LD泵浦环形单频Nd∶YVO4激光器的频率调谐特性研究

利用激光谐振腔内标准具的选模调谐特性和激光晶体自身的标准具作用 ,通过调节插入标准具和激光晶体的倾斜度及微调谐振腔长度 ,在 L D泵浦 Nd∶ YVO4 单频激光器上实现了精确调谐 ,最大可调谐范围约 1 0 0 GHz     

《色谱》杂志被俄罗斯《文摘杂志》收录

《色谱》杂志继连续15年入选美国化学文摘《CA》千刊表,并且被美国《医学索引》(IM)及 《分析文摘》(AA)检索系统收录之后,2000年又被俄罗斯《文摘杂志》(Abstract Journal) 收录。     

光电负反馈抑制全固化单频激光器的强度噪声

实验研究了激光二极管抽运的Nd:YVO4环形单频激光器的强度噪声特性,通过光电负反馈调制激光二极管抽运源,使激光器的弛豫振荡噪声受到抑制,在300kHz弛豫振荡峰处输出光的强度噪声被降低25dB。     

小型全固化非经典光场产生系统的实验研究

利用激光二极管（LD）抽运的内腔倍频YVO4／KTP激光器发出的0.53μm的激光,经由α－切割的KTP晶体构建的半整块非简并边疆光学参量振荡腔（CW NOPO）内参量下转换,获得了强度量子相关非经典光场,其强度差噪声低于标准量子极限3.2dB,抽运阈值低于10mW。     

离子色谱法测定钇镝镱中微量氯

稀土金属中氯的测定,通常用比浊法进行,该法灵敏度低,且误差较大。以离子色谱法分析,有多种前处理方法。本文采用直接溶样,再将氯转化为可直接测定形式的方法。该方法不需加稳定剂,可直接测定。１　实验部分１１　仪器与试剂ＺＩＣ３离子色谱仪（青岛崂山电子仪器实验所）;ＹＳＡ阴离子色谱柱（核工业北京化工冶金研究院）;ＬＳＢ离子色谱泵（北京卫星厂星达公司）;浓氨水、硝酸银为优级纯,其余试剂为分析纯,样品和淋洗液均用去离子水配制和稀释。１２　分析方法称取钇、镝、镱试样１００００ｇ,置于１００ｍＬ烧杯中…     

4，4’-二氨基苯磺酰苯胺的酰胺衍生物的合成及其液晶性的初步探讨

合成了10个4，4’-二氨基苯磺酰苯胺的酰胺衍生物，并通过示差扫描量热法(DSC)与偏光显微镜测定这些衍生物的液晶性，发现4-氨基-4’-(对甲氧基)苯甲酰胺基苯磺酰苯胺(4g)具有液晶现象．     

某型振动轮噪声数值模拟及优化分析

空中声源的辐射噪声谱包括宽带连续谱和窄带线谱,线谱能量高于连续谱。与水下声源相比,空中声源的运动速度普遍较高,线谱多普勒频移明显,可用于进行水下对空中声源的运动参数估计。首先通过时频分析提取接收信号的瞬时频率,而后利用非线性最小二乘法将瞬时频率提取值与预测值相拟合,进而估计声源的运动参数(声源的运动速度、静止频率、与接收器最小水平距离及经过最近点时刻)。仿真与实验均能较为准确地估计出声源运动参数,同时在实验中实现了水下对空中运动声源的测距和定位,测距误差小于15.8%。在满足一定信噪比和保证足够多普勒信息的情况下,该参数估计方法具有很好的适用性。     

Application of the HKS in the identification of kaons produced in the reaction （e,e＇K^＋）

At Jefferson Laboratory the experiment E02-017 was carried out to investigate the fission associated with kaons in the hypernuclei-producing interaction p（e,K^＋e＇）A. The newly installed high resolution kaon spectrometer （HKS） in Hall C was used as a key instrument to identify kaons. This paper introduces the HKS hardware and describes the way the kaons are identified. Maintaining most of the kaons （nearly 100%） in the data, HKS identifies kaons with a purity of -67% in this experiment. The resolution of the kaon target time reconstructed by HKS reaches 0.42 ns.     

Monte Carlo simulation of the property of a scintillation bar in the multi-neutron correlation spectrometer

To perform a kinematically complete measurement of the dissociation reaction for neutron-rich nuclei, a multi-neutron correlation spectrometer is proposed at Peking University. A Monte Carlo simulation code based on GEANT4 is developed for a single scintillation bar which processes not only the energy deposition but also the light propagation in the scintillator and the light collection and conversion to signal at the end of the bar in a realistic way. The simulating method is described in detail in this paper, and the timing and position resolutions and detector efficiency are studied based on the simulation and compared with the experimental results. A new method of crosstalk rejection has been demonstrated to be important for the design of the whole spectrometer.     

Generation of a squeezed state at 1.55 μm with periodically poled LiNbO3

We report on the generation of a squeezing vacuum at 1.55 μm using an optical parametric amplifier based on periodically poled LiNbO 3.Using three specifically designed narrow linewidth mode cleaners as the spatial mode and noise filter of the laser at 1.55 μm and 775 nm,the squeezed vacuum of up to 3.0 dB below the shot noise level at 1.55 μm is experimentally obtained.This system is compatible with standard telecommunication optical fibers,and will be useful for continuous variable long-distance quantum communication and distributed quantum computing.