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Large Eddy Simulation of New Vortex Generator Enhancing Heat Exchange of Solar Energy

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湖南大学学报（自然科学版） 2009年第S1期36卷 186-192页

作者： WEN Juan,YANG Li,QI Cheng-ying(department of Thermal Power Engineering,hebei university of technology,tianjin 300401,china) department of Thermal Power Engineering Hebei University of Technology Tianjin 300401 China

This paper put forward a new-type vortex generator enhancing heat exchange of solar air-drier and air-heater on the gas side,and investigated the mechanism of heat transfer enhancement and drag reduction by the influence of vortex generators on the coherent structure of turbulent boundary *** flow and heat transfer characteristics of rectangle channel with bevel-cut half-elliptical column vortex generators were obtained using large eddy simulation(LES)and the hydromechanics software *** instantaneous properties of velocity,temperature and pressure in channel were *** coherent structure of turbulent boundary layer flow was showed,and the characteristic of vortex induced by inclined-cut semi-ellipse vortex generator and its influence on turbulent coherent structure were *** the effect mechanism of turbulent coherent structure on flow field,pressure field and temperature field was *** on the results,the heat transfer coefficient and drag reduction of the new vortex generator with different pitch angles were ***,the coherent effects of the increased wall heat transfer and the decreased skin friction do not satisfy the Reynolds *** turbulent coherent structure can be controlled through the geometry of the vortex generator,so the heat transfer and drag reduction can also be *** we can seek suitable form of vortex generator and structure parameters,in order to achieve the enhanced heat transfer and flow of drag reduction in the solar air-heater and solar air-drier.

关键词： large eddy simulation vortex generator bevel-cut half-elliptical column coherent structure heat transfer enhancement

Principle of limitation of physical quantities and cyclic universe

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Science china(physics,Mechanics & Astronomy) 2008年第5期51卷 451-458页

作者： HE GuoZhu department of physics,Nankai university,tianjin 300071,china department of physics Nankai University Tianjin China

A close study of Heisenberg uncertainty principles reveals many significant facts,and all four major physical quantities,energy,time,momentum and length,have both lower and upper ***,many questions come *** are these limits?Some answers may lead to the understanding of the development of our *** is the shortest limit of time?At the beginning of big bang,there exists a tre-mendously short time,the Planck *** may be just the shortest time limit in our *** longest time limit might be the lifetime of our *** longest length might be the final diameter of our expanding *** these lead to a finite *** more coupling formulae are formed for the other two pairs of physical quantities,mass and speed,thermal energy and *** four physical quantities must also have *** already knew that speed has upper limit and temperature has lower *** these two formulae,Planck and Einstein equations are derived *** most other physical quantities are somewhat related to these major physical quantities,it seems that there exists a principle of limitation of physical quantities.A quantitative sketch of big bang is *** also shows that our universe will contract back to another big *** principle of limitation opens up some fields of *** may bring nature back to the harmony and determined world described by classical physics.

关键词： principle of limitation of physical quantities limits coupling formulae cyclic universe extension of conven-tional quantum mechanics no uncertainty for physical quantities quantitative evaluation of big bang

Tunneling Through Black Rings

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Communications in Theoretical physics 2007年第5期47卷 835-842页

作者： ZHAO Liu department of physics,Nankai university,tianjin 300071,china department of physics Nankai University Tianjin 300071 China

Hawking radiation of black ring solutions to 5-dimensional Einstein-Maxwell-dilaton theory is analyzedby use of the Parikh-Wilczek tunneling *** get the correct tunneling amplitude and emission rate,we adoptand develop the Angheben-Nadalini-Vanzo-Zerbini covariant approach to cover the effects of rotation and electronicdischarge all at once,and the effect of back reaction is also taken into *** constitutes a unified approach tothe tunneling *** the first law of thermodynamics for black rings holds,the emission rate is proportionalto the exponential of the change of Bekenstein-Hawking *** calculation for black ring temperatures agreesexactly with the results obtained via the classical surface gravity method and the quasi-local formalism.

关键词： black ring radiation tunneling method

Views on “Principle of limitation of physical quantities and cyclic universe”

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Science china(physics,Mechanics & Astronomy) 2010年第9期53卷 1772-1774页

作者： LI LianGang department of physics,School of Sciences,tianjin university,tianjin 300072,china department of physics School of Sciences Tianjin University Tianjin China

This paper presents an analysis of a paper entitled "Principle of limitation of physical quantities and cyclic universe" and proposes different results for some formulae from that *** addition,this paper shows that the principle of limits coupling may lead to an approximation of current theories(i.e.,quantum theory and relativistic theory),which have interesting correlations with the Plank formula and the special theory of relativity.

关键词： principle of limitation of physical quantities limits coupling formulae Plank formula theory of relativity

Low－Temperature　Spectral　Properties　and　Zero－Phonon　Transitions　of　Alkali　Halide　Crystal　Materials　Bombarded　with　Electrons　and　Implanted　with　Ions

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Chinese Journal of Lasers 1995年第2期B4卷 111-116页

作者： GU Hongen(department of Applied physics, tianjin university, tianjin 300072, china) tianjin Univ Tianjin China

Ｌｏｗ－ＴｅｍｐｅｒａｔｕｒｅＳｐｅｃｔｒａｌＰｒｏｐｅｒｔｉｅｓａｎｄＺｅｒｏ－ＰｈｏｎｏｎＴｒａｎｓｉｔｉｏｎｓｏｆＡｌｋａｌｉＨａｌｉｄｅＣｒｙｓｔａｌＭａｔｅｒｉａｌｓＢｏｍｂａｒｄｅｄｗｉｔｈＥｌｅｃｔｒｏ... 详细信息

Ｌｏｗ－ＴｅｍｐｅｒａｔｕｒｅＳｐｅｃｔｒａｌＰｒｏｐｅｒｔｉｅｓａｎｄＺｅｒｏ－ＰｈｏｎｏｎＴｒａｎｓｉｔｉｏｎｓｏｆＡｌｋａｌｉＨａｌｉｄｅＣｒｙｓｔａｌＭａｔｅｒｉａｌｓＢｏｍｂａｒｄｅｄｗｉｔｈＥｌｅｃｔｒｏｎｓａｎｄＩｍｐｌａｎｔｅｄｗｉｔ...

关键词： zero-phonon transition. color centers

Low-temperature optical spectra and zero-phonon transition of color centers in γ-rayed lithium fluoride crystals

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Chinese Journal of Lasers 1993年第5期B2卷 59-63页

作者： Honggen Gu (department of physics, tianjin university, tianjin 300072,china) tianjin Univ Tianjin China

The zero-phonon lines on R2, R~+, N1and R′2centers and some new narrow lines have been observed in bivalent-metal-doped and air-grown LiF crystals irradiated by γ-ray in the temperature range of 9.5—130K. The spect... 详细信息

关键词： low-temperature spectra zero-phonon transition color-centers in LiF2

Search for B_c (ns) via the B_c (ns) → B_c (ms) π^+ π^- transition at LHCb and Z^0 factory

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Science china(physics,Mechanics & Astronomy) 2010年第11期53卷 2019-2024页

作者： KE HongWei 1 & LI XueQian 2 1 School of Science,tianjin university,tianjin 300072,china 2 School of physics,Nankai university,tianjin 300071,china School of Science Tianjin University Tianjin China School of physics Nankai University Tianjin China

It is interesting to study the characteristics of the whole family of B c which contains two different heavy *** and the proposed Z 0 factory provide an opportunity because a large database of the B c family will be achieved.B c and its excited states can be identified via their decay *** suggested by experimentalists,B-c (ns) → B c +γ is not easy to be clearly measured,instead,the trajectories of π + and π- occurring in the decay of B c (ns) → B c (ms) + π + π( n > m ) can be unambiguously identified,thus the measurement seems easier and more reliable;therefore this mode is more favorable at the early running stage of LHCb and the proposed Z 0 *** this work,we calculate the rate of B c (ns) → B c (ms) + π + π-in terms of the QCD multipole-expansion and the numerical results indicate that the experimental measurements with the luminosity of LHC and Z 0 factory are feasible.

关键词： meson hadronic decay QCD multipole-expansion

Robustness and breakup of the spiral wave in a two-dimensional lattice network of neurons

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Science china(physics,Mechanics & Astronomy) 2010年第4期53卷 672-679页

作者： MA Jun 1,2, TANG Jun 2 , ZHANG AiHua 3 & JIA Ya 2 1 department of physics, Lanzhou university of technology, Lanzhou 730050, china 2 department of physics, Central china Normal university, Wuhan 430079, china 3 College of Electrical and Information Engineering, Lanzhou university of technology, Lanzhou 730050, china department of physics Lanzhou University of Technology Lanzhou China department of physics Central China Normal University Wuhan China College of Electrical and Information Engineering Lanzhou University of Technology Lanzhou China

The robustness and breakup of spiral wave in a two-dimensional lattice networks of neurons are investigated. The effect of small- world type connection is often simplified with local regular connection and the long-range connection with certain probability. The network effect on the development of spiral wave can be better described by local regular connection and changeable long-range connection probability than fixed long-range connection probability because the long-range probability could be changeable in realistic biological system. The effect from the changeable probability for long-range connection is simplified by multiplicative noise. At first, a stable rotating spiral wave is developed by using appropriate initial values, parameters and no-flux boundary conditions, and then the effect of networks is investigated. Extensive numerical studies show that spiral wave keeps its alive and robust when the intensity of multiplicative noise is below a certain threshold, otherwise, the breakup of spiral wave occurs. A statistical factor of synchronization in two-dimensional array is defined to study the phase transition of spiral wave by checking the membrane potentials of all neurons corresponding to the critical parameters(the intensity of noise or forcing current)in the curve for factor of synchronization. The Hindmarsh-Rose model is investigated, the Hodgkin-Huxley neuron model in the presence of the channel noise is also studied to check the model independence of our conclusions. And it is found that breakup of spiral wave is easier to be induced by the multiplicative noise in presence of channel noise.

关键词： spiral wave factor of synchronization breakup multiplicative noise robustness

Quantum Entanglement of Two Flux Qubits Induced by an Auxiliary SQUID

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Communications in Theoretical physics 2007年第12期48卷 1003-1008页

作者： SHI Tao SONG Zhi department of physics,Nankai university,tianjin 300071,china department of physics Nankai University Tianjin 300071 China

We revisit a theoretical scheme to create quantum entanglement of two three-level superconducting quantuminterference devices (SQUIDs) with the help of an auxiliary *** this scenario,two three-level systems are coupledto a quantized cavity field and a classical external field and thus form dark *** quantum entanglement can beproduced by a quantum measurement on the auxiliary *** investigation emphasizes the quantum effect of theauxiliary *** the experimental feasibility and accessibility of the scheme,we calculate the time evolution of thewhole system including the auxiliary *** ensure the efficiency of generating quantum entanglement,relationsbetween the measurement time and dominate parameters of the system are analyzed according to detailed calculations.

关键词： superconducting quantum interference device entangled state quantum information dark state