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云台山是一处以崖墙、瀑布为主体的山水地貌型世界级地质公园,其多层分布的崖墙、深邃幽静的峡谷和谷中谷现象等对研究云台山地区的新构造运动,具有重要的指示意义。云台山地区的新构造运动,不仅具有间歇性抬升特征,而且具有差异性、掀斜性抬升特征。形成了黄河南移、河流同步弯曲等现象和复杂的地貌景观。 相似文献
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Ryuichi Kurosawa M. M. Romanova Tim J. Harries 《Monthly notices of the Royal Astronomical Society》2008,385(4):1931-1945
We present 3D simulations of rotationally induced line variability arising from complex circumstellar environment of classical T Tauri stars (CTTS) using the results of the 3D magnetohydrodynamics (MHD) simulations of Romanova et al., who considered accretion on to a CTTS with a misaligned dipole magnetic axis with respect to the rotational axis. The density, velocity and temperature structures of the MHD simulations are mapped on to the radiative transfer grid, and corresponding line source function and the observed profiles of neutral hydrogen lines (Hβ, Paβ and Brγ) are computed using the Sobolev escape probability method. We study the dependency of line variability on inclination angles ( i ) and magnetic axis misalignment angles (Θ). We find the line profiles are relatively insensitive to the details of the temperature structure of accretion funnels, but are influenced more by the mean temperature of the flow and its geometry. By comparing our models with the Paβ profiles of 42 CTTS observed by Folha & Emerson, we find that models with a smaller misaligngment angle (Θ < ∼15°) are more consistent with the observations which show that majority of Paβ are rather symmetric around the line centre. For a high inclination system with a small dipole misalignment angle (Θ≈ 15°) , only one accretion funnel (on the upper hemisphere) is visible to an observer at any given rotational phase. This can cause an anticorrelation of the line equivalent to the width in the blue wing ( v < 0) and that in the red wing ( v > 0) over half of a rotational period, and a positive correlation over the other half. We find a good overall agreement of the line variability behaviour predicted by our model and those from observations. 相似文献
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坦桑尼亚某金矿的磁力、激电异常特征 总被引：3，自引：0，他引：3
坦桑尼亚某金矿是与条带状含铁建造（BIF）有关的隐伏金矿床。为了查明该金矿脉的分布情况,开展了地面高精度磁力勘查。△T异常特征以负异常为主,负异常峰值大于正异常,正异常为伴生异常,总体上反映了BIF在平面上的延伸方向和构造方向特征;激电测深断面异常以视电阻率等值线“下凹”、视极化率等值线“上凸”为表现形式,二者分别反映了断面内的构造位置和BIF形态特征。本区磁力和激电异常对BIF体的隐伏特征反映的均很明显,依据二者的测量成果,进行钻孔定位,指导钻探施工,钻遇了目的层,收到了很好的效果。 相似文献
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焦作市典型煤矿塌陷区地质灾害危险性分析及防治对策 总被引：2，自引：0，他引：2
由于大规模地开发矿产资源,使焦作市成为地质灾害的易发区,引起的地质灾害分布范围广,危害程度大,已造成巨大的经济损失和人员伤亡。本文以焦作市某城中村改造建设场地地质灾害危险性评估为例,用概率积分法等数理统计的方法对采煤塌陷区的采深采厚比和地表移动变形值进行了预测,对焦作市典型煤矿区形成的地面塌陷、地裂缝等地质灾害的危险性进行了分析,并提出了相应的防治对策。为今后矿山的设计和地质灾害防治工作提供一定的科学依据。 相似文献
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