排序方式： 共有94条查询结果，搜索用时 265 毫秒
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Fayun Liang Mingyi Zhao Chengrui Qin Yajie Jia Zhongwei Wang Guiping Yue 《Marine Georesources & Geotechnology》2020,38(1):114-121
AbstractThe construction of a 100-km road network is planned on a land reclamation area in the Oujiang Estuary in China. The embankment had a height of 4 m and a base width of 60 m. The reclamation area is newly filled by a 3-m dredger fill on a 48-m thick layer of marine clay. Estimation of the settlement of the future road network is difficult. To guide the construction of the road network, a 1/100-scale centrifuge model test was performed with a marine clay sample from the construction site to simulate the layered settlements and evaluate the drainage effect of prefabricated vertical drains in the dredger fill in the following 10 years. The results of the centrifuge modeling test are verified by 10-month in situ monitoring, which shows agreement between the centrifuge modeling test results and the in situ results. The test results indicate that additional time is needed to reinforce the newly added dredger fill by the surcharge preloading method to uplift the elevation of the reclamation area with dredger fill. 相似文献
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城市基准地价评估回归模型分析与改进 总被引：12，自引：0，他引：12
从分析现行基准地价回归建模的必要性入手 ,分析了建模存在的问题 ,研究了基准地价经济内涵、模型参数和影响因素层次的有关问题 ,在此基础上提出了基准地价建模的新思路 ,并改进了基准地价修正系数法 相似文献
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内蒙古中部红格尔图地区花岗岩的成因及构造背景——LA-ICP-MS锆石U-Pb年龄、地球化学的制约 总被引：1，自引：0，他引：1
内蒙古察右后旗红格尔图花岗岩岩体位于索伦缝合带以南,主要为正长花岗岩和二长花岗岩,富硅(70.44%~78.80%),富碱(7.46%~10.74%),贫镁、铁、钛等,A/CNK值在0.95~1.41之间,碱铝指数AKI值在0.68~0.97之间,碱度率AR值在3.30~6.68之间,为弱过铝质-过铝质类碱性系列花岗岩;稀土元素总量变化范围大,轻稀土元素富集,重稀土元素亏损,Eu呈负异常(δEu=0.03~0.89);富集高场强元素Th、U、Hf、Ta、Y等,亏损大离子亲石元素Sr、Ba、Eu等;高场强元素和值((Zr+Nb+Ce+Y)350×10~(-6))明显偏低,该岩体属于高分异I型花岗岩,形成于后造山(后碰撞)伸展构造环境。LA-ICP-MS锆石同位素测年,获得锆石~(206)Pb/~(238)U年龄加权平均值分别为267.2±1.4Ma、269.2±1.6Ma和272.1±1.2Ma,表明该岩体形成于中二叠世,因此研究区内两大板块碰撞缝合的时间应该至少早于该岩体的形成时代,即应该至少早于267.2~272.1Ma。 相似文献
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Yajie Zhang Yao Li Jing Ge Gaopeng Li Zhisheng Yu Haishan Niu 《Environmental Earth Sciences》2018,77(12):462
Drought monitoring is a key topic in environmental monitoring and assessment although there is still a need to determine the correlation between drought monitoring indices and remote sensing products. We analyzed the correlation between the self-calibrating Palmer Drought Severity Index (sc_PDSI), the Standardized Precipitation Index and the Standardized Precipitation Evapotranspiration Index (SPEI) and terrestrial water storage monitored through the Gravity Recovery and Climate Experiment (GRACE) on a monthly timescale from 2002 to 2015 in China. As a consequence of anomalies in the soil water budget, the highly significant correlation between the sc_PDSI and the GRACE satellite-observed terrestrial water storage suggested that these two datasets are the most suitable for use in monitoring droughts. In comparing the three drought indices, the sc_PDSI was introduced as a means of drought monitoring in the Yangtze, Pearl, Huaihe, Southeast and Songhua River Basins, whereas the SPEI was found to be more applicable to other major river basins, such as the Inland River Basin. These diverse spatial behaviors are caused by the differences between the hydrological droughts characterized by these three drought indices. 相似文献
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针对地磁适配性分析中,单一的特征指标不能满足适配性精度要求的问题,该文提出一种多指标综合评价体系方法,建立以地磁标准差、地磁信息熵、相关系数及粗糙度为一体的综合评价模型;在确定权重方面,由于主观赋权法及客观赋权法各有优缺点,提出利用主、客观加权赋权法组合权重来确定每个指标的权重系数.能够较好地利用地磁的各种特征信息对地磁基准图候选区域进行综合分析,实现分析结果的全面性.基于多指标融合的地磁适配性分析的MATLAB仿真结果表明:运用此方法能够直观地反映出各候选区域适配性能的好坏,该方法在评价地磁适配性方面有效,其方法可应用于地磁匹配导航领域的研究. 相似文献
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Jianbu Wang Zhaoyang Lin Yuanqing Ma Guangbo Ren Zijun Xu Xiukai Song Yi Ma Andong Wang Yajie Zhao 《海洋学报(英文版)》2022,41(6):31-40
Spartina alterniflora as an alien invasive plant, poses a serious threat to the ecological functions of the coastal wetland of the Jiaozhou Bay. As of 2019, the distribution area of S. alterniflora in the Jiaozhou Bay has reached more than 500 hm2. For this reason, combined with field surveys, remote sensing monitoring of the invasion S.alterniflora in the Jiaozhou Bay has been carried out. To accurately identify S. alterniflora within the Jiaozhou Bay coastal wetland, we used a new m... 相似文献
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河网是地形结构的核心要素,能够有效地反映DEM对地表形态的刻画能力。实现不同分辨率条件下DEM河网相似性测度对DEM地形综合、DEM质量评估及DEM不确定性分析等研究具有重要意义。基于此,本文以黄土高原典型样区为研究区,基于5 m高精度DEM建立的多分辨率DEM数据集,构建了地形特征自适应的DEM河网自动提取方法,建立了综合拓扑关系、方位关系、距离关系及属性特征四维信息的河网相似性度量模型,并分析了河网相似性变化特征及其与地形参数的相关性。实验结果显示,河网自动提取方法的制图精度和用户精度均在90%以上,总体精度优于Passalacqua等提出的GeoNet方法,能够有效实现不同分辨率下河网较高精度提取;河网相似性度能综合反映河网空间分布特征的差异性,河网相似度与分辨率变化率之间的幂函数关系R2达0.978,且河网相似度与高程、坡度中误差分别表现为幂函数和对数函数关系,后者对数关系显著性优于前者幂函数关系。研究表明,在以河网作为DEM构建重要数据源的背景下,本文的研究成果可为DEM质量及其应用适宜性的定量评价提供基础。 相似文献
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Full waveform inversion( FWI)is a high resolution inversion method,which can reveal detailed in-formation of the structure and lithology under comPlex geological background. It is limited by many kinds... 相似文献
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气象站和卫星降雨资料估算降雨侵蚀力时存在无法反映空间异质性且精度差的问题,基于CLDAS多源融合降水,利用EI60模型从不同的时空尺度对中国的降雨侵蚀力进行评估,并结合降雨量、侵蚀性降雨次数、侵蚀密度等指标,探讨降雨对土壤侵蚀的潜在作用。结果表明：（1） CLDAS降雨侵蚀力与地面实测数据在不同的时间尺度均有良好的回归关系,相关系数达到0.8以上,与CMORPH降雨侵蚀力相比,其相对误差显著降低,可以准确反映全国范围的降雨侵蚀力季节性变异。（2） 在2001—2020年,不同雨量区的降雨侵蚀力、降雨量和侵蚀性降雨次数的变化趋势基本一致,高雨量区的年际变化波动剧烈,侵蚀性降雨次数和暴雨过程协同影响降雨侵蚀力的大小。（3） 空间上,中国的降雨侵蚀力值的特点为东南沿海地区高、西北内陆地区低。时间上,侵蚀性降雨集中在5—8月,夏、秋两季对土壤造成的侵蚀影响更大。（4） 通过对年降雨量、年侵蚀密度和年暴雨量进行分区定量分析,结果表明暴雨量与侵蚀密度成正相关关系,即年降雨量一定,暴雨事件越多,降雨侵蚀密度越大。 相似文献