检索结果-内蒙古大学图书馆

A preliminary study on the volcanic intrusive complex type beryllium metallogenic belt from the southeast coast of China

引用

Science China Earth Sciences 2022年第8期65卷 1586-1600页

作者： Can RAO Rucheng WANG Fuyuan WU Xudong CHE Xiaofeng LI Qi WANG Zhiqi ZHANG Runqiu WU Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province School of Earth SciencesZhejiang UniversityHangzhou310027China State Key Laboratory for Mineral Deposits Research School of Earth Sciences and EngineeringNanjing UniversityNanjing210023China State Key Laboratory of Lithosphere Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China

Beryllium(Be)is one of the unsubstitutable key metals in strategic emerging industries and national defense industries,mainly originating from volcanogenic Be ***,volcanogenic Be deposits have become important research objects of key metal deposits,with a focus on their occurrence,metallogenic mechanism,and resource *** the southeast coast of China,the Late Mesozoic volcanic intrusive complex has a good Be metallogenic background,and strong Be mineralization occurs in some *** geological investigation and analyses of samples from Southeast zhejiang as well as Northeast and Southeast Fujian indicate that Be mineralization in the southeast coast of China is closely related to the hydrothermal processes in the volcanic intrusive *** Southeast zhejiang,Be ore in the Qingtian area mainly occurs in granite porphyry,with the Be content reaching 939 ppm,while strong Be mineralization from Zhangji rhyolite porphyry in the Pingyang area contains up to 11400 ppm *** Xiapu County,Northeastern Fujian,the Dawan Be deposit is characterized by constituents of helvite and *** Pinghe County,Southeastern Fujian,the Fulishi Be ore is a quartz vein beryl-type *** results suggest that the volcanic intrusive complex area in the southeast coast of China has a wide range of Be mineralization and better Be metallogenic potential,and it is expected to become an important Be metallogenic belt in ***,we should thoroughly investigate the Be resources of granite porphyry,rhyolite porphyry,quartz porphyry,and quartz vein in this volcanic rock area,which can provide a theoretical basis for the exploration and guiding prospecting of volcanic intrusive complex Be deposits.

关键词： Volcanogenic Be deposit Beryllium resources Be-bearing minerals Beryllium metallogenic belt Southeast coast of China

来源：评论

学校读者我要写书评

暂无评论

Near-Surface Radial Anisotropy Tomography of Geothermal Reservoir Using Dense Seismic Nodal Array 10

Near-Surface Radial Anisotropy Tomography of Geothermal Rese...

引用

10th International Conference on Environmental and Engineering Geophysics, ICEEG 2023

作者： Guan, Bo Xia, Jianghai Liu, Ya Zhang, Hao Zhou, Changwei Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province Zhejiang University Hangzhou China Zhejiang Geophysical and Geochemical Prospecting Academy Hangzhou Zhejiang 310000 China

The development and utilization of geothermal energy has become an indispensable part in the process of urbanization in China. Near-surface tomographic imaging based on ambient noise is increasingly widely used in geothermal exploration. To construct the subsurface structure of Shear-wave velocity in Andi town, zhejiang province, recordings of ambient noise data of 4.7 days were recorded by a dense seismic array composed of 192 stations with an aperture of about 5 km. Analysis of array beamforming in high-frequency bands indicated the approximately uniformly distributed of noise sources. We applied seismic interferometry to retrieve both Rayleigh and Love waves. We used two-station analysis to obtain dispersion images and the corresponding high-quality dispersion curves were extracted by automated codes. 3-D tomographic results down to a depth of 1.6 km of S-wave velocity structure and radial anisotropy parameters were obtained using direct surface wave radial anisotropy tomography method. The anomalies of S-wave velocity and radial anisotropy parameters were combined to infer the storage of geothermal reservoir in Andi town. Furthermore, the accuracy of our results was verified by the borehole data. © Published under licence by IOP Publishing Ltd.

关键词： Surface waves

来源：评论

学校读者我要写书评

暂无评论

Predecessor Rain Events in the Yangtze River Delta Region Associated with South China Sea and Northwest Pacific Ocean(SCS-WNPO)Tropical Cyclones

引用

Advances in Atmospheric Sciences 2023年第6期40卷 1021-1042页

作者： Huiyan XU Xiaofan LI Jinfang YIN Dengrong ZHANG Zhejiang Provincial Key Laboratory of Urban Wetlands and Regional Change School of Information Science and TechnologyHangzhou Normal UniversityHangzhou 311121China Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province School of Earth SciencesZhejiang UniversityHangzhou 310027China State Key Laboratory of Severe Weather(LaSW) Chinese Academy of Meteorological Sciences(CAMS)Beijing 100081China

Predecessor rain events(PREs) in the Yangtze River Delta(YRD) region associated with the South China Sea and Northwest Pacific Ocean(SCS-WNPO) tropical cyclones(TCs) are investigated during the period from 2010 to *** indicate that approximately 10% of TCs making landfall in China produce PREs over the YRD region;however,they are seldom forecasted. PREs often occur over the YRD region when TCs begin to be active in the SCS-WNPO with westward paths, whilst the cold air is still existing or beginning to be present. PREs are more likely to peak in June and September. The distances between the PRE centers and the parent TC range from 900 to 1700 km. The median value of rain amounts and the median lifetime of PREs is approximately 200 mm and 24 h, respectively. Composite results suggest that PREs form in the equatorward jet-entrance region of the upper-level westerly jet(WJ), where a 925-hPa equivalent potential temperature ridge is located east of a 500-hPa trough. deep moisture is transported from the TC vicinity to the remote PREs region. The ascent of this deep moist air in front of the 500-hPa trough and frontogenesis beneath the equatorward entrance region of the WJ is advantageous for the occurrence of PREs in the YRD region. The upper-level WJ may be affected by the subtropical high and westerly trough in the Northwest Pacific Ocean, and the occurrence of PREs may favor the maintenance of the upper-level WJ. The upper-level outflow of TCs in the SCS plays a secondary role.

关键词： tropical cyclone heavy rain westerly trough upper-level jet stream

来源：评论

学校读者我要写书评

暂无评论

Modified Frequency-Bessel Transform Method for Dispersion Imaging of Rayleigh Wave from Ambient Seismic Noise 9

Modified Frequency-Bessel Transform Method for Dispersion Im...

引用

9th International Conference on Environmental and Engineering Geophysics, ICEEG 2020

作者： Xi, Chaoqiang Xia, Jianghai Dai, Tianyu Liu, Ya Ning, Ling Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province School of Earth Sciences Zhejiang University Hangzhou China Institute of Geophysics and Geomatics China University of Geosciences Wuhan China

Surface wave methods based on ambient noise have gained much attention from geophysical and civil engineering communities because of the limited application of traditional seismic surveys in highly populated urban areas. Higher modes information is important in dispersion curve inversion for shear-wave velocity structure. A method using the Frequency-Bessel (F-J) transform is for extracting the multimode dispersion curves from ambient seismic noise recordings. At high frequencies, the measured dispersion energy image by the F-J transform, however, would usually be polluted by a type of "crossed"artifacts. We proposed a modified frequency-Bessel (MFJ) transform by replacing the Bessel function in the F-J method with the Hankel function to attenuate the artifacts. A numerical simulation and a real-world example indicate the effectiveness of the proposed MFJ method in improving the accuracy of Rayleigh wave dispersion measurements, compared with the F-J method. © Published under licence by IOP Publishing Ltd.

关键词： Rayleigh waves

来源：评论

学校读者我要写书评

暂无评论

Early Cenozoic Reactivation of a Pre-Existing Crustal Boundary Along the Kuantan Shan-Hei Shan Area North of the Jiuxi Basin, Northeastern Tibetan Plateau

引用

Tectonics 2025年第5期44卷

作者： Kaixuan An Xiubin Lin Jialun Huang Lei Wu Hanlin Chen Xiaogan Cheng Chunyang Li Yaguang Chen Ziyi Wang Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province School of Earth Sciences Zhejiang University Hangzhou China Research Center for Structures in Oil and Gas Bearing Basins Ministry of Education Hangzhou China China Southern Petroleum Exploration & Development Corporation PetroChina Haikou China Research Institute of Petroleum Exploration and Development Sinopec Southwest Oil and Gas Company Chengdu China

The Cenozoic India-Eurasia collision and continued convergence resulted in the formation of the Tibetan Plateau and the significant reactivation of intracontinental structures located over 1,500 km from the collision zone. However, the timing and mechanisms driving this reactivation remain debated, resulting in competing models about the Cenozoic evolution of the plateau margins. This study aims to address this issue by focusing on the northeastern Tibetan Plateau and investigating the depositional sequences, source-to-sink relationships, and deformation structures along the northeastern margin. Stratigraphic analysis reveals an upward-thinning sequence beginning with high-energy conglomerates in the Eocene, followed by an upward-coarsening sequence. Detrital zircon U-Pb dating analysis indicates a reorganization of sediment dispersal during the middle Miocene, shifting from northern provenances to southern provenances. Structural analysis of a seismic profile traversing the present deforming front of the northeastern Tibetan Plateau shows steep boundary faults and positive flower structures, accommodating ∼2.2 km of Cenozoic shortening (∼7.5% strain). These findings suggest that pre-existing weak zones within the Eurasian plate were reactivated immediately following the initial India-Eurasia collision. Combined with previous geophysical studies, a pre-existing crustal boundary is also imaged along the deforming front of the northeastern Tibetan Plateau, acting as a fixed convergence zone between two terranes throughout the Cenozoic. This zone is characterized by steeply dipping faults, positive flower structures, and minimal shortening, exemplifying intracontinental convergence between terranes of comparable rheological strength. The Bei Shan, Kuantan Shan and Hei Shan were reactivated immediately following the initial India-Eurasia collision Kuantan Shan-Hei Shan area is a pre-existing crustal boundary, with steep boundary faults, positive flower structures and mi

关键词： northeastern Tibetan Plateau early Cenozoic reactivation pre-existing crustal boundary stratigraphic and detrital zircon analysis structural analysis

来源：评论

学校读者我要写书评

暂无评论

Detection of Low-Velocity Layer Using Passive Surface-Wave data and deep Learning: An Application in the Urban Area of Hangzhou, China 10

Detection of Low-Velocity Layer Using Passive Surface-Wave D...

引用

10th International Conference on Environmental and Engineering Geophysics, ICEEG 2023

作者： Chen, Xinhua Xing, Huaixue Pang, Jingyin Zhou, Changjiang Xia, Jianghai Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province School of Earth Sciences Zhejiang University Zhejiang Hangzhou310027 China Nanjing Center of the Geologicasl Survey China Geological Survey Nanjing210016 China

Passive surface-wave methods using dense seismic arrays have gained growing attention in near-surface high-resolution imaging in urban environments. deep learning (DL) can release a tremendous workload brought by dense seismic arrays. We presented a case study of shear-wave velocity (Vs) structure imaging in the Hangzhou urban area (eastern China) using DL inversion. Noise data were recorded by dense linear arrays with approximately 5 m spacing deployed along two crossing roads for investigating the top 80 m of the subsurface. Phase-velocity dispersion curves are extracted from virtual shot gathers using multichannel analysis of surface waves. We divided the area where the low-velocity layer (LVL) may exist into three layers with a thickness of 5 m. We gave the four layers weak constraints to generate training dataset and adopted a convolutional neural network to directly invert fundamental-mode Rayleigh-wave phase velocity for 1D Vs models. To improve the accuracy, we further applied the sensitivities to weight the loss function in DL inversion. The obtained pseudo-2D Vs profiles correspond to the velocities estimated from logging data and previous survey. The well-trained neural network successfully identified that the LVL is located at 50-60 m deep. And this network was also achieved accurately the inversion of a dense seismic network nearby. The results of this survey demonstrate the accuracy and efficiency of delineating near-surface structures from traffic-induced noise using the DL technique, which has great potential for monitoring subsurface changes in urban areas. © Published under licence by IOP Publishing Ltd.

关键词： Shear waves

来源：评论

学校读者我要写书评

暂无评论

Distributions of dissolved oxygen and apparent oxygen utilization in the Cosmonaut Sea and Amundsen Sea in austral summer 2022

引用

Advances in Polar Science 2024年第3期35卷 327-369页

作者： DING Yufei ZHU Changfeng ZHANG Cai ZHANG Haifeng ZHAO Jun GUO Xiaoze ZHANG Wei PAN Jianming Key Laboratory of Marine Ecosystem Dynamics Ministry of Natural ResourcesHangzhou 310012China Second Institute of Oceanography Ministry of Natural ResourcesHangzhou 310012China Organic Geochemistry Unit Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang ProvinceSchool of Earth SciencesZhejiang UniversityHangzhou 310027China

Dissolved oxygen(DO)and apparent oxygen utilization(AOU)are essential parameters for evaluating the impact of climate change on marine *** this study,we utilized data on DO and AOU collected from the Amundsen Sea(western Antarctic)and the Cosmonaut Sea(eastern Antarctic)during the 38th Chinese National Antarctic Research Expedition,along with chlorophyll a(Chl a)data,to analyze the impact of primary production and the spatial distribution and structural features of water masses in these *** findings show that the standard deviation range of parallel DO samples is between 0.1 and 3.9μmol·L^(-1),meeting the precision criteria of the survey *** values lower than 0.0μmol·L^(-1) were commonly observed in the surface waters of both regions,with the highest incidence in the polynya of Amundsen Sea,indicating a strong influence of high primary *** Cosmonaut Sea exhibited the highest AOU values(higher than 160.0μmol·L^(-1))in the 75-500 m layer,while AOU value in the Amundsen Sea did not exceed 160.0μmol·L^(-1),suggesting potential upwelling of Circumpolar deep Water to 100 m in the Cosmonaut Sea with minimal changes in its properties,whereas significant changes were noted in the properties of upwelling modified Circumpolar deep Water in the Amundsen *** values lower than 125.0μmol·L^(-1)were detected in the near-bottom waters of the Cosmonaut Sea,indicating the presence of Antarctic Bottom Water.

关键词： dissolved oxygen apparent oxygen utilization Southern Ocean water mass chlorophyll a

来源：评论

学校读者我要写书评

暂无评论

Calculation of Noise Cross-Correlation Functions between Different Types of Sensors without Removing Instrument Responses 10

Calculation of Noise Cross-Correlation Functions between Dif...

引用

10th International Conference on Environmental and Engineering Geophysics, ICEEG 2023

作者： Liu, Ya Xia, Jianghai Zhang, Hao Guan, Bo Xi, Chaoqiang Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province School of Earth Sciences Zhejiang University Hangzhou China State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines School of Earth and Environment Anhui University of Science and Technology Huainan China

The noise cross-correlation function between two stations provides an efficient way for understanding the subsurface structure. Removing instrument response is a necessary step for the calculation of the noise cross-correlation function (NCF) between different types of sensors, which requires the knowledge of the instrument response. However, the instrument response files may be missing or not provided, restricting us to only the calculation of NCF between the same type of instruments. We propose to calculate the NCF between different sensors deployed at the same site and obtain the phase differences between different instrument responses. The phase differences can then be removed resulting in the unbiased NCF between different sensors deployed at different locations. The effectiveness of our method is verified through a real data example. © Published under licence by IOP Publishing Ltd.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Distal axis sulfide mineralization on the ultraslow-spreading Southwest Indian Ridge:an LA-ICP-MS study of pyrite from the East Longjing-2 hydrothermal field

引用

Acta Oceanologica Sinica 2021年第5期40卷 105-113页

作者： Shili Liao Chuanwei Zhu Jianping Zhou Weiyong Liu Junyu Yu Jin Liang Weifang Yang Wei Li Jia Liu Chunhui Tao Second Institute of Oceanography Ministry of Natural ResourcesHangzhou 310012China Key Laboratory of Submarine Geosciences Ministry of Natural ResourcesHangzhou 310012China State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province School of Earth SciencesZhejiang UniversityHangzhou 310027China

The newly discovered East Longjing-2 hydrothermal field(ELHF-2)is located on the Dragon Horn oceanic core complex of the ultraslow-spreading Southwest Indian Ridge,approximately 12 km from the ridge *** study measured the chemical compositions of pyrite from ELHF-2 using a laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS)to investigate the genesis of the *** generations of pyrite were classified,and found that:Py1 and Py2,rich in V,Mn,U,and Se,occur in altered basalt debris and the silica alteration matrix,***3 was mainly intergrown with chalcopyrite in quartz veins and had higher Cu,In,Ag,Sb,and Au contents than Py1 and *** elements,such as Au,Se,and Pb,are likely presented as direct substitution with Fe^(2+)in pyrite,while Cu,Zn,Co,Ni,and Ag probably occur both as direct substitution with Fe and as distributed micro-to nanoparticle-sized ***,the occurrence of V,Mn,and U is likely presented as oxide *** element geochemistry suggested that the pyrite was formed under hightemperature conditions,and the ore forming elements were likely derived from ultramafic *** addition,Py1and Py2 were formed under higher water/rock ratio and higher temperature conditions,with more seawater involvement compared with *** formation of ELHF-2 was probably driven by exothermic serpentinization reactions with an additional magmatic *** study shows that high-temperature hydrothermal circulation driven by magmatic activity can be developed on distal rift flank areas of magma-starved ultraslow-spreading ridges.

关键词： pyrite geochemistry LA-ICP-MS hydrothermal activity Southwest Indian Ridge

来源：评论

学校读者我要写书评

暂无评论

Response of ocean acidification to atmospheric carbon dioxide removal

引用

Journal of Environmental Sciences 2024年第6期140卷 79-90页

作者： Jiu Jiang Long Cao Xiaoyu Jin Zechen Yu Han Zhang Jianjie Fu Guibin Jiang School of Environment Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Key Laboratory of Geoscience Big Data and Deep Resources of Zhejiang Province School of Earth SciencesZhejiang UniversityHangzhou 310058China Zhejiang Climate Center Hangzhou 310052China

Artificial CO_(2)removal from the atmosphere(also referred to as negative CO_(2)emissions)has been proposed as a potential means to counteract anthropogenic climate *** we use an Earth system model to examine the response of ocean acidification to idealized atmospheric CO_(2)removal *** our simulations,atmospheric CO_(2)is assumed to increase at a rate of 1%per year to four times its pre-industrial value and then decreases to the pre-industrial level at a rate of 0.5%,1%,2%per year,*** results show that the annual mean state of surface ocean carbonate chemistry fields including hydrogen ion concentration([H^(+)]),pH and aragonite saturation state respond quickly to removal of atmospheric CO_(2).However,the change of seasonal cycle in carbonate chemistry lags behind the decline in atmospheric CO_(2).When CO_(2)returns to the pre-industrial level,over some parts of the ocean,relative to the pre-industrial state,the seasonal amplitude of carbonate chemistry fields is substantially *** results also show that changes in deep ocean carbonate chemistry substantially lag behind atmospheric CO_(2)*** CO_(2)returns to its pre-industrial value,the whole-ocean acidity measured by[H^(+)]is 15%-18%larger than the pre-industrial level,depending on the rate of CO_(2)*** study demonstrates that even if atmospheric CO_(2)can be lowered in the future as a result of net negative CO_(2)emissions,the recovery of some aspects of ocean acidification would take decades to centuries,which would have important implications for the resilience of marine ecosystems.

关键词： Carbon dioxide removal Net negative CO_(2)emission Ocean acidification Climate change Earth system modeling

来源：评论

学校读者我要写书评

暂无评论

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

请选择保存的检索档案：

请选择收藏分类：

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

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

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：