聚吡咯纳米线的恒电位合成及形貌分析

采用恒电位法,直接在石墨电极表面快速合成聚吡咯纳米线,并重点研究了聚吡咯纳米线的生成过程及形貌变化规律。结果表明,聚吡咯纳米线的生成包括成核和生长过程,纳米线的形貌随聚合条件的不同而变化,直径随聚合电位、吡咯单体浓度、电解质浓度的升高而增大,这是由于不同聚合条件下聚吡咯的成核速率不同引起的。     

高效液相色谱法分离测定3-取代-(R,S)-β-丙氨酸对映异构体

以1-氟-2,4-二硝基-5-L-缬氨酰胺(Marfey试剂)为衍生试剂,采用反相高效液相色谱法分离了3-取代-(R,S)-β- 丙氨酸对映异构体。采用梯度洗脱(流动相 A:体积分数为0.1%的三氟乙酸乙腈溶液;流动相B:体积分数为0.1%的三氟乙 酸水溶液)成功分离了 32种3-取代-(R,S)-β-丙氨酸衍生物,所有化合物都是R型异构体衍生物(R-L)较S型异构体衍生物 (S-L)先洗脱。除3-羟基苯和4-羟基苯的疏水参数较小,但其取代的β-丙氨酸衍生物的保留时间较长、分离因子较小外, 其他疏水参数大的取代基的β-丙氨酸衍生物保留时间都长于疏水参数小的取代基的β-丙氨酸衍生物。该文同时测定了R -和S-β-丙氨酸的对映体过剩值。     

Synthesis and characterization of highly soluble wholly aromatic polyamides containing both furanyl and phenyl units

This paper presents the synthesis and characterization of two series of polymeric compounds comprising eight furan-based polyamides prepared via melt polycondensation at low temperatures using various combinations of five aromatic raw materials. The chemical and physical structures and thermal stabilities of the obtained polyamides were investigated by various characterization methods. In addition, the polyamides were subjected to solubility testing in five common organic solvents. The results showed that the proposed furan-based polyamides possessed thermal stabilities similar to those of conventional high-performance aromatic polyamides, but with greatly improved solubility. Accordingly, the introduction of furan groups increased the solubility of the polyamides with respect to the solubility of their individual precursors, which is highly advantageous for subsequent polyamide processing and expanding their range of potential applications.     

Adaptive fuzzy finite-time control of stochastic nonlinear systems with actuator faults

Nonlinear Dynamics - This paper considers the finite-time control problem for a class of nonlinear stochastic systems with actuator faults/failure. A fast convergence feedback control algorithm...     

Strong solutions for the generalized Perona-Malik equation for image restoration

In this paper we establish the existence and uniqueness of strong solutions for the generalized Perona-Malik equation of the fourth order for image restoration in dimension one.     

Total synthesis of aeruginosin 298-A analogs containing ring oxygenated variants of 2-carboxy-6-hydroxyoctahydroindole

Aeruginosins are a family of naturally occurring oligopeptides sharing a common perhydroindole-2-carboxylic acid (l-Choi) core structure. Many aeruginosins exhibit inhibitory activity against serine proteases including thrombin. Aeruginosin 298-A is a tetrapeptide containing the l-Choi core structure and three other unusual amino acids or their derivatives; it is a thrombin and trypsin inhibitor. As part of our effort in finding effective thrombin inhibitors from natural product analogs and to understand the influence of the rigid bicyclic amino acid to the thrombin inhibition activities, we synthesized two aeruginosin 298-A analogs in which the l-Choi is replaced with ring oxygenated perhydroindole-2-carboxylic acids. The Choi variants are enantiomers synthesized from d- and l-glucose, respectively. The preparation of the aeruginosin 298-A analogs containing the ring oxygenated Choi variants and their inhibition activities toward thrombin and trypsin are reported.     

电气信息类专业高级程序设计教学内容和方法的探索与实践

从电气信息类专业高级程序设计实践教学出发,针对学生对高级程序设计学习的畏惧、学习动力不足、积极性不高、实际践行不够等问题,提出了完整的解决方案:学习动力的完全激发,学习兴趣的逐步培养,知识点的重点突破,实践上的逐步推进.通过一系列环环相扣的教学措施,使电气信息类学生对高级程序设计的掌握,不仅满足通过全国计算机等级考试的目标,而且能够站在专业发展的角度上重视计算机程序开发语言,充分理解和掌握计算机语言学习的方法和规律,并在未来的专业学习上践行软硬件均衡设计的理念.     

浅谈轧钢厂整流变压器运行与管理

本文介绍了日照钢铁热轧1580带钢厂整流变压器的运行与管理,主要介绍了9台主电机整流变压器基本原理、结构优点、维护管理经验和故障解决方法,提高整流变压器的稳定性和经济性,避免设备出现事故,影响生产。     

人耳音高感知的心理声学基本理论

在简述人耳听觉构造和基底膜选频特性的基础上,详细介绍了解释人耳音高感知现象的两个心理声学基本理论,即"部位学说"和"时间论",同时介绍了部位学说和时间论在解释人耳音高感知存在的不足,以及人耳音高感知的心理声学模型.