Scheme for implementing quantum dense coding with four-particle decoherence-free states in an ion trap

This paper proposes an experimentally feasible scheme for implementing quantum dense coding of trapped-ion system in decoherence-free states. As the phase changes due to time evolution of components with different eigenenergies of quantum superposition are completely frozen, quantum dense coding based on this model would be perfect. The scheme is insensitive to heating of vibrational mode and Bell states can be exactly distinguished via detecting the ionic state.     

Theoretical analysis of quantum game in cavity QED

Recent years,several ways of implementing quantum games in different physical systems have been presented.In this paper,we perform a theoretical analysis of an experimentally feasible way to implement a two player quantum game in cavity quantum electrodynamic(QED).In the scheme,the atoms interact simultaneously with a highly detuned cavity mode with the assistance of a classical field.So the scheme is insensitive to the influence from the cavity decay and the thermal field,and it does not require the cavity to remain in the vacuum state throughout the procedure.     

Fast scheme for generating quantum-interference states and GHZ state of N trapped ions

We propose a fast scheme to generate the quantum-interference states of N trapped ions. In the scheme the ions are driven by a standing-wave laser beam whose carrier frequency is tuned such that the ion transition can take place. We also propose a simple and fast scheme to produce the GHZ state of N hot trapped ions and this scheme is insensitive to the heating of vibrational motion, which is important from the viewpoint of decoherence.     

高效析氧电催化剂Co3O4@NiMn-LDH异质结构阵列的制备

我们合理设计和制备了一种新型的高性能析氧电催化剂——泡沫镍负载Co_3O_4@NiMn-LDH(层状双金属氢氧化物)三维异质结构阵列(Co_3O_4@NiMn-LDH/NF)。这种基于泡沫镍基底的三维异质结构催化剂经简单的两步水热反应即可制得。对比Co_3O_4、NiMn-LDH及传统RuO2催化剂,所制备的Co_3O_4@NiMn-LDH/NF催化剂展示出更优异的电催化析氧性能。在1 mol·L~(-1)KOH溶液中,电流密度为50 mA·cm~(-2)时的过电势仅为282 mV,塔菲尔斜率为64 mV·dec~(-1)。通过有效的界面工程设计,使异质结构陈列Co_3O_4@NiMn-LDH发挥出Co_3O_4和NiMn-LDH各自优异的电催化性能。其中,基于泡沫镍基底生长的活性组分Co_3O_4纳米线阵列作为中间核支撑结构,保持了良好的空隙率,不仅有利于暴露更多的活性位点,而且有利于电解液的扩散和气体产物的释放;而依附于Co_3O_4纳米线阵列上的NiMn-LDH异质结构纳米片层则富有更多的亲水性基团,使得活性位点更易与水结合,从而促进氧析出反应的进行。     

典型自动步枪枪管系统三维瞬态温度场计算分析

为了研究连续射击过程中周期性高频火药气体热冲击引起的枪管传热问题,本文建立了一套枪管系统传热三维仿真模型,给出了射击过程边界条件和参数的确定方法。以某典型小口径自动步枪为研究对象,计算了带有Cr镀层的某小口径自动步枪枪管系统在连续热冲击下的瞬态温度,分析了其温度场分布规律,计算结果得到了试验结果的验证。计算结果表明:枪管同一圆截面上,随着节点距离枪管轴线距离增大,其温度波动越来越小;枪管周边零件对枪管传热有着重要影响,尤其对与周边零件接触的枪管部分,考虑与否温度计算结果相差76%左右。射击时枪管向瞄准基座传热有迟滞现象,温度明显升高主要发生在空冷时期,同一时刻瞄准基座节点温度随与枪管轴线距离增加而减小;远离枪管轴线的瞄准基座上节点初始温度升高较慢而随着时间和射弹量增长温度升高明显加快。     

辐射传输中的相函数展开方法研究

从辐射传输方程中相函数的展开方法出发，分别介绍了δ-M展开法和δ-fit展开法，并对这两种相函数展开方法进行了比较。结果表明，在相函数展开中，当所取勒让德多项式的阶数相同时，δ-M法的图像始终在真实相函数附近波动，始终无法逼近真实的相函数的值，而δ-fit法符合较好。     

Linear optics implementation for quantum game under quantum noise

It has recently been shown that linear optics alone would suffice to implement efficient quantum computation. Quantum computation circuits using coherent states as the logical qubits can be constructed from very simple linear networks, conditional measurements and coherent superposition resource states. We present the quantum game under quantum noise and a proposal for implementing the noisy quantum game using only linear optics.     

Distributed quantum computation with superconducting qubit via LC circuit using dressed states

A scheme is proposed where two superconducting qubits driven by a classical field interacting separately with two distant LC circuits connected by another LC circuit through mutual inductance,are used for implementing quantum gates.By using dressed states,quantum state transfer and quantum entangling gate can be implemented.With the help of the time-dependent electromagnetic field,any two dressed qubits can be selectively coupled to the data bus (the last LC circuit),then quantum state can be transferred from one dressed qubit to another and multi-mode entangled state can also be formed.As a result,the promising perspectives for quantum information processing of mesoscopic superconducting qubits are obtained and the distributed and scalable quantum computation can be implemented in this scheme.     

La_2Cu_(1-x)V_xO_(4+δ)(0≤x≤0.08)的晶体结构及电输运性质

本文研究了La2Cu1-xVxOv+δ(0≤x≤0.08)的结构及电输运性质.用Rietveld方法对所有样品的X射线衍射谱进行了拟合.结果表明,全部样品都具有正交对称性,晶胞参数随掺杂量的增加几乎没有变化.随着V掺杂量增加到0.08,而La2Cu1-xVxO4+δ中过量氧的平均值从0.006增加到0.007.没有掺杂的样品由于氧过量而存在相分离状态,体系中存在超导相与绝缘相的竞争相互作用.随着V掺杂量增加,超导相受到破坏,我们认为,V掺杂对超导电性抑制的原因可能是载流子浓度的减少和载流子的局域化所致.     

基于组合拟合法的冰晶粒子的光散射计算

利用组合拟合法计算了冰晶粒子的单次散射特性。给出了消光效率因子、单次散射反照度及非对称因子的拟合公式,利用拟合公式对有效粒子尺度为20μm和120μm的六种冰晶粒子的消光效率因子、单次散射反照度及非对称因子进行了计算。结果表明,粒子的消光效率因子、单次散射反照率和非对称因子随着入射波长的增加有着较大的起伏,后两者随着波长的增加而变化趋势基本一致;对于单次散射反照率来说,在可见光波段,反照率非常接近于1;在短波段,粒子的非对称因子变化较小,并且随着波长的增加,非对称因子会逐渐增大。