期刊文献+
共找到27篇文章
< 1 2 >
每页显示 20 50 100
论行为组织学在高校图书馆管理中的应用
1
作者 黄本华 《云南图书馆》 1997年第3期51-54,共4页
关键词 高校图书馆 图书馆管理 行为组织学 应用
下载PDF
浅谈行为组织学在企业人力资源管理中的运用
2
作者 唐志宏 马耿杰 王根映 《中文科技期刊数据库(文摘版)教育》 2019年第3期283-283,共1页
随着社会经济的发展,企业管理面临越来越多的难题和挑战。人力资源管理作为企业管理的重要组成部分,直接影响着企业内部环境和经济利益。将行为组织学应用于人力资源管理中,能够优化人力资源管理理论,提升管理的科学性和合理性,促进企... 随着社会经济的发展,企业管理面临越来越多的难题和挑战。人力资源管理作为企业管理的重要组成部分,直接影响着企业内部环境和经济利益。将行为组织学应用于人力资源管理中,能够优化人力资源管理理论,提升管理的科学性和合理性,促进企业管理水平的发展。在此基础上,本文将对行为组织学在企业人力资源管理的运用策略进行探索,为企业管理和发展提供参考和帮助。 展开更多
关键词 行为组织学 人力资源管理 运用策略
下载PDF
Preparation,microstructure and degradation behavior of Mg−2Zn−0.4Sc−0.2Zr alloy wire
3
作者 Yu-qing HE Ri-chu WANG +3 位作者 Xiao-hui DUAN Xiang PENG Yu-si CHEN Yan FENG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第11期3585-3598,共14页
A biodegradable Mg−2Zn−0.4Sc−0.2Zr(ZK20−0.4Sc)alloy wire with a diameter of 0.5 mm was prepared by a combination of hot extrusion and cold-drawing.The average grain size of ZK20−0.4Sc alloy wire on the longitudinal se... A biodegradable Mg−2Zn−0.4Sc−0.2Zr(ZK20−0.4Sc)alloy wire with a diameter of 0.5 mm was prepared by a combination of hot extrusion and cold-drawing.The average grain size of ZK20−0.4Sc alloy wire on the longitudinal section along the drawing direction is approximately 7.3μm.The texture results show relatively strong<1020>and weak<1010>fiber texture components parallel to the drawing direction.The ZK20−0.4Sc alloy wire exhibits better mechanical properties with the tensile strength,yield strength and elongate of(329±2)MPa,(287±2)MPa and(14.2±0.5)%,respectively.The better mechanical properties are mainly attributed to the grain refinement strengthening,dislocation strengthening and precipitation strengthening.With the immersion time increasing to 14 d,the corrosion type transfers from filament corrosion and pitting corrosion to severe localized corrosion. 展开更多
关键词 Mg alloy wire cold drawing MICROSTRUCTURE mechanical properties degradation behavior
下载PDF
Improvement of microstructure and mechanical properties of Al−Cu−Li−Mg−Zn alloys through water-cooling centrifugal casting technique
4
作者 Qing-bo YANG Wen-jing SHI +4 位作者 Wen LIU Miao WANG Wen-bo WANG Li-na JIA Hu ZHANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第11期3486-3503,共18页
The microstructure and mechanical properties of as-cast Al−Cu−Li−Mg−Zn alloys fabricated by conventional gravity casting and centrifugal casting techniques combined with rapid solidification were investigated.Experime... The microstructure and mechanical properties of as-cast Al−Cu−Li−Mg−Zn alloys fabricated by conventional gravity casting and centrifugal casting techniques combined with rapid solidification were investigated.Experimental results demonstrated that compared with the gravity casting technique,the water-cooling centrifugal casting technique significantly reduces porosity,refinesα(Al)grains and secondary phases,modifies the morphology of secondary phases,and mitigates both macro-and micro-segregation.These improvements arise from the synergistic effects of the vigorous backflow,centrifugal field,vibration and rapid solidification.Porosity and coarse plate-like Al13Fe4/Al7Cu2Fe phase result in the fracture before the gravity-cast alloy reaches the yield point.The centrifugal-cast alloy,however,exhibits an ultra-high yield strength of 292.0 MPa and a moderate elongation of 6.1%.This high yield strength is attributed to solid solution strengthening(SSS)of 225.3 MPa,and grain boundary strengthening(GBS)of 35.7 MPa.Li contributes the most to SSS with a scaling factor of 7.9 MPa·wt.%^(-1).The elongation of the centrifugal-cast alloy can be effectively enhanced by reducing the porosity and segregation behavior,refining the microstructure and changing the morphology of secondary phases. 展开更多
关键词 Al−Cu−Li−Mg−Zn alloy water-cooling centrifugal casting microstructure mechanical properties segregation behavior
下载PDF
Microstructure and high temperature tribological behavior of laser cladding Ni60A alloys coatings on 45 steel substrate 被引量:21
5
作者 张健 胡玉 +2 位作者 谭小军 郭亮 张庆茂 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第5期1525-1532,共8页
The crack-free Ni60 A coating was fabricated on 45 steel substrate by laser cladding and the microstructure including solidification characteristics, phases constitution and phase distribution was systematically inves... The crack-free Ni60 A coating was fabricated on 45 steel substrate by laser cladding and the microstructure including solidification characteristics, phases constitution and phase distribution was systematically investigated. The high temperature friction and wear behavior of the cladding coating and substrate sliding against GCr15 ball under different loads was systematically evaluated. It was found that the coating has homogenous and fine microstructure consisting of γ(Ni) solid solution, a considerable amount of network Ni-Ni3 B eutectics, m^23C6 with the floret-shape structure and Cr B with the dark spot-shape structure uniformly distributing in interdendritic eutectics. The microhardness of the coating is about 2.6 times as much as that of the substrate. The coating produces higher friction values than the substrate under the same load condition, but the friction process on the coating keeps relatively stable. Wear rates of the coating are about 1/6.2 of that of the substrate under the higher load(300 g). Wear mechanism of the substrate includes adhesion wear, abrasive wear, severe plastic deformation and oxidation wear, while that of the coating is merely a combination of mild abrasive wear and moderate oxidation wear. 展开更多
关键词 laser cladding Ni60A alloy 45 steel MICROSTRUCTURE tribological behavior
下载PDF
Effects of process parameters on mechanical properties and microstructures of creep aged 2124 aluminum alloy 被引量:7
6
作者 湛利华 李炎光 黄明辉 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第7期2232-2238,共7页
A series of tests were carried microstructures of 2124 aluminum alloy in increase of aging time, temperature and low-to-peak-to-low manner. No significant out to investigate the effects of process parameters on mechan... A series of tests were carried microstructures of 2124 aluminum alloy in increase of aging time, temperature and low-to-peak-to-low manner. No significant out to investigate the effects of process parameters on mechanical properties and creep aging process. The results show that creep strain and creep rate increase with the applied stress. The hardness of specimen varies with aging time and stress in a effect of temperature on hardness of material is seen in the range of 185-195 ℃. The optimum mechanical properties are obtained at the conditions of (200 MPa, 185 ℃, 8 h) as the result of the coexistence of strengthening S" and S' phases in the matrix by transmission electron microscopy (TEM). TEM observation shows that applied stress promotes the formation and growth of precioitates and no obvious stress orientation effect is observed in the matrix. 展开更多
关键词 aluminum alloy creep aging behavior age hardening mechanical property MICROSTRUCTURE process parameter
下载PDF
Effect of zinc addition on microstructure and mechanical properties of Mg-7Y-3Sm-0.5Zr alloy
7
作者 赵阳 王渠东 高岩 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第8期1924-1929,共6页
The effect of zinc addition on the microstructure and mechanical properties of Mg-7Y-3Sm-0.5Zr casting alloy was investigated. Creep test was carried out at 200-300 °C under 50-120 MPa. Within the limits of the c... The effect of zinc addition on the microstructure and mechanical properties of Mg-7Y-3Sm-0.5Zr casting alloy was investigated. Creep test was carried out at 200-300 °C under 50-120 MPa. Within the limits of the creep test conditions used in this study, the creep activation energy of the investigated alloys was in the range of 156-221 kJ/mol. The microstructure evolution during creep was characterized by optical metallography, SEM and TEM. The results show that the creep life of the alloy is increased from 52.2 to 152.8 h at 300 °C under 50 MPa by only 1% addition of Zn, though both the alloys have similar creep behaviors below 250 °C, which suggests that the thermally stable compound and lamellar structure can improve the high temperature creep resistance of the alloy with the addition of Zn. 展开更多
关键词 Mg-Y-Sm-Zr alloy ZINC microstructure mechanical properties creep behavior
下载PDF
Effect of heat treatment on microstructures and mechanical properties of high vacuum die casting Mg-8Gd-3Y-0.4Zr magnesium alloy 被引量:8
8
作者 王栀沁 张彬 +4 位作者 李德江 Robert FRITZSCH 曾小勤 Hans J.ROVEN 丁文江 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第12期3762-3768,共7页
The microstructure, the content of compounds, mechanical properties and fracture behavior of high vacuum die casting Mg-8Gd-3Y-0.4Zr alloy (mass fraction, %) under T4 condition and T6 condition were investigated. Th... The microstructure, the content of compounds, mechanical properties and fracture behavior of high vacuum die casting Mg-8Gd-3Y-0.4Zr alloy (mass fraction, %) under T4 condition and T6 condition were investigated. The microstructure for the as-cast Mg-8Gd-3Y-0.4Zr alloy mainly consists ofα-Mg and eutectic Mg24(Gd,Y)5 compound. After solution treatment, the eutectic compounds dissolve massively into the Mg matrix. The main composition of solution-treated alloys is supersaturated α-Mg and cuboid-shaped phase. The T4 heat treated samples have increasing cuboidal particles with the increase of heat treatment temperature, which turn out good mechanical properties. The optimum T4 heat treatment for high vacuum die cast Mg-8Gd-3Y-0.4Zr alloy is 475 ℃, 2 h according to microstructure results. The optimum ultimate strength and elongation of solution-treated Mg-8Gd-3Y-0.4Zr alloy are 222.1 MPa and 15.4%, respectively. The tensile fracture mode of the as-cast, and T6 heat treated alloys is transgranular quasi-cleavage fracture. 展开更多
关键词 Mg-8Gd-3Y-0.4Zr alloy heat treatment MICROSTRUCTURE mechanical property fracture behavior
下载PDF
Effect of ageing process on microstructure, corrosion behaviors and mechanical properties of Al-5.6Zn-1.6Mg-0.05Zr alloy 被引量:4
9
作者 SHAO Hong-bang HUANG Yuan-chun WANG Yan-ling 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第3期1029-1040,共12页
The influence of different ageing processes on the microstructure, corrosion behaviors and mechanical properties of extruded Al-5.6Zn-1.6Mg-0.05Zr(wt.%) alloy was studied in this work. The changes of morphology, size ... The influence of different ageing processes on the microstructure, corrosion behaviors and mechanical properties of extruded Al-5.6Zn-1.6Mg-0.05Zr(wt.%) alloy was studied in this work. The changes of morphology, size and distribution of MgZn_(2)precipitate with ageing temperature and time were revealed by optical and electron microscopy. Intergranular corrosion(IGC) and exfoliation corrosion(EXCO) tests were carried out to assess the changes in corrosion susceptibility of the tempered alloy, and some white spots on the surface of the sample aged for longer time were found to be precursors of pits. Electrochemical cyclic polarization test depicted the corrosion behavior under different tempers. Ageing influences on the mechanical behaviors of the alloy were revealed by evaluating its microhardness and tensile strength. The microscopic features of the strengthening phases determined by the ageing procedure directly affect the corrosion resistance and mechanical properties of the alloy. 展开更多
关键词 Al-Zn-Mg alloy MICROSTRUCTURE corrosion behavior mechanical properties ageing process
下载PDF
Effect of hot extrusion on microstructure and tribological behavior of Al_(2)O_(3p) reinforced 7075 aluminum-matrix composites 被引量:4
10
作者 LEI Yu-shun YAN Hong +4 位作者 WEI Zhi-fan XIONG Jun-jie ZHANG Peng-xiang WAN Jian-ping WANG Zhi-lu 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第8期2269-2284,共16页
The effects of hot extrusion and addition of Al_(2)O_(3p) on both microstructure and tribological behavior of 7075 composites were investigated via optical microscopy(OM),scanning electron microscopy(SEM),energy dispe... The effects of hot extrusion and addition of Al_(2)O_(3p) on both microstructure and tribological behavior of 7075 composites were investigated via optical microscopy(OM),scanning electron microscopy(SEM),energy dispersive spectrometry(EDS),and transmission electron microscopy(TEM).The experimental consequences reveal that the optimal addition of Al_(2)O_(3p) was 2 wt%.After hot extrusion,the Mg(Zn,Cu,Al)2 phases partially dissolve into the matrix and generate many uniformly distributed aging precipitation particles,the Al_(7)Cu_(2)Fe phases are squeezed and broken,and the Al_(2)O_(3p) become uniform distribution.The microhardness of as-extruded 2 wt%Al_(2)O_(3p)/7075 composites reaches HV 170.34,increased by 41.5%than as-cast composites.The wear rate of as-extruded 2 wt%Al_(2)O_(3p)/7075 composites is further lower than that of as-cast composites under the same condition.SEM-EDS analyses reveal that the reinforced wear resistance of composites can put down to the protective effect of the Al_(2)O_(3p) reinforced transition layer.After hot extrusion,the transition layer becomes stable,which determines the reinforced wear resistance of the as-extruded composites. 展开更多
关键词 7075 alloy AL2O3P COMPOSITES hot extrusion MICROSTRUCTURE tribological behavior
下载PDF
Microstructure and electrochemical corrosion behavior of selective laser melted Ti−6Al−4V alloy in simulated artificial saliva 被引量:12
11
作者 Jiang JU Jing-jing LI +6 位作者 Min JIANG Meng-ya LI Li-xiang YANG Kai-ming WANG Chao YANG Mao-dong KANG Jun WANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第1期167-177,共11页
Ti−6Al−4V alloy was fabricated via selective laser melting(SLM)to improve its corrosion resistance for implant.The microstructure and electrochemical corrosion behavior were investigated using scanning electron micros... Ti−6Al−4V alloy was fabricated via selective laser melting(SLM)to improve its corrosion resistance for implant.The microstructure and electrochemical corrosion behavior were investigated using scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),transmission electron microscopy(TEM),electrochemical test and contact angle test.It can be found that the as-selective laser melted(as-SLMed)Ti−6Al−4V alloys showβcolumnar microstructure in building direction and nearly circular checkerboard microstructure in scanning direction,while the wrought and wrought+HT samples exhibit equiaxed microstructure.The as-SLMed Ti−6Al−4V alloy exhibits better corrosion resistance than the wrought and wrought+HT samples due to hydrophobicity,high grain boundary density and uniform distribution of alloying elements in simulated artificial saliva at 37℃. 展开更多
关键词 Ti−6Al−4V alloy selective laser melting MICROSTRUCTURE electrochemical corrosion behavior
下载PDF
Effects of TiB_2+TiC content on microstructure and wear resistance of Ni55-based composite coatings produced by plasma cladding 被引量:6
12
作者 Xin-jie ZHANG Hong-zhi CUI +3 位作者 Jia-feng WANG Guo-song ZHANG Yu-qiao ZHAO Kang SUN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第1期132-142,共11页
TiB2-TiC reinforced Ni55 matrix composite coatings were in-situ fabricated via plasma cladding on steels using Ti, B4C, and Ni55 as precursor materials at different proportions. Effects of TiB2+TiC content of ceramics... TiB2-TiC reinforced Ni55 matrix composite coatings were in-situ fabricated via plasma cladding on steels using Ti, B4C, and Ni55 as precursor materials at different proportions. Effects of TiB2+TiC content of ceramics phase on the microstructure and wear resistance were studied. The results showed that ceramic phases TiB2 and TiC were in-situ synthesized by plasma cladding, and the ceramic phase content significantly affected tribological performance and the wear mechanism of coatings under different loads. The composite ceramics protected coatings from further delamination wear by crack-resistance under a load of 30 N. Severe abrasive wear and adhesive wear were prevented when the load increased to 60 N because of the high hardness and strength of ceramic phases. Moreover, a compacted layer appeared on the wear surface of coatings with high content of ceramic phases, which effectively decreased the friction coefficient and wear rate. The TiB2-TiC composite ceramics significantly improved the wear performance of metal matrix composite coatings by different mechanisms under loads of 30 and 60 N. 展开更多
关键词 metal matrix composite coating plasma cladding MICROSTRUCTURE tribological behavior wear mechanism
下载PDF
Effect of Li addition on mechanical properties and ageing precipitation behavior of extruded Al-3.0 Mg-0.5 Si alloy 被引量:3
13
作者 YANG Xiao-kun XIONG Bai-qing +6 位作者 LI Xi-wu YAN Li-zhen LI Zhi-hui ZHANG Yong-an LI Ya-nan WEN Kai LIU Hong-wei 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第9期2636-2646,共11页
The effect of Li(2.0 wt%)addition on mechanical properties and ageing precipitation behavior of Al-3.0 Mg 0.5 Si was investigated by tensile test,dynamic elasticity modulus test,scanning electron microscopy(SEM),trans... The effect of Li(2.0 wt%)addition on mechanical properties and ageing precipitation behavior of Al-3.0 Mg 0.5 Si was investigated by tensile test,dynamic elasticity modulus test,scanning electron microscopy(SEM),transmission electron microscopy(TEM)and high-resolution transmission electron microscopy(HRTEM)images.The results show that the tensile strength of the Li-containing alloy can be significantly improved;however,the ductility is sharply decreased and the fracture mechanism changes from ductile fracture to intergranular fracture.The elasticity modulus of the Li-containing alloy increases by 11.6%compared with the base alloy.The microstructure observation shows that the Li addition can absolutely change the precipitation behavior of the base alloy,andδ′-Al_(3)Li phase becomes the main precipitates.Besides,β′′-Mg_(2)Si andδ′-Al_(3)Li dual phases precipitation can be visibly observed at 170℃ ageing for 100 h,although the quantity ofδ′-Al_(3)Li phase is more thanβ′′-Mg_(2)Si phase.The width of the precipitate-free zone(PFZ)of the Li-containing alloy is much wider at the over-ageing state than the base alloy,which has a negative impact on the ductile and results in the decrease of elongation. 展开更多
关键词 Al-3.0 Mg-0.5 Si alloy Li addition microstructure ageing behavior mechanical properties dynamic elasticity modulus
下载PDF
Microstructure and mechanical properties of laser additive repaired Ti17 titanium alloy 被引量:11
14
作者 Zhuang ZHAO Jing CHEN +3 位作者 Qiang ZHANG Hua TAN Xin LIN Wei-dong HUANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第12期2613-2621,共9页
Laser additive manufacturing technology with powder feeding was employed to repair wrought Ti17titanium alloy with small surface defects.The microstructure,micro-hardness and room temperature tensile properties of las... Laser additive manufacturing technology with powder feeding was employed to repair wrought Ti17titanium alloy with small surface defects.The microstructure,micro-hardness and room temperature tensile properties of laser additive repaired(LARed)specimen were investigated.The results show that,cellular substructures are observed in the laser deposited zone(LDZ),rather than the typicalαlaths morphology due to lack of enough subsequent thermal cycles.The cellular substructures lead to lower micro-hardness in the LDZ compared with the wrought substrate zone which consists of duplex microstructure.The tensile test results indicate that the tensile deformation process of the LARed specimen exhibits a characteristic of dramatic plastic strain heterogeneity and fracture in the laser repaired zone with a mixed dimple and cleavage mode.The tensile strength of the LARed specimen is slightly higher than that of the wrought specimen and the elongation of11.7%is lower. 展开更多
关键词 laser additive repair Ti17 titanium alloy microstructure mechanical properties deformation behavior
下载PDF
Microstructure and mechanical properties of as-cast Mg-8Li-xZn-yGd(x=1,2,3,4;y=1,2) alloys 被引量:6
15
作者 Si-jie OUYANG Wen-cai LIU +5 位作者 Guo-hua WU Hao JI Zhan-kui GAO Xiang PENG Zhong-quan LI Wen-jiang DING 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第6期1211-1222,共12页
The as-cast Mg-8 Li-xZn-yGd(x=1 2, 3,4;y=1,2;wt.%)alloys were prepared in a vacuum induction furnace and their microstructure and mechanical properties were investigated. The results show that the increase of Zn conte... The as-cast Mg-8 Li-xZn-yGd(x=1 2, 3,4;y=1,2;wt.%)alloys were prepared in a vacuum induction furnace and their microstructure and mechanical properties were investigated. The results show that the increase of Zn content results in the volume fraction of W-phase(Mg3 Zn3 Gd2) increasing while that of Mg3 Gd phase decreasing. The strength of Mg-8 Li-xZn-1 Gd alloys is improved with the increase of Zn content,which is ascribed to the second phase strengthening of fine strip-like W-phase and the solid solution strengthening of Zn element.For Mg-8 Li-4 Zn-yGd alloys,the increase of Gd content leads to the appearance of coarse and discontinuous net-like W-phase, which decreases the strength. The Mg-8 Li-4 Zn-1 Gd alloy exhibits an optimum comprehensive performance with the yield strength, ultimate tensile strength and elongation of 154.7 MPa, 197.0 MPa and 12.4%, respectively. In addition,the aging behavior of the typical alloys was also investigated. 展开更多
关键词 Mg-Li-Zn-Gd alloy W-phase microstructure mechanical properties aging behavior
下载PDF
Effect of Gd on microstructure, mechanical properties, and corrosion behavior of as-homogenized Mg-8Li-3Al-2Zn-0.2Zr alloy 被引量:4
16
作者 Yue-hua SUN Ri-chu WANG +1 位作者 Chao-qun PENG Xiao-feng WANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第8期2494-2509,共16页
The microstructure observation,tensile test,electrochemical measurement,and corrosion morphology characterization were conducted to study the effect of Gd on the microstructure,mechanical properties,and corrosion beha... The microstructure observation,tensile test,electrochemical measurement,and corrosion morphology characterization were conducted to study the effect of Gd on the microstructure,mechanical properties,and corrosion behavior of as-homogenized Mg−8Li−3Al−2Zn−0.2Zr(LAZ832−0.2Zr)alloy.The addition of trace Gd can improve the mechanical properties of as-homogenized LAZ832−0.2Zr alloy by refining the microstructure,reducing the content of AlLi softening phase,and forming Al_(2)Gd strengthening phase.Meanwhile,the addition of trace Gd can weaken the microgalvanic corrosion between matrix phase and AlLi phase,inhibit the galvanic corrosion betweenα-Mg phase andβ-Li phase,and result in the formation of dense oxide film containing Gd_(2)O_(3),thereby improving the corrosion resistance of the alloy.When the Gd content is 1.0 wt.%,the alloy shows the best comprehensive properties with the ultimate tensile strength of 189.8 MPa,elongation of 42.3%,and corrosion rate(determined by hydrogen evolution)of 0.86 mm·a^(−1). 展开更多
关键词 Mg-Li alloy rare earth Gd MICROSTRUCTURE mechanical properties corrosion behavior
下载PDF
Microstructure,mechanical properties and corrosion behavior of quaternary Mg−1Zn−0.2Ca−xAg alloy wires applied as degradable anastomotic nails 被引量:13
17
作者 Ying-zhong MA De-xin WANG +3 位作者 Hong-xiang LI Chang-lin YANG Fu-song YUAN Ji-shan ZHANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第1期111-124,共14页
The microstructure,mechanical properties and corrosion behavior of quaternary degradable Mg−1Zn−0.2Ca−xAg(x=1,2,4 wt.%)alloy wires,intended as anastomotic nails,were investigated.It was found that these Ag-containing ... The microstructure,mechanical properties and corrosion behavior of quaternary degradable Mg−1Zn−0.2Ca−xAg(x=1,2,4 wt.%)alloy wires,intended as anastomotic nails,were investigated.It was found that these Ag-containing alloy wires mainly consist of Mg matrix and Ag17Mg54 phase,characterized by SEM,EDS,XRD and TEM.Tensile and knotting tests results demonstrate the superior mechanical properties of these alloy wires.Especially,Mg−1Zn−0.2Ca−4Ag alloy exhibits the highest mechanical properties,i.e.an ultimate tensile strength of 334 MPa and an elongation of 8.6%.Moreover,with increasing Ag content,the corrosion rates of these alloy wires remarkably increase due to the formation of more micro-galvanic coupling between Mg matrix and Ag17Mg54 phase,shown by mass loss and scanning Kelvin probe force microscopy(SKPFM)results.The present alloy can be completely degraded within 28 d,satisfying the property requirements of anastomotic nails. 展开更多
关键词 Mg−Zn−Ca−Ag alloy DEGRADABILITY anastomotic nails MICROSTRUCTURE mechanical properties corrosion behavior
下载PDF
Microstructure, sintering behavior and mechanical properties of SiC/MoSi_2 composites by spark plasma sintering 被引量:1
18
作者 Xin-xin HAN Ya-lei WANG +3 位作者 Xiang XIONG Heng LI Zhao-ke CHEN Wei SUN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第5期957-965,共9页
SiC/MoSi2 composites were synthesized at different temperatures by spark plasma sintering using Mo, Si and SiC powders as raw materials. The phase composition, microstructure and mechanical properties of the as-prepar... SiC/MoSi2 composites were synthesized at different temperatures by spark plasma sintering using Mo, Si and SiC powders as raw materials. The phase composition, microstructure and mechanical properties of the as-prepared composites were investigated and the sintering behavior was also discussed. Results show that SiC/MoSi2 composites are composed of MoSi2, SiC and trace amount of Mo4.8Si3C0.6 phase and exhibit a fine-grain texture. During the synthesis process, there was an evolution from solid phase sintering to liquid phase sintering. When sintered at 1600 °C, the SiC/MoSi2 composites present the most favorable mechanical properties, the Vickers hardness, bending strength and fracture toughness are 13.4 GPa, 674 MPa and 5.1 MPa·m^1/2, respectively, higher 44%, 171%, 82% than those of monolithic MoSi2. SiC can withstand the applied stress as hard phase and retard the rapid propagation of cracks as second phase, which are beneficial to the improved mechanical properties of Si C/MoSi2 composites. 展开更多
关键词 SiC/MoSi2 composite MICROSTRUCTURE sintering behavior mechanical properties spark plasma sintering
下载PDF
Microstructure, mechanical properties and corrosion behavior of commercial 7N01 alloys 被引量:1
19
作者 Pei-hao ZHAO Xiao-lan WU +9 位作者 Yang LIU Kun-yuan GAO Sheng-ping WEN Wu WEI Li RONG Hui HUANG Hong WU De-jing ZHOU Qian ZHANG Zuo-ren NIE 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第3期778-789,共12页
The effect of grain morphology and precipitates on mechanical properties and corrosion behavior of two commercial 7 N01 alloys was studied using transmission electron microscopy(TEM) and scanning electron microscopy(S... The effect of grain morphology and precipitates on mechanical properties and corrosion behavior of two commercial 7 N01 alloys was studied using transmission electron microscopy(TEM) and scanning electron microscopy(SEM) equipped with electron backscatter diffraction(EBSD). Results showed that the recrystallization degree of the outer surface of 7 N01-I alloy was lower than that of 7 N01-II alloy. The main strengthening precipitates of two alloys were mainly η’ phases. The grain boundary precipitates(GBPs) of 7 N01-I alloy distributed discontinuously, while those of 7 N01-II alloy distributed continuously. The strength of two 7 N01 alloys was similar, but the maximum corrosion depth of 7 N01-I alloy was less than that of 7 N01-II alloy, because the discontinuous GBPs and the lower recrystallization degree of outer surface of 7 N01-I alloy were favorable for improving corrosion behavior. Different models of strengthening mechanism were discussed, and the corrosion behavior was correlated with microstructure. 展开更多
关键词 7N01 alloys MICROSTRUCTURE mechanical properties corrosion behavior
下载PDF
Diagnostic utility of narrow-band imaging endoscopy for pharyngeal superfi cial carcinoma 被引量:7
20
作者 Noboru Yoshimura Kenichi Goda +5 位作者 Hisao Tajiri Yukinaga Yoshida Takakuni Kato Yoichi Seino Masahiro Ikegami Mitsuyoshi Urashima 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第45期4999-5006,共8页
AIM: To investigate the endoscopic features of pharyngeal superfi cial carcinoma and evaluate the utility of narrow-band imaging (NBI) for this disease. METHODS: In the present prospective study, 335 patients underwen... AIM: To investigate the endoscopic features of pharyngeal superfi cial carcinoma and evaluate the utility of narrow-band imaging (NBI) for this disease. METHODS: In the present prospective study, 335 patients underwent conventional white light (CWL) en-doscopy and non-magnifi ed/magnifi ed NBI endoscopy, followed by an endoscopic biopsy, for 445 superfi cial lesions in the oropharynx and hypopharynx. The macroscopic appearance of superfi cial lesions was categorized as either elevated (< 5 mm in height), flat, or depressed (not ulcerous). Superficial carcinoma (SC) was defi ned as a superfi cial lesion showing high-grade dysplasia or squamous cell carcinoma on histology. The color, delineation, and macroscopic appearances of the lesions were evaluated by CWL endoscopy. The ratio of the brownish area/intervascular brownish epithelium (IBE), as well as microvascular proliferation, dilation, and irregularities, was determined by non-magnifi ed/ magnifi ed NBI endoscopy. An experienced pathologist who was unaware of the endoscopic fi ndings made the histological diagnoses. By comparing endoscopic fi ndings with histology, we determined the endoscopic features of SC and evaluated the diagnostic utility of NBI. RESULTS: The 445 lesions were divided histologically into two groups: a non-SC group, including non-neoplasia and low-grade dysplasia cases, and an SC group. Of the 445 lesions examined, 333 were classified as non-SC and 112 were classif ied as SC. There were no significant differences in age, gender, or the location of the lesions between the patients in the two groups. The mean diameter of the SC lesions was signif icantly greater than that of non-SC lesions (11.0 ± 7.6 mm vs 4.6 ± 3.6 mm, respectively, P < 0.001). Comparisons of CWL endoscopy fi ndings for SC and non-SC lesions by univariate analysis revealed that the incidence of redness (72% vs 41%, respectively, P < 0.001) and a flat or depressed type of lesion (58% vs 44%, respectively, P = 0.013) was significantly higher in the SC group. Using non-magnifi ed NBI endoscopy, the incidence of a brownish area was signifi cantly higher for SC lesions (79% vs 57%, respectively, P < 0.001). On magnifi ed NBI endoscopy, the incidence of IBE (68% vs 33%, P < 0.001) and microvascular proliferation (82% vs 51%, P < 0.001), dilation (90% vs 76%, P =0.002), and irregularity (82% vs 31%, P < 0.001) was also signifi cantly higher for the SC compared with the non-SC lesions. Multivariate analysis revealed that the incidence of redness (P = 0.022) on CWL endoscopy and IBE (P < 0.001) and microvascular irregularities (P < 0.001) on magnif ied NBI endoscopy was signif icantly higher in SC than non-SC lesions. Redness alone exhibited signifi cantly higher sensitivity and signifi cantly lower specifi city for the diagnosis of SC compared with redness plus IBE and microvascular irregularities (72% vs 52%, P = 0.002; and 59% vs 92%, P < 0.001, respectively). The accuracy of redness plus IBE and irregularities for the diagnosis of SC was signifi cantly greater than using redness alone (82% vs 62%, respectively, P < 0.001). CONCLUSION: Redness, IBE, and microvascular irregularities appear to be closely related to SC lesions. Magnifi ed NBI endoscopy may increase the diagnostic accuracy of CWL endoscopy for SC. 展开更多
关键词 Narrow-band imaging Magnified endoscopy Endoscopic diagnosis PHARYNX Pharyngeal cancer Superfi cial carcinoma Squamous cell carcinoma DYSPLASIA
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部