非晶态As_2S_8半导体薄膜的光激励现象的研究及应用

实验研究了非晶态As2S8半导体薄膜在紫外汞灯和He_Cd激光照射下的光诱导现象,证实了光照射后的As2S8薄膜的折射率增大,体积缩小,可见光吸收谱的吸收带蓝移。在此基础上,应用光折变效应试制了As2S8条波导,观测到As2S8条波导的光阻断效应,实现了光_光效应的开关功能。     

Study of BESⅢ MUC offine software with cosmic-ray data

Cosmic-ray data of 90 M events have been collected and used for calibration,alignment as well as detector tuning. A special tracking algorithm for the BESⅢ muon counter is developed and verified with Monte-Carlo simulation and then further confirmed with the cosmic-ray data. The obtained strip resolutions are in good agreement with the design values. A new alignment approach for the BESⅢ muon counter is confirmed with the cosmic-ray data and proposed to be used in future analysis of experimental data.     

光学双向推扫空间相机的设计与实验

对于搭载单向积分TDI探测器的推扫式空间光学相机,探测器的积分方向是限制卫星敏捷机动任务规划的一项重要限制。利用在光学系统中加入法线方向与光轴成一定角度的平面镜可以改变系统物像正倒关系而不影响光程及像质的特点,设计了光学双向推扫系统。为了验证其方案的合理性,设计并装调了光学双向推扫相机工程样机。对该相机进行外景成像实验,成像实验结果与预期一致,光路切换效果明显,验证了其适应两种飞行方向的能力。总结工程样机研制过程,提出了后续需要考虑的问题,为后续光学双向推扫相机在型号上应用打下基础。     

Multi-fractal analysis of highway traffic data

The purpose of the present study is to investigate the presence of multi-fractal behaviours in the traffic time series not only by statistical approaches but also by geometrical approaches. The pointwise H\"{o} lder exponent of a function is calculated by developing an algorithm for the numerical evaluation of H\"{o} lder exponent of time series. The traffic time series observed on the Beijing Yuquanying highway are analysed. The results from all these methods indicate that the traffic data exhibit the multi-fractal behaviour.     

《高等学校化学学报》在中国科技期刊总被引频次的总排序表中居第三位

据中国科技信息研究所编辑出版的《1 999年中国科技期刊引证报告》( 2 0 0 0年 1 1月 )公布的结果 ,《高等学校化学学报》在中国科技期刊总被引频次的总排序表中居第三位 (见附表 )。总被引频次是指某期刊自创刊以来所刊载的全部论文在统计当年被引作参考文献的总次数。这是一个非常客观的评价指标 ,可以显示期刊被使用和受重视的程度以及在学术交流中的作用。总排序表是指中国科技信息研究所选作中国科技论文统计源的 1 3 70余种科技期刊按被引频次大小所做的总排序。中国科技期刊总被引频次排序表 (节选 )名次期刊名称 被引频次影响因子1…     

旋转变换综合问题的解决策略探析

旋转变换是新课程标明确规定的重要内容之一,由于它有利于培养学生实践与操作能力,形成空间观念和运动变化意识,故在各地中考中,出现了将旋转变换融人到几何图形的证明和计算中的综合试题,使问题充满着动感,富于变换,本文试就旋转变换思想在中考数学试题中的应用加以说明. 一、旋转变换知识归纳 1.定义:在平面内,将一个图形绕一个定点沿某个方向转动一个角度形成新的图形,这样的图形运动叫做图形的旋转,这个定点叫做旋转中心,图形转动的角叫做旋转角.旋转变换分为全等变换和相似变换.     

光化学反应的从头算研究

光化学反应是最基本也是最重要的物理化学过程之一,在诸多领域有着广泛的应用。由于计算方法的限制以及光化学反应过程的错综复杂性,光化学反应机理的从头算研究是极具挑战性的国际前沿课题之一。本文综述了近20年来羰基化合物光化学反应机理从头算研究的一些进展,总结了羰基化合物电子激发态的特性和光化学反应过程的规律性,为深入研究光化学反应提供一些有用的信息。     

Neutrino Emission and Cooling of Dark-Matter-Admixed Neutron Stars

The GW170817 binary neutron star merger event in 2017 has raised great interest in the theoretical research f neutron stars. The structure and cooling properties of dark-matter-admixed neutron stars are studied here using relativistic mean field theory and cooling theories. The non-self-annihilating dark matter(DM) component is assumed to be ideal fermions, among which the weak interaction is considered. The results show that pulsars J1614-2230, J0348+0432 and EXO 0748-676 may all contain DM with the particle mass of 0.2–0.4 GeV. However,it is found that the effect of DM on neutron star cooling is complicated. Light DM particles favor the fast cooling of neutron stars, and the case is converse for middle massive DM. However, high massive DM particles, around1.0 GeV, make the low mass(around solar mass) neutron star still undergo direct Urca process of nucleons at the core, which leads the DM-admixed stars cool much more quickly than the normal neutron star, and cannot support the direct Urca process with a mass lower than 1.1 times solar mass. Thus, we may conjecture that if small(around solar mass) and super cold(at least surface temperature 5–10 times lower than that of the usual observed data) pulsars are observed, then the star may contain fermionic DM with weak self-interaction.     

离散的Painlevé方程Ⅱ的有理解

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