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111.
We discuss the different physical processes that are important to understand the thermal X-ray emission and absorption spectra of the diffuse gas in clusters of galaxies and the warm-hot intergalactic medium. The ionisation balance, line and continuum emission and absorption properties are reviewed and several practical examples are given that illustrate the most important diagnostic features in the X-ray spectra.  相似文献   
112.
我国股票市场现状分析   总被引:1,自引:0,他引:1  
我国股票市场成长之快和成绩之卓著是令人瞩目的。但是由于发展时间短,制度不健全等原因,存在着诸多问题。通过对我国股票市场的现状的分析,总结了股票市场当前存在的问题,探索了产生问题的原因,并提出了解决问题的对策。  相似文献   
113.
Linsky  Jeffrey L.  Wilson  T. L.  Rood  R. T. 《Space Science Reviews》1998,84(1-2):309-315
This report summarizes the issues discussed in Working Group VI concerning the accuracy of measurements of D/H and 3He/H in the local interstellar medium, possible systematic errors, and emerging trends in the results.  相似文献   
114.
Complex organic molecules are widely observed in star-forming regions, although their formation mechanisms are not well understood. Solid-state chemistry is thought to play an important role, but the solid-state reaction network is poorly known. We provide a list of purely thermal reactions involving electronically stable reactants to complement existing grain chemistry networks. The kinetic parameters of the reactions are given when available. These reactions lead to the formation of complex organic molecules, which were not considered previously. Eventually, these complex molecules are either released into the gas phase or incorporated into the organic residue found in meteorites. Thermal reactions are important because they are not limited by the UV flux or the slow diffusion of the radicals, and because they involve both surface and mantle molecules. Thermal reactions represent an important step in the formation of complex organic molecules that constitute the primitive material of comets and asteroids.  相似文献   
115.
We present the results of analysis XMM-Newton data of galaxy cluster CL0016+16, which enables us to trace X-ray emission and temperature profile up to the virial radius. We obtained similar results using three different backgrounds. We checked the possibility of detection of cluster emission up to the virial radius with XMM-Newton data with hydrodynamical cosmology simulation from the Adaptive Mesh Refinement technique, code RAMSES by Teyssier [Teyssier, R. Cosmological hydrodynamics with adaptive mesh refinement. A new high resolution code called RAMSES. A&A 385, 337, 2002], convolution with XMM-Newton and the data base of the spectra by Sauvageot et al. [Sauvageot, J.-L., Belsole, E., Pratt, G.W. The late merging phase of a galaxy cluster: XMM EPIC observations of A 3266. A&A, 444, 673, 2005]. For the first time we were able to compute the mass of CL0016 up to R200, we found, assuming hydrostatic equilibrium framework, M200 = (1.15 ± 0.11) × 1015M.  相似文献   
116.
粗集理论已成功应用于数据挖掘,如基于粗集方法的属性发现和决策规则的约简等。中介集合论是以中介逻辑为基础,也可以用于数据挖掘。文中将两者相结合,提出了中介粗集的概念。中介粗集是普通粗集的推广,为不完全信息系统的数据挖掘提供了新的工具,不仅可用于一般的信息系统,还适用于数据取空值的信息系统(允许结论取空值)。利用中介粗集进行数据挖掘不但可以得出粗集理论中的约简,还能得到更为简洁的中介约简。文中还给出了  相似文献   
117.
118.
关于复合材料结构强度的分布函数   总被引:2,自引:0,他引:2  
依据近十年来发表的有关论文和的30组实验数据,按照工程应用对分布函数的要求;合理,有一定精度,使用简单,方便,确定使用正态分布。该分布函数符合实验数据,给出的标准值合理。  相似文献   
119.
多源信息融合技术包括数据级、特征级和决策级3个层级。在海洋探测应用中,现有方法存在信息获取、融合质量及目标识别等难点问题,提出了体系化探测、分布式融合和利用先验知识的解决思路。体系化探测能够全面获取原始信息,分布式融合可以在降低计算复杂度的同时减少信息损失,先验知识能够在决策级融合中提高目标识别的准确性。此外,还提出了构建探测系统和先验知识库、优化智能算法和模型等未来信息融合技术发展方向。  相似文献   
120.
Since more than one decade ago, several institutions started to offer a large variety of Operative Space Weather (SWx) products. This is of major importance because Space Weather events can affect aviation communications, global positioning systems, grid electric power, satellite technologies, and human health in space. The scientific potential on solar-terrestrial physics in Argentina motivated the creation of an interdisciplinary Laboratory of Space Weather in Argentina. The Argentinean Space Weather Laboratory (in Spanish ‘Laboratorio Argentino de Meteorología del esPacio’, LAMP) was initiated in 2016, and it carries out daily monitoring of real-time information (space and ground-based instruments) on Space Weather. The information is synthesized on a weekly bulletin as a summary of the Space Weather conditions, and it is posted on a website (spaceweather.at.fcen.uba.ar). The analyzed information includes own data and of other centers that offer them publicly, and it is also analyzed and discussed later on, during monthly briefings. In particular, one of the regional products that is included in the briefing discussions and it was developed by LAMP in collaboration with INPE-EMBRACE, involves Vertical Total Electron Content (VTEC) maps in the Argentinean region. LAMP set up a Space Weather Laboratory in the Antarctic peninsula, in the Argentine Marambio base, where a Water Cherenkov radiation Detector (WCD) was installed during the Argentinean Antarctic campaign (January-March of 2019). This detector is the southern node of a Latin American Collaboration (LAGO, Latin American Giant Observatory), which is a network of WCDs installed throughout more than 10 Latin American countries.  相似文献   
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