检索结果-南通市图书馆

Computer Modeling in Engineering & Sciences 2025年第1期142卷 691-712页

作者： Quynh-Anh Thi Bui Dam Duc Nguyen Hiep Van Le Indra Prakash Binh Thai Pham Civil Engineering Department University of Transport Technology54 Trieu KhucThanh XuanHanoi100000Vietnam DDG(R)geological survey of India Gandhinagar382010India

Determination of Shear Bond strength(SBS)at interlayer of double-layer asphalt concrete is crucial in flexible pavement *** study used three Machine Learning(ML)models,including K-Nearest Neighbors(KNN),Extra Trees(ET),and Light Gradient Boosting Machine(LGBM),to predict SBS based on easily determinable input ***,the Grid Search technique was employed for hyper-parameter tuning of the ML models,and cross-validation and learning curve analysis were used for training the *** models were built on a database of 240 experimental results and three input variables:temperature,normal pressure,and tack coat *** validation was performed using three statistical criteria:the coefficient of determination(R2),the Root Mean Square Error(RMSE),and the mean absolute error(MAE).Additionally,SHAP analysis was also used to validate the importance of the input variables in the prediction of the *** show that these models accurately predict SBS,with LGBM providing outstanding ***(Shapley Additive explanation)analysis for LGBM indicates that temperature is the most influential factor on ***,the proposed ML models can quickly and accurately predict SBS between two layers of asphalt concrete,serving practical applications in flexible pavement structure design.

关键词： Shear bond asphalt pavement grid search optimization machine learning

Application of BeiDou navigation satellite system in emergency rescue of natural hazards: a case study for field geological survey of qinghai−Tibet plateau

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

Geo-Spatial Information Science 2018年第4期21卷 294-301页

作者： Ming Hao Jianlong Zhang Ruiqing Niu Changrong Deng Hong Liang National Engineering Research Center for Geographic Information System WuhanChina Chengdu Center of China geological survey ChengduChina

In recent years,geological and mineral resources exploration in China has expanded to deep hinterland of the qinghai−Tibet Plateau and other regions with complex geological *** special natural conditions of qinghai−Tibet Plateau determine the characteristics of“life-forbidden zone”that is characterized by alpine hypoxia,changeable weather,complex road conditions,and beast *** particular,the work in wild depopulated zones with severe environment and poor communications imposes serious threats to the life safety of geological ***,how to guarantee the safety of geological personnel working on the qinghai−Tibet Plateau and how to reduce or even avoid casualty of geological personnel have currently become the urgent *** this study,an emergency rescue information system for field geological survey is constructed based on BeiDou Navigation Satellite System.A case study of emergency rescue has been conducted in the depopulated zone of the qinghai−Tibet Plateau and good effects have been achieved,providing security assurance for personnel engaged in field geological survey on the qinghai−Tibet Plateau and technical support for the emergency rescue in case of natural hazards on the qinghai−Tibet *** BeiDou Navigation Satellite System(BDS)can be effectively used to locate and communicate in the emergency rescue for rigorous geological survey task where there is no network signal for the mobile phone,and the emergency rescue guarantee system is independent,reliable,and relatively *** application value of BDS is demonstrated in the geological field.

关键词： BeiDou navigation satellite system(BDS) natural hazard emergency rescue qinghai−Tibet plateau

Early Permian–Late Triassic Magmatism in the Tuotuohe Region of the qinghai–Tibet Plateau: Constraints on the Tectonic evolution of the Western Segment of the Jinshajiang Suture

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

Acta Geologica Sinica(English Edition) 2014年第2期88卷 498-516页

作者： QIAN Ye SUN Fengyue LI Bile LI Shijin ZHAO Junwei College of Earth Sciences Jilin University qinghai geological survey No.5 geological and Mineral survey Institute of qinghai Province

In this paper we present new zircon U-Pb ages,whole-rock major and trace element analyses,and zircon Hf isotopic data for magmatic rocks in the Tuotuohe region of the western segment of the Jinshajiang *** aim is to constrain the Early Permian-Late Triassic tectonic evolution of the *** from the magmatic rocks of the Tuotuohe region are euhedralsubhedral in shape and display fine-scale oscillatory zoning as well as high Th/U ratios （0.4-4.6）,indicating a magmatic *** zircon U-Pb ages obtained using LA-ICP-MS are 281 ± 1 Ma,258 ± 1 Ma,244 ± 1 Ma,and 216 ± 1 Ma,which indicate magmatism in the Early Permian-Late Triassic.A diorite from Bashihubei （BSHN） has SiO2 =57.18-59.97 wt％,Al2O3=15.70-16.53 wt％,and total alkalis （Na2O ＋ K2O） =4.46-6.34 wt％,typical of calc-alkaline and metaluminous series.A gabbro from Bashibadaoban （BSBDB） belongs to the alkaline series,and is poor in SiO2 （45.46-54.03 wt％） but rich in Al2O3 （16.19-17.39 wt％） and total alkalis （Na2O ＋ K2O =5.48-6.26 wt％）.The BSHN diorite and the BSBDB gabbro both display an enrichment of LREEs and LILEs and depletion of HFSEs,and they have no obvious Eu anomaly; they have relatively low MgO contents （2.54-4.93 wt％）,Mg# values of 43 to 52,and low Cr and Ni contents （8.07-33.6 ppm and 4.41-14.2 ppm,respectively）,indicating they differentiated from primitive mantle *** have low Nb/U,Ta/ U,and Ce/Pb ratios （1.3-9.6,0.2-0.8,and 0.1-18.1,respectively）,and their initial Hf isotopic ratios range from ＋9.6 to ＋16.9 （BSHN diorite） and ＋6.5 to ＋12.6 （BSBDB gabbro）,suggesting their primary magmas were derived mainly from the partial melting of a mantle wedge that had been metasomatized by subduction *** all the new data together,we conclude that the western and eastern segment of the Jinshajiang suture regions underwent identical processes of evolution in the Early Permian-Late Triassic：oceanic crust subduction before the Early Permian,continental collision during the Early-Middle T

关键词： zircon U-Pb chronology zircon Hf isotopes geochemistry tectonic setting Tuotuohe region Jinshajiang suture qinghai-Tibet Plateau

Zircon U-Pb Ages of the Granodioritic Porphyry in the Laba Molybdenum Deposit,Yunnan,SW China and Its geological Implication

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2014年第4期88卷 1183-1194页

作者： YU Haijun LI Wenchang YIN Guanghou LU Yingxiang CAO Xiaomin HUANG Dingzhu DONG Tao ZHANG Youming Yunnan geological survey bureau

The Geza island-arc is a well-known mineralization concentration area, part of the Sanjiang Domain at the east margin of the Tibetan Plateau. In recent years, several Late Yanshanian granitic intrusions and associated deposits have been found in this region, the largest one of which in the Shangri-La region is the Laba molybdenum deposit. Previous studies suggested that the timing of the Laba mineralization is 85 ±2 Ma. However, the ages of the granodioritic porphyry remain unknown. In this study, LA-ICP-MS U-Pb dating of zircons from three samples of the molybdenite-bearing granodioritic porphyry has been conducted with resulting dates of 85.00±0.23 Ma （MSWD = 0.58）, 85.28 ± 0.28 Ma （MSWD = 1.12）, and 84.83 ± 0.26 Ma （MSWD = 0.79）, respectively, indicating that these granodioritie porphyries formed in the Late Yanshanian around -85 Ma. Combined with the geological features of the mineralization, the Laba deposit is spatially, temporally, and probably genetically associated with the granodioritic porphyries. In addition, the ages of the Laba deposits are consistent with the other Late Yanshanian intrusions and mineralization, suggesting that the mineralization was probably generated under an intra-plate extensional environment during the Late Cretaceous.

关键词： geochronology mineralogy U-Pb dating of zircons Geza island-arc Cretaceous,molybdenum Yunnan province Tibetan plateau

Zircon U-Pb Age of the Shangxu Gold Deposit from Bangong-Nujiang Co, Northern Tibet, and Restriction on the Early Cretaceous Orogenic Gold Mineralisation

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2018年第4期92卷 1664-1666页

作者： HUANG Hanxiao LI Guangming LIU Hong CAO Huawen ZHANG Zhilin Chengdu Center China Geological Survey Chengdu 610081 China No.5 geological Party of Tibet geological Exploration bureau Golmud 816000 Qinghai China

Objective The Tibetan Plateau is the largest continent-to-continent collision belt in the world. Two orogenic gold mineralisation belts have been recognized in this collision belt, which are as follows： the Indus-Yarlung Zangbo suture zone orogenic gold belt （IYOG）, represented by the Mayoumu and Bangbu gold deposits, and the Ailaoshan orogenic gold belt （AOG）, whose typical cases include the Zhenyuan and Chang＇an gold deposits. The IYOG formed during 54-45 Ma corresponds to the compressional deformation during the early stages of the collision of the plates of India and Eurasia, whereas the AOG formed in 38-29 Ma corresponds to that during the later stage of the collision. Recently, several medium- to large-sized gold deposits （e.g., the Dacha and Shangxu deposits） have been discovered along the Bangong Co-Nujiang suture belt, which indicates that another orogenic gold mineralisation belt existed within the Tibetan Plateau. However, the lack of a mineral suitable for dating or for altering the minerals that were affected by various tectonic thermal events causes difficulty to perform accurate dating. This study is based on the Shangxu gold deposit and analyses the genesis of zircon in gold-bearing quartz veins as well as the accurate gold-forming age by hydrothermal zircon micro probe analysis using the U-Pb （LA-ICP-MS） method.

关键词： ICP MS Pb

Geochronology, Geochemistry and Sr-Nd-Pb-Hf Isotopes of No. I Complex from the Shitoukengde Ni–Cu Sulfide Deposit in the Eastern Kunlun Orogen, Western China: Implications for the Magmatic Source, Geodynamic Setting and Genesis

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2018年第1期92卷 106-126页

作者： LI Liang SUN Fengyue LI Bile LI Shijin CHEN Guangjun WANG Wei YAN Jiaming ZHAO Tuofei DONG Jun ZHANG Dexin College of Earth Sciences Jilin University Changchun 130061 China qinghai bureau of geological survey Xining 810001 China No. 108 geological Party Sichuan Bureau of Geology and Mineral Exploration Chengdu 611230 China

The Shitoukengde Ni-Cu deposit, located in the Eastern Kunlun Orogen, comprises three mafic-ultramafic complexes, with the No. I complex hosting six Ni-Cu orebodies found recently. The deposit is hosted in the small ultramafic bodies intruding Proterozoic metamorphic rocks. Complexes at Shitoukengde contain all kinds of mafic-ultramafic rocks, and olivine websterite and pyroxene peridotite are the most important Ni-Cu-hosted rocks. Zircon U-Pb dating suggests that the Shitoukengde Ni-Cu deposit formed in late Silurian （426-422 Ma）, and their zircons have ~Hf（t） values of-9.4 to 5.9 with the older TDMm ages （0.80-1.42 Ga）. Mafic-ultramafic rocks from the No. I complex show the similar rare earth and trace element patterns, which are enriched in light rare earth elements and large ion iithophile elements （e.g., K, Rb, Th） and depleted in heavy rare earth elements and high field strength elements （e.g., Ta, Nb, Zr, Ti）. Sulfides from the deposit have the slightly higher ~34S values of 1.9-4.3%o than the mantle （0 ~ 2%o）. The major and trace element characteristics, and Sr-Nd-Pb and Hf, S isotopes indicate that their parental magmas originated from a metasomatised, asthenospheric mantle source which had previously been modified by subduction-related fluids, and experienced significant crustal contamination both in the magma chamber and during ascent triggering S oversaturation by addition of S and Si, that resulted in the deposition and enrichment of sulfides. Combined with the tectonic evolution, we suggest that the Shitoukengde Ni-Cu deposit formed in the post-collisional, extensional regime related to the subducted oceanic slab break-off after the Wanbaogou oceanic basalt plateau collaged northward to the Qaidam Block in late Silurian.

关键词： Sr-Nd-Pb-Hf isotopes crustal contamination oceanic slab break-off post-collisionalextension Shitoukengde Ni-Cu deposit Eastern Kunlun Orogen

In situ Elemental and Boron Isotopic Geochemistry of Tourmalines from Pegmatites in the Edanggang Li-Be Deposit in the Quanji Massif， NW China

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2023年

作者： Xuan Zhou Tong Pan Shan-Ping Li Qing-Feng Ding College of Earth Sciences， Jilin University bureau of geological Exploration & Development of qinghai Province qinghai geological survey Institute

The Edanggang area is characterized by small-scale Li-Be-bearing granitic pegmatites in the Quanji Massif， northwest China. The genesis of these Li-Be-bearing pegmatites remains unresolved. In this study， we use tourmalines as an indicator to constrain the genesis of them. In situ major and trace elements and boron isotopic compositions of tourmaline are analyzed. Two types of tourmalines are recongnized， i.e.， coarse-grained tourmaline (Tur 1) and fine tourmaline (Tur 2). Both types tourmalines share similar geochemical characteristics and are enriched in Fe， Na， and Al， but relatively depleted in Ca and Mg， with compositions close to alkali-group tourmaline and schorl. Petrography， chemical discrimination diagrams， and Al occupations in the Y-site suggest that the tourmalines are magmatic origin formed in the late stage of granitic pegmatite crystallization. Low V and Sr contents， and relatively high Co/Ni ratios of tourmalines are also in agreement with the above origin. The δ11B values of all tourmalines vary from -14.13‰ to -10.40‰， indicating the boron in the pegmatites was mainly derived from parental granitic pegmatite magma. The last-formed magmatic mineral assemblages of magmatic crystallizations in the Early Triassic might contribute to predominant Li and Be reserves rather than the late external hydrothermal metasomatism.

关键词：

Fluid Inclusion and H-O Isotope Geochemistry of the Phapon Gold Deposit, NW Laos: Implications for Fluid Source and Ore Genesis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Earth Science 2019年第1期30卷 80-94页

作者： Linnan Guo Shusheng Liu Lin Hou Jieting Wang Meifeng Shi Qiming Zhang Fei Nie Yongfei Yang Zhimin Peng Chengdu Center China Geological Survey Tianjin North China geological Exploration bureau

The Phapon gold deposit, located in northern Laos, is a unique large-scale gold deposit in Luang Prabang-Loei metallogenic belt. It is hosted in the Lower Permian limestone and controlled by a NE-trending ductile-brittle fault system. There are three types of primary ore including auriferous calcite vein type, disseminated type, and breccia type, and the first two are important in the Phapon gold deposit. Based on fluid inclusion petrography and microthermometry, three types of primary fluid inclusions including type 1 liquid-rich aqueous, type 2 vapor-rich aqueous and type 3 daughter mineralbearing aqueous were identified in hydrothermal calcite grains. The ore-forming fluids are normally homogeneous, as indicated by the widespread type 1 inclusions with identical composition. The coexistence of type 1 and type 2 inclusions, showing similar final homogenization temperature but different compositions, indicate that fluid immiscibility did locally take place in both two types of ores. The results of microthermometry and H-O isotopes geochemistry indicate that there are little differences on ore-fluid geochemistry between the auriferous calcite vein-type and disseminated type ores. The oreforming fluids are characterized by medium-low temperatures(157–268 oC) and low salinity(1.6 wt.%–9.9 wt.% NaCl eq.). It is likely to have a metamorphic-dominant mixed source, which could be associated with dehydration and decarbonisation of Lower Permian limestone and Middle–Upper Triassic sandstones during the dynamic metamorphism. The fluid-wallrock interaction played a major role, and the locally occurred fluid-immiscible processes played a subordinate role in gold precipitation. Combined with the regional and ore deposit geology, and ore-fluid geochemistry, we suggest that the Phapon gold deposit is best considered to be a member of the epizonal orogenic deposit class.

关键词： fluid inclusion H-O isotopes fluid source ore genesis Phapon gold deposit northern Laos

Junction and Evolution of the Qinling,Qilian and Kunlun Orogenic Belts

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2000年第2期74卷 223-228页

作者： SUN Yangui CHEN Zhengxing LIU Yong’an WANG Tongqing ZHANG Zhiyong qinghai Regional survey and Comprehensive geological Party 107 Nanchuan West RoadXiningQinghai Province 810012 qinghai Institute of geological and Mineral Exploration Xining 810012Qinghai

As the main part of the “central mountain system” in the continent of China, the Qinling, Qilian and Kunlun orogenic belts have been comprehensively and deeply studied since the 1970s and rich fruits have been reaped. However, these achievements were mostly confined to an individual orogenic belt and the study of the mutual relationship among the three orogenic belts was obliged to depend on comparative studies. Different views were produced therefrom. The material composition and structural features of the junction region show that there are several epicontinental and intracontinental transform faults developed in different periods. Restricted by these transform faults, the large-scale lateral movements and, as a consequence, complicated magmatism and tectonic deformation took place in the orogenic belts. According to these features, the authors put forward a three-stage junction and evolution model and point out that there is not a single junction zone traversing from west to east but that the three orogenic belts have been joined progressively by the epicontinental and intracontinental transform faults.

关键词： central mountains Qinling Qilian and Kunlun orogenic belts junction and evolution intracontinental transform fault

Significant lake expansion has accelerated permafrost degradation on the qinghai-Tibet Plateau

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第1期21卷 68-83页

作者： LI Qingpeng LIU Wenhui LIU Hairui ZHOU Guanghao SONG Xianteng LI Qing LUO Bingnan SONG Bangxu ZHANG Qi Department of geological Engineering Qinghai UniversityXining 810016China College of Eco-Environmental Engineering Qinghai UniversityXining 810016China Xining Center for Integrated Natural Resources survey China Geological SurveyXining 810000China

In recent years, lakes on the qinghai-Tibet Plateau have become more responsive to climate change. In September 2011, Zonag Lake in Hoh Xil experienced sudden drainage, the water eventually flowed into Yanhu Lake, which caused Yanhu Lake to continue to expand. The potential collapse of Yanhu Lake could directly threaten the operational safety of the adjacent qinghai-Tibet Highway, qinghai-Tibet Railway. To explore the implications of expanding lakes on the surrounding permafrost, we selected Hoh Xil Yanhu Lake on the qinghai-Tibet Plateau to study the effect of lake expansion on permafrost degradation. The permafrost degradation in the Yanhu Lake basin from October 2017 to December 2022 was inverted using Sentinel-1 satellite image data and small baseline subset interferometry synthetic aperture radar(SBAS-In SAR) technology. Additionally, permafrost degradation from February 2007 and February 2010 was analyzed using advanced land observing satellite phased array-type L-band synthetic aperture radar(ALOS PALSAR) satellite images and differential interferometric synthetic aperture radar(D-In SAR) technique. The results showed that the permafrost around Yanhu Lake experienced accelerated degradation. Prior to the expansion of Yanhu Lake, the average annual deformation rate along the line of sight(LOS) direction was 6.7 mm/yr. After the expansion, the rate increased to 20.9 mm/yr. The integration of spatial-temporal distribution maps of surface subsidence, Wudaoliang borehole geothermal data, meteorological data, Yanhu Lake surface area changes, and water level changes supports the assertion that the intensified permafrost degradation could be attributed to lake expansion rather than the rising air temperature. Furthermore, permafrost degradation around Yanhu Lake could impact vital infrastructure such as the adjacent qinghai-Tibet Highway and qinghai-Tibet Railway.

关键词： Lake expansion SBAS-InSAR D-InSAR Permafrost deformation qinghai-Tibet Plateau