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Molecular dynamics simulations of helium transport through inorganic mineral nanopores

Science China earth Sciences 2025年第1期68卷 237-252页

作者： Dandan SONG Ping GUAN Chi ZHANG Jiahao REN school of earth and Space Sciences Peking UniversityBeijing100871China

Helium transport through nanoscale inorganic mineral pores and pore throats is essential for its overall *** elucidate helium's transport dynamics within nanopores,we employed equilibrium and non-equilibrium molecular dynamics simulations to investigate helium's static self-diffusion and pressure-driven flow in quartz slit-shaped *** also introduced water and various gases,including hydrogen,methane,ethane,nitrogen,and carbon dioxide,into the nanopores to assess their influence on helium *** findings indicate minimal helium adsorption on quartz pore *** conditions where the pore size is less than 5 nm and the pressure under 10 MPa,environmental factors markedly influence helium *** pore sizes,high temperatures,and low gas pressures enhance helium desorption and facilitate faster *** observed a positive correlation between helium flow velocity and factors such as pore size,pressure gradient,and surface smoothness of the ***,the presence of pore water and carrier gases in quartz nanopores,which diffuse more slowly than helium,tends to reduce helium surface adsorption and slow its *** the carrier gases studied,nitrogen showed similar adsorption capacity,diffusivity,and stability to helium,while carbon dioxide displayed the highest adsorption capacity and the slowest diffusion rate,markedly differing from *** on the simulation results,we concluded that water and carrier gases primarily function as transport mediums in helium migration,moving together with ***,which shares similar properties with helium,effectively assists in this co-migration ***,carbon dioxide,due to its high adsorption capacity and slow diffusion,tends to be lost during *** a result,gas reservoirs with high nitrogen levels and low carbon dioxide levels are more likely to have higher helium ***,the smaller pore sizes and higher gas pressures in caproc

关键词： Helium transport Slit nanopores Molecular dynamics simulations Diffusion Flow carriers

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Constraints on what controls millennial-scale basin-wide denudation across mountain belts,Asia

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Science China earth Sciences 2025年第1期68卷 74-93页

作者： Ye YANG Steven A.BINNIE Sheng XU Cong-Qiang LIU Tibor J.DUNAI Institute of Surface-earth System Science School of Earth System ScienceTianjin UniversityTianjin300072China Institute of Geology and Mineralogy University of CologneCologne50674Germany

The terrestrial cosmogenic nuclide dataset consisting of 1233^(10)Be measurements of fluvial sediment samples across the Asian mountain belts is used to constrain the influence of climate,tectonics and topography on earth-surface denudation processes.^(10)Be-derived basin-wide denudation rates were recalculated using a Monte Carlo simulation approach that relied on pixel-by-pixel production *** rates derived span four orders of magnitude,from 7.4±0.7 mm kyr^(-1)(1σ;Central Tibetan Plateau)to 9,646_(-744)^(+777)mm kyr^(-1)(1σ;Southern Tibetan Plateau),with a median of 186 mm kyr^(-1).Comparing our results with the traditional basin-wide production rate scaling model using a centroid coordinate and mean elevation,suggests that 96.6%of production rates will be underestimated using the latter method,especially for basins with a large *** bias between both methods reaches as large as 40%,caused by basin hypsometry and the nonlinear scaling of production rate with elevation and *** of the correlations between uniformly recalculated denudation rates and tectonics,climate,topography and rock lithology will facilitate the extrapolation of denudation rates in unknown basins using available *** the perspective of local scales,precipitation coupled with neotectonics-driven landslides is likely the most influential factor in subtropical Taiwan Island,while topography primarily constrains surface denudation rates in the eastern Tibetan Plateau within a narrow range of *** highland regions with glacier coverage,such as the Pamir,central and southern Tibetan Plateau high denudation rates are affected by glaciation,whereas lower precipitation and high erosion base level may limit river incision and evolving relief in the Central Tibetan *** contrast to local-scale findings highlighting a dominant factor constraining denudation rate,our large-scale quantitative analyses across the Asian mountain belts finds that(1)topographic

关键词： ^(10)Be-derived denudation rate Climate change Tectonic uplift Topographic gradient Asian mountains

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Three-dimensional internal multiple elimination in complex structures using Marchenko autofocusing theory

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Petroleum Science 2025年第1期22卷 222-233页

作者： Pei-Nan Bao Ying Shi Xin-Min Shang Hong-Xian Liang Wei-Hong Wang school of earth Sciences Northeast Petroleum University Geophysical Research Institute of Shengli Oilfield Sinopec

Internal multiples are commonly present in seismic data due to variations in velocity or density of subsurface media. They can reduce the signal-to-noise ratio of seismic data and degrade the quality of the image. With the development of seismic exploration into deep and ultradeep events, especially those from complex targets in the western region of China, the internal multiple eliminations become increasingly challenging. Currently, three-dimensional(3D) seismic data are primarily used for oil and gas target recognition and drilling. Effectively eliminating internal multiples in 3D seismic data of complex structures and mitigating their adverse effects is crucial for enhancing the success rate of drilling. In this study, we propose an internal multiple prediction algorithm for 3D seismic data in complex structures using the Marchenko autofocusing theory. This method can predict the accurate internal multiples of time difference without an accurate velocity model and the implementation process mainly consists of several steps. Firstly, simulating direct waves with a 3D macroscopic velocity ***, using direct waves and 3D full seismic acquisition records to obtain the upgoing and downgoing Green's functions between the virtual source point and surface. Thirdly, constructing internal multiples of the relevant layers by upgoing and downgoing Green's functions. Finally, utilizing the adaptive matching subtraction method to remove predicted internal multiples from the original data to obtain seismic records without multiples. Compared with the two-dimensional(2D) Marchenko algorithm, the performance of the 3D Marchenko algorithm for internal multiple prediction has been significantly enhanced, resulting in higher computational accuracy. Numerical simulation test results indicate that our proposed method can effectively eliminate internal multiples in 3D seismic data,thereby exhibiting important theoretical and industrial application value.

关键词： Marchenko Internal multiple elimination Autofocusing Three-dimensional seismic data

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Statistical characteristics and classification of ionospheric mid-latitude trough as revealed by the observations of DMSP-F18

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earth and Planetary Physics 2025年第1期9卷 137-147页

作者： Yi Liu JiuHou Lei FuQing Huang Su Zhou school of earth and Space Sciences University of Science and Technology of ChinaHefei 230026China school of Science Guiyang UniversityGuiyang 550005China

Statistical characteristics and the classification of the topside ionospheric mid-latitude trough are systemically analyzed,using observations from the Defense Meteorological Satellite Program F18(DMSP-F18)*** data was obtained at an altitude of around 860 km in near polar orbit,throughout *** study identified the auroral boundary based on the in-situ electron density and electron spectrum,allowing us to precisely determine the location of the mid-latitude *** differs from most previous works,which only use Total Electron Content(TEC)or in-situ electron *** our study,the troughs exhibited a higher occurrence rate in local winter than in summer,and extended to lower latitudes with increasing geomagnetic *** was found that the ionospheric mid-latitude trough,which is associated with temperature changes or enhanced ion drift,exhibited distinct ***,the ionospheric mid-latitude troughs related to electron temperature(Te)peak were located more equatorward of auroral oval boundary in winter than in *** ionospheric mid-latitude troughs related to Te-maximum were less frequently observed at 60−70°S magnetic latitude and 90−240°E ***,the troughs related to ion temperature(Ti)maximums were observed at relatively higher latitudes,occurring more frequently in *** addition,the troughs related to ion velocity(Vi)maximums could be observed in all *** troughs with the maximum-Ti and maximum-Vi were located closer to the equatorward boundary of the auroral oval at the nightside,and in both *** implies that enhanced ion drift velocity contributes to increased collisional frictional heating and enhanced ion temperatures,resulting in a density depletion within the trough region.

关键词： topside ionosphere mid-latitude trough ionospheric main trough auroral oval boundary temperature maximum

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Solar flare forecasting based on a Fusion Model

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earth and Planetary Physics 2025年第1期9卷 171-181页

作者： YiYang Li ShiYong Huang SiBo Xu ZhiGang Yuan Kui Jiang QiYang Xiong RenTong Lin school of earth and Space Science Technology Hubei Luojia LaboratoryWuhan UniversityWuhan 430072China

Solar flare prediction is an important subject in the field of space *** learning technology has greatly promoted the development of this *** this study,we propose a novel solar flare forecasting model integrating Deep Residual Network(ResNet)and Support Vector Machine(SVM)for both≥C-class(C,M,and X classes)and≥M-class(M and X classes)*** collected samples of magnetograms from May 1,2010 to September 13,2018 from Space-weather Helioseismic and Magnetic Imager(HMI)Active Region Patches and then used a cross-validation method to obtain seven independent data *** then utilized five metrics to evaluate our fusion model,based on intermediate-output extracted by ResNet and SVM using the Gaussian kernel *** results show that the primary metric true skill statistics(TSS)achieves a value of 0.708±0.027 for≥C-class prediction,and of 0.758±0.042 for≥M-class prediction;these values indicate that our approach performs significantly better than those of previous *** metrics of our fusion model’s performance on the seven datasets indicate that the model is quite stable and robust,suggesting that fusion models that integrate an excellent baseline network with SVM can achieve improved performance in solar flare ***,we also discuss the performance impact of architectural innovation in our fusion model.

关键词： solar flare pace weather deep learning Fusion Model

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Advances in origin of high oxidation state of magmas associated with porphyry Cu-(Mo-Au) deposits

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Science China earth Sciences 2025年第3期68卷 953-956页

作者： Rui WANG Jingbo ZHANG State Key Laboratory of Geological Processes and Mineral Resources Frontiers Science Center for Deep-time Digital Earth Institute of Earth Sciences China University of Geosciences school of earth Sciences and Resources China University of Geosciences

1. Introduction Porphyry Cu-(Mo-Au) deposits, hereafter termed as porphyry Cu deposits, are typical magmatic-hydrothermal systems spatially and genetically associated with shallow,intermediate to felsic porphyritic intrusions. These deposits exhibit well-developed alteration zoning and are characterized by veinlet-disseminated mineralization.

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Drought-induced desiccation cracking in surface soil:Two-dimensional characterization by FEM-OFDR framework

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Science China Technological Sciences 2025年第3期68卷 282-301页

作者： Jinjian XU Chaosheng TANG Zhaojun ZENG Lin LI Junzheng ZHANG Tengfei GAO Bin SHI school of earth Sciences and Engineering Nanjing University

Drought-induced desiccation cracking can trigger several weakening mechanisms in surface soils, potentially precipitating instability and failure of slopes and earthen structures. To investigate the potential application of distributed fibre optical sensing(DFOS) based on optical frequency domain reflectometry(OFDR) technology in characterizing the twodimensional(2D) desiccation cracking processes of surface soils, a comprehensive test device is utilized to conduct soil evaporation tests, continuously record water content changes, desiccation cracking evolution, and FO sensing strain status. A deep learning-based quantitative analysis method is employed to meticulously examine the relationship between 2D cracking geometric parameters and strain status. The comprehensive analysis not only reveals the mutual feedback response mechanism between the strain status and the soil evaporation-shrinkage-cracking processes, but also clarifies the early detection distance of OFDR technology for 2D desiccation cracking. Specifically, OFDR technology can detect the propagation of horizontal desiccation cracks up to 23 mm in advance with a strain measurement accuracy of 1 με. To address the spatial continuity issue in OFDR sensing strain data, an innovative high-resolution characterization framework is proposed by combining the finite element method(FEM) and OFDR technology, referred to as the FEM-OFDR framework. Comparative results indicate that the proposed FEM significantly surpasses both the kriging and radial basis function(RBF) methods in inferring missing OFDR sensing strain data. Notably, during the drying process, reaching a critical water content causes the local decoupling between the uncracked clods and the substrate, resulting in a decreasing trend in the sensing strain at the crack position. This study provides crucial technical means and theoretical support for a deeper understanding of the mechanisms driving 2D desiccation-induced shrinkage and cracking in surface

关键词： soil desiccation cracking distributed fibre optical sensing optical frequency domain reflectometry finite element method 2D crack patterns monitoring mechanism

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Extended pan-spectrum fitting of energetic particle spectra

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earth and Planetary Physics 2025年第02期 366-374页

作者： WenYan Li LingHua Wang YongFu Wang XinNian Guo QianYi Ma school of earth and Space Sciences Peking University

The energy spectrum of energetic particles in space often shows a non-thermal spectral shape with two spectral transitions/breaks over a wide energy range, carrying crucial information about their acceleration, release and transportation process. To self-consistently characterize the spectral features of energetic particles, here we propose a novel extended pan-spectrum（EPS） formula to fit the particle energy-flux spectrum, which has the merit that can incorporate many commonly used spectrum functions with one spectral transition, including the pan-spectrum, double-power-law, Kappa, Ellison-Ramaty（ER） functions, etc. The formula can also determine the spectral shape with two spectral transitions, including the triple-power-law function, Kappa distribution（at low energy）plus power law（at high energy）, power law（at low energy） plus ER function, etc. Considering the uncertainties in both J and E, we can fit this EPS formula well to the representative energy spectra of various particle phenomena in space, including solar energetic particles（electrons, protons,3He and heavier ions）, anomalous cosmic rays, solar wind suprathermal particles（halo and superhalo electrons;pick-up ions and the suprathermal tail）, etc. Therefore, the EPS fitting can help us self-consistently determine the spectral features of different particle phenomena, and improve our understanding of the physical nature of the origin, acceleration, and transportation of energetic particles in space.

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Halogen composition and heterogeneity in the continental lithospheric mantle

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Science China earth Sciences 2025年第1期68卷 310-314页

作者： Chunfei CHEN State Key Laboratory of Geological Processes and Mineral Resources School of Earth SciencesChina University of GeosciencesWuhan430074China

*** Halogens,including fluorine(F),chlorine(Cl),bromine(Br),and iodine(I),are highly mobile and water-soluble elements that can become significantly enriched in melts and *** fluids and melts,halogens react with nearly all metals and readily form complexes with metal cations,significantly influencing the distribution of metal elements between different ***,halogens play a crucial role in the migration,enrichment,and mineralization of key metals in the lithosphere(Weis et al.,2012;Liu et al.,2024).

关键词： metals fluorine elements

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The composition of magmatic-hydrothermal fluids and their related metal mineralization

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Science China earth Sciences 2025年第1期68卷 208-225页

作者： Qihai SHU Jun DENG State Key Laboratory of Geological Processes and Mineral Resources School of Earth Sciences and ResourcesChina University of GeosciencesBeijing100083China Frontiers Science Center for Deep-time Digital earth China University of GeosciencesBeijing100083China

Magmatic hydrothermal deposits are important sources of many bulk,precious,and rare metals,and have attracted interest from both academic and industrial ***,it is still unclear if the major enrichment of the ore-forming metals occurs in the parental magma source region,during the magma evolution,or after the fluid *** inclusions trapped in hydrothermal minerals crystallized in the early,high-temperature stage before metal precipitation record information close to that of the initially exsolved magmatic fluids,which are helpful in revealing whether the metals have been already significantly enriched prior to the hydrothermal *** this study,available compositional data of such early-stage fluid inclusions from magmatic hydrothermal systems globally have been *** results indicate that the concentrations of Cu,Sn,and W respectively from the Cu-,Sn-,and W-mineralized fluids are significantly higher than the hydrothermal systems that do not produce ores with the corresponding *** suggests that Cu,Sn,and W could have already been enriched in the magma source and/or magma evolution *** Mo concentrations show no difference between Mo-mineralized and Mobarren fluid systems,indicating no significant pre-enrichment in the source region or during the magma *** also implies that an efficient collection of Mo from a large volume of magmas is required to account for the formation of a large Mo *** all the hydrothermal fluids contain high concentrations of Fe and Zn-Pb,but only a few of them eventually form Fe or Zn-Pb deposits,reflecting an important role of the hydrothermal evolution process on the selective metal *** above results indicate that different metals are enriched in different stages of a magmatic hydrothermal system,and that the major roles played in the formation of a deposit vary with the metal *** addition to the metal concentrations in the orerelated magmas and fluids

关键词： Magmatic hydrothermal deposits Fluid inclusions LA-ICP-MS Metal enrichment Mineralization mechanism

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