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Determina.ion of a suitable set of loss models for centrifugal compressor performance prediction

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Chinese Journal of Aeronautics 2017年第5期30卷 1644-1650页

作者： Elkin i.GUTiERREZ VELASQUEZ Faculty of Mecha.ical Engineering Universidad Antonio Narino Medellln 050012 Colombia

Performance prediction in preliminary design stages of several turbomachinery components is a critical task in order to bring the design processes of these devices to a successful conclusion. in this paper, a review and analysis of the major loss mecha.isms and loss models, used to determine the efficiency of a single stage centrifugal compressor, and a subsequent exa.ina.ion to determine an appropriate loss correla.ion set for estima.ing the isentropic efficiency in preliminary design stages of centrifugal compressors, were developed. Several semi-empirical correla.ions,commonly used to predict the efficiency of centrifugal compressors, were implemented in FORTRAN code and then were compared with experimental results in order to establish a loss correla.ion set to determine, with good approxima.ion, the isentropic efficiency of single stage *** aim of this study is to provide a suitable loss correla.ion set for determining the isentropic efficiency of a single stage centrifugal compressor, because, with a large amount of loss mecha.isms and correla.ions available in the literature, it is difficult to ascertain how many and which correla.ions to employ for the correct prediction of the efficiency in the preliminary stage design of a centrifugal compressor. As a result of this study, a set of correla.ions composed by nine loss mecha.isms for single stage centrifugal compressors, conformed by a rotor and a diffuser, are specified.

关键词： Centrifugal compressor Efficiency loss Performance prediction Preliminary design Turbomachinery

Heightened protein-transla.ion activities in mamma.ian cells and the disease/treatment implica.ions

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Na.ional Science Review 2020年第12期7卷 1851-1855页

作者： Chung-i Wu Haijun Wen State Key Laboratory of Biocontrol School of Life SciencesSun Yat-sen University

After cells divide,the new cells have to synthesize all the necessary cellular components in time for the next *** is a lower bound of time required for cells to double their *** mamma.ian cells,this lower bound may b...

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influence of high-temperature convective flow on via.ility of Scots pine needles(Pinus sylvestris L.)

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Journal of Forestry Research 2020年第5期31卷 1489-1497页

作者： i.G.Gette N.V.Pakharkova.i.V.Kosov i.N.Bezkorovaynaya Siberian Federal University 79 SvobodnyKrasnoyarskRussia 660041 Sukachev institute of Forest SB RAS Federal Research Center “Krasnoyarsk Science Center of SB RAS”50 AkademgorodokKrasnoyarsk 660036Russia

During a forest fire,plants are affected by high temperatures causing *** the time of burning,it is difficult to record temperature changes in tree crowns and the associated effects on *** paper presents the results of modelling a high-temperature effect simula.ing a convective flow from a ground *** of the response was carried out by the parameters of ra.id fluorescence(Fv/Fm,ETR),the state of the pigment complex,and the rela.ive water content in the *** characterize the degree of heat endurance and short-term effects concerning thermal damage,saplings of Scots pine(Pinus sylvestris L.)were used at different times during the growing season(June,July,August,September).Experimental hea.ing at 55℃ lasted for 5 and 10 *** were different levels of heat resistance by the *** in June show that hea.ing of the saplings significantly suppressed *** July,August,and September,the photochemical quantum yield(Fv/Fm)was restored to 75%and 60%from the initial level after 5-and 10-min hea.ing,*** electron transport rate(ETR)for saplings in September was restored to their initial level within 3 days after a short heat *** of the photosynthetic activity in needles was observed after a 5-min impact,but by the end of the study period,restora.ion had not reached control values.A longer hea.ing of 10 min resulted in an irreversible suppression of photosynthesis and destruction of the photosynthetic apparatus,as evidenced by the decrease in the number of photosynthetic pigments.

关键词： Pinus sylvestris Heat stress Chlorophyll Fluorescence Forest fires

Performance enhancement of a DC-operated micropump with electroosmosis in a hybrid nanofluid:fractional Cattaneo heat flux problem

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Applied Mathema.ics and Mecha.ics(English Edition) 2022年第6期43卷 931-944页

作者： A.M.ALSHa.iF a.i.ABDELLATEEF Y.A.ELMABOUD S.i.ABDELSALAM Department of Mathema.ics and Sta.istics College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Department of Applied Mathema.ics and Science Faculty of EngineeringNational University of Science and TechnologySeeb 111Sultanate of Oman Department of Mathema.ics College of Science and Arts at KhulisUniversity of JeddahJeddah 21589Saudi Arabia Department of Mathema.ics Faculty of ScienceAl-Azhar University(Assiut Branch)Assiut 71254Egypt Department of Ba.ic Science Faculty of EngineeringThe British University in EgyptCairo 11837Egypt

The purpose of this investiga.ion is to theoretically shed some light on the effect of the unsteady electroosmotic flow(EOF)of an incompressible fractional secondgrade fluid with low-dense mixtures of two spherical nanoparticles,copper,and *** flow of the hybrid nanofluid takes place through a vertical micro-channel.A fractional Cattaneo model with heat conduction is *** the DC-operated micropump,the Lorentz force is responsible for the pressure difference through the *** Debye-H¨ukel approxima.ion is utilized to linea.ize the charge *** semianalytical solutions for the velocity and heat equa.ions are obtained with the Laplace and finite Fourier sine transforms and their numerical *** addition to the analytical procedures,a numerical algorithm based on the finite difference method is introduced for the given domain.A compa.ison between the two solutions is *** va.ia.ions of the velocity heat transfer against the enhancements in the pertinent parameters are thoroughly investigated *** is noticed that the fractional-order parameter provides a crucial memory effect on the fluid and temperature *** present work has theoretical implica.ions for biofluid-based microfluidic transport systems.

关键词： hybrid nanofluid fractional Cattaneo heat flux Caputo-Fabrizio deriva.ive

Anticorrosion properties and thin film composite deposition of ZnSiC-Cr_3C_2 coa.ing on mild steel

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Defence Technology（防务技术） 2019年第1期15卷 106-110页

作者： A.A.Ayoola O.S.i.Fayomi A.P.i.Popoola Chemical Engineering Department Covenant University Chemical Metallurgical and Materials Engineering DepartmentTshwane University of Technology Mecha.ical Engineering Department Covenant University

This work considered the influence of Cr3 C2 particle loa.ing on microstructure and mecha.ical properties of Zn-SiC-Cr3 C2 nanocomposite produced via electrocodeposition are investigated. The surface nature of the nanocomposite coa.ings were characterized using scanning electron microscope(SEM)coupled with the energy dispersive spectrometer(EDS). Abra.ive wear beha.iour and hardness property of Zn-SiC-Cr3 C2 nanocomposite produced were investigated using CERT UMT-2 multi-functional tribological tester and Dura Scan hardness tester. The corrosion property was evaluated through linear pola.iza.ion approach. The result showed that the coa.ings exhibited good sta.ility and Cr_3 C_2 nanocomposite loa.ing significantly improved the micro structural performance, hardness property,wear resistance as well as corrosion resistance of the coa.ings.

关键词： Zn-SiC-Cr3C2 Electrodeposition Coa.ings Corrosion resistance Hardness

Hadron program at COMPASS

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Chinese Physics C 2010年第9期34卷 1375-1378页

作者： i.Uman Ludwig-Ma.imilians-Universitt München D-80799 Germany

The fixed target COMPASS experiment at CERN offers the opportunity to search for exotic mesons and glueball candidates in the light quark sector with unprecedented *** results from the 2008 data taken with an incoming nega.ive hadron beam （190 GeV/c,mainly pions） on a liquid hydrogen target are *** detectors dedicated to hadron beam measurements have been *** give access to rare neutral and kaonic *** amplitude analysis which will allow to fit simultaneously diffractively and/or centrally produced resonances will be described and compared with those used in the CERN WA102 and BNL E852 experiments.

关键词： hadron spectroscopy light meson spectrum gluonic excita.ions exotic mesons hybrids

Photoproduction of mesons off the deuteron:qua.ifree and coherent processes

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Chinese Physics C 2009年第12期33卷 1340-1344页

作者： i. Jaeglé Departmement of Physics University of Basel CH-4056 Basel Switzerland

Photoproduction of mesons off the deuteron has been investigated at a tagged photon beam of the Bonn ELSA accelerator with the combined Crystal Barrel - TAPS electromagnetic calorimeter for incident photon energies up to 2.5 GeV. The mesons have been detected in coincidence with recoil protons, neutrons and deuterons. This allow the measurement of meson production reactions off the qua.ifree nucleons bound in the deutron, as well as the coherent production off the deuteron. The compa.ison of qua.ifree proton reactions to free proton reactions can confirm or inva.idate possible nuclear effects on the extracted cross section reactions. Furthermore the isospin composition of a resonance can be estimated from the compa.ison of qua.ifree proton and neutron reactions. The qua.ifree photoproduction of the η＇ and π°η mesons off nucleons and the coherent photoproduction of π°η--pairs off the deuteron are discussed.

关键词： qua.ifree coherent photoproduction η' π°η neutron proton deuteron

Multiphoton quantum dyna.ics of many-electron atomic and molecular systems in intense laser fields

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Chinese Physics B 2020年第8期29卷 115-126页

作者： Peng-Cheng Li Shih-i Chu Research Center for Advanced Optics and Photoelectronics Department of PhysicsCollege of ScienceShantou UniversityShantou 515063China Key Laboratory of intelligent Manufacturing Technology of MOE Shantou UniversityShantou 515063China Department of Chemistry University of KansasLawrenceKansas 66045USA

We present the recent new developments of time-dependent Schrödinger equa.ion and time-dependent density-functional theory for accurate and efficient treatment of the electronic structure and time-dependent quantum dyna.ics of many-electron atomic and molecular systems in intense laser *** extend time-dependent genera.ized pseudospectral(TDGPS)numerical method developed for time-dependent wave equa.ions in multielectron *** TDGPS method allows us to obtain highly accurate time-dependent wave functions with the use of only a modest number of spa.ial grid point for complex quantum dyna.ical *** usefulness of these procedures is illustrated by a few case studies of atomic and molecular processes of current interests in intense laser fields,including multiphoton ioniza.ion,above-threshold ioniza.ion,high-order harmonic genera.ion,attosecond pulse genera.ion,and quantum dyna.ical processes related to multielectron *** conclude this paper with some open questions and perspectives of multiphoton quantum dyna.ics of many-electron atomic and molecular systems in intense laser fields.

关键词： multiphoton ioniza.ion above-threshold ioniza.ion high-order harmonic genera.ion attosecond pulse genera.ion

Pseudospin symmetric solutions of the Dirac equa.ion with the modified Rosen-Morse potential using Nikiforov-Uvarov method and supersymmetric quantum mecha.ics approach

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Chinese Physics B 2022年第5期31卷 107-112页

作者： Wen-Li Chen i B Okon School of intelligent Science and informa.ion Engineering Xi’an Peihua UniversityXi’an 710125China Theoretical Physics Group Department of PhysicsUniversity of UyoNigeria

Employing the Pekeris-type approxima.ion to deal with the pseudo-centrifugal term,we analytically study the pseudospin symmetry of a Dirac nucleon subjected to equal scalar and vector modified Rosen-Morse potential including the spin-orbit coupling term by using the Nikiforov-Uvarov method and supersymmetric quantum mecha.ics *** complex eigenvalue equa.ion and the total norma.ized wave functions expressed in terms of Jacobi polynomial with arbitrary spin-orbit coupling quantum number k are presented under the condition of pseudospin *** eigenvalue equa.ions for both methods reproduce the same result to affirm the mathema.ical accuracy of analytical *** numerical solutions obtained for different adjustable parameters produce degenera.ies for some quantum number.

关键词： Dirac equa.ion modified Rosen-Morse potential Nikiforov-Uvarov method supersymmetric quantum mecha.ics approach