Cr,Nd:YAG self-Q-switched laser with high efficiency output

The high efficient laser performance of self-Q-switched laser in the co-doped Cr⁴⁺,Nd³⁺:YAG microchip with 1.8 mm thickness was demonstrated. The slope efficiency is varied with the reflectivity of output coupler at 1064 nm, and the highest slope efficiency of 26% was obtained for 95% reflectivity of output coupler at 1064 nm. The pulse width, the single pulse energy and the pulse repetition rate for different reflectivity of the output couplers were measured, and the experimental results agree with the numerical calculations of the passively Q-switched rate equations. This can lead to develop the diode laser pumped monolithic self-Q-switched solid-state microchip lasers, especially for the intracavity frequency-doubled solid-state microchip lasers.     

双水相体系中镧与钛的分离及光谱性能

在聚乙二醇-硫酸铵-铬天青S双水相体系中，用铬天青S作萃取剂，研究了La(Ⅲ），Ti(Ⅳ），Zr（Ⅳ）的液-液萃取行为，在pH5.5时，实现了体系中La(Ⅲ）与Ti(Ⅳ)的分离，通过加入表面活性剂测定光谱方法，研究了高聚物相中La(Ⅲ）的存在形态。     

Cr^4＋：YAG的可饱和吸收特性与被动Q开关性能研究

运用速率方程计算了Ｃｒ＾４＋：ＹＡＧ晶体的可饱和吸收特性参数，包括初始吸收系数，饱和吸收系数，饱和光强和损耗调制度，用Ｃｒ＾４＋：ＹＡＧ对脉冲和连续Ｎｄ：ＹＡＧ激光器进行了被动调Ｑ，在脉冲Ｎｄ：ＹＡＧ激光器上得到了８ｎｓ的调Ｑ激光脉冲，在连续Ｎｄ：ＹＡＧ激光器的调Ｑ中得到了间隔和幅度抖动小于５％的输出脉冲充列。     

Vortex breakdown over a delta wing with oscillating leading edge flaps

 The effects of oscillating leading-edge flaps on leading-edge vortices and vortex breakdown were investigated for a delta wing with upward-deflected flaps. The variation of breakdown location revealed hysteresis loops. The time-averaged breakdown location over one cycle may move upstream or downstream compared to the quasi-steady case, depending on the amplitude of flap oscillations and angle of attack. Measurements of the phase-averaged velocity upstream of breakdown did not reveal any correlation to the response of breakdown location. The effect of oscillating flaps is largest when the breakdown location is near the trailing-edge region in the static case. Received: 2 February 1997/Accepted: 7 April 1997     

神经网络法计算镉（Ⅱ）,羟基及碳酸根三元体系的形态分布

采用前馈线笥网络ＢＰ算法，计算了Ｃｄ６２＋－ＯＨ＾－ＣＯ＾２－３三元体系的累积稳定常数。用Ｈｏｐｆｉｅｌｄ反馈网络研究了体系中络合物的形态分布。溶液中溶解的ＣＯ２对ｌｇβ１的计算结果有重要影响，对ｌｇβ２，ｌｇβ３，ｌｇβ４的结果影响不大。     

实际光栅系统分辨本领的实验验证

本文通过光栅衍射实验对钠光双线结构的观测，验证了实际光栅系统的分辨本领。     

m-Uniformization and metrization of fuzzy topological spaces

In this paper the fuzzy pseudo metric is introduced in the fuzzy unit interval and based on it theorems on m-uniformization and metrization of fuzzy topological spaces are proved.     

一类非线性抛物型方程非线性边值问题整体范围内差分方法的可解性

在非线性抛物型方程边值问题可解性的研究中,用有限差分法进行先验估计也是一个常用的方法。但使用有限差分法所得出的可解性往往是局部的,同时在非线性边界的估计中也遇到了一定的困难。 1962年,K.Rektorys在[1][2]中首次用有限差分法证明了一类非线性抛物型方程的边值问题在整体范围内的可解性,但他只研究了第一边值问题及一些简单的其它边值问题,对于非线性边值问题,我们还没有见到用有限差分法取得成功的报导。     

Reaction of carbon dioxide with trialkylalkynyl borates — a novel method for the synthesis of stereospecific α,β-unsaturated acids

Carboxylation of lithium trialkylalkynylborate can take place under favourable conditions. Protonation of the reaction product yields (Z)-α,β-unsaturated acid.