过氧化聚吡咯膜修饰电极色谱电化学用于帕金森试验动物的研究

研制了一种新型的过氧化聚吡咯膜修饰电极（OPPy/CME)作为液相色谱电化学检测器,该电极可以用来检测生物体内的单胺类神经递质及其代谢产物。用药物建立了帕金森动物试验模型,对不同情况下的试验动物脑内单胺类神经递质及其代谢产物通过微渗析取样和液相色谱电化学检测联用技术进行了测定。初步探讨了试验动物产生帕金森病的机理,为研制和筛选更有效的治疗帕金森病的新药提供了一种准确、可靠的分析手段。     

三维编织CMC的弯曲断裂研究

从界面断裂的角度出发，对三维编织CMC的断裂作了理论研究和数值分析，对于三点弯曲试件，通过数值拟合修正了能量释放率G的理论表达式中的自由常数A，同时也研究了材料的各个参变量对于断裂韧性的影响，由此得出了一个基本完善的三点弯曲试件断裂韧性G的理论公式，该能量释放率方法可以应用于单试件的试验计算，与断裂韧性的柔度标定方法相比，该方法一方面可以减少试验件数量；另一方面，试验结果显示出在试件切口尺雨处于0．4≤a/W≤0.5时，可以获得比较稳定的断裂韧性值。     

Electrochemical Determination of Phenylethanolamine A Based on Nafion/MWCNTs/AuNPs Modified Carbon Electrode

Phenylethanolamine A (PEA), a β‐agonist, was found to be illegally used as a growth promoter in pigs last year, causing Chinese government's great attention. Here, a sensitive electrochemical method was developed for detecting PEA by immobilization of gold nanoparticles (AuNPs), multiwalled carbon nanotubes (MWCNTs) and Nafion on the surface of a glassy carbon electrode (GCE). The Nafion/MWCNTs/AuNPs film was characterized by scanning electronic micrographs (SEM) and electrochemical impedance spectroscopy (EIS). The electrochemical behaviors of PEA at the modified GCE were investigated in detail. The synergetic effects of AuNPs, MWCNTs and Nafion amplify the electrochemical reduction signal of PEA, and result in high sensitivity for PEA determination. Under the optimal conditions, the electrochemical sensor shows a wide linear range of 0.01 to 10 (mol/L with a detection limit of 0.005 µmol/L. Moreover, the fabricated sensor presents high selectivity and long‐term stability, which paves a new way for simple, rapid, sensitive detection of PEA.     

Structural, elastic and electronic properties of transition metal carbides TMC (TM=Ti, Zr, Hf and Ta) from first-principles calculations

The structural, elastic and electronic properties of TiC, ZrC, HfC and TaC have been investigated by first-principles calculations using the plane-wave pseudopotential method. Different exchange-correlation functionals regarding the local density approximation and the PBE, RPBE and PW91 forms of generalized gradient approximation are taken into account. The NaCl-type cubic structures of TMC (TM=Ti, Zr, Hf and Ta) are optimized and confirmed to be mechanically stable. The elastic properties such as the elastic constants, bulk modulus, shear modulus, Young’s modulus and Poisson’s ratio of TMC are investigated, and the performances of LDA and GGA are discussed. The electronic density of state, electron charge density and Mulliken population analysis have been explored to discuss the electronic properties and bonding behaviors of TMC. The present calculation results compare satisfactorily with the experimental data and previous theoretical calculations.     

组合拓扑方法在组合学和图论中的应用

本文介绍组合拓扑方法在图论和组合学中的应用，探索一些新的离散问题和连续问题的关系，介绍目前有关这方面的新结果及发展动向。本文主要介绍同调理论在图论中的应用，与图有关的复形及性质，不动点定理在离散问题中的应用等。文中提出了一些新结果及可供研究的新问题。     

关于Whitney和Tutte猜想

ｗｈｉｔｎｅｙ和Ｔｕｔｔｅ把平面四色问题化为只与圈上的４染色集有关的问题来研究，从而探讨四色问题的理论证明；提出了一个蕴含着四色定理的猜想。本文研究开集的组合不变性，从而证明Ｗｈｉｔｎｅｙ和Ｔｕｔｔｅ的猜想不成立。     

Effect of composition on the glass-forming tendency of barium aluminosilicate gels derived from metal alkoxides

The effect of composition on the glass-forming tendency of barium aluminosilicate gels derived from metal alkoxides with compositions near the theoretical composition of barium feldspar was studied. Results indicated that, in the experimental range, larger SiO₂ content and larger BaO/Al₂O₃ ratio were advantageous to glass formation. A criterion for glass formation in the studied system was established as (b+3−4y)/(2y+s(1+b)/(100−s))<J_c, where b is the BaO/Al₂O₃ ratio, s the mol percentage of SiO₂, y the fraction of four-coordinated aluminum over the total amount of aluminum, and J_c is a constant for a definite experimental condition. The criterion showed good fitness with the experimental results.     

TNT determination based on its degradation by immobilized HRP with electrochemical sensor

Based on the mechanism of 2,4,6-Trinitrotoluene (TNT) degradation, an amperometric hydrogen peroxide biosensor was constructed for the determination of trace amounts of TNT by immobilization of MWCNTs, HRP and Nafion onto the surface of glassy carbon electrode (GCE). The Nafion/MWCNTs/HRP biosensor was capable of degrading TNT with the consumption of H₂O₂ and HRP in 0.2 mol/L PBS (pH 7.0). Trace TNT was quantitative analyzed by the current decrease of H₂O₂ at the reductive potential of −0.35 V using cyclic voltammetry (CV). Effect of the ratio of MWCNTs/HRP, initial concentration of H₂O₂ and electrolyte’s pH were also optimized by CV. Under the optimal conditions, the current decrease of H₂O₂ that was consumed by TNT degradation was proportional to TNT ranging from 8.8 × 10⁻⁹ mol/L to 2.64 × 10⁻⁷ mol/L with a detection limit of 3.0 × 10⁻⁹ mol/L (S/N = 3). It developed a new way for simple, rapid and sensitive measurement of trace TNT.     

LC with Novel Electrochemical Detection for Analysis of Monoamine Neurotransmitters in Rat Brain After Administration of (R)-Salsolinol and (R)-N-Methylsalsolinol

A novel electrochemical detector with an acetylcholine film has been developed for HPLC. The chemically modified electrode is an efficient electrocatalyst of (R)-salsolinol ((R)-Sal), (R)-N-methylsalsolinol ((R)-NMSal), and monoamine neurotransmitters, enabling highly sensitive detection. The electrode is also stable and long-lived. Combined with microdialysis sampling, HPLC with the novel detector enabled successful study of changes in the concentrations of monoamine neurotransmitters in rat brain after the injection of (R)-salsolinol and (R)-N-methylsalsolinol.     

3-甲基邻苯二酚/糠胺型聚苯并噁嗪的制备与性能

通过分子设计合成了含有酚羟基的3-甲基邻苯二酚/糠胺型苯并噁嗪(M-f). 通过差示扫描量热法(DSC)测得M-f的放热峰值温度(T_p)为172 ℃, 而间甲酚/糠胺型苯并噁嗪(MC-f)的T_p为244 ℃, 表明酚羟基的引入有利于降低苯并噁嗪的开环固化温度. 通过非等温DSC法研究2种苯并噁嗪单体的固化动力学, Kissinger法和Ozawa法的计算结果均表明M-f的表观活化能低于MC-f. 此外, 通过拉伸剪切强度测试考察了聚苯并噁嗪对于金属基材的黏附性能, M-f聚合物对于铝和低碳钢基材的拉伸剪切强度分别为2.53 MPa和3.09 MPa, 均高于MC-f聚合物.