High-Average-Power Nanosecond Quasi-Phase-Matched Single-Pass Optical Parametric Generator in Periodically Poled Lithium Niobate

A pulsed nanosecond optical parametric generator (OPG) in periodically poled lithium niobate (PPLN) crysal is presented. The pump laser is an acousto-optically Q-switched Nd:YVO4 laser with the maximum average power of 6.58 W. When the repetition rate is 50kHz and the pulse width of the pump source is 80ns, the maximum average total output power of the single-pass PPLN OPG is about 1.9 W, which includes 1.322 W of 1.536μm signal radiation. The length of the PPLN crystal is only 38.7mm (at room temperature) with a grating period of 28.93μm (at room temperature). The 1.502-1.536μm signal radiation and 3.652-3.465μm idler radiation are obtained by adjusting the PPLN crystal temperature from 155℃ to 250℃.     

过氧聚钨酸薄膜上光栅的制备

用过氧聚钨酸（PPTA）水溶液，通过离心涂膜法在显微镜载玻片上制备了具有光滑表面且厚度为100nm的PPTA薄膜，利用PPTA薄膜在紫外光照下可研制光栅以及其它光学元件的薄膜材料，具有很高的利用价值。     

分子诱导效应指数与链烷烃的沸点

利用基团的诱导效应指数，首次提出了分子的诱导效应指数的概念，并定义了 链烷烃的有效碳链长度NC＝（MIs,N/MIb,N)·N，式中MIs,N,MIb,N分别为直链和支 链异构体的分子诱导效应指数。研究结果表明，链烷烃的沸点Tb(℃）与NC关系是 ：1n(806.5-Tb)=6.9824-0.11431NC^2/3     

超临界流体萃取—胶束电动毛细管色谱法分离测定大黄中蒽醌类组 …

采用ＳＦＥ－ＭＥＣＣ法分离测定大黄中的芦荟大黄素，大黄素和大黄素。萃取条件为压力４１．４ＭＰａ，温度５０℃，改性剂量０．４ｍＬ。被测组分在１０ｍｉｎ得到全部分离。本法准确，简便，快速，结果令人满意。     

Synthesis of N-（α-Alkoxyalkyl）benzotriazoles Catalyzed by Acidic Ionic Liquid at Room Temperature

N-（α-Alkoxyalkyl）benzotriazoles were synthesized via the condensation of benzotriazole with various aldehydes and alcohols catalyzed by acidic ionic liquid [hmim]HSO4 at room temperature. The yield was up to 99%. This novel method was effective when triethoxymethane was utilized instead of alcohols. Moreover, acidic ionic liquid could be reused easily with no significant degradation of its catalytic activity.     

钇对Nd-Fe-Al-Ni非晶合金热稳定性与晶化行为的影响

采用差示扫描量热法（DSC）、X射线衍射（XRD）和透射电镜（TEM）研究了Y对Nd-Fe-Al-Ni非晶合金热稳定性和晶化行为的影响。结果表明,淬火态的Nd60Fe20Al10Ni10-xYx（x=0,2）合金基本为非晶组织同时还含有少量的淬态相,Y的加入抑制了淬态相的析出。加入Y后,非晶合金的晶化开始温度和晶化峰值温度都向高温方向移动,证明其热稳定性提高。Y的加入改变了合金的晶化方式和最终晶化产物,使非晶基体中析出的晶化相更加弥散圆整细小。并且Y具有在化学上钝化氧杂质的作用,从而抑制了氧的有害作用。利用Kissinger方程获得了Nd60Fe20Al10Ni8Y2非晶合金的晶化开始和晶化峰值激活能分别为1.21和1.16 eV。     

大气中阻塞形成的一个理论

本文提出了偶极子阻塞形成的一个新理论。文中首先使用多重尺度方法研究了基本气流具有弱切变的非线性正压Rossby波,得到了它的波包满足非线性Schr-dinger方程。指出:当Rossby波的波数满足k~2/3相似文献   

超临界流体萃取-胶束电动毛细管色谱法分离测定大黄中蒽醌类组分的含量

采用ＳＴＥ－ＭＥＣＣ法分离测定大黄中的芦荟大黄素，大黄素和大黄酸。萃取条件为压 力４１．４ＭＰａ，温度５０℃，改性剂量０．４ｍＬ。被测组分在１０ｍｉｎ得到全部分离。本法准确、简 便、快速、结果令人满意。     

Optical pulse shaper with integrated slab waveguide for arbitrary waveform generation using optical gradient force

Integrated optical pulse shaper opens up possibilities for realizing the ultra high-speed and ultra wide-band linear signal processing with compact size and low power consumption. We propose a silicon monolithic integrated optical pulse shaper using optical gradient force, which is based on the eight-path finite impulse response. A cantilever structure is fabricated in one arm of the Mach–Zehnder interferometer（MZI） to act as an amplitude modulator. The phase shift feature of waveguide is analyzed with the optical pump power, and five typical waveforms are demonstrated with the manipulation of optical force. Unlike other pulse shaper schemes based on thermo–optic effect or electro–optic effect, our scheme is based on a new degree of freedom manipulation, i.e., optical force, so no microelectrodes are required on the silicon chip,which can reduce the complexity of fabrication. Besides, the chip structure is suitable for commercial silicon on an insulator（SOI） wafer, which has a top silicon layer of about 220 nm in thickness.     

油楠树脂油化学成分的研究

采用毛细管气相色谱-质谱(CGC-MS)联用技术对油楠树脂油的化学成分进行研究,共分离出42个峰,并确认了其中39种成分,占总油量的94.31%。分离出的主要成分为蓖麻油酸(17.91%);7,7,8,8-四甲基二环[4.2.0]辛烷-1(6),3-二烯-2,5-二酮(7.60%);1,2-二乙基-3,4-二甲基-苯(6.70%);1,2,6,6-四甲基-1,3-环己二烯(5.35%);n-棕榈酸(4.47%);1,3,4-三甲基-3-环己烯-1-甲醛(4.17%)。