Calculating Hamiltonian parameters for Yb^3＋ in a low-symmetry lattice site, and fitting the structure and levels of Yb^3＋ ：RETaO4 （RE = Gd, Y, and Sc）

An iterative method is used to find the values of the Hamiltonian parameters for Yb^3＋ in a given low-symmetry crys- talline site. Samples of Yb^3＋ ：RETaO4 （RE = Gd, Y, and Sc） were prepared and their structures were determined. Based on the obtained structural data, their orbital-spin parameters and crystal field parameters were fitted by the superposition model （SM）. Using the crystal field parameters obtained by the SM fitting as the initial parameters, the Hamiltonian parameters were fitted iteratively. The calculated and experimental energy levels for Yb^3＋：RETaO4 are consistent, and the maximal mean-root-square deviation is only 2.84 cm^- 1, indicating that the method is effective to determine the Hamiltonian parameters of Yb^3＋ in low-symmetry crystalline sites.     

La3PO7:Eu3+纳米晶的制备和光谱性质

通过燃烧法合成了Eu³⁺掺杂的含氧磷酸镧(La₃PO₇:Eu³⁺)纳米晶颗粒材料。样品的结构、形貌和粒径分别由X射线衍射、扫描电镜和透射电子显微镜得到。测量了样品的发射光谱、激光选择激发光谱和时间分辨光谱。实验结果表明:样品展示的较强红光发射来自于Eu³⁺ 的⁵D₀→⁷F₂辐射跃迁,Eu³⁺在La₃PO₇基质中至少占据两种不同的格位,且具有较低的格位对称性。     

Characteristics of 355 nm Laser Damage in KDP and DKDP Crystals

We present the characteristics of bulk damage induced by the third harmonic of Nd：YAG laser irradiation in KDP and DKDP crystals. Bulk damage occurs as a few or a series of pinpoints consisting of a core and the deforming zone. The results of a 1-on-1 test reveal that the pinpoint size increases with incvreasing fluence, and the pinpoint density increases exponentially with increasing fluence. The results of an s-on-1 test indicate that the pinpoint density increases gradually with laser pulse number, but the size does not grow. These results are consistent with a model in which nanoabsorbers are assumed to exist in the crystal and the initiation of damage is determined by heating them to the critical temperature.     

Fe2O2/SiO2对异辛醇氧化生成异辛酸反应的催化性能研究

采用浸渍法制备了系列的Ｆｅ２Ｏ３／ＳｉＯ２催化剂,并用ＸＲＤ,ＢＥＴ,ＴＧＤＴＧ和ＳＥＭ等手段对催化剂进行了表征;考察了不同Ｆｅ负载量和焙烧温度的Ｆｅ２Ｏ３／ＳｉＯ２催化剂对异辛醇氧化生成异辛酸反应的催化活性的影响,确定了最佳催化剂制备条件．结果表明,Ｆｅ负载量为４％,焙烧温度为５００℃时,催化剂活性组分Ｆｅ２Ｏ３的在载体上分散均匀,晶粒大小基本一致,催化剂比表面积较大,催化剂活性达到最佳,异辛酸选择性最高可达５５．１４％,收率可达２２．４１％．     

双束激光法测量凸透镜焦距虚物成实像方法

结合几何原理和激光光源的特性,提出一种应用凸透镜虚物成实像情况下简便测量凸透镜焦距的方法,该方法可以作为大学生的设计性、探究性和创新性的实验项目。     

两分量BEC精确Floquet解的弱驱动不稳定性分析

研究了两分量玻色．爱因斯坦凝聚系统（BEC）的精确Floquet态的不稳定性问题．将两分量玻色一爱因斯坦系统囚禁于一个光格势中,同时用一个可随时间周期调节的激光驻波驱动,可得到精确的Floquet态．应用李雅普诺夫稳定性标准和线性稳定性分析方法,如果驱动场的强度小于光格势强度的两倍时,系统将发生相的blowing-up现象而导致不稳定,将这种不稳定性称之为弱驱动不稳定性．通过调节驱动场强度可避免这种不稳定性。     

CFO光伏“反醒”

2012年,光伏市畅可谓实实在在地遭遇“严冬”,各种负面因素同时汇集,冲击着国内光伏企业。许多中小企业面临危局,甚至已经停产倒闭。“御寒”、“双反”、“寻钱”、“突破口”这些光伏行业的关键词,如今恰恰反映了CFO们应履行的职责和将面临的挑战。为此,     

Efficient and compact diode-end-pumped conductively cooled Q-switched Nd:YLF laser operating at 527 nm

A novel, compact diode-end-pumped conductively cooled Q-switched Nd:YLF laser is developed. A diode-end-pumped pair of Nd:YLF slabs and an intracavity-frequency-doubled configuration are adopted to increase conversion efficiency. Using 49.8-mJ incident pump pulse energy at 500-Hz repetition rate, the laser obtains 11-mJ pulse energy and 5.5-W average output power at 527-nm wavelength, achieving an optical-optical conversion efficiency of 22%. The pulsewidth is less than 15 ns, and the beam quality factors are Mx2=1.28 and M y2=1.12.