卟啉超分子化合物在分子器件中的应用

分子电子器件已成为近年来的一个研究热点，卟啉类化合物因为光敏性好、性能稳定、易于修饰等优点成为分子器件研究的理想模型化合物。本文着重介绍了它在分子器件中的最新应用进展。     

[Ru(phen)2dppz]2+二聚及对DNA键合性质的影响

研究发现, [Ru(phen)2dppz]2+表现出非常强的自聚合倾向, 并显著影响DNA的键合性质, 有关方面的研究应引起科研工作者的足够重视.     

DYNAMIC PROPERTIES OF MAIN SOUNDER IN BLACK CICADA (C. atrata Fabricius)~*

In this paper, the dynamic properties of the main sounder (the sounding muscle (SMc) and the sounding membrane (SM)) and the generating mechanism of amplitude-modulation pulse train (AMPT) are given. The acting process of SMc is a quasi-simple harmonic contraction vibration. The amplitudes of soundless and sounding contracting motion are about 17.2 /μm and 29.4/μm, respectively, and the efficiency of dynamic sounding is about 17％, The unsounded motion of SM is a quasi-simple harmonic vibration, and the amplitude is about 7.81/μm. The sounding motion of SM is a complex vibration, and the amplitude is about 12.66 μm. In each syllable of the song, AMPT_(1,2,3) are separately produced by driving vibrations (V_1,2,3)) of three long ribs in the upper half of SM, and the peaks of V_(1,2,3) lead the first pulse of high amplitude in AMPT_(1,2,3) by 0.156 ms, respectively. The membrane structure in the lower half of SM is mainly to transmit contracting movement of SMc.     

Determination of three compounds in Aloe vera by capillary electrophoresis

A capillary electrophoretic assay for determining aloe-emodin (AE), methyl p-coumarate (MC), and 3,4-dihydro-6,8-dihydroxyl-[(3s)-2'-acetyl-3'-hydroxyl-5'-methoxy-benzyl]-isocoumarin (DDI) in Aloe vera has been developed. Baseline separation was achieved within 15 min using a running buffer of 20 mm borax containing 10% (v/v) acetonitrile at pH 10.5. A linear relationship between the peak area and the concentration of the analytes was found in the ranges 5-500, 10-1000 and 2-1000 micro g/mL for AE, MC and DDI, respectively, with correlation coefficients of 0.9992-0.9998. The relative standard deviations of migration time and peak area were within 0.17-0.19 and 1.52-3.37%, respectively. The recoveries of AE, MC and DDI were 105, 102 and 96.4%. The contents of AE, MC and DDI in Aloe vera were measured to be 5.13, 0.768 and 1.30 mg/g, respectively.     

电爆炸箔断路开关的理论和实验研究

 采用金属箔电爆炸过程的二维数值计算模型，对含电爆炸金属箔断路开关的电感储能脉冲功率调节系统进行了数值计算。以此为基础，研制出了一种低电感型的电爆炸箔断路开关，并以4μF/75kV脉冲电容器组作为初级能源，13Ω电阻作为负载进行实验研究。研究结果表明：在负载上可获得约250kV，脉宽大于400ns的脉冲电压。     

S-5N全固态重复频率脉冲发生器

 主要介绍S-5N的结构及测试实验结果。S-5N型全固态重复频率脉冲发生器是目前国际上同类源中峰值功率和平均功率均为最大的一台。随负载大小的变化，S-5N脉冲发生器的输出电压为400～600kV，输出电流2～3kA，输出脉冲半高宽40～50ns，单脉冲输出能量40～65J。 S-5N脉冲发生器在300Hz重复频率条件下可连续工作，500Hz重复频率条件下可连续工作3min，平均输出功率高达30kW。     

基于开关控制的兴趣实验设计

设计了开关控制实验,专门对常见的开关特点及使用进行探讨,根据开关特点搭建相应的控制电路,用近似于工程项目的形式锻炼学生对开关的灵活应用,激发了学生实验的兴趣和积极性.     

Twin liquid crystals and segmented thermotropic polyesters containing azobenzene—effect of spacer length on LC properties

We report systematic studies on a homologous series of twin liquid crystalline (LC) molecules based on phenyl and naphthyl azobenzene ( PnP and NpnNp ) as well as segmented copolyesters based on them. The twin series had the structure azobenzene–oligooxyethylene–azobenzene, where the ethyleneoxy length was varied from 2 to 6 units. The LC properties of the twin series depended on the chemical structure of the azochromophore and also the length of the central oligooxyethylene segment. The PnP series exhibited smectic LC properties for n > three oligooxyethylene units. Conversely, NpnNp series exhibited spherulitic phases only for the shortest member – Np2Np . One non‐LC short spacer twin ( P2P ) and one LC long spacer twin ( P6P ) were incorporated as part of a main chain polyester composed of fully aliphatic segments of sebacate and di or tetraethylene glycol (DEG/TEG) units by melt polycondensation. Non‐LC P2P formed LC polymers even at low (5 mol %) incorporation in DEG‐based copolymers, whereas the LC‐ P6P could do so only at 30 mol % incorporation. The LC properties of the twin molecules as well as copolymers were studied using differential scanning calorimetry, polarized light microscopy (PLM) along with variable temperature wide angle X‐ray diffraction. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

On the formation of smaller p‐block endohedral fullerenes: Bonding analysis in the E@C20 (E = Si,Ge, Sn,Pb) series from relativistic DFT calculations

Experimentally characterized endohedral metallofullerenes are of current interest in expanding the range of viable fullerenic structures and their applications. Smaller metallofullerenes, such as M@C₂₈, show that several d‐ and f‐block elements can be efficiently confined in relatively small carbon cages. This article explores the potential capabilities of the smallest fullerene cage, that is, C₂₀, to encapsulate p‐block elements from group 14, that is, E = Si, Ge, Sn, and Pb. Our interest relates to the bonding features and optical properties related to E@C₂₀. The results indicate both s‐ and p‐type concentric bonds, in contrast to the well explored endohedral structures encapsulating f‐block elements. Our results suggest the E@C₂₀ series to be a new family of viable endohedral fullerenes. In addition spectroscopic properties related to electron affinity, optical, and vibrational were modeled to gain further information useful for characterization. Characteristic optical patterns were studied predicting a distinctive first peak located between 400 and 250 nm, which is red‐shifted going to the heavier encapsulated Group 14 atoms. Electron affinity properties expose different patterns useful to differentiate the hollow C₂₀ fullerene to the proposed p‐block endohedral counterparts. © 2017 Wiley Periodicals, Inc.