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High-efficiency and flexible photonic microwave harmonic down-converter based on self-oscillation optical frequency combs

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Chinese Optics Letters 2024年第6期22卷 196-204页

作者： Xin zhang Tao Pu Huatao Zhu Yunshan zhang Gengze Wu jin li Jilin Zheng College of Information and Communications National University of Defense TechnologyWuhan 430010China College of Communications Engineering Army Engineering University of PLANanjing 210007China College of Electronic and Optical Engineering&College of Flexible Electronics(Future Technology) Nanjing University of Posts and TelecommunicationsNanjing 210023China

Photonic microwave harmonic down-converters (PMHDCs) based on self-oscillation optical frequency combs (OFCs) are interesting because of their broad bandwidth compared with plain optoelectronic oscillators. In this paper, a high-efficiency and flexible PMHDC is proposed and demonstrated. The properties of the OFC, such as the carrier-to-noise ratio (CNR),bandwidth and free spectral range (FSR), and the influence of optical injection, are investigated. The broadband OFC provides a frequency tunable and high-quality local oscillation (LO), which guarantees flexible down-conversion for the radio frequency (RF) signal. The sideband selective amplification (SSA) effect not only improves the conversion efficiency but also promotes single-sideband modulation. The conversion range can reach 100 GHz. The 12–40 GHz RF signal can be downconverted to intermediate frequency (IF) signals with a high conversion efficiency of 14.9 dB. The fixed 40-GHz RF signal is flexibly down-converted to an IF signal with the frequency from 55.4 to 2129.4 MHz. The phase noise of an IF signal at a frequency offset of 10 kHz is the same as that of the input RF signal. The PMHDC shows great performance and will find applications in radio-over-fiber (RoF) networks, electronic warfare receivers, avionics, and wireless communication systems.

关键词： frequency down-conversion optical frequency comb optical injection optoelectronic oscillation

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Numerical Analysis on the Static Performance of Gas Journal Bearing by Using Finite Element Method

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Nanomanufacturing and Metrology 2024年第1期7卷 28-47页

作者： Pengfeng Wang Yuntang li Xiang Gao Yueliang Ye Ruirui li Xiaolu li Yuan Chen Jie jin Cong zhang College of Modern Science and Technology China Jiliang UniversityJinhua 322002China College of Mechanical and Electrical Engineering China Jiliang UniversityHangzhou 310018China

In this paper,finite element method is used to calculate the static performance of gas journal bearing,in which rotation speed term is introduced into the stiffness matrix of linear triangular element to realize the performance calculation of the bearing with rotation *** results indicate that the average gas film thicknesses corresponding to the maximum load capac-ity and stiffness,and the minimum attitude angle increase with the growth of orifice *** capacity and stiffness significantly improved with the increase of rotation speed,eccentricity ratio and supply pressure when the bearing has thin average gas film *** angle increases with the growth of rotation speed,while the growth rate slows down or even decreases at high *** most effective way of reducing attitude angle is to increase supply *** can be found that rotation speed affects attitude angle through changing gas pressure difference between two orifices,while other parameters have the same effect by changing gas pressure at orifice outlet.

关键词： Finite element method(FEM) Gas journal bearing Stiffness matrix Attitude angle

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A self-driving solution for resource-constrained autonomous vehicles in parked areas

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High-Confidence Computing 2024年第1期4卷 32-42页

作者： jin Qian liang zhang Qiwei Huang Xinyi liu Xiaoshuang Xing Xuehan li College of Information Engineering Taizhou UniversityTaizhou 225300China Engineering Research Center of Integration and Application of Digital Learning Technology Ministry of EducationBeijing 100039China School of Computer Science and Engineering Changshu Institute of TechnologyChangshu 215500China The School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China

Autonomous vehicles in industrial parks can provide intelligent,efficient,and environmentally friendly transportation services,making them crucial tools for solving internal transportation *** the characteristics of industrial park scenarios and limited resources,designing and implementing autonomous driving solutions for autonomous vehicles in these areas has become a research *** paper proposes an efficient autonomous driving solution based on path planning,target recognition,and driving decision-making as its core *** designs for path planning,lane positioning,driving decision-making,and anti-collision algorithms are *** analysis and experimental validation of the proposed solution demonstrate its effectiveness in meeting the autonomous driving needs within resource-constrained environments in industrial *** solution provides important references for enhancing the performance of autonomous vehicles in these areas.

关键词： Autonomous vehicles Path planning Target recognition Driving decision-making Self-driving

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Synergistic mechanisms of AMF and biochar driving rhizosphere fungal community in shallot in barren soil

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Horticultural Plant Journal 2024年第5期10卷 1252-1256页

作者： Zishan li Yingyue li Qing zhang Zihua zhang Jiaqing Jiang Tao Huang Chunge Mei Fulang Wu Beijiu Cheng Xiaoyu li jin Chen National Engineering Laboratory of Crop Stress Resistance Breeding Schools of Life SciencesAnhui Agricultural UniversityHefeiAnhui 230036China

The addition of biochar(BC)or Arbuscular mycorrhizal fungi(AMF)alone has been reported to promote plant growth,while their synergistic effects on Allium schoenoprasum root morphology and rhizosphere fungal community in barren soil is still *** this study,we investigated the effects of BC and AMF(Funneliformis mosseae)on plant growth and root morphology in barren soil and revealed the structure of soil fungal communities Therefore,a greenhouse pot trial consisting of five treatments was *** results showed that the combination of biochar and AMF significantly improved plant biomass,nutrient uptake,mycorrhizal colonization rates and soil properties and significantly impacted rhizosphere fungal community composition and *** significantly increased the fungal community stability and enhanced their positive correlation with *** findings indicated that the combination of AMF and biochar play synergic role for plant growth and rhizosphere fungal community in barren soil.

关键词： soil rhizosphere barren

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5S-Heudelotinone alleviates experimental colitis by shaping the immune system and enhancing the intestinal barrier in a gut microbiota-dependent manner

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Acta Pharmaceutica Sinica B 2024年第5期14卷 2153-2176页

作者： Qing Meng Jianshuang Guo Ke Lv Yang liu jin zhang Mingyue li Xirui Cheng Shenghua Chen Xiaoguang Huo Quan zhang Yue Chen jing li State Key Laboratory of Medicinal Chemical Biology College of PharmacyNankai UniversityTianjin 300353China College of Chemistry and Frontiers Science Center for New Organic Matter Haihe Laboratory of Sustainable Chemical TransformationsNankai UniversityTianjin 300071China Accendatech Company Ltd.Tianjin 300193China

Aberrant changes in the gut microbiota are implicated in many diseases,including inflammatory bowel disease(IBD).Gut microbes produce diverse metabolites that can shape the immune system and impact the intestinal barrier integrity,indicating that microbe-mediated modulation may be a promising strategy for preventing and treating *** fecal microbiota transplantation and probiotic supplementation are well-established IBD therapies,novel chemical agents that are safe and exert strong effects on the gut microbiota are urgently ***,we report the total synthesis of heudelotinone and the discovery of 5S-heudelotinone(an enantiomer)as a potent agent against experimental colitis that acts by modulating the gut microbiota.5S-Heudelotinone alters the diversity and composition of the gut microbiota and increases the concentration of short-chain fatty acids(SCFAs);thus,it regulates the intestinal immune system by reducing proinflammatory immune cell numbers,and maintains intestinal mucosal integrity by modulating tight junctions(TJs).Moreover,5S-heudelotinone(2)ameliorates colitis-associated colorectal cancer(CAC)in an azoxymethane(AOM)/dextran sulfate sodium(DSS)-induced in situ carcinoma ***,these findings reveal the potential of a novel natural product,namely,5S-heudelotinone,to control intestinal inflammation and highlight that this product is a safe and effective candidate for the treatment of IBD and CAC.

关键词： 5S-heudelotinone Total synthesis Inflammatory bowel disease Gut microbiota Short-chain fatty acids Immune system Intestinal barrier Drug discovery

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High-performance terahertz modulators induced by substrate field in Te-based all-2D heterojunctions

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light(Science & Applications) 2024年第3期13卷 577-586页

作者： Pujing zhang Qihang liang Qingli Zhou jinyu Chen Menglei li Yuwang Deng Wanlin liang liangliang zhang Qinghua zhang lin Gu Chen Ge Kui-juan jin Cunlin zhang Guozhen Yang Department of Physics Key Laboratory of Terahertz OptoelectronicsMinistry of Educationand Beijing Advanced Innovation Center for Imaging Theory and TechnologyCapital Normal UniversityBeijing 100048China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Department of Materials Science and Engineering Beijing National Center for Electron Microscopy and Laboratory of Advanced MaterialsTsinghua UniversityBeijing 100084China

High-performance active terahertz modulators as the indispensable core components are of great importance for the next generation communication ***,they currently suffer from the tradeoff between modulation depth and ***,we introduce two-dimensional(2D)tellurium(Te)nanofilms with the unique structure as a new class of optically controlled terahertz modulators and demonstrate their integrated heterojunctions can successfully improve the device performances to the optimal and applicable levels among the existing all-2D broadband *** photoresponse measurements confirm the significant impact of the stacking *** first clarify the direction of the substrate-induced electric field through first-principles calculations and uncover the unusual interaction mechanism in the photoexcited carrier dynamics associated with the charge transfer and interlayer exciton *** advances the fundamental and applicative research of Te nanomaterials in high-performance terahertz optoelectronics.

关键词： performance field terahertz

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SimHOEPI:A resampling simulator for generating single nucleotide polymorphism data with a high-order epistasis model

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Quantitative Biology 2024年第2期12卷 197-204页

作者： Yahan li Xinrui Cai Junliang Shang Yuanyuan zhang jin-Xing liu School of Computer Science Qufu Normal UniversityRizhaoChina School of Information and Control Engineering Qingdao University of TechnologyQingdaoChina School of Health and life Sciences University of Health and Rehabilitation SciencesQingdaoChina

Epistasis is a ubiquitous phenomenon in genetics,and is considered to be one of main factors in current efforts to unveil missing heritability of complex *** data is crucial for evaluating epistasis detection tools in genome-wide association studies(GWAS).Existing simulators normally suffer from two limitations:absence of support for high-order epistasis models containing multiple single nucleotide polymorphisms(SNPs),and inability to generate simulation SNP data *** this study,we proposed a simulator SimHOEPI,which is capable of calculating penetrance tables of high-order epistasis models depending on either prevalence or heritability,and uses a resampling strategy to generate simulation data *** of SimHOEPI are the preservation of realistic minor allele frequencies in sampling data,the accurate calculation and embedding of high-order epistasis models,and acceptable simulation time.A series of experiments were carried out to verify these properties from different *** results show that SimHOEPI can generate simulation SNP data independently with high-order epistasis models,implying that it might be an alternative simulator for GWAS.

关键词： high-order epistasis model penetrance table resampling strategy simulation single nucleotide polymorphisms

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Concurrent hetero-/homo-geneous electrocatalysts to bi-phasically mediate sulfur species for lithium-sulfur batteries

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Journal of Energy Chemistry 2024年第6期93卷 663-668,I0016页

作者： Rui-Bo lingHu jin-Xiu Chen jin-Hao zhang Bo-Quan li Qing-Shan Fu Gulnur Kalimuldina Geng-Zhi Sun Yunhu Han Long Kong Xi’an Institute of Flexible Electronics(IFE) Northwestern Polytechnical UniversityXi’an 710129ShaanxiChina Institute of Advanced Materials Nanjing Tech UniversityNanjing 211816JiangsuChina Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China Department of Mechanical and Aerospace Engineering School of Engineering and Digital SciencesNazarbayev UniversityKabanbay Batyr Ave.53Astana 010000Kazakhstan

Expediting redox kinetics of sulfur species on conductive scaffolds with limited charge accessible surface is considered as an imperative approach to realize energy-dense and power-intensive lithium-sulfur(li-S)*** this work,the concept of concurrent hetero-/homo-geneous electrocatalysts is proposed to simultaneously mediate liquid-solid conversion of lithium polysulfides(liPSs)and solid lithium disulfide/sulfide(li_(2)S_(2)/li_(2)S)propagation,the latter of which suffers from sluggish reduction kinetics due to buried conductive scaffold surface by extensive deposition of li_(2)S_(2)/li_(2)*** selected model material to verify this concept is a two-in-one catalyst:carbon nanotube(CNT)scaffold supported iron-cobalt(Fe-Co)alloy nanoparticles and partially carbonized selenium(C-Se)*** Fe-Co alloy serves as a heterogeneous electrocatalyst to seed li_(2)S_(2)/li_(2)S through sulphifilic active sites,while the C-Se sustainably releases soluble lithium polyselenides and functions as a homogeneous electrocatalyst to propagate li_(2)S_(2)/li_(2)S via solution *** bi-phasic mediation of the sulfur species benefits reduction kinetics of liPS conversion,especially for the massive li_(2)S_(2)/li_(2)S growth scenario by affording an additional solution directed route in case of conductive surface being largely *** strategy endows the li-S batteries with improved cycling stability(836 mA h g^(-1)after 180 cycles),rate capability(547 mA h g^(-1)at 4 C)and high sulfur loading superiority(2.96 mA h cm^(-2)at 2.4 mg cm^(-2)).This work hopes to enlighten the employment of bi-phasic electrocatalysts to dictate liquid-solid transformation of intermediates for conversion chemistry batteries.

关键词： lithium-sulfur batteries Electrocatalysis lithium polysulfides Sulfur cathode Energy density

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Self-assembly of perovskite nanocrystals:From driving forces to applications

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Journal of Energy Chemistry 2024年第1期88卷 561-578,I0013页

作者： Yi li Fei zhang School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin 300072China

Self-assembly of metal halide perovskite nanocrystals(NCs)into superlattices can exhibit unique collective properties,which have significant application values in the display,detector,and solar cell *** review discusses the driving forces behind the self-assembly process of perovskite NCs,and the commonly used self-assembly methods and different self-assembly structures are ***,we summarize the collective optoelectronic properties and application areas of perovskite superlattice ***,we conclude with an outlook on the potential issues and future challenges in developing perovskite NCs.

关键词： Self-assembly Metal halide perovskite Nanocrystals Driving forces

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Guidance strategy of motion camouflage for spacecraft pursuit-evasion game

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Chinese Journal of Aeronautics 2024年第3期37卷 312-319页

作者： Jianqing li Chaoyong li Yonghe zhang Space Information Research Institute Hangzhou Dianzi UniversityHangzhou 310018China College of Electrical Engineering Zhejiang UniversityHangzhou 310027China Key Lab of Microsatellites Chinese Academy of SciencesShanghai 201210China

This work is inspired by a stealth pursuit behavior called motion camouflage whereby a pursuer approaches an evader while the pursuer camouflages itself against a predetermined *** formulate the spacecraft pursuit-evasion problem as a stealth pursuit strategy of motion camouflage,in which the pursuer tries to minimize a motion camouflage index defined in this *** Euler-Hill reference frame whose origin is set on the circular reference orbit is used to describe the *** on the rule of motion camouflage,a guidance strategy in open-loop form to achieve motion camouflage index is derived in which the pursuer lies on the camouflage constraint line connecting the central spacecraft and *** order to dispose of the dependence on the evader acceleration in the open-loop guidance strategy,we further consider the motion camouflage pursuit problem within an infinite-horizon nonlinear quadratic differential *** saddle point solution to the game is derived by using the state-dependent Riccati equation method,and the resulting closed-loop guidance strategy is effective in achieving motion *** are performed to demonstrate the capabilities of the proposed guidance strategies for the pursuit–evasion game scenario.

关键词： Pursuit-evasion problem Motion camouflage Differential game Guidance strategy Orbit control

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