离子阱质谱计及其在团簇科学中的应用

在离子阱物理和技术基础上，发展了离子阱质谱技术，并将这一高灵敏原位检测技术用于激光溅射产生并囚禁碳原子团簇离子，质量选择存储以及化学反应等研究，并报道了相关应用研究的进展和结果。     

基于FPGA的亚像元图像融合系统的设计与实现

研究并设计了基于FPGA的亚像元图像融合系统，该系统能够在接收到亚像元相机输出的两路CCD图像信号后，实时地将其融合并显示．搭建了亚像元图像融合实验平台，介绍了系统的组成以及主要电路的实现方法，并进行了实验验证．结果表明，图像融合效果好，设计方案可行．     

非对称布置液滴在波纹状基底上的聚并过程

基于润滑理论建立在波纹基底上两个含表面活性剂液滴聚并的演化模型，模拟液滴位于波纹基底波峰和波谷处的聚并过程，分析液滴初始间距和基底高度对聚并的影响，并与对称布置液滴进行比较.结果表明：液滴高度随时间呈现五个阶段变化；活性剂浓度在短时间内完成三个阶段变化；初始间距的增大将延长液滴及活性剂聚并时间；增大基底高度将缩短液滴及活性剂聚并时间；非对称液滴相较于对称液滴聚并时间短，聚并速度快.     

双叉同时进液氢化物发生器

本文介绍一种新型的双叉同时进液氢化物发生器，考察并确定了原子荧光光度法测定砷的条件，并同时应用于砷、锑等元素的测定。结构简单，操作方便，分析快速，检测限低，稳定性好。     

外电场对弹簧振子系统运动特性的影响

设计了一个受周期驱动带电弹簧振子的实验装置，并建立系统的动力学方程，用线性稳定性分析的方法确定平衡点并分析平衡点的稳定性，利用数值计算并结合多种分析方法求解和判断非线性方程解的各种性质，得到存在电场力作用情况下系统的一些新特性。     

火灾烟雾颗粒凝并分形特性研究

火灾烟雾颗粒因布朗运动由初期的主粒子凝并形成大颗粒的凝团结构，其外形呈现出分形特征，根据分形理论对火灾烟雾颗粒凝团结构进行分析研究，采用场发射扫描电镜对多种材料的烟雾颗粒图像进行测试，通过对烟雾凝团图像进行处理，获得了火灾探测中常见的多种材料的分形维数和分形系数，给出了烟雾颗粒的主粒子粒径，并对其影响因素进行了对比分析，为火灾烟雾探测中颗粒凝并分形特性研究提供有益的探索. 关键词： 火灾 烟雾 颗粒 凝并 分形     

苯并（a）Bei的同步荧光法测定条件研究

本文研究了题述方法的测定条件，并引入系统校正以消除同系物苯并（ｋ）荧蒽对苯并（ａ）Ｂｅｉ（ＢａＰ）的测定干扰，在其他文献中未见报道，此法较现行的普通荧光窄基线法测定操作简便快速，实样测定结果满意。     

Flash动画学习技巧——分析与模仿

本文从另一角度阐述了快速掌握Flash软件的方法，并从对Rash文件的模仿和解析人手，结合几款破解软件做了深入探讨，对快速掌握并使用软件，迅速成长为动画制作高手，有较好的指导性。     

北京大学加速器质谱计

北京大学重离子物理研究所和技术物理系研制的加速器质谱计于１９９２年圆满建成并投入使用，在两年多的运行中，性能不断得到改进，并取得了大量的应用成果，简要介绍其性能特点，运行情况和应用概况。     

掺杂金微粒Na2O—B2O3—SiO2系统玻璃的溶胶—凝胶方法制备及其光学…

采用正硅酸乙酯，硼酸，乙醇钠为先驱体，乙醇，乙二醇甲醚和乙醇为先驱体溶剂，并采用氯化金的水溶液为掺杂金微粒的先驱体，通过热处理使氯化金分解出金原子而使其长出金微粒，达到制备掺杂金微粒玻璃的目的，在钠硼硅系统干胶的制备过程中，详细地研究了氯化钠的引入量等对大块干胶性质的影响，并确定了引入氯化金的适宜浓度，详细研究了干胶向玻璃转变的制备工艺，并成功地制备了掺杂金微粒的大块玻璃，采用Ｘ－射线衍射仪进行掺     

Aerial Video Trackers Review

Target tracking technology that is based on aerial videos is widely used in many fields; however, this technology has challenges, such as image jitter, target blur, high data dimensionality, and large changes in the target scale. In this paper, the research status of aerial video tracking and the characteristics, background complexity and tracking diversity of aerial video targets are summarized. Based on the findings, the key technologies that are related to tracking are elaborated according to the target type, number of targets and applicable scene system. The tracking algorithms are classified according to the type of target, and the target tracking algorithms that are based on deep learning are classified according to the network structure. Commonly used aerial photography datasets are described, and the accuracies of commonly used target tracking methods are evaluated in an aerial photography dataset, namely, UAV123, and a long-video dataset, namely, UAV20L. Potential problems are discussed, and possible future research directions and corresponding development trends in this field are analyzed and summarized.     

Parameter design of a liquid-filled sloshing system

<正>The nonlinear governing equations of the liquid sloshing modals in a cylindrical storage tank are established. Through analytical analysis,the analytical expressions of the solutions of this kind of system are obtained.With different parameters,the dynamical behaviors of the solutions are different from the trivial ones.To prevent system instability,two selection principles that the stiffness equations are positive-definite and the nonlinear terms of the system are not regenerative elements are given.Meanwhile,numerical simulations are also given,which confirm the analytical results.     

约束对Birkhoff系统Noether对称性和守恒量的影响

研究约束对Birkhoff系统的Noether对称性和守恒量的影响．首先，建立了Birkhoff系统的运动微分方程．其次，给出了系统Noether对称性的判据．然后，讨论了受约束作用后，Birkhoff系统的Noether对称性发生的变化，并给出了系统的Noether对称性以及守恒量保持不变的条件．最后，举例说明结果的应用． 关键词： 分析力学 Birkhoff系统 约束 Noether对称性 守恒量     

Some remarks concerning stability for nonstationary quantum systems

The problem of characterizing stability and instability for general nonstationary quantum systems is investigated. Some characterizations are reported and some elementary properties of a topological characterization are established. Then, it is proven, by considering a simple example, that there are nonperiodic driven systems whose orbits are neither precompact nor leave on average any compact set. Autocorrelation measures are computed and the possible roles of the generalizes quasienergy operator and energy growth are briefly discussed.     

亲水性材料固相萃取-紫外导数光谱法检测血中茚满二酮灯抗凝 …

本文报导了血中茚满二酮类抗凝血杀鼠剂敌鼠、氯敌鼠、杀鼠酮的亲水性材料固相萃取－紫外导数光谱检测法。血样用pＨ５缓冲液等体积稀释后加于西雷脱硅藻土柱上,柱用乙酸乙 酯洗脱,将洗脱液挥发干净,剩余物用pＨ１０缓冲液溶解,测定所得溶液的二阶导数光谱进行定性和定量分析。三种杀鼠剂以１０mg／Ｌ的量加于空白血中测得萃取率为８５％以上,血中三种杀鼠剂的检出限低于２ｍｇ／Ｌ。萃取中亲水性硅藻土可用硅胶和氧化铝代替,     

过渡金属原子掺杂的锯齿型磷烯纳米带的磁电子学特性

利用基于密度泛函理论的第一性原理方法,研究了掺杂铁、钴和镍原子的锯齿型磷烯纳米带(ZPNR)的磁电子学特性.研究表明,掺杂和未掺杂ZPNR的结构都是稳定的.当处于非磁态时,未掺杂和掺杂钴原子的ZPNR为半导体,而掺杂铁或者镍原子的ZPNR为金属.自旋极化计算表明,未掺杂和掺杂钴原子的ZPNR无磁性,而掺杂铁或者镍原子的ZPNR有磁性,但只能表现出铁磁性.处于铁磁态时,掺杂铁原子的ZPNR为磁性半导体,而掺杂镍原子的ZPNR为磁性半金属.掺杂铁或者镍原子的ZPNR的磁性主要由杂质原子贡献,产生磁性的原因则是在ZPNR中存在未配对电子.掺杂位置对ZPNR的磁电子学特性有一定的影响.该研究对于发展基于磷烯纳米带的纳米电子器件具有重要意义.     

Ablation of Transparent Materials Using Excimer Lasers for Photonic Applications

For many years, the development of effective ablation or laser machining techniques for making micro-optical components has been the key factor in the birth of new photonic devices and systems. In this article, the ablation characteristics of two types of the most important transparent materials, transparent polymers and glasses, are studied. Simple shaped microcavities are first machined for studying the fundamental ablation parameters, including threshold fluence, effective absorption coefficient, and ablation rate. In studying polymer ablation, five standard grades and five proprietary polymeric compounds are selected. Ablation techniques using these transparent polymers for making arrayed ferrules and curved microlenses are presented. Applications of these ablated microstructures for optical fiber connectors, optical fiber coupling and alignment, and transparent chip encapsulants, are introduced and demonstrated with emphasis on the quality of the ablated profiles and dimensions to satisfy the required performance. In glass ablation, borosilicate glasses are considered and their associated ablation behaviors are studied. The procedures to ablate glass-based arrayed microstructures with flat and curved surfaces are described. The utilizations of these arrayed microstructures for optical waveguide, wave absorber, and beam guider, are specifically discussed. Finally, concluding remakes for future trends are presented.     

Periodic waves in nonlinear metamaterials

Periodic waves are presented in this Letter. With symbolic computation, equations for monochromatic waves are studied, and analytic periodic waves are obtained. Factors affecting properties of periodic waves are analyzed. Nonlinear metamaterials, with the continuous distribution of the dielectric permittivity obtained, are different from the ones with the discrete distribution.     

对声波和弹性波传播模拟的Hamilton系统方法

建立了离散化网格上的准粒子体系，引入此体系的Hamilton系统描述，用来模拟声波和弹性波的传播.介绍了准粒子间相互作用的九点模型并给出互作用系数.证明了Hamilton系统方法 和声波、弹性波方程的关系，并给出两个方法中所使用物理量的关系.使用辛算法对给定的 介质模型进行数值模拟. 关键词： Hamilton系统方法 九点互作用模型 声波方程 弹性波方程 辛算法