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1.
Usual cylinder construction neglect planar analyticity and the resulting cylinder is contaminated by j-plane cuts. Beginning with input planar amplitudes that are manifestly consistent with a pole-to-pole planar bootstrap, a three-dimensional cylinder equation is formulated, incorporating planar analyticity. The output cylinder is now free of j-plane cuts. The bare pomeron is a simple pole with trajectory intercept slightly above one.  相似文献   

2.
In this article, non‐linear propagation of ingoing and outgoing electrostatic waves on the ion time scale in an unmagnetized, non‐relativistic electron‐ion (ei) plasma in the presence of warm ions, ion kinematic viscosity, and trapped Maxwellian electrons was examined in a non‐planar geometry. In the weak non‐linearity limit, modified soliton and shock equations were derived with the inclusion of electron trapping in cylindrical and spherical geometries. The finite difference method was used to solve all these equations in the non‐planar geometries using the planar versions of these equations as an initial input. The results were compared with their counterparts with quadratic non‐linearity and the main differences were expounded. It was shown that the spatio‐temporal scales over which the shocks form for the non‐planar trapped Burgers equation are much shorter by comparison with the shocks admitted by the non‐planar trapped Korteweg de Vries Burgers equation. It was also found that unlike their non‐linear shock counterparts, the solitary structures admitted by the non‐planar trapped Korteweg de Vries equation exhibit a phase shift.  相似文献   

3.
王理林  王志军  林鑫  王猛  黄卫东 《中国物理 B》2012,21(6):66801-066801
The morphological stability of a planar interface with different crystallographic orientations is studied under a small positive temperature gradient using a transparent model alloy of succinonitrile.Novel experimental apparatus is constructed to provide a temperature gradient of about 0.37 K/mm.Under this small temperature gradient,the planar interface instability depends largely on the crystallographic orientation.It is shown experimentally that the effect of interfacial energy anisotropy on planar interface stability cannot be neglected even in a small temperature gradient system.Higher interfacial energy anisotropy leads the planar interface to become more unstable,which is different from the stabilizing effect of the interfacial energy on the planar interface.The experimental results are in agreement with previous theoretical calculations and phase field simulations.  相似文献   

4.
黏性介质中圆截面弹性细杆的平面振动   总被引:2,自引:0,他引:2       下载免费PDF全文
刘延柱 《物理学报》2005,54(11):4989-4993
讨论圆截面弹性细杆在黏性介质中的平面振动. 基于Kirchhoff理论,以杆中心线的Frenet坐标系为参考系,建立其动力学方程,杆中心线为任意平面曲线时,其扭转振动与弯曲振动解耦. 讨论两端固定条件下任意形状杆的平面扭转振动,以及无扭转的轴向受压直杆和圆环杆的平面弯曲振动,导出其自由振动频率和阻尼系数. 证明空间域内压杆的Lyapunov稳定性和欧拉稳定性条件为时域内渐近稳定性的充分必要条件,或无阻尼压杆的稳定性必要条件. 圆环杆平衡恒满足渐近稳定性条件. 关键词: 弹性细杆 黏性介质 扭转振动 弯曲振动  相似文献   

5.
The Hall effect and magnetoresistance in Cr(50 Å)/Co(200 Å) bilayer films prepared by ion sputtering on a silicon substrate are investigated at room temperature. The planar Hall effect revealed in the bilayer films differs from the planar Hall effect observed usually in that it is symmetric with respect to the sign of the change in the rotation angle of the magnetic moment in the film plane. Under conditions where the symmetric planar Hall effect is realized, the change in the Hall resistance is more than 10% and exceeds the anisotropic magnetoresistance by two orders of magnitude. The hysteresis loops are measured at different orientations of magnetic fields. The planar Hall effect is studied in a weak longitudinal magnetic field. The results obtained demonstrate that the symmetric planar Hall effect is associated with the multidomain structure of the cobalt film in Cr/Co bilayer composites.  相似文献   

6.
王新兵  徐启阳 《光学学报》1997,17(10):440-1444
平板波导内的场按自由空间传播的厄米高斯函数展开,计算了平板波导谐振腔的耦合损失,给出了平板波导中EH11模的耦合损失与球镜的曲率及位置的关系。结果表明存在两种特定的结构使耦合损失最小。  相似文献   

7.
The classical planar Richtmyer–Meshkov instability(RMI) at a fluid interface supported by a constant pressure is investigated by a formal perturbation expansion up to the third order,and then according to definition of nonlinear saturation amplitude(NSA) in Rayleigh–Taylor instability(RTI),the NSA in planar RMI is obtained explicitly.It is found that the NSA in planar RMI is affected by the initial perturbation wavelength and the initial amplitude of the interface,while the effect of the initial amplitude of the interface on the NSA is less than that of the initial perturbation wavelength.Without marginal influence of the initial amplitude,the NSA increases linearly with wavelength.The NSA normalized by the wavelength in planar RMI is about 0.11,larger than that corresponding to RTI.  相似文献   

8.
Experimental multielement planar and channel waveguide structures induced by coherent radiation in bulk samples of photorefractive lithium niobate and planar waveguides on their basis including those formed in a projection scheme with scaling of image dimensions are described. The possibility of linear and nonlinear light localization in optically-induced bulk and planar one-dimensional photorefractive photonic superlattices is demonstrated. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 57–62, September, 2008.  相似文献   

9.
Solitary wave evolution of optical planar vortices in isotropie self-defoeusing photorefractive media is investigated in detail. We demonstrate that the formation of a planar vortex soliton intensively depends on the diameter and maximum intensity of the input vortex Seam. The exact solutions of planar vortex solitons are obtained due to the Petviashvili iteration method. It is found that, with the increasing soliton maximum intensity, the soliton core will be gradually diminished to a minimum value.  相似文献   

10.
The point spread function (PSF) in gradient-index planar optics for implementation of crossover interconnects is studied. Gradient-index (GRIN) planar optics is made with refractive substrate providing a smart optical diffraction-limited imaging. We use as a figure of merit the space-bandwidth product (SBP) of the planar imaging system in order to estimate the number of data channels which can be handled in crossover interconnects. For a selfoc semirod-lens of 3 mm diameter, a crossover network configuration of 703 × 703 channels can be designed.  相似文献   

11.
Planar defects in three-dimensional chalcogenide glass photonic crystals   总被引:1,自引:0,他引:1  
Here we report on the direct laser writing fabrication of Fabry-Perot-type planar microcavities in a three-dimensional (3D) photonic crystal (PhC) embedded within a high-refractive nonlinear chalcogenide glass (ChG) film. The fabricated planar microcavities in a nonlinear ChG 3D PhC facilitate the observation of resonant modes inside the stop gap. The experimental results show that the length of the planar cavity can be well controlled by the fabrication power and thus be used to tune the defect modes. The tunability of the observed defect modes is confirmed by the theoretical prediction.  相似文献   

12.
The control of spontaneous emission is one of important characteristics of a planar microcavity. The integrals in the spherical coordinate for TE and TM modes spontaneous emission spectra of a quantum well (QW) embedded in a planar microcavity are derived with new variables dependent on wavelength and Taylor series including the two polarizations of the vacuum field. The approximate expressions of spontaneous emission in QW planar microcavities are obtained. The approximate results show that spontaneous emission spectra agree well with that in the numerical integral for planar semiconductor microcavities, in which Fermi-Dirac distribution functions of electrons and holes are considered. The main contribution to the spontaneous emission, radiated into all direction, has been found.  相似文献   

13.
The planar Hall effect in a ferromagnetic conductor is considered within a simple two-liquid hydro-dynamic model. It is shown that, even in the simple case of an isotropic Fermi surface in the absence of thermal spread, the magnitude of the Hall effect is comparable to that in semiconductors because of the presence of two groups of conduction electrons with their spins parallel and perpendicular to the quantization axis, respectively. In addition to the planar Hall field, a spin flux parallel to this field arises, with the consequence that the extent of spin polarization of the conduction electrons varies along the Hall field direction (planar spin Hall effect).  相似文献   

14.
15.
The self-consistent dynamics of a dislocation ensemble in an elastic field of a planar mesodefect has been considered within the kinetic approach. The effective Airy stress function for a planar mesodefect, which takes into account the screening effect of a system of distributed dislocation charges, has been obtained. Coordinate dependences of the stress tensor components and the dislocation charge density for the considered screened system have been found. Its elastic energy and misorientation of the regions adjacent to the planar mesodefect have been calculated.  相似文献   

16.
Theoretical predictions and experiments demonstrate that solid state mechanics should consider, along with a structurally equilibrium 3D crystalline subsystem, a structurally nonequilibrium planar subsystem as a complex of all surface layers and internal interfaces with broken translation invariance. Primary plastic flow of a loaded solid develops in its structurally nonequilibrium planar subsystem as channeled nonlinear waves of local structural transformations that determine the self-organization law of multiscale plastic flow. These waves initiate mesoscale rotational deformation modes, giving rise to all types of microscale strain-induced defects in the planar subsystem. The strain-induced defects are emitted into the crystalline subsystem as an inhibitor of nonlinear waves of plastic flow in the planar subsystem. Plastic deformation of solids, whatever the loading type, evolves in the field of rotational couple forces. Loss of hierarchical self-consistency by rotational deformation modes culminates in fracture of material as an uncompensated rotational deformation mode on the macroscale.  相似文献   

17.
为了提高场效应晶体管太赫兹探测器的响应度并降低噪声等效功率,需要对探测器集成平面天线的结构进行合理设计与优化,本文对集成平面天线结构的场效应晶体管太赫兹探测器的研究进行了深入调研。首先,对场效应晶体管太赫兹探测器的工作原理进行了分析,介绍了集成平面天线如何解决耦合太赫兹波效率低的问题。然后,介绍了一些常用的平面天线结构,包括偶极子天线、贴片天线、缝隙天线、grating-gate和其他类型的结构,比较了各种天线的性能以及引入后对太赫兹探测器响应度的影响。通过对比不同天线结构的探测器响应度和噪声等效功率等参数指标,发现:采用平面天线结构之后,场效应晶体管太赫兹探测器的响应度有了大幅度的提升,各种类型的天线对探测器响应度都有不同程度的提升。本文着重介绍了几种集成于场效应晶体管的平面天线结构,包括各种天线的性能和研究进展,最后分析了场效应晶体管太赫兹探测器存在的问题和发展趋势。  相似文献   

18.
Transmission electron microscopy is applied to study the diamond film grown in a CH4 and H2 gaseous mixture by microwave plasma assisted chemical vapour deposition. Defects in the nanometre scale, dislocation loops, arefirst observed in diamond films. The dislocation loops are found to be of co-existence with planar defects and are next to the planar defects for {111} faceting grains. A possible mechanism is suggested to interpret the co-existence of dislocation loops with planar defects.  相似文献   

19.
We reports a phase-space structure of MeV proton beam planar channelled along {110} planes in Si crystal using simulation results with the help of a computer code FLUX. The aim is to understand channelling conditions suitable for disorder measurement in crystals. Phase-space distribution of a planar channelled proton beam evolutes in a systematic fashion when it travels into the crystal. Planar channelled beam oscillates between phase-like and space-like conditions in which a part of the beam becomes under phase and space criticalities. These criticality conditions in planar channelling are analysed, explained and discussed with the perspective of defect measurement in crystals.  相似文献   

20.
Jianfeng Dong  Chao Xu   《Optics Communications》2009,282(19):3899-3904
Chiral nihility meta-material is a special case of chiral medium, in which both the permittivity and permeability are equal to zero. The feature of surface wave modes (or surface polaritons) in the planar chiral nihility waveguides which the core or cladding consist of chiral nihility meta-materials is investigated. The dispersion curves, electromagnetic fields, energy flow distribution and the power of surface wave modes in the planar chiral nihility waveguides are presented for typical parameters. Some novel peculiarities such as anomalous dispersion curves, the power flows opposite to the wave vector propagation direction in the planar chiral nihility waveguides have been found.  相似文献   

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