基于扫描隧道显微镜的原子电子云结构

本文简要介绍了扫描隧道显微镜的基本工作原理，展示了一些扫描样品（石墨和铜）的电子云图，在简要介绍量子力学关于原子电子云结构基本理论的基础上，通过理论上的电子云结构与扫描结果的比较，在一定程度上验证了量子力学关于原子电子云结构理论的正确性．     

中药柴胡中K、Ca、Zn、Fe和Mn含量测定及清除自由基机制分析

研究了柴胡中金属元素的作用为治疗呼吸系统疾病提供依据.选取柴胡粉碎、干燥至恒重,采用HNO3-HClO4湿法消化,用原子吸收分光光度计测定宏量元素钙、钾和微量元素铁、锰、锌的含量.测定结果表明,柴胡中含有丰富的金属元素.用原子吸收分光光度法测定中草药中金属元素含量,方便迅速.结果准确,测定结果为临床上合理利用柴胡清除自由基、预防和治疗呼吸系统疾病提供科学依据,也为大力开发、利用中药柴胡提供了有用的数据.     

ICP-AES快速测定土壤中硫含量

采用ICP-AES研究土壤中硫含量的测定.以王水消解土壤试样,优化全谱型ICP-AES分析条件测定土壤中S的含量,检出限为5.7ng/mL(180.7nm)和8.6ng/mL(182.0nm).测定土壤标准物质中的S含量,测定结果在标称值范围内,连续测定10个平行样其相对标准偏差均小于2%.方法快速、简单、准确.     

红枣中微量元素含量的测定

用火焰原子吸收光谱法(FAAS)测定了红枣中K、Ca、Mg、Cu、Mn、Zn、Fe等7种微量元素的含量.实验方法加入标准样回收率在99.4%-105.2%之间,RSD在0.4%-1.3%之间,分析结果令人满意.红枣中含有丰富的微量元素,其含量由高到低的排列顺序为:Fe、K、Ca、Mg、Zn、Mn、Cu,说明红枣具有很高的营养价值.     

FAAS法测定硫酸中的铜、铁和锌

采用火焰原子吸收光谱法测定硫酸中铜、铁和锌,确定了最佳仪器工作条件和样品处理方法.在选择好的实验条件下,测定铜的特征浓度为0.005μg/mL/1%;铁的特征浓度为0.014μg/mL/1%吸收;锌的特征浓度为0.002μg/mL/1%吸收.回收率分别为铜97.7%-98.2%,铁98.2%-99.4%,锌96.8%-98.7%.     

火焰原子吸收光谱法测定滑子蘑中镉、铜、铅和锌

采用HNO3-HClO4(15∶2)作消解液进行溶样,火焰原子吸收光谱法同时测定滑子蘑中镉、铜、铅、锌的分析方法,优化了仪器工作参数、消解及萃取条件,进行了精密度以及共存离子的干扰实验.在最佳测定条件下,4种元素校准曲线相关性好(r为0.9955-0.9999),仪器精密度为0.6%-2.1%,样品加标回收率为94.2%-104.0%,精密度为2.2%-4.3%,方法快捷、准确、灵敏度高,精密度较好,适用于日常分析检测工作,结果令人满意.     

Shear Viscosity to Non-Equilibrium Entropy Density Ratio of Hot Quark-Gluon Plasma at Finite Chemical Potential

In the framework of irreversible thermodynamics, we study the transport properties of hot quark-gluon plasmas. The viscous entropy production at finite chemical potential as well as the shear viscosity to non-equilibrium entropy density ratio is investigated in weakly coupled limit by using kinetic theory. The results show that the chemical potential contributes positively to their ratio compared to the pure temperature case. The ratio exhibits two boundaries in the coupling strength in which a minimum value of 0.42 is found at αs=0.6.     

Effect of Pretreatment of TaN Substrates on Atomic Layer Deposition Growth of Ru Thin Films

The polycrystalline ruthenium films are grown on TaN substrates by atomic layer deposition （ALD） using bis（cyclopentadienyl） ruthenium [RuCp2] and oxygen as ruthenium precursor and reactant respectively at a deposition temperature of 330℃. The low-energy Ar ion bombardment and Ru pre-deposition are performed to the underlying TaN substrates before ALD process in order to improve the Ru nucleation. X-ray diffraction, x-ray photoelectron spectroscopy, scanning electron microscopy and atomic force microscopy are carried out to characterize the properties of ALD Ru films. The results show that the nucleation density of Ru films with Ar^＋ bombardment to the underlying TaN substrates is much higher than that of the ones without any pretreatment. The possible reasons are discussed.     

Simultaneous Magneto-Optical Trapping of Fermionic ^40K and Bosonic ^87Rb Atoms

We report on simultaneous magneto-optical trapping of fermionic ^40K and bosonic 87Rb atoms. This trap is the first step towards quantum degenerate fermi gas ^40K. Laser lights for the two-species magneto-optical trap （MOT） are generated from diode lasers and tapered amplifier. The enriched ^40K dispenser is utilized in the experimental setup. We obtain up to 10^7 -10^8 ^40K and 10^8 -10^9 ^87Rb atoms respectively in the steady-state single-species MOT.     

Scheme for Realizing Kerr Nonlinearity in Cavity QED

We propose a scheme for realizing the Kerr-type nonlinearity for a cavity mode. In the scheme the cavity mode interacts with a single three-level atom dispersively. Under certain conditions, the evolution of the cavity field, decoupled from the atomic degree of freedom, corresponds to the Kerr effect. The scheme can be generalized to implement cross-Kerr effect and two-qubit phase gates for two cavity modes.