Device for non-disruptive taking of melt samples from a compounding process and direct injection molding

A concept for taking a sample from a polymer melt stream plus the direct processing of this melt to specimen is presented. Therefore, a melt sampling and direct injection molding (MSIM) device was developed. Process parameters were studied and the set-up was implemented successfully. Using the MSIM device, different thermoplastics were processed and provided specimen characterized. The mechanical material properties from samples of the MSIM process show a good consistency compared with data from conventional processes. The MSIM device can be used in production processes for quality control, e.g. color or mechanical properties, as well as in the field of research and development to reduce development cycles.     

富氧燃烧烟气喷淋脱水过程数值模拟

富氧燃烧系统中,脱硫后的高湿烟气需要经过脱水处理才能作为循环烟气利用,喷淋塔是一种常用的脱水设备。本文用CFD(Computational Fluid Dynamics)方法对喷淋塔的烟气脱水过程进行了三维建模模拟,得到了喷淋塔内的温湿度分布并用实验结果进行了验证。通过该模型分析了喷嘴的操作参数和运行特性对液滴平均运动时间和脱水效果的具体影响,讨论了数值模拟中出口烟气"过饱和"现象的成因,研究了不凝气组分对脱水过程的影响,为富氧燃烧脱水系统的设计提供了基础数据和理论方法。     

VICON程序模拟氧碘化学激光器3维喷管流场的可行性探讨

 用VICON程序对化学氧碘激光器(COIL)喷管冷流场进行了3维模拟,得出的计算区几何较准确地反映了模拟装置的几何变化。主气流方向和副气流方向的分点数反映出了此2维平面内的气动特性,对不同流量的模拟结果对比分析得出穿透过度与穿透不够一样,致使主副气流混合不好。对带化学反应的情况进行了模拟,显现出副气流从喷孔出来后穿进主气流的马蹄形结构的变化过程,这些说明VICON程序可用来模拟研究COIL喷管流场特性。     

KMnO4-甲醛化学发光体系测定对乙酰氨基酚

基于对乙酰氨基酚在酸性介质下对KMnO4-甲醛化学发光体系强烈的增敏作用,建立了对乙酰氨基酚的流动注射化学发光测定方法。在最佳测试条件下,方法对对乙酰氨基酚的检出限(S/N=3)为1.0×10-10mol/L,线性范围为1.0×10-9～1.0×10-5mol/L对乙酰氨基酚,相关系数R为0.9993;对1.0×10-6mol/L的对乙酰氨基酚溶液平行测定11次,其RSD为1.1%。该方法可应用于药物中对乙酰氨基酚含量的测定。     

水蒸汽蒸馏条件下鱼腥草中癸酰乙醛的高效提取及质谱定性

根据质谱学规律,剖析了在电子轰击下中药材鱼腥草中最关键的抗菌成分鱼腥草素(癸酰乙醛)的离子形成机理:癸酰乙醛的分子中存在两个-C=O,处于端位上的-C=O活性远大于-CH3,易失去H2O(M+-18)、CO(M+-28)等基团,产生较强的m/z180、170等离子碎片,此外,还易失去H2O+H2O(M+-36)、H2O+CO(M+-46)、CO+CO(M+-56)等基团,产生m/z162、152、142等离子碎片,这同实验中得到的癸酰乙醛质谱图完全吻合,纠正了文献中对癸酰乙醛的错误定性。在此基础上采用常规、Ar气保护和减压三种水蒸汽蒸馏方式提取鱼腥草挥发油,发现在惰性气氛或较低温度下有利于癸酰乙醛的提取,与常规水蒸汽蒸馏条件相比,Ar气保护下癸酰乙醛的含量从0.03%提高至0.53%,而减压条件下癸酰乙醛的溶出效率进一步提高至3.37%。研究表明常规水蒸汽蒸馏条件下癸酰乙醛易氧化分解是得到较少癸酰乙醛的根本原因。     

注入热焓法测定萃取磷酸中三氧化硫

以钡离子与硫酸根离子沉淀反应的热效应为基础，通过测定孤立体系中的温度变化，建立了测定萃取磷酸中三氧化硫的注入热焓法，该法在４．０－３２．０ｇ／Ｌ范围内可准确测定ＳＯ３的含量，相对标准偏差为１．８％；标准加入回收率为９８％－１０３％。     

用碳黑微电极伏安法测定多巴胺

研究了多巴胺(DA)在碳黑微电极上的电化学行为,试验结果表明,在pH 4.5(pH 3.8~5.2)的磷酸盐缓冲介质(PBS)中,多巴胺在伏安图0.21 V处的二阶导数峰高与其浓度在6×10-6~2×10-5mol.L-1之间保持线性关系,其检出限(3σ)为1×10-6mol.L-1;将此方法应用于多巴胺针剂试样的分析,测定结果的RSD值(n=5)均小于2.4%,用标准加入法做回收率试验,结果在96%~102%之间。此方法所测得结果与碘量法测得的结果之间无显著差异。     

Numerical study on soot removal in partial oxidation of methane to syngas reactors

The serious carbon deposition existing in catalytic partial oxidation of methane (CPOM) to syngas process is one of the key problems that impede its industrialization. In this study, 3-dimensional unsteady numerical simulations of the soot formation and oxidation in oxidation section in a heat coupling reactor were carried out by computational fluid dynamics (CFD) approach incorporating the Moss-Brookes model for soot formation. The model has been validated and proven to be in good agreement with experiment results. Effects of nozzle type, nozzle convergence angle, channel spacing, number of channels, radius/height ratio, oxygen/carbon ratio, preheat temperature and additional introduction of steam on the soot formation were simulated. Results show that the soot formation in oxidation section of the heat coupling reactor depends on both nozzle structures and operation conditions, and the soot concentration can be greatly reduced by optimization with the maximum mass fraction of soot inside the oxidation reactor from 2.28% to 0.0501%, and so that the soot mass fraction at the exit reduces from 0.74% to 0.03%.     

毛细管区带电泳法测定板蓝根注射液中四种核苷的含量

采用毛细管区带电泳法测定了板蓝根注射液中胞苷、腺苷、鸟苷和尿苷的含量。电泳条件:采用未涂层石英毛细管(32.5 cm×50 μm i.d.,有效长度23.5 cm),以60 mmol/L硼砂溶液-10%(体积分数)异丙醇-20%（体积分数）乙腈为运行缓冲液,在25 ℃下以20 kV恒压电泳分离,压力进样 (1 kPa×10 s),检测波长254 nm。对电泳条件各因素进行了讨论,如缓冲液的种类、浓度和pH值,有机改性剂的种类和浓度,分离电压和毛细管温度等。样品经0.45 μm微孔滤膜过滤后直接进样;采用外     

The solvent venting injection technique in capillary supercritical fluid chromatography

A solvent venting technique for injection of volumes up to 1 μl on 50 μm i.d. SFC columns has been compared to direct injection methods. The peak broadening and peak splitting observed with direct injection have been examined and found to be related to the starting pressure, the column temperature, and the sample solvent, in addition to the sample volume. The solvent venting technique removed peak splitting and improved the column efficiency. With a proper selection of experimental conditions, the sample recovery was 100%. The major part of the solvent was eluted in 15–20 s. Several applications have been demonstrated.