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Microwave peak absorption frequency of liquid

Science china(physics,Mechanics & Astronomy) 2008年第9期51卷 1254-1263页

作者： han guangze1 & chen mingdong2 1 department of physics,south china university of technology,guangzhou 510640,china 2 guangzhou Auto College,south china university of technology,guangzhou 510800,china department of physics South China University of Technology Guangzhou China guangzhou Auto College South China University of Technology Guangzhou China

Microwave-assisted extraction is a new effective method which has practical ap-plications in many fields. Microwave heating is one of its physical mechanisms,and it also has the characteristic of selectivity. When the applied microwave fre-quency equals a certain absorption frequency of the material (or specific compo-nent),the material will intensively absorb microwave energy. This is also known as resonant absorption,and the frequency is called the peak absorption frequency which depends on the physical structure of the material. In this work,dynamic hy-drogen bond energy was included in molecular activation energy; with the liquid cell model,the expression of interaction energy between dipolar molecules was derived. The rotational relaxation time was gotten from the Eyring viscosity formula. Then based on the relationship between dielectric dissipation coefficient and re-laxation time,the expression of microwave peak absorption frequency as a func-tion of the material physical structure,rotational inertia and electrical dipole mo-ment of molecules was established. These theoretical formulas were applied to water and benzene,and the calculated results agree fairly well with the experi-mental data. This work can not only deepen the study of the interaction between microwave and material,but also provide a possible guide for the experiment of microwave-assisted extraction.

关键词： microwave-assisted extraction microwave heating relaxation time liquid viscosity peak absorption fre-quency

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Linearly time-varying channel estimation and training power allocation for OFDM/MIMO systems using superimposed training

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Science china(Information Sciences) 2011年第7期54卷 1456-1470页

作者： ZhanG han 1,DAI XianHua 2 & Pan DaRu 1 1 School of physics and Telecommunication Engineering,south china Normal university,guangzhou 510006,china 2 department of Information Science and technology,SUN Yat-sen university,guangzhou 510026,china School of physics and Telecommunication Engineering South China Normal University Guangzhou China department of Information Science and technology SUN Yat-sen University Guangzhou China

We address the problem of estimating the linearly time-varying (LTV) channel of orthogonal frequency division multiplexing (OFDM)/multiple-input multiple-output (MIMO) systems using superimposed training (ST).The LTV channel is modeled by truncated discrete Fourier *** on this model,a two-step approach is adopted to estimate the LTV channel over multiple OFDM *** also present performance analysis of the channel estimation and derive a closed-form expression for the channel estimation *** is shown that the estimation variances,unlike that of the conventional ST-based schemes,approach to a fixed lower-bound as the training length increases,which is directly proportional to information-pilot power *** wireless communication systems with a limited transmission power,we optimize the ST power allocation by maximizing the lower bound of the average channel *** results show that the proposed approach outperforms the frequency-division multiplexed training schemes.

关键词： OFDM/MIMO systems linearly time-varying channel estimation superimposed training training power allocation

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Properties of Rotating Neutron Stars in the Relativistic σ-ω Model

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Communications in Theoretical physics 2004年第1期41卷 51-54页

作者： WEN De-Hua~(1,2) chen Wei~3 WANG Xian-Ju~1 AI Bao-Quan~1 LIU Guo-Tao~1 LIU Liang-Gang~1 1 department of physics,Zhongshan university,guangzhou 510275,china2 department of physics,south china university of technology,guangzhou 510641,china3 department of physics,Jinan university,guangzhou 510632,china department of physics Zhongshan University Guangzhou 510275 China department of physics South China University of Technology Guangzhou 510641 China department of physics Jinan University Guangzhou 510632 China

The properties such as the moment of inertia,the surface redshift and the radius of gyration of rotatingneutron stars in the relativistic σ-ω model are studied with the Hartle’s *** relation between the angularvelocity of the fluid relative to the local inertial frame and the uniform angular velocity relative to the infinite iscalculated.

关键词： relativistic σ-ω model rotating neutron star equation of state

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Degradation of nitrobenzene in wastewater by γ-ray irradiation

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Journal of Environmental Sciences 2004年第3期16卷 364-366页

作者： ZhanG Shu juan 1, FENG Shao hong 1, YU han qing 1,* , LI Qian rong 2 (1 department of Chemistry, university of Science & technology of china, Hefei 230026, china. 2 Research Center for physics & Chemistry, university of Science & technology of china, Hefei 230026, china) department of Chemistry University of Science & Technology of China Hefei 230026 China Research Center for physics & Chemistry University of Science & Technology of China Hefei 230026 China

The degradation of nitrobenzene(NB) by γ ray irradiation was studied. The influences of dose rate and initial NB concentration were investigated in details. At a dose rate of 55 Gy/min, the degradation kinetics was pseudo first order at NB concentrations from 0 2 mmol/L to 4 0 mmol/L. At an initial NB concentration of 0 8 mmol/L, the degradation of NB at various dose rates also followed pseudo first order kinetics. Dissolved oxygen was found to have a positive effect on NB degradation. The degradation products were identified as nitrophenol, nitrosobenzene, and hydroquinone, and so on. Based on the product analysis, possible degradation pathways of nitrobenzene were proposed.

关键词： degradation irradiation nitrobenzene(NB) kinetics

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A fractal study for nucleate pool boiling heat transfer of nanofluids

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Science china(physics,Mechanics & Astronomy) 2010年第1期53卷 30-37页

作者： XIAO BoQi 1 , JIANG GuoPing 2 & chen LingXia 1 1 department of physics and Electromechanical Engineering, Sanming university, Sanming 365004, china 2 Earthquake Engineering Research Test Center, guangzhou university, guangzhou 510405, china department of physics and Electromechanical Engineering Sanming University Sanming China Earthquake Engineering Research Test Center Guangzhou University Guangzhou China

In this paper, a fractal model for nucleate pool boiling heat transfer of nanofluids is developed based on the fractal distribution of nanoparticles and nucleation sites on boiling surfaces. The model shows the dependences of the heat flux on nanoparticle size and the nanoparticle volume fraction of the suspension, the fractal dimension of the nanoparticle and nucleation site, temperature of nanofluids and properties of fluids. The fractal model predictions show that the natural convection stage continues relatively longer in the case of nanofluids. The addition of nanoparticles causes a decrease of the pool nucleate boiling heat transfer. The nucleate pool boiling heat transfer coefficient is decreased by increasing particle concentration. An excellent agreement between the proposed model predictions and experimental data is found. The validity of the fractal model for nucleate pool boiling heat transfer is thus verified.

关键词： nanofluid nucleate pool boiling fractal heat transfer

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Density-functional formula for strongly correlated systems

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Progress in Natural Science:Materials International 2005年第5期15卷 395-401页

作者： WANG Huaiyu1*, han Rushan2 and chen Nanxian1(1. department of physics, Tsinghua university, Beijing 100084, china 2. department of physics, Peking university, Beijing 100871, china) Dept. of Phys. Tsinghua Univ. Beijing 100084 China Dept. of Phys. Peking Univ. Beijing 100871 China

Density functional method is applied for strongly correlated systems. Based on the assumption that the systems are composed of electrons in singly-occupied orbitals and those in doubly-occupied orbitals, a set of self-consistent equations are obtained by standard variation procedure. The equations consist of two parts. One part is to solve the wave functions of the electrons in singly-occupied orbitals and the other is to solve the wave functions of the electrons in doubly-occupied orbitals. The physical meanings of the terms appearing in the equations are discussed.

关键词： density-functional theory strongly correlated systems doubly-occupied orbital two-particle wave function self-consistent equations.

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Reply to“Comment on ‘Recent progress in thermodynamics of radiation—Exergy of radiation,effective temperature of photon and entropy constant of photon'”

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Science china(Technological Sciences) 2010年第3期53卷 878-880页

作者： chen ZeShao 1,MO SongPing 1,2 &HU Peng 1 1department of Thermal Science and Energy Engineering,university of Science and technology of china,Hefei 230027,china 2 Faculty of Material and Energy,Guangdong university of technology,guangzhou 510006,china department of Thermal Science and Energy Engineering University of Science and Technology of China Hefei China Faculty of Material and Energy Guangdong University of Technology Guangzhou China

Two counterexamples in Liu's comment on'Recent Progress in Thermodynamics of Radiation—Exergy of radiation,effective temperature of photon and entropy constant of photon'are analyzed and the incorrect applications of the related concepts are *** similarities and differences between the concepts of the effective temperature of photon,the exergy of spectral radiation,the entropy constant of photon and the macroscopic concepts of temperature,exergy,and entropy are further *** duality of radiant energy,micro-state quantum characteristic and macro-state thermal characteristic is presented.

关键词： thermodynamics of radiation photon entropy

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New stylophorans(Echinodermata) from the Upper Cambrian of Guangxi,south china

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Science china Earth Sciences 2008年第2期51卷 181-186页

作者： han NaiRen1 & chen GuiYing1,2 1 department of Resources and Environmental Engineering, Guilin university of technology, Gulin 541004, china 2 Faculty of Earth Sciences, china university of Geoscience, Wuhan 430074, china department of Resources and Environmental Engineering Guilin University of Technology Gulin China Faculty of Earth Sciences China University of Geoscience Wuhan China

This paper describes for the first time the cornute stylophorans (Echinodermata) in china. The new material came from the Guole Formation of the Furongian (Late Cambrian) in the Guole area of Jingxi, Guangxi Province, south china. These new cornute specimens are preserved in situ and found along with well-preserved trilobites and brachiopods. One new species, Phyllocystis jingxiensis sp. nov., is proposed to accommodate these unusual materials. The new species is defined by the small, heart-shaped theca with the frame composed of ten narrow, smooth and thick marginal plates, three adoral plates and distinctive zygal and aulacophore. Both supracentrals and infracentrals are polygonal-outlined. The marginal plate M1' on the inferior face extends posteriorly to form zygal that possesses a broadened proximal end and the proximal portion joining with the conjunction between M4 and M5 on the inferior face. Aulacophore comprises ten segments at its proximal part and is conical at the middle part (named stylocone). Its distal portion is rather long and bears conspicuous ambulacrum grooves. Tectals are horizontally arranged on superior face and obliquely arranged on inferior face. Both cothurnopore and anal pyramid are vaguely seen on the right anterior corner and the extremity of theca's superior face.

关键词： Phyllocystis Stylophora Echinodermata Cambrian Guangxi south china

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A New Lie Algebra and a Way to Generate Multiple Integrable Couplings

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Communications in Theoretical physics 2007年第12期48卷 979-982页

作者： FENG Bin-Lu~(1,2)and han Bo~1~1 department of Mathematics,Harbin Institute of technology,Harbin 150001,china~2 department of Mathematics,Weifang university,Weifang 261000,china department of Mathematics Harbin Institute of Technology Harbin 150001 China department of Mathematics Weifang University Weifang 261000 China

A new higher-dimensional Lie algebra is constructed,which is used to generate multiple integrable *** this,we come to a general approach for seeking multi-integrable couplings of the known integrablesoliton equations.

关键词： Lie algebra integrable hierarchy Hamiltonian structure

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HARDY-SOBOLEV INEQUALITIES WITH GENERAL WEIGHTS AND REMAINDER TERMS

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Acta Mathematica Scientia 2008年第3期28卷 469-478页

作者：陈志辉沈尧天 School of Mathematical Sciences South China University of Technology

The Hardy-Sobolev inequality with general weights is established, and it is shown that the constant is optimal. The two weights in this inequality are determined by a Bernoulli equation. In addition, the authors obtain the Hardy-Sobolev inequality with general weights and remainder terms. By choosing special weights, it turns to be many versions of the Hardy-Sobolev inequality and the Caffarelli-Kohn-Nirenberg inequality with remainder terms in the literature.

关键词： Hardy-Sobolev inequality general weight best constant

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