腈吡螨酯及其异构体的合成与生物活性研究

以丙酮和草酸二乙酯为原料,经Claisen缩合,Knorr法环化等一系列反应合成腈吡螨酯及其异构体,其结构经Mass和1H NMR等确证。初步生物活性测定结果表明,腈吡螨酯(E体)在低至1.0 mg/L浓度下对红蜘蛛仍表现出95.11%的优异活性,而相同条件下腈吡螨酯的异构体(Z体)对红蜘蛛的活性仅64.35%。     

Effects of light-emitting diode illumination on the quality of fresh-cut cherry tomatoes during refrigerated storage

The effects of light-emitting diode (LED) illumination on the quality of fresh-cut cherry tomatoes were investigated. Tomatoes were exposed continuously to red, green, blue and white LED light for 7 days and control samples stored in darkness. Results showed that blue light treatment significantly led to more total soluble solids, lycopene concentration and individual phenolic compounds (chlorogenic acid, caffeic acid, rutin) after 7 days of storage. On day-5, green and blue light-treated tomatoes showed relatively higher firmness than samples treated by other lights and the control. At the early stage of storage, blue light could preserve the fresh flavour of tomatoes compared to other treatments. Overall, the blue light was most effective in the quality preservation of fresh-cut cherry tomatoes and could be used as a novel strategy in the preservation of fresh-cut fruits and vegetables during shelf life.     

异丙隆及其间位异构体、邻位异构体分析方法研究

采用高效液相色谱和气相色谱相结合,对异丙隆及其间位异构体、邻位异构体进行分离和测定。试验结果表明:异丙隆线性相关系数为0.996 1,相对标准偏差为0.19%,平均回收率为100.11%;间位异构体线性相关系数为0.995 9,相对标准偏差为2.26%,平均回收率为97.05%;邻位异构体线性相关系数为0.992 5,相对标准偏差为5.02%,平均回收率为97.61%。     

Novel packing‐enhanced distillation separation of isoamyl alcohol isomer: Experimental and pilot scale study

Separation of isoamyl isomers by means of internally enhanced ordinary distillation was investigated in this work. Because of very close boiling points between the target components of the mixture, a novel paralleling spiral packing of extremely low HEPT was experimentally developed with success for this purpose. A coupled scheme of pilot scale was subsequently setup separating 2‐methyl‐butanol and 3‐methyl‐butanol from fusel oil, usually low‐class byproduct of fuel bioethanol manufactures. Basically, batch distillation is used to remove light ends and the continuous partner to separate 2‐methyl‐butanol and 3‐methyl‐butanol. Operating results satisfactorily suggested that the concentration of 2‐methyl‐butanol was over 99 wt % with the yield over 80%. Computational flowsheet simulation was also done with the outcome in good agreement with the tested onsite to facilitate industrial design. © 2011 American Institute of Chemical Engineers AIChE J, 2011     

Influence of isomer ratio and ring substituents in decomposition activation energies of α,α,α′,α′‐tetrasubstituted dibenzyls

Diethyl‐2,3‐dicyano‐2,3‐di‐(X‐substituted phenyl) succinates (X = p‐OCH₃, p‐CH₃, p‐Cl, H, p‐NO₂) can initiate the free‐radical polymerization of styrene. The decomposition rate constant and activation energy were measured by means of a dilatometer, and the results showed that they were strongly dependent on the ratio of meso‐ and dl‐isomers in the polysubstituted dibenzyl compounds and the properties of the ring substituents. On the other hand, it was found that the polystyrenes, which were obtained by initiation with hydrogen, had a much larger average molecular weight than that with p‐OCH₃ and p‐CH₃. The experimental phenomena were correlated with the structure of the radical resulting from hydrogen. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2964–2971, 2001     

β‐Carotene Investigation Using Photoacoustic Spectroscopy Over Several Concentration Mixtures Under β‐Carotene‐Free Sesame Oil

Abstract

Photoacoustic and optical transmission spectroscopies were applied over several beta‐carotene contents under vegetable sesame‐oil. Those spectroscopic techniques were applied to investigate β‐carotene presence, to distinguish different known linear conjugated polyenes, and to obtain qualitative concentrations of all‐trans‐retinine, 15‐cis‐retinine, 11‐cis‐isomer, and 15‐monocis‐retinine present in the geometric isomer constitution of beta‐carotene. Photoacoustic spectroscopy was demonstrated to be a very useful tool to investigate very low traces of β‐carotene undoubtedly without causing any damage to the studied substance.     

硝基苯甲酸同分异构体分析及其在废水预处理中的应用

间硝基苯甲酸生产及精制过程中会产生大量高浓度硝基苯甲酸同分异构体废水. 为了选择和优化废水预处理的工艺条件,需要分离和检测样品中的各种硝基苯甲酸. 本研究建立一种采用高效液相色谱分离检测硝基苯甲酸同分异构体的方法,使用XDB-C18色谱柱,以甲醇-乙酸溶液(pH=3.0)(体积比为35:65)为流动相,紫外检测波长为267 nm,考察了流动相组成、体积比、pH值及流速等对硝基苯甲酸同分异构体分离度的影响. 结果表明:邻、间、对硝基苯甲酸分别在12.14～194.0 mg/L、13.78～220.4 mg/L、6.450～103.2 mg/L范围内线性关系良好,相关性系数R²均大于0.999 5,相对标准偏差均小于1.04%. 利用该方法能够为间硝基苯甲酸精制废水预处理过程提供分析.     

1,2,4-三氮唑类杀菌剂的研究进展

综述了1，2，4－三氮唑类杀菌剂的开发现状和研究进展，对其光学异构体的制备，构效关系及其分离等进行了讨论，指出1，2，4－三氮唑类杀菌剂具有高效、广谱、低毒、低抗性等特点，发展前景好。     

液固吸附色谱法分离番茄红素异构体

本文应用液固色谱法成功对5个样品中番茄红素的异构体实现了分离。5个样品中的番茄红素均以反式结构为主，但差异很大，新鲜番茄中反式的番茄红素占96．38％，1％番茄红素油树脂中反式结构的番茄红素只有37．65％。根据其特征紫外吸收和保留时间等特征对异构体的种类进行了初步复写。为进一步研究番茄红素异构体的物化性质和生理活性打下了基础。     

硝硫磷混酸对甲苯一硝化选择性的影响及工艺过程研究

以甲苯为原料,考察了硝硫磷混酸对甲苯一硝化选择性的影响,结果表明:在保证硝化能力的前提下,水的质量分数以20%为宜,磷酸的引入明显降低了邻对比,提高了对硝基甲苯的选择性。利用响应面软件对间歇工艺条件进行了优化,适宜的工艺条件为硝酸/硫酸/磷酸/水(质量比)=0.1∶0.29∶0.41∶0.2,加料温度40℃,加料时间30min,反应温度60℃,反应时间180min,硝化比1.19,搅拌速率330r/min,在此条件下甲苯转化率为99.28%,邻对比1.31,对硝基甲苯收率41.55%。同时对静态混合管式连续选择性硝化工艺进行初步探索,进行了相同反应时间条件下的间歇对照试验,结果表明,采用静态混合反应技术后的硝硫磷混酸硝化过程,可以提高甲苯转化率,强化传质传热效果。