A New Solar Radio Spectrometer at 1.10-2.06 GHz and First Observational Results   总被引：1，自引：0，他引：1  

Hui-Rong Ji  Qi-Jun Pu  Yi-Hua Yan  Yu-Ying Liu  Zhi-Jun Chen  Cheng-Ming Tan  Cong-Ling Cheng  De-Bang Lao  Shu-Ke Li  Zhi-Qiang Wang  Min-Hong Yu  Jian-Nong Liu  Li-Kang Zhang  Ji-Yong Gao National Astronomical Observatories  Chinese Academy of Sciences  Beijing  Hebei Semiconductor Research Institute  Shijiazhuang 《中国天文和天体物理学报》2005,5(4):433-441

An improved Solar Radio Spectrometer working at 1.10-2.06 GHz with much improved spectral and temporal resolution, has been accomplished by the National Astronomical Observatories and Hebei Semiconductor Research Institute, based on an old spectrometer at 1-2 GHz. The new spectrometer has a spectral resolution of 4 MHz and a temporal resolution of 5ms, with an instantaneous detectable range from 0.02 to 10 times of the quiet Sun flux. It can measure both left and right circular polarization with an accuracy of 10% in degree of polarization. Some results of preliminary observations that could not be recorded by the old spectrometer at 1-2 GHz are presented.  相似文献   

中国大陆科学钻探先导孔零偏VSP资料解释   总被引：3，自引：3，他引：0  

姜修道  朱光明  朱龙生  张文波  李桂花 《地球科学与环境学报》2004,26(1):55-60

用六级三分量检波器在中国大陆科学钻探先导孔中实施了零偏VSP测量.数据处理结果表明,中国大陆科学钻探孔区超高压变质岩石的地震波速度主要介于4500～7000m/s之间,显著高于一般的沉积岩地区,而且随深度变化不明显.声波测井速度系统地稍低于VSP层速度,可能是由于井壁处岩石的完整性受到破坏而造成的.地震波速度与岩石密度和岩性存在明确的对应关系,榴辉岩的密度和地震波速度均显著高于片麻岩类岩石;由榴辉岩退变生成的斜长角闪岩类岩石,其密度和地震波速度均呈现出较大的变化,主要与其退变质程度有关;超基性岩中的裂隙系统导致其密度和地震波速度大幅度下降.由于榴辉岩与其他岩石类型之间存在较大的波阻抗差异,因此用零偏VSP资料标定该区地震波的地质层位是有效的.关于地震波反射的原因,通过综合研究地震波(包括反射纵波、上行转换横波、井筒波)的特征、岩石速度和密度分布以及井径变化,认为主要是岩性分界面、韧性剪切带和断裂(带),但还有一些因素尚待进一步研究.  相似文献   

关于网络用户经济效益评测模型的研究     

岳正华  李黎 《成都信息工程学院学报》2001,16(2):141-144

着重讨论了网络用户经济效益的内涵以及用户的投入量和产出量，并提出了评价网络用户经济效益的指标体系，包括成本降低率，成本利润增长率、产品开发时间约率、市场占有增长率等系列指标。  相似文献   

山东省区域地质构造演化探讨   总被引：13，自引：0，他引：13       下载免费PDF全文

宋明春  李洪奎 《山东国土资源》2001,17(6):12-21

山东省区域地质构造演化分为5个阶段.①陆核形成阶段形成太古宙高级区,地壳分异成稳定的花岗岩穹窿和活动的绿岩带,第一次克拉通化完成.②陆块发生形成阶段地壳向刚性发展,在华北陆核硅铝壳的基础上先后有3次张开、闭合裂谷作用,第二次克拉通化完成.这一阶段演化在鲁西地区主要表现为挤压作用,形成大量造山花岗岩;鲁东地区则以拉张作用为主,形成海槽,产生沉积.③秦昆洋形成演化阶段四堡期沿鲁东南部地壳拉张,在华北板块与扬子板块间形成秦昆洋.晋宁期秦昆洋关闭,华北板块与扬子板块对接碰撞,沿胶南造山带产生大量同碰撞花岗岩,同时产生超高压变质作用及形成丰富多彩的碰撞构造.晋宁运动最终形成统一的原始中国古陆,第三次克拉通化完成.④陆块发展阶段鲁西地区地壳频繁升降,形成广泛的海相及海陆交互相沉积;鲁东地区则以造山抬升为主,地层沉积较少.⑤滨太平洋发展阶段该阶段的主要特征是断块构造发育,形成盆岭构造格局,产生大陆边缘花岗岩,构造体系由古亚洲构造域转向滨太平洋构造域.  相似文献   

The Magnetic Topological Structure and Energy of the 2B/X2 Flare in NOAA 8100     

Yihua Yan  Yang Liu  Maki Akioka  Fengsi Wei 《Solar physics》2001,201(2):337-355

In this paper, we reconstruct the finite energy force-free magnetic field of the active region NOAA 8100 on 4 November 1997 above the photosphere. In particular, the 3-D magnetic field structures before and after a 2B/X2 flare at 05:58 UT in this region are analyzed. The magnetic field lines were extrapolated in close coincidence with the Yohkoh soft X-ray (SXR) loops accordingly. It is found that the active region is composed of an emerging flux loop, a complex loop system with differential magnetic field shear, and large-scale, or open field lines. Similar magnetic connectivity has been obtained for both instants but apparent changes of the twisting situations of the calculated magnetic field lines can be observed that properly align with the corresponding SXR coronal loops. We conclude that this flare was triggered by the interaction of an emerging flux loop and a large loop system with differential magnetic field shear, as well as large-scale, or open field lines. The onset of the flare was at the common footpoints of several interacting magnetic loops and confined near the footpoints of the emerging flux loop. The sheared configuration remained even after the energetic flare, as demonstrated by calculated values of the twist for the loop system, which means that the active region was relaxed to a lower energy state but not completely to the minimum energy state (two days later another X-class flare occurred in this region).  相似文献   

CSCO_3 CYCLES IN SALAWUSU RIVER BASINSINCE 150KA B.P.     

LUO Kai-li    LI Bao-sheng    ZHU Yi-zhi  JIN He-ling  ZHANG David Dian  YAN Man-cun  LI Hou-xin  YAO Chun-xia  ZHANG Yu-hongf . Department of Geography  South China Normal University  Guangzhou  P. R. China  . State Key Labor 《中国地理科学(英文版)》2001,11(4):336-342

About 70years ago，Frenc卜卜alaeohdoglst回LL sc卜dars al卜ome and a卜road卜ave successively con－HARD de Chardin P．et al．Initiated the Quaternary ducted large amount ofwork on the Later Quaternarygeologlcal research In the ＞alawusu River Basin of strata（TEILHARD，1924； YUAN，1978； LI，1987；desert region of Northern China and established th，ZHENG，1989； SUN et al，1996； LI et al，1993），Salawusu Formation门EILHARD，1924）．Sine，then，palaeobiology…  相似文献   

Urban tourism research methodology     

Tao Wei  Zhong Wen-hui  Hong Yan 《中国地理科学(英文版)》2005,15(2):173-178

  相似文献   

Energy flow in Branchiura sowerbyi (Oligochaeta: tubificidae) in a shallow macrophyte-dominated lake, Biandantang Lake     

Yan Yunjun  Liang Yanling 《中国海洋湖沼学报》2004,22(4):403-407

The energy flow ofBranchiura sowerbyi was studied for the first time in China in a shallow macrophytic lake, Biandantang Lake, Hubei Province. The energy flow was calculated from the measurement of flesh production (12.5241kJ/m²a), egestion (517.7302kJ/m²a), metabolism (38.3273 kJ/m²a), and excretion (4.3798kJ/m²a). The net growth efficiency of the species is about 22.7%, which accords well with the generally reported value for oligochaetes. In addition, the relationship between starvation respiration (R, mgO₂/ind·d), wet weight (Ww, mg) and temperature (T, °C) were also measured, with the regression function beingR=0.008Ww^0.736 e^0.050T. Project supported by NSFC (30270278, 3960019), the foundation of the government of Hubei Province (No. 2000J109), and the foundation of Ecological Station, CAS in the Institute of Hydrobiology.  相似文献   

基于Chandra的活动星系核观测     

李丹丹  王竞  陈阳  何香涛 《天文学进展》2005,23(3):239-247

活动星系核（AGN）是宇宙中最奇特的天体之一。它是真正意义上的全波天体，其中X射线波段的发射功率占到全波段功率的50％左右。AGN的X射线辐射研究涉及天体物理中的最基本问题，例如能量产生、辐射机制和宇宙论等，而Chandra X射线卫星的高分辨率图像和光谱对这一研究有着重要作用。以Chandra卫星的部分观测结果为例，简要介绍了几类不同类型AGN的X射线辐射研究进展：（1）宽吸收线类星体APM08279＋5255（z=3．91）的X射线谱分析，以及高红移类星体的观测概况；（2）Seyfert星系NGC 4151延展X射线发射问题的解决，及NGC 1068X射线辐射与光学波段的高激发态发射线（[OⅢ]λ5007）有很强相关性的发现；（3）6个BLLac天体样本的X射线环境分析；（4）射电星系X射线喷流的观测等。  相似文献   

三类密近双星自转同步性参量的理论计算和统计分析     

李林森 《中国天文和天体物理学报》1997,(4)

利用双星自转同步性理论给出了６９个三类密近双星系统中９３个子星的临界同步自转参量和临界自转周期．并把利用临界自转同步参量所计算的临界自转周期与由气体星自转不稳定理论所计算的临界自转周期做了比较，其结果是两者均属同一量级．  相似文献