基于六粒子纠缠态和Bell态测量的量子信息分离

通过介绍六粒子纠缠态的新应用研究,提出了一个二粒子任意态的信息分离方案.在这个方案中,发送者Alice、控制者Charlie和接受者Bob共享一个六粒子纠缠态,发送者先执行两次Bell基测量;然后控制者执行一次Bell基测量;最后接受者根据发送者和控制者的测量结果,对自己拥有的粒子做适当的幺正变换,从而能够重建要发送的...     

状态转变增强拉曼光谱

表面增强拉曼散射(SERS)是公认的超灵敏的光谱工具.和传统的优化SERS基底材料或构筑完美的结构策略相比,我们提出了一种极其简单和灵敏的方法,该方法被命名为状态转变增强拉曼光谱(STERS).这种STERS检测方法可广泛的应用于毒品安全检测、食品安全和环境保护等方面.如果我们把这种方法和便携式拉曼光谱仪结合,这种应用...     

不良导体导热系数与温度关系研究

采用稳态平板法测量不良导体的导热系数时,关键是得到稳态时不良导体的传热速率。根据稳态时传热速率与散热铝盘的散热速率相等,可以测定自然冷却过程中,稳态时散热铝盘温度T2所对应的冷却速率。基于Matlab软件,分析并绘制曲线直观反映出温度、时间、冷却速率三者之间的关系,用拟合法研究了不良导体导热系数随温度变化的关系。     

带孔片状不良导体导热系数测试方法探究

推导出稳态法测量带孔片状不良导体导热系数的适用公式,并采用有效的方法对光盘进行了测试分析.     

基于五离子最大纠缠态的优化隐形传态和超密集编码

我们提出了一个制备五离子最大纠缠态的方案,并利用该纠缠态实现任意两量子比特的隐形传送和超密集编码。超密集编码的信息容量满足Holevo bound,这意味着通过发送三个量子比特可以传送五个经典比特的信息。     

中医五行学说思维模型研究

研究中医五行学说思维模型,根据五行系统的特点,结合线性系统控制理论,通过把五行矩阵对角化,得到五行系统可镇定的充要条件和状态观测器存在的充要条件,并给出具体的求解算法．     

关于Haar 酉元的一个注记

设M 是一个Ⅱ₁ 型因子, τ 是M 的正规的、忠实的迹态, U ∈ M 是一个Haar 酉元, p ∈ M是一个投影, τ (p) = (1/n) (n > 3, n ∈ Z), p 和U 自由. 我们用初等方法证明了若pUp = wh 是pUp 的极分解, 则w 也是一个Haar 酉元且w 和h 是自由的. 我们还给出了pUp 的矩的刻画.     

Numerical methods for computing ground states and dynamics of nonlinear relativistic Hartree equation for boson stars

Efficient and accurate numerical methods are presented for computing ground states and dynamics of the three-dimensional (3D) nonlinear relativistic Hartree equation both without and with an external potential. This equation was derived recently for describing the mean field dynamics of boson stars. In its numerics, due to the appearance of pseudodifferential operator which is defined in phase space via symbol, spectral method is more suitable for the discretization in space than other numerical methods such as finite difference method, etc. For computing ground states, a backward Euler sine pseudospectral (BESP) method is proposed based on a gradient flow with discrete normalization; and respectively, for computing dynamics, a time-splitting sine pseudospectral (TSSP) method is presented based on a splitting technique to decouple the nonlinearity. Both BESP and TSSP are efficient in computation via discrete sine transform, and are of spectral accuracy in spatial discretization. TSSP is of second-order accuracy in temporal discretization and conserves the normalization in discretized level. In addition, when the external potential and initial data for dynamics are spherically symmetric, the original 3D problem collapses to a quasi-1D problem, for which both BESP and TSSP methods are extended successfully with a proper change of variables. Finally, extensive numerical results are reported to demonstrate the spectral accuracy of the methods and to show very interesting and complicated phenomena in the mean field dynamics of boson stars.     

Time-dependent density functional theory study on electronic excited states of the hydrogen-bonded solute-solvent phenol-(H2O)n (n=3-5) clusters

The solute-solvent interactions of hydrogen-bonded phenol-(H₂O)_n (n=3-5) clusters in electronic excited states were investigated by means of the time-dependent density functional theory (TDDFT) method. The geometric structures and IR spectra in ground state, S₁ state, and T₁ state of the clusters, were calculated using the density functional theory (DFT) and TDDFT methods. Only the ring form isomer, the most stable one of the cluster, was considered in this study. Four, five and six intermolecular hydrogen bonds were formed in phenol-(H₂O)₃, phenol-(H₂O)₄, and phenol-(H₂O)₅ clusters, respectively. Based on the analysis of IR spectra, it is revealed that the “window region” between unshifted and shifted absorption bands in both S₁ and T₁ state becomes broader compared with that in ground state for the corresponding clusters. Furthermore, two interesting phenomenon were observed: (1) with the anticlockwise order of the ring formed by the intermolecular hydrogen bonds in the H-bonded phenol-(H₂O)_n (n=3-5) clusters, the strengths of the intermolecular hydrogen bonds decrease in all the S₀, S₁ and T₁ states; (2) upon electronic excitation, the smaller the distance between phenol and water is, the larger the change of intermolecular hydrogen bonds strength is. Moreover, the intermolecular hydrogen bond (phenolic OH is the H donor) is strengthened in excited state compared with that in ground state. But the intermolecular hydrogen bond (phenolic OH is the H acceptor) is weakened in excited state.     

Intercept-resend attacks on Chen et al.'s quantum private comparison protocol and the improvements

Recently, Chen et al. presented a novel quantum private comparison (QPC) protocol using triplet GHZ state to enable two parties to compare the equality of their information without revealing the content. The protocol is rather promising because it only requires single-photon measurement with the help of a semi-honest third party to complete the secret comparison. However, this study will point out that a weakness could occur in the eavesdropping check phase. That is, an intercept-resend attack could be launched by one of the two participants to reveal the information content of the other participant—a result that contradicts to the security requirement of a QPC. Fortunately, two solutions are possible to avoid the attack.