萃取剂乳化特性的分光光度法研究

溶剂萃取过程容易发生乳化现象而影响过程的正常进行。本文提出用分光光度法研究乳化过程及乳化液的特性，并介绍了方法的原理、实施过程及绘制时间－透光率曲线（t-T%）的实例。     

火焰原子吸收分光光度法测定饲料中的铬

强制性国家标准GB 13078—2001规定了饲料中铬的限量。文章针对饲料中铬含量测定的国家标准方法GB/T 13088—1991的不足,建立了火焰原子吸收分光光度(FAAS)法测定饲料中铬含量的分析方法。分别研究了不同的乙炔流量、燃烧器高度和干扰抑制剂氯化铵的添加量对三价铬[Cr(Ⅲ)]和六价铬[Cr(Ⅵ)]测定灵敏度的影响;比较了用Cr(Ⅲ)和Cr(Ⅵ)标准曲线测定饲料样品中铬的结果,两组测定的平均值经t检验,无显著性差异。FAAS法测定铬的灵敏度为0.014 μg·mL-1;检出限为0.70 mg·kg-1,标准添加回收率为94.4%～104.9%,同一样品重复测定(6～7次)的相对标准偏差(RSD)为1.90%～4.08%。该方法与GB/T 13088—1991相比具有简便、快速、准确等优点,其检出限满足GB 13078—2001规定的饲料中铬的限量要求。     

甲壳素邓要—火焰原子吸收分光光度法测定痕量铜

利用甲壳对金属离子的选择性吸附，研究了甲壳素快速吸附离子的吸附条件和洗脱条件，在火焰原子吸收分光光度计上进行铜的测定，方法简单快速吸附离子的吸附检出限为８．０ｄｎｇ／ｍＬ，精密度ＲＳＤ为３．６％，用于矿样中痕量铜的测定，分析结果与推荐值吻合。     

微波消化-石墨炉原子吸收分光光度法测定进口西洋参中的铅

本文对进口西洋参中铅的测定方法进行了研究。本文利用微波消化比常规法更快、更安全、更环保、更准确的优点,对西洋参进行了前处理;利用石墨炉原子吸收分光光度法灵敏、高速、耗样量少等优点,对西洋参进行测定。本文设定了微波消化条件的程序,对微波消解的混合酸进行了选择,解决了最终的消化液其酸度对测定的影响问题,并对石墨炉原子吸收的测定条件进行了研究。依据多次实验结果,选择了合适的灰化温度和原子化温度,确定了最终的石墨炉升温程序。本方法铅的线性范围为0～100μg·L~(-1),检出限为2.80μg·L~(-1),相对标准偏差为0.91％,回收率为98.13％,方法的精密度及准确度均令人满意。     

固相萃取富集-火焰原子吸收分光光度法测定水中的镉

强阴离子交换固相萃取柱萃取富集 ,火焰原子吸收分光光度法测定环境水样中镉 ,方法相对标准偏差在 2 .5 %— 3.5 %之间 ,加标回收率在 97%— 1 0 4 %之间 ,结果令人满意     

原子吸收分光光度法同时测定粮谷中痕量镉和胂

本文利用干扰效应并采用模拟退火－误差反向传播人工神经网络算法辅助原子吸收分光光度法在单波长下对粮谷中痕量镉和砷的同时测定进行了研究,取得了满意结果。标准加入法的回收率分别为91％－98％和87％－92％,7次平行测定结果的相对标准偏差均小于4％。该法快速、简单。     

原子吸收分光光度法同时测定粮谷中痕量镉和砷

本文利用干扰效应并采用模拟退火 误差反向传播人工神经网络算法辅助原子吸收分光光度法在单波长下对粮谷中痕量镉和砷的同时测定时行了研究 ,取得了满意结果。标准加入法的回收率分别为 91%～98%和 87%～ 92 % ,7次平行测定结果的相对标准偏差均小于 4%。该法快速、简单     

分光光度法测定吸收液中二氧化氮的质量控制

探讨了分光光度法测定吸收液中二氧化氮,采用盲样与已知标准样品进行比对,结果表明,该法符合质量控制要求,并对可能影响质控结果的因素进行了讨论。     

巯基棉富集─火焰原子吸收分光光度法测定水中的微量铁

本文详细考查了巯基棉富集Ｆｅ（Ⅲ）的条件，发现微量铁（Ⅲ）在ｐＨ值为５－８的条件下能为巯基棉定量吸附．１ｍｏｌ／Ｌ盐酸５ｍＬ能将巯基棉吸附的Ｆｅ（Ⅲ）定量洗脱，０．１ｇ巯基棉的饱和吸附量为９０μｇ，样品分析测定结果的相对标准偏差小于３．４％，９８．４％－９８．８％。     

吉林省查干湖水体悬浮颗粒物光谱吸收特性研究

用分光光度计法确定查干湖复杂光学特性水体悬浮颗粒物的光谱特性与吸光幅度,在室内可控实验中利用定量滤膜技术对2009年7月15日和10月12日两期水体采集样品处理获得了以藻类色素颗粒和非色素颗粒(无机沉积物,有机碎屑)两种光活性颗粒物质为主要贡献的总悬浮颗粒物吸收光谱,结果显示7月份总悬浮颗粒物光谱吸收谱形在400～42...     

Noninvasive molecular identification of particulate matter in lungs by Raman microspectrometry

A new method for the analysis of particulate matter in lungs is proposed. It combines the exhaled breath condensate technique and Raman spectroscopy. The sampling method is noninvasive, which is suitable for the detection of occupational exposure to dust. The chemical composition of dust particles is assessed by Raman microspectroscopy. The effectiveness of this method as a means of identifying markers of occupational exposure to mica dust is evaluated. Copyright © 2011 John Wiley & Sons, Ltd.     

Identification and classification of organic and inorganic components of particulate matter via Raman spectroscopy and chemometric approaches

In this paper, a novel method for developing a tree‐like classifier which differentiates between organic and inorganic particulate matter by means of Raman spectroscopy is introduced. The algorithm is fully automatic and optimises itself without any human interaction. This method uses a tree‐like structure to classify Raman spectra as a decision tree. On every knot of this tree, the optimal classifier is automatically obtained, tested and trained. The optimal classifier is an artificial neural network, linear discriminant analysis or a support vector machine, where different kernels are possible. The support vector machine is optimised by the simulated annealing method to achieve the best possible classifier. After the training, a hold‐out experiment with two completely independent sets of Raman spectra was tried to show the abilities of this method for real‐world application. Copyright © 2010 John Wiley & Sons, Ltd.     

Char characteristics and particulate matter formation during Chinese bituminous coal combustion

The characteristics of char particles and their effects on the emission of particulate matter (PM) from the combustion of a Chinese bituminous coal were studied in a laboratory-scale drop tube furnace. The raw coal was pulverized and divided into three sizes, <63, 63–100, and 100–200 μm. These coal samples were subjected to pyrolysis in N₂ and combusted in 20 and 50% O₂ at 1373, 1523, and 1673 K, respectively. Char samples were obtained by glass fiber filters with a pore size of 0.3 μm, and combustion-derived PM was size-segregated by a low pressure impactor (LPI) into different sizes ranging from 10.0 to 0.3 μm. The characteristics of char particles, including particle size distribution, surface area, pore size distribution, swelling behavior and morphology property, were studied. The results show that, coal particle size and pyrolysis temperature have significant influence on the char characteristics. The swelling ratios of char samples increase with temperature increasing from 1373 to 1523 K, then decrease when the temperature further increases to 1623 K. At the same temperature, the swelling ratios of the three size fractions are markedly different. The finer the particle size, the higher the swelling ratio. The decrease of swelling ratio at high temperature is mainly attributed to the high heating rate, but char fragmentation at high temperature may also account for the decrease of swelling ratio. The supermicron particles (1–10 μm) are primarily spherical, and most of them have smooth surfaces. Decreasing coal particle size and increasing the oxygen concentration lead to more supermicron-sized PM formation. The influence of combustion temperature on supermicron-sized PM emission greatly depends on the oxygen concentration.     

PM2.5和PM10排放的一维炉煤燃烧实验研究

我国煤烟污染十分严重。燃煤排放的PM10和PM2.5表面富集了大量的有毒痕量元素,进入大气后,对环境的危害极大。本文在一维炉中对不同煤种分别在650℃,850℃,950℃下燃烧PM的排放进行实验研究,发现PM10和PM2.5的排放量随温度升高有增加的趋势;随煤种含S量的增加,其排放量也增加;随着煤灰分的增加,PM10和PM2.5的排放量也有增大的趋势,煤中矿物质的种类和形态对其排放有明显的控制作用。     

利用光学多通道分析仪与分光光度计测定叶绿素的紫外-可见光区吸收光谱

应用分析化学中常用的吸光光度法,通过光学多通道分析仪和紫外-可见分光光度计对叶绿素提取液和叶绿素晶体分别进行了紫外-可见光区吸收光谱的探测,并对其吸收曲线进行了分析和研究.根据实验结果对文献中的一些数据进行了讨论.     

分光测色仪的设计研究

介绍了测色分光光度计的基本要求和特点 ;简要说明了测色分光光度计软件系统的基本组成和要求 ;分析了波长范围对色度计算精度的影响 ;并对色度计量中标准白板的要求做了介绍     

The composition and optical absorption coefficient of atmospheric particulate matter

The optical absorption spectra of atmospheric dust as determined by transmission and diffuse reflectance spectroscopic methods is discussed in the 0.4 to 40 um wavelength range. Quantitative measurements are presented which show the imaginary refractive index to be about 0.007i, with little wavelength dependence, in the 0.4 to 1.3 μm spectral interval. The absorption coefficients of individual materials found in atmospheric dust are also given. This work suggests that atmospheric dust may be composed mainly of weakly absorbing particles contaminated with small amounts of very strongly absorbing materials such as free carbon. The implications of this are discussed from the point of view of laser beam attenuation and lidar return signals. Mie theory computations for ruby lidar wavelengths are shown which suggest that for some models of atmospheric dust, the concept of an average imaginary refractive index may be misleading. Thus, it may be necessary to consider the individual complex refractive indices and size distributions of more than one constituent material present in the dust. This implies that anthropogenic contributions to the atmospheric aerosol, such as free carbon and other strong absorbers, may be of greater optical significance than their relative concentrations might indicate.     

The Fisher information measure and Shannon entropy for particulate matter measurements

We investigated the dynamics of particulate matter data, recorded in Tito, a small industrial area of southern Italy. The analysis of these signals was performed using the Fisher information measure (FIM), which is a powerful tool for investigating complex and nonstationary signals, and the Shannon entropy, which is a well-known tool for investigating the degree of disorder in dynamical systems. Our results point to an increase of disorder and complexity from fine to coarse particulates.     

磁化等离子体对平面电磁波吸收特性的数值研究与全波仿真

研究了平面电磁波在磁化、稳定、二维、非均匀等离子体中的传播特性;采用等效输入阻抗方法计算非均匀磁化等离子体层对不同模式入射电磁波的功率吸收情况。结果表明,电子数密度、碰撞频率和外磁场大小是等离子体对电磁波功率吸收的主要影响因素。采用等效介电常数的方法模拟等离子体特性,代入有限元软件进行平面电磁波入射等离子体仿真,得到了非寻常波与右旋极化波的吸收特性。根据数值计算和全波仿真结果可知,当等离子体密度为1017 m-3、碰撞频率2.5 GHz、外加磁场的磁感应强度为0.15 T时,磁化等离子体对电磁波有强烈的吸收特性。