固体微/纳米尺度传热理论研究进展

随着半导体技术的飞速发展,器件的尺寸已进入到微/纳米尺度。由于量子效应、表面及界面效应,使得微尺度下的热物性与宏观尺度下有了明显的区别。人们针对微观传热领域的特点,发展了声子玻尔兹曼传输方程、分子动力学等方法,取得了一定的成果,但仍存在不少问题。一些基础概念问题,特别是非平衡态下的局域温度的定义,有待澄清。本文主要回顾近年来微/纳米尺度传热在理论和数值模拟方面的进展,以及目前所面临的挑战和问题。     

空心光束的产生及其在现代光学中的应用

近年来,随着激光应用技术的发展,各种中心强度为零的激光束被相继产生,并正在形成一个新颖的所谓空心光束(也称暗中空光束)的大家族。作为激光导管、光学镊子(光钳)和光学扳手,空心光束在微观粒子(如微米粒子、纳米粒子、自由电子、生物细胞和原子或分子等)的精确、无接触操纵和控制中有着广泛的应用。本文将首先给出空心光束的定义及其参数,并详细介绍各种空心光束产生的基本原理、方法及其实验结果。其次,就空心光束的分类及其应用场合进行了简单归纳与讨论。最后就空心光束在微观粒子(包括微米粒子、纳米粒子、生物细胞和自由电子等)的光学囚禁与操控中的应用进行简要综述,并就空心光束的产生与应用及其未来研究与应用前景进行了简短总结与展望。     

Influence of thermal annealing duration of buffer layer on the crystalline quality of In0.82Ga0.18As grown on InP substrate by LP-MOCVD

In_0.82Ga_0.18As epilayers were grown on InP substrates using a two-step growth technique by LP-MOCVD. A homogeneous low-temperature (450 °C) In_0.82Ga_0.18As buffer layer was introduced to improve the crystalline quality of epilayers. The influence of low-temperature buffer layer deposition condition, such as thermal annealing duration, on the crystalline quality of the In_0.82Ga_0.18As epilayer was investigated. Double-crystal X-ray diffraction measurement, Hall measurement, and Raman scattering spectrum were used to evaluate the In_0.82Ga_0.18As epilayers. Atomic force microscope was used to study the surface morphology. It is found that the In_0.82Ga_0.18As epilayer, with buffer layer thermal annealing for 5 min, exhibits the best crystalline quality. The change of the surface morphology of the buffer layer after thermal annealing treatment was suggested to explain the phenomenon.     

Study of radiation background at the north crossing point of the BEPCⅡ in collision mode

Understanding the radiation background at the north crossing point (NCP) in the tunnel of BEPCII is crucial for the performance safety of the High Purity Germanium (HPGe) detector, and in turn of great significance for long-term stable running of the energy measurement system. Therefore, as the first step, a NaI(Tl) detector is constructed to continuously measure the radiation level of photons as background for future experiments. Furthermore, gamma and neutron dosimeters are utilized to explore the radiation distribution in the vicinity of the NCP where the HPGe detector will be located. Synthesizing all obtained information, the shielding for neutron irradiation is studied based on model-dependent theoretical analysis.     

极化(e,2e)碰撞电离的研究进展

传统（ｅ,２ｅ）谱学已成为研究原子和分子电子结构和电离机制的强有力工具之一,本文首先简要回顾了迄今国内外传统（ｅ,２ｅ）谱学研究的历史和现状。然后,再重点介绍近几年开展极化（ｅ,２ｅ）碰撞电离研究的进展。     

Synthesis and antibacterial activity of ethyl 2-amino-6-methyl-5-oxo- 4-aryl-5,6-dihydro-4H-pyrano[3,2-c]quinoline-3-carboxylate

The three-component reaction of 4-hydroxy-1-methyl-2(1H)-quinolinone, aromatic aldehydes and ethyl cyanoacetate was carried out in the presence of a catalytic amount of 4-dimethyl aminopyridine(DMAP) in aqueous ethanol. The reactions result in the formation of pyranoquinoline derivatives in excellent yields. Antibacterial activity has been evaluated against Gram positive and Gram negative bacteria for some of the synthesized compounds. The results indicated that these compounds are moderately effective against bacterial growth and their effectiveness is highest against Pseudomonas aeruginosa.     

Electrochemical sensor based on f-SWCNT and carboxylic group functionalized PEDOT for the sensitive determination of bisphenol A

A simple,sensitive,and reliable method for the voltammetric determination of bisphenol A(BPA) by using carboxylic group functionalized single-walled carbon nanotubes(f-SWCNT)/carboxylic-functionalized poly(3,4-ethylenedioxythiophene)(PC4) complex modified glassy carbon electrode(GCE) has been successfully developed.The electrochemical behavior of BPA at the surface of the modified electrode is investigated by electrochemical techniques.The cyclic voltammetry results show that the as-prepared electrode exhibits strong catalytic activity toward the oxidation of BPA with a well-defined anodic peak at 0.623 V in PBS(0.1 mol/L,pH 7.0).The surface morphology of the 3D network of composite film is beneficial for the adsorption of analytes.Under the optimized conditions,the oxidation peak current is proportional to BPA concentration in the range between 0.099 and 5.794 μmol/L(R~2 = 0.9989),with a limit of detection of 0.032 μmol/L(S/N = 3).The enhanced performance of the sensor can be attributed to the excellent electrocatalytic property of/-SWCNT and the extraordinary conductivity of PC4.Furthermore,the proposed modified electrode displays high stability and good reproducibility.The good result on the voltammetric determination of BPA also indicates that the asfabricated modified electrode will be a good candidate for the electrochemical determination and analysis of BPA.     

Allyl phthalazinone synthesis,polymerization and polymer properties

A phthalazinone monomer with an allyl group, i.e. 4-（3-allyl-4-hydroxyphenyl）phthalazin-1（2H）-one, was synthesized and then copolymerized with 4-（4-hydroxylphenyl）（2H）-phthalazin-1-one and 2,6- diflurobenzonitrile by means of aromatic nucleophilic polycondensation to provide a series of crosslinkable poly（aryl ether nitrile）s. The virgin copolymers exhibited good solubility in polar organic solvents with relative high molecular weights （Mw： 45,130-58,403, inherent viscosities： 0.58-0.75 dL/ g）. After cross-linking, the thermal stability and solvent resistance of the polymer increased.     

Nickel-catalyzed cross-coupling reaction of alkynyl bromides with Grignard reagents

We describe a convenient method for the synthesis of 1,2-disubstituted acetylenes via a cross-coupling reaction of （bromoethynyl）benzene with Grignard reagents. The reaction of （bromoethynyl）benzene （1 mmol） with Grignard reagent （1.3 mmol） mediated by NiCl2 （4 mol%） and （p-CH3Ph）3P （8 mol%） in THF could produce 1,2-disubstituted acetylenes in good yields at room temperature.