ROCKS & MINERALS DETERMINATION AND ANALYSIS     

《Abstract of Chinese Geological Literature》2014,(4)

正20142093Chen Daohua(Guangzhou Marine Geological Survey,Guangzhou 510075,China);Diao Shaobo The Latest Progress of Geological Marine Testing Technology in China(Rock and Mineral Analysis,ISSN0254-5357,CN11-2131/TD,32(6),2013,p.850-859,105refs.)Key words:chemical analysis,China  相似文献   

GEOCHEMICAL EXPLORATION     

《Abstract of Chinese Geological Literature》2014,(4)

正20142366Bi Yuanqing(Institute of Geophysical and Geochemical Survey Technology of Anhui Province,Hefei 230022,China);Fang Junhua Analysis of Ore-Prospecting Potential in the Taojiaxiang Mining Site,Zongyang County(Geology of Anhui,ISSN1005-6157,CN34-1111/P,23(4),2013,p.256-260,5illus.,10refs.)  相似文献   

OCEANOGRAPHY & MARINE GEOLOGY     

《Abstract of Chinese Geological Literature》2014,(4)

正20141900Lan Xianhong(Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology,Ministry of Land and Resources,Qingdao 266071,China);Zhang Zhixun Geochemical Characteristics of Trace Elements of Sediments from Drillhole SFK-1  相似文献   

日照海岸带沙滩侵蚀现状及沉积物粒度特征分析     

种衍飞  郝义 《海洋地质前沿》2020,36(1):19-29

通过对日照市海岸带2个重点沙滩的现场调查和沉积物粒度计算,综合分析了沙滩的侵蚀现状和粒度参数特征。海滨国家森林公园沙滩北部和南部处于侵蚀状态,中部为缓慢淤积状态;万平口海水浴场沙滩北部、中部总体呈侵蚀趋势,南部为淤积状态。海滨国家森林公园沙滩的平均粒径总体要小于万平口海水浴场沙滩,这与两沙滩的坡度不同有关,平均粒径从滩肩到低潮线逐渐变小。海滨国家森林公园沙滩的分选性要好于万平口海水浴场沙滩,分选系数具有由陆向海、由北向南逐渐变小的趋势。沙滩的滩肩和滩面处频率曲线主要为双峰,峰态平坦,物质来源复杂,低潮线处频率曲线主要为单峰,峰态尖锐,物质来源单一。  相似文献   

国外军事地质学热点问题     

李万伦  吕鹏  孟庆奎  王铭晗 《地质论评》2020,66(1):189-196

近年来以美国为代表的西方军事强国在军事地质学领域已取得了很大进展,尤其在应对未来战争方面作了许多准备。通过系统搜集国际军事地球科学会议(ICMG)和美国地质学会(GSA)有关军事地质学的最新专题研讨会论文与其他公开出版资料,梳理了当前国外军事地质学研究的热点问题并阐述了其新进展,其中作战领域包括地形情报研究、军事基地选址、潜在特殊战场环境调查、地下重要设施评价、非常规作战环境调查;非作战领域则包括抢险救灾、生态环境保护和环境安全评价等。最后分析了当前军事地质学研究存在的问题,并指出了其未来发展趋势。  相似文献   

Development of detachable replaceable links for eccentrically braced frames     

Mehmet Bakır Bozkurt  Sina Kazemzadeh Azad  Cem Topkaya 《地震工程与结构动力学》2019,48(10):1134-1155

Eccentrically braced frames (EBFs) can be repaired after a major earthquake by replacing the links. The link replacement is not a straightforward process and is influenced by the type of the link and the amount of residual frame deformations. The past decade has witnessed the development of different types of replaceable links such as end-plated links, web connected links, bolted flange and web spliced links, and collector beam and brace spliced links. All of the developed replaceable link details, except the web connected links, are not suitable for link replacement under residual frame drift. In this paper, a detachable replaceable link detail which is based on splicing the link at its mid-length is proposed. The detail is well suited for installation under residual frame drifts. In addition, the weight and size of the members to be transported and erected are reduced significantly, thereby facilitating the replacement procedure. Performance of this proposed replaceable link is studied by conducting six nearly full scale EBF tests under quasi-static cyclic loading. The link length ratio, type of end-plated mid-splice connection, and the amount of residual drift are considered as test variables. The test results revealed that the inelastic rotation capacity of the detachable replaceable links exceeds the requirements of the AISC Seismic Provisions for Structural Steel Buildings. No failures are observed in the end-plated mid-splice connections demonstrating the potential of the proposed details. The detachable replaceable links are investigated by numerical analysis as well to further validate their applicability and to develop design recommendations.  相似文献   

MEEMD-Elman神经网络的电离层TEC预报模型     

汤俊  高鑫 《大地测量与地球动力学》2020,40(4):395-399

利用IGS中心提供的不同纬度的电离层TEC值,建立基于改进的集总平均经验模态分解(MEEMD)算法和Elman回归神经网络(ERNN)模型相结合的电离层TEC预报模型。实验结果表明,在低、中、高不同纬度采用本文方法预报5 d电离层TEC的预测值的均方根误差最优可达到0.96 TECu,相对精度最优达到95.4%,精度较EMD-ERNN模型及单一ERNN模型有显著提高。  相似文献   

Understanding coastal wetland hydrology with a new regional‐scale,process‐based hydrological model          下载免费PDF全文

Yu Zhang  Wenhong Li  Ge Sun  Guofang Miao  Asko Noormets  Ryan Emanuel  John S. King 《水文研究》2018,32(20):3158-3173

Coastal wetlands represent an ecotone between ocean and terrestrial ecosystems, providing important services, including flood mitigation, fresh water supply, erosion control, carbon sequestration, and wildlife habitat. The environmental setting of a wetland and the hydrological connectivity between a wetland and adjacent terrestrial and aquatic systems together determine wetland hydrology. Yet little is known about regional‐scale hydrological interactions among uplands, coastal wetlands, and coastal processes, such as tides, sea level rise, and saltwater intrusion, which together control the dynamics of wetland hydrology. This study presents a new regional‐scale, physically based, distributed wetland hydrological model, PIHM‐Wetland, which integrates the surface and subsurface hydrology with coastal processes and accounts for the influence of wetland inundation on energy budgets and evapotranspiration (ET). The model was validated using in situ hydro‐meteorological measurements and Moderate Resolution Imaging Spectroradiometer (MODIS) ET data for a forested and herbaceous wetland in North Carolina, USA, which confirmed that the model accurately represents the major wetland hydrological behaviours. Modelling results indicate that topographic gradient is a primary control of groundwater flow direction in adjacent uplands. However, seasonal climate patterns become the dominant control of groundwater flow at lower coastal plain and land–ocean interface. We found that coastal processes largely influence groundwater table (GWT) dynamics in the coastal zone, 300 to 800 m from the coastline in our study area. Among all the coastal processes, tides are the dominant control on GWT variation. Because of inundation, forested and herbaceous wetlands absorb an additional 6% and 10%, respectively, of shortwave radiation annually, resulting in a significant increase in ET. Inundation alters ET partitioning through canopy evaporation, transpiration, and soil evaporation, the effect of which is stronger in cool seasons than in warm seasons. The PIHM‐Wetland model provides a new tool that improves the understanding of wetland hydrological processes on a regional scale. Insights from this modelling study provide benchmarks for future research on the effects of sea level rise and climate change on coastal wetland functions and services.  相似文献   

基于多源数据的山东省围填海造地特点及发展趋势研究          下载免费PDF全文

安国强 《海洋开发与管理》2018,35(3):15-20

文章基于文献资料分析、官方数据汇总、国产高分辨率资源卫星遥感影像信息提取以及发展趋势研判等方法,对改革开放以来山东省全海域范围内围填海造地的历史发展、现状特征、发展趋势及其对生态环境的影响进行了分析和总结,并提出相关的政策建议。研究表明:改革开放以来,山东省围填海造地累计已超过4.58万hm~2。21世纪以来围填海造地进入快速增长时期,尤其是2010年以来,全省围填海造地又掀起了一次新的热潮,其面积和速度都远远超过了历史水平。鉴于围填海造地对环境和生态的巨大影响,文章提出了加强管理、严格环境影响评价、引入生态环境补偿机制以及建立分级填海评估制度和年度监测机制等建议。  相似文献   

鄂尔多斯地块周缘垂直形变场负位错反演与应变积累研究     

张希  刘立炜  郝明  白卓立 《大地测量与地球动力学》2019,39(6):551-556

利用鄂尔多斯地块及其周缘1970～2014年的垂直形变速率场资料，借助负位错反演研究该区域长期应变积累。结果表明，地块东北缘山西断陷带中北段年均能量积累增量、剪应力强度都较高，西南缘六盘山断裂与渭河断裂西段次之；山西断陷带中南段至晋陕交界处年均剪应力强度较高且显示一定程度的能量积累；西秦岭构造区尤其西秦岭北缘断裂西段、晋冀蒙交界区也反映一定程度的能量积累特性。  相似文献