火焰原子吸收光谱法测定食盐中痕量铅

对巯基棉富集 Pb( )的条件作了研究 ,经过巯基棉分离富集后 ,用火焰原子吸收光谱法测定了食盐中的痕量铅 ,实验回收率 97.3%— 97.5 % ,RSD<5 %。方法简便 ,可用于食盐中痕量铅的测定     

巯基棉分离富集-火焰原子吸收光谱法测定钙盐中的痕量铅和镉

巯基棉分离富集 ,火焰原子吸收光谱法同时测定钙盐中的痕量铅、镉 ,大量钙不干扰铅、镉的测定。方法简单易行 ,结果令人满意的。     

巯基棉分离富集-FAAS法测定海水中的痕量镉

借助巯基棉分离富集技术 ,以火焰原子吸收光谱法测定海水中的痕量镉。该方法的回收率为94 .0 %— 97.0 % ,相对标准偏差为 4 .9%。结果表明 ,该方法简单易行 ,具有较好的准确度和精密度     

巯基棉富集-火焰原子吸收光谱法测定卤水中的痕量银

利用巯基棉富集银,将富集银后的巯基棉灰化,用王水将银氧化并控制30％的盐酸酸度,火焰原子吸收光谱法测定卤水中的痕量Ag.对流速、富集时间和酸度等因素进行了实验,方法可用于卤水中痕量银的分析.检出限为(3S/N)=0.002mg/L,加标回收率为99.0％-101％.相对标准偏差为3.21％(n-11).     

巯基棉分离富集-火焰原子吸收法测定中药材中的铅

通过巯基棉分离富集后 ,采用火焰原子吸收方法成功测定了怀药 (怀山药、怀牛膝、怀菊花、)中的痕量铅 ,并对富集铅的条件及洗脱条件、干扰因素进行了探讨。本实验回收率在 97 0 %～ 1 0 2 0 % RSD <4 3 %。此方法简单易行、方便快速 ,结果令人满意 ,可用于测定中药材中的痕量铅。     

巯基棉分离富集—火焰原子吸收光谱法测定钠盐试剂中的痕量镉

偏硼酸钠，无水乙酸钠，无水碳酸钠，磷酸氢二钠等试剂中的痕量镉，经巯基棉分离和富集后，以火焰原子吸收光谱法进行测定。方法简便，快速，测定的相对标准偏差均小于４．６１％。     

巯基棉富集废水中痕量镓镉铅的化学光谱测定

本文主要研究了利用巯基棉在pH5—6.5的微酸性条件下,富集废水中痕量镓、镉、铅等元素的化学光谱测定。进行了一系列化学干扰及光谱条件等试验。用本法测定了废水样品,获得了较满意的结果。该法具有简便、快速及灵敏的特点。     

巯基棉分离富集-FAAS法测定爆玉米花中痕量铅

本文借助巯基棉分离富集技术,以火焰原子吸收光谱法（ＦＡＡＳ）测定爆玉米花中痕量铅。该方法采用巯基棉做分离富集剂,简便易行,并能有效的消除共存元素的干扰,回收率为９７．５％－１０６．０％。     

巯基棉富集分离-石墨炉原子吸收法直接测定蜂蜜中的痕量铅

本文研究了用巯基棉直接富集蜂蜜中的痕量铅,使铅与干扰物质分离,再用石墨炉原子吸收法测定铅的方法。一、实验部分(一)仪器与试剂1.日本岛津AA-670原子吸收分光光度计。2.GFA-4A型石墨炉原子化器。3.硝酸铅(高纯)。4.巯基棉:参照文献[1]制备。(二)实验原理     

水样中铜,铅,镉的巯基棉富集火焰原子吸收测定

在测定水样中铜、铅及镉的时候用巯基棉在采样现场富集简便快速,且灵敏准确,避免了样品运送的不便和萃取富集的繁琐。     

混合物物态方程的计算

 在采用体积相加原理计算混合物物态方程的基础上,建立了一种物理模型确定混合物温度。根据混合物中各组分温度和压强平衡条件,采用压强-密度迭代方法计算给出混合物物态方程,编制了两种组分的混合物物态方程计算程序。为检验建立的温度模型的合理性及程序的有效性,分析了不同密度、温度状态的氢（H2）和钨（W）组成的混合物状态参量,计算了以下情形及其组合情形的混合物物态方程：H₂和W以不同质量比混合;质量比固定,单组分状态不同;温度区间和密度区间不同。研究表明:实际应用中在建立的混合物温度模型基础上确定的混合物物态方程是合理的。     

分子费米共振拉曼光谱强度分析

测量了CCl₄和CS₂分子的Raman光谱。用Bertran理论和群论等相关理论对其光谱强度进行了分析,获得了发生费米共振分子的拉曼光谱强度的特殊规律： (1)发生费米共振的基频和倍频(和频)间发生能量转移,两光谱强度大小相互接近,当发生费米共振的基频和倍频(和频)间距离很小时,两发生费米共振的光谱强度相等(R=1);(2)能出现倍频光谱强度高于其基频光谱强度;(3)也会观测到费米共振光谱,而观测不到参与费米共振的和频中的基频光谱。此研究对化学、材料科学中的分子结构、材料成分等研究中的谱线认证、归属有很好的参考价值。     

Infrared Quantitative Study of Acetylation of Microspheres of Polystyrene

Abstract

Fourier transform infrared spectroscopy has been used to study quantitatively the acetylation of monodisperse polystyrene microspheres with diameters ranging from 7 to 9μm. The CH₂ stretching infrared vibration mode at 2921 cm^?1 was used as the internal intensity standard. The acetylation extent could be easily measured by comparing the relative intensities of the bands of acetyl group (1678, 1415, 1359 cm^?1) or the bands due to the para-substituted benzene ring to the band at 2921 cm^?1 from the calibration curve.     

Asymptotic properties of sequences of iterates of nonlinear transformations

By considering functions defined on the unit interval with a single zero minimum and a single unit maximum we are led to a version of the doubling or universal transformation. The fixed point functions of this doubling transformation have certain invariance properties under conjugacy. These invariance properties lead to a widening of the concept of universality to power law conjugacy classes in which the Feigenbaum divergence parameter is a function only of the product of the powers with which iterating functions approach unity at the maximum and zero at the minimum. We also construct an effective method for computing the divergence parameter from iterates, and derivatives of iterates, generated by the appropriate fixed point function.On leave from Mathematics Department, University of Melbourne, Parkville, Victoria 3052, Australia.     

Application of the method of X-ray fluorescence analysis for determination of the degree of chlorination of copper phthalocyanin

To whom correspondence should be addressd.     

BSA-SDS-Ag聚合物纳米微粒的制备及其水凝胶性质的研究（Ⅰ）

报道了BSA－SDS－Ag聚合物纳米微粒的制备及水凝胶的性质,用X射线衍射（XRD）、透射电镜（TEM）、傅里叶变换红外（FT－IR）光谱考察了这种聚合物微粒的结构,微粒粒径32nm左右,用UV／Vis光谱及SEM考察了冰凝胶的性,表明Ag^ 离子先与BSA产生化学键合,再学原了Ag粒,进行聚合成网状结构的聚合物。     

Basin of attraction of cycles of discretizations of dynamical systems with SRB invariant measures

Computer simulations of dynamical systems arediscretizations, where the finite space of machine arithmetic replaces continuum state spaces. So any trajectory of a discretized dynamical system is eventually periodic. Consequently, the dynamics of such computations are essentially determined by the cycles of the discretized map. This paper examines the statistical properties of the event that two trajectories generate the same cycle. Under the assumption that the original system has a Sinai-Ruelle-Bowen invariant measure, the statistics of the computed mapping are shown to be very close to those generated by a class of random graphs. Theoretical properties of this model successfully predict the outcome of computational experiments with the implemented dynamical systems.     

Electron microscopy study of aggregation of microclusters of sulphur

A study of aggregation of sulphur particles in colloidal suspension of sulphur in water-methanol mixture using TEM and electron diffraction is reported. From the micrographs the aggregates formed have been found to be random and tenuous indicating a fractal structure. The electron diffraction patterns of the aggregates are used to study the mechanism of diffusion and reaction limited aggregation.     

Some peculiarities of deep PT-changes of physical properties of rocks

Abstract

Results of petrophysical PT-experiments are discussed. Used is a method of program modeling of experiments. Thermobaric dependence of elastic properties of acid, intermediate and basic rocks as well as elastic wave velocity anisotropy in amphibolites is studied. Deep PT-regimes effect on electrical resistance of dry and water-saturated rocks has been studied. PT-conditions of full loss of the remanent magnetization of volcanites have been established. A number of regional petrophysical lithosphere models has been constructed.