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The Adjustment Analysis Method of the Active Surface Antenna Based on Convolutional Neural Network

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Research in Astronomy and Astrophysics 2024年第6期24卷 294-306页

作者： You ban Shang Shi Na Wang Qian xu Shufei Feng School of Mechanical Engineering Xinjiang UniversityUrumqi 830017China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China

Active surface technique is one of the key technologies to ensure the reflector accuracy of the millimeter/submillimeter wave large reflector *** antenna is complex,large-scale,and high-precision equipment,and its active surfaces are affected by various factors that are difficult to comprehensively deal *** this paper,based on the advantage of the deep learning method that can be improved through data learning,we propose the active adjustment value analysis method of large reflector antenna based on deep *** method constructs a neural network model for antenna active adjustment analysis in view of the fact that a large reflector antenna consists of multiple panels spliced *** on the constraint that a single actuator has to support multiple panels(usually 4),an autonomously learned neural network emphasis layer module is designed to enhance the adaptability of the active adjustment neural network *** classical 8-meter antenna is used as a case study,the actuators have a mean adjustment error of 0.00252 mm,and the corresponding antenna surface error is0.00523 *** active adjustment result shows the effectiveness of the method in this paper.

关键词： techniques:radar astronomy telescopes methods:analytical methods:numerical

Hybrid hard carbon framework derived from polystyrene bearing distinct molecular crosslinking for enhanced sodium storage

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Carbon Energy 2024年第7期6卷 178-190页

作者： Yuqian Qiu Guangshen Jiang Yanxia Su Xinren Zhang Yuxuan Du Xiaosa xu Qian Ye Jinbo Zhang Miaohan ban Fei xu Hongqiang Wang State Key Laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene(NPU)Xi'anChina State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhouChina Shaanxi Yanchang Petroleum(Group)Co. Ltd.Dalian Institute of Chemical Physics Xi'anClean Energy(Chemical)Research InstituteXi'anChina

Exploiting high-performance yet low-cost hard carbon anodes is crucial to advancing the state-of-the-art sodium-ion ***,the achievement of superior initial Coulombic efficiency(ICE)and high Na-storage capacity via low-temperature carbonization remains challenging due to the presence of tremendous defects with few closed ***,a facile hybrid carbon framework design is proposed from the polystyrene precursor bearing distinct molecular bridges at a low pyrolysis temperature of 800℃ via in situ fusion and embedding *** is realized by integrating triazine-and carbonylcrosslinked polystyrene nanospheres during *** triazine crosslinking allows in situ fusion of spheres into layered carbon with low defects and abundant closed pores,which serves as a matrix for embedding the well-retained carbon spheres with nanopores/defects derived from carbonyl ***,the hybrid hard carbon with intimate interface showcases synergistic Na ions storage behavior,showing an ICE of 70.2%,a high capacity of 279.3 mAh g^(-1),and long-term 500 cycles,superior to carbons from the respective precursor and other reported carbons fabricated under the low carbonization *** present protocol opens new avenues toward low-cost hard carbon anode materials for high-performance sodiumion batteries.

关键词： closed pores hybrid hard carbons hypercrosslinking polystyrenes low-temperature carbonization sodium storage

Pentanidium-Catalyzed Direct Assembly of Vicinal All-Carbon Quaternary Stereocenters through C(sp^(3))–C(sp^(3))Bond Formation

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CCS Chemistry 2021年第10期3卷 2192-2200页

作者： xu ban Yifan Fan Tuan-Khoa Kha Richmond Lee Choon Wee Kee Zhiyong Jiang Choon-Hong Tan International Scientific and Technological Cooperation Base of Chiral Chemistry Henan UniversityKaifeng 475004 Division of Chemistry and Biological Chemistry Nanyang Technological UniversitySingapore 637371 School of Chemistry and Molecular Bioscience University of WollongongWollongongNSW 2522 Molecular Horizons University of WollongongWollongongNSW 2522 Process&Catalysis Research Institute of Chemical and Engineering SciencesSingapore 627899

The stereoselective construction of vicinal all-carbon quaternary stereocenters has long been a formidable synthetic *** asymmetric coupling of a tertiary carbon nucleophile with a tertiary carbon electrophile is themost straightforward approach,but it is sterically and energetically ***,we describe a catalytic asymmetric substitution,where racemic tertiary bromides coupled directly with racemic secondary or tertiary carbanion.

关键词： ion-paired catalyst asy mmetric substitu-tion SN2 substitution SN2X substitution all-carbon quaternary stere ocenters

Effect of resistant starch supplementation on the diversity and composition of human gut microbiota: A systematic review and meta-analysis

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Food Science and Human Wellness 2024年

作者： Jiaxin xu Haocun Kong Caiming Li Xiaofeng ban Zhaofeng Li Collaborative Innovation Center of Food Safety and Quality Control， Jiangnan University School of Food Science and Technology， Jiangnan University State Key Laboratory of Food Science and Technology， Jiangnan University

Resistant starch (RS) has attracted much researchers’ attention because of its health-beneficial effects. Gut microbiota obviously shapes human health， but the effects of RS supplementation on the changes of human gut microbiota remain unclear. This observational meta-analysis aimed to reveal the effects of RS intake on alpha diversity and composition of gut microbiota through meta-analysis. Two independent authors systematically searched articles from inception until February 2023 on four electronic databases. Twenty-four highly relevant trials were included conforming to Preferred Reporting Items for Systematic reviews and Meta-Analysis protocol， and a total of 816 individuals were included. Significant heterogeneity analyses revealed that RS intake notably decreased Shannon index (WMD: –0.11; 95% CI: –0.21， –0.01)， and stimulated the composition of health promoting bacteria genera， including Bifidobacterium (WMD: 1.75; 95% CI: 0.39， 3.11; WMD: 0.36; 95% CI: 0.04， 0.69)， Faecalibacterium (WMD: 0.70; 95% CI: 0.20， 1.20; ES: 0.91; 95% CI: 0.60， 1.23)， and Prevotella (WMD: 0.35; 95% CI: 0.01， 0.69). Taken together， the present study revealed that changes in the gut microbiota diversity and genera were correlated with RS supplementation， which may contribute to benefits in human health.

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基于C—H脱氢的协同可见光不对称烯丙基烷基化反应

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有机化学 2022年第7期42卷 2248-2249页

作者：班旭江智勇河南师范大学化学化工学院河南新乡453007

自由基反应是有机合成化学领域研究的一个热点,通过自由基途径可以实现对多种复杂的化学分子结构的构建.但长期以来,由于自由基本身具有高反应活性、短生命周期和不易控的特性,它在有机合成,特别是不对称有机合成中的应用受到了极大的限... 详细信息

自由基反应是有机合成化学领域研究的一个热点,通过自由基途径可以实现对多种复杂的化学分子结构的构建.但长期以来,由于自由基本身具有高反应活性、短生命周期和不易控的特性,它在有机合成,特别是不对称有机合成中的应用受到了极大的限制.进入21世纪以来,随着过渡金属催化和有机小分子催化等分支学科的不断发展,自由基化学在不对称有机合成中的应用得到了长足的发展.

关键词：有机合成化学过渡金属催化自由基反应高反应活性自由基化学

社会信任与现金持有动态调整:作用机制与调整效果——基于寻租理论的解释

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财经论丛 2021年第2期 57-67页

作者：罗付岩班旭桂林理工大学商学院广西桂林541004 东北财经大学会计学院辽宁大连116025

为检验社会信任的道德约束观和道德风险观占优程度,以2007~2017年沪深A股非金融类上市公司为样本,实证检验了社会信任对现金持有动态调整的影响,并深入探究其作用机制与调整效果。研究发现:(1)社会信任降低了现金持有动态调整速度,加大... 详细信息

为检验社会信任的道德约束观和道德风险观占优程度,以2007~2017年沪深A股非金融类上市公司为样本,实证检验了社会信任对现金持有动态调整的影响,并深入探究其作用机制与调整效果。研究发现:(1)社会信任降低了现金持有动态调整速度,加大了现金持有偏离程度;(2)管理者会利用社会信任进行寻租,引发道德风险,难以优化企业现金持有结构,从而弱化现金持有动态调整;(3)在非国有企业、内部治理机制不完善的企业中,社会信任降低现金持有动态调整速度更显著;(4)进一步研究动态调整的经济后果发现,现金持有偏离程度越大、经营效率越差,越不利于企业的持续性健康发展。本文丰富了现金持有动态调整的影响因素及经济后果的研究,同时为非正式制度背景下社会信任影响企业现金持有动态调整行为提供了来自寻租理论的新解释。

关键词：社会信任现金持有动态调整调整速度偏离程度寻租

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社会信任与股权资本成本

经济经纬 2021年第6期38卷 150-160页

作者：姜英兵班旭东北财经大学会计学院辽宁大连116025

基于供给侧结构性改革和践行社会主义核心价值观的时代背景,以2010—2017年沪深A股非金融类上市公司数据为样本,实证检验了社会信任对股权资本成本的影响,并利用中介效应模型深入探究二者的作用机制。研究发现:(1)社会信任能够显著降低... 详细信息

基于供给侧结构性改革和践行社会主义核心价值观的时代背景,以2010—2017年沪深A股非金融类上市公司数据为样本,实证检验了社会信任对股权资本成本的影响,并利用中介效应模型深入探究二者的作用机制。研究发现:(1)社会信任能够显著降低股权资本成本;(2)中介机制表明,社会信任通过提升财务信息透明度与股票流动性,缓解了信息不对称程度,导致股权资本成本下降;(3)法律环境与社会信任互为补充,在法律环境越好的地区,社会信任降低股权资本成本的效果越明显。上述研究厘清了社会信任与股权资本成本的关系及作用机制,为企业降低股权资本成本提供了来自社会信任视角的解释,也为政府积极培育信任环境提供了经验证据。

关键词：社会信任股权资本成本财务信息透明度股票流动性中介效应

Riverine sulfate sources and behaviors in arid environment,Northwest China:Constraints from sulfur and oxygen isotopes

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Journal of Environmental Sciences 2024年第3期137卷 716-731页

作者： Yifu xu Wenjing Liu Bing xu Zhifang xu Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

The fate of riverine sulfate ion (SO_(4)^(2-)) and its environmental effects in arid environment are difficult to evaluate due to its complicated sources and strongly coupled behaviors with water cycle which is significantly modified by *** understand the sulfur cycle in aquatic systems in arid environment,the chemical and sulfur and oxygen isotopic compositions (δ^(34)S_(SO4)and δ^(18)O_(SO4)) of major rivers around the Badain Jaran Desert,northwestern China,were *** rivers had averaged SO_(4)^(2-)content at 1336μmol/L,over 10times higher than the global *** δ^(34)S_(SO4)and δ^(18)O_(SO4)values ranged from-5.3‰to+11.8‰and+1.6‰to+12.8‰,*** end-member analysis and the inverse model showed that riverine sulfate was mainly derived from evaporites dissolution (0-87%),sulfide oxidation (13%-100%) and precipitation (0-33%),indicating heterogeneity in sulfur sources and behaviors along the river drainage with the lithology variations and climate *** isotopic tools combining with hydro-chemistry compositions could be applied to reveal sulfur cycle in arid *** on the calculation,sulfide oxidation plays the primary role in the headwater and upstream in the Qilian-Mountains area,where sulfide is widely *** the proportion of evaporites dissolution contributing to riverine sulfate is much higher in downstream in a drier ***,less precipitation and higher temperature can lead to more intensive evaporation,affecting the process of sulfide oxidation and enhancing the rates of evaporites dissolution and sulfate precipitation in the basin.

关键词： Sulfur and oxygen isotopes Source apportionment Inverse model Arid environment Inland rivers Northwestern China

Laboratory evaluation of high-friction thin overlays for pavement preservation

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Frontiers of Structural and Civil Engineering 2024年第6期18卷 936-948页

作者： Ouming xu Rentao xu Lintong JIN School of Highway Chang’an UniversityXi’an 710064China School of Materials Science and Engineering Chang’an UniversityXi’an 710061China

Traditional asphalt concrete(AC)and stone matrix asphalt(SMA),which are used as thin asphalt overlays,are common maintenance strategies to enhancing ride quality,skid resistance,and ***,several studies have used a novel asphalt mixture known as a high-friction thin overlay(HFTO)to improve surface ***,it remains uncertain whether the laboratory properties of HFTO differ significantly from those of conventional *** study aims to evaluate the laboratory properties of HFTO mixtures and compare them with those of AC and *** mixtures with nominal maximum size of 9.5 mm were produced in the laboratory,and performance tests were conducted,including wheel tracking test,low temperature flexural creep test,moisture susceptibility test,Cantabro Abrasion Test,Marshall Test,sand patch test,British pendulum test,and indoor tire-rollingdown *** results showed that the HFTO exhibited a lower tire/pavement noise than the AC and ***,HFTO had superior high-temperature stability,larger macro texture,and higher skid resistance in comparison to those of AC,but lower than those of ***,HFTO mixtures may be considered a suitable replacement for traditional AC mixtures in regions where skid resistance and noise reduction are concerns.

关键词： road engineering pavement maintenance high friction thin overlay performance skid resistance tire/pavement noise