2017-08-09新疆精河Ms6.6地震附近区域相对应变的变化分析     

高丽娟  邢喜民  高歌  李尚伟 《大地测量与地球动力学》2019,39(10):1002-1006

2017年精河M_S6.6地震震前，尼勒克、巴伦台和小泉沟台钻孔应变仪记录到显著的应变变化，经现场落实确认，异常是可靠的。根据这3个台的记录资料计算相对应变的变化，结果表明，地震前最大（小）主应变大小和方向分别出现明显加速和急剧偏转变化。此外还发现，相对应变场异常期间主方向与震源机制解P轴方位较为一致。  相似文献   

Character and origin of De Geer moraines in the Seacoast region of New Hampshire,USA          下载免费PDF全文

Samantha N. Sinclair  Joseph M. Licciardi  Seth W. Campbell  Brian M. Madore 《第四纪科学杂志》2018,33(2):225-237

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基于圆柱多段拟合的隧道中轴线提取方法研究     

荆海峰  李广云  王力  杨文锋 《大地测量与地球动力学》2018,38(2):211-215

提出基于圆柱多段拟合的隧道中轴线提取方法。首先对隧道点云数据进行预处理，并将点云按隧道走向分成不同区段；然后对各区段依据轴线与表面点云法线垂直关系，提取精度较低的中轴线；最后对各区段利用圆柱多段拟合，提取精度较高的中轴线。实验表明，隧道中轴线的提取在一定的采样区间具有较高的稳定性，对直线和弯曲的圆形隧道有良好的适用性，算法可靠，精度较高。  相似文献   

河外H2O超脉泽源及与其相关的分子谱线的观测和研究     

俞志尧 《天文学进展》2002,20(3):256-264

自从在活动星系核NGC4945的视线方向上发现第一个河外H2O超脉泽源以来，迄今为止已发现了19个河外H2O超脉泽源，对与活动星系核成协和河外H2O超脉泽源及分子谱线的观测和研究是探测和研究活动星系核核区中央源，拱核气体和尘埃环性质的非常有效的工具，主要评述对河外H2O超脉泽源及与其相关分子谱线的搜索，观测和理论研究现状。  相似文献   

High-resolution H i and radio continuum observations of the SNR G290.1−0.8     

Estela M. Reynoso †  Simon Johnston  Anne J. Green  Bärbel S. Koribalski 《Monthly notices of the Royal Astronomical Society》2006,369(1):416-424

We have observed the supernova remnant (SNR) G290.1−0.8 in the 21-cm H  i line and the 20-cm radio continuum using the Australia Telescope Compact Array (ATCA). The H  i data were combined with data from the Southern Galactic Plane Survey to recover the shortest spatial frequencies. In contrast, H  i absorption was analysed by filtering extended H  i emission, with spatial frequencies shorter than 1.1 kλ. The low-resolution ATCA radio continuum image of the remnant shows considerable internal structure, resembling a network of filaments across its 13-arcmin diameter. A high-resolution ATCA radio continuum image was also constructed to study the small-scale structure in the SNR. It shows that there are no structures smaller than ∼17 arcsec, except perhaps for a bright knot to the south, which is probably an unrelated object. The H  i absorption study shows that the gas distribution and kinematics in front of SNR G290.1−0.8 are complex. We estimate that the SNR probably lies in the Carina arm, at a distance 7 (±1) kpc. In addition, we have studied nearby sources in the observed field using archival multiwavelength data to determine their characteristics.  相似文献   

The Orion nebula (M42) Herbig–Haro object, HH 201, within the tip of a molecular finger     

M. F. Graham  J. Meaburn  M. P. Redman 《Monthly notices of the Royal Astronomical Society》2003,343(2):419-426

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地下洞库勘察中的深斜孔钻探和压水试验技术          下载免费PDF全文

吉孟瑞  孙桂明  吴昌庆  原华山 《山东国土资源》2001,17(2):56-60

青岛市黄岛区拟建设海底地下油气储藏库,前期地质勘察工作要求施工倾角45°、深220m的取心钻孔4个,并在孔内分段进行压水试验.本文介绍了如何利用XY-4型金刚石小口径钻机施工基岩深斜孔及压水试验技术.  相似文献   

On the Line Formation in Stellar Magnetized Atmospheres     

Zhong-Quan Qu  Xiao-Yu Zhang  Zhi Xu 《中国天文和天体物理学报》2001,1(2):161-175

1 INTRODUCTIONIn the previous paper (on et al. 1999, hereafter Paper I), we investigated the wavelength-dependence of four colltribution functions (CFs) derived from dmerent formal solutions andreferring to different emergellt quantities in the unpolarized case. Because one cannot generallyassign a single formation region to the whole line band in a real stellar atmosphere, e.g., the solaratmosphere, instead, the line formation region can be defined as the layers deviating farthestfrom t…  相似文献   

Time-dependent photoionization opacities in dense gamma-ray burst environments     

Davide Lazzati  Rosalba Perna  Gabriele Ghisellini 《Monthly notices of the Royal Astronomical Society》2001,325(4):L19-L23

The recent detection of a transient absorption feature in the X-ray prompt emission of GRB 990705 showed the importance of such observations in the understanding of gamma-ray bursts and their progenitors. We investigate the time dependence of photoionization edges during the prompt emission of bursts in different environments. We show that their variability can be used to infer the density and geometry of the surrounding medium, giving important clues to unveil the nature of the burst progenitor.  相似文献   

Effective collision strengths with inclusion of resonance for hyperfine-structure transitions in H- and Li-like ions     

Hong Lin Zhang  Douglas H. Sampson 《Monthly notices of the Royal Astronomical Society》2001,322(3):433-437

Calculations are made of the resonance contribution to electron-impact excitation of H-like ¹³C and Li-like ²³Na, ²⁵Mg, ²⁷Al and ²⁹Si to the upper hyperfine levels that produce millimetre (mm) lines of likely astrophysical interest. The resonance contribution is found to be very important for these Li-like ions, considerably more important than for Li-like ⁵⁷Fe considered previously. However, resonances are found to be rather unimportant for H-like ¹³C. The effect of radiative decay on the resonance contribution is found to be insignificant in all of the present calculations.  相似文献