检索结果-南通市图书馆

Comparison of microstructure and mechanical behavior of Ti-35Nb manufactured by laser powder bed fusion from elemental powder mixture and prealloyed powder

引用

Journal of Materials science & Technology 2022年第10期105卷 1-16页

作者： J.C.Wang y.J.Liu s.X.Liang y.s.zhang L.Q.Wang T.B.sercombe L.C.zhang school of Engineering Edith Cowan University270 Joondalup DriveJoondalupPerthWA 6027Australia school of Engineering M050The University of Western Australia35 Stirling HighwayCrawleyPerthWA 6009Australia Northwest Institute for Nonferrous Metal Research Xi’an 710016China state Key Laboratory of Metal Matrix Composites School of Material Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Although different types of powder feedstock are used for additive manufacturing via laser powder bed fusion(L-PBF),limited work has attempted to directly compare the microstructure and mechanical behavior of components manufactured from those powder feedstock.This work investigated the microstructure,phase composition,melt pool morphology,and mechanical properties of a prealloyed Ti-35Nb alloy manufactured using L-PBF and compared these to their counterparts produced from elemental powder mixture.The samples manufactured from the powder mixture are composed of randomly distributed undissolved Nb in theα/βmatrix,resulting from the unstable melt pool during the melting of the powder mixture.By contrast,parts produced from prealloyed powder display a homogeneous microstructure withβandαphases,owing to the full melting of prealloyed powder,therefore,a more stable melt pool to achieve a homogeneous microstructure.The Ti-35Nb manufactured from prealloyed powder exhibits large tensile ductility(about 10 times that of the counterparts using mixed powder),attributed to the high homogeneity in microstructure and chemical composition,strong interface bonding,relatively low oxygen content,and the existence of a large amount ofβphase.This work sheds insights into understanding the effect of powder feedstock on the melt pool stability therefore the microstructure and mechanical behavior of the resultant parts.

关键词： Titanium-niobium Powder bed fusion Additive manufacturing Melt pool stability Microstructure Mechanical properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

PROPAGATION OF HIGH POWER MICROWAVE PULsEs IN AIR BREAKDOWN ENVIRONMENT

PROPAGATION OF HIGH POWER MICROWAVE PULSES IN AIR BREAKDOWN ...

引用

International Conference on Millimeter Wave and Far-Infrared Technology

作者： s.P.Kuo y.s.zhang Paul Kossey Department of Electrical Engineering & Computer science Polytechnic University Route 110FarmingdaleNY 11735U.S.A. Air Force Geophysics Laboratory Hanscon AFBMA 01731U.S.A.

＜正＞A chamber experiment is conducted to study the propagation of high power microwave pulses through the the air.The Paschen breakdown condition has been determined.Two mechanisms responsible for two different degr...

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Realization of entanglement-assisted weak value amplification

Realization of entanglement-assisted weak value amplificatio...

引用

第十八届全国量子光学学术会议

作者：陈江山 B.H.Liu y.s.zhang 中国科学技术大学 Laboratory of Quantum Information University of Science and Technology of ChinaUniversity of Science and Technology of China

Weak value amplification（WVA） has been used to enhance the sensitivity of a linear detector response to small interaction parameter. However, the generating of a large weak value gives rise to reduction in post-selection probability, which restricts the practicability of the WVA technique. Recently, theoretical works have shown that the utilization of entanglement can increase the efficiency to the WVA method. specifically, it’s demonstrated that by entangling n quantum states of system, the maximum post-selection probability scales quadratically with n. In this work, we demonstrate the experimental realization of entanglement-assisted weak value amplification, which shows that importing quantum entanglement can indeed improve the efficiency of WVA with effect.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

sTUDy OF TCP PHAsE PRECIPITATING IN GH4199 sUPERALLOy

引用

Acta Metallurgica sinica(English Letters) 2004年第5期17卷 645-650页

作者： T.Cui y.s.zhang s.W.Guo L.Wang H.C.yang schoolofMaterialsandMetallurgy NortheasternUniversityShenyang110004ChinaManuscriptreceived15July2003 inrevisedform19January2004

The precipitating regulation and mechanism of TCP phase (μ phase and σ phase) are studied, using electron hole number (EHN) theory, phase analysis technology and TEM observation. The results indicate that the EHN in studied alloy is 2.311-2.348 which is higher than that of critical EHN of μ phase precipitate (2.30), so μ phase could precipitate if there is enough thermo-exposition. In contrast, the calculated EHN is less than that of critical EHN of σ phase precipitate (2.52). However the σ phase is also observed by TEM. Enrich of Cr and Mo around γ phase after γ′phase precipitated leads to σ phase precipitated.

关键词： superalloy TCP phase electron hole number

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Thermo-kinetic characteristics on stabilizing hetero-phase interface of metal matrix composites by crystal plasticity finite element method

引用

Journal of Materials science & Technology 2024年第2期169卷 53-67页

作者： y.B.zhang s.J.song F.Liu state Key Laboratory of solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Analytical&Testing Center Northwestern Polytechnical UniversityXi’an 710072China

Using dislocation-based constitutive modeling in three-dimension crystal plasticity finite element(3D CPFE)simulations,co-deformation and instability of hetero-phase interface in different material systems were herein studied for polycrystalline metal matrix composites(MMCs).Local stress and strain fields in two types of 3layer MMCs such as fcc/fcc Cu-Ag and fcc/bcc Cu-Nb have been predicted under simple compressive deformations.Accordingly,more severe strain-induced interface instability can be observed in the fcc/bcc systems than in the fcc/fcc systems upon refining to metallic nanolayered composites(MNCs).By detailed analysis of stress and strain localization,it has been demonstrated that the interface instability is always accompanied by high-stress concentration,i.e.,thermodynamic characteristics,or high strain prevention i.e.,kinetic characteristics,at the hetero-phase interface.It then follows that the thermodynamic driving forceG and the kinetic energy barrier Q during dislocation and shear banding can be adopted to classify the deformation modes,following the so-called thermo-kinetic correlation.Then by inserting a high density of high-energy interfaces into the Cu-Nb composites,such thermo-kinetic integration at the hetero-phase interface allows a successful establishment of MMCs with the high△G-high Q deformation mode,which ensures high hardening and uniform strain distri-bution,thus efficiently suppressing the shear band,stabilizing the hetero-phase interface,and obtaining an exceptional combination in strength and ductility.such hetero-phase interface chosen by a couple of thermodynamics and kinetics can be defined as breaking the thermo-kinetic correlation and has been proposed for artificially designing MNCs.

关键词： Thermodynamics and kinetics Physics-based constitutive modeling Hetero-phase interface Crystal plasticity finite element

来源：

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

Distinct Electrical and Mechanical Responses of a Cu-10Fe Composite Prepared by Hot-Pressed sintering and Post Treatment

引用

Acta Metallurgica sinica(English Letters) 2024年第2期37卷 255-265页

作者： X.y.yue s.y.Peng X.zhang C.N.He y.Z.Tian Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China school of Materials science and Engineering and Tianjin Key Laboratory of Composite and Functional Materials Tianjin UniversityTianjin300350China Research Centre for Metallic Wires Northeastern UniversityShenyang110819China

A Cu-10wt%Fe composite was prepared through hot-pressed sintering,and the material was subsequently solution treated.The hot-pressed sintered and solution treated materials were rolled and aged.The precipitation behavior and performance changes were systematically studied by using scanning electron microscopy and transmission electron microscopy.In contrast to the hot-pressed sintered specimen,the solution treatment significantly affects the thermal stability and properties of the Cu-10wt%Fe composite.The Cu-10wt%Fe composite was prepared after solid solution,cold rolling and aging at 773 K for 1 h,and it obtained excellent tensile strength of 494 MPa,uniform elongation of 16.3%,electrical conductivity of 51.1%IACs and softening temperature of 838 K.Mechanisms for the distinct difference in thermal stability and properties between hot-pressed sintered and solution treated specimens were analyzed.These findings provide a theoretical basis for designing high-performance Cu-based in-situ composites by post treatment.

关键词： Cu-Fe composite Hot-pressed sintering Thermal stability strength Electrical conductivity

来源：

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

青藏高原东北缘岩石层结构:高原横向生长的机制

引用

世界地震译丛 2018年第2期49卷 144-161页

作者： X.Z.shen M.Liu y.Gao W.J.Wang y.T.shi M.J.An y.s.zhang X.Z.Liu 钱银苹(译) 李敏娟(译) 沈旭章(校) 不详中国地震局兰州地震研究所

青藏高原东北缘及其周边亚洲板块(北部到阿拉善块体,东部到鄂尔多斯块体)岩石层结构的探测对了解青藏高原的抬升和横向生长具有重要的意义。本研究利用布设在青藏高原东北缘和周边区域的高密度地震台阵所记录的波形,计算s波和P波接收函... 详细信息

青藏高原东北缘及其周边亚洲板块(北部到阿拉善块体,东部到鄂尔多斯块体)岩石层结构的探测对了解青藏高原的抬升和横向生长具有重要的意义。本研究利用布设在青藏高原东北缘和周边区域的高密度地震台阵所记录的波形,计算s波和P波接收函数,研究岩石层结构。结果表明,鄂尔多斯块体和阿拉善块体下方的地幔岩石层中存在较强、相对稳定的负速度梯度,其深度范围在70~150km,这与典型稳定的大陆岩石层类似;相比之下,在青藏高原东北部下方地幔岩石层的速度梯度相对较弱和较模糊,这可能是由于地幔岩石层高温和存在部分熔融物质造成的;青藏高原与鄂尔多斯块体和阿拉善块体边界之间的岩石层结构变化剧烈,这两个块体作为刚性边界限制了青藏高原的横向变化。此外,在青藏高原东北角到银川地堑区域的地幔岩石层结构是相似的,这可能意味着从青藏高原东北角到鄂尔多斯块体和阿拉善块体之间的过渡间隔区内存在横向地幔流。这个过渡带的地壳结构为青藏高原横向生长提供了证据。特别是,在海原断裂和天景山断裂之间出现了地壳增厚和双地壳的证据,该区域可能是青藏高原在东北缘横向生长的前沿。

关键词：青藏高原东北缘岩石层变形 P波和s波接收函数海原和六盘山断裂地幔流

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Construction of 2D/2D Ti_(3)C_(2)T_(x)MXene/Cds heterojunction with photothermal effect for efficient photocatalytic hydrogen production

引用

Journal of Materials science & Technology 2024年第4期171卷 1-9页

作者： T.y.Huang Z.yang s.y.yang Z.H.Dai y.J.Liu J.H.Liao G.y.Zhong Z.J.Xie y.P.Fang s.s.zhang Key Laboratory for Biobased Materials and Energy of Ministry of Education Guangdong Laboratory for Lingnan Modern AgricultureCollege of Materials and EnergySouth China Agricultural UniversityGuangzhou 510643China school of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China school of Chemical Engineering and Energy Technology Guangdong Provincial Key Laboratory of Distributed Energy SystemsDongguan University of TechnologyDongguan 523808China

The insensitivity of semiconductors to visible and infrared light is a key constraint on the utilization of light energy in photocatalytic reactions.Constructing photocatalysts with full-spectrum absorption through surface engineering is an effective approach to fully harnessing light energy in semiconductor materials.Herein,a novel stable Ti_(3)C_(2)T_(x)MXene/Cds heterojunction catalyst is obtained by in-situ epitaxial growth of two-dimensional(2D)Cds nanosheets on 2D MXene interface via a solvothermal method.The exceptional light absorption properties of MXene confer outstanding full-spectrum driven photocat-alytic hydrogen evolution capability upon the heterogeneous catalyst.The unique 2D/2D structure effectively mitigated the recombination of photogenerated carriers,enhancing the photocatalytic performance of the catalyst.Moreover,the composite catalyst exhibits a significantly higher surface temperature of 80.4℃under visible light irradiation at an intensity of 0.1 W/cm^(2),which is 1.84 times higher than that of Cds.Under irradiation of visible and near infrared light,the composite catalyst with photothermal ef-fect demonstrates a remarkable hydrogen evolution rate of 65.4 mmol g^(-1)h^(-1),which is 7.2 times higher than that of Cds catalyst.This study introduces a novel approach for constructing full-spectrum absorption catalysts and expands the application of the photothermal effect in photocatalytic hydrogen evolution research.

关键词： Two-dimensional structure Heterostructure Photothermal effect Photocatalyst Hydrogen evolution

来源：

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

Exercise preconditioning alleviates ischemia-induced memory deficits by increasing circulating adiponectin

引用

Neural Regeneration Research 2025年第5期20卷 1445-1454页

作者： Meifeng Zheng Borui zhang sonata s y yau Kwok-Fai so Li zhang Haining Ou Department of Rehabilitation Medicine Guangzhou Medical UniversityGuangzhouGuangdong ProvinceChina Department of Rehabilitation Medicine The Fifth Clinical College of Guangzhou Medical UniversityGuangzhouGuangdong ProvinceChina Key Laboratory of CNs Regeneration(Ministry of Education) Guangdong-Hong Kong-Macao Institute of CNS RegenerationJinan UniversityGuangzhouGuangdong ProvinceChina Department of Rehabilitation sciences The Hong Kong Polytechnic UniversityHong Kong Special Administrative RegionChina state Key Laboratory of Brain and Cognitive science Li Ka Shing Faculty of MedicineThe University of Hong KongHong Kong Special Administrative RegionChina Center for Exercise and Brain science School of PsychologyShanghai University of SportShanghaiChina Neuroscience and Neurorehabilitation Institute University of Health and Rehabilitation SciencesQingdaoShandong ProvinceChina

Cerebral ischemia is a major health risk that requires preventive approaches in addition to drug therapy.Physical exercise enhances neurogenesis and synaptogenesis,and has been widely used for functional rehabilitation after stroke.In this study,we determined whether exercise training before disease onset can alleviate the severity of cerebral ischemia.We also examined the role of exercise-induced circulating factors in these effects.Adult mice were subjected to 14 days of treadmill exercise training before surgery for middle cerebral artery occlusion.We found that this exercise pre-conditioning strategy effectively attenuated brain infarct area,inhibited gliogenesis,protected synaptic proteins,and improved novel object and spatial memory function.Further analysis showed that circulating adiponectin plays a critical role in these preventive effects of exercise.Agonist activation of adiponectin receptors by Adipo Ron mimicked the effects of exercise,while inhibiting receptor activation abolished the exercise effects.In summary,our results suggest a crucial role of circulating adiponectin in the effects of exercise pre-conditioning in protecting against cerebral ischemia and supporting the health benefits of exercise.

关键词： adiponectin cerebral ischemia exercise pre-conditioning hippocampus memory function middle cerebral artery occlusion prefrontal cortex synaptic proteins treadmill exercise

来源：

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

Data-Driven Learning Control Algorithms for Unachievable Tracking Problems

引用

IEEE/CAA Journal of Automatica sinica 2024年第1期11卷 205-218页

作者： Zeyi zhang Hao Jiang Dong shen samer s.saab the school of Mathematics Renmin University of ChinaBeijing 100872China IEEE the school of Engineering Lebanese American UniversityByblos 2038Lebanon

For unachievable tracking problems, where the system output cannot precisely track a given reference, achieving the best possible approximation for the reference trajectory becomes the objective. This study aims to investigate solutions using the Ptype learning control scheme. Initially, we demonstrate the necessity of gradient information for achieving the best approximation.subsequently, we propose an input-output-driven learning gain design to handle the imprecise gradients of a class of uncertain systems. However, it is discovered that the desired performance may not be attainable when faced with incomplete information.To address this issue, an extended iterative learning control scheme is introduced. In this scheme, the tracking errors are modified through output data sampling, which incorporates lowmemory footprints and offers flexibility in learning gain design.The input sequence is shown to converge towards the desired input, resulting in an output that is closest to the given reference in the least square sense. Numerical simulations are provided to validate the theoretical findings.

关键词： Data-driven algorithms incomplete information iterative learning control gradient information unachievable problems

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：