排序方式： 共有27条查询结果，搜索用时 797 毫秒
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Hu Sheng Qiu Haijun Wang Ninglian Wang Xingang Ma Shuyue Yang Dongdong Wei Na Liu Zijing Shen Yongdong Cao Mingming Song Zhaopeng 《Landslides》2022,19(6):1265-1295
Landslides - According to local villagers, the main Beiguo landslide on the Heyang Loess Tableland in China occurred several decades ago (the specific time is unknown). After the initial occurrence... 相似文献
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梳理了现有3种地震灾害人员死亡评估模型,并基于甘肃地区历史中强地震(MS4.7~6.0),对人员死亡评估模型进行震例计算。结果表明:(1)针对甘肃地区中强地震,3种模型的评估结果与实际结果基本处于同一数量级,可用于地震后快速盲评估计算,为地震后政府和应急管理部门应急指挥决策提供科学依据;(2)当中强地震震中烈度达到Ⅷ度时,这3种评估模型的计算结果与实际人员死亡人数存在较大误差,需要根据专家经验进行人机交互修正,依据地震灾区地理环境、社会经济、人口空间分布等资料进行综合分析支撑应急决策;(3)在甘肃地区中强地震的人员死亡评估中,李雯模型因考虑了地震灾区面积、区域适用性要优于其他两类模型。 相似文献
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大洼地区毗邻大型生油洼陷—清水洼陷,多级断裂及多期不整合面构成复合油气输导体系,成藏条件优越。但本区火山岩储层岩性岩相复杂、喷发环境多变。为进一步明确储层发育特征及油气成藏主控因素,本次研究利用15 口井107.73 m的岩心、270块薄片及测井资料综合分析,认为大洼地区Mz-Ⅰ段形成于水下喷发环境,发育溢流相玻质碎屑岩亚相玄武质火山角砾岩及溢流相熔岩亚相玄武岩;Mz-Ⅱ段形成于水上喷发环境,发育爆发相凝灰亚相流纹质凝灰岩及溢流相熔岩亚相安山岩。其中玄武质火山角砾岩储集性能最好,平均孔隙度19.3%,平均渗透率6.71×10~(-3) μm~2,玄武岩物性最差,平均孔隙度9.2%,平均渗透率0.23×10~(-3) μm~2。根据录测井及地震资料分析,认识到大洼地区中生界火山岩具有良好源储配置关系且发育多期次断裂及不整合面组成的复合油气输导体系。结合试油试采资料进一步确定油气藏的分布,明确成藏主控因素,建立油气成藏模式。研究表明,储层品质受控于岩性岩相、火山喷发环境及构造活动,油气成藏主要受控于源储配置关系及输导体系,油藏类型为构造-岩性复合型油藏,西侧近油源且近台安—大洼断层的有利岩性岩相带为有利勘探目标区。 相似文献
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地图数字注记识别的神经网络方法 总被引：1，自引：0，他引：1
讨论了基于径向基函数网络（RBFN）的地图数字注记识别问题。在分析了网络结构和训练算法的基础上,用地回扫描数据进行了识别实验。结果表明,本文提出的方法用于地图数字注记识别是非常有效的。 相似文献
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社区尺度下南京鼓楼区养老设施综合评价研究 总被引：1，自引：0，他引：1
针对南京市鼓楼区提出的打造"15 min养老圈"规划,该文选取养老助餐设施为研究对象,基于百度交通距离,结合社区精细尺度,从养老助餐设施数量、服务规模、空间可达性等多维度构建养老助餐设施综合评价模型,测度鼓楼区各社区养老助餐设施建设成果.结果表明:①鼓楼区现有养老助餐设施已覆盖95.5％的老龄人口,基本实现"15 min养老圈"规划,并揭示了未来养老助餐设施重点布局区域;②高斯两步移动搜索法有效地测度了鼓楼区养老助餐设施的空间可达性,鼓楼区约有91个社区的可达性属于中等及以上水平,占比75.8％;③鼓楼区养老助餐设施综合评价达到中等及以上水平的社区占比93.3％,同时也存在养老供需不匹配的问题. 相似文献
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Xinghong Cheng Debin Su Deping Li Lu Chen Wenjing Xu Meilin Yang Yongcheng Li Zhizhong Yue Zijing Wang 《大气科学进展》2014,31(6):1460-1468
The variation of air temperature measurement errors using two different radiation shields （DTR502B Vaisala,Finland,and HYTFZ01,Huayun Tongda Satcom,China） was studied.Datasets were collected in the field at the Daxing weather station in Beijing from June 2011 to May 2012.Most air temperature values obtained with these two commonly used radiation shields were lower than the reference records obtained with the new Fiber Reinforced Polymers （FRP） Stevenson screen.In most cases,the air temperature errors when using the two devices were smaller on overcast and rainy days than on sunny days; and smaller when using the imported rather than the Chinese shield.The measured errors changed sharply at sunrise and sunset,and reached maxima at noon.Their diurnal variation characteristics were,naturally,related to changes in solar radiation.The relationships between the record errors,global radiation,and wind speed were nonlinear.An improved correction method was proposed based on the approach described by Nakamura and Mahrt （2005） （NM05）,in which the impact of the solar zenith angle （SZA） on the temperature error is considered and extreme errors due to changes in SZA can be corrected effectively.Measurement errors were reduced significantly after correction by either method for both shields.The error reduction rate using the improved correction method for the Chinese and imported shields were 3.3％ and 40.4％ higher than those using the NM05 method,respectively. 相似文献
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基于中国1993—2017年的历史地震资料,通过对四个现行地震灾害人员死亡评估模型进行对比,深入分析不同模型在不同震级(M)及不同地区的适用性和精度。研究结果表明:(1)当M6.0时,四个模型评估结果与实际死亡人数数量级基本一致,均适用于震后人员伤亡快速评估;当6.0≤M7.0时,四个模型评估结果与实际死亡人数差距较大,经过参数修正后的刘金龙模型评估结果相对较好;当M≥7.0时,四个模型的评价结果都不理想,需要结合震区地理环境、经济条件等进行人工修正才能使用;(2)在地震较多的云南、四川、甘肃、新疆、西藏五个省份中,GB/T 30352-2013评估结果优于其他三个模型;在四川、云南、甘肃地区评估时需考虑次生地质灾害因素的影响,不然可能会导致评估误差较大。研究结果可为各级政府和应急管理部门地震灾害应急业务能力的提升提供技术支持。 相似文献
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Haitao Zhang Jinfeng Bi Gaofeng He Zijing Guo 《Marine Georesources & Geotechnology》2013,31(4):467-476
ABSTRACTThe purpose of this paper is to analyze the stability of submarine slope during the natural gas hydrate dissociation. A model is deduced to calculate the excess pore fluid pressure. In addition, a new method is proposed to define and calculate the factor of safety (FoS) of the submarine slope. Case study is also performed, results of which show that dissociation of hydrates would decrease the stability of submarine slope. If the cohesion of the hydrate-bearing sediments is small, the submarine slope would become unstable because of the shear failure. If the cohesion of the hydrate-bearing sediments is large enough, the tensile failure would happen in the hydrate-bearing sediments and the excess pore pressure may explode the submarine slope. Under the drained condition, the submarine slope may remain stable because the buildup of excess pore fluid pressure could not take place. Moreover, FoS would be underestimated by the assumption that natural gas hydrates dissociate in the horizontally confined space, but would be overestimated by only taking into account of the base of the natural gas hydrate-bearing sediments. The compressibility factor of natural gas should also be considered because treating natural gas as ideal gas would underestimate the stability of submarine slope. 相似文献
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固体酸是７０年代末发展起来的一类新型的催化材料,对有机反应具有较强的催化活性,且副反应少,产物易分离,污染少［１］。粘土固体酸是以蒙脱石类粘土为基质材料,通过采用不同的物理或化学方法在不同的条件下调控层间域而制备的,其催化活性和选择性与其表面酸的类型、浓度及强度等有关［２］,为此我们采用离子交换法,以不同类型的阳离子为取代剂,在不同条件下取代交换进入蒙脱石层间,研究制备方法及条件对表面酸性的影响,并考察了催化性能。１ 实验部分１－１ 原料与试剂钠基膨润土（浙江临安产,主要成分为蒙脱石,用沉降法提… 相似文献