He原子电子动量谱学实验结果的理论分析

对作者所在实验室最近完成的Ｈｅ原子电子动量谱学实验结果进行了详细的理论分析。在平面波冲量近似和扭曲波冲量近似下，利用三类典型的Ｈｅ原子基态波函数，对Ｗｅｉｇｏｌｄ几何条件下的（ｅ，２ｅ）反应的三重微分截面进行了计算，并与实验结果作了详细的比较，结果表明Ｌ（１）电子动量谱学是直接获取电子波函数信息的有用方法；（２）平面波冲量近全民族 扭曲波冲量近似得到的电子动量谱形状的差别并不大。     

谱学

谱学是研究“源”（辐射源、吸收源、振源等）的强度（或振辐、相位、能量等）按不同波长（或频率、质量等）进行排列的理论、解释和应用的一门科学。谱学包括原子光谱学、分子光谱学、波谱学、能谱学、频谱学、,谱学和质谱学等,是从本世纪三十年代开始迅速发展,并在科学和技术中得到广泛的应用。日本、美国、加拿大等国,都有全国性的谱学学会和会刊。谱学的国际学术报告会也很活跃。例如1991年在挪威卑尔根召开了第27届谱学国际学术报告会,有41个国家、540余名代表参加了会议,交流论文439篇;1993年6—7月在英国约克市召开了第28届谱学国际…     

探测单个原子的X射线谱学

日本的研究人员首次成功地使用X射线谱学探测到单个的原子,向着用X射线研究纳米级的结构和器件迈出重要一步．     

电子动量谱仪的研制和He原子的电子动量谱学实验

此文概要描述了国内首台电子动量谱仪的研制，以及利用这台谱仪对Ｈｅ原子进行电子动量谱学实验所得的结果。     

三七不同部位成分的谱学性质研究

采用不同溶剂提取了三七的不同部位,即提取三七皮和芯的化学成分,通过研究提取液的紫外-可见光谱(UV-Vis),傅里叶变换红外光谱(FTIR)、荧光光谱(FS)、电喷雾离子质谱(ESI-MS)及高效液相色谱(HPLC),寻找谱学特征与其化学成分的相关性,从化学成分的角度解释了三七皮与芯的药理效应差异的可能原因。     

电子动量谱学研究的新进展

简要地说明了电子动量谱学的特色、意义和发展情况．概要地描述了本实验室最近研制成功的一台第二代电子动量谱仪的结构和达到的性能指标，以及利用该谱仪所取得的一些物理和化学研究成果．扼要地说明电子动量谱学的发展趋势．     

纳米材料科学中的谱学研究

谱学分析方法是研究纳米体系结构和性能3的重要手段之一,对纳米材料进行深入研究离不开各种谱学方法的表征,本文综述了常用的谱学方法,如紫外可见光谱,红外光谱,拉曼光谱,穆斯堡尔谱,正电子湮没及光声光谱等在纳米材料研究中的最新进展,结合典型实例,对各种谱学方法的原理,特点以及在纳米体系研究中所能提供的重要信息进行了归纳和分析,展望了谱学分析方法在纳米科技研究中进一步的应用前景,以及在纳米材料研究中建立纳米尺度分辨的谱学检测方法和发展新的谱学技术等重要的发展方向。     

He原子电离能谱和He的ls电子动量谱测量

介绍利用作者最近研制成功的先进的多功能（ｅ，２ｅ）电子能谱仪实验装置研制量得到的Ｈｅ原子电离能谱和Ｈｅ的ｌｓ电子动量谱实验结果。     

高聚物正电子谱学的研究进展

简要介绍了近年来正电子谱学在聚合物微结构研究中的主要应用及进展,大量实验事实表明,正电子谱学是表征高聚物微结构的极灵敏方法。     

Comparison of Detection Limits in Atomic Fluorescence and Absorption Spectroscopy

Dagnall, Taylor, and West have recently compared detection limits for a number of metals in atomic fluorescence and absorption spectroscopy and have concluded that “atomic fluorescence measurements using an electrodeless discharge tube are inherently more sensitive than those obtainable by atomic absorption measurements”. Likewise West and Williams have compared the two techniques for magnesium²and silver³, using high-intensity hollow-cathode lamps as sources, and have found much lower detection limits in fluorescence than in absorption.     

Hypernuclear Spectroscopy with Stable Heavy Ion Beams and Rare-isotope Beams:HypHI Project at GSI and FAIR

The international HypHI collaboration proposes to perform hypernuclear spectroscopy with stable heavy ion beams and rare isotope beams at GSI and FAIR in order to study neutron and proton rich hypernuclei and to measure directly hypernuclear magnetic moments for the first time.The project is divided into four phases.In the first Phase 0 experiment,the feasibility of precise hypernuclear spectroscopy with heavy ion beams will be demonstrated by observing π~- decay channels of ~e_ΛH,~4_ΛH and ~5_ΛHe with ~6Li projectiles at 2 AGeV impinging on a ~(12)C target.In the later Phases 1 through 3,studies of proton and neutron rich hypernuclei,direct measurements of hypernuclear magnetic moments and the spectroscopy of hypernuclei toward the nucleon drip-lines are planned.     

Central Elements of Atomic Effect Algebras

Various conditions ensuring that an atomic effect algebra is a Boolean algebra are presented. PACS: 02.10.-v.     

LIBS技术对羊毛脂复合物中重金属元素的成分分析

利用激光诱导击穿光谱技术对市面上某型号口红的羊毛脂复合物中重金属元素进行分析,使用波长为532nm的激光在口红表面击穿诱导高温等离子体,通过对MCP增益、延迟、门宽三个参数的优化来获得最佳光谱.由发射光谱线的强度计算等离子体的电子温度,研究了激光诱导等离子体的电子温度随时间演化的特性.     

时间分辨原子发射光谱诊断脉冲放电气体束等离子体

建成了一套脉冲放电气体束和原子发射光谱等离子体诊断实验装置,利用这套实验装置测量了不同放电条件下等离子体的时间分辨发射光谱,并采用玻尔兹曼作图法和Hα谱线斯塔克展宽法研究了等离子体的原子温度、离子温度和自由电子密度等参数的演化。实验结果表明,脉冲放电的总电量对等离子体参数的演化有较大影响;脉冲放电气体束等离子体中的离子温度远高于原子温度,自由电子密度相对较低,等离子体处于非局域热平衡状态。A special designed pulsed discharge nozzle (PDN) ion source and a plasma diagnostics system based on the atomic emission spectroscopy were constructed. The time-resolved emission spectra of Argon atoms and ions in the region of 300-800 nm were observed and analyzed. The plasma temperatures, including atomic and ionic temperatures, were simulated by Boltzmann plot method, and the free electron density was simulated through the Stark broadening of Hα line. The evolution of these plasma parameters were investigated by high-resolution time-resolved emission spectra. The results show that the total energy struck on the pulsed gas beam is the most important factor which determines the plasma properties and its evolution. The plasma in PDN is concluded into non-local thermodynamic equilibrium (non-LTE) during the evaluation because of the low electron density and the big difference between the temperatures of Argon atoms and ions in all discharge conditions.     

Comparison of Flameless Atomic Absorption Spectroscopy with Neutron Activation Analysis for Vanadium in Beach Asphalt

One of the major arguments against using trace metal characterization as a tool to identify oil spills is lack of reliability of the data. With this in mind, the precision of flameless atomic absorption spectroscopy and of neutron activation analysis was determined for vanadium in crude oil residues. Thirty crude oil residues (beach asphalts) were analyzed by both methods, and the results compared. For neutron activation analysis, the population mean was 195 ppm, and the standard deviation of the method was 5.38 ppm. For flameless atomic absorption spectroscopy, the population mean was 202 ppm, and the standard deviation 19.5 ppm.     

Evaluation of Carbon Rod Atomizer for Routine Analysis of Vanadium in Crude Oil by Atomic Absorption Spectroscopy

Abstract

The Carbon Rod Atomizer (CRA) was evaluated for routine trace analysis of vanadium in crude oil by atomic absorption spectroscopy with a carbon (graphite) tube as a micro-furnace. Two crude oil samples were analyzed, both by standard addition and standard working curve methods, and the results confirmed by analysis with flame atomic absorption spectroscopy using a fuel-rich nitrous oxide-acetylene flame. Because of the relative involatility of vanadium at the temperature of the CRA, quantitative recoveries of vanadium in crude oil occur only when the vanadium content of the sample injected into the CRA does not exceed the limit of about 1 × 10^?8 g. A sensitivity (weight/1% absorption) of 7.0 × 10^?11 g and detection limit (signal-to-root-mean-square-noise equal to two) of 6.9 × 10^?12 are reported.     

太赫兹时域光谱技术的重金属离子吸附检测方法研究

随着工业化进程的不断推进,水体重金属污染问题日益严重。秸秆具有来源广泛、价格低廉、易再生等优点,故成为水体重金属污染处理的理想吸附剂。为研究太赫兹波技术在水体重金属污染检测的应用前景,实验选取原始秸秆和碱化秸秆分别对重金属离子进行吸附,利用太赫兹时域光谱技术(THz-TDS)在室温氮气环境下对原始秸秆样品、碱化秸秆样品、原始秸秆吸附重金属离子样品、碱化秸秆吸附重金属离子样品和碱化秸秆吸附重金属离子解吸后的样品进行光谱测量,秸秆经碱化处理后处于1.75～1.85 THz的杂合吸收峰带吸收系数有明显下降,并伴有肩峰式吸收带后移的现象,在吸附重金属离子后,原始秸秆样品中原有的1.75～1.85 THz杂合吸收带消失,却在1.8～2.05 THz形成了杂合吸收带。碱化秸秆在1.7～2.05 THz呈现复杂的多个肩峰式吸收,而碱化秸秆吸附重金属样品在1.7～2.05 THz呈现平滑的强吸收带,碱化秸秆吸附重金属离子水解吸后吸收谱线近乎平行。结合秸秆及碱化吸附重金属的化学反应过程对吸收谱进行分析,可得到不同组分样品的分子振动及官能团信息,并得到碱化秸秆吸附重金属应为络合吸附和静电吸附两种吸附方式。证明了太赫兹时域光谱技术在水体重金属污染检测中的可靠性和良好的应用前景。     

重离子熔合反应与双核模型

简单介绍了兰州-北京-吉森合作组对合成超重核的重离子反应进行的初步研究。研究的重点是熔合阶段的反应机制。在原有双核模型的基础上做了一些改进,把耗散相对运动过程与核子转移过程耦合起来,从更微观的角度来描写双核系统向全熔合复合核的演化。在双核过程中的每一步求解主方程,不对驱动势做谐振子近似。同时,还探讨了原子核形变与相对取向对驱动势的影响,存活几率与复合核蒸发中子的奇偶效应,以及入射道中原子核非弹性激发对俘获截面的影响等。In recent years, the Lanzou-Beijing-Giessen collaboration has studied the heavy ion reactions which are lead to the formation of super-heavy nuclei. The study emphases the mechanism of the fusion stage of the reactions. Based on the so called Di-nuclear System Model, some improvements have been made. The main points are the coupling of the dissipation of relative motion energy, angular momentum with nucleon transfer, and solving the Master equation in every step of the nucleon transfer with exact driving potentials, in order to describe the evolution of the system more microscopically. At the same time, we also discussed the effects of nuclear deformation and their relative orientation on the driving potentials, and studied the survive probability of the compound nuclei and its old-even effects, as well as the influence of inelastic excitations of nuclei in entrance channels to the capture cross sections.     

Ion Mobility Measurements and Ion Chemical Reaction Studies at Heavy Elements in a Buffer Gas Cell

Drift time measurements of ions in a buffer gas cell filled with argon have been performed from which changes of the ion mobility and ionic radii for various heavy elements and their compounds were determined. The ionic radius of americium shrinks by (3.1 1.3)% with respect to that of plutonium, and an increase of the radius by (28 2)% of plutonium oxide with respect to plutonium was found. Ion chemical reactions of erbium ions were studied online in an argon buffer gas cell to which the reaction gases oxygen (O) and methane (CH) were added. The erbium ions were implanted into the buffer gas cell with an energy of 50 MeV. The online measured reaction constant = (3.2 0.4) 10 cm/(molecule s) for the reaction Er + O ErO + O agrees with a reference measurement = (3.6 0.4) 10 cm/(molecule s), performed with a Fourier-Transform-Mass-Spectrometer.