检索结果-南通市图书馆

Changjiang River sediment delivering into the sea in response to water storage of Sanxia Reservoir in 2003

Acta Oceanologica Sinica 2006年第2期25卷 71-79页

作者： CHU Zhongxin ZHAI Shikui CHEN Xiufa college of Marine geosciences Ocean University of China Qingdao 266003 China Development and Research center China Geological Survey Beijing 100083 China

The Sanxia Reservoir on the Changjiang River stored water from 1 to 10 June and from 25 October to 5 November in 2003, elevating the water level to 135 and 139 m above mean sea level at the dam, respectively. A monthly dataset of water discharge, suspended sediment concentration （SSC） and sediment load of the Changjiang River from 1953 to 2003 measured at the Datong Hydrological Gauging Station of the downstreammost Changjiang River was mainly used to examine the Changjiang River sediment delivering into the sea in 2003 in response to the Sanxia Reservoir water storages in the same year. The results show that （1） compared with those in 2002, 2001, and the multi-yearly （1953-2000） average, both annual SSC and sediment load at Datong in 2003 were markedly reduced, and they were even smaller than the multi-yearly （1953-2000） minimum, although the annual runoff in 2003 did not change largely; and （2） compared with those in the corresponding months in 2002, 2001 and the multi-monthly average from 1953 to 2000, monthly SSC and sediment load at Datong both in June and November of 2003 were also markedly reduced, and those in June 2003 were even smaller than the multi-monthly minimum from 1953 to 2000. These may indicate that sediment sedimentation in the Sanxia Reservoir resulting from the Sanxia Reservoir water storage should be the main cause of the decreased annual and monthly SSC and sediment load of the Changjiang River into the sea in 2003. Besides, it seems that the Sanxia Reservoir water storage in the early June （flood season） of 2003 had more impacts on the decreased monthly SSC into the sea than that in the late October and early November （approximately non-flood season） of 2003.

关键词： Changjiang (Yangtze) River Sanxia Reservoir water storage sediment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An Experimental Study on the Wave-Induced Pore Water Pressure Change and Relative Influencing Factors in the Silty Seabed

引用

Journal of Ocean University of China 2014年第6期13卷 911-916页

作者： LI Anlong LUO Xiaoqiao LIN Lin YE Qing LI Chunyu Key Lab of Submarine geosciences and Prospecting Techniques Ministry of EducationOcean University of China college of Marine geosciences Ocean University of China CNPC Research Institute of engineering Technology Shengli Xinke Marine survey and Mapping Co.Ltd.

In this study, a flume experiment was designed to investigate the characteristics of wave-induced pore water pressure in the soil of a silty seabed with different clay contents, soil layer buried depths and wave heights respectively. The study showed that water waves propagating over silty seabed can induce significant change of pore water pressure, and the amplitude of pore pressure depends on depth of buried soil layer, clay content and wave height, which are considered as the three influencing factors for pore water pressure change. The pressure will attenuate according to exponential law with increase of soil layer buried depth, and the attenuation being more rapid in those soil layers with higher clay content and greater wave height. The pore pressure in silty seabed increases rapidly in the initial stage of wave action, then decreases gradually to a stable value, depending on the depth of buried soil layer, clay content and wave height. The peak value of pore pressure will increase if clay content or depth of buried soil layer decreases, or wave height increases. The analysis indicated that these soils with 5% clay content and waves with higher wave height produce instability in bed easier, and that the wave energy is mostly dissipated near the surface of soils and 5% clay content in soils can prevent pore pressure from dissipating immediately.

关键词： wave action silty seabed pore water pressure development influencing factor

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The Late Mesozoic Granodiorites from the Southwest Basin in the South China Sea and Its Tectonic Implication

引用

Journal of Earth Science 2012年第3期23卷 268-276页

作者：张振国杜远生高莲凤方念乔杨胜雄刘坚宋成兵 Faculty of Earth Sciences China University of Geosciences college of Mining engineering Hebei United University Key Laboratory of Mineral Development and Security Technology of Hebei Province School of Ocean Sciences China University of Geosciences Guangzhou Marine Geological survey of the Ministry of Land and Resources of China

The southwest basin is a key to study the origin and development of the South China Sea（SCS）.We do not know much about its boundaries,geological history,and the formation of its sea floor because it has a complex and highly re-gional structural background,notable sediment activity,and yet few floor *** a grano-diorite sample was collected from the southern margin of the southwest basin of the South China *** results indicated that the 40Ar-39Ar ages of biotites in the sample are 110.3±0.5 Ma,suggesting that they were prod-ucts of magmatic intrusion during the Early Cretaceous *** sample＇s geochemistry showed it had high SiO2,K2O,and Al2O3 but low TiO2 *** discriminant diagrams suggested that the sample might represent extrusion-related magmatism,either in an arc or forearc setting in the SCS area and that the sample mainly belonged to the syncollision type,whose formation was related to *** sample may be part of the main rock that made up the boundaries of rift *** process of tension cracking was similar to the development of the Red Sea,in which the rifting and sagging occurred in the continental *** southwest basin may not be an original ocean,but a rift developed through finite extension on continental crust *** oceanic crust came into being when the width and depth of the rift valley reached a certain *** granodiorite sample we collected provides a means of determining the boundary of the southwest basin and the clues that may help researchers expand relevant *** constitutes an important datum regarding the analysis of the formation and development of the SCS.

关键词： Late Mesozoic granodiorite the southwest basin the South China Sea, ^40Ar/^39Ar age,tectonic implication.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

First-Arrival Picking Method for Active Source Data with Ocean Bottom Seismometers Based on Spatial Waveform Variation Characteristics

引用

Journal of Ocean University of China 2024年第4期23卷 970-980页

作者： LIU Hongwei XING Lei ZHU Henghua ZHANG Jin ZHANG Jing LIU Huaishan Key Laboratory of Submarine geosciences and Prospecting Techniques Ministry of EducationCollege of Marine GeosciencesOcean University of ChinaQingdao 266100China Laboratory for Marine Mineral Resources Qingdao Marine Science and Technology CenterQingdao 266071China college of Underwater Acoustic engineering Harbin Engineering UniversityHarbin 150001China Shandong Institute of Geological survey Jinan 250014China

The precision and reliability of first-arrival picking are crucial for determining the accuracy of geological structure inversion using active source ocean bottom seismometer(OBS)refraction *** methods for first-arrival picking based on sample points are characterized by theoretical errors,especially in low-sampling-frequency OBS data because the travel time of seismic waves is not an integer multiple of the sampling *** this paper,a first-arrival picking method that utilizes the spatial waveform variation characteristics of active source OBS data is ***,the distribution law of theoretical error is examined;adjacent traces exhibit variation characteristics in their ***,a label cross-correlation superposition method for extracting highfrequency signals is presented to enhance the first-arrival picking *** from synthetic and field data verify that the proposed approach is robust,successfully overcomes the limitations of low sampling frequency,and achieves precise outcomes that are comparable with those of high-sampling-frequency data.

关键词： first-arrival picking spatial waveform variation label cross-correlation superposition method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Sources of high-temperature water and gas inrush during tunnel excavation:A case of Bangfu tunnel in Southwest China

引用

Journal of Rock Mechanics and Geotechnical engineering 2024年第12期16卷 5027-5049页

作者： Guo-Hua Zhang Zhong-Zhi Xie Bo-Wen Zhang Yu-Yong Jiao Jun-Peng Zou Jin-Quan Wu Feng Xiong Zhi-Cheng Tang Factory of engineering China University of GeosciencesWuhan430074China Key Laboratory of Geological survey and Evaluation of Ministry of Education China University of GeosciencesWuhan430074China Lincang Transportation Bureau Lincang677099China

Cases of simultaneous inrush of high-temperature water and harmful gases are infrequently reported in areas without geothermal anomalies,hydrocarbon source rock,or coal *** this,we investigated the origin,development,and formation of the high-temperature water and harmful gases that rushed into Bangfu tunnel,Southwest *** excavation of the Bangfu tunnel through the F1-2 fault in sandstone,a significant incident occurred involving a sudden influx of high-temperature water(45.4℃)of NaeHCO_(3)type and harmful gases(CO_(2),H2S).An extensive geological examination uncovered a fault network extending from the crust to the mantle in the tunnel site *** site features a substantial presence of both surface water and ***,within the middle crust at depths ranging from 19 km to 23 km,there are high-temperature ductile melts enriched with fluids and *** and experiments conducted on the harmful gases reveal that the primary source is identified in the crust,with the mantle source being secondary,followed by the atmospheric source being a minimal *** hydrochemical and isotopic composition characteristics of the hightemperature rushed water indicate its evolution was formed through the infiltration of atmospheric precipitation from cold groundwater of the CaeHCO_(3)*** mechanism underlying the formation of the inrush high-temperature water and harmful gases can be outlined as *** fault network,spanning from the crust to the mantle,serves as a migration pathway for the inflow *** volatiles and high-temperature melts make heat energy facilitate the inrush activity,while groundwater contributes to heat transfer and acts as a medium for gas *** mantle-derived volatiles migrate towards the surface through the fault network,they mix with high-temperature melts and crust-derived gases,forming a crust-mantle mixed *** processes such as deep hydrothermal circulation,shallo

关键词： Tunnel construction Water and gas inrush Harmful gases High-temperature water Genetic mechanism

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Changing provenance of late Cenozoic sediments in the Jianghan Basin

引用

Geoscience Frontiers 2015年第4期6卷 605-615页

作者： Lei Shao Shengyuan Yuan Chang'an Li Chunguo Kang Wenjing Zhu Yindi Liu Jietao Wang Wuhan Center of Geological survey China Geological Survey Faculty of Earth Sciences China University of Geosciences college of Urban Planning & Environment Science Xuchang University State Key Laboratory of Biogeology and Environmental Geology Institute of Geophysics & Geomatics China University of Geosciences Hubei Institute of Geological Sciences

The Yangtze River is one of the most important components of the East Asia river system. In this study, sediments in the Jianghan Basin, middle Yangtze River, were selected for trace element and rare earth element （REE） measurements, in order to decipher information on the change of sediment provenance and evolution of the Yangtze River. According to the elemental variations, the late Cenozoic sediments of the Jianghan Basin could be divided into four parts. During 2.68-2,28 Ma and 1.25-0 Ma, proveJ nance of the sediments was consistent, whereas sediments were derived from variable sources during 2.28-1.25 Ma. Comparison of the elemental compositions between the Pliocene and Quaternary sediments revealed a change in sediment source from a more felsic source area to a more basic source area around the Pliocene--Quaternary boundary. Input from the Emeishan LIP should account for this provenance change, Based on the provenance analysis of sediments in the Jianghan Basin, we infer that the Yangtze River developed into a large river with its drainage basin extended to the Emeishan LIP no later than the Pliocene-Quaternary boundary.

关键词： Yangtze River Jianghan Basin Trace element REE Provenance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Heavy metals in suspended matters during a tidal cycle in the turbidity maximum around the Changjiang(Yangtze) Estuary

引用

Acta Oceanologica Sinica 2015年第10期34卷 36-45页

作者： ZHANG Huaijing ZHAI Shikui ZHANG Aibin ZHOU Yonghua YU Zenghui college of Marine geosciences Ocean University of China Key Laboratory of Submarine geosciences and Prospecting Techniques Ministry of Education Qingdao Huanhai Marine engineering Prospecting Institute

In order to discuss the content distributions and fluxes of heavy metals in suspended matters during a tidal cycle in the turbidity maximum around the Changjiang （Yangtze） Estuary, the contents of heavy metals （Zn, Pb, Cd, Co and Ni） have been analyzed. During a tidal cycle, the average contents of heavy metals are in the order of Zn〉Ni〉Pb〉Co〉〉Cd. The average contents in ebb tide are generally higher than that in flood tide. However, at the inshore Sta. 11, influenced by the contamination from the nearby waste treatment plant, the average contents of Zn and Ni in flood tide are higher than those in ebb fide and at the offshore Sta. 10, the content of Cd in flood tide higher than that in ebb tide due to marine-derived materials. The five heavy metals, mainly terrigenous, are transported towards east-northeast, and settle down with suspended matters in the area between Sta. 11 and Sta. 10. Influenced by marine-derived materials, the flux value of Cd does not alter significantly with obviously changing in flux direction towards northwest. The source of heavy metals, the salinity of water and the concentration of suspended matters are the main factors controlling the content distributions of heavy metals during a tidal cycle. There is a positive correlation between the contents of heavy metals （Zn, Pb, Co and Ni） and the salinity of water, while the opposite correlation between the contents and the concentrations of suspended matters. Because of marine-derived materials, the content of Cd is not correlated with the concentration of suspended matters and the salinity of water.

关键词： Changjiang (Yangtze) Estuary turbidity maximum zone tidal cycle suspended matters content ofheavy metal flux of heavy metal

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A new shear rheological model for a soft interlayer with varying water content

引用

Water Science and engineering 2018年第2期11卷 131-138页

作者： Chong Ma Hong-bin Zhan Wen-min Yao Hua-zhou Li School of Mathematics and Physics China University of Geosciences Faculty of engineering China University of Geosciences Department of Geology and Geophysics Texas A&M University College Station

The rheological behavior of a soft interlayer is critical to understanding slope stability, which is closely related to the water content of the soft interlayer. This study used the soft interlayer of the Permian Maokou Formation in Southwest China as an example to perform ring shear creep tests with different water content amounts. The effect of water content on the creep properties of the soft interlayer was analyzed, and a new shear rheological model was established. This research produced several findings. First, the ring shear creep deformation of the soft interlayer samples varied with the water content and the maximum instantaneous shear strain increment occurred near the saturated water content. As the water content increased, the cumulative creep increment of the samples increased. Second, the water content significantly affected the long-term strength of the soft interlayer, which decreased with the increase of water content, exhibiting a negative linear correlation. Third, a constitutive equation for the new rheological model was derived, and through fitting of the ring shear creep test data, the validity and applicability of the constitutive equation were proven. This study has developed an important foundation for studying the long-term deformation characteristics of a soft interlayer with varying water content.

关键词： Soft interlayer Ring shear creep test Rheological constitutive model Water content

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Stratigraphic identification using real-time drilling data

引用

Journal of Rock Mechanics and Geotechnical engineering 2024年第9期16卷 3452-3464页

作者： Minglong You Zhikai Hong Fei Tan Hao Wen Zhanrong Zhang Jiahe Lv Faculty of engineering China University of GeosciencesWuhan430074China China Railway Siyuan survey and Design Group Co. Wuhan430063China

Identification of stratigraphic interfaces and lithology is a key aspect in geological and geotechnical *** this study,a monitoring while-drilling system was developed,along with a corresponding data pre-processing *** method can handle invalid drilling data generated during manual *** correlation between various drilling parameters was analyzed,and a database of stratigraphic interfaces and key lithology identification based on the monitoring parameters was *** average drilling speed was found to be the most suitable parameter for stratigraphic and lithology identification,and when the average drilling speed varied over a wide range,it corresponded to a stratigraphic *** average drilling speeds in sandy mudstone and sandstone strata were in the ranges of 0.1e0.2 m/min and 0.2e0.29 m/min,*** results obtained using the present method were consistent with geotechnical survey *** proposed method can be used for realtime lithology identification and represents a novel approach for intelligent geotechnical surveying.

关键词： Monitoring while-drilling Drilling parameters Geotechnical stratigraphy Lithology identification

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A New Criterion for Defining Inhomogeneous Slope Failure Using the Strength Reduction Method

引用

Computer Modeling in engineering & Sciences 2022年第8期132卷 413-434页

作者： Chengya Hua Leihua Yao Chenguang Song Qihang Ni Dongfang Chen School of engineering and Technology China University of GeosciencesBeijing100083China Center for Hydrogeology and Environmental Geology China Geological SurveyTianjin300309China

A new variational method treating the system as a whole with rigorous mathematical and physical derivation was presented in this *** with classical and engineering examples,variational energy expressions of slopes were *** addition,the calculation programs were written in the FISH language set in FLAC3D(fast Lagrangian analysis of continua in three dimensions)*** of safety(FOSs)of the models were determined by the variational method based on the strength reduction method(SRM)and then compared with other criteria or *** result showed that the variational method reflected the process of slope plasticity and failure uniformly and was feasible to analyze the stability of inhomogeneous *** method was applicable to both two-dimensional and three-dimensional heterogeneous *** small error with other criteria or methods also showed the accuracy of this *** method unified other criteria,avoided the artificial error of other criteria,and provided a logical derivation for the instability of heterogeneous *** method considered the system as a whole and avoided the shortcomings of the general method of one-sided instability *** proposed method is of great significance as it considers the coupling effect of stress and strain of materials and gives the mechanical basis for the instability of complex slopes.

关键词： Strength reduction method variational method inhomogeneous slopes stability

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：