基于临近比较的快速拉曼光谱基线校正方法

拉曼光谱成像技术是基于拉曼散射效应所开发的一项现代检测技术,在现代生产、科学研究过程中使用非常广泛。拉曼光谱信号受荧光效应和仪器等方面的影响,往往会产生基线漂移,严重影响对信号特征的进一步提取。因此,必须对拉曼光谱信号进行基线校正。传统的基线校正方法,只针对单一光谱信号,计算量较大,在处理由大量拉曼信号组成的成像数据时,耗时较长且效果不佳。该文提出一种基于临近比较的快速基线校正方法,根据在相同背景下采集的光谱之间的相关性,实现快速基线校正,提高了拉曼成像数据的处理速度。     

现代仪器分析技术在潲水油检测中的应用

综述了近年来光谱、色谱、质谱、核磁共振等现代仪器分析技术在潲水油检测中的应用现状和发展,并对其应用前景进行了展望(引用文献46篇)。     

Cu的负载方法对CuSAPO-34脱除柴油车尾气中NOx的影响

采用X射线衍射、扫描电镜、原子吸收、程序升温还原、X射线吸收近边吸收谱、X射线光电子能谱、氮吸附等手段对水热合成(HS)、等体积浸渍(PVI)与离子交换(IE)法制备的CuSAPO-34样品进行了表征,并评价了老化前后催化剂上C₃H₆-SCR与NH₃-SCR脱除模拟柴油车尾气中NO_x的反应活性.结果表明,IE法制得的催化剂活性最高,尤其在C₃H₆-SCR低温阶段;PVI法制得的催化剂活性最差.制备方法影响CuSAPO-34催化剂的比表面积、孔径分布和活性组分价态从而改变其催化活性.各催化剂均存在Cu⁺和Cu²⁺,但比例明显不同.HS样品以Cu²⁺为主,另两种样品则含较多的Cu⁺.老化不仅部分破坏了分子筛的形貌、降低了分子筛的比表面积,尤其是表面Cu含量,而且有部分Cu生成了CuSO₄,使得老化后催化剂的脱硝活性降低.PVI法制得的催化剂老化后活性下降幅度最小,表明该分子筛抗老化能力较强.     

Synthesis of polymer–inorganic patchy microcapsules with tunable patches

We introduce a facile and versatile approach for the formation of ball-like polymer–inorganic patchy microcapsules with a tunable shell by combining sol–gel chemistry of silica precursor and phase separation between the polymer and the precursor. Firstly, chloroform-in-water emulsion droplets containing poly(methyl methacrylate) (PMMA), silica precursor [tetraethyl orthosilicate (TEOS)] and co-surfactant sodium dioctyl sulfosuccinate (Aerosol OT or AOT) were prepared by shaking the mixture by hand. Due to the added AOT, water molecules diffuse into the chloroform droplets, and the tiny water droplets would coalesce gradually, triggering the formation of double emulsion droplets. Upon further solvent evaporation, the concentration of the polymer and the silica precursor in the oil shell of the double emulsions increases, leading to the phase separation between the polymer and the precursors (and partially formed silica through the hydrolysis and condensation of TEOS). Because of the confined geometry of the oil shell in the double emulsions, polymeric disc-like structures, stabilized by AOT, were dispersed in the silica precursors. Meanwhile, the silica precursor hydrolyzed and condensed when brought in contact with the aqueous solution, ultimately leading to the formation of a mineralized shell around the polymer domains and the hybrid patchy microcapsules. Effect of synthesis conditions, such as the amount of TEOS, AOT, and PMMA used, the pH value, and solvent evaporation rate on interfacial behavior of the solvent/water; and the morphology of the patchy microcapsules were investigated. Patchy microcapsules with tunable patch size and shape can be generated through tailoring the experimental parameters. Our study indicates that the hybrid patchy microcapsules can be formed by taking advantage of the sol–gel chemistry and the phase separation process, and the underlying generality of the synthesis procedure allows for a variety of applications, including drug storage, coatings, delivery, catalysis, and smart building blocks in self-assembling systems.     

One-Pot Conversion of Aldehyde Sodium Bisulfites into Nitriles

Direct conversion of aldehyde sodium bisulfites to the corresponding nitriles can be easily performed by the reaction of an aldehyde sodium bisulfites with a slight execss of hydroxylamine hydrochloride in refluxing toluene and in the presence of 1.0 equivalents of pyridine as catalyst.     

基于氟硅烷改性 UIO-66-OH的疏水金属有机骨架材料的制备及在灰岩类石质文物保护中的应用

疏水材料的研制一直是石质文物保护工作中的难点问题。本工作制备了一种新型疏水金属有机骨架(MOF)材料,即采用氟硅烷修饰含有2-羟基对苯二甲酸桥联配体的Zr-MOF以获得UIO-O-FS材料,并对材料进行了FTIR、X射线衍射、N₂吸附-脱附、热重、扫描电镜和透射电镜等表征分析以及抗侵蚀试验。试验结果表明,该材料具有良好的疏水性、固结性、耐酸性和耐盐性,是一种新型石质文物保护材料。     

硅镁凝胶对杉木的强化及固着机制研究

硅镁凝胶浸渍改性杉木在物理力学性能方面提升较佳,探究硅镁凝胶在杉木中的固着性能和机制,对后续研究与创新具有一定意义。以硅镁凝胶为改性药剂,人工林杉木为基材,浸渍干燥后制得改性杉木。通过FTIR和XPS分析杉木素材和改性杉木的化学成分和结合方式,并对硅镁凝胶在木材中的分布以及改性杉木的渗透性进行探讨。实验结果表明：硅镁凝胶浸渍改性杉木的物理力学性能得到明显改善,密度均达到0.5 g·cm-3以上,抗压强度和抗弯强度相比杉木素材分别提升了99.73%和58.48%,端面硬度从3 659 N提升到5 843 N,基本已达到中等木材的性能指标。EDS结果证明药剂在杉木细胞腔中填充状况良好,Si,O,Na和Mg等主要元素与浸渍药剂硅镁凝胶相符且分布均匀。对浸洗前后的改性杉木试样和素材分别进行分层XPS测试,改性材的O/C增大,各元素在不同深度的含量十分接近,硅镁凝胶在杉木中分布均匀,具有良好的渗透性;浸洗后Si元素含量稳定,而钠元素有所降低,可能是部分钠盐的溶解流失造成,且不同深度的元素含量变化趋于一致,改性杉木的抗流失性较好。相比于硅酸钠浸渍改性杉木,硅镁凝胶改性杉木在96 h流失率降低到10.8%,抗流失效果较好。FTIR测试结果表明硅酸钠溶液对杉木的木质素和半纤维素有破坏和脱出作用,对杉木的通透性有所改善,且更容易与药剂形成化学键结合。C,O和Si元素的XPS谱图结果表明,改性后C(1s)向低结合能偏移,性质更加稳定,O—H结合大量减少,Si—O结合增多,硅镁凝胶能够在杉木中形成稳定的Si—O—C化学结构,药剂能够在细胞壁上实现高效固着。研究结果为改性材的药剂流失性检测和固着性研究提供新的思路,为硅镁凝胶浸渍改性杉木后续研究提供一定的理论支持。     

加速溶剂萃取-在线衍生-气相色谱-质谱法同时分析土壤中有机氯农药和酸性除草剂

建立了土壤中13种极性除草剂与20种非极性有机氯农药的同时萃取检测的方法.利用加速溶剂萃取过程中的温度环境与溶剂环境,使强极性氯代酸性除草剂与五氟苄基溴在萃取池内反应,酯化产物的极性显著降低.利用丙酮溶剂使之与非极性的有机氯农药同时萃取;利用衍生产物与有机氯农药的高电负性使除草剂与有机氯农药在气相色谱负化学源质谱上同时...     

Synthesis and herbicidal activity of 5-(4-hydroxybenzyl)-2-thioxoimidazolidin-4-one esters

A series of novel 5-(4-hydroxybenzyl)-2-thioxoimidazolidin-4-one esters were synthesized under mild conditions by the reaction of 5-(4-hydroxybenzyl)-2-thioxoimidazolidin-4-one and carboxylic acids with DCC and DMAP as the promoters. Their structures were confirmed by 1H-NMR, IR, ESI-MS and elemental analysis. The preliminary bioassy results indicated that some of compounds exhibit good herbicidal activity against Zea mays, Triticum aestivum and Arabidopsis thaliana. The further greenhouse test showed that compounds 6-16 and 6-28 have 60%, 50% and 50% efficacy against Stellaria media, Echinochloa crus-galli and Setaria viridis at 1,000 g/ha, respectively.