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1.
1 Introduction  FRT(FractionalFourierTransform )wasfirstlyintroducedbyNamiasin 1 980asamathematictoolinquantummechanics[1] .In1 993,MendlovicandOzaktasimplementedtheFRTatopticalfieldwhentheystudiedgradientindex (GRIN )fiber[2 ] andappliedthepuremathematicformulatio…  相似文献   

2.
1IntroductionDuringrecentyearsfractionalFouriertransform(FRT)hasbenatractedmuchatentioninawidefieldofapplications.ThefirstFRT...  相似文献   

3.
1 IntroductionFig.1DualgalvanometerscaningsystemForlaserdisplaytechnology,thescanningsystembasedongalvanometerisakeydevice(Fig.1).BycontrollingtheXYscanner,thelaserbeamsaresteeredsoquickly,thatthegraphicsandcartoncanbedisplayedonascreenorthebeameff…  相似文献   

4.
1 Introduction  Opticalfastfrequency hopingcode divisionmultiple accesssystems (FFHOCDMA)haverecentlybeen proposedasacandidateforopticallocalareanetworks(LANs) [1,2 ] .Inthisscheme ,FBGsarecodingdevices,whichslicethespectrumoftheincoming pulsetoreflect .Theoutpu…  相似文献   

5.
InvestigationofFarInfraredWaveguideFreeElectronLaserDrivenbyRFLinacHUSuxing;FUEnsheng(ShanghaiInstituteofOpticalandFineMechan...  相似文献   

6.
LaserInducedDamageinCVDDiamondFilmsQIUHongFANZhengxiu(ShanghaiInstituteofOpticsandFineMechanics,ChineseAcademyofSciences,P.O....  相似文献   

7.
ProposalforEfficiencyEnhancementofaFarInfraredFreeElectronLaser¥HUSuxing;FUEnsheng;XUZhizhan(ShanghaiInstiuteofOpticsandFineM...  相似文献   

8.
1 Introduction  TheLPFGisatypeoftransmissiongratingbasedontheprincipleofcouplingtheguidedfundamentalmodetotheforwardpropagatingcladdingmodes.UnliketheBragggrating ,therefractiveindexperturbationofLPFG’shaveamuchgreaterperiodicitythanthewavelengthofthel…  相似文献   

9.
1IntroductionWiththedevelopmentoftheintegratedopticsandfabricationtechnologyofsemiconductor,opticalFouriertransform(OFT)isbec...  相似文献   

10.
PureDispersiveOpticalBistabilityofFour-levelSysteminaFabry-PerotCavity¥JIYing;LINFucheng(ShanghaiInstituteofOpticsandFineMech...  相似文献   

11.
对托卡马克平衡反演数值计算代码EFTT进行了改进,使之适用于EAST装置的磁流体平衡研究.用改进后的平衡反演代码EFTT模拟了EAST装置稳态阶段的偏滤器平衡位形.提出极向场线圈电流作为线性方程组主约束条件。期望位形作为从约束条件,求解非对称电流条件下自由边界平衡问题的方法.结果表明。该方法能较为容易地得到非对称电流条件产生的平衡位形,在非对称电流条件下自由边界平衡计算是收敛的.  相似文献   

12.
It is necessary to reduce the currents of poloidal field(PF) coils as small as possible, during the static equilibrium design procedure of Experimental Advanced Superconductive Tokamak(EAST). The quasi-snowflake(QSF) divertor configuration is studied in this paper. Starting from a standard QSF plasma equilibrium, a new QSF equilibrium with 300 kA total plasma current is designed. In order to reduce the currents of PF6 and PF14, the influence of plasma shape on PF coil current distribution is analyzed. A fixed boundary equilibrium solver based on a non-rigid plasma model is used to calculate the flux distribution and PF coil current distribution. Then the plasma shape parameters are studied by the orthogonal method. According to the result, the plasma shape is redefined, and the calculated equilibrium shows that the currents of PF6 and PF14 are reduced by 3.592 kA and 2.773 kA, respectively.  相似文献   

13.
First it is shown that each extremal equilibrium state is representable as limit of Gibbs states in finite volumes, and that an analogous statement holds for extremal invariant equilibrium states. Secondly we prove that for negative pair interactions only one equilibrium state exists which minimizes (resp. maximizes) the particle density, but that in general there are more than two extremal invariant equilibrium states with the same particle density. In this context, periodic interactions are studied.  相似文献   

14.
It is pointed out that the usual (Gibbs) thermal equilibrium state in Minkowski spacetime is no longer a thermal equilibrium state for a uniformly accelerated observer. Similarly, the thermal equilibrium state in Kruskal spacetime is not a thermal state for a Schwarzschild observer.  相似文献   

15.
邹兴  陈松泽  郭照立 《计算物理》2020,37(6):653-666
流体系统在重力作用下,流体压力可与重力相平衡,达到静力平衡状态.常规的有限差分和有限体积方法无法在离散尺度上保持这种平衡态,常常产生虚假速度等非物理现象.通过将重力源项的体积分改写为网格界面值的加权平均,实现离散条件下压力与重力的精细平衡,得到一种Navier-Stokes (NS)方程的精细平衡气体动理学格式.该格式可以在机器精度上精确地保持等温条件下的静力平衡态以及捕捉平衡态附近的小扰动传播.同时,该格式还能求解自然界中更常见的非等温平衡态.此类平衡态除了要求静力平衡还要求热流平衡.利用提出的格式求解NS方程,可以得到静止(机器精度下的零速度)的非等温平衡态,并且密度和温度分布都具有二阶精度.通过多个算例验证格式的有效性,表明该格式可更好地模拟重力场下的温度、密度的分层流动.  相似文献   

16.
Recent studies on confined crystals of charged colloidal particles are reviewed, both in equilibrium and out of equilibrium. We focus in particular on direct comparisons of experiments (light scattering and microscopy) with lattice sum calculations and computer simulations. In equilibrium we address buckling and crystalline multilayering of charged systems in hard and soft slit confinement. We discuss also recent crystalline structures obtained for charged mixtures. Moreover we put forward possibilities to apply external perturbations, in order to drive the system out of equilibrium. These include electrolyte gradients as well as the application of shear and electric fields.  相似文献   

17.
In a graphical game agents play with their neighbors on a graph to achieve an appropriate state of equilibrium. Here relevant problems are characterizing the equilibrium set and discovering efficient algorithms to find such an equilibrium (solution). We consider a representation of games that extends over graphical games to deal conveniently with both local a global interactions and use the cavity method of statistical physics to study the geometrical structure of the equilibria space. The method also provides a distributive and local algorithm to find an equilibrium. For simplicity we consider only pure Nash equilibria but the methods can as well be extended to deal with (approximated) mixed Nash equilirbia.  相似文献   

18.
We discuss the possibility of equilibrium (and thermalization) in heavy-ion collisions at intermediate energies within a transport model. This was achieved by dividing the nuclear matter into different collision zones. We find that those nucleons which experience at least ten collisions are close to complete equilibrium whereas others never achieve any equilibrium.  相似文献   

19.
Stability of SIRS system with random perturbations   总被引:1,自引:0,他引:1  
Qiuying Lu 《Physica A》2009,388(18):3677-3686
Epidemiological models with bilinear incidence rate λSI usually have an asymptotically stable trivial equilibrium corresponding to the disease-free state, or an asymptotically stable non-trivial equilibrium (i.e. interior equilibrium) corresponding to the endemic state. In this paper, we consider an epidemiological model, which is an SIRS model with or without distributed time delay influenced by random perturbations. We present the stability conditions of the disease-free equilibrium of the associated stochastic SIRS system.  相似文献   

20.
We give a simple sufficient condition for a completely positive dynamical semigroup of a N-level system to have a unique (invariant) equilibrium state and for every initial state to approach this equilibrium state as t → ∞. We estimate the rate of approach to equilibrium.  相似文献   

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