Flux Fluctuations in the One Dimensional Nearest Neighbors Symmetric Simple Exclusion Process

Let J(t) be the the integrated flux of particles in the symmetric simple exclusion process starting with the product invariant measure ν _ρ with density ρ. We compute its rescaled asymptotic variance: $$\mathop {\lim }\limits_{t \to \infty } t^{ - 1/2} \mathbb{V}J(t) = \sqrt {2/\pi } (1 - \rho )\rho$$ Furthermore we show that t ^?1/4 J(t) converges weakly to a centered normal random variable with this variance. From these results we compute the asymptotic variance of a tagged particle in the nearest neighbor case and show the corresponding central limit theorem.     

自制四端低值电阻的标定

用直接或间接测量法,标定自制四端低值电阻。将测量数据用加权平均法给出测量结果。     

Submean Variance Bound for Effective Resistance of Random Electric Networks

We study a model of random electric networks with Bernoulli resistances. In the case of the lattice \({\mathbb{Z}^2}\) , we show that the point-to-point effective resistance between 0 and a vertex v has a variance of order at most \({({\rm log} |v|)^{\frac{2}{3}}}\) , whereas its expected value is of order log | v|, when v goes to infinity. When d ≠ 2, expectation and variance are of the same order. Similar results are obtained in the context of p- resistance. The proofs rely on a modified Poincaré inequality due to Falik and Samorodnitsky [7].     

用Word 2000绘制物理图形的快捷方法

Word 2000的绘图功能相当强大,在使用中对于常用的图形单元,我们可以利用它提供的"自动图文集"和"自定义菜单"功能把自己花费一定功夫制作的图形,设置成菜单或工具栏上的一个按钮,下次再用时只要单击这个按钮,就可以轻松插入相应的图形.     

Connection-Matrix Eigenvalues in the Ising Model: Taking into Account Interaction with Next-Nearest Neighbors

Doklady Physics - The connection matrix of the Ising model on a $$d$$-dimensional hypercube is investigated. In addition to the interactions between the nearest neighbors, the interactions between...     

The Further Estimations of the Q-Balls with One-Loop Motivated Effective Potential

The analytical estimations on the Friedberg-Lee-Sirlin typed Q-balls is performed. The two-field Q-balls are also discussed under the one-loop motivated effective potential subject to the temperature. We argue under the analytical consideration that the parameters from the potential can be regulated to lead the energy per unit charge of Q-balls to be lower to keep the model stable. If the energy density is low enough, the Q-balls can become candidates of dark matter. It is also shown rigorously that the two-field Q-balls can generate in the first-order phase transition and survive while they are affected by the expansion of the universe. The analytical evaluations show that the Q-balls with one-loop motivated effective potential can exist with the adjustment of coefficients of terms. We cancel the infinity in the energy to obtain the necessary conditions consist with those imposed in the previous work. According to the approximate expressions instead of curves versus the model parameters with a series of fixed values, the lower temperature will reduce the energy density, so there probably have been more and more stable Friedberg-Lee-Sirlin typed Q-balls to become the dark matter in the expansion of the universe.

     

The Integrated Density of States of the Random Graph Laplacian

We analyse the density of states of the random graph Laplacian in the percolating regime. A symmetry argument and knowledge of the density of states in the nonpercolating regime allows us to isolate the density of states of the percolating cluster (DSPC) alone, thereby eliminating trivially localised states due to finite subgraphs. We derive a nonlinear integral equation for the integrated DSPC and solve it with a population dynamics algorithm. We discuss the possible existence of a mobility edge and give strong evidence for the existence of discrete eigenvalues in the whole range of the spectrum.     

The Creation of Spectral Gaps by Graph Decoration

We present a mechanism for the creation of gaps in the spectra of self-adjoint operators defined over a Hilbert space of functions on a graph, which is based on the process of graph decoration. The resulting Hamiltonians can be viewed as associated with discrete models exhibiting a repeated local structure and a certain bottleneck in the hopping amplitudes.     

Graph State-Based Quantum Secret Sharing with the Chinese Remainder Theorem

Quantum secret sharing (QSS) is a significant quantum cryptography technology in the literature. Dividing an initial secret into several sub-secrets which are then transferred to other legal participants so that it can be securely recovered in a collaboration fashion. In this paper, we develop a quantum route selection based on the encoded quantum graph state, thus enabling the practical QSS scheme in the small-scale complex quantum network. Legal participants are conveniently designated with the quantum route selection using the entanglement of the encoded graph states. Each participant holds a vertex of the graph state so that legal participants are selected through performing operations on specific vertices. The Chinese remainder theorem (CRT) strengthens the security of the recovering process of the initial secret among the legal participants. The security is ensured by the entanglement of the encoded graph states that are cooperatively prepared and shared by legal users beforehand with the sub-secrets embedded in the CRT over finite fields.     

Renormalization of the Effective Electron Mass Governing the Period of Microwave-Induced Resistance Oscillations in ZnO/MgZnO Heterojunctions

The phenomenon of microwave-induced magnetoresistance oscillations is studied in a series of ZnO/MgZnO heterojunctions characterized by different two-dimensional electron densities n. It is found that the effective electron mass m* determined from the period of microwave-induced magnetoresistance oscillations depends essentially on this parameter. For high densities, the value of m* tends to the effective electron mass in bulk ZnO, while for low densities, m* increases pronouncedly and becomes considerably larger than the electron cyclotron mass. The experimental results give clear evidence of a significant impact of the electron–electron interaction on microwave-induced magnetoresistance oscillations.     

欧姆表有效量程的分析

在使用万用表的实验中，多数教材均提到欧姆表(万用表的欧姆档)的测量存在一个有效量程，在这个有效量程范围内，测出的数据才是较准确的．然而各教材对欧姆表有效量程的规定并不一致．文1献[1]认为1/5R中～5R中应为欧姆表的有效量程(R中为各档的中值电阻)；文献[2]认为欧姆表各档     

Covering Rules and Nearest Neighbour Configurations of the Dodecagonal Quasiperiodic Structure

A dodecagonal quasiperiodic structure can be generated by duster covering and the quasilattice is described in terms of the quasi-unit cell. We study the structural properties of the two-dimensional dodecagonal quasilattice in the covering scheme. The pair covering rules and the nearest neighbour configurations are determined. It is shown that the dodecagonal structure is more complicated than those of decagonal and octagonal quasilattices.     

The Effective Theory of Strings

We show that the Nambu–Goto string, and its higher dimensional generalizations, can be quantized, in the sense of an effective theory, in any dimension of the target space. The crucial point is to consider expansions around classical string configurations. We are using tools from perturbative algebraic quantum field theory, quantum field theory on curved spacetimes, and the Batalin–Vilkovisky formalism. Our model has some similarities with the Lüscher–Weisz string, but we allow for arbitrary classical background string configurations and keep the diffeomorphism invariance.     

Phase Transformations and Thermodynamic Properties of the Potts Model with q = 4 on a Hexagonal Lattice with Interactions of Next-Nearest Neighbors

Physics of the Solid State - The magnetic structures of the ground state, phase transitions, and the thermodynamic properties of a two-dimensional ferromagnetic Potts model with the number of spin...     

Nearest neighbour diagnostic statistics on the accuracy of APT solute cluster characterisation

Diagnostic statistics and information theory techniques have been developed to investigate the accuracy to which solute clusters characterised in atom probe tomography (APT) data can reflect the true nature of the physical clusters in the original specimen. Simulated atom-probe datasets representing a range of atomic solute clustering within a pseudo-binary alloy upon an fcc aluminium lattice were generated for the study. The effectiveness of partitioning the APT-like simulated data based upon a binary classification defined by a distance threshold d _max upon the kth nearest neighbour distance distribution was investigated. Information theory was also used to optimise the selection of the threshold d _max. Analysis of variation was performed upon a factorial design of data simulations with low and high levels of: solute concentration; short-range order; and background to the mass-to-charge-state-ratio spectrum. This meta-analysis showed that the background levels have a significant compromising effect upon the binary classification in low solute systems with relatively low or random levels of clustering. Although the random clustering of higher solute concentrations is better analysed, significantly non-random clustering in both low and high solute concentrations is analysed well despite the presence of high levels of background. A meta-analysis of the binary classification upon a simulated dispersion of coherent precipitates within a similar matrix was also undertaken. Optimal k and d _max parameters are likely a dependent upon the physical dimensions of precipitate size as well as the precipitate/matrix solute concentrations.     

控制光速的有效方法——电磁诱导透明的原理和应用

光速减慢是自然界的一种普遍现象，并不是什么新奇的发现．例如，光在不同介质中的传播速度不同，都比真空中慢．问题的关键在于我们能将光速减慢到什么程度，怎样控制光速为人类社会服务．经过不懈努力，人们已经初步实现了控制光速的减慢，甚至还可以将光速减慢为零，进而把光存储起来．上述进展都是通过20世纪90年代发展起来的电磁诱导透明技术实现的．本文对该技术的原理和应用前景作一简要介绍．     

Effective hamiltonians with relativistic corrections: The Foldy-Wouthuysen transformation versus the direct Pauli reduction

Two different methods of obtaining “effective 2 × 2 hamiltonians” which include relativistic corrections to nonrelativistic calculations are discussed. The standard Foldy-Wouthuysen transformation generates hamiltonians which order by order in 1/M decouple the upper from the lower components. The upper left-hand block then defines an effective 2 × 2 Foldy-Wouthuysen hamiltonian. In the second method the matrix element of the interaction hamiltonian of the Dirac representation is evaluated between free positive-energy states and reduced to two-component form. The resulting expression (possibly expanded in 1/M) then defines what we call the “direct Pauli reduction” effective 2 × 2 hamiltonian. We wish to investigate under which circumstances the two approaches yield the same result. Using a generic interaction with harmonic time dependence we show that differences in the corresponding effective S-matrices do arise beyond first-order perturbation theory. We attribute them to the fact that the use of the direct reduction effective hamiltonian involves the additional approximation of neglecting contributions from the negative-energy intermediate states, an approximation which is unnecessary in the Foldy-Wouthuysen case as there the 4 × 4 hamiltonian does not connect positive- and negative-energy states. We conclude that at least in the cases where the relativistic hamiltonian is known, using the direct Pauli reduction effective hamiltonian introduces spurious relativistic effects and therefore the Foldy-Wouthuysen reduction should be preferred.     

Effect of Growing Size of Interaction Neighbors on the Evolution of Cooperation in Spatial Snowdrift Game

In this paper,we study the influence of the size of interaction neighbors(k) on the evolution of cooperation in the spatial snowdrift game.At first,we consider the effects of noise K and cost-to-benefit ratio r,the simulation results indicate that the evolution of cooperation depends on the combined action of noise and cost-to-benefit ratio.For a lower r,the cooperators are multitudinous and the cooperation frequency ultimately increases to 1 as the increase of noise.However,for a higher r,the defectors account for the majority of the game and dominate the game if the noise is large enough.Then we mainly investigate how k influences the evolution of cooperation by varying the noise in detail.We find that the frequency of cooperators is closely related to the size of neighborhood and cost-to-benefit ratio r.In the case of lower r,the augmentation of k plays no positive role in promoting the cooperation as compared with that of k = 4,while for higher r the cooperation is improved for a growing size of neighborhood.At last,based on the above discussions,we explore the cluster-forming mechanism among the cooperators.The current results are beneficial to further understand the evolution of cooperation in many natural,social and biological systems.     

The Four Lives of a Nuclear Accelerator

Electrostatic accelerators have emerged as a major tool in research and industry in the second half of the twentieth century. In particular in low energy nuclear physics they have been essential for addressing a number of critical research questions from nuclear structure to nuclear astrophysics. This article describes this development on the example of a single machine which has been used for nearly sixty years at the forefront of scientific research in nuclear physics. The article summarizes the concept of electrostatic accelerators and outlines how this accelerator developed from a bare support function to an independent research tool that has been utilized in different research environments and institutions and now looks forward to a new life as part of the experiment CASPAR at the 4,850” level of the Sanford Underground Research Facility.