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关键词： Zirconium-based metal-organic frameworks   Analytical chemistry   Applications   Sensing   Sample pretreatment   Chromatography  

摘要： Advances in analytical chemistry are contingent upon development of material sciences. Environmental samples, with complex matrices and low target concentrations, warrant good analysis performances. Zirconium-based metal-organic frameworks (Zr-MOFs) have robust skeletons, excellent stability, ultra-high specific surface area, elaborate pore structure, and well designability, possessing different functions for detection/sensing, sample pretreatment, and chromatographic stationary phase. Summarizing recent progress of Zr-MOFs in analytical chemistry can promote methodological development and further applications of Zr-MOFs. This review will comprehensively summarize research that has been conducted so far on the analytical applications of Zr-MOFs. Oriented to the requirement of materials applied for analysis, we will focus on applications of Zr-MOFs as pollutant sensors, extraction adsorbents, and chromatographic stationary phases. Knowledge gaps will be identified and future line of research on Zr-MOFs in analytical chemistry will be recommended. It is expected that research on evolving porous materials, especially for sample analysis, will benefit from this review. (C) 2020 Elsevier B.V. All rights reserved.

关键词： Nanofibers   Optical analysis   Electrochemical analysis   Ionization techniques   Sample preparation   Sensor   Ultra-thin layer chromatography  

摘要： Nanofibers are solid fibers with diameters ranging from a few to hundreds of nanometers and lengths up to several meters. Nanofibers can offer many attractive properties, such as high specific surface area and large aspect ratio, and satisfy some special needs of analytical chemistry using different functionalization and modification methods. Nanofibers have been applied in different analytical techniques and processes, including optical analysis (colorimetery, fluorescence, chemiluminescence, surface-enhanced Raman scattering), ultra-thin layer chromatography, mass spectrometry ionization techniques, electrochemical analysis, sample preparation techniques, gas sensors and biological sensors. The trends and advances of application techniques based on nanofibers and the corresponding synthesis or derivatization methods were summarized and compared according to the survey of more than 1100 articles in recent two decades. The challenges and prospects of nanofiber-based applications in analytical chemistry were also addressed finally. (C) 2020 Elsevier B.V. All rights reserved.

关键词： pillar[5]arenes   Planar chirality   Recent progress   Analysis   Separation  

摘要： In this review, we highlight recent significant advancements for the systematic investigation of achiral, planar chiral and chiral configurations of pillar[5]arenes. Compared to the traditional macrocyclic molecule, these interesting frame structures have drawn a lot of attention in analytical chemistry and separation science in recent years, due to their unique superiority advantages such as pillar-shaped frame, electron-rich cavity and easy to functionalize. Although considering the abundant research results on pillar[5]arenes, there have been few reviews on the synthesis of planar chiral or chiral pillar[5] arenes, as well as summarizing from the perspective of separation science. From this review, we hope to provide a useful reference for researchers working in separation science and inspire new discoveries in the field of chiral pillar[5]arene-based separation materials. Finally, we have described the future perspectives of construction chiral pillar [5]arene, interactions and mechanisms between analytes may further enhance our understanding in this exciting field. (C) 2020 Elsevier B.V. All rights reserved.

关键词： 食品安全   检测   化学技术   应用  

摘要： 这几年来随着社会的不断发展,人们的生活水平和经济水平都得到了提高,并且对食品安全问题也越来越重视,对食品安全的要求也越来越高。在食品科学工程中,食品的安全性主要依托科学的检测方式和检测手段来完成。食品检测工程中需要运用到多种检测技术,其中化学检测技术作为一种比较常见的检测手段,在食品安全检测过程中发挥出重要作用。本文主要探究了食品安全监测中化学检测技术的应用途径,希望能为以后的食品检测工作提供一定借鉴。

关键词： 食品安全   检测   化学技术   应用  

摘要： 目前来说,我国对于食品的检验检测还是比较严格的,除了相关的技术标准之外,我国还制定了相应的法律法规以进行约束。可以说,食品安全是和每个人生活息息相关的大事,食品出现问题,则会严重影响人们健康,并导致不良社会后果。要想全面保证食品的安全,则需要对食品进行安全检测检验,利用先进仪器设备和科学的食品检验检测方法,对食品情况进行数据认定,才能提高食品质量,更好地维护人们的身体健康。文章论述了食品安全检测中化学技术的应用,仅供参考。

关键词： Chemical looping hydrogen production   Water-gas shift   Energy grade   Exergy analysis  

摘要： Three reactors chemical looping (TRCL) is a promising hydrogen production process without needing H-2 purification and capturing CO2 directly. Based on the deficient research on the energy conversion mechanism in TRCL and the role of external heat sources in the TRCL process, this paper studied the thermodynamic characteristics of energy conversion in methane-TRCL and syngas-TRCL and water-gas shift (WGS) systems, and established the mathematical model of the related parameters through the concept of energy grade. Meanwhile, in this system the energy grade effects of input heat, heat quantity, hydrogen concentration in syngas and steam quantity on the thermodynamic performance are studied. The results show that the TRCL system of methane and syngas has the highest exergy efficiency with 89% and 88.3% respectively, while the energy grade of external input heat is 0.694. Under mentioned above, methane-TRCL is suitable for the case where the heat input value is greater than 310.52 kJ/mol, and the syngas-TRCL system is more efficient than WGS system with 4.8%. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

关键词： 食品安全检测   分析化学技术   应用  

摘要： 近年来,我国社会发生了许多食品安全方面的事故,导致人们对于食品的安全产生一些恐惧心理。现在的食品工业却是存在许多问题,并且其中许多与化学有关联。社会迫切需要管理和改善人们的食品安全,使用先进的科学技术方法,合理有效地控制和管理食品安全领域,让食品检验可以更好地保证食品的安全。在本文中,根据一些检测食品安全的措施,分析研究了化学技术对于食品安全产生的一些影响。

关键词： 无机及分析化学   教学方法   教学效果  

摘要： 无机及分析化学是化学、化工专业必修课程。如何提高无机及分析化学的教学效果也是该领域研究的一个主要方向。本文基于教育心理学以及无机及分析化学的教学目标,探讨相应的教学方法及策略。

关键词： 化学分析   仪器   检测   质量  

摘要： 在化工材料检测中,化学分析极为重要,不仅是化工材料得以正常生产的保障,同时也是化工材料质量监督的必要手段。但是在实际的检验过程中,因为容易受到多方面因素的影响,所以不断加大化学分析检验的管理力度,对相关影响因素进行严格的控制,从而对整个化学分析过程的质量进行严格的把控。文章对化学分析仪器的计量检测工作的重要性进行分析,详细阐述计量检测依据、标准物质以及后续管理工作,并对当前行业存在的问题进行分析后给出相应建议。