茚三酮缩7-氨基-8-羟基喹啉-5-磺酸催化荧光测定痕量钒(Ⅴ)及其催化反应机理

合成了新型席夫碱类试剂茚三酮缩7－氨基－8－羟基喹啉－5－磺酸，建立了该试剂催化荧光测定痕量钒（Ⅴ）的新体系，反应在盐酸体系中进行，其λex／λm为325／448（nm），钒（Ⅴ）的量在0～40．0μg／L、40.0～160．0μg／L呈良好线性关系，检测下限为1.7μg／L，方法用于水样痕量钒的测定，结果令人满意。此外，还详细探讨了反应机理和动力学方程。     

Phase-field modeling of wetting on structured surfaces

We study the dynamics and equilibrium profile shapes of contact lines for wetting in the case of a spatially inhomogeneous solid wall with stripe defects. Using a phase-field model with conserved dynamics, we first numerically determine the contact line behavior in the case of a stripe defect of varying widths. For narrow defects, we find that the maximum distortion of the contact line and the healing length is related to the defect width, while for wide defects, it saturates to constant values. This behavior is in quantitative agreement with the experimental data. In addition, we examine the shape of the contact line between two stripe defects as a function of their separation. Using the phase-field model, we also analytically estimate the contact line configuration and find good qualitative agreement with the numerical results.     

水杨醛缩7-氨基-8-羟基喹啉-5-磺酸催化荧光法测定痕量钒(Ⅴ)

水杨醛缩7-氨基-8-羟基喹啉-5-磺酸（简称S7N8Q5S）在酸性介质中分解，产物呈现荧光，V（V）对该反应具有催化作用，本文建立了催化荧光法测定痕量钒的新方法。体系在PH=2的柠檬酸钠-盐酸缓冲溶液中，λex／λem=342／499（nm）。测定V（V）的最佳反应条件为0.04％S7NSQ5S5.0mL，5％KBrO35．0mL，缓冲溶液5．0mL，90℃加热5min。V（V）含量在12.0～40.0μg／L的范围内有良好的线性。将该方法用于钒铬钢样品及水样中痕量钒的测定，结果满意。本文还详细探讨了反应机理。     

CNTs-Pt甲醛传感器和CNTs-Au葡萄糖传感器的研究

采用化学气相沉积(CVD)技术,通过CH₄裂解法制备了碳纳米管(CNTs)。使用旋转圆盘处理机(SDP)自组装技术,将纳米Pt和纳米Au电沉积在CNTs上对其进行修饰。随后,通过将铂粒子电化学沉积在CNTs修饰的玻碳电极(GCE)上以及利用静电效应将葡萄糖氧化酶固定在金电极上,制备了CNTs-Pt/GCE和CNTs-Au修饰电极。最后,使用循环伏安法(CV)研究了葡萄糖在CNTs-Au和甲醛在CNTs-Pt/GCE上的电化学性能。结果表明,由于纳米金粒子与CNTs可以有效地增加电极的比表面积提高其电子转移速率,因此,CNTs-Au生物传感器具有良好的重复性、稳定性和快速的葡萄糖检测响应,可用于临床血清葡萄糖浓度的检测。另外,由于Pt的高度分散和CNTs与Pt的协同作用增强了电极表面的活性位点,使得CNTs-Pt/GCE在甲醛的检测过程中展现出了较高的灵敏度和良好的重现性。     

Study of coals by high resolution solid state nuclear magnetic resonance

By using high resolution solid state nuclear magnetic resonance method, six coal samples coming from four countries were investigated. Twelve structural parameters of these samples were measured and compared withthose of Chinese coals. Spectral editing experiment was carried out and¹⁵N NMR spectrum was obtained. Project supported by the National Natural Science Foundation of China (Grant No. 19774068)and the NEDO’s International Joint Research Program of Japan.     

Pseudo-Anosov Mapping Classes and Their Representations by Products of Two Dehn Twists

Let S be a Riemann surface of analytically finite type （p, n） with 3p-3＋n 〉 0. Let a ∈ S and S = S - {a}. In this article, the author studies those pseudo-Anosov maps on S that are isotopic to the identity on S and can be represented by products of Dehn twists. It is also proved that for any pseudo-Anosov map f of S isotopic to the identity on S, there are infinitely many pseudo-Anosov maps F on S - {b} = S - {a, b}, where b is a point on S, such that F is isotopic to f on S as b is filled in.     

温度对Hβ分子筛催化剂结炭影响的13C CP/MAS NMR研究

对Hβ分子筛催化苯胺烷基化反应中结炭随反应温度变化的TG DTA和¹³CCP/MASNMR研究表明,结炭的主要组成为缩聚芳烃化合物及少量烯烃.随反应温度的升高,结炭量增大,脂肪烃含量减少,芳烃含量增加.当反应温度达到500℃时,焦炭的主要组成为稠环芳烃.     

NMR invisible" aluminum species in dealuminated mordenite zeolite:a ~1H/~(27)Al TRAPDOR NMR study

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用高分辨核磁共振氢谱观测细胞代谢和氧含量的关系

生命现象只有通过完整的机体才能体现，如细胞的特性和功能只有当它以完整的细胞存在时材鼙硐殖隼矗执暮舜殴舱癯上螅ˋlRI）已接近一般细胞尺度的分辨水平，为研究生命现提供了重要的手段·此外高分辨液体核磁共振（NA4R）在活细胞研究中的应用已有许多报导'］，例如通过