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A Dual-Band Coaxial Waveguide Mode Converter for High-Power Microwave Applications

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Chinese Physics Letters 2011年第6期28卷 326-328页

作者： ZHANG Qiang YUAN Cheng-Wei liu lie Lab 206 College of Optoelectronic Science and EngineeringNational University of Defense TechnologyChangsha 410073

A dual-band coaxial waveguide mode converter is *** the converter,the TEM mode(***)and TM01 circular waveguide(***01)mode are transformed simultaneously into TE11 coaxial waveguide(***11)mode and TE11 circular waveguide(***11)mode,*** optimized geometrical dimensions are achieved by employing the mode coupling theory.A mode converter at 1.3 GHz and 5.0 GHz is designed,and conversion efficiencies of ***−***11 and ***01−***11 are 99.88%and 99.70%at central frequency,*** the frequency ranges 1.15–1.51 GHz and 4.87–5.19 GHz,the conversion efficiency exceeds 90%.A good agreement between theoretical calculations and computer simulations is observed,demonstrating the feasibility of the dual-band mode converter.

关键词： waveguide coaxial Converter

Industrial Fusion Cascade Detection of Solder Joint

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Computers, Materials & Continua 2024年第10期81卷 1197-1214页

作者： Chunyuan Li Peng Zhang Shuangming Wang lie liu Mingquan Shi Chongqing School University of Chinese Academy of SciencesChongqing UniversityChongqing400044China Automatic Reasoning and Cognition Research Center Chongqing Institute of Green and Intelligent TechnologyChinese Academy of SciencesChongqing400714China College of Artificial Intelligence Chongqing SchoolUniversity of Chinese Academy of SciencesChongqing400714China Design Department Liuzhou Fuzhen Bodywork Industrial Co.Ltd.Liuzhou545006China

With the remarkable advancements in machine vision research and its ever-expanding applications,scholars have increasingly focused on harnessing various vision methodologies within the industrial ***,detecting vehicle floor welding points poses unique challenges,including high operational costs and limited portability in practical *** address these challenges,this paper innovatively integrates template matching and the Faster RCNN algorithm,presenting an industrial fusion cascaded solder joint detection algorithm that seamlessly blends template matching with deep learning *** algorithm meticulously weights and fuses the optimized features of both methodologies,enhancing the overall detection ***,it introduces an optimized multi-scale and multi-template matching approach,leveraging a diverse array of templates and image pyramid algorithms to bolster the accuracy and resilience of object *** integrating deep learning algorithms with this multi-scale and multi-template matching strategy,the cascaded target matching algorithm effectively accurately identifies solder joint types and positions.A comprehensive welding point dataset,labeled by experts specifically for vehicle detection,was constructed based on images from authentic industrial environments to validate the algorithm’s *** demonstrate the algorithm’s compelling performance in industrial scenarios,outperforming the single-template matching algorithm by 21.3%,the multi-scale and multitemplate matching algorithm by 3.4%,the Faster RCNN algorithm by 19.7%,and the YOLOv9 algorithm by 17.3%in terms of solder joint detection *** optimized algorithm exhibits remarkable robustness and portability,ideally suited for detecting solder joints across diverse vehicle ***,this study’s dataset and feature fusion approach can be a valuable resource for other algorithms seeking to enhance their solder joint detection cap

关键词： Cascade object detection deep learning feature fusion multi-scale and multi-template matching solder joint dataset

Broadband absorption of macro pyramid structure based flame retardant absorbers

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Journal of Materials Science & Technology 2022年第33期128卷 228-238页

作者： Hengda Sun Ying Zhang Yue Wu Yue Zhao Ming Zhou lie liu Shaolong Tang Guangbin Ji College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China General Test Systems Inc. Shenzhen 518102China National Laboratory of Solid State Microstructures Nanjing UniversityNanjing 210093China

Flame-retardant materials with good electromagnetic wave absorption play an increasingly important role in Over-the-Air(OTA)tests in microwave anechoic *** this work,carbon nanotubes and ammonium polyphosphate(CNTs@APP)composite were prepared by crosslinking with the silane coupling agent(KH550).The flame retardancy is improved with the increase of ***,the microwave absorption performance(MAP)and processing difficulty changed greatly as ***,magnesium aluminum double-layer metal hydroxide(LDH)was obtained by coprecipitation method and processing into the coating,so as to realize flame retardancy which reaches the limiting oxygen index(LOI)of 24.8%and good MAP at the same ***,a high-frequency structure simulator(HFSS^(TM))was used to simulate the pyramid model to realize the broadband absorption,and the optimal parameter range was obtained,that is,when the total height of the material is 40 mm,the height of the base accounts for 1/5-1/3,and the tangent of the half top angle is near 1/5,which result in the best ***,the broadband absorption of 14.36 GHz(3.64-18 GHz)was realized when the base height is 1/3,and the broadband absorption of 14 GHz(4-18 GHz)can be realized under the condition of large-angle oblique incidence of 0°-60°.

关键词： Electromagnetic wave absorption Broad bandwidth Pyramid structure Flame retardant HFSS^(TM)

QTL analysis of leaf photosynthesis rate and related physiological traits in Brassica napus

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Journal of Integrative Agriculture 2015年第7期14卷 1261-1268页

作者： YAN Xing-ying QU Cun-min LI Jia-na CHEN Li liu lie-zhao College of Agronomy and Biotechnology Southwest University Biotechnology Research Center Southwest University

Rapeseed （Brassica napus L.） oil is the crucial source of edible oil in China. In addition, it can become a major renewable and sustainable feedstock for biodiesel production in the future. It is known that photosynthesis products are the primary sources for dry matter accumulation in rapeseed. Therefore, increasing the photosynthetic efficiency is desirable for the raise of rapeseed yield. The objective of the present study was to identify the genetic mechanism of photosynthesis based on the description of relationships between different photosynthetic traits and their quantitative trait loci （QTL） by using a recombinant inbred line （RIL） population with 172 lines. Specifically, correlation analysis in this study showed that internal CO2 concentration has negative correlations with other three physiological traits under two different stages. Totally, 11 and 12 QTLs of the four physiological traits measured at the stages 1 and 2 were detected by using a high-density single nu- cleotidepolymorphism （SNP） markers linkage map with composite interval mapping （CIM）, respectively. Three co-localized QTLs on A03 were detected at stage 1 with 5, 5, and 10% of the phenotypic variation, respectively. Other two co-localized QTLs were located on A05 at stage 2, which explained up to 12 and 5% of the phenotypic variation, respectively. The results are beneficial for our understanding of genetic control of photosynthetic physiological characterizations and improvement of rapeseed yield in the future.

关键词： Brassica napus photosynthesis quantitative trait loci (QTL)

High-performance SiO/C as anode materials for lithium-ion batteries using commercial SiO and glucose as raw materials

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Rare Metals 2021年第5期40卷 1110-1117页

作者： Zi-Long Wu Shan-Bao Ji lie-Kai liu Tian Xie Long Tan Hao Tang Run-Guang Sun School of Materials Science and Engineering Nanchang UniversityNanchang 330031China

Silicon monoxide(SiO)is considered as a promising anode material for lithium-ion batteries(LIBs)due to its higher capacity and longer cycle life than those of graphite and silicon,*** this study,glucose was developed as a suitable and inexpensive carbon source to synthesize SiO/C composite with a high *** addition,the effects of the calcination temperature and the amount of c arbon source on the electrochemical performance of the SiO/C composite were *** addition of 5 wt%glucose and a calcination temperature of 800℃ demonstrated the optimum conditions for SiO/C *** resultant SiO/C showed an initial charge capacity of 1259 mAh·g^(-1) and a high initial coulombic efficiency of 71.9%.A charge capacity of 850 mAh·g^(-1) after 100 cycles at 200 mA·g^(-1) was achieved,demonstrating the best value of the SiO/C-based *** composition changes of SiO under the calcination temperature played a significant role in the electrochemical ***,the obtained SiO/C material with a high capacity and good stability is suitable for LIB applications as an anode material.

关键词： Lithium-ion battery Anode material Silicon monoxide Glucose Carbon coating SiO/C

From intrinsic dielectric loss to geometry patterns: Dual-principles strategy for ultrabroad band microwave absorption

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Nano Research 2021年第5期14卷 1495-1501页

作者： Bin Quan Weihua Gu Jiaqi Sheng Xinfeng Lv Yuyi Mao lie liu Xiaogu Huang Zongjun Tian Guangbin Ji College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing210016China School of Chemistry and Materials Science Nanjing University of Information Science&TechnologyNanjing210044China National Center of Supervision and Inspection on Additive Manufacturing Products Quality Wuxi214000China Shenzhen General Test Systems Inc Taohuayuan Hi-Tech ParkShenzhen518102China College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing210016China

As electromagnetic absorbers with wide absorption bandwidth are highly pursued in the cutting-edge electronic and telecommunication industries, the traditional dielectric or magnetic bulky absorbers remain concerns of extending the effective absorption bandwidth. In this work, a dual-principle strategy has been proposed to make a better understanding of the impact of utilizing conductive absorption fillers coupled with implementing artificial structures design on the absorption performance. In the comparison based on the microscopic studies, the carbon nanotubes (CNTs)-based absorbers are confined to narrow operating bandwidth and relatively fixed response frequency range, which can not fulfill the ever-growing demands in the application. With subsequent macroscopic structure design based on the CNTs-based dielectric fillers, the artificial patterns show much more broadened absorption bandwidth, covering the majority of C-band, the whole X-band, and Ku-band, due to the tailored electromagnetic parameters and more reflections and scatterings. The results suggest that the combination of developing microscopic powder/bulky absorbers and macroscopic configuration design will fundamentally extend the effective operating bandwidth of microwave.

关键词： geometry patterns numerical simulation three-dimensional(3D)printing broadband microwave absorption

Dual-Functional Lithiophilic/Sulfiphilic Binary-Metal Selenide Quantum Dots Toward High-Performance Li-S Full Batteries

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Nano-Micro Letters 2023年第5期15卷 169-186页

作者： Youzhang Huang Liang Lin Yinggan Zhang lie liu Baisheng Sa Jie Lin Laisen Wang Dong-Liang Peng Qingshui Xie State Key Lab for Physical Chemistry of Solid Surfaces Fujian Key Laboratory of Surface and Interface Engineering for High Performance MaterialsCollege of MaterialsXiamen UniversityXiamen 361005People’s Republic of China Shenzhen Research Institute of Xiamen University Shenzhen 518000People’s Republic of China College of Materials Science and Engineering Multiscale Computational Materials FacilityFuzhou UniversityFuzhou 350100People’s Republic of China

The commercial viability of lithium-sulfur batteries is still challenged by the notorious lithium polysulfides(Li PSs)shuttle effect on the sulfur cathode and uncontrollable Li dendrites growth on the Li ***,a bi-service host with Co-Fe binary-metal selenide quantum dots embedded in three-dimensional inverse opal structured nitrogen-doped carbon skeleton(3DIO FCSe-QDs@NC)is elaborately designed for both sulfur cathode and Li metal *** highly dispersed FCSe-QDs with superb adsorptive-catalytic properties can effectively immobilize the soluble Li PSs and improve diffusion-conversion kinetics to mitigate the polysulfide-shutting ***,the 3D-ordered porous networks integrated with abundant lithophilic sites can accomplish uniform Li deposition and homogeneous Li-ion flux for suppressing the growth of *** advantage of these merits,the assembled Li-S full batteries with 3DIO FCSe-QDs@NC host exhibit excellent rate performance and stable cycling ability(a low decay rate of 0.014%over 2,000 cycles at 2C).Remarkably,a promising areal capacity of 8.41 mAh cm^(-2)can be achieved at the sulfur loading up to 8.50 mg cm^(-2)with an ultra-low electrolyte/sulfur ratio of 4.1μL mg^(-1).This work paves the bi-serve host design from systematic experimental and theoretical analysis,which provides a viable avenue to solve the challenges of both sulfur and Li electrodes for practical Li-S full batteries.

关键词： Dual-functional host Fe_(2)CoSe_(4)quantum dots Shuttle effect Dendrite-free Li anode Li-S full batteries

Pure-high-even-order dispersion bound solitons complexes in ultra-fast fiber lasers

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Light(Science & Applications) 2024年第5期13卷 957-972页

作者： Ying Han Bo Gao Honglin Wen Chunyang Ma Jiayu Huo Yingying Li Luyao Zhou Qi Li Ge Wu lie liu College of Communication Engineering Jilin UniversityChangchun 130012China. Research Center of Circuits and Systems Peng Cheng LaboratoryShenzhen 518055China. International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China. College of Electronic Science and Engineering Jilin UniversityChangchun 130012China

Temporal solitons have been the focus of much research due to their fascinating physical *** solitons can form bound states,which are fundamentally crucial modes in fiber laser and present striking analogies with their matter molecules counterparts,which means they have potential applications in large-capacity transmission and alloptical information *** traditionally,second-order dispersion has been the dominant dispersion for conventional solitons,recent experimental and theoretical research has shown that pure-high-even-order dispersion(PHEOD)solitons with energy-width scaling can arise from the interaction of arbitrary negative-even-order dispersion and Kerr *** these advancements,research on the bound states of PHEOD solitons is currently *** this study,we obtained PHEOD bound solitons in a fiber laser using an intra-cavity spectral pulse shaper for high-order dispersion ***,we experimentally demonstrate the existence of PHEOD solitons and PHEOD bound solitons with pure-quartic,-sextic,-octic,and-decic *** simulations corroborate these experimental ***,vibrating phase PHEOD bound soliton pairs,sliding phase PHEOD bound soliton pairs,and hybrid phase PHEOD bound tri-soliton are discovered and *** results broaden the fundamental understanding of solitons and show the universality of multi-soliton patterns.

关键词： dispersion solitons soliton

Bubble Motion in Transformer Oil under Non-Uniform Electric Fields

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Chinese Physics Letters 2013年第3期30卷 163-167页

作者： CAI Dan liu lie CHENG Guo-Xin ZHANG Qiang ZHAO Xue-Long ZHAO Qi College of Optoelectric Science and Engineering National University of Defense TechnologyChangsha 410073

We investigate the bubble motion in transformer oil under a typical non-uniform electric *** on the principle of virtual work,an analytical equation is derived for the electric force putting on the *** bubble's visualized motion graphics are then obtained by using the finite-element method,which utilizes Comsol Multiphysics *** effects of bubble radius and release position on the motion trajectory are *** is found that,under the non-uniform electric field,the bubbles have a long residence time between the *** accordingly can lead to a higher probability of forming a bubble-bridge along the bubble motion *** bubbles with a particular radius or release position are easier to form bubble-bridge between the *** can increase the chance of liquid breakdown.

关键词： field. bubble radius