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Simulation of the Earth' s gravitational field recovery from GRACE using the energy balance approach

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Progress in Natural science:Materials International 2005年第7期15卷 596-601页

作者： ZHENG Wei, LU Xiaolei, HSU Houtse, SHAO Chenggang, LUO Jun and WANG Nengchao ( department of physics, huazhong university of science and technology, wuhan 430074, china Institute of Geodesy and Geophysics, Chinese Academy of sciences, wuhan 430077, china department of Mathematics, huazhong university of science and technology, wuhan 430074, china) department of physics Huazhong University of Science and Technology Wuhan 430074 China. department of Mathematics Huazhong University of Science and Technology Wuhan 430074 China. Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China

Based on the measurement principles of GRACE satellites, the observation equations are set up using the energy balance approach. The Earth's gravitational field complete up to degree and order 120 is recovered applying the preconditioning conjugate gradient iterative approach by numerical simulation. Assuming an accuracy of 1 μm/s in range-rate measurements of the K-band microwave ranging system, the matching relationships of accuracies of K-band microwave ranging system, SuperSTAR Accelerometer, position vector and velocity vector measurements are investigated.

关键词： the Earth’s gravitational field GRACE satellites energy balance approach preconditioning conjugate gradient method.

Quantum Theory of Femtosecond Soliton Propagation in Single-Mode Optical Fibers

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Communications in Theoretical physics 2004年第6期41卷 943-948页

作者： CHEN Shi-Hua ZHANG Shao-Wu SHI Du-Fang department of physics,huazhong university of science and technology,wuhan 430074,china department of physics Huazhong University of Science and Technology Wuhan 430074 China

In this paper we have derived the generalized QNLS equation with considering the third-order dispersion andKerr dispersion,which can be applicable to the femtosecond regime and is suitable for discussing the quantum propertiesof femtosecond solitons in single-mode optical fibers,as compared with its classical *** quantum operatorequation can be solved by many methods such as the linearized perturbations and phase-space ***,owingto the fact that this quantum equation is rather similar to its classical counterpart,all these methods can be facilitatedto a great extent by citing correctly the classical results obtained before.

关键词： generalized QNLS equation single-mode-optical fibers third-order dispersion

KTN thin films prepared by pulsed laser deposition on transparent single crystal quartz(100)

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science china(physics,Mechanics & Astronomy) 2005年第1期48卷 33-43页

作者： WANG Xiaodong, PENG Xiaofeng & ZHANG Duanming Laboratory of Phase Change and Interfacial Transport Phenomena, department of Thermal Engineering, Tsinghua university, Beijing 100084, china department of physics, huazhong university of science and technology, wuhan 430074, china 1. Laboratory of Phase Change and Interfacial Transport Phenomena Department of Thermal Engineering Tsinghua University 100084 Beijing China 2. department of physics Huazhong University of Science and Technology 430074 Wuhan China

Using the Sol-Gel method to produce the KTN ultrafine powder and the sintering technique with K2O atmosphere to prepare KTN ceramics as the targets instead of the KTN single crystal, highly oriented KTN thin films were produced on the transparent single crystal quartz (100) by the pulsed laser deposition (PLD). Since the thermal stress sustained by the quartz is relatively small, the limit temperature of the quartz substrates(300℃) is much lower than that of the P-Si substrates (560℃); the prepared thin film is at amorphous state. Increasing the pulsed laser energy density in the process incorporated with annealing the film after deposition at different temperatures converts the amorphous films into crystal. The optimal pulsed laser energy density and annealing temperature were 2.0 J/cm2 and 600℃, respectively. A discussion was made to understand the mechanism of film production at relatively low substrate temperature by PLD and effects of the annealing temperatures on the forming of the perovskite phase, and optimal conditions for the orientation of the crystal grain.

关键词： PLD technology, KTN thin film, single crystal quartz, pulsed energy density, annealing, perovskitephase.

Exact eigenstates for a class of models describing multiphoton processes in the presence of seven bosonic modes

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science china(physics,Mechanics & Astronomy) 2004年第6期47卷 649-657页

作者： ZHAN Zhiming1,LI Weibin2,YOU Jun2,XIE Xiaotao2 & YANG Wenxing2 1.State Key Laboratory of Laser technology,huazhong university of science and technology,wuhan 430074,china 2.department of physics,huazhong university of science and technology,wuhan 430074,china 1. State Key Laboratory of Laser technology Huazhong University of Science and Technology 430074 Wuhan China 2. department of physics Huazhong University of Science and Technology 430074 Wuhan China

We present the analytical expressions of eigenstates and eigenenergies by using a parameter λ without the assumption of Bethe anzatz for three kinds of seven-bosonic-mode mixing models. The parameter is shown to be determined by the roots of a simple polynomial. We also demonstrate the exact analytical expressions of eigenstates and energies without any unknown parameter.

关键词： spectra, eigenstate, eigenvalue.

Output Rate of Atomic Four-Wave Mixing in Two-Component Bose-Einstein Condensate

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Communications in Theoretical physics 2004年第5期41卷 695-698页

作者： LI Jia-Hua~1 LI Wei-Bing~1 PENG Ju-Cun~2 1 department of physics,huazhong university of science and technology,wuhan 430074,china2 department of physics,Xiaogan Normal university,Xiaogan 432100,china department of physics Xiaogan Normal University Xiaogan 432100 China

In this letter,following the proposal of Heurich et al.[***.A63(2001)033605],we analyze anddiscuss output rate of atomic four-wave mixing in the two-component Bose-Einstein condensate under the condition ofthe steady *** results show that the magnitude of the signal beam increases with the increase of the intensityof the probe beam,up to a saturated value,then it decreases as the probe beam *** influence of theinteraction range on the signal beam is also *** particular,it is worth while pointing out that in contrast tothe previous solutions,our obtained analytical solutions are of very simple and explicit forms,which open the door forfurther investigating the related physical mechanisms.

关键词： atomic four-wave mixing steady state Bose-Einstein condensate

A Method for Identification of Selenoprotein Genes in Archaeal Genomes

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Genomics,Proteomics & Bioinformatics 2009年第Z1期 62-70页

作者： Mingfeng Li, Yanzhao Huang, and Yi Xiao Biomolecular physics and Modeling Group, department of physics, huazhong university of science and technology, wuhan 430074, china.

The genetic codon UGA has a dual function: serving as a terminator and encoding selenocysteine. However, most popular gene annotation programs only take it as a stop signal, resulting in misannotation or completely missing selenoprotein genes. We developed a computational method named Asec-Prediction that is specific for the prediction of archaeal selenoprotein genes. To evaluate its effectiveness, we first applied it to 14 archaeal genomes with previously known selenoprotein genes, and Asec-Prediction identified all reported selenoprotein genes without redundant results. When we applied it to 12 archaeal genomes that had not been researched for selenoprotein genes, Asec-Prediction detected a novel selenoprotein gene in Methanosarcina acetivorans. Further evidence was also collected to support that the predicted gene should be a real selenoprotein gene. The result shows that Asec-Prediction is effective for the prediction of archaeal selenoprotein genes.

关键词： archaea selenocysteine selenoprotein SECIS SelB gene prediction

Cavity-Enhanced Third Harmonic Generation

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Communications in Theoretical physics 2005年第2期43卷 318-320页

作者： YANG Xiao-Xue~1 WU Ying~(1,2)1 State Key Laboratory for Laser Technique and physics department,huazhong university of science and technology,wuhan 430074,china2 Center for Cold Atom physics,the Chinese Academy of sciences,wuhan 430071,china State Key Laboratory for Laser Technique and physics department Huazhong University of Science and Technology Center for Cold Atom physics the Chinese Academy of Sciences

We derive the analytical expression of microcavity-enhanced factor for third harmonic generation in termsof detunings,linewidths,and the Purcell factors of the relevant microcavity *** is suitable for microcavitics wi... 详细信息

关键词： microcavities third harmonic generation quantum optics multi-wave mixing

A New Synthetical Model of High-Power Pulsed Laser Ablation

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Communications in Theoretical physics 2007年第7期48卷 163-168页

作者： ZHANG Duan-Ming FANG Ran-Ran LI Zhi-Hua GUAN Li LI Li TAN Xin-Yu LIU Dan LIU Gao-Bin HU De-Zhi department of physics,huazhong university of science and technology,wuhan 430074,china department of physics Huazhong University of Science and Technology Wuhan 430074 China

We develop a new synthetical model of high-power pulsed laser ablation,which considers the dynamicabsorptance,vaporization,and plasma *** the corresponding heat conduction equations with the initial andboundary conditions are *** numerical solutions are obtained under the reasonable technical parameter condi-tions by taking YBa_2Cu_3O_7 target for *** space-dependence and time-dependence of temperature in targetat a certain laser fluence are presented,then,the transmitted intensity through plasma plume,space-dependence oftemperature and ablation rate for different laser fluences are significantly *** a result,the satisfactorily goodagreement between our numerical results and experimental results indicates that the influences of the dynamic absorp-tance,vaporization,and plasma shielding cannot be *** all the three mechanisms above simultaneouslyinto account for the first time,we cause the present model to be more practical.

关键词： pulsed laser ablation dynamic absorptance vaporization laser produced plasma

Analytical Results of Steady-State Populations in Multiphoton Electromagnetically Induced Transparency

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Communications in Theoretical physics 2004年第12期 887-890页

作者： YANG Xiao-Xue,~(1,2) LUO Jin-Ming,~2 WU Ying~(1,2,3)~1State Key Laboratory for Laser Technique,huazhong university of science and technology,wuhan 430074,china~2physics department,huazhong university of science and technology,wuhan 430074,china~3Center for Cold Atom physics,the Chinese Academy of sciences,wuhan 430071,china

We present the explicit analytical expressions of the steady-state probability amplitudes and populationsof atom levels in N-photon electromagnetically induced transparency for an arbitrary positive integer N.

关键词： electromagnetically induced transparency multi-wave mixing