energy *** and potential opportunities are proposed to offer new insights into prospects of this material.

关键词： Highly aligned graphene aerogels Quantitative characterization of alignment Multifunctional composites Anisotropic properties Multifunctional applications

含多齿不同间隙的人字星型齿轮系统的齿距误差相位匹配研究

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Acta Mechanica Sinica 2024年第3期40卷 242-260页

作者：陈家俊朱如鹏陈蔚芳李苗苗尹逊民张晓旭 National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing210016China 703 Research Institute China Shipbuilding Industry CorporationHarbin150000China School of energy Science and engineering Harbin Institute of TechnologyHarbin150000China

在加工过程中,齿轮不可避免地会产生齿距误差,这会加剧人字星型齿轮系统(HSGT)的振动和噪声.尽管加工精度是有限的,但通过适当的组合误差相位可以进一步提高系统的动态性能.本工作中,根据齿距误差的周期性及其对间隙的影响,推导了传动... 详细信息

在加工过程中,齿轮不可避免地会产生齿距误差,这会加剧人字星型齿轮系统(HSGT)的振动和噪声.尽管加工精度是有限的,但通过适当的组合误差相位可以进一步提高系统的动态性能.本工作中,根据齿距误差的周期性及其对间隙的影响,推导了传动过程中啮合齿对形成的不同齿隙,然后分别考虑各齿对的啮合状态和误差激振力.建立了在齿距误差影响下含有多齿不同间隙的HSGT动力学模型,并通过齿轮箱振动实验验证了该模型的可靠性.基于该模型分析了人字中心齿轮两侧误差相位的调整对均载性能的影响机理,探索了三个平行星型齿轮最优的误差相位组合.当齿距误差值一定时,本研究可以指导HSGT中各人字齿轮误差相位的组合,从而减少振动,提高系统的均载性能.

关键词： Herringbone gear Star gear system Pitch error Time-varying backlash Load-sharing characteristics

Durable K-ion batteries with 100% capacity retention up to 40,000 cycles

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Carbon energy 2024年第5期6卷 201-212页

作者： Xianlu Lu Zhao Liang Zhi Fang Dongdong Zhang Yapeng Zheng Qiao Liu Dingfa Fu Jie Teng Weiyou Yang Institute of Micro/Nano Materials and Devices Ningbo University of TechnologyNingboZhejiangChina College of Materials Science and engineering Hunan UniversityChangshaChina College of Mechanical and Vehicle engineering Hunan UniversityChangshaChina

Currently,the major challenge in terms of research on K-ion batteries is to ensure that they possess satisfactory cycle stability and specific capacity,especially in terms of the intrinsically sluggish kinetics induced by the large radius of K+***,we explore high-performance K-ion half/full batteries with high rate capability,high specific capacity,and extremely durable cycle stability based on carbon nanosheets with tailored N dopants,which can alleviate the change of volume,increase electronic conductivity,and enhance the K+ion *** as-assembled K-ion half-batteries show an excellent rate capability of 468 mA h g^(−1) at 100 mA g^(−1),which is superior to those of most carbon materials reported to ***,the as-assembled half-cells have an outstanding life span,running 40,000 cycles over 8 months with a specific capacity retention of 100%at a high current density of 2000 mA g^(−1),and the target full cells deliver a high reversible specific capacity of 146 mA h g^(−1) after 2000 cycles over 2 months,with a specific capacity retention of 113%at a high current density of 500 mA g^(−1),both of which are state of the art in the field of K-ion *** study might provide some insights into and potential avenues for exploration of advanced K-ion batteries with durable stability for practical applications.

关键词： carbon nanosheet cycle stability K-ion batteries rate performance specific capacity

Vibration and noise mechanism of a 110 kV transformer under DC bias based on finite element method

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Global energy Interconnection 2024年第4期7卷 503-512页

作者： Ziyang Li Xujun Lang Bo Yang Xiaolin Liu Hao Wang Zhang Li Shandong Electric Power engineering Consulting Institute Co. Ltd.Jinan 250013P.R.China School of Electrical engineering Shandong UniversityJinan 250061P.R.China

Global energy and environmental issues are becoming increasingly problematic,and the vibration and noise problem of 110 kV transformers,which are the most widely distributed,have attracted widespread attention from both inside and outside the *** bias is one of the main contributing factors to vibration noise during the normal operation of *** clarify the vibration and noise mechanism of a 110 kV transformer under a DC bias,a multi-field coupling model of a 110 kV transformer was established using the finite element *** electromagnetic,vibration,and noise characteristics during the DC bias process were compared and quantified through field circuit coupling in parallel with the power frequency of AC,harmonic,and DC power *** was found that a DC bias can cause significant distortions in the magnetic flux density,force,and displacement distributions of the core and *** contributions of the DC bias effect to the core and winding are different at Kdc=*** this point,the core approached saturation,and the increase in the core force and displacement ***,the saturation of the core increased the leakage flux,and the stress and displacement of the winding increased *** sound field distribution characteristics of the 110 kV transformer under a DC bias are related to the force *** the DC bias coefficient was 1.25,the noise sound pressure level reached 73.6 dB.

关键词： Transformer DC bias Vibration Noise

Second-harmonic generation in periodic fork-shaped χ^((2)) gratings at oblique incidence

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Chinese Optics Letters 2024年第4期22卷 101-105页

作者：盛艳刘山胡效康陈鑫徐天翔赵如薇 Wieslaw Kroli kowski Laboratory of Infrared Materials and Devices Research Institute of Advanced TechnologiesNingbo UniversityNingbo 315211China engineering Research Center for Advanced Infrared Photoelectric Materials and Devices of Zhejiang Province Ningbo UniversityNingbo 315211China department of Quantum Science and Technology Research School of PhysicsAustralian National UniversityCanberra ACT 2601Australia School of Physics and Optoelectronics engineering Xidian UniversityXi’an 710071China

Three-dimensional(3D) nonlinear photonic crystals have received intensive interest as an ideal platform to study nonlinear wave interactions and explore their applications. Periodic fork-shaped gratings are extremely important in this context because they are capable of generating second-harmonic vortex beams from a fundamental Gaussian wave, which has versatile applications in optical trapping and materials engineering. However, previous studies mainly focused on the normal incidence of the fundamental Gaussian beam, resulting in symmetric emissions of the second-harmonic vortices. Here we present an experimental study on second-harmonic vortex generation in periodic fork-shaped gratings at oblique incidence, in comparison with the case of normal incidence. More quasi-phase-matching resonant wavelengths have been observed at oblique incidence, and the second-harmonic emissions become asymmetric against the incident *** results agree well with theoretic explanations. The oblique incidence of the fundamental wave is also used for the generation of second-harmonic Bessel beams with uniform azimuthal intensity distributions. Our study is important for a deeper understanding of nonlinear interactions in a 3D periodic medium. It also paves the way toward achieving highquality structured beams at new frequencies, which is important for manipulation of the orbital angular momentum of light.

关键词： second-harmonic generation nonlinear photonic crystal periodically poled ferroelectric crystal quasi-phase matching nonlinear wavefront shaping

A Predictive energy Management Strategies for Mining Dump Trucks

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energy engineering 2024年第3期121卷 769-788页

作者： Yixuan Yu Yulin Wang Qingcheng Li Bowen Jiao College of Mechanical and Electrical engineering Qingdao UniversityQingdao266071China

The plug-in hybrid vehicles(PHEV)technology can effectively address the issues of poor dynamics and higher energy consumption commonly found in traditional mining dump ***,plug-in hybrid electric trucks can achieve excellent fuel economy through efficient energy management strategies(EMS).Therefore,a series hybrid system is constructed based on a 100-ton mining dump truck in this *** inspired by the dynamic programming(DP)algorithm,a predictive equivalent consumption minimization strategy(P-ECMS)based on the DP optimization result is *** on the optimal control manifold and the SOC reference trajectory obtained by the DP algorithm,the P-ECMS strategy performs real-time stage parameter optimization to obtain the optimal equivalent factor(EF).Finally,applying the equivalent consumption minimization strategy(ECMS)realizes real-time *** simulation results show that the equivalent fuel consumption of the P-ECMS strategy under the experimentally collected mining cycle conditions is 150.8 L/100 km,which is 10.9%less than that of the common CDCS strategy(169.3 L/100 km),and achieves 99.47%of the fuel saving effect of the DP strategy(150 L/100 km).

关键词： Mining dump truck energy management strategy plug-in hybrid electric vehicle equivalent consumption minimization strategy dynamic programming