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Effect of Welding Processes and consumables on Tensile and impact Properties of High Strength Quenched and Tempered Steel Joints

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Journal of iron and Steel Research(international) 2008年第6期15卷 87-94页

作者： g Magudeeswaran V Balasubramanian g Madhusudhan Reddy T S Balasubramanian center for Advanced Materials Joining and Research(cEMAJOR) Department of Manufacturing EngineeringAnnamalai University Metal Joining Sec.ion Defence MetallurgicalResearch Laboratory Special Vehicles Division Combat Vehicles Research and Development Establishment

Quenched and tempered steels are prone to hydrogen induced crac.ing in the heat affected zone after welding. The use of austenitic stainless steel consumables to weld the above steel was the only available remedy because of higher solubility for hydrogen in austenitic phase. in this investigation, an attempt was made to determine a suitable consumable to replace expensive austenitic consumables. Two different consumables, namely, austenitie stain less steel and low hydrogen ferritic steel, were used to fabricate the joints by shielded metal are welding （SMAW） and flux cored arc welding （FcAW） processes. The joints fabricated by using low hydrogen ferritic steel consumables showed superior transverse tensile properties, whereas joints fabricated by using austenitic stainless steel consumables exhibited better impact toughness, irrespec.ive of the welding process used. The SMAW joints exhibited superior mechanical and impact properties, irrespec.ive of the consumables used, than their FcAW counterparts.

关键词： shielded metal arc welding process flux cored arc welding process austenitie stainless steel low hydro gen ferritic steel transverse tensile property impact toughness

Windowing Techniques, the Welch Method for improvement of Power Spectrum Estimation

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computers, Materials & continua 2021年第6期67卷 3983-4003页

作者： Dah-Jing Jwo Wei-Yeh chang i-Hua Wu Department of communications Navigation and Control EngineeringTaiwan Ocean UniversityKeelung202-24TaiwanChina innovative Navigation Technology Ltd. Kaohsiung801TaiwanChina

This paper revisits the characteristics of windowing techniques with various window func.ions involved,and successively investigates spectral leakage mitigation utilizing the Welch *** discrete Fourier transform(DFT)is ubiquitous in digital signal processing(DSP)for the spectrum analysis and can be efciently realized by the fast Fourier transform(FFT).The sampling signal will result in distortion and thus may cause unpredictable spectral leakage in discrete spectrum when the DFT is *** is implemented by multiplying the input signal with a window func.ion and windowing amplitude modulates the input signal so that the spectral leakage is evened ***,windowing processing reduces the amplitude of the samples at the beginning and end of the *** addition to selec.ing appropriate window func.ions,a pretreatment method,such as the Welch method,is effec.ive to mitigate the spectral *** to the noise caused by imperfect,nite data,the noise reduc.ion from Welch’s method is a desired *** nonparametric Welch method is an improvement on the periodogram spectrum estimation method where the signal-to-noise ratio(SNR)is high and mitigates noise in the estimated power spectra in exchange for frequency resolution *** periodogram technique based on Welch method is capable of providing good resolution if data length samples are appropriately *** design of nite impulse response(FiR)digital lter using the window technique is rstly *** inuence of various window func.ions on the Fourier transform spectrum of the signals is *** on spectral resolution based on the traditional power spectrum estimation and various window-func.ion-based Welch power spectrum estimations is presented.

关键词： Window func.ions Welch method discrete Fourier transform spectral leakage

Forming of Space charge Wave with Broad Frequency Spectrum in Helical Relativistic Two-Stream Electron Beams

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c.inese Physics Letters 2017年第7期34卷 150-154页

作者： A.Lysenko i.Volk A.Serozhko O.Rybalko Department of Applied Mathematics and complex Systems Modelling Sumy State University Sumy 40007 Ukraine Department of Electrical Engineering Technical University of Denmark Kgs. Lyngby 2800 Denmark

We elaborate a quadratic nonlinear theory of plural interac.ions of growing space charge wave （ScW） harmonics during the development of the two-stream instability in helical relativistic electron beams. it is found that in helical two-stream electron beams the growth rate of the two-stream instability increases with the beam entrance angle. An ScW with the broad frequency spectrum, in which higher harmonics have higher amplitudes, forms when the frequency of the first ScW harmonic.is much less than the c.itical frequency of the two-stream instability. For helical electron beams the spectrum expands with the increase of the beam entrance angle. Moreover, we obtain that utilizing helical electron beams in multiharmonic two-stream superheterodyne free-electron lasers leads to the improvement of their amplification characteristics, the frequency spectrum broadening in multiharmonic signal generation mode, and the reduc.ion of the overall system dimensions.

关键词： ScW Forming of Space charge Wave with Broad Frequency Spectrum in Helical Relativistic Two-Stream Electron Beams

Microwave drying kinetics and quality characteristics of corn

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international Journal of Agricultural and Biological Engineering 2013年第1期6卷 90-99页

作者： Songül gürsoy Ruplal choudhary Dennis g.Watson Department of Agricultural Mac.inery Faculty of AgricultureDicle University21280DiyarbakirTurkey Department of Plant Soil and Agricultural SystemsMC 4415Southern Illinois UniversityCarbondaleIL 62901 USA

in recent years,microwave(MW)drying has gained popularity as an alternative drying method for a wide variety of food and agricultural products because of increasing concerns over product quality and produc.ion ***,the determination of drying kinetics that accurately desc.ibes microwave drying characteristics is crucial for the optimization of operating parameters,performance improvement of the drying system and product *** objec.ive of this study was to investigate the drying kinetics and the quality characteristics of corn kernels,especially the effects of different initial moisture contents(18.3%,26.3%,34.3%and 42.3%db),MW power levels(70,175 and 245 W)and exposure time(80 s and 120 s)on the drying kinetics,drying rate and various key quality *** results indicated that the increased drying rate at higher power levels(P3,245 W)reduced the drying time considerably but increased stress crack index and reduced *** addition,it reduced bulk density,true density and thousand grain weight(TgW).The germination rate of corn was the highest at MW power level P1(70 W),with the lowest drying rate and observed to decrease with increase in initial moisture *** reduc.ion in exposure time decreased stress crack index and increased germination rate,bulk density and true *** correlation analysis among drying rate,germination,stress-crack index(Sci),bulk density,true density and TgW showed that increasing drying rate could lead to an increase in Sci and decrease in germination,bulk density and true density.

关键词： microwave drying corn stress-crack germination bulk density true density

Dc Plasma Technology Applied to Powder Metallurgy: an Overview

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Plasma Science and Technology 2013年第1期15卷 70-81页

作者： A. N. KLEiN R. P. cARDOSO H. c. PAVANATi c. BiNDER A. M. MALiSKA g. HAMMES D. FUSAO A. SEEBER S. F. BRUNATTO J. L. R. MUZART LabMat (Materials Laboratory) Departamento de Engenharia Mec~nica Universidade Federal de Santa Catarina (UFSC) 88040-900 FlorianSpolis - SC Brazil Departamento de Engenharia Mecanica Universidade Federal do Parana (UFPR) 81531-990 Curitiba- PR Brazil Departamento Academico de Metal-Mecanica Instituto Federal de Santa Catarina (IFSC) 88020-300 Florianopolis - SC Brazil Universidade Tecnologica Federal do Parana (UTFPR) 84016-210 Ponta Grossa - PR Brazil centro de ciencia e Tecnologia Universidade de Caxias do Sul 95070-560 Caxias do Sul- RS Brazil

Dc plasma is a very promising technology for processing different materials, and is becoming especially interesting when low environmental impact and high-performance treatments are needed. Some of the intrinsic characteristics of Dc plasma technology, which make it suitable for powder metallurgy （PM） and powder injec.ion molding （PiM） parts produc.ion, are low- pressure processing and plasma environment high reac.ivity. Moreover it can be considered as a highly competitive green technology. in this work, an overview of some of the important Dc plasma techniques applied to PM and PiM parts processing is presented. Emphasis is given to the desc.iptions of the main characteristics and the technique potentials of plasma-assisted nitriding, plasma-assisted thermal debinding, plasma-assisted sintering, and simultaneously plasma-assisted sintering and surface alloying. The aspects presented and discussed in this paper indicate that Dc plasma processes are promising and competitive techniques for PM and PiM parts processing.

关键词： powder metallurgy Dc glow discharge plasma nitriding plasma sintering,plasma-assisted thermal debinding surface alloying

Simultaneous scheduling of mac.ines and automated guided vehicles in flexible manufacturing systems using genetic algorithms

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Journal of central South University 2011年第5期18卷 1473-1486页

作者： i.A.chaudhry S.Mahmood M.Shami National University of Sciences & Technology (NUST) IslamabadPAKISTAN

The problem of simultaneous scheduling of mac.ines and vehicles in flexible manufacturing system (FMS) was addressed.A spreadsheet based genetic algorithm (gA) approach was presented to solve the problem.A domain independent general purpose gA was used,which was an add-in to the spreadsheet *** adaptation of the propritary gA software was demonstrated to the problem of minimizing the total completion time or makespan for simultaneous scheduling of mac.ines and vehicles in flexible manufacturing *** results are presented for a benchmark with 82 test problems,which have been constructed by other *** ac.ieved results are comparable to the previous *** proposed approach can be also applied to other problems or objec.ive func.ions without changing the gA routine or the spreadsheet model.

关键词：柔性制造系统遗传算法调度机自动导引车电子表格软件车辆调度完工时间完成时间

The technology for detec.ion of gamma-ray burst with gEcAM satellite

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Radiation Detec.ion Technology and Methods 2022年第1期6卷 12-25页

作者： X.Q.Li X.Y.Wen Z.H.An c.c.i Z.chang g.chen c.chen Y.Y.Du M.gao R.gao K.gong D.Y.guo J.J.He D.J.Hou Y.g.Li c.Y.Li g.Li L.Li X.F.Li M.S.Li X.H.Liang X.J.Liu Y.Q.Liu F.J.Lu H.Lu B.Meng W.X.Peng F.Shi X.L.Sun H.Wang J.Z.Wang Y.S.Wang H.Z.Wang X.Wen S.Xiao S.L.Xiong Y.B.Xu Y.P.Xu S.Yang J.W.Yang Q.B.Yi D.L.Zhang Fan Zhang S.N.Zhang c.Y.Zhang c.M.Zhang Fei Zhang X.Y.Zhao Y.Zhao X.Zhou c.S.Zhang J.P.Yu L.chang K.K.Zhang J.Huang Y.M.chen X.B.Han institute of High Energy Physics CASBeijing 100049China Xiangtan University Xiangtan 411105China Beijing Normal University Beijing 110875China Beijing glass Research institute Beijing 101100China innovation Academy for Microsatellites of cAS Shanghai 201204China

introduc.ion The main physical objec.ive of the gEcAM satellite is to detect gamma-ray bursts,which is related to gravitational waves of double compact object *** gEcAM satellite also detects and investigates various bursts of high-energy celestial *** and methods in this study,we designed,developed and calibrated the payload and launched it into orbit with gEcAM *** payload consists of the gamma ray detector(gRD,for detec.ing 4 keV–4 MeV X/γray),the charged particle detector(cPD,for detec.ing 150 keV–5 MeV charged particle),and the electronic box(EBOX).The all-sky field coverage is ac.ieved via two 229-degree large-area satellites positioned 180 degrees apart and are on opposite sides of the *** satellite is equipped with 25 gRDs and 8 cPDs;thus,the satellite can identify charged particle bursts in ***-ray detectors adopt lanthanum bromide crystal technology combined with silicon *** is the first time that this technology was used massively in space *** The gEcAM satellite can quickly determine the direc.ion of gamma-ray bursts(positioning)via indexing and fitting method,while the transmit variability,energy spectrum and direc.ion of the gamma-ray bursts guide subsequent observations through the Beidou-3 RDSS in quasi-real *** will play an important role in the study of high energy celestial bursts.

关键词： gEcAM gamma-ray burst Lanthanum bromide crystal Silicon photomultiplier Beidou short message

Effect of Quantizing Magnetic Field on cyclotron Energy and cyclotron Effec.ive Mass in Size Quantized Films with Non-Parabolic Energy Band

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c.inese Physics Letters 2007年第9期24卷 2639-2641页

作者： B.i.gULiYEV R.F.EMiNBEYLi A. KORKUT Yuzunc.i Yll University Art and Science Faculty Physics Department 65080 Van Turkey

The Fermi energy, cyclotron energy and cyclotron effec.ive mass of degenerate electron gas in a sizeoquantized semiconductor thin film with non-parabolic energy bands are studied. The influences of quantizing magnetic field on these quantities in two-band approximation of the Kane model are investigated. it is shown that the Fermi energy oscillates in a magnetic field. The period and positions of these oscillations are found as a func.ion of film thickness and concentration of electrons. cyclotron energy and cyclotron effec.ive mass are investigated as a func.ion of film thickness in detail The results obtained here are compared with experimental data on gaAs quantum wells.

关键词： coated conductor buffer layer self-epitaxy ceO2

Studies on the anti-asthmatic and antitussive properties of aqueous leaf extract of Bryophyllum pinnatum in rodent species

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Asian Pacific Journal of Tropical Medicine 2013年第6期6卷 421-425页

作者： Edward O Salami Raymond i Ozolua Stephen O Okpo gerald i Eze Dickson O Uwaya Department of Pharmacology and Toxicology Faculty of Pharmacy University of Benin Department of Anatomy School of Basic Medical SciencesUniversity of Benin Department of Pharmacology and Toxicology Faculty of PharmacyUniversity of Benin

Objec.ive:To evaluate the antiasthmatic and antitussive properties of the aqueous leaf extract of Bryophyilum pinnatum {***)(BP) ***:Ovalbiunin-sensilized guinea pigs which were treated with BP for 21 consecutive days were exposed to 0.2%histamine aerosol in a glass *** viscosity,white blood cell and lymphocyte counts and tracheal wall morphometry were *** of cough were counted pre and post acute exposure of extract-treated(X7 d) guinea pigs to 7.5%citric acid aerosol in a *** red expectoration was estimated in mice after 7 d of daily administration of ***:Doses of 200 and 400 mg/kg/day(×21 d) BP significantly increased the time for guinea pigs to experience preconvulsive *** and salbutamol(0.5 mg/kg/day×21 d) reduced mucus viscosity in the sensitized group to values comparable with *** blood cell,lymphocyte counts and tracheal morphometry were not significantly *** doses of BP also significantly reduced the bouts of cough but only 400 mg/kg/day significantly inhibited the amount of phenol red ***:BP has demonstrated antiasthmatic and antitussive properties in these rodent *** properties may underscore its use in Nigerian ethnomedicine.

关键词： Bryophyllum pinnatum Antiasthmatic Antitussive Airway histology