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Fracture toughness and destructive mechanism of ductile nanoporous metallic glass and its crystal-impregnated nanocomposite

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Science China(Technological Sciences) 2023年第11期66卷 3328-3342页

作者： ZHANG YuHang XU JianFei HU YiQun SU Lei DING SuHang WU WenWang XIA re Key Laboratory of Hydraulic Machinery Transients(Wuhan University) Ministry of EducationWuhan 430072China Department of Engineering Mechanics School of Naval ArchitectureOcean&Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Nanoporous metallic glasses(NPMGs)and crystalline/amorphous nanocomposites exhibit superior ductility over bulk macroscopic metallic glasses(MGs).Their fracture behaviors re.ain a mystery due to experimental technical *** this work,the fracture behaviors of pre-cracked NPMGs and crystal-impregnated nanoporous metallic glasses(CINPMGs)are investigated through large-scale molecular dynamics simulations,and the MG and crystal phases are.amorphous Cu_(50)Zr_(50)and crystalline B2CuZr,*** toughness is determined by simultaneously considering the surface energy and plastic dissipated *** results confirm the excellent plasticity of both the pre-cracked NPMGs and *** progressive necking and ductile rupture of ligaments are responsible for generating NPMGs with prominent ductility and fracture ***,secondary cracking is also triggered,which can consume energy without extending the major crack,thus further improving fracture *** is also found that the fracture toughness of NPMGs can be improved by increasing the solid fraction of MG,and linear re.ation between fracture toughness and solid fraction can be *** impregnation effectively inhibits global failure.as the crystal phase shields the individual amorphous *** plastic flow characterized by shear bands is observed in CINPMGs,and this homogeneous global deformation is facilitated by the crystalline/amorphous ***,the fracture toughness of CINPMGs is higher than that of the constituent single phases,re.ardless of the volume fraction of each *** material charts manifest that these two types of materials demonstrate promising potential in the material selection library for advanced structural design.

关键词： nanoporous metals crack fracture toughness nanocomposites metallic glasses

Profile of Full-Term Births in Maternity Wards of Public Hospitals in Douala Cameroon

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Peripheral nerve regeneration and intraneural re.ascularization

Open Journal of Obstetrics and Gynecology（妇产科期刊） 2024年第5期 705页

作者： Henri Essome Merlin Boten Bounyom Astrid Ndolo Kondo Ingrid Doriane Ofakem Ilick Fulbert Mangala Nkwele Irène Cyrielle Edjoa Mboe Michel Roger Ekono Alphonse Ngalame Nyong Robert Tchounzou Moustapha Bilkissou Junie Ngaha Yaneu Marga Vanina Ngono Akam Gervais Mounchikpou Ngouhouo Grâce Tocki Toutou Théophile Nana Njamen Valère Mve Koh Pascal Foumane

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neural regeneration research 2019年第1期14卷 24-33页

作者： Martial Caillaud Laurence Richard Jean-Michel Vallat Alexis Desmoulière Fabrice Billet University of Limoges Myelin Maintenance and Peripheral Neuropathies Faculties of Medicine and Pharmacy University Hospital of Limoges Department of Neurology "Reference Center for Rare Peripheral Neuropathies" Department of Neurology

Peripheral nerves are particularly vulnerable to injuries and are involved in numerous pathologies for which specific treatments are lacking. This review summarizes the pathophysiological features of the most common traumatic nerve injury in humans and the different animal models used in nerve regeneration studies. ~Ihe current knowledge concerning Wallerian degeneration and nerve regrowth is then described. Finally, the involvement of intraneural vascularization in these processes is addressed. As intraneural vascularization has been poorly studied, histological experiments were carried out from rat sciatic nerves damaged by a glycerol injection. The results, taken together with the data from literature, suggest that re.ascularization plays an important role in peripheral nerve regeneration and must therefore be studied more carefully.

关键词： compression crush transection Sunderland's classification Wallerian degeneration angiogenesis traumatic glycerol

Mechanics and Wave Propagation Characterization of Chiral S-Shaped Auxetic Metastructure

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Acta Mechanica Solida Sinica 2022年第4期35卷 571-586页

作者： Qingsong Zhang Wenjie Hong Jianfei Xu Yuhang Zhang Suhang Ding Wenwang Wu re Xia Key Laboratory of Hydraulic Machinery Transients(Wuhan University) Ministry of EducationWuhan430072China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing100081China Hubei Key Laboratory of Waterjet Theory and new Technology Wuhan UniversityWuhan430072China

Auxetic metastructures have attracted tremendous attention because of their robust multifunctional properties and promising potential industrial *** paper studies the in-plane mechanical behaviors of a chiral S-shaped metastructure subjected to tensile loading in both X-direction and Y-direction and wave propagation properties using the finite element(FE)*** re.ationships between structural parameters and elastic behaviors are.also *** results indicate that the orientation of chiral S-shaped metastructure under tensile loading in the X-direction exhibits higher auxeticity and ***,the band structures and the edge modes of each band gap of the chiral S-shaped metastructure.are explored,and the re.ations between band gap properties and structural parameters are.also systematically ***,we explore the wave mitigation of the chiral S-shaped metastructures by regulating the structural ***,the transmission properties of the finite chiral S-shaped periodic metastructures are studied to confirm the results of band gap *** study promotes the engineering application of vibration isolation of chiral structures based on the band gap theory.

关键词： Auxetic metastructures Mechanical properties Band gaps Wave mitigation

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桥丝式电点火头发火时间一致性试验研究

爆破器材 2024年第4期53卷 23-27页

作者：杨刚彭星新孙热刘芳谢全民姚颖康江汉大学精细爆破国家重点实验室湖北武汉430056 中铁十一局集团第四工程有限公司湖北武汉430073 武汉爆破有限公司湖北武汉430056

为了确定桥丝式电点火头发火时间一致性的影响因素,采用高速摄影法对单个电点火头、电点火头串联组和电点火头并联组的发火过程和发火时间进行研究。试验结果表明:对于单个电点火头,发火电流超过1.4 A时,平均发火时间在5.0 ms内,继续增... 详细信息

为了确定桥丝式电点火头发火时间一致性的影响因素,采用高速摄影法对单个电点火头、电点火头串联组和电点火头并联组的发火过程和发火时间进行研究。试验结果表明:对于单个电点火头,发火电流超过1.4 A时,平均发火时间在5.0 ms内,继续增加发火电流,发火时间缩短趋势减缓;电点火头串联组的发火电流不宜低于1.8 A,发火时间差可控制在1.5 ms内;电点火头的发火时间一致性,并联组明显优于串联组。在进行组网爆破作业时,对于内置电点火头的一次性膨胀爆破管,推荐采用并联组网,普通电(220 V)可将电点火头的发火时间差控制在0.1 ms以内。

关键词：电点火头发火时间串联组网并联组网一致性

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A multi-agent system for itinerary suggestion in smart environments

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CAAI Transactions on Intelligence Technology 2021年第4期6卷 377-393页

作者： Alessandra De Paola Salvatore Gaglio Andrea Giammanco Giuseppe Lo re Marco Morana Universita degzi studi di Palermo PalermoItaly Srart Cities and Comtnunitics Natioral Jab CINI-Consorzio Interuniversitario Nazionale per l'Infortnatica PalerinoItaly

Modem smart environments pose several challenges,among which the design of intelligent algorithms aimed to assist the *** a variety of points of interest are.available,for instance,trajectory recommendations are needed to suggest users the most suitable itineraries based on their interests and contextual *** in many cases,these interests must be explicitly requested and their lack causes the so-called cold-start ***,lengthy travelling distances and excessive crowdedness of specific points of interest make itinerary planning more *** address these aspects,a multi-agent itinerary suggestion system that aims at assisting the users in an online and collaborative way is proposed.A profiling agent is responsible for the detection of groups of users whose movements are characterised by similar semantic,spatial and temporal features;then,a recommendation agent leverages contextual information and dynamically associates the current user with the trajectory clusters according to a Multi-Armed Bandit policy;Framing the trajectory recommendation as a reinforcement learning problem permits to provide high-quality suggestions while avoiding both cold-start and preference elicitation *** effectiveness of the approach is demonstrated by some deployments in real-life scenarios,such as smart campuses and theme parks.

关键词： artificial intelligence pattern recognition

MicroRNAs as emerging biomarkers and therapeutic targets for pancreatic cancer

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World Journal of Gastroenterology 2014年第32期20卷 11199-11209页

作者： Marion Gayral Sébastien Jo Naima Hanoun Alix Vignolle-Vidoni Hubert Lulka Yannick Delpu Aline Meulle Marlène Dufresne Marine Humeau Maёl Chalret du Rieu Barbara Bournet Janick Sèlves Rosine Guimbaud Nicolas Carrère Louis Buscail Jérome Torrisani Pierre Cordelier Cancer research Center of Toulouse Team 10 UMR INSERM U1037Université Paul Sabatier P?le Digestif Centre Hospitalier Universitaire Toulouse

Despite tremendous efforts from scientists and clinicians worldwide, pancreatic adenocarcinoma(PDAC) re.ains a deadly disease due to the lack of early diagnostic tools and reliable therapeutic approaches. Consequently, a majority of patients(80%) display an advanced disease that results in a low resection rate leading to an overall median survival of less than 6 months. Accordingly, robust markers for the early diagnosis and prognosis of pancreatic cancer, or markers indicative of survival and/or metastatic disease are des-perately needed to help alleviate the dismal prognosis of this cancer. In addition, the discovery of new therapeutic targets is mandatory to design effective treatments. In this review, we will highlight the translational studies demonstrating that microRNAs may soon translate into clinical applications as long-awaited screening tools and therapeutic targets for PDAC.

关键词： MicroRNAs Biomarkers Pancreatic cancer Therapeutic targets Pre.ancerous lesions

Isolation and characterization of five novel mini-M conotoxins from the venom of mollusk-hunter snail Conus bandanus

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Asian Pacific Journal of Tropical Biomedicine 2020年第8期10卷 343-352页

作者： Nguyen Bao Jean-Pière LE CAER Phan Thi Khanh Vinh Faculty of Food Technology Nha Trang University02 Nguyen Dinh ChieuNha TrangKhanh HoaVietnam Institut de Chimie des Substances Naturelles Centre de Recherche de Gif-FRC3115-UPR 2301F-91198 Gif-sur-YvetteFrance

Objective:To determine the new M-superfamily conotoxins from molluscivorous snail Conus bandanus in ***:Conus bandanus venom was fractionated and purified on HPLC system with an analytical reversed-phase C18 column in order to screen small *** primary structure of peptide was analyzed by matrix-assisted laser desorption/ionization time of flight tandem mass spectrometry using collision-induced dissociation and confirmed by Edman’s degradation ***:Five new conotoxins were biochemically characterized from the crude venom of the mollusk-hunting cone snail Conus bandanus,which were collected at Ke Ga reef of the Nha Trang Bay(Vietnam).Each conotoxin had 15 or 16 amino acid residues and shared the same characteristic cysteine framework V as–CC–C–C–CC–.They were termed as Bn3 b,Bn3 c,Bn3 d,Bn3 e and Bn3 f following the conotoxins ***:The conotoxins Bn3 b,Bn3 e,and Bn3 f are categorized in the mini-M conotoxins of the M1 branch,while conotoxins Bn3 c and Bn3 d are categorized in the mini-M conotoxins of the M2 *** homological analysis reveals that these conotoxins could serve as promising probe compounds for voltage-gated sodium channels.

关键词： Mini-M conotoxin Conus bandanus Cone snail venom

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浅埋煤层烧变岩地球化学与变质矿物相特征

西北大学学报（自然科学版） 2024年第2期54卷 329-344页

作者：杨帆热西提·亚力坤薛小渊宋世骏胡俭张泽宇姬中奎黄雷陕西煤业化工集团神木张家峁矿业有限公司陕西神木719316 西北大学地质学系/大陆动力学国家重点实验室陕西西安710069 中国煤炭科工西安研究院〔集团〕有限公司陕西西安710054 陕西省煤矿水害防治技术重点实验室陕西西安710077

以陕北张家峁井田延安组2^(2),3^(1)段烧变岩为研究对象,对其进行岩石地球化学迁移规律以及变质矿物相特征分析。结果表明,该区烧变岩为低碱性硅铝质变质岩,横向上钙碱性分布不均一,少部分烧变样品烧失量大且CaO含量高,Fe元素迁移聚集... 详细信息

以陕北张家峁井田延安组2^(2),3^(1)段烧变岩为研究对象,对其进行岩石地球化学迁移规律以及变质矿物相特征分析。结果表明,该区烧变岩为低碱性硅铝质变质岩,横向上钙碱性分布不均一,少部分烧变样品烧失量大且CaO含量高,Fe元素迁移聚集。Zr相容性比Hf更好,Ba元素富集可能与后期水文作用有关,稀土元素分配趋势线为略微轻稀土富集型,烧变作用对稀土元素的分配影响相对有限。烧变岩原生矿物多具有烧蚀特征,镜下发育烧蚀边、气孔构造等,新生矿物呈集合体充填矿物间或矿物裂缝中。矿物相组合与热接触变质作用中发生高热变质的透长岩相相近,但变质压力更低,温度更高。烧变岩层由下而上可分为薄层板状烧烤岩、烧熔岩、厚层板状烧烤岩、厚层层状烧烤岩的岩石组合,鳞石英+方石英相较莫来石+堇青石+赤铁矿能更好表征岩石烧变程度的强弱,同层烧烤岩下部烧变程度高于上部,烧熔岩上部板状烧烤岩烧变程度高于下部板状烧烤岩。研究区烧变岩具有“隐伏”的特点,且存在同沉积期烧变作用,除暴露在河谷阶地的烧变岩层外,部分烧变岩层埋于更新世地层和残余延安组地层之下。早期形成的烧变岩层后期被破坏,多期烧变地层相互叠置形成现今火烧区。

关键词：烧变岩张家峁井田地球化学变质矿物相热接触变质作用透长岩相