检索结果-南通市图书馆

采用高压固溶制备具有均匀腐蚀行为的高强度抗菌Zn-4Ag-Mn合金

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2024年第7期34卷 2231-2244页

作者：牛堃宁张德闯齐福刚林建国戴翌龙湘潭大学材料科学与工程学院湘潭411105 湘潭大学低维材料及应用技术教育部重点实验室湘潭411105

采用高压固溶(HPS)法制备Zn-4Ag-Mn合金,获得高强度、可均匀降解、抗菌的植入材料。显微组织表征表明,HPS处理使Zn-4Ag-Mn合金晶粒比铸态(AC)合金的细化57.9%,其第二相平均尺寸减小到10.2μm。压缩、维氏硬度和磨损摩擦试验表明,HPS合... 详细信息

采用高压固溶(HPS)法制备Zn-4Ag-Mn合金,获得高强度、可均匀降解、抗菌的植入材料。显微组织表征表明,HPS处理使Zn-4Ag-Mn合金晶粒比铸态(AC)合金的细化57.9%,其第二相平均尺寸减小到10.2μm。压缩、维氏硬度和磨损摩擦试验表明,HPS合金具有较高的力学性能,抗压屈服强度为333.5MPa,维氏硬度为Hv 89.5。电化学腐蚀和浸泡腐蚀试验表明,HPS处理优化合金的耐蚀性,使其腐蚀均匀。此外。经抗菌实验测试,HPS处理的Zn-4Ag-Mn合金具有优异的抗菌性能,抗菌率为71.6%。这些结果表明,HPS处理的Zn-4Ag-Mn是一种很有前途的生物可降解植入材料。

关键词： Zn-Ag-Mn合金高压固溶高强度均匀腐蚀抗菌性能

不同模具角度下反复弯曲-压平变形工艺对AZ31镁合金板材显微组织演变和变形行为的影响

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2024年第3期34卷 812-832页

作者：李旻昊卢立伟范宇田马旻吴志强周涛齐福刚张华湖南科技大学机电工程学院湘潭411201 湖南科技大学难加工材料高效精密加工湖南省重点实验室湘潭411201 湖南科技大学材料科学与工程学院湘潭411201 重庆理工大学材料科学与工程学院重庆400054 湘潭大学材料科学与工程学院湘潭411105 烟台大学精准材料高等研究院烟台264005

采用不同角度模具的反复弯曲-压平变形工艺制备AZ31镁合金板材。通过FEM、OM、EBSD和硬度计研究AZ31镁合金在反复弯曲-压平变形过程中的显微组织演变和变形行为。结果表明,150°/150°模具在所有三组实验中都表现出最佳性能。随着道次... 详细信息

采用不同角度模具的反复弯曲-压平变形工艺制备AZ31镁合金板材。通过FEM、OM、EBSD和硬度计研究AZ31镁合金在反复弯曲-压平变形过程中的显微组织演变和变形行为。结果表明,150°/150°模具在所有三组实验中都表现出最佳性能。随着道次的增加,合金的等效应变由于剪切和弯曲作用而显著提高。经过4道次后,合金的平均晶粒尺寸显著细化至1.7μm,基面织构被弱化,这是非基面滑移、动态再结晶和孪生引起的;尤其是锥面滑移有利于引发动态再结晶和孪生。合金的硬度值达到HV 77,这是滑移、孪生和动态再结晶竞争产生的显微组织和织构综合作用的结果。

关键词： AZ31镁合金板材显微组织演变变形行为反复弯曲-压平工艺模具角度

Directed Self-assembly of Vertical PS-b-PMMA Nanodomains Grown on Multilayered Polyelectrolyte Films

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2020年第1期38卷 92-99,I0008页

作者： Kai Liu Chun-Ming Yang Bo-Ming Yang Lan Zhang Wen-Chao Huang Xiao-Ping Ouyang fu-gang qi Nie Zhao Feng-gang Bian College of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai201204China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai201204China

Layer-by-layer polyelectrolyte self-assembly, a common method for preparing high-quality ultra-thin films, was employed to direct the self-assembly behavior of polystyrene-block-poly(methyl methacrylate)(PS-b-PMMA) block copolymer for the first time. Differing from the previous neutral polymer brushes anchored to silicon substrates via chemical modification, polyelectrolyte multilayers(PEMs) were anchored by electrostatic interaction and provided a stable, smooth, and neutral interface. In the present study, PS-b-PMMA was deposited on poly(acrylamide hydrochloride)/poly(acrylic acid)(PAH/PAA) PEMs prepared by layer-by-layer self-assembly to successfully yield vertical nanodomains after thermal annealing. Seven layered PEMs revealed an excellent, smooth surface, with a low roughness of 0.6 nm. The periodic structure with interlamellar spacing of 47 nm was determined by grazing-incidence small-angle X-ray scattering(GISAXS). The morphology of the PS-b-PMMA nanodomains depended on the polyanion-to-polycation concentration ratio, which is related to the interaction between the block copolymer and the substrate. Our results demonstrate that layer-by-layer self-assembly is a helpful method for the phase separation of block polymers and the fabrication of vertical, ordered nanodomains.

关键词： Block copolymer Polyelectrolyte Self-assembly GISAXS

Effect of bias voltage on microstructure,mechanical and tribological properties of TiAlN coatings

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2022年第11期32卷 3596-3609页

作者： Hong-shuai CAO fu-jia LIU Hao LI Wen-zhong LUO fu-gang qi Li-wei LU Nie ZHAO Xiao-ping OUYANG School of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education Xiangtan UniversityXiangtan 411105China Hunan Provincial Key Laboratory of High Efficiency and Precision Machining of Difficult-to-Cut Material Hunan University of Science and TechnologyXiangtan 411201China

TiAlN multilayer coatings composed of TiAl and TiAlN layers were deposited on ZL109 alloys using filtered cathodic vacuum arc(FCVA)*** effect of bias voltage on the microstructure and properties of the coating was systematically *** results show that the coating exhibits a multi-phase structure dominated by TiAlN *** the bias voltage increases,the orientation of TiAlN changes from(200)plane to(111)plane due to the increase of atomic mobility and lattice *** hardness,elastic modulus and adhesion of the coating show the same trend of change,that is,first increase and then *** the bias voltage is 75 V,the coating exhibits the highest hardness(~30.3 GPa),elastic modulus(~229.1 GPa),adhesion(HF 2)and the lowest wear rate(~4.44×10^(−5)mm^(3)/(N·m)).Compared with bare ZL109 alloy,the mechanical and tribological properties of TiAlN coated alloy surface can effectively be improved.

关键词： TiAlN coatings filtered cathodic vacuum arc bias voltage microstructure mechanical properties wear

Effect of Y addition on microstructure and mechanical properties of Mg-Zn-Mn alloy

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2014年第5期24卷 1352-1364页

作者：齐福刚张丁非张孝华潘复生中国工程物理研究院表面物理与化学重点实验室绵阳621907 重庆大学材料科学与工程学院重庆400045

The effects of Y on the microstructure and mechanical properties of Mg-6Zn-lMn alloy were investigated. The results show that the addition of Y has significant effect on the phase composition, microstructure and mechanical properties of Mg-6Zn-lMn alloy. Varied phases compositions, including Mg7Zn3, I-phase （Mg3YZn6）, W-phase （Mg3Y2Zn3） and X-phase （MgI2YZn）, are obtained by adjusting the Zn to Y mass ratio. Mn element exists as the fine Mn particles, which are well distributed in the alloy. Thermal analysis and microstructure observation reveal that the phase stability follows the trend of X〉W〉/〉MgTZn3. In addition, Y can improve the mechanical properties of Mg-Zn-Mn alloy significantly, and the alloy with Y content of 6.09% has the best mechanical properties. The high strength is mainly due to the strengthening by the grain size refinement, dispersion strengthening by fine Mn particles, and introduction of the Mg-Zn-Y ternary phases.

关键词： Mg-Zn-Mn alloy Y microstructure mechanical property fracture

Effect of Al addition on microstructure and mechanical properties of Mg−Zn−Sn−Mn alloy

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2021年第7期31卷 1951-1968页

作者： Cai-hong HOU Zhi-song YE fu-gang qi qing WANG Lian-hui LI Xiao-ping OUYANG Nie ZHAO School of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education Xiangtan UniversityXiangtan 411105China China Railway Eryuan Engineering Group Co. Ltd.Chengdu 610000China

The microstructure and properties of the as-cast,as-homogenized and as-extruded Mg−6Zn−4Sn−1Mn(ZTM641)alloy with various Al contents(0,0.5,1,2,3 and 4 wt.%)were investigated by OM,XRD,DSC,SEM,TEM and uniaxial tensile *** results show that when the Al content is not higher than 0.5%,the alloys are mainly composed of α-Mg,Mg_(2)Sn,Al_(8)Mn_(5)and Mg_(7)Zn_(3)*** the Al content is higher than 0.5%,the alloys mainly consist ofα-Mg,Mg_(2)Sn,MgZn,Mg_(32)(Al,Zn)_(49),Al_(2)Mg_(5)Zn_(2),Al_(11)Mn_(4)and Al_(8)Mn_(5)phases.A small amount of Al(≤1%)can increase the proportion of fine dynamic recrystallized(DRXed)grains during hot-extrusion *** roomtemperature tensile test results show that the ZTM641−1Al alloy has the best comprehensive mechanical properties,in which the ultimate tensile strength is 332 MPa,yield strength is 221 MPa and the elongation is 15%.Elevatedtemperature tensile test results at 150 and 200℃ show that ZTM641−2Al alloy has the best comprehensive mechanical properties.

关键词： Mg−Zn−Sn−Mn alloy Al microstructure mechanical properties dynamic recrystallization nucleation

Development of component stiffness equations for thread-fixed one-side bolt connections to an enclosed rectangular hollow section column under tension

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2024年第4期18卷 568-586页

作者： fu-Wei WU Yuan-qi LI Department of Structural Engineering Tongji UniversityShanghai 200092China State Key Laboratory of Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China

The derivation and validation of analytical equations for predicting the tensile initial stiffness of threadfixed one-side bolts(TOBs),connected to enclosed rectangular hollow section(RHS)columns,is presented in this *** unknown stiffness components are considered:the TOBs connection and the enclosed RHS ***,the trapezoidal thread of TOB,as an equivalent cantilevered beam subjected to uniformly distributed loads,is analyzed to determine the associated *** on the findings,the thread-shank serial-parallel stiffness model of TOB connection is *** analysis of the tensile stiffness of the enclosed RHS face due to two bolt forces,the four sidewalls are treated as rotation constraints,thus reducing the problem to a two-dimensional plate *** to the load superposition method,the deflection of the face plate is resolved into three components under various boundary and load *** to the plate deflection theory of Timoshenko,the analytical solutions for the three deflections are derived in terms of the variables of bolt spacing,RHS thickness,height to width ratio,***,the validity of the above stiffness equations is verified by a series of finite element(FE)models of T-stub *** proposed component stiffness equations are an effective supplement to the component-based method.

关键词： initial stiffness component based method thread-fixed one-side bolt rectangular hollow sections analytical equation

Solar evaporation for simultaneous oil-water separation and electricity generation with Janus wood-based absorbers

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

Frontiers of Environmental Science & Engineering 2024年第2期18卷 13-23页

作者： Yue Yang Ze fu qi Zhang Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse School of Environmental and Biological EngineeringNanjing University of Science&TechnologyNanjing 210094China Key Laboratory of Industrial Ecology and Environmental Engineering(Ministry of Education) School of Environmental Science and TechnologyDalian University of TechnologyDalian 116024China National Laboratory of Solid State Microstructures Collaborative Innovation Center of Advanced MicrostructuresCollege of Engineering and Applied SciencesKey Laboratory of Intelligent Optical Sensing and Manipulation(Ministry of Education)Jiangsu Key Laboratory of Artificial Functional MaterialsNanjing UniversityNanjing 210093China

Oily wastewater from ocean oil spills endangers marine ecosystems and human health. Therefore, developing an effective and sustainable solution for separating oil-water mixtures is urgent. Interfacial solar photothermal evaporation is a promising approach for the complete separation of two-phase mixtures using only solar energy. Herein, we report a carbonized wood-based absorber with Janus structure of comprising a hydrophobic top-layer and an oleophobic bottom-layer for simultaneous solar-driven oil-water separation and electricity generation. Under sunlight irradiation, the rapid evaporation of seawater will induce a separation of oil-water mixtures, and cause a high salt concentration region underlying the interface, while the bottom “bulk water” maintains in a low salt concentration, thus forming a salinity gradient. Electricity can be generated by salinity gradient power. Therefore, oil-water separation efficiency of > 99% and derived extra electricity power of ~0.1 W/m2 is achieved under solar radiation, demonstrating the feasibility of oil-water separation and electricity production synchronously directly using solar energy. This work provides a green and cost-effective path for the separation of oil-water mixtures.

关键词： Oily wastewater Carbonized wood Salinity gradient Electricity generation Solar irradiation

An Example of Embedded Singular Continuous Spectrum for Discrete Schrödinger Operators

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

Acta Mathematica Sinica,English Series 2024年第8期40卷 1837-1849页

作者： Zheng qi fu Xiong LI Laboratory of Mathematics and Complex Systems(Ministry of Education) School of Mathematical SciencesBeijing Normal UniversityBeijing 100875P.R.China

We present an example of a potential such that the corresponding discrete Schrödinger operator has singular continuous spectrum embedded in the absolutely continuous spectrum.

关键词： Sparse potentials singular continuous spectrum Prüfer variables