壳聚糖电流变体的导电特性

电流变体是由高介电颗粒分散在低介电油相中组成的悬浮液,在电场作用下,其表观粘度急剧增大甚至发生固化,这种转变过程速度快（达毫秒级）而且是可逆的［１］．由于这种独特的电场响应性,电流变体有广阔的工程应用前景．但电流变体在显示电流变效应的同时也表现出复杂...     

Cyclotron Resonance of an Interface Magnetopolaron at Finite Temperatures

Taking into account the interaction of an electron with both bulk longitudinal-optical (LO) and interface-optical (IO) phonons, the cyclotron resonance of an interface magnetopolaron at finite temperatures is investigated by using the generalized Larsen perturbation-theory method. It is shown that the absorption and emission resonance must be considered at the same time at finite temperatures. The results also show the important role played by the electron-IO phonon interaction. For the GaAa/GaSb structure, splitting of the cyclotron resonance spectrum and temperature dependence of the threefold splitting cyclotron resonance mass of the magnetopolaron in the resonant magnetic field region are studied.     

BASIC EQUATIONS, THEORY AND PRINCIPLE OF COMPUTATIONAL STOCK MARKET (Ⅲ)-BASIC THEORIES

By basic equations, two basic theories are presented: 1. Theory of stock’s value v^*(t)=v^*(0) exp (ar₂^*t);2. Theory of conservation of stock’s energy. Let stock’s energy Φbe defined as a quadratic function of stock’s price v and its derivative v, Φ=Av²+Bv+Cv²+Dv, under the constraint of basic equation, the problem was reduced to a problem of constrained optimization along optimal path. Using Lagrange multiplier and Euler equation of variation method, it can be proved that Φkeeps conservation for any v,v. The application of these equations and theories on judgement and analysis of tendency of stock market are given, and the judgement is checked to be correct by the recorded tendency of Shenzhen and Shanghai stock markets.     

The Tafel–Heyrovsky route in the kinetic mechanism of the hydrogen evolution reaction

The examination of the dependence of surface coverage on overpotential for the kinetic mechanism of the hydrogen evolution reaction (HER) through the Volmer–Heyrovsky route shows that, under certain conditions, the Tafel re-adsorption can be produced. On this basis, the HER could be described with the contribution of Tafel and Heyrovsky elementary steps. The present communication derives and analyses the kinetic mechanism of the HER for the Tafel–Heyrovsky route, under Frumkin adsorption conditions.     

域外奇源分布法场点解的唯一性

应用奇源解的核函数沿距离递减的条件和积分不等式,可证这类奇源在凸域外分布只要满足以它产生的响应来表达的边界条件时,所引起相应的域内场点解是唯一的。文中给出这类奇源的部分例子,如Kelvin的点力,点圆力偶(PRC)等。并给出PRC分布解回转体扭转问题的场点解的唯一性证明作为应用例。     

Resonant Frequency of Impurity Polaron in a Quantum Well

It is shown that the resonant frequency ω_c^* of a magnetopolaron bound to a Coulomb impurity in a GaAs/Ga_1-xAl_x AS quantum well is lower than that oflongitudinal optical (LO) phonons owing to the effect of the Coulomb potential. Using MacDonald method to treat the Coulomb potential we come to the conclusion that ω_c^* is really below the frequency of LO phonons but not "pinning" at a frequency near that of TO phonons.     

Solar cells sensitized by porphyrin dyes containing a substituted carbazole donor with synergistically extended absorption and suppressed the dye aggregation

To achieve high power conversion efficiency (PCE), three porphyrin sensitizers have been synthesized and explored to simultaneously enhance the photocurrent (J_sc) and photovoltage (V_oc). On basis of the XW4, a benzothiadiazole (BTD) unit has been introduced to afford XW57 with the aim to extend the absorption wavelength and enhance the light harvesting ability. As a result, a J_sc of 13.72 mA/cm² has been obtained for XW57, higher than that of XW4. On this basis, XW58 has been prepared by modifying the carbazole-based donor with two bulky dihexyloxyphenyl groups, and the superior anti-aggregation character raises the V_oc from 781 mV (XW4) to 844 mV. When both the BTD unit and the bulky groups are introduced to the acceptor and donor units, respectively, the resulting sensitizer XW59 exhibits a highest PCE value of 7.34% with synergistically enhanced J_sc of 13.19 mA/cm² and V_oc of 793 mV. These results provide further insight into developing high performance dye-sensitized solar cells     

织构深度对不锈钢表面油润滑条件下摩擦学性能影响的试验和仿真研究

采用激光加工技术在不锈钢表面构造深度不同的沟槽型织构图案，通过UMT摩擦磨损试验机测试了不同织构深度的不锈钢表面在PAO6油润滑条件下的摩擦磨损性能，利用表面轮廓仪和扫描电镜(SEM)对摩擦前后的沟槽形貌进行表征分析，采用计算流体动力学(CFD)方法对试验进行模拟并计算，结合ANSYS Fluent软件模拟分析结果，探究了沟槽织构深度对不锈钢表面在油润滑条件下的摩擦学性能的影响机理. 研究结果表明:加工的沟槽织构及其织构深度显著影响不锈钢表面在PAO油润滑条件下的摩擦磨损行为，织构深度为10 μm的不锈钢表面获得最好的抗磨和减摩效果，与未织构表面相比，其摩擦系数与磨痕宽度降低了60%以上. 这主要是由于织构深度为10 μm的不锈钢表面在摩擦过程中，润滑油通过其收敛区域时产生了很好的楔效应，润滑油产生的升力较大，改善了该织构表面在摩擦过程的润滑状态，从而呈现很好的摩擦学性能.      

Effective enhancement of the emission efficiency of tetraphenylporphyrin in solid state by tetraphenylethene modification

Evidently enhanced red emission efficiency from the solid state of tetraphenylporphyrin derivative was achieved by modification with tetraphenylethene units.     

Hexabenzocoronene Graphitic Nanocoils Appended with Crown Ethers: Supramolecular Chirality Induced by Host–Guest Interaction

We have designed and synthesized two new achiral hexa-peri-hexabenzocoronene (HBC) derivatives, HBC^CE and HBC^TEG-CE , which bear the crown ether as the pendant for the amino acid binding site. The HBC^CE self-assembled into a racemic mixture of P- and M-handed helical nanocoils, however, in the presence of chiral amino acid guests, it formed helical nanocoils with one-handed screw sense. The effects of the concentration, type and configuration of the guests on the induced circular dichroism (ICD) during the co-assembly of HBC^CE with chiral amino acids were also investigated. Additionally, after complete removal of the chiral guests, the optically active nanocoils did not racemize, even in the presence of excess amino acids with the opposite configuration. In contrast, HBC^TEG-CE with a long triethylene glycol (TEG) chain between the crown ether group and the HBC unit did not exhibit ICD during the co-assembly with chiral amino acids.