类锂离子C^3 光电离过程的研究     

冯向华  马轩文 《测绘学院学报》2000,17(2):152-153,156

使用Ｒ－矩阵方法,采用三态密耦图像计算了类锂离子Ｃ＾３＋激发态１ｓ＾２２ｐ＾２Ｐ的光电离截面,并给出了不同过程及不同分波的截面。计算结果揭示了光电离过程中的Ｒｙｄｂｅｒｇ系列共振。  相似文献   

Star formation in the Cepheus Flare region – II. A-type stars associated with IRAS sources     

M. Kun  †  J. Vinkó ‡  L. Szabados 《Monthly notices of the Royal Astronomical Society》2000,319(3):777-790

In order to reveal the star-forming history of the molecular cloud complex we studied the intermediate mass stellar population in the Cepheus Flare region. (Paper I dealt with the distance and the young stellar object candidates of the region.) Correlating the IRAS Point Source Catalogue and Faint Source Catalogue positions with those of 1214 B8–A8 and 1760 F0–F5 type stars brighter than     and classified during an objective prism survey, we identified 19 stars showing far-infrared excess emission in the Cepheus Flare region. In addition to the 16 stars whose counterparts are given in the IRAS catalogues, we found three more stars with infrared excess not recognized before. In order to identify the young medium-mass stars associated with the Cepheus Flare molecular clouds we observed the optical spectra of the IR-excess stars, and using published optical photometry and the IRAS data we examined their spectral energy distributions (SEDs) and IRAS two-colour diagram. The observations resulted in the discovery of a new Herbig Ae/Be star, BD +68°1118, coinciding with IRAS 21169+6842. More evolved HAe/Be stars may be SAO 19953, BD +67°1314 and BD +69°1231, whose H α lines showed weak emission components. Possible β Pictoris- or Vega-type stars may be HD 203854, HD 212826 and HD 216486, whereas the far-infrared fluxes at the positions of BD +72°1018, HD 210806 and HD 217903 can be attributed to the heating of the interstellar environment. We used distances and radial velocities of the stars derived from the spectroscopy and published optical photometry as indicators of their relations to the clouds. Information on the environment of the observed stars deduced from the diffuse interstellar band at λ 6613 is briefly discussed.  相似文献   

Wavelength dependence of angular diameters of M giants: an observational perspective     

A. P. Jacob  T. R. Bedding  J. G. Robertson  M. Scholz 《Monthly notices of the Royal Astronomical Society》2000,312(4):733-746

We discuss the wavelength dependence of angular diameters of M giants from an observational perspective. Observers cannot directly measure an optical-depth radius for a star, despite this being a common theoretical definition. Instead, they can use an interferometer to measure the square of the fringe visibility. We present new plots of the wavelength-dependent centre-to-limb variation (CLV) of intensity of the stellar disc as well as visibility for Mira and non-Mira M giant models. We use the terms 'CLV spectra' and 'visibility spectra' for these plots. We discuss a model-predicted extreme limb-darkening effect (also called the narrow-bright-core effect) in very strong TiO bands which can lead to a misinterpretation of the size of a star in these bands. We find no evidence as yet that this effect occurs in real stars. Our CLV spectra can explain the similarity in visibilities of R Dor (M8IIIe) that have been observed recently, despite the use of two different passbands. We compare several observations with models, and find that the models generally underestimate the observed variation in visibility with wavelength. We present CLV and visibility spectra for a model that is applicable to the M supergiant α Ori.  相似文献   

南北带强震年度预测能力估计   总被引：1，自引：1，他引：0  

刘蒲雄  刘连柱  车时  黄德瑜  吕晓健  韩丹  张宇霞 《地震》2006,26(2):38-44

对中国地震局原分析预报中心测震学科1988～1999年度划定的南北地震带强震(M≥7)危险区进行了回顾和分析。 结果表明, 从过程角度研究前兆地震活动图像及其演变是年度和中短期强震预测的有效途径, 这为南北地震带强震震情跟踪提供了条件。  相似文献   

基于R语言的NetCDF文件分析和可视化应用   总被引：3，自引：0，他引：3  

刘培宁  韩笑  杨福兴 《气象科技》2014,42(4):629-634

气象领域目前有多种广泛应用的气象数据分析和可视化工具集,包括GrADS、NCL、CDO和IDL等。R语言是一种由统计学家开发的统计计算和绘图的语言和环境,具有大数据处理的能力。R语言数量众多的扩展包为R语言用于海量气象数据分析和可视化提供了强有力的支持。基于R语言对NCEP发布的数据集进行了统计分析和可视化,展示了R语言在气象数据处理和可视化方面的应用。结合R语言提供的贝叶斯统计扩展包和高性能并行计算扩展包探讨了R语言在气象数据处理和可视化应用方面的广泛前景。  相似文献   

Polarimetric properties of the reflection nebula R Mon/NGC 2261     

Masafumi Matsumura  Munezo Seki 《Astrophysics and Space Science》1995,224(1-2):513-514

The linear polarization of the reflection nebula R Mon/NGC 2261 has been observed since November 1991 with a multi-channel polarimeter at Dodaira Observatory, one of the branches of the National Astronomical Observatory of Japan. Results of the observations are reported.  相似文献   

信阳市人体舒适度指数变化及未来趋势分析     

吴世安 《气象与环境科学》2017,40(3):59-64

利用信阳气象站1961-2013年的观测资料计算逐日人体舒适度指数(CIHB),运用线性倾向估计、滑动平均和滑动标准差,分析了信阳CIHB的变化趋势,以及舒适日数变化趋势。在此基础上,运用R/S分析法对CIHB及舒适日数变化趋势进行了预测。结果表明:1)信阳的年均CIHB呈显著上升趋势,线性趋势为0.016/a。春、冬季的平均CIHB呈显著上升趋势,且趋势强度相当。秋季平均CIHB虽呈上升趋势,但趋势不显著。夏季平均CIHB呈显著下降趋势。冬季CIHB标准差总体上没有明显的增大或减小趋势,夏季CIHB标准差不断减小,表明信阳出现极端天气气候事件的概率没有增加。2)信阳舒适日数呈显著增加趋势,达0.359天/a,冷、热日数呈减少趋势,趋势强度冷日数的大于热日数的。3)通过R/S分析,年、季平均CIHB具有长期相关的特征,未来的年及春、秋、冬季平均CIHB将继续上升,夏季平均CIHB将继续下降。年舒适日数具有长期相关的特征,未来年舒适日数仍将增加,年冷、热日数继续减少。  相似文献   

钢筋混凝土框架柱侧向变形能力的研究   总被引：1，自引：3，他引：1  

熊朝晖  潘德恩 《地震工程与工程振动》2001,21(2):103-108

本文介绍了8根钢筋混凝土柱的往复荷载试验、并且与理论计算结果进行了对比，另外，通过对收集到的103根钢筋混凝土框架柱试验的数据分析。，峄影响柱位移角的因素进行了讨论，最后提出了钢筋混凝土柱位移角以及为满足变形能力要求所需箍筋量的估算方法。  相似文献   

Fractal Method for Statistical Analysis Geological Data     

Meng Xianguo Zhao Pengda China University of Geosciences  Wuhan 《中国地质大学学报(英文版)》1991,(1)

This paper establishes the phase space in the light of spacial series data,discussesthe fractal structure of geological data in terms of correlated functions and studies thechaos of these data.In addition,it introduces the R/S analysis for time series analysisinto spacial series to calculate the structural fractal dimensions of ranges and standard de-viation for spacial series data,and to establish the fractal dimension matrix and the proce-dures in plotting the fractal dimension anomaly diagram with vector distances of fractal di-mension.At last,it has examples of its application.  相似文献   

昆明盘龙江江岸对震害的影响     

刘汉雄  非明伦 《地震研究》1990,13(3):283-290

如果在昆明及其附近地区发生强烈的破坏性地震,当地震波传播到盘龙江江岸这一特定的场地条件时,对震害会产生怎样的影响?本文根据在强震考察中看到的一些河岸破坏的情况和对盘龙江江岸地区的一些工程水文地质资料及局部地区脉动观测结果分析指出:(1)强震时江岸地区易发生地裂,地陷和塌方等地基失效现象而加大震害。(2)由于江岸地区的土层含有饱和的砂土层,强震时易引起砂土液化导致地基失效而加大震害。(3)由于江岸地形的影响,强震时对振动起放大作用而加大震害。所以在昆明的城市规划建设中,盘龙江两岸在离岸边30米内最好不要建筑任何结构物,以免在强震时造成严重的破坏。  相似文献