Provincial evaluation of vulnerability to geological disaster in China and its influencing factors: a three-stage DEA-based analysis   总被引：1，自引：0，他引：1  

Mingze Li  Jun Lv  Xin Chen  Nan Jiang 《Natural Hazards》2015,79(3):1649-1662

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北京平原地区V_S30估算模型适用性研究   总被引：1，自引：1，他引：0  

江志杰  彭艳菊  方怡  吕悦军  修立伟  黄帅 《震灾防御技术》2018,13(1):75-86

本文使用基于钻孔测井数据的3类模型，即常速度外推模型、速度梯度模型、双深度参数外推模型，通过对北京地区460个深度超过30m的钻孔剪切波速资料进行分析，详细探究了V_S30估算模型在本研究区的适用性。研究结果表明双深度参数外推模型在估算V_S30上准确度很高，其不需要大量的数据进行回归分析，且不具有区域独立性，可以为全球包括北京地区场地类别划分提供依据，进而在震害快速评估中用于确定场地影响，是一种值得推广的估算模型。  相似文献   

仿真技术在深弹发射装置环境适应性分析中的应用          下载免费PDF全文

吕学能  祝凌云  徐巨华 《数字海洋与水下攻防》2018,1(2):55-58

深弹发射装置安装在甲板部位,使用环境恶劣,过去均采用传统的试验方法进行环境适应性考核。最近几年,随着三维设计的广泛应用,仿真技术也开始发挥作用,以发射装置接线箱的冲击响应为例，介绍仿真技术在发射装置环境适应性分析中的应用。通过案例分析可知,仿真分析对于发现机械结构设计中的薄弱环节还是非常有效的,它突破了环境试验受限于试验样机和特定环境条件的限制,可以在较短的时间内得到仿真结果,对装备模型进行及时修正。  相似文献   

Numerical study on transient harbor oscillations induced by successive solitary waves   总被引：1，自引：1，他引：0  

Junliang Gao  Chunyan Ji  Yingyi Liu  Xiaojian Ma  Oleg Gaidai 《Ocean Dynamics》2018,68(2):193-209

Tsunamis are traveling waves which are characterized by long wavelengths and large amplitudes close to the shore. Due to the transformation of tsunamis, undular bores have been frequently observed in the coastal zone and can be viewed as a sequence of solitary waves with different wave heights and different separation distances among them. In this article, transient harbor oscillations induced by incident successive solitary waves are first investigated. The transient oscillations are simulated by a fully nonlinear Boussinesq model, FUNWAVE-TVD. The incident successive solitary waves include double solitary waves and triple solitary waves. This paper mainly focuses on the effects of different waveform parameters of the incident successive solitary waves on the relative wave energy distribution inside the harbor. These wave parameters include the incident wave height, the relative separation distance between adjacent crests, and the number of elementary solitary waves in the incident wave train. The relative separation distance between adjacent crests is defined as the ratio of the distance between adjacent crests in the incident wave train to the effective wavelength of the single solitary wave. Maximum oscillations inside the harbor excited by various incident waves are also discussed. For comparison, the transient oscillation excited by the single solitary wave is also considered. The harbor used in this paper is assumed to be long and narrow and has constant depth; the free surface movement inside the harbor is essentially one-dimensional. This study reveals that, for the given harbor and for the variation ranges of all the waveform parameters of the incident successive solitary waves studied in this paper, the larger incident wave heights and the smaller number of elementary solitary waves in the incident tsunami lead to a more uniform relative wave energy distribution inside the harbor. For the successive solitary waves, the larger relative separation distance between adjacent crests can cause more obvious fluctuations of the relative wave energy distribution over different resonant modes. When the wave height of the elementary solitary wave in the successive solitary waves equals to that of the single solitary wave and the relative separation distance between adjacent crests is equal to or greater than 0.6, the maximum oscillation inside the harbor induced by the successive solitary waves is almost identical to that excited by the single solitary wave.  相似文献   

Watershed delineation using hydrographic features and a DEM in plain river network region          下载免费PDF全文

Zhengqing Lai  Shuo Li  Guonian Lv  Zhirong Pan  Guosong Fei 《水文研究》2016,30(2):276-288

Watershed delineation is a required step when conducting any spatially distributed hydrological modelling. Automated approaches are often proposed to delineate a watershed based on a river network extracted from the digital elevation model (DEM) using the deterministic eight‐neighbour (D8) method. However, a realistic river network cannot be derived from conventional DEM processing methods for a large flat area with a complex network of rivers, lakes, reservoirs, and polders, referred to as a plain river network region (PRNR). In this study, a new approach, which uses both hydrographic features and DEM, has been developed to address the problems of watershed delineation in PRNR. It extracts the river nodes and determines the flow directions of the river network based on a vector‐based hydrographic feature data model. The river network, lakes, reservoirs, and polders are then used to modify the flow directions of grid cells determined by D8 approach. The watershed is eventually delineated into four types of catchments including lakes, reservoirs, polders, and overland catchments based on the flow direction matrix and the location of river nodes. Multiple flow directions of grid cells are represented using a multi‐direction encoding method, and multiple outflows of catchments are also reflected in the topology of catchments. The proposed approach is applied to the western Taihu watershed in China. Comparisons between the results obtained from the D8 approach, the ‘stream burning’ approach, and those from the proposed approach clearly demonstrate an improvement of the new approach over the conventional approaches. This approach will benefit the development of distributed hydrological models in PRNR for the consideration of different types and multiple inlets and outlets of catchments. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

大兴安岭南段赛罕乌拉石海剖面分析及其与蒙山拦马墙石河结构对比   总被引：1，自引：0，他引：1  

吕洪波  高于  浦津  孟和达来  欧阳江城  巴特尔  刘波  张云喜  李桂林 《地质论评》2020,66(6):1572-1587

石海（石河/冰石河）作为冰缘地貌的重要标志之一，在国内地学界尚未引起足够的重视，以至于缺少介绍石海结构特征的中文文献，更未建立判别标准，在地貌认知阶段就发生很多误判。为了揭示石海的剖面结构特征，笔者等对位于大兴安岭南段的赛罕乌拉国家级自然保护区乌兰坝石海首次进行了开挖解剖，从而归纳了原生石海的基本结构特征：岩块棱角鲜明，呈镂空状堆积，岩块直径总体上上大下小。根据野外调查确认，赛罕乌拉海拔1800 m以上的区域至少还存在着局部现代石海，也就是说，还残存着不连续冻土带，而且保持年平均气温0℃左右的气候环境。根据赛罕乌拉现今气候记录和石海分布，笔者等估算了全新世初期赛罕乌拉石海开始发育时的地表温度在0~-4℃，而今天年平均气温已经升高到2℃，升温幅度2~6℃。根据赛罕乌拉石海剖面结构特征，笔者等对山东蒙山石河进行了结构对比，认为二者剖面结构基本一致，排除了前人近年来争议明显的冰川侧碛堤和泥石流成因说。结构对比揭示山东蒙山境内全新世早期至少局部存在过冰缘气候环境，而这也为山东境内更新世冰川地貌研究提供了重要的信息。此外，本研究也为中国冰缘地貌解剖和资源调查提供了一个可以参考的研究实例。  相似文献   

New magnetostratigraphic and pedostratigraphic investigations of loess deposits in north‐east China and their implications for regional environmental change during the Mid‐Pleistocene climatic transition          下载免费PDF全文

Lin Zeng  Huayu Lu  Shuangwen Yi  Yongxiang Li  Anqi Lv  Wenchao Zhang  Zhiwei Xu  Haifeng Wu  Han Feng  Mengchun Cui 《第四纪科学杂志》2016,31(1):20-32

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甘孜-玉树断裂带晚第四纪走滑速率与滑动分解作用     

吕丽星  李传友  魏占玉  董金元  谭锡斌  石峰  苏鹏 《震灾防御技术》2017,12(3):456-468

滑动速率是研究断裂运动学特征、地震活动性和区域应变分配的重要参数和依据。前人关于甘孜-玉树断裂带滑动速率的研究结果存在较大差异，因此，其晚第四纪滑动速率有待进一步调查研究。本文基于卫星影像解译和野外实地考察，对甘孜-玉树断裂带西段（玉树断裂）上典型断错地貌点进行测量分析，得到玉树断裂晚第四纪走滑速率为6.6±0.1-7.4±1.2mm/a。通过与前人对甘孜-玉树断裂带东段（甘孜断裂）滑动速率的研究结果进行对比，发现甘孜-玉树断裂带东、西段滑动速率不一致，其原因是甘孜断裂的左旋滑移在向西传递的过程中，一部分应变被分配到了巴塘盆地南缘断裂上。巴塘盆地南缘断裂的存在很好地解释了玉树断裂的走滑速率比甘孜断裂偏低的原因。但是，从区域变形来看，巴塘盆地南缘断裂分配的滑动速率恰好说明了甘孜-玉树断裂带东、西段及鲜水河断裂带的水平构造变形是协调一致的。  相似文献   

震后典型建筑物倒塌分类及救援特点分析     

刘晶晶  宁宝坤  吕瑞瑞  胡杰 《震灾防御技术》2017,12(1):220-229

震后建筑物倒塌造成人员埋压，快速的搜索与营救是有效减少伤亡的重要途径之一。本文通过研究震后典型建筑物倒塌类型，从建筑物垂直和水平破坏角度出发，提出一套三级分类体系，并对每类倒塌建筑物的受力及生存空间进行讨论。同时结合大量文献及汶川地震救援案例资料，重点分析总结各类建筑物救援时的路线选择、救援通道建立、被困人员施救等技术特点。  相似文献   

The maize evapotranspiration in the background of climate change: a case study in arid area     

Buchun Liu  Xurong Mei  Guohua Lv  Youlu Yang  Meilan Bai  Yongfeng Wu  Jiqing Song  Wenbo Bai 《水文研究》2012,26(5):633-639

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