去甲氨噻肟酸乙酯合成研究

去甲氨噻肟酸乙酯是半合成头孢菌素药物的重要中间体之一.报道了在环合反应中,采用甲醇和水(体积比为1∶1)的混合溶剂代替二氯甲烷,甲醇等单一溶剂,反应温度在25℃左右下进行,收率明显提高,可达56.2%,结果令人满意.产品结构用1HNMR验证.     

锌系工件的静电粉末涂装和工艺管理

讨论了锌系工件喷涂的相关工艺、现场管理、技术参数、质量检验和环境要求等。     

循环荷载作用下重塑饱和粉黏土的刚度弱化特性研究

以东海大桥海上风电场项目为课题背景,通过动三轴系统对重塑饱和粉质黏土开展一系列长期不排水循环加载三轴试验,分别考虑围压、动应力比和频率3种因素,特别是对高频(f5 Hz)下土体的动力弱化特性进行了研究。试验结果表明:累积塑性应变与累积孔压随着循环次数的增加而增大并且趋于稳定,呈现出应变软化和孔压软化现象。割线动变形刚度模量和割线动弹性刚度模量则随着循环次数的增加,先急剧降低然后趋于稳定,从而表现出刚度弱化现象。进一步研究了割线动弹性刚度模量与循环应变幅值的关系,割线动弹性刚度模量的衰减趋势受动应力比和频率的影响不大,与围压有关,围压越大,割线动弹性刚度模量衰减趋势越慢,衰减稳定幅值越低。     

不同地区不同等级复烤烟叶中重要致香物质的分析比较

本文采用同时蒸馏萃取(SDE)/气相色谱/质谱联用法(GC/MS)对相同品种、不同地区、不同等级复烤烟叶中的重要致香物质进行分析比较;并且对同时蒸馏萃取法进行重复性和回收率试验。结果表明相同品种、不同地区、不同等级复烤烟叶中重要致香物质的含量差别较大;同时蒸馏萃取法具有良好的重复性和较高的回收率。     

Electrochemical investigations of copper behaviour in different cupric complex solutions: Voltammetric study

The electrochemical behaviour of copper has been investigated in different cupric complex solutions by cyclic voltammetry. In pyridinic and picolinic solutions the reduction of cupric complex occurred in two stages leading to Cu(I) and Cu(0), respectively. The electrodeposited copper is oxidized in two steps leading to Cu(I) and Cu(II) as in ammoniacal cupric complex solutions. In glycine, alanine, sulfamic acid and ethylenediamine solutions, the cuprous complex is an intermediate in the cupric complex reduction but it is not detected during the oxidation of the electrodeposited copper in these solutions. In EDTA and triethanolamine solutions, the cuprous complex is not observed. The rate of copper etching was determined in pyridinic and ammoniacal cupric solutions and was shown to be faster in ammoniacal cupric solutions than in the pyridinic solutions.     

An ExPosition of multivariate analysis with the singular value decomposition in R

ExPosition is a new comprehensive R package providing crisp graphics and implementing multivariate analysis methods based on the singular value decomposition (svd). The core techniques implemented in ExPosition are: principal components analysis, (metric) multidimensional scaling, correspondence analysis, and several of their recent extensions such as barycentric discriminant analyses (e.g., discriminant correspondence analysis), multi-table analyses (e.g.,multiple factor analysis, Statis, and distatis), and non-parametric resampling techniques (e.g., permutation and bootstrap). Several examples highlight the major differences between ExPosition and similar packages. Finally, the future directions of ExPosition are discussed.     

Prediction of multicomponent adsorption equilibrium of gas mixtures including supercritical components

A new model to predict the adsorption equilibrium of mixtures containing supercritical components was presented. The difference in the adsorption mechanism between the supercritical components and the condensable components was accounted for in the new model. Lateral interaction in the adsorbed phase was also considered in the local isotherm. The new model was verified by the experimental data of the mixture CH₄/CO₂/C₂H₆ on activated carbon JX101 collected for 283-313 K and pressures up to . It was also verified with the experimental data published previously in literature. Considerable improvement in the prediction precision was achieved in using the new model to predict the adsorption of mixtures on activated carbon.     

陈化过程中不同部位烤烟烟叶香味成分变化的研究

采用SDE-GC/MS法对陈化过程中不同部位烤烟烟叶的香味成分进行分析检测,并按照香味物质的产生来源对分析结果进行了分类研究。结果表明,陈化过程中不同部位烟叶的香味物质的变化情况差别明显。从香味成分的变化情况看,各个部位适宜的陈化时间有所不同:上部烟叶2年以上,中部烟叶1.5~2年,下部烟叶1年左右。     

循环经济与浮法玻璃工艺的发展

在玻璃行业贯彻循环经济的理念,改进工艺思想和方法,节约资源,降低消耗,提高资源利用率,减少污染物排放,是我们对后人应负的责任和对地球应尽的义务。     

循环灰条件下1-甲基萘催化裂解的实验研究

热解气化过程中 ,促进焦油的裂解使之转化为高热值煤气 ,对高挥发分劣质煤和生物质燃料的清洁高效利用具有重要的意义 .在固定床反应器上 ,以石英砂和两种烟煤在循环流化床锅炉上燃烧形成的循环灰为床料 ,实验研究了焦油中含量较高的 1 -甲基萘的裂解反应 ,测定了反应动力学参数 .结果表明 ,与石英砂条件下相比 ,循环灰促进了 1 -甲基萘的裂解 ,反应活化能降低 ,裂解气体的总产率提高