第三族金属氧化物离子对二氧化碳转化的红外光谱研究

本文利用红外光解离光谱研究了第三族金属氧化物离子对二氧化碳分子的转化机制. 研究表明,对于[ScO(CO₂)_n]⁺体系,在n≤4时,形成了溶剂化结构;在n=5时,形成了碳酸盐结构,实现了二氧化碳的转化. 对于[YO(CO₂)_n]⁺体系,需要4个二氧化碳分子就可以实现二氧化碳的转化. 而在[YO(CO₂)_n]⁺体系中,只发现了溶剂化结构,没有观察到碳酸盐结构. 理论计算表明,[YO(CO₂)_n]⁺体系拥有最小的溶剂化结构向碳酸盐结构转化能垒,[LaO(CO₂)_n]⁺体系拥有最大的溶剂化结构向碳酸盐结构转化能垒. 本文从分子水平揭示了不同金属氧化物离子对二氧化碳分子转化的影响规律.     

ZnS:Tm薄膜电致发光的激发过程

利用电子束蒸发方法制得ITO-Y2O3-ZnS:Tm3+-Y2O3-Al结构的薄膜可以得到蓝色电致发光.本文首次报导了ZnS:Tm3+薄膜与ZnS:Er3+、ZnS:Tb3+薄膜电致发光的激发过程有所不同.Tm3+离子的激发可以通过某些杂质中心到Tm3+离子的能量传递来实现.     

SU(2)格点规范理论SIN作用量在有限温度下的解除禁闭的相变

我们对SU(2)群格点规范理论的Sinl-Sin((1/2)T_rU_p)作用量做了有限温度下的Monte Carlo计算,观察到一个高温下解除禁闭的相变。临界点是Tc≈334±40Mev,这与使用Wilson作用量及其它类型作用量所得结果可以相容。     

量子点接触对单电子量子态的量子测量

研究了用介观量子点接触(QPC)对单电子两态和多态系统的量子测量问题.发现,在任意测量电压下,该测量问题不能用标准的Lindblad量子主方程描述.考虑了测量仪器和被测系统之间的能量交换对细致平衡关系的影响,对该问题提供了一个恰当的理论描述,并对未来的固态量子测量和量子反馈控制可能产生一定影响. 关键词： 量子测量 量子比特 细致平衡 退局域化     

kHz激光器在武汉卫星观测站的测距实验

高重复频率激光器是kHz卫星激光测距系统的重要组成部分,提高激光发射频率可以有效地获得更多的观测数据,这是当今卫星激光测距领域的发展方向.针对武汉卫星观测站进行的kHz激光测距实验,介绍了kHz激光器的工作过程和原理,分析了影响高重复频率回波探测的因素.实验结果表明:对实验过程中所观测到的中低轨卫星,观测数据量提高了1...     

线性与非线性波的Chebyshev广义有限谱模拟

给出求解二维线性与非线性波的Chebyshev广义有限谱模拟方法.结合时间层次的高精度预报-校正方法，模拟了二维线性浅水驻波和波在浅滩的非线性变形.方法能够准确模拟水波的物理特征. 关键词： Chebyshev广义有限谱 线性波 非线性波     

掺钼ZnO透明导电薄膜的太赫兹电磁波传输性质

采用直流磁控反应溅射方法,通过调节氧分压在玻璃基底上制备了不同载流子浓度的掺Mo的ZnO（ZMO）透明导电薄膜.应用太赫兹电磁波时域光谱技术研究了ZMO导电膜的太赫兹电磁波透射性质及介电响应,得到了与频率相关的电导率、能量吸收和薄膜折射率,实验结果与经典Drude模型相符很好.ZMO导电膜的太赫兹电磁波脉冲透射性质表明,通过调节ZMO薄膜的载流子浓度,该导电膜可作为应用于衬底和光学器件等太赫兹电磁波频率范围的宽带抗反射涂层. 关键词： 太赫兹电磁波光谱 薄膜电导率 宽带抗反射 透明导电薄膜     

Two-dimensional Riemann problem of the Euler equations to the Van der Waals gas around a sharp corner

In this paper, we study the Riemann problem of the two-dimensional (2D) pseudo-steady supersonic flow with Van der Waals gas around a sharp corner expanding into vacuum. The essence of this problem is the interaction of the centered simple wave with the planar rarefaction wave, which can be solved by a Goursat problem or a mixed characteristic boundary value and slip boundary value problem for the 2D self-similar Euler equations. We establish the hyperbolicity and a priori C¹ estimates of the solution through the methods of characteristic decompositions and invariant regions. Moreover, we construct the pentagon invariant region in order to obtain the global solution. In addition, based on the generality of the Van der Waals gas, we construct the subinvariant regions and get the hyperbolicity of the solution according to the continuity of the subinvariant region. At last, the global existence of solution to the gas expansion problem is obtained constructively.     

Practical alternating least squares for tensor ring decomposition

Tensor ring (TR) decomposition has been widely applied as an effective approach in a variety of applications to discover the hidden low-rank patterns in multidimensional and higher-order data. A well-known method for TR decomposition is the alternating least squares (ALS). However, solving the ALS subproblems often suffers from high cost issue, especially for large-scale tensors. In this paper, we provide two strategies to tackle this issue and design three ALS-based algorithms. Specifically, the first strategy is used to simplify the calculation of the coefficient matrices of the normal equations for the ALS subproblems, which takes full advantage of the structure of the coefficient matrices of the subproblems and hence makes the corresponding algorithm perform much better than the regular ALS method in terms of computing time. The second strategy is to stabilize the ALS subproblems by QR factorizations on TR-cores, and hence the corresponding algorithms are more numerically stable compared with our first algorithm. Extensive numerical experiments on synthetic and real data are given to illustrate and confirm the above results. In addition, we also present the complexity analyses of the proposed algorithms.     

Finite difference method for 2-D and 3-D nonlinear free surface wave problems

A finite difference method is developed for the numerical modelling of the 2-D and 3-D unsteady potential flow generated by transient disturbances on the free surface, on which the nonlinear boundary conditions are fully satisfied. The unknown function is computed with an iteration scheme processing in a transformed time-invariant space. After the velocity is calculated, the location of the free surface is renewed and so is the value of velocity on it. The boundary-value problem of the governing equation is then solved at the next time step. The present method incorporates the FFT. Consequently, a tri-diagonal equation system is obtained which could be readily solved. The feasibility of this method has been demonstrated by 2-D and 3-D examples corresponding to different initial disturbances. This work is supported by the science foundation of Academia Sinica. The paper had been accepted by the XVIth International Congress of IUTAM, Lyngby, Denmark, August, 1984.