电感耦合等离子体原子发射光谱法测定烟花爆竹烟火药剂中锆

<正>烟花爆竹是一种备受欢迎的娱乐产品,人们习惯在节假日燃放烟花爆竹来表达喜庆祝福。烟花爆竹的绚丽效果是由其含有的烟火药剂燃烧爆炸产生的,烟火药剂通常含有氧化剂、还原剂、着色剂、粘合剂以及一些产生特殊效果的物质[1],有的甚至含有一些禁限用物质,如铅、锆等,以达到更好的燃放效     

烟火药剂中高氯酸盐定性检测方法研究

本文提出了一种烟火药剂中高氯酸盐定性检测方法。将中性红用于高氯酸盐的定性检测;根据烟火药剂的组成特点对可能干扰检测结果的化学组分做了详细研究,提出了用0℃的10%KCl溶液洗涤样品排除干扰的步骤;对现有13类烟花爆竹用烟火药剂组成进行分析后,确立了用5%CaCl2溶液脱附碳粉中高氯酸盐的前处理步骤。研究结果表明,方法检出限为100ng·g-1。与以往的分析方法相比,本方法具有简单、实用、可靠等优点,可发展为烟花爆竹用烟火药剂中高氯酸盐定性检测的技术。     

ICP-AES法测定烟花爆竹药物中的砷、汞、铅

为了禁止含砷、汞、铅物质应用到烟花爆竹药物中,建立ICP-AES方法,在烟花爆竹药物经乙醇、丙酮及硝酸处理后,选用As 189.042 nm、Hg 194.227 nm、Pb 220.353 nm分析线同时测定这3种元素的含量,结果:相对标准偏差为1.97%~2.71%,回收率为98.5%~101%.方法操作简单快速,检出限低、干扰小,结果准确可靠.     

一种快速半定量检测烟花爆竹用烟火药盲样中汞含量的方法

本发明公开一种快速半定量检测烟花爆竹用烟火药盲样中汞含量的方法,属于分析测试技术领域。将烟火药样品从烟花爆竹产品中解剖出来,研磨,过筛,干燥,冷却至室温,以能量色散型X射线荧光光谱仪为检测仪器,采用强度法建立分析方法,将样品装入仪器样品杯中,再将待测样品置于检测仪器测试舱内,记录仪器上显示的汞元素特征谱线的荧光强度值,估算汞元素在样品中的含量,再进一步选择适当的分析仪器准确定量分析烟花爆竹用烟火药中的汞含量。本发明方法操作简单,效率高,所估算样品中的汞含量与其实际含量相差较小,且能为进一步选择准确定量分析样品中汞含量的方法提供依据。     

ICP-AES法测定烟花爆竹中16种化学成分的不确定度评定

采用电感耦合等离子体-原子发射光谱(ICP-AES)法测定烟花爆竹中16种化学成分并对测定结果的不确定度进行了评定和计算,提供了评定过程所需的各参数的采集和计算方法,定量表征了测定结果的可信程度.由计算得到的合成标准不确定度可以看出,不确定度主要来源于校准曲线的非线性,从而对此测定方法的可行性和准确性进行了科学的判断.     

ICP-AES法测定烟花爆竹中禁限用药物

以5%HNO3处理烟花爆竹内药物样品,以ICP-AES法测定样品中K、Na、P、Mg、Ba、Cu、B、Sr、Sb、Ga、Ge、Al、Ti、Mn、Pb、As 16种元素。比较了不同酸、不同浓度时样品的处理方法,5%HNO3为最佳样品处理条件。对4个不同厂家产品进行了测定和加标回收研究,测定结果的相对标准差小于5%(n=5),各元素的回收率在93.4%～114.3%之间。     

TD/GC-MS法分析燃放烟花爆竹产生的大气有机污染物

利用热脱附/气相色谱-质谱(TD/GC-MS)联用技术初步分析了实验室燃放烟花爆竹产生的大气有机污染物。将烟花爆竹在密闭的实验室里进行燃放,用装有Tenax-TA吸附剂的不锈钢采样管以200 mL/min流量富集,连接热脱附装置进行解吸,最后通过气质联用技术结合massworks软件综合定性,结果表明爆竹类鞭炮燃放过程中会产生3种大气污染物,分别是二氧化硫、二硫化碳和糠醛。烟雾型烟花燃放产生24种有毒大气污染物,分属于呋喃、醛酮、芳烃、醇酯和酚4类。     

高效液相色谱-串联质谱法测定食用香精中高氯酸盐的含量

正近来,奶粉、茶叶、饮用水中检出高氯酸盐的报道引发了社会的关注[1~(-3)]。高氯酸盐化学结构十分稳定,可在正常环境条件下存在数十年,被认为是一种持久的化学污染物[4-7]。高氯酸盐应用于工业产品如军工、烟花爆竹、纺织物固定剂、电镀、橡胶制品、染料、涂料、冶炼和电池等产品的生产过程中[8~(-1)0]。由于高氯酸盐易溶于水,在工业生产和废物处理的过程中,该物质容易进入环境体系中,造成     

无机化学微信平台的构建与实践研究

针对无机化学传统教学模式的不足,构建了无机化学微信平台。介绍了构建平台必需的微信公众号和微信群的建立过程和方法。分析了无机化学微信平台在教学中的实践效果,弥补了传统教学中的不足。讨论了无机化学微信平台的积极作用,提高了教师教学水平和学生的学习能力,达到了师生双赢的目的。     

分析化学实验课程教学大纲的标准化改造与构建

基于工程教育专业认证标准的要求,结合专业课程的特点,对我校制药工程专业的分析化学实验教学大纲进行了标准化改造。标准化的教学大纲更加突出了专业适用性,关联了教学要求与教学内容和考核评定,增加了考核量化指标与课程持续改进的方式,进一步规范了分析化学实验课程的教学。标准教学大纲的构建为实验教学活动提供了更加明确的指导,有利于缩小不同教师教学的差异性,保证了实验教学的质量,为建立可持续完善的工程类实验教学标准体系提供了具体参考。     

Evaluation of effective thermal conductivity of fireworks compositions

Effective thermal conductivity of fireworks raw materials and their mixture have been measured by the temperature modulated DSC and the hot wire method, in order to predict spontaneous ignition properties precisely. As a result, an excellent linear correlation has been obtained between the density and the λ_e by the TMDSC method. Moreover, the low-density data by the hot wire method lie on the extrapolated point of the linear correlation. Thus, the λ_e within the ordinary limit of fireworks composition can be measured by the TMDSC method. Krupiczka’s estimation method shows a good agreement with the experimental values.     

High‐Nitrogen‐Based Pyrotechnics: Development of Perchlorate‐Free Green‐Light Illuminants for Military and Civilian Applications

The development of perchlorate‐free hand‐held signal illuminants for the US Army’s M195 green star parachute is described. Compared with the perchlorate‐containing control, the optimized perchlorate‐free illuminants were less sensitive toward various ignition stimuli while offering comparable burn times and visible‐light outputs. The results were also important from the perspective of civilian fireworks because the development of perchlorate‐free illuminants remains an important objective of the commercial fireworks industry.     

High-nitrogen-based pyrotechnics: longer- and brighter-burning, perchlorate-free, red-light illuminants for military and civilian applications

The full-up prototype testing of perchlorate-free, hand-held, signal illuminants for the US Army's M126A1 red star parachute hand-held signal is described. Compared to the perchlorate-containing control, the disclosed illuminants yielded excellent stabilities toward various ignition stimuli while offering superior pyrotechnic performance. Militarily, the illuminants provided further evidence that development of smaller hand-held signal items in an environmentally conscious way is a realistic and obtainable goal. The results are also important from the perspective of civilian fireworks, as the development of brighter, longer-burning, and environmentally compatible red-light-emitting pyrotechnics is now possible.     

Experimental analysis on nano scale flash powder composition in fireworks manufacturing

The flash powder composition is used in the fireworks industry to manufacture the firecrackers which consist of potassium nitrate, aluminium and sulphur in 75 μm range. This study focuses on the synthesis of nano and micro flash powders with different trials of composition. The particle sizes of the nanochemicals are 142.8, 93.10 and 91.28 nm for KNO₃, Al and S, respectively. The nano flash powder is mixed with micron flash powder in different ratios to manufacture the crackers and thus the noise level for the crackers are found. Thermal analysis was conducted in differential thermal and thermo gravimetric analyser. Also, impact sensitivity and friction sensitivity of the nano flash powder are analysed. The nano flash powder shows low ignition temperature compared to micron and also has high mechanical sensitivity. Fire crackers which contains one gram of 100 % nano flash powder emits the threshold noise level of 125 dB(AI) in spite of 4 g of 10 % nano flash powder for the same composition.     

烟花中绽放北京奥运理念——绿色化学诠释新北京新奥运

介绍了中国烟花发生和发展的历史梗概,以及烟花中的化学知识和化学反应原理,阐述了北京奥运会和残奥会上烟花所体现出来的“科技奥运”、“绿色奥运”和“人文奥运”,诠释并展现了绿色化学的新视野。     

Thermal explosion model and calculation of sphere fireworks and crackers

In order to analyze thermal safety of fireworks and crackers, thermal explosion models of three kinds of sphere fireworks and crackers with different structures are achieved on the basis of thermal explosion theory, and thermal resistance of shell and effective Biot number are deduced as for boundary conditions. Two models are calculated with target-shooting method in Matlab program, and the rationality is proved through comparison of numerical solution and classical solution. Meanwhile, calculation steps are shown about a type of firework. The study has a great significance to thermal safety analysis of fireworks and crackers.     

Modeling and calculation of thermal explosion time to ignition of cylindrical fireworks and crackers

To analyze the thermal safety of cylindrical fireworks and crackers in storage and transportation, this article establishes a physical model and a mathematical model of thermal explosion time to ignition of finite cylindrical fireworks and crackers. And in order to simplify the thermal explosion model, effective Biot number about boundary condition is deduced according to the theory of heat transfer. The partial differential equation of thermal explosion model are calculated with difference method in Matlab program, to obtain the time to ignition as well as the temperature–time history before explosion system explodes. The rationality of effective Biot number and calculation method is proved through comparison of calculation solution and literature solution. Being the first to solve the problem of two-dimensional thermal explosion unsteady-state model of fireworks and crackers, where the upper surface, lower surface, and side surface have different heat dissipation conditions. Meanwhile, calculation steps were shown about a type of fireworks.     

Research of critical ambient temperature of cylindrical fireworks and crackers

To study the influence of temperature on cylindrical fireworks and crackers in production and storage, this article establishes a physical and mathematical model of thermal explosion critical ambient temperature of finite cylindrical fireworks with shell based on two-dimensional steady state thermal explosion theory. The numerical program is written by difference method and Newton-homotopy method. The partial differential equations of thermal explosion model are calculated in Matlab. Comparison of numerical solutions and classical solutions proves the accuracy of model. The influence of Biot number of each surface and length diameter ratio on critical ambient temperature is analyzed. It is founded that the scope of length diameter ratio is $ 0.08 < H < 4.3 $ when Biot number tends to infinite. The thermal safety temperature of the fireworks without inner barrel when it is stored individually is obtained. This provides theoretical support for the safety of fireworks and crackers in production, storage transportation, and setting off process.