基于GaSe差频产生8～19μm可调中红外辐射

利用Nd:YAG激光器抽运内腔KTP光学参量振荡器,得到了输出为2μm附近的双波长,并在满足Ι类相位匹配条件下,在GaSe中共线差频产生8～19μm连续宽调谐调的中红外辐射.在8.76μm处脉冲最大能量达33.66μJ,峰值功率7.4kW,光子转换效率达4.43%左右.分析了影响能量转化效率的原因,提出了补偿走离的措施.     

All-Solid-State Nd:YAG Laser Operating at 1064nm and 1319nm under 885nm Thermally Boosted Pumping

We report a high-effciency Nd：YAG laser operating at 1064 nm and 1319nm, respectively, thermally boosted pumped by an all-solid-state Q-switched Ti：sapphire laser at 885 nm. The maximum outputs of 825.4 m W and 459.4mW, at 1064nm and 1319nm respectively, are obtained in a 8-ram-thick 1.1 at.% Nd：YAG crystal with 2.1 W of incident pump power at 885nm, leading to a high slope efficiency with respect to the absorbed pump power of 68.5% and 42.0%. Comparative results obtained by the traditional pumping at 808nm are presented, showing that the slope efficiency and the threshold with respect to the absorbed pump power at 1064nm under the 885nm pumping are 12.2% higher and 7.3% lower than those of 808rim pumping. At 1319nm, the slope efficiency and the threshold with respect to the absorbed pump power under 885nm pumping are 9.9% higher and 3.5% lower than those of 808 nm pumping. The heat generation operating at 1064 nm and 1319 nm is reduced by 19.8% and 11.1%, respectively.     

3α-氨基-2β,17β-二羟基-16β-哌啶基-5α-雄甾烷和2β-氨基-3α,17β-二羟基-16β-哌啶基-5α-雄甾烷的合成

本文报道了3α-氨基-2β,17β-二羟基-16β-哌啶基-5α-雄甾烷和2β-氨基-3α,17β-二羟基-16β-哌啶基-5α-雄甾烷的合成方法。     

3α-氨基-2β,17β-二羟基-16β-哌啶基-5α-雄甾烷和2β-氨基-3α,17β-二羟基-16β-哌啶基-5α-雄甾烷的合成

1975年Varg ftig等发现,3α-氨基-2β-羟基-5α-雄甾-17-酮盐酸盐(Org 6001)具有抗心律失常作用,它不仅口服有效,疗效优于利多卡因,而且无激素活性,被认为是一类新型结构的抗心律失常药。以后,人们又对Org 6001进行了一系列的结构改造工作,但     

急性瘦肉精中毒检材的QuEChERS净化-液质联用快速确证方法

目前液相色谱串联质谱法测定动物源性食品中瘦肉精普遍采用酶水解提取、固相萃取净化的方式处理样品,该方法耗时长、分析成本高。 本研究采用酸水解和酶水解两种提取方式结合QuEChERS(Quick,Easy,Cheap,Effective,Rugged,Safe)净化和高效液相色谱串联质谱建立了动物性食品中特布他林、沙丁胺醇、莱克多巴胺和克伦特罗4种β2受体激动剂的快速定性确证和定量检测方法。 采用酶水解提取-QuEChERS净化处理样品,在电喷雾离子源正离子扫描(ESI+)和多反应监测(MRM)模式下,4种瘦肉精在1.0~20.0 μg/L浓度之间呈线性,线性相关系数均大于0.999,检出限和定量限分别为0.1和0.3 μg/kg,猪肉和牛肉样品中4种化合物的回收率为78.5%~112%,相对标准偏差RSD为2.8%~8.9%。 采用酸水解法代替酶水解提取时,尽管对于样品中莱克多巴胺测定结果稍偏低,但样品前处理时间大大缩短。 两种提取方法结合使用对于提高瘦肉精引起的食物中毒应急处置效率具有重要意义。     

金属配合物与DNA的弱相互作用

介绍了金属配合物与DNA相互作用的嵌入、沟槽和静电3种主要模式,并介绍了目前常用的研究方法,包括紫外-可见吸收光谱法、荧光光谱、黏度法、循环伏安法。     

基于GaSe差频产生8~19 μm可调中红外辐射

利用Nd∶YAG激光器抽运内腔KTP光学参量振荡器,得到了输出为2 μm附近的双波长,并在满足Ι类相位匹配条件下,在GaSe中共线差频产生8~19 μm连续宽调谐调的中红外辐射.在8.76 μm处脉冲最大能量达33.66 μJ,峰值功率7.4 kW,光子转换效率达4.43%左右.分析了影响能量转化效率的原因,提出了补偿走离的措施.     

硼烷结构的电子计数规则

基于分子轨道理论计算，已有各种讨论硼烷结构的电子计数方法。本文扼要介绍了Wade规则与两个新的电子计数规则，并简单介绍了新计数规则在研究复杂硼烷结构中的应用。     

High-Quality Continuous-Wave Imaging with a 2.53THz Optical Pumped Terahertz Laser and a Pyroelectric Detector

A cw terahertz （THz） transmission imaging system is demonstrated and a high-quality THz image can be obtained using a pyroelectric detector. The factors that affect the imaging quality, such as the THz wavelength, spot size on the sample surface, step length of the motor, and frequency of the chopper, are theoretically and experimentally investigated. The experimental results show that the maximum resolution of the THz image can reach 0.4mm with the THz wavelength of 118.8μm, the spot size of 1.8mm and the step length of 0.25mm.