掺入Ni元素的LiCoO2晶体光谱结构及电子顺磁共振g因子

在弱场图像下,利用Racah不可约张量算符方法得到了三角对称3d4/3d6电子组态的210阶可完全对角化的微扰哈密顿矩阵、最近邻点电荷模型晶体结构常量公式和电子顺磁共振g因子公式.研究了LiCoO2晶体和掺入Ni的LiCoO2:Ni晶体中Co3+的基态能级、晶体结构和电子顺磁共振g因子.考虑了LiCoO2晶体和LiCoO2:Ni晶体中自旋单重态和三重态对Co3+基态能级的影响,讨论了LiCoO2晶体和在LiCoO2晶体中掺杂Ni后Co3+局域结构常量大小的变化是引起Co3+的基态能级变化的主要原因,理论和实验都证实了这一点.还计算了掺杂前后的电子顺磁共振g因子,计算结果与实验值符合得较好.     

Au/SiO2纳米复合薄膜的微结构及光吸收特性研究

用多靶磁控溅射技术制备了Au/SiO2纳米多层薄膜.利用透射电子显微镜以及吸收光谱对Au/SiO2复合薄膜的微观结构、表面形貌及光学性能进行了表征和测试.研究结果表明:单层Au/SiO2薄膜中Au沉积时间小于10s时,分散在SiO2中的Au颗粒随Au的沉积时间的延长而增大;当沉积时间超过10s后,Au颗粒的尺寸几乎不随沉积时间变化,但Au颗粒的形状由网络状结构变为薄膜状结构.[Au(t1)SiO2(600)]×5多层薄膜在540-560nm波长附近有明显的表面等离子共振吸收峰,且吸收峰的强度随Au的沉积时间增加而增强.基于修正后的Maxwell-Garnett (M-G)有效媒质理论,讨论了金属颗粒的形状对等离子共振吸收峰的峰位和强度的影响.模拟的吸收光谱与实验吸收光谱形状、趋势及吸收峰位相符合.     

Au/SiO2纳米多层薄膜的制备及其性质表征

利用多靶磁控溅射技术制备了Au/SiO2纳米颗粒分散氧化物多层复合薄膜.研究了在保持Au单层颗粒膜沉积时间一定时薄膜厚度一定、变化SiO2的沉积时间及SiO2的沉积时间一定而改变薄膜厚度时,多层薄膜在薄膜厚度方向的微观结构对吸收光谱的影响.研究结果表明:具有纳米层状结构的Au/SiO2多层薄膜在560nm波长附近有明显的表面等离子共振吸收峰,吸收峰的强度随Au颗粒的浓度增加而增强,在Au颗粒浓度相同的情况下,复合薄膜光学吸收强度随薄膜厚度的增加而增强.但当金属颗粒的浓度增加到一定程度时,金属颗粒相互接触,没有观察到纳米层状结构,薄膜不显示共振吸收峰特征.用修正后的M-G(Maxwell-Garnett)理论对吸收光谱进行了模拟,得到了与实验一致的结果.     

The effect of configuration complex on dielectronic recombination process in highly ionized plasmas

This paper analyses the effect of configuration complex on dielectronic recombination （DR） process in highly ionized plasmas （Xe^26＋, Dy^38＋, W^46＋） by using the multiconfiguration relativistic Hartree-Fock method. Resonant and nonresonant radiative stabilizing transitions and decays to autoionizing levels followed by radiative cascades are included. Collisional transitions following electron capture are neglected. The remarkable difference between the isoelectronic trend of the rate coefficients for DR through 3d^94l4l′ and through 3d^94l5l′ is emphasized. The trend of DR through 3d^94l4l′ shows irregularities at relatively low temperature due to the progressive closing of DR channels as atomic number Z increases.     

中国环流器二号A(HL-2A)超声分子束注入最新结果

HL-2A装置电子回旋共振加热时,氘脉冲超声分子束穿越分界面,等离子体各项重要参数,包括等离子体储能、极向比压、中平面线平均密度、中心密度和温度上升,中子产额急剧增加. 超声分子束注入有可能较常规脉冲送气在台基顶部提供较强的粒子源,被认为是可供ITER替换脉冲送气的加料方法之一. HL-2A装置氢超声分子束注入的平均速度约为1.7km,与溢流(分子流)注入真空的速度测量作了比较. 关键词： 超声分子束注入 托卡马克 飞行时间法 加料     

Progress in improving thermodynamics and kinetics of new hydrogen storage materials

Hydrogen storage material has been much developed recently because of its potential for proton exchange membrane (PEM) fuel cell applications. A successful solid-state reversible storage material should meet the requirements of high storage capacity, suitable thermodynamic properties, and fast adsorption and desorption kinetics. Complex hydrides, including boron hydride and alanate, ammonia borane, metal organic frameworks (MOFs), covalent organic frameworks (COFs) and zeolitic imidazolate frameworks (ZIFs), are remarkable hydrogen storage materials because of their advantages of high energy density and safety. This feature article focuses mainly on the thermodynamics and kinetics of these hydrogen storage materials in the past few years.     

An improved quantum repeater protocol using hyperentangled state purification

This article indicates an improved protocol of quantum repeaters through the scheme of nest entanglement purification [Phys. Rev. Lett. 81, 5932 (1998)]. The hyperentangled photon pairs are utilized to overcome the limitations of long distance quantum communication via noisy channels. In addition, it is mentioned that if there are imperfect quantum operations and noises in realistic communication, the fidelities of hyperentangled quantum channels will be improved compared with the traditional entangled states.     

高损伤阈值三倍频分离膜

 设计了Nd：YAG激光用三倍频分离膜,膜层材料为SiO₂和HfO₂。经过优化,膜系在355 nm处的反射率在99%以上,在532 nm和1 064 nm处透射率也在99%以上。采用电子束蒸发技术,在熔融石英基底上制备了样品,经测量,制备的分离膜光学性能与设计值接近。分离膜在355 nm激光辐照下的损伤阈值为5.1 J/cm²,并用微分干涉显微镜表征了薄膜损伤形貌。     

利用透射电镜衬度像变化判定位错环类型及注氢纯铁中形成的位错环分析

本文分两部分,第一部分研究了利用透射电镜衬度像变化判定材料中位错环类型的方法,即采用所谓inside-outside方法来判断位错环为空位型位错环或间隙型位错环. 第二部分讨论了加速器注氢纯铁在673—773 K时效后形成的位错环的类型. 关键词： 透射电镜 空位型位错环 间隙型位错环 氢     

Cluster synchronization in a network of non-identical dynamic systems

Cluster synchronization in a network of non-identical dynamic systems is studied in this paper, using two-cluster synchronization for detailed analysis and discussion. The results show that the common intercluster coupling condition is not always needed for the diffusively coupled network. Several sufficient conditions are obtained by using the Schur unitary triangularization theorem, which extends previous results. Some numerical examples are presented for illustration.