人工神经网络在激光诱导击穿光谱数据分析中的应用进展

激光诱导击穿光谱(L IBS)具有实时、远程、多元素同时分析的优点,近年来在工业在线分析领域逐渐受到关注,发挥着重要作用.但基于发射光谱本身的特性,L IBS存在光谱噪声、基线漂移、自吸收和重叠峰等现象;又由于环境变化、激光能量波动、基体效应、样品表面形貌等因素,造成光谱稳定性和重现性差.这些问题导致光谱信息与定性、定...     

近红外光谱技术在饲草分析中的应用现状及展望

饲草是畜牧业生产的物质基础,饲草质量的好坏直接关系到畜产品质量的好坏。控制饲草质量、检测饲草原料的成分是饲草生产中非常重要的一环。近红外光谱技术是20世纪70年代发展起来的一项高效、快速的现代分析技术。它综合运用了计算机技术、光谱技术和化学计量学等多个学科的最新研究成果,以其独特的优点在多个领域得到了广泛的应用。尽管NIRS技术在饲草分析上的应用起步较晚, 但越来越被人们所重视。目前,近红外光谱技术不仅能测定饲草中的水分、粗蛋白、粗纤维和粗脂肪等常规成分,还能测定饲草中的矿物质、微量元素和酶类等非常规成分,预测饲草的抗营养成分。而且还可进行饲草的生物学效价评定,从而评定饲草的利用率及营养价值,并能分析草地的植物组成和饲草的茎叶比例。文章综合阐述了近红外光谱技术在饲草分析中的应用现状,并对其应用前景进行了展望。     

制备气相色谱仪的改进及应用研究进展

气相色谱已经成为一种常规的分析手段,但以制备为目的的气相色谱的应用还较少.目前尚没有商品化的制备气相色谱仪,需要对传统的分析型气相色谱仪加以改进,以达到高效分离制备目标化合物的目的.本文综述了国内外对制备气相色谱仪改进工作的研究进展,包括汽化室、色谱柱、分流装置、收集系统等的改进.另外,总结了制备气相色谱在各领域的应用...     

Functional Poly(ionic liquid) Porous Membranes: From Fabrications to Advanced Applications†

Polyelectrolyte porous membranes (PPMs) belong to the most interesting classes of materials, because the synergy of tunable pore sizes and charge nature of polyelectrolyte endow them with wide-ranging practical applications. However, owing to the water solubility and ionic nature of the polyelectrolytes, traditional polyelectrolytes are difficult to use in scalable preparation of high-quality PPMs through the well-developed industrial methods. Poly(ionic liquid)s (PIL) are a subclass of functional polyelectrolytes bearing ionic liquid groups in their repeating unites, inheriting the advantages of ionic liquids (ILs) and macromolecular architecture features. In recent years, along with rapid development of PIL materials chemistry, considerable and significant developments involving the novel preparation methods, and structure-property-function relationships of PPMs have been made. In this review, we highlight the latest discovery and proceedings of PPMs, particularly the advancements in how to tailor structures and properties of PPMs by rational structure design of PILs. The formation mechanisms of various PPMs were also discussed in detail from the viewpoint of PILs molecular structures. A future perspective of the challenges and promising potential of PPMs is cast on the basis of these achievements. We expect that these analyses and deductions will be useful for the design of useful PPMs and serve as a source of inspiration for the design of future multifunctional PPMs.      

A dual-functional chemosensor based on acylhydrazone derivative for rapid detection of Zn(II) and Mg(II): Spectral properties,recognition mechanism and application studies

In this work, an acylhydrazone derivative (QN62) was developed via the one-step condensation of 6-hydroxy-2-naphthoic hydrazide with quinoline-8-carboxaldehyde. The structure of the QN62 compound was characterized by ¹H NMR, ¹³C NMR, HR-MS (ESI), and X-ray crystallography. As a dual-functional turn-on fluorescence chemosensor, QN62 exhibited rapid recognition for Zn²⁺ in DMSO-H₂O (4:1, v/v) and Mg²⁺ in ethanol-H₂O (9:1, v/v). The enhancement in fluorescence detection was associated with the coordination reaction between QN62 and the target ions, which promoted intramolecular charge transfer and prevented the CN isomerization process. Simultaneously, a rapid color change from colorless to yellowish-green or yellow under UV light (365 nm) was easily visible to the naked eye. Under optimal conditions, the limit of detection and limit of quantification were 32.3 nM and 97.8 nM for Zn²⁺ and 16.1 nM and 48.9 nM for Mg²⁺, respectively. The recognition mechanism was reasonably speculated based on analysis of the Job’s plot, HR-MS, ¹H NMR, and density functional theoretical calculations. Utilizing silica-gel plates fabricated from the QN62 chemosensor, the visual and rapid identification of Zn²⁺ and Mg²⁺ was successfully achieved, which could provide a convenient approach for on-site detection in environmental fields. The QN62 chemosensor could also quantify trace amounts of Zn²⁺ and Mg²⁺ in water samples. Furthermore, the cell imaging experiments indicated that QN62 could effectively sense intracellular Zn²⁺ and Mg²⁺, providing potential applications in biological systems.     

离子液体功能化环糊精化合物的合成及应用

离子液体功能化环糊精化合物(ILs-CD)兼具环糊精"内疏水、外亲水"的结构特性和离子液体的低毒性、低蒸气压、电化学窗口宽、热稳定性和化学稳定性高等特性,是一类有巨大发展潜力的新型大环化合物.本文主要根据合成的ILs-CD化合物的阳离子不同对其进行了分类,并介绍了其合成方法,同时阐述了其在电化学、环境、食品、医药、催化...