CO和SCN~-在高分散Pt及Pd表面异常红外光学行为的电化学现场FTIR反射光谱研究

在玻碳基底上沉积Pt和Pd，在以CO和SCN-为探针分子的电化学现场FTIR反射光谱研究中，首次观察到异常红外光学行为，其中包括吸附物种的谱带方向倒反以及谱峰强度显著增强等．     

碳氢化合物、醛、酮和硫醇的定量结构-色谱保留指数相关性研究

采用平衡电负性和相对化学键长对传统距离矩阵进行修正,构建新拓扑指数Nt。结合路径数,建立碳氢化合物、醛、酮和硫醇等化合物在24种极性和非极性色谱柱上的定量结构-色谱保留指数关系(QSRR)模型,23种模型的相关系数大于0.99。模型经留n法交叉检验,显示出良好稳健性和预测能力。模型物理意义明确,表明色谱保留指数可用分子的大小、平衡电负性、支化度和形状等内在结构信息进行有效表征。模型经Needham公式分析,结果显示新指数Nt对保留指数影响最大。借助Hyperchem软件进行对比研究,结果表明拓扑化学法优于量子化学AM1法。     

On the Criteria of Instability for Electrochemical Systems

Both cyclic-voltammetry-based and impedance-based experimental criteria that have been developed recently for the oscillatory electrochemical systems are critically appraised with two typical categories of oscillators.Consistent conclusions can be drawn by the two criteria for the category of oscillators that involve the coupling of charge transfer mainly with surface steps(e.g.ad-and desorption)such as in the electrooxidation of C1 organic molecules.Whereas,impedance-based criterion is not applicable to the category of oscillators that involve the coupling of charge transfer mainly with mass transfer(e.g.diffusion and convection) such as in the Fe(CN)6^3- reduction accompanying periodic hydrogen evolution.The reason is that the negative impedance cannot include the feedback information of convection mass transfer induced by the hydrogen evolution.However,both positive and negative nonlinear feedbacks,i.e., the diffusion-limited depletion and convection-enhanced replenishment of the Fe(CN)6^3- surface concentration,that coexist between the bistability,i.e.,Fe(CN)6^3- reduction with and without hydrogen evolution at lower and higher potential sides respectively,are all reflected in the crossed cyclic voltammogram(CCV).It can be concluded that the voltammetry-based criterion(in time domain)is more intuitive,less time-consuming and has a wider range of applications than the impedancebased one (in frequency domain).     

一类自伴随Lubrication方程的对称,守恒律,拉格朗日函数和精确解

本文借助李对称分析研究了一类自伴随的Lubrication方程,此类方程可用来描述液体薄膜动力学行为.基于非奇异的局域守恒律乘子和李对称方法,我们系统地推导出了此类方程的局域守恒律,非局域相关系统,李对称和一些有趣的精确解.此模型的非局域相关系统在本文中被首次研究,可用于寻找原方程更丰富的解空间.此外,基于局域守恒律和变分原则,我们推导出原方程的四类拉格朗日函数.     

基于期望损失厌恶的供应链期权契约协调研究

以一个损失厌恶销售商与一个损失中性供应商组成的两级供应链为背景,利用期望损失厌恶理论对销售商在期权契约下的最优采购策略进行了研究,并证明了期望损失厌恶理论能有效克服传统基于前景理论的研究中因参考点外生且固定假设带来的弊端。在此基础上,进一步给出了供销双方在期权契约下实现协调共赢的条件,分析了销售商损失厌恶程度,期权契约价格等参数对供应链协调共赢机制的影响。结果显示:销售商的损失厌恶偏好并不会改变权利金分配整体供应链利润的作用,但会增强销售商分享收益的能力,改变供销双方利润或效用水平对权利金,产品销售价格和生产成本的敏感程度,且较高的损失厌恶偏好还会阻碍供销双方协调共赢目标的达成。     

基于异质预期的量子伯川德博弈复杂动力机制分析

针对伯川德双寡头垄断博弈经济系统中出现的混沌现象,利用量子博弈论,构建了基于有限理性与天真预期行为的量子伯川德动态博弈模型,分析了量子纠缠度对纳什均衡点稳定性及复杂动力行为的影响。结果表明:量子纠缠度能增强该系统的稳定性,企业价格调整速度达到某一程度时会导致该系统的复杂混沌特性,纠缠度可以有效控制混沌状态。最后利用数值模拟从分岔、最大李雅普诺夫指数、奇怪吸引子、初始条件敏感性及分数维数方面验证了理论准确性。     

PROPERTIES OF TEMPERATURE DEPENDENCE OF THRESHOLD IN PURE AND IMPUHITY-DOPED BLUE BRONZES

Temperature dependence of the threshold of pure and impurity-doped blue bronzes has been studied. It is found that for pare blue bronzes the threshold field near 100K has an anomalous peak, but for impurity-doped samples no anomaly is observed in the range of liquid nitrogen temperature, and the value of the threshold field gradu-ally increases with the decrease of temperature. The results show that in the high-quality pure blue bronzes, there may exist an incommensurate to quasi-commensurate transition near 100K. But for the impurity-doped or "dirty" pure samples, such an incommensurate to quasi-commensurate transition near 100K can be extensively re-strained by impurities or defects, which leads to a pure incommensurate CDW in a wide temperature range.     

一系列氢键诱导液晶复合物的合成及表征

以２－氰基－３－（４－（２－氯－３－甲基－１－丁酰氧基）－苯基丙烯酸（Ａ）为质子给体，Ｎ－（４－吡啶基亚甲基）－４－烷氧基苯胺（ｎＳＳＺ）为质子受体，合成了一系列新的氢键复和物，经红外光谱证实了分子间氢键的存在，通过ＤＳＣ，偏光方法及Ｘ射线衍射方法对其液晶行为进行研究，结果表明复合物呈现近晶相行为。     

稀土磷酸盐发光材料的微波合成

稀土磷酸盐发光材料的微波合成徐文国，田一光，刘淼，刘海堂，方光华，庞文琴（吉林大学化学系，环境科学系，长春，１３００２３）关键词微波合成，稀土磷酸盐，微晶玻璃，玻璃态，发光材料稀土磷酸盐发光材料的研究是当前材料科学的热门研究课题。它们一般通过高温固相...     

Electrooxidation Mechanism of Methanol at Pt-Ru Catalyst Modified GC Electrode in Electrolytes with Different pH Using Electrochemical and SERS Techniques

The electrochemical and in-situ surface-enhanced Raman spectroscopy （SERS） techniques were used to investigate the electrooxidation behavior of methanol in acidic, neutral and alkaline media at a Pt-Ru nanoparticle modified glassy carbon （Pt-Ru/GC） electrode. The results showed that methanol could be dissociated spontaneously at the Pt-Ru/GC electrode to produce a strongly adsorbed intermediate, CO. It was found that CO could be oxidized more easily in the alkaline medium than in the acidic and neutral media. The peak potential of methanol oxidation was shifted from 0.663 and 0.708 V in the acidic and neutral media to -0.030 V in the alkaline medium, which is due to that the adsorption strength of CO on the Pt surface in the alkaline medium is weaker than that in the acidic and neutral media. The final product of the methanol oxidation is CO2. However, in the alkaline medium, CO2 produced would form CO3^2- and HCO3^- resulting in the decrease in the alkaline concentration and then in the decrease in the performance of DMFC. Therefore, the performance of the alkaline DMFC is not Stable.