简易OMA系统作钢样光谱快速定性分析

本文介绍了用一维ＣＣＤ摄象头，多色仪及微机组成的光学多道分析仪系统（简称ＯＭＡ），研究了该系统作光谱化学分析的可行性，自编软件完成波长校正和谱线查找后，自动报出定性和半定量分析结果。     

XeCl准分子激光的超精细光谱结构

本文通过振动-旋转耦合的旋转谱线计算,解释了XeCl准分子激光的超精细光谱结构.计算结果与实验很好地符合.     

准分子激光线宽压缩方法的研究

介绍了准分子激光线宽压缩的各种方法及其各自特点,并用单个标准具对308nmXeCI准分子激光进行了线宽压缩实验。     

准分子激光拉曼种子源

对准分子激光拉曼种子源进行了深入研究。采用波导型拉曼地增强拉曼转换，并在氢气中掺入一定比分的氦气来控制向各阶斯托克斯光的能量转换。当无掺杂时，获得一阶斯托克斯光的最大转换效率η＿（ｍａｘ）＝３７％。当在氢气中掺入氦气比分为５％时，在泵浦能量范围５０～８０ｍＪ内获得一阶高转换效率（η＇≥９５％η＿（ｍａｘ）），二阶及高阶斯托克斯光的转换受到抑制。对实验结果进行了理论分析。     

准分子激光的光束波面测量技术

准分子激光在激光光刻和微细加工中有广泛的应用,要求激光具有好的稳定性和光束波面均匀性。介绍了准分子激光的波面特性以及波面分析测量技术。用波面分析仪对XeCl和ArF激光特性进行全面的测量和评估,给出了主要参数的测量结果,重点分析了光束均匀性。     

准分子激光近年应用的进展

本文简述了准分子激光的发展历史、原理、现状及展望，介绍了准分子激光在染料激光、光谱学、光刻、薄膜沉积、表面处理、精密机械加工及医学领域的几种主要应用．     

准分子激光的光束波面测量技术

 准分子激光在激光光刻和微细加工中有广泛的应用，要求激光具有好的稳定性和光束波面均匀性。介绍了准分子激光的波面特性以及波面分析测量技术。用波面分析仪对XeCl和ArF激光特性进行全面的测量和评估，给出了主要参数的测量结果，重点分析了光束均匀性。     

KrF准分子激光的饱和参量与最佳激光输出

本文研究了在激光达到饱和强度下的上能级弛豫速率及泵浦速率两个参量与激光输出强度的关系。激光达到饱和强度时,上能级弛豫速率等于受激跃迁几率。根据这一特性,研究了Ar在4个大气压到6个大气压之间的四组N_(Ar)和N_(F_2),粒子数密度的Ar—Kr-F_2系统。计算了在给定激发速率和外耦合下的激光输出能量密度随Kr所占混合气体的比例而变化的关系。最后,从饱和强度下的上能级弛豫速率和泵浦速率得到了最大激光输出的条件,相应的激发速率、气压和气体混合的比例。     

ArF准分子激光振荡放大系统的研究

研究了ＡｒＦ准分子激光振荡放大系统，中心波长１９３ｎｍ，用一只闸流管作为开关元件，通过主充放电网络匹配，有效地解决了两台器件的放电抖动，振荡放在倍数达到约５０倍，系统单脉冲输出能量５０ｍＪ，光束发射角低于０．２０ｍｒａｄ。     

原子光谱分析的进展及其应用

文章综述了原子光谱领域分析仪器及分析方法的最新研究进展;例如原子吸收光谱(AAS)、原子发射光谱(AES)、原子荧光光谱(AFS)、激光诱导击穿光谱(LIBS)以及原子质谱(AMS)等,重点关注在食品、医药及其相关领域中的应用。近年出现的芯片实验室和微等离子体,促进了原子分析仪器的微型化发展,而激光及其联用技术在形态分析中的应用仍颇为流行。     

Coulomb expansion of laser-excited ion plasmas

We determine the electric field in mm-sized clouds of cold Rb+ ions, produced by photoionization of laser-cooled 87Rb atoms in a magneto-optical trap, using the Stark effect of embedded Rydberg atoms. The dependence of the electric field on the time delay between the ion plasma production and the probe of the electric field reflects the Coulomb expansion of the plasma. Our experiments and models show expansion times <1micros.     

消热差大相对孔径中波红外望远物镜的研制

为满足低成本空间热成像系统重量轻、适应环境温度范围宽的要求,研制了消热差的大相对孔径中波红外望远物镜,其焦距为100mm,F数为1,全视场角为5°.物镜设计采用了匹兹伐结构型式,仅由两块硅(Si)透镜和一块锗(Ge)的折/衍混合透镜组成,能够实现-20～+60℃环境温度变化范围内光学被动消热差.对实际加工的红外物镜进行...     

New approach for understanding the fundamental chemistry of the oxidative sample digestion in spectrochemical analysis

The process known as “wet digestion” is widely used in analytical chemistry as the most common way of dissolving solid samples for elemental spectrochemical analysis. Wet digestion involves the use of oxidizing reagents and acids–mainly HNO₃, H₂O₂, H₂SO₄, HClO₄, and other complementary acid reagents such as HF, HCl, or their mixtures. Wet digestion has become popular and attractive to users in part owing to the application of modern equipment with new technologies such as temperature-controlled heating blocks, microwave systems, and automated digestion systems, among others. Nonetheless, the use of modern, sophisticated instruments does not change the physical and chemical foundations of the classic chemical process. Until now, simplified equations have been used to explain this process. However, fundamental chemical mechanisms and thermodynamic concepts have been commonly left aside. In this work, the acid digestion of samples has been approached based on the chemical reactions, detailing the role and the effect of main reagents and intermediaries. The reactions that can occur during the digestion process have been specified considering the fundamental thermodynamic properties of the reagents used, especially the oxidizing reagents HNO₃ and H₂O₂. This article will be a beneficial resource for students, instructors, and professionals alike.     

Characterization of third-harmonic generation from femtosecond laser-excited silicon

Third-harmonic generation (THG) from silicon crystals excited by femtosecond pulses has been studied. THG as a function of probe pulse delay from linear and circularly polarized probe pulses was examined. Both polarizations exhibit a fast, 300 fs drop in THG when the Si is pumped by pulses with fluence above the melting threshold. This drop for both polarizations indicates that electronic effects dominate THG in laser-melted Si since structural effects should principally influence THG from linearly polarized probes, suggesting that care needs to be exercised in interpreting THG signal as an ultrafast probe of crystalline structure in semiconductors.     

A compact TEA CO2 laser for field-based spectrochemical analysis of geological samples

A compact capacitor-transfer TEA CO₂ laser of 180 mJ output energy and 50 ns pulse duration in half width was designed and constructed for field use. This laser is suitable for laser microprobe spectrochemical analysis on geological and mining samples. Experiments show that the use of helium as a surrounding gas suppresses the continuous emission spectrum of the plasma, thus increasing the S/N ratio. Using glass as standard samples, the minimum detectable concentrations are estimated with Zn neutral line and F ionic line to be 60 ppm and 500 ppm, respectively.     

快速收敛的低复杂度稀疏水声信道估计方法*

针对水声信道的稀疏特性,本文基于集员L1范数约束比例调节仿射投影算法,在不增加稳态误差的前提下,首先采用一种鲁棒集员滤波思想,通过设定动态误差门限加速算法收敛速度;另外针对其矩阵计算复杂度高问题,利用历史的比例调节矩阵优化信道更新方程,使得某些过程矩阵可通过递归方法更新,从矩阵运算角度降低了计算复杂度。湖试和海试数据处理结果表明,面对弱时变和强时变信道时,此方法相对已有稀疏水声信道估计方法略微降低稳态误差的同时具有更快的收敛速度,并从矩阵运算和迭代次数两个方面降低了计算复杂度。