大百合中微量元素测定的研究

研究了火焰原子吸收光谱法同时测定大百合中多种微量元素的条件,测定了在不同生长时期大百合中K, Ca, Na, Mg, Fe, Zn, Mn, Cu和Cr等九种元素的含量,方法的相对标准偏差介于0.2%～2.1%之间,平均回收率在97.8%～104.9%之间,分析结果满意。结果表明,大百合中Zn, K, Ca, Mg和Mn等人体必须的生命元素含量较高,提示了大百合具有较高的营养价值。     

新型吡唑啉酮衍生物的制备

以氢氧化钾为催化剂,1-苯基-3-甲基-吡唑啉-5-酮与取代苯甲醛亚胺反应合成了新型1-苯基-3-甲基-吡唑啉-5-酮衍生物——1-苯基-3-甲基-4-(1-N-氯乙胺基-1-取代苯基)甲基-吡唑啉-5-酮,其结构经1H NMR,IR,MS和元素分析表征。     

香格里拉产小叶杜鹃花挥发性成分的GC-MS分析

研讨香格里拉县小叶杜鹃花的挥发油化学成分,为进一步合理开发利用其药用资源提供试验依据。利用水蒸汽同时蒸馏萃取法(SDE)提取小叶杜鹃花的挥发性化学成分,通过气相色谱-质谱联用技术(GC-MS)对各个色谱峰定性,并采用色谱峰面积归一法获得各个化合物的相对含量。从小叶杜鹃花挥发油中共分离鉴定了73个色谱峰,占挥发油总量的85.53%。小叶杜鹃花挥发油主要成分有α-蒎烯(14.00%)、正二十三烷(9.51%)、7-甲氧基-2,2-二甲基-3-色烯(6.26%)、正二十烷(6.11%)、苯乙醇(5.10%)、1-Heneicosyl formate(4.60%)等。     

Delay-dependent BIBO stability analysis of switched uncertain neutral systems

This paper presents the analysis of delay-dependent bounded input bounded output (BIBO) stability for a class of switched uncertain neutral systems. The uncertainty is assumed to be of structured linear fractional form which includes the norm-bounded uncertainty as a special case. First, by introducing the general variation-of-constants formula of neutral systems with perturbation, the BIBO stability property of general linear switched neutral systems with perturbation is established. Next, combining the general variation-of-constants formula with the state-dependent switching rule, new approaches are presented to design the feedback controller and the switching rules. Furthermore, the BIBO stability criteria are obtained in terms of the so-called Lyapunov–Metzler linear matrix inequalities (LMIs). Finally, simulation examples are given to demonstrate the effectiveness and the potential of the proposed techniques in this paper.     

应用搅拌棒吸附萃取-热脱附-气质联用技术分析人工唾液捕集吸收的卷烟主流烟气成分

采用人工唾液捕集卷烟主流烟气,应用搅拌棒吸附萃取法(SBSE)提取其中的化学成分,利用热脱附(TD)-气相色谱-质谱(GC-MS)进行分析。对脱附温度、脱附时间、冷阱温度、萃取时间及NaCl加入量等影响因素进行考察,获得优化的实验条件。在优化条件下,同一样品的6次测定所得44个组分的峰面积的相对标准偏差(RSD)平均值小于10%,说明所建方法重现性较好。应用本方法分析某品牌卷烟烟气成分的结果表明:SBSE-TD-GC-MS联用技术可用于人工唾液捕集吸收的烟气化学成分的快速分析测定。     

Reduction of the Sharma–Tasso–Olver equation and series solutions

This paper considers series solutions of the Sharma–Tasso–Olver (STO) equation. By using the extended homogenous balance method, we reduce the STO equation to a linear PDE and obtain Bäcklund transformation of it. Furthermore, the self-transformation of solutions for the STO equation is obtained. By the Bäcklund transformation and various series solutions of the PDE, abundant exact solutions of the STO equation are obtained including the multi-solitary wave solution, trigonometric function series solution, rational series solution and solution consisting of the three types of solutions.     

热重-流动载气液滴微吸附体系的建立及其应用于卷烟纸的热解产物分析

将液相微萃取技术用于流动载气条件下热重逸出组分的吸附,自行设计和建立了热重-流动载气液滴微吸附(TG-GFSDMA)联用装置,并结合气相色谱-质谱(GC-MS),建立了可以进行热重逸出组分分析的检测系统.使用该系统并结合划分温度段连续取样法,研究了卷烟纸在主失重区的热失重行为及其热解逸出产物,并考察了热重载气流量对液滴...     

New Isoprenylated Aurones from the Flowers of Rosa damascena

A phytochemical investigation of the flowers of Rosa damascena resulted in the isolation of three new isoprenylated aurones, damaurones C–E ( 1 – 3 , resp.), together with six known compounds, 4 – 9 . The structures of the new compounds were elucidated by spectroscopic methods, including extensive 1D‐ and 2D‐NMR experiments.     

二氧化钛选择性光催化降解有机污染物研究进展

半导体二氧化钛已被广泛应用于有机污染物的光催化降解,但其主要是通过光与二氧化钛作用产生的羟基自由基与有机污染物发生自由基氧化反应,这种自由基反应在降解污染物时没有选择性,当几种有机污染物共存时,它优先催化降解吸附在其表面的高浓度污染物,而低浓度的有机污染物因吸附量少而达不到有效降解。因此,研究开发具有高选择性的能降解低浓度高毒性有机污染物的二氧化钛材料是环境科学领域亟待解决的热点之一。本文综述了近十年来二氧化钛选择性光催化降解有机污染物的研究动态和主要成果,并对未来发展趋势进行展望。