检索结果-南通市图书馆

TEM observation of oxidation of CuZnAlMnNi shape memory alloy

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2001年第21期46卷 1837-1839页

作者： BAI Yujun LU Chengwei geng guili YIN Longwei Mechanical Department Shandong University of Science and TechnologyJi’nan 250031China Materials Science and Engineering Shandong UniversityJi’nan 250061China

The atmospheric oxidation of a quenched CuZnAlMnNi alloy after ion-polishing was examined by transmission electron microscopy (TEM). It was found that a lot of oxide grains with various sizes yield homogeneously on the surface of the alloy after exposure at room temperature for 90 d. The grains mainly form along the planes of stacking fault, meanwhile, they can also be observed at the stacking fault tetrahedrals or around the dislocation lines. The formation of the oxides gives rise to the reduction of the stacking faults, and even complete disappearance in some zones, which is partly responsible for the decrement of shape memory effect (SME) of the alloy quenched during long-term holding at room temperature.

关键词： shape memory alloy oxidation stacking fault tetrahedral dislocation line.

DSC　STUDY　OF　MARTENSITIC　TRANSFORMATION　KINETICS　IN　A　Cu－Zn－Al－Mn－Ni　SHAPE　MEMORY　ALLOY

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1996年第1期9卷 56-58页

作者： geng guili BAI Yujun PENG Qifeng(Institute for Materials Engineering,Shandong University of Technology,Jinan 250014,China) Shandong Univ of Technology Jinan China

The kinetics of the reversible martensitic transformation in a Cu-Zn-Al-Mn-Ni shape memory alloy has been studied by means of differential scanning *** apparent activation energy has been calculated and the kinetic equations of positive and adverse martensitic transformation have been established with the variations of temperature and time.

关键词： shape memory alloy positive and adverse martensitic transformation phase transformation kinetics DSC study

Formation Mechanism of Curved Martensite Structures in Cu-based Shape Memory Alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2000年第1期16卷 79-81页

作者： Yujun BAI, Qiquan SHI,guili geng, Dongsheng SUN and Xiufang BIAN (Institute of Materials Engineering, Shandong University of Technology, Jinan 250061, China) Institute of Materials Engineering Shandong University of Technology Jinan 250061 China

The curved martensite structures have been observed in CuZnAI-based shape memory alloys by both transmission electron microscope and optical microscope. It was found that the curved martensite structures observed in as-solution treated, as-aged and as-trained alloys usually occurred around dislocation tangles or precipitate, at the plate boundary or grain boundary, and when the growing plates collided with each other or alternate mutually.

关键词： Formation Mechanism of Curved Martensite Structures in Cu-based Shape Memory Alloys Cu

Influence of Heating Rate on Double Reversible Transformation in CuZnAlMnNi Shape Memory Alloy

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2001年第2期20卷 117-120页

作者： Yujun Bai, Chengwei Lu, Xiangang Xu, guili geng, Longwei Yin (Mechanical Department, Shandong University of Science and Technology, Jinan 250031, China Institute of Materials Science and Engineering, Shandong University, Jinan 250061, China) Shandong Univ Sci & Technol Dept Mech Jinan 250031 Peoples R China Shandong Univ Inst Mat Sci & Engn Jinan 250061 Peoples R China

The influence of heating rate on double reversible transformation in CuZnAlMnNi shape memory alloy was investigated by differential scanning calorimetry. It was found that rapid heating inhibits X -->M transformation but is favorable to the reverse martensite transformation, giving rise to the approach of the two transformation peaks. With the decrease of heating rate, the two transformation peaks separate gradually.

关键词： double reversible transformations heating rate CuZnAlMnNi shape memory alloy differential scanning calorimetry

热循环对 Cu Zn Al Mn Ni记忆合金中双可逆相变的影响(英文)

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2002年第2期31卷 89-91页

作者：白玉俊徐现刚耿贵立山东科技大学机械系山东大学材料科学与工程学院山东济南250061 山东大学材料科学与工程学院

通过差示扫描量热技术 ,研究了热循环对 Cu- 2 3.6 Zn- 4 .4 7Al- 0 .2 3Mn- 0 .17Ni形状记忆合金中双可逆相变的影响。结果表明 ,X→ M转变温度随热循环的进行而降低 ,而马氏体逆转变的温度几乎不发生变化。

关键词：形状记忆合金差示扫描量热技术双可逆相变热循环

Mixed Dead-time Effect Suppression Strategy for Modular Multilevel Converters

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第3期10卷 1075-1084页

作者： Zhi geng Minxiao Han School of Electrical and Electronic Engineering North China Electric Power UniversityBeijing 102206China IEEE

Dead time is necessary for the coupled power switches to prevent shoot-through,especially in the modular multilevel converters(MMCs)with a large number of power *** paper proposes a dead-time effect suppression strategy for MMCs with nearest level *** operational principles of MMCs are first *** to the operational features of MMCs,the method that removes a switching signal from the coupled switches and the reduced switching frequency voltage balancing algorithms(RSFVBAs)are mixed in the proposed *** the intervals that are furthest away from the zerocrossing points(ZCP)of arm currents,the single switching signal method can completely eliminate the dead-time effect(DTE).Alternatively,the DTE is suppressed by the RSFVBA in intervals that are close to the *** the combination of the two methods,the dependence of the DTE suppression method on currents is reduced and the influences of ZCP are also released without degrading the normal operation performance of ***,the output performance of MMCs is improved and the voltage stress on the arm inductor dramatically ***,the validation of the method is verified by the simulation results with the professional tool Matlab/Simulink.

关键词： Dead-time effect modular multilevel converters switching frequency voltage balancing algorithm

Investigation and measurement of old building response to the overlapped shield tunnel of multiple schemes in the sandy cobble stratum

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

Underground Space 2024年第2期15卷 260-274页

作者： Xue Li Aopeng geng School of Geoscience and Technology Southwest Petroleum UniversityChengduSichuan 610500China China Railway Construction Bridge Engineering Bureau Group Co. Ltd.Tianjin 300300China

Ground movements due to tunneling are becoming increasingly critical as buildings are located around construction *** study proposes a new combined reinforcement method using a foundation grouting oblique pipe *** former improves the bearing capacity of the subsoil,and the latter blocks the transmission of soil deformation,which weakens the influence of construction during overlapped tunnel *** on this new method,a case study of the shield tunneling response to an old building in Line 6 of China’s Chengdu Metro is ***,three-dimensional numerical models without reinforcement,traditional foundation grouting reinforcement,and the new combined reinforcement schemes were *** numerical simulation performance was verified using a set of field instrumentation data,which demonstrated that the old building response to the overlapped tunnels was under control,and the maximum deformation,angular distortion,and principal tensile strain of the building were 5.25 mm,5.1010–6 rad/m,and 0.0081%,*** with the traditional reinforcement scheme,the deformation,angular distortion,and principal tensile strain in the combined reinforcement scheme were reduced by 54.78%,71.02%,and 70.22%,*** results have important implications for the design and construction of shield tunnels and their response to old buildings.

关键词： Overlapped tunnels Reinforcement schemes Under-crossing Old building Numerical simulation

Boosting electrocatalytic nitrate reduction to ammonia via Cu_(2)O/Cu(OH)_(2)heterostructures promoting electron transfer

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

Nano Research 2024年第6期17卷 4898-4907页

作者： Jing geng Sihan Ji Anhui Province International Research Center on Advanced Building Materials School of Materials Science and Chemical EngineeringAnhui Jianzhu UniversityHefei 230601China Anhui Province Key Laboratory of Advanced Building Materials Anhui Jianzhu UniversityHefei 230601China School of Energy Materials and Chemical Engineering Hefei UniversityHefei 230601China

Electrocatalytic nitrate(NO_(3)^(−))reduction to ammonia(NH_(3))offers a viable approach for sustainable NH_(3)production and environmental ***(Cu)possesses a distinctive electronic structure,which can augment the reaction kinetics of NO_(3)^(−)and impede hydrogen evolution reaction(HER),rendering it a promising contender for the electrosynthesis of NH_(3)from NO_(3)^(−).Nevertheless,the role of Cu_(2)O in copper-based catalysts still requires further investigation for a more comprehensive ***,the Cu_(2)O/Cu(OH)_(2)heterostructures are successfully fabricated through liquid laser irradiation using CuO nanoparticles as a *** and theoretical researches reveal that Cu_(2)O/Cu(OH)_(2)heterostructure exhibits enhanced electrocatalytic performance for NO_(3)^(−)to NH_(3)because Cu(OH)_(2)promotes electron transfer and reduces the valence state of Cu active site in Cu_(2)***−0.6 V(*** hydrogen electrode(RHE)),the NH_(3)yield reaches its maximum at 1630.66±29.72μg·h^(−1)·mgcat^(−1),while the maximum of Faraday efficiency(FE)is 76.95%±5.51%.This study expands the technical scope of copper-based catalyst preparation and enhances the understanding of the electrocatalytic mechanism of NO_(3)^(−)to NH_(3).

关键词： Cu_(2)O/Cu(OH)_(2)heterostructures electron transfer ammonia synthesis electrocatalysts nitrate

加热速率对CuZnAlMnNi记忆合金中双可逆相变的影响(英文)

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

稀有金属材料与工程 2002年第5期31卷 379-381页

作者：白玉俊鲁成伟徐现刚耿贵立尹龙为山东科技大学山东济南250031 山东大学材料科学与工程学院山东济南250061

通过差示扫描量热技术研究了不同的加热速率对CuZnAlMnNi记忆合金中双可逆相变的影响。结果表明:快速加热抑制了X→M转变却有利于马氏体逆转变,使两个相变峰靠近;随着加热速率的降低,两个相变峰逐渐分离。

关键词：双可逆相变加热速率 CuZnAlMnNi 形状记忆合金差示扫描量热技术