氢化物的气相富集及其在超痕量分析中的应用

本文从富集原理及其在光谱超痕量分析的应用方面分别对这几种氢化物发生后的气相富集技术进行了较详细地综述.这些气相富集方法包括液氮冷却捕集技术、气球收集技术、石墨炉原位捕集技术、吸收液吸收技术及固体吸附技术等.并对这些氢化物气相富集技术的潜力,及与各种光谱分析法联用的发展前景也进行了讨论.     

吹扫捕集与气相色谱-质谱联用测定水体中的芳烃化合物

利用吹扫捕集-气相色谱-质谱联用技术,对化工厂附近有可能受污染的地表水进行了定性和定量分析。同时对吹扫捕集的试验条件进行了优化,得到了满意的结果。     

氢化物—原子荧光法测定植物及人发中的痕量硒

本文研究开发了在捕集剂覆盖下低温焙烧富集分离氢化物原子荧光光谱法测定植物和人发样品中的痕量硒，本方法克服了使用混合酸分解样品时，有机物质不能彻底分解而给测定带来的不利影响。其方法精密度和准确度均能满足测定的要求。     

HG—100型氢化物原位富集石墨炉自动进样器

作者根据氢化物原位富集分析方法,研制了一台原子吸收用的石墨炉自动进样器。该仪器与原子吸收仪相配合,适于分析As,Se等能形成氢化物的诸元素。     

缝式石英管原子化器用于氢化物原子吸收光谱分析的研究

由于氢化物原子吸收法具有较高的测定灵敏度,这种技术的应用日益广泛。作为氢化物法的原子化器,文献中曾使用过电加热或火焰加热的石英管、氩-氢或氮-氢火焰、氧化亚氮-乙炔焰、空气-乙炔焰、空气-氢、石英管中的氢氧焰以及石墨炉等。这些原子化器虽然各有所长,但是,在使用加热石英管时,原子化的机理比较复杂,可形成氢化物元素间的气相干扰比较严重,在使用过程中石英管的特性会逐渐变坏,灵敏度下降。使用空气-乙炔、氧化亚氮-乙炔     

纤维集合体对PM_(2.5)过滤特性的数值模拟

本文基于对气相场的分析以及颗粒运动轨迹的计算,结合AutoCAD中的Lisp程序以及前处理软件Gambit,建立三维纤维集合体过滤介质模型来研究纤维介质对气溶胶颗粒的捕集效率。利用计算流体力学(CFD)对纤维间气固两相流动特性进行数值模拟研究,用欧拉法处理气相场的同时用拉格朗日方法处理离散颗粒场,探究不同线密度(ρ)、不同孔隙率(e)下纤维集合体对PM_(2.5)的捕集特性。结果表明:对于同一种丝束,纤维集合体的捕集效率随着孔隙率的增加而减小。在相同的孔隙率下,纤维集合体的捕集效率随着纤维线密度的增大而减少。     

石英缝管原子捕集-火焰原子吸收光谱法测定化探样品中的铅

采用石英缝管原子捕集技术,可实现原子高效捕集和瞬间释放,使火焰原子吸收法测定铅的灵敏度比常规FAAS测定铅的灵敏度提高三至四倍。精密度与火焰原子吸收法相同。通过实验,建立了石英缝管原子捕集-火焰原子吸收光谱法测定化探样品中铅的分析方法,方法的检出限（CL）可达3.82μg/g,精密度（RSD）可达1.72%,应用于化探样品中铅的测定效果令人满意。     

氢化物-石墨炉原子吸收光谱法的进展

本文评述了氢化物-石墨炉原子吸收光谱的新进展。内容包括发展沿革、氢化物输入石墨炉方式、氢化物分解和沉积、原子化机理、干扰和应用等部份。指出同时把石墨炉作为氢化物沉积和原子化的工具这种新的联合方式,是近年来氢化物原子吸收法的引人注目的进展,将会获得进一步的发展和应用。本法的主要优点是气相和液相干扰很少。参考文献25篇。     

氢化物—石墨炉原子吸收光谱法的进展

本文评述了氢化物－石墨炉原子吸收光谱的新进展。内容包括发展沿革、氢化物输入石墨炉方式、氢化物分解和沉积、原子化机理、干扰和应用等部分。指出同时把石墨炉作为氢化物沉积和原子化的工具这种新的联合方式，是近年来氢化物原子吸收法的引人注目的进展，将会获得进一步的发展和应用。本法的主要优点是气相和液相干扰很少。参考文献25篇。     

循环流化床富氧燃烧技术研究进展

富氧燃烧(Oxy-fuel combustion)技术作为燃烧中CO₂捕集技术,在技术适用性和经济性上具有较强的优势。循环流化床富氧燃烧技术(Oxy-CFBC)兼顾富氧燃烧和循环流化床燃烧的优点,燃料适应性广,烟气中CO₂富集程度高,易于低成本实现CO₂的捕集。本文梳理了近十五年国内外学者对Oxy-CFBC技术的研究成果,从Oxy-CFBC装置、流化特性、燃烧特性、污染物生成与控制、燃料、富氧燃烧电站系统优化、新一代循环流化床富氧燃烧技术以及国内外专利情况等方面进行了总结和分析,最后对Oxy-CFBC在中国未来发展趋势进行展望。     

Broadband measurements on ultrasonic tank lining materials

The need for good absorbing materials in ultrasonic test tanks is described, although few systematic measurements appear to have been reported to date. Measurements of transmission and reflection on neoprene, paraffin wax, rubber car mat and plastic door mat are reported in the frequency range 1 – 5 MHz and for angles of incidence up to 45°. Neoprene and paraffin wax appear to have excellent characteristics. The paper includes a discussion of experimental problems, a brief comparison with similar techniques in audio acoustics, and identifies two important areas for further work.     

Universality classes for the ricepile model with absorbing properties

The absorbing "ricepile" model with stochastic toppling rules has been numerically studied. Local limited, local unlimited, nonlocal limited, and nonlocal unlimited versions of the absorbing model have been investigated. Transport properties and different dynamical regimes of all of the models have been analyzed, from the point of view of self-organized criticality. Phase transitions between different dynamical regimes were studied in detail. It was shown that the absorbing models belong to two different universality classes.     

两级双溶液除湿/再生模块实验研究

本文依据氯化钙溶液和氯化锂溶液对空气中水蒸气的不同的吸收能力,提出并搭建了两级双溶液除湿/再生模块实验装置.对氯化钙溶液的预除湿能力进行了实验验证,分析了处理空气流速、氯化钙溶液流速和氯化锂溶液流速对模块的除湿性能的影响,以及再生空气速度对系统再生性能的影响.并进一步计算了系统的能耗情况,在增加空气热回收率为50%的再生空气热回收器的典型工况下,最低平均再生热量降低至3.3 kJ/g,系统COP为2.05.     

The potential use of plume imaging for real-time monitoring of laser ablation cleaning of stonework

In this work, the potential of plume imaging was investigated as a real-time monitoring technique for the control of the laser cleaning process in cultural heritage objects with emphasis on encrusted stonework. Optical pulses generated by Nd:YAG laser were used to remove a high absorbing layer of crust from the surface of a lower absorbing marble substrate. Two regimes of operation have been employed for laser cleaning test, Q-switched ns mode, and short free running μs mode. Laser induced breakdown spectroscopy (LIBS) was also employed to study the stratigraphy of the cleaned surfaces, and thus to confirm the validity of the suggested monitoring technique. The tests proved the prospective of introducing plume imaging techniques as a straightforward and inexpensive tool for the real-time monitoring of laser ablation and the determination of the critical point for a safe surface cleaning intervention.     

The Improvement of PML Approach for the Calculation of Microwave and Millimeter Waves Circuit

The improved PML absorbing boundary condition have been introduced in this paper. The reflection coefficient of the absorbing boundary condition is less than the reflection coefficient of Berenger's PML algorithm. And in order to validate the theory and its effectiveness, We have applied the absorbing boundary condition to the calculation of microwave and millimeter waves circuit and get its reflection coefficient S ₁₁. The numerical result is shown in this paper.     

On the formation of amorphous layers by interdiffusion in zirconium-copper system

Formation of amorphous phase by solid state reaction has been observed in bulk copper-zirconium couples. Transmission electron microscopy (TEM), Auger electron spectroscopy (AES) and differential scanning calorimetry (DSC) techniques have been employed to detect and study the amorphous phase. The experimental observations have been explained with a model, which considers the breakdown of the a-zirconium lattice due to the solute enrichment beyond a certain limit where the nucleation of the amorphous phase becomes thermodynamically possible. The present-experiments convincingly show that amorphous phase can form in bulk diffusion couples made from large-grained well-annealed material and conclusively establish that the presence of crystal defects in high concentrations is not a pre-requisite for the formation of amorphous phase.     

Characterization of organic material micro-structures transferred by laser in nanosecond and picosecond regimes

The laser-induced forward transfer technique has been performed on thin layers of conducting organic materials for applications in plastic micro-electronics.This process is a promising alternative for fabrication of organic electronic components on flexible supports when usual techniques, such like ink-jet printing, cannot be considered. For example, when the organic material has no solubility properties or when complex architectures are needed.Experiments on the influence of pulse duration (nanosecond and picosecond) and wavelength on a large range of fluences have been proceeded using different lasers. An optimization of the process has been carried out by inserting a thin layer of absorbing metallic material between the substrate and the organic film. The advantage of this technique is to preserve organic layers from being damaged by thermal and photochemical effects during the interaction.The morphology and thickness of the deposit have been investigated by optical and scanning electronic microscopy. This experimental study is supplemented by electrical characterization of the deposits.     

Generalized ellipsometric method for the determination of all the optical constants of the system: Optically absorbing film on an absorbing substrate

A numerical method has been developed to evaluate all the optical parameters of the system of an optically absorbing film on an absorbing substrate using ellipsometric measurements. The generality and validity of the algorithm has been investigated for different ideal cases. In addition the effects of the actual limited precision of ellipsometric measurements as well as the problem of multiple solutions have been studied.     

水体中纳米颗粒检测的研究进展

纳米颗粒在工业和化妆品等行业中的大规模应用,致使大量纳米颗粒进入水环境中,不可避免的产生了一系列的环境问题,同时对生物和人体造成不良影响,因此水环境中纳米颗粒的富集及其检测技术受到广泛关注。目前,多种技术可对水环境中痕量纳米颗粒浓度等特征进行检测,但其在灵敏度和精度方面均存在一定局限性。归纳了目前水环境中纳米颗粒的预处理技术,如超滤分离技术、色谱分离技术、固相萃取技术及浊点萃取技术;综述常用的纳米颗粒与离子检测技术,如光谱分析技术、电感耦合等离子质谱技术及电化学技术。通过对各种方法进行对比分析,使纳米颗粒预处理及检测技术能够被系统广泛的认识。并在此基础上对纳米颗粒的预处理及检测技术的发展前景进行了展望。     

碳团簇型雷达隐身涂料环境稳定性研究

平面环状碳团簇是一种特殊的大分子,利用其转动能级跃迁的谱线富集于1～20 GHz的微波区的特性,研究了碳团簇型隐身涂料的吸收性能稳定性及其机械特性,结果表明,该隐身涂料基本满足吸波材料的技术要求,是一种实用型的隐身材料.