多纵模激光器模式的锁定

本文用数学方法较详细地分析了三个不同频率的光波的叠加和多纵模激光器模式的锁定。证明了模式锁定的条件。首次较准确系统地给出了三个不同频率的光波叠加产后的光波电场和叠加后的光强曲线和七个纵模锁定后的光波电场Ｅ（ｔ），电场的包络Ａ（ｔ）和光强的包络Ａ＾２（ｔ）曲线。     

循环伏安法中铂对乙醇定量吸附特性的研究

本文论述循环伏安法（ＣＶ）中铂（Ｐｔ）对乙醇（ＥｔＯＨ）的定量吸附特性,及其对葡萄酒中ＥｔＯＨ测定的应用问题。用自制的Ｐｔ梳状工作电极。在０．１Ｍ的ＮａＯＨ溶液中,ＥｔＯＨ的氧化峰电位为－２４０ｍＶ（相对Ａｇ／ＡｇＣｌ参比电极）。以３σ背景值计,检出限为０．０２３％（Ｖ／Ｖ）。样品分析结果准确度为９５．２－１０４．７％重现性范围２．８－３．１％ＲＳＤ（ｎ＝８）。校准曲线的线性动态范围０．１－８％（     

A STUDY ON ISOZYMES OF 5 SPECIES IN POLYYONATUM MILL

本文采用聚丙烯酰胺凝胶电泳技术分析了安徽产黄精属（ｐｏｌｙｙｏｎａｔｕｍｍｉｌ．）五种七个居群植物的过氧化物酶（ＰＯＤ）、酯酶（ＥＳＴ）同工酶,比较了居群间酶谱差异,并对获得的酶谱资料进行了聚类分析（ＵＰＧＭＡ）．结果表明：１）七个居群植物可明显分为５个有效种：Ａ１和Ａ２为一种,Ｂ１和Ｂ２为一种,Ｃ,Ｄ,Ｅ分别为三个不同种,此结果与有关形态分类的研究结果一致;２）酶谱特征显示居群间呈多样性;且种间居群差异明显大于种内居群差异;３）本文认为Ｂ１,Ｂ２（长梗黄精）为较进化的种,Ｅ（琅琊黄精）为较古老种．     

乙烯系单体自由基聚合的阻聚效应(ⅩⅪ)——羟胺类化合物对苯乙烯—甲基丙烯酸甲酯共聚合的影响

研究了二乙基羟胺（ＤＥＨＡ）、二异丙基羟胺（ＤＩＰＨＡ）和吗啉羟胺（ＭＰＨＡ）对偶氮二异丁腈（ＡＩＢＮ）引发的苯乙烯（Ｍ１）－甲基丙烯酸甲酯（Ｍ２）在６０℃共聚合的行为．结果表明,３种羟胺对Ｓｔ－ＭＭＡ共聚合表现出不同的阻聚功效,它们的阻聚活性次序为ＤＥＨＡ＞ＤＩＰＨＡ＞ＭＰＨＡ．同时观察到Ｓｔ－ＭＭＡ共聚合竞聚率发生变化,随着所用羟胺的浓度加大,Ｓｔ－ＭＭＡ交替共聚合倾向增大．此外还讨论了聚合温度对诱导期、共聚合速率和共聚物组成的影响．     

腔内石英晶片产生的Nd:YAG激光纵模分裂现象

为了获得１．０６μｍ波长的双频激光,在二极管泵浦Ｎｄ：ＹＡＧ激光器的谐振腔内放置一石英晶片,观察到了纵模分裂现象,分裂量（即频率差）可随晶片的转动而在整个纵模间隔上调谐。当腔内既有选模元件（熔凝石英Ｆ－Ｐ标准具）又有石英晶片时,同样能够产生纵模分裂现象（产生两个频率）,但ｏ模和ｅ模不能同时起振。纵模分裂量的实测值与理论相吻合。     

A1Et2C1／t—BuC1引发α—蒎烯阳离子聚合

考察了Ａ１Ｅｔ２Ｃ１／ｔ－ＢｕＣ１引发体系的α－蒎烯阳离子聚合反应行为。结果表明，Ａ１Ｅｔ２Ｃ１单独不能引发α－蒎烯聚合，与ｔ－ＢｕＣ１复合后才具有引发活性。其引发活性随ｔ－ＢｕＣ１／Ａ１Ｅｔ２Ｃ１的不同而变化，质谱分析表明α－蒎烯聚合产物中存在ｔ－ＢｕＣ１和基（ＣＨ３）３Ｃ，证明ｔ－ＢｕＣ１参与了链的引发反应。进一步实验还有表明：ｔ－ＢｕＣ１与Ａ１Ｅｔ２Ｃ１相互作用除生成活性物质Ｂｕ＾＋ＡｌＥｔ     

溴化苄对二乙基胺甲基膦酸锆的季铵化及三相催化反应

首次制得二乙基胺甲基膦酸锆－亚磷酸锆Ｚｒ（ＨＰＯ＿３）＿（２－ｘ）·（Ｏ＿３ＰＣＨ＿２ＮＥｔ＿２）＿ｘ·Ｈ＿２Ｏ（ＺＤＥＡＭＰ－ＺＰ，ｘ＝０．７５，０．６０，０．５０）．将ＺＤＥＡＭＰ－ＺＰ用溴化苄季铵化，得到部分季铵化的产物：溴化苄基二乙基铵甲基膦酸锆－二乙基胺甲基膦酸锆－业磷酸锆Ｚｒ（ＨＰＯ＿３）＿（２－ｘ）·（Ｏ＿３ＰＣＨ＿２ＮＥｔ＿２）＿（ｘ－ｙ）·（Ｏ＿３ＰＣＨ＿２Ｎ￣＋Ｅｔ＿２·ＣＨ＿２Ｐｈ·Ｂｒ￣－）＿ｙ·Ｈ＿２Ｏ（Ｙ＜Ｘ，ＺＢＤＥＡＭＰＢ－ＺＤＥＡＭＰ－ＺＰ）．ＺＢＤＥＡＭＰＢ－ＺＤＥＡＭＰ－ＺＰ用于进行液／固／液或固固／液三相催化的亲核取代成醚、卤代烃和羧酸盐合成酯及二氯卡宾加成反应，均得到良好的结果。催化剂易于分离和回收，通常回收７０％～１００％，催化剂重复使用１０次以上无明显失活。     

椭圆曲线上的Rho－Multistage方法

本文描述椭圆曲线Ｅ（Ｆｑ）上的一种离散对数的计算方法，这种算法的复杂度为Ｏ（ｔ１／２）．其中ｔ是Ｐ（∈Ｅ（Ｆｑ））的阶数ｍ的最大素因子．     

AlEt_2Cl／t－BuCl引发α－蒎烯阳离子聚合

考察了ＡｌＥｔ_２Ｃｌ／ｔ－ＢｕＣｌ引发体系的α－蒎烯阳离子聚合反应行为。结果表明，ＡＩＥｔ_２Ｃｌ单独不能引发α－蒎烯聚合，与ｔ－ＢｕＣｌ复合后才具有引发活性，其引发活性随ｔ－ＢｕＣｌ／ＡｌＥｔ_２Ｃｌ的不同而变化，质谱分析表明α－蒎烯聚合产物中存在ｔ－ＢｕＣｌ残基（ＣＨ_３）_３Ｃ，证明ｔ－ＢｕＣｌ参与了链的引发反应。进一步实验还表明，ｔ－ＢｕＣｌ与ＡｌＥｔ_２Ｃｌ相互作用除生成活性物质ＢｕＡｌＥｔ_２Ｃｌ_２外，还有烷基化的产物ＡｌＥｔＣｌ_２，ＡｌＣｌ_３生成，聚合反应条件及引发剂加料方式对α－蒎烯转化率及聚合产物组成都有影响。     

RE（NO3）3—Ala—H2O三元体系在25℃时的半微量相平衡研究

测定了ＲＥ（ＮＯ３）３－Ａｌａ－Ｈ２Ｏ（ＲＥ＝Ｓｍ，Ｇｄ，Ｅｒ）三元体系在２５℃时的溶解度和饱和溶液折光率，绘制了相应的溶解度图与饱和溶液折光率曲线。各体系的溶解度曲线与折光率曲线均由４支组成分别与ＲＥ（ＮＯ３）３．ｎＨ２Ｏ（ＲＥ＝Ｓｍ，Ｇｄ，ｎ＝６；ＲＥ＝Ｅｒ，ｎ＝５），ＲＥ（Ａｌａ）（ＮＯ３）３．Ｈ２Ｏ，ＲＥ（Ａｌａ）４（ＮＯ３）３．Ｈ２Ｏ和Ａｌａ的晶体相对应。     

Optical frequency comb generation from a monolithic microresonator

Optical frequency combs provide equidistant frequency markers in the infrared, visible and ultraviolet, and can be used to link an unknown optical frequency to a radio or microwave frequency reference. Since their inception, frequency combs have triggered substantial advances in optical frequency metrology and precision measurements and in applications such as broadband laser-based gas sensing and molecular fingerprinting. Early work generated frequency combs by intra-cavity phase modulation; subsequently, frequency combs have been generated using the comb-like mode structure of mode-locked lasers, whose repetition rate and carrier envelope phase can be stabilized. Here we report a substantially different approach to comb generation, in which equally spaced frequency markers are produced by the interaction between a continuous-wave pump laser of a known frequency with the modes of a monolithic ultra-high-Q microresonator via the Kerr nonlinearity. The intrinsically broadband nature of parametric gain makes it possible to generate discrete comb modes over a 500-nm-wide span (approximately 70 THz) around 1,550 nm without relying on any external spectral broadening. Optical-heterodyne-based measurements reveal that cascaded parametric interactions give rise to an optical frequency comb, overcoming passive cavity dispersion. The uniformity of the mode spacing has been verified to within a relative experimental precision of 7.3 x 10(-18). In contrast to femtosecond mode-locked lasers, this work represents a step towards a monolithic optical frequency comb generator, allowing considerable reduction in size, complexity and power consumption. Moreover, the approach can operate at previously unattainable repetition rates, exceeding 100 GHz, which are useful in applications where access to individual comb modes is required, such as optical waveform synthesis, high capacity telecommunications or astrophysical spectrometer calibration.     

Orthogonally linear polarized lasers (I) — principle and devices

Two kinds of orthogonally polarized lasers, i.e. Zeeman dual-frequency lasers and four-frequency ring lasers (laser gyros) have been developed since the invention of lasers, in which circularly polarized lights oscillate. This paper summarizes recent progress of the study on orthogonally linear polarized lasers with the standing wave cavity. Firstly, the expression of producing orthogonally linear polarized lights in standing wave cavity, i.e. laser frequency splitting, is given. Almost all the birefringence effects made in laser cavity are used to produce orthogonally linear polarized lights. The effect includes quartz crystal birefringence effect, calcite birefringence effect, stress (photo-elastic) birefringence effect and electro-optical birefringence effect. Secondly, several physical phenomena of orthogonally linear polarized lasers are discovered such as aberrance of frequency splitting curves caused by optical activity of quartz crystal, order-passing of longitudinal modes with frequency splitting and strong modes competition. Finally, because the traditional Zeeman dual frequency laser cannot output frequency difference larger than 3 MHz, the approaches of obtaining larger frequency difference are studied. The sequential results, several kinds of orthogonally polarized lasers, are described, such as birefringence dual frequency lasers outputting a frequency difference from 40 MHz to hundreds of megahertz, birefringence-Zeeman dual frequency lasers outputting a frequency difference from 1 MHz to hundreds of megahertz, the LD pumped YAG birefringence dual frequency laser outputting frequency difference of several gigahertz, and the lasers whose longitudinal mode spacing is c4L instead of c2L.     

Orthogonally linear polarized lasers(Ⅰ)--principle and devices

Two kinds of orthogonally polarized lasers, i.e. Zeeman dual-frequency lasers and four-frequency ring lasers (laser gyros) have been developed since the invention of lasers, in which circularly polarized lights oscillate. This paper summarizes recent progress of the study on orthogonally linear polarized lasers with the standing wave cavity. Firstly, the expression of producing orthogonally linear polarized lights in standing wave cavity, i.e. laser frequency splitting, is given. Almost all the birefringence effects made in laser cavity are used to produce orthogonally linear polarized lights. The effect includes quartz crystal birefringence effect, calcite birefringence effect,stress (photo-elastic) birefringence effect and electro-optical birefringence effect. Secondly, several physical phenomena of orthogonally linear polarized lasers are discovered such as aberrance of frequency splitting curves caused by optical activity of quartz crystal, order-passing of longitudinal modes with frequency splitting and strong modes competition. Finally, because the traditional Zeeman dual frequency laser cannot output frequency difference larger than 3 MHz, the approaches of obtaining larger frequency difference are studied. The sequential results, several kinds of orthogonally polarized lasers, are described, such as birefringence dual frequency lasers outputting a frequency difference from 40 MHz to hundreds of megahertz, birefringence-Zeeman dual frequency lasers outputting a frequency difference from 1 MHz to hundreds of megahertz, the LD pumped YAG birefringence dual frequency laser outputting frequency difference of several gigahertz, and the lasers whose longitudinal mode spacing is c/4L instead of c/2L.     

主动锁模激光器的稳定性分析

主动锁模光纤激光器是未来远程超高速光纤通信系统的理想光发射源和光时钟源。主动锁模光纤激光器的腔长较长,当外界环境条件发生变化时,腔长容易受到机械震动及温度变化的影响而发生漂移。本文主要从长期不稳定性和短期不稳定性两方面分析了主动锁模光纤激光器的稳定性问题。介绍了弛豫振荡、超模噪声的解决方案。同时阐述了再生锁模技术控制腔长的方案,对主动锁模激光器的实验研究有一定的参考意义。     

双轴晶体有效非线性系数精确表达式

考虑了晶体内基频光电位移矢量D.电场强度矢量E的离散及倍频光极化矢量P,电位移矢量D的离散,推出了双轴晶体有效非线性系数(d_(eff))的精确表达式,讨论了有效非线性系数绝对值的对称性并给出了双轴晶体TSCCC和dLAP的有效非线性系数的空间分布。     

主动锁模半导体激光器腔内光脉冲幅度的变化

用速率方程讨论主动锁模半导体激光器,考虑了光脉冲的传输效应和各光学元件对光脉冲的影响.根据泵浦信号每一周期后系统状态应重现这一条件,得到了短光脉冲幅度在腔内随位置的变化,并进而求出输出功率及系统的其他一些重要参量.     

Molecular fingerprinting with the resolved modes of a femtosecond laser frequency comb

The control of the broadband frequency comb emitted from a mode-locked femtosecond laser has permitted a wide range of scientific and technological advances--ranging from the counting of optical cycles for next-generation atomic clocks to measurements of phase-sensitive high-field processes. A unique advantage of the stabilized frequency comb is that it provides, in a single laser beam, about a million optical modes with very narrow linewidths and absolute frequency positions known to better than one part in 10(15) (ref. 5). One important application of this vast array of highly coherent optical fields is precision spectroscopy, in which a large number of modes can be used to map internal atomic energy structure and dynamics. However, an efficient means of simultaneously identifying, addressing and measuring the amplitude or relative phase of individual modes has not existed. Here we use a high-resolution disperser to separate the individual modes of a stabilized frequency comb into a two-dimensional array in the image plane of the spectrometer. We illustrate the power of this technique for high-resolution spectral fingerprinting of molecular iodine vapour, acquiring in a few milliseconds absorption images covering over 6 THz of bandwidth with high frequency resolution. Our technique for direct and parallel accessing of stabilized frequency comb modes could find application in high-bandwidth spread-spectrum communications with increased security, high-resolution coherent quantum control, and arbitrary optical waveform synthesis with control at the optical radian level.     

导波模态类型对锚固锚杆无损检测的影响

纵向模态、扭转模态和弯曲模态超声导波在锚固锚杆结构中衰减的差异性巨大,研究这3种模态超声导波的传播规律对无损检测中测试波的选择具有重要指导意义.应用全局矩阵法的理论计算方法和数值模拟方法分别对这3种模态导波的频散规律和传播规律进行研究,两种方法的研究结果吻合较好.研究结果表明,纵向模态在高频范围内存在衰减为20~44 dB/m的超声导波;扭转模态的所有导波衰减都大于180 dB/m;弯曲模态的导波衰减也大于50 dB/m.因此,纵向模态高频范围的超声导波由于衰减小、易激发等优点可以作为无损检测中的首选测试波.      

超短脉冲“8”字形被动锁模掺铒光纤激光器

利用非线性放大环形镜被动锁模方法对锁模光纤激光器进行实验研究,引入色散管理方法,实现了"8"字形掺铒光纤激光器的自启动被动锁模,在1 550 nm波段上得到了光谱宽度16 nm、脉宽为1.77×10 13s的超短脉冲输出.泵浦功率在300 mW时,激光器实现了重复频率为19.7 MHz,平均输出功率12 mW的锁模脉冲输出.整个激光腔为全光纤结构,而且操作简单,锁模输出状态下的激光器可以在光学平台上稳定运行数小时.     

新型通用变流器的理论及应用

本文介绍一种新型通用变流器,其输入输出波形均是正弦的;在电感负载时输入功率因数角可调(可以为0甚至超前);调频范围几乎不受限制。本文从开关模型入手,导出了具有实用价值的在正弦型多输入、多输出条件下通用变流器的调制函数矩阵[E(t)]的一般形式,并给出了[E(t)]的一些重要性质。本文对通用变流器在AC—DC,DC—AC,AC—AC 三种状态下进行了试验研究,其结果表明特性良好,与理论分析相符。