玻璃陶瓷材料中Tm3+离子红外到蓝色上转换发光

系统研究了PbF2+GeO2+WO3ⅩⅣTmF3玻璃陶瓷材料中,在近红外光(1.06μm)激发下,Tm3+离子的发光特性.实验中观测到Tm3+离子的两组峰值位置分别在20920cm-1和22173cm-1的蓝色上转换发光,并证实这两组上转换发光分别与吸收三个和四个光子有关,同时建立了上转换发光的模型.为了选择最佳掺杂浓度,详细地测量了Tm3+离子峰值为20920cm-1的蓝色上转换发光强度与TmF3浓度的关系.     

一类非线性抛物型变分不等方程的全局吸引子及弱近似惯性流形

对由一类非线性抛物型变分不等方程所描述的无穷维动力系统，给出了存在全局吸引子及弱近似惯性流形的充分条件．     

Crystal Structure of L-Quebrachitol

L-Quebrachitol (1) isolated from the root of Elaeagnus formosana Nakai (Elaeagnaceae) has not been reported before for any species of the genus of Elaeasnus. Its structure was established from spectral data and was completely characterized by single-crystal X-ray analysis. L-Quebrachitol crystallizes in the monoclinic system, space group P2₁, with cell parameters are a = 6.702(4), b = 7.207(4), c = 8.758(5) Å, β = 90.24(5)° and Z = 2.     

环状连续强激光下光学薄膜的瞬温和热畸变

详细研究了非冷却光学薄膜元件在环形激光光束辐照下的瞬态温度分布和随后的热畸变，并且用泰曼干涉仪实际测量了连续波氧碘激光辐照各种非冷却光学元件的热畸变量并与理论计算相比较，分析结果表明理论和实验相一致。     

Study of asymmetric charge writing on Pb(Zr,Ti)O3 thin films by Kelvin probe force microscopy

Polycrystalline Pb(Zr_0.55Ti_0.45)O₃ thin film was deposited on Pt/Ti/SiO₂/Si(1 0 0) by radio-frequency-magnetron sputtering method, and the writing of charge bits on the surface of PZT thin film was studied by Kelvin probe force microscopy. It is found that the surface potential of the negative charge bits are higher than those of the corresponding positive ones. When ferroelectric polarization switching occurs, the potential difference becomes even more remarkable. A qualitative model was proposed to explain the origin of the asymmetric charge writing. It is demonstrated that the internal field in the interface layer, which is near the ferroelectric/electrode interface in ferroelectric film, is likely to be the cause for the occurrence of this phenomenon.     

共振下n维Lienard型方程的2π周期解

本文在跨共振点条件下证明n维Lienard型方程存在2π周期解.     

《光谱学与光谱分析》2007年征订启事

The authors achieved the temporal coherent control in an Er^3＋ doped telluride glass, one kind of disordered solids. The upconversion at 670 nm was modulated and the dephasing time was simulated as 300 fs. Moreover, the photon echo signal gave the dephasing time due to the phonon interaction. The agreement between the two data indicates that the interaction between the wavepacket and the phonon leads to the fast disappearance of wavepackets interference, which is helpful for the tech- nique to be applied to the disordered solids.     

Scanning tunnelling microscope studies of growth of RuO2（110） thin layer on Ru（0001）

This paper reports that the growth of RuO_x(110) thin layer growth on Ru(0001) has been investigated by means of scanning tunnelling microscope (STM). The STM images showed a domain structure with three rotational domains of RuO_x(110) rotated by an angle of 120℃. The as-grown RuO_x(110) thin layer is expanded from the bulk-truncated RuO_x(110) due to the large mismatch between RuO_x(110) and the Ru(0001) substrate. The results also indicate that growth of RuO_x(110) thin layer on the Ru(0001) substrate by oxidation tends first to formation of the Ru-O (oxygen) chains in the [001] direction of RuO_x(110).     

关于四元数矩阵乘积迹的不等式

设 H~(m×n)为 m×n 四元数矩阵的集合,σ_1(A)≥…≥σ_n(A)为 A∈H~(mxn)的奇异值。本文证明了:1)设 A∈H~(mxm),B∈H~(mxm),r=min(m,m),则|tr(4B)|≤c r σ_i(A)σ_i(B).2)设 A_i∈H~(mxm),i=1,2,…,n,(A_1A_2…A_n)k为 A_1A_2…A_n 的任一个 k 阶主子阵,则|tr(A_1.A_2…A_n)_k|≤sun form i=1 to k σ_i(A_1)…σ_i(A_n).我们还得到四元数矩阵迹的其它一些不等式。这些结果推广和改进了文[1],[2]中的结果,进一步解决了 Bellman 猜想。     

大学物理实验中分类教学的探索和研究

本文对大学物理实验课程的教学现状进行了分析,提出了对大学物理实验课程进行分类教学改革的指导思想和遵循的原则及采取的措施。