China launched the 45th satellite in the BeiDou Navigation Satellite System (BDS) as well as the BeiDou 2 GEO-8 satellite into orbit on a LM-3C carrier rocket from the Xichang Satellite Launch Center at 23:48 Beijing ...China launched the 45th satellite in the BeiDou Navigation Satellite System (BDS) as well as the BeiDou 2 GEO-8 satellite into orbit on a LM-3C carrier rocket from the Xichang Satellite Launch Center at 23:48 Beijing time on May 17,2019. The LM-3C carrier rocket was developed by the China Academy of Launch Vehicle Technology (CALT),This was the 101st mission of the LM-3 series launch vehicle,the 200th mission of the LM launch vehicle family that was developed by CALT and the 304th mission of the LM family.展开更多
Ion-solvaing membranes(ISMs)have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices.This article provides an overview of structural composition,per...Ion-solvaing membranes(ISMs)have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices.This article provides an overview of structural composition,performance advan-tages,research progress,ion conduction mechanism and existing issues of ISMs,primarily classifying them according to the matrix structure.A detailed analysis of performance enhancement methods,key performance indicators of ISMs and performance influencing factors is also presented.The article contributes to further optimizing the design and application of ion-solvation membranes,providing theoretical support for the development of fields such as hydrogen production through electrolysis of water and electrochemical energy in the future.展开更多
Copper manufactured by laser powder bed fusion(LPBF)process typically exhibits poor strength-ductility coordination,and the addition of strengthening phases is an effective way to address this issue.To explore the eff...Copper manufactured by laser powder bed fusion(LPBF)process typically exhibits poor strength-ductility coordination,and the addition of strengthening phases is an effective way to address this issue.To explore the effects of strengthening phases on Cu,Cu-carbon nanotubes(CNTs)composites were prepared using LPBF technique with Cu-CNTs mixed powder as the matrix.The formability,microstructure,mechanical properties,electrical conductivity,and thermal properties were studied.The result shows that the prepared composites have high relative density.The addition of CNTs results in inhomogeneous equiaxed grains at the edges of the molten pool and columnar grains at the center.Compared with pure copper,the overall mechanical properties of the composite are improved:tensile strength increases by 52.8%and elongation increases by 146.4%;the electrical and thermal properties are also enhanced:thermal conductivity increases by 10.8%and electrical conductivity increases by 12.7%.展开更多
Hydraulic theory predicts a positive coupling between leaf hydraulic conductance(K_(leaf))and stomatal conductance(g_(s));however,this theory has not been fully supported by observations,and underlying mechanisms are ...Hydraulic theory predicts a positive coupling between leaf hydraulic conductance(K_(leaf))and stomatal conductance(g_(s));however,this theory has not been fully supported by observations,and underlying mechanisms are poorly understood.Partitioning K_(leaf)into inside-xylem(K_(x))and outside-xylem(K_(ox))components offers a refined framework for elucidating the regulation of g_(s) by leaf hydraulics.While optimal planting density may enhance water use efficiency(WUE)through modulation of g_(s),corresponding changes in leaf hydraulic properties and their influence on gas exchange remain unclear.We examined relationships among K_(x),K_(ox),g_(s),leaf photosynthetic rate(A_(N)),and WUE,and analyzed the structural determinants of K_(ox)in cotton grown under eight planting densities:12,18,24,36,48,60,72,and 84 plants m^(–2).Results showed that as planting density increased,K_(leaf)and A_(N) remained stable,whereas K_(ox)and g_(s) declined significantly.Leaf thickness and the volume fraction of inter-cellular air space were key structural factors influencing K_(ox).Neither K_(leaf)nor K_(x)correlated with A_(N) or g_(s);however,K_(ox)exhibited a significant positive correlation with g_(s).Furthermore,K_(ox)was negatively correlated with WUE.These findings indicate that K_(ox)modulates g_(s) to minimize water loss without compromising A_(N),thereby enhancing WUE in cotton across varying planting densities.展开更多
Typically used thermal insulation materials such as foam insulation and fibreglass may pose notable health risks and environmental impacts thereby resulting in respiratory irritation andwaste disposal issues,respectiv...Typically used thermal insulation materials such as foam insulation and fibreglass may pose notable health risks and environmental impacts thereby resulting in respiratory irritation andwaste disposal issues,respectively.While these materials are affordable and display good thermal insulation,their unsustainable traits pertaining to an intensive manufacturing process and poor disposability are major concerns.Alternative insulation materials with enhanced sustainable characteristics are therefore being explored,and one type of material which has gained notable attention owing to its low carbon footprint and low thermal conductivity is natural fibre.Among the few review studies conducted on Natural Fibre Reinforced Composite(NFRC)insulation boards,the multitude of factors and underlying mechanisms affecting their thermal conductivity performance have been sparsely covered.This review study aimed to address this gap by providing a holistic overview of some of the key intrinsic and extrinsic factors affecting the thermal conductivity performance of NFRCs.Key intrinsic factors pertaining to the microstructural features and to the physico-mechanical traits of NFRCs,namely the fibre lumen size,α,and the fibre-matrix thermal conductivity ratio,β,respectively,were found to largely affect the Transverse Thermal Conductivity(TTC)in NFRC boards.Extrinsic factors,which were found to indirectly affect NFRCs’thermal conductivity,such as fibre pre-processing,composite manufacturing and environmental factors,were also covered.Some of the noteworthy NFRC featureswhich were found to affect their thermal conductivity are volume fraction of fibres,bulk density and porosity.The findings of this study highlight the need for additional research investigation to address the foregoing limitations observed in NFRC thermal insulation boards by considering appropriate natural fibres,composition and fabrication techniques.The fabrication of high-grade NFRC boards,which will display an optimum balance between enhanced thermal insulation and long-term durability performance,could further replace conventionally used thermal insulation boards in the modern building and construction industry.展开更多
In the context of the global energy low-carbon transition,phase change energy storage technology becomes a key technology to solve the problem of intermittent renewable energy.Oriented phase change composites(OCPCMs)r...In the context of the global energy low-carbon transition,phase change energy storage technology becomes a key technology to solve the problem of intermittent renewable energy.Oriented phase change composites(OCPCMs)receive widespread attention in practical energy storage applications due to their unique oriented thermally conductive structure,which achieves significant thermal conductivity enhancement in specific directions while retaining the high energy storage capacity of the phase change components.This review systematically summarizes the overall analysis of OCPCMs from synthesis and preparation to application scenarios in recent years.Herein,we introduce the analysis of the heat transfer mechanism of the materials and explore the advantages of the oriented structure in OCPCMs in the heat transfer behavior from a bionic perspective.We then focus on summarizing and generalizing the methods for preparing OCPCMs,giving suggestions for suitable methods according to different scenarios.Besides,we discuss the application of finite element simulation methods to the monitoring of the thermal management behavior of OCPCMs,and look into the potential future application areas of such materials.Finally,it is hoped that this review will provide guidance for the academic community in developing high-performance OCPCMs.展开更多
MXene is a promising conductive nanofiller for hydrogels due to its excellent electricity conductivity and water dispersibility.However,MXene is prone to oxidize in the presence of air and water,resulting in a signifi...MXene is a promising conductive nanofiller for hydrogels due to its excellent electricity conductivity and water dispersibility.However,MXene is prone to oxidize in the presence of air and water,resulting in a significant loss of conductivity.Polydopamine(PDA)has been coated on MXene to enhance its antioxidation stability via the physical barrier and chemical reducing ability of PDA,which unavoidably causes severe aggregation and a significant decrease in conductivity due to the crosslinking and insulation of PDA.Herein,we propose a facile strategy to construct a highly conductive,stable,and self-healing MXene-based polyvinyl alcohol(PVA)hydrogel by a controlled assembly of PDA and cellulose nanocrystal(CNC).PDA is first formed by oxidation self-polymerization in PVA solution without the presence of CNC and MXene,which can effectively reduce the content of aggregation-inducing groups and avoid the formation of an insulating PDA layer on the surface of MXene.The addition of CNCs results in the easy dispersion of a high content of MXene via hydrogen bonding and electrostatic interactions.The PVA-PDA hydrogel with MXene and CNC as conductive and reinforcing nanofillers(PP-CM)is cross-linked by dynamic borax covalent bonds and shows a conductivity of 7.14 S m^(-1).The introduction of PDA effectively protects MXene and results in only a 14%decrease in conductivity after 7 days,significantly improving antioxidant stability.This hydrogel also possesses rapid self-healing capabilities,achieving 90.5%self-healing efficiency within 10 min.This versatile approach opens new avenues for the preparation and application of MXene-based conductive hydrogels.展开更多
Proton exchange membrane(PEM)is an integral component in fuel cells which enables proton transport for efficient energy conversion.Sulfonated Polyether Ether Ketone(SPEEK)has emerged as a cost-effective option with no...Proton exchange membrane(PEM)is an integral component in fuel cells which enables proton transport for efficient energy conversion.Sulfonated Polyether Ether Ketone(SPEEK)has emerged as a cost-effective option with non-fluorinated aromatic backbones for Proton Exchange Membrane Fuel Cell(PEMFC)applications,even though it exhibits lower proton conductivity compared to Nafion.This work aims to study the influence of Sulfonated Chitosan(SCS)concentrations on proton conductivity of SPEEK-based PEM at room temperature.SPEEK was synthesized using a sulfonation process with concentrated sulfuric acid at room temperature.SCS was synthesized via reflux of CS and 1.2 M H2SO4 with a ratio of 1:35(w/v)at 90℃ for 30 min.The composite membranes of SPEEK-SCS were formed with four different SCS concentrations,using the solution castingmethod,andDimethyl Sulfoxide(DMSO)was used as a solvent.The composite membranes synthesized include pure SPEEK(S0),SPEEK with 1%SCS(S1),SPEEK with 2%SCS(S2),and SPEEK with 3%SCS(S3).Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),water uptake,degree of swelling,Ionic exchange capacity(IEC)with Electrochemical impedance spectroscopy(EIS)were used to characterize the composite membranes in terms of composition,crystallinity,water absorption,dimensional changes,number of exchangeable ions in membranes,and proton conductivity,respectively.Notably,S3 had the highest water uptake and the lowest degree of swelling.S2 had the highest proton conductivity among the SPEEK-SCS composite membranes at room temperature with 3.44×10^(−2) Scm^(-1).展开更多
To investigate the long-term fracture conductivity behavior of propped fractures under the high-temperature and high-pressure conditions of deep shale gas reservoirs in the Sichuan Basin,this study systematically anal...To investigate the long-term fracture conductivity behavior of propped fractures under the high-temperature and high-pressure conditions of deep shale gas reservoirs in the Sichuan Basin,this study systematically analyzed the effects of closure stress,proppant concentration,formation temperature,and proppant size combination.Conductivity experiments were conducted using the HXDL-2C long-term proppant conductivity evaluation system under simulated reservoir conditions to determine the time-dependent evolution of fracture conductivity.The results showed that the 50-h conductivity retention of the rock-plate experiments ranged from 22%to 28%.With increasing closure stress,fracture conductivity exhibited a rapid decline.Under a formation temperature of 120℃ and a proppant concentration of 5 kg·m^(-2),the short-term conductivity of 70/140 mesh quartz-sand-propped fractures was 2.37μm^(2)·cm,which decreased to 0.66μm^(2)·cm after long-term testing.When the closure stress increased to 80 MPa,the short-term and long-term conductivities further declined to 1.36μm^(2)·cm and 0.39μm^(2)·cm,respectively.Increasing the proppant concentration from 5 to 7.5 kg·m^(-2)at 120℃ and 80 MPa improved both short-term and long-term conductivities by enlarging the effective fracture width;however,the conductivity decay rate accelerated,and the 50-h retention dropped from 27.2%to 22.8%.Raising the temperature from 120℃ to 140℃ promoted proppant crushing and compaction,intensified shale creep,and accelerated fracture closure,reducing long-term conductivity from 0.37 to 0.30μm^(2)·cm.Under identical conditions,40/70 mesh ceramic proppants maintained significantly higher conductivities than 70/140 mesh quartz sand,with short-term and long-term values of 8.71 and 2.19μm^(2)·cm,respectively,at 120℃,80 MPa,and 5 kg·m^(-2).Pure quartz-sand systems failed to maintain effective conductivity under high-temperature and high-stress conditions,whereas adding 20%40/70 mesh ceramic proppant and thoroughly mixing it,the long-term conductivity has increased by 2.3 times,improving fracture stability while reducing overall cost.A predictive equation was derived from the experimental results to capture the dynamic decay characteristics of fracture conductivity.These outcomes provide a valuable experimental basis and technical support for optimizing fracturing fluid design,proppant selection,and operation parameters in deep shale formations.展开更多
In this study,multilayer lamination welding was employed to prepare graphene/copper(Gr/Cu)composite billets from graphene-coated copper foils,followed by multi-pass cold drawing to produce Φ1 mm Gr/Cu composite wires...In this study,multilayer lamination welding was employed to prepare graphene/copper(Gr/Cu)composite billets from graphene-coated copper foils,followed by multi-pass cold drawing to produce Φ1 mm Gr/Cu composite wires.Microstructure and property analyses in both the cold-drawn and annealed states show that the incorporation of graphene significantly improves the ductility and electrical conductivity of the copper wire.After annealing at 350℃ for 30 minutes,the composite wire demonstrates a tensile strength of 270 MPa and an electrical conductivity of 102.74%IACS,both superior to those of pure copper wire under identical conditions.At 150℃,the electrical conductivity of the annealed composite wire reaches 72.60%IACS,notably higher than the 68.19%IACS of pure copper.The results suggest that graphene is uniformly distributed within the composite wire,with minimal impact on conductivity,while effectively refining the copper grain structure to enhance ductility.Moreover,graphene suppresses copper lattice vibrations at elevated temperatures,reducing the rate of conductivity degradation.展开更多
Charcot-Marie-Tooth disease(CMT) is a heterogeneous group of inherited peripheral neuro pathies;it is characterized by muscle weakness and wasting,as well as sensory dysfunction,that typically begins during adolescenc...Charcot-Marie-Tooth disease(CMT) is a heterogeneous group of inherited peripheral neuro pathies;it is characterized by muscle weakness and wasting,as well as sensory dysfunction,that typically begins during adolescence and ultimately leads to lifelong disability.Occurring in~1 in 2500individuals,CMT is the most common hereditary neuromuscular condition and results from mutations in> 100 different genes.CMT is grouped into type1(CMT1),where demyelination and loss of nerve conduction velocity occur,type 2(CMT2),where motor and sensory axons degenerate without loss of myelination/nerve conduction velocity,and intermediate CMT,where both demyelination and axon loss present alongside intermediate nerve condu ction velocities.展开更多
Waste glass fibers were used as the main raw materials to prepare foamed glass-ceramics with 0-14 wt%H_(3)BO_(3)as a flux agent.The effects of H_(3)BO_(3)on the crystallization process,foaming behavior,and physical pr...Waste glass fibers were used as the main raw materials to prepare foamed glass-ceramics with 0-14 wt%H_(3)BO_(3)as a flux agent.The effects of H_(3)BO_(3)on the crystallization process,foaming behavior,and physical properties of CaO-MgO-Al_(2)O_(3)-SiO_(2)foamed glass-ceramics were investigated.The results showed that the main crystalline phase of the foamed glass-ceramics was anorthite with diopside as a minor crystalline phase,which exhibited a typical surface crystallization process.The addition of H_(3)BO_(3)modified the surface of glass powders and inhibited crystal precipitation obviously.The low melting point of H_(3)BO_(3)and the decrease of crystallinity jointly promoted the growth of pores,resulting in a reduction of bulk density and an increase in porosity.The compressive strength and thermal conductivity of the samples were linearly related to the bulk density.In particular,the sample added with 10 wt%H_(3)BO_(3)exhibited excellent properties,possessing a low coefficient of thermal conductivity 0.081 W/(m·K)and relatively high compressive strength 3.36 MPa.展开更多
With the miniaturization and high-frequency evolution of antennas in 5G/6G communications,aerospace,and transportation,polymer composite papers integrating superior wave-transparent performance and thermal conductivit...With the miniaturization and high-frequency evolution of antennas in 5G/6G communications,aerospace,and transportation,polymer composite papers integrating superior wave-transparent performance and thermal conductivity for radar antenna systems are urgently needed.Herein,a down-top strategy was employed to synthesize poly(p-phenylene benzobisoxazole)precursor nanofibers(prePNF).The prePNF was then uniformly mixed with fluorinated graphene(FG)to fabricate FG/PNF composite papers through consecutively suction filtration,hot-pressing,and thermal annealing.The hydroxyl and amino groups in prePNF enhanced the stability of FG/prePNF dispersion,while the increasedπ-πinteractions between PNF and FG after annealing improved their compatibility.The preparation time and cost of PNF paper was significantly reduced when applying this strategy,which enabled its large-scale production.Furthermore,the prepared FG/PNF composite papers exhibited excellent wave-transparent performance and thermal conductivity.When the mass fraction of FG was 40 wt%,the FG/PNF composite paper prepared via the down-top strategy achieved the wave-transparent coefficient(|T|2)of 96.3%under 10 GHz,in-plane thermal conductivity(λ_(∥))of 7.13 W m^(−1)K^(−1),and through-plane thermal conductivity(λ_(⊥))of 0.67 W m^(−1)K^(−1),outperforming FG/PNF composite paper prepared by the top-down strategy(|T|2=95.9%,λ_(∥)=5.52 W m^(−1)K^(−1),λ_(⊥)=0.52 W m^(−1)K^(−1))and pure PNF paper(|T|2=94.7%,λ_(∥)=3.04 W m^(−1)K^(−1),λ_(⊥)=0.24 W m^(−1)K^(−1)).Meanwhile,FG/PNF composite paper(with 40 wt%FG)through the down-top strategy also demonstrated outstanding mechanical properties with tensile strength and toughness reaching 197.4 MPa and 11.6 MJ m^(−3),respectively.展开更多
The global energy crisis and electricity shortage pose unprecedented challenges.Bio-based solar-driven ionic power generation devices with flexibility,photothermal self-healing and scalability hold great promise for s...The global energy crisis and electricity shortage pose unprecedented challenges.Bio-based solar-driven ionic power generation devices with flexibility,photothermal self-healing and scalability hold great promise for sustainable electricity and alleviating energy crisis.Here,inspired by plant transpiration,a multifunctional bio-based ion conductive elastomer with solar power generation capability was designed by engineered synergy among epoxy natural rubber,cellulose nanofibrils,lithium bis(trifluoromethane)sulfonimide and eumelanin.The film exhibits an outstanding stretchability(1072%)and toughness(22.7 MJ m^(-3)).The favorable synergy of low thermal conductivity,high hygroscopicity and photothermal conversion performance endowed the film with a large thermal gradient under light illumination,driving efficient water transpiration.Furthermore,the excellent interfacial compatibility between eumelanin and matrix facilitates the formation of space charge regions,which further enhances Li^(+)transport.The film demonstrates excellent evaporation rate(2.83 kg m^(-2)h^(-1)),output voltage(0.47 V)and conductivity(5.11×10^(-2)S m^(-1)).Notably,the film exhibits remarkable photothermal self-healing performance even in saline environment,achieving 99.6%healing efficiency of output voltage.Therefore,the film demonstrates significant prospects for applications in photo-thermoelectric generation and solar-driven ionic power generation.展开更多
Developing catalysts with excellent stability while significantly reducing the overpotential of the oxygen evolution reaction(OER) is crucial for advancing overall water splitting(OWS) systems.In this study,we synthes...Developing catalysts with excellent stability while significantly reducing the overpotential of the oxygen evolution reaction(OER) is crucial for advancing overall water splitting(OWS) systems.In this study,we synthesized the electrode material Ce-NiCo-LDHs@SnO_(2)/NF through a two-step hydrothermal reaction,where Ce-doped NiCo-LDHs are grown on nickel foam modified by a SnO_(2) layer.Ce doping adjusts the internal electronic distribution of Ni Co-LDHs,while the introduction of the SnO_(2) layer enhances electron transfer capability.Together,these factors contribute to the reduction of the OER energy barrier and experimental evidence confirms that the reaction proceeds via the lattice oxygen evolution mechanism(LOM).Consequently,Ce-NiCo-LDHs@SnO_(2)/NF exhibits high level electrochemical performance in OER,requiring only 234 m V overpotential to achieve a current density of 10 m A/cm^(2),with a Tafel slope of just 27.39 m V/dec.When paired with Pt/C/NF,an external potential of only 1.54 V is needed to drive OWS to attain a current density amounting to 10 m A/cm^(2).Furthermore,the catalyst demonstrates stability for 100 h during the OWS stability test.This study underscores the feasibility of enhancing the OER performance through Ce doping and the introduction of a conductive SnO_(2) layer.展开更多
Acid mine drainage(AMD)leachate is a global pollutant issue that impacts groundwater environment quality.This study investigated the feasibility of a composite biopolymer-amended bentonite as a geosynthetic clay liner...Acid mine drainage(AMD)leachate is a global pollutant issue that impacts groundwater environment quality.This study investigated the feasibility of a composite biopolymer-amended bentonite as a geosynthetic clay liner core material to contain AMD leachate.The real AMD leachate with a pH of 3.1,sourced from an acidic pyrite tailings site,was employed as a specific test leachate used in this study.The composite biopolymer was composed of welan gum(WG)and xanthan gum(XG)at different dry weight-based ratios.Modified fluid loss(MFL)tests were conducted to evaluate hydraulic conductivity(k)of bentonites to optimize WG:XG ratio.Rheological properties of biopolymer solutions were measured,serving as indicative parameters of biopolymer elution.The results indicated biopolymer-amended bentonites with the WG:XG ratio of 8:2 possessed lowest k(1.5×10^(−11)m/s to 7.2×10^(−11)m/s),lower than unamended bentonite(1.2×10^(−10)m/s to 8.6×10^(−10)m/s)in the AMD leachate condition.In addition,biopolymer solutions with WG:XG ratio of 8:2 exhibited highest viscosity.Thermogravimetric analysis,ultraviolet–visible spectroscopy,and Fourier transform infrared spectroscopy were conducted on the composite biopolymer,revealing that WG and XG interacted via physical cross-linking.Additionally,scanning electron microscopy and atomic force microscopy images indicated that a physical cross-linking and dense network structure conformation was developed in the composite biopolymer hydrogel at the WG:XG ratio of 8:2.The results demonstrate that the composite biopolymer is a promising low-carbon amendment material for enhancing containment performance of bentonite used in geosynthetic clay liners to contain AMD leachate.展开更多
Transient electromagnetic methods are increasingly adopted for field investigation of oil pollution because they provide rapid,non-invasive imaging of subsurface electrical conductivity across depths relevant to vados...Transient electromagnetic methods are increasingly adopted for field investigation of oil pollution because they provide rapid,non-invasive imaging of subsurface electrical conductivity across depths relevant to vadose-zone impacts,groundwater plumes,and coastal transition zones.This review synthesizes recent advances that have expanded TEM(Transient Electromagnetic Method)’s environmental applicability,including higher dynamic range receivers,multi-moment acquisition that improves shallow-to-deep sensitivity,and diversified deployment platforms spanning ground,mobile/towed,airborne,and coastal/marine configurations,with emerging UAV(Unmanned Aerial Vehicle)options for constrained access.We emphasize the electrical and geochemical basis of hydrocarbon-related signatures,showing why fresh releases may appear resistive through NAPL(Non-Aqueous Phase Liquid)displacement of conductive pore water,whereas aged contamination often produces conductive responses driven by biodegradation,redox evolution,and elevated ionic strength.Because these responses are non-unique and can be confounded by clay-rich lithology,salinity gradients,temperature variability,and cultural infrastructure,contemporary interpretation has shifted toward process-consistent conceptual site models and uncertainty-aware products that communicate depth of investigation and resolution limits.A thematic synthesis of field applications indicates TEM is most reliable for mapping hydrogeological architecture,delineating plausible plume corridors,prioritizing intrusive sampling,and supporting monitoring where repeatability and background variability are controlled.The review concludes that TEM delivers the greatest decision value when integrated in a weight-of-evidence framework with hydrogeology,geochemistry,and targeted ground truth,and it highlights future needs in standardized reporting,robust time-lapse appraisal,and stronger petrophysical links to hydrocarbon transformation.展开更多
The thermal conductivity of nanofluids is an important property that influences the heat transfer capabilities of nanofluids.Researchers rely on experimental investigations to explore nanofluid properties,as it is a n...The thermal conductivity of nanofluids is an important property that influences the heat transfer capabilities of nanofluids.Researchers rely on experimental investigations to explore nanofluid properties,as it is a necessary step before their practical application.As these investigations are time and resource-consuming undertakings,an effective prediction model can significantly improve the efficiency of research operations.In this work,an Artificial Neural Network(ANN)model is developed to predict the thermal conductivity of metal oxide water-based nanofluid.For this,a comprehensive set of 691 data points was collected from the literature.This dataset is split into training(70%),validation(15%),and testing(15%)and used to train the ANN model.The developed model is a backpropagation artificial neural network with a 4–12–1 architecture.The performance of the developed model shows high accuracy with R values above 0.90 and rapid convergence.It shows that the developed ANN model accurately predicts the thermal conductivity of nanofluids.展开更多
Hydrochloric acid(HCl)extensively exists in deep underground projects,arising from the transportation of industrial raw materials or fracturing fluids of petroleum engineering.It results in corrosion,which can signifi...Hydrochloric acid(HCl)extensively exists in deep underground projects,arising from the transportation of industrial raw materials or fracturing fluids of petroleum engineering.It results in corrosion,which can significantly impact the stability of surrounding rock structures.Therefore,in-depth analysis of the degradation of rock corroded by the HCl solution is an essential task for underground engineering.In this study,the granite specimens are initially treated with the HCl solution with various concentrations.Then,the tests and analyses,such as electrical conductivity(EC)measurements,mineral composition assays,and Brazilian splitting tests,are employed to investigate the corrosion mechanism of the HCl solution.Our results and findings are generally as follows:(1)As the immersion time increases,the EC exhibits a relatively high level at pH value of 1,a decreasing trend at pH value of 3,and an increasing trend at pH value of 5 and 7.(2)The HCl solutions with various concentration have different effect on mineral composition,characterized by an increase in proportion of SiO_(2) and a reduction in proportion of Na_(2)O,Al_(2)O_(3),K_(2)O,MgO,and CaO,as the solution pH value decreases.(3)After immersion in the solutions with pH values of 1,3,and 5,the tensile strength of the granite decreases by 23.85%,20.84%,and 20.24%;the average stiffness of the specimen decreases by 29.29%,23.43%,and 11.97%;the proportion of releasable energy increases by 6%,4%,and -2%;the releasable energy decreases by 54.96%,26.09%,and 14.52%;and the dissipated energy decreases by approximately 68.85%,41.39%,and 5.41%,respectively.(4)The evolution of physical and mechanical properties of the immersed granite specimen can be analyzed from a chemical aspect.The corrosive action of HCl cleaves Si–O and Al–O chemical bonds within the granite,particularly altering the tetrahedral structures of its silicate components.This process involves breaking existing chemical bonds and the formation of new ones,ultimately destroying the silicate molecular structures.As the concentration of HCl increases,the rate of these reactions accelerates,progressively weakening the chemical bonds and consequently deteriorating the mechanical characteristics of the granite.These findings can deepen our knowledge about the corrosion effect of HCI solutions on natural surrounding rocks and serve as references for further research on rock corrosion mechanisms in underground engineering.展开更多
文摘China launched the 45th satellite in the BeiDou Navigation Satellite System (BDS) as well as the BeiDou 2 GEO-8 satellite into orbit on a LM-3C carrier rocket from the Xichang Satellite Launch Center at 23:48 Beijing time on May 17,2019. The LM-3C carrier rocket was developed by the China Academy of Launch Vehicle Technology (CALT),This was the 101st mission of the LM-3 series launch vehicle,the 200th mission of the LM launch vehicle family that was developed by CALT and the 304th mission of the LM family.
基金supported by the National Key Research and Development Program of China (2022YFE0138900)the “Scientific and Technical Innovation Action Plan” Basic Research Field of Shanghai Science and Technology Committee (19JC1410500)。
文摘Ion-solvaing membranes(ISMs)have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices.This article provides an overview of structural composition,performance advan-tages,research progress,ion conduction mechanism and existing issues of ISMs,primarily classifying them according to the matrix structure.A detailed analysis of performance enhancement methods,key performance indicators of ISMs and performance influencing factors is also presented.The article contributes to further optimizing the design and application of ion-solvation membranes,providing theoretical support for the development of fields such as hydrogen production through electrolysis of water and electrochemical energy in the future.
基金National Key Research and Development Program of China(2023YFB4606400)Supported by Longmen Laboratory Frontier Exploration Topics(LMQYTSKT003)。
文摘Copper manufactured by laser powder bed fusion(LPBF)process typically exhibits poor strength-ductility coordination,and the addition of strengthening phases is an effective way to address this issue.To explore the effects of strengthening phases on Cu,Cu-carbon nanotubes(CNTs)composites were prepared using LPBF technique with Cu-CNTs mixed powder as the matrix.The formability,microstructure,mechanical properties,electrical conductivity,and thermal properties were studied.The result shows that the prepared composites have high relative density.The addition of CNTs results in inhomogeneous equiaxed grains at the edges of the molten pool and columnar grains at the center.Compared with pure copper,the overall mechanical properties of the composite are improved:tensile strength increases by 52.8%and elongation increases by 146.4%;the electrical and thermal properties are also enhanced:thermal conductivity increases by 10.8%and electrical conductivity increases by 12.7%.
基金financially supported by the Tianshan Talent Development Program,China for Yali Zhangthe Natural Science Foundation of Xinjiang Production and Construction Corps,China(2024DA002)the Earmarked Fund for XJARS-Cotton,China(XJARS-03)。
文摘Hydraulic theory predicts a positive coupling between leaf hydraulic conductance(K_(leaf))and stomatal conductance(g_(s));however,this theory has not been fully supported by observations,and underlying mechanisms are poorly understood.Partitioning K_(leaf)into inside-xylem(K_(x))and outside-xylem(K_(ox))components offers a refined framework for elucidating the regulation of g_(s) by leaf hydraulics.While optimal planting density may enhance water use efficiency(WUE)through modulation of g_(s),corresponding changes in leaf hydraulic properties and their influence on gas exchange remain unclear.We examined relationships among K_(x),K_(ox),g_(s),leaf photosynthetic rate(A_(N)),and WUE,and analyzed the structural determinants of K_(ox)in cotton grown under eight planting densities:12,18,24,36,48,60,72,and 84 plants m^(–2).Results showed that as planting density increased,K_(leaf)and A_(N) remained stable,whereas K_(ox)and g_(s) declined significantly.Leaf thickness and the volume fraction of inter-cellular air space were key structural factors influencing K_(ox).Neither K_(leaf)nor K_(x)correlated with A_(N) or g_(s);however,K_(ox)exhibited a significant positive correlation with g_(s).Furthermore,K_(ox)was negatively correlated with WUE.These findings indicate that K_(ox)modulates g_(s) to minimize water loss without compromising A_(N),thereby enhancing WUE in cotton across varying planting densities.
文摘Typically used thermal insulation materials such as foam insulation and fibreglass may pose notable health risks and environmental impacts thereby resulting in respiratory irritation andwaste disposal issues,respectively.While these materials are affordable and display good thermal insulation,their unsustainable traits pertaining to an intensive manufacturing process and poor disposability are major concerns.Alternative insulation materials with enhanced sustainable characteristics are therefore being explored,and one type of material which has gained notable attention owing to its low carbon footprint and low thermal conductivity is natural fibre.Among the few review studies conducted on Natural Fibre Reinforced Composite(NFRC)insulation boards,the multitude of factors and underlying mechanisms affecting their thermal conductivity performance have been sparsely covered.This review study aimed to address this gap by providing a holistic overview of some of the key intrinsic and extrinsic factors affecting the thermal conductivity performance of NFRCs.Key intrinsic factors pertaining to the microstructural features and to the physico-mechanical traits of NFRCs,namely the fibre lumen size,α,and the fibre-matrix thermal conductivity ratio,β,respectively,were found to largely affect the Transverse Thermal Conductivity(TTC)in NFRC boards.Extrinsic factors,which were found to indirectly affect NFRCs’thermal conductivity,such as fibre pre-processing,composite manufacturing and environmental factors,were also covered.Some of the noteworthy NFRC featureswhich were found to affect their thermal conductivity are volume fraction of fibres,bulk density and porosity.The findings of this study highlight the need for additional research investigation to address the foregoing limitations observed in NFRC thermal insulation boards by considering appropriate natural fibres,composition and fabrication techniques.The fabrication of high-grade NFRC boards,which will display an optimum balance between enhanced thermal insulation and long-term durability performance,could further replace conventionally used thermal insulation boards in the modern building and construction industry.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.FRF-KST-25-001)the Beijing Natural Science Foundation(No.L253029)。
文摘In the context of the global energy low-carbon transition,phase change energy storage technology becomes a key technology to solve the problem of intermittent renewable energy.Oriented phase change composites(OCPCMs)receive widespread attention in practical energy storage applications due to their unique oriented thermally conductive structure,which achieves significant thermal conductivity enhancement in specific directions while retaining the high energy storage capacity of the phase change components.This review systematically summarizes the overall analysis of OCPCMs from synthesis and preparation to application scenarios in recent years.Herein,we introduce the analysis of the heat transfer mechanism of the materials and explore the advantages of the oriented structure in OCPCMs in the heat transfer behavior from a bionic perspective.We then focus on summarizing and generalizing the methods for preparing OCPCMs,giving suggestions for suitable methods according to different scenarios.Besides,we discuss the application of finite element simulation methods to the monitoring of the thermal management behavior of OCPCMs,and look into the potential future application areas of such materials.Finally,it is hoped that this review will provide guidance for the academic community in developing high-performance OCPCMs.
基金support from Youth Promotion of Guangdong Natural Science Foundation(2024A1515030005)Guangdong Province Ordinary Universities Characteristic Innovation Project(2024KTSCX096)+4 种基金Guangdong Province University Key Field Special Program(2023ZDZX3002)Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education)Naikai University,Guangdong Provincial Key Laboratory of Optical Information Materials and Technology(No.2023B1212060065)Programs of Science and Technology Department of Yunnan Province(202301AT070217)MOE International Laboratory for Optical Information Technologies,the 111 Project,Science and Technology Bureau of Huzhou(2022GG24)ScienceK Ltd.
文摘MXene is a promising conductive nanofiller for hydrogels due to its excellent electricity conductivity and water dispersibility.However,MXene is prone to oxidize in the presence of air and water,resulting in a significant loss of conductivity.Polydopamine(PDA)has been coated on MXene to enhance its antioxidation stability via the physical barrier and chemical reducing ability of PDA,which unavoidably causes severe aggregation and a significant decrease in conductivity due to the crosslinking and insulation of PDA.Herein,we propose a facile strategy to construct a highly conductive,stable,and self-healing MXene-based polyvinyl alcohol(PVA)hydrogel by a controlled assembly of PDA and cellulose nanocrystal(CNC).PDA is first formed by oxidation self-polymerization in PVA solution without the presence of CNC and MXene,which can effectively reduce the content of aggregation-inducing groups and avoid the formation of an insulating PDA layer on the surface of MXene.The addition of CNCs results in the easy dispersion of a high content of MXene via hydrogen bonding and electrostatic interactions.The PVA-PDA hydrogel with MXene and CNC as conductive and reinforcing nanofillers(PP-CM)is cross-linked by dynamic borax covalent bonds and shows a conductivity of 7.14 S m^(-1).The introduction of PDA effectively protects MXene and results in only a 14%decrease in conductivity after 7 days,significantly improving antioxidant stability.This hydrogel also possesses rapid self-healing capabilities,achieving 90.5%self-healing efficiency within 10 min.This versatile approach opens new avenues for the preparation and application of MXene-based conductive hydrogels.
文摘Proton exchange membrane(PEM)is an integral component in fuel cells which enables proton transport for efficient energy conversion.Sulfonated Polyether Ether Ketone(SPEEK)has emerged as a cost-effective option with non-fluorinated aromatic backbones for Proton Exchange Membrane Fuel Cell(PEMFC)applications,even though it exhibits lower proton conductivity compared to Nafion.This work aims to study the influence of Sulfonated Chitosan(SCS)concentrations on proton conductivity of SPEEK-based PEM at room temperature.SPEEK was synthesized using a sulfonation process with concentrated sulfuric acid at room temperature.SCS was synthesized via reflux of CS and 1.2 M H2SO4 with a ratio of 1:35(w/v)at 90℃ for 30 min.The composite membranes of SPEEK-SCS were formed with four different SCS concentrations,using the solution castingmethod,andDimethyl Sulfoxide(DMSO)was used as a solvent.The composite membranes synthesized include pure SPEEK(S0),SPEEK with 1%SCS(S1),SPEEK with 2%SCS(S2),and SPEEK with 3%SCS(S3).Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),water uptake,degree of swelling,Ionic exchange capacity(IEC)with Electrochemical impedance spectroscopy(EIS)were used to characterize the composite membranes in terms of composition,crystallinity,water absorption,dimensional changes,number of exchangeable ions in membranes,and proton conductivity,respectively.Notably,S3 had the highest water uptake and the lowest degree of swelling.S2 had the highest proton conductivity among the SPEEK-SCS composite membranes at room temperature with 3.44×10^(−2) Scm^(-1).
基金funding for this research comes fromHubei Provincial Natural Science Foundation(2022CFB690)the Open Foundation(UOG2024-03)of Cooperative Innovation Center of Unconventional Oil+1 种基金Gas,Yangtze University(Ministry of Education&Hubei Province)and the Open Foundation(YQZC202302)of Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering(Yangtze University)the National Natural Science Foundation of China(Grant no.U23B20156).
文摘To investigate the long-term fracture conductivity behavior of propped fractures under the high-temperature and high-pressure conditions of deep shale gas reservoirs in the Sichuan Basin,this study systematically analyzed the effects of closure stress,proppant concentration,formation temperature,and proppant size combination.Conductivity experiments were conducted using the HXDL-2C long-term proppant conductivity evaluation system under simulated reservoir conditions to determine the time-dependent evolution of fracture conductivity.The results showed that the 50-h conductivity retention of the rock-plate experiments ranged from 22%to 28%.With increasing closure stress,fracture conductivity exhibited a rapid decline.Under a formation temperature of 120℃ and a proppant concentration of 5 kg·m^(-2),the short-term conductivity of 70/140 mesh quartz-sand-propped fractures was 2.37μm^(2)·cm,which decreased to 0.66μm^(2)·cm after long-term testing.When the closure stress increased to 80 MPa,the short-term and long-term conductivities further declined to 1.36μm^(2)·cm and 0.39μm^(2)·cm,respectively.Increasing the proppant concentration from 5 to 7.5 kg·m^(-2)at 120℃ and 80 MPa improved both short-term and long-term conductivities by enlarging the effective fracture width;however,the conductivity decay rate accelerated,and the 50-h retention dropped from 27.2%to 22.8%.Raising the temperature from 120℃ to 140℃ promoted proppant crushing and compaction,intensified shale creep,and accelerated fracture closure,reducing long-term conductivity from 0.37 to 0.30μm^(2)·cm.Under identical conditions,40/70 mesh ceramic proppants maintained significantly higher conductivities than 70/140 mesh quartz sand,with short-term and long-term values of 8.71 and 2.19μm^(2)·cm,respectively,at 120℃,80 MPa,and 5 kg·m^(-2).Pure quartz-sand systems failed to maintain effective conductivity under high-temperature and high-stress conditions,whereas adding 20%40/70 mesh ceramic proppant and thoroughly mixing it,the long-term conductivity has increased by 2.3 times,improving fracture stability while reducing overall cost.A predictive equation was derived from the experimental results to capture the dynamic decay characteristics of fracture conductivity.These outcomes provide a valuable experimental basis and technical support for optimizing fracturing fluid design,proppant selection,and operation parameters in deep shale formations.
基金Funded by Hunan Provincial Natural Science Foundation(No.2023JJ40074)Hunan Provincial Education Department Excellent Youth Project(No.21B0757)Hunan Provincial Engineering Technology Center(No.2022TP2036)。
文摘In this study,multilayer lamination welding was employed to prepare graphene/copper(Gr/Cu)composite billets from graphene-coated copper foils,followed by multi-pass cold drawing to produce Φ1 mm Gr/Cu composite wires.Microstructure and property analyses in both the cold-drawn and annealed states show that the incorporation of graphene significantly improves the ductility and electrical conductivity of the copper wire.After annealing at 350℃ for 30 minutes,the composite wire demonstrates a tensile strength of 270 MPa and an electrical conductivity of 102.74%IACS,both superior to those of pure copper wire under identical conditions.At 150℃,the electrical conductivity of the annealed composite wire reaches 72.60%IACS,notably higher than the 68.19%IACS of pure copper.The results suggest that graphene is uniformly distributed within the composite wire,with minimal impact on conductivity,while effectively refining the copper grain structure to enhance ductility.Moreover,graphene suppresses copper lattice vibrations at elevated temperatures,reducing the rate of conductivity degradation.
基金funding from the Medical Research Council (MR/S006990/1, MR/Y010949/1)the Rosetrees Trust (M806)the UCL Neurogenetic Therapies Programme funded by The Sigrid Rausing Trust and the UCL Therapeutic Acceleration Support scheme supported by funding from MRC IAA 2021 UCL MR/X502984/1 (to JNS)。
文摘Charcot-Marie-Tooth disease(CMT) is a heterogeneous group of inherited peripheral neuro pathies;it is characterized by muscle weakness and wasting,as well as sensory dysfunction,that typically begins during adolescence and ultimately leads to lifelong disability.Occurring in~1 in 2500individuals,CMT is the most common hereditary neuromuscular condition and results from mutations in> 100 different genes.CMT is grouped into type1(CMT1),where demyelination and loss of nerve conduction velocity occur,type 2(CMT2),where motor and sensory axons degenerate without loss of myelination/nerve conduction velocity,and intermediate CMT,where both demyelination and axon loss present alongside intermediate nerve condu ction velocities.
基金Funded by Shandong Provincial Youth Innovation Team Development Plan of Colleges and Universities(No.2022KJ100)National Natural Science Foundation of China(No.52172019)。
文摘Waste glass fibers were used as the main raw materials to prepare foamed glass-ceramics with 0-14 wt%H_(3)BO_(3)as a flux agent.The effects of H_(3)BO_(3)on the crystallization process,foaming behavior,and physical properties of CaO-MgO-Al_(2)O_(3)-SiO_(2)foamed glass-ceramics were investigated.The results showed that the main crystalline phase of the foamed glass-ceramics was anorthite with diopside as a minor crystalline phase,which exhibited a typical surface crystallization process.The addition of H_(3)BO_(3)modified the surface of glass powders and inhibited crystal precipitation obviously.The low melting point of H_(3)BO_(3)and the decrease of crystallinity jointly promoted the growth of pores,resulting in a reduction of bulk density and an increase in porosity.The compressive strength and thermal conductivity of the samples were linearly related to the bulk density.In particular,the sample added with 10 wt%H_(3)BO_(3)exhibited excellent properties,possessing a low coefficient of thermal conductivity 0.081 W/(m·K)and relatively high compressive strength 3.36 MPa.
基金the support from the National Natural Science Foundation of China(52473083,52373089,52403085)Natural Science Basic Research Program of Shaanxi(2024JC-TBZC-04)+2 种基金the Innovation Capability Support Program of Shaanxi(2024RS-CXTD-57)Natural Science Basic Research Plan in Shaanxi Province of China(2024JC-YBMS-279)Natural Science Foundation of Chongqing,China(2023NSCQMSX2547)
文摘With the miniaturization and high-frequency evolution of antennas in 5G/6G communications,aerospace,and transportation,polymer composite papers integrating superior wave-transparent performance and thermal conductivity for radar antenna systems are urgently needed.Herein,a down-top strategy was employed to synthesize poly(p-phenylene benzobisoxazole)precursor nanofibers(prePNF).The prePNF was then uniformly mixed with fluorinated graphene(FG)to fabricate FG/PNF composite papers through consecutively suction filtration,hot-pressing,and thermal annealing.The hydroxyl and amino groups in prePNF enhanced the stability of FG/prePNF dispersion,while the increasedπ-πinteractions between PNF and FG after annealing improved their compatibility.The preparation time and cost of PNF paper was significantly reduced when applying this strategy,which enabled its large-scale production.Furthermore,the prepared FG/PNF composite papers exhibited excellent wave-transparent performance and thermal conductivity.When the mass fraction of FG was 40 wt%,the FG/PNF composite paper prepared via the down-top strategy achieved the wave-transparent coefficient(|T|2)of 96.3%under 10 GHz,in-plane thermal conductivity(λ_(∥))of 7.13 W m^(−1)K^(−1),and through-plane thermal conductivity(λ_(⊥))of 0.67 W m^(−1)K^(−1),outperforming FG/PNF composite paper prepared by the top-down strategy(|T|2=95.9%,λ_(∥)=5.52 W m^(−1)K^(−1),λ_(⊥)=0.52 W m^(−1)K^(−1))and pure PNF paper(|T|2=94.7%,λ_(∥)=3.04 W m^(−1)K^(−1),λ_(⊥)=0.24 W m^(−1)K^(−1)).Meanwhile,FG/PNF composite paper(with 40 wt%FG)through the down-top strategy also demonstrated outstanding mechanical properties with tensile strength and toughness reaching 197.4 MPa and 11.6 MJ m^(−3),respectively.
基金financially supported by the National Natural Science Foundation of China(22175044)the Guangxi Natural Science Foundation(2023GXNSFDA026049)the Guangxi Major Talents Program(GXR-1BGQ2424023)。
文摘The global energy crisis and electricity shortage pose unprecedented challenges.Bio-based solar-driven ionic power generation devices with flexibility,photothermal self-healing and scalability hold great promise for sustainable electricity and alleviating energy crisis.Here,inspired by plant transpiration,a multifunctional bio-based ion conductive elastomer with solar power generation capability was designed by engineered synergy among epoxy natural rubber,cellulose nanofibrils,lithium bis(trifluoromethane)sulfonimide and eumelanin.The film exhibits an outstanding stretchability(1072%)and toughness(22.7 MJ m^(-3)).The favorable synergy of low thermal conductivity,high hygroscopicity and photothermal conversion performance endowed the film with a large thermal gradient under light illumination,driving efficient water transpiration.Furthermore,the excellent interfacial compatibility between eumelanin and matrix facilitates the formation of space charge regions,which further enhances Li^(+)transport.The film demonstrates excellent evaporation rate(2.83 kg m^(-2)h^(-1)),output voltage(0.47 V)and conductivity(5.11×10^(-2)S m^(-1)).Notably,the film exhibits remarkable photothermal self-healing performance even in saline environment,achieving 99.6%healing efficiency of output voltage.Therefore,the film demonstrates significant prospects for applications in photo-thermoelectric generation and solar-driven ionic power generation.
基金supported by the National Natural Science Foundation of China (No.52274304)。
文摘Developing catalysts with excellent stability while significantly reducing the overpotential of the oxygen evolution reaction(OER) is crucial for advancing overall water splitting(OWS) systems.In this study,we synthesized the electrode material Ce-NiCo-LDHs@SnO_(2)/NF through a two-step hydrothermal reaction,where Ce-doped NiCo-LDHs are grown on nickel foam modified by a SnO_(2) layer.Ce doping adjusts the internal electronic distribution of Ni Co-LDHs,while the introduction of the SnO_(2) layer enhances electron transfer capability.Together,these factors contribute to the reduction of the OER energy barrier and experimental evidence confirms that the reaction proceeds via the lattice oxygen evolution mechanism(LOM).Consequently,Ce-NiCo-LDHs@SnO_(2)/NF exhibits high level electrochemical performance in OER,requiring only 234 m V overpotential to achieve a current density of 10 m A/cm^(2),with a Tafel slope of just 27.39 m V/dec.When paired with Pt/C/NF,an external potential of only 1.54 V is needed to drive OWS to attain a current density amounting to 10 m A/cm^(2).Furthermore,the catalyst demonstrates stability for 100 h during the OWS stability test.This study underscores the feasibility of enhancing the OER performance through Ce doping and the introduction of a conductive SnO_(2) layer.
基金funding support from the National Natural Science Foundation of China(Grant No.42477178)the National Key Research and Development Program of China(Grant No.2023YFC3709600)the Primary Research and Development Plan of Anhui Province(Grant No.2023t07020018).
文摘Acid mine drainage(AMD)leachate is a global pollutant issue that impacts groundwater environment quality.This study investigated the feasibility of a composite biopolymer-amended bentonite as a geosynthetic clay liner core material to contain AMD leachate.The real AMD leachate with a pH of 3.1,sourced from an acidic pyrite tailings site,was employed as a specific test leachate used in this study.The composite biopolymer was composed of welan gum(WG)and xanthan gum(XG)at different dry weight-based ratios.Modified fluid loss(MFL)tests were conducted to evaluate hydraulic conductivity(k)of bentonites to optimize WG:XG ratio.Rheological properties of biopolymer solutions were measured,serving as indicative parameters of biopolymer elution.The results indicated biopolymer-amended bentonites with the WG:XG ratio of 8:2 possessed lowest k(1.5×10^(−11)m/s to 7.2×10^(−11)m/s),lower than unamended bentonite(1.2×10^(−10)m/s to 8.6×10^(−10)m/s)in the AMD leachate condition.In addition,biopolymer solutions with WG:XG ratio of 8:2 exhibited highest viscosity.Thermogravimetric analysis,ultraviolet–visible spectroscopy,and Fourier transform infrared spectroscopy were conducted on the composite biopolymer,revealing that WG and XG interacted via physical cross-linking.Additionally,scanning electron microscopy and atomic force microscopy images indicated that a physical cross-linking and dense network structure conformation was developed in the composite biopolymer hydrogel at the WG:XG ratio of 8:2.The results demonstrate that the composite biopolymer is a promising low-carbon amendment material for enhancing containment performance of bentonite used in geosynthetic clay liners to contain AMD leachate.
文摘Transient electromagnetic methods are increasingly adopted for field investigation of oil pollution because they provide rapid,non-invasive imaging of subsurface electrical conductivity across depths relevant to vadose-zone impacts,groundwater plumes,and coastal transition zones.This review synthesizes recent advances that have expanded TEM(Transient Electromagnetic Method)’s environmental applicability,including higher dynamic range receivers,multi-moment acquisition that improves shallow-to-deep sensitivity,and diversified deployment platforms spanning ground,mobile/towed,airborne,and coastal/marine configurations,with emerging UAV(Unmanned Aerial Vehicle)options for constrained access.We emphasize the electrical and geochemical basis of hydrocarbon-related signatures,showing why fresh releases may appear resistive through NAPL(Non-Aqueous Phase Liquid)displacement of conductive pore water,whereas aged contamination often produces conductive responses driven by biodegradation,redox evolution,and elevated ionic strength.Because these responses are non-unique and can be confounded by clay-rich lithology,salinity gradients,temperature variability,and cultural infrastructure,contemporary interpretation has shifted toward process-consistent conceptual site models and uncertainty-aware products that communicate depth of investigation and resolution limits.A thematic synthesis of field applications indicates TEM is most reliable for mapping hydrogeological architecture,delineating plausible plume corridors,prioritizing intrusive sampling,and supporting monitoring where repeatability and background variability are controlled.The review concludes that TEM delivers the greatest decision value when integrated in a weight-of-evidence framework with hydrogeology,geochemistry,and targeted ground truth,and it highlights future needs in standardized reporting,robust time-lapse appraisal,and stronger petrophysical links to hydrocarbon transformation.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(2021R1A6A1A10044950).
文摘The thermal conductivity of nanofluids is an important property that influences the heat transfer capabilities of nanofluids.Researchers rely on experimental investigations to explore nanofluid properties,as it is a necessary step before their practical application.As these investigations are time and resource-consuming undertakings,an effective prediction model can significantly improve the efficiency of research operations.In this work,an Artificial Neural Network(ANN)model is developed to predict the thermal conductivity of metal oxide water-based nanofluid.For this,a comprehensive set of 691 data points was collected from the literature.This dataset is split into training(70%),validation(15%),and testing(15%)and used to train the ANN model.The developed model is a backpropagation artificial neural network with a 4–12–1 architecture.The performance of the developed model shows high accuracy with R values above 0.90 and rapid convergence.It shows that the developed ANN model accurately predicts the thermal conductivity of nanofluids.
基金National Science Fund for Distinguished Young Scholars,Grant/Award Number:52225403State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering,Grant/Award Number:SDGZK2404Fundamental Research Funds for the Central Universities,Grant/Award Number:2023KYJD1006。
文摘Hydrochloric acid(HCl)extensively exists in deep underground projects,arising from the transportation of industrial raw materials or fracturing fluids of petroleum engineering.It results in corrosion,which can significantly impact the stability of surrounding rock structures.Therefore,in-depth analysis of the degradation of rock corroded by the HCl solution is an essential task for underground engineering.In this study,the granite specimens are initially treated with the HCl solution with various concentrations.Then,the tests and analyses,such as electrical conductivity(EC)measurements,mineral composition assays,and Brazilian splitting tests,are employed to investigate the corrosion mechanism of the HCl solution.Our results and findings are generally as follows:(1)As the immersion time increases,the EC exhibits a relatively high level at pH value of 1,a decreasing trend at pH value of 3,and an increasing trend at pH value of 5 and 7.(2)The HCl solutions with various concentration have different effect on mineral composition,characterized by an increase in proportion of SiO_(2) and a reduction in proportion of Na_(2)O,Al_(2)O_(3),K_(2)O,MgO,and CaO,as the solution pH value decreases.(3)After immersion in the solutions with pH values of 1,3,and 5,the tensile strength of the granite decreases by 23.85%,20.84%,and 20.24%;the average stiffness of the specimen decreases by 29.29%,23.43%,and 11.97%;the proportion of releasable energy increases by 6%,4%,and -2%;the releasable energy decreases by 54.96%,26.09%,and 14.52%;and the dissipated energy decreases by approximately 68.85%,41.39%,and 5.41%,respectively.(4)The evolution of physical and mechanical properties of the immersed granite specimen can be analyzed from a chemical aspect.The corrosive action of HCl cleaves Si–O and Al–O chemical bonds within the granite,particularly altering the tetrahedral structures of its silicate components.This process involves breaking existing chemical bonds and the formation of new ones,ultimately destroying the silicate molecular structures.As the concentration of HCl increases,the rate of these reactions accelerates,progressively weakening the chemical bonds and consequently deteriorating the mechanical characteristics of the granite.These findings can deepen our knowledge about the corrosion effect of HCI solutions on natural surrounding rocks and serve as references for further research on rock corrosion mechanisms in underground engineering.
