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反应谱特征周期的统计分析 被引量:27
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作者 刘文锋 付兴潘 +2 位作者 于振兴 陈学中 张辛 《青岛理工大学学报》 CAS 2009年第5期1-7,共7页
特征周期是反应谱的重要参数,是工程抗震设计的关键参数,但物理意义不明确、涉及因素多、结果离散,研究成果相对较少.从反应谱的本质出发,提出了反应谱特征周期的概率法.搜集近期1491条地震记录,采用概率法(97%)和美国FEMA-450(2003)法... 特征周期是反应谱的重要参数,是工程抗震设计的关键参数,但物理意义不明确、涉及因素多、结果离散,研究成果相对较少.从反应谱的本质出发,提出了反应谱特征周期的概率法.搜集近期1491条地震记录,采用概率法(97%)和美国FEMA-450(2003)法,以中国抗震规范特征周期分类为依据,研究了反应谱特征周期的统计规律.研究表明:概率法从面积比确定特征周期,力学概念明确,确定标准统一,与美国FEMA-450(2003)法有较好的一致性;近期地震波的特征周期分布特征表明,抗震规范规定的不同场地、不同地震分组的特征周期区段,地震记录数量不同,长周期效应不容忽视.特征周期与震级、场地类别和震中距的关系复杂且离散,特征周期呈区间分布规律,分布区间值较大,区间内部定量关系仍较难确定.特征周期与震级、场地类别和震中距的相关性不明显,反应谱特征周期按场地类别、震中距(地震分组)确定,存在不确定的风险,美国抗震规范以反应谱参数直接确定特征周期的方法,抗震规范修订时值得借鉴. 展开更多
关键词 反应谱特征周期 概率法 FEMA-450法 统计规律 离散 区间分布规律 建议
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Gully Erosion Regionalization of Black Soil Area in Northeastern China 被引量:13
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作者 YANG Jiuchun ZHANG Shuwen +3 位作者 CHANG Liping LI Fei LI Tianqi GAO Yan 《Chinese Geographical Science》 SCIE CSCD 2017年第1期78-87,共10页
Gully erosion is the frequent and main form of soil erosion in the black soil area of the northeastern China, which is one of the most important commodity grain production bases in China. It is encroaching upon the fe... Gully erosion is the frequent and main form of soil erosion in the black soil area of the northeastern China, which is one of the most important commodity grain production bases in China. It is encroaching upon the fertile farmland there. Regionalization of gully erosion can reveal the spatial distribution and regularity of the development of gully erosion. Based on the eco-geographical regional background features of the black soil area, this study combined the regionalization with influencing factors of the development of gully erosion. GIS spatial analysis, geostatistical analysis, spatial statistics, reclassification, debris polygon processing and map algebra methods were employed. As a result, the black soil area was divided into 12 subregions. The field survey data on type, length, volume and other characteristics indicators of gully erosion were used to calibrate the results. Then the features of every subregion, such as where the gully erosion is, how serious it is, and why it happens and develops, were expounded. The result is not only an essential prerequisite for gully erosion surveys and monitoring, but also an important basis for gully erosion prevention. 展开更多
关键词 regionalization gully erosion soil and water conservation black soil area northeastern China
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Spatial distribution rules and affecting factors of BIF in Anshan-Benxi area
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作者 WANG Wenqi ZHANG Wei +2 位作者 PENG Chong ZHU Ming XUE Linfu 《Global Geology》 2015年第2期109-116,121,共9页
A detailed investigation on 3D spatial distribution rules of Banded Iron-bearing Formation(BIF) with methods of gravity-magnetic inversion and 3D modeling of iron mine is presented based on the former analysis in the ... A detailed investigation on 3D spatial distribution rules of Banded Iron-bearing Formation(BIF) with methods of gravity-magnetic inversion and 3D modeling of iron mine is presented based on the former analysis in the Anshan-Benxi area.Three dimension spatial distribution types of BIF are concluded as hook-like,tabularlike and "W"-like.BIF was mainly developed in three types of space including(1) the syncline cores,(2)cover coverage area,and(3) the deeper buried area where the range of tectonic uplift is small.The influences of tectonism,magmatic intrusion and uplift-erosion on the spatial distribution shapes of BIF are clarified. 展开更多
关键词 Anshan-Benxi area BIF geometric types iron ore bodies affecting factors
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