共查询到20条相似文献,搜索用时 9 毫秒
1.
M. Fukuyama 《Journal of statistical physics》2000,98(5-6):1049-1061
Georgii's theorem ensures that, restricted to two-dimensional planes, a single ocean (i.e., infinite connected component) of a ground state and islands (i.e., finite connected components) are observed in lattice spin systems at sufficiently low temperature. This paper extends his results for higher dimensional hyperplanes. Our proof is mainly based on a kind of Peierls argument and is different from Georgii's, which relies on the percolation method. 相似文献
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It is well know that systems with an interaction decaying as a power of the distance may have critical exponents that are different from those of short-range systems. The boundary between long-range and short-range is known, however the behavior in the crossover region is not well understood. In this paper we propose a general form for the crossover function and we compute it in a particular limit. We compare our predictions with the results of numerical simulations for two-dimensional long-range percolation. 相似文献
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We consider a successful Kerr–Newman formulation of elementary particles and deduce a mass independent but spin-dependent short-range force and point out that exactly such an inexplicable force has been experimentally detected. 相似文献
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We consider a successful Kerr–Newman formulation of elementary particles and deduce a mass-independent but spin-dependent
short-range force and point out that exactly such an inexplicable force has been experimentally detected. 相似文献
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V. B. Kashirin 《Russian Physics Journal》2005,48(9):936-939
A numerical investigation is made of some details of the short-range order in model amorphous structures with free boundaries
and a number of different interaction potentials. Five- and seven-member rings — typical features of amorphous structures
— are found out in all two-dimensional cross-sections of the generated clusters. Histograms of distribution of the nearest-neighbor
numbers are constructed and an analysis of the positions of atoms with different coordination numbers within a model cluster
volume is performed. An evaluation is made of the effects of the boundary on the coordination number distribution.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 42–45, September, 2005. 相似文献
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Renjun Duan Massimo Fornasier Giuseppe Toscani 《Communications in Mathematical Physics》2010,300(1):95-145
We study the stability of the equilibrium states and the rate of convergence of solutions towards them for the continuous kinetic version of the Cucker-Smale flocking in presence of diffusion whose strength depends on the density. This kinetic equation describes the collective behavior of an ensemble of organisms, animals or devices which are forced to adapt their velocities according to a certain rule implying a final configuration in which the ensemble flies at the mean velocity of the initial configuration. Our analysis takes advantage both from the fact that the global equilibrium is a Maxwellian distribution function, and, on the contrary to what happens in the Cucker-Smale model (IEEE Trans Autom Control 52:852–862, 2007), the interaction potential is an integrable function. Precise conditions which guarantee polynomial rates of convergence towards the global equilibrium are found. 相似文献
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The objective of ISLES (Inverse-Square Law Experiment in Space) is to perform a null test of Newton's law in space with a resolution of one part in 105 or better at 100 m. ISLES will be sensitive enough to detect axions with the strongest allowed coupling and probe large extra dimensions of string theory down to a few m. The experiment will be cooled to 2 K, which permits superconducting magnetic levitation of the test masses. This soft, low-loss suspension, combined with a low-noise SQUID, leads to extremely low intrinsic noise in the detector. To minimize Newtonian errors, ISLES employs a near null source, a circular disk of large diameter-to-thickness ratio. Two test masses, also disk-shaped, are suspended on the two sides of the source mass at a nominal distance of 100 m. The signal is detected by a superconducting differential accelerometer. 相似文献
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MAWei-Xing HUZhao-Hui ZHOULi-Juan ZHUJi-Zhen LUJuan 《理论物理通讯》2003,40(6):699-701
Based on Glauber Multiple Scattering Theory, high-energy proton elastic scattering on halo-like nucleus ^13C is studied in a single nucleon wave function with low angular momentum configurations. A great agreement with experimental data is obtained and the theoretical prediction clearly shows that 13U has a neutron halo-like structure.Then, the origin and nature of nuclear halo phenomena are explained in terms of nuclear short-range correlations. Our conclnsion shows ttiat the origin of nuclear halo-like phenomena originates from short range nuclear correlation. 相似文献
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Properties of Random Overlap Structures (ROSt)’s constructed from the Edwards-Anderson (EA) Spin Glass model on ℤ d with periodic boundary conditions are studied. ROSt’s are ℕ×ℕ random matrices whose entries are the overlaps of spin configurations sampled from the Gibbs measure. Since the ROSt construction is the same for mean-field models (like the Sherrington-Kirkpatrick model) as for short-range ones (like the EA model), the setup is a good common ground to study the effect of dimensionality on the properties of the Gibbs measure. In this spirit, it is shown, using translation invariance, that the ROSt of the EA model possesses a local stability that is stronger than stochastic stability, a property known to hold at almost all temperatures in many spin glass models with Gaussian couplings. This fact is used to prove stochastic stability for the EA spin glass at all temperatures and for a wide range of coupling distributions. On the way, a theorem of Newman and Stein about the pure state decomposition of the EA model is recovered and extended. 相似文献
12.
We study the size distribution of coding and non-coding regions in DNA sequences. For most organisms we observe that the size distribution P
c(S) of the coding regions of size S shows short range distribution, whereas the size distribution of the non-coding regions follows a power-law decay P
nc(S) S
–1 – , with power exponents indicating clear long-range behavior. We argue, using the Generalized Central Limit Theorem, that the long-range distributions observed in the non-coding are related to the lower level clustering of purines and pyrimidines (1d islands) which follow similar long-range laws. We also address the question of clustering of coding segments in the two complementary strands of DNA. We observe a short-range clustering of coding regions in both strands, expressed by an exponential decay in the clustering size distribution. The decay exponent expresses the degree of short-range correlations and the deviation from random clustering. 相似文献
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Based on Glauber Multiple Scattering Theory, high-energy proton elastic scattering on halo-like nucleus 13C is studied in a single nucleon wave function with low angular momentum configurations. A great agreement with experimental data is obtained and the theoretical prediction clearly shows that 13 C has a neutron halo-like structure.Then, the origin and nature of nuclear halo phenomena are explained in terms of nuclear short-range correlations. Our conclusion shows that the origin of nuclear halo-like phenomena originates from short range nuclear correlation. 相似文献
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Location-based ITS applications, especially the applications based on Vehicle-to-Vehicle (V2V) communication, require the absolute or relative location information of the communicating objects. GPS receivers are often used to give the absolute locations of the objects. However, the updating rate and the resolution of GPS receivers are not sufficient for neighboring and highly mobile vehicles.This paper renders two designs, a one-dimensional IR signal-source tracker and a two-dimensional IR signal-source tracker, to estimate the location of a communicating target. By analyzing the strength of the received signal, the relative location of the target is identified once the communication data are received. The realized 1D and 2D IR signal-source tracker can give the precise location, where the repeated tests on the 2D tracker show the given locations with low deviation. Since these two tracker designs are realized with the same IR components in the Dedicated Short-Range Communication (DSRC), the communicating devices, the roadside unit (RSU) and the onboard unit (OBU), can use the 1D or 2D tracker design depending on the application to locate each other, and then to control the radiation direction for saving power, to facilitate the completeness of transactions, and to locate vehicles in V2V applications.In this work, the proposed devices are designed, realized and tested. The experimental results show that these two designs are feasible. 相似文献
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We investigate the short-range correlations in light nuclei. The highly correlated many-body states are obtained with an explicitly correlated basis which enables us to get a precise solution of a many-body Schrödinger equation for a realistic interaction. We show two-body density distributions for the different spin-isospin channels calculated from three- and four-body states to investigate the short-range correlations between nucleon pairs. At distances below 1 fm a universal behavior is found which does not depend on the many-body states. The universality is also seen in high momentum components of the two-body momentum distributions. 相似文献
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传统超导体具有大的相干长度 ,借助于由隧穿测量给出的电流 -电压关系 ,可以反演出电声子相互作用的谱密度α2 F(ω) .对于高温超导体来说 ,情况完全不同 ,它的相干长度很短 ,为要研究其中的相互作用谱密度 ,最好的办法是采用红外光反射率测量或进行中子非弹性散射实验 .最近 ,美国橡树岭 (OakRidge)国家实验室的P .C .Dai等 ,对YBa2 Cu3O6 x(YBCO)系列样品 ,给出了中子非弹性散射研究的新数据 .结果表明 ,短程反铁磁自旋关联 ,在超导形成中起着重要的作用 .中子散射与X射线散射的区别主要在于 :X射线散射的强… 相似文献
18.
The non-Hermitian PT-symmetric system can live in either unbroken or broken PT-symmetric phase. The separation point of the unbroken and broken PT-symmetric phases is called the PT-phase-transition point.Conventionally, given an arbitrary non-Hermitian PT-symmetric Hamiltonian, one has to solve the corresponding Schrodinger equation explicitly in order to determine which phase it is actually in. Here, we propose to use artificial neural network(ANN) to determine the PT-phase-transition points for non-Hermitian PT-symmetric systems with short-range potentials. The numerical results given by ANN agree well with the literature, which shows the reliability of our new method. 相似文献
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We use a field theoretical approach to describe the exact General Relativity via a rank-two symmetric tensor field ϕμv. We examine the hypothesis that the long range gravitational field has a local counterpart mediated by massive spin-2 bosons which preserves the SU(2) × U(1) gauge symmetry of Electroweak interaction. 相似文献
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We introduce a model for self-organized dynamics which, we argue, addresses several drawbacks of the celebrated Cucker-Smale (C-S) model. The proposed model does not only take into account the distance between agents, but instead, the influence between agents is scaled in term of their relative distance. Consequently, our model does not involve any explicit dependence on the number of agents; only their geometry in phase space is taken into account. The use of relative distances destroys the symmetry property of the original C-S model, which was the key for the various recent studies of C-S flocking behavior. To this end, we introduce here a new framework to analyze the phenomenon of flocking for a rather general class of dynamical systems, which covers systems with non-symmetric influence matrices. In particular, we analyze the flocking behavior of the proposed model as well as other strongly asymmetric models with “leaders”. 相似文献