气相色谱条件对混合醇分离的影响

本文以氮气做载气,考察了气相色谱条件,如色谱柱、柱箱温度、载气流速等对混合醇分离速度和分离度的影响。实验表明,以HP-5毛细管柱为色谱柱,当柱箱温度为90℃,载气流速为2 m L/min时,混合醇能够得到比较理想的分离效果。     

脂肪醇聚氧乙烯醚气相色谱定性定量分析

采用毛细管气相色谱法分离测定脂肪醇聚氧乙烯醚混合物,对色谱条件进行了考察和优化,确定了最佳色谱条件:程序升温200℃(2 min),10℃/min,340℃(∞);气化室温度350℃;离子化室温度350℃;载气N2,流速30 mL/min;柱前压10 Psi(约69 kPa);氢气流速20 mL/min;空气流速300...     

气相色谱法测定氯代苯酚含量

采用气相色谱法测定了氯代苯酚的含量。研究色谱条件,即进样口温度：120℃;检测器（FID）温度240℃;采用程序升温;载气为氮气;流速为30mL／min。在该条件下,系列氯代酚达到理想的分离效果。     

海洛因GC-FID分析方法的色谱条件优化

通过考察流速、分流比、色谱柱升温程序对柱效、保留时间、峰面积等指标的影响规律,对海洛因毒品GC-FID分析方法的色谱条件进行了优化,以使海洛因GC-FID分析方法更好地应用于日常办案。优化的色谱条件为:色谱柱:DB-5石英玻璃毛细管柱(30m×0.32mm×0.25μm);载气:N2,纯度99.99%;进样温度:280℃;流速:1mL·min~-1;分流比:20∶1;升温程序:以150℃为初始柱温,以12℃·min~-1升温至300℃,在300℃保持7min;检测温度:300℃。     

Nd -P -O催化剂上甘油脱水生产丙烯醛反应性能

分别以磷酸、焦磷酸和三聚磷酸为磷源制备了稀土磷氧类化合物,并以甘油脱水生产丙烯醛反应为模型反应,对该类化合物催化性能进行比较.研究反应温度、载气流速、反应空速和反应溶液浓度对催化剂性能的影响,得到最佳反应条件:反应温度320℃,载气流速30 mL · min-1,甘油空速227 h-1,甘油水溶液浓度36.5％,此条件...     

毛细管气相色谱法定量分析腐霉利

采用DB-35石英毛细管色谱柱和FID检测器,以邻苯二甲酸二丁酯为内标物,在适宜的色谱条件下对腐霉利进行定量分析。色谱条件为柱箱温度220℃;进样口温度280℃,检测器温度280℃,气体流速为载气（N2）6mL／min,燃气（H2）30mL／min,助燃气（Air）300mL／min,分流比20：1。本方法的变异系数0．316％,平均回收率99．82％,线性相关系数为0．9999。     

苯胺及其衍生物的气相色谱分析方法研究

建立了气相色谱法对苯胺及其五种衍生物进行分离与同时测定的方法。最佳色谱分离条件如下:HP-5MS空心毛细管柱(30 m×0.32 mm×0.25μm);程序升温方式:初始温度70℃,以20℃/min升至150℃,保持1 min;以氮气为载气,流速为5.0 m L/min;尾吹气(氮气)流速为30 m L/min;氢气流速为35 m L/min;空气流速为400 m L/min;不分流进样,进样量为1μL;进样口温度为260℃,检测器温度为320℃。在最佳实验条件下,六种组分在4 min内全部出峰,达到较好的分离,实现对组分的分离与同时检测。     

气相色谱法测定环己酮中的微量轻组分

采用气相色谱法测定环己酮中微量轻组分含量,探讨了色谱柱、柱温、气化温度、检测温度、载气流量对环己酮及其组分色谱分离的影响。结果表明:选用强极性毛细管色谱柱AB-Wax 60 m×0.32 mm×0.5μm,采用程序升温法,以升温速率20℃/min升温至色谱柱初始温度100℃,保持时间10 min,再以10℃/min升至色谱柱终温150℃,保持时间30 min,在进样口温度为250℃,氢火焰离子化检测器温度为280℃,载气为氮气,流量为1.5 mL/min,进样量为0.6μL的条件下,采用气相色谱仪测定环己酮中微量轻组分含量,环己酮中微量轻组分能得到很好地分离,通过峰面积外标法定量,测定结果的加标回收率为96.3%～97.2%,相对标准偏差为0.86%～1.13%。     

胡椒环中二氯甲烷残留的气相色谱分析

采用气相色谱法直接测定了胡椒环中二氯甲烷的残留量。色谱条件为:毛细管柱(AT.SE—54,0.25mm×50m),氢火焰离子检测器,气化和检测温度为200℃,柱温为160℃,以氮气作为载气,流速为1ml/min,最后以面积归一法结合相对校正因子计算其含量。     

渣油硫模拟蒸馏方法研究及在渣油固定床加氢处理过程应用

用气相色谱技术,采用高温模拟蒸馏软件,优化了色谱条件,建立高温模拟蒸馏法测定渣油中硫的新方法,此方法的准确度和精密度满足工作要求;并考察不同工艺条件下,渣油中硫含量的变化趋势。结果表明:在柱温:初始温度为40℃,保持0 min,以25℃/min升至430℃,保持5 min;载气:高纯氦气,流速为20 mL/min;进样量:0.5μL的色谱条件下,方法的精密度和准确度好。同温度下,随着加氢深度的增大,同沸点区间内的硫含量逐渐降低;在同一加氢过程中,随着沸点增加,硫含量先增加后随之降低,在530~610℃沸点区间内硫含量最大。同一加氢深度下,温度升高,同沸点区间内的硫含量降低;在同一温度下,随沸点增加,硫含量先增加后降低,在530~610℃沸点区间内硫含量最大。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

我国聚碳酸酯工业发展概况

介绍我国聚碳酸酯生产能力和消费需求,对聚碳酸酯在信息工业中的应用作了简短介绍     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003     

气化给煤系统故障分析

气化给煤装置自投运以来,出现了气化煤仓堵煤、称重给煤机输送皮带因跑偏而损伤以及清扫装置故障频繁等问题,多次造成气化系统减负荷运行。通过对出现的各种问题进行分析,找到了产生这些问题的原因,并有针对性地采用配煤和改进清扫链等措施,使出现的问题得到了极大的改善。     

醋酸纤维素取代基分布与性质的关系

分析了以吡啶为溶剂的醋酸纤维素的13C-NMR核磁共振谱,得出了三种不同位置羟基的取代度。结合X—射线和DSC分析,初步说明具有相同取代度但未经水解和经过水解的醋酸纤维素(CA) 性质上的差异是由于三个羟基上的取代度分布不同及消晶程度差异所致。     

Generalization of vdW type of equations of state

1 INTRODUCTIONBecause of importance of equations of state (EOS)in science and industry,hundreds forms of EOS havebeen presented since latter 19th century.It seems impossible to develop a general equation covering vari-ous kinds of EOS.But for cubic EOS,several generalequations have been reported already. Martin presented the first general equation whichis following p=RT/V-α(T)/(υ β)(υ γ) δ(T)/υ(υ β)(υ γ) (1) Kumar et a1.presented an equation called the most general form of a density-cubic or, alterna tively,volume-cubic mathematical equation,the form of which is as follows     

船舶柴油机涡轮增压器的清洗

采用喷射清洗剂的方法，清洗涡轮叶片积炭。