检索结果-南通市图书馆

Effect of homogenization process on the hardness of Zn-Al-Cu alloys

在线全文

学校读者我要写书评

暂无评论

International Journal of minerals,metallurgy and materials 2015年第10期22卷 1076-1081页

作者： Jose D.Villegas-Cardenas maribel l.saucedo-munoz Victor m.l.pez-Hirata Antonio De Ita-De la Torre Erika O.Avila-Davila Jorge luis Gonzalez-Velazquez Department of metallurgy and materials Instituto Politecnico Nacional(IPN-ESIQIE)Mexico City 07300Mexico Department of Industrial Engineering Universidad Politecnica del Valle de MexicoMexico CityMexico Department of materials Universidad Autonoma Metropolitana(UAM)Unidad AzcapotzalcoMexico

The effect of a homogenizing treatment on the hardness of as-cast Zn–Al–Cu alloys was investigated. Eight alloy compositions were prepared and homogenized at 350 °C for 180 h, and their Rockwell 'B' hardness was subsequently measured. All the specimens were analyzed by X-ray diffraction and metallographically prepared for observation by optical microscopy and scanning electron microscopy. The results of the present work indicated that the hardness of both alloys(as-cast and homogenized) increased with increasing Al and Cu contents; this increased hardness is likely related to the presence of the θ and τ′ phases. A regression equation was obtained to determine the hardness of the homogenized alloys as a function of their chemical composition and processing parameters, such as homogenization time and temperature, used in their preparation.

关键词： zinc–aluminum–copper alloys casting hardness homogenization phases microstructure

Geological and Fluid Inclusion Studies of the Dongpo Tungsten Skarn Ore Deposit,China

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 1986年第2期5卷 140-157页

作者：卢焕章 CRAWFORD m.l. Bryn mawr College Department of Geology Institute of Geochemistry Academia Sinica PA.19010 U.S.A.

The Dongpo tungsten ore deposit,the largest scheelite skam deposit in China,is located atthe contact of a *** granite with a Devonian *** mineralization associatedwith the granite includes W,Bi-mo,Cu-Sn and Pb-Zn *** W mineralization stages areshown by the occurrence of ore in massive skarn deposits and in later cross-cutting *** garnet/pyroxene ratio,the hedenbergite and diopside-rich pyroxene and the andradite-richgarnet show the deposit belongs to the oxidized skarn *** fluid inclusion studies ofgranite,greisen,skarn and vein sam.l.s reveal three types of fluid inclusion:(1)liquid-rich,(2)gas-rich and(3)inclusions with several daughter ***(3)is by far the mostcommon in both skarn and vein *** dominant daughter mineral in fluid inclusions isrhembic,highly birefringent,and does not dissolve on heating even at 530℃.We assume thatthis mineral is *** liquid phase in most of the fluid inclusions has low to moderate sa-linities:0—15 wt.%;in a few has higher salinities(30—40 wt.% NaCl equivalent).The ho-mogenization temperatures of inclusions in the skarn stage range from 350℃ to 530℃,later tung-sten mineralization-stage inclusions homogenize between 200℃ and 300℃,as do inclusions in *** inclusions in granite and greisen resem.l. those of the late tungsten mineralization stage,with low salinity and homogenization temperatures of 200°—360℃.The tungsten-forming fluidsare probably a mixture that came from biotite granite and the surrounding country rocks.

关键词： Th Geological and Fluid Inclusion Studies of the Dongpo Tungsten Skarn Ore Deposit,China

Emerging role of A-kinase anchoring protein 5 signaling in reward circuit function

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第10期20卷 2913-2914页

作者： William J.Flerlage mark l.Dell’Acqua Brian m.Cox Fereshteh S.Nugent Uniformed Services University of the Health Sciences Department of Pharmacology and Molecular TherapeuticsBethesdaMDUSA Department of Pharmacology University of Colorado School of MedicineAnschutz Medical CampusAuroraCOUSA

There is a strong evidence supporting the hypothesis of synaptic dysfunction as a major contributor to neural circuit and network disruption underlying emotional and mood dysregulation in psychiatric disorders(Simmons et al.,2024).Diverse sets of distinct m.l.cular signaling pathways converge on the synapse to regulate synaptogenesis,synaptic function,and synaptic plasticity in brain regions and circuits through com.l.x interactions organized by numerous m.l.ivalent protein scaffolds,including the fam.l. of proteins known as A-kinase anchoring proteins(AKAPs).

关键词： function supporting

ATOmIZATION CAUSED BY BOTTOm FlOW ENERGY DISSIPATION

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2001年第1期13卷 23-27页

作者： Hu, m.l. liang, Z.C. Zeng, Y.H. Wuhan Univ. of Hydraulic and Electr. Wuhan 430072 China

Bottom flow energy dissipation is one of the common energy dissipation methods for flood-releasing structures with high water head. measures of this energy dissipation depend mainly on the turbulent action of hydraulic jump. In this paper, the physical process and the calculating methods of the atomization caused by bottom flow energy dissipation were studied, the computation models of atomization quantity for the self-aerated flow in overflow and hydraulic jump regions are presented, and the main results are of theoretical and practical significance for the hydraulic and electric engineering.

关键词： Energy dissipation Hydraulic jump Hydrodynamics

Getting physical with medical education:Exercise based virtual anatomy review classes for medical students

在线全文

学校读者我要写书评

暂无评论

World Journal of methodology 2025年第1期15卷 20-25页

作者： Nadeesha R Samarasinghe Taniya S Nagpal michele l Barbeau Charys m martin Division of General Surgery Faculty of MedicineUniversity of British ColumbiaVancouver V6T 1Z3BCCanada Faculty of Kinesiology Sport and RecreationUniversity of AlbertaEdmonton T6G 2R3ABCanada Anatomy and Cell Biology University of Western OntarioLondon N6A 3K7ONCanada Department of Anatomy and Cell Biology Schulich School of Medicine and DentistryThe University of Western OntarioLondon N6A 3K7ONCanada

The benefits of regular physical activity are well ***,few studies have examined the effectiveness of integrating physical activity(PA)into curricula within a post-secondary *** investigate the incorporation of PA into medical curriculum,we developed a series of optional exercise-based review sessions designed to reinforce musculoskeletal(mSK)anatomy course *** synchronous sessions were co-taught by a group fitness instructor and an anatomy *** fitness instructor would lead students through both strength and yoga style exercises,while the anatomy instructor asked questions about relevant anatomical structures related to course material previously *** the sessions,participants were asked to evaluate the classes on their self-reported exam preparedness in improving mSK anatomy knowledge,PA levels,and mental *** participants com.l.ted surveys;a majority agreed that the classes increased understanding of mSK concepts(90.0%)and activity levels(97.7%).many(70.0%)felt that the classes helped reduce *** majority of respondents(90.0%)agreed that the classes contributed to increased feelings of social ***,medical students saw benefit in PA based interventions to supplement mSK course *** with increasing activity levels and promoting health behaviours,integrating PA into medical curriculum may improve comprehension of learning material,alleviate stress and foster social connectivity among medical students.

关键词： medical education musculoskeletal Anatomy Exercise Online learning

ISOTHERm.l.SECTION OF mg-Zn-la SYSTEm IN mg RICH CORNER AT 350℃

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 metallurgica Sinica(English letters) 2008年第5期21卷 329-335页

作者： m.l. Huang H.X. li H. Ding Y.P. Ren S.m. Hao School of materials and metallurgy Northeastern University Shenyang 110004 China

Alloys of mg-Zn-la system in mg rich corner at 350℃ have been prepared in this study. Scanning electron microscopy （SEm）, electron probe microanalysis with energy dispersive X-ray spectroscopy （EPmA-EDS）, and X-ray diffraction （XRD） have been used to identify the phase equilibrium and the composition of each phase in the alloys. As a result, the isotherm.l.section of mg-Zn-la system in mg rich corner at 350℃ has been determined. The result shows that, in addition to some binary phases, there exists a linear ternary compound called T-phase in mg-Zn-la system at 350℃, in which the la content is about 8 at. pct ±0.4 at. pct and the Zn content is 8 at. pct- 48 at. pct. The T-phase has a C-centered orthorhombic crystal structure, and the lattice parameters are a=0.965-1.020 nm, b=1.121 1.142 nm, c=0.950-0.977 nm.

关键词： mg-Zn-la system Phase equilibrium T-phase Isotherm.l.section

Effect of two-step cooling process on mechanical properties of TRIP steel with high performance

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2018年第4期25卷 426-432页

作者： m.l. li H. Jiang Y.l. He l.B. Chen G.T. Zhang H. Wang X.G. lu l. li School of materials Science and Engineering Shanghai University Shanghai 200072 China State Key laboratory of Advanced Special Steel Shanghai University Shanghai 200072 China Pangang Group Research Institute Panzhihua 617000 Sichuan China

A novel two-step cooling experiment was established to sim.l.te the slow cooling process of continuous annealing production line for transformation-induced plasticity （TRIP） steel. The microstructures and mechanical properties of TRIP steel soaked at 700℃ for different time were investigated by tensile test, scanning electron microscopy, X-ray diffraction, and thermodynamic and kinetic calculation. It is shown that the steel soaked for 15 s exhibits the optim.l.product of strength and elongation （PSE 〉 30,000 mPa%） due to the transformation of austenite to proeutectoid ferrite, which delays the bainite transformation and improves the stability of retained austenite. In addition, the mechanical properties of TRIP steel soaked over 30 s are much lower, resulting from the precipitation of cementite, which decreases the stability of retained austenite and weakens the TRIP effect.

关键词： Transformation induced plasticity steel Two-step cooling microstructure mechanical property

THE mICROSTRUCTURE AND COmPRESSIVE PROPERTIES IN NiAl(Co) mATRIX COmPOSITE

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 metallurgica Sinica(English letters) 1996年第6期9卷 653-657页

作者： l.Chen Y.F. Han C.H Tao and m.l. Xie(Beijing Institute of Aeronautical materials, Beijing 100095, ) Beijing Inst of Aeronautical Materials Beijing China

The microstructures of NiAl(Co)-TiB_2 composite prepared using exotherm.l.dispersion (XD) method have been studied by optical microscopy, XRD, EDS, and TEm The results show that, TiB_2 paritcles are typically single crystal, and fairly uniformly distributed. The matrix mainly consists of β-NiAl phase, ll_2γ′Ni_3Al phase and δ-Ni_3Al phase. The δNi_3Al has a fcc crystal structure with lattice parameter a=*** data of compressive testing at room temperature show that the room temperature ductility of NiAl(Co) matrix composite is much better than that of stoichiometric NiAl.

关键词： intermetallic compound exotherm.l.dispersion method

Best operating conditions to produce hydroxyapatite nanoparticles by means of a spinning disc reactor

在线全文

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2014年第2期8卷 156-160页

作者： A. F. D' Intino B. de Caprariis m.l. Santarelli N. Verdone A. Chianese Department of Chemical Engineering Sapienza University via Eudossiana 00184 Rome Italy

In this work, mg2＋ doped hydroxyapatite （mg-HAP） nanoparticles were produced by a reactionprecipitation process by using a spinning disc reactor （SDR） at high rotational speed. The production process of these nanoparticles consisted of the neutralization reaction between two aqueous solutions of calcium chloride and ammonia orthophosphate at room temperature. By operating at pH = 10, a high purity mg-HAP nanoparticles were obtained. In particular, they were 51 nm in average size when the two reagents were fed over the disc symmetrically at 3 cm from the disc center and a rotational speed of the disc reactor equal to 1400 r/min was adopted.

关键词： hydroxyapatite nanoparticles spinning discreactor