A gradient structure was introduced into a metal laminated target plate,and the anti-penetration simulation of the gradient structure was compared with that of a uniform-layer-thickness target plate by finite element ...A gradient structure was introduced into a metal laminated target plate,and the anti-penetration simulation of the gradient structure was compared with that of a uniform-layer-thickness target plate by finite element simulation.The analysis was verified by an impact experiment.Results show that the high-level thickness and appropriate percentage of Ti alloy at the upper side of the gradient structure provide greater impact resistance against the bullet,which increases the warhead breakage and enhances the anti-penetration performance.In addition,during the impact process,the stress is transmitted and reflected in the form of waves in each layer of the target plate,and the interaction between the compression and tension waves causes non-synergistic deformation of the target plate and leads to delamination.The gradient target plate takes penetration resistance a step further through the higher energy absorption rate and more consumption of the bullet kinetic energy.This research provides a theoretical basis for the application of gradient structures in metallic laminated armor.展开更多
Optical phase-gradient metasurfaces have garnered significant attention for enabling flexible light manipulation,with applications across diverse domains.In this work,we will demonstrate that the metasurfaces with pha...Optical phase-gradient metasurfaces have garnered significant attention for enabling flexible light manipulation,with applications across diverse domains.In this work,we will demonstrate that the metasurfaces with phase gradient modulation can be used to achieve illusion optics,featuring the advantages of simple geometric structure and feasible implementation compared with the well-known transformation optics method.The underlying mechanism is the anomalous diffraction law caused by the phase gradient,which provides a theoretical basis for freely manipulating the propagation path of light.By considering a specific example,we will demonstrate that the phase gradient can transform spatial coordinates in real space into illusion space,thereby converting a plane in real space into a curved surface structure in illusion space to achieve the illusion effect.This approach provides a viable alternative to transformation optics for designing illusion devices.展开更多
Recycling spent lithium-ion(Li+)batteries is critical for achieving environmental conservation and the strategic recovery of essential resources.Compared with conventional methods for recovering cathode materials,whic...Recycling spent lithium-ion(Li+)batteries is critical for achieving environmental conservation and the strategic recovery of essential resources.Compared with conventional methods for recovering cathode materials,which are energy-intensive and prone to secondary pollution,the direct regeneration approach has emerged as a rapid and highly efficient method,gaining widespread attention in recent years.However,this approach faces major challenges,including degraded electrochemical performances and limited economic value.This study,therefore,proposes a high-value direct regeneration strategy to convert degraded spent LiFePO_(4)(S-LFP)into a gradient manganese(Mn)-doped regenerated LiFe_(0.7)Mn_(0.3)PO_(4)/C(R-LFMP)composite.This method leverages the inherent microcracks and Li vacancies present in S-LFP,likely acting as diffusion channels for the Mn^(2+)/Li^(+)ions.Through a two-step mechanochemical ball-milling and carbothermal reduction process,this approach achieves simultaneous Li replenishment and surface-localised Mn gradient doping with enhanced structural control.Notably,the R-LFMP exhibits an exceptional electrochemical performance.At 0.1 C,it delivers a discharge capacity of 161.4 mA h g^(−1)and an energy density of 563.5 Wh kg^(−1)(representing a 60.5%improvement over S-LFP).Additionally,it maintains 83%capacity retention after 900 cycles at 0.5C,a considerable enhancement compared to commercial LFMP(62%).Furthermore,the regenerated cathode material generates a net profit of$7.102 kg^(−1),surpassing the profitability of conventional recycling methods by 90%.Overall,this study introduces a transformative and sustainable LFP regeneration technology,achieving breakthroughs in electrochemical restoration and high-value recycling,while paving the way for the closed-loop utilisation of LFP-based energy storage systems.展开更多
Dear Editor,Mountain systems have long been refuges for many species,often viewed as"islands"that promote speciation due to geographic isolation(Rahbek et al.,2019).Their high environmental heterogeneity fos...Dear Editor,Mountain systems have long been refuges for many species,often viewed as"islands"that promote speciation due to geographic isolation(Rahbek et al.,2019).Their high environmental heterogeneity fosters centers of endemism,and they harbor over 85%of global species diversity(Zhao et al.,2022).Consequently,mountains are key systems for exploring biodiversity patterns along elevational gradients,where species richness often follows four recognized models:monotonic decrease,unimodal pattern(forward and backward peak patterns),and low plateau followed by a decrease along the elevational gradient(McCain et al.,2010).展开更多
Lichens exhibit exceptional ecological adaptability,thriving in diverse habitats ranging from temperate forests to extreme environments.They colonize various substrates,including tree bark,rocks,soil,and artificial su...Lichens exhibit exceptional ecological adaptability,thriving in diverse habitats ranging from temperate forests to extreme environments.They colonize various substrates,including tree bark,rocks,soil,and artificial surfaces,playing critical roles as bioindicators of air quality and environmental change.Despite their ecological and economic importance,regions like Pakistan remain underexplored for lichen diversity,leaving significant gaps in knowledge about local lichen flora.This study hypothesizes that the ecological diversity and environmental gradients in the Hazara Division,Khyber Pakhtunkhwa,significantly influence the distribution,composition,and community structure of lichens.Field surveys were conducted from March 2021 to December 2023 across 48 locations in the Hazara Division,covering diverse altitudes,aspects,and vegetation types.Epiphytic lichens were sampled using standardized transect methods with vertical grids on tree stems.Specimens were collected,shade-dried,and identified using chemical spot tests.Multivariate analyses,including TWINSPAN,CCA,and DCA,were employed to examine species-environment relationships.A total of 97 lichen species were identified across 44 genera and 19 families.Physciaceae was the dominant family(24 species).Foliose lichens represented 55%of the total species,highlighting morphological diversity.Among the recorded species,11 were new to Pakistan,and 30 were newly documented for the Himalayan region of Hazara.The study documented 52 host tree species across 36 genera,with Quercus being the most dominant genus.Multivariate analyses identified seven distinct lichen communities.Altitude and road distance emerged as the strongest drivers of lichen distribution,with specific species exhibiting distinct responses to environmental gradients.In DCA ordination the Eigen value was maximum for axis 1,(0.67)followed by axis 2(0.56).The maximum gradients was 5.87 recorded axis 1.Canonical Correspondence Analysis captured 15.09%of the total variation,with significant contributions from altitude,temperature,and substrate type.The per mutation result for all axis were pseudo(F=1.1,P=0.01).The result showed that species,stand and environmental variables were in linear combination with each other.This study provides the first comprehensive assessment of lichen diversity and ecology in the Hazara Division,unveiling significant species-environment relationships and ecological patterns.The findings underscore the importance of multivariate analysis in lichen studies and highlight the region's potential for further ecological and conservation research.展开更多
Urbanization has profoundly reshaped biodiversity,yet its impacts on community seasonal changes remain poorly understood.Here,we used citizen science data from 839 bird species in 37 cities and their corresponding rur...Urbanization has profoundly reshaped biodiversity,yet its impacts on community seasonal changes remain poorly understood.Here,we used citizen science data from 839 bird species in 37 cities and their corresponding rural areas in China to assess how urbanization alters seasonal changes in bird communities.We calculated Sørensen beta dissimilarity indices(β_(sor))between seasons to compare the seasonality of communities in urban and rural areas and decomposed these indices into turnover(β_(sim))and nestedness(β_(nes))components.We evaluated whether there are differences in the latitudinal clines in community seasonality between urban and rural areas,and explored whether environmental and socio-economic factors affect the urbanization-driven changes in community seasonality.Our results show that the overall seasonalβ_(sor)in urban communities was 16.2%higher than in rural areas,due to a 49.5%increase inβ_(nes)(urban:0.22±0.12 vs.rural:0.15±0.08),but there was no significant difference inβ_(sim).In rural areas,β_(sor)increased with latitude,butβ_(sor)showed no latitudinal trend in urban communities.Human population emerges as a key predictor of urbanization-driven changes in the species turnover and nestedness components,with larger cities showing lower species turnover but higher nestedness components.We conclude that urbanization alters the seasonality of bird communities through nestedness components,decouples the relationship between community seasonality and latitude,and concentrates its impacts in densely populated cities.Future research must employ long-term monitoring to track how urbanization changes bird communities in space and time.展开更多
Suffusion refers to the loss of fineparticles within the soil matrix without any associated volume change,induced by hydrodynamic forces.This study investigated the suffusion of sand-clay mixtures through one-dimensio...Suffusion refers to the loss of fineparticles within the soil matrix without any associated volume change,induced by hydrodynamic forces.This study investigated the suffusion of sand-clay mixtures through one-dimensional soil column experiments under a stepwise increase in hydraulic gradient(i),aiming to evaluate the critical hydraulic gradient(icrit)as a function of the size ratio between sand and clay,clay type,and ionic concentration.It was found that icrit was less than 0.1 for all sand-clay mixtures examined in this study.In addition,the lower peak concentrations of filtrated clay observed in sand-illite mixtures,compared to those of sand-kaolinite mixtures at the same level of i,suggest that illite particles are more susceptible to suffusion.Overall,the observed breakthrough curves,mass fraction of filtrated clay,volume of outflow,and total injection time presented in this study highlight the importance of considering clay type,sand-to-clay size ratio,and ionic concentration when assessing the suffusion behavior of clay-containing soils under a stepwise increase in hydraulic gradient.展开更多
Wetlands are vital ecosystems that perform essential functions such as climate regulation,environmental purification,material circulation and energy flow.They play an essential role in global biogeochemical cycles,dri...Wetlands are vital ecosystems that perform essential functions such as climate regulation,environmental purification,material circulation and energy flow.They play an essential role in global biogeochemical cycles,driven primarily by microorganisms.Understanding the distribution of wetland microorganisms across different temperature zones is key to comprehending their ecological roles.A meta-analysis of 704 wetland soil samples on microbial communities was conducted,using statistical methods like analysis of variance,principal component analysis,non-metric nultidimensional scaling,and structural equation modeling to examine biogeography and diversity across temperature zones.Our findings revealed a clear latitudinal diversity gradient pattern,with the highest microbial abundance in the tropics and the lowest in the southern temperate zone,which differed significantly from other temperature zones.Proteobacteria(37.76%-51.04%),Acidobacteria(5.11%-30.70%)and Bacteroidetes(3.43%-16.16%)dominanted the bacterial communities.Notably,the southern temperate zone showed significant variations,with a higher prevalence of Acidobacteria(30.07%).To investigate the causes of this variability,we screened 177 core microbiome and identified latitude as the core environmental factor influencing microbial community composition.Moreover,soil microorganisms exhibited strong nitrogen cycling potentials(particularly nirD and nirB)and carbon cycling potentials(especially accA),with gene abundances showing little variation across temperature zones.Wetland bacterial communities also demonstrated high stability,with average variation degree index values ranging from 0.1 to 0.3.Our results improve the understanding of the diversity and biogeographic mechanisms of wetland bacterial communities and hold significant implications for the management and conservation of wetlands.展开更多
The Qaidam Basin,a typical alpine arid inland basin on the northern Qinghai-Xizang Plateau,China,hosts wetland ecosystems that are strongly constrained by topography and extreme climate.These ecosystems exhibit pronou...The Qaidam Basin,a typical alpine arid inland basin on the northern Qinghai-Xizang Plateau,China,hosts wetland ecosystems that are strongly constrained by topography and extreme climate.These ecosystems exhibit pronounced spatiotemporal heterogeneity and fragmented distribution patterns,rendering them highly sensitive to environmental change.This study integrated Sentinel-2 remote sensing imagery with the SedInConnect model to delineate wetland patch distributions and calculate the Index of Connectivity(IC)values across the basin.Based on IC values,we stratified field sampling sites into high-,moderate-,and lowconnectivity gradient groups to analyze the relationships among plant community characteristics,vegetation spatial patterns,and wetland connectivity in the Qaidam Basin.Partial Least Squares Path Modeling(PLSPM)was further employed to quantify the driving mechanisms underlying wetland vegetation characteristics.The results revealed that wetland connectivity across the basin was generally low,with IC values up to 1.32 and displaying a west-to-east decreasing gradient.The west and northwest were characterized by relatively continuous high-connectivity wetland networks,while fragmented and low-connectivity wetlands predominated in the east and southeast.Connectivity regulated wetland vegetation patterns primarily by affecting patch size,fragmentation,and internal adjacency.High-connectivity areas had higher class area(CA),largest patch index(LPI),and area-weighted mean patch size(AREA_AM)than low-connectivity areas.Connectivity had the strongest effect on vegetation coverage,which declined sharply from 87.577%in highconnectivity areas to 12.152%in low-connectivity areas.Meanwhile,species diversity showed a moderately negative response to connectivity changes,whereas species evenness remained relatively unaffected.PLS-PM explained 78.300%and 67.500%of the variance in vegetation community and vegetation pattern,respectively.Climate played a dominant role in shaping vegetation characteristics,with significant negative effects on both vegetation community and pattern.Topography influenced vegetation indirectly through climate,and connectivity was influenced by both drivers and exerted positive effects on vegetation community and pattern.This study reveals the multi-pathway driving mechanisms underlying vegetation pattern formation in alpine wetlands,providing a theoretical foundation and decision-support framework for the scientific conservation and adaptive management of wetlands in the Qaidam Basin.展开更多
Transformer models face significant computational challenges in private inference(PI).Existing optimization methods often rely on isolated techniques,neglecting joint structural and operational improvements.We propose...Transformer models face significant computational challenges in private inference(PI).Existing optimization methods often rely on isolated techniques,neglecting joint structural and operational improvements.We propose IG-3D,a unified framework that integrates structured compression and operator approximation through accurate importance assessment.Our approach first evaluates attention head importance using Integrated Gradients(IG),offering greater stability and theoretical soundness than gradient-based methods.We then apply a threedimensional optimization:(1)structurally pruning redundant attention heads;(2)replacing Softmax with adaptive polynomial approximation to avoid exponential computations;(3)implementing layer-wise GELU substitution to accommodate different layer characteristics.A joint thresholdmechanism coordinates compression across dimensions under accuracy constraints.Experimental results on the GLUE benchmark show that our method achieves an average 2.9×speedup in inference latency and a 50%reduction in communication cost,while controlling the accuracy loss within 2.3%,demonstrating significant synergistic effects and a superior accuracy-efficiency trade-off compared to single-technique optimization strategies.展开更多
Anammox bacteria in constructed wetlands(CWs)play pivotal role in sustainable nitrogen transformation,yet existing studies lack comprehensive analysis of environmental gradients and microbial interactions,both key fac...Anammox bacteria in constructed wetlands(CWs)play pivotal role in sustainable nitrogen transformation,yet existing studies lack comprehensive analysis of environmental gradients and microbial interactions,both key factors in anammox bacteria enrichment.This study investigated the mechanisms driving anammox bacteria enrichment in lab-scale simulated CWs treating high-nitrogen wastewater,focusing on bacterial community re-sponses across wetland layers with various strategies,including continuous up-flow influent,nitrogen loading increase,effluent recirculation,intermittent influent,and anammox bacteria inoculation.Results showed that total relative and absolute abundances of anammox bacteria ranged from 0.77%to 12.50%and from 0.13 to 6.46×10^(7) copies/g,respectively.Dissolved oxygen and pH had significant positive correlations with the absolute abundance of anammox bacteria,while organic matter and nitrate negatively impacted their relative abundance.Permutational multivariate analysis of variance indicated that spatial heterogeneity explained more variation in anammox bacteria abundance(43.44%)compared to operational strategies(8.58%).In terms of microbial interactions,60 dominant species exhibited potential correlations with anammox bacteria,comprising 170 interactions(105 positive and 65 negative),which suggested that anammox bacteria generally foster cooperative relationships with dominant bacteria.Notably,significant interspecies interactions were observed between Candidatus Kuenenia(dominant anammox bacteria in CWs)and species within the genera Chitinivibrio-nia and Anaerolineaceae,suggesting that microbial interactions primarily manifest as indirect facilitative effects rather than direct mutualistic relationships.Given that the Normalized Stochasticity Ratio in CWs were<50%,this study inferred that environmental gradients have greater influence on anammox bacteria than microbial interactions.展开更多
Mountain ecosystems offer natural gradients for exploring biodiversity patterns;however,the elevational patterns of plant species and phylogenetic diversity in the eastern Pamir Plateau remain poorly understood.As a b...Mountain ecosystems offer natural gradients for exploring biodiversity patterns;however,the elevational patterns of plant species and phylogenetic diversity in the eastern Pamir Plateau remain poorly understood.As a biogeographical junction of the Central Asian mountain ranges,the eastern Pamir Plateau in China is geographically connected to the main part of the Pamir Plateau in Tajikistan,resulting in significant climatic and topographical heterogeneity and unique regional vegetation communities.In this study,we established 5 elevational transects and 91 plots (1500–4870 m) in the eastern Pamir Plateau to investigate the patterns and environmental drivers of plant diversity at both regional and local spatial scales.We examined diversity patterns and community composition using regression models and community structure analysis and quantified the relative importance of environmental factors using a random forest model.The results showed a distinct differentiation along elevation gradients,with overall plant diversity,herbaceous plant diversity,and phylogenetic diversity index increasing with elevation,whereas woody plant diversity declined.The phylogenetic structure indices (including net relatedness index and nearest taxon index) exhibited heterogeneous elevational responses,indicating that community assembly was jointly driven by environmental filtering and niche differentiation.Soil nutrients,water availability,and temperature were the primary environmental drivers,with soil factors predominantly influencing herbaceous plant diversity,while climatic variables dominated woody plant diversity.These findings demonstrate that plant diversity along elevational gradients of the eastern Pamir Plateau exhibits the characteristic patterns of a unique arid mountain ecosystem,where enhanced soil fertility and moderate moisture at higher elevations partly offset energy limitations,thereby maintaining plant diversity through functional convergence of closely related lineages.This pattern of biodiversity maintenance contrasts with the divergence-driven community assembly processes commonly observed in humid mountain systems.Overall,this study contributes to a better understanding of biodiversity maintenance in the eastern Pamir Plateau.Given its geographical continuity with the Pamir Plateau in Tajikistan,our findings can provide a basis for alpine conservation efforts across arid Central Asia.展开更多
The paleo-geothermal gradient is a crucial parameter for converting the thermal history to the exhumation history.However,the precise estimation of this parameter has been a challenge.This paper presents a simple two-...The paleo-geothermal gradient is a crucial parameter for converting the thermal history to the exhumation history.However,the precise estimation of this parameter has been a challenge.This paper presents a simple two-step method to model the paleo-geothermal gradient using low-temperature thermochronology.(1)It uses the Monte Carlo approach to generate thermal histories in a vertical section randomly and calculates the entire thermal history within the goodnessof-fit thresholds based on different paleo-geothermal gradients.(2)It selects the optimum paleogeothermal gradient by comparing the entire thermal history within different goodness-of-fit thresholds.We validated the method with apatite(U-Th)/He and fission track data collected from two drill cores in the Haiyuan-Liupanshan region.The result revealed that the best-fit paleo-geothermal gradient was~42℃/km during the Early Cretaceous–Miocene and has decreased rapidly to 20℃/km since~10 Ma.The crust thickening in the study area may explain the rapid reduction in the paleogeothermal gradient since~10 Ma.Our results are consistent with earlier studies in the region,suggesting that our simple and more intuitive approach provides an alternative method for paleogeothermal gradient modeling.展开更多
In this study,an architecture featuring a gradient conductive network structure and three-dimensional dual-continuous network structure is constructed in a carbon nanotubes/cellulose-boron nitride/poly(vinyl alcohol)(...In this study,an architecture featuring a gradient conductive network structure and three-dimensional dual-continuous network structure is constructed in a carbon nanotubes/cellulose-boron nitride/poly(vinyl alcohol)(CNT/cellulose-BN/PVA)composite.Using cellulose aerogel as a template,CNT were incorporated into the cellulose template by vertically impregnating the CNT suspension.Following the impregnation of BN/PVA and high-pressure compression,three-dimensional dual-continuous network structure was successfully constructed in the CNT/cellulose-BN/PVA composite.The comprehensive performance of the composite,including electromagnetic interference(EMI)shielding and Joule heating performance,was investigated.The results indicate that the total EMI shielding effectiveness(SE)for the CNT/cellulose-BN/PVA composite reveals similar values for electromagnetic waves incident from different directions,but totally different shielding mechanisms.For the CNT/cellulose-BN/PVA composite with three impregnation cycles of CNT,the EMI SE values exceeded 39 dB for electromagnetic waves incident from both the high-and low-CNT-content sides.93%of the microwaves were reflected when electromagnetic waves were incident from the high-CNT-content side,while the reflection coefficient decreased to 0.44 for the transverse direction.In addition,the construction of the dual-continuous network structure enabled the composite to exhibit both excellent electrical conductivity and good thermal conductivity simultaneously,endowing the material with good Joule heating performance.CNT/cellulose-BN/PVA composite films have significant potential for application as EMI shielding materials in extremely cold weather.展开更多
Prevention of biological invasion requires understanding how alien species invade native communities.Although studies have identified mechanisms that underlie plant invasion in some habitats,limited attention has focu...Prevention of biological invasion requires understanding how alien species invade native communities.Although studies have identified mechanisms that underlie plant invasion in some habitats,limited attention has focused on invasion patterns along elevational gradients.In this study,we asked which factors drive the global and regional distribution of the invasive plant Galinsoga quadriradiata along elevational gradients.To answer this question,we examined whether human activities(i.e.,roads)promote G.quadriradiata invasion,how seed dispersal-related traits of G.quadriradiata change along elevation gradients,and whether G.quadriradiata has adapted to high-elevation environments through phenotypic plasticity or genetic variation.On the global scale,we found that human activities and road density positively contribute to the G.quadriradiata expansion in mountainous areas.Field surveys in China revealed significant elevational differences in the seed dispersal traits of G.quadriradiata,with higher-elevation populations exhibiting lower dispersal ability and generally lower genetic diversity.Under common conditions,high-elevation populations showed higher leaf mass ratio but lower root mass ratio and reproductive allocation.This suggests that high-elevation environments create a barrier to dispersal for G.quadriradiata,and that G.quadriradiata has adapted phenotypically to these conditions.Our study indicates that the elevational invasion pattern of G.quadriradiata is shaped by multiple factors,particularly human activities and phenotypic adaptability.In addition,our finding that G.quadriradiata invasion at high elevations is not constrained by low genetic diversity indicates that monitoring and management of G.quadriradiata in mountainous areas should be strengthened.展开更多
Selective extraction of precious metals from urban mines plays a crucial role in mitigating the risk of depletion of precious metal resources and reducing waste pollution.However,a major obstacle in precious metal ext...Selective extraction of precious metals from urban mines plays a crucial role in mitigating the risk of depletion of precious metal resources and reducing waste pollution.However,a major obstacle in precious metal extraction lies in the difficulty of distinguishing the subtle differences in the physicochemical characteristics between them,especially gold and palladium.Herein,a proton-driven separation system was presented for cascade recovery of gold and palladium from waste-printed circuit boards(W-PCBs)leachate using poly(amidoxime)(PAO)hydrogel.This exhibits an ultra-high capacity,extra-fast rate,and excellent selectivity for the extraction of Au(Ⅲ)and Pd(Ⅱ).Notably,the separation of Au(Ⅲ)and Pd(Ⅱ)can be achieved with high selectivity at pH=0,resulting in a remarkable separation factor of k_(Au(Ⅲ)/Pd(Ⅱ))=36.5.This was demonstrated to originate from the differential mechanism of PAO hydrogel for the capture of Au(Ⅲ)and Pd(Ⅱ)under proton-mediated conditions.Drawing inspiration from the mechanism,the proton-driven cascade recovery system demonstrates remarkable efficiency in sequentially recovering 99.92%of gold and 99.05%of palladium from W-PCBs acid leachate.This research opens up a strategy to precisely separate and recover precious metals from e-waste of urban mines.展开更多
In this paper,our main goal is to study a new mathematical model which describes the frictional contact between a foundation and a deformable body which is composed of viscoplastic materials and where the process is c...In this paper,our main goal is to study a new mathematical model which describes the frictional contact between a foundation and a deformable body which is composed of viscoplastic materials and where the process is considered dynamic.The contact condition on the normal plane is modeled by a unilateral constraint condition for a version of normal velocity in which the memory effect and the adhesion are considered.On the tangential plane a frictional contact condition is governed by the Clarke subdifferential of a locally Lipschitz function,and the evolution of the bonding field is governed by an ordinary differential equation.We formulate this problem as coupled system that consists of two ordinary differential equations and a variational-hemivariational inequality.Then,the existence,uniqueness and continuous dependence of the solution on the data results concerning the abstract system are established.Finally,we use the abstract results to show the existence and uniqueness of the solution to the contact problem.展开更多
A three-dimensional(3D)electromagnetic(EM)inversion algorithm based on the nonlinear conjugate gradient(NLCG)method and a two-color plane Gauss-Seidel(GS)multigrid(MG)forward solver is developed to improve inversion e...A three-dimensional(3D)electromagnetic(EM)inversion algorithm based on the nonlinear conjugate gradient(NLCG)method and a two-color plane Gauss-Seidel(GS)multigrid(MG)forward solver is developed to improve inversion efficiency.The results indicate that the computational efficiency of each inversion can be improved by approximately a factor of three by using the proposed MG solver.First,the accuracy of the MG solver is validated through a test on a synthetic model.Next,the numerical performance of the inversion algorithm is evaluated using this model.Finally,the inversion algorithm is applied to a field EM data collected at the Beiya gold polymetallic ore district.A 3D resistivity model is obtained,and the formation process of the metal ore is analyzed.展开更多
基金National Defense Basic Scientific Research Program of China(JCKY2020408B002,WDZC2022-12)Key Research and Development Program of Shanxi Province(202102050201011,202202050201014)Fundamental Research Program of Shanxi Province(20210302124178,20210302123061,202103021224183)。
文摘A gradient structure was introduced into a metal laminated target plate,and the anti-penetration simulation of the gradient structure was compared with that of a uniform-layer-thickness target plate by finite element simulation.The analysis was verified by an impact experiment.Results show that the high-level thickness and appropriate percentage of Ti alloy at the upper side of the gradient structure provide greater impact resistance against the bullet,which increases the warhead breakage and enhances the anti-penetration performance.In addition,during the impact process,the stress is transmitted and reflected in the form of waves in each layer of the target plate,and the interaction between the compression and tension waves causes non-synergistic deformation of the target plate and leads to delamination.The gradient target plate takes penetration resistance a step further through the higher energy absorption rate and more consumption of the bullet kinetic energy.This research provides a theoretical basis for the application of gradient structures in metallic laminated armor.
基金supported by the National Natural Science Foundation of China (Grant Nos.12274313 and 62375234)the Gusu Leading Talent Plan for Scientific and Technological Innovation and Entrepreneurship (Grant No.ZXL2024400)。
文摘Optical phase-gradient metasurfaces have garnered significant attention for enabling flexible light manipulation,with applications across diverse domains.In this work,we will demonstrate that the metasurfaces with phase gradient modulation can be used to achieve illusion optics,featuring the advantages of simple geometric structure and feasible implementation compared with the well-known transformation optics method.The underlying mechanism is the anomalous diffraction law caused by the phase gradient,which provides a theoretical basis for freely manipulating the propagation path of light.By considering a specific example,we will demonstrate that the phase gradient can transform spatial coordinates in real space into illusion space,thereby converting a plane in real space into a curved surface structure in illusion space to achieve the illusion effect.This approach provides a viable alternative to transformation optics for designing illusion devices.
基金supported by the National Key Research and Development Program of China(2023YFB3809300).
文摘Recycling spent lithium-ion(Li+)batteries is critical for achieving environmental conservation and the strategic recovery of essential resources.Compared with conventional methods for recovering cathode materials,which are energy-intensive and prone to secondary pollution,the direct regeneration approach has emerged as a rapid and highly efficient method,gaining widespread attention in recent years.However,this approach faces major challenges,including degraded electrochemical performances and limited economic value.This study,therefore,proposes a high-value direct regeneration strategy to convert degraded spent LiFePO_(4)(S-LFP)into a gradient manganese(Mn)-doped regenerated LiFe_(0.7)Mn_(0.3)PO_(4)/C(R-LFMP)composite.This method leverages the inherent microcracks and Li vacancies present in S-LFP,likely acting as diffusion channels for the Mn^(2+)/Li^(+)ions.Through a two-step mechanochemical ball-milling and carbothermal reduction process,this approach achieves simultaneous Li replenishment and surface-localised Mn gradient doping with enhanced structural control.Notably,the R-LFMP exhibits an exceptional electrochemical performance.At 0.1 C,it delivers a discharge capacity of 161.4 mA h g^(−1)and an energy density of 563.5 Wh kg^(−1)(representing a 60.5%improvement over S-LFP).Additionally,it maintains 83%capacity retention after 900 cycles at 0.5C,a considerable enhancement compared to commercial LFMP(62%).Furthermore,the regenerated cathode material generates a net profit of$7.102 kg^(−1),surpassing the profitability of conventional recycling methods by 90%.Overall,this study introduces a transformative and sustainable LFP regeneration technology,achieving breakthroughs in electrochemical restoration and high-value recycling,while paving the way for the closed-loop utilisation of LFP-based energy storage systems.
基金supported by grants from the National Natural Science Foundation of China(Grant No.32360333)the Guizhou Provincial Science and Technology Projects(Grant Nos.ZK[2022]540 and[2023]099)+1 种基金the Survey of Amphibian and Reptile Resources in Leigongshan National Nature Reserve and Literature Publishing Services(P5226002023000019)the Guizhou Provincial Science and Technology Innovation Talent Team Construction Project 2024[Qian Ke He Talent CXTD(2025)053].
文摘Dear Editor,Mountain systems have long been refuges for many species,often viewed as"islands"that promote speciation due to geographic isolation(Rahbek et al.,2019).Their high environmental heterogeneity fosters centers of endemism,and they harbor over 85%of global species diversity(Zhao et al.,2022).Consequently,mountains are key systems for exploring biodiversity patterns along elevational gradients,where species richness often follows four recognized models:monotonic decrease,unimodal pattern(forward and backward peak patterns),and low plateau followed by a decrease along the elevational gradient(McCain et al.,2010).
文摘Lichens exhibit exceptional ecological adaptability,thriving in diverse habitats ranging from temperate forests to extreme environments.They colonize various substrates,including tree bark,rocks,soil,and artificial surfaces,playing critical roles as bioindicators of air quality and environmental change.Despite their ecological and economic importance,regions like Pakistan remain underexplored for lichen diversity,leaving significant gaps in knowledge about local lichen flora.This study hypothesizes that the ecological diversity and environmental gradients in the Hazara Division,Khyber Pakhtunkhwa,significantly influence the distribution,composition,and community structure of lichens.Field surveys were conducted from March 2021 to December 2023 across 48 locations in the Hazara Division,covering diverse altitudes,aspects,and vegetation types.Epiphytic lichens were sampled using standardized transect methods with vertical grids on tree stems.Specimens were collected,shade-dried,and identified using chemical spot tests.Multivariate analyses,including TWINSPAN,CCA,and DCA,were employed to examine species-environment relationships.A total of 97 lichen species were identified across 44 genera and 19 families.Physciaceae was the dominant family(24 species).Foliose lichens represented 55%of the total species,highlighting morphological diversity.Among the recorded species,11 were new to Pakistan,and 30 were newly documented for the Himalayan region of Hazara.The study documented 52 host tree species across 36 genera,with Quercus being the most dominant genus.Multivariate analyses identified seven distinct lichen communities.Altitude and road distance emerged as the strongest drivers of lichen distribution,with specific species exhibiting distinct responses to environmental gradients.In DCA ordination the Eigen value was maximum for axis 1,(0.67)followed by axis 2(0.56).The maximum gradients was 5.87 recorded axis 1.Canonical Correspondence Analysis captured 15.09%of the total variation,with significant contributions from altitude,temperature,and substrate type.The per mutation result for all axis were pseudo(F=1.1,P=0.01).The result showed that species,stand and environmental variables were in linear combination with each other.This study provides the first comprehensive assessment of lichen diversity and ecology in the Hazara Division,unveiling significant species-environment relationships and ecological patterns.The findings underscore the importance of multivariate analysis in lichen studies and highlight the region's potential for further ecological and conservation research.
基金supported by the National Natural Science Foundation of China(Grant No.32271733)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2023A1515011045)。
文摘Urbanization has profoundly reshaped biodiversity,yet its impacts on community seasonal changes remain poorly understood.Here,we used citizen science data from 839 bird species in 37 cities and their corresponding rural areas in China to assess how urbanization alters seasonal changes in bird communities.We calculated Sørensen beta dissimilarity indices(β_(sor))between seasons to compare the seasonality of communities in urban and rural areas and decomposed these indices into turnover(β_(sim))and nestedness(β_(nes))components.We evaluated whether there are differences in the latitudinal clines in community seasonality between urban and rural areas,and explored whether environmental and socio-economic factors affect the urbanization-driven changes in community seasonality.Our results show that the overall seasonalβ_(sor)in urban communities was 16.2%higher than in rural areas,due to a 49.5%increase inβ_(nes)(urban:0.22±0.12 vs.rural:0.15±0.08),but there was no significant difference inβ_(sim).In rural areas,β_(sor)increased with latitude,butβ_(sor)showed no latitudinal trend in urban communities.Human population emerges as a key predictor of urbanization-driven changes in the species turnover and nestedness components,with larger cities showing lower species turnover but higher nestedness components.We conclude that urbanization alters the seasonality of bird communities through nestedness components,decouples the relationship between community seasonality and latitude,and concentrates its impacts in densely populated cities.Future research must employ long-term monitoring to track how urbanization changes bird communities in space and time.
基金supported by the National Research Foundation of Korea(NRF)grants(Grant Nos.RS-2020-NR049594 and RS-2022-NR071877)the Korea Agency for Infrastructure Technology Advancement under the Ministry of Land,Infrastructure and Transport(Grant No.RS-2024-00410248).
文摘Suffusion refers to the loss of fineparticles within the soil matrix without any associated volume change,induced by hydrodynamic forces.This study investigated the suffusion of sand-clay mixtures through one-dimensional soil column experiments under a stepwise increase in hydraulic gradient(i),aiming to evaluate the critical hydraulic gradient(icrit)as a function of the size ratio between sand and clay,clay type,and ionic concentration.It was found that icrit was less than 0.1 for all sand-clay mixtures examined in this study.In addition,the lower peak concentrations of filtrated clay observed in sand-illite mixtures,compared to those of sand-kaolinite mixtures at the same level of i,suggest that illite particles are more susceptible to suffusion.Overall,the observed breakthrough curves,mass fraction of filtrated clay,volume of outflow,and total injection time presented in this study highlight the importance of considering clay type,sand-to-clay size ratio,and ionic concentration when assessing the suffusion behavior of clay-containing soils under a stepwise increase in hydraulic gradient.
基金supported by the National Natural Science Foundation of China(No.52070019).
文摘Wetlands are vital ecosystems that perform essential functions such as climate regulation,environmental purification,material circulation and energy flow.They play an essential role in global biogeochemical cycles,driven primarily by microorganisms.Understanding the distribution of wetland microorganisms across different temperature zones is key to comprehending their ecological roles.A meta-analysis of 704 wetland soil samples on microbial communities was conducted,using statistical methods like analysis of variance,principal component analysis,non-metric nultidimensional scaling,and structural equation modeling to examine biogeography and diversity across temperature zones.Our findings revealed a clear latitudinal diversity gradient pattern,with the highest microbial abundance in the tropics and the lowest in the southern temperate zone,which differed significantly from other temperature zones.Proteobacteria(37.76%-51.04%),Acidobacteria(5.11%-30.70%)and Bacteroidetes(3.43%-16.16%)dominanted the bacterial communities.Notably,the southern temperate zone showed significant variations,with a higher prevalence of Acidobacteria(30.07%).To investigate the causes of this variability,we screened 177 core microbiome and identified latitude as the core environmental factor influencing microbial community composition.Moreover,soil microorganisms exhibited strong nitrogen cycling potentials(particularly nirD and nirB)and carbon cycling potentials(especially accA),with gene abundances showing little variation across temperature zones.Wetland bacterial communities also demonstrated high stability,with average variation degree index values ranging from 0.1 to 0.3.Our results improve the understanding of the diversity and biogeographic mechanisms of wetland bacterial communities and hold significant implications for the management and conservation of wetlands.
基金funded by the National Natural Science Foundation of China(42230720)the 2023 Annual Qinghai Province"Kunlun Talents-High-end Innovation and Entrepreneurship Talent"Program Project.
文摘The Qaidam Basin,a typical alpine arid inland basin on the northern Qinghai-Xizang Plateau,China,hosts wetland ecosystems that are strongly constrained by topography and extreme climate.These ecosystems exhibit pronounced spatiotemporal heterogeneity and fragmented distribution patterns,rendering them highly sensitive to environmental change.This study integrated Sentinel-2 remote sensing imagery with the SedInConnect model to delineate wetland patch distributions and calculate the Index of Connectivity(IC)values across the basin.Based on IC values,we stratified field sampling sites into high-,moderate-,and lowconnectivity gradient groups to analyze the relationships among plant community characteristics,vegetation spatial patterns,and wetland connectivity in the Qaidam Basin.Partial Least Squares Path Modeling(PLSPM)was further employed to quantify the driving mechanisms underlying wetland vegetation characteristics.The results revealed that wetland connectivity across the basin was generally low,with IC values up to 1.32 and displaying a west-to-east decreasing gradient.The west and northwest were characterized by relatively continuous high-connectivity wetland networks,while fragmented and low-connectivity wetlands predominated in the east and southeast.Connectivity regulated wetland vegetation patterns primarily by affecting patch size,fragmentation,and internal adjacency.High-connectivity areas had higher class area(CA),largest patch index(LPI),and area-weighted mean patch size(AREA_AM)than low-connectivity areas.Connectivity had the strongest effect on vegetation coverage,which declined sharply from 87.577%in highconnectivity areas to 12.152%in low-connectivity areas.Meanwhile,species diversity showed a moderately negative response to connectivity changes,whereas species evenness remained relatively unaffected.PLS-PM explained 78.300%and 67.500%of the variance in vegetation community and vegetation pattern,respectively.Climate played a dominant role in shaping vegetation characteristics,with significant negative effects on both vegetation community and pattern.Topography influenced vegetation indirectly through climate,and connectivity was influenced by both drivers and exerted positive effects on vegetation community and pattern.This study reveals the multi-pathway driving mechanisms underlying vegetation pattern formation in alpine wetlands,providing a theoretical foundation and decision-support framework for the scientific conservation and adaptive management of wetlands in the Qaidam Basin.
文摘Transformer models face significant computational challenges in private inference(PI).Existing optimization methods often rely on isolated techniques,neglecting joint structural and operational improvements.We propose IG-3D,a unified framework that integrates structured compression and operator approximation through accurate importance assessment.Our approach first evaluates attention head importance using Integrated Gradients(IG),offering greater stability and theoretical soundness than gradient-based methods.We then apply a threedimensional optimization:(1)structurally pruning redundant attention heads;(2)replacing Softmax with adaptive polynomial approximation to avoid exponential computations;(3)implementing layer-wise GELU substitution to accommodate different layer characteristics.A joint thresholdmechanism coordinates compression across dimensions under accuracy constraints.Experimental results on the GLUE benchmark show that our method achieves an average 2.9×speedup in inference latency and a 50%reduction in communication cost,while controlling the accuracy loss within 2.3%,demonstrating significant synergistic effects and a superior accuracy-efficiency trade-off compared to single-technique optimization strategies.
基金supported by Natural Science Foundation of Xiamen,China(No.3502Z20227232)the STS Project of Fujian-CAS(No.2023T3018)Bureau of International Cooperation,Chinese Academy of Sciences(No.322GJHZ2022035MI).
文摘Anammox bacteria in constructed wetlands(CWs)play pivotal role in sustainable nitrogen transformation,yet existing studies lack comprehensive analysis of environmental gradients and microbial interactions,both key factors in anammox bacteria enrichment.This study investigated the mechanisms driving anammox bacteria enrichment in lab-scale simulated CWs treating high-nitrogen wastewater,focusing on bacterial community re-sponses across wetland layers with various strategies,including continuous up-flow influent,nitrogen loading increase,effluent recirculation,intermittent influent,and anammox bacteria inoculation.Results showed that total relative and absolute abundances of anammox bacteria ranged from 0.77%to 12.50%and from 0.13 to 6.46×10^(7) copies/g,respectively.Dissolved oxygen and pH had significant positive correlations with the absolute abundance of anammox bacteria,while organic matter and nitrate negatively impacted their relative abundance.Permutational multivariate analysis of variance indicated that spatial heterogeneity explained more variation in anammox bacteria abundance(43.44%)compared to operational strategies(8.58%).In terms of microbial interactions,60 dominant species exhibited potential correlations with anammox bacteria,comprising 170 interactions(105 positive and 65 negative),which suggested that anammox bacteria generally foster cooperative relationships with dominant bacteria.Notably,significant interspecies interactions were observed between Candidatus Kuenenia(dominant anammox bacteria in CWs)and species within the genera Chitinivibrio-nia and Anaerolineaceae,suggesting that microbial interactions primarily manifest as indirect facilitative effects rather than direct mutualistic relationships.Given that the Normalized Stochasticity Ratio in CWs were<50%,this study inferred that environmental gradients have greater influence on anammox bacteria than microbial interactions.
基金supported by the National Key Research and Development Program of China (2024YFE0214200)the National Natural Science Foundation of China (42201072)。
文摘Mountain ecosystems offer natural gradients for exploring biodiversity patterns;however,the elevational patterns of plant species and phylogenetic diversity in the eastern Pamir Plateau remain poorly understood.As a biogeographical junction of the Central Asian mountain ranges,the eastern Pamir Plateau in China is geographically connected to the main part of the Pamir Plateau in Tajikistan,resulting in significant climatic and topographical heterogeneity and unique regional vegetation communities.In this study,we established 5 elevational transects and 91 plots (1500–4870 m) in the eastern Pamir Plateau to investigate the patterns and environmental drivers of plant diversity at both regional and local spatial scales.We examined diversity patterns and community composition using regression models and community structure analysis and quantified the relative importance of environmental factors using a random forest model.The results showed a distinct differentiation along elevation gradients,with overall plant diversity,herbaceous plant diversity,and phylogenetic diversity index increasing with elevation,whereas woody plant diversity declined.The phylogenetic structure indices (including net relatedness index and nearest taxon index) exhibited heterogeneous elevational responses,indicating that community assembly was jointly driven by environmental filtering and niche differentiation.Soil nutrients,water availability,and temperature were the primary environmental drivers,with soil factors predominantly influencing herbaceous plant diversity,while climatic variables dominated woody plant diversity.These findings demonstrate that plant diversity along elevational gradients of the eastern Pamir Plateau exhibits the characteristic patterns of a unique arid mountain ecosystem,where enhanced soil fertility and moderate moisture at higher elevations partly offset energy limitations,thereby maintaining plant diversity through functional convergence of closely related lineages.This pattern of biodiversity maintenance contrasts with the divergence-driven community assembly processes commonly observed in humid mountain systems.Overall,this study contributes to a better understanding of biodiversity maintenance in the eastern Pamir Plateau.Given its geographical continuity with the Pamir Plateau in Tajikistan,our findings can provide a basis for alpine conservation efforts across arid Central Asia.
基金supported by the National Natural Science Foundation of China(Nos.42072229,42030301,41102131,41972049,41972302 and 41977231)the Guangdong Basic and Applied Basic Research Foundation(No.2025A1515010724)+3 种基金the Guangdong Natural Science Foundation(No.2021A1515011658)the Science and Technology Program of Guangzhou(No.202002030184)the Special Fund for Basic Scientific Research of Central Colleges,Chang'an University(No.300102260502)the Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project(No.2024ZD1001003)。
文摘The paleo-geothermal gradient is a crucial parameter for converting the thermal history to the exhumation history.However,the precise estimation of this parameter has been a challenge.This paper presents a simple two-step method to model the paleo-geothermal gradient using low-temperature thermochronology.(1)It uses the Monte Carlo approach to generate thermal histories in a vertical section randomly and calculates the entire thermal history within the goodnessof-fit thresholds based on different paleo-geothermal gradients.(2)It selects the optimum paleogeothermal gradient by comparing the entire thermal history within different goodness-of-fit thresholds.We validated the method with apatite(U-Th)/He and fission track data collected from two drill cores in the Haiyuan-Liupanshan region.The result revealed that the best-fit paleo-geothermal gradient was~42℃/km during the Early Cretaceous–Miocene and has decreased rapidly to 20℃/km since~10 Ma.The crust thickening in the study area may explain the rapid reduction in the paleogeothermal gradient since~10 Ma.Our results are consistent with earlier studies in the region,suggesting that our simple and more intuitive approach provides an alternative method for paleogeothermal gradient modeling.
基金financially supported by the National Natural Science Foundation of China(No.52103127)the Opening Project of the State Key Laboratory of Polymer Materials Engineering(Sichuan University)(No.sklpme2022-4-10)Shaanxi Provincial Science and Technology Department(No.2025GH-YBXM-042).
文摘In this study,an architecture featuring a gradient conductive network structure and three-dimensional dual-continuous network structure is constructed in a carbon nanotubes/cellulose-boron nitride/poly(vinyl alcohol)(CNT/cellulose-BN/PVA)composite.Using cellulose aerogel as a template,CNT were incorporated into the cellulose template by vertically impregnating the CNT suspension.Following the impregnation of BN/PVA and high-pressure compression,three-dimensional dual-continuous network structure was successfully constructed in the CNT/cellulose-BN/PVA composite.The comprehensive performance of the composite,including electromagnetic interference(EMI)shielding and Joule heating performance,was investigated.The results indicate that the total EMI shielding effectiveness(SE)for the CNT/cellulose-BN/PVA composite reveals similar values for electromagnetic waves incident from different directions,but totally different shielding mechanisms.For the CNT/cellulose-BN/PVA composite with three impregnation cycles of CNT,the EMI SE values exceeded 39 dB for electromagnetic waves incident from both the high-and low-CNT-content sides.93%of the microwaves were reflected when electromagnetic waves were incident from the high-CNT-content side,while the reflection coefficient decreased to 0.44 for the transverse direction.In addition,the construction of the dual-continuous network structure enabled the composite to exhibit both excellent electrical conductivity and good thermal conductivity simultaneously,endowing the material with good Joule heating performance.CNT/cellulose-BN/PVA composite films have significant potential for application as EMI shielding materials in extremely cold weather.
基金supported by the National Natural Science Foundation of China(32271584 and 31600445)the Natural Science Basic Research Plan in Shaanxi Province of China(2020JM-286)+2 种基金the Fundamental Research Funds for the Central Universities(GK202103072,GK202103073)the National College Students'Innovative Entrepreneurial Training Plan Program(202310718085)Special Research Project in Philosophy and Social Sciences of Shaanxi Province(2022HZ1795).
文摘Prevention of biological invasion requires understanding how alien species invade native communities.Although studies have identified mechanisms that underlie plant invasion in some habitats,limited attention has focused on invasion patterns along elevational gradients.In this study,we asked which factors drive the global and regional distribution of the invasive plant Galinsoga quadriradiata along elevational gradients.To answer this question,we examined whether human activities(i.e.,roads)promote G.quadriradiata invasion,how seed dispersal-related traits of G.quadriradiata change along elevation gradients,and whether G.quadriradiata has adapted to high-elevation environments through phenotypic plasticity or genetic variation.On the global scale,we found that human activities and road density positively contribute to the G.quadriradiata expansion in mountainous areas.Field surveys in China revealed significant elevational differences in the seed dispersal traits of G.quadriradiata,with higher-elevation populations exhibiting lower dispersal ability and generally lower genetic diversity.Under common conditions,high-elevation populations showed higher leaf mass ratio but lower root mass ratio and reproductive allocation.This suggests that high-elevation environments create a barrier to dispersal for G.quadriradiata,and that G.quadriradiata has adapted phenotypically to these conditions.Our study indicates that the elevational invasion pattern of G.quadriradiata is shaped by multiple factors,particularly human activities and phenotypic adaptability.In addition,our finding that G.quadriradiata invasion at high elevations is not constrained by low genetic diversity indicates that monitoring and management of G.quadriradiata in mountainous areas should be strengthened.
基金supported by the National Natural Science Foundation of China grant nos.52470149(P.H.Shao)and 52125002(X.B.Luo)the National Key Research and Development Program of China grant no.2023YFC3905903(P.H.Shao)Nanchang Hangkong University Doctoral Start-up Fund grant no.EA202502100(Y.Y.Zhou).
文摘Selective extraction of precious metals from urban mines plays a crucial role in mitigating the risk of depletion of precious metal resources and reducing waste pollution.However,a major obstacle in precious metal extraction lies in the difficulty of distinguishing the subtle differences in the physicochemical characteristics between them,especially gold and palladium.Herein,a proton-driven separation system was presented for cascade recovery of gold and palladium from waste-printed circuit boards(W-PCBs)leachate using poly(amidoxime)(PAO)hydrogel.This exhibits an ultra-high capacity,extra-fast rate,and excellent selectivity for the extraction of Au(Ⅲ)and Pd(Ⅱ).Notably,the separation of Au(Ⅲ)and Pd(Ⅱ)can be achieved with high selectivity at pH=0,resulting in a remarkable separation factor of k_(Au(Ⅲ)/Pd(Ⅱ))=36.5.This was demonstrated to originate from the differential mechanism of PAO hydrogel for the capture of Au(Ⅲ)and Pd(Ⅱ)under proton-mediated conditions.Drawing inspiration from the mechanism,the proton-driven cascade recovery system demonstrates remarkable efficiency in sequentially recovering 99.92%of gold and 99.05%of palladium from W-PCBs acid leachate.This research opens up a strategy to precisely separate and recover precious metals from e-waste of urban mines.
基金supported by the NSF of Shanxi(202303021221168)the Industry-university-research project of Shanxi Datong University(2022CXY10,2022CXY13).
文摘In this paper,our main goal is to study a new mathematical model which describes the frictional contact between a foundation and a deformable body which is composed of viscoplastic materials and where the process is considered dynamic.The contact condition on the normal plane is modeled by a unilateral constraint condition for a version of normal velocity in which the memory effect and the adhesion are considered.On the tangential plane a frictional contact condition is governed by the Clarke subdifferential of a locally Lipschitz function,and the evolution of the bonding field is governed by an ordinary differential equation.We formulate this problem as coupled system that consists of two ordinary differential equations and a variational-hemivariational inequality.Then,the existence,uniqueness and continuous dependence of the solution on the data results concerning the abstract system are established.Finally,we use the abstract results to show the existence and uniqueness of the solution to the contact problem.
基金financially supported by the National Science and Technology Major Project,China(No.2024ZD1002100)the National Natural Science Foundation of China(Nos.42330801,42474112,42504062)+1 种基金the China Postdoctoral Science Foundation(No.2024M761704)Shuimu Tsinghua Scholar Program of Tsinghua University,China(No.2024SM114)。
文摘A three-dimensional(3D)electromagnetic(EM)inversion algorithm based on the nonlinear conjugate gradient(NLCG)method and a two-color plane Gauss-Seidel(GS)multigrid(MG)forward solver is developed to improve inversion efficiency.The results indicate that the computational efficiency of each inversion can be improved by approximately a factor of three by using the proposed MG solver.First,the accuracy of the MG solver is validated through a test on a synthetic model.Next,the numerical performance of the inversion algorithm is evaluated using this model.Finally,the inversion algorithm is applied to a field EM data collected at the Beiya gold polymetallic ore district.A 3D resistivity model is obtained,and the formation process of the metal ore is analyzed.
