瓦斯爆炸机理及预防措施

分析了瓦斯爆炸的条件,发生的主要反应及其反应机理,指出相应的预防措施及事后急救方法,并介绍合理利用瓦斯能源的途径。     

Cauchy problem for the generalized Davey-Stewartson systems in Besov spaces and some counterexamples

In this paper, the Cauchy problem of the generalized ellipse-ellipse type Davey-Stewartson systems is discussed. When the dimension of space is greater than or equal to two, we get a unique global solution in Besov spaces by contraction mapping argument. Moreover, by using the F-expansion method, the exact periodic wave solutions for the generalized ellipse-ellipse type Davey-Stewartson systems are discussed, some counter examples are given.     

Positive almost periodic solutions for shunting inhibitory cellular neural networks with time-varying and continuously distributed delays

In this paper shunting inhibitory cellular neural networks (SICNNs) with time-varying and continuously distributed delays are considered. Some new sufficient conditions for the existence and exponential stability of the positive almost periodic solutions are established.     

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。     

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.     

Computational insights into allosteric interaction between benzoazepin-2-ones and lung cancer-associated PDK1: Implications for activator design

3-Phosphoinositide-dependent kinase-1 (PDK1) plays a key role in the regulation of physiological processes and its catalytic activity is tightly regulated by allosteric modulators which bind to the PDK1 Interacting Fragment (PIF) pocket. However, details on the allosteric modulators regulation of the PDK1 catalytic activity remain elusive. Here, molecular docking and molecular dynamics (MD) simulations were performed to investigate the allosteric regulation of PDK1 induced by one of the benzoazepin-2-ones, the most potent compound 17 (BAZ2O). Molecular docking and MD simulation revealed that BAZ2O was located in the PIF pocket formed by residues from β4 and β5 sheets and helices αB and αC. BAZ2O formed a hydrogen bond with Arg131 and participated in hydrophobic interactions with Ile119, Thr148, Gln150, Leu155 and Phe157. Further comparative analyses of PDK1 in its apo and BAZ2O-bound states unveiled that BAZ2O promoted the structural coupling between the important catalytic domains of PDK1, including the activation loop and the helices αB and αC, thereby stabilizing the PDK1 conformation for catalysis. Understanding the allosteric interaction of PDK1 with small molecules provides a potentially valuable possibility of designing more potent allosteric modulators with therapeutic implications for lung cancer.     

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。     

固相萃取-高效液相色谱-串联质谱法测定中药西南金丝梅中26种农药残留量

提出了高效液相色谱-串联质谱法测定西南金丝梅中26种农药残留量的方法。样品用乙腈振荡提取,提取液经氨基固相萃取小柱净化。用shim-packXR-ODS色谱柱分离,采用电喷雾离子化正离子方式及多反应监测模式进行测定。26种农药的质量浓度在0.01～2.5mg·L-1范围内与峰面积呈线性关系,检出限(3S/N)在4.16×10-5～2.85×10-4 mg·kg-1之间。在3个标准加入水平下进行了精密度和回收试验,方法的回收率在78.4%～112%之间,测定值的相对标准偏差(n=5)在1.2%～11%之间。