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Pullout of the Cylindrical Helicoidal Fiber

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Acta Mechanica Solida Sinica 2024年第3期37卷 444-456页

作者： Chenhan Hu Weihao Tao hongjun yu Qinghua Qin Jianshan Wang Department of Mechanics Tianjin UniversityTianjin300054China Department of Astronautic Science and Mechanics Harbin Institute of TechnologyHarbin150001China Department of Materials Science Shenzhen MSU-BIT UniversityShenzhen518172China

The multi-layer cylindrical helicoidal fiber structure(MCHFS)exists widely in biological materials such as bone and wood at the *** typically function as reinforcing elements to enhance the toughness of *** this study,we establish a shear lag-based pullout model of the cylindrical helicoidal fiber(CHF)for investigating interlayer stress transfer and debonding behaviors,with implications regarding the underlying toughening mechanism of *** on the shear lag assumptions,analytical solutions for the stress and displacement fields of the MCHFS during the pullout are derived by considering the CHF as a cylindrically monoclinic material and verified through the 3D finite element *** is found that the helical winding of CHF results in both axial and hoop interlayer shear *** the helical winding angle and the elastic moduli of the fiber and matrix have significant influences on interlayer stress *** work reveals a new interlayer stress transfer mechanism in the MCHFS existing widely in biological materials.

关键词： Cylindrical helicoidal fiber structure Cylindrically monoclinic material Helical winding of fiber Pullout Interlayer stress transfer

NUMERICAL SIMULATION OF CRACK GROWTH IN BRITTLE MATRIX OF PARTICLE REINFORCED COMPOSITES USING THE XFEM TECHNIQUE

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Acta Mechanica Solida Sinica 2012年第1期25卷 9-21页

作者： Zhiyong Wang Li Ma Linzhi Wu hongjun yu Center for Composite Materials Harbin Institute of TechnologyHarbin 150001China

Crack growth in particle reinforced composites is significantly influenced by the character of the reinforcement *** accurately deal with such problems,the extended finite element method （XFEM） was employed and *** simulations are accomplished by using a new domain expression of an interaction integral for evaluating stress intensity factors （SIFs）,and by adopting the maximum hoop stress criterion for crack-growth direction *** deflection/attraction mechanisms and their associated energy release rate variations are *** is shown that the applied numerical method allows a considerable flexibility and can be used in more general *** crack-tip shielding and amplifying behaviors are clearly observed.

关键词： crack growth energy release rate crack-tip shielding and amplifying extended finite element method

Distribution of platelet-derived growth factor-alpha receptor expressing oligodendrocyte precursor cells in the adult rat brain

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Neural Regeneration Research 2009年第12期4卷 1093-1098页

作者： hongjun yu Jun Fei Xue Luo Zhongxiang Yao Department of Rehabilitation Southwest Hospital Third Military Medical University Chongqing 400038 China Department of Histology and Embryology Third Military Medical University Chongqing 400038 China Trauma Center of Daping Hospital Third Military Medical University Chongqing 400038 China

BACKGROUND： Studies have demonstrated that NG2-positive glial cells in the adult rats are predominantly located in the gray and white matter of the cerebral cortex and hippocampus. Platelet-derived growth factor-a receptor （PDGF-αR） cells are a subset of oligodendrocytes, which are not as mature as NG2-positive cells. Distribution and migration of PDGF-αR-positive cells in the rat brain remain poorly understood. OBJECTIVE： Using immunohistochemical methods, the distribution of oligodendrocyte precursor cells （PDGF-αR-positive） was analyzed in the adult rat brain. DESIGN, TIME AND SETTING： Immunohistochemical study was performed at the Department of Histology and Embryology of the Third Military Medical University from September 2007 to September 2008. MATERIALS： Rabbit anti-PDGF-αR polyclonal antibody was purchased from Santa Cruz Biotechnology, USA. Streptomycin-avidin-biotin complex immunohistochemistry kit was purchased from Zhongshan Goldenbridge Biotechnology, China. METHODS： Whole brains from 5 healthy, adult, Wistar rats were collected for immunohistochemistry, and the mean value of PDGF-αR-expressing cells was quantified. The absolute values were translated to ranked data of high, moderate, and low grades （high grade： 10 positive cells; moderate grade： 5-9 cells; low grade：〈 5 cells in a 400 × visual field）. Based on the number of cell processes and branches, as well as the number of PDGF-αR-positive cells, in different regions, the cells were classified into three categories, i.e., type Ⅰ-Ⅲ. From type I to type Ill, the number of processes gradually increased. MAIN OUTCOME MEARSURES： The number and distribution of PDGF-αR-positive cells in different brain regions of adult rats. RESULTS： PDGF-αR-positive cells were located in the forebrain and midbrain, but not in the cerebellum or brainstem. In the olfactory bulb and hippocampus, a total of 60% PDGF-αR-positive cells were type Ⅰ and these cells were not mature as others. In the cerebral cortex, olfactory s

关键词： Platelet-derived growth factor-α receptor oligodendrocyte progenitor cells brain distribution

Evaluation of diagnostic ratios of medium and serious weathered oils from five different oil sources

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Acta Oceanologica Sinica 2016年第4期35卷 1-8页

作者： HE Shijie WANG Chuanyuan LI Yantai yu hongjun HAN Bin School of Resources and Environmental Engineering Ludong University Yantai 264025 China Yantai Institute of Coastal Zone Research Chinese Academy of Sciences Yantai 264003 China University of Chinese Academy of Sciences Beijing 100049 China Institute of Public Administration Shandong Economic University Jinan 250014 China First Institute of Oceanography State Oceanic Administration Qingdao 266061 China

Laboratory experiments were conducted to simulate oil weathering process, a medium to long term weathering process for 210-d, using samples collected from five different oil resources. Based on relative deviation and repeatability limit analysis about indexes of these samples, the results show there had been significant changes in diagnostic ratios among the initial and weathered samples of different oils during this process. Changes of selected n-alkane diagnostic ratios of all oil samples displayed more obviously than diagnostic ratios of terpanes,steranes and PAHs in this process. Almost all selected diagnostic ratios of terpanes, steranes and PAHs can be efficiently used in tracking sources of hydrocarbon pollution, differentiating from the n-alkane diagnostic *** these efficient diagnostic ratios, only four ratios maintained good stability in the weathering processes and are more suitable because their relative deviation（RSD） are lower than 5%.

关键词： identification of spilled oils medium to long term weathering process simulation experiment biomarker ratios

Steady formation analysis onmulti-robot systems

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Journal of Control and Decision 2017年第1期4卷 12-31页

作者： yutong Liu hongjun yu Cheng-Chew Lim Peng Shi School of Electrical and Electronic Engineering University of AdelaideAdelaideAustralia

In this paper,a controller is designed for a group of cooperative robots to achieve the stable *** network among the robots is assumed unavailable and each robot can only measure the displacements relative to their *** controller will enable the robots to move to a predefined formation or a special formation under a suitable protocol which we will *** will discuss the effect of different sizes of the multi-vehicle system and conduct simulations to verify the effectiveness of the proposed controller and the formation protocols.

关键词： Formation control limited sensing range controller design size of multi-vehicle system

Paleoenvironmental changes during the late Quaternary as inferred from foraminifera assemblages in the Laizhou Bay

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Acta Oceanologica Sinica 2014年第10期33卷 10-18页

作者： YAO Jing yu hongjun XU Xingyong YI Liang CHEN Guangquan SU Qiao Key Laboratory of Marine Geology and Environment Institute of Oceanology Chinese Academy of Sciences Key Laboratory of Marine Sedimentology and Environmental Geology First Institute of OceanographyState Oceanic Administration University of Chinese Academy of Sciences State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences

Controlled by climate changes, there were three large-scale transgressions and regressions around the Bohai Sea during the late Quaternary, which were accepted by most geologists. However, a big controversy still exists about the time when the transgressions occurred separately. In order to find out the process of the paleoenvironmental changes around the Bohai Sea in the late Quaternary, the foraminifera assemblages from a new borehole Lz908 in the southern coast of the Laizhou Bay were studied, and then the transgressive strata were indentified. Combined with accelerator mass spectrometry radiocarbon 14C（AMS14C） and optically stimulated luminescence（OSL） ages, the occurrence time of these transgressions were re-determined. The result showed that three major large-scale transgressions occurred separately at the beginning of marine isotopic stage 7（MIS7）, the last interglacial period（MIS5） and the Holocene. In addition, a small-scale transgression occurred in the mid-MIS6, and the corresponding transgressive stratum was deposited. The transgressive deposition of MIS3 was also discovered in this study. However, the characteristics of the foraminifera indicated the environment during this period was colder than that in the MIS5. By comparison with the global sea-level changes, the paleoenvironmental changes around the Bohai Sea in the late Quaternary can be consistent with the global climate changes.

关键词： foraminifera assemblage late Quaternary environmental changes Laizhou Bay Bohai Sea

Exploratory Precipitation in North-Central China during the Past Four Centuries

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Acta Geologica Sinica(English Edition) 2010年第1期84卷 223-229页

作者： YI Liang yu hongjun XUXingyong YAO Jing SU Qiao GE Junyi Yantai Institute of Coastal Zone Research for Sustainable Development Chinese Academy of Sciences Yantai Shandong 264003 China Institute of Oceanology Chinese Academy of Sciences Qingdao Shandong 266071 China First Institute of Oceanography State Oceanic Administration Qingdao Shandong 266061 China Institute of Earth Environment Chinese Academy of Sciences Xi＇an Shaanxi 710075 China Graduate School of Chinese Academy of Sciences Beijing 100039 China

Two robust precipitation reconstructions were conducted by combining tree-ring chronologies, dryness/wetness indices from historical documents, and climate data from the global grid. It was found that the recurrent drought history of a region can help us understand the variability of precipitation. Several dry/wet periods during the past four centuries and potential cycles of precipitation variation were determined. Furthermore, the reconstructions are not only consistent well with each other in North-central China, but also in good agreement with variations of precipitation in northeastern Mongolia, the Longxi area in Gangsu Province and the Dulan area of Qinghai Province, and the snow accumulation of the Guliya glacier. These synchronous variations indicate that it is valuable to study various climate records, find common information and determine the driving force of climate change.

关键词： precipitation reconstruction dryness/wetness index tree-ring chronology North-centralChina

Magnetic properties indicate the sources of hadal sediments in the Yap Trench,northwest Pacific Ocean

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Journal of Oceanology and Limnology 2020年第3期38卷 665-678页

作者： CHEN yu YANG Jichao DADA Olusegun A YANG Yaomin LIN Zhen CUI Zhen XU yue yu hongjun LIU Baohua Institute of Deep Sea Science and Engineering Chinese Academy of ScienceSanya 572000China National Deep Sea Center Ministry of Natural Resources(MNR)Qingdao 266237China Dept.of Marine Science&Technology Federal University of TechnologyAkure 340252Nigeria University of Chinese Academy of Science Beijing 100049China

Magnetic minerals in marine sediments are often masked by the primary natural remanent magnetization and material source *** order to understand sedimentary environment and sources of sediments in the abyss,we studied 126 samples of five bottom surface cores collected by the Jiaolong Submersible at 4000-7000 m in depth during the third stage of the China's 38th Ocean *** magnetic properties of the sediments were analyzed using Thermosusceptibility(k-T)curves and Day *** results show that the magnetic minerals in the sediments of the Yap Trench are mainly maghemite,and the overall magnetic and soft magnetic properties were *** magnetic particles of sediments are dominated by pseudo single domains(PSD)*** main source of sediment is locally-derived basalt debris and volcanic debris,and the process of sedimentation is gravity-like flow deposition.

关键词： magnetic property material resource hadal sediment Yap Trench

Comparative Proteomic Analysis of Cucumber Fruits Under Nitrogen Deficiency At the Fruiting Stage

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Horticultural Plant Journal 2021年第1期7卷 59-72页

作者： Jia Hao Qiang Li hongjun yu Heng Wang Lin Chai Tiantian Miao Weijie Jiang Institute of Vegetables and Flowers Chinese Academy of Agricultural SciencesBeijing 100081China

Nitrogen deficiency is a major factor that affects the yield and quality of horticultural *** expressed proteins were identified in cucumber fruit under nitrogen deficiency treatment,and are expected to be highly useful for dissecting carbon,nitrogen and ascorbate metabolism in cucumber and for improving nitrogen fertilizer *** plants grown hydroponically in Hoagland solution were transferred to nitrogen-free conditions for 3 or 5 d after the blossom of female *** proteome profiles were assessed using twodimensional *** relative expression of the genes encoding 50 selected differentially expressed proteins and 4 key enzymes in carbon metabolism was analyzed by *** showed that most of the identified differentially expressed proteins were mainly associated with carbon metabolism,amino acid biosynthesis,ascorbate metabolism,and *** phosphorylation was enhanced,while the pentose phosphate pathway was *** metabolism and the synthesis of most amino acids was affected significantly,and ascorbate might be accumulated under nitrogen deficiency in cucumber fruit.

关键词： cucumber fruit nitrogen deficiency proteomics