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A study of the effect of local scour on the flow field near the spur dike 被引量:1
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作者 Yu-Tian Li Jie-Min Zhan Wing-Hong Onyx Wai 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2024年第2期98-105,共8页
The flow field near a spur dike such as down flow and horseshoe vortex system(HVS)are susceptible to the topographic changes in the local scouring process,resulting in variation of the sediment transport with time.In ... The flow field near a spur dike such as down flow and horseshoe vortex system(HVS)are susceptible to the topographic changes in the local scouring process,resulting in variation of the sediment transport with time.In this study,large eddy simulations with fixed-bed at different scouring stages were conducted to investigate the changes in flow field.The results imply that the bed deformation leads to an increase in flow rate per unit area,which represent the capability of sediment transportation by water,in the scour hole.Moreover,the intensity of turbulent kinetic energy and bimodal motion near the sand bed induced by the HVS were also varied.However,the peak moments between the two sediment transport mechanisms were different.Hence,understanding the complex feedback mechanism between topography and flow field is essential for the local scour problem. 展开更多
关键词 Spur dike Local scour Large eddy simulation Down flow Horseshoe vortex system
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Early Cretaceous Metasomatized Lithospheric Mantle beneath the Central Jiangnan Orogen in South China:Geochemical and Sr-Nd Isotope Evidence from the Tuanshanbei Dolerite
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作者 WANG Cheng WEI Hantao +1 位作者 LIU Qingquan YANG Zhao 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第3期602-616,共15页
It is well established that Cretaceous magmatism in the South China Block(SCB)is related to the Paleo-Pacific subduction.However,the starting time and the associated deep crust-mantle processes are still debatable.Maf... It is well established that Cretaceous magmatism in the South China Block(SCB)is related to the Paleo-Pacific subduction.However,the starting time and the associated deep crust-mantle processes are still debatable.Mafic dike swarms carry important information on the deep earth(including mantle)geodynamics and geochemical evolution.In the Jiangnan Orogen(South China).there is no information on whether the Mesozoic magmatic activities in this region are also directly related to the Pacific subduction or not.In this study,we present detailed zircon U-Pb geochronological,wholerock element and Sr-Nd isotope data for Early Cretaceous Tuanshanbei dolerite dikes,and provide new constraints on the condition of the lithospheric mantle and mantle dynamics of the SCB during that time.LA-ICP-MS zircon U-Pb dating suggests that this dolerite erupted in the Early Cretaceous(~145 Ma).All samples have alkaline geochemical affinities with K_(2)O+Na_(2)O=3.11-4.04 wt%,K_(2)O/Na_(2)O=0.50-0.72,and Mg^(#)=62.24-65.13.They are enriched in LILE but depleted in HFSE with higher initial^(87)Sr/^(86)Sr ratio(0.706896-0.714743)and lower ε_(Nd)(t)(-2.61 to-1.67).They have high Nb/U,Nb/La,La/Sm and Rb/Sr,and low La/Nb,La/Ta,Ce/Pb,Ba/Rb,Tb/Yb and Gd/Yb ratios.Such geochemical signatures suggest that the fractional crystallization is obvious but crustal contamination play a negligible role during magmatic evolution.Tuanshanbei dolerite were most likely derived from low-degree(2%-5%)partial melting of a phlogopite-bearing mantle material consisted of~85% spinel peridotite and~15% garnet peridotite previously metasomatized by asthenospherederived fluids/melts with minor subduction-derived fluids/melts.Slab-rollback generally lead to the upwelling of the hot asthenosphere.The upwelling of asthenosphere consuming the lithospheric mantle by thermo-mechanical-chemical erosion.The lithospheric mantle may have partially melted due to the heating by the upwelling asthenosphere and lithospheric extension.It is inferred that the Tuanshanbei dolerite might be associated with the initial slab rollback and corresponding lithospheric extension occurred potentially at ca.145 Ma. 展开更多
关键词 Early Cretaceous mafic dike metasomatized lithospheric mantle Tuanshanbei dolerite Jiangnan Orogen South China
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Numerical three-dimensional modeling of earthen dam piping failure
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作者 Zhengang Wang 《Water Science and Engineering》 EI CAS CSCD 2024年第1期72-82,共11页
A physically-based numerical three-dimensional earthen dam piping failure model is developed for homogeneous and zoned soil dams.This model is an erosion model,coupled with force/moment equilibrium analyses.Orifice fl... A physically-based numerical three-dimensional earthen dam piping failure model is developed for homogeneous and zoned soil dams.This model is an erosion model,coupled with force/moment equilibrium analyses.Orifice flow and two-dimensional(2D)shallow water equations(SWE)are solved to simulate dam break flows at different breaching stages.Erosion rates of different soils with different construction compaction efforts are calculated using corresponding erosion formulae.The dam's real shape,soil properties,and surrounding area are programmed.Large outer 2D-SWE grids are used to control upstream and downstream hydraulic conditions and control the boundary conditions of orifice flow,and inner 2D-SWE flow is used to scour soil and perform force/moment equilibrium analyses.This model is validated using the European Commission IMPACT(Investigation of Extreme Flood Processes and Uncertainty)Test#5 in Norway,Teton Dam failure in Idaho,USA,and Quail Creek Dike failure in Utah,USA.All calculated peak outflows are within 10%errors of observed values.Simulation results show that,for a V-shaped dam like Teton Dam,a piping breach location at the abutment tends to result in a smaller peak breach outflow than the piping breach location at the dam's center;and if Teton Dam had broken from its center for internal erosion,a peak outflow of 117851 m'/s,which is 81%larger than the peak outflow of 65120 m3/s released from its right abutment,would have been released from Teton Dam.A lower piping inlet elevation tends to cause a faster/earlier piping breach than a higher piping inlet elevation. 展开更多
关键词 3D dam breach model 2D shallow water equations 3D slope stability analysis Piping failure Teton Dam Quail Creek Dike
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2.7-Ga-old mafic dike in the Trans-North China Orogen of the North China Craton and its tectonic significance
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作者 Haiyan Liu Chong Peng 《Acta Geochimica》 EI CAS CSCD 2023年第6期1124-1129,共6页
We studied an Archean mafic dike in the TransNorth China Orogen of the North China Craton, which has a magmatic age of 2701 ± 83 Ma and is currently the oldest mafic dike in the North China Craton. Such an old di... We studied an Archean mafic dike in the TransNorth China Orogen of the North China Craton, which has a magmatic age of 2701 ± 83 Ma and is currently the oldest mafic dike in the North China Craton. Such an old dike is extremely rare in the world. The presence of mafic dikes indicates that the North China Craton was in a tensional tectonic environment at 2.7 Ga. Geochemical characteristics reveal that this mafic dike belongs to continental tholeiitic basalt. Results from Hf isotope analysis reveal that the mafic dike originates from a depleted mantle. The plate assembly in the North China landmass was realized during the Archean era(2.7 Ga), and a thick and stable continental crust was formed. Therefore, the first cratonization of the North China Craton was completed before 2.7 Ga. The intrusion of the 2.7-Ga-old mafic dike from the deep lithospheric mantle of the continent indicates that the North China Craton has undergone a period of extensional tectonic activity. This event marks a significant extensional event that occurred after the cratonization of the North China Craton. 展开更多
关键词 ARCHEAN Mafic dike Trans-North China Orogen North China Craton Hf CRATONIZATION
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Vestiges of the Kerguelen Mantle Plume in Southern Tibet:Evidence from 123-117 Ma Magmatism in the Dingri Area of the Central Tethys Himalaya
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作者 YAN Songtao WU Qingsong +4 位作者 LI Hu DAI Xuejian ZHU Lidong WANG Jie XIN Chongyang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2023年第4期1163-1180,共18页
The widely distributed Early Cretaceous magmatism in the Tethys Himalaya(TH)of southern Tibet is related to the Kerguelen mantle plume.Associated magmatic activity products are distributed in the eastern TH,where the ... The widely distributed Early Cretaceous magmatism in the Tethys Himalaya(TH)of southern Tibet is related to the Kerguelen mantle plume.Associated magmatic activity products are distributed in the eastern TH,where the active age is earlier than the peak ages of the Kerguelen mantle plume.This study investigated magmatic activity of the Dingri area in the central TH which was coeval with the Kerguelen mantle plume.The intrusion in the Dingri area contains diabases and monzonites.The zircon age of diabase is 123±1 Ma,and that of monzonite is 117±1 Ma.Geochemistry and Sr-Nd isotopic analyses show that the mafic-intermediate dikes were formed in an intraplate extensional environment.The diabase is derived from the enriched lithospheric mantle and monzonite is derived from partial melting of the lower crust,with both magmatic evolutions being contaminated by crustal materials.These characteristics are similar to those of the Rajmahal-Sylhet basalt,a typical Kerguelen mantle plume product.The discovery of the Dingri mafic-intermediate dikes of the central TH suggests that the TH and Rajmahal-Sylhet Traps formed a continuous mantle plume overflow magmatic belt which was a product of the continuous eruption of the Kerguelen mantle plume. 展开更多
关键词 GEOCHRONOLOGY mafic-intermediate dikes Kerguelen mantle plume central Tethys Himalaya East Gondwana
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中西正义观之比较 被引量:11
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作者 邓晓芒 《华中科技大学学报(社会科学版)》 CSSCI 北大核心 2015年第1期60-69,共10页
中国传统正义观除了昙花一现的墨家外,主要是儒家对"义"(義)的宣扬和阐释,它相对于"仁"更偏重外在的制度设计,但其根源在于内心情感上的"合宜",是立足于自然亲情之上的天经地义的等级关系(礼)。与此相对... 中国传统正义观除了昙花一现的墨家外,主要是儒家对"义"(義)的宣扬和阐释,它相对于"仁"更偏重外在的制度设计,但其根源在于内心情感上的"合宜",是立足于自然亲情之上的天经地义的等级关系(礼)。与此相对照,古希腊的"正义"(dike)的特点,一是强调公平或一视同仁;二是强调对不公平的惩罚,不徇私情;三是在人间正义和神的正义之间拉开了无限的距离,使人间正义带上了神圣性,并承认从神圣正义的高度可以对人间正义的不足进行批判或纠正;四是由理性所建立起来的正义原则的普遍性和可操作性,"理治"是古希腊民主制的基本原则。正是这些特点为西方现代民主制提供了最原始的基因,同时也体现了与中国传统的"义"的思想的根本区别。 展开更多
关键词 义(義) 正义(dike) 公平 情理 民主制
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法律何以成为正义——从themis到dike
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作者 程志敏 郑兴凤 《重庆广播电视大学学报》 2012年第3期14-18,共5页
法律女神忒弥斯代表着西方最早的规范性思想,后来却逐渐为"正义"所取代。themis(法律)与dike(正义)本身有着深刻而密切的联系,由于都具有"审判"的涵义,二者逐渐合流,dike取代了themis而上升为社会生活的主导规范。... 法律女神忒弥斯代表着西方最早的规范性思想,后来却逐渐为"正义"所取代。themis(法律)与dike(正义)本身有着深刻而密切的联系,由于都具有"审判"的涵义,二者逐渐合流,dike取代了themis而上升为社会生活的主导规范。在这个过程中,本来主要指"审判"的dike吸收了审判过程的"公正"要求,变成了一种伦理品质,即"正义"。dike继承并集成了themis的众多属性,其内涵从司法领域上升到伦理政治的高度,逐渐取代了神法themis。这充分证明,法律的本质就在于正义。 展开更多
关键词 忒弥斯(themis) 正义(dike) 法律 审判 规范
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K-Ar Geochronology of Mesozoic Mafic Dikes in Shandong Province, Eastern China: Implications for Crustal Extension 被引量:17
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作者 LIUShen HURuizhon ZHAOJunhong FENGCaixia 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第6期1207-1213,共7页
Based on K-Ar isotope analyses, Mesozoic mafic (and alkali ultramafic) dikes from western and eastern Shandong Province, China, are dated at 88.2±1.70 Ma to 169.5±3.7 Ma with the majority of ages ranging fro... Based on K-Ar isotope analyses, Mesozoic mafic (and alkali ultramafic) dikes from western and eastern Shandong Province, China, are dated at 88.2±1.70 Ma to 169.5±3.7 Ma with the majority of ages ranging from 90 Ma to 140 Ma. The emplacement of the dikes suggests a major Yanshanian (Cretaceous) crustal extension in Shandong province. Together with other available age data, this study suggests four periods of crustal extension at about 80 Ma, 100 Ma, 120 Ma and 140 Ma, respectively. Besides the effect of collapse of the Yanshanian orogenic belt on the emplacement of the mafic dikes in Shandong in the Cretaceous, the mantle plume and the extensive left-lateral advection and extension of the Tanlu fault also have controlled the crustal extension and the emplacement of the mafic dikes in eastern Shandong and western Shandong, respectively. 展开更多
关键词 crustal extension mafic dike K-Ar age mantle plume Tanlu fault SHANDONG eastern China
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Geochemical Characteristics and Genesis of the Luxi-Xianrenzhang Diabase Dikes in Xiazhuang Uranium Orefield, Northern Guangdong Province 被引量:14
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作者 LING Hongfei SHEN Weizhou +5 位作者 DENG Ping JIANG Shaoyong JIANG Yaohui YE Haimin PU Wei TAN Zhengzhong 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2005年第4期497-506,共10页
The Luxi-Xianrenzhang diabase dikes were emplaced into the eastern part of the Guidong composite granitoids in northern Guangdong Province at the end of the Early Cretaceous. They show tholeiitic features, enrichment ... The Luxi-Xianrenzhang diabase dikes were emplaced into the eastern part of the Guidong composite granitoids in northern Guangdong Province at the end of the Early Cretaceous. They show tholeiitic features, enrichment in large ion lithophile elements, slight enrichment in light rare earth elements, depletion in Zr and Hf, and basically no depletion in Nb and Ta and no Eu anomaly. They are similar to intraplate basalt in terms of trace element characteristics. They have high εNd(t) values (3.6-4.9), initial ^87Sr/^86Sr ratios (0.70530-70641) and δ^18O values and Dupal anomaly of Pb isotope compositions. Their Sr-Nd, Pb-Sr, Pb-Nd and Pb-Pb isotopes plot between DMM and EMII, with Pb similar to EMII, Nd relatively close to DMM and Sr in between. This profile suggests that the diabase dikes studied were derived from partial melting of a mantle source that had been subjected to metasomatism by fluids originated from a subduction zone under a tectonic environment of crustal extension and lithosphere thinning in the late Yanshanian. 展开更多
关键词 GEOCHEMISTRY main and trace elements Nd-Sr-Pb-O isotopes diabase dikes GUANGDONG
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Numerical analysis and geophysical monitoring for stability assessment of the Northwest tailings dam at Westwood Mine 被引量:13
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作者 Coulibaly Yaya Belem Tikou Cheng LiZhen 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第4期701-710,共10页
The Westwood Mine aims to reuse the tailings storage facility #1(TSF #1) for solid waste storage, but,downstream of the Northwest dike is considered critical in terms of stability. This paper uses numerical modeling a... The Westwood Mine aims to reuse the tailings storage facility #1(TSF #1) for solid waste storage, but,downstream of the Northwest dike is considered critical in terms of stability. This paper uses numerical modeling along with geophysical monitoring for assessing the Northwest dike stability during the restoration phase. The impact of waste rock deposition in the upstream TSF #1 is considered. The geophysical monitoring is based on electrical resistivity methods and was used to investigate the internal structure of the dike embankment in different deposition stages. The numerical simulations were performed with SLOPE/W code. The results show a factor of safety well above the minimum recommended value of 1.5. Geophysical monitoring revealed a vertical variation in the electrical resistivity across the dike, which indicates a multilayer structure of the embankment. Without any current in situ data, the geophysical monitoring helped estimating the nature of the materials used and the internal structure of the embankment. These interpretations were validated by geological observation of geotechnical log of the embankment. Based on this study, it is recommended that the water polishing pond be partly filled before waste rock is deposited in TSF #1. In addition, to ensure the stability of the dike, the piezometric head monitoring prior to and during waste rock deposition is recommended. 展开更多
关键词 Mine tailings impoundment DIKE Embankment Numerical analysis Factor of safety Geophysical monitoring
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Identification of Five Stages of Dike Swarms in the Shanxi-Hebei-Inner Mongolia Border Area and Its Tectonic Implications 被引量:9
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作者 SHAOJi'an ZHAIMingguo +1 位作者 ZHANGLüqiao LIDaming 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第1期320-330,共11页
Dike swarms are generally ascribed to intrusion of mantle-source magma result from extension. Basic dike swarms around the Shanxi-Hebei-Inner Mogolia borders in the northern peripheral area of the North China Craton c... Dike swarms are generally ascribed to intrusion of mantle-source magma result from extension. Basic dike swarms around the Shanxi-Hebei-Inner Mogolia borders in the northern peripheral area of the North China Craton can be divided into five age groups according to isotopic dating: 1800-1700 Ma, 800-700 Ma, 230 Ma, 140-120 Ma, and 50-40 Ma. Geological, petrological and isotope geochemical features of the five groups is investigated in order to explore the variation of the mantle material composition in the concerned area with time. And the various extensional activities reflected by the five groups of dike swarms are compared with some important tectonic events within the North China Craton as well as around the world during the same period. 展开更多
关键词 dike swarms North China Craton extensional events isotopic dating global tectonic movement
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Experiments and numerical simulations on transport of dissolved pollutants around spur dike 被引量:8
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作者 Li-ping CHEN Jun-cheng JIANG 《Water Science and Engineering》 EI CAS 2010年第3期341-353,共13页
The flow field around a spur dike has three-dimensional characteristics. In order to analyze the influence of the flow field on pollutant transport, based on a compressive volume of fluid (VOF) scheme, the three-dim... The flow field around a spur dike has three-dimensional characteristics. In order to analyze the influence of the flow field on pollutant transport, based on a compressive volume of fluid (VOF) scheme, the three-dimensional transient compressive pollutant transport model (CPTM) and the cubic equation (CE) bounded differencing scheme were developed. For the calibration and validation of CPTM, laboratory experiments were carried out in a flume with a non-submerged spur dike. The spur dike was angled at 60°, 90°, and 120° from the upstream direction. The simulation results agreed with the experimental results. The simulations and experiments showed that the distribution of pollutant concentration was determined by circumfluence and the main flow. Concentration decay in the circumfluenee zone was slower than that in the main flow. Downstream of the spur dike, the concentration fluctuation became intensive with the increase of spur dike angle. 展开更多
关键词 VOF spur dike dissolved pollutant numerical simulation experiment
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Stability of the Guiding Dike in Yangtze Estuary Under the Wave Load 被引量:6
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作者 闫澍旺 刘润 +1 位作者 范期锦 谢世楞 《China Ocean Engineering》 SCIE EI 2005年第4期659-670,共12页
During the construction of the guiding dike in the Yangtze Estuary, some of the caisson structures sank into the soil for 1 -5 m or slid about 20 m away from the original place when a strong storm attacked this area. ... During the construction of the guiding dike in the Yangtze Estuary, some of the caisson structures sank into the soil for 1 -5 m or slid about 20 m away from the original place when a strong storm attacked this area. Dynamic triaxial tests were carried out to simulate the behavior of foundation soils under wave loading. The test results show that the excessive settlement and lateral movement of the caissons are due to the weakening of the soft clay strength during the strong storm. The test results also show that the ability of the soft clay to resist the wave force will be greatly increased when the soft soil samples are suitably improved. Based on the test results, an improvement method combining vertical drains with surcharge loading was proposed to strengthen the foundation soil. On the improved soil foundation, the dike has been reconstructed and undergone several strong storms without any damage. A finite element approach has been developed for analyzing the settlement and stability of the dike under the action of strong storm. 展开更多
关键词 soft clay strength weakening DIKE dynamic triaxial test FE analysis
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Minimum critical thickness of dike for ore-bearing fluid injection:A new approach applied to the Shihu gold deposit,Hebei Province,North China 被引量:6
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作者 Dedong Li Yuwang Wang +4 位作者 Jingbin Wang Zhaohua Luo Jiulong Zhou Zongfeng Yang Cui Liu 《Geoscience Frontiers》 SCIE CAS 2012年第5期717-728,共12页
According to the metallogenic theory by transmagmatic fluid (TMF), one magmatic intrusion is a channel of ore-bearing fluids, but not their source. Therefore, it is possible to use TMF's ability for injection into ... According to the metallogenic theory by transmagmatic fluid (TMF), one magmatic intrusion is a channel of ore-bearing fluids, but not their source. Therefore, it is possible to use TMF's ability for injection into and for escaping t^om the magmatic intrusion to evaluate its ore-forming potential. As the ore-bearing fluids cannot effectively inject into the magmatic intrusion when the magma fully crystal- lized, the cooling time and rates viscosity varied can be used to estimate the minimum critical thickness of the intrusion. One dimensional heat transfer model is used to determine the cooling time for three representative dikes of different composition (granite porphyry, quartz diorite and diabase) in the Shihu gold deposit. It also estimated the rates viscosity varied in these time interval. We took the thickness of dike at the intersection of the cooling time -- thickness curve and the rates viscosity varied versus thick- ness curve as the minimum critical thickness. For the ore-bearing fluids effectively injecting into the magma, the minimum critical thicknesses for the three representative dikes are 33.45 m for granite porphyry, 8.22 m for quartz diorite and 1.02 m for diabase, indicating that ore-bearing dikes must be thicker than each value. These results are consistent with the occurrence of ore bodies, and thus they could be applied in practice. Based on the statistical relationship between the length and the width of dikes, these critical thicknesses are used to compute critical areas: 0.0003--0.0016 km2 for diabase, 0.014--0.068 km2 for quartz diorite and 0.011-0.034 km2 for granite porphyry. This implies that ore- bearing minor intrusions have varied areas corresponding to their composition. The numerical simulation has provided the theoretical threshold of exposed thickness and area of the ore-bearing intrusion. These values can be used to determine the ore-forming potentials of dikes. 展开更多
关键词 Dike swarm Cooling time Numerical simulationMinor intrusion Critical thickness Transmagmatic fluid
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Experimental study on inner slope failure mechanism of seawall by coupling effect of storm surge and wave 被引量:4
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作者 PAN Junning WANG Shupeng +2 位作者 SUN Tianting CHEN Maowen WANG Dengting 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2019年第6期1912-1920,共9页
In the context of global climate change,the impact of group-occurring ocean dynamic disasters on China's offshore areas is becoming more and more intense.The study of the effect of existing ocean dynamic disasters... In the context of global climate change,the impact of group-occurring ocean dynamic disasters on China's offshore areas is becoming more and more intense.The study of the effect of existing ocean dynamic disasters on offshore hazard-bearing bodies mostly focuses on the effect of single disaster-causing factors,and it is still insufficient to study storm surge and dynamic wave coupling&reinforcement effects as well as the process of the dynamic response of such hazard-bearing bodies as seawalls.This study firstly realized the synchronous process of water level and wave through continuous tide generation and wave generation by the wave maker and tide generating device,so as to realize the dynamic coupling simulation of storm surge and wave in the laboratory.Then the physical model test of the typical seawall section was carried out under the dynamic coupling of storm surge and wave as well as at a conventional fixed water level respectively.In the process of test wave overtopping discharge and the damage process of the levee crown and backwall of seawalls were observed and compared,and their damage mechanism was also studied. 展开更多
关键词 sea DIKE storm surge WAVE OVERTOPPING WAVE LEVEE overflowing coupling
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Ordovician Granitoids and Silurian Mafic Dikes in the Western Kunlun Orogen, Northwest China:Implications for Evolution of the Proto-Tethys 被引量:3
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作者 ZHANG Qichao WU Zhenhan +3 位作者 LI Shan LI Kan LIU Zhiwei ZHOU Qing 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第1期30-49,共20页
The western Kunlun orogen in the northwest Tibet Plateau is related to subduction and collision of Proto-and Paleo-Tethys from early Paleozoic to early Mesozoic. This paper presents new LA-ICPMS zircon U-Pb ages and L... The western Kunlun orogen in the northwest Tibet Plateau is related to subduction and collision of Proto-and Paleo-Tethys from early Paleozoic to early Mesozoic. This paper presents new LA-ICPMS zircon U-Pb ages and Lu-Hf isotopes, whole-rock major and trace elements, and Sr–Nd isotopes of two Ordovician granitoid plutons(466–455 Ma) and their Silurian mafic dikes(~436 Ma) in the western Kunlun orogen. These granitoids show peraluminous high-K calcalkaline characteristics, with(^(87)Sr/^(86)Sr)_i value of 0.7129–0.7224, ε_(Nd)(t) values of -9.3 to -7.0 and zircon ε_(Hf)(t) values of -17.3 to -0.2, indicating that they were formed by partial melting of ancient lower-crust(metaigneous rocks mixed with metasedimentary rocks) with some mantle materials in response to subduction of the Proto-Tethyan Ocean and following collision. The Silurian mafic dikes were considered to have been derived from a low degree of partial melting of primary mafic magma. These mafic dikes show initial ^(87)Sr/^(86)Sr ratios of 0.7101–0.7152 and ε_(Nd)(t) values of -3.8 to -3.4 and zircon ε_(Hf)(t) values of -8.8 to -4.9, indicating that they were derived from enriched mantle in response to post-collisional slab break-off. Combined with regional geology, our new data provide valuable insight into late evolution of the Proto-Tethys. 展开更多
关键词 High-K CALC-ALKALINE GRANITOIDS mafic DIKES Western KUNLUN OROGEN Proto-Tethys
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Numerical Study of Storm Surge Inundation in the Southwestern Hangzhou Bay Region During Typhoon Chan-Hom in 2015 被引量:3
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作者 WANG Kai HOU Yijun +2 位作者 LI Shuiqing DU Mei LI Rui 《Journal of Ocean University of China》 SCIE CAS CSCD 2020年第2期263-271,共9页
Storm surge inundation is a major concern in marine hazard risk assessment during extreme weather conditions.In this study,a high-resolution coupled model(the ADVanced CIRCulation model+the Simulating WAves Nearshore ... Storm surge inundation is a major concern in marine hazard risk assessment during extreme weather conditions.In this study,a high-resolution coupled model(the ADVanced CIRCulation model+the Simulating WAves Nearshore model)was used to investigate the storm surge inundation in the southwestern Hangzhou Bay region during Typhoon Chan-hom in 2015.The simulated hydrodynamic processes(sea surface wave and storm tide)were validated with measured data from wave buoys and tide gauges,indicating that the overall performance of the model was satisfactory.The storm surge inundation in the coastal area was simulated for several idealized control experiments,including different wave effects(wave-enhanced wind stress,wave-enhanced bottom stress,and wave radiation stress).Dike overflowing cases with different dike heights and dike breaking cases with different dike breach lengths were considered in the simulation.The results highlight the necessity of incorporating wave effects in the accurate simulation of storm surge inundation.Dike height significantly influences the magnitude and phase of the maximum inundation area in the dike overflowing cases,and dike breach length is an important factor impacting the magnitude of the maximum inundation area in the dike breaking cases.This study may serve as a useful reference for accurate coastal inundation simulation and risk assessment. 展开更多
关键词 storm surge typhoon waves dike overflowing dike breaking INUNDATION ADCIRC+SWAN
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Risk Analysis and Assessment of Overtopping Concerning Sea Dikes in the Case of Storm Surge 被引量:4
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作者 王莉萍 黄桂玲 +2 位作者 陈正寿 梁丙臣 刘桂林 《China Ocean Engineering》 SCIE EI CSCD 2014年第4期479-487,共9页
Risk analysis and assessment relating coastal structures has been one of the hot topics in the area of coastal protection recently. In this paper, from three aspects of joint return period of multiple loads, dike fail... Risk analysis and assessment relating coastal structures has been one of the hot topics in the area of coastal protection recently. In this paper, from three aspects of joint return period of multiple loads, dike failure rate and dike continuous risk prevention respectively, three new risk analysis methods concerning overtopping of sea dikes are developed. It is worth noting that the factors of storm surge which leads to overtopping are also considered in the three methods. In order to verify and estimate the effectiveness and reliability of the newly developed methods, quantified mutual information is adopted. By means of case testing, it can be found that different prior variables might be selected dividedly, according to the requirement of special engineering application or the dominance of loads. Based on the selection of prior variables, the correlating risk analysis method can be successfully applied to practical engineering. 展开更多
关键词 sea dikes risk analysis failure rate mutual information
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A Possible Mechanism to Thin Lithosphere of the North China Craton: Insights from Cretaceous Mafic Dikes in the Jiaodong Pensinsula 被引量:8
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作者 MA Liang JIANG Shaoyong +1 位作者 Albrecht W.Hofmann XU Yigang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第S1期106-108,共3页
The North China Craton(NCC)is a classic case of the destruction of an ancient craton,in that it records the loss of more than 100 km of ancient refractory lithospheric mantle during the Mesozoic(e.g.,Menzies et al.,19... The North China Craton(NCC)is a classic case of the destruction of an ancient craton,in that it records the loss of more than 100 km of ancient refractory lithospheric mantle during the Mesozoic(e.g.,Menzies et al.,1993).This 展开更多
关键词 Insights from Cretaceous Mafic Dikes in the Jiaodong Pensinsula NCC
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Influence of Spur Dike on Hydrodynamic Exchange Between Channel and Shoal of Generalization Estuary in Physical Model Test 被引量:3
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作者 JIAO Zeng-xiang Dou Xi-ping +2 位作者 ZHENG Jin-hai ZHANG Xin-zhou GAO Xiang-yu 《China Ocean Engineering》 SCIE EI CSCD 2017年第5期624-630,共7页
Widely applied in maintaining estuarial waterway depth, the spur dike has played an important role in currents and sediment exchange between channel and shoal and sediment back-silting in the channel. Through establis... Widely applied in maintaining estuarial waterway depth, the spur dike has played an important role in currents and sediment exchange between channel and shoal and sediment back-silting in the channel. Through establishing a generalized physical model at a bifurcated estuary and conducting current tests under the joint action of runoff and tide, the influence of the spur dike length on current exchange between channel and shoal is analyzed. Results show that when the spur dike length reaches a certain value, the direction of the flow velocity shear front between the channel and shoal will change. The longer the spur dike, the larger the transverse fluctuating velocity at the peak of flood in the channel shoal exchange area, while the transport of the transverse hydrodynamics is obvious in the process of flood. There is an optimum length of spur dike when the shear stress in the channel and the longitudinal velocity in flood and ebb reach the maximum, and the flow velocity will decrease when the spur dike length is smaller or larger than the optimum. For a certain length of spur dike, the larger the channel shoal elevation difference, the larger the peak longitudinal flow velocity in the middle of the navigation channel in flood and ebb. However, the transverse flow velocity will first decrease and then increase. The transverse transportation is obvious when the channel shoal elevation difference increases. 展开更多
关键词 spur dike HYDRODYNAMICS flow velocity channel shoal exchange physical model
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