Quantum Key Distribution Using High-Dimensional Quantum Error-Avoiding Code

Using high-dimensional quantum error-avoiding code, we present two new quantum key distribution protocols over a collective noisy channel, i.e. six-photon and five-photon quantum error-avoiding codes. Compared with the previous protocols using four-photon and three-photon quantum error-avoiding code, the qubit efficiencies of the new protocols have increases of 16.67% and 5% respectively. In addition, the security of these protocols is analysed with a conclusion that the new protocols are much more secure than the four-photon and three-photon ones.     

Dimensional Properties of Fractional Brownian Motion

Let B^α = {B^α（t）,t E R^N} be an （N,d）-fractional Brownian motion with Hurst index α∈ （0, 1）. By applying the strong local nondeterminism of B^α, we prove certain forms of uniform Hausdorff dimension results for the images of B^α when N 〉 αd. Our results extend those of Kaufman for one-dimensional Brownian motion.     

高能物理学发展的回顾和展望

 从电弱统一理论提出到现在已经过去了23年.量子色动力学从诞生到现在也已经历了17年,在这期间CERN建成了E_cm=60GeV的质子对撞机ISR;FNAL和CERN分别建成了能量为500GeV和450GeV的质子同步加速器.     

关于Lipschitz域上反射Brown运动的游程

本文具体刻画有界 Lipschitz 域上的反射 Brown 运动跨过某给定时刻 t 的离开 Martin 边界的游程．在此基础上,给出 Lipschitz 域上的反射 Brown 运动的边界过程的 L(?)vy 系统．     

Design of Two-Dimensional Photonic Crystal Edge Emitting Laser for Photonic Integrated Circuits

An edge emitting laser based on two-dimensional photonic crystal slabs is proposed. The device consists of a square lattice microcavity, which is composed of two structures with the same period but different radius of air-holes, and a waveguide. In the cavity, laser resonance in the inner structure benefits from not only the anomalous dispersion characteristic of the first band-edge at the M point in the first Brillouin-zone but also zero photon states in the outer structure. A line defect waveguide is introduced in the outer structure for extracting photons from the inner cavity. Three-dimensional finite-difference time-domain simulations apparently show the in-plane laser output from the waveguide. The microcavity has an effective mode volume of about 3.2（λ/nslab）^3 for oscillation mode and the quality factor of the device including line defect waveguide is estimated to be as high as 1300.     

Non-Achievability of Metal-Insulator Transition in Two-Dimensional Systems

We present a simple demonstration of the nonfeasibility of metal-insulator transition in an exactly two-dimensional （2D） system. The Hartree-Fock potential in the 3D system is suitably modified and presented for the 2D case. The many body effects are included in the screening function, and binding energies of a donor are obtained as a function of impurity concentration so as to find out the possible way leading metal-insulator transition in the 2D system. While solving for the binding energy for a shallow donor in an isolated well of a GaAs/Ga1-x Als As superlattice system within the effective mass approximation, it leads to unphysical results for higher concentrations. It shows that the phase transition, the bound electron entering into the conduction band whereby （H）min=0, is not possible beyond this concentration. The results suggest thai a phase transition is impossible in 213 systems, supporting the scaling theory of localization. The results are compared with the existing data available and discussed in the light of existing literature.     

无穷维线性空间中的非游荡算子

本文研究无穷维线性空间一类具有混沌特性的线性算子；非游荡算子。这是无穷维线性混沌系统中一类有广泛意义的算子，同时本文给出了非游荡算子紧集上的超循环分解。     

胃泌素有关肽溶液构象的2D-NMR研究

用2D NMR深入研究了五肽、四肽胃泌素在 DMSO 中的构象。利用 COSY 谱、Relayed-COSY 谱、DQF-J 分解谱和 NOESY 谱归属了全部共振峰。计算了肽键平面的Φ角、旋转异构体分布和旋转异构体之间自由能差。根据 NOESY 谱得到了距离约束条件。结合Φ角及旋转异构体分布, 推导出五肽胃泌素分子的构象膜型。结果表明, 五肽、四肽胃泌素在 DMSO 中以半角构象存在, 在其主要的旋转异构体中 Trp 的吲哚环和 Met 的 S 原子具有类似5,1-benzothiazocine 三维结构, 可能是具有生物活性的原因。