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Three-Dimensional Multi-Phase Microscopic Simulation of Service Life of Recycled Large Aggregate Self-Compacting Concrete

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Journal of Materials Science and Chemical Engineering 2024年第4期12卷 126-135页

作者： Jing Li Lina Gao libo liu Liao Zhang Jianhua Zheng Jing Gao College of Pipeline and Civil Engineering China University of Petroleum (East China) Qingdao China China Huanqiu Contracting & Engineering Co. Ltd. Beijing China School of Civil and Transportation Engineering Beijing University of Civil Engineering and Architecture Beijing China The Fourth Construction Co. Ltd. of China Construction Eighth Engineering Division Qingdao China

Recycled large aggregate self-compacting concrete (RLA-SCC) within multiple weak areas. These weak areas have poor resistance to chloride ion erosion, which affects the service life of RLA-SCC in the marine environment. A three-dimensional multi-phase mesoscopic numerical model of RLA-SCC was established to simulate the chloride ions transportation in concrete. Experiments of RLA-SCC immersing in chloride solution were carried out to verify the simulation results. The effects of recycled large aggregate (RLA) content and RLA particle size on the service life of concrete were explored. The results indicate that the mesoscopic numerical simulation results are in good agreement with the experimental results. At the same depth, the closer to the surface of the RLA, the greater the chloride ion concentration. The service life of RLA-SCC in marine environment decreases with the increase of RLA content. Compared with the service life of 20% content, the service life of 25% and 30% content decreased by 20% and 42% respectively. Increasing the particle size of RLA can effectively improve the service life of RLA-SCC in chloride environment. Compared with the service life of 50 mm particle size, the service life of 70 mm and 90 mm increased by 61% and 163%, respectively. .

关键词： Recycled Large Aggregate Self-Compacting Concrete Mesoscopic Mode Chloride Ion Diffusion Numerical Analysis

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Large-scale inverted-V channels of upflowing oxygen ions pumped by Alfvén waves

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Earth and Planetary Physics 2023年第6期7卷 640-654页

作者： Hui Zhang Jun Zhong SuiYan Fu ZuYin Pu Yong Wei Lun Xie libo liu QiAn Chen Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth Sciences University of Chinese Academy of SciencesBeijing 100049China Heilongjiang Mohe National Observatory of Geophysics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China School of Earth and Space Sciences Peking UniversityBeijing 100871China

Large-scale inverted-V channels of upflowing oxygen ions are frequently identified in data collected by Cluster,at all local times,near the open-closed field line boundary over Earth’s high-latitude ionosphere-occur with downward propagating MHD Alfvén waves which have cascaded into kinetic regimes of plasma.The transverse acceleration of the oxygen ions in the center of these structures is interpreted as the integrated energization by these waves along the channels.Also observed within the channels are upward parallel electric fields,a key characteristic of kinetic Alfvén waves,which may contribute not only to lifting the ions but also to precipitating aurora electrons that might initiate ion upflow in the ionosphere below.Statistics on five-year observations of Cluster show that the channels typically form during geomagnetic perturbations,particularly when solar-wind dynamic pressure is high or highly fluctuated.Near the open-closed field line boundary,the stronger the wave power,the higher the upward oxygen flux and the higher the beam energy,indicating that these waves provide a simple but efficient way to drive oxygen upflows.

关键词： oxygen ions dispersive Alfvén waves ion outflow parallel electric field

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Ciprofloxacin stress changes key enzymes and intracellular metabolites of Lactobacillus plantarum DNZ-4

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Food Science and Human Wellness 2022年第2期11卷 332-340页

作者： Pin Chen Xiaoqian Chen Wei Yu Bo Zhou Lihua liu Yuzhuo Yang Peng Du libo liu Chun Li Key Laboratory of Dairy Science Ministry of EducationFood Science CollegeNortheast Agricultural UniversityHarbin 150030China Institute of Animal Science(IAS) Chinese Academy of Agricultural Sciences(CAAS)Beijing 100193China National Dairy Product Quality Supervision and Inspection Center Harbin 150024China

Ciprofloxacin(CIP)is an antibiotic used to treat infections caused by bacteria.In this experiment,key enzymes and intracellular metabolites of Lactobacillus plantarum DNZ-4 was researched under CIP stress.The results showed that the activities of hexokinase,pyruvate kinase,β-galactosidase and Na^(+),K^(+)-ATPase after 1/2 minimum bacteriostatic concentration(MIC)CIP treatment were significantly decreased(P<0.01).Gas chromatography-mass spectrometry was used to analysis the changes of main metabolites in the cells and principal component analysis and partial least square model were constructed.The results indicated that CIP could cause changes in intracellular fatty acids,carbohydrates and amino acids,and the mechanism of amino acid metabolism under CIP stress was significantly inhibited.L.plantarum DNZ-4 made stress response to CIP by regulating the ratio of saturated fatty acids and unsaturated fats.This experiment revealed the changes of growth and metabolism mechanism of L.plantarum DNZ-4 under CIP stress,which help to provide technical means for the development of effective probiotics preparation products.

关键词： Ciprofl oxacin Lactobacillus plantarum DNZ-4 Key enzymes Metabolism

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New understanding achieved from 2 years of Chinese ionospheric investigations

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Science Bulletin 2016年第7期61卷 524-542页

作者： libo liu Weixing Wan Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences Beijing National Observatory of Space Environment Institute of Geology and Geophysics Chinese Academy of Sciences Geoscience School University of the Chinese Academy of Sciences

In the mainland of China, the number of ionospheric research groups is more than 10. Around 110 articles related to ionospheric physics have been published during 2014–2015. In this annual national report of the Committee on Space Research(COSPAR), we will outline some recent progresses in ionospheric studies conducted by the Chinese mainland scientists in the past 2 years. These investigations cover(1) the ionosphere responses to geomagnetic activities;(2) ionospheric climatology and structures;(3) couplings between the ionosphere, plasmasphere and lower atmosphere, and possible seismic signatures in the ionosphere;(4) ionospheric irregularities and scintillation;(5) ionospheric models, data assimilation and simulations;(6) ionospheric dynamics and electrodynamics;(7) progresses in the observation methodology and technique; and(8) planetary ionospheres. Such investigations will strengthen our ability to monitor the ionosphere,provide a better understanding of the ionospheric states and the underlying fundamental processes, and improve the ionospheric modeling, forecasting, and related applications.

关键词：电离层耦合中国大陆电离层闪烁电离层模型物理相关地球磁场低层大气地震信号

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Recent ionospheric investigations in China(2018–2019)

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Earth and Planetary Physics 2020年第3期4卷 179-205页

作者： libo liu WeiXing Wan Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China Beijing National Observatory of Space Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100101China College of Earth and Planetary Sciences University of the Chinese Academy of SciencesBeijing 100019China

Since the release of the 2018 National Report of China on ionospheric research(liu LB and Wan WX,2018)to the Committee on Space Research(COSPAR),scientists from China's Mainland have made many new fruitful investigations of various ionospheric-related issues.In this update report,we briefly introduce more than 130 recent reports(2018–2019).The current report covers the following topics:ionospheric space weather,ionospheric structures and climatology,ionospheric dynamics and couplings,ionospheric irregularity and scintillation,modeling and data assimilation,and radio wave propagation in the ionosphere and sounding techniques.

关键词： ionosphere ionospheric storm ionospheric climatology ionospheric irregularity GNSS space weather

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Ionospheric precursors of strong earthquakes observed using six GNSS stations data during continuous five years(2011-2015)

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Geodesy and Geodynamics 2023年第1期14卷 65-79页

作者： H.E.Eshkuvatov B.J.Ahmedov Y.A.Tillayev M.Arslan Tariq M.Ali Shah libo liu Ulugh Beg Astronomical Institute Astronomy St.33Tashkent 100052Uzbekistan National University of Uzbekistan University St.4Tashkent 100174Uzbekistan Institute of Fundamental and Applied Research National Research University TIIAMEKori Niyoziy 39Tashkent 100000Uzbekistan Centre for Earthquake Studies National Centre for PhysicsIslamabadPakistan Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijingChina College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Heilongjiang Mohe Observatory of Geophysics Institute of Geology and GeophysicsChinese Academy of SciencesBeijingChina

This study reports the morphological characteristics of anomalous variations in Global Navigation Satellite System Total Electron Content(GNSS-TEC) prior to the strong local earthquakes(EQ) that occurred during the period of 2011-2015.We have analyzed 20 earthquakes of magnitude M> 5.6.A statistical technique is implemented on the data of six GNSS stations located in Tashkent,Kitab,and Maidanak in Uzbekistan,and Islamabad,Multan,Quetta in Pakistan.The results show continuous anomalous variations in TEC during 24 h befo re the occupancy of local earthquakes.It is shown that the precursors before the occurrence of strong earthquakes,in particular of magnitude 5.7,7.7,7.5,7.8 and 7.3 are detected near Eastern Uzbekistan(26 May 2013),Southwestern Pakistan(24 September 2013),Hindukush region of Afghanistan(26 October 2015),and Central Nepal(25 April 2015) and(12 May 2015),respectively.The ionospheric anomalies appearing before the strong earthquakes at six GNSS stations are registered in 14cases(70%) out of 20 selected EQs.It is depicted that anomalies referred to as ionospheric precursors appeared about 1-7 days prior to the occurrence of strong earthquakes.

关键词： GNSS TEC Earthquakes Ionospheric precursors

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PtrDJ1C,an atypical member of the DJ-1 superfamily,is essential for early chloroplast development and lignin deposition in poplar

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Horticultural Plant Journal 2023年第5期9卷 1039-1054页

作者： Xinwei Wang Chunxue Shao libo liu Yue Wang Yaqi An Hui Li Yunwei Ding Yanping Jing Xiaojuan Li Jianwei Xiao College of Biological Sciences and Biotechnology Beijing Forestry UniversityBeijing 100083China Hebei North University ZhangjiakouHebei 075000China National Engineering Research Center of Tree Breeding and Ecological Restoration Beijing Forestry UniversityBeijing 100083China Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants Ministry of EducationCollege of Biological Sciences and BiotechnologyBeijing Forestry UniversityBeijing 100083China

The nuclear-encoded factors and the photosynthetic apparatus have been studied extensively during chloroplast biogenesis.However,many questions regarding these processes remain unanswered,particularly in perennial woody plants.As a model material of woody plants,poplar not only has very significant value of research,but also possesses economic and ecological properties.This study reports the Populus trichocarpa DJ-1C(PtrDJ1C)factor,encoded by a nuclear gene,and a member of the DJ-1 superfamily.PtrDJ1C knock-out with the CRISPR/Cas9 system resulted in different albino phenotypes.Chlorophyll fluorescence and immunoblot analyses showed that the levels of photosynthetic complex proteins decreased significantly.Moreover,the transcript level of plastid-encoded RNA polymerase-dependent genes and the splicing efficiency of several introns were affected in the mutant line.Furthermore,rRNA accumulation was abnormal,leading to developmental defects in chloroplasts and affecting lignin accumulation.We concluded that the PtrDJ1C protein is essential for early chloroplast development and lignin deposition in poplar.

关键词： PtrDJ1C Chloroplast development Gene expression Lignin Poplar

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Contribution of the Chinese Meridian Project to space environment research:Highlights and perspectives

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Science China Earth Sciences 2023年第7期66卷 1423-1438页

作者： Chi WANG Jiyao XU libo liu Xianghui XUE Qinghe ZHANG Yongqiang HAO Gang CHEN Hui LI Guozhu LI Bingxian LUO Yajun ZHU Jiangyan WANG State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China School of Earth and Space Sciences University Science and Technology of ChinaHefei 230026China Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space SciencesShandong UniversityWeihai 264209China School of Earth and Space Sciences Peking UniversityBeijing 100191China Department of Space Physics School of Electronic InformationWuhan UniversityWuhan 430072China Key Laboratory of Science and Technology on Environmental Space Situation Awareness National Space Science CenterChinese Academy of SciencesBeijing 100190China

The Chinese Meridian Project(CMP)is devoted to establishing a comprehensive ground-based monitoring network for China’s space weather research.CMP is a major national science and technology infrastructure project with the participation of more than 10 research institutions and universities led by the National Space Science Center of the Chinese Academy of Sciences.CMP is planned to be constructed in two phases:CMP phasesⅠandⅡ.The first phase(CMP-Ⅰ)started construction in2008 and completed in 2012,after which it entered the operation stage.The 10-year observation of CMP-Ⅰhas made significant scientific discoveries and achievements in the research fields of the middle and upper atmospheric fluctuations,metal layers in the mesosphere and lower thermosphere,ionospheric disturbances and irregularities,geomagnetic disturbances,and influences of solar activity.The review summarizes the main observations and research achievements,space weather forecast modeling and methods based on CMP-Ⅰover the past 10 years,and presents a future extension perspective along with the construction of CMP-Ⅱ.

关键词： Chinese Meridian Project Ground-based observation network Space weather Solar-terrestrial physics

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Collaborative Learning Method for Natural Image Captioning

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国际计算机前沿大会会议论文集 2022年第1期 249-261页

作者： Rongzhao Wang libo liu School of Information Engineering Ningxia UniversityYinchuanChina

We propose a collaborative learning method to solve the natural image captioning problem.Numerous existing methods use pretrained image classification CNNs to obtain feature representations for image caption generation,which ignores the gap in image feature representations between different computer vision tasks.To address this problem,our method aims to utilize the similarity between image caption and pix-to-pix inverting tasks to ease the feature representation gap.Specifically,our framework consists of two modules:1)The pix2pix module(P2PM),which has a share learning feature extractor to extract feature representations and a U-net architecture to encode the image to latent code and then decodes them to the original image.2)The natural language generation module(NLGM)generates descriptions from feature representations extracted by P2PM.Consequently,the feature representations and generated image captions are improved during the collaborative learning process.The experimental results on the MSCOCO 2017 dataset prove the effectiveness of our approach compared to other comparison methods.

关键词： Image captioning Pix2pix inverting Collaborative learning

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视频文本跨模态检索研究综述

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计算机工程与应用 2024年第4期60卷 1-20页

作者：陈磊习怡萌刘立波宁夏大学信息工程学院银川750021

模态代表着数据特定的存在形式,不同模态数据的快速增长,使得多模态学习受到广泛关注。跨模态检索作为多模态学习的一个重要分支,在图文方面已得到显著发展。然而视频相对于图像而言承载了更多模态的数据,也包含更广泛的信息,能够满足... 详细信息

模态代表着数据特定的存在形式,不同模态数据的快速增长,使得多模态学习受到广泛关注。跨模态检索作为多模态学习的一个重要分支,在图文方面已得到显著发展。然而视频相对于图像而言承载了更多模态的数据,也包含更广泛的信息,能够满足用户对信息检索全面性、灵活性的要求,近年来逐渐成为跨模态检索的研究热点。为全面认识和理解视频文本跨模态检索及其前沿工作,对现有代表性方法进行了梳理和综述。首先归纳分析了当前基于深度学习的单向、双向视频文本跨模态检索方法,对每类方法中的经典工作进行了详细分析并阐述了优缺点。接着从实验的角度给出视频文本跨模态检索的基准数据集和评价指标,并在多个常用基准数据集上比较了一些典型方法的性能。最后讨论了视频文本跨模态检索的应用前景、待解决问题及未来研究挑战。

关键词：多模态跨模态检索深度学习特征提取

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