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journal of magnesium and Alloys 2024年第1期12卷 332-344页

作者： Z.Y.Xue X.j.Li j.H.Chu m.m.Li D.N.Zou L.b.Tong School of metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China State Key Laboratory of Advanced Design and manufacturing for Vehicle body Hunan UniversityChangsha 410082China

The poor corrosion and wear resistances of mg alloys seriously limit their potential applications in various *** conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient *** the current study,we design a double-layer epoxy composite coating on mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly *** outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)*** FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier *** Ce film connects the outer layer with the substrate,showing the transition *** corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling *** synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of mg alloys.

关键词： mg alloy Functionalized graphene Epoxy coating Corrosion/wear resistance blocking layer

Exact solution and transient behavior for torsional vibration of functionally graded finite hollow cylinders

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Acta mechanica Sinica 2009年第4期25卷 555-563页

作者： H. m. Wang C. b. Liu H. j. Ding Department of mechanics Zhejiang University Department of Civil Engineering Zhejiang University

Exact solutions are obtained for transient torsio- nal responses of a finitely long, functionally graded hollow cylinder under three different end conditions, i.e. free-free, free-fixed and fixed-fixed. The cylinder with its external surface fixed is subjected to a dynamic shearing stress at the internal surface. The material properties are assumed to vary in the radial direction in a power law form, while keep invariant in the axial direction. With expansion in the axial direction in terms of trigonometric series, the governing equations for the unknown functions about the radial coordinate r and time t are deduced. by applying the variable substitution technique, the superposition method and the separation of variables consecutively, series-form solutions of the equations are obtained. Natural frequencies and the transient torsional responses are finally discussed for a functionally graded finite hollow cylinder.

关键词： Exact solution Functionally graded material Finite hollow cylinder Transient torsional vibration

Resveratrol attenuates metabolic,sperm,and testicular changes in adult Wistar rats fed a diet rich in lipids and simple carbohydrates

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Asian journal of Andrology 2019年第2期21卷 201-207页

作者： Fabiana A de Oliveira Waldemar S Costa Francisco j b Sampaio bianca m Gregorio Urogenital Research Unit Biomedical CenterState University of Rio de JaneiroRio de Janeiro 20551-030Brazil

High-fat diets affect male reproduction and sexual ***,we evaluated the effects of prolonged resveratrol administration on the metabolic,sperm,and testicular parameters of rats fed a cafeteria *** Wistar rats were divided at weaning into control(Cv n=20)and cafeteria(CAF,n=16)*** 3 months,half of them were given daily supplementations of resveratrol(C-R,n=10;CAF-R,n=8)at a dosage of 30 mg kg-1 body mass for 2 *** were killed at 5 months of age,and blood,spermatozoa,and testes were collected for further *** were analyzed by one-way ANOVA,and Pmoted hyperglycemia(Pment with resveratrol reversed this condition(Pm viability and motility,while resveratrol improved these parameters(Fmorphology,the height of the seminiferous epithelium was reduced in the CAF group compared with that of the C group(P=0.0007).Spermatogenic cell proliferation was also reduced in the CAF group compared with that of the C ***,the CAF-R showed an increase in cell proliferation rate compared with that of the untreated CAF group(P=0.0024).Although it did not modify body mass,the consumption of a CAF diet promoted hyperglycemia,adverse testicular morphology remodeling,and abnormal sperm,which were attenuated by treatment with resveratrol,thus suggesting a protective effect of this antioxidant on spermatogenesis.

关键词： cafeteria diet morphology resveratrol spermatozoa testicle

A review of research on spontaneous combustion of coal

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International journal of mining Science and Technology 2020年第3期30卷 303-311页

作者： m.Onifade b.Genc Department for management of Science and Technology Development Ton Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Applied Sciences Ton Duc Thang UniversityHo Chi Minh CityVietnam The School of mining Engineering University of the WitwatersrandSouth Africa

Coal oxidation at low temperatures is the heat source liable for the self-heating and spontaneous combustion of coal. This phenomenon has imposed severe problems in coal related industries. Attempts to understand this phenomenon by previous researchers have provided significant progress. It is wellknown that coal oxidation at low temperatures involves oxygen consumption and formation of gaseous and solid oxidation products. This process is majorly influenced by temperature, oxidation history of coal,coal properties, particle size distribution of the coal, etc. The current understanding of the phenomenon of self-heating and spontaneous combustion of coal is discussed along with the different experimental and numerical models established to predict self-heating characteristics of coal. This paper focuses on the global position of the study carried out by academics, research institutes and industries on spontaneous combustion of coal and coal mine fires. Within this framework, the generally used spontaneous combustion techniques to predict the spontaneous combustion liability of coal were evaluated. These techniques are well-known in their usage, but no specific method has become a standard to predict the spontaneous combustion liability. Further study is still needed to indicate a number of impending issues and to obtain a more complete understanding on the phenomenon.

关键词： Coalfields Experimental Numerical Propensity Self-heat Statistical method

Improved mechanical properties of SiC fiber reinforced silica-based ceramic cores fabricated by stereolithography

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journal of materials Science & Technology 2022年第21期116卷 161-168页

作者： W.Zheng j.m.Wu S.Chen K.b.Yu j.Zhang Y.S.Shi State Key Laboratory of materials Processing and Die&mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Engineering Research Center of Ceramic materials for Additive manufacturing Ministry of EducationWuhan 430074China

Silica-based ceramic cores have been widely used to fabricate aero-engine hollow blades due to their moderate high temperature mechanical properties and excellent *** this study,silica-based ceramics with SiC fiber addition were prepared via stereolithography,and the influence of SiC fiber content on mechanical properties of the obtained silica-based ceramics was *** the increase of SiC fiber content,linear shrinkage gradually decreased,while room temperature flexural strength and high temperature flexural strength first increased and then *** SiC fiber content increased to 4.0 wt%,linear shrinkage was reduced to 0.62%resulting from the oxidation of ***,room temperature flexural strength was improved from 11.79 mPa to 23.83 mPa and high temperature flexural strength was enhanced from 15.64 mPa to 34.62 mPa with 4.0 wt%SiC fiber addition due to the reinforcement of fibers and the enhancedβ-cristobalite content,which meets the need of ceramic ***,it demonstrates the capability of fabricating high-performance and high-precision silica-based ceramic cores reinforced by SiC fibers via stereolithography for rapid manufacturing of hollow blades.

关键词： Silica-based ceramic cores Stereolithography SiC fiber mechanical properties Hollow blades

EFFECT OF COLD WORKING ON THE AGING PROPERTIES OF Cu-Cr-Zr-mg ALLOY bY ARTIFICIAL NEURAL NETWORK

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Acta metallurgica Sinica(English Letters) 2004年第5期17卷 741-746页

作者： j.H.Su H.j.Li Q.m.Dong P.Liu b.X.Kang b.H.Tian CollegeofmaterialsScienceandEngineering NorthwesternPolytechnicalUniversityXi＇an710072China GollegeofmaterialsScienceandEngineering HenanUniversityofScienceandTechnologyLuoyang471003China

A developmental research has been carried out to deal with the high performance of Cu-Cr-Zr-mg lead frame alloy by artificial neural network (ANN). Using the cold working to assist in the aging hardening can improve the the hardness and electrical conductivity properties of Cu-Cr-Zr-mg lead frame alloy. This paper studies the effect of different extent of cold working on the aging properties by a supervised ANN to model the non-linear relationship between processing parameters and the properties. The back-propagation (bP) training algorithm is improved by Levenberg-marquardt algorithm. A basic repository on the domain knowledge of cold worked aging processes is established via sufficient data mining by the network. The predicted values of the ANN coincide well with the tested data. So an important foundation has been laid for prediction and optimum controlling the rolling and aging properties of Cu-Cr-Zr-mg alloy.

关键词： Cu-Cr-Zr-mg alloy cold working aging artificial neural network (ANN)

In situ neutron diffraction unravels deformation mechanisms of a strong and ductile Fe Cr Ni medium entropy alloy

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journal of materials Science & Technology 2022年第21期116卷 103-120页

作者： L.Tang F.Q.jiang j.S.Wróbel b.Liu S.Kabra R.X.Duan j.H.Luan Z.b.jiao m.m.Attallah D.Nguyen-manh b.Cai School of metallurgy and materials University of BirminghamB152TTUnited Kingdom Institute of metal Research Chinese Academy of SciencesShenyang 110016China Faculty of materials Science and Engineering Warsaw University of Technologyul.Wołoska 141Warsaw 02-507Poland State Key Laboratory for Powder metallurgy Central South UniversityChangsha 410083China Rutherford Appleton Laboratory ISIS FacilityDidcot OX110QXUnited Kingdom Department of materials Science and Engineering City University of Hong KongKowloonHong KongChina Department of mechanical Engineering The Hong Kong Polytechnic UniversityHung HomHong KongChina CCFE United Kingdom Atomic Energy AuthorityAbingdonOxfordshire OX143DBUnited Kingdom

We investigated the mechanical and microstructural responses of a high-strength equal-molar medium entropy FeCrNi alloy at 293 and 15 K by in situ neutron diffraction *** 293 K,the alloy had a very high yield strength of 651±12 mPa,with a total elongation of 48%±5%.At 15 K,the yield strength increased to 1092±22 mPa,but the total elongation dropped to 18%±1%.Via analyzing the neutron diffraction data,we determined the lattice strain evolution,single-crystal elastic constants,stacking fault probability,and estimated stacking fault energy of the alloy at both temperatures,which are the critical parameters to feed into and compare against our first-principles calculations and dislocation-based slip system *** density functional theory calculations show that the alloy tends to form shortrange order at room ***,atom probe tomography and atomic-resolution transmission electron microscopy did not clearly identify the short-range ***,at 293 K,experimental measured single-crystal elastic constants did not agree with those determined by first-principles calculations with short-range order but agreed well with the values from the calculation with the disordered configuration at 2000 *** suggests that the alloy is at a metastable state resulted from the fabrication *** view of the high yield strength of the alloy,we calculated the strengthening contribution to the yield strength from grain boundaries,dislocations,and lattice *** lattice distortion contribution was based on the Varenne-Luque-Curtine strengthening theory for multi-component alloys,which was found to be 316 mPa at 293 K and increased to 629 mPa at 15 K,making a significant contribution to the high yield *** plastic deformation,dislocation movement and multiplication were found to be the dominant hardening mechanism at both temperatures,whereas twinning and phase transformation were not *** is mainly due to the high stack

关键词： medium entropy alloy multi-component alloy Cryogenic temperature Neutron diffraction

Soils in extraterrestrial space: Need for studies under microgravity

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Pedosphere 2024年第1期34卷 13-14页

作者： m.b.KIRKHAm Department of Agronomy Kansas State UniversityManhattan KS 66506USA

With the increased interest of plants in space, gravity cannot be ignored when studying soil-plant-water relations. Therefore, it is important to understand the water relations of soils under zero gravity in space or under reduced gravity on the moon or mars. This paper outlines the problems of moving water in soils under zero gravity or microgravity, as well as growing plants in these soils. It is suggested that microgravity experiments could be done on Earth using both soils and plants. Results from such experiments could be used to grow plants when mankind establishes bases on the moon and mars.

关键词： soils soil bases

meson-production experiments at COSY-jülich

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Chinese Physics C 2010年第9期34卷 1263-1268页

作者： m.büscher Institute für Kernphysik and jülich Center for Hadron Physics

Selected results from experiments at COSY-jülich are presented： an attempt to measure the mass of the η meson with high precision （ANKE facility）,first steps towards the detection of rare η decays （WASA）,and s... 详细信息

关键词： meson production

Alloy design by dislocation engineering

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journal of materials Science & Technology 2018年第3期34卷 417-420页

作者： m.X.Huang b.b.He Department of mechanical Engineering The University of Hong Kong

Ultra-high strength alloys with good ductility are ideal materials for lightweight structural application in various industries. However, improving the strength of alloys frequently results in a reduction in ductility, which is known as the strength-ductility trade-off in metallic materials. Current alloy design strategies for improving the ductility of ultra-high strength alloys mainly focus on the selection of alloy composition （atomic length scale） or manipulating ultra-fine and nano-grained microstructure （grain length scale）. The intermediate length scale between atomic and grain scales is the dislocation length scale. A new alloy design concept based on such dislocation length scale, namely dislocation engineering, is illustrated in the present work. This dislocation engineering concept has been successfully substantiated by the design and fabrication of a deformed and partitioned （D＆P） steel with a yield strength of 2,2 GPa and an uniform elongation of 16%. In this D＆P steel, high dislocation density can not only increase strength but also improve ductility. High dislocation density is mainly responsible for the improved yield strength through dislocation forest hardening, whilst the improved ductility is achieved by the glide of intensive mobile dislocations and well-controlled transformation-induced plasticity （TRIP） effect, both of which are governed by the high dislocation density resulting from warm rolling and martensitic transformation during cold rolling. In addition, the present work proposes for the first time to apply such dislocation engineering concept to the quenching and partitioning （Q＆P） steel by incorporating a warm rolling process prior to the quenching step, with an aim to improve simultaneously the strength and ductility of the Q＆P steel. It is believed that dislocation engineering provides a new promising alloy design strategy for producing novel strong and ductile alloys.

关键词： Alioy design Dislocation engineering D&P steel Q&P steel TRIP Warm rolling