Remote Generation of Entanglement for Individual Atoms via Optical Fibres

The generation of atomic entanglement is discussed in a system that atoms are trapped in separate cavities which are connected via optical fibres. Two distant atoms can be projected to Bell-state by synchronized turning off of the local laser fields and then performing a single quantum measurement by a distant controller. The distinct advantage of this scheme is that it works in a regime where Δ≈κ〉〉g, which makes the scheme insensitive to cavity strong leakage. Moreover, the fidelity is not affected by atomic spontaneous emission.     

Influence of Dopants in ZnO Films on Defects

The influence of dopants in ZnO films on defects is investigated by slow positron annihilation technique. The results show S that parameters meet S_Al>S_un>S_Ag for Al-doped ZnO films, undoped and Ag-doped ZnO films. Zinc vacancies are found in all ZnO films with different dopants. According to S parameter and the same defect type, it can be induced that the zinc vacancy concentration is the highest in the Al-doped ZnO film, and it is the least in the Ag-doped ZnO film. When Al atoms are doped in the ZnO films grown on silicon substrates, Zn vacancies increase as compared to the undoped and Ag-doped ZnO films. The dopant concentration could determine the position of Fermi level in materials, while defect formation energy of zinc vacancy strongly depends on the position of Fermi level, so its concentration varies with dopant element and dopant concentration.     

Finite-Difference Lattice Boltzmann Scheme for High-Speed Compressible Flow: Two-Dimensional Case

Lattice Boltzmann (LB) modeling of high-speed compressible flows has long been attempted by various authors. One common weakness of most of previous models is the instability problem when the Mach number of the flow is large. In this paper we present a finite-difference LB model, which works for flows with flexible ratios of specific heats and a wide range of Mach number, from $0$ to 30 or higher. Besides the discrete-velocity-model by Watari [Physica A 382 (2007) 502], a modified Lax--Wendroff finite difference scheme and an artificial viscosity are introduced. The combination of the finite-difference scheme and the adding of artificial viscosity must find a balance of numerical stability versus accuracy. The proposed model is validated by recovering results of some well-known benchmark tests: shock tubes and shock reflections. The new model may be used to track shock waves and/or to study the non-equilibrium procedure in the transition between the regular and Mach reflections of shock waves, etc.     

Influence of Velocity Shell Correlations on Anomalous Scaling Exponents of Passive Scalars in Shell Models

We propose a new approach to the old-standing problem of the anomaly of the scaling exponents of passive scalars of turbulence. Different to the original problem, the distribution function of the prescribed random velocity field is multi-dimensional normal and delta-correlated in time. Here, our random velocity field is spatially correlative. For comparison, we also give the result obtained by the Gaussian random velocity field without spatial correlation. The anomalous scaling exponents H(p) of passive scalar advected by two kinds of random velocity above are determined for structure function up to p=15 by numerical simulations of the random shell model with Runge-Kutta methods to solve the stochastic differential equations. We observed that the H(p)'s obtained by the multi-dimensional normal distribution random velocity are more anomalous than those obtained by the independent Gaussian random velocity.     

Self-dual Vortices in Schrödinger-Chern-Simons Model

By making use of the U(1) gauge potential decomposition theory and the φ-mapping topological current theory, we investigate the Schrödinger-Chern-Simons model in the thin-film superconductor system and obtain an exact Bogomolny self-dual equation with a topological term. It is revealed that there exist self-dual vortices in the system. We study the inner topological structure of the self-dual vortices and show that their topological charges are topologically quantized and labeled by Hopf indices and Brouwer degrees. Furthermore, the vortices are found generating or annihilating at the limit points and encountering, splitting or merging at the bifurcation points of the vector field φ.     

绕Hydronautics水翼空化云流动的实验研究

采用高速全流场显示技术和DPIV对空化水翼近壁处的空化云流动形态和运动机理进行了讨论.结果表明:绕Hydronautics翼型的空化云运动是一个准周期性过程:稳定空泡团初生在翼型前部,向翼型后部发展布满整个翼面,在翼型后缘出现汽泡团旋涡,伴随反向运动,最终向下游脱落.当前条件下空泡团旋涡脱落周期约为74 ms.空化区与主流区的交界面上存在较大的速度梯度,一组对涡出现在翼型尾部处交界面上.此外,采用以空泡为示踪粒子的DPIV能够对空化流动流速分布进行有效测量.     

基于PIC方法的二维束流动力学模拟程序及其初步应用

为了深入研究强流负氢束在强流质子回旋加速器CYCIAE-100轴向注入线中的传输, 利用split-operator方法分解外场和束流自身的空间电荷场的作用. 对外 场利用单粒子跟踪技术, 采用一阶线性近似; 对空间电荷场采用PIC方法, 利用 快速傅里叶变换求解Poisson方程. 用FORTRAN95语言开发了一个基于面向对象技术的二维宏粒子传输计算程序CYCPIC2D, 本程序可以计算任意分布的强流束在输运线上的传输.最后给出了对CYCIAE-100注入线的模拟计算结果, 并和程序ORBIT, TRACE 3-D的结果进行比对验证, 结果表明: 空间电荷效应在此注入线上有较大的影响, 而且3个程序计算的不同中性化的结果基本上一致; 束流强度达到几十毫安时, 基于PIC方法的两个程序CYCPIC2D和ORBIT的计算结果完全吻合, 而线性近似程序TRACE 3-D有明显差异.     

基于支持向量机的模型传递方法研究

模型传递是以数学方法通过在2台不同仪器之间寻求一种变换关系来增强光谱仪数据通用性、可比性的一种基本途径。由于实际测量数据具有非线性特征,加上校正样本集合的有限性,使得解决小样本条件下非线性关系的模型传递问题显得尤为重要。文章在概述支持向量机基本原理的基础上,探讨了支持向量机方法在光谱仪的模型传递问题中的应用,提出了基于支持向量机的分段直接校正方法,最后采用计算机模拟的方式对该方法进行了举例说明,并和人工神经网络方法进行了相应的比较。     

电压敏感染料di-4-ANEPPS的光谱研究

实验研究了电压敏感染料di-4-ANEPPS在家兔心肌组织中的吸收光谱和荧光光谱特性。结果表明,含染料组织的光吸收普遍大于对照组,在450～550 nm波段吸收谱差异更明显;染料在心室组织中的最大吸收峰为(479.75±0.44) nm。通过测量含染料心脏不同部位的荧光光谱,首次发现心室组织、心房组织和主动脉的最大荧光峰位有一定差异,其相对荧光强度则与染料的分布浓度有关。根据三维和二维荧光光谱分别确定了含染料心房和心室组织的最佳荧光激发波长和荧光测定波长。利用心房和心室组织的静息电位差,在不同波长激发光下测量了染料的荧光光谱移动,确定了光标测量实验的最佳激发光和相应荧光检测波长范围。这些研究结果为心脏光学标测系统的设计提供了理论依据。     

色谱光谱法测试超临界压力下穿心莲内酯的结晶规律

以30%和95%的穿心莲内酯为实验原料,采用超临界CO2萃取结晶法考察了不同压力下穿心莲内酯在结晶板上的分布规律,同时也考察了晶体的晶型和红外光谱的变化规律。研究证实： 高效液相色谱分析,不同压力下穿心莲内酯在结晶板上都按纯度梯度结晶分布;X射线衍射分析,压力越高,晶体越趋于向比较单一的晶面上择优生长;红外光谱分析,压力的变化,并没有引起穿心莲内酯化学结构的改变。