The activation of HCl by cationic Au in the presence of C2H2 is important for the construction of active Au sites and in acetylene hydrochlorination.Here,we report a strategy for activating HCl by the Au-based support...The activation of HCl by cationic Au in the presence of C2H2 is important for the construction of active Au sites and in acetylene hydrochlorination.Here,we report a strategy for activating HCl by the Au-based supported ionic liquid phase(Au–SILP)technology with the[N(CN)2^–]anion.This strategy enables HCl to accept electrons from[N(CN)2^–]anions in Au–[N(CN)2^–]complexes rather than from pure[Bmim][N(CN)2],leading to notable improvement in both the reaction path and the stability of the catalyst without changing the reaction triggered by acetylene adsorption.Furthermore,the induction period of the Au–SILP catalyst was shown to be absent in the reaction process due to the high Au(III)content in the Au(Ⅲ)/Au(Ⅰ)site and the high substrate diffusion rate in the ionic liquid layer.This work provides a facile method to improve the stability of Au-based catalysts for acetylene hydrochlorination.展开更多
The remediation of lead-contaminated dredged sediments(LDS)presents significant environmental challenges.This study investigates the solidification/stabilization(S/S)mechanisms of ordinary Portland cement(OPC)modified...The remediation of lead-contaminated dredged sediments(LDS)presents significant environmental challenges.This study investigates the solidification/stabilization(S/S)mechanisms of ordinary Portland cement(OPC)modified with nano-silica(NS)across a continuum from nanoscale interactions to macroscopic performance.For this,a series of macroscopic experiments was conducted to evaluate the mechanical performance and lead-encapsulation efficiency,including unconfined compressive strength(UCS)and toxicity characteristic leaching procedure(TCLP).Microstructural and phase transformations were characterized using X-ray diffraction,thermogravimetric analysis,and scanning electron microscope.Molecular dynamics simulations revealed the interactions between NS-modified cement,calcium silicate hydrates(C-S-H)gel,and Illite,focusing on interaction energies,atomic density distributions and structural changes.Macroscopic analyses demonstrated that increasing NS content from 0%to 8%improved Pb-immobilization rate from 88.7%to 97.6%and enhanced UCS from 764 kPa to 1358 kPa.These improvements were attributed to NS enhancing the microstructural integrity of C-S-H gel and filling pores in samples.Nanoscale simulations elucidated that Pb-stabilization occurs through coordination bonds with oxygen atoms in the C-S-H silicon chains and on Illite surfaces,complemented by the formation of stable Pb_(3)(CO)_(3)(OH)_(2)precipitates.Additionally,the simulations revealed that Ca^(2+)migration from hydration products to mineral surfaces generated substantial repulsive interaction energies,reducing Illite layer dispersion.However,the presence of Pb impeded further Ca^(2+)migration,leading to expansion of the C-S-H gel,which collectively degraded the mechanical properties of the material.Furthermore,wet-dry and freeze-thaw cycles showed that after 10 cycles,UCS and TCLP results still met the United States Environmental Protection Agency standards,confirming long-term durability.This study provides a theoretical foundation for resource utilization of the contaminated sediments and offers a perspective for design of the cement-based curing agents,particularly in addressing variations in pollutant concentrations and environmental conditions,advancing the application of responsive and controlled release curing agents.展开更多
Li-metal batteries(LMBs)regain research prominence owing to the ever-increasing high-energy requirements.Commercially available carbonate electrolytes exhibit unfavourable parasitic reactions with Limetal anode(LMA),l...Li-metal batteries(LMBs)regain research prominence owing to the ever-increasing high-energy requirements.Commercially available carbonate electrolytes exhibit unfavourable parasitic reactions with Limetal anode(LMA),leading to the formation of unstable solid electrolyte interphase(SEI)and the breed of Li dendrites/dead Li.Significantly,lithium nitrate(LiNO_(3)),an excellent film-forming additive,proves crucial to construct a robust Li_(3)N/Li_(2)O/Li_(x)NO_(y)-rich SEI after combining with ether-based electrolytes.Thus,the given challenge leads to natural ideas which suggest the incorporation of LiNO_(3) into commercial carbonate for practical LMBs.Regrettably,LiNO_(3) demonstrates limited solubility(~800 ppm)in commercial carbonate electrolytes.Thence,developing stable SEI and dendrite-free LMA with the incorporation of LiNO_(3) into carbonate electrolytes is an efficacious strategy to realize robust LMBs via a scalable and cost-effective route.Therefore,this review unravels the grievances between LMA,LiNO_(3)and carbonate electrolytes,and enables a comprehensive analysis of LMA stabilizing mechanism with LiNO_(3),dissolution principle of LiNO_(3) in carbonate electrolytes,and LiNO_(3) introduction strategies.This review converges attention on a point that the LiNO_(3)-introduction into commercial carbonate electrolytes is an imperious choice to realize practical LMBs with commercial 4 V layered cathode.展开更多
The influence of prior austenite deformed at different temperature on the subsequent continuous cooling bainitic transformation has been investigated in an C-Ma-Cr-Ni-Mo plastic die steel. The results show that the pr...The influence of prior austenite deformed at different temperature on the subsequent continuous cooling bainitic transformation has been investigated in an C-Ma-Cr-Ni-Mo plastic die steel. The results show that the prior deformation in low temperature region of austenite retards significantly the bainitic transformation. For the same continuous cooling schedule, as austenite deformed at lower temperature, the quantity of the classical sheaf-like bainite becomes less. The present results show that severe deformation leads to mechanical stabilization of austenite and causes the difficulty of bainitic ferrite propagation into the austenite.展开更多
A series of tests were performed to investigate the macroscopic properties and the stabilization mechanism of calcium lignosulphonate modified expansive soil.Compared with natural soil,soil modified by 4%calcium ligno...A series of tests were performed to investigate the macroscopic properties and the stabilization mechanism of calcium lignosulphonate modified expansive soil.Compared with natural soil,soil modified by 4%calcium lignosulphonate showed 56.5%increased 28 days unconfined compressive strength and 23.8%decreased free expansion rate.The X-ray diffraction analysis results indicate the existence of cation exchange and the reduction of montmorillonite interplanar spacing.The X-computed tomography results demonstrate that calcium lignosulphonate decreased the porosity and optimized the pore distribution.The calcium lignosulphonate also increased the stability of the suspension system according to the Zeta potential results.Moreover,the results of rheological tests show that the moderate amount of calcium lignosulphonate enhanced the yield stress and the plastic viscosity,proving the formation of a strong connection between soil particles.展开更多
The effects of the concentration of monomer, crosslinking agent, initiator, stabilizer, and the polarity of medium on the polymerization kinetics were investigated. The results show that the rate of polymerization (Rp...The effects of the concentration of monomer, crosslinking agent, initiator, stabilizer, and the polarity of medium on the polymerization kinetics were investigated. The results show that the rate of polymerization (Rp) and conversion increased with the increase of monomer concentration from 8% to 15% (total mass); the water content in dispersion medium and the initiator 2, 2′ -azobis (isobutyronitrile) (AIBN) concentration increased as well. Rp and conversion decreases with the increase of PVP when it is low, while it increases when it is high. Moreover, PVP plays an important role in microsphere stabilization. The stabilization mechanism was investigated primarily, which involves both adsorbing mechanism and graft mechanism. Within a certain range of crosslinking degree, Rp and conversion increased with the increase of the crosslinker concentration. The effect can be ignored when crosslinker concentration is above 0.3 % (total mass), and the reason was that the monomer can hardly be diffused into the microsphere phase with a certain degree of crosslinking.展开更多
The controllable active thermo-atmosphere combustor(CATAC) has become a utilizable and effective facility because it benefits the optical diagnostics and modeling. This paper presents the modeling research of the auto...The controllable active thermo-atmosphere combustor(CATAC) has become a utilizable and effective facility because it benefits the optical diagnostics and modeling. This paper presents the modeling research of the auto-ignition and flames of the H2/N2(H2/CH4/N2,or H2/H2O2/N2) mixture on a CATAC,and shows curves varying with temperatures of auto-ignition delay,the height of the site of auto-ignition of lifted flames,and flame lift-off height. The results of auto-ignition delay and the lift-off height are compared the experimental results to validate the model. A turning point can be seen on each curve,identified with criterion temperature. It can be concluded that when the co-flow temperature is higher than the criterion temperature,the auto-ignition and lifted flame of the mixture are not stable. Conversely,below the criterion temperature,the mixture will auto-ignite in a stable fashion. Stabilization mechanisms of auto-ignition and lifted flames are analyzed in terms of the criterion temperature.展开更多
During the development of low or ultra-low permeability oil resources,the alternative energy supply becomes a prominent issue.In recent years,carbon dots(CDs)have drawn much attention owing to their application potent...During the development of low or ultra-low permeability oil resources,the alternative energy supply becomes a prominent issue.In recent years,carbon dots(CDs)have drawn much attention owing to their application potential in oil fields for reducing injection pressure and augmenting oil recovery.However,carbon dots characterized of small size,high surface energy are faced with several challenges,such as self-aggregation and settling.The preparation of stably dispersed carbon dots nanofluids is the key factor to guarantee its application performance in formation.In this work,we investigated the stability of hydrophilic carbon dots(HICDs)and hydrophobic carbon dots-Tween 80(HOCDs)nanofluids.The influences of carbon dots concentration,sorts and concentration of salt ions as well as temperature on the stability of CDs were studied.The results showed that HICDs are more sensitive to sort and concentration of salt ions,while HOCDs are more sensitive to temperature.In addition,the core flooding experiments demonstrated that the pressure reduction rate of HICDs and HOCDs nanofluids can be as high as 17.88%and 26.14%,respectively.Hence,the HICDs and HOCDs nanofluids show a good application potential in the reduction of injection pressure during the development of low and ultra-low permeability oil resources.展开更多
In this work,selective laser melting(SLM)process is used to prepare the AlNi6TiZr alloy.By analyzing the printing quality and mechanical properties of the printed specimens with different process parameters,the SLM fo...In this work,selective laser melting(SLM)process is used to prepare the AlNi6TiZr alloy.By analyzing the printing quality and mechanical properties of the printed specimens with different process parameters,the SLM forming window of AlNi6TiZr is obtained.The relative density of the sample printed with 270 W-1100 mm/s(laser energy density:82 J/mm3)reaches 99.7%,exhibiting excellent mechanical properties(yield strength(YS):421.7 MPa;ultimate tensile strength(UTS):480.4 MPa).After an aging treatment of 325 ℃-12 h,the YS and UTS of the sample increased to 494 MPa and 550.7 MPa,respectively.Adding Ni,Ti,and Zr components promoted the generation of multi-phase precipitates in the Al alloy and improved the synergistic strengthening effect of multi-phases.The hard-shell structure(HSS)formed by the Al_(3)Ni phase at the grain boundary significantly strengthened the grain boundary strength.The precipitated Al_(3)(Ti,Zr)phases at the grain boundaries prevent grain growth and dislocation movement.The Al_(3)Ni and Al_(3)(Ti,Zr)phases have good thermal stability that can still maintain excellent enhancement effects at high temperature.AlNi6TiZr alloy has great application prospects in medium and high-temperature environments.展开更多
The ZnO quantum dots（QDs） were synthesized with improved chemical solution method.The size of the ZnO QDs is exceedingly uniform with a diameter of approximately 4.8 nm,which are homogeneously dispersed in ethanol.T...The ZnO quantum dots（QDs） were synthesized with improved chemical solution method.The size of the ZnO QDs is exceedingly uniform with a diameter of approximately 4.8 nm,which are homogeneously dispersed in ethanol.The optical absorption edge shifts from 370 nm of bulk material to 359 nm of QD materials due to the quantum size effect,while the photoluminescence peak shifts from 375 nm to 387 nm with the increase of the density of ZnO QDs.The stability of ZnO QDs was studied with different dispersion degrees at 0？C and at room temperature of 25？C.The agglomeration mechanisms and their relationship with the emission spectra were uncovered for the first time.With the ageing of Zn O QDs,the agglomeration is aggravated and the surface defects increase,which leads to the defect emission.展开更多
Theoretically,copper–niobium(Cu-Nb)composite superconducting cavities have excellent potential for high thermal and mechanical stability.They can appropriately exploit the high-gradient surface processing recipes dev...Theoretically,copper–niobium(Cu-Nb)composite superconducting cavities have excellent potential for high thermal and mechanical stability.They can appropriately exploit the high-gradient surface processing recipes developed for the bulk niobium(Nb)cavity and the thick copper(Cu)layer’s high thermal conductivity and rigidity,thereby enhancing the operational stability of the bulk Nb cavities.This study conducted a global review of the technical approaches employed for fabricating Cu-Nb composite superconducting cavities.We explored Cu-Nb composite superconducting cavities based on two technologies at the Institute of Modern Physics,Chinese Academy of Sciences(IMP,CAS),including their manufacturing processes,radio-frequency(RF)characteristics,and mechanical performance.These cavities exhibit robust mechanical stability.First,the investigation of several 1.3 GHz single-cell elliptical cavities using the Cu-Nb composite sheets indicated that the wavy structure at the Cu-Nb interface influenced the reliable welding of the Cu-Nb composite parts.We observed the generation and trapping of magnetic flux density during the T_c crossing of Nb in cooldown process.The cooling rates during the T_c crossing of Nb exerted a substantial impact on the performance of the cavities.Furthermore,we measured and analyzed the surface resistance R_(s)attributed to the trapped magnetic flux induced by the Seebeck effect after quenching events.Second,for the first time,a low-beta bulk Nb cavity was plated with Cu on its outer surface using electroplating technology.We achieved a high peak electric field E_(pk)of~88.8 MV/m at 2 K and the unloaded quality factor Q_(0)at the E_(pk)of 88.8 MV/m exceeded 1×10^(10).This demonstrated that the electroplating Cu on the bulk Nb cavity is a practical method of developing the Cu-Nb composite superconducting cavity with superior thermal stability.The results presented here provide valuable insights for applying Cu-Nb composite superconducting cavities in superconducting accelerators with stringent operational stability requirements.展开更多
Evaluating the stabilized lead(Pb)-contaminated soils through sampling and laboratory testing involves costly and time-consuming processes.Therefore,this study employed a low-cost and non-destructive resistivity tool ...Evaluating the stabilized lead(Pb)-contaminated soils through sampling and laboratory testing involves costly and time-consuming processes.Therefore,this study employed a low-cost and non-destructive resistivity tool to evaluate the Pb-contaminated soils stabilized by electrolytic manganese residue(EMR)-based geopolymer(EG-OPC)from the strength and environmental benefits perspective.First,unconfined compressive strength(UCS)and leaching tests were conducted to study the stabilization effectiveness of EG-OPC.Results indicated that the UCS values of soil(5000 mg/kg of pollutants)stabilized by 20%EG-OPC were 4.87 MPa and 8.13 MPa after 7 d and 60 d of curing,respectively.After 60 d of curing,the Pb concentration in the leachate reached 44 mg/L,far lower than the control group(321 mg/L).Second,soil,pore water,and leachate resistivity(ERS,ERW,and ERL)were measured to establish fitting relationships with strength parameters and pollution risk.The good fitting results(e.g.ERS/ERW versus UCS/secant modulus(E50):correlation coefficient R2 z 0.9,ERS/ERW versus Pb contents:R2 z 0.9,and ERL versus Pb2þconcentration:R2¼0.92)and well used Archie's law(ERS versus ERW:R2>0.9)indicate that the resistivity can be used to evaluate the stabilization effectiveness.Furthermore,the microscopic results revealed two behaviors,demonstrating the reliability of resistivity:(1)with the hydration process,resistivity increases due to a denser structure and lower amounts of free water and Pb ions,and(2)the addition of Pb reduces resistivity due to its inhibition or even destructive effects on cementation and formation of hydration products.展开更多
Microbial polysaccharides,due to their unique physicochemical properties,have been shown to effec-tively enhance the stability of foam fracturing fluids.However,the combined application of microbial polysaccharides an...Microbial polysaccharides,due to their unique physicochemical properties,have been shown to effec-tively enhance the stability of foam fracturing fluids.However,the combined application of microbial polysaccharides and surfactants under high-temperature and high-salinity conditions remain poorly understood.In this study,we innovatively investigate this problem with a particular focus on foam stabilization mechanisms.By employing the Waring blender method,the optimal surfactant-microbial polysaccharide blends are identified,and the foam stability,rheological properties,and decay behavior in different systems under varying conditions are systematically analyzed for the first time.The results reveal that microbial polysaccharides significantly enhance foam stability by improving the viscoelasticity of the liquid films,particularly under high-salinity and high-temperature conditions,leading to notable improvements in both foam stability and sand-carrying capacity.Additionally,scanning electron microscopy(SEM)is used to observe the microstructure of the foam liquid films,demonstrating that the network structure formed by the foam stabilizer within the liquid film effectively inhibits foam coarsening.The Lauryl betaine and Diutan gum blend exhibits outstanding foam stability,superior sand-carrying capacity,and minimal core damage,making(LAB+MPS04)it ideal for applications in enhanced production and reservoir stimulation of unconventional reservoirs.展开更多
Building a superhydrophobic coating on a carbon steel substrate is an effective strategy for enhancing metal protection.A practical approach to producing a series of superhydrophobic Ni/SiO_(2)composite coatings(SSN)u...Building a superhydrophobic coating on a carbon steel substrate is an effective strategy for enhancing metal protection.A practical approach to producing a series of superhydrophobic Ni/SiO_(2)composite coatings(SSN)using one-step electrodeposition method is shown.The effect of processing parameters on surface structure and wettability was thoroughly explored,resulting in the identification of three typical surface morphologies.The prepared coating with petal-like structure(SSN-3)obtained under the optimum parameters exhibited the best water repellency,achieving a contact angle of 162.7°and a sliding angle of 4.1°.The droplet bouncing behavior on SSN coatings surface was studied,and the delayed icing time was recorded.Meanwhile,the mechanical stability and chemical corrosion resistance of SSN coatings were focused.The superhydrophobic SSN-3 coating with unique surface structure exhibited excellent reliability.The anticorrosion mechanism of SSN-3 coating was discussed,and its corrosion protection efficiency was up to 98.5%.The superior properties of the superhydrophobic SSN-3 coating make it suitable for diverse applications.展开更多
Magnesium(Mg)-based composites are expected to be useful for biodegradable bone-implant materials due to their degradability,similar elastic modulus to that of bone,and biofunctionalities.However,their rapid degradati...Magnesium(Mg)-based composites are expected to be useful for biodegradable bone-implant materials due to their degradability,similar elastic modulus to that of bone,and biofunctionalities.However,their rapid degradation,poor biotribology performance,and lack of vascularization and antibacterial activity are not conducive to bone-fixation applications.In this study,an in situ Mg_(2)Ge/Mg-Cu-P composite with a nominal composition of Mg-10Ge-2Cu-0.5P(denoted MGCP)was prepared via phosphorus(P)-modified casting followed by hot extrusion for biodegradable bone-fixation applications.For comparison,an in situ Mg_(2)Ge/Mg-Cu composite(Mg-10Ge-2Cu,denoted MGC)was prepared under the same conditions without P-modification.The hot-extruded(HE)MGCP sample showed significantly improved corrosion resistance with corrosion rates of 2.2 mm/y and 2.51 mm/y as measured by potentiodynamic-polarization and hydrogen-release testing in Dulbecco’s Modified Eagle Medium supplemented with fetal bovine serum(denoted DMEM).The HE MGCP also exhibited notably enhanced mechanical properties and biotribological resistance in DMEM,with an σ_(UTS) of ~304.2 MPa,σ_(TYS) of ~202.5 MPa,elongation of ~12.3%,σ_(UCS) of 769.0 MPa,σ_(CYS) of 208.0 MPa,and Brinell hardness of 105.3 HB,along with smallerσ_(TYS) andσ_(CYS) decreases after 3 d of immersion in Hanks’solution.In comparison to pure titanium and Mg,the HE MGCP demonstrated much greater cytocompatibility,angiogenic capacity,and osteogenic differentiation and mineralization capability.Furthermore,the HE MGCP displayed markedly higher in vitro antibacterial activity,in vivo antibacterial and anti-inflammatory ability,and good biosafety in a rat subcutaneous-implantation model compared to pure titanium and Mg,indicating significant potential for biodegradable bone-fixation applications.展开更多
Based on A356 aluminum alloy,aluminum foams were prepared by gas injection foaming process with pure nitrogen,air and some gas mixtures.The oxygen volume fraction of these gas mixtures varied from 0.2%to 8.0%.Optical ...Based on A356 aluminum alloy,aluminum foams were prepared by gas injection foaming process with pure nitrogen,air and some gas mixtures.The oxygen volume fraction of these gas mixtures varied from 0.2%to 8.0%.Optical microscopy,scanning electron microscopy（SEM） and Auger electron spectroscopy（AES） were used to analyze the influence of oxygen content on cell structure,relative density,macro and micro morphology of cell walls,coverage area fraction of oxide film,thickness of oxide film and other aspects.Results indicate that the coverage area fraction of oxide film on bubble surface increases with the increase of oxygen content when the oxygen volume is less than 1.2%.While when the oxygen volume fraction is larger than 1.6%,an oxide film covers the entire bubble surface and aluminum foams with good cell structure can be produced.The thicknesses of oxide films of aluminum foams produced by gas mixtures containing 1.6%-21%oxygen are almost the same.The reasons why the thickness of oxide film nearly does not change with the variation of oxygen content and the amount of oxygen needed to achieve 100%coverage of oxide film are both discussed.In addition,the role of oxide film on bubble surface in foam stability is also analyzed.展开更多
A series of stearates with different rare-earth ion were investigated as thermal stabilizers for rigid PVC at 180 ℃ in air. Their stabilizing efficiency was based on measuring the rate of dehydrochlorination. The res...A series of stearates with different rare-earth ion were investigated as thermal stabilizers for rigid PVC at 180 ℃ in air. Their stabilizing efficiency was based on measuring the rate of dehydrochlorination. The resulted revealed the higher stabilizing efficiency of the investigated rare-earth stearates as thermal stabilizers for rigid PVC compared with the thermal stabilizers for industry: calcium stearate, zinc stearate, butyl stannum mercaptide, phosphite esters, β-diketone and epoxidized sunflower oil. This was well illustrated by longer incubation period (T_S) values and lower rate of dehydrochlorination. The stable efficiency was affected by the nature of rare-earth element's individual electronic shell. The mechanism for the stabilizing effect of rare-earth stearates was proposed. The result was experimentally proved based on IR spectrum.展开更多
At present,all kinds of municipal solid waste incineration (MSWI) fly ash stabilization technology has been reported and successfully applied in many countries.However,leaching procedures are very different that the t...At present,all kinds of municipal solid waste incineration (MSWI) fly ash stabilization technology has been reported and successfully applied in many countries.However,leaching procedures are very different that the technologies lack uniform standard,and it is even impossible to predict the long-term stabilization.Geochemical model can explain the environmental stabilization based on chemical phase and thermodynamic crystal structure,and it is also able to guide the development of environment-friendly stabi...展开更多
Carbon dioxide(CO2) capture and storage(CCS) is considered widely as one of promising options for CO2emissions reduction,especially for those countries with coal-dominant energy mix like China.Injecting and storing a ...Carbon dioxide(CO2) capture and storage(CCS) is considered widely as one of promising options for CO2emissions reduction,especially for those countries with coal-dominant energy mix like China.Injecting and storing a huge volume of CO2in deep formations are likely to cause a series of geomechanical issues,including ground surface uplift,damage of caprock integrity,and fault reactivation.The Shenhua CCS demonstration project in Ordos Basin,China,is the first and the largest full-chain saline aquifer storage project of CO2in Asia.The injection started in 2010 and ended in 2015.during which totally 0.3 million tonnes(Mt) CO2was injected.The project is unique in which CO2was injected into 18 sandstone formations simultaneously and the overlying coal seams will be mined after the injection stopped in 2015.Hence,intense geomechanical studies and monitoring works have been conducted in recent years,including possible damage resulting from the temperature difference between injected CO2and formations,injection induced stress and deformation change,potential failure mode and safety factor,interaction between coal mining and CO2geological storage,determination of injection pressure limit,and surface monitoring by the interferometric synthetic aperture radar(InSAR) technology.In this paper,we first described the background and its geological conditions of the Shenhua CCS demonstration project.Then,we gave an introduction to the coupled thermo-hydro-mechano-chemical(THMC) processes in CO2geological storage,and mapped the key geomechanical issues into the THMC processes accordingly.Next,we proposed a generalized geomechanical research flowchart for CO2geological storage projects.After that,we addressed and discussed some typical geomechanical issues,including design of injection pressure limit.CO2injection induced near-field damage,and interaction between CO2geological storage and coal mining,in the Shenhua CCS demonstration project.Finally,we concluded some insights to this CCS project.展开更多
The well understanding of interaction forces between single dispersed droplets is crucial to the understanding of emulsion stabilization mechanism.Recently,many studies have reported the direct quantitative measuremen...The well understanding of interaction forces between single dispersed droplets is crucial to the understanding of emulsion stabilization mechanism.Recently,many studies have reported the direct quantitative measurements of interaction forces between 20-200μm single droplet coated polymers by atomic force microscope(AFM).These studies have revealed many important results about the relationship of the interaction forces and the droplet deformation.However,these studies of the quantitative relationship between the measured interaction forces and the separation distance of the front end of the droplet have rarely been reported.Optical tweezer instrument can make it possible to establish the quantitative relationship between the measured force and the separation distance of the front end of the droplet,which will make better understanding of the interaction mechanisms between droplets.Due to the differences of the measuring mechanism between atomic force microscopy(AFM)and optical tweezers,the theory model of AFM measurements cannot be fitted with the force measurement by optical tweezers.We have made an exhaustive comparison of the measuring differences between AFM and optical tweezer instrument in this work.Moreover,we built a numerical model to derive the repulsive pressure through the measured force curve in order to quantify the measured force of two micron-sized oil droplet coated polymers by optical tweezers.Furthermore,the novel method can be extended to other micron-sized emulsion systems,and these findings will be a vital progress on quantitative force measurements between micron-sized droplets.展开更多
文摘The activation of HCl by cationic Au in the presence of C2H2 is important for the construction of active Au sites and in acetylene hydrochlorination.Here,we report a strategy for activating HCl by the Au-based supported ionic liquid phase(Au–SILP)technology with the[N(CN)2^–]anion.This strategy enables HCl to accept electrons from[N(CN)2^–]anions in Au–[N(CN)2^–]complexes rather than from pure[Bmim][N(CN)2],leading to notable improvement in both the reaction path and the stability of the catalyst without changing the reaction triggered by acetylene adsorption.Furthermore,the induction period of the Au–SILP catalyst was shown to be absent in the reaction process due to the high Au(III)content in the Au(Ⅲ)/Au(Ⅰ)site and the high substrate diffusion rate in the ionic liquid layer.This work provides a facile method to improve the stability of Au-based catalysts for acetylene hydrochlorination.
基金the supports from the National Natural Science Foundation of China(Grant Nos.42177163 and 42307232)the China Postdoctoral Science Foundation of China(Grant No.2022M723347).
文摘The remediation of lead-contaminated dredged sediments(LDS)presents significant environmental challenges.This study investigates the solidification/stabilization(S/S)mechanisms of ordinary Portland cement(OPC)modified with nano-silica(NS)across a continuum from nanoscale interactions to macroscopic performance.For this,a series of macroscopic experiments was conducted to evaluate the mechanical performance and lead-encapsulation efficiency,including unconfined compressive strength(UCS)and toxicity characteristic leaching procedure(TCLP).Microstructural and phase transformations were characterized using X-ray diffraction,thermogravimetric analysis,and scanning electron microscope.Molecular dynamics simulations revealed the interactions between NS-modified cement,calcium silicate hydrates(C-S-H)gel,and Illite,focusing on interaction energies,atomic density distributions and structural changes.Macroscopic analyses demonstrated that increasing NS content from 0%to 8%improved Pb-immobilization rate from 88.7%to 97.6%and enhanced UCS from 764 kPa to 1358 kPa.These improvements were attributed to NS enhancing the microstructural integrity of C-S-H gel and filling pores in samples.Nanoscale simulations elucidated that Pb-stabilization occurs through coordination bonds with oxygen atoms in the C-S-H silicon chains and on Illite surfaces,complemented by the formation of stable Pb_(3)(CO)_(3)(OH)_(2)precipitates.Additionally,the simulations revealed that Ca^(2+)migration from hydration products to mineral surfaces generated substantial repulsive interaction energies,reducing Illite layer dispersion.However,the presence of Pb impeded further Ca^(2+)migration,leading to expansion of the C-S-H gel,which collectively degraded the mechanical properties of the material.Furthermore,wet-dry and freeze-thaw cycles showed that after 10 cycles,UCS and TCLP results still met the United States Environmental Protection Agency standards,confirming long-term durability.This study provides a theoretical foundation for resource utilization of the contaminated sediments and offers a perspective for design of the cement-based curing agents,particularly in addressing variations in pollutant concentrations and environmental conditions,advancing the application of responsive and controlled release curing agents.
基金the support by the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(2019R01006)the National Natural Science Foundation of China(NSFC:12205252)+3 种基金A Project Supported by Scientific Research Fund of Zhejiang Provincial Education Department(Y202250795)the Research Funds of Institute of Zhejiang University-Quzhou,the Basic Public Welfare Research Special Project of Zhejiang Province(LZY22B040001)the Science and Technology Project of Quzhou Research Institute,Zhejiang University(IZQ2021KJ2032)the Independent Scientific Research Project of Quzhou Research Institute,Zhejiang University(IZQ2021RCZX007)。
文摘Li-metal batteries(LMBs)regain research prominence owing to the ever-increasing high-energy requirements.Commercially available carbonate electrolytes exhibit unfavourable parasitic reactions with Limetal anode(LMA),leading to the formation of unstable solid electrolyte interphase(SEI)and the breed of Li dendrites/dead Li.Significantly,lithium nitrate(LiNO_(3)),an excellent film-forming additive,proves crucial to construct a robust Li_(3)N/Li_(2)O/Li_(x)NO_(y)-rich SEI after combining with ether-based electrolytes.Thus,the given challenge leads to natural ideas which suggest the incorporation of LiNO_(3) into commercial carbonate for practical LMBs.Regrettably,LiNO_(3) demonstrates limited solubility(~800 ppm)in commercial carbonate electrolytes.Thence,developing stable SEI and dendrite-free LMA with the incorporation of LiNO_(3) into carbonate electrolytes is an efficacious strategy to realize robust LMBs via a scalable and cost-effective route.Therefore,this review unravels the grievances between LMA,LiNO_(3)and carbonate electrolytes,and enables a comprehensive analysis of LMA stabilizing mechanism with LiNO_(3),dissolution principle of LiNO_(3) in carbonate electrolytes,and LiNO_(3) introduction strategies.This review converges attention on a point that the LiNO_(3)-introduction into commercial carbonate electrolytes is an imperious choice to realize practical LMBs with commercial 4 V layered cathode.
文摘The influence of prior austenite deformed at different temperature on the subsequent continuous cooling bainitic transformation has been investigated in an C-Ma-Cr-Ni-Mo plastic die steel. The results show that the prior deformation in low temperature region of austenite retards significantly the bainitic transformation. For the same continuous cooling schedule, as austenite deformed at lower temperature, the quantity of the classical sheaf-like bainite becomes less. The present results show that severe deformation leads to mechanical stabilization of austenite and causes the difficulty of bainitic ferrite propagation into the austenite.
基金Funded by National Natural Science Foundation of China(Nos.51890904 and 51508090)National Key Technology R&D Program of China(No.2017YFB0309904)the National Basic Research Program of China(973 Program)(No.2015CB655100)。
文摘A series of tests were performed to investigate the macroscopic properties and the stabilization mechanism of calcium lignosulphonate modified expansive soil.Compared with natural soil,soil modified by 4%calcium lignosulphonate showed 56.5%increased 28 days unconfined compressive strength and 23.8%decreased free expansion rate.The X-ray diffraction analysis results indicate the existence of cation exchange and the reduction of montmorillonite interplanar spacing.The X-computed tomography results demonstrate that calcium lignosulphonate decreased the porosity and optimized the pore distribution.The calcium lignosulphonate also increased the stability of the suspension system according to the Zeta potential results.Moreover,the results of rheological tests show that the moderate amount of calcium lignosulphonate enhanced the yield stress and the plastic viscosity,proving the formation of a strong connection between soil particles.
基金Supported by the National Natural Science Foundation of China (20901063)Wuhan Chenguang Scheme (201050231049)the Open Research Fund of Key Laboratory for Green Chemical Process of Ministry of Education(GCP201003)
文摘The effects of the concentration of monomer, crosslinking agent, initiator, stabilizer, and the polarity of medium on the polymerization kinetics were investigated. The results show that the rate of polymerization (Rp) and conversion increased with the increase of monomer concentration from 8% to 15% (total mass); the water content in dispersion medium and the initiator 2, 2′ -azobis (isobutyronitrile) (AIBN) concentration increased as well. Rp and conversion decreases with the increase of PVP when it is low, while it increases when it is high. Moreover, PVP plays an important role in microsphere stabilization. The stabilization mechanism was investigated primarily, which involves both adsorbing mechanism and graft mechanism. Within a certain range of crosslinking degree, Rp and conversion increased with the increase of the crosslinker concentration. The effect can be ignored when crosslinker concentration is above 0.3 % (total mass), and the reason was that the monomer can hardly be diffused into the microsphere phase with a certain degree of crosslinking.
基金Project supported by the National Basic Research Program (973) of China (No. 2007CB210005)the National Natural Science Foundation of China (Nos. 50676055 and 50946052)+1 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 200802471052)the Shanghai Rising-Star Program (No.07QA14055),China
文摘The controllable active thermo-atmosphere combustor(CATAC) has become a utilizable and effective facility because it benefits the optical diagnostics and modeling. This paper presents the modeling research of the auto-ignition and flames of the H2/N2(H2/CH4/N2,or H2/H2O2/N2) mixture on a CATAC,and shows curves varying with temperatures of auto-ignition delay,the height of the site of auto-ignition of lifted flames,and flame lift-off height. The results of auto-ignition delay and the lift-off height are compared the experimental results to validate the model. A turning point can be seen on each curve,identified with criterion temperature. It can be concluded that when the co-flow temperature is higher than the criterion temperature,the auto-ignition and lifted flame of the mixture are not stable. Conversely,below the criterion temperature,the mixture will auto-ignite in a stable fashion. Stabilization mechanisms of auto-ignition and lifted flames are analyzed in terms of the criterion temperature.
基金supported by the National Natural Science Foundation of China(51704313)the Chang Jiang Scholars Program(No.T2014152)。
文摘During the development of low or ultra-low permeability oil resources,the alternative energy supply becomes a prominent issue.In recent years,carbon dots(CDs)have drawn much attention owing to their application potential in oil fields for reducing injection pressure and augmenting oil recovery.However,carbon dots characterized of small size,high surface energy are faced with several challenges,such as self-aggregation and settling.The preparation of stably dispersed carbon dots nanofluids is the key factor to guarantee its application performance in formation.In this work,we investigated the stability of hydrophilic carbon dots(HICDs)and hydrophobic carbon dots-Tween 80(HOCDs)nanofluids.The influences of carbon dots concentration,sorts and concentration of salt ions as well as temperature on the stability of CDs were studied.The results showed that HICDs are more sensitive to sort and concentration of salt ions,while HOCDs are more sensitive to temperature.In addition,the core flooding experiments demonstrated that the pressure reduction rate of HICDs and HOCDs nanofluids can be as high as 17.88%and 26.14%,respectively.Hence,the HICDs and HOCDs nanofluids show a good application potential in the reduction of injection pressure during the development of low and ultra-low permeability oil resources.
基金Post Graduate Innovation Funding Project of Hebei Province(No.CXZZSS2023041)Hebei Natural Science Foundation of China(No.E2021203138)Special Project for Local Science and Technology Development Guided by the Central Government of Hebei Province(236Z1805G).
文摘In this work,selective laser melting(SLM)process is used to prepare the AlNi6TiZr alloy.By analyzing the printing quality and mechanical properties of the printed specimens with different process parameters,the SLM forming window of AlNi6TiZr is obtained.The relative density of the sample printed with 270 W-1100 mm/s(laser energy density:82 J/mm3)reaches 99.7%,exhibiting excellent mechanical properties(yield strength(YS):421.7 MPa;ultimate tensile strength(UTS):480.4 MPa).After an aging treatment of 325 ℃-12 h,the YS and UTS of the sample increased to 494 MPa and 550.7 MPa,respectively.Adding Ni,Ti,and Zr components promoted the generation of multi-phase precipitates in the Al alloy and improved the synergistic strengthening effect of multi-phases.The hard-shell structure(HSS)formed by the Al_(3)Ni phase at the grain boundary significantly strengthened the grain boundary strength.The precipitated Al_(3)(Ti,Zr)phases at the grain boundaries prevent grain growth and dislocation movement.The Al_(3)Ni and Al_(3)(Ti,Zr)phases have good thermal stability that can still maintain excellent enhancement effects at high temperature.AlNi6TiZr alloy has great application prospects in medium and high-temperature environments.
基金Project supported by the FRFCU(Grant No.2016JBM066)863 Program(Grant No.2013AA032205)+1 种基金the National Natural Science Foundation of China(Grant Nos.61575019,51272022,and 11474018)RFDP(Grant Nos.20120009130005 and 20130009130001)
文摘The ZnO quantum dots（QDs） were synthesized with improved chemical solution method.The size of the ZnO QDs is exceedingly uniform with a diameter of approximately 4.8 nm,which are homogeneously dispersed in ethanol.The optical absorption edge shifts from 370 nm of bulk material to 359 nm of QD materials due to the quantum size effect,while the photoluminescence peak shifts from 375 nm to 387 nm with the increase of the density of ZnO QDs.The stability of ZnO QDs was studied with different dispersion degrees at 0？C and at room temperature of 25？C.The agglomeration mechanisms and their relationship with the emission spectra were uncovered for the first time.With the ageing of Zn O QDs,the agglomeration is aggravated and the surface defects increase,which leads to the defect emission.
基金supported by the Large Research Infrastructures China initiative Accelerator Driven System(No.2017-000052-75-01-000590)the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2022422)+1 种基金the Young Scientists of National Natural Science Foundation of China(No.12005275)the Advanced Energy Science and Technology Guangdong Laboratory(No.HND22PTZZYY)。
文摘Theoretically,copper–niobium(Cu-Nb)composite superconducting cavities have excellent potential for high thermal and mechanical stability.They can appropriately exploit the high-gradient surface processing recipes developed for the bulk niobium(Nb)cavity and the thick copper(Cu)layer’s high thermal conductivity and rigidity,thereby enhancing the operational stability of the bulk Nb cavities.This study conducted a global review of the technical approaches employed for fabricating Cu-Nb composite superconducting cavities.We explored Cu-Nb composite superconducting cavities based on two technologies at the Institute of Modern Physics,Chinese Academy of Sciences(IMP,CAS),including their manufacturing processes,radio-frequency(RF)characteristics,and mechanical performance.These cavities exhibit robust mechanical stability.First,the investigation of several 1.3 GHz single-cell elliptical cavities using the Cu-Nb composite sheets indicated that the wavy structure at the Cu-Nb interface influenced the reliable welding of the Cu-Nb composite parts.We observed the generation and trapping of magnetic flux density during the T_c crossing of Nb in cooldown process.The cooling rates during the T_c crossing of Nb exerted a substantial impact on the performance of the cavities.Furthermore,we measured and analyzed the surface resistance R_(s)attributed to the trapped magnetic flux induced by the Seebeck effect after quenching events.Second,for the first time,a low-beta bulk Nb cavity was plated with Cu on its outer surface using electroplating technology.We achieved a high peak electric field E_(pk)of~88.8 MV/m at 2 K and the unloaded quality factor Q_(0)at the E_(pk)of 88.8 MV/m exceeded 1×10^(10).This demonstrated that the electroplating Cu on the bulk Nb cavity is a practical method of developing the Cu-Nb composite superconducting cavity with superior thermal stability.The results presented here provide valuable insights for applying Cu-Nb composite superconducting cavities in superconducting accelerators with stringent operational stability requirements.
基金supported by the National Key R&D Program of China(Grant No.2022YFC3901204)the Foundation for Distinguished Young Scholars of Hubei Province,China(Grant No.2021CFA096)the National Natural Science Foundation of China(Grant No.U20A20320).
文摘Evaluating the stabilized lead(Pb)-contaminated soils through sampling and laboratory testing involves costly and time-consuming processes.Therefore,this study employed a low-cost and non-destructive resistivity tool to evaluate the Pb-contaminated soils stabilized by electrolytic manganese residue(EMR)-based geopolymer(EG-OPC)from the strength and environmental benefits perspective.First,unconfined compressive strength(UCS)and leaching tests were conducted to study the stabilization effectiveness of EG-OPC.Results indicated that the UCS values of soil(5000 mg/kg of pollutants)stabilized by 20%EG-OPC were 4.87 MPa and 8.13 MPa after 7 d and 60 d of curing,respectively.After 60 d of curing,the Pb concentration in the leachate reached 44 mg/L,far lower than the control group(321 mg/L).Second,soil,pore water,and leachate resistivity(ERS,ERW,and ERL)were measured to establish fitting relationships with strength parameters and pollution risk.The good fitting results(e.g.ERS/ERW versus UCS/secant modulus(E50):correlation coefficient R2 z 0.9,ERS/ERW versus Pb contents:R2 z 0.9,and ERL versus Pb2þconcentration:R2¼0.92)and well used Archie's law(ERS versus ERW:R2>0.9)indicate that the resistivity can be used to evaluate the stabilization effectiveness.Furthermore,the microscopic results revealed two behaviors,demonstrating the reliability of resistivity:(1)with the hydration process,resistivity increases due to a denser structure and lower amounts of free water and Pb ions,and(2)the addition of Pb reduces resistivity due to its inhibition or even destructive effects on cementation and formation of hydration products.
基金supported by the Key Technology Research on Increasing Recovery Rate in Tight Sandstone Gas Reservoirs,a Major Scientific and Technological Special Project of China National Petroleum Corporation(Project No.2023ZZ25).
文摘Microbial polysaccharides,due to their unique physicochemical properties,have been shown to effec-tively enhance the stability of foam fracturing fluids.However,the combined application of microbial polysaccharides and surfactants under high-temperature and high-salinity conditions remain poorly understood.In this study,we innovatively investigate this problem with a particular focus on foam stabilization mechanisms.By employing the Waring blender method,the optimal surfactant-microbial polysaccharide blends are identified,and the foam stability,rheological properties,and decay behavior in different systems under varying conditions are systematically analyzed for the first time.The results reveal that microbial polysaccharides significantly enhance foam stability by improving the viscoelasticity of the liquid films,particularly under high-salinity and high-temperature conditions,leading to notable improvements in both foam stability and sand-carrying capacity.Additionally,scanning electron microscopy(SEM)is used to observe the microstructure of the foam liquid films,demonstrating that the network structure formed by the foam stabilizer within the liquid film effectively inhibits foam coarsening.The Lauryl betaine and Diutan gum blend exhibits outstanding foam stability,superior sand-carrying capacity,and minimal core damage,making(LAB+MPS04)it ideal for applications in enhanced production and reservoir stimulation of unconventional reservoirs.
基金the Natural Science Foundation of Chongqing of China(Nos.CSTB2024NSCQ-MSX1013 and cstc2021jcyj-msxmX1139)the Science and Technology Research Program of Chongqing Education Commission(Nos.KJZD-K202304502,KJQN202201214,KJQN202001243 and KJZD-M202301201)the Opening Project of Material Corrosion and Protection Key Laboratory of Sichuan province(No.2024CL05).
文摘Building a superhydrophobic coating on a carbon steel substrate is an effective strategy for enhancing metal protection.A practical approach to producing a series of superhydrophobic Ni/SiO_(2)composite coatings(SSN)using one-step electrodeposition method is shown.The effect of processing parameters on surface structure and wettability was thoroughly explored,resulting in the identification of three typical surface morphologies.The prepared coating with petal-like structure(SSN-3)obtained under the optimum parameters exhibited the best water repellency,achieving a contact angle of 162.7°and a sliding angle of 4.1°.The droplet bouncing behavior on SSN coatings surface was studied,and the delayed icing time was recorded.Meanwhile,the mechanical stability and chemical corrosion resistance of SSN coatings were focused.The superhydrophobic SSN-3 coating with unique surface structure exhibited excellent reliability.The anticorrosion mechanism of SSN-3 coating was discussed,and its corrosion protection efficiency was up to 98.5%.The superior properties of the superhydrophobic SSN-3 coating make it suitable for diverse applications.
基金supported by the Zhejiang Public Welfare Technology Application Research Project of China(No.LTGY24H140002,No.LTGY23H140002,No.LGF22H140008)Wenzhou Medical University Basic Scientific Research Expenses Project(KYYW202331)the financial support for this research by the Australian Research Council(ARC)through the Discovery Project(DP240101131).
文摘Magnesium(Mg)-based composites are expected to be useful for biodegradable bone-implant materials due to their degradability,similar elastic modulus to that of bone,and biofunctionalities.However,their rapid degradation,poor biotribology performance,and lack of vascularization and antibacterial activity are not conducive to bone-fixation applications.In this study,an in situ Mg_(2)Ge/Mg-Cu-P composite with a nominal composition of Mg-10Ge-2Cu-0.5P(denoted MGCP)was prepared via phosphorus(P)-modified casting followed by hot extrusion for biodegradable bone-fixation applications.For comparison,an in situ Mg_(2)Ge/Mg-Cu composite(Mg-10Ge-2Cu,denoted MGC)was prepared under the same conditions without P-modification.The hot-extruded(HE)MGCP sample showed significantly improved corrosion resistance with corrosion rates of 2.2 mm/y and 2.51 mm/y as measured by potentiodynamic-polarization and hydrogen-release testing in Dulbecco’s Modified Eagle Medium supplemented with fetal bovine serum(denoted DMEM).The HE MGCP also exhibited notably enhanced mechanical properties and biotribological resistance in DMEM,with an σ_(UTS) of ~304.2 MPa,σ_(TYS) of ~202.5 MPa,elongation of ~12.3%,σ_(UCS) of 769.0 MPa,σ_(CYS) of 208.0 MPa,and Brinell hardness of 105.3 HB,along with smallerσ_(TYS) andσ_(CYS) decreases after 3 d of immersion in Hanks’solution.In comparison to pure titanium and Mg,the HE MGCP demonstrated much greater cytocompatibility,angiogenic capacity,and osteogenic differentiation and mineralization capability.Furthermore,the HE MGCP displayed markedly higher in vitro antibacterial activity,in vivo antibacterial and anti-inflammatory ability,and good biosafety in a rat subcutaneous-implantation model compared to pure titanium and Mg,indicating significant potential for biodegradable bone-fixation applications.
基金Project(51371104)supported by the National Natural Science Foundation of China
文摘Based on A356 aluminum alloy,aluminum foams were prepared by gas injection foaming process with pure nitrogen,air and some gas mixtures.The oxygen volume fraction of these gas mixtures varied from 0.2%to 8.0%.Optical microscopy,scanning electron microscopy（SEM） and Auger electron spectroscopy（AES） were used to analyze the influence of oxygen content on cell structure,relative density,macro and micro morphology of cell walls,coverage area fraction of oxide film,thickness of oxide film and other aspects.Results indicate that the coverage area fraction of oxide film on bubble surface increases with the increase of oxygen content when the oxygen volume is less than 1.2%.While when the oxygen volume fraction is larger than 1.6%,an oxide film covers the entire bubble surface and aluminum foams with good cell structure can be produced.The thicknesses of oxide films of aluminum foams produced by gas mixtures containing 1.6%-21%oxygen are almost the same.The reasons why the thickness of oxide film nearly does not change with the variation of oxygen content and the amount of oxygen needed to achieve 100%coverage of oxide film are both discussed.In addition,the role of oxide film on bubble surface in foam stability is also analyzed.
文摘A series of stearates with different rare-earth ion were investigated as thermal stabilizers for rigid PVC at 180 ℃ in air. Their stabilizing efficiency was based on measuring the rate of dehydrochlorination. The resulted revealed the higher stabilizing efficiency of the investigated rare-earth stearates as thermal stabilizers for rigid PVC compared with the thermal stabilizers for industry: calcium stearate, zinc stearate, butyl stannum mercaptide, phosphite esters, β-diketone and epoxidized sunflower oil. This was well illustrated by longer incubation period (T_S) values and lower rate of dehydrochlorination. The stable efficiency was affected by the nature of rare-earth element's individual electronic shell. The mechanism for the stabilizing effect of rare-earth stearates was proposed. The result was experimentally proved based on IR spectrum.
文摘At present,all kinds of municipal solid waste incineration (MSWI) fly ash stabilization technology has been reported and successfully applied in many countries.However,leaching procedures are very different that the technologies lack uniform standard,and it is even impossible to predict the long-term stabilization.Geochemical model can explain the environmental stabilization based on chemical phase and thermodynamic crystal structure,and it is also able to guide the development of environment-friendly stabi...
基金the National Natural Science Foundation of China(Grant No.41274111)the Shenhua Group(Grant No.CSCLC-03-JS-2014-08)the National Department Public Benefit Research Foundation of MLR,China(Grant No.201211063-4-1)
文摘Carbon dioxide(CO2) capture and storage(CCS) is considered widely as one of promising options for CO2emissions reduction,especially for those countries with coal-dominant energy mix like China.Injecting and storing a huge volume of CO2in deep formations are likely to cause a series of geomechanical issues,including ground surface uplift,damage of caprock integrity,and fault reactivation.The Shenhua CCS demonstration project in Ordos Basin,China,is the first and the largest full-chain saline aquifer storage project of CO2in Asia.The injection started in 2010 and ended in 2015.during which totally 0.3 million tonnes(Mt) CO2was injected.The project is unique in which CO2was injected into 18 sandstone formations simultaneously and the overlying coal seams will be mined after the injection stopped in 2015.Hence,intense geomechanical studies and monitoring works have been conducted in recent years,including possible damage resulting from the temperature difference between injected CO2and formations,injection induced stress and deformation change,potential failure mode and safety factor,interaction between coal mining and CO2geological storage,determination of injection pressure limit,and surface monitoring by the interferometric synthetic aperture radar(InSAR) technology.In this paper,we first described the background and its geological conditions of the Shenhua CCS demonstration project.Then,we gave an introduction to the coupled thermo-hydro-mechano-chemical(THMC) processes in CO2geological storage,and mapped the key geomechanical issues into the THMC processes accordingly.Next,we proposed a generalized geomechanical research flowchart for CO2geological storage projects.After that,we addressed and discussed some typical geomechanical issues,including design of injection pressure limit.CO2injection induced near-field damage,and interaction between CO2geological storage and coal mining,in the Shenhua CCS demonstration project.Finally,we concluded some insights to this CCS project.
基金the supports of the National Natural Science Foundation of China(2147612121322604)for this work。
文摘The well understanding of interaction forces between single dispersed droplets is crucial to the understanding of emulsion stabilization mechanism.Recently,many studies have reported the direct quantitative measurements of interaction forces between 20-200μm single droplet coated polymers by atomic force microscope(AFM).These studies have revealed many important results about the relationship of the interaction forces and the droplet deformation.However,these studies of the quantitative relationship between the measured interaction forces and the separation distance of the front end of the droplet have rarely been reported.Optical tweezer instrument can make it possible to establish the quantitative relationship between the measured force and the separation distance of the front end of the droplet,which will make better understanding of the interaction mechanisms between droplets.Due to the differences of the measuring mechanism between atomic force microscopy(AFM)and optical tweezers,the theory model of AFM measurements cannot be fitted with the force measurement by optical tweezers.We have made an exhaustive comparison of the measuring differences between AFM and optical tweezer instrument in this work.Moreover,we built a numerical model to derive the repulsive pressure through the measured force curve in order to quantify the measured force of two micron-sized oil droplet coated polymers by optical tweezers.Furthermore,the novel method can be extended to other micron-sized emulsion systems,and these findings will be a vital progress on quantitative force measurements between micron-sized droplets.
