光场位相算符和逆算符的Weyl编序展开

用有序算符内的积分技术, 推导了光场位相算符和逆算符的Weyl编序展开形式, 并利用该结果获得了相算符的经典对应以及某些新的特殊函数的生成函数和新的积分公式, 尤其是导出了带负次幂的复高斯积分的积分公式. 关键词： Weyl编序 位相算符 有序算符内的积分     

稳恒磁场对Fe-Fe50 wt.%Si扩散偶中间相生长的影响

本文考察了Fe-Fe50 wt.%Si扩散偶在1200℃ 无磁场以及稳恒磁场下扩散层生长规律. 利用真空浇注强制冷却技术制备Fe-Fe50 wt.%Si扩散偶, 将制备的扩散偶进行1200℃不同磁感应强度下的热处理. 对获得热处理后试样进行SEM与EDS线扫描分析, 结果表明, 无论无磁场还是稳恒磁场下Fe-Fe50 wt.%Si扩散偶均生成两个扩散层, 即FeSi相层和Fe-Si固溶体层, 并且发现0.8 T下的两个扩散层宽度均小于0 T磁场下试样. 按照抛物线规律, 计算了扩散偶中间扩散层的互扩散系数, 发现0.8 T磁场下FeSi相层和Fe-Si固溶体层的互扩散系数较无磁场下 分别降低了26.7%与34.1%. 通过对磁吉布斯自由能的计算, 发现0.8 T磁场对扩散激活能Q的影响不足以影响扩散过程. 但扩散过程中原子振动频率ν会受到磁场的影响, 进而影响扩散常数D₀, 磁场对原子振动频率的影响可以用拉莫尔旋进理论进行解释. 关键词： Fe-Fe50wt.%Si扩散偶 稳恒磁场 FeSi相 Fe-Si固溶体     

AB/CD嵌段共聚物共混体系多尺度结构的自洽场模拟

本文采用自洽场理论模拟了AB/CD嵌段共聚物共混体系的自组装. 改变组分B与D间的相互作用, 得到了不同空间尺度上的两种层状结构和只能在非对称组成情况才能得到的核壳结构. 结果表明, 这种多尺度结构的形成是因为BD间排斥作用的减弱或者吸引 作用的增强导致二者间相互融合程度的增加. 当BD间的相互融合程度与AB和CD间的相互融合程度相当时, 体系会发生宏观层状与微观层状结构间的转变. 此外, 本文还从能量角度揭示了体系发生这种结构转变的深层次原因. 关键词： 嵌段共聚物 共混 多尺度结构 自洽场     

非对称Halo异质栅应变Si SOI MOSFET的二维解析模型

为了进一步提高深亚微米SOI (Silicon-On-Insulator) MOSFET (Metal-Oxide Semiconductor Field Effect Transistor) 的电流驱动能力, 抑制短沟道效应和漏致势垒降低效应, 提出了非对称Halo异质栅应变Si SOI MOSFET. 在沟道源端一侧引入高掺杂Halo结构, 栅极由不同功函数的两种材料组成. 考虑新器件结构特点和应变的影响, 修正了平带电压和内建电势. 为新结构器件建立了全耗尽条件下的表面势和阈值电压二维解析模型. 模型详细分析了应变对表面势、表面场强、阈值电压的影响, 考虑了金属栅长度及功函数差变化的影响. 研究结果表明,提出的新器件结构能进一步提高电流驱动能力, 抑制短沟道效应和抑制漏致势垒降低效应, 为新器件物理参数设计提供了重要参考. 关键词： 非对称Halo 异质栅 应变Si 短沟道效应     

Synthesis,Characterization, and Antibacterial Activity of RE(III) Complexes with L-Isoleucine and 1,10-Phenanthroline

Six new ternary rare-earth (La, Eu, Sm, Nd, Y, Yb) complexes with L-isoleucine and 1,10-phenanthroline have been synthesized. Their compositions were characterized as RE(Ile)₃PhenCl₃ · 4H₂O (RE = La, Eu, Sm, Nd, Y, Yb; Ile = L-isoleucine; phen = 1,10-phenanthroline) by elemental analysis, EDTA titration, molar conductance measurement, UV spectra, FT-IR spectra, and TG-DTA. The average diameters of growth inhibition area and the minimal inhibitory concentration (MIC) of the complexes were studied by disc diffusion method and dilution method in nutrient broth. The results showed that the ternary rare-earth complexes strongly exhibited the antibacterial activity against Escherichia coli and Staphylococcus aureus and that their antibacterial effects were better than those of rare-earth chlorides, L-isoleucine, and 1,10-phenanthroline.     

Free exciton emission in forward-biased CdS MIS diodes

The radiative decay of free excitons with the emission of 0, 1, or 2LO phonons has been observed in electroluminescence in Cds MIS diodes operated in forward bias at temperatures in the range 40 – 77K. The line shapes and temperature dependence of the ILO and 2LO phonon assisted replicas are discussed in terms of the distribution of kinetic energy of the excitons with an effective temperature equal to that of the lattice.     

ON THE ESSENTIAL SPECTRUM OF PSEUDODIFFERENTIAL OPERATORS （Ⅱ）

This paper coutinues the studies of the essential spectrum of nonsemi-bounded pseudodifferential operators. The author improves the results in [5] in some sense. For the relativistic Schrodinger operator,√(-Δ+m^2)+v(x),complete results are obtained.     

An improved evaluation of the neutron background in the PandaX-Ⅱ experiment

In dark matter direct detection experiments,neutron is a serious source of background,which can mimic the dark matter-nucleus scattering signals.In this paper,we present an improved evaluation of the neutron background in the PandaX-II dark matter experiment by a novel approach.Instead of fully relying on the Monte Carlo simulation,the overall neutron background is determined from the neutron-induced high energy signals in the data.In addition,the probability of producing a dark-matter-like background per neutron is evaluated with a complete Monte Carlo generator,where the correlated emission of neutron(s)andγ(s)in the(α,n)reactions and spontaneous fissions is taken into consideration.With this method,the neutron backgrounds in the Run 9(26-ton-day)and Run 10(28-ton-day)data sets of PandaX-II are estimated to be(0.66±0.24)and(0.47±0.25)events,respectively.     

The High Energy X-ray telescope (HE) onboard the Insight-HXMT astronomy satellite

The Insight-Hard X-ray Modulation Telescope(Insight-HXMT) is a broadband X-ray and γ-ray(1-3000 ke V) astronomy satellite. One of its three main telescopes is the High Energy X-ray telescope(HE). The main detector plane of HE comprises 18 Na I(Tl)/Cs I(Na) phoswich detectors, where Na I(Tl) is used as the primary detector to measure ~ 20-250 ke V photons incident from the field of view(FOV) defined by collimators, and Cs I(Na) is used as the active shielding detector to Na I(Tl) by pulse shape discrimination. Additionally, Cs I(Na) is used as an omnidirectional γ-ray monitor. The HE collimators have a diverse FOV,i.e. 1.1°×5.7°(15 units), 5.7°×5.7°(2 units), and blocked(1 unit). Therefore, the combined FOV of HE is approximately5.7°×5.7°. Each HE detector has a diameter of 190 mm resulting in a total geometrical area of approximately 5100 cm2, and the energy resolution is ~15% at 60 ke V. For each recorded X-ray event by HE, the timing accuracy is less than 10 μs and the deadtime is less than 10 μs. HE is used for observing spectra and temporal variability of X-ray sources in the 20-250 ke V band either by pointing observations for known sources or scanning observations to unveil new sources. Additionally, HE is used for monitoring the γ-ray burst in 0.2-3 Me V band. This paper not only presents the design and performance of HE instruments but also reports results of the on-ground calibration experiments.     

NO分子宏观气体热力学性质的理论研究

采用量子统计系综理论,研究了基态NO分子宏观气体摩尔熵、摩尔内能、摩尔热容等热力学性质.首先应用课题组前期建立的变分代数法(variational algebraic method, VAM)计算获得了基态NO分子的完全振动能级,得到的VAM振动能级作为振动部分,结合欧拉-麦克劳林渐进展开公式的转动贡献,应用于经典的热力学与统计物理公式中,从而计算得到了1000-5000 K温度范围内NO宏观气体的摩尔内能、摩尔熵和摩尔热容.将不同方法计算得到的摩尔热容结果分别与实验值进行比较,结果表明基于VAM完全振动能级获得的结果优于其他方法获得的理论结果.振动部分采用谐振子模型对无限能级求和计算热力学性质的方法有一定的局限性,应当使用有限的完全振动能级进行统计求和.