The Synthesis of Covalent Triazine-Based Frameworks via Friedel–Crafts Reactions of Cyanuric Chloride with Thienyl and Carbazolyl Derivatives for Fluorescence Sensing to Picric Acid,Iodine and Capturing Iodine

A multifunctional thiophene-based covalent triazine framework (TTPATTh) with triphenylamine as core is synthesized by Friedel–Crafts reaction of cyanuric chloride with thienyl derivative for the first time. The yield of TTPATTh (99.59%) is far higher than that of the carbazole-based CTF (TTPATCz, 47.03%). TTPATTh and TTPATCz possess high BET surface areas with 1235 and 2501 m² g^–1 as well as high pore volumes with 1.60 and 2.23 cm³ g^–1, respectively. TTPATTh and TTPATCz have high thermal stability with high thermal decomposition temperatures of 514 and 598 °C in nitrogen atmosphere. With the introduction of triazine rings, the fluorescence sensing sensitivities of TTPATTh and TTPATCz to picric acid and iodine are improved significantly. Especially for TTPATTh, the K_sv values reach 5.95 × 10⁵ and 1.61 × 10⁴ L mol^–1, and LODs reach 1.02 × 10^–12 and 1.86 × 10^–12 mol L^–1. To the best of the knowledge, this is the most sensitive value among thiophene-based porous organic polymers to PA and I₂. Furthermore, TTPATTh and TTPATCz can also adsorb iodine in vapor phase, cyclohexane solution and aqueous solution, and release iodine by heating or in ethanol solution. The efficiency of controlling the release of iodine is higher than that in ethanol.     

氧化铝超浓相输送系统计量新装置的研究开发

本文介绍了我国首例铝电解大组氧化铝超浓相输送管路上安装电子秤进行氧化铝静态称量连续下料自动计量新方法、新装置及其使用精度的有关基本情况。     

贵金属的化学发光分析

介绍化学发光分析的基本原理和测试技术,及其应用于测定贵金属的几种化学发光反应,并展望其前景。     

Ce对过共晶Al—Si合金熔体粘滞性和结构的影响

研究了Ce对Al—16％Si合金熔体粘滞性的影响。结果表明：Ce的加入增加了合金熔体的粘度，且随着Ce含量的增加粘度值也增加。结合加入Ce的Al—16％Si合金氢含量的变化、凝固组织和DSC曲线研究了熔体结构的变化，分析了粘度与液态结构变化之间的关系。     

TRIZ理论中物质-场的不同应用

通过对飞机发动机机罩概念设计中的物-场分析，简要概括了在实际的概念设计中应该如何应用和把握物质-场分析的侧重点。     

从霞石的结构特征探析其在陶瓷中的应用

霞石主要生成于富含Na2O而贫SiO2的碱性火成岩及伟晶岩中，晶体呈六方短柱状、厚板状、等粒状集合体或致密块状产出。Na2O、K2O合量为14％～20％，高于长石类。在陶瓷生产中用其取代部分长石，具有较强的熔剂效应，能显著的降低产品     

Side-Surface Structure of a Commercial β-Silicon Carbide Whisker

The side surfaces of a commercial β-SiC whisker were analyzed by calculating the surface energy and observing the microstructure of the whiskers. The results indicated that the side surfaces displayed a type of zigzag structure and were composed of {111}, {110}, and {100} crystal planes.     

Comments on “Exact and approximate feedback linearization without the linear controllability assumption [Automatica 48 (2012) 2221–2228]”

The conditions for state feedback linearization suggested in the aforementioned article are shown, by means of counterexamples, not to be sufficient. In view of this, modified results are proposed for ensuring the sufficiency.     

Humidity sensitivity of polypyrrole and polypyrrole/SBA‐15 host–guest composite materials

Polypyrrole (PPY) and PPY/SBA‐15 host–guest composite materials have been prepared using chemical synthesis route and characterized by XRD, IR, N₂ adsorption–desorption isotherms, and SEM. The humidity sensitive properties (HSP) of this kind of materials have been studied by analyzing the variation curve of impedance as a function of relative humidity. It was found that the PPY/SBA‐15 host–guest composites materials exhibit better HSP than that of the corresponding pure PPY. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3301–3305, 2006     

大孔树脂法精制甘草酸

介绍了用大孔树脂从甘草中分离精制甘草酸的方法。大孔树脂是目前广泛采用的分离天然产物的方法。用大孔树脂精制甘草酸,使甘草酸和其他杂质得到很好的分离,明显改善了甘草酸的质量。在纯度测定时,采用香草醛-硫酸比色法能准确测定甘草酸纯度。另外,实验使用草酸还原Fe3+的方法改善产品颜色,并在进样前先用活性炭脱色,这两种方法同时使用有效地改善了产品的颜色。