Transmission Properties of THz Radiation Pulses through Very Deep Zero-Order Metallic Gratings

Very deep zero-order metallic grating structures are processed to study the transmission properties of THz radiation pulses. The experiments have been performed with two samples. The delay of the THz pulses and the corresponding resonantly enhanced transmission spectra through the samples are observed. To explain the extraordinary transmission we have treated the samples as Fabry-Perot resonators through resonant excitation of the coupled surface plasmon polaritons filled in the cavities between the metal slats. The experimental results are in reasonable agreement with the numerical simulation. Our results show that THz-time-domain spectroscopy may be an effective technique for studying the optical properties of various THz microstructured devices.     

Quantum Logic Network for Probabilistic Teleportation of Two-Particle State in a General Form

A simplification scheme of probabilistic teleportation of two-particle state in a general form is given.By means of the primitive operations consisting of single-qubit gates,two-qubit controlled-not gates,Von Neumann measure-ment and classically controlled operations,we construct and efficient quantum logical network for implementing the new scheme of probabilistic teleportation of a two-particle state in a general form.     

Bayesian estimation of keyword confidence in Chinese Continuous speech recognition

In a syllable-based speaker-independent Chinese continuous speech recognition system based on classical Hidden Markov Model(HMM),a Bayesian approach of keyword confidence estimation is studied,which utilizes both acoustic layer scores and syllable-based statistical language model(LM) score.The Maximum a posteriori(MAP) confidence measure is proposed,and the forward-backward algorithm calculating the MAP confidence scores is deduced.The performance of the MAP confidence measure is evaluated in keyword spotting application and the experiment results show that the MAP confidence scores provide high discriminability for keyword candidates.Furthermore,the MAP confidence measure can be applied to various speech recognition applications.     

Bush连续不可微函数的分形性质

本文对用递推关系确定的Bush连续不可微函数,找出了迭代函数系(IFS),从而得到它的级数表达式和所具有的自仿射分形的有关性质.最后还计算出函数图象的Hausdorff 维数的准确值.     

玻色-爱因斯坦凝聚——一种新的宏观物质状态

 2001年10月9日,瑞典皇家科学院宣布,2001年诺贝尔物理学奖授予美国国家标准技术研究所与科罗拉多大学的联合天体物理研究所(JILA)39岁的教授康奈尔(E.A.Cornell)和50岁的教授维曼(C.E.Wieman)以及美国麻省理工学院(MIT)43岁的德裔教授凯特勒(W.Ketterle).     

斜孔气膜冷却数值模拟分析

本文通过数值模拟分析圆柱孔和扩散孔的单斜孔气膜冷却特性,考察复合角、孔型和吹风比对流场和气膜冷却效果的影响。结果表明,复合角的引入使气膜侧向分布更宽,但冷却效果沿主流方向衰减更快。适中吹风比得到的气膜能更有效的保护壁面。在相同吹风比和复合角条件下,扩散孔的气膜冷却效率比圆柱孔更好,且冷却更为均匀持久。     

既不离散也不连续的随机变量

讨论了既不离散也不连续的随机变量 ,并纠正了有关文献中关于连续型随机变量定义中的错误 .     

利用Cluster State实现远程态制备

量子态是量子信息的载体，因此，从某种意义上说，量子信息过程就是量子态的传递和操作的过程。量子态的远程制备包括量子隐形传态（Telepotation）和远程态制备（Remote State Preparation（RSP））。远程态制备是一种利用纠缠和经典通讯传输量子态的简单方法，相比较量子态telepotation耗费的资源更少（1 ebit and 1 cbit）。Cluster State是一种特殊的量子态，在量子计算方案中有着广泛的应用。我们实验上利用SPDC产生的偏振纠缠双光子，加入时间比特，构造出Cluster State，并利用Cluster State实现了量子态的远程制备。     

Ir β+/EC衰变及其系统性分析

在在束实验条件下用γ-γ符合方法研究了具有β⁺/EC衰变性质的核素^176,178Ir的衰变γ射线. 另外借助氦喷嘴快速带传输系统在排除在束干扰的条件下, 进一步对¹⁷⁶Ir的β⁺/EC衰变进行了研究, 在确认在束测量新γ射线的同时建议了¹⁷⁶Ir的一个低自旋同核异能态. 从衰变系统性方面对^176,178Ir核中存在同核异能态的合理性和可能性进行了分析.