气象电报收集、分发系统在业务中的应用     

叶秋英  源艳芬  梁慎青 《广东气象》2002,(1):40-41

全省气象电报收集、分发系统是负责收集全省各观测站的气象资料，及时处理并分发到北京、香港、澳门等各个服务单位，它有易操作，报文处理迅速，易维护等特点，提高了电报的传输时效。  相似文献   

古构造残余应力场对震源的作用     

安欧 《华北地震科学》1995,13(4):27-34

本文根据中国西南部四个强震带残余应力场水平和铅直分布的测量和实验研究结果，讨论了古构造残余应力场对震源的作用：降低震源岩体强度，增大震源岩体形变，与现今应力场迭加在一起促成地震，随岩体破裂释放残余弹性能加到震源释放的现今弹性能中去提高震级和地震活动水平。  相似文献   

CorelDRAW X4底纹填充工具在首饰效果图中的应用     

吴树玉 《地质科学译丛》2009,(3):38-41

CoreIDRAW作为一款功能强大的矢量绘图软件在首饰效果图的绘制上具有明显的优势与发展潜力。简要地介绍了CoreIDRAW在首饰行业中的应用。通过实例详细介绍了利用其底纹填充工具绘制各类弧面型或珠形宝石以及具有拉丝、喷砂效果的金属肌理的方法与技巧,初步总结了其底纹库中适于表现宝石外观的底纹样式及其相应的颜色参数。结果表明,CoreIDRAWX4底纹填充工具以其丰富的底纹样式和直观便捷的操作方式,为首饰设计人员的绘图工作带来便利。  相似文献   

The applications of the MHD Alfvén wave oscillation model for kHz quasi‐periodic oscillations     

C.M. Zhang  H.X. Yin  Y.H. Zhao  H.K. Chang  L.M. Song 《Astronomische Nachrichten》2007,328(6):491-498

In this paper, we improve the previous work on the MHD Alfvén wave oscillation model for the neutron star (NS) kHz quasi‐periodic oscillations (QPOs), and compare the model with the updated twin kHz QPO data. For the 17 NS X‐ray sources with the simultaneously detected twin kHz QPO frequencies, the stellar mass M and radius R constraints are given by means of the derived parameter A in the model, which is associated with the averaged mass density of the star as 〈ρ 〉 = 3M /(4πR³) ≃ 2.4 × 10¹⁴ (A /0.7)² g/cm³, and we also compare the M ‐R constraints with the stellar equations of state. Moreover, we also discuss the theoretical maximum kHz QPO frequency and maximum twin peak separation, and some expectations on SAX J1808.4–3658 are mentioned, such as its highest kHz QPO frequency ∼ 870 Hz, which is about 1.4–1.5 times less than those of the other known kHz QPO sources. The estimated magnetic fields for both Z sources (about Eddington accretion rate ) and Atoll sources (∼ 1% ) are approximately ∼10⁹ G and ∼10⁸ G, respectively. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

A near‐infrared/optical/X‐ray survey in the centre of σ Orionis     

J.A. Caballero 《Astronomische Nachrichten》2007,328(9):917-927

Because of the intense brightness of the OB‐type multiple star system σ Ori, the low‐mass stellar and substellar populations close to the centre of the very young σ Orionis cluster is poorly know. I present an IJHK_s survey in the cluster centre, able to detect from the massive early‐type stars down to cluster members below the deuterium burning mass limit. The near‐infrared and optical data have been complemented with X‐ray imaging. Ten objects have been found for the first time to display high‐energy emission. Previously known stars with clear spectroscopic youth indicators and/or X‐ray emission define a clear sequence in the I vs. I – K_s diagram. I have found six new candidate cluster members that follow this sequence. One of them, in the magnitude interval of the brown dwarfs in the cluster, displays X‐ray emission and a very red J – K_s colour, indicative of a disc. Other three low‐mass stars have excesses in the K_s band as well. The frequency of X‐ray emitters in the area is 80±20 %. The spatial density of stars is very high, of up to 1.6±0.1 arcmin^–2. There is no indication of lower abundance of substellar objects in the cluster centre. Finally, I also report two cluster stars with X‐ray emission located at only 8000–11000 AU to σ Ori AB, two sources with peculiar colours and an object with X‐ray emission and near‐infrared magnitudes similar to those of previously‐known substellar objects in the cluster. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

利用CDMA 1X+VPN技术实现十三陵地震前兆观测系统信息集成     

泽仁志玛  李志雄  周克昌  杨颖  吴利军 《地震》2009,29(3):86-92

依托“中国地震数据观测网络”项目,中国地震局地震预测研究所建立了以十三陵地震中心台为前兆台网部,8个无人值守的前兆台站为一体的前兆观测系统。 这套系统利用中国联通的CDMA 1X网络将台站接入到Internet网络,并利用VPN(Virtual Private Network)技术在Internet网络上开辟一条安全、 稳定传输隧道,实现了前兆台站、 观测设备与十三陵前兆台网部的信息集成。 文中以十三陵地震前兆观测系统为例,主要介绍了如何利用CDMA 1X 无线网络和VPN(Virtual Private Network)技术实现前兆观测系统信息集成。 十三陵地震前兆观测系统的正常运行证明,利用CDMA 1X +VPN技术的前兆观测系统组网模式可以做到投资少、 见效快、传输可靠等优势,值得推广应用。  相似文献   

Fourier‐resolved spectroscopy of AGN using XMM‐Newton data     

I. E. Papadakis  Z. Ioannou  D. Kazanas 《Astronomische Nachrichten》2006,327(10):1047-1054

We present a brief account of the theory on which the novel method of ‘Fourier‐resolved spectroscopy’ is based. We summarize the results from the past application of this method to the study of Galactic Black Hole candidate sources and MCG‐6‐30‐15, and we present new results from the Fourier‐resolved spectroscopy of archival XMM‐Newton data of five AGN, namely, Mrk 766, NGC 3516, NGC 3783, NGC 4051 and Ark 564. When we combine all the past and present results from Galactic sources and AGN, we find that the slope of the Fourier‐resolved spectra in accreting black hole systems decreases with increasing frequency as ∝ f ^–0.25, irrespective of whether the system is in its High or Low state. We find significant evidence that the iron line in Mrk 766, NGC 3783 and NGC 4051 is variable on time scales ∼1 day – 1 hour. There is an indication that, just like in Galactic sources, the equivalent width of the line in the Fourier‐resolved spectra of AGN decreases with increasing frequency. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

Light bending models in AGNs     

G. Miniutti 《Astronomische Nachrichten》2006,327(10):969-976

We review the MCG–6‐30‐15 observations and results that provided the motivation for the light bending model. We present a summary of the main properties of the model and discuss its application to MCG–6‐30‐15 briefly mentioning other X‐ray sources showing the same qualitative behaviour. Finally, we report on one of the most spectacular cases so far of short‐timescale variability of a redshifted Fe K line in the Seyfert galaxy NGC 3516, most likely due to an orbiting spot or flare in the relativistic region of the accretion disc. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

X‐ray spectra and polarization from accreting black holes: polarization from an orbiting spot     

M. Dov iak  V. Karas  G. Matt 《Astronomische Nachrichten》2006,327(10):993-996

The polarization from a spot orbiting around Schwarzschild and extreme Kerr black holes is studied. We assume different models of local polarization. Firstly, as a toy model we set the local polarization vector either normal to the disc plane, or perpendicular to the toroidal magnetic field. Then we examine the more realistic situation with a spot arising due to the emission from the primary source above the disc. We employ either Rayleigh single scattering or Compton multiple scattering approximations. The time dependence of the degree and angle of polarization during the spot revolution is examined as a function of the observer's inclination angle and black hole angular momentum. The gravitational and Doppler shifts, lensing effect as well as time delays are taken into account. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

The broad iron line physics: summary and outlook     

Y. Tanaka 《Astronomische Nachrichten》2006,327(10):1098-1100

A brief overview of the ESAC/XMM‐Newton Science Operations Centre Workshop on “Variable and Broad Iron Lines around Black Holes” is presented. Following the relativistic disk‐line theory of accreting black holes, ASCA discovered such broad iron lines from several AGN. XMM‐Newton and Chandra confirmed the ASCA results, but also found more complexities. It was pointed out that poor modelling of the continuum may mimic broad iron line, if ionized absorbers are present. This degeneracy between the broad line and the continuum shape was shown to be resolved by separately determining the continuum and the reflection component with use of an accurate hard X‐ray spectrum obtained with Suzaku. As a result, the relativistic broad iron lines are now robust. Time variations of the primary continuum and the reflection component are often decoupled, the latter varying little. This is explained by the light bending model that applies in the region near to an extreme Kerr hole. The red‐ and/or blueshifted transient iron line features were found with XMM‐Newton, some of which revealed a possible quasi‐periodicity. Such transient features are important dynamical probes of the black hole vicinity. The remaining issues are briefly mentioned. Finally, there is no doubt that the broad line physics continues to be extremely important. Prospects for the future development are discussed, which justify large next‐generation missions. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献