近红外超快强激光在LiF晶体内空间选择性诱导产生色心

通过显微镜聚焦近红外超快强激光作用在垂直于激光束移动的LiF晶体样品上，在LiF晶体中连续地诱导产生色心。以一定的间隔．反复移动该激光束的焦斑可在LiF晶体内空间选择性地诱导产生稳定的色心区。测定了不同条件下形成的色心区的吸收光谱，结果表明用近红外超快强激光可在LiF晶体中诱导产生具有激光效应的色心。

Investigation of extinction in unsteady flames in turbulent combustion by 2D-LIF of OH radials and flamelet analysis

An experimental and theoretical investigation of premixed turbulent combustion in an engine simulator is presented. The distribution of hydroxyl radicals formed in the combustion of propane/air mixtures was visualized by 2D-LIF and used to monitor the progress of the combustion process. For stoichiometric mixtures, images showed a continuous wrinkled flame front, while in lean (λ=1.5) mixtures, local flame extinction was observed as discontinuities in the reaction zone. A bright active reaction zone was still observed in flame inlets and closed concave structures. The effects of self-absorption and of collisional quenching on the fluorescence signal are considered and appear to have only a minor net influence on the shape and width of the flame front. The images are evaluated and interpreted in terms of the Lewis number effect and the laminar flamelet model. Analysis was performed by determining the contour lines of the images (specifically, the ratios of average maximum to equilibrium OH concentration) and comparing with corresponding ratios from unstrained flame simulations. The results show that although the degree of turbulence is not high enough for straining effects to be important, flamelet curvature does play a significant role in the combustion of lean mixtures; this is manifested by a mean effective flame velocity that is less than the laminar burning velocity. © 1991 Combustion Institute.

Color center conversion by femtosecond pulse laser irradiation in LiF : F-2 crystals

We report the observation of intense spontaneous emission of green light from LiF:F-2:F-3(+) centers in active channel waveguides generated in lithium fluoride crystals by near-infrared femtosecond laser radiation. While irradiating the crystal at room temperature with 405 nm light from a laser diode, yellow and green emission was seen by the naked eye. Stripe waveguides were fabricated by translating the crystal along the irradiated laser pulse, and their guiding properties and fluorescence spectra at 540 nm demonstrated. This single-step process inducing a waveguide structure offers a good prospect for the development of a waveguide laser in bulk LiF crystals.

Studying the Attribution of LiF in OLED by the C-V Characteristics

The organic light-emitting device (OLED) with simple structures of indium tin oxide (ITO)/tris(8-quinolinolato) aluminum (Alq(3))/LiF/Al and ITO/Alq(3)/Al was fabricated to analyze the contribution of LiF in OLED. We used the C-V characteristics to investigate the contribution of LiF in OLED and found that the capacitance of the above-mentioned structures was 12.5 nF and 77.5 nF, respectively. It is shown that the LiF layer affects the property of OLED resulting in the change of the capacitance of the device.

DyF_3－BaF_2－LiF三元系熔体结构的计算机模拟研究

ＭｏｎｔｅＣａｒｌｏ法计算机模拟研究ＤｙＦ_３－ＢａＦ_２－ＬｉＦ三元系熔体，得到了离子间偏径向分布函数、局部结构和能量分布等信息．研究表明：Ｆ~－聚集在Ｄｙ~（３＋）周围，主要组成以ＤｙＦ_６~（３－）形式的八面体络离子；Ｌｉ~＋以“游离”状态存在，其平均位能较高，在电解中起到迁移电流的作用：氟离子可分为“端氟”、“游氟”和“桥氟”三类，不同行为的氟其位能也不同、通过“桥氟”组成诸如Ｆｍ－Ｄｙ－Ｆ－Ｄｙ－Ｆｎ或Ｆｍ－Ｄｙ　Ｄｙ－Ｆｎ较复杂的离子集团；与ＤｙＦ_３－ＬｉＦ二元系熔体模拟结果相比较，ＢａＦ_２的加入使ＤｙＦ_６~（３－）形式的八面体络离子较为紧密及有序．

DyF_3－LiF系熔体结构的计算机模拟研究

用ＭｏｎｔｅＣａｒｌｏ法计算机模拟研究ＤｙＦ＿３－ＬｉＦ系熔体，得到了径向分布函数和局部结构等信息。研究表明，Ｆ紧密聚集在Ｄｙ￣（３＋）周围，而与Ｌｉ之间却存在一定的缝隙。该熔体中主要存在着二种离子类型：以Ｄｙ￣（３＋）为中心的ＤｙＦ型络离子（以ＤｙＦ的八面体络离子为主）和“游离状”的Ｌｉ离子。同时，由于Ｆ的聚集，一些ＤｙＦ型络离子通过“氟桥”组成Ｄｙｍ型更加复杂的离子集团。各类离子位能计算表明：Ｌｉ是该熔体中位能最高的离子，在电解过程中起到迁移电流的作用．

Na_3AlF_6-LiF-RE_2O_3体系表面张力的研究

用最大气泡压力法,采用三因子一次回归正交设计,研究了Na_3AlF_6-LiF-RE_2O_3体系的表面张力,得出表面张力(Y)与RE_2O_3含量(c_1)、LiF含量(c_2)及溶体温度(t)的回归方程如下:Y=260.78+4.088c_1+0.073c_2+0.557c_1c_2-0.136t-0.00483c_1t-0.00050c_2t。

LaF_3-LiF熔体结构的X射线衍射分析

熔盐是固体盐类的高温熔体,与其他液体一样,具有近程有序和远程无序的特性。对于其结构的研究和表征要比完全有序的晶体和完全无序的气体困难得多。传统的熔盐结构理论多以伪晶格模型为基础,虽能解释熔盐的某些规律,但与熔盐结构的真实情况相差甚远。较为严格的理论是分布函数理论。与格子理论不同,它不以任何物理模型为依据,而是从解决粒了间相互作用势出发的统计力学理论,该方法的特点是以求出径向分布函数去解整个体系的构型积分,然后求出其全部热力学量。但由于通过建立有关积分方程式(如