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Effects of the Centre－of－Mass Motion on the Population Trapping of Ultracold Atoms

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Chinese Physics Letters 2003年第11期20卷 1950-1953页

作者：熊锦张智明 DepartmentofElectronicEngineering ShanghaiJiaoTongUniversityShanghai200030 DepartmentofPhysics ShanghaiJiaoTongUniversityShanghai200240

We investigate the effects of the atomic centre-of-mass motion on atomic population trapping in a two-mode micromaser injected with ultracold Λ-type three-level atoms. We find that in the mazer regime (the case in which the atomic kinetic energy is much smaller than the atom-field interaction energy), the interplay between reflection and transmission of the ultracold atom leads to the destruction of the atomic population trapping.

关键词： Kinetic energy

POSTBUCKLING OF PRESSURE-LOADED SHEAR DEFORMABLE LAMINATED CYLINDRICAL PANELS

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Applied Mathematics and Mechanics(English Edition) 2003年第4期24卷 402-413页

作者：沈惠申 SchoolofCivilEngineeringandMechanics ShanghaiJiaotongUniversity

A postbuckling analysis is presented for a shear deformable laminated cylindrical panel of finite length subjected to lateral pressure. The governing equations are based on Reddy's higher order shear deformation shell theory with von Krmn_Donnell_type of kinematic nonlinearity. The nonlinear prebuckling deformations and initial geometric imperfections of the panel are both taken into account. A boundary layer theory of shell buckling, which includes the effects of nonlinear prebuckling deformations, large deflections in the postbuckling range, and initial geometric imperfections of the shell, is extended to the case of shear deformable laminated cylindrical panels under lateral pressure. A singular perturbation technique is employed to determine the buckling loads and postbuckling equilibrium paths. The numerical illustrations concern the postbuckling response of perfect and imperfect, moderately thick, cross_ply laminated cylindrical panels. The effects played by transverse shear deformation, panel geometric parameters, total number of plies, fiber orientation, and initial geometric imperfections are studied.

关键词： structural stability buckling postbuckling cylindrical panel higher order shear deformable shell theory boundary layer theory of shell buckling singular perturbation technique

Preparation of Poly (ethylene oxide)(PEO)Modified Tungsten Oxide Hybrid Films via Sol-Gel Processing

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Journal of Wuhan University of Technology(Materials Science) 2003年第1期18卷 4-6页

作者：袁坚 shanghaijiaotonguniversity

Poly (ethylene axide) (PEO) modified WO 3 thin films were prepared on glass substrates with special *** sol gel transition proess was investigated by using DTA-TG,SEM and *** electrochemical characteristic of the films was studied by cyclic voltmmetry *** results show that PEO has heavy effects on the crystallization of WO 3 during structure evolution because of the interaction between PEO and WO *** increases the crystallization temperature of the gels and thus improves the electrochemical properties and cyclic life of WO 3 film as electrochromic materials.

关键词： sol gel dipcoating films electrochromic PEO WO 3

PLAIN CASCADE RESEARCH ON A REVERSIBLE COMBINED BLADE

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Chinese Journal of Mechanical Engineering 2003年第1期16卷 40-41,53页

作者： OuyangHua YangBo 等 KeyLaboratoryofEducationMinistryofpowerMachineryandEngineering ShanghaiJiaotongUniversityShanghai200030China KeyLaboratoryofEducationMinistryofpowerMachineryandEngineering ShanghaiJiaotongUniversity

A new type fully reversible combined blade is presented, which can fully reverse airflow during the inverse ventilation by simply reversion. It is suitable for reversible axial flow fans used in tunnel and mine ventilation. The optimal parameters such as overlap ratio and pitch ratio are determined through cascade experiment. Experiment results also show a big promotion of maximum lift coefficient C1,max and stall attack angle a1,max compared to the existing bi-directional symmetry airfoils.

关键词： Axial flow fan Reversible ventilation Combined cascade

Study on an environmental-friendly and high-efficient fuel cell energy conversion system

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Journal of Environmental Sciences 2003年第1期15卷 97-101页

作者： YULi－jun CAOGuang－yi 等 SchoolofPowerandEnergyEngineering ShanghaiJiaotongUniversityShanghai200240China InstituteoifFuelCell ShanghaiJiaotongUniversityShanghai200030China

The kinds and the distribution of the coal in China are investigated. The results indicated that the 80% coal in China is used by the method of the coal gasification. The possibility of utilization and development of the fuel cell power plant in China is analyzed. A combined cycle generation system is designed. Its net electrical efficiency is about 55%(LHV), which is higher than that of the fire power plant. So it is environmental friendly and high efficient generation mode.

关键词： energy conservation pollution control fuel cell power plant coal gasification

Derivation of Exact Eigenvalues and Eigenfunctions Based on the Analytical Transfer Matrix Method

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Chinese Physics Letters 2004年第11期21卷 2089-2092页

作者：何英曹庄琪沈启舜 DepartmentofPhysics ShanghaiJiaoTongUniversityShanghai200240

We extend the analytical transfer matrix method (ATMM) to calculate both the energy eigenvalues and wavefunctions for the Morse potential and the regulated Coulomb potential. Derivations of the exact eigenenergies and eigenfunctions are presented in detail by the ATMM. We compare our results with that obtained by relaxational approach and the eigenvalue moment method, and it is shown that the ATMM can produce accurate eigenvalues. The eigenfunctions by the ATMM are also proven to be correct and meaningful.

关键词： Eigenvalues and eigenfunctions

Focusing Ultrasonic Field of Holed Cap Spherical Shell Transducer Using the Spheroidal Beam Equation

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Chinese Physics Letters 2002年第3期19卷 355-357页

作者：夏荣民寿文德等 DepartmentofBiomedicalEngineering ShanghaiJiaoTongUniversityShanghai200030

A large aperture transducer with an inner hole has been used to validate the feasibility of using the spheroidal beam equation to solve the acoustic field of the inner holed transducer. The numerical results of severa... 详细信息

关键词： Transducers

Approach for workflow modeling using π-calculus

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Journal of Zhejiang University Science 2003年第6期4卷 643-650页

作者：杨东张申生 DepartmentofIndustrialEngineering ShanghaiJiaotongUniversityShanghai200030China DepartmentofComputer ShanghaiJiaotongUniversityShanghai200030China

As a variant of process algebra, π calculus can describe the interactions between evolving processes. By modeling activity as a process interacting with other processes through ports, this paper presents a new approach: representing workflow models using π calculus. As a result, the model can characterize the dynamic behaviors of the workflow process in terms of the LTS (Labeled Transition Semantics) semantics of π calculus. The main advantage of the workflow model's formal semantic is that it allows for verification of the model's properties, such as deadlock free and normal termination. Moreover, the equivalence of workflow models can be checked through weak bisimulation theorem in the π calculus, thus facilitating the optimization of business processes.

关键词： Workflow modeling π calculus Business process modeling

Research on Mediate Temperature Decomposition of High Nitrogen Austenite

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材料热处理学报 2004年第5期25卷 214-216页

作者： LIXiao-ling BEIDuo-hui HUMing-juan ZHUZu-chang SchoolofMaterialScienceandEngineering ShanghaiJiaoTongUniversityShanghaiChina

The decomposed products from high nitrogen austenite aging at 225°C were investigated by TEM. It is found that the shape of decomposition products inside the austenite grains is not regular and not strictly oriented. Preferential nucleation of y-Fe4N at dislocations and grain boundaries has been observed. It also has been found that during the first stage of the high nitrogen austenite decomposition a large quantity of ultra-fine /-Fe4N precipitate inside the parent austenite, which has been thought to be the undecomposed region before. The ultimate products are composed of highly dispersed a-Fe and /-Fe4N, with both of them maintaining nanometer scale. The micro-hardness of them can be as high as 900HV.

关键词：高氮奥氏体温度分解微硬度 TEM