Effects of Organic Acids on the Release of Fruity Esters in Water: An Insight at the Molecular Level

It is well known that organic acids (OAs) could affect the flavour of fruit juices and beverages. However, the molecular mechanism of aroma release is still unclear. In this study, the effects of citric acid (CA), L-(-)-malic acid (MA) and L-lactic acid (LA) on the release of six selected esters and their sensory perception were investigated by means of HS-GC-MS analyses and odour detection threshold determination, respectively. Meanwhile, the density functional theory (DFT) calculation was employed to explore the interaction modes between esters and OAs. HS-GC-MS analyses showed that the concentration and the type of OAs regulated the release of esters. The results were basically consistent with the detection threshold change of those esters. The DFT calculation suggested that the main intermolecular interaction was hydrogen bonds, and several esters could form a ternary ring structure with OAs through hydrogen bonds. The interactions can induce the different release behaviours of esters in OAs water solution. The number of carboxyl functional groups in OAs and the spatial conformation of esters appeared to influence the magnitude of the interaction. The above results demonstrated the mechanism of OAs affecting the release of esters and indicated a possible flavour control way by using different OAs and OA concentrations.     

基于垂直结构的有机光发射晶体管制备与性能研究

制备了一种有机垂直光发射晶体管, 兼具有机发光二极管的发光和晶体管的开关调节两个功能.其结构为一个有机发光单元垂直堆叠在一个电容单元上,两单元通过一个共有的源电极连在一起.当电容单元被充电时,积累在源电极的电荷能有效地调节源极与有机层之间的载流子注入势垒,从而达到控制源漏输出电流的大小,最终控制发光单元发光的强度.实验结果表明,器件可提供02 mA的输出电流,其大小可驱动发光单元发光,工作电压（开启电压）为6 V.这种垂直集成方案,实现了器件多功能化,为有机发光二极管有源矩阵驱动的实际应用提供了一种新的解决方法. 关键词： 有机光发射晶体管 垂直 电容     

双轴压缩下颗粒物质剪切带的形成与发展

本文采用离散元方法,研究了双轴压缩的颗粒体系在刚性边界约束下,局部剪切带的形成和发展过程,注重分析了细观的体积分数、配位数、颗粒旋转角度等参数以及力链结构形态的演变.并从颗粒体系jamming 相图中J点附近的边壁压强和配位数随体积分数的标度规律出发,分析了剪切带内外的体积分数和配位数的变化.结果表明:剪切带形成于颗粒体系的塑性变形开始阶段,此时体系发生剪胀,颗粒体积分数减小,颗粒体系抵抗旋转的能力降低,开始出现细小剪切带,随着轴向应变的继续,细小剪切带发生连接,最终导致贯穿性优势剪切带形成 关键词： 颗粒物质 力链 双轴压缩 剪切带     

Separation of Macroamounts of Metal Pairs – Part 1. Separation of Cadmium and Cobalt

The separation factors of cadmium and cobalt were performed on varying cadmium, zinc and cobalt concentrations in the original aqueous solution. A long chain amine (Amberlite LA-2) and an organophosphorus solvent (TBP) have been investigated. In most cases the values of the separation factor increases with the increase of metal concentration in the aqueous phase. The various possibilities of chemical and radiochemical separations of the metal pair are reported.     

Untersuchungen zum Verhalten der Pt-Metalle gegenüber festen und flüssigen Kationenaustauschern mit Hilfe der Radiotracermethode

Mit Hilfe radioaktiver Nuklide wurde die Aufnahme der Pt-Metalle aus chloridhaltigen Lösungen sowoht durch feste (Wofatit KPS) als auch durch flüssige Kationenaustauscher (Bis-2-äthylhexylphosphorsäure) bei Variation des pH-Wertes, der Vorbehandlung sowie der Edelmetallkonzentration bestimmt. Pt und Ir wurden nur geringfügig, Pd und Rh dagegen deutlich stärker adsorbiert. Beide Austauschertypen zeigten qualitativ das gleiche Verhalten. Die gefundenen Abhängigkeiten der Adsorption wurden auf das komplexchemische Verhalten der Pt-Metalle zurückgeführt. Es werden Verfahren zur schnellen radiochemischen Reinigung der benutzten Nuklide angegeben.     

Synthesis of two dihydropyrroloindoledione‐based copolymers for organic electronics

Two novel dihydropyrroloindoledione (DPID)‐based copolymers have been synthesized in a two directional approach and characterized (gel permeation chromatography (GPC), ultraviolet‐visible (UV–vis), cyclic voltammetry, and computational models). These planar, broad absorption copolymers show promise for use in organic electronics, with deep energy levels and low bandgaps. The two‐directional Knoevenagel condensation used demonstrates the versatility of DPID as a useful yet underexploited conjugated unit. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Flexible active matrix addressed displays manufactured by printing and coating techniques

A flexible electrochromic active matrix addressed display, including 8 × 8 pixels, is demonstrated by using solution processing based on standard printing and coating manufacturing techniques. Each organic electrochromic display (OECD) pixel and its corresponding organic electrochemical transistor (OECT) are located on different sides of the flexible PET substrate. Electronic vias generated through the plastic substrate connects each OECD pixel with one addressing OECT. When comparing this display with actively addressed OECDs with all its components located on the same side, the present approach based on this electronic via substrate provides an enhanced pixel resolution and a relatively more simplified manufacturing process. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012     

高效液相色谱法同时测定生物质乳酸发酵液中有机酸及糖类化合物

建立了高效液相色谱(HPLC)同时测定生物质乳酸发酵液中有机酸及糖类的分析方法。使用Bio-Rad Aminex HPX-87H色谱柱,以5 mmol/L的H2SO4为流动相,在柱温55 ℃,流速0.6 mL/min条件下,采用示差折光检测器进行检测。结果表明,该方法可在17 min内实现发酵液中各种有机酸和糖类化合物等的完全分离与定量,6种有机酸和3种糖类化合物在0.15～5.19 g/L范围内的线性关系良好,回归方程的线性相关系数在0.9998以上。将该法用于米根霉发酵液的检测,两个水平的加标回收率为96.91%～103.11%,相对标准偏差(n=6)为0.81%～4.61%。该法适用于微生物发酵液中多种有机酸和糖类的快速、高效分离和定量测定。     

中德化学启蒙教材有机内容比较

就化学启蒙教育阶段有机化学教学内容,将德国的《今日化学SⅠ》、国内的沪教版、人教版、鲁教版4套教材,从知识内容的选取、组织呈现等角度进行了比较,并在实验设计、作业设计、拓展学习3方面向教材编写和教学实践提出了建议。