High－Power Blue Light Generation by External Frequency Doubling of an Optical Parametric Oscillator ＊

We report on an all-solid-state high-power quasi-continuous blue light source by the frequency doubling of asignal wave from an optical parametric oscillator (OPO). A 50-mm-long LiB305 (LBO) crystal is used for theOPO, which is pumped by a diode-pumped Nd:YAG green laser (1OkHz, 50ns). Tunable blue emission in a newnonlinear crystal BiB306 (BiBO) is obtained with a wavelength range from 450 to 495 nm. The average power ofthe signal output is as high as 9.3 W from 924 to 970nm. The maximum output of the blue laser with the secondharmonic walk-off compensation is 1.3W average power at 470nm for 6.2W of OPO signal light at 940nm.     

煤烟对食物、饮水氟污染的研究

测定了云南滇东“燃煤污染型”氟病区新、陈玉米(皮、饭)、饮用水(自然井水、泉水、室内缸水、开水)的含氟量，并对玉米、豆娄、辣椒进行水洗脱氟试验，结果证明由于用煤方式不当，造成室内食物、饮水的污染，发生氟中毒。     

The Relationship Between New Ion Channels and Ectopic Discharges From a Region of Nerve Injury

Changes in ectopic discharges from axons in an injured nerve were examined while agents that interact with ion channels were applied to the site of the nerve injury. Tetraethylammonium (TEA) greatly facilitated spontaneous ectopic discharges or evoked ectopic firing in previously silent axons.Tetrodotoxin, an Na~+ channel blocker,completely blocked spontaneous discharges.Verapamil, La3~+, and Mn2~+, agents that interact with Ca2~+ channels,blocked spontaneous discharges and depressed the responses evoked by TEA, noradrenaline and high concentration of K~+.Increasing Ca2~+ levels facilitated ectopic discharges and this effect was blocked by La3~+ and Mn2~+. Normal axons (from uninjured nerves) were insensitive to all the effects seen in the axons from the injured nerve.These results suggest that following nerve injury the membrane of the regenerating sprout contains new ion channels, particularly Ca2~+ channels, anti that these channels are responsible for the generation of ectopic discharges.     

腔内倍频Nd:YVO4晶体激光获得的大功率671nm红光

本文报道了由双端泵浦Nd:YVO4晶体产生1342nm基频光，经过非线性晶体LBO腔内产生的671nm的红光光源。泵浦功率19.5W时，产生的671nm的红光平均功率是2.9W。光光转换效率为14.9%。分析了最近泵浦光斑尺寸，最佳聚焦位置，减少热透镜效应对输出功率的影响。双端泵浦结构和准连续运行模式大大减弱了热透镜效应。     

云南名香烟等嗜好物品含氟量的研究

本文报道了（１）十二种云南高档和普通香烟含氟量为５．４４３４×１０－６～８．５８４×１０－６，平均７．２２３±０．９９４０×１０－６，湖南笑梅、Ｍｏｒｅ香烟含氟显为１２．５４２×１０－６和６．１４８×１０－６；（２）用高氟玉米和小麦酿造的６０°和５０°白酒，含氟量分别为０．０７４±０．００４ｍｇ／Ｌ和０．０７６±０．００６ｍｇ／Ｌ；（３）西双版纳和广东大丰咖啡及雀巢咖啡含氟量范围１．６７２×１０－６～４．４４６×１０－６，平均３．１１０×１０－６±１．３０６×１０－６；（４）昆明市售花茶、红茶、绿茶、砖茶共３０份，含氟量分别为７５．５×１０－６±７．０７×１０－６、１０．４．１３×１０－６±６０．６６×１０－６、６２．２×１０－６±４８．０８×１０－６和３０５．５×１０－６。上述四种嗜好物品除茶叶含氟量高，饮茶过量会引起氟中毒外，其余三种与氟中毒关系不大．     

神经损伤区新生离子通道与异常电活动的关系

本文报道在因慢性压迫而引起损伤并产生异常传入放电的神经纤维上,应用几种离子通道药物局部作用于神经损伤区或全身注射,观察受伤神经纤维传入电活动的变化。实验表明,在神经损伤后而产生异常传入电活动的背景上,K~+通道的阻断剂四乙胺(TEA)使异常放电频率明显增加;Na~+通道阻断剂河豚毒素(TTX)浸润神经损伤区使异常放电活动消失;Ca~(2+)通道阻断剂异搏定,或影响Ca~(2+)通道的Mn~(2+),La~(3+)离子,不但抑制自发的异常电活动,而且可阻止TEA,去甲肾上腺素(NA)或K~+在损伤区诱发的异常放电。相反,增加神经损伤区的Ca~(2+)浓度使放电增加。这些离子通道药物对神经损伤区的异常放电的易化或抑制作用与对正常传入神经纤维电活动的不敏感性迥然不同,提示神经损伤后发生的异常传入电活动与损伤区的轴突膜上新生离子通道有关,其中可能有新生的Ca~(2+)通道,并参与异常放电的产生。