线聚焦激光辐照Al靶所产生的紫外X射线谱线

本文叙述了采用线聚焦激光幅照Al靶所产生的高离化态离子的紫外X射线(XUV)谱线。利用Cowan的原子能级程序计算了不同离化态的离子谱线的波长和振子强度gf,辨认出140条离子谱线,其中有82条新谱线。 关键词：     

激光沉积超导薄膜过程中出射粒子速度的飞行时间谱分析

采用飞行时间谱技术,测量了准分子激光烧蚀沉积高温超导薄膜过程中,由靶面出射粒子的飞行速度。研究了粒子速度与充氧压及其激光能量密度的关系。讨论了高能粒子在薄膜原位低温外延生长中的作用。     

Anharmonic corrections for linear triatomic molecules subject to the Rennet-Teller effect

The effects of vibrational anharmonic terms and of the g_K -correction on the energy levels of a triatomic molecule in a degenerate electronic state are considered. The electronic wavefunctions are described using the approach first suggested in the original paper of Renner. Formulae for the anharmonic corrections in a number of different situations are derived. For an electronic Π state the corrections are given in the form where i runs over the various contributions and x ₁, x ₂, … depend on the anharmonic force constants. The functions F_i can be determined numerically (see equations (4.3) and 4.7)). For the case without spin-orbit interaction the F_i s are given explicitly to first order in ∈ in table 1. Further-more, the same results apply for levels with |K|=v ₂+1 even if the spinorbit interaction is not negligible. Explicit results for levels with |K|<v ₂ including spin-orbit interaction are given in tables 2 and 3. The cases with larger values for Λ (2, 3, …) are also considered. The energy level formulae for a Δ state differ from those derived earlier by Merer and Travis. In particular, the small separation between the vibronic Φ and Π levels with v ₂=1 is now found to be 4g_K . The additional terms that arise from end-over-end rotation of the molecule are discussed in § 6.     

Wavenumber Calibration of CCD Detector Raman Spectrometers Controlled by a Sinus Arm Drive

Abstract

The calibration procedures needed for use of dispersive Raman spectrometers have been reviewed. Like other high‐precision spectrometers incorporating moving gratings, Raman spectrometers are subject to problems with wavenumber scale accuracy. Commercially available Raman spectrometers of types DILOR‐HORIBA LabRam and RENISHAW System 1000 have been examined for wavenumber scale stability, linearity, and reproducibility. For reliable use of the wavenumber data, daily calibration is a necessity. A procedure to examine the linearity of such mechanical drive systems is presented. A new finding was that the examined spectrometers give wavenumber calibration errors that were quite reproducible from day to day at a given temperature in the laboratory but depended markedly on the selected setting of the gratings. Knowledge of this linearity problem is essential for obtaining a reliable calibration. The most correct calibration was obtained by the use of certain “golden” settings of the sinus drive at a constant temperature of the laboratory. In this way, the examined spectrometers could be used with better precision, without daily calibration, provided the temperature of the room was constant or corrected for. A procedure for correction of these errors by the software is suggested.     

肝肿瘤细胞HepG2代谢指纹及代谢足迹的NMR分析

细胞代谢特征的分析是认识细胞生物化学过程物质基础的一个关键点. 该文使用培养72 h的肝肿瘤细胞HepG2为模型,使用一维与二维核磁共振谱学分析方法, 分析了该细胞本身及其培养液中代谢物的组成,确定了50余种覆盖三羧酸循环、糖酵解、氨基酸合成、脂肪酸与胞膜代谢、嘌呤与嘧啶代谢等多个代谢途径的代谢物,发现细胞本身与培养基中代谢物组成能够分别提供“细胞代谢指纹”与“细胞代谢足迹”等互补性信息. 同时发现此方法可用于研究植物次生代谢物槲皮素对肝肿瘤细胞HepG2代谢的影响. 结果表明,核磁共振波谱技术是分析细胞代谢组特征和研究药物对细胞代谢影响规律的有效手段.     

Born-Infeld电动力学的U1主丛表述

本文给出了Born-Infeld电动力学的U₁主丛表述,以及检验粒子在Born-Infeld电磁场中的运动方程,检验粒子受到两个力,一个相当于Lorentz力,一个相当于Poincaré压力。     

Comparative yields of alkali elements and thallium from uranium irradiated with GeV protons,3He and12C

Mass-separated ion beams of the alkali elements Na, K, and Fr, and of the element Tl, were produced by bombarding a uranium target with 600 MeV protons, 890 MeV³He^{2 +}, and 936 MeV¹²C^{4 +}. Isotopic production yields are reported. In the case of the¹²C beam, these are thick target yields. Absolute cross-sections for the proton beam data were deduced by normalizing the delay-time corrected yield curves to measured cross-sections. For products farthest away from stability, the³He^{2 +} beam generally gives the highest yields.     

Regenerative simulation of TES processes

Regenerative simulation has become a familiar and established tool for simulation-based estimation. However, many applications (e.g., traffic in high-speed communications networks) call for autocorrelated stochastic models to which traditional regenerative theory is not directly applicable. Consequently, extensions of regenerative simulation to dependent time series is increasingly gaining in theoretical and practical interest, with Markov chains constituting an important case. Fortunately, a regenerative structure can be identified in Harris-recurrent Markov chains with minor modification, and this structure can be exploited for standard regenerative estimation. In this paper we focus on a versatile class of Harris-recurrent Markov chains, called TES (Transform-Expand-Sample). TES processes can generate a variety of sample paths with arbitrary marginal distributions, and autocorrelation functions with a variety of functional forms (monotone, oscillating and alternating). A practical advantage of TES processes is that they can simultaneously capture the first and second order statistics of empirical sample paths (raw field measurements). Specifically, the TES modeling methodology can simultaneously match the empirical marginal distribution (histogram), as well as approximate the empirical autocorrelation function. We explicitly identify regenerative structures in TES processes and proceed to address efficiency and accuracy issues of prospective simulations. To show the efficacy of our approach, we report on a TES/M/1 case study. In this study, we used the likelihood ratio method to calculate the mean waiting time performance as a function of the regenerative structure and the intrinsic TES parameter controlling burstiness (degree of autocorrelation) in the arrival process. The score function method was used to estimate the corresponding sensitivity (gradient) with respect to the service rate. Finally, we demonstrated the importance of the particular regenerative structure selected in regard to the estimation efficiency and accuracy induced by the regeneration cycle length.     

用于SCA ASIC测试的数字读出模块设计

高速开关电容阵列(SCA)具有高速采样、低功耗的特点,基于SCA的高速波形数字化是目前高精度时间测量的一个重要研究方向。为此,我们开展SCA芯片的研究,目前已设计完成原型ASIC设计,并正在进行后续版本的改进设计。为便于未来多版本ASIC的测试和评估,需设计具有一定通用性的数字读出模块,本论文工作主要介绍此模块的设计工作以及相应的数据读出软件。数字读出模块基于FPGA实现对待测ASIC的控制、配置及数据读出,采用DDR3片外存储芯片,使用USB3.0等接口进行数据传输;上位机软件基于Python3.7设计,实现了数据采集与波形绘制等功能。目前已使用设计完成的数字读出模块对第2版SCA ASIC进行了初步的测试,测试结果表明,此读出模块工作正常,且SCA芯片输出结果符合预期。     

基于伪模态转换的红外目标融合检测算法

为提高红外图像目标检测的精度和实时性,提出一种基于伪模态转换的红外目标融合检测算法.首先,利用双循环的生成对抗网络无需训练图像场景匹配的优势,获取红外图像所对应的伪可见光图像;然后,构建残差网络对双模态图像进行特征提取,并采取add叠加方式对特征向量进行融合,利用可见光图像丰富的语义信息来弥补红外图像目标信息的缺失,从而提高检测精度;最后,考虑到目标检测效率问题,采用YOLOv3单阶段检测网络对双模态目标进行三个尺度的预测,并利用逻辑回归模型对目标进行分类.实验结果表明,该算法能够有效地提高目标检测准确率.