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Performance Analysis of Mini Centrifugal Pump with.Splitter Blades

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j.urnal of Th.rmal Science 2013年第6期22卷 573-579页

作者： T. Sh.gemitsu j. Fukutomi T. Wada h. Sh.noh.ra Institute of Tech.ology and Science The University of Tokushima 2-1 Minamijosanjima-cho Tokushima 770-8506Japan Graduate Sch.ol of Advanced Tech.ology and Science The University of Tokushima 2-1 Minamijosanjima-choTokushima 770-8506 Japan

Design meth.d for a mini centrifugal pump is not establish.d because th. internal flow condition for th.se small-sized fluid mach.nes is not clarified and conventional th.ory is not suitable for small-sized pumps. Th.n, a semi-open impeller for th. mini centrifugal pump with.55mm impeller diameter is adopted in th.s research.to take simplicity and maintenance into consideration. Splitter blades are adopted in th.s research.to improve th. performance and internal flow condition of mini centrifugal pump h.ving large blade outlet angle. Th. performance tests are conducted with.th.se rotors in order to investigate th. effect of th. splitter blades on th. performance and internal flow condition of th. mini centrifugal pump. A th.ee dimensional steady numerical flow analysis is conducted to analyze rotor, volute efficiency and loss caused by a vortex. It is clarified from th. experimental results th.t th. performance of th. mini centrifugal pump is improved by th. effect of th. splitter blades. Flow condition at outlet of th. rotor becomes uniform and back flow regions are suppressed in th. case with.th. splitter ***, th. volute efficiency increases and th. vortex loss decreases. In th. present paper, th. performance of th. mini centrifugal pump is sh.wn and th. flow condition is clarified with.th. results of th. experiment and th. numerical flow analysis. Furth.rmore, th. performance analyses of th. mini centrifugal pumps with.and with.ut th. splitter blades are conducted.

关键词： Centrifugal pump Performance Internal flow Splitter blade

Stability of Dirac Equation in Four-Dimensional Gravity

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Ch.nese Ph.sics Letters 2017年第6期34卷 10-13页

作者： F. Safari h. j.fari j. Sadegh. S. j. j.h.ston D. Baleanu Department of Math.matics University of Mazandaran Babolsar Iran Ph.sics Department University of Mazandaran Babolsar 4716-95447 Iran Department of Math.matical Sciences University of South Africa UNISA 0003 South Africa Department of Math.matics Faculty of Art and Science Cankaya University Balgat 06530 Turkey Institute of Space Sciences Magurele-Bueharest Romania

We introduce th. Dirac equation in four-dimensional gravity wh.ch.is a generally covariant form. We ch.ose th. suitable variable and solve th. corresponding equation. To solve such.equation and to obtain th. corresponding bispinor, we employ th. factorization meth.d wh.ch.introduces th. associated Laguerre polynomial. Th. asso- ciated Laguerre polynomials h.lp us to write th. Dirac equation of four-dimensional gravity in th. form of th. sh.pe invariance equation. Th.s we write th. sh.pe invariance condition with.respect to th. secondary quantum number. Finally, we obtain th. spinor wave function and ach.eve th. corresponding stability of condition for th. four-dimensional gravity system.

关键词： Stability of Dirac Equation in Four-Dimensional Gravity

NEURAL NETWORK MODELING FOR ESTIMATION OF SCOUR DEPTh.AROUND BRIDGE PIERS

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j.urnal of h.drodynamics 2007年第3期19卷 378-386页

作者： LEE T. L. j.NG D. S. Zh.NG G. h. h.NG j. h. Department of Construction Tech.ology Leader University Tainan 709 China Sch.ol of Civil Engineering The University of Sydney NSW 2006 Australia Department of Resource and Environment Leader University Tainan 709 China Department of Civil Engineering National Chung Hsing University Taichung 402 China

It is essential to predict th. scour depth.around bridge piers for h.draulic engineers involved in th. economical design of bridge pier foundation. Conventional investigations h.ve long been of th. opinion th.t empirical scour prediction equations based on laboratory data over predict scour depth.. In th.s article, th. Back-Propagation Neural Network （BPN） was applied to predict th. scour depth.in order to overcome th. problem of exclusive and th. nonlinear relationsh.ps. Th. observations obtained from th.rteen states in USA was verified by th. present model. From th. comparison with.conventional experimental meth.ds, it can be found th.t th. scour depth.around bridge piers can be efficiently predicted using th. BPN.

关键词： Back-Propagation Neural Network (BPN) prediction bridge pier scour depth

Performance of th. geometric approach.to fault detection and isolation in SISO,MISO,SIMO and MIMO systems

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j.urnal of Zh.j.ang University-Science A(Applied Ph.sics & Engineering) 2007年第9期8卷 1443-1451页

作者： RAh.MI N. SADEGh. M. h. MAh.OOB M. j. Mech.nical Engineering Department University of TabrizTabriz ***Iran Mech.nical Engineering Department University of TehranTehran ***Iran

In th.s paper, a geometric approach.to fault detection and isolation （FDI） is applied to a Multiple-Input Multipie-Output （MIMO） model of a frame and th. FDI results are compared to th. ones obtained in th. Single-Input Single-Output （SISO）, Multiple-Input Single-Output （MISO）, and Single-Input Multiple-Output （SIMO） cases. A proper distance function based on parameters obtained from parametric system identification meth.d is used in th. geometric approach. ARX （Auto Regressive with.exogenous input） and VARX （Vector ARX） models with.12 parameters are used in all of th. above-mentioned models. Th. obtained results reveal th.t by increasing th. number of inputs, th. classification errors reduce, even in th. case of applying only one of th. inputs in th. computations. Furth.rmore, increasing th. number of measured outputs in th. FDI sch.me results in decreasing classification errors. Also, it is sh.wn th.t by using probabilistic space in th. distance function, fault diagnosis sch.me h.s better performance in comparison with.th. deterministic one.

关键词： Fault detection and isolation (FDI) Multivariate systems Parametric system identification Linear regression Distance functions

Nucleon Finite Volume Effect and Nuclear Matter Properties in a Relativistic Mean-Field Th.ory

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Communications in Th.oretical Ph.sics 2006年第6X期46卷 1052-1058页

作者： R. Costa A.j. Santiago h. Rodrigues j. Sa Borges Instituto de Fisica Universidade do Estado do Rio de Janeiro Rio de Janeiro-RJ 20559-900 Brazil Centro Federal de Educ~ao Tecnológica Rio de j.neiro Brazil

Effects of excluded volume of nucleons on nuclear matter are studied, and th. nuclear properties th.t follow from different relativistic mean-field model parametrizations are compared. We sh.w th.t, for all tested parametrizations, th. resulting volume energy al and th. symmetry energy j.are around th. acceptable values of 16 MeV and 30 MeV, and th. density symmetry L is around 100 MeV. On th. oth.r h.nd, models th.t consider only linear terms lead to incompressibility Ko much.h.gh.r th.n expected. For most parameter sets th.re exists a critical point （pc, δc）, wh.re th. minimum and th. maximum of th. equation of state are coincident and th. incompressibility equals zero. Th.s critical point depends on th. excluded volume parameter r. If th.s parameter is larger th.n 0.5 fm, th.re is no critical point and th. pure neutron matter is predicted to be bound. Th. maximum value for neutron star mass is 1.85M⊙, wh.ch.is in agreement with.th. mass of th. h.aviest observed neutron star 4U0900-40 and corresponds to r = 0.72 fm. We also sh.w th.t th. ligh. neutron star mass （1.2M⊙） is obtained for r ≌ 0.9 fro.

关键词： nuclear matter relativistic models nuclear matter aspects of neutron stars

A fast-running meth.d for blast load prediction sh.elding by a protective barrier

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Defence Tech.ology（防务技术） 2020年第2期16卷 308-315页

作者： S.-h.Sung j.-W.Ch.ng Agency for Defense Development Yuseong P.O.Box 35DaeJeon395-600South Korea

Th.s study presents a simplified blast load prediction meth.d on structures beh.nd a protective *** proposed meth.d is basically an empirical approach.based on Kingery-Bulamsh.K-B)ch.rt and finite element(FE)analysis *** th.s end,th.s study divides th. structure into th.ee regions by th.ee critical *** loads at each.critical point can be calculated based on K-B ch.rt and an approximation according to FE analysis ***,peak reflected overpressure and impulse distributed on th. structure can be approximately estimated by linearly connecting blast loads at each.critical *** order to confirm a feasibility of th. proposed meth.d,a series of numerical simulations were carried *** simulation results were compared with.FE analysis results wh.ch.are presented in th. open *** such.comparisons,it was found th.t th. proposed meth.d is applicable to predict blast loads on structures beh.nd a protective barrier.

关键词： Blast loads Protective barrier Sh.ck wave Fast running model Kingery-Bulmash

Metamaterial-based graph.ne th.rmal emitter

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Nano Research 2018年第7期11卷 3567-3573页

作者： Ch.ng Sh. Nath.n h. Mah.meister Isaac j. Luxmoore Geoffrey R. Nash College of Engineering Mathematics and PhysicaI Sciences University of Exeter Exeter EX4 4QF UK

A th.rmal emitter composed of a frequency-selective surface metamaterial layer and a h.xagonal boron nitride-encapsulated graph.ne filament is demonstrated. Th. broadband th.rmal emission of th. metamaterial （consisting of ring resonators） was tailored into two discrete bands, and th. measured reflection and emission spectra agreed well with.th. simulation results. Th. h.gh.modulation frequencies th.t can be obtained in th.se devices, coupled with.th.ir operation in air, confirm th.ir feasibility for use in applications such.as gas sensing.

关键词： graph.ne h.xagonal boron nitride th.rmal emitter infrared metamaterial

NUMERICAL INVESTIGATION OF STRAIGh.-LINE LASER FORMING UNDER Th. TEMPERATURE GRADIENT MECh.NISM

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Acta Metallurgica Sinica(English.Letters) 2006年第2期19卷 144-150页

作者： Y.j. Sh. h. Sh.n Z.Q. Yao j. h. Sch.ol of Mech.nical and Power Engineering Shanghai Jiaotong University Shanghai 200030 China

Laser forraing is a new flexible and dieless forming tech.ique. To ach.eve th. h.gh.accuracy forming, th. temperature gradient mech.nism （TGM） is studied. In th. analysis of TGM, th. plate bends about x-axis and about y-axis as well. To understand th. deformation trend, th. numerical simulation of deformation of plate is conducted by ch.osing different laser powers, laser spot diameters, scanning speeds, length., width. and th.cknesses. From th. results of simulation, it can be seen th.t th. laser spot diameter, th. scanning speed, laser power and th.ckness of plate play dominant roles in th. laser forming process. h.wever, th. bending angles αx and αy sh.w different trends with.th. variation of parameters. In addition, in comparison with.above four parameters, th. effect of length.and width.of plate on th. beading angle may be neglected, but th.ir effects are significant for th. bending radius R.

关键词： laser forming temperature gradient mech.nism metal plate

STUDY ON TEMPERATURE FIELD INDUCED IN h.Gh.FREQUENCY INDUCTION h.ATING

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Acta Metallurgica Sinica(English.Letters) 2006年第3期19卷 190-196页

作者： h. Sh.n Z.Q. Yao Y.j. Sh. j. h. Sch.ol of Mech.nical Engineering Shanghai Jiaotong University Shanghai 200030 China

A math.matical model was establish.d for th. temperature field developed during h.gh.frequency induction h.ating （h.Ih. by Maxwell＇s equations. It required solving th. coupled equations of th. electromagnetic and temperature fields. Th. numerical simudation was performed using FEMLAB. Th. comparison of th. calculations using th. proposed model with.experimental results sh.wed a very good correlation. Th. effects of th. h.ating parameters in h.gh.frequency induction such.as th. distance between th. plate and th. coil, th. applied current, th. frequency, and th. turns of th. coil on th. temperature profiles developed in th. plate were also discussed using th. establish.d model.

关键词： h.gh.frequency induction temperature field numerical simudation