检索结果-南通市图书馆

Analysis and Modeling of Friction Stir Processing-Based Crack Repairing in 2024 Aluminum Alloy

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2017年第3期30卷 228-237页

作者： Jun-Gang Ren Lei Wang Dao-Kui Xu li-yang xie Zhan-Chang Zhang Department of Mechanical Engineering and Automation Northeastern University Department of Electromechanical Engineering Shenyang Aerospace University Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of Sciences

Abstract A friction stir processing-based method was used to repair cracks in the 2024 aluminum alloy plates. The temperature field and plastic material flow pattern were analyzed on the basis of experimental and finite element simulation results. Microstructure and tensile properties of the repaired specimens were studied. The results showed that the entire crack repairing was a solid-phase process and plastic materials tended to flow toward the shoulder center and then resulted in the repairing of cracks. Meanwhile, the coarse grain structures were refined in repaired zone （RZ）, while the grains in thermal-mechanically affected zone and heat-affected zone were elongated and driven to grow up. Meanwhile, large phases are crushed into small particles and dispersed inside the RZ. Finally, the strength of the repaired specimens can be restored dramatically and their ductility can be partially restored. After heat treatment, the tensile properties of the repaired specimens can be further enhanced.

关键词： Friction stir processing Crack repairing Aluminum alloy Microstructure Hardness Tensile properties

Measurement of S-Wave Scattering Length between 6li and 88Sr Atoms Using Interspecies Thermalization in an Optical Dipole Trap

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2019年第7期36卷 27-30页

作者： Xiao-Bin Ma Zhu-Xiong Ye li-yang xie Zhen Guo li You Meng Khoon Tey State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics Tsinghua University Beijing 100084 Collaborative Innovation Center of Quantum Matter Beijing 100084

We report the creation of the first mixture of ^6li and ^88Sr atoms in an optical dipole trap. Using this mixture,a measurement of the interspecies thermalization process is carried out and the previously unknown interspecies s-wave scattering length between ^6li and ^88Sr atoms is extracted to be |a6 li-88 Sr|=(380-100^+160)a0 with a0 being the Bohr radius from the rate of interspecies thermalization.

关键词： We report the creation optical dipole trap

Study on the hydrogen absorption properties of a YGdTbDyHo rare-earth high-entropy alloy

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 127-135页

作者： Tongyue li Ziliang xie Wenjiao Zhou Huan Tong Dawen yang Anjia Zhang Yuan Wu Xiping Song State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China Whole Win(Beijing)Materials Sci.&Tech.Co. Ltd.Beijing 100083China

This study investigated the microstructure and hydrogen absorption properties of a rare-earth high-entropy alloy(HEA),*** indicated that the YGdTbDyHo alloy had a microstructure of equiaxed grains,with the alloy elements distributed *** hydrogen absorption,the phase structure of the HEA changed from a solid solution with an hexagonal-close-packed(HCP)structure to a high-entropy hydride with an faced-centered-cubic(FCC)structure without any secondary phase *** alloy demonstrated a maximum hydrogen storage capacity of 2.33 H/M(hydrogen atom/metal atom)at 723 K,with an enthalpy change(ΔH)of-141.09 kJ·mol^(-1)and an entropy change(ΔS)of-119.14 J·mol^(-1)·K^(-1).The kinetic mechanism of hydrogen absorption was hydride nucleation and growth,with an apparent activation energy(E_(a))of 20.90 kJ·mol^(-1).Without any activation,the YGdTbDyHo alloy could absorb hydrogen quickly(180 s at 923 K)with nearly no incubation period *** reason for the obtained value of 2.33 H/M was that the hydrogen atoms occupied both tetrahedral and octahedral *** results demonstrate the potential application of HEAs as a high-capacity hydrogen storage material with a large H/M ratio,which can be used in the deuterium storage field.

关键词： rare-earth high-entropy alloy hydrogen absorption capacity pressure–composition–temperature curves kinetics

Suspended sediment transport of the Hangzhou Bay and its related hydrodynamic analyses

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 1993年第1期12卷 39-50页

作者： li Bogen, yang Zhaoqing and xie Qinchun Second Institute of Oceanography, State Oceanic Administration, P. O. Box 1207, Hangzhou 310012, China

The 25-h measurements of current speed, flow direction, water depth, suspended sediment concentration and salinity were carried out at six anchored stations in the study area during spring and neap tides in winter of 1987 and summer of 1989. Caculations and analyses of the data obtained show that large amounts of suspended sediments are moved back and forth under the action of tidal current, and the net transport of sediment is small, with its predominance upstream in winter and downstream in summer. These calculations and analyses also suggest that the advective transport of sediment is dominant, while the vertical gravitational circulation of the suspended sediment comes next. Meantime, it is indicated that tidal currents play a major role in the suspended sediment transport, and residual flows have effect on the net transport of the suspended sediment, which is more remarkable during neap tide than during spring tide.

关键词： Suspended sediment transport of the Hangzhou Bay and its related hydrodynamic analyses Bay

Tectonic Evolution of Tertiary Basins in circum-Pacific Belt of China and Their Geodynamic Setting

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 1997年第1期16卷 4-10页

作者： li Sitian yang Shigong xie XinongFaculty of Earth Resources, China University of Geosciences, Wuhan 430074

? Tertiary basins distributed mainly in two zones in the CircumPacific region of China, which includes a rift basin zone in continental area and a continental margin basin zone in offshore area of west Pacific Ocean. Extensional regime dominated the evolution processes of the basins, and in many cases the extensional process was accompanied by dextral strikeslip movement. Mantle upwelling or plumes have been found beneath the rift zone and the marginal sea basins by geophysical and volcanic petrology research. Based upon the regional studies, the basin formation, lithosphere thinning and mantle upwelling may be caused by the superimposed effect of three processes: (1) subduction of Pacific plate, (2) subduction of IndiaAustralia plate which is the main controlling factor for the opening of the South China Sea and (3) collision of India with Eurasia. 

关键词： rifting basin geodynamics mantle upwelling plume.

Perilipin-2 mediates ferroptosis in oligodendrocyte progenitor cells and myelin injury after ischemic stroke

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第7期20卷 2015-2028页

作者： Jian yang Jiang Wu Xueshun xie Pengfei Xia Jinxin Lu Jiale liu Lei Bai Xiang li Zhengquan Yu Haiying li Department of Neurosurgery&Brain and Nerve Research Laboratory The First Affiliated Hospital of Soochow UniversitySuzhouJiangsu ProvinceChina Institute of Stroke Research Soochow UniversitySuzhouJiangsu ProvinceChina

Differentiation of oligodendrocyte progenitor cells into mature myelin-forming oligodendrocytes contributes to *** of remyelination due to oligodendrocyte progenitor cell death can result in severe nerve *** is an iron-dependent form of regulated cell death caused by membrane rupture induced by lipid peroxidation,and plays an important role in the pathological process of ischemic ***,there are few studies on oligodendrocyte progenitor cell *** analyzed transcriptome sequencing data from GEO databases and identified a role of ferroptosis in oligodendrocyte progenitor cell death and myelin injury after cerebral *** analysis suggested that perilipin-2(PliN2)was involved in oligodendrocyte progenitor cell ***2 is a lipid storage protein and a marker of hypoxia-sensitive lipid droplet *** further investigation,we established a mouse model of cerebral ischemia/*** found significant myelin damage after cerebral ischemia,as well as oligodendrocyte progenitor cell death and increased lipid peroxidation levels around the infarct *** ferroptosis inhibitor,ferrostatin-1,rescued oligodendrocyte progenitor cell death and subsequent myelin *** also found increased PliN2 levels in the peri-infarct area that co-localized with oligodendrocyte progenitor ***2 knockdown rescued demyelination and improved neurological *** findings suggest that targeting PliN2 to regulate oligodendrocyte progenitor cell ferroptosis may be a potential therapeutic strategy for rescuing myelin damage after cerebral ischemia.

关键词： bioinformatics bulk RNA sequencing ferroptosis ischemic stroke myelin injury oligodendrocyte progenitor cell perilipin-2 single-cell RNA sequencing

Turbulent Agglomeration of Microparticles in a Cylinder Wake Flow Using LES-DEM:Focusing on the Effect of the Reynolds Number

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2025年第1期34卷 34-49页

作者： WANG Shuang MU lin li Xue xie Jun DONG Ming School of Energy and Power Engineering Dalian University of Technology School of Optical Information and Energy Engineering Wuhan Institute of Technology School of Energy and Environment Shenyang Aerospace University

Turbulent agglomeration is viewed as a promising technology for enhancing fine particle removal *** better understand particle transport,agglomeration behaviors,and fluid-particle interactions,we numerically explored these phenomena under cylindrical vortex wake influence using a coupled large eddy simulation and discrete element method（LES-DEM） *** validity of the LES approach was verified by comparison with available direct numerical simulation（DNS） *** adopted the Johnson-Kendall-Roberts（JKR） contact model for particle-particle *** particle dispersion and agglomeration characteristics of particles with different diameters（dp=2-20 μm） in the laminar and transition of shear layer（TrSL） flow regimes were *** particles were concentrated at the vortex centers,while larger particles accumulated around the *** agglomeration efficiency exhibited an M-shaped profile spanwise（y-direction）.With increasing Reynolds number,the agglomeration efficiency and turbulence intensity *** particle agglomeration efficiency peaks at a certain Reynolds ***,at higher Reynolds numbers,reducing the residence time of particles in the flow field decreases the agglomeration efficiency.

关键词： discrete element method large eddy simulation microparticle particle agglomeration

High-throughput screening of CO_(2) cycloaddition MOF catalyst with an explainable machine learning model

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Green Energy & Environment 2025年第1期10卷 132-138页

作者： Xuefeng Bai Yi li Yabo xie Qiancheng Chen Xin Zhang Jian-Rong li Beijing Key Laboratory for Green Catalysis and Separation and Department of Chemical Engineering College of Materials Science&EngineeringBeijing University of TechnologyBeijing100124China

The high porosity and tunable chemical functionality of metal-organic frameworks(MOFs)make it a promising catalyst design ***-throughput screening of catalytic performance is feasible since the large MOF structure database is *** this study,we report a machine learning model for high-throughput screening of MOF catalysts for the CO_(2) cycloaddition *** descriptors for model training were judiciously chosen according to the reaction mechanism,which leads to high accuracy up to 97%for the 75%quantile of the training set as the classification *** feature contribution was further evaluated with SHAP and PDP analysis to provide a certain physical understanding.12,415 hypothetical MOF structures and 100 reported MOFs were evaluated under 100℃ and 1 bar within one day using the model,and 239 potentially efficient catalysts were *** them,MOF-76(Y)achieved the top performance experimentally among reported MOFs,in good agreement with the prediction.

关键词： Metal-organic frameworks High-throughput screening Machine learning Explainable model CO_(2)cycloaddition

Effect of T7951 secondary aging treatment on crack propagation behavior of 7055 aluminum alloy

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

Transactions of Nonferrous Metals Society of China 2016年第4期26卷 938-944页

作者：周松王磊谢里阳回丽许良东北大学机械工程与自动化学院沈阳110004 沈阳航空航天大学航空制造工艺数字化国防重点学科实验室沈阳110136

The crack propagation rates of T6 peak aging and T7951 secondary aging 7055 aluminium alloys were tested under stress ratios (R) of 0.6, 0.05 and ?1, respectively. The microstructures and fracture surfaces were analyzed by TEM and SEM. The results reveal that the crack propagation rate is affected by the stress ratio and microstructure such as the distribution, dimension and volume fraction of matrix precipitates, grain boundary precipitates and precipitate free zone. For both heat-treated specimens, crack propagation rate increases with the improvement of R when it is a positive value while crack propagation rate at R=?1 is much similar to that at R=0.06. The crack growth rates exhibit no obvious difference in lower stress intensity factor range (ΔK), while the difference starts to be obvious when ΔK exceeds certain value. The fracture analysis testifies a better fracture toughness for 7055-T7951 with a smaller striation space in Paris region.

关键词： 7055 aluminum alloy T7951 secondary aging crack propagation fracture surface morphology