上海5FW胶片的相对标定

介绍了利用阶梯衰减片对上海５ＦＷ胶片进行相对标定的原理，方法和操作步骤。同时对实验所得的数据处理的数学模型进行了详细的阐述，利用完善的数学模型和实验数据得到５ＦＷ胶片的乳剂特性曲线，最后介绍了变波长标定。     

抽运光分布对二极管抽运激光器振荡光光束质量的影响

研究了二极管抽运激光器（DPL）中抽运光的空间分布对振荡光光束质量的影响.通过对端面 抽运情形下光场运动方程的研究，发现不均匀的空间增益分布会影响激光振荡的模式，并且 使得基模振荡光偏离高斯分布.引入一个称之为抽运光影响因子参数，来判断这种影响的程 度.研究表明，这个参数计算方便而且实用.在对基模调Q脉冲激光的研究中发现，由于抽运 光的影响，脉冲前沿的场分布将由远离高斯分布向接近高斯分布变化，称之为脉冲前沿的场 倏变现象. 关键词： 激光二极管 二极管抽运激光器 光束质量     

关于 L1(μ )上有界线性算子的 逼近性质与局部化性质

本文指出: Banach空间 L1 (μ )到 Banach空间 X 中的有界线性算子的紧性、弱紧性、可凹性与 Riesz可表示性分别在逼近意义与局部化意义下相互等价.     

快速凝固Al-Ti-RE合金中金属间化合物相的研究

通过快速凝固技术，Al-Ti合金中添加稀土元素可以产生细小、弥散、均匀分布的金属间化合物相。由于这种化合物相具有优良的热稳定性，快速凝固的Al-Ti-RE合金可作为高温材料使用。使用透射电子显微镜(TEM)和其它检测手段研究表明这种金属间相是金刚石立方结构，晶格常数a=1.77736nm，空间群Fd3m。该相优先于其它化合物相从熔体重直接形成，孪晶在形核阶段起着重要作用，晶粒沿二十面体的每一个外表面呈辐射状生长的。     

高灵敏度原子荧光光谱系统应用于砷、硒形态分析的研究

将实验室自制的高灵敏度原子荧光光谱系统与色谱分离、在线紫外光前处理装置联用,实现了元素形态的液相色谱分离、在线紫外消解、蒸气发生及原子荧光光谱测定,并以砷、硒两元素为例对系统的分析性能进行研究。样品通过加热混旋提取、离心、过滤,使用反相色谱柱并以5.0 mmol/L磷酸氢二铵缓冲溶液(pH 5.7)-0.5 mmol/L四丁基溴化铵(TBAB)-1%甲醇为流动相进行分离;三价砷(AsO3-3)、二甲基砷(DMA)、一甲基砷(MMA)、五价砷(AsO3-4)可在7 min内进行分离和测定,硒代胱氨酸(SeCys)、硒代蛋氨酸(SeMet)、四价硒(SeO2-3)、六价硒(SeO2-4)的测定约需11 min。在优化实验条件下,方法检出限(DLs,S/N=3)为0.08~0.74μg/L;相对标准偏差(RSD,n=7)为1.4%~7.9%,实际样品的加标回收率为82.5%~116.5%;砷、硒各形态在0.28~40.0μg/L和0.38~80.0μg/L范围内线性良好。建立的联用系统稳定性好、检出限低,可实现样品中低浓度砷、硒形态的准确测定。     

表面增强拉曼光谱在DNA检测中的应用

表面增强拉曼光谱(Surface Enhanced Raman Spectroscopy,SERS)由于具有光谱分辨率高、信息量大,不受水的干扰,灵敏度高等优点,在生命科学等研究领域得到了广泛应用。近几年来,SERS技术在DNA分析领域中得到迅速的发展,成为国内外研究的热点。本文主要对SERS进行了介绍,并对应用于DNA检测的一些最新SERS技术进行较为全面的综述,展望了SERS技术的应用前景。     

基于熵权和综合指数法的西部矿业城市环境可持续发展综合评价北大核心

构建了包含环境治理系统、废物处理系统和城市绿化系统3个维度,共17个指标的矿业城市环境可持续发展的指标体系,借助熵权法对评价指标进行动态赋权,利用综合指数法对矿业城市六盘水2004-2011年的环境可持续发展进行了综合评价,并对3个子系统进行了评价,结果发现,矿业城市六盘水的环境可持续发展能力是逐年上升的,3个子系统的可持续发展能力也在逐步提升..     

First principles study on the structural, electronic and optical properties of diluted magnetic semiconductors Zn1-xCoxX （X=S, Se, Te）

The electronic and optical properties of zincblende ZnX（X=S, Se, Te） and ZnX：Co are studied from density functional theory （DFT） based first principles calculations. The local crystal structure changes around the Co atoms in the lattice are studied after Co atoms are doped. It is shown that the Co-doped materials have smaller lattice constant （about 0.6%-0.9%）. This is mainly due to the shortened Co-X bond length. The （partial） density of states （DOS） is calculated and differences between the pure and doped materials are studied. Results show that for the Co-doped materials, the valence bands are moving upward due to the existence of Co 3d electron states while the conductance bands are moving downward due to the reduced lattice constants. This results in the narrowed band gap of the doped materials. The complex dielectric indices and the absorption coefficients are calculated to examine the influences of the Co atoms on the optical properties. Results show that for the Co-doped materials, the absorption peaks in the high wavelength region are not as sharp and distinct as the undoped materials, and the absorption ranges are extended to even higher wavelength region.     

Temperature－Dependent Photoluminescence of ZnTe Films Grown on Si Substrates

ZnTe films have been prepared on Si substrates by metal-organic chemical vapour deposition (MOCVD), and the temperature-dependent photoluminescence (PL) properties were investigated. The near-band-edge (NBE) emission of the ZnTe sample at 83K shows an asymmetry line shape, which can be decomposed into two Gaus-siam lines labelled by FE and BE. Temperature-dependent PL intensity of the NBE peak shows two variation regions, and an expression with two dissociation channels fits well to the experimental data. The results of the temperature-dependent full width at half maximum (FWHM) and peak energy were well understood under the framework of the two-dissociation-channel model. That is, at low temperature, the emission from bound excitons governs the NBE peak, while above 157K, the free exciton emission becomes dominant gradually. A simple model with three energy levels was employed to describe the variation in emission intensity of BE and FE with temperature.