β-环糊精交联树脂富集-氢化物发生原子荧光光谱法测定水中的三苯基锡

提出利用β-环糊精交联树脂分离富集环境水样中的三苯基锡并结合氢化物发生原子荧光光谱法,对其消解物进行定量分析的新方法,通过实验优化其化学和仪器条件,方法灵敏度高、精密度好,检出限为0.1 ng·mL-1,相对标准偏差RSD为2.64%(0.04μg·mL-1),成功地用于实际水样中三苯基锡的分析.     

Study on Atomic Fluorescence Spectrometry Excited by Synchrotron Radiation

将同步辐射作为原子荧光的新型激发光源,建立了同步辐射原子荧光光谱分析装置,并对具体实验条件,如气体流速、分析物酸度、预还原试剂以及氢化物发生体系浓度等进行优化. 利用该装置测定了原子荧光代表分析物?砷的同步辐射原子荧光激发谱线. 在主要的10条谱线中,7条与现有文献记载十分吻合,其中4条系首次以原子荧光手段获得,另3条系首次发现. 对谱线所对应的激发电位以及可能的跃迁过程进行了分析,特别是对234.99 nm强峰的产生机理进行了探讨,并建立了能级跃迁模型.     

微波消解-氢化物发生-原子荧光光谱法测定羊栖菜中汞

建立了微波消解-氢化物发生-原子荧光光谱法测定羊栖菜中汞的方法,系统地研究了微波消解、氢化物发生的最佳条件,利用加标回收试验,对分析方法进行了验证.本方法具有简便、快速、灵敏度高等优点,检出限为0.05μg/L,RSD为1.5%,样品加标回收率为93.8%-105.3%.     

悬浮进样-氢化物发生-原子吸收光谱法测定化妆品中的微量砷

建立了一种悬浮进样-流动注射-氢化物发生-原子吸收光谱测定化妆品中痕量砷的新方法,实验考察和优化了影响砷信号强度的氢化物发生条件和悬浮条件.以无水乙醇作分散剂,1.5g/L琼脂作稳定剂,得到了满意的分析效果.方法具有操作简易、快速,灵敏度高等特点.     

流动注射在线离子交换预富集 HG-AFS测定痕量铅

研究了流动注射在线离子交换预富集与氢化物发生原子荧光光谱法的联用技术。设计了双柱并联富集、串联洗脱的在线离子交换流路及操作程序 ,优化了各项化学条件及操作参数。方法操作简便 ,灵敏度高 ,干扰少 ,在采样频率为 30个样 / h条件下 ,检出限为 0 .0 0 6 1ng/ m L,较常规氢化物发生原子荧光光谱法降低了 2 0倍 ,RSD为 5 .78% (n=10 ,Pb 10 ng/ m L )。适用于痕量铅的测定 ,结果令人满意。     

断续流动-氢化物发生原子荧光光谱法测定硫磺中的微量砷

采用断续流动-无色散氢化物发生原子荧光光谱法测定硫磺样品中的微量砷含量。采用一系列单一变量优化了酸度、还原剂浓度、共存元素以及载流流速对氢化物发生的影响,本方法快速简单、灵敏度高、检出限低。检测线性范围为1．0—100μg/L,检出限为为0．519μg／L,回收率为91．4％-99．2％。     

氢化物发生-原子荧光光谱法测定进口未焙烧黄铁矿中总砷含量的不确定度评定

以氢化物发生-原子荧光光谱法测定进口未焙烧黄铁矿中总砷含量为例,建立了数学模型,对测试过程中的各个分量进行分步计算和合成,计算出扩展不确定度为0.007％,评定结果表明校准曲线是氢化物发生-原子荧光光谱法测定进口未焙烧黄铁矿中总砷含量不确定度的主要影响因素.     

流动注射-氢化物发生-原子荧光光谱法测定牛奶中的铅

建立了流动注射-氢化物发生-原子荧光光谱法测定奶制品中铅含量的分析方法,对仪器条件和反应条件进行了选择、优化。方法的检出限为0.30μg/L,相对标准偏差小于4.7%,回收率为90.0%—114.5%,符合食品中痕量元素的分析要求。     

氢化物发生-原子荧光光谱法同时测定纺织品中的砷和锑

湿法消化样品,断续流动-无色散氢化物发生-原子荧光光谱法同时测定纺织品中的砷,研究了酸度、KBH4浓度、仪器主要条件参数对实验结果的影响,以及硫脲 抗坏血酸混合液对干扰元素的消除作用。在经过优化的实验条件下,本方法砷和锑的精密度分别为1.69%和2.75%,检出限分别为0.5605μg·L-1和0.4670μg·L-1,方法的加标回收率在94.71%—96.85%之间,该方法能简单快速、准确的测定纺织品中砷和锑的残留量。     

氢化物发生-原子荧光法测定饮料中砷含量的不确定度评定

本文以氢化物发生-原子荧光光谱法测定饮料中砷含量为实例,建立了数学模型,对测试过程中不确定度的各个分量进行了分步计算及合成,计算出扩展不确定度为0.0011mg/L.结果表明校准曲线是氢化物原子荧光法测定饮料中砷含量不确定度的主要影响因素.     

Comparison between theoretical calculations and high-resolution measurements of pressure broadening for near-infrared water spectra

We report N₂ and air foreign pressure broadening coefficients of more than twenty rovibrational transitions of water vapor in the 935-nm spectral region, and these measurements are compared to new theoretical calculations. The data were obtained using the frequency-stabilized cavity ring-down spectroscopy method, yielding relative uncertainties for the broadening parameters in the range 0.4-2.2%. The sensitivity of measured broadening parameters to the choice of line shape functions is discussed, and systematic differences between experimentally determined collisional broadening coefficients are shown for the cases when the observed line narrowing is interpreted in terms of Dicke-narrowing or the speed-dependence of the collisional broadening and shifting. Theoretical models of pressure broadening for these transitions agree with the measurements to within 4% for most transitions with an average relative difference of 0.63%.     

高灵敏度的光纤光栅压强传感器

基于光纤布拉格光栅传感模型 ,提出了一种等强度梁与波纹管相结合的高灵敏度的光纤布拉格光栅压强传感器 ,推导了光纤布拉格光栅反射波中心波长相对偏移量与压强之间的解析关系式 ,从理论和实验上给出了压强灵敏度系数。该传感器的理论和实验压强灵敏度系数分别是 1.4 76× 10 -2 MPa-1、1.35× 10 -2 MPa-1,是裸光纤光栅的 74 5 5倍和 6 80 8倍 ,理论值与实验值吻合得很好。同时指出通过调节等强度梁和波纹管的参量 ,可以将该传感器的压强灵敏度系数做得很高 ,直至破坏了光纤布拉格光栅。     

地层渗透参数反演计算

利用渗流源网格压力(及井底压力)对网格渗透率导数关系(称为渗透率压力场敏感系数)实现由三维渗流方程压强数值解计算井底压力对网格渗透参数导数的计算.基于渗透率压力场敏感系数的计算结果构造地层渗透参数反演方程,由多井系统井压监测数据实现反演地层渗透参数的计算.算例显示:反演方法对均匀(或分块均匀)油藏模型的计算取得了较好的结果,反演迭代10次后计算结果与模型参数的最大相对误差收敛于1%之内.该方法对油藏动态模拟研究及实现油藏参数动态跟踪具有实际意义.     

Measurements of O2-broadening and -shifting parameters of water vapor spectral lines in the second hexad region

Oxygen pressure induced broadening and shifting coefficients for water vapor absorption lines in the 8600–9010 cm⁻¹ region have been measured and calculated. The spectra were recorded with a Bruker IFS 125HR spectrometer at a spectral resolution of 0.01 cm⁻¹ for lines with angular moment of the upper states up to 10. Calculations of line broadening and shifting coefficients are performed using a semi-empirical approach. The method is based on the impact theory of broadening, and includes the correction factors whose parameters can be determined by fitting the broadening or shifting coefficients to the experimental data. The comparison of our calculations with the experimental values argues that the semi-empirical method is quite acceptable for the determination of the water vapor absorption line profile parameters.     

Collisional line widths of autoperturbed N2: Measurements and quantum calculations

In this work we present new experimental and theoretical values for the line broadening coefficients of the Q-branch Raman lines of autoperturbed N₂. For the experimental determination of the coefficients, high resolution stimulated Raman spectra of the Q-branch of N₂ at different pressures were obtained at 77, 194 and 298 K. Simultaneously, quantum dynamical calculations, performed on two potential energy surfaces, were carried out for the system between 77 and 298 K, rendering a set of theoretical line broadening coefficients that could be directly compared to those obtained from the present measurements and the previous ones. Within the limit of considering the colliding molecules distinguishable we discuss the ortho and para contributions to the pressure broadening cross-sections. Because such calculations are time consuming we indicate routes to circumvent this difficulty. We observe a reasonable agreement between theoretical and experimental values of the collisional line broadening coefficients at all the studied temperatures.     

基于波长调制-直接吸收光谱方法的CO分子1567 nm处谱线参数高精度标定

直接吸收光谱(DAS)可直接测量分子吸收率函数,并通过拟合吸收率函数确定待测气体参数.波长调制-直接吸收光谱(WM-DAS)在DAS基础上,结合了波长调制光谱(WMS)中谐波分析思想,利用傅里叶变换复现吸收率函数,可有效提高吸收率函数的测量精度.本文利用WM-DAS方法结合长光程气体吸收池,在室温低压条件下,对CO分子1567 nm处R5-R11近红外弱吸收谱线吸收率函数进行了精确复现,其拟合残差标准差低至3×10^-5,随后根据测得的吸收率函数对谱线的碰撞展宽、Dicke收敛以及速度依赖的碰撞展宽系数等光谱参数进行了高精度标定,并将其与高灵敏度的连续波腔衰荡光谱(CW-CRDS)测量结果进行了比较,实验结果表明该方法与CW-CRDS测量结果具有高度一致性,更具有系统简单、测量速度快、对环境要求低等优点.     

Semi-empiric approach to the calculation of H2O and CO2 line broadening and shifting

A semi-empiric approach to the calculation of spectral line half-widths and shifts is proposed. This approach is based on the Anderson approximation and includes the correction factors, the parameters of which can be determined by fitting the broadening or shifting coefficients to the experimental data. This allows sufficiently accurate predictions of the parameters of line profiles that were not measured. The coefficients of CO₂ and H₂O spectral line broadening and shifting due to air and nitrogen pressure are calculated, as well as the coefficients of their temperature dependence. The calculated coefficients agree satisfactorily with measured values.     

Cavity enhanced absorption spectroscopy measurements of?pressure-induced broadening and shift coefficients in?the?υ1+υ3 combination band of ammonia

Cavity enhanced absorption spectroscopy is performed using an external cavity diode laser operating around 1516 nm. We demonstrate a sensitivity of 6×10⁻⁸ cm⁻¹ Hz^−1/2 and utilise a simple method to measure pressure-induced broadening and shift coefficients. The broadening and shift coefficients for six gases (helium, neon, argon, xenon, oxygen and nitrogen) have been determined at room temperature for four transitions in the υ ₁+υ ₃ combination band of ammonia. Comparisons of the broadening coefficients with previous work in this region, where it exists, show good agreement. The broadening and shift coefficients of nitrogen and oxygen are also in good agreement with calculated values using the Robert and Bonamy theory. Both the broadening and shift coefficients show a clear trend through the rare gases, which can be explained in terms of the varying magnitude of the long range attractive forces operating between the colliding partners. We also demonstrate the application of the Parmenter–Seaver formalism to estimate the potential well depth of the ammonia dimer from the obtained broadening coefficients. The obtained well depth agrees well with theoretical calculations.     

Diode-laser measurements of O2, N2 and air-pressure broadening and shifting of NH3 in the 10 μm spectral region

Using a tunable diode-laser spectrometer, we have measured the O₂, N₂, air-shift and broadening coefficients for 5 lines of ammonia in the R branch of the ν₂ band. These lines are located in the spectral range 1030-1070 cm⁻¹. The pressure shift and broadening are obtained by fitting the measured shapes of these lines by a Voigt profile. The broadening parameters and shift coefficients are compared to the results of theoretical calculations based on the semiclassical Robert-Bonamy formalism (RB) in which the intermolecular potential includes electrostatic, induction, and dispersion energy contributions. The variation of these coefficients with rotational and vibrational quantum numbers is examined. The results are generally in satisfactory agreement with experimental data.     

Determination of the Absorbing and Scattering Properties of the Sea Floor in a Shallow Water Environment by the Spectra of Wide-Band Signals

Sound propagation in a shallow sea is considered within the framework of the two-component model of the sea floor. The porosity and the coefficients of absorption and volume scattering are treated as the parameters characterizing the sea floor. These parameters are determined on the basis of the comparison between the experimental and theoretical frequency spectra of a signal received from a wide-band source. A conclusion is made about the relative contributions of different mechanisms of losses (absorption or scattering) in the sea floor at different sound frequencies.