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Effect of coaxial laser cladding parameters on bead formation

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international Journal of minerals,metallurgy and materials 2017年第5期24卷 550-556页

作者： A.i.Noskov A.Kh.Gilmutdinov R.m.Yanbaev Kazan National Research Technical University 10 Karl Marx Str. Kazan 420111 Republic of Tatarstan Russian Federation

We investigated the shape and morphology of nickel-based powder particles (Sulzer metco) and coatings produced by laser gas-powder deposition onto steel substrates. Laser deposition was performed using an LC-10 iPG-Photonics laser complex equipped with a 10-kW fiber laser. The shape and microstructure of the samples were studied using optical and electronic microscopy and X-ray diffraction analysis. The results showed that the deposition speed and laser power significantly influenced the shape and size of the beads. The depth of diffusion of nickel into the steel substrate after deposition was less than 20 μm; the microstructure of the resulting coating was fcc Fe3Ni. As a result, detailed information about the form and shape of the filler powder, modes of its deposition, and the resulting coating structure was obtained; this information is important for the production of high-quality products by additive technologies.

关键词： laser cladding additive manufacturing microstructure morphology bead formation

Epistasis and maternal Effect in Resistance to Puccinia coronata ***. avenae Eriks in Oats(Avena sp.)

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Agricultural Sciences in China 2010年第10期9卷 1462-1466页

作者： Bnejdi F Hammami i Allagui m B Saadoun m el Gazzah m Laboratoire de Génétique et Biométrie Faculté des Sciences de Tunis Université Tunis institut National de la Recherche Agronomique de Tunisie(iNRAT) Rue Hadi Karray

The objective of this paper was to investigate the mode of heredity for resistance in oats （Avena sp.） to crown rust caused by Puccinia coronata Cda. f. sp. avenae Eriks, Eight generations of 2 crosses were used to estimate genetic effects and narrow-sense heritability （NSH）. Separate generation means analysis （GmA） indicated a complex gene action controlling this trait with additive, dominance, epistatic and maternal effects （mE）. The genetic model which assumed no epistasis and no mE did not accurately describe the resistance to P. coronata. in both crosses, the digenic epistatic model with mE was sufficient to explain variation in generation means for isolate CRec58 and isolate CRec46. Additive dominance and epistatic components were negative in most cases, suggesting that gene effects contributed more to the resistance than to the susceptibility. The estimated values of NSH were 15-99% depending upon the cross and isolates. The results indicated that appropriate choice of maternal parent and recurrent selection would increase resistance to crown rust in oats.

关键词： epistasis heritability maternal effect resistance

mφller Energy-momentum Complex in General Relativity for Higher Dimensional Universes

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Chinese Physics Letters 2007年第7期24卷 1821-1824页

作者： m. Aygiin S. Aygiin i. Yflmaz H. Baysal i. Tarhan Department of Physics Art and Science Faculty Canakkale Onsekiz Mart University 17020 Canakkale Thrkey Department of Secondary Science and mathematics Education Faculty of Education~anakkale Onsekiz Mart University 17100 Canakkale Turkey

Using the mφ11er energy-momentum definition in general relativity （GR） we calculate the total energy-momentum distribution associated with （n 4- 2）-dimensional homogeneous and isotropic model of the universe. it is found that total energy of m^ller is vanishing in （n 4- 2） dimensions everywhere but n-momentum components of mφ11er in （n 4- 2） dimensions are different from zero. Also, we evaluate the static Einstein Universe, FRW universe and de Sitter universe in four dimensions by using （n 4- 2）-type metric, then calculate the mφ11er energy-momentum distribution of these spacetimes. However, our results are consistent with the results of Banerjee and Sen, Xulu, Radinschi, Vargas, Cooperstock-israelit, A ygiin et al., Rosen, and Johri et al. in four dimensions.

关键词： Energy-momentum Relativity Dimensional

A scale-integrated exploration model for orogenic gold deposits based on a mineral system approach

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Geoscience Frontiers 2020年第3期11卷 719-738页

作者： David i.Groves m.Santosh Liang Zhang Orebusters Pty Ltd Gwelup6018WAAustralia State Key Laboratory of Geological Processes and mineral Resources China University of Geosciences(Beijing)Beijing100083China Dept.of Earth Sciences University of AdelaideSA5005Australia Yonsei Frontier Lab Yonsei UniversitySeoul120-749Republic of Korea

Concept-based orogenic gold exploration requires a scale-integrated approach using a robust mineral system *** genetic hypotheses for orogenic gold deposits that involve near-surface or magmatic-hydrothermal fluids are now negated in terms of a global mineral system *** models involve metamorphic fluids,but the fluid source has been *** metamorphic-fluid models are most widely-accepted but there are serious problems for Archean deposits,and numerous Chinese provinces,including Jiaodong,where the only feasible fluid source is *** all orogenic gold deposits define a coherent mineral system,there are only two realistic sources of fluid and gold,based on their syn-mineralization geodynamic *** are from devolatilization of a subducted oceanic slab with its overlying gold-bearing sulfide-rich sedimentary package,or release from mantle lithosphere that was metasomatized and fertilized during a subduction event,particularly adjacent to craton *** this model,CO_2 is generated during decarbonation and S and ore-related elements released from transformation of pyrite to pyrrhotite at about 500 ℃.This orogenic gold mineral system can be applied to conceptual exploration by first identifying the required settings at geodynamic to deposit *** these settings,it is then possible to define the critical gold mineralization processes in the system:fertility,architecture,and *** geological parameters that define these processes,and the geological,geophysical and geochemical proxies and responses for these critical parameters can then be *** the geodynamic to province scales,critical processes include a tectonic thermal engine and deep,effective,fluid plumbing system driven by seismic swarms up lithosphere-scale faults in an oblique-slip regime during uplift late in the orogenic cycle of a convergent *** the district to deposit scale,the important processes are fluid focussing into regio

关键词： mineral systems Orogenic gold Sub-crustal fluids Convergent margins Gold exploration

A case study of the stability of a non-typical bleeder entry system at a *** mine

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international Journal of mining Science and Technology 2020年第1期30卷 25-31页

作者： T.m.Klemetti m.A.Van Dyke i.B.Tulu D.Tuncay NiOSH Pittsburgh mining Research Division Pittsburgh 15236USA Department of mining Engineering West Virginia UniversityMorgantown 26505USA

Longwall abutment loads are influenced by several factors,including depth of cover,pillar sizes,panel dimensions,geological setting,mining height,proximity to gob,intersection type,and size of the *** does proximity to the gob affect pillar loading and entry condition?Does the gob influence depend on whether the abutment load is a forward,side,or rear loading?Do non-typical bleeder entry systems follow the traditional front and side abutment loading and extent concepts?if not,will an improved understanding of the combined abutment extent warrant a change in pillar design or standing support in bleeder entries?This paper details observations made in the non-typical bleeder entries of a moderate depth longwall panel—specifically,data collected from borehole pressure cells and roof extensometers,observations of the conditions of the entries,and numerical modeling of the bleeder entries during longwall *** primary focus was on the extent and magnitude of the abutment loading experienced due to the extraction of the longwall *** to the layout of the longwall panels and bleeder entries,the borehole pressure cells(BPCs)and roof extensometers did not show much change due to the advancing of the first ***,they did show a noticeable increase due to the second longwall advancement,with a maximum of about 4 mPa of pressure increase and 5mmof roof *** observations of the conditions showed little to no change from before the first longwall panel extraction began to when the second longwall panel had been advanced more than 915 *** pillar spalling was observed on the corners of the pillars closest to the longwall gob as well as an increase in water in the *** addition to the observations and instrumentation,numerical modeling was performed to validate modeling procedures against the monitoring results and evaluate the bleeder *** Consulting Group’s FLAC3D numerical modeling software was used to evaluate the bl

关键词： Abutment loading Longwall instrumentation Bore hole pressure cells Pillar loading Yield pillar Bleeder pillar

Control of animal brucellosis: the malaysian experience

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Asian Pacific Journal of Tropical medicine 2016年第12期9卷 1111-1115页

作者： m.Zamri-Saad m.i.Kamarudin Research Centre for Ruminant Diseases Faculty of Veterinary MedicineUniversiti Putra Malaysia Department of Veterinary Services malaysia Ministry of Agriculture and Agro-based Industry

Brucellosis is a zoonotic disease characterized by reproductive failure in animals and undulent fever in humans. in cattle, it is caused by Brucella abortus while in goats by Brucella melitensis, the main cause of brucellosis in humans. Brucellosis in livestock has been associated with importation of animals from breeder herd of unknown disease status. The prevalence of bovine brucellosis Brucella abortus in 2014 ranged between 1%-2% in Thailand and indonesia, and 4%-5% in malaysia and myanmar. Prevalence of goat brucellosis Brucella melitensis is approximately 1% in malaysia and Thailand. ‘Test-and-slaughter' is the general policy against brucellosis adopted by most ASEAN countries to eradicate the disease. Under this program, the Rose Bengal Plate Test(RBPT) is used as the screening test to identify infected farm/herd while the Complement Fixation Test(CFT) is the confirmatory test. The test-and-slaughter eradication strategy that was implemented since 1979 had managed to keep the prevalence rate to less than 5%, from 3.3% in 1979, 0.23% in 1988, 1% in 1998 and 5% in 2016. The test-and-slaughter program seemed effective in reducing the prevalence of brucellosis but was unable to eradicate the disease due to several factors, which include failure to locate and identify the remaining affected animals and to control their movement, importation of breeder animals from non-brucellosis free countries and lack of participation by the farmers following unrealiable test results. To support the eradication policy, research activities since 1980 s have suggested combinations of serological tests to improve diagnosis while surveillance should be focused on hotspots areas. The prevalence can be further reduced by strictly sourcing breeder animals from brucella-free areas or countries.

关键词： Brucellosis Animal Control

Coherence of SH-waves near a semi-circular inclusion-the role of interference and standing waves

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Earthquake Engineering and Engineering Vibration 2021年第3期20卷 535-552页

作者： Z.Tokmechi R.S.Jalali m.D.Trifunac m.i.Todorovska Department of Civil Engineering Faculty of EngineeringUniversity of GuilanP.O.Box 3756RashtIran Department of Civil Engineering University of Southern CaliforniaLos AngelesCalifornia 90089USA Department of Civil Engineering Tianjin UniversityTianjin 300350China

We present examples of a controlled numerical experiment that contribute towards understanding of the physical phenomena that lead to the reduction of coherency of strong earthquake ground *** show examples for separation distance of 100 m between the two points on the ground surface,which is in the range of engineering *** examples illustrate the consequences of:(a)standing waves that result from interference of the incident and reflected waves from a near vertical contrast in material properties,(b)standing waves within a concave inhomogeneity(a semi-circular valley in our examples),and(c)smaller motions in the diffraction zone,behind the *** show that it is possible to reduce coherency,to the extent observed for recorded strong earthquake ground motion,even by a single inclusion in a half space,for incident ground motion that is *** also illustrate the combined effects of geometric spreading and finite fault width,superimposed on the otherwise dominating effects caused by *** examples show reduction of coherence for specific angles of incident waves,while,for other angles of incidence,the coherence remains essentially equal to one.

关键词： coherence of strong motion coherence in the presence of standing waves coherence caused by interference reduction of coherence for radiation from large faults

morphology,structure and magnetic behavior of orthorhombic and hexagonal HoFeO_(3)synthesized via solution combustion approach

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Journal of Rare Earths 2022年第2期40卷 296-301,I0004页

作者： K.D.martinson i.S.Kondrashkova m.i.Chebanenko A.S.Kiselev T.Yu Kiseleva V.i.Popkov ioffe institute 26 PoliteknicheskayaSL Petersburg194021Russia Saint Petersburg State institute of Technology 26 MoskovskySt.Petersburg190013Russia Faculty of Physics M.V.Lomonosov State UniversityLeninskie CoryMoscow119991Russia

Nanostructured HoFeO_(3)powders were obtained by solution combustion method at various glycinenitrate ratios(G/N=0.2,0.4,...,1.4).According to X-ray powder diffractometry data,the presence of two modifications of HoFeO_(3)in the synthesized samples was established:orthorhombic(Pbnm)and hexagonal(P63/mmc).The crystallite size of the obtained compositions varies from 62±6 to 29±3 nm,depending on the G/N *** magnetic structure studies,it is found that HoFeO_(3)obtained with a stoichiometric amount of glycine in the reaction solution is in the magnetically ordered state and is represented by a sextet with quadrupole splitting(QS)=0 mm/s,isomeric shift(iS)=0.36 mm/s and effective field strength(Heff)=497 *** to the results of vibrational magnetometry,it is found that the orthoferrites obtained have a ferromagnetic structure,the main parameters of which(ms,mr and Hc)systematically change with a change in the redox ratio of the reaction mixture and,as a consequence,their phase composition,and reach maximum values at a G/N ratio=*** the samples obtained with a significant excess and lack of glycine(G/N=0.2 and 1.4),despite their amorphous nature,hysteresis loops characteristic of the ferromagnetic state of the substance is *** is hopeful to obtain a pure hexagonal modification of HoFeO_(3)via heat treatment on amorphous products of glycine-nitrate combustion.

关键词： Crystal structure Rare earth compounds Perovskites Nanomaterials magnetic materials

Tribological Characterization of Commercial Pure Titanium Processed by multi-Directional Forging

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Acta metallurgica Sinica(English Letters) 2019年第7期32卷 857-868页

作者： i. Ansarian m. H. Shaeri m. Ebrahimi P. minarik Department of materials Science and Engineering Imam Khomeini International University (IKIU) P.O. Box 34148-9681 & Qazvin Iran Department of mechanical Engineering Faculty of Engineering University of Maragheh P.O. Box 55136-533 Maragheh Iran Department of Physics of materials Faculty of Mathematics and Physics Charles University Prague Czech Republic

This work discusses tribological properties of commercial pure (CP) titanium processed by multi-directional forging (mDF) up to six passes at room temperature and 220 ℃. For this purpose, wear test was conducted by dry sliding pin-on-disk method on the initial and ultrafine grained samples using different stress magnitudes of 1, 1.5 and 2 mPa. The results showed that wear resistance of CP titanium increases after the first pass of mDF in comparison with the initial condition, irrespective of the applied normal stress. For example, the average wear rate of mDFed samples was decreased about 30% and 24%, after first pass at room temperature and 220 ℃, respectively. However, average wear rate of the samples processed by six mDF passes was reduced about 40% at lower normal loads;it was increased about 9% at higher ones as compared to the initial condition. it was also found that the dominated wear mechanisms were abrasive and delaminated at the lower stresses, while the delamination mechanism was intensified and a slight adhesion was observed during the higher applied normal loads.

关键词： multi-directional forging Commercial pure titanium Tribological behavior Wear mechanisms