6 results on '"Xu, Duoxun"'
Search Results
2. Construction of a novel high-end think tank system based on natural resource observation data
- Author
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QIAN Jianli, BAI Dong, XU Duoxun, HUANG Qingdongzhi, JIN Xiaowen
- Subjects
natural resources ,observational data ,high-end think tanks ,systems framework ,unified management ,Environmental sciences ,GE1-350 ,Biology (General) ,QH301-705.5 - Abstract
[Objective] In the face of the new requirements and needs of the “two unified” management of natural resources, the ability to acquire natural resources intelligence, analyze and mine natural resources information, and support decision making in natural resources management is lagging behind the needs of development, and it is of great significance to build a new type of high-end think tank system in the field of natural resources for the comprehensive management of natural resources, the study of key issues, and the formulation of relevant policies.[Methods] This study summarized and analyzed the basis and characteristics of existing natural resources observation data in China as well as the current situation of the construction of think tanks in the field of natural resources in China and internationally, and described the current situation of natural resources observation data. [Results] Based on natural resources observation data and focusing on serving the needs of comprehensive natural resources management and ecological civilization construction, we proposed an overall framework of a novel high-end think tank system, consisting of data management, technical support, organizational guarantee, and application service system. [Conclusion] The construction of a new type of high-end think tank system for natural resources is a long-term work, which needs to sum up experience, gradually enrich and improve the content of the construction of the think tank system in the field of natural resources and the relevant institutional mechanism; strengthen the integration, access, supply and sharing mechanism with existing think tank platforms; establish a think tank alliance of China’s natural resources field to achieve the positive interactive situation of mutual exchange of information, mutual use of resources, mutual complementation of strengths, and mutual promotion of development, so as to achieve a positive and interactive situation of mutual promotion. It will also establish an alliance of think tanks in the field of natural resources in China, so as to achieve a benign interactive situation of mutual exchange of information, mutual use of resources, complementarity of advantages and mutual promotion of development, and to support and serve the fine, intelligent and scientific management of natural resources in the new era.
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- 2024
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3. Major ion hydrogeochemistry and health risk of groundwater nitrate in selected rural areas of the Guanzhong Basin, China.
- Author
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Xu, Duoxun, Li, Peiyue, Chen, Xin, Yang, Shengfei, Zhang, Pei, and Guo, Fa
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WATER chemistry , *GROUNDWATER , *WATER pollution , *GROUNDWATER purification , *GROUNDWATER pollution , *RURAL geography , *GROUNDWATER analysis - Abstract
In this study, the hydrochemical characteristics of groundwater were assessed based on 64 shallow groundwater samples collected in the Guanzhong Basin, China, and the health risk of nitrate (NO3-) in drinking water was assessed. In addition, the spatial distributions of major water quality indicators were investigated, while bivariate plots, saturation index, and stable isotopes were used to reveal the processes controlling groundwater hydrogeochemistry. The results showed that groundwater in the study area was mostly fresh water. However, the maximum and average NO3– concentrations were 397.0 and 92.9 mg/L, respectively, indicating serious groundwater NO3– pollution. The percolation of contaminated river water exhibited considerable impacts on groundwater quality. Carbonate dissolution was the major process controlling the hydrochemical characteristics of groundwater, while human activities were responsible for the high concentrations of groundwater pollutants, especially NO3–. Evaporation fraction of groundwater in the study area revealed by stable hydrogen and oxygen isotopes ranged from 4 to 13% and 4 to 11%, respectively. High non-carcinogenic health risks of NO3– to adults and children were observed in about 46.88 and 75% of the collected groundwater samples, respectively. The risk value ranges were 0-6.00 and 0-14.06, with average values of 1.36 and 3.19, for adults and children, respectively. [ABSTRACT FROM AUTHOR]
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- 2023
- Full Text
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4. Mid-Neoproterozoic Tadong amphibolites at the junction of the East Kunlun and Western Qinling Orogens – a record of continental rifting during the break-up of Rodinia.
- Author
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Li, Ruibao, Pei, Xianzhi, Yang, Shuanhai, Wei, Liyong, Li, Zuochen, Yang, Gaoxue, Xu, Duoxun, Liu, Mannian, and Kou, Ting
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AMPHIBOLITES ,VOLCANIC ash, tuff, etc. ,LASER ablation ,LASER ablation inductively coupled plasma mass spectrometry ,RODINIA (Supercontinent) - Abstract
Mid-Neoproterozoic rift-related Tadong amphibolites (TDA) are situated in the junction of the East Kunlun Orogen (EKO) and the West Qinling Orogen (WQO) in western China, and have important significance in the break-up of the Supercontinent Rodinia. The mineral assemblage of the TDA exhibits amphibolite facies metamorphism, and the protolith is basic volcanic rocks. Here, we present a detailed laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) zircon U–Pb age and geochemical data of TDA. LA-ICP-MS U–Pb zircon age determination indicates that the basic volcanics formed at ca. 743–711 Ma. Geochemically, TDAs are characterized by low SiO2(46.06–50.18%), K2O (0.66–1.86%), and Mg#(40–45) and high TiO2(1.9–3.5%), and are attributed to tholeiite basalts. Their chondrite-normalized REE patterns are characterized by moderate enrichments in LREEs (LREE/HREE = 4.98–5.51) with insignificant Eu anomalies (δEu = 0.99–1.12). The primitive mantle-normalized trace element diagrams are characterized by pronounced enrichment of high-field-strength elements (HFSEs, e.g. REE, Nb, Ta, Zr, Hf) with slightly positive anomalies of Ti, which is different from the subduction zone basalts and normal mid-ocean ridge basalts (NMORBs), but similar to the ocean-island basalts (OIBs) and Emeishan continental flood basalts (ECFBs), resembling the features of an OIB-like mantle source. Most samples exhibit high Nb/Ta (16.6–17.4), Nb/La (0.70–0.94), and positive ΔNb (ΔNb = 1.74 + log (Nb/Y) − 1.92*log (Zr/Y)) values. These geochemical features suggest that the Tadong basaltic rocks were most likely derived from an OIB-like mantle source and were the products of a lower degree partial melting of garnet lherzolite. Along with the tectonic discrimination diagrams, it is further inferred that these rocks were formed in a continental rifting setting. These results from our research confirm the existence of continental rifting in the junction of the EKO and the WQO in the mid-late Neoproterozoic, implying that the rifting is a response to the break-up of the Supercontinent Rodinia. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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5. Petrogenesis and geodynamic significance of the Late Triassic Tadong adakitic pluton in West Qinling, central China.
- Author
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Yang, Gaoxue, Yang, Shuanhai, Wei, Liyong, Li, Zuochen, Li, Ruibao, Xu, Duoxun, and Liu, Mannian
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PETROGENESIS ,GEODYNAMICS ,TRIASSIC Period ,IGNEOUS intrusions ,PLATE tectonics ,STRUCTURAL geology - Abstract
The tectonic setting of the West Qinling orogenic belt (QOB) during the Middle–Late Triassic remains a subject of debate. Petrogenesis of adakitic granodiorite plays a critical role in determining the nature of the lower continental crust and mantle dynamics during orogenic processes in the region. The Tadong adakitic granodiorite pluton in the western part of the West QOB is an important element of this system. Its petrogenesis can place severe constraints on the nature of the lower continental crust and mantle dynamics during the formation of the orogenic belt. U–Pb dates obtained through zircon laser-ablation inductively coupled mass spectrometry indicate that the Tadong pluton was emplaced at 220.2 ± 2.5 Ma, coeval with abundant magmatic rocks in the region. This indicates a prominent magmatic event in the western part of West Qinling during the Late Triassic. Geochemically the granodiorites are metaluminous to peraluminous high-K calc-alkalic and characterized by relatively high SiO2(63.84–67.91 wt.%), Al2O3(15.39–16.54 wt.%), and Sr (435.08–521.64 ppm), and low MgO (1.16–1.88 wt.%; Mg# = 38–46), Y (5.49–8.84 ppm) and Yb (0.34–0.91 ppm) contents, variable Eu anomalies (Eu/Eu* = 0.87–1.1), and high Sr/Y (51.72–84.45) ratios. These are compositional features of adakites that are commonly assumed to have been produced through partial melting of subducted oceanic basalt. In addition, the adakitic rocks are relatively enriched in light rare earth elements, large ion lithophile elements (Rb, Ba, Sr, Th, and K), and depleted in high field strength elements. However, petrological, geochronological, and geochemical characteristics indicate that the adakitic rocks were most likely formed by partial melting of a thickened mafic lower crust. Therefore, we suggest that the Tadong adakitic granodiorites were produced in a syn-collisional regime and associated with asthenospheric upwelling triggered by slab break-off or gravitational instability. This mechanism was responsible for generating the Late Triassic magmatism of West Qinling. [ABSTRACT FROM PUBLISHER]
- Published
- 2015
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6. A preliminary discussion on a framework for health geological survey and evaluation.
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Zhang, Husheng, Yang, Zhongfang, Yu, Tao, Xia, Xueqi, Yang, Qiong, Xu, Duoxun, and Yang, Shengfei
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HEALTH surveys , *GEOLOGICAL surveys , *RISK assessment , *TRACE elements , *ECOLOGICAL zones , *PROBLEM solving - Abstract
While the Healthy China strategy is being implemented, the China Geological Survey has proposed and deployed a health geological survey project, starting a new journey of health geological survey and evaluation to support and serve the construction of Healthy China. However, there are still many urgent problems to be solved in this project, such as the survey vision, the framework of the evaluation indicators, the risk identification method, and the service scopes of the potential achievements. Therefore, in this paper, a framework for health geological survey and evaluation was proposed, which includes regional health geological survey zoning and local ecological risk identification. At regional scale, the framework of indicators, grading standard, score calculation, zoning method of health geological survey, identification of beneficial and harmful health geological factors, and application of achievements were proposed. These contents were presented based on the core evaluation indicators (e.g., the chemical composition, physicochemical properties, topography, and climate of the crustal surface environment caused by geological evolution processes) and the optional evaluation indicators (e.g., sanitary condition, economic level and geo-environment). At local scale, the selection of evaluation area, workflow, risk identification and the application of achievements were proposed to avoid the ecological risks of harmful trace elements and develop beneficial health geological resources. • Proposal of the framework of health geology survey and evaluation. • Presentation of regional health geological survey zoning evaluation indicator and method. • Establishment of the criterion for ecological risk evaluation at a local scale. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
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