The Mailong gold deposit is located in the eastern section of the East Kunlun orogenic belt and is one of the recently discovered important gold polymetallic deposits in the Qinhai Gouli region.The primary host rocks ...The Mailong gold deposit is located in the eastern section of the East Kunlun orogenic belt and is one of the recently discovered important gold polymetallic deposits in the Qinhai Gouli region.The primary host rocks of the Mailong gold deposit consist of intermediate-acid intrusive rocks from the Varisian and Indosinian periods,as well as the Precambrian Jinshuikou Group,with mineralization controlled by northeast and northwest faults.The alteration of the host rocks is mainly characterized by silicification,sericitization,chloritization,and carbonatization.Based on the cross-cutting relationships of the veins,the hydrothermal mineralization of the gold deposit can be categorized into three stages:the quartz-pyrite stage,the quartzpolymetallic sulfide stage,and the quartz-carbonate stage.Microthermometry of fluid inclusions indicates that the Mailong gold deposit belongs to a low-density(0.73–0.86 g/cm3),medium-temperature(240–340℃),and medium-salinity(4.01–10.74 wt%NaCl)NaCl-CO2-H2O fluid system.The C-H-O isotopic analysis suggests that the mineralizing fluids is derived from magmatic water,with later contributions from atmospheric precipitation.In-situ S isotopic results indicate that the mineralizing materials mainly derive from igneous rocks.A comprehensive analysis concludes that the Mailong gold deposit is a mesothermal hydrothermal vein-type gold deposit controlled by structural factors.展开更多
The TiB+TiC dual-reinforced B_(4)C/TC4 composite was in-situ fabricated via incorporating 0.5wt%B_(4)C reinforcement during the laser melting deposition process.Different heat treatments of annealing and solid solutio...The TiB+TiC dual-reinforced B_(4)C/TC4 composite was in-situ fabricated via incorporating 0.5wt%B_(4)C reinforcement during the laser melting deposition process.Different heat treatments of annealing and solid solution were used to regulate the microstructure,mechanical properties,and corrosion properties of B_(4)C/TC4 composite.Results show that with the increase in temperature from 500℃to 800°C,partial lamellarα-Ti in the as-deposited sample is gradually transformed into equiaxedα-Ti,accompanied by the disappearance of basketweave microstructure.At 1100°C,a small portion of TiC phase suffers fusion.This composite exhibits the optimal combination of strength and plasticity after annealing at 500℃for 4 h followed by furnace cooling,which is attributed to the stress release effect and the refined basketweave microstructure.However,this composite shows a decline in corrosion resistance after various heat treatments due to grain coarsening and micro-galvanic corrosion.展开更多
The fatigue crack growth rate of a novel Ti-6Al-4V-1Mo titanium alloy,which is developed for laser directed energy deposition technique,was investigated before and after cyclic heat treatment(CHT).Changes in microstru...The fatigue crack growth rate of a novel Ti-6Al-4V-1Mo titanium alloy,which is developed for laser directed energy deposition technique,was investigated before and after cyclic heat treatment(CHT).Changes in microstructure,fracture surfaces,and crack growth paths were analyzed before and after CHT.Results indicate that in the stable crack growth region,the growth rates for the as-deposited and cyclic heat-treated specimens follow the relationships da/dN=1.8651×10^(−8)(ΔK)^(3.2271)and da/dN=1.4112×10^(−8)(ΔK)^(3.1125),respectively.Compared with that at the as-deposited state,the microstructure after CHT is transformed from a uniform basket-weave microstructure to a dual-phase microstructure consisting of near-sphericalαandβ-transformed matrix phases.The cyclic process also disrupts the continuity of the grain boundaryα(αGB)at the primaryβ-phase grain boundary.The coarsening of primaryαand the disruption ofαGB continuity are the primary factors to release stress concentration and promote crack deflection,thereby decreasing the fatigue crack growth rate.Additionally,the increased occurrence of crack branching,secondary cracking,and crack bridging in cyclic heat-treated specimens further reduces the crack driving force and slows the fatigue crack growth rate.展开更多
Strontianite-rich carbonatite,containing over 30 vol%carbonate minerals predominantly composed of strontianite(SrCO3),is identified in the Zhengjialiangzi ore segment of the Muluozhai rare earth element(REE)deposit,we...Strontianite-rich carbonatite,containing over 30 vol%carbonate minerals predominantly composed of strontianite(SrCO3),is identified in the Zhengjialiangzi ore segment of the Muluozhai rare earth element(REE)deposit,western Sichuan Province,China.It exhibits a unique mineral assemblage dominated by strontianite,fluorite,bastnäsite,barite,calcite and dolomite,distinguishing it from conventional calcio-,magnesio-,ferro-,or natro-carbonatites.The rock shows extreme enrichment in REEs(ΣREE=47335-64367 ppm),with strong LREE/HREE fractionation[(La/Yb)N=1151-2119]and notably high concentrations of high-value critical REEs(e.g.,Pr,Nd,Tb,Dy),5-10 times greater than those in local calcite-dominated carbonatites.Trace element patterns indicate significant enrichment in REEs,Sr,and Ba,along with depletion in high-field-strength elements(HFSEs;e.g.,Nb,Ta,Zr,Hf).In-situ Sr isotopes of strontianite[(^(87)Sr/^(86)Sr)i=0.706190-0.707305]indicate an enriched mantle source(EMI-EMII).Sr enrichment is attributed to initial mantle source enrichment and extensive fractional crystallization,possibly accompanied by minor wall-rock assimilation.We propose that the strontianite-rich carbonatite formed from a highly evolved,Sr-and REEs-rich carbonatitic magma that intruded into shallow structural breccias,followed by rapid cooling.Its formation is associated with a continuous melt-fluid evolutionary process that is characteristic of carbonatitic systems.展开更多
Epithermal deposits are characterized by complex low-temperature hydrothermal alterations, but the links between mineralization and superimposed alteration are obscure and require further elucidation. This study emplo...Epithermal deposits are characterized by complex low-temperature hydrothermal alterations, but the links between mineralization and superimposed alteration are obscure and require further elucidation. This study employs shortwave infrared(SWIR) spectral scalars for alteration mineral mapping and three-dimensional modeling of the Ulan Uzhur Ag polymetallic deposit, a newly discovered epithermal deposit in the Qimantagh. Alteration zoning transitions from illitemuscovite-carbonate-pyrite in the core(Zone Ⅰ), through muscovite ± illite-kaolinite-chlorite-carbonate(Zone Ⅱ), to muscovite-chlorite-biotite(Zone Ⅲ) at the periphery. The Zone Ⅰ with mineralization features long-wavelength white mica(wAlOH > 2207 nm) with a high Illite Crystallinity(IC)(mean > 2.0), suggesting a relatively high-temperature environment conducive to mineralization. Petrographic analyses with fluid inclusion and IC curve characteristics suggests that fluid boiling may be a pivotal mechanism for mineral precipitation. Furthermore, surface mapping and deep threedimensional modeling of spectral characteristics reveal a correlation between long-wavelength white mica, high IC and mineralization zones. These findings indicate that SWIR spectroscopy reveal the evolution of fluids and provide valuable guidance for future exploration efforts.展开更多
Aeolian deposits across the Yarlung Zangbo River Basin on the southern Tibetan Plateau record the landscape and atmospheric evolution of Earth's Third Pole.The complex mountain-basin system exhibits nonlinear resp...Aeolian deposits across the Yarlung Zangbo River Basin on the southern Tibetan Plateau record the landscape and atmospheric evolution of Earth's Third Pole.The complex mountain-basin system exhibits nonlinear responses to climate forcing,complicating the interpretation of its high-altitude environmental dynamics.Investigating the magnetic enhancement mechanism of aeolian deposits offers an opportunity to decipher climate signals.Our analysis of three aeolian sections from the basin indicates that magnetic minerals are predominantly low-coercivity ferrimagnetic minerals,and grain sizes fine from upper to lower reaches due to climate shifts from arid to humid.Magnetic enhancement in the upper reaches primarily originates from dust input,while dust input and pedogenesis contribute variably over time in the middle and lower reaches.Similar complex patterns occur in the Ili basin,a mountain-basin system in northwestern China.They differ from the Chinese Loess Plateau,where long-distance-transported dust is well-mixed and the pedogenic enhancement model is applied,and desert peripheries where short-distance dust is transported and the dust input model is applied.We summarize the magnetic enhancement mechanisms in various settings and offer a new framework for applying magnetic techniques in paleoclimate reconstruction within global mountain-basin systems,which highlights the need for caution in interpreting their magnetic susceptibility records.展开更多
Pulse tube cryocoolers are widely employed in cryogenic systems,where gas contamination has become a critical factor limiting both performance and service life.To further investigate the condensation behavior of conta...Pulse tube cryocoolers are widely employed in cryogenic systems,where gas contamination has become a critical factor limiting both performance and service life.To further investigate the condensation behavior of contaminants,this study develops a two-dimensional axisymmetric model of a linear-type cryocooler to simulate the transport and deposition processes of trace CO_(2),evaluating the impact of contamination on system pressure drop under various operating conditions.Results indicate that CO_(2)diffusion is primarily driven by concentration gradients.The CO_(2)deposition rate increases markedly at low temperatures and high concentrations,with over 90%of deposition occurring in the cold-end heat exchanger.Under different concentration distributions,dry ice predominantly accumulates in the cold-end heat exchanger;however,notable differences emerge in the pulse tube.In the uniform distribution case,CO_(2)tends to deposit along the inner wall of the pulse tube,whereas in the gradual release scenario,deposition mainly occurs on the cold-end flow straightening mesh screen.Dry ice deposition significantly increases the pressure drop across the system and decreases the pressure wave amplitude,resulting in a degradation of cooling capacity.This study lays a foundation for further investigation into the thermal properties of contaminant layers and provides theoretical guidance for optimizing cold-end components to improve contamination resilience.展开更多
Glacier landslide cascading hazards pose threats to communities and infrastructure,affected by complex processes including the amplification of mass flow volume through erosion and entrainment,transformation of hazard...Glacier landslide cascading hazards pose threats to communities and infrastructure,affected by complex processes including the amplification of mass flow volume through erosion and entrainment,transformation of hazard types,ice-water phase change,and enhanced mobility of the mass flow.Scientifically simulating these physical phenomena proves challenging.This study introduces GMFA(glacier mass flow analysis),an integrated numerical model that advances the field by:(1)proposing depth-averaged fluctuation energy and internal energy equations,(2)incorporating the ice-water phase change and the entrainment-deposition process,and(3)capturing their effects on mass flow runout characteristics.The model employs the finite volume method to solve the multi-physics coupled governing equations,enabling efficient large-scale simulations.The model is verified through three numerical tests covering flow dynamics,temperature evolution,and thermo-hydro-mechanical runout processes.The model is applied to analyze a hazard chain that occurred on 10 September 2020 on the Tibetan Plateau.The multi-scenario simulation results indicate an entrained mass volume of(4.95±0.11)×10^(5)m^(3),and a ratio of entrained mass volume to source material volume of 0.44.The solid concentration decreases from 0.6-0.7 to 0.1-0.15 with increasing runout distance,indicating a transition from avalanche to debris flood.The internal energy rises by(3-4)×10^(3)kJ/m^(3),driving rapid ice melting from 0.1 to 0.2 to near-zero concentration.The model effectively quantifies volume amplification,ice-water phase changes,and multi-hazard transformations.This model pushes the geoscience frontier,extending computational capability from single-to multi-hazard simulations and providing a powerful tool for analyzing glacier cascading hazards.展开更多
The gut microbiota has emerged as a pivotal regulator of host lipid metabolism and energy homeostasis.A growing body of evidence reveals that variations in the composition and metabolic activity of intestinal microbes...The gut microbiota has emerged as a pivotal regulator of host lipid metabolism and energy homeostasis.A growing body of evidence reveals that variations in the composition and metabolic activity of intestinal microbes are closely associated with differences in adipose tissue deposition across species.Notably,increased abundance of Firmicutes and a reduced proportion of Bacteroidetes and butyrate-producing bacteria have been linked to enhanced fat accumulation.Key microbial metabolites such as short-chain fatty acids(SCFAs)influence lipid metabolism through multiple pathways,including the activation of GPR41/43 receptors,modulation of the bile acid–FXR/TGR5 axis,and regulation of hepatic lipogenesis.Additionally,the gut–brain axis plays a critical role in controlling feeding behavior via neuroendocrine signaling.This review summarizes current advances in understanding the roles of dominant bacterial phyla and beneficial genera—including Clostridium butyricum and Faecalibacterium prausnitzii—in fat metabolism.We further explore the mechanisms by which gut microbiota modulate lipid synthesis and catabolism through SCFA production,bile acid signaling,and AMPK/PPAR-related pathways.These insights highlight the potential of microbiota-targeted strategies to restore lipid metabolic balance,offering novel opportunities for applications in health management,nutritional interventions,and microbial therapeutics.展开更多
The Mianhuakeng uranium deposit,characterized by uranium-rich granite,serves as a key site for research into crustal radioactive heating.Based on 45 rock samples,this study reviews that the host granite in the Mianhua...The Mianhuakeng uranium deposit,characterized by uranium-rich granite,serves as a key site for research into crustal radioactive heating.Based on 45 rock samples,this study reviews that the host granite in the Mianhuakeng uranium deposit has a high radioactive heat production rate(avg.5.50μW/m³)and a low Th/U ratio(avg.2.62).Uranium-rich granite and its alteration zone within the upper crust(0-5 km depth)contribute about 45%of the total radioactive heat production,wich is crucial for controlling geothermal resource distribution.For uranium-thermal at tectonic plate margins,a symbiotic geological model was proposed:Firstly,subduction of the Pacific Plate caused upwelling of the asthenosphere,generating a high heat-flow background.Secondly,heat transfer is enhanced by major faults such as the Youdong and Mianhuakeng faults.Subsequently,uranium was mobilized,transported,and enriched within the granite through deep siliceous hydrothermal activity and associated alteration.Ultimately,the uranium enrichment in granite leads to increased radioactive heat production,resulting in local thermal anomalies.This model provides a theoretical support for exploring and developing uranium-thermal symbiotic resources in South China.展开更多
The rapid proliferation of microelectronics,coupled with the advent of the internet ofthings(IoT)era,has created an urgent demand for miniaturized,integrable,and reliable on-chip energystorage systems.All-solid-state ...The rapid proliferation of microelectronics,coupled with the advent of the internet ofthings(IoT)era,has created an urgent demand for miniaturized,integrable,and reliable on-chip energystorage systems.All-solid-state thin-film microbatteries(TFMBs),distinguished by their intrinsicsafety,compact design,and compatibility with microfabrication techniques,have emerged as promisingcandidates to power next-generation IoT devices.Nevertheless,in contrast to the well-establisheddevelopment of conventional lithium-ion batteries,the advancement of TFMBs remains at an earlystage,facing persistent challenges in materials innovation,interface optimization,and scalable manufacturing.This review critically examines the pivotal role of vapor deposition technologies,includingmagnetron sputtering,pulsed laser deposition,thermal/electron-beam evaporation,chemical vapordeposition,and atomic layer deposition,in the fabrication and performance modulation of TFMBs.We systematically summarize recent progress in thin-film electrodes and solid-state electrolytes,withparticular emphasis on how deposition parameters dictate crystallinity,lattice orientation,and ionictransport in functional layers.Furthermore,we highlight strategies for solid-solid interface engineering,three-dimensional structural design,andmultifunctional integration to enhance capacity retention,cycling stability,and interfacial compatibility.Looking ahead,TFMBs are expectedto evolve toward multifunctional platforms,exhibiting mechanical flexibility,optical transparency,and hybrid energy-harvesting compatibility,thereby meeting the heterogeneous energy requirements of future IoT ecosystems.Overall,this review provides a comprehensive perspective onvapor-phase-enabled TFMB technologies,delivering both theoretical insights and technological guidelines for the scalable realization of highperformancemicroscale power sources.展开更多
Intramuscular fat(IMF)content serves as the key determinants of meat quality.Emerging evidence indicates that gut microbiota and their metabolites significantly influence IMF deposition levels by modulating host lipid...Intramuscular fat(IMF)content serves as the key determinants of meat quality.Emerging evidence indicates that gut microbiota and their metabolites significantly influence IMF deposition levels by modulating host lipid metabolism through multiple pathways,positioning microbial regulation as a pivotal target for meat quality improvement.However,existing studies remain fragmented,predominantly focusing on isolated mechanisms or correlations without a systematic view of the regulatory network.This review consolidates the core mechanisms through which microbiota-derived metabolites including short-chain fatty acids,bile acids,branched-chain amino acids,trimethylamine N-oxide,tryptophan derivatives,succinate,polyamines etc.,regulate IMF deposition and proposes a targeted intervention framework,the“gut microbiota/metabolites-IMF axis”.By integrating these insights,we provide a theoretical foundation and define practical research pathways to assess the potential of microbial-based strategies for improving meat quality in swine production.展开更多
Background Excessive abdominal fat in broilers not only reduces feed efficiency and increases processing costs but also raises environmental concerns.This pathological overaccumulation results from complex metabolic d...Background Excessive abdominal fat in broilers not only reduces feed efficiency and increases processing costs but also raises environmental concerns.This pathological overaccumulation results from complex metabolic dysregulation across multiple organs.While current research largely centers on adipogenesis within adipose tissue,a comprehensive understanding of the cross-organ regulatory factors influencing this process remains elusive.Results Here,we employed a high-fat diet(HFD)model and multi-omics approaches to investigate cross-organ regulatory mechanisms underlying abdominal fat deposition in broilers.Our results demonstrated that HFD not only promoted fat accumulation but also altered meat quality traits.Through 16S rRNA amplicon sequencing,we identified significant gut microbiota dysbiosis in HFD-fed chickens,manifested by an increased abundance of Lactobacillus and a decreased abundance of Enterococcus.However,jejunal microbiota transplantation from HFD donors did not induce abdominal fat deposition in recipient chickens.Metabolomic profiling revealed that HFD elevated the level of succinic acid,a metabolite positively correlated with Lactobacillus abundance and potentially generated by Lactobacillus.This increase in succinic acid(SA)further triggered metabolic inflammation response in both jejunal tissue and serum.In vivo validation established succinic acid as a key inflammatory mediator facilitating HFD-induced cross-organ communication between the jejunum and abdominal adipose tissue,enhancing intestinal lipid uptake and subsequent abdominal fat deposition.Bulk and single-nucleus RNA sequencing(snRNA-seq)revealed that HFD induced macrophage population expansion and intensified adipocyte-macrophage crosstalk.Adipocyte-macrophage co-culture systems further elucidated that macrophages are an indispensable factor in succinic acid-induced fat deposition.Conclusion This study delineates a succinic acid-driven"gut-fat axis"governing abdominal fat deposition in broilers,integrating gut microbiota dysbiosis and macrophage-mediated inflammatory adipogenesis.By identifying succinic acid as a cross-organ signaling molecule that enhances lipid absorption and activates macrophage-dependent adipogenesis,we establish systemic metabolic-immune crosstalk as a pivotal regulatory mechanism.These findings redefine fat deposition as a process extending beyond adipose-centric models,advancing multi-omics-guided strategies for sustainable poultry production.展开更多
BaFe_(12)O_(19)(BaM)thin films with thicknesses ranging from 15 nm–200 nm were deposited on Al_(2)O_(3)(0001)substrates by pulsed laser deposition(PLD).X-ray diffraction patterns show that a buffer layer with a thick...BaFe_(12)O_(19)(BaM)thin films with thicknesses ranging from 15 nm–200 nm were deposited on Al_(2)O_(3)(0001)substrates by pulsed laser deposition(PLD).X-ray diffraction patterns show that a buffer layer with a thickness of nearly 60 nm forms on the substrate,and then a c-axis perpendicularly oriented Ba M thin film grows on the buffer layer.Atomic force microscopy results indicate that the Ba M thin film exhibits a spiral island growth mode on the buffer layer.Magnetic hysteresis loop results confirm that the buffer layer exhibits no significant magnetic anisotropy,while the Ba M thin film exhibits perpendicular magnetic anisotropy.The out-of-plane coercivity decreases with increasing Ba M thin-film thickness due to the combined effect of grain size growth and lattice strain relaxation.The 200 nm thick film exhibits optimum magnetic properties with M_(s)=319 emu/cm^(3) and H_(c)=1546 Oe.展开更多
The widely distributed loess deposits in the Yellow River Basin exhibit unique engineering geological characteristics.The variations in their thickness and stratigraphic structure significantly amplify ground motion p...The widely distributed loess deposits in the Yellow River Basin exhibit unique engineering geological characteristics.The variations in their thickness and stratigraphic structure significantly amplify ground motion parameters,directly influencing the regional seismic hazard risk level.This study methodically conducted on-site studies and observations of building collapses and damages resulting from seismic amplification effects,using the Wenchuan M_(S)8.0 earthquake as a case study.Comprehensive experimental and numerical simulation studies were carried out.A large-scale shaking table test was performed,and numerical models for 14 different loess sites types were established.Various types of seismic waves were incorporated into these models for systematic numerical simulation calculations.The research reveals the mechanisms by which loess deposit thickness and stratigraphic structure in the Yellow River Basin affect seismic ground motion amplification.The results indicate that as the epicentral distance increases,the peak ground motion shows a marked attenuation trend,with the horizontal component attenuating substantially faster than the vertical component.As the overlying loess layer thickness increases from 50 to 100 m,the seismic intensity may escalate by 3−4 degrees,and the peak acceleration may amplify by 1.5−2.2 times.With the augmentation of loess deposit thickness and the proliferation of soil layers,both the peak acceleration response spectrum and the characteristic period demonstrate an upward tendency,exhibiting slight fluctuations contingent upon the seismic wave type.展开更多
TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing Ti...TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing TiB_(2)coatings have disadvantages such as high equipment costs,complicated processes,and highly toxic gas emissions.This paper proposes an environmentally friendly method,which requires inexpensive equipment and simple processing,for preparing TiB_(2)coating on molybdenum via electrophoretic deposition within Na3AlF6-based molten salts.The produced TiB_(2)layer had an approximate thickness of 60μm and exhibited high density,outstanding hardness(38.2 GPa)and robust adhesion strength(51 N).Additionally,high-temperature oxidation experiments revealed that,at900℃,the TiB_(2)coating provided effective protection to the molybdenum substrate against oxidation for 3 h.This result indicates that the TiB_(2)coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.展开更多
Aqueous zinc-ion batteries(AZIBs) have advantages including low economic cost and high safety.Nevertheless,the serious hydrogen evolution reactions(HER) and rampant growth of Zn dendrite hinder their further developme...Aqueous zinc-ion batteries(AZIBs) have advantages including low economic cost and high safety.Nevertheless,the serious hydrogen evolution reactions(HER) and rampant growth of Zn dendrite hinder their further development.Herein,potassium acetate(KAc) additive with cation/anion synergy effect is added into the ZnSO_(4) electrolyte to effectively promote the oriented uniform Zn deposition and suppress side reactions.According to density functional theory calculation and experimental results,CH_(3)COO^(-)(Ac^(-))anions are capable of forming stronger hydrogen bonds with H_(2)O molecules,leading to an expanded electrochemical stability window,reduced the reactivity of H_(2)O,and hence suppressing HER.Meanwhile,Ac-anions can also preferentially adsorb onto the Zn anode,promoting dense deposition towards the(100) crystal plane.Besides,dissociated K^(+) ions serve as electrostatic shielding cations,which significantly promote uniform Zn deposition and prevent dendrite formation.Thus,the Zn||Zn symmetric cell demonstrates an impressive cycle lifespan of 3000 h at 1.0 m A/cm^(2).Furthermore,the Zn||MnO_(2) full battery exhibits superior stability with a capacity retention of 86.95 % at 2.0 A/g after 4000 cycles.Therefore,the cation/anion synergy effect in KAc additive offers a viable solution to address HER and hinder dendrite growth at the interface of Zn anodes.展开更多
The giant Upper Yangtze Pb-Zn metallogenic province,also known as the Sichuan-Yunnan-Guizhou(SYG)Pb-Zn province hosting>500 carbonate-hosted epigenetic Pb-Zn deposits that contain>20 Mt Pb+Zn base metal reserves...The giant Upper Yangtze Pb-Zn metallogenic province,also known as the Sichuan-Yunnan-Guizhou(SYG)Pb-Zn province hosting>500 carbonate-hosted epigenetic Pb-Zn deposits that contain>20 Mt Pb+Zn base metal reserves.The giant Maoping Pb-Zn deposit is the second largest deposit in this province and owns>5 Mt Pb+Zn metal reserves with ore grades of 12 wt.%-30 wt.%Pb+Zn.Such large tonnages and high grades make it among the top 100 similar mineral deposits in the world.The ore bodies are predominantly located within the strata of the Upper Devonian(Zaige Formation)and Lower(Baizuo Formation)-Upper(Weining Formation)Carboniferous.The principal ore minerals consist of galena(Gn),sphalerite(Sp),and pyrite(Py),while the primary gangue minerals include dolomite(Dol),calcite(Cal),and quartz(Qtz).Three mineralization stages of carbonate minerals have been identified:(1)pre-sulfide stage 1,(2)syn-sulfide stage 2,and(3)post-sulfide stage 3.Trace elements and C-O-Sr isotopes of three stages’carbonate minerals,together with S-Pb isotopes of sulfides,revealing that the metamorphic basement rocks played the role of the metal source during the early stage of Pb-Zn mineralization,whereas the metal contribution of the sedimentary wall rocks found to be more prominent during the late stage of Pb-Zn mineralization.In addition,the dissolution of marine carbonate rocks and CO_(2)degassing may have also played an important role in the formation of the Maoping deposit.Furthermore,syn-sulfide stage 2 calcite has a U-Pb age of 214±20 Ma obtained by LA-ICPMS in-situ analyses,suggesting that the hydrothermal mineralization occurred during the Triassic.Our study proposes a new coupled metallogenic model of fluid-structure-lithology assemblage and provides new insights about the formation and evolution of the Maoping deposit with significant implication for understanding and exploration of similar Pb-Zn deposits worldwide.展开更多
Laser directed energy deposition(LDED)is an emerging branch of metal-based additive manufacturing(AM)processes,offering unprecedented capabilities for high-performance fabrication with complex geometries and near-net ...Laser directed energy deposition(LDED)is an emerging branch of metal-based additive manufacturing(AM)processes,offering unprecedented capabilities for high-performance fabrication with complex geometries and near-net shapes.This technology is gathering increasing attention from industries such as biomedical,automotive,and aerospace.However,achieving consistent part quality and desired material properties is challenging due to intricate processing parameters and potential process defects such as dynamic melt-pool behavior and localized heat accumulation.This paper reviews recent advances in on-line quality control,focusing on in-situ measurement and closed-loop control for efficient assurance of LDED-fabricated parts.The quality principles,encompassing accuracy and material performance,are summarized to lay a foundation for understanding the mechanisms of quality defects and influencing factors.This review explores and thoroughly compares advancements in indirect process measurements,such as optical,thermal,and acoustic monitoring with direct quality measurements,including laser-line scanning and operando synchrotron X-ray imaging.Depending on the sensing techniques,this paper highlights a hierarchical control strategy for adaptive parameter regulation on intra-layer and inter-layer scales.The requirements and performance of various state-of-the-art controllers are critically compared to indicate their suitable applications.The importance of machine learning in detecting process anomalies and predicting build quality based on sensory signals is also outlined.Future directions are proposed towards adaptive,automated,and intelligent quality control,with a focus on multi-modal monitoring,physics-informed neural networks for interpretable analysis,and multi-objective control applications.展开更多
Quartz vein-type tungsten deposits are a common W deposit type.Their ore vein distribution was previously considered to be controlled by regional horizontal tectonic stress.In this paper,14 tungsten deposits with fan-...Quartz vein-type tungsten deposits are a common W deposit type.Their ore vein distribution was previously considered to be controlled by regional horizontal tectonic stress.In this paper,14 tungsten deposits with fan-shaped mineralization in SE China are summarized,and the relations between their ore veins and granite and the ore-forming structural stress field are analyzed.These deposits have a post-magmatic hydrothermal genesis and involve the formation of two sets of veins with similar strike and opposite dips at the top of the ore-causative granite bodies,forming a vertical fan-shaped profile.Their ore veins were coeval with the underlying granite bodies,and generally extend along the long axis of the granite.In such fan-shaped ore formation,the stress is highly focused at the top of the granite and gradually weakens outward.The maximum principal stress(σ1)is perpendicular to the granite contact surface,and radiates outward from the pluton.Meanwhile,the minimum principal stress(σ3)forms an arc-shaped band parallel to the contact surface.Our findings,together with published numerical modeling indicate that the emplacement dynamics of granitic magma(rather than regional horizontal tectonic stress)are essential controls on the distribution of ore veins in quartz vein-type tungsten deposits.展开更多
基金Supported by Qinghai Provincial Geological Exploration Special Fund Project(No.2023085029KY004).
文摘The Mailong gold deposit is located in the eastern section of the East Kunlun orogenic belt and is one of the recently discovered important gold polymetallic deposits in the Qinhai Gouli region.The primary host rocks of the Mailong gold deposit consist of intermediate-acid intrusive rocks from the Varisian and Indosinian periods,as well as the Precambrian Jinshuikou Group,with mineralization controlled by northeast and northwest faults.The alteration of the host rocks is mainly characterized by silicification,sericitization,chloritization,and carbonatization.Based on the cross-cutting relationships of the veins,the hydrothermal mineralization of the gold deposit can be categorized into three stages:the quartz-pyrite stage,the quartzpolymetallic sulfide stage,and the quartz-carbonate stage.Microthermometry of fluid inclusions indicates that the Mailong gold deposit belongs to a low-density(0.73–0.86 g/cm3),medium-temperature(240–340℃),and medium-salinity(4.01–10.74 wt%NaCl)NaCl-CO2-H2O fluid system.The C-H-O isotopic analysis suggests that the mineralizing fluids is derived from magmatic water,with later contributions from atmospheric precipitation.In-situ S isotopic results indicate that the mineralizing materials mainly derive from igneous rocks.A comprehensive analysis concludes that the Mailong gold deposit is a mesothermal hydrothermal vein-type gold deposit controlled by structural factors.
基金Tianjin Municipal Natural Science Foundation(23JCYBJC00040)National Natural Science Foundation of China(52175369)。
文摘The TiB+TiC dual-reinforced B_(4)C/TC4 composite was in-situ fabricated via incorporating 0.5wt%B_(4)C reinforcement during the laser melting deposition process.Different heat treatments of annealing and solid solution were used to regulate the microstructure,mechanical properties,and corrosion properties of B_(4)C/TC4 composite.Results show that with the increase in temperature from 500℃to 800°C,partial lamellarα-Ti in the as-deposited sample is gradually transformed into equiaxedα-Ti,accompanied by the disappearance of basketweave microstructure.At 1100°C,a small portion of TiC phase suffers fusion.This composite exhibits the optimal combination of strength and plasticity after annealing at 500℃for 4 h followed by furnace cooling,which is attributed to the stress release effect and the refined basketweave microstructure.However,this composite shows a decline in corrosion resistance after various heat treatments due to grain coarsening and micro-galvanic corrosion.
基金National Key Research and Development Program of China(2024YFB4610803)。
文摘The fatigue crack growth rate of a novel Ti-6Al-4V-1Mo titanium alloy,which is developed for laser directed energy deposition technique,was investigated before and after cyclic heat treatment(CHT).Changes in microstructure,fracture surfaces,and crack growth paths were analyzed before and after CHT.Results indicate that in the stable crack growth region,the growth rates for the as-deposited and cyclic heat-treated specimens follow the relationships da/dN=1.8651×10^(−8)(ΔK)^(3.2271)and da/dN=1.4112×10^(−8)(ΔK)^(3.1125),respectively.Compared with that at the as-deposited state,the microstructure after CHT is transformed from a uniform basket-weave microstructure to a dual-phase microstructure consisting of near-sphericalαandβ-transformed matrix phases.The cyclic process also disrupts the continuity of the grain boundaryα(αGB)at the primaryβ-phase grain boundary.The coarsening of primaryαand the disruption ofαGB continuity are the primary factors to release stress concentration and promote crack deflection,thereby decreasing the fatigue crack growth rate.Additionally,the increased occurrence of crack branching,secondary cracking,and crack bridging in cyclic heat-treated specimens further reduces the crack driving force and slows the fatigue crack growth rate.
基金the National Natural Science Foundation of China(Grant No.42203073 and 41472072)Basic Scientific Research Fund of the Institute of Geology,CAGS(Grant No.J2317)Sichuan Science and Technology Program(Grant No.2023NSFSC0272).
文摘Strontianite-rich carbonatite,containing over 30 vol%carbonate minerals predominantly composed of strontianite(SrCO3),is identified in the Zhengjialiangzi ore segment of the Muluozhai rare earth element(REE)deposit,western Sichuan Province,China.It exhibits a unique mineral assemblage dominated by strontianite,fluorite,bastnäsite,barite,calcite and dolomite,distinguishing it from conventional calcio-,magnesio-,ferro-,or natro-carbonatites.The rock shows extreme enrichment in REEs(ΣREE=47335-64367 ppm),with strong LREE/HREE fractionation[(La/Yb)N=1151-2119]and notably high concentrations of high-value critical REEs(e.g.,Pr,Nd,Tb,Dy),5-10 times greater than those in local calcite-dominated carbonatites.Trace element patterns indicate significant enrichment in REEs,Sr,and Ba,along with depletion in high-field-strength elements(HFSEs;e.g.,Nb,Ta,Zr,Hf).In-situ Sr isotopes of strontianite[(^(87)Sr/^(86)Sr)i=0.706190-0.707305]indicate an enriched mantle source(EMI-EMII).Sr enrichment is attributed to initial mantle source enrichment and extensive fractional crystallization,possibly accompanied by minor wall-rock assimilation.We propose that the strontianite-rich carbonatite formed from a highly evolved,Sr-and REEs-rich carbonatitic magma that intruded into shallow structural breccias,followed by rapid cooling.Its formation is associated with a continuous melt-fluid evolutionary process that is characteristic of carbonatitic systems.
基金supported by the Natural Science Foundation of China(Grant No.42372346,41802080,42030809,41873043).
文摘Epithermal deposits are characterized by complex low-temperature hydrothermal alterations, but the links between mineralization and superimposed alteration are obscure and require further elucidation. This study employs shortwave infrared(SWIR) spectral scalars for alteration mineral mapping and three-dimensional modeling of the Ulan Uzhur Ag polymetallic deposit, a newly discovered epithermal deposit in the Qimantagh. Alteration zoning transitions from illitemuscovite-carbonate-pyrite in the core(Zone Ⅰ), through muscovite ± illite-kaolinite-chlorite-carbonate(Zone Ⅱ), to muscovite-chlorite-biotite(Zone Ⅲ) at the periphery. The Zone Ⅰ with mineralization features long-wavelength white mica(wAlOH > 2207 nm) with a high Illite Crystallinity(IC)(mean > 2.0), suggesting a relatively high-temperature environment conducive to mineralization. Petrographic analyses with fluid inclusion and IC curve characteristics suggests that fluid boiling may be a pivotal mechanism for mineral precipitation. Furthermore, surface mapping and deep threedimensional modeling of spectral characteristics reveal a correlation between long-wavelength white mica, high IC and mineralization zones. These findings indicate that SWIR spectroscopy reveal the evolution of fluids and provide valuable guidance for future exploration efforts.
基金National Natural Science Foundation of China,No.42501182The Open Foundation of Key Laboratory of Western China’s Environmental System,Ministry of Education,Lanzhou Universitythe Fundamental Research Funds for the Central Universities,No.lzujbky-2024-jdzx01。
文摘Aeolian deposits across the Yarlung Zangbo River Basin on the southern Tibetan Plateau record the landscape and atmospheric evolution of Earth's Third Pole.The complex mountain-basin system exhibits nonlinear responses to climate forcing,complicating the interpretation of its high-altitude environmental dynamics.Investigating the magnetic enhancement mechanism of aeolian deposits offers an opportunity to decipher climate signals.Our analysis of three aeolian sections from the basin indicates that magnetic minerals are predominantly low-coercivity ferrimagnetic minerals,and grain sizes fine from upper to lower reaches due to climate shifts from arid to humid.Magnetic enhancement in the upper reaches primarily originates from dust input,while dust input and pedogenesis contribute variably over time in the middle and lower reaches.Similar complex patterns occur in the Ili basin,a mountain-basin system in northwestern China.They differ from the Chinese Loess Plateau,where long-distance-transported dust is well-mixed and the pedogenic enhancement model is applied,and desert peripheries where short-distance dust is transported and the dust input model is applied.We summarize the magnetic enhancement mechanisms in various settings and offer a new framework for applying magnetic techniques in paleoclimate reconstruction within global mountain-basin systems,which highlights the need for caution in interpreting their magnetic susceptibility records.
基金supported by the National Natural Science Foundation of China(No.52376012)the Aeronautical Science Foundation of China(20230024047001).
文摘Pulse tube cryocoolers are widely employed in cryogenic systems,where gas contamination has become a critical factor limiting both performance and service life.To further investigate the condensation behavior of contaminants,this study develops a two-dimensional axisymmetric model of a linear-type cryocooler to simulate the transport and deposition processes of trace CO_(2),evaluating the impact of contamination on system pressure drop under various operating conditions.Results indicate that CO_(2)diffusion is primarily driven by concentration gradients.The CO_(2)deposition rate increases markedly at low temperatures and high concentrations,with over 90%of deposition occurring in the cold-end heat exchanger.Under different concentration distributions,dry ice predominantly accumulates in the cold-end heat exchanger;however,notable differences emerge in the pulse tube.In the uniform distribution case,CO_(2)tends to deposit along the inner wall of the pulse tube,whereas in the gradual release scenario,deposition mainly occurs on the cold-end flow straightening mesh screen.Dry ice deposition significantly increases the pressure drop across the system and decreases the pressure wave amplitude,resulting in a degradation of cooling capacity.This study lays a foundation for further investigation into the thermal properties of contaminant layers and provides theoretical guidance for optimizing cold-end components to improve contamination resilience.
基金supports from the National Natural Science Foundation of China(Grant No.U20A20112)the Research Grants Council of the Hong Kong SAR Government,China(Grant Nos.T22-606/23-R and 16206923).
文摘Glacier landslide cascading hazards pose threats to communities and infrastructure,affected by complex processes including the amplification of mass flow volume through erosion and entrainment,transformation of hazard types,ice-water phase change,and enhanced mobility of the mass flow.Scientifically simulating these physical phenomena proves challenging.This study introduces GMFA(glacier mass flow analysis),an integrated numerical model that advances the field by:(1)proposing depth-averaged fluctuation energy and internal energy equations,(2)incorporating the ice-water phase change and the entrainment-deposition process,and(3)capturing their effects on mass flow runout characteristics.The model employs the finite volume method to solve the multi-physics coupled governing equations,enabling efficient large-scale simulations.The model is verified through three numerical tests covering flow dynamics,temperature evolution,and thermo-hydro-mechanical runout processes.The model is applied to analyze a hazard chain that occurred on 10 September 2020 on the Tibetan Plateau.The multi-scenario simulation results indicate an entrained mass volume of(4.95±0.11)×10^(5)m^(3),and a ratio of entrained mass volume to source material volume of 0.44.The solid concentration decreases from 0.6-0.7 to 0.1-0.15 with increasing runout distance,indicating a transition from avalanche to debris flood.The internal energy rises by(3-4)×10^(3)kJ/m^(3),driving rapid ice melting from 0.1 to 0.2 to near-zero concentration.The model effectively quantifies volume amplification,ice-water phase changes,and multi-hazard transformations.This model pushes the geoscience frontier,extending computational capability from single-to multi-hazard simulations and providing a powerful tool for analyzing glacier cascading hazards.
基金supported by National Key R&D Program of China(2024YFF1001500)Sichuan Science and Technology Program(2021YFYZ0007,2024NSFSC0298,SCCXTD-2025-8)+1 种基金China Agriculture Research System(CARS-35)National Natural Science Foundation of China(32421005)。
文摘The gut microbiota has emerged as a pivotal regulator of host lipid metabolism and energy homeostasis.A growing body of evidence reveals that variations in the composition and metabolic activity of intestinal microbes are closely associated with differences in adipose tissue deposition across species.Notably,increased abundance of Firmicutes and a reduced proportion of Bacteroidetes and butyrate-producing bacteria have been linked to enhanced fat accumulation.Key microbial metabolites such as short-chain fatty acids(SCFAs)influence lipid metabolism through multiple pathways,including the activation of GPR41/43 receptors,modulation of the bile acid–FXR/TGR5 axis,and regulation of hepatic lipogenesis.Additionally,the gut–brain axis plays a critical role in controlling feeding behavior via neuroendocrine signaling.This review summarizes current advances in understanding the roles of dominant bacterial phyla and beneficial genera—including Clostridium butyricum and Faecalibacterium prausnitzii—in fat metabolism.We further explore the mechanisms by which gut microbiota modulate lipid synthesis and catabolism through SCFA production,bile acid signaling,and AMPK/PPAR-related pathways.These insights highlight the potential of microbiota-targeted strategies to restore lipid metabolic balance,offering novel opportunities for applications in health management,nutritional interventions,and microbial therapeutics.
基金supported by the National Natural Science Foundation of China(41902310,42372348,42372286)Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project(2024ZD1003607)+2 种基金China Geological Survey Projects(DD20230700802,DD20221819)the Basic Research Fund of the Chinese Academy of Geological Sciences(JKYQN202306)Key Research and Development Program of Shanxi Province,China(202102090301009).
文摘The Mianhuakeng uranium deposit,characterized by uranium-rich granite,serves as a key site for research into crustal radioactive heating.Based on 45 rock samples,this study reviews that the host granite in the Mianhuakeng uranium deposit has a high radioactive heat production rate(avg.5.50μW/m³)and a low Th/U ratio(avg.2.62).Uranium-rich granite and its alteration zone within the upper crust(0-5 km depth)contribute about 45%of the total radioactive heat production,wich is crucial for controlling geothermal resource distribution.For uranium-thermal at tectonic plate margins,a symbiotic geological model was proposed:Firstly,subduction of the Pacific Plate caused upwelling of the asthenosphere,generating a high heat-flow background.Secondly,heat transfer is enhanced by major faults such as the Youdong and Mianhuakeng faults.Subsequently,uranium was mobilized,transported,and enriched within the granite through deep siliceous hydrothermal activity and associated alteration.Ultimately,the uranium enrichment in granite leads to increased radioactive heat production,resulting in local thermal anomalies.This model provides a theoretical support for exploring and developing uranium-thermal symbiotic resources in South China.
基金supported by the National Key Research and Development Program of China(2023YFA1608800)Guangdong Basic and Applied Basic Research Foundation(2024A1515012385,2024B1515120042)+5 种基金Shenzhen Foundation Research Fund(JCYJ20240813095004006)the National Natural Science Foundation of China(12426301,12275119,52227802)Shenzhen Science and Technology Program(KQTD20200820113047086)Shenzhen Key Laboratory of Solid State Batteries(SYSPG20241211173726011)Guangdong-Hong Kong-Macao Joint Laboratory for Photonic-Thermal-Electrical Energy Materials and Devices(2019B121205001)Guangdong Provincial Key Laboratory of Energy Materials for Electric Power(2018B030322001)。
文摘The rapid proliferation of microelectronics,coupled with the advent of the internet ofthings(IoT)era,has created an urgent demand for miniaturized,integrable,and reliable on-chip energystorage systems.All-solid-state thin-film microbatteries(TFMBs),distinguished by their intrinsicsafety,compact design,and compatibility with microfabrication techniques,have emerged as promisingcandidates to power next-generation IoT devices.Nevertheless,in contrast to the well-establisheddevelopment of conventional lithium-ion batteries,the advancement of TFMBs remains at an earlystage,facing persistent challenges in materials innovation,interface optimization,and scalable manufacturing.This review critically examines the pivotal role of vapor deposition technologies,includingmagnetron sputtering,pulsed laser deposition,thermal/electron-beam evaporation,chemical vapordeposition,and atomic layer deposition,in the fabrication and performance modulation of TFMBs.We systematically summarize recent progress in thin-film electrodes and solid-state electrolytes,withparticular emphasis on how deposition parameters dictate crystallinity,lattice orientation,and ionictransport in functional layers.Furthermore,we highlight strategies for solid-solid interface engineering,three-dimensional structural design,andmultifunctional integration to enhance capacity retention,cycling stability,and interfacial compatibility.Looking ahead,TFMBs are expectedto evolve toward multifunctional platforms,exhibiting mechanical flexibility,optical transparency,and hybrid energy-harvesting compatibility,thereby meeting the heterogeneous energy requirements of future IoT ecosystems.Overall,this review provides a comprehensive perspective onvapor-phase-enabled TFMB technologies,delivering both theoretical insights and technological guidelines for the scalable realization of highperformancemicroscale power sources.
基金financially supported by the National Key Research and Development Program of China(2023YFD1301303)the National Natural Science Foundation of China(No.32202715)+1 种基金the National Natural Science Foundation of China(No.23DAA00403)Double first-class discipline promotion project under grant(No.2023B10564001)。
文摘Intramuscular fat(IMF)content serves as the key determinants of meat quality.Emerging evidence indicates that gut microbiota and their metabolites significantly influence IMF deposition levels by modulating host lipid metabolism through multiple pathways,positioning microbial regulation as a pivotal target for meat quality improvement.However,existing studies remain fragmented,predominantly focusing on isolated mechanisms or correlations without a systematic view of the regulatory network.This review consolidates the core mechanisms through which microbiota-derived metabolites including short-chain fatty acids,bile acids,branched-chain amino acids,trimethylamine N-oxide,tryptophan derivatives,succinate,polyamines etc.,regulate IMF deposition and proposes a targeted intervention framework,the“gut microbiota/metabolites-IMF axis”.By integrating these insights,we provide a theoretical foundation and define practical research pathways to assess the potential of microbial-based strategies for improving meat quality in swine production.
基金supported by the National Key Research and Development Program of China(2022YFF1000201)National Scientific Foundation of China(32272861)the China Agriculture Research System of MOF and MARA(CARS-41)。
文摘Background Excessive abdominal fat in broilers not only reduces feed efficiency and increases processing costs but also raises environmental concerns.This pathological overaccumulation results from complex metabolic dysregulation across multiple organs.While current research largely centers on adipogenesis within adipose tissue,a comprehensive understanding of the cross-organ regulatory factors influencing this process remains elusive.Results Here,we employed a high-fat diet(HFD)model and multi-omics approaches to investigate cross-organ regulatory mechanisms underlying abdominal fat deposition in broilers.Our results demonstrated that HFD not only promoted fat accumulation but also altered meat quality traits.Through 16S rRNA amplicon sequencing,we identified significant gut microbiota dysbiosis in HFD-fed chickens,manifested by an increased abundance of Lactobacillus and a decreased abundance of Enterococcus.However,jejunal microbiota transplantation from HFD donors did not induce abdominal fat deposition in recipient chickens.Metabolomic profiling revealed that HFD elevated the level of succinic acid,a metabolite positively correlated with Lactobacillus abundance and potentially generated by Lactobacillus.This increase in succinic acid(SA)further triggered metabolic inflammation response in both jejunal tissue and serum.In vivo validation established succinic acid as a key inflammatory mediator facilitating HFD-induced cross-organ communication between the jejunum and abdominal adipose tissue,enhancing intestinal lipid uptake and subsequent abdominal fat deposition.Bulk and single-nucleus RNA sequencing(snRNA-seq)revealed that HFD induced macrophage population expansion and intensified adipocyte-macrophage crosstalk.Adipocyte-macrophage co-culture systems further elucidated that macrophages are an indispensable factor in succinic acid-induced fat deposition.Conclusion This study delineates a succinic acid-driven"gut-fat axis"governing abdominal fat deposition in broilers,integrating gut microbiota dysbiosis and macrophage-mediated inflammatory adipogenesis.By identifying succinic acid as a cross-organ signaling molecule that enhances lipid absorption and activates macrophage-dependent adipogenesis,we establish systemic metabolic-immune crosstalk as a pivotal regulatory mechanism.These findings redefine fat deposition as a process extending beyond adipose-centric models,advancing multi-omics-guided strategies for sustainable poultry production.
文摘BaFe_(12)O_(19)(BaM)thin films with thicknesses ranging from 15 nm–200 nm were deposited on Al_(2)O_(3)(0001)substrates by pulsed laser deposition(PLD).X-ray diffraction patterns show that a buffer layer with a thickness of nearly 60 nm forms on the substrate,and then a c-axis perpendicularly oriented Ba M thin film grows on the buffer layer.Atomic force microscopy results indicate that the Ba M thin film exhibits a spiral island growth mode on the buffer layer.Magnetic hysteresis loop results confirm that the buffer layer exhibits no significant magnetic anisotropy,while the Ba M thin film exhibits perpendicular magnetic anisotropy.The out-of-plane coercivity decreases with increasing Ba M thin-film thickness due to the combined effect of grain size growth and lattice strain relaxation.The 200 nm thick film exhibits optimum magnetic properties with M_(s)=319 emu/cm^(3) and H_(c)=1546 Oe.
基金supported by the Earthquake Science and Technology Spark Plan Project(No.XH23041C)The Natural Science Foundation of Gansu Province(No.22JR11RA090)Gansu Lanzhou Geophysics National Observation and Research Station(No.2021Y14).
文摘The widely distributed loess deposits in the Yellow River Basin exhibit unique engineering geological characteristics.The variations in their thickness and stratigraphic structure significantly amplify ground motion parameters,directly influencing the regional seismic hazard risk level.This study methodically conducted on-site studies and observations of building collapses and damages resulting from seismic amplification effects,using the Wenchuan M_(S)8.0 earthquake as a case study.Comprehensive experimental and numerical simulation studies were carried out.A large-scale shaking table test was performed,and numerical models for 14 different loess sites types were established.Various types of seismic waves were incorporated into these models for systematic numerical simulation calculations.The research reveals the mechanisms by which loess deposit thickness and stratigraphic structure in the Yellow River Basin affect seismic ground motion amplification.The results indicate that as the epicentral distance increases,the peak ground motion shows a marked attenuation trend,with the horizontal component attenuating substantially faster than the vertical component.As the overlying loess layer thickness increases from 50 to 100 m,the seismic intensity may escalate by 3−4 degrees,and the peak acceleration may amplify by 1.5−2.2 times.With the augmentation of loess deposit thickness and the proliferation of soil layers,both the peak acceleration response spectrum and the characteristic period demonstrate an upward tendency,exhibiting slight fluctuations contingent upon the seismic wave type.
基金supported by the Original Exploratory Program of the National Natural Science Foundation of China(No.52450012)。
文摘TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing TiB_(2)coatings have disadvantages such as high equipment costs,complicated processes,and highly toxic gas emissions.This paper proposes an environmentally friendly method,which requires inexpensive equipment and simple processing,for preparing TiB_(2)coating on molybdenum via electrophoretic deposition within Na3AlF6-based molten salts.The produced TiB_(2)layer had an approximate thickness of 60μm and exhibited high density,outstanding hardness(38.2 GPa)and robust adhesion strength(51 N).Additionally,high-temperature oxidation experiments revealed that,at900℃,the TiB_(2)coating provided effective protection to the molybdenum substrate against oxidation for 3 h.This result indicates that the TiB_(2)coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.
基金financially supported by the National Natural Science Foundation of China (No.52372188)the 111 Project (No.D17007)2023 Introduction of studying abroad talent program。
文摘Aqueous zinc-ion batteries(AZIBs) have advantages including low economic cost and high safety.Nevertheless,the serious hydrogen evolution reactions(HER) and rampant growth of Zn dendrite hinder their further development.Herein,potassium acetate(KAc) additive with cation/anion synergy effect is added into the ZnSO_(4) electrolyte to effectively promote the oriented uniform Zn deposition and suppress side reactions.According to density functional theory calculation and experimental results,CH_(3)COO^(-)(Ac^(-))anions are capable of forming stronger hydrogen bonds with H_(2)O molecules,leading to an expanded electrochemical stability window,reduced the reactivity of H_(2)O,and hence suppressing HER.Meanwhile,Ac-anions can also preferentially adsorb onto the Zn anode,promoting dense deposition towards the(100) crystal plane.Besides,dissociated K^(+) ions serve as electrostatic shielding cations,which significantly promote uniform Zn deposition and prevent dendrite formation.Thus,the Zn||Zn symmetric cell demonstrates an impressive cycle lifespan of 3000 h at 1.0 m A/cm^(2).Furthermore,the Zn||MnO_(2) full battery exhibits superior stability with a capacity retention of 86.95 % at 2.0 A/g after 4000 cycles.Therefore,the cation/anion synergy effect in KAc additive offers a viable solution to address HER and hinder dendrite growth at the interface of Zn anodes.
基金supported by the National Natural Science Foundation of China(41872095,U1812402 and 42172082)the Research Startup Project(YJRC4201804)of Yunnan University to J.-X.Zhou.
文摘The giant Upper Yangtze Pb-Zn metallogenic province,also known as the Sichuan-Yunnan-Guizhou(SYG)Pb-Zn province hosting>500 carbonate-hosted epigenetic Pb-Zn deposits that contain>20 Mt Pb+Zn base metal reserves.The giant Maoping Pb-Zn deposit is the second largest deposit in this province and owns>5 Mt Pb+Zn metal reserves with ore grades of 12 wt.%-30 wt.%Pb+Zn.Such large tonnages and high grades make it among the top 100 similar mineral deposits in the world.The ore bodies are predominantly located within the strata of the Upper Devonian(Zaige Formation)and Lower(Baizuo Formation)-Upper(Weining Formation)Carboniferous.The principal ore minerals consist of galena(Gn),sphalerite(Sp),and pyrite(Py),while the primary gangue minerals include dolomite(Dol),calcite(Cal),and quartz(Qtz).Three mineralization stages of carbonate minerals have been identified:(1)pre-sulfide stage 1,(2)syn-sulfide stage 2,and(3)post-sulfide stage 3.Trace elements and C-O-Sr isotopes of three stages’carbonate minerals,together with S-Pb isotopes of sulfides,revealing that the metamorphic basement rocks played the role of the metal source during the early stage of Pb-Zn mineralization,whereas the metal contribution of the sedimentary wall rocks found to be more prominent during the late stage of Pb-Zn mineralization.In addition,the dissolution of marine carbonate rocks and CO_(2)degassing may have also played an important role in the formation of the Maoping deposit.Furthermore,syn-sulfide stage 2 calcite has a U-Pb age of 214±20 Ma obtained by LA-ICPMS in-situ analyses,suggesting that the hydrothermal mineralization occurred during the Triassic.Our study proposes a new coupled metallogenic model of fluid-structure-lithology assemblage and provides new insights about the formation and evolution of the Maoping deposit with significant implication for understanding and exploration of similar Pb-Zn deposits worldwide.
基金supported by Royal Academy of Engineering(IF2223B-125)Royal Society(IECR3213107)。
文摘Laser directed energy deposition(LDED)is an emerging branch of metal-based additive manufacturing(AM)processes,offering unprecedented capabilities for high-performance fabrication with complex geometries and near-net shapes.This technology is gathering increasing attention from industries such as biomedical,automotive,and aerospace.However,achieving consistent part quality and desired material properties is challenging due to intricate processing parameters and potential process defects such as dynamic melt-pool behavior and localized heat accumulation.This paper reviews recent advances in on-line quality control,focusing on in-situ measurement and closed-loop control for efficient assurance of LDED-fabricated parts.The quality principles,encompassing accuracy and material performance,are summarized to lay a foundation for understanding the mechanisms of quality defects and influencing factors.This review explores and thoroughly compares advancements in indirect process measurements,such as optical,thermal,and acoustic monitoring with direct quality measurements,including laser-line scanning and operando synchrotron X-ray imaging.Depending on the sensing techniques,this paper highlights a hierarchical control strategy for adaptive parameter regulation on intra-layer and inter-layer scales.The requirements and performance of various state-of-the-art controllers are critically compared to indicate their suitable applications.The importance of machine learning in detecting process anomalies and predicting build quality based on sensory signals is also outlined.Future directions are proposed towards adaptive,automated,and intelligent quality control,with a focus on multi-modal monitoring,physics-informed neural networks for interpretable analysis,and multi-objective control applications.
基金funded by the National Key Research&Development Program of China(No.2021YFC2900100)the Guangxi Natural Science Foundation(No.2022GXNSFFA035025)+3 种基金the Chinese National Natural Science Foundation(No.42372099)the China Geological Survey(No.DD20190379)the Science&Technology Fundamental Resources Investigation Program(No.2022FY101800)the Major Talent Program of Guangxi Zhuang Autonomous Region,and the Innovation Project of Guangxi Graduate Education(No.YCSW2023345)。
文摘Quartz vein-type tungsten deposits are a common W deposit type.Their ore vein distribution was previously considered to be controlled by regional horizontal tectonic stress.In this paper,14 tungsten deposits with fan-shaped mineralization in SE China are summarized,and the relations between their ore veins and granite and the ore-forming structural stress field are analyzed.These deposits have a post-magmatic hydrothermal genesis and involve the formation of two sets of veins with similar strike and opposite dips at the top of the ore-causative granite bodies,forming a vertical fan-shaped profile.Their ore veins were coeval with the underlying granite bodies,and generally extend along the long axis of the granite.In such fan-shaped ore formation,the stress is highly focused at the top of the granite and gradually weakens outward.The maximum principal stress(σ1)is perpendicular to the granite contact surface,and radiates outward from the pluton.Meanwhile,the minimum principal stress(σ3)forms an arc-shaped band parallel to the contact surface.Our findings,together with published numerical modeling indicate that the emplacement dynamics of granitic magma(rather than regional horizontal tectonic stress)are essential controls on the distribution of ore veins in quartz vein-type tungsten deposits.
