Faithful quantum secure direct communication protocol against collective noise

An improved quantum secure direct communication (QSDC) protocol is proposed in this paper.Blocks of entangled photon pairs are transmitted in two steps in which secret messages are transmitted directly.The single logical qubits and unitary operations under decoherence free subspaces are presented and the generalized Bell states are constructed which are immune to the collective noise.Two steps of qubit transmission are used in this protocol to guarantee the security of communication.The security of the protocol against various attacks are discussed.     

X-ray studies of the domain formation in rocks under blasting

Quartz plates placed in concrete are used to model the rock blasting procedure. Quartz fragments resulted from blasting are studied by small-angle X-ray scattering. Obtained grains in the quartz fragments are approximately 200–220 nm in size. The samples are discovered to contain low-dimensional (linear) components; the further the sample is from the explosion center, the coarser the grains are in it. Superlattice parameters of the studied fragments are estimated. It is suggested that domain boundaries in the sample quartz fragments are linear objects, such as dislocation walls.     

Nuclear vibrations and rotations of like nucleons in the same shell in even-even nuclei

The vibrational and rotational motions in even nuclei are considered. A microscopic study of these motions leads to a relation between the vibrational motion in spherical nuclei and the rotational motion in deformed nuclei. Nuclei with like nucleons in the same shell are considered. The quadrupole two-body interactions are used in the large singlej-shell of even nuclei. The energies and transition operators of nuclei in the nuclear rotational region are calculated using this microscopic method. Quadrupole moments are also calculated. These calculations are compared with the rotational model of the aligned coupling scheme. The present calculations are in good agreement with previous calculations.     

Stokes eigenmodes in square domain and the stream function–vorticity correlation

The Stokes eigenmodes in the square are numerically determined and their symmetry properties are identified. The spectra evolution laws are in excellent qualitative agreement with the theoretical asymptotic predictions proposed by Constantin and Foias (in “Navier–Stokes equations”, University of Chicago Press, 1988), . The slopes are reported here and are found to be specific to the eigenmodes symmetry family. The dynamic equilibria are analyzed and show a linear relationship between the vorticity and the stream function in the core of the eigenmodes. These features of the Stokes eigenmodes confined in the square are shared by the fully periodic Stokes eigenmodes.     

约束对Birkhoff系统Noether对称性和守恒量的影响

研究约束对Birkhoff系统的Noether对称性和守恒量的影响．首先，建立了Birkhoff系统的运动微分方程．其次，给出了系统Noether对称性的判据．然后，讨论了受约束作用后，Birkhoff系统的Noether对称性发生的变化，并给出了系统的Noether对称性以及守恒量保持不变的条件．最后，举例说明结果的应用． 关键词： 分析力学 Birkhoff系统 约束 Noether对称性 守恒量     

Calculated correlations between material parameters and electro-optical performance of twisted nematic displays

Computer calculations of the optical transmission of TN-LCDs as a function of the applied voltage are presented. In particular, the wavelength and angular dependence of half transmission voltages and sharpness of transmission curves are examined. Furthermore the lowest relaxation rates of the linearized dynamical equations, neglecting backflow effects are calculated. The dielectrical anisotropy and the elastic parameters are varied systematically in the calculations over ranges that actually occur in nematics. Although the results are too complex to be condensed in simple general statements they are helpfull in designing optimal nematic mixtures for a given display application.     

Quantum noise frequency correlations of multiply scattered light

Frequency correlations in multiply scattered light that are present in quantum fluctuations are investigated. The speckle correlations for quantum and classical noise are compared and are found to depend markedly differently on optical frequency, which was confirmed in a recent experiment. Furthermore, novel mesoscopic correlations are predicted that depend on the photon statistics of the incoming light.     

Shadowing effects in nuclear parton distributions for small values ofx

The shadowing corrections to gluon and quark distributions in nuclei in the region of small values ofx are discussed. They are related to parton distributions in a pomeron which are in principle measurable in hard diffractive processes on the nucleon target. Multiple scattering corrections to shadowing are considered in a model dependent way. The perturbative QCD evolution of shadowing is also taken into account. Various possibilities of the partonic content of a pomeron are considered. It is shown in particular that the conventional parametrizations of parton distributions in a pomeron which are based on the assumption that it consists mostly of gluons imply substantial nuclear shadowing in gluon distributions in heavy nuclei. Possible phenomenological implications of shadowing corrections in nuclear parton distributions for various semi-hard processes with nuclear targets are briefly discussed.     

Mean-field theories of spin glasses

Different kinds of mean-field theories (MFT) of spin glasses (SG) are reviewed. A brief introductory review of major experimental results, which have to be explained theoretically, is presented in the beginning. Marshall-Klein-Brout type random local field theories are described qualitatively. Edwards-Anderson MFT of SG transition is introduced after defining the various relevant order parameters. Almost all the static and dynamic approaches to the solution of the Sherrington-Kirkpatrick model are reviewed in detail. The existence of mixed phase(s) in the MFT of vector SG is examined critically in the light of recent theories and experiments. The existence of macroscopic anisotropy energy in SG and their microscopic origin are mentioned. The upper and lower critical dimensionalities obtained by different authors are enlisted. The concept of frustration and its deeper connection with other branches of human knowledge are indicated. Nonlinear susceptibilities, spin wave and relaxational modes in SG are also reviewed. The two-level-system picture of SG, its physical basis and important consequences are presented. The Tholence-Tournier-Wohlfarth phenomenological cluster model of SG is discussed with a stress on the role of measurement time. SG transition has been described as percolation and localization-delocalization problems. Some special features of the local field distribution in SG are mentioned. Some results of computer simulation on the various models of SG are summarized. The theories of the transport properties of SG are enlisted. Recent trends in the theory of SG are indicated at the end.     

Validity of the semiclassical periodic orbit approximation in the two- and three-disk problems

The high-lying resonances in the quantum mechanical scattering problem of a point particle from two or three equally sized (and spaced) circular hard disks in the two-dimensional plane are predicted quite well by the classical cycle expansion. There are, however, noticeable deviations for the lowest resonances. Therefore, the leading corrections from creeping paths to the cycle expansion in the two-disk scattering problem are constructed. Generalizations to the three-disk problem are indicated. The size of the corrections are estimated. They are shown to be too small to account for the deviations mentioned above. Finally, arguments are given that, for the two- and three-disk problem, the semiclassical predictions of the low-lying resonance poles are bound to fail.     

Higgs masses in the standard,multi-Higgs and supersymmetric models

Theoretical constraints and limits on the masses of Higgs scalars in the standard electroweak model, in electroweak models with additional Higgs doublets and in various supersymmetric models are presented. In the standard model, the lower limit on the Higgs mass, based on vacuum stability arguments, is reviewed in detail, as are “upper limits” based on perturbative constraints. In most grand unified and all supersymmetric models, however, at least two doublets are needed. The masses of the various Higgs scalars in the two-doublet model are discussed and constraints on their masses are found, including the generalization of the above limits. The results are then generalized to models with more than two doublets. Finally, recent attempts at constructing models with low-energy supersymmetry are reviewed and it is shown that in many models, fairly stringent tree-level mass relations among the Higgs scalars can be found. These relations are interesting in that they do not refer to the supersymmetric partners of ordinary particles, and they are most restrictive in models in which the supersymmetry is explicitly broken, i.e., via arbitrary mass terms.     

Thermodynamics of electrons in the graphene bilayer

Some problems of the thermodynamics of electrons in a doped graphene bilayer are considered. Analytical expressions are derived for chemical potential and specific heat in the limiting cases of low and high temperatures. The Seebeck and Thomson coefficients are estimated. Landau levels are studied using a semi-classical approach. An expression for thermodynamic potential is obtained and the de Haas-van Alphen oscillations are studied. The oscillations of magnetic entropy and electron temperature in a magnetic field, i.e., the oscillating magnetocaloric effect, are investigated. For all parameters, the cases of graphene bilayer and monolayer are compared.     

Numerical model for nonlinear standing waves and weak shocks in thermoviscous fluids.

Nonlinear standing waves in a one-dimensional tube are studied numerically by using a finite-difference algorithm. The numerical code models the acoustic field in resonators for homogeneous, thermoviscous fluids. Calculations are performed exclusively in the time domain, and all harmonic components are obtained by one resolution. The fully nonlinear differential equation is written in Lagrangian coordinates. It is solved without truncation. Effects of absorption are included. Displacement and pressure wave forms are calculated at different locations and results are shown for different excitation levels and tube lengths. Amplitude distributions along the resonator axis for every harmonic component are also evaluated. Simulations are performed for amplitudes ranging from linear to strongly nonlinear and weak shock. A very good concordance with classic experimental and analytical results is obtained.     

导板光互连光斑位置偏移的研究

随着人们对信息处理与交换速度和容量提出的更高的要求,出现了光互连．它具有并行处理、传播速度快、信息量大、空间频带宽、串音小和能量损耗低等优点,因此它在光计算机和信息处理领域中成为越来越吸引人的课题［１～４］提出光电结合的计算机系统．实现光－电混合计算．ＳａｕｅｒＦ提出了将电子元件组成的电路板安装在光导板上的方法［５,６］．每个电路板除了包括计算机本身要求的功能外,还装上发射信号的光源和接收信号的探测器,借助全息元件的耦合,以光导板作为光信息交换的通道．这种互连方式传输信息,结合光电优点,利用Ｂｒ…     

Fiber optics in japan

This paper describes the recent progress in research and development of fiber optics in Japan. A review is presented of recent developments in fiber manufacturing, cabling, and fiber splicing. Experimental results are given for an optical communication system with optoelectronic components. Theoretical analysis and fundamental experiments are not included, nor are research activities in such devices as lasers or in such applications as those in medical fields. Transmission characteristics of optical fibers—in particular loss and pulse spreading—are assessed from the viewpoint of their structures. Various methods of fiber strengthening and structuring cables are described from the viewpoint of mechanical strength. Coupling efficiencies of detachable connectors and methods of permanent fiber splicing are described. Experimental results on optical fiber communication systems are presented and coupling techniques between a light source and an optical fiber are described.     

Fiber optics in japan

Abstract

This paper describes the recent progress in research and development of fiber optics in Japan. A review is presented of recent developments in fiber manufacturing, cabling, and fiber splicing. Experimental results are given for an optical communication system with optoelectronic components. Theoretical analysis and fundamental experiments are not included, nor are research activities in such devices as lasers or in such applications as those in medical fields. Transmission characteristics of optical fibers—in particular loss and pulse spreading—are assessed from the viewpoint of their structures. Various methods of fiber strengthening and structuring cables are described from the viewpoint of mechanical strength. Coupling efficiencies of detachable connectors and methods of permanent fiber splicing are described. Experimental results on optical fiber communication systems are presented and coupling techniques between a light source and an optical fiber are described.     

Stationary Striations due to Interaction of Two Ionization Waves in Xenon Glow Discharge

Experimental observations on stationary striations in the positive column of xenon discharge are reported. Stationary striations are observed when two ionization waves exist simultaneously in the positive column at low pressure and high current region. These stationary striations are caused by nonlinear interference of two backward ionization waves of which frequencies are either equal or are in the ratio 1:2. The spatial intervals for the striated pattern are equal to the reciprocal of the difference between the wave-numbers of two ionization waves.     

Aerial Video Trackers Review

Target tracking technology that is based on aerial videos is widely used in many fields; however, this technology has challenges, such as image jitter, target blur, high data dimensionality, and large changes in the target scale. In this paper, the research status of aerial video tracking and the characteristics, background complexity and tracking diversity of aerial video targets are summarized. Based on the findings, the key technologies that are related to tracking are elaborated according to the target type, number of targets and applicable scene system. The tracking algorithms are classified according to the type of target, and the target tracking algorithms that are based on deep learning are classified according to the network structure. Commonly used aerial photography datasets are described, and the accuracies of commonly used target tracking methods are evaluated in an aerial photography dataset, namely, UAV123, and a long-video dataset, namely, UAV20L. Potential problems are discussed, and possible future research directions and corresponding development trends in this field are analyzed and summarized.     

小波分析及神经网络方法在核物理及核工程中的应用

介绍了小波分析和神经网络方法在核物理及核工程领域的应用现状。 分别对小波分析及神经网络方法的基本原理进行了介绍, 详细讨论了小波变换中的多分辨分析方法在γ能谱平滑以及核电站设备监测等方面的应用, 讨论了连续小波变换在γ能谱分析、 粒子种类鉴别以及核反应堆安全监测等领域的应用。 同时, 还详细介绍了神经网络方法在以上各领域的发展现状。 最后, 展望了两种方法在核安全检测、 核辐射防护以及核电站实时监控等领域的发展趋势。 Applications of wavelet analysis and neutral networks in the field of nuclear physics and engineering are reviewed. The principle of these two methods are introduced briefly, and then the applications of multiresolution analysis technique in the smoothing of γ ray spectroscopy, and in nuclear power plant monitoring are discussed in detail. Applications of the continuous wavelet analysis method in γ ray spectroscopy analysis, in particle identification , and in nuclear reactor safety monitoring are also talked over. In addition, the applications of neutral networks in above fields are introduced. Finally, the trends of the future development for these two methods are prospected.