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1.
Our article (Chin. Phys. Lett. 26 (2009) 017102) was attempting to calculate the possible existence of the window effects on the physiological signal changes by the external electric field. It is attempted mainly to combine the vibrated-ion model of Panagopoulos et al.(Refs. in our article) and the cellular model of Kuster et al. (Ref. in our article) and Tortes et al. (Ref. in our article). We did not attempt to take the initiative of theoretical bases of both the groups.  相似文献   

2.
Numerical modelling on the transient electromagnetic scattering by a two-dimensional (21)) cylinder located on a time-evolving rough surface is presented by using time-domain integral equations. The proposed special choice of a tapered Gauss pulse incident wave removes the truncation error from the rough surface. Additionally, a two-level averaging technique is utilized to overcome the instability from the time marching procedure of solving integral equations. Excellent correspondences between the surface current distributions, as well as the far-zone fields, computed by the proposed method and that obtained by the traditional method of moments associated with the inverse discrete Fourier transformation scheme demonstrate the accuracy of the modelling.  相似文献   

3.
For interpreting the production mechanism of surface-wave plasmas sustained along a metal rod, electromagnetic simulation on the electromagnetic field distributions and particle-in-cell/Monte Carlo collision (PIC/MCC) simulation of the ionization process are present. The results show that the enhanced electric field of surface plasmon polaritons (SPPs) can be excited in the ion sheath layer between the negative-voltage metal rod and the surface-wave plasmas, which is responsible for maintaining the plasma discharge. Moreover, the spatio-temporal evolutions of plasma density and electric fields are simulated by the PIC/MCC model. It is further suggested that the expanded ion sheath layer can extend the length of plasma domain by increasing the plasma absorbed energy from SPPs.  相似文献   

4.
An asymmetric Jerusalem unit and the frequency selective surface (FSS) structure composed of such units are designed. The transmittance of the designed FSS structure is calculated by mode-matching method and compared with the test results. The comparison results show that the FSS center frequency of the asymmetric structure unit drifts little with the variation of the incident angles of the electromagnetic waves and keeps relatively stable. The research offers a new choice for the application of FSS under the large scanning angle of electromagnetic waves.  相似文献   

5.
Ravasz et al. structured a deterministic model of a geometrically growing network to describe metabolic networks. Inspired by the model of Ravasz et al., a random model of a geometrically growing network is proposed. It is a model of copying nodes continuously and can better describe metabolic networks than the model of Ravasz et al. Analysis shows that the analytic method based on uniform distributions (i.e., Barabási-Albert method) is not suitable for the analysis of the model and the simulation process is beyond computing power owing to its geometric growth mechanism. The model can be better analyzed by the Poisson process. Results show that the model is scale-free with a self-similarity degree exponent, which is dependent on the common ratio of the growth process and similar to that of fractal networks.  相似文献   

6.
A simple and efficient screening model for studying the effects of superstrong magnetic fields (such as those of magnetars) on thermonuclear reaction rates on magnetar surfaces is proposed in this paper. The most interesting thermonuclear reactions, including hydrogen burning by the CNO cycle and helium burning by the triple alpha reaction, are investigated on the surface ofmagnetars. We find that the superstrong magnetic fields can increase the thermonuclear reaction rates by many orders of magnitude. The enhancement may have a dramatic effect on the thermonuclear runaways and bursts on the surfaces of magnetars.  相似文献   

7.
An efficiently iterative analytical-numerical method is proposed for two-dimensional (2D) electromagnetic scattering from a perfectly electric conducting (PEC) target buried under a dielectric rough surface. The basic idea is to employ the Kirchhoff approximation (KA) to accelerate the boundary integral method (BIM). Below the rough surface, an iterative system is designed between the rough surface and the target. The KA is used to simulate the initial field on the rough surface based on the Fresnel theory, while the target is analyzed by the boundary integral method to obtain a precise result. The fields between the rough surface and the target can be linked by the boundary integral equations below the rough surface. The technique presented here is highly efficient in terms of computational memory, time, and versatility. Numerical simulations of two typical models are carried out to validate the method.  相似文献   

8.
Based on the model of the two calcium stores developed by Goldbeter, the influence of external magnetic field on the calcium concentration has been discussed. We believe that the cell membrane is a major site of interaction for extremely-low-frequency (ELF) electromagnetic fields, and the permeability of ions can be changed with the changing electromagnetic fields. It is shown that magnetic field initiates intraeellular calcium oscillation with a threshold in flux density, and that the calcium oscillations do not occur if the density of magnetic field is below the threshold. The results of theoretical calculation are consistent with that of the experiment. The intracellular free calcium concentrations of different cells exposed to the same magnetic fields are different from each other. It is indicated that the different behaviors such as oscillation, rise and invariability of calcium concentration are associated with the sort of cells.  相似文献   

9.
易煦农  刘劲松  陈欢  杜秋姣 《中国物理 B》2010,19(11):114207-114207
This paper derives the force of the electromagnetic radiation on left-handed materials (LHMs) by a direct applica-tion of the Lorentz law of classical electrodynamics.The expressions of radiation force are given for TE-polarised and TM-polarised fields.The numerical results demonstrate that electromagnetic waves exert an inverse lateral radiation force on each edge of the beams,that is,the lateral pressure is expansive for TE-polarised beams and compressive for TM-polarised beams.The investigation of the radiation force will provide insights into the fundamental properties of LHMs and will provide to better understanding of the interaction of light with LHMs.  相似文献   

10.
Recently, Liu et al. proposed a so-called extended Anderson-Higgs mechanism by studying the (2+1)-dimensional Ginzburg-Landau model in the pseudogap region of high-Tc superconductor (Phys. Rev. B 65 (2002) 132513). We revisit this problem based on a general decomposition of the U(1) gauge potential. Using the bulk superconductor and superconduct ring as examples, we obtain a simpler expression for the extended Anderson-Higgs mechanism. In the former case we indicate that all the phase field can always be "eaten up" by the pure gauge term A||. In the latter case, we decompose the phase field as θ(x) = θ1(x) + θ2(x) and find that only the phase field θ1 connected with Anderson-Higgs mechanism can be canceled by the pure-gauge term A||. On the other hand, the remaining phase field θ2 connected with A⊥ is multi-valued, which can induce new physical effects such as A-B effect and flux quantization. It is natural to conclude that there is no longitudinal phase fluctuation effect in high-temperature superconductors since longitudinal phase θ1 is connected with pure-gauge term.  相似文献   

11.
Observables on hypergraphs are described by event-valued measures. We first distinguish between finitely additive observables and countably additive ones. We then study the spectrum, compatibility, and functions of observables. Next a relationship between observables and certain functionals on the set of measures M(H) of a hypergraph H is established. We characterize hypergraphs for which every linear functional on M(H) is determined by an observable. We define the concept of an effect and show that observables are related to effect-valued measures. Finally, we define operational transformations from M(H) to itself and show that they can be described as a certain combination of effects.On leave from University of Berne, Institute of Mathematical Statistics, Sidlerstrasse 5, CH-3012 Berne, Switzerland.  相似文献   

12.
13.
用SURFMN和SURFMN_TFCOIL代码计算了由HL-2M装置磁场线圈安装误差产生的误差场。根据国外托克马克装置TF和PF线圈安装误差的取值范围,以及HL-2A装置安装的经验,计算选取的TF线圈和PF线圈最大位移范围为3~8mm,最大倾斜角度为0.05~0.1°。选取9组数据计算了误差场的概率密度分布和累计概率分布。结果发现:在TF和PF线圈安装误差取值范围内,随磁场线圈最大移位增大概率密度显著变平,误差场B3-mode/BT的分布范围显著增大;磁场线圈的位移比倾斜对误差场的影响更大;当磁场线圈最大位移达到5mm时误差场大于2×10-4的概率都比较大,特别是线圈最大位移等于8mm时,误差场大于2×10-4的概率在60%以上。  相似文献   

14.
We report on magnetooptic measurements on thin Gd films (3 Åd Gd 1000 Å) grown on an y buffer layer and covered with a 100-Å Y protective top layer. Measurements were carried out in the temperature range from 2 to 300 K and for magnetic field up to 0.3 T. The effect of different growth conditions on the magnetic properties was examined. For films prepared at 300°C, ferromagnetic phase transitions have been observed for nominal film thicknesses down to about one monolayer of Gd. The thickness dependence of the Curie temperatureT C follows a power law with an exponent =1.6 close to the theoretical value for a 3D-Ising ferromagnet.  相似文献   

15.
We classify the measures on the lattice of all closed subspaces of infinite-dimensional orthomodular spaces (E, ) over fields of generalized power series with coefficients in . We prove that every -additive measure on can be obtained by lifting measures from the residual spaces of (E, ). The measures being lifted are known, for the residual spaces are Euclidean. From the classification we deduce, among other things, that the set of all measures on is not separating.Research supported by the Swiss National Science Foundation.  相似文献   

16.
Contrary to the eleven-parameter group consisting of Poincaré-transformations and dilatations, the group of so-called special conformal transformations can act on the Minkowski space only as a local conformal Lie transformation group. We show that the universal covering space of the compactified Minkowski space , together with an appropriate metric \(\tilde g\) on it, form a suitable Lorentz manifold that admits universal covering group of the “conformal group” of as a transitive Lie transformation group. This group respects the causality notion on usually defined on a Lorentz manifold. However, possesses only seven isometries in contrast to the well-known ten isometries on the Minkowski space , which correspond to conservation of energy-momentum and angular-momentum.  相似文献   

17.
Deformation quantization on varieties with singularities offers perspectives that are not found on manifolds. The Harrison component of Hochschild cohomology, vanishing on smooth manifolds, reflects information about singularities. The Harrison 2-cochains are symmetric and are interpreted in terms of abelian *-products. This paper begins a study of abelian quantization on plane curves over , being algebraic varieties of the form , where R is a polynomial in two variables; that is, abelian deformations of the coordinate algebra ). To understand the connection between the singularities of a variety and cohomology we determine the algebraic Hochschild (co)homology and its Barr–Gerstenhaber–Schack decomposition. Homology is the same for all plane curves , but the cohomology depends on the local algebra of the singularity of R at the origin. The Appendix, by Maxim Kontsevich, explains in modern mathematical language a way to calculate Hochschild and Harrison cohomology groups for algebras of functions on singular planar curves etc. based on Koszul resolutions.   相似文献   

18.
Novikov algebras were introduced in connection with the Poisson brackets of hydrodynamic type and Hamiltonian operators in the formal variational calculus. On the other hand, there can be geometry and Lagrangian mechanics on homogenous spaces related to Novikov algebras. The nondegenerate symmetric bilinear forms on Novikov algebras can be regarded as the pseudometrics, and some additional identities for these forms correspond to some conserved quantities. In particular, there is an important kind of conserved nondegenerate symmetric bilinear forms that correspond to the pseudo-Riemannian connections such that parallel translation preserves the bilinear form on the tangent spaces. Moreover, the fact that the left multiplication operators form a Lie algebra for a Novikov algebra is compatible with such a form. However, we show in this note that there are no such forms on most Novikov algebras in low dimensions.  相似文献   

19.
Classical ergodic theory was built on -algebras. The aim of this paper is toprove the individual ergodic theorem on more general structures—mon productMV algebras.  相似文献   

20.
It is proved that the space of all bounded real-valued valuations with (0)=0 on a complemented lattice is isomorphic to the space of all real-valued totally additive measures on a suitable complete Boolean algebra.  相似文献   

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