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61.
Window factor analysis(WFA)is a self-modeling method for extracting the concentration profiles ofindividual components from evolutionary processes such as flow injection,chromatography,titrationsand reaction kinetics.The method takes advantage of the fact that each component lies in a specificregion along the evolutionary axis,called the‘window’.Theoretical equations are derived.The methodis used to extract the concentration profiles and spectra of seven bismuth species from data obtained byGemperline and Hamilton,who injected bismuth perchlorate into a flowing stream of hydrochloric acid.  相似文献   
62.
流动注射-光度法测定地质样品中痕量碘   总被引:2,自引:2,他引:2  
利用I~-对4,4′-四甲基二氨基二苯甲烷(4,4′-TMB-DPM)与氯胺T反应的催化作用,建立了流动注射-分光光度测定地质样品中痕量碘的方法。采用不等流速合并带法,分析速度快、节省试剂、灵敏度高。与高温水解法释放I~-相结合,使样品处理简单、干扰离子少。对于含I~-10μg/L的水样,其RSD(n=19)为1.1%,检出限为0.3ng/ml。用于水系沉积物、土壤分析时,含碘1.6×10~(-6)的样品RSD(n=10)为6.1%,检出限为0.08×10~(-6)。测量速度50N/h。  相似文献   
63.
An analysis is presented of the orbital injection errors for the Lageos III satellite mission. Several methods are introduced for the solution of the Inverse Problem in the Theory of Errors. The novelty of the present approach consists in the use of the full geopotential covariance matrix in the error propagation equations. The GEM-T1 covariance matrix is used. It is found that by properly accounting for the correlation among the even zonal harmonic coefficients the acceptable error bounds increase by an order of magnitude with respect to the case when only the variances are used. The most stringent constraint, even when using the full covariance, is on inclination, whose nominal value must be realized within approximately 0.1° for the recovery of the Lense-Thirring precession to be successful at the 3% level (accounting only for injection errors). The associated tolerance in the semimajor axis is about 30 km while that in eccentricity is approximately 0.2. However, if the errors in semimajor axis and eccentricity can be kept to the routinely achievable levels respectively of 10 km and 0.004, then the tolerance in inclination can be relaxed to 0.2°.  相似文献   
64.
Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been applied to determine the elemental composition of the surface layer, as well as of the first interior layer, of quartz grains from the mine tailings from Kristineberg (northern Sweden) in order to determine concentration gradients between these two layers. The quartz grains were collected from the oxidized and unoxidized zones within the tailings. The aim of this study is to assess the role of quartz surfaces as sites for the attenuation of solutes from the mine-tailings porewater. Concentrations of Cu, Ag, Sb, Pb and Bi are highest near the surface of each grain and decrease towards the interior. The surface concentration of Cu, Zn and Pb is more pronounced within the unoxidized than within the oxidized zone of the tailings. Cu exhibits a distinct concentration peak at the surface of the quartz grains below the pre-remediation oxidation front. For Zn and Ce the trend of high surface concentration is less pronounced than for Cu or Pb. Silver, Bi and As are preferably adsorbed within the uppermost layers of the oxidized zone where the pH is as high as 6.2. The conversion of intensity signals of the elements to concentration values in ppm was done by using external standards (NIST silicate glass).  相似文献   
65.
Based on a self-consistent solution of the equations of gas dynamics, kinetics of hydrogen atomic level populations, and radiative transfer, we analyze the structure of a shock wave that propagates in a partially ionized hydrogen gas. We consider the radiative transfer at the frequencies of spectral lines by taking into account the effects of a moving medium in the observer's frame of reference. The flux in Balmer lines is shown to be formed behind the shock discontinuity at the initial hydrogen recombination stage. The Doppler shift of the emission-line profile is approximately one and a half times smaller than the gas flow velocity in the Balmer emission region, because the radiation field of the shock wave is anisotropic. At Mach numbers M1?10 and unperturbed gas densities σ1=10?10 g cm?3, the Doppler shift is approximately one third of the shock velocity U1. The FWHM of the emission-line profile δ ? is related to the shock velocity by δ ? k ? U1, where k ? = 1, 0.6, and 0.65 for the Hα, Hβ, and Hγ lines, respectively.  相似文献   
66.
We analyse long-lasting (several hours) Pc1 pearl pulsations with decreasing, increasing or constant central frequencies. We show that nonstationary pearl events (those with either decreasing or increasing central frequency) are observed simultaneously with increasing auroral magnetic activity at the nightside magnetosphere while the stationary events (constant central frequency) correspond to quiet magnetic conditions. Events with decreasing central frequency are observed mostly in the late morning and daytime whereas events with increasing central frequency appear either early in the morning or in the afternoon. We explain the diurnal distribution of the nonstationary pearl pulsations in terms of proton drifts depending on magnetic activity, and evaluate the magnetospheric electric field based on the variation of the central frequency of pearl pulsations.  相似文献   
67.
In usual incoherent scatter data analysis, the plasma distribution function is assumed to be Maxwellian. In space plasmas, however, distribution functions with a high energy tail which can be well modeled by a generalized Lorentzian distribution function with spectral index kappa (kappa distribution) have been observed. We have theoretically calculated incoherent scatter spectra for a plasma that consists of electrons with kappa distribution function and ions with Maxwellian neglecting the effects of the magnetic field and collisions. The ion line spectra have a double-humped shape similar to those from a Maxwellian plasma. The electron temperatures are underestimated, however, by up to 40% when interpreted assuming Maxwellian distribution. Ion temperatures and electron densities are affected little. Accordingly, actual electron temperatures might be underestimated when an energy input maintaining a high energy tail exists. We have also calculated plasma lines with the kappa distribution function. They are enhanced in total strength, and the peak frequencies appear to be slightly shifted to the transmitter frequency compared to the peak frequencies for a Maxwellian distribution. The damping rate depends on the electron temperature. For lower electron temperatures, plasma lines for electrons with a distribution function are more strongly damped than for a Maxwellian distribution. For higher electron temperatures, however, they have a relatively sharp peak.  相似文献   
68.
采用AGMP-1阴离子交换树脂,分别以7mol/L HCl、2mol/L HCl、0.5mol/L HNO3作为淋洗剂,可有效分离Cu、Fe、Zn。介绍了方法的基本原理、化学分离过程及混合标准溶液与地质标样的分离结果。结果表明,Cu、Fe、Zn回收率均接近100%,标准溶液在离子交换分离前后同位素组成一致,可以满足多接收器等离子体质谱对Cu、Fe、Zn同位素高精度分析的要求。  相似文献   
69.
宋小年  冯天培 《岩矿测试》2006,25(2):189-190196
采用电感耦合等离子体发射光谱法测定硅铝丝(Al—1%Si)中Si及杂质元素Fe和Cu。确定了最少取样量和样品溶解方法,优化了元素分析谱线和仪器的测量条件。实验表明,方法的加标回收率为99%~1叭%,相对标准偏差(n=6)低于1.4%,Si、Fe、Cu的检出限分别为8.5、1.0和0.4μg/L。该方法应用于快速测定键合硅铝丝中的各种元素,结果满意。  相似文献   
70.
以北京市老城区雨洪控制与利用示范工程为背景.对天然降雨、不同下垫面雨水径流、示范工程处理过程雨水径流以及地下水水质进行分析研究,通过示范工程对雨洪的处理利用效果,探讨雨水回灌至地下能否对地下水环境产生负面影响。  相似文献   
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