检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

水中构筑物表面生物膜形成物理化学过程

生物化学与生物物理进展 2024年第1期51卷 145-157页

作者：申锴高飞黄须强卢小鹏周慧敏李卫荣铁镝大连交通大学连续挤压教育部工程研究中心大连116028 东北大学材料科学与工程学院沈阳110819

水中构筑物表面生物膜的形成会加速构筑物的腐蚀,严重影响其使用效率和寿命;成熟后的生物膜老化脱落或受水力剪切作用进入主体水中,会造成水体二次污染,对动植物生长和人类生活造成重大影响。生物膜的形成是由单个细菌黏附到表面开始的... 详细信息

水中构筑物表面生物膜的形成会加速构筑物的腐蚀,严重影响其使用效率和寿命;成熟后的生物膜老化脱落或受水力剪切作用进入主体水中,会造成水体二次污染,对动植物生长和人类生活造成重大影响。生物膜的形成是由单个细菌黏附到表面开始的,经过可逆黏附到不可逆黏附的过渡后,细菌分泌的胞外聚合物(extracellular polymeric substances, EPSs)会加速表面微菌落的形成,再通过细菌间的群体感应(quorum sensing,QS)使细菌启动表型和基因型变化,最终促使成熟生物膜的形成。本文综述了生物膜形成的不同阶段所涉及的物理化学过程(薄膜形成阶段、细菌黏附阶段、胞外聚合物膜阶段、群体感应调节生物膜阶段和生物膜成熟与表征),分析总结了本领域各方向的最新研究进展,归纳并阐明了水中构筑物表面生物膜形成的机理和影响因素,为生物膜防控、清除和利用等相关研究领域提供了理论依据。

关键词：水中构筑物生物膜细菌黏附物理化学过程胞外聚合物群体感应调节

在线全文

学校读者我要写书评

暂无评论

海洋大气环境下镁合金腐蚀行为研究进展

稀有金属材料与工程 2024年第4期53卷 1170-1180页

作者：周慧敏黄须强孔令菲陈建鑫高飞刘绍红陈民芳张晋铁镝东北大学材料科学与工程学院辽宁沈阳110819 天津理工大学材料科学与工程学院天津300384 大连交通大学连续挤压教育部工程研究中心辽宁大连116028

本文综合研究了海洋大气环境下镁合金腐蚀行为的研究进展,比较分析了各种因素对腐蚀行为的影响,对当前研究进展进行总结并对未来研究方向进行展望。在海洋大气环境下,表面薄电解质溶液膜的包覆是镁合金发生电化学腐蚀的主要原因,且多发... 详细信息

本文综合研究了海洋大气环境下镁合金腐蚀行为的研究进展,比较分析了各种因素对腐蚀行为的影响,对当前研究进展进行总结并对未来研究方向进行展望。在海洋大气环境下,表面薄电解质溶液膜的包覆是镁合金发生电化学腐蚀的主要原因,且多发生局部腐蚀。相比于内陆大气环境,海洋大气中含有较多无机盐气溶胶颗粒,导致点蚀成为主要的局部腐蚀形式。相对湿度的升高会导致薄电解质膜厚度增加,进而加速整体腐蚀速率。随气温上升,镁合金的大气腐蚀速率线性增加,而空气中的CO_(2)可以抑制NaCl对镁合金的侵蚀。该领域未来需更多关注具体使役环境下合金的腐蚀机理,以及各种环境因素对腐蚀行为的协同作用机制,以指导海洋用镁合金材料的设计和制备。

关键词：镁合金海洋环境腐蚀大气腐蚀局部腐蚀

Evolution of secondary phase particles during deformation of Al-5Ti-1B master alloy and their effect on α-Al grain refinement

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2018年第12期34卷 2297-2306页

作者： Hong Yu Ning Wang Renguo Guan di tie Zheng Li Yanan An Yang Zhang State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'an 710072China School of Materials Science and Engineering Northeastern University.Shenyang 110819 China

Addition of Al-5Ti-1B alloy to molten aluminum alloys can refine α-Al grains effectively and thereby improve their strength and toughness. TiAl;and TiB;in Al-5Ti-1B alloy are the main secondary-phase particles for refinement, while the understanding on the effect of their sizes on α-Al grain refinement continues to be fragmented. Therefore, Al-5Ti-1B alloys with various sizes and morphologies of the secondary-phase particles were prepared by equal channel angular pressing（ECAP）. Evolution of the secondary-phase particles during ECAP process and their impact on α-Al grain refinement were studied by X-ray diffraction and scanning electron microscope（SEM）. Results show that during the ECAP process, micro-cracks firstly appeared inside TiAl;particles and then gradually expanded, which resulted in continuous refinement of TiAl;particles. In addition, micro-distribution uniformity of TiB;particles was improved due to the impingement of TiAl;particles to TiB;clusters during deformation. Excessively large sizes of TiAl;particles would reduce the number of effective heterogeneous nucleus and thus resulted in poor grain refinement effectiveness. Moreover, excessively small TiAl;particles would reduce inhibitory factors for grain growth Q and weaken grain refinement effectiveness. Therefore, an optimal size range of 18-22 μm for TiAl;particles was suggested.

关键词： Equal channel angular pressing process Secondary phases Refinement mechanism Grain refinement effect

Shear Model of Metal Melt Flowing on Vibration Wall and Effect of Shear Stress on Solidification Microstructure

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2018年第6期31卷 650-658页

作者： Ren-Guo Guan Xiang Wang Ying-Qiu Shang di tie Run-Ze Chao School of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 China School of Materials Science and Engineering Northeastern University Shenyang 110819 China Luoyang Ship Material Research Institute Luoyang 471000China

In this work,the shear model of metal melt flowing on vibration surface is established,and coupling effects of vibration and shear on the distribution of shear stress in melt and melt solidification microstructure are *** results show that the transition of melt from laminar flow to turbulent flow occurs earlier with increasing vibration frequency and vibration *** the laminar flow melt,shear stress in melt decreases with increasing vertical length,but it decreases firstly and then stabilizes with increasing flow *** the turbulent flow melt,shear stress decreases firstly and then stabilizes with increasing vertical length,but it increases with increasing flow *** the increase in vibration frequency and amplitude,shear stress along flow direction in laminar flow melt increases,while shear stresses along both flow direction and vertical direction in turbulent flow melt *** stress in melt decreases with increasing length along vertical *** the increase in flow length,shear stress decreases firstly and then stabilizes in laminar flow melt,while it increases in turbulent flow *** the increase in vibration frequency and amplitude,shear stress increases in laminar flow melt,while it stabilizes in turbulent flow *** on theoretical calculation,the maximum shear stress in melt during vibration shear flow is always much lower than the yield strength of a-Al grain,so the shear stress induced by vibration shear flow cannot break columnar crystal,which agrees with the experiment ***,the model can explain the shear constitutive relation of melt flow on vibration surface relatively well.

关键词： Solidification Flow near surface Shear Vibration Columnar crystal

Surface destructive mechanism on high-temperature ablation, supersonic-erosion, dreg-adherence and corrosion

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2004年第z1期14卷 429-434页

作者： XIAO Jun CHEN Jian-min ZHOU Hui-di LI tie-hu ZHANG Qiu-yu State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China College of Materials Science and Engineering Northwestern Polytechnic University Xi''an 710072 China State Key Laboratory of Solid LubricationLanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China State Key Laboratory of Solid LubricationLanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China College of Materials Science and EngineeringNorthwestern Polytechnic University Xi''an 710072 China College of Materials Science and EngineeringNorthwestern Polytechnic University Xi''an 710072 China

The exhaust and flame from a supersonic airborne missile high-energy smoke-born engine (SAMHSE) may lead to high-temperature ablation, supersonic-erosion, dreg-adherence (HTASED) and corrosion on the launcher slide track, causing serious problems to the operation and decreasing the lifetime of the launcher. Therefore, it is imperative to study the destructive mechanism so as to guarantee the smooth operation and increase the lifetime of military equipments. Accordingly, HTASED and corrosion were systematically observed and analyzed with the emphasis placed on the mechanism investigations making use of a series evaluation tests, typical missile engine simulation tests, national military standard methods, scanning electron microscopy and electrochemical corrosion tests. It is found that the thermal impact of high-temperature flame and supersonic erosion of corrosive melting particle jet of the SAMHSE lead to surface defects of micro-cracks, denudation and corrosive residue. Some defects reach to metal base becoming to "corrosive channels". Repetitive HTASED may cause ablation-adhesion fatigue stress, which enhances the surface corrosion and destruction. HTASED and corrosion are related to the type of a SAMHSE fuel and experience of the launcher. Surface destruction is related to synergistic effects of the HTASED. The ablated and failed Al or steel surface is liable to electrochemical corrosion characterized by pitting in humid and salt-spray environment.

关键词： high-temperature ablation supersonic-erosion dreg-adherence simulating test supersonic airborne missile high-energy smoke-born engine corrosion

Understanding the precipitation mechanism of copper-bearing phases in Al-Mg-Si system during thermo-mechanical treatment

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第1期96卷 226-232页

作者： Hongmei Jin Renguo Guan Xianxiang Huang Ying Fu Jin Zhang Xiaolin Chen Yu Wang Fei Gao di tie Key Laboratory of Lightweight Structural Materials Liaoning Province School of Materials Science and EngineeringNortheastern UniversityShenyang 110819China Engineering Research Center of Continuous Extrusion Ministry of EducationDalian Jiaotong UniversityDalian 116028China

Al-Mg-Si alloys(6000 series)exhibit a promising prospect as conductive materials due to their high specific strength,high electrical conductivity,excellent formability,good weldability,corrosion resistance and relatively low cost[1-3].These optimum properties are largely attributed to the formation of small-sized,coherent or semi-coherent and metastable phases brought by aging treatment[1,4].

关键词： corrosion treatment coherent

In vivo degradability and biocompatibility of a rheo-formed Mg–Zn–Sr alloy for ureteral implantation

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2022年第6期10卷 1631-1639页

作者： di tie Renguo Guan Huinan Liu Minfang Chen Sviatlana A.Ulasevich Ekaterina V.Skorb Patricia Holt-Torres Xiaopeng Lu Norbert Hort Engineering Research Center of Continuous Extrusion Ministry of EducationDalian Jiaotong UniversityDalian 116028China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China Department of Bioengineering University of CaliforniaRiversideCA 92521USA School of Materials Science and Engineering Tianjin University of TechnologyTianjin 300384China Infochemistry Scientific Center ITMO UniversitySt.Petersburg 192007Russia Magnesium Innovation Center-MAGIC Helmholtz Zentrum GeesthachtGeesthacht D-21502Germany

The introduction of biodegradable implant materials has significantly improved the postoperative subjective feelings of patients within the past few decades,among which magnesium alloy is widely considered a favorable choice as its appropriate biodegradability and evident antibacterial ***,we reveal a semisolid rheo-formed Mg–Zn–Sr alloy ureteral implant that displayed suitable degradability and biocompatibility in a pig *** non-dendritic microstructure was observed in the rheo-formed alloy,which led to ca.47%increase in ultimate tensile strength(from 195.0 MPa to 288.1 MPa)and more homogeneous degradation process compared with the untreated *** post-interventional inflammation or pathological changes of the test animals were observed during the implantation period,and the corrosion rate(0.22±0.04 mm·y^(-1))perfectly fitted the clinical ureteral stent indwelling *** urine bacteria numbers decreased from 88±13 CFU·mL^(-1)at 7 weeks post operation to 59±8 CFU·mL^(-1)at 14 weeks post operation,which confirmed the evident antibacterial activity of the *** study demonstrates that the Mg–Zn–Sr alloy is clinically safe for urinary system,enabling its efficacious use as ureteral implant materials.

关键词： In vivo Biodegradability Biocompatibility Mg–Zn–Sr alloy Ureteral implant

Organic thin-film transistors and related devices in life and health monitoring

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第2期17卷 426-444页

作者： Chenfang Sun tie Wang Tianjin Key Laboratory of Drug Targeting and Bioimaging Life and Health Intelligent Research InstituteTianjin University of TechnologyTianjin 300384China

The early determination of disease-related biomarkers can significantly improve the survival rate of ***,a series of explorations for new diagnosis technologies,such as optical and electrochemical methods,have been devoted to life and health *** thin-film transistor(OTFT),as a state-of-the-art nano-sensing technology,has attracted significant attention from construction to application owing to the merits of being label-free,low-cost,facial,and rapid detection with multi-parameter ***,interference from non-specific adsorption is inevitable in complex biological samples such as body liquid and exhaled gas,so the reliability and accuracy of the biosensor need to be further improved while ensuring sensitivity,selectivity,and ***,we overviewed the composition,mechanism,and construction strategies of OTFTs for the practical determination of disease-related biomarkers in both body fluids and exhaled *** results show that the realization of bio-inspired applications will come true with the rapid development of high-effective OTFTs and related devices.

关键词： organic thin-film transistors biosensors biomarkers organic bioelectronics organic semiconductors healthcare

In vivo urinary compatibility of Mg-Sr-Ag alloy in swine model

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bioactive Materials 2022年第1期7卷 254-262页

作者： di tie Norbert Hort Minfang Chen Renguo Guan Sviatlana Ulasevich Ekaterina V.Skorb Dapeng Zhao Yili Liu Patricia Holt-Torres Huinan Liu Engineering Research Center of Continuous Extrusion Ministry of EducationDalian Jiaotong UniversityDalian116028China Magnesium Innovation Center Helmholtz-Zentrum GeesthachtD-21502GeesthachtGermany School of Materials Science and Engineering Tianjin University of TechnologyTianjin300384China Infochemistry Scientific Center ITMO UniversitySt.Petersburg192007Russia College of Biology Hunan University410082ChangshaChina Department of Urology China Medical UniversityShenyang110084China Department of Bioengineering Bourns College of EngineeringUniversity of California at RiversideCA92521USA

A biodegradable metallic ureteral stent with suitable mechanical properties and antibacterial activity remains a *** we reveal the scientific significance of a biodegradable Mg-Sr-Ag alloy with a favorable combination of balanced mechanical properties,adjustable indwelling time in urinary tract and evident antibacterial activity via in vivo experiments in a swine *** to the rheo-solidification process,equiaxial microstructure and significantly refined grains(average grain size:27.1μm)were ***17Sr2 and Mg4Ag were found as the primary precipitates in the matrix,due to which the alloy obtained ca.111%increase in ultimate tensile strength in comparison to pure *** the in vitro and in vivo results demonstrated the satisfactory biocompatibility of the *** evaluation and bioindicators analysis suggested that there was no tissue damage,inflammation and lesions in the urinary system caused by the degradation *** stent also improved the post-operative bladder functions viewed from the urodynamic *** findings highlight the potential of this alloy as antibacterial biodegradable urinary implant material.

关键词： In vivo Magnesium alloy Biodegradable metals Mechanical properties Urinary compatibility