Materials and Methods

Materials and Methods Synthesis of thionyl chloride-activated succinamidopropyl-glass beads     

Determination of sulfur dioxide in vitriol plant wastewater by using a polyNiMe4TAA electrochemically modified Pt microelectrode

A Pt microelectrode modified with nickel(II) polytetramethyldibenzo[b,i]tetraaza[14]annulene was prepared by electropolymerization of nickel(II) tetramethyldibenzo[b,i]tetraaza[14]annulene monomers and applied to determine sulfur dioxide in vitriol plant wastewater. For determination of SO2 with this electrochemically modified Pt microelectrode, the linear range was from 9.6 x 10(-6) to 2.4 x 10(-4) mol L-1, the sensitivity was 1.8 x 10(-4) A L mol-1, the detection limit was calculated to be 4.8 x 10(-6) mol L-1 (S/N = 3), the response time was less than 20 s and the relative standard deviation was found to be 2.1% on analyzing 4.8 x 10(-5) mol L-1 SO2 solution repeatedly (n = 7). These results demonstrated good accuracy compared with those obtained by the conventional iodimetric method.     

Simultaneous determination of p-hydroxybenzaldehyde, p-hydroxybenzyl alcohol, 4-(beta-D-glucopyranosyloxy)-benzyl alcohol, and sugars in Gastrodia elata blume measured as their acetylated derivatives by GC-MS

A method for the simultaneous separation and determination of the active constituents and three sugars in the roots of Gastrodia elata Blume (GE), which is used as a famous Chinese traditional herbal medicine, by gas chromatography-mass spectrometry is established. The samples are acetylated with pyridine-acetic anhydride. The contents of 4-hydroxybenzaldehyde, 4-hydroxybenzyl alcohol (HA), fructose, glucose, 4-(beta-D-glucopyranosyloxy)-benzyl alcohol (GA), and sucrose in GE are 0.004%, 0.03%, 1.36%, 1.12%, 1.97%, and 4.25%, respectively, and the detection limits are 1.5, 3.0, 11.0, 5.0, 33.0, and 35.0 pg, respectively. The contents of HA and GA in the urine and brain of a mouse are also determined. This method is simple, reliable, and quick for the simultaneous determination of the active constituents and sugars in GE.     

The uranium-Xylidyl Blue I complex and its application in linear sweep polarography

The linear sweep polarographic wave of the uranium-Xylidyl Blue I complex in ethylenediamine-1,10-phenanthroline-hydrochloric acid medium has been studied. The complex, corresponding to UO(2)(XBI)(2-)(2) with log beta' = 9.09 (by polarography), 8.81 (by spectrophotometry), is strongly adsorbed on the surface of the mercury electrode. The polarographic wave is attributed to the reduction of Xylidyl Blue I in the complex. The method is very sensitive with a detection limit of 3 x 10(-8)M. The wave height is proportional to the concentration of uranium over the range 8 x 10(-8)-7 x 10(-6)M. Solvent extraction is used to separate possible interferences. The recommended procedure has been applied to the determination of trace amounts of uranium in ores.     

Preparation and application of selenite ion selective electrode

A new selenite ion selective electrode using 4,6-dibromopiaselenole as active material, PVC as membrane matrix and dibutyl phthalate as plasticizer has been developed. An analytically useful potential change occurs from about 10(-6)-10(-1)M Se(IV), and the slope of the linear portion is -23.6 mV/10-fold change in Se(IV) concentration at a temperature of 21 degrees . The electrode shows fairly good selectivity for selenite ion over other anions and has been used for the successful determination of total selenium in human hair.     

Relationship between the molybdenum phases and the conversion of n-butane over Mo/HZSM-5

The conversion of n-C₄H₁₀ was undertaken on MoO₃/HZSM-5 catalyst at 773–973 K and the phases of molybdenum species were detected by XRD. The XRD results show that bulk MoO₃ on HZSM-5 can be readily reduced by n-C₄H₁₀ to MoO₂ at 773 K and MoO₂ can be gradually carburized to molybdenum carbide above 813 K. The molybdenum carbide formed from the carburization of MoO₂ with n-C₄H₁₀ below 893 K is -MoC_1−x with fcc-structure, while hcp-molybdenum carbide formed above 933 K. During the evolution of MoO₃ to MoO₂ (>773 K) or the carburization of MoO₂ to molybdenum carbide (>813 K), deep oxidation, cracking and coke deposition are serious, in particular at higher reaction temperatures, these lead to the poor selectivity to aromatics. Aromatization of n-C₄H₁₀ can proceed catalytically on both Mo₂C/HZSM-5 and MoO₂/HZSM-5, the distribution of the products for the two catalysts is similar below 813 K, but the activity for Mo₂C/HZSM-5 is much higher than that for MoO₂/HZSM-5.     

Matrix Effects and Behaviors of Elements in Oxalic Acid Medium by Inductively Coupled Plasma Mass Spectrometry

Because of its high sensitivity, wide dynamic range and relative freedom from interferences, inductively coupled plasma mass spectrometry (ICP-MS) has been developed for the determination of trace and ultra-trace levels of elements in various fields1. Due…     

Fluoro-substituted DPP-bisthiophene conjugated polymer with azides in the side chains as ambipolar semiconductor and photoresist

Photoresists are essential for the fabrication of flexible electronics through all-photolithographic processes. Single component semiconducting photoresist exhibits both semiconducting and photo-patterning properties, and as a result, the device fabrication process can be simplified. However, the design of semiconducting polymeric photoresist with ambipolar semiconducting property remains challenging. In this paper, we report a single component semiconducting photoresist (PFDPPF4T-N₃) by incorporating azide groups and noncovalent conformation locks into the side alkyl chains and conjugated backbones of a diketopyrrolopyrrole-based conjugated polymer, respectively. The results reveal that PFDPP4FT-N₃ exhibits ambipolar semiconducting property with hole and electron mobilities up to 1.12 and 1.17 cm² V^?1 s^?1, respectively. Moreover, field effect transistors with the individual photo-patterned thin films of PFDPPF4T-N₃ also show ambipolar semiconducting behavior with hole and electron mobilities up to 0.66 and 0.80 cm² V^?1 s^?1, respectively. These results offer a simple yet effective design strategy for high-performance single component semiconducting photoresists, which hold great potential for flexible electronics processed by all photolithography.

     

特征线法在求解非线性液相吸附色谱模型中的应用

本文应用特征线法求解非线性液相吸附色谱分离过程模型，论述了特征线法的原理和步骤，讨论了时间步长和空间步长对模型数值解的影响，并用色谱分离甘露醇和山梨醇以及分离蔗糖和还原糖的实验进行验证，用特征线法计算的理论流出曲线与实验流出线吻合较好。本文还分折了模型中各个参数的灵敏度，结果表明：吸附等温方程Q＝Ci*／（ai＋biCi*）中参数ai比参数bi以及总传质系数ki有更高的灵敏度。     

大鼠脑组织中不同部位单胺类神经递质含量的HPLC测定

单胺类神经递质,多巴胺(DA)、去甲肾上腺素(NA)和肾上腺素(A)是哺乳动物和人类中枢重要的信息传递物质。了解脑组织中各部位单胺类神经递质的含量对于研究其生理功能、有关疾病的诊断和药物及手术疗效的评价均有重要的意义。