植物酸碱指示剂研究及应用--一次有趣的研究性学习

就植物酸碱指示剂材料的筛选,植物色素提取液的稳定性,色素晶体的提取,色素临时提取液的变色情况测试,色素提取液测酸雨等方面进行研究,旨在学会科学研究的方法。     

一组新氨基酸描述子用于肽定量构效关系研究

用主成分分析从20种天然氨基酸0D～3D结构信息中收集到的共1369个描述子变量得到了一组新氨基酸描述子(SZOTT), 将其用于血管紧张素转化酶抑制剂和苦味二肽结构表征并以偏最小二乘法建立定量构效关系模型, 得复相关系数R_CU²分别为0.894和0.908, 留一法交互检验的复相关系数R_CV²分别为0.828和0.736, 估计均方根误差RMS分别为0.331和0.195. 研究结果表明, SZOTT描述子含信息量大, 操作简便, 结构表达能力强, 有望在多肽定量构效关系研究中得到进一步推广.     

Preparation and Electrochemical Performance of Three-Dimensional Vertically Aligned Graphene by Unidirectional Freezing Method

Three-dimensional vertically aligned graphene (3DVAG) was prepared by a unidirectional freezing method, and its electrochemical performances were evaluated as electrode materials for zinc−ion hybrid supercapacitors (ZHSCs). The prepared 3DVAG has a vertically ordered channel structure with a diameter of about 20−30 μm and a length stretching about hundreds of microns. Compared with the random structure of reduced graphene oxide (3DrGO), the vertical structure of 3DVAG in a three−electrode system showed higher specific capacitance, faster ion diffusion, and better rate performance. The specific capacitance of 3DVAG reached 66.6 F·g⁻¹ and the rate performance reached 92.2%. The constructed 3DVAG zinc−ion hybrid supercapacitor also showed excellent electrochemical performance. It showed good capacitance retention up to 94.6% after 3000 cycles at the current density of 2 A·g⁻¹.     

Microstructure of polymers obtained by cationic polymerization of endo-dicyclopentadiene

endo-Dicyclopentadiene (DCPD) was polymerized by various cationic initiating systems in different solvents. IR and ¹H NMR results show that four types of structural units are formed due to the corresponding addition modes: the addition on the norbornenic (NB) double bond generates unit I and rearranged unit II, while the addition on the cyclopentenic (CP) double bond produces unit III and rearranged unit IV. The reaction medium has a stronger effect on the microstructure of the polymer (PDCPD) than initiating systems. The polymers prepared in toluene and n-hexane contain all four structural units, while the polymer produced in methylene chloride is composed of structural units II and IV. © 1996 John Wiley & Sons, Inc.     

氢气泡模板法电沉积制备三维多孔铜薄膜

应用阴极析氢气泡模板法电沉积制备三维多孔铜薄膜,基础电解液组成为0.2 mol.dm-3CuSO4和1.5 mol.dm-3H2SO4.研究了电流密度(0.5~8.0 A.cm-2)、温度(20~70℃)、支持电解质(Na2SO4)以及添加剂HC l和聚乙二醇(PEG)等对薄膜的孔径大小和孔壁结构的影响.扫描电子显微镜(SEM)分析表明,降低镀液温度和添加Na2SO4、PEG都可降低孔径的大小,但对孔壁结构无影响.加入微量的氯离子可显著改变薄膜的孔壁结构,得到孔壁结构较为致密的三维多孔铜电极.循环伏安(CV)测试结果显示三维多孔铜薄膜电极在碱性条件下电氧化甲醇的电流密度比光滑铜电极提高了近20倍.     

数学的默会知识及其教学意义

讨论了数学默会知识的涵义以及主要特点,论述了数学默会知识对数学学习和数学研究的影响及其对数学教学的意义.     

基于电化学发光和阻抗技术研究DNA单碱基错配

单碱基错配的识别和稳定性差异在核酸多态性研究中至关重要。在同一电化学传感器平台上,采用电化学发光（ECL）和电化学阻抗（EIS）2种技术,协同研究DNA链中不同类型和不同位点的单碱基错配识别和稳定性差异。电极表面具有茎环构象的探针DNA与完全互补DNA、不同类型或不同位点单碱基错配DNA杂交前后的ECL和EIS信号强度变化有显著差异。信号强度变化可揭示单碱基错配识别的稳定性。结果表明,DNA链中心位点的C-A单碱基错配稳定性低于链两端的,靠近键合电极表面双链链端的C-A单碱基错配稳定性低于非键合电极表面双链链端的,同一中心位点C-X碱基对的稳定性顺序为C-G?C-T>C-A≥C-C。研究结果可为核酸多态性研究提供参考。     

极性晶体中强耦合表面磁极化子特性

研究极性晶体中表面磁极化子的特性。采用Huybrechts线性组合算符和幺正变换方法,导出了晶体中强耦合表面磁极化子处于基态的振动频率和有效哈密顿量,讨论了坐标z的两种极限情况,对RbCl晶体进行了数值计算。结果表明:振动频率和平行有效哈密顿量随磁场的增加而增大。     

非对称量子阱中非线性光学吸收系数的计算

非对称量子阱中的非线性光学效应因其潜在的实用价值而引起人们的广泛关注,而量子阱内带间的光学吸收问题对研究远红外光学探测器件具有重要的理论指导意义.以Pschl-Teller势阱为例研究了影响非对称量子阱中的非线性光学吸收系数的因素.考虑到带间的电子弛豫,用量子力学中的密度矩阵算符理论导出了Pschl-Teller势阱中的线性与三阶非线性光学吸收系数的表达式.因该势阱中有两个可调参数,通过调节系统的参数,发现该系统的非线性光学吸收系数呈规律性的变化.以典型的GaAs/AlGaAs非对称量子阱为例作了数值计算,通过调节系统的参数,数值计算结果表明,入射光强以及系统的非对称性对量子阱的非线性光学吸收系数有较大的影响,从而为实验上研究非对称量子阱的非线性光学效应提供了必要的理论依据.     

Newly Emerging Strategies in Antiviral Drug Discovery: Dedicated to Prof. Dr. Erik De Clercq on Occasion of His 80th Anniversary

Viral infections pose a persistent threat to human health. The relentless epidemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global health problem, with millions of infections and fatalities so far. Traditional approaches such as random screening and optimization of lead compounds by organic synthesis have become extremely resource- and time-consuming. Various modern innovative methods or integrated paradigms are now being applied to drug discovery for significant resistance in order to simplify the drug process. This review provides an overview of newly emerging antiviral strategies, including proteolysis targeting chimera (PROTAC), ribonuclease targeting chimera (RIBOTAC), targeted covalent inhibitors, topology-matching design and antiviral drug delivery system. This article is dedicated to Prof. Dr. Erik De Clercq, an internationally renowned expert in the antiviral drug research field, on the occasion of his 80th anniversary.