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FCF-LDH/BiVO4 with synergistic effect of physical enrichment and chemical adsorption for efficient reduction of nitrate

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Green Energy & Environment 2024年第7期9卷 1112-1121页

作者： Yajie bai Zhenyuan Fang Yong Lei Lijing Liu Huaiquan Zhao Hongye bai Weiqiang Fan Weidong Shi School of Chemistry and Chemical Engineering Jiangsu University School of Chemistry Beihang University Institute of Physics & IMN Macronano Technische Universit?t Ilmenau

Photoelectrochemical NO3-reduction（PEC NITRR） not only provides a promising solution for promoting the global nitrogen cycle,but also converts NO3-to the important chemicals（NH3）.However,it is still a great challenge to prepare catalysts with excellent NO3-adsorption/activation capacity to achieve high ***,we designed a novel Fe2+～Cu2+Fe3+LDH/BiVO4（FCF-LDH/BVO） catalyst with synergistic effect of chemical adsorption and physical ***2+in FCF-LDH/BVO provides the rich Lewis acid sites for the adsorption of NO3-,and the appropriate layer spacing of FCF-LDH further promotes the physical enrichment of NO3-in its interior,thus realizing the effective contact between NO3-and active sites(Fe2+).FCF-LDH/BVO showed excellent NH3production performance(FENH3=66.1%,rNH3=13.8 μg h-1cm-2) and selectivity(FENO2-=2.5%,rNO2-=4.9 μg h-1cm-2) in 0.5 mol *** addition,FCF-LDH/BVO maintains the desirable PEC stability for six cycle experiments,showing great potential for practical ***14NO3-and15NO3-isotope test provides strong evidence for further verification of the origin of N in the generated *** LDH catalyst has a great potential in PEC removal of NO3-from groundwater.

关键词： LDH Lewis acid sites Physical enrichment Photoelectrochemical NO 3 − Reduction Ammonia

低膨胀系数铸铁的多层激光熔覆分析及高温氧化磨损行为研究

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表面工程与再制造 2024年第1期24卷 59-60页

作者： Changyao Ouyang rui Wang Chunjiang Zhao Runze Wei Huan Li rui Deng Qiaofeng bai Yingliang Liu School of Mechanical Engineering Taiyuan University of Science and Technology Taiyuan 030024 China School of Mechanical and Equipment Engineering Hebei University of Engineering Handan 056038 China School of Intelligent Industry Shanxi Institute of Electronic Technology Linfen 041000 China Shuozhou Jinhua Industrial Co. Ltd. Shuozhou 036000 China

激光熔覆是铸铁零件修复和强化的关键工艺之一。为进一步提高激光熔覆在铸铁上的应用,为其表面熔覆提供可行的技术途径。本文在发动机缸体常用的铸铁材料球墨铸铁和灰铸铁表面熔覆不同的合金粉末。分析了铸铁表面多种粉末的多层熔覆层,... 详细信息

激光熔覆是铸铁零件修复和强化的关键工艺之一。为进一步提高激光熔覆在铸铁上的应用,为其表面熔覆提供可行的技术途径。本文在发动机缸体常用的铸铁材料球墨铸铁和灰铸铁表面熔覆不同的合金粉末。分析了铸铁表面多种粉末的多层熔覆层,探讨了Fe基涂层在高温下的氧化磨损行为。

关键词：激光熔覆高温氧化球墨铸铁铸铁零件灰铸铁多层熔覆低膨胀系数铸铁材料

星载微波部件微放电阈值的改进多粒子蒙特卡罗计算方法

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高电压技术 2024年第4期50卷 1752-1759页

作者：张娜曹猛王瑞白春江崔万照中国空间技术研究院西安分院空间微波通信全国重点实验室西安710100 西安交通大学电信学部电子科学与工程学院电子物理与器件教育部重点实验室西安710049

星载微波部件的微放电效应是导致航天器谐振类设备失谐、噪声电平抬高、输出功率下降,甚至影响通信信道乃至整个微波传输系统彻底失效的瓶颈问题之一。在设计阶段对星载微波部件微放电效应进行精准的评估是减少地面反复试验,避免延误研... 详细信息

星载微波部件的微放电效应是导致航天器谐振类设备失谐、噪声电平抬高、输出功率下降,甚至影响通信信道乃至整个微波传输系统彻底失效的瓶颈问题之一。在设计阶段对星载微波部件微放电效应进行精准的评估是减少地面反复试验,避免延误研制周期的重要手段。为了进一步改善现有蒙特卡洛方法的计算准确度问题,文中提出了一种精度更高的计算星载微波部件微放电阈值的蒙特卡罗方法,该方法对参与微放电过程的初始电子进行了动态调整,采用四阶龙格-库塔法推进微波部件中电子的运动轨迹,基于Furman模型描述电子与微波表面相互作用的二次电子发射过程,按照碰撞电子产生的实际二次电子个数及对应能量参与碰撞时刻后的微放电过程,该多粒子-多碰撞过程更加客观、准确地表征了微放电效应发生的物理过程。以平板传输线和同轴传输线为例,文中所提出的方法相对于已有的蒙特卡罗方法计算精度显著提升,同时计算效率优于商用CST的粒子模拟结果。

关键词：微放电二次电子发射蒙特卡罗方法阈值微波部件

Nitrogen availability mediates the effects of roots and mycorrhizal fungi on soil organic carbon decomposition:A meta-analysis

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Pedosphere 2024年第2期34卷 289-296页

作者： Tongshuo bai Yunpeng QIU Shuijin HU Ecosystem Ecology Laboratory College of Resources and Environmental SciencesNanjing Agricultural UniversityNanjing 210095China Department of Entomology&Plant Pathology North Carolina State UniversityRaleigh NC 27695USA

Plant roots and their associated mycorrhizal fungi critically mediate the decomposition of soil organic carbon(C),but the general patterns of their impacts over a broad geographical range and the primary mediating factors remain *** on a synthesis of 596 paired observations from both field and greenhouse experiments,we found that living roots and/or mycorrhizal fungi increased organic C decomposition by 30.9%,but low soil nitrogen(N)availability(i.e.,high soil C:N ratio)critically mitigated this promotion *** addition,the positive effects of living roots and/or mycorrhizal fungi on organic C decomposition were higher under herbaceous and leguminous plants than under woody and non-leguminous plants,***,there was no significant difference between arbuscular mycorrhizal fungi and ectomycorrhizal fungi in their effects on organic C ***,roots and/or mycorrhizal fungi significantly enhanced the decomposition of leaf litter but not root *** findings advance our understanding of how roots and their symbiotic fungi modulate soil C dynamics in the rhizosphere or mycorrhizosphere and may help improve predictions of soil global C balance under a changing climate.

关键词： arbuscular mycorrhizal fungi ectomycorrhizal fungi leaf litter leguminous plant mycorhizosphere rhizosphere root litter soil C:N ratio

Grassland-type ecosystem stability in China differs under the influence of drought and wet events

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Journal of Arid Land 2024年第5期16卷 615-631页

作者： CAO Wenyu bai Jianjun YU Leshan School of Geography and Tourism Shaanxi Normal UniversityXi'an 710119China International Business School Shaanxi Normal UniversityXi'an 710119China

Ecological stability is a core issue in ecological research and holds significant implications forhumanity. The increased frequency and intensity of drought and wet climate events resulting from climatechange pose a major threat to global ecological stability. Variations in stability among different ecosystemshave been confirmed, but it remains unclear whether there are differences in stability within the sameterrestrial vegetation ecosystem under the influence of climate events in different directions and ***'s grassland ecosystem includes most grassland types and is a good choice for studying this *** study used the Standardized Precipitation Evapotranspiration Index-12 (SPEI-12) to identify thedirections and intensities of different types of climate events, and based on Normalized DifferenceVegetation Index (NDVI), calculated the resistance and resilience of different grassland types for 30consecutive years from 1990 to 2019 (resistance and resilience are important indicators to measurestability). Based on a traditional regression model, standardized methods were integrated to analyze theimpacts of the intensity and duration of drought and wet events on vegetation stability. The resultsshowed that meadow steppe exhibited the highest stability, while alpine steppe and desert steppe had thelowest overall stability. The stability of typical steppe, alpine meadow, temperate meadow was at anintermediate level. Regarding the impact of the duration and intensity of climate events on vegetationecosystem stability for the same grassland type, the resilience of desert steppe during drought was mainlyaffected by the duration. In contrast, the impact of intensity was not significant. However, alpine steppewas mainly affected by intensity in wet environments, and duration had no significant impact. Ourconclusions can provide decision support for the future grassland ecosystem governance.

关键词： grassland ecosystem stability resistance resilience different climate types drought climate event wet climate event

Stellar Populations of AGN-host Dwarf Galaxies Selected with Different Methods

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Research in Astronomy and Astrophysics 2024年第6期24卷 52-67页

作者： Xiejin Li 赵应和 Jinming bai Yunnan Observatories Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Radio Astronomy and Technology Chinese Academy of SciencesBeijing 100101China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650011China

In this paper we investigate the stellar populations and star formation histories of 235 active galactic nucleus(AGN)-host dwarf galaxies,consisting of four samples identified separately with different methods(i.e.,radio,X-ray,mid-IR and variability),utilizing the synthesis code STARLIGHT and spectra from the Sloan Digital Sky Survey Data Release *** results show that the variability sample is the oldest,while the mid-IR sample is the youngest,for which the luminosity at 4020?is dominated(>50%)by the young population(t10~8yr).The light-weighted mean stellar age of the whole sample is in general about 0.7 dex younger than the optical sample studied in Cai et *** compare the population results between fitting models with and without a power-law(PL)component and find that the neglect of a PL component would lead to an under-and over-estimation by 0.2 and0.1 dex for the light-and mass-weighted mean stellar age,respectively,for our sample of dwarf galaxies,which has a mean fractional contribution of~16%from the *** addition,we obtain further evidence for a possible suppression of star formation in the host galaxy by the central *** also find that there exists an anticorrelation between the extinction-corrected[O III]luminosity and light-weighted mean stellar age,confirming our previous finding that there is a physical connection between AGN and star-forming activities in AGN-host dwarfs.

关键词： galaxies:dwarf galaxies:active galaxies:stellar content

AI enhances drug discovery and development

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national Science Review 2024年第3期11卷 52-54页

作者： Fang bai Shiliang Li Honglin Li Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology ShanghaiTech University Lingang Laboratory Innovation Center for AI and Drug Discovery East China Normal University

The advent of the third wave of artificial intelligence(AI) heralds a new era in drug discovery. AI-powered techniques can be characteristic of identifying features that are difficult for humans to interpret from big ...

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Design and mechanical properties analysis of a cellular Waterbomb origami structure

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Theoretical & Applied Mechanics Letters 2024年第3期14卷 193-202页

作者： Yongtao bai Zhaoyu Wang Yu Shi School of Civil Engineering Chongqing UniversityChongqing 400045China Research Center of Steel Structure Engineering Chongqing UniversityChongqing 400045China

Cellular structures are commonly used to design energy-absorbing structures,and origami structures are becominga prevalent method of cellular structure *** paper proposes a foldable cellular structure based on theWaterbomb origami *** geometrical configuration of this structure is ***-static compressiontests of the origami tube cell of this cellular structure are conducted,and load-displacement relationship curvesare *** simulations are carried out to analyze the effects of aspect ratio,folding angle,thicknessand number of layers of origami tubes on initial peak force and specific energy absorption(SEA).Calculationformulas for initial peak force and SEA are obtained by the multiple linear regression *** degree ofinfluence of each parameter on the mechanical properties of the single-layer tube cell is *** resultsshow that the cellular structure exhibits negative stiffness and periodic load-bearing capacity,as well as foldingangle has the most significant effect on the load-bearing and energy-absorbing *** adjusting the designparameters,the stiffness,load-bearing capacity and energy absorption capacity of this cellular structure can beadjusted,which shows the programmable mechanical properties of this cellular *** foldability andthe smooth periodic load-bearing capacity give the structure potential for application as an energy-absorbing structure.

关键词： Cellular structure Waterbomb origami Mechanical metamaterial Numerical simulation Energy absorption

Analyses of Political Crisis Impact on Tourism:A Panel Counterfactual Approach with Internet Search Index

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Journal of Systems Science & Complexity 2024年第4期37卷 1581-1603页

作者： HUANG bai SUN Yuying YANG Boyu School of Statistics and Mathematics Central University of Finance&EconomicsBeijing 102206China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China Center for Forecasting Science Chinese Academy of SciencesBeijing 100190China School of Economics and Management University of Chinese Academy of SciencesBeijing 100190China

Existing research has shown that political crisis events can directly impact the tourism ***,the current methods suffer from potential changes of unobserved variables,which poses challenges for a reliable evaluation of the political crisis *** paper proposes a panel counterfactual approach with Internet search index,which can quantitatively capture the change of crisis impacts across time and disentangle the effect of the event of interest from the *** also provides a tool to examine potential channels through which the crisis may affect tourist *** research empirically applies the framework to analyze the THAAD event on tourist flows from the Chinese Mainland to South *** highlight the strong and negative short-term impact of the political crisis on the tourists' intentions to visit a *** paper provides essential evidence to help decision-makers improve the management of the tourism crisis.

关键词： Composite search index counterfactual analysis political crisis search query data tourism demand