Hyperpolarizabilities for the one-dimensional infinite single-electron periodic systems. II. Dipole-dipole versus current-current correlations

Based on Takayama-Lin-Liu-Maki model, analytical expressions for the third-harmonic generation, dc Kerr effect, dc-induced second-harmonic optical Kerr effect, optical Kerr effect or intensity-dependent index of refraction, and dc-electric-field-induced optical rectification are derived under the static current-current (J0J0) correlation for one-dimensional infinite chains. The results of hyperpolarizabilities under J0J0 correlation are then compared with those obtained using the dipole-dipole correlation. The comparison shows that the conventional J0J0 correlation, albeit quite successful for the linear case, is incorrect for studying the nonlinear optical properties of periodic systems.     

Effect of solvent composition on free release static coating of capillary columns

Summary Three aspects with respect to the selection of solvents for static coating of capillary columns, i.e. coating speed, occurrence of bumping and solubility of stationary phases are discussed. Hypotheses are proposed in an attempt to explain the observed facts that mixed solvents result in much higher coating speeds than those obtained from pure solvents, that a proper choice of solvents together with a good and uniform deactivitation of the column inner wall is needed to prevent bumping. Stationary phase solubility vs. solvent composition is also briefly discussed.     

Direct STM investigation of cinchona alkaloid adsorption on Cu(III)

Scanning tunneling microscopy (STM) combined with cyclic voltammetry has been employed to investigate the adsorption of cinchonine on Cu(111). Similar to cinchonidine, cinchonine forms a long-range ordered adlayer with (4 x 4) symmetry on the substrate. The structural details on molecular adsorption were obtained by high-resolution STM images. On the basis of the previous results and obtained STM images, the quinoline ring is proposed to lie parallel to Cu(111) and serve as an anchoring group. The chiral quinuclidine moiety extends out of the surface to facilitate the interaction with the prochiral reactants.     

有限群的某些数量关系

在有限单群分类过程中，其阶恰包含3个素因子的群，即所谓K3-群构成了一类需要单独进行处理的单群类．利用Sylow定理和G1auberman正规p-补定理分别对两类阶具有3个素因子的群：p^2qr和p^3qr阶群进行了讨论，在一定条件下证明了它们都是非可换单群，即K3-群，并且分别同构于A5和L(2，7)．     

韶关市药用鱼类调查研究

本文根据对韶关市区及所属曲江、南雄、乳源等县市市场及野外调查结果，对食用鱼中药用鱼的肉、骨、肠、胆、血、鳔、肝、头、皮等药用价值进行了归类研究。     

新型乙醇气敏半导体材料CdFe_2O_4

采用化学共沉淀和固相反应相结合的方法制备出单相ＣｄＦｅ２Ｏ４，实验表明，ＣｄＦｅ２Ｏ４作为一种尖晶石型结构的复合氧化物，是电子导电型半导体，具有良好的酒敏性能．且有较好的化学稳定性和气敏稳定性     

巨型模锻水压机立柱应力在线检测及保护系统

通过对100MN多向模锻水压机的立柱在偏载工况下的受力状态的简要分析,并根据立柱应力特征与水压机的结构特点,提出了一种新型的非接触式立柱应力在线检测方法。以电涡流传感器为基本单元,并采用动态“O”点技术,建立了100MN多向模锻水压机的应力检测与保护系统及其软件。实验研究及应用表明,所研制的系统具有良好的稳定性和抗干扰能力,同时很好地抑制了零漂对检测精度的影响,该检测方法可应用于大型机械(轧机、挤压机等)封闭框架应力的间接检测。