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《广州化工》2016,(10)
采用原子荧光光度法及火焰原子吸收法,考察了云南省不同产地的凹纹胡蜂成虫的重金属、常量、微量元素的含量,促进胡蜂资源的开发利用。结果表明:云南省德宏州、保山市、曲靖市的凹纹胡蜂的重金属总量分别为6.8870μg·g-1、6.9970μg·g-1、7.5428μg·g-1,其常、微量元素的总量分别为736.1235μg·g-1、766.6284μg·g-1、743.4732μg·g-1。凹纹胡蜂体内的重金属含量均在国家药材标准的管理范围之内,即重金属含量小于百万分之十,砷盐含量小于百万分之二,该法稳定性好,结果可靠,故对药材饮片的重金属、常量、微量元素的含量的测定、质量控制提供有益的参考。 相似文献
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采用AlCl3对膨润土进行改性,利用微波辐照强化制备柱撑膨润土,考察了制备条件的影响,并进行了富营养化水磷的吸附试验.结果表明,当微波辐照强度为50 W·g-1、辐照时间6 min时,微波强化柱撑膨润土的层间距d001为2.35 nm,比表面积为120.65 m2·g-1,微孔总体积为0.247 cm2·g-1,离子交换容量为1.80 mmol·g-1,比传统柱撑膨润土有明显增加;在原水磷的质量浓度为10 mg·L-1、pH为7、微波强化柱撑膨润土投加量为1.0g·L-1、反应时间在20min时,对磷的去除率可以达97.3%. 相似文献
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稀散元素是铅锌矿石中重要的伴生元素,为了综合利用铅锌矿资源,在地质、选矿上经常要考查稀散元素镓、锗、铟、铊的含量。研究了利用电感耦合等离子体质谱法测定铅锌矿中镓、铟、锗、铊4种稀散元素,选取了最佳仪器分析条件,通过在线加入内标校正基体效应和接口效应,检出限分别为0.02μg·g-1、0.01μg·g-1、0.03μg·g-1和0.05μg·g-1,相对标准偏差(RSD)为0.85%~2.84%,回收率在93.3%~102.3%之间,明显优于其他分析方法。该方法样品前处理简便、快捷,测定结果准确,令人满意。 相似文献
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《广州化工》2017,(1)
测定当归中Cu、Fe、Mn、Zn、Pb、As 6种元素的含量,为当归的现代研究提供依据。本实验采用微波消解法处理当归,采用火焰原子吸收法测定Cu、Fe、Mn、Zn 4种元素的含量,采用石墨原子吸收法测定Pb、As 2种元素的含量。结果表明,当归中Cu、Fe、Mn、Zn、Pb、As 6种元素的含量分别为4.95μg·g~(-1)、333.65μg·g~(-1)、7.75μg·g~(-1)、13.34μg·g~(-1)、0.68μg·g~(-1)、0.56μg·g~(-1)。该方法快捷、简单、准确,加标回收率在97.4%~111.43%之间,RSD在0.38%~1.88%之间。 相似文献
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为了综合利用锶矿资源,在地质、选矿上经常要考查伴生的微量元素Th、U、Mo、Cu、Pb、Zn、Ni、Cr等的含量。研究利用电感耦合等离子体质谱法测定锶矿石中Th、U、Mo、Cu、Pb、Zn、Ni、Cr,选取了最佳仪器分析条件,检出限分别为0.019μg·g-1、0.007μg·g-1、0.01μg·g-1、0.08μg·g-1、0.37μg·g-1、0.14μg·g-1、0.08μg·g-1、0.35μg·g-1,相对标准偏差(RSD)为0.94%~3.41%,方法回收率在95.6%~103.1%之间。该方法具有前处理过程简单、引入干扰少、准确度、精密度、检出限满足要求,同时具有线性范围广、测试速度快等特点,适合锶矿石中Th、U、Mo、Cu、Pb、Zn、Ni、Cr等元素的测定。 相似文献
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目的测定丹参、金银花、天麻、薄荷、蒲公英五种中药材中重金属的含量,对重金属元素污染情况进行考察和研究。方法样品经微波消解后,采用电感耦合等离子质谱法(ICP-MS)直接对5种中药材试液中Pb、As、Cu、Cr、Cd的含量进行测定。结果各元素线性关系良好(r≥0.9996),Pb、As和Cd的质量浓度在0.1~100μg·L-1范围内呈良好线性关系,检出限分别为0.025、0.026、0.048μg·L-1,Cu、Cr的质量浓度在10~100μg·L-1范围内呈良好线性关系,检出限分别为2.5、2.4μg·L-1。以丹参样品作加标回收试验,回收率在99.0%~108.5%之间。结论方法准确、灵敏度高、可为中药材中重金属及有害元素的检测、质量控制提供方法参考。 相似文献
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A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases. 相似文献
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ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l/3为氧气,2/3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中:A一混… 相似文献
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面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。 相似文献
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P. P. Budnikoff 《Journal of the American Ceramic Society》1924,7(11):817-820
The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO3 and determination of CaO by KMnO4 titration, the SO3 by Andrews method of titration of BaCrO4 has been found to give very reliable results with the least consumption of time. 相似文献
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用两个形状指数表征粉煤灰颗粒形貌的研究 总被引:5,自引:0,他引:5
引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。 相似文献
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A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.
Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology. 相似文献
Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology. 相似文献
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本文以三种典型煤的碳燃烧为研究对象,分别采用简单一维沉降燃烧方式和等温加热燃烧方式,实验研究了煤在快速加热条件下,其碳的初期和中,后期燃烧过程。以实验为基础,建立了煤的碳燃烧模型,变工况数值模拟了煤的碳燃烧过程,揭示了煤不同条件下的单颗粒碳燃烧特性。 相似文献
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提出了有双官能团酸相对分子质量调节剂存在时己内酰胺水解聚合过程动力学模型 ,并进行了实验验证 .对不同温度下聚合产物组成和各影响因素对数均聚合度的影响进行了模拟 .结果表明 ,数均聚合度随进料中水、氨基己酸及相对分子质量调节剂浓度的增加而减小 ,其中水的浓度影响较显著 ,且在考察浓度范围内相对分子质量调节剂浓度 [R]0 ≤ 0 0 0 68mol·kg- 1 时数均聚合度基本不变 ,而 [R]0 >0 0 0 68mol·kg- 1 时数均聚合度则显著减小 .无氨基己酸及相对分子质量调节剂时数均聚合度亦随水浓度增加而减小 . 相似文献
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ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES 总被引:5,自引:0,他引:5
Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log10 viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log10 viscosity as a function of soda content are smooth up to 50% Na2O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO2, 2Na2O) due to Molecular Substitution of CaO, MgO and Al2O3 for Na2O The effect is clearly brought out by plotting (from the results of English) the change of log10η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature Ta. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log10η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A12O3) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al2O3) per 100°. At the aggregation temperature the change of log10η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al2O3. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log10η due to substitution of an oxide for Na2O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na2O-CaO-SiO2. Change of Viscosity of Glass (4SiO2, 2Na2O) due to of Substitution of B2O3 for SiO2 The change of log10η (from the results of English) is plotted as a function of temperature, and also the change of log10η per per cent B2O3. The curves are more complex than for the substitution for Na2O. 相似文献
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