Effect of electric field on the spectrum and the persistent current of a quantum ring with two electrons （II） additional effect of a charged impurity

This paper studies the effect of a charged impurity together with or without an external homogeneous electric field on a quantum ring threaded by a magnetic field B and containing two electrons. The potential caused by the impurity has been plotted which is helpful to the understanding of the electronic structures inside the ring. The deep valley appearing in the potential curve is the source of localization, which affects seriously the Aharonov-Bohm oscillation （ABO） of the energy and persistent current. It also causes the fluctuation of the total orbital angular momentum L of the pair of electrons. It is found that the appearance of the impurity reduces the domain of the fractional ABO. During the increase of B, the domain of the integral ABO may appear earlier when B is even quite small. The transition from the localized states to extended states has also been studied. Furthermore, it has deduced a set of related formulae for a transformation, by which an impurity with a charge ep placed at an arbitrary point Rp is equivalent to an impurity with a revised charge ep placed at the X-axis with a revised radial distance Rp. This transformation facilitates the calculation and make the analysis of the physical result clearer.     

Line-Width Reduction of a Laser Diode Array Using an External Cavity with Two Feedback Mirrors

A novel Littman-Metcalf external cavity laser diode array with two feedback mirrors is introduced. The linewidth broadening effect caused by smile can be reduced by the novel external cavity. At the drive current of 16A, the line-width is narrowed to 0.1 nm from free-running width of 1.6 nm with output efficiency of 84%.     

自旋团簇量子主方程的复合动力学对称性和热力学性质

基于三同核线型自旋团簇(每个粒子的自旋为S=1/2)的非自治量子主方程,研究了处于热辐射场中的自旋团簇的热力学性质.利用新颖的代数动力学方法,即引入动力学群的左右表象,不仅发现了自旋团簇的一个子空间态具有的SU(2)U(1)U(1)结构,而且对该子空间态在演化中所产生的耗散和退相干性质进行了计算.     

组分挥发对熔体提拉法晶体生长的影响

本文从熔体组分挥发产生杂质这一观点出发，研究了二元化合物ＡｍＢｎ熔体中的杂质产生率以及过剩组分杂质在熔体和晶体中的浓度，并导出了浓度分布的数学表达式，分析了组分挥发对熔体提拉法晶体生长的影响，并对其结果进行了讨论。     

1,4-二氢吡啶衍生物的合成及其与牛血清白蛋白的相互作用

以对甲苯磺酸为催化剂,一锅法合成了一系列1,4-二氢吡啶衍生物,并对其进行了红外光谱、质谱和核磁共振表征。采用荧光光谱法、紫外光谱法对2,6-二甲基-4-苯乙烯-1,4-二氢吡啶-3,5-二甲酸乙酯(1a)与BSA在不同温度的相互作用进行了研究。在298K时,Kq为2.43×10~(12)L·mol~(-1)·s~(-1),Ka为4.15×10~3L·mol~(-1),n为0.82,ΔS为65.12J·mol~(-1)·K~(-1),ΔH为-1.24k J·mol~(-1)。研究表明,1a对BSA具有荧光猝灭作用,且1a与BSA的主要作用力可能是疏水作用力(ΔS0)。     

基于渐变折射率透镜的低损耗1×N微结构光纤耦合方法

提出了一种新型的、基于单个径向渐变折射率(GRIN)透镜的1×N光纤耦合方法,并基于水平入射以及垂直斜面入射光线的传播方程建立了用于求解点光源发出的光束在GRIN透镜斜面入射后的成像点的计算方法。通过将透镜前端面加工成多斜面棱镜,将输入光分为多束,光束聚焦位置可以通过系统参数来调整;被分割开的光束经会聚、优化像差后,实现1×N低损耗耦合,并进行了仿真研究;通过优化斜面倾角、物距等关键参数实现了光纤低损耗耦合。该设计方案结构简单,易于装配,为各类光子晶体光纤、多芯光纤、光纤组束和光纤合光提供了实用的耦合方法。     

基于Steger图像算法的光纤布拉格光栅寻峰技术

分析了实际光纤布拉格光栅(FBG)反射谱的特性,建立了FBG反射峰超高斯模型。将图像处理技术用于FBG寻峰,提出了一种基于Steger图像算法的FBG寻峰技术,并给出了非对称光谱中心波长修正公式及峰值亚步长修正公式。Steger寻峰算法兼具滤波和寻峰功能,具有较强的抗噪能力,能克服步长限制,有效消除非对称光谱的干扰。通过理论仿真及实际寻峰研究,对比了该算法与不同寻峰算法在不同采样步长、噪声大小、光谱非对称性下的峰值检测精度。结果表明,该方法较质心法、高斯拟合法具有显著优势。     

New theory of Lorentz violation from a general principle

We report that a general principle of physical independence of mathematical background manifolds brings a replacement of common derivative operators by co-derivative ones. Then we obtain a new Lagrangian for the ordinary minimal standard model with supplementary terms containing the Lorentz invariance violation information measured by a new matrix, denoted as the Lorentz invariance violation matrix. We thus provide a new fundamental theory to study Lorentz invariance violation effects consistently and systematically.     

Bochner-Riesz算子的极大交换子的Hardy型估计

证明了Bochner-Riesz算子的极大交换子是一个从局部Hardy空间h1(Rn)到空间h1q(Rn)=h1(Rn)+Lq(Rn)(q＞1)上的有界算子.     

HIV-1蛋白酶的质子化状态

将分子动力学模拟和分子力学-泊松/波耳兹曼方法相结合,研究在HIV蛋白酶和抑制剂ABT-538的复合物中的不同质子化位置.结果表明：不同的质子化状态对蛋白酶的温度因子、蛋白酶和抑制剂的结合自由能及氢键都有很大影响.用分子力学-泊松/波耳兹曼方法计算显示：在B链中,25号天冬氨酸OD1氧原子被质子化的结合自由能最强,计算得到的温度因子和实验值比较吻合.另外,由氢键分析看出：在此质子化状态中,药物和蛋白酶、药物和W301水分子、W301水分子和蛋白酶形成的氢键在整个动力学模拟过程中最稳定.