Exchange环的K0群的正向凸子群格

本文证明了：(1)Exchange环R的K0群的正向凸子群格同构于R的稳定余有限半本原理想格；(2)稳定有限、半本原的exchange环R是单的当且仅当它是K0-单的并且满足逼近弱s^*—可比性，推广了Goodearl，Ara等人的结果。     

逆序数的应用

本文通过“1 4-1 5”智力玩具和最优戴断切割问题两个实例 ,讨论了逆序数在解决实际问题中的应用     

外汇储备规模与多元变量弹性系数的实证研究

中国外汇储备近几年的迅速增长引发了关于中国外汇储备规模是否适度的广泛讨论。本文从需求的角度,运用计量经济学的多元线性回归的方法,建立中国外汇储备与平均进口倾向、进口和国际收支三变量的双对数模型,通过计算并通过相关检验得到外汇储备与相关变量的弹性系数。为预测和制定相关政策提供依据。     

铁磁-绝缘层-铁磁-d波超导结中的量子干涉效应对微分电导与散粒噪声的影响

通过求解BogoliubovedeGennes(BdG)方程,利用推广的BlonderTinkhamKlapwijk(BTK)理论,计算铁磁绝缘层铁磁d波超导结中的微分电导、平均电流和散粒噪声功率.研究表明,系统的微分电导和散粒噪声与平均电流的比值都随中间铁磁层厚度作周期性振荡,振荡的幅度随绝缘层势垒增高而变大,随铁磁层中磁交换劈裂的增强而变小. 关键词： 微分电导 散粒噪声 磁交换劈裂     

统计优化迭代法测量质子交换波导折射率分布

提出了一种用于拟合测量渐变波导的折射率分布的新的理论处理。该方法把统计优化手段导入循环迭代法 ,可适用于费米函数这一类曲线变化范围大、且有多个自变量的函数。实验上用焦磷酸质子交换制备了LiNbO3波导样品 ,用该方法对退火后的折射率分布作了测量拟合 ,折射率拟合值与实验值的均方差为± 8.2× 10 - 4。     

A compact optical heterodyne interferometer by optical integration and its application

A compact high-resolution optical heterodyne interferometer combining a two-frequency light module and a minute optical system is described. The light module, which generates two independent frequencies of light, is fabricated by proton exchange method on LiNbO₃ substrate. We report an experiment evaluating measurement accuracy using a micro-displacement measurement system which incorporates this interferometer. Results of the experiment with a standard thickness sample show high thermal stability with maximum measurement error of 1.8 nm at a temperature from 19°C to 33°C. The system was used to measure the hysteresis of a piezoelectric element for displacements of several nm, thereby making it possible to analyze the system quantitatively in practice.     

Pseudo cyclic ionophores: ‘Binary-effect’ of quinolinyloxy groups at both ends of oligoethylene glycols on the conformational stabilization of their complexes with alkali metal salts

A series of noncyclic neutral ionophores has been synthesized by the reaction of oligoethylene glycol dihalides with 8-quinolinol. Complexation properties for alkali metal picrates were evaluated from solvent extraction and bulk liquid membrane transport experiments. Complexation profiles of the newly synthesized ionophores with a hexyl chain were similar to those of their homologues without the hexyl chain in the extraction experiments. Among them, the pentaethylene glycol derivatives showed the highest extraction efficiency and selectivity towards potassium ion. From the¹H NMR spectra (400 MHz), the change in chemical shifts of the aromatic protons upon the addition of alkali metal thiocyanates suggested the existence of a stabilization effect which is caused by intramolecular stacking conformations between the quinoline rings during complexation. Aryl stacking interactions depend on the size of the cations and on the chain length of the oligoethylene glycol. The relationship between transport ability towards alkali metal cations and lipophilicity of these ionophores is also discussed.     

双电荷交换反应与双重子共振态

提出了核双电荷交换反应的双重子共振态的反应机制,成功地解释了长期以来一直困惑着人们的共振区反应的角分布的实验结果.说明了共振区核双电荷交换反应是寻找双重子共振态的一个可能的途径.     

Enantioseparation of Dencichine and D-Isomer on L-Cysteine Derivative Phase by Ligand-exchange Chromatography

Dencichine (β-N-oxalyl-L-α, β-diaminopropionic acid, L-ODAP), a nonprotein amino acid, is a haemostatic agent present in important Chinese medicinal herbs such as Panax notoginseng, as well as other Panax species1. It was first isolated from the seeds …     

改性壳聚精膜用于醇水混合液分离的研究──Ⅲ．超细粉末填充壳聚精膜

首次制备了用Ｓｉ３Ｎ４，ＳｉＯ２，ＴｉＨ４超细粉末填充的改性壳聚精膜，并将其用于乙醇／水混合液的分离中。实验表明壳聚糖膜经超细粉末填充后强度增大，溶胀度减小。用于乙醇／水混合液渗透蒸发分离时，分离因子和渗透通量都有提高，并在填充量为１６．７％附近出现极大值。随着料液中乙醇含量的增大，渗透通量减小，分离因子增大；随着料液温度的升高渗透通量显著增大，分离因子则稍有下降。并简单讨论了超细粉末在乙醇／水混合液分离中的作用。