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sintered Fe-0.8%c-1.0%si-0.4%cu P/M steel Preform Behaviour During cold Upsetting

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Journal of Iron and steel Research(International) 2008年第5期15卷 81-87页

作者： A Rajeshkannan K s Pandey s shanmugam R Narayanasamy Thiagarajar college of Engineering ThiruparankundramMadurai 625015Tamil NaduIndia Maulana Azad National Institute of Technology Bhopal 462007Madhya PradeshIndia Department of Mechanical Engineering National Institute of TechnologyTiruchirappalli 620015Tamil NaduIndia Department of Production Engineering National Institute of TechnologyTiruchirappalli 620015Tamil NaduIndia

cold upsetting experiments were carried out on sintered Fe 0.8%c1.0%si-0. 4%cu steel preforms in order to evaluate their deformation characteristics. Powder preforms of 86 % of theoretical density, with two different ratios of height to diameter, were prepared using a suitable die set assembly on a 1.0 MN capacity hydraulic testing machine. sintering was carried out in an electric muffle furnace for 1.5 h at 1 150 ℃. Each sintered compact was subjected to incremental loading of 0.04 MN under dry friction condition till a crack appeared at the free surfaces. The experimental results were critically analysed, the stress as a function of strain and densification was obtained, then the work hardening behaviour was analyzed. It has been found that in the process of enhancing densification, strength and strain hardening is also induced during upsetting, but the work hardening behaviour is not homogenously enhanced against strain and densification.

关键词： cold upsetting stress height strain densification work hardening behaviour

Global operational land imager Landsat-8 reflectance-based active fire detection algorithm

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International Journal of Digital Earth 2018年第2期11卷 154-178页

作者： s.s.Kumar D.P.Roy Plant and Environmental sciences New Mexico State UniversityLas CrucesNMUSA Geospatial sciences center of Excellence South Dakota State UniversityBrookingsSDUSA

A global operational land imager(GOLI)Landsat-8 daytime active fire detection algorithm is *** utilizes established contextual active fire detection approaches but takes advantage of the significant increase in fire reflectance in Landsat-8 band 7(2.20μm)relative to band 4(0.66μm).The detection thresholds are fixed and based on a statistical examination of 39 million non-burning Landsat-8 ***-temporal tests based on band 7 reflectance and relative changes in normalized difference vegetation index in the previous six months are used to reduce commissions *** probabilities of active fire detection for the GOLI and two recent Landsat-8 active fire detection algorithms are simulated to provide insights into their performance with respect to the fire size and *** algorithms are applied to 11 Landsat-8 images that encompass a range of burning conditions and *** and omission errors are assessed by visual interpretation of detected active fire locations and by examination of the Landsat-8 images and higher spatial resolution Google Earth *** GOLI algorithm has lower omission and comparable commission errors than the recent Landsat-8 active fire detection *** GOLI algorithm has demonstrable potential for global application and is suitable for implementation with other Landsat-like reflective wavelength sensors.

关键词： Earth observation remote sensing visible/infrared remote sensing

REVIEW OF PARTIcLE PHYsIcs Particle Data Group

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chinese Physics c 2016年第10期40卷 1-28页

作者： c. Patrignani (Particle Data Group) Chinese Physics C 40 100001 (2016)

The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,062 new measurements from 721 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. All the particle properties and search limits are listed in summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, cosmology, Particle Detectors, colliders, Probability and statistics. Among the 117 reviews are many that are new or heavily revised, including new reviews on Pentaquarks and Inflation. The complete Review is published online in a journal and on the website of the Particle Data Group （http：//pdg. lbl. gov）. The printed PDG Book contains the summary Tables and all review articles but no longer includes the detailed tables from the Particle Listings. A Booklet with the summary Tables and abbreviated versions of some of the review articles is also available.

关键词： PROTON-PROTON cOLLIsIONs DEEP-INELAsTIc scATTERING HIGGs-BOsON PRODUcTION TO-LEADING-ORDER sTRONG-cOUPLING cONsTANT ANOMALOUs MAGNETIc-MOMENT PRODUcTION cROss-sEcTION GRAND UNIFIED THEORIEs QUARK-PAIR PRODUcTION ELEcTROWEAK sYMMETRY-BREAKING

Finite element models to represent seismic activity of the Indian plate

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Geoscience Frontiers 2017年第1期8卷 81-91页

作者： s.Jayalakshmi s.T.G.Raghukanth Department of civil Engineering Indian Institute of TechnologyMadras 600036India

Quantification of seismic activity is one of the most challenging problems faced by earthquake engineers in probabilistic seismic hazard analysis. currently, this problem has been attempted using empirical approaches which are based on the regional earthquake recurrence relations from the available earth- quake catalogue. However, at a specified site of engineering interest, these empirical models are asso- ciated with large number of uncertainties due to lack of sufficient data. Due to these uncertainties, engineers need to develop mechanistic models to quantify seismic activity. A wide range of techniques for modeling continental plates provides useful insights on the mechanics of plates and their seismic activity. Among the different continental plates, the Indian plate experiences diffused seismicity. In India, although Himalaya is regarded as a plate boundary and active region, the seismicity database indicates that there are other regions in the Indian shield reporting sporadic seismic activity. It is expected that mechanistic models of Indian plate, based on finite element method, simulate stress fields that quantify the seismic potential of active regions in India, This article explores the development of a finite element model for Indian plate by observing the simulated stress field for various boundary conditions, geological and theological conditions. The study observes that the magnitude and direction of stresses in the plate is sensitive to these conditions, The numerical analysis of the models shows that the simulated stress field represents the active seismic zones in India.

关键词： Indian platePlate driving forcesFinite element modeseismicitycratons

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弹道式再入弹头参数设计的计算机程序

导弹与航天运载技术(中英文) 1981年第11期 23-32页

作者： s.s.Melvin D.c.Mausser 杨炳尉

已研制出一个计算机程序,供快速进行弹道式再入弹头的参数设计之用。它能定出一个(或是一类)弹头,使它们在一组给定的设计约束条件内,达到最小重量。本文介绍了使用这个程序的具体技术及计算结果。输入数据包括:弹头的性能特征参数、弹... 详细信息

已研制出一个计算机程序,供快速进行弹道式再入弹头的参数设计之用。它能定出一个(或是一类)弹头,使它们在一组给定的设计约束条件内,达到最小重量。本文介绍了使用这个程序的具体技术及计算结果。输入数据包括:弹头的性能特征参数、弹头构架的特征参数、弹头内部组装要求、弹头重量及几何方面的约束条件。输出数据描绘出满足上述输入约束条件的最终弹头。输出数据中包括弹头的重量和重心、弹头构架的确定、以及弹头内部组装安排。此外,还提供出初始再入条件下和弹着点条件下的重量、重心、弹头的几何外形、静稳定裕度和弹道系数。本程序对设计先进弹头特别有用,目为它能很快地定出满足初始设计要求的那种弹头。

关键词：弹头弹道系数半锥角参数设计计算机程序

EFFEcT OF sEN DEsIGN ON sURFAcE FLUcTUATION AND sOLIDIFYING sHELL IN sLAB MOLD AND ITs OPTIMIZATION

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Acta Metallurgica sinica(English Letters) 2008年第5期21卷 341-350页

作者： D.F. Wu s.s. cheng school of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China

Turbulent flow and heat transfer coupled with solidification in slab continuous casting mold was studied by numerical simulation method. Volume of fluid （VOF） model is used to solve steel-air two-phase flow problem and enthalpy-porosity scheme is introduced to solve the fluid flow problem involving solidification. contributions of various nozzle port angles and port widths and heights on the free surface fluctuation and the thickness of solidifying shell in slab mold were particularly investigated, based on which the structure of submerged entry nozzle was optimized. Flow inside the common nozzle port cannot fill the entire outlet area, having a recirculation in the upper portion of the port, which is enlarged for the nozzle port with both larger height and width. Results show that the flow in mold cavity is mainly controlled by the nozzle port angle. The increase of the angle of upper face of the port to shape a roughly streamlined inner-wall improves the effective area fraction of the nozzle, resulting in less jet impingement, weaker free surface turbulence and thicker solidifying steel shell.

关键词： slab continuous casting submerged entry nozzle Optimization Numerical simulation

Nanoparticle shape Effect on a sodium–Alginate Based cu–Nanofluid under a Transverse Magnetic Field

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Fluid Dynamics & Materials Processing 2023年第7期19卷 1875-1896页

作者： samia Rani H.A.M.Al–sharifi Mohammad s.Zannon Abid Hussanan Zafar Ullah Department of Mathematics Division of Science and TechnologyUniversity of EducationLahore54000Pakistan Department of Mathematics College of Education for Pure SciencesUniversity of KerbalaKerbala1125Iraq Department of Mathematics Faculty of ScienceTafila Technical University(TTU)Al-IessTafila66110Jordan

sodium-alginate(sA)based nanofluids represent a new generation of fluids with improved performances in terms of heat *** work examines the influence of the nanoparticle shape on a non–Newtonian viscoplastic cu–nanofluid pertaining to this *** particular,a stretching/shrinking sheet subjected to a transverse magnetic field is *** proposed cu–nanofluid consists of four different nanoparticles having different shapes,namely bricks,cylinders,platelets,and blades dispersed in a mixture of sodium alginate with Prandtl number Pr=*** similarity transformations are employed to reduce non–linear PDEs into a system of ODEs and these equations and related boundary conditions are solved numerically by means of a Runge–Kutta–Fehlberg(RKF)***,analytical solutions are obtained through the application of a MAPLE built–in differential equation solver(Dsolve).The behavior of prominent parameters against velocity and temperature is *** is found that the temperature increases for all shapes of nanoparticles with the viscoplastic parameter and the Eckert number.

关键词： Nanofluid magnetic field viscous dissipation Dsolve

Matrix Representation of Recursive sequences of Order 3 and Its Applications

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Journal of Mathematical Research with Applications 2018年第3期38卷 221-235页

作者： Tianxiao HE Jeff H.-c.LIAO Peter J.-s.sHIUE Department of Mathematics Illinois Wesleyan University Department of Mathematics Taiwan Normal University Department of Mathematical sciences University of Nevada

Here presented is a matrix representation of recursive number sequences of order 3 defined by a;= pa;+ qa;+ ra;with arbitrary initial conditions a;, a;= 0, and a;and their special cases of Padovan number sequence and Perrin number sequence with initial conditions a;= a;= 0 and a;= 1 and a;= 3, a;= 0, and a;= 2, respectively. The matrix representation is used to construct many well known and new identities of recursive number sequences as well as Pavodan and Perrin sequences.

关键词： recursive number sequence of order 3 matrix representation of recursive number sequences Padovan number sequence Perrin number sequence Tribonacci polynomial sequence

Metasomatic stages and scapolitization Effects on chemical composition of Pasveh Pluton,NW Iran

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Journal of Earth science 2011年第5期22卷 619-631页

作者： s A Mazhari s Amini J Ghalamghash F Bea Department of Geology Payame Noor University Department of Geology Tarbiat Moallem University Geological survey of Iran Department of Mineralogy and Petrology Fuentenueva CampusUniversity of Granada

Pasveh gabbros are mafic component of a plutonic complex in the northwest sanandaj- sirjan Zone. These cumulative rocks are composed of plagioclase and calcic clinopyroxene （cpx）, which yield unusually high caO （〉19 wt.%） in whole-rock chemistry. Petrographical and geochemical data suggest that Pasveh gabbros can be divided into two groups： free scapolite and scapolite-bearing gabbros. The second group has higher Na20, K20, and P205 relative to free scapolite ones and is enriched in LIL （large ion lithophile） and HFs （high field strength） elements. Two stages of metasomatism affected the primary composition of mafic rocks. Firstly, high temperature reaction caused to invert primary high Ti clinopyroxene to low Ti cUnopyroxene＋high Ti amphibole. This reaction was extensive and included all gabbroic samples. Hydrothermal fluids involved in this process can be derived from dehydration reactions of country rocks or from other magmas incorporated in the formation of Pasveh complex pluton. The second metasomatic stage relates to scapolitization of limited parts of gabbroic rocks. An external saline fluid, which is composed of major NacI and minor KcI and P205 components, impacted locally on Pasveh gabbros and formed the second metasomatic stage. Possible sources of Na and cl are primary evaporites or brines, which were present in the host sediments of the gabbros. The carbonate-free nature of these hydrothermal fluids suggests that hydrothermal fluids responsible for the formation of scapolite in Pasveh gabbros are derived from marine evaporitic parentage.

关键词： Iran sanandaj-sirjan Zone Pasveh pluton gabbro metasomatism high Ti cpx low Ti cpx amphibole scapolite.