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An experimental study on metal precipitation driven by fluid mixing: implications for genesis of carbonate-hosted lead–zinc ore deposits 被引量:3
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作者 Yan Zhang Runsheng Han +2 位作者 xing ding Junjie He Yurong Wang 《Acta Geochimica》 EI CAS CSCD 2019年第2期202-215,共14页
A type of carbonate-hosted lead–zinc(Pb–Zn)ore deposits, known as Mississippi Valley Type(MVT)deposits, constitutes an important category of lead–zinc ore deposits. Previous studies proposed a fluid-mixing model to... A type of carbonate-hosted lead–zinc(Pb–Zn)ore deposits, known as Mississippi Valley Type(MVT)deposits, constitutes an important category of lead–zinc ore deposits. Previous studies proposed a fluid-mixing model to account for metal precipitation mechanism of the MVT ore deposits, in which fluids with metal-chloride complexes happen to mix with fluids with reduced sulfur, producing metal sulfide deposition. In this hypothesis, however, the detailed chemical kinetic process of mixing reactions, and especially the controlling factors on the metal precipitation are not yet clearly stated. In this paper, a series of mixing experiments under ambient temperature and pressure conditions were conducted to simulate the fluid mixing process, by titrating the metal-chloride solutions, doping withor without dolomite, and using NaHS solution. Experimental results, combined with the thermodynamic calculations, suggest that H_2S, rather than HS^-or S^(2-),dominated the reactions of Pb and/or Zn precipitation during the fluid mixing process, in which metal precipitation was influenced by the stability of metal complexes and the pH. Given the constant concentrations of metal and total S in fluids, the pH was a primary factor controlling the Pb and/or Zn metal precipitation. This is because neutralizing or neutralized processes for the ore-forming fluids can cause instabilities of Pb and/or Zn chloride complexes and re-distribution of sulfur species, and thus can facilitate the hydrolysis of Pb and Zn ions and precipitation of sulfides. Therefore, a weakly acidic to neutral fluid environment is most favorable for the precipitation of Pb and Zn sulfides associated with the carbonate-hosted Pb–Zn deposits. 展开更多
关键词 METAL PRECIPITATION Fluid mixing Sulfur species MVT lead-zinc ORE DEPOSITS Carbonate-hosted lead-zinc DEPOSITS
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Extraction of niobium from the Bayan Obo Fe-REE-Nb deposit:A comprehensive review and new insights
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作者 Kaixuan Liu xing ding +1 位作者 Haotian Liu Xiaolong Huang 《Acta Geochimica》 2025年第5期1074-1100,共27页
With the development of aviation,superconducting,and other steel industries,the demand for niobium(Nb)has significantly increased worldwide,positioning it as a critical strategic metal.The Bayan Obo rare-earth element... With the development of aviation,superconducting,and other steel industries,the demand for niobium(Nb)has significantly increased worldwide,positioning it as a critical strategic metal.The Bayan Obo rare-earth elements(REE)-Nb-iron(Fe)deposit contains over 70% of China’s Nb resources and hosts the world’s largest reserves of REE.However,due to technical and environmental challenges,a substantial portion of the Nb resources remains underutilized and stored in tailings.Research and development of efficient,environmentally friendly,low-energy consumption,and less complex methods for extracting Nb from the Bayan Obo tailings possess significant scientific value and strategic importance.This paper reviews the current research status and distinctive geological and mineralogical characteristics of Nb resources in the Bayan Obo deposit,as well as existing pyrometallurgical and hydrometallurgical technologies for extracting Nb from ores and tailings,subsequently comparing their advantages to guide the development of new processes.Based on a comprehensive consideration of the technical,economic,environmental,quality,and safety aspects,it is suggested that future research should prioritize establishing a systematic recommendation procedure for targeted Nb-bearing mineral characterization and analysis for the Bayan Obo tailings,developing fluoride-free or low-fluoride hydrometallurgical techniques,and exploring innovative methods for Nb mineral coarsening.This review thus provides new insights into the efficient utilization of the Bayan Obo Nb resources and supports the development of innovative and effective strategies for optimizing Nb extraction from ores and tailings. 展开更多
关键词 NIOBIUM Nb mineral Extraction technique Bayan Obo HF leaching
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数字经济与世界贸易格局重塑--基于新型数字基础设施视角 被引量:19
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作者 邢丁 贺娅萍 徐康宁 《经济问题探索》 CSSCI 北大核心 2022年第11期162-174,共13页
数字经济正在成为重组全球要素资源、重塑全球经济结构、改变全球竞争格局的关键因素。文章基于2002-2020年62个世界主要国家的面板数据构建动态空间计量模型,以新型数字基础设施建设的互联网发展指数测度数字经济发展水平,考察数字经... 数字经济正在成为重组全球要素资源、重塑全球经济结构、改变全球竞争格局的关键因素。文章基于2002-2020年62个世界主要国家的面板数据构建动态空间计量模型,以新型数字基础设施建设的互联网发展指数测度数字经济发展水平,考察数字经济对世界经济地理重塑的影响效应,并对数字经济背景下的劳动力成本变化效应进行了检验。研究发现:数字信息基础设施的区域发展差异显著推动了国际贸易格局发生调整。从空间异质性看,互联网推广和应用下的网络链接效应对不同经济板块的影响表现出差异性,促进了以贸易结构性调整为特征的世界经济格局变化。从时间异质性看,2009-2020年的数字化效应高于2002-2008年,人力资本结构对贸易的影响与互联网发展水平密切相关。 展开更多
关键词 数字经济 经济地理重塑 贸易结构 劳动力成本
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中国数字经济与企业集聚空间格局重塑 被引量:8
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作者 邢丁 徐康宁 《科学学研究》 CSSCI CSCD 北大核心 2024年第3期528-540,共13页
数字经济已成为重塑社会经济空间组织的重要力量。基于2011-2020年中国285个城市面板数据,使用GIS空间分析、空间杜宾模型和地理加权回归模型,分析数字经济空间格局演变及其对企业空间集聚的重塑效应。结果表明:(1)2011-2020年中国数字... 数字经济已成为重塑社会经济空间组织的重要力量。基于2011-2020年中国285个城市面板数据,使用GIS空间分析、空间杜宾模型和地理加权回归模型,分析数字经济空间格局演变及其对企业空间集聚的重塑效应。结果表明:(1)2011-2020年中国数字经济发展水平的空间分布呈现出东高西低的分布特征,高值区主要集聚在东部沿海地区以及部分省会城市。(2)2011-2020年规模以上工业企业的空间集聚格局始终呈现出“东高西低”型的分布特征,并逐渐向中西部地区扩散。(3)总体来说,数字经济对企业集聚起分散作用,且相比于小城市,数字经济对大城市企业空间集聚的分散力更强。(4)数字经济对企业空间集聚的影响存在空间异质性,数字经济对东部地区和沿海地区的企业集聚有更大的分散力。 展开更多
关键词 数字经济 企业集聚 空间分布 空间异质性
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The formation of porphyry copper deposits 被引量:12
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作者 Weidong Sun Jin-tuan Wang +6 位作者 Li-peng Zhang Chan-chan Zhang He Li Ming-xing Ling xing ding Cong-ying Li Hua-ying Liang 《Acta Geochimica》 EI CAS CSCD 2017年第1期9-15,共7页
Copper is a moderately incompatible chalcophile element.Its behavior is strongly controlled by sulfides.The speciation of sulfur is controlled by oxygen fugacity.Therefore,porphyry Cu deposits are usually oxidized(wit... Copper is a moderately incompatible chalcophile element.Its behavior is strongly controlled by sulfides.The speciation of sulfur is controlled by oxygen fugacity.Therefore,porphyry Cu deposits are usually oxidized(with oxygen fugacities > AFMQ +2)(Mungall 2002;Sun et al.2015).The problem is that while most of the magmas at convergent margins are highly oxidized,porphyry Cu deposits are very rare,suggesting that high oxygen fugacity alone is not sufficient.Partial melting of mantle peridotite even at very high oxygen fugacities forms arc magmas with initial Cu contents too low to form porphyry Cu deposits directly(Lee et al.2012;Wilkinson 2013).Here we show that partial melting of subducted young oceanic slabs at high oxygen fugacity(>AFMQ +2) may form magmas with initial Cu contents up to >500 ppm,favorable for porphyry mineralization.Pre-enrichment of Cu through sulfide saturation and accumulation is not necessarily beneficial to porphyry Cu mineralization.In contrast,remelting of porphyritic hydrothermal sulfide associated with iron oxides may have major contributions to porphyry deposits.Thick overriding continental crust reduces the "leakage" of hydrothermal fluids,thereby promoting porphyry mineralization.Nevertheless,it is also more difficult for ore forming fluids to penetrate the thick continental crust to reach the depths of 2—4 km where porphyry deposits form. 展开更多
关键词 Porphyry Cu deposit Oxygen fugacity Slabmelting SULFIDE SULFATE SOLUBILITY
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Effect of F-Rich Fluids on the A-Type Magmatism and Related Metal Mobilization:New Insights from the Fogang-Nankunshan-Yajishan Igneous Rocks in Southeast China 被引量:8
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作者 xing ding Koulin Su +2 位作者 Haibo Yan Jinlong Liang Weidong Sun 《Journal of Earth Science》 SCIE CAS CSCD 2022年第3期591-608,共18页
About 45%of tungsten,~20%of tin,and~9%of fluorite of known world reserves are associated with Late Mesozoic igneous rocks,Southeast(SE)China.Here we demonstrate that Fogang granite,the largest inland batholith,is main... About 45%of tungsten,~20%of tin,and~9%of fluorite of known world reserves are associated with Late Mesozoic igneous rocks,Southeast(SE)China.Here we demonstrate that Fogang granite,the largest inland batholith,is mainly of A2-type that is commonly found in post-orogenic settings and experienced plate subduction induced metasomatism.In contrast,the Yajishan syenite and Nankunshan granite intruding the Fogang granite~20 Ma later are of A1-type formed in intraplate settings.We found that F-rich fluid fractionation,which could make the decline of Ga/Al ratio,total(Nb+Y+Ce+Zr)and Zr concentrations,Nb/Ta and Zr/Hf ratios,leads to chemical variations of a few Fogang granites changing from A2-type to highly fractionated or I-and S-type granitoids.Crystal and Frich fluid fractionations,as well as crustal contamination most likely derived from the Fogang granite,result in some Nankunshan granites developing from A1-type into A2-type.These late-or post-magmatic processes should be taken into account carefully when discriminating the petrogenetic types of igneous rocks,especially for the A2-type suites.Combining with the distribution of 180-140 Ma A1-and A2-type igneous rocks,rare metal deposits,and fluorite deposits in SE China,we highlight the significant role of slab-released F-rich fluids in formation of A-type suites and subsequent chemical differentiation and rare metal and fluorine mineralization.A model of flat-slab northeastward rollback is thus proposed,in which the subduction front reached somewhere near Fogang and then started to roll back at~165 Ma.The inland Jurassic granites of SE China represent a unique locality for formation of A-type suites and their associated mineralization.These granites are not anorogenic,but they are the result of slab rollback from a flat slab,founding of that slab at shallow levels,and metasomatism of by F-rich fluids related to slab heating by the asthenosphere. 展开更多
关键词 A-type granite alkaline F-rich fluids slab rollback rare metal rare earth elements Nb/Ta
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Major Miocene geological events in southern Tibet and eastern Asia induced by the subduction of the Ninetyeast Ridge 被引量:4
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作者 Xinlei Sun Wei-dong Sun +8 位作者 Yong-bin Hu Wei ding Trevor Ireland Mei-zhen Zhan Ji-qiang Liu Ming-xing Ling xing ding Zhao-feng Zhang Wei-ming Fan 《Acta Geochimica》 EI CAS CSCD 2018年第3期395-401,共7页
Cenozoic adakitic rocks in the Gangdese changed from barren continental melts to ore-forming slab melts at * 23 Ma. The distribution and chemical characteristics of the ore-forming adakites point to an association wit... Cenozoic adakitic rocks in the Gangdese changed from barren continental melts to ore-forming slab melts at * 23 Ma. The distribution and chemical characteristics of the ore-forming adakites point to an association with the Ninetyeast Ridge. The subduction of the thick,rigid Ninetyeast Ridge changed the geometry and rheology of the eastern Tibetan Plateau lithosphere and asthenosphere, restrained the eastward escape of asthenospheric mantle as well as continental fragments, and promoted the uplift and building of the Tibetan Plateau, which consequently changed the tectonic and climatic regimes in eastern Asia. 展开更多
关键词 RIDGE SUBDUCTION Eastern TIBETAN Plateau CENOZOIC mineralization Seismic anomaly
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The production of iron oxide during peridotite serpentinization:Influence of pyroxene 被引量:3
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作者 Ruifang Huang Chiou-Ting Lin +3 位作者 Weidong Sun xing ding Wenhuan Zhan Jihao Zhu 《Geoscience Frontiers》 SCIE CAS CSCD 2017年第6期1311-1321,共11页
Serpentinization produces molecular hydrogen(H2)that can support communities of microorganisms in hydrothermal fields;H2 results from the oxidation of ferrous iron in olivine and pyroxene into ferric iron,and conseque... Serpentinization produces molecular hydrogen(H2)that can support communities of microorganisms in hydrothermal fields;H2 results from the oxidation of ferrous iron in olivine and pyroxene into ferric iron,and consequently iron oxide(magnetite or hematite)forms.However,the mechanisms that control H2 and iron oxide formation are poorly constrained.In this study,we performed serpentinization experiments at 311℃ and 3.0 kbar on olivine(with <5% pyroxene),orthopyroxene,and peridotite.The results show that serpentine and iron oxide formed when olivine and orthopyroxene individually reacted with a saline starting solution.Olivine-derived serpentine had a significantly lower FeO content(6.57±1.30 wt.%)than primary olivine(9.86 wt.%),whereas orthopyroxene-derived serpentine had a comparable FeO content(6.26±0.58 wt.%)to that of primary orthopyroxene(6.24 wt.%).In experiments on peridotite,olivine was replaced by serpentine and iron oxide.However,pyroxene transformed solely to serpentine.After 20 days,olivine-derived serpentine had a FeO content of 8.18±1.56 wt.%,which was significantly higher than that of serpentine produced in olivine-only experiments.By contrast,serpentine after orthopyroxene had a slightly higher FeO content(6.53±1.01 wt.%)than primary orthopyroxene.Clinopyroxene-derived serpentine contained a significantly higher FeO content than its parent mineral.After 120 days,the FeO content of olivine-derived serpentine decreased significantly(5.71±0.35 wt.%),whereas the FeO content of orthopyroxene-derived serpentine increased(6.85±0.63 wt.%)over the same period.This suggests that iron oxide preferentially formed after olivine serpentinization.Pyroxene in peridotite gained some Fe from olivine during the serpentinization process,which may have led to a decrease in iron oxide production.The correlation between FeO content and SiO_2 or AI_2 O_3 content in olivine-and orthopyroxene-derived serpentine indicates that aluminum and silica greatly control the production of iron oxide.Based on our results and data from natural serpentinites reported by other workers,we propose that aluminum may be more influential at the early stages of peridotite serpentinization when the production of iron oxide is very low,whereas silica may have a greater control on iron oxide production during the late stages instead. 展开更多
关键词 SERPENTINIZATION Iron OXIDE PERIDOTITE ORTHOPYROXENE SILICA Aluminum
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Zircon saturation model in silicate melts:a review and update 被引量:3
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作者 Tongbin Shao Ying Xia +2 位作者 xing ding Yongfeng Cai Maoshuang Song 《Acta Geochimica》 EI CAS CSCD 2020年第3期387-403,共17页
Zircon stability in silicate melts-which can be quantitatively constrained by laboratory measurements of zircon saturation-is important for understanding the evolution of magma.Although the original zircon saturation ... Zircon stability in silicate melts-which can be quantitatively constrained by laboratory measurements of zircon saturation-is important for understanding the evolution of magma.Although the original zircon saturation model proposed by Watson and Harrison(Earth Planet Sci Lett 64(2):295-304,1983) is widely cited and has been updated recently,the three main models currently in use may generate large uncertainties due to extrapolation beyond their respective calibrated ranges.This paper reviews and updates zircon saturation models developed with temperature and compositional parameters.All available data on zircon saturation ranging in composition from mafic to silicic(and/or peralkaline to peraluminous)at temperatures from 750 to 1400℃ were collected to develop two refined models(1 and 2) that may be applied to the wider range of compositions.Model 1 is given by lnCZr(melt)=(14.297±0.308)+(0.964 ± 0.066).M-(11113±374)/r,and model 2 given by lnCZr(melt)=(18.99±0.423)-(1.069±0.102)·lnG-(12288±593)/T,where CZr(melt) is the Zr concentration of the melt in ppm and parameters M [=(Na+K+2 Ca)/(Al·Si)](cation ratios) and G [=(3·Al2 O3+SiO2)/(Na2-O+K2 O+CaO+MgO+FeO)](molar proportions)represent the melt composition.The errors are at one sigma,and T is the temperature in Kelvin.Before applying these models to natural rocks,it is necessary to ensure that the zircon used to date is crystallized from the host magmatic rock.Assessment of the application of both new and old models to natural rocks suggests that model 1 may be the best for magmatic temperature estimates of metaluminous to peraluminous rocks and that model 2 may be the best for estimating magmatic temperatures of alkaline to peralkaline rocks. 展开更多
关键词 Zircon Zircon saturation MODEL Silicate melt Mafic to silicic melts Peraluminous to peralkaline compositions Igneous rocks THERMOMETER
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Iodine-doping-assisted tunable introduction of oxygen vacancies on bismuth tungstate photocatalysts for highly efficient molecular oxygen activation and pentachlorophenol mineralization 被引量:3
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作者 Shengyao Wang Zhongliang Xiong +2 位作者 Nan Yang xing ding Hao Chen 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第10期1544-1553,共10页
In this work,the tunable introduction of oxygen vacancies in bismuth tungstate was realized via asimple solvothermal method with the assistance of iodine doping.With the predictions afforded bytheoretical calculations... In this work,the tunable introduction of oxygen vacancies in bismuth tungstate was realized via asimple solvothermal method with the assistance of iodine doping.With the predictions afforded bytheoretical calculations,the as-prepared bismuth tungstate was characterized using various tech-niques,such as X-ray diffraction,Raman spectroscopy,scanning electron microscopy,transmissionelectron microscopy,X-ray photoelectron spectroscopy,electron spin resonance spectroscopy,anduV-Vis diffuse reflectance spectroscopy.The different concentrations of the oxygen vacancies onbismuth tungstate were found to be intensely correlated with iodine doping,which weakened thelattice oxygen bonds.Owing to the sufficient oxygen vacancies introduced in bismuth tungstate as aresult of iodine doping,the molecular oxygen activation was remarkably enhanced,thus endowingbismuth tungstate with high activity for the photocatalytic degradation of sodium pentachloro-phenate.More encouraging is the total organic carbon removal rate of sodium pentachlorophenateover iodine-doped bismuth tungstate that exceeded 90%in only 2 h and was 10.6 times higher thanthat of the pristine bismuth tungstate under visible light irradiation.Moreover,the mechanism,through which the degradation of sodium pentachlorophenate over iodine-doped bismuth tung-state is enhanced,was speculated based on the results of radical detection and capture experiments.This work provides a new perspective for the enhanced photocatalytic degradation of organochlo-rine pesticides from the oxygen vacancy-induced molecular oxygen activation over iodine-dopedbismuth tungstate. 展开更多
关键词 Iodine doping Oxygen vacancy Bismuth tungstate PHOTOCATALYST Molecular oxygen activation NaPCP
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Intelligent risk identification of gas drilling based on nonlinear classification network 被引量:2
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作者 Wen-He Xia Zong-Xu Zhao +4 位作者 Cheng-Xiao Li Gao Li Yong-Jie Li xing ding Xiang-Dong Chen 《Petroleum Science》 SCIE EI CSCD 2023年第5期3074-3084,共11页
During the transient process of gas drilling conditions,the monitoring data often has obvious nonlinear fluctuation features,which leads to large classification errors and time delays in the commonly used intelligent ... During the transient process of gas drilling conditions,the monitoring data often has obvious nonlinear fluctuation features,which leads to large classification errors and time delays in the commonly used intelligent classification models.Combined with the structural features of data samples obtained from monitoring while drilling,this paper uses convolution algorithm to extract the correlation features of multiple monitoring while drilling parameters changing with time,and applies RBF network with nonlinear classification ability to classify the features.In the training process,the loss function component based on distance mean square error is used to effectively adjust the best clustering center in RBF.Many field applications show that,the recognition accuracy of the above nonlinear classification network model for gas production,water production and drill sticking is 97.32%,95.25%and 93.78%.Compared with the traditional convolutional neural network(CNN)model,the network structure not only improves the classification accuracy of conditions in the transition stage of conditions,but also greatly advances the time points of risk identification,especially for the three common risk identification points of gas production,water production and drill sticking,which are advanced by 56,16 and 8 s.It has won valuable time for the site to take correct risk disposal measures in time,and fully demonstrated the applicability of nonlinear classification neural network in oil and gas field exploration and development. 展开更多
关键词 Gas drilling Intelligent identification of drilling risk Nonlinear classification RBF Neural Network K-means algorithm
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Chloridion-induced dual tunable fabrication of oxygen-deficient Bi_(2)WO_(6) atomic layers for deep oxidation of NO 被引量:1
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作者 Xianglong Yang Shengyao Wang +6 位作者 Ting Chen Nan Yang Kai Jiang Pei Wang Shu Li xing ding Hao Chen 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第6期1013-1023,共11页
Engineering an efficient interface is a trustworthy strategy for designing advanced photocatalytic systems for solar energy conversion.Herein,oxygen-deficient Bi_(2)WO_(6)atomic layers without organic residues were su... Engineering an efficient interface is a trustworthy strategy for designing advanced photocatalytic systems for solar energy conversion.Herein,oxygen-deficient Bi_(2)WO_(6)atomic layers without organic residues were successfully fabricated via a facile solvothermal strategy by the multifunctional regulatory mechanism of introduced chloridion.Both DFT calculations and speciation determination revealed that chloridion displayed a more pronounced effect in the controllable synthesis of oxygen-deficient Bi_(2)WO_(6)atomic layers without organic residues:ultrathinning and defect-engineering.This built-in multi-cooperative interface endowed Bi_(2)WO_(6)with intriguing photoelectrochemical properties,O_(2) activation ability,and ultrahigh activity in visible-light powered deep oxidation of NO.A reasonable photocatalytic mechanism was proposed based on in situ infrared spectroscopy analysis and theoretical calculations.We believe that this multi-cooperative interface engineering of oxygen-deficient Bi_(2)WO_(6)atomic layers without organic residues could provide new insights into the design of two-dimensional(2D)layered materials with efficient active sites and pave the way for efficient NO photooxidation systems. 展开更多
关键词 Oxygen vacancy Bi_(2)WO_(6)atomic layers Chloridion PHOTOCATALYSIS NO oxidation
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基于单粒子的半量子相互身份认证协议
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作者 韩子龙 李玉凌 +4 位作者 张波 杨怀仁 邢丁 杜响剑 窦钊 《中国科学:物理学、力学、天文学》 北大核心 2025年第4期73-79,共7页
身份认证在保护通信安全方面起着非常重要的作用.本文提出了一种以单粒子为资源的半量子相互身份认证协议.它只需执行单量子比特测量和重新排序操作而不需其他复杂的操作就能使量子参与者和经典参与者在没有第三方的情况下相互进行身份... 身份认证在保护通信安全方面起着非常重要的作用.本文提出了一种以单粒子为资源的半量子相互身份认证协议.它只需执行单量子比特测量和重新排序操作而不需其他复杂的操作就能使量子参与者和经典参与者在没有第三方的情况下相互进行身份认证,并且无需公开任何身份认证密钥信息.安全性分析表明,所提协议能够防御冒充攻击、拦截-测量-重放攻击、纠缠-测量攻击和特洛伊木马攻击.与其他现有协议的比较表明,我们的协议在实用性方面具有优势. 展开更多
关键词 半量子身份认证 相互认证 单粒子
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Deterministic resonance fluorescence improvement of single quantum dots by optimized surface passivation
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作者 Junyi Zhao Runze Liu +12 位作者 Gengyan Zou Zhenxuan Ge Qihang Zhang Yukun Qiao xing ding Guoqiu Jiang Yiyang Lou Yongpeng Guo Tunghsun Chung Yuming He Chaoyang Lu Yongheng Huo Jianwei Pan 《Light(Science & Applications)》 2025年第6期1711-1717,共7页
The degradation caused by surface states restricts the performance of near-surface semiconductor quantum dots(QDs).Here,we demonstrate optimized passivation techniques to improve the resonance fluorescence(RF)with dot... The degradation caused by surface states restricts the performance of near-surface semiconductor quantum dots(QDs).Here,we demonstrate optimized passivation techniques to improve the resonance fluorescence(RF)with dotto-dot comparisons.These optimized techniques,for the first time,reduce the linewidth and noise level of existing pulsed-RF signals,as well as revive pulsed-RF signals which originally are vanishing.The improvements are confirmed to originate from reduced surface state density and electric field after passivation,through optical and surface science characterizations.Our study promotes applications of the passivation techniques in thin-film quantum devices,paving the way for the further development of optimal QD-based quantum light sources. 展开更多
关键词 reduced surface state density quantum dots optimized passivation techniques deterministic resonance fluorescence resonance fluorescence rf quantum dots qds herewe surface passivation electric field
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Experimental investigation on niobium species and its thermodynamic stability in fluoride-bearing hydrothermal fluids
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作者 Ruilong PAN xing ding +3 位作者 Haotian LIU Zebang YI Cheng XU Xiaolong HUANG 《Science China Earth Sciences》 2025年第11期3578-3588,共11页
The roles and mechanisms governing fluid mobility and hydrothermal mineralization of niobium(Nb)in geological processes have remained poorly understood,which hinders comprehensive insights into its geochemical propert... The roles and mechanisms governing fluid mobility and hydrothermal mineralization of niobium(Nb)in geological processes have remained poorly understood,which hinders comprehensive insights into its geochemical properties and oreforming processes.This study investigates complexation,speciation,and thermodynamic stability of Nb within 0.07-0.28 mol/L fluoride-containing hydrothermal solutions at 100 MPa and 100-550℃via high-temperature hydrolysis experiments of potassium fluoniobate.The experimental and thermodynamic calculation results reveal a novel complex species,Nb(OH)_(4)F_(2)^(-),and determine for the first time its temperature-dependent hydrolysis constant through ln K=-6749/T+4.37.Combined with previous studies,this study identifies the dominant Nb species in natural acidic hydrothermal systems as Nb(OH)_(4)F_(2)^(-)and Nb(OH)_(3)F_(2)^(0)under low-fluoride conditions,shifting to Nb(OH)_(3)F_(3)^(-)and Nb(OH)_(2)F_(3)^(0)in high-fluoride environments.Based on quantitative characterization and comparative analysis of multiple metal complex stabilities,it is demonstrated that Nb,Sn(IV),and Ti exhibit remarkably similar hydrolysis behaviors and thermodynamic stabilities of their dominant complexes in F^(-)bearing hydrothermal fluids,resulting in analogous fluid mobility.Rising temperature and decreasing F-activity,as well as changing pH,are thus identified as the primary mechanisms to trigger destabilization of these metal complexes,leading to their co-precipitation or paragenetic associations during geological processes. 展开更多
关键词 NIOBIUM Niobium fluoride complex Potassium fluoniobate HYDROLYSIS Fluoride-bearing fluids
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Multifunctional core/satellite polydopamine@Nd^3+- sensitized upconversion nanocomposite: A single 808 nm near-infrared light-triggered theranostic platform for in vivo imaging-guided photothermal therapy 被引量:18
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作者 xing ding Jianhua Liu +6 位作者 Dapeng Liu Junqi Li Fan Wang Leijiao Li Yinghui Wang Shuyan Song Hongjie Zhang 《Nano Research》 SCIE EI CAS CSCD 2017年第10期3434-3446,共13页
Significant attenuation and overheating, caused by the absorption of the excitation band (980 nm) in water, are the major obstacles in the in vivo application of lanthanide-doped upconversion nanoparticles (UCNPs)... Significant attenuation and overheating, caused by the absorption of the excitation band (980 nm) in water, are the major obstacles in the in vivo application of lanthanide-doped upconversion nanoparticles (UCNPs). Therefore, appropriately- structured Nd3^+-doped UCNPs with 808 nm excitation could be a promising alternative. Herein, we developed core-shell-shell structured Nd3^+-sensitized UCNPs as imaging agents, and decorated them onto the surface of polydopamine (PDA) to construct a novel multifunctional core/satellite nanotheranostic (PDA@UCNPs) for in vivo imaging guidance photothermal therapy using single 808 nm laser irradiation. The core-shell-shell structured design enabled outstanding upconversion luminescence properties and strong X-ray attenuation, thereby making the nanocomposites potential candidates for excellent upconversion luminescence/computed tomography dual modal imaging. In addition, the PDA core not only provides high photothermal conversion efficiency and outstanding antitumor effect, but also endows the platform with robust biocompatibility owing to its natural features. Therefore, this multifunctional nanocomposite could be a promising theranostic in future oncotherapy, with high therapeutic effectiveness but low side effects. This study would stimulate interest in designing bio- application-compatible multifunctional nanocomposites, especially for cancer diagnosis and treatment in vivo. 展开更多
关键词 Nd^3+-sensitized upconversion nanopartides dual-modality imaging photothermal therapy multifunctional theranostic platform biocompatibility
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The influence of silica on reaction rates and molecular hydrogen(H_(2))generation during olivine hydrothermal alteration 被引量:1
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作者 Ruifang HUANG Weidong SUN +3 位作者 xing ding Yusheng ZHAO Yibing LI Xiuqi SHANG 《Science China Earth Sciences》 SCIE EI CAS CSCD 2024年第1期222-233,共12页
Hydrothermal alteration of olivine greatly influences geodynamics and the recycling of volatiles(such as water and carbon)in subduction zones.Silica is an important component of geological fluids,and its influence on ... Hydrothermal alteration of olivine greatly influences geodynamics and the recycling of volatiles(such as water and carbon)in subduction zones.Silica is an important component of geological fluids,and its influence on the hydrothermal alteration of olivine remains poorly constrained.In this study,we performed experiments at 300–515℃and 3.0 kbar(1 bar=10^(5)Pa)by reacting well homogenized mixtures of olivine and silica powders with saline solutions(0.5 mol L^(−1)NaCl).Silica greatly influences the reaction pathways,reaction rates,and molecular hydrogen(H_(2))formation during olivine hydrothermal alteration.In experiments at 300℃and 3.0 kbar with mixtures of olivine and 10 wt%silica,olivine was replaced by serpentine and talc.The proportions of serpentine and talc were determined according to standard curves based on infrared spectroscopy analyses.Around 6.5%serpentine and 12%talc were produced after an experimental duration of 7 days,which had no change after a longer period(14 days).Compared to the kinetics in silica-free systems,the rates of olivine hydrothermal alteration in experiments with 10 wt%silica are much lower.The overall reaction is:4.5Forsterite+5.5SiO_(2),aq+4H_(2)O=Serpentine+2Talc.With the addition of more silica(20 wt%and 40 wt%),olivine was transformed into talc.The rates of reaction were much faster,e.g.,for experiments with olivine and 20 wt%silica,43%of talc was produced after 14 days,which increased to 77%for experiments with 40 wt%silica over the same period.The overall reaction is:3Forsterite+5SiO_(2),aq+2H_(2)O=2Talc.In experiments at 400–505℃and 3.0 kbar,the promoting effect of silica on olivine hydrothermal alteration was also observed,which is closely associated with a decrease in Gibbs free energies of olivine hydrothermal alteration.At 300℃and 3.0 kbar,silica decreased H_(2)formed during olivine hydrothermal alteration by around an order of magnitude,resulting in an increase in oxygen fugacity.Based on measured H_(2),we calibrated oxygen fugacities,ranging from 0.96 to 3.41 log units below FMQ(fayalite-magnetitequartz buffer assemblage).This study suggests that the infiltration of SiO_(2)-bearing fluids into peridotites greatly influences redox conditions and the rates of olivine hydrothermal alteration. 展开更多
关键词 Olivine hydrothermal alteration SILICA SERPENTINIZATION HYDROGEN SERPENTINE
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New hydrous phases in the Al_(2)O_(3)-SiO_(2)-H_(2)O system under the mantle transition zone conditions
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作者 Baoyun WANG Jin LIU +4 位作者 Suyu FU Pu XIAO Li LI xing ding Wansheng XIAO 《Science China Earth Sciences》 SCIE EI CAS CSCD 2023年第4期730-737,共8页
Hydrous minerals in the subducting slabs are potential water carriers into the deep mantle,and thus the synthesis of new hydrous phases is significant in our understanding of water circulation throughout the Earth’s ... Hydrous minerals in the subducting slabs are potential water carriers into the deep mantle,and thus the synthesis of new hydrous phases is significant in our understanding of water circulation throughout the Earth’s interior.In this study,we report the two new hydrous phases,Al_(2)SiO_(6)H_(2)and Al_(5.5)Si_(4)O_(18)H_(3.5)(hereafter referred to simply as phases Psi and Phi,respectively),which are synthesized in the Al_(2)O_(3)-SiO_(2)-H_(2)O system at 15.5 GPa,1400℃and 17.5 GPa,1600℃ by using Sakura2500-ton multi-anvil apparatus.The luminescence spectra of Cr3+show the phase Psi has characteristic peaks at 687,693 and705 nm,while phase Phi has characteristic peaks at 691,696 and 708 nm.Single-crystal X-ray diffraction (SCXRD) refinements yield a monoclinic structure of both phases (space group P2_(1)) with ideal chemical formulae of Al_(2)SiO6H2and Al5.5Si4O18H3.5respectively.The determined lattice parameters for phase Psi are a=9.4168±0.0016Å,b=4.3441±0.0007Å,c=9.4360±0.002Åand β=119.726±0.005°at ambient pressure and 300 K,while the phase Phi has a=7.2549±0.0018Å,b=4.3144±0.001Å,c=8.0520±0.002Å,and β=101.740±0.009°at ambient pressure and 250 K.Electron microprobe analyses (EPMA) show the chemical compositions of phases Psi and Phi to be Al_(1.99)Si_(0.85)O_(6)H_(2.62)and Al_(5.58)Si_(2.81)O_(18)H_(8.03),respectively,which slightly deviate from the ideal formulae inferred from SCXRD measurements.This may result from the disorder or substitution of Al and Si by H in the crystal structures under our synthesis conditions.Our study suggests that phases Psi and Phi are the two potential water carriers at the upper part of the mantle transitions zone,providing new insights into how deep water is stored in this region. 展开更多
关键词 New hydrous phases Mantle transition zone Al_(2)O_(3)-SiO_(2)-H_(2)O system Al_(2)SiO_(6)H_(2) Al_(5.5)Si_(4)O_(18)H_(3.5)
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Quality evaluation tool for animal experiments and the usage specifications
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作者 Jinlong Li Yuxiang Dai +8 位作者 xing ding Ming Yan Ke Zhu Wei Wu Ziming Wu Yueli Sun Min Yao Xuejun Cui Yongjun Wang 《Guideline and Standard in Chinese Medicine》 2023年第1期19-24,共6页
The animal experiment is the best method for therapeutic efficacy testing of various treatment methods before clinical application and serves as an irreplaceable“live reagent”and“live precise instrument,”thus play... The animal experiment is the best method for therapeutic efficacy testing of various treatment methods before clinical application and serves as an irreplaceable“live reagent”and“live precise instrument,”thus playing a vital role in biomedical science research.However,there were significant differences between the results of animal experiments and clinical efficacy in previousfindings that are hard to ignore,especially in cerebrovascular accident research due to the unsatisfactory specification of animal experiments.Accordingly,more prescriptive and standard tools are required for evaluating the quality of animal experiments.This study will introduce the current commonly used quality evaluation tools for animal experiments. 展开更多
关键词 animal experiments ARRIVE 2.0 CAMARADES 10-item checklist quality evaluation tool STAIR syrcle
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