开放式声化学反应体系中的反应动力学

采用气液传质的双膜理论建立了开放体系中声化学反应的动力学模型，同时用声源频率为500 kHz，声强为3 W·cm^-2的超声波在开放式声化学反应器内引发被空气饱和溶解的KI纯水溶液中的声化学反应，并检测反应过程中溶液的电导率，pH值改变及KI溶液中I₂的析出量，结果表明，它们与超声辐照时间之间呈线性关系，与理论模型吻合。     

Multimodal Interfaces for Cell Phones and Mobile Technology

By modeling users' natural spoken and multimodal communication patterns, more powerful and highly reliable interfaces can be designed that support emerging mobile technology. In this paper, we highlight three different examples of research that is advancing state-of-the-art mobile technology. The first is the development of fusion-based multimodal systems, such as ones that combine speech and pen or touch input, which are substantially improving the robustness and stability of system recognition. The second is modeling of multimodal communication patterns to establish open-microphone engagement techniques that work in challenging multi-person mobile settings. The third is new approaches to adaptive processing, which are able to transparently guide user input to match system processing capabilities. All three research directions are contributing to the design of more reliable, usable, and commercially promising mobile systems of the future.     

X射线光电子能谱仪的开放使用与管理

X射线光电子能谱仪(XPS)是材料表面元素定性和半定量分析的重要手段之一,是表面分析科研工作的必备仪器.为提高测试效率,实施了大型仪器设备开放共享优化,总结了在推动XPS开放过程中管理的经验和体会.     

窄内径多孔层开管柱的制备及在液相色谱中的应用

近年来,微纳分离技术由于其内在的优势而受到越来越多的关注.多孔层开管柱是一种重要的微分离柱形式,与粗内径的多孔层开管柱(>25μm)相比,窄内径的多孔层开管柱具有更高的分离效率和更低的试剂消耗量.本文综述了内径≤25μm的窄内径多孔层开管毛细管柱的制备方法、与质谱检测联用技术以及在液相色谱中的应用研究进展,对其发展前景进行了展望.     

Polydopamine‐assisted immobilization of zeolitic imidazolate framework‐8 for open‐tubular capillary electrochromatography

In this work, we developed a capillary column modified with zeolitic imidazolate framework‐8 as a novel stationary phase for open‐tubular capillary electrochromatography. To immobilize zeolitic imidazolate framework‐8 onto the inner surface of silica capillary, a bio‐inspired polydopamine functionalization was used to functionalize the capillary surface with polydopamine. First, a polydopamine layer was assembled inside the capillary. Second, due to noncovalent adsorption and covalent reaction ability, polydopamine could attract and anchor zeolitic imidazolate framework‐8 onto the inner surface of capillary. It has been demonstrated that zeolitic imidazolate framework‐8 was successfully grafted on the inner wall of the capillary by scanning electron microscopy, and Fourier transform infrared spectroscopy. The electro‐osmotic flow characteristics of capillaries were also investigated by varying the pH value and acetonitrile content of mobile phase. The zeolitic imidazolate framework‐8 coating not only increased the phase ratio of open‐tubular column, but also improved the interactions between tested analytes and the stationary phase. Three groups of isomers including acidic, basic, and neutral compounds were well separated on the zeolitic imidazolate framework‐8 bonded column, with theoretic plate numbers up to 1.9 × 10⁵ N for catechol. The repeatability of the prepared columns was also studied, and the relative standard deviations for intra‐ and interday runs were less than 5%.     

Open tubular capillary column of 50 μm internal diameter with a very high separation efficiency for the separation of peptides in CEC and LC

A specially designed long open tubular capillary column (50 μm internal diameter and 112 cm effective length) was prepared by fabrication of a thin three‐component co‐polymer layer on the inner surface of silica capillary. A pretreated silica capillary was reacted with 4‐(chloromethyl)phenyl isocyanate in the presence of dibutyltin dichloride as catalyst followed by sodium diethyl dithiocarbamate. Then a thin polymer layer was made on the inner surface of capillary by reversible addition‐fragmentation transfer polymerization of styrene, N‐phenylacrylamide, and methacrylic acid. A carefully adjusted formulation of reaction mixture and elaborated procedures were adopted to secure formation of the co‐polymer layer of enhanced separation performance. The co‐polymer immobilized open tubular capillary column was used for the separation of a synthetic mixture of five peptides and excellent separation efficiency (over 1.7 million per column) was obtained in the capillary electrochromatography mode. Such excellent separation efficiencies of ca. 1 m column have not been obtained in the isocratic elution mode so far. The column was also used for separation of the peptides in the liquid chromatography mode to show very good separation efficiency (average 286 700 per column).     

An Open‐Circuit Voltage and Power Conversion Efficiency Study of Fullerene Ternary Organic Solar Cells Based on Oligomer/Oligomer and Oligomer/Polymer

Variations in the open‐circuit voltage (V _oc) of ternary organic solar cells are systematically investigated. The initial study of these devices consists of two electron‐donating oligomers, S2 (two units) and S7 (seven units), and the electron‐accepting [6,6]‐phenyl C71 butyric acid methyl ester (PC₇₁BM) and reveals that the V _oc is continuously tunable due to the changing energy of the charge transfer state (E _ct) of the active layers. Further investigation suggests that V _oc is also continuously tunable upon change in E _ct in a ternary blend system that consists of S2 and its corresponding polymer (P11):PC₇₁BM. It is interesting to note that higher power conversion efficiencies can be obtained for both S2:S7:PC₇₁BM and S2:P11:PC₇₁BM ternary systems compared with their binary systems, which can be ascribed to an improved V _oc due to the higher E _ct and an improved fill factor due to the improved film morphology upon the incorporation of S2. These findings provide a new guideline for the future design of conjugated polymers for achieving higher performance of ternary organic solar cells.

     

Analysis of compounds of environmental concern: II. Diphenyl ethers

Nineteen halogenated and/or nitrated diphenyl ethers (currently listed in EPA Method 8111) have been separated on a DB-5/ DB-1701 column pair connected to an inlet splitter and separate electron capture detectors. Retention times are included for 10 additional compounds evaluated for their suitability as internal standards or surrogate compounds for incorporation into Method 8111. Method reproducibility and linearity are discussed, and results are presented for extracts of two real samples spiked with the 19 diphenyl ethers and analyzed using the dual-column dual-detector arrangement.     

绿色氧化法制备联苯类化合物的研究性实验设计与实践*

以苯甲醛和丙酮为原料,利用Robinson增环反应先制备3-甲基-5-苯基环己-2-烯-1-酮,再引导学生设计并研究了水相绿色氧化3-甲基-5-苯基环己-2-烯-1-酮合成联苯类化合物3-乙氧基-5-甲基-1,1′-联苯的影响因素,利用核磁共振确定了产物结构。该研究性实验教学以绿色化学为中心,结合了2步连续反应,产物易提纯且产率高,并开展了开放式大型分析仪器教学和测试,对学生有机合成实验能力和科学研究能力的培养具有很好的教学效果。     

新型聚合物多孔涂层毛细管开管柱的制备及电色谱研究

以甲基丙烯酸缩水甘油酯(GMA)和乙二醇二甲基丙烯酸酯(EDMA)为前驱体制备了新型聚合物多孔涂层毛细管开管(PLOT)柱固定相。通过优化聚合反应时间、致孔剂比例及交联剂比例获得了色谱性能良好的PLOT柱,扫描电镜结果显示毛细管柱内的多孔涂层厚度适中且均匀。在毛细管电色谱模式下,PLOT柱以反相色谱分离机理有效分离了中性、酸性和碱性小分子。人血清白蛋白(HSA)共价结合的蛋白亲和PLOT柱对5对手性对映体实现了较好的分离,且其分离度远高于HSA修饰的单层聚合物毛细管开管柱。PLOT柱分离烷基苯的日内、日间和柱间的相对标准偏差分别小于1.7%、4.8%和7.8%。