An optical scheme for conditional generation of W state and photon-added coherent state

We propose a simple scheme to generate an arbitrary photon-added coherent state of a travelling optical field by combining an array of degenerate parametric amplifiers and corresponding single-photon detectors. Particularly, when the single-photon-added coherent state is observed by developing the novel technique of Zavatta et al （2004 Science 306 660）, we can simultar/eously obtain the generalized N-qubit W state.     

溶液自由基ESR谱的计算机模拟

根据溶液自由基电子自旋共振(ESR)原理,用高级BASIC语言编写了溶液自由基谱的模拟程序。自由基的ESR能级用一级近似求解,谱线的线型采用洛仑兹和高斯型的混合线型函数,程序规定体系中核自旋量子数可从1/2到7/2,不等性核的数目最多可达10组,每组中等性核的数目原则上不受限制。通过二萘嵌苯阳离子自由基和硝基苯负离子自由基谱模拟二个例子加以说明,模拟结果是满意的。     

Bombieri's theorem in short intervals

The well-known Bombieri-A. I. Vinogradov theorem states that (1) $$\sum\limits_{q \leqslant x^{\tfrac{1}{2}} (\log x)^{ - s} } {\mathop {\max }\limits_{(a,q) = 1} \mathop {\max }\limits_{y \leqslant x} } \left| {\psi (y,q;a) - \frac{y}{{\varphi (q)}}} \right| \ll \frac{x}{{(\log x)^A }},$$ whereA is an arbitrary positive constant,B=B(A)>0, and as usual, $$\psi (x,q;a) = \sum\limits_{\mathop {n \leqslant x}\limits_{n = a(q)} } {\Lambda (n),}$$ Λ being the Von Mangoldt's function. The problem of finding a result analogous to (1) for short intervals was investigated by many authors. Using Heath-Brown's identity and the approximate functional equation for DirichletL-functions, A. Perelli, J. Pintz and S. Salerno in 1985 established the following extension of Bombieri's theorem: Theorem 1. (2) $$\sum\limits_{q \leqslant Q} {\mathop {\max }\limits_{(a,q) = 1} \mathop {\max }\limits_{h \leqslant y} \mathop {\max }\limits_{\frac{x}{2}< \approx \leqslant x} } \left| {\psi (z + h,q;a) - \psi (z,q;a) - \frac{h}{{\varphi (q)}}} \right| \ll \frac{y}{{(\log x)^A }}$$ where A>0 is an arbitrary constant,y=x ^θ $$\frac{7}{{12}}< \theta \leqslant 1, Q = x^{\frac{1}{{40}}} .$$ ,Q=x ^1/40. By improving the basic lemma which A. Perelli, J. Pintz and S. Salerno used as the main tool to prove Theorem 1, we obtain Theorem 2.Under the same condition as in Theorem 1,for Q=x ^1/38.5, (2)still holds.     

双频激光泵浦光纤放大器中的原子相干效应

用密度矩阵的方法从理论上分析了不同频率的两个激光场混合泵浦的光纤放大器中，由光场诱导的原子相干效应。并由此引入相干修正因子，通过修正的速率方程讨论了两光场与原子的相干作用对放大器增益的影响。     

非晶态Fe40Ni38Mo4B18（2826MB）合金粉末的高压压结与磁性研究

 本文研究了非晶态软磁材料Fe₄₀Ni₃₈Mo₄B₁₈（2826MB）合金粉末在高压下加温压结成三维大尺寸产品的可行性，并通过压结样品的复数导磁率在弱交变磁场中的行为，探讨了压结条件对压结样品的软磁性能的影响。结果表明，在本实验所采用的压力范围内，压结温度对压结样品的性能的影响大于压结压力的影响。     

Si1-xCex/Si量子阱发光材料制备及特性研究

在si(100)衬底上用分子束外延成功生长了Si_(1-x)Ge_x/si量子阱发光材料,发现在生长过程中背景杂质含量直接影响材料的发光特性,用光致发光(PL)和卢瑟福背散射(RBS)对样品质量进行标定。在PL测量中观察到合金量子阱带边激子分辨峰,并对发光峰能和峰宽作了讨论。 关键词：     

RIBLL束流诊断

描述了兰州放射性离子次级束流线(RIBLL)上研制并安装使用的放射性束流(RIB)诊断装置的种类、结构、性能及在AIBLL上的位置和功能.重点叙述了以光纤为基础的几种诊断元件,它们探测效率高、响应时间快、制作容易、性能稳定.给出了RIB¹⁷N等高图,说明诊断装置辅助MBLL得到RIB的水平.     

Quantum Fluctuations in a Mesoscopic Inductance Coupling Circuit

Starting from the equation of motion of a mesoscopic inductance coupling circuit,the quantum fluctuations of charge and current in the circuit are investigated inboth the eigenstates of the system and the squeezed vacuum state. The resultsshow that there exist quantum fluctuations of the charge and current in bothcases, and the fluctuations in each component circuit are connected.     

Homoclinic solutions in periodic difference equations with saturable nonlinearity

In this paper, a periodic difference equation with saturable nonlinearity is considered. Using the linking theorem in combination with periodic approximations, we establish sufficient conditions on the nonexistence and on the existence of homoclinic solutions. Our results not only solve an open problem proposed by Pankov, but also greatly improve some existing ones even for some special cases.     

一种半球形天空亮度测量仪器的研制

在大气光学领域中,天空亮度分布有着重要的应用.简要介绍了天空亮度的测量原理,在分析同类测量仪器的基础上,提出了一种用于白天的,可见及近红外波段天空亮度测量仪器的设计,介绍了系统的组成和探测器的选择.经过定标,仪器能够得到天空亮度的绝对值,其结果反映了真实天空亮度分布的变化.该仪器弥补了传统的天空亮度测量仪器住测量波段、实时性、便携性等方面的不足,更好地满足了实际的科研需求.