The growth of computing power in data centers(DCs)leads to an increase in energy consumption and noise pollution of air cooling systems.Chip-level cooling with high-efficiency coolant is one of the promising methods t...The growth of computing power in data centers(DCs)leads to an increase in energy consumption and noise pollution of air cooling systems.Chip-level cooling with high-efficiency coolant is one of the promising methods to address the cooling challenge for high-power devices in DCs.Hybrid nanofluid(HNF)has the advantages of high thermal conductivity and good rheological properties.This study summarizes the numerical investigations of HNFs in mini/micro heat sinks,including the numerical methods,hydrothermal characteristics,and enhanced heat transfer technologies.The innovations of this paper include:(1)the characteristics,applicable conditions,and scenarios of each theoretical method and numerical method are clarified;(2)the molecular dynamics(MD)simulation can reveal the synergy effect,micro motion,and agglomeration morphology of different nanoparticles.Machine learning(ML)presents a feasiblemethod for parameter prediction,which provides the opportunity for the intelligent regulation of the thermal performance of HNFs;(3)the HNFs flowboiling and the synergy of passive and active technologies may further improve the overall efficiency of liquid cooling systems in DCs.This review provides valuable insights and references for exploring the multi-phase flow and heat transport mechanisms of HNFs,and promoting the practical application of HNFs in chip-level liquid cooling in DCs.展开更多
Conversion and capture of carbon pollutants based on carbon dioxide to valuable green oil-field chemicals are target all over the world for controlling the global warming.The present article used new room temperature ...Conversion and capture of carbon pollutants based on carbon dioxide to valuable green oil-field chemicals are target all over the world for controlling the global warming.The present article used new room temperature amphiphilic imidazolium ionic liquids with superior surface activity in the aqueous solutions to convert carbon dioxide gas to superior amphiphilic calcium carbonate nanoparticles.In this respect,tetra-cationic ionic liquids 2-(4-dodecyldimethylamino)phenyl)-1,3-bis(3-dodecyldimethylammnonio)propyl)bromide-1-H-imidazol-3-ium acetate and 2-(4-hexyldimethylamino)phenyl)-1,3-bis(3-hexcyldimethylammnonio)propyl)bromide-1 H-imidazol-3-ium acetate were prepared.Their chemical structures,thermal as well as their carbon dioxide absorption/desorption characteristicswere evaluated.Theywere used as solvent and capping agent to synthesize calcium carbonate nanoparticles with controlled crystalline lattice,sizes,thermal properties and spherical surface morphologies.The prepared calcium carbonate nanoparticles were used as additives for the commercial water based drilling mud to improve their filter lose and rheology.The data confirm that the lower concentrations of 2-(4-dodecyldimethylamino)phenyl)-1,3-bis(3-dodecyldimethylammnonio)propyl)bromide-1-H-imidazol-3-ium acetate achieved lower seawater filter lose and improved viscosities.展开更多
Bubble breakup at T-junction microchannels is the basis for the numbering-up of gas−liquid two-phase flow in parallelized microchannels. This article presents the bubble breakup in viscous liquids at a microfluidic T-...Bubble breakup at T-junction microchannels is the basis for the numbering-up of gas−liquid two-phase flow in parallelized microchannels. This article presents the bubble breakup in viscous liquids at a microfluidic T-junction. Nitrogen is used as the gas phase, and glycerol-water mixtures with different mass concentration of glycerol as the liquid phase. The evolution of the gas−liquid interface during bubble breakup at the microfluidic T-junction is explored. The thinning of the bubble neck includes the squeezing stage and the rapid pinch-off stage. In the squeezing stage, the power law relation is found between the minimum width of the bubble neck and the time, and the values of exponents α1 and α2 are influenced by the viscous force. The values of pre-factors m_(1) and m_(2) are negatively correlated with the capillary number. In the rapid pinch-off stage, the thinning of the bubble neck is predominated by the surface tension, and the minimum width of the bubble neck can be scaled with the remaining time as power-law. The propagation of the bubble tip can be characterized by the power law between the movement distance and the time, with decreasing exponent as increased liquid viscosity.展开更多
In liquid rocket engines,regenerative cooling technology is essential for preserving structural integrity under extreme thermal loads.However,non-uniform coolant flow distribution within the cooling channels often lea...In liquid rocket engines,regenerative cooling technology is essential for preserving structural integrity under extreme thermal loads.However,non-uniform coolant flow distribution within the cooling channels often leads to localized overheating,posing serious risks to engine reliability and operational lifespan.This study employs a three-dimensional fluid–thermal coupled numerical model to systematically investigate the influence of geometric parameters-specifically the number of inlets,the number of channels,and inlet manifold configurations-on flow uniformity and thermal distribution in non-pyrolysis zones.Key findings reveal that increasing the number of inlets from one to three significantly enhances flow uniformity,reducing mass flow rate deviation from 1.2%to below 0.3%.However,further increasing the inlets to five yields only marginal improvements indicating diminishing(<0.1%),returns beyond three inlets.Additionally,temperature non-uniformity at the combustion chamber throat decreases by 37%-from 3050 K with 18 channels to 1915 K with 30 channels-highlighting the critical role of channel density in effective thermal regulation.Notably,while higher channel counts improve cooling efficiency,they also result in increased pressure losses of approximately 18%–22%,emphasizing the need to balance thermal performance against hydraulic resistance.An optimal configuration comprising 24 channels and three inlets was identified,providing minimal temperature gradients while maintaining acceptable pressure losses.The inlet manifold structure also plays a pivotal role in determining flow distribution.Configuration 3(Config-3),which features an enlarged manifold and reduced inlet velocity,achieves a 40%reduction in velocity fluctuations compared to Configuration 1(Config-1).This improvement leads to a more uniform mass flow distribution,with a relative standard deviation(RSD)of less than 0.15%.Furthermore,this design effectively mitigates localized hot spots near the nozzle-where temperature gradients are most severe-achieving a reduction of approximately 1135 K.展开更多
In this work,we proposed a strategy for the hydrolysis of native corn starch after the treatment of corn starch in an ionic liquid aqueous solution,and it is an awfully“green”and simple means to obtain starch with l...In this work,we proposed a strategy for the hydrolysis of native corn starch after the treatment of corn starch in an ionic liquid aqueous solution,and it is an awfully“green”and simple means to obtain starch with low molecular weight and amorphous state.X-ray diffraction results revealed that the natural starch crystalline region was largely disrupted by ionic liquid owing to the broken intermolecular and intramolecular hydrogen bonds.After hydrolysis,the morphology of starch changed from particles of native corn starch into little pieces,and their molecular weight could be effectively regulated during the hydrolysis process,and also the hydrolyzed starch samples exhibited decreased thermal stability with the extension of hydrolysis time.This work would counsel as a powerful tool for the development of native starch in realistic applications.展开更多
Separation of 2-methylfuran(2-MF)and methanol(MeOH)azeotropes is a key challenge in biofuel production because of the efficiency and sustainability issues of conventional methods.In this study,ionic liquids(ILs)were i...Separation of 2-methylfuran(2-MF)and methanol(MeOH)azeotropes is a key challenge in biofuel production because of the efficiency and sustainability issues of conventional methods.In this study,ionic liquids(ILs)were introduced as green solvents for separation of 2-MF/MeOH through liquid–liquid equilibrium(LLE)experiment.Three ILs,namely 1-ethyl-3-methylimidazole dihydrogen phosphate([EMIM][H_(2)PO_(4)]),1-propyl-3-methylimidazole dihydrogen phosphate([PMIM][H_(2)PO_(4)])and 1-butyl-3-methylimidazole dihydrogen phosphate([BMIM][H_(2)PO_(4)]),were screened out from 425 candidates using the conductor-like screening model for real solvents(COSMO-RS).Then,the ternary LLE data of 2-MF(1)+MeOH(2)+ILs(3)were determined at 30℃ and 101.32 kPa.Results confirmed[EMIM][H_(2)PO_(4)]as the best performer,achieving a selectivity of 343.86 and a distribution coefficient of 36.66 for MeOH—significantly higher than[PMIM][H_(2)PO_(4)]and[BMIM][H_(2)PO_(4)].The accuracy of the LLE data was verified by Othmer–Tobias and Hand equations(R^(2)>0.90).The non-random two liquid model was used to correlate the experimental data(RMSD<2%).Besides,the combination of electrostatic surfaces potential,independent gradient model based on Hirshfeld partition,mean square displacement and radial distribution functions revealed strong electrostatic interactions between[H_(2)PO_(4)]^(–) and MeOH.Interaction energy analysis further emphasizes the mechanism of MeOH separation from a mixture of 2-MF and MeOH by ILs.This work provides a multiscale strategy for the separation of 2-MF and MeOH azeotropes,highlighting the potential of ILs to improve biofuel purification while reducing energy and environmental costs.展开更多
The inability to access brain tissue has greatly hindered our ability to study and care for individuals suffering from psychiatric and neurological conditions.Critics have questioned efforts to develop peripheral bloo...The inability to access brain tissue has greatly hindered our ability to study and care for individuals suffering from psychiatric and neurological conditions.Critics have questioned efforts to develop peripheral blood biomarkers in neurological and psychiatric disorders based on the assertion that disease pathology is limited to the brain.The discovery that all tissues,including the brain,release extracellular vesicles(Raposo and Stoorvogel,2013)and cell free DNAs(Chan et al.,2013)into various body fluids has provided a potential way to measure activity from inaccessible tissues like the central nervous system(CNS)and has given rise to the term“liquid biopsy.”The development of liquid biopsies that can diagnose and predict the course of psychiatric and neurological disorders would be transformative.The ability to predict episodic events such as mania,depression,and risk for suicide would be particularly useful for psychiatric care as it would enable the development of interventions that prevent mortality and improve outcomes.Additionally,biomarkers that are informative about drug response and aid in treatment decisions would be a significant advance in psychiatric care as it would prevent patients from having to endure multiple courses of ineffective treatments and side effects.展开更多
This study investigates the droplet formation for the liquid–liquid two-phase flow within a square T-junction microchannel through numerical simulation using volume of fluid method and experimental visualization usin...This study investigates the droplet formation for the liquid–liquid two-phase flow within a square T-junction microchannel through numerical simulation using volume of fluid method and experimental visualization using high-speed camera imaging.The T-junction microchannel has a cross-sectional width of 0.6 mm and a total length of 27.3 mm.The solution of cyclohexane with 2%and 3%mass concentrations of sorbitan trioleate surfactant were used as the continuous phase,and water was used as the dispersed phase.Slug flow,characteristic of squeezing regime,were predominantly observed.The effects of liquid–liquid two-phase flow rate ratio,and dimensionless number on droplet size,and pressure drop were investigated.The squeezing regime was mapped for 0.0005≤Ca_(c)≤0.0052(capillary number)and 0.1≤q≤10(flow rate ratio).The pressure drops of slugs were in the range from 40 Pa to 200 Pa.The slug lengths were measured between 1 mm and 9 mm.A universal flow map dependent on Ca_(c)Re_(d)^(0.5) are projected to investigate the droplet formation behavior in T-junction microchannel.Correlation expressions are proposed to predict pressure drops and the slug lengths for liquid–liquid two-phase flow in a square T-junction microchannel,using dimensionless numbers such as flow rate ratio and capillary number.The result shows that large continuous phase flow rates facilitate smaller slugs,whereas higher dispersed phase flow rates result in longer shorts.展开更多
As the global textile industry has accelerated its transition to a circular economy,iterative innovation in regenerated cellulose fibers has become a key industry focus.With viscose fiber having been industrialized fo...As the global textile industry has accelerated its transition to a circular economy,iterative innovation in regenerated cellulose fibers has become a key industry focus.With viscose fiber having been industrialized for over a century and lyocell fiber gaining market recognition because of its environmentally friendly process,which is the next regenerated cellulose fiber.Herein,ionic liquids with low vapor pressure,nonflammability,relatively simple recovery,and high dissolution efficiency were used to fabricate regenerated cellulose fibers.The viscose and lyocell properties of the fibers were systematically compared,including microscopic morphology,dyeing behavior,fibrillation resistance,mechanical properties,yarn-forming capacity,and fabric performance.The ionic liquid(IL)fiber exhibited a smooth surface and circular cross-section,with the highest tensile strength,moderate dyeing and fibrillation properties,and similar spinning and weaving performance.This work can provide a reference for the commercial application of regenerated cellulose fibers fabricated from ionic liquid.展开更多
The preparation of ionic liquid gel electrolyte can reduce the occurrence of side effects and extend battery life.In the DMSO-ILZE electrolyte composed of DMSO,1-ethyl-3-methylimidazole tetrafluoroborate(EMIMBF_(4))an...The preparation of ionic liquid gel electrolyte can reduce the occurrence of side effects and extend battery life.In the DMSO-ILZE electrolyte composed of DMSO,1-ethyl-3-methylimidazole tetrafluoroborate(EMIMBF_(4))and Zn(BF_(4))_(2),the supramolecular gelatorβ-cyclodextrin(β-CD)was added,and then a gel electrolyte(CD-ILZE)for zinc-ion batteries was prepared through host-vip interaction betweenβ-CD and DMSO-ILZE electrolyte.The gel electrolyte has good conductivity between-30 and 80℃,which is found by fitting the Arrhenius equation that the gel electrolyte satisfies the liquid law within this temperature range.In addition,the supramolecular gel electrolyte can effectively decrease hydrogen evolution corrosion and the formation of zinc dendrites.Compared with the battery prepared by DMSO-ILZE electrolyte(about 1100 h),the prepared Zn||Zn battery exhibits a more stable cycle(over 2800 h)at a current density of 0.5 m A·cm^(-2).At 0.1 A·g^(-1),the prepared Zn||V_(2)O_(5)gel electrolyte cell has a capacity of 30 m Ah·g^(-1)and a capacity retention rate of 85.17%after more than 1500 cycles.The CD-ILZE supramolecular gel electrolyte can inhibit the formation of hydrogen evolution corrosion and zinc dendrites,and improve the cycling performance of the battery.展开更多
Rhegmatogenous retinal detachment(RRD)is a serious ocular condition marked by the separation of the neuroretina from the retinal pigment epithelium(RPE).The pathogenesis of RRD involves intricate molecular and cellula...Rhegmatogenous retinal detachment(RRD)is a serious ocular condition marked by the separation of the neuroretina from the retinal pigment epithelium(RPE).The pathogenesis of RRD involves intricate molecular and cellular mechanisms,including inflammation,cell migration,and the activation of proliferative signaling pathways.One of the most challenging complications of RRD is proliferative vitreoretinopathy(PVR),which refers to the proliferation and contraction of fibrocellular membranes on the retinal surface and in the vitreous cavity.PVR is a major cause of surgical failure in RRD,as it can lead to recurrent retinal detachment and severe vision loss.However,the pathogenesis of PVR is not yet fully understood,and the treatment options are quite limited.Recent advances in analytical techniques have offered valuable insights into the molecular alterations present in the subretinal fluid(SRF)of patients with RRD.This review seeks to consolidate the current knowledge regarding the SRF profile in RRD and PVR,emphasizing potential biomarkers and therapeutic targets.展开更多
Joining magnesium(Mg)alloys to steel is difficult due to metallurgical incompatibility.Applying a zinc(Zn)coating to steel enables formation of a thin Mg-Zn eutectic phase layer during welding,which promotes strong bo...Joining magnesium(Mg)alloys to steel is difficult due to metallurgical incompatibility.Applying a zinc(Zn)coating to steel enables formation of a thin Mg-Zn eutectic phase layer during welding,which promotes strong bonding.However,in joints created with Friction-stir assisted scribe technology(FAST),this Mg-Zn eutectic phase layer occasionally extends from the interface to the surface of the Mg sheet.This phenomenon is attributed to the formation of a liquid-state Mg-Zn eutectic phase,coupled with the distinctive material flow induced by the FAST tool.Microstructural analysis confirmed that the Mg-Zn eutectic phase comprisesα-Mg and the Mg_(21)Zn_(25)intermetallic compound.Lap shear tensile tests revealed that when the Mg-Zn eutectic phase migration pathway aligned with the stir zone boundary,it led to reduced joint strength and premature fracture along the eutectic phase pathway.This indicates that liquid metal embrittlement(LME)occurred during FAST joining of Mg alloy and galvanized steel.These findings highlight the critical importance of controlling tool features and process parameters in FAST welding to prevent LME-related failures in dissimilar Mg/steel assemblies.展开更多
Dimethylphenols serve as important intermediates in synthesizing pharmaceuticals and agrochemicals,yet traditional distillation struggles to separate their isomers due to minimal boiling point differences,and the deve...Dimethylphenols serve as important intermediates in synthesizing pharmaceuticals and agrochemicals,yet traditional distillation struggles to separate their isomers due to minimal boiling point differences,and the development of melt crystallization is hampered by lacking solid–liquid equilibrium (SLE) data for some isomers.Therefore,the SLE data of both binary and ternary mixtures of 2,3-dimethylphenol (2,3-DMP),3,5-dimethylphenol (3,5-DMP),and 3,4-dimethylphenol (3,4-DMP) were determined by using differential scanning calorimetry in this work.Additionally,crystallographic analysis was conducted to investigate the thermodynamic characteristics of these mixtures.The experimental results indicated that all the systems investigated in this research exhibited eutectic behavior.The experimentally obtained SLE data were well correlated with the Wilson and non-random two-liquid models.The excess thermodynamic functions were calculated to analyze the types and intensities of the molecular interactions occurring in the mixtures.Furthermore,this study developed a model for the correlation between the theoretical crystallization yield and the actual cooling yield and final yield in melt crystallization.This study has furnished reliable data essential for developing and optimizing the melt crystallization process of mixtures of 2,3-DMP,3,5-DMP,and 3,4-DMP.展开更多
The formation of copper deposits is closely related to hydrothermal processes.Understanding the migration of copper in hydrothermal fluids aids in reconstructing mineralization processes and deciphering deposit genesi...The formation of copper deposits is closely related to hydrothermal processes.Understanding the migration of copper in hydrothermal fluids aids in reconstructing mineralization processes and deciphering deposit genesis.Copper primarily exists as Cu^(+)and Cu^(2+)in hydrothermal solutions,with redox conditions governing their interconversion.In chloride-rich geological fluids,Cu-Cl complexes are considered critical for copper transport.However,the specific types and valence transitions of Cu-Cl complexes under varying hydrothermal conditions remain poorly understood.This study employed in situ Raman spectroscopy to systematically analyze Cu+HCl and CuCl_(2)+K_(2)S_(2)O_(3)/H_(2) systems under saturated vapor pressure at 25-300℃,elucidating the effects of temperature,Cl^(-)concentration,and redox conditions on copper speciation.In the Cu^(+)HCl system,copper dissolved as monovalent Cu-Cl complexes.At high temperatures(>200℃),[CuCl_(2)]^(-)is the dominated species,whereas[CuCl_(3)]^(2-)becomes prevalent at lower temperatures and higher HCl concentrations.For the Cu^(2+)-Cl system,the dominant species transitioned from[Cu(H_(2)O)n]^(2+)(<50℃)to[CuCl_(4)]^(2-)(100℃)and further to[CuCl]^(+)and[CuCl_(2)]^(0) at 300℃.The introduction of reducing agents(K_(2)S_(2)O_(3)/H_(2))facilitated Cu^(2+)→Cu^(+)reduction,thereby stabilizing Cu^(+)-Cl complexes and inducing partial copper precipitation.The behavior of copper in chloriderich hydrothermal fluids observed in this study indicates that high-temperature oxidizing fluids facilitate Cu mobilization,while cooling and redox changes promote deposition and ore minerals formation.展开更多
Pediatric cancers are particularly significant due to their uncommon occurrence in children,driven by a variety of underlying factors.Because of their distinct molecular and genetic makeup,which makes early detection ...Pediatric cancers are particularly significant due to their uncommon occurrence in children,driven by a variety of underlying factors.Because of their distinct molecular and genetic makeup,which makes early detection challenging,they are linked to problems.Diagnostic methods like imaging and tissue biopsy are only effective when the tumor has reached a size that can be identified.The liquid biopsy technique,the least intrusive and most convenient diagnostic method,is the subject of this review.It focuses on the significance of single cell analysis in examining uncommon cancer types.The many biomarkers found in bodily fluids and the cancer types they are linked to in children have been assessed,as has the potential route towards early detection and cancer recurrence forecasting.Combining the single cell liquid biopsy with the newest technologies,such as computational and multi-omics approaches,which have improved the efficiency of processing massive and unique genetic data,appears promising.This article discusses on a number of case reports for uncommon pediatric malignancies,such as Neuroblastoma,Medulloblastoma,Wilms Tumor,Rhabdomyosarcoma,Ewing Sarcoma,and Retinoblastoma,as well as their liquid biopsy profiles.Furthermore,the findings raise ethical questions regarding the therapeutic application of the technology as well as possible difficulties related to clinical translation.The likelihood that this single cell liquid biopsy will be clinically validated and eventually used as a routine diagnostic tool for uncommon pediatric cancers will rise with the realistic approach to sensitivity monitoring,specificity upgrading,and optimization.展开更多
While desalination is a key solution for global freshwater scarcity,its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems.Solar interfa...While desalination is a key solution for global freshwater scarcity,its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems.Solar interfacial evaporation offers sustainable management potential,yet inevitable salt nucleation at evaporation interfaces degrades photothermal conversion and operational stability via light scattering and pathway blockage.Inspired by the mangrove leaf,we propose a photothermal 3D polydopamine and polypyrrole polymerized spacer fabric(PPSF)-based upward hanging model evaporation configuration with a reverse water feeding mechanism.This design enables zero-liquiddischarge(ZLD)desalination through phase-separation crystallization.The interconnected porous architecture and the rough surface of the PPSF enable superior water transport,achieving excellent solar-absorbing efficiency of 97.8%.By adjusting the tilt angle(θ),the evaporator separates the evaporation and salt crystallization zones via controlled capillary-driven brine transport,minimizing heat dissipation from brine discharge.At an optimal tilt angle of 52°,the evaporator reaches an evaporation rate of 2.81 kg m^(−2) h^(−1) with minimal heat loss(0.366 W)under 1-sun illumination while treating a 7 wt%waste brine solution.Furthermore,it sustains an evaporation rate of 2.71 kg m^(−2) h^(−1) over 72 h while ensuring efficient salt recovery.These results highlight a scalable,energy-efficient approach for sustainable ZLD desalination.展开更多
As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises s...As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises structural concerns,and the latter is of aerodynamic interest.Thus,panel aeroelasticity in shock-dominated flow represents a vital topic for the development and optimization of supersonic vehicles and propulsion systems.This review systematically summarizes recent advances in the methodologies applied to capture structural and fluid dynamics,including theoretical models,numerical simulations,and wind tunnel experiments.The application of data-driven modal decomposition,an advanced technique to extract physically crucial features,on the topic is introduced.From the perspective of FSIs,the distinctive aeroelastic behaviors in shock-dominated flow,including hysteresis phenomena and nonlinear responses,are highlighted.From the perspective of SBLIs,the modifications in their spatial and temporal characteristics imposed by the aeroelastic responses are emphasized.Motivated by the interaction between the shock waves and structural response,different strategies have been proposed to implement aeroelastic suppression and shock control,which have the potential to enhance structural safety and aerodynamic performance in the next generation of high-speed flight vehicles.展开更多
Porous ionic liquid electrospray thrusters are the ideal propulsion technology for CubeSats because of their structural simplicity,high thrust accuracy and plume self-neutralization.The electrowetting technology can r...Porous ionic liquid electrospray thrusters are the ideal propulsion technology for CubeSats because of their structural simplicity,high thrust accuracy and plume self-neutralization.The electrowetting technology can replenish the propellant for the emitter online,thus prolonging the lifetime of the thruster.In order to gain a deeper understanding of its operating characteristics,the changes in thruster performance before and after propellant replenishment deserve to be scrutinized.In this study,the performance changes of a porous electrowetting ionic liquid electrospray thruster are tested by voltage-current test and time-of-flight mass spectrometry over a long operating time.The experimental results show that asymmetric operation with a negative current less than positive current for a long period of time causes anions to compensate for the emission after accumulation at the emitter,resulting in a phenomenon that the negative current is much larger than positive current.The reason for the difference in emission characteristics between the positive and negative modes is that the plume in the positive mode is quite ionized while the plume in the negative mode contains liquid droplets.This study provides a reference for the selection of operating conditions for ionic liquid electrospray thrusters.展开更多
Current experimental techniques still face challenges in clarifying the structural and dynamic properties of helium(He)in liquid lithium(Li).A critical example of this technical hurdle is the formation of He bubbles,w...Current experimental techniques still face challenges in clarifying the structural and dynamic properties of helium(He)in liquid lithium(Li).A critical example of this technical hurdle is the formation of He bubbles,which significantly affects the transport of He within liquid Li—a vital aspect when considering liquid Li as a plasma-facing material in nuclear fusion reactors.We develop a machine-learning-based deep potential(DP)with ab initio accuracy for the Li-He system and perform molecular dynamics simulations at temperatures ranging from 470 K to 1270 K with a wide range of He concentrations.We observe that He atoms exhibit a tendency to aggregate and form clusters and bubbles in liquid Li.Notably,He clusters exhibit a significant increase in size at elevated temperatures and high concentrations of He,accompanied by the phase separation of Li and He atoms.We also observe an anomalous non-linear relationship between the diffusion coefficient of He and temperature,which is attributed to the larger cluster size at higher temperatures.Our study provides a deeper understanding of the behavior of He in liquid Li and further supports the potential application of liquid Li under extreme conditions.展开更多
基金funded by the Science and Technology Project of Tianjin(No.24YDTPJC00680)the National Natural Science Foundation of China(No.52406191).
文摘The growth of computing power in data centers(DCs)leads to an increase in energy consumption and noise pollution of air cooling systems.Chip-level cooling with high-efficiency coolant is one of the promising methods to address the cooling challenge for high-power devices in DCs.Hybrid nanofluid(HNF)has the advantages of high thermal conductivity and good rheological properties.This study summarizes the numerical investigations of HNFs in mini/micro heat sinks,including the numerical methods,hydrothermal characteristics,and enhanced heat transfer technologies.The innovations of this paper include:(1)the characteristics,applicable conditions,and scenarios of each theoretical method and numerical method are clarified;(2)the molecular dynamics(MD)simulation can reveal the synergy effect,micro motion,and agglomeration morphology of different nanoparticles.Machine learning(ML)presents a feasiblemethod for parameter prediction,which provides the opportunity for the intelligent regulation of the thermal performance of HNFs;(3)the HNFs flowboiling and the synergy of passive and active technologies may further improve the overall efficiency of liquid cooling systems in DCs.This review provides valuable insights and references for exploring the multi-phase flow and heat transport mechanisms of HNFs,and promoting the practical application of HNFs in chip-level liquid cooling in DCs.
基金supported by Science,Technology&Innovation Funding Authority(STDF)under grant(No.47062).
文摘Conversion and capture of carbon pollutants based on carbon dioxide to valuable green oil-field chemicals are target all over the world for controlling the global warming.The present article used new room temperature amphiphilic imidazolium ionic liquids with superior surface activity in the aqueous solutions to convert carbon dioxide gas to superior amphiphilic calcium carbonate nanoparticles.In this respect,tetra-cationic ionic liquids 2-(4-dodecyldimethylamino)phenyl)-1,3-bis(3-dodecyldimethylammnonio)propyl)bromide-1-H-imidazol-3-ium acetate and 2-(4-hexyldimethylamino)phenyl)-1,3-bis(3-hexcyldimethylammnonio)propyl)bromide-1 H-imidazol-3-ium acetate were prepared.Their chemical structures,thermal as well as their carbon dioxide absorption/desorption characteristicswere evaluated.Theywere used as solvent and capping agent to synthesize calcium carbonate nanoparticles with controlled crystalline lattice,sizes,thermal properties and spherical surface morphologies.The prepared calcium carbonate nanoparticles were used as additives for the commercial water based drilling mud to improve their filter lose and rheology.The data confirm that the lower concentrations of 2-(4-dodecyldimethylamino)phenyl)-1,3-bis(3-dodecyldimethylammnonio)propyl)bromide-1-H-imidazol-3-ium acetate achieved lower seawater filter lose and improved viscosities.
基金supports for this project from State Key Laboratory of Chemical Safety(SKLCS–2024001)are gratefully acknowledged。
文摘Bubble breakup at T-junction microchannels is the basis for the numbering-up of gas−liquid two-phase flow in parallelized microchannels. This article presents the bubble breakup in viscous liquids at a microfluidic T-junction. Nitrogen is used as the gas phase, and glycerol-water mixtures with different mass concentration of glycerol as the liquid phase. The evolution of the gas−liquid interface during bubble breakup at the microfluidic T-junction is explored. The thinning of the bubble neck includes the squeezing stage and the rapid pinch-off stage. In the squeezing stage, the power law relation is found between the minimum width of the bubble neck and the time, and the values of exponents α1 and α2 are influenced by the viscous force. The values of pre-factors m_(1) and m_(2) are negatively correlated with the capillary number. In the rapid pinch-off stage, the thinning of the bubble neck is predominated by the surface tension, and the minimum width of the bubble neck can be scaled with the remaining time as power-law. The propagation of the bubble tip can be characterized by the power law between the movement distance and the time, with decreasing exponent as increased liquid viscosity.
基金supported by the Key project of Hunan Provincial Education Department(Grant Number:22A0485)The Natural Science Foundation of Hunan(Grant Number:2024JJ5293)The Key project of Hunan University of Arts and Science(Grant Number:23ZZ08).
文摘In liquid rocket engines,regenerative cooling technology is essential for preserving structural integrity under extreme thermal loads.However,non-uniform coolant flow distribution within the cooling channels often leads to localized overheating,posing serious risks to engine reliability and operational lifespan.This study employs a three-dimensional fluid–thermal coupled numerical model to systematically investigate the influence of geometric parameters-specifically the number of inlets,the number of channels,and inlet manifold configurations-on flow uniformity and thermal distribution in non-pyrolysis zones.Key findings reveal that increasing the number of inlets from one to three significantly enhances flow uniformity,reducing mass flow rate deviation from 1.2%to below 0.3%.However,further increasing the inlets to five yields only marginal improvements indicating diminishing(<0.1%),returns beyond three inlets.Additionally,temperature non-uniformity at the combustion chamber throat decreases by 37%-from 3050 K with 18 channels to 1915 K with 30 channels-highlighting the critical role of channel density in effective thermal regulation.Notably,while higher channel counts improve cooling efficiency,they also result in increased pressure losses of approximately 18%–22%,emphasizing the need to balance thermal performance against hydraulic resistance.An optimal configuration comprising 24 channels and three inlets was identified,providing minimal temperature gradients while maintaining acceptable pressure losses.The inlet manifold structure also plays a pivotal role in determining flow distribution.Configuration 3(Config-3),which features an enlarged manifold and reduced inlet velocity,achieves a 40%reduction in velocity fluctuations compared to Configuration 1(Config-1).This improvement leads to a more uniform mass flow distribution,with a relative standard deviation(RSD)of less than 0.15%.Furthermore,this design effectively mitigates localized hot spots near the nozzle-where temperature gradients are most severe-achieving a reduction of approximately 1135 K.
文摘In this work,we proposed a strategy for the hydrolysis of native corn starch after the treatment of corn starch in an ionic liquid aqueous solution,and it is an awfully“green”and simple means to obtain starch with low molecular weight and amorphous state.X-ray diffraction results revealed that the natural starch crystalline region was largely disrupted by ionic liquid owing to the broken intermolecular and intramolecular hydrogen bonds.After hydrolysis,the morphology of starch changed from particles of native corn starch into little pieces,and their molecular weight could be effectively regulated during the hydrolysis process,and also the hydrolyzed starch samples exhibited decreased thermal stability with the extension of hydrolysis time.This work would counsel as a powerful tool for the development of native starch in realistic applications.
基金supported by the National Natural Science Foundation of China(22278272)Natural Science Foundation of Liaoning Province(2024-MS-129).
文摘Separation of 2-methylfuran(2-MF)and methanol(MeOH)azeotropes is a key challenge in biofuel production because of the efficiency and sustainability issues of conventional methods.In this study,ionic liquids(ILs)were introduced as green solvents for separation of 2-MF/MeOH through liquid–liquid equilibrium(LLE)experiment.Three ILs,namely 1-ethyl-3-methylimidazole dihydrogen phosphate([EMIM][H_(2)PO_(4)]),1-propyl-3-methylimidazole dihydrogen phosphate([PMIM][H_(2)PO_(4)])and 1-butyl-3-methylimidazole dihydrogen phosphate([BMIM][H_(2)PO_(4)]),were screened out from 425 candidates using the conductor-like screening model for real solvents(COSMO-RS).Then,the ternary LLE data of 2-MF(1)+MeOH(2)+ILs(3)were determined at 30℃ and 101.32 kPa.Results confirmed[EMIM][H_(2)PO_(4)]as the best performer,achieving a selectivity of 343.86 and a distribution coefficient of 36.66 for MeOH—significantly higher than[PMIM][H_(2)PO_(4)]and[BMIM][H_(2)PO_(4)].The accuracy of the LLE data was verified by Othmer–Tobias and Hand equations(R^(2)>0.90).The non-random two liquid model was used to correlate the experimental data(RMSD<2%).Besides,the combination of electrostatic surfaces potential,independent gradient model based on Hirshfeld partition,mean square displacement and radial distribution functions revealed strong electrostatic interactions between[H_(2)PO_(4)]^(–) and MeOH.Interaction energy analysis further emphasizes the mechanism of MeOH separation from a mixture of 2-MF and MeOH by ILs.This work provides a multiscale strategy for the separation of 2-MF and MeOH azeotropes,highlighting the potential of ILs to improve biofuel purification while reducing energy and environmental costs.
基金supported by Department of Defense grant HT9425-24-1-0030 a grant from the Stanley Medical Research Institute(to SS).
文摘The inability to access brain tissue has greatly hindered our ability to study and care for individuals suffering from psychiatric and neurological conditions.Critics have questioned efforts to develop peripheral blood biomarkers in neurological and psychiatric disorders based on the assertion that disease pathology is limited to the brain.The discovery that all tissues,including the brain,release extracellular vesicles(Raposo and Stoorvogel,2013)and cell free DNAs(Chan et al.,2013)into various body fluids has provided a potential way to measure activity from inaccessible tissues like the central nervous system(CNS)and has given rise to the term“liquid biopsy.”The development of liquid biopsies that can diagnose and predict the course of psychiatric and neurological disorders would be transformative.The ability to predict episodic events such as mania,depression,and risk for suicide would be particularly useful for psychiatric care as it would enable the development of interventions that prevent mortality and improve outcomes.Additionally,biomarkers that are informative about drug response and aid in treatment decisions would be a significant advance in psychiatric care as it would prevent patients from having to endure multiple courses of ineffective treatments and side effects.
基金supports for this project from the National Natural Science Foundation of China(22378295).
文摘This study investigates the droplet formation for the liquid–liquid two-phase flow within a square T-junction microchannel through numerical simulation using volume of fluid method and experimental visualization using high-speed camera imaging.The T-junction microchannel has a cross-sectional width of 0.6 mm and a total length of 27.3 mm.The solution of cyclohexane with 2%and 3%mass concentrations of sorbitan trioleate surfactant were used as the continuous phase,and water was used as the dispersed phase.Slug flow,characteristic of squeezing regime,were predominantly observed.The effects of liquid–liquid two-phase flow rate ratio,and dimensionless number on droplet size,and pressure drop were investigated.The squeezing regime was mapped for 0.0005≤Ca_(c)≤0.0052(capillary number)and 0.1≤q≤10(flow rate ratio).The pressure drops of slugs were in the range from 40 Pa to 200 Pa.The slug lengths were measured between 1 mm and 9 mm.A universal flow map dependent on Ca_(c)Re_(d)^(0.5) are projected to investigate the droplet formation behavior in T-junction microchannel.Correlation expressions are proposed to predict pressure drops and the slug lengths for liquid–liquid two-phase flow in a square T-junction microchannel,using dimensionless numbers such as flow rate ratio and capillary number.The result shows that large continuous phase flow rates facilitate smaller slugs,whereas higher dispersed phase flow rates result in longer shorts.
基金financially supported by the National Natural Science Foundation of China(Nos.22005226 and 52203124)Center for Carbon Neutral Chemistry,Institute of Chemistry,Chinese Academy of Sciences(No.CCNC-202402)+1 种基金the Basic and Advanced Research Project from Wuhan Science and Technology Bureau(No.2022013988065201)Hubei Integrative Technology and Innovation Center for Advanced Fiberous Materials,project(No.XC2024G3013)。
文摘As the global textile industry has accelerated its transition to a circular economy,iterative innovation in regenerated cellulose fibers has become a key industry focus.With viscose fiber having been industrialized for over a century and lyocell fiber gaining market recognition because of its environmentally friendly process,which is the next regenerated cellulose fiber.Herein,ionic liquids with low vapor pressure,nonflammability,relatively simple recovery,and high dissolution efficiency were used to fabricate regenerated cellulose fibers.The viscose and lyocell properties of the fibers were systematically compared,including microscopic morphology,dyeing behavior,fibrillation resistance,mechanical properties,yarn-forming capacity,and fabric performance.The ionic liquid(IL)fiber exhibited a smooth surface and circular cross-section,with the highest tensile strength,moderate dyeing and fibrillation properties,and similar spinning and weaving performance.This work can provide a reference for the commercial application of regenerated cellulose fibers fabricated from ionic liquid.
文摘The preparation of ionic liquid gel electrolyte can reduce the occurrence of side effects and extend battery life.In the DMSO-ILZE electrolyte composed of DMSO,1-ethyl-3-methylimidazole tetrafluoroborate(EMIMBF_(4))and Zn(BF_(4))_(2),the supramolecular gelatorβ-cyclodextrin(β-CD)was added,and then a gel electrolyte(CD-ILZE)for zinc-ion batteries was prepared through host-vip interaction betweenβ-CD and DMSO-ILZE electrolyte.The gel electrolyte has good conductivity between-30 and 80℃,which is found by fitting the Arrhenius equation that the gel electrolyte satisfies the liquid law within this temperature range.In addition,the supramolecular gel electrolyte can effectively decrease hydrogen evolution corrosion and the formation of zinc dendrites.Compared with the battery prepared by DMSO-ILZE electrolyte(about 1100 h),the prepared Zn||Zn battery exhibits a more stable cycle(over 2800 h)at a current density of 0.5 m A·cm^(-2).At 0.1 A·g^(-1),the prepared Zn||V_(2)O_(5)gel electrolyte cell has a capacity of 30 m Ah·g^(-1)and a capacity retention rate of 85.17%after more than 1500 cycles.The CD-ILZE supramolecular gel electrolyte can inhibit the formation of hydrogen evolution corrosion and zinc dendrites,and improve the cycling performance of the battery.
文摘Rhegmatogenous retinal detachment(RRD)is a serious ocular condition marked by the separation of the neuroretina from the retinal pigment epithelium(RPE).The pathogenesis of RRD involves intricate molecular and cellular mechanisms,including inflammation,cell migration,and the activation of proliferative signaling pathways.One of the most challenging complications of RRD is proliferative vitreoretinopathy(PVR),which refers to the proliferation and contraction of fibrocellular membranes on the retinal surface and in the vitreous cavity.PVR is a major cause of surgical failure in RRD,as it can lead to recurrent retinal detachment and severe vision loss.However,the pathogenesis of PVR is not yet fully understood,and the treatment options are quite limited.Recent advances in analytical techniques have offered valuable insights into the molecular alterations present in the subretinal fluid(SRF)of patients with RRD.This review seeks to consolidate the current knowledge regarding the SRF profile in RRD and PVR,emphasizing potential biomarkers and therapeutic targets.
基金PNNL is operated by Battelle Memorial Institute for the U.S.Department of Energy under contract DE-AC05-76RL01830sponsored by the DOEEERE,Vehicle Technology Office,through the Joining Core Program.
文摘Joining magnesium(Mg)alloys to steel is difficult due to metallurgical incompatibility.Applying a zinc(Zn)coating to steel enables formation of a thin Mg-Zn eutectic phase layer during welding,which promotes strong bonding.However,in joints created with Friction-stir assisted scribe technology(FAST),this Mg-Zn eutectic phase layer occasionally extends from the interface to the surface of the Mg sheet.This phenomenon is attributed to the formation of a liquid-state Mg-Zn eutectic phase,coupled with the distinctive material flow induced by the FAST tool.Microstructural analysis confirmed that the Mg-Zn eutectic phase comprisesα-Mg and the Mg_(21)Zn_(25)intermetallic compound.Lap shear tensile tests revealed that when the Mg-Zn eutectic phase migration pathway aligned with the stir zone boundary,it led to reduced joint strength and premature fracture along the eutectic phase pathway.This indicates that liquid metal embrittlement(LME)occurred during FAST joining of Mg alloy and galvanized steel.These findings highlight the critical importance of controlling tool features and process parameters in FAST welding to prevent LME-related failures in dissimilar Mg/steel assemblies.
基金funded by the National Natural Science Foundation of China(22308358,22208346,22421003)IPE Project for Frontier Basic Research(QYJC-2023-05)CAS Project for Young Scientists in Basic Research(YSBR-038).
文摘Dimethylphenols serve as important intermediates in synthesizing pharmaceuticals and agrochemicals,yet traditional distillation struggles to separate their isomers due to minimal boiling point differences,and the development of melt crystallization is hampered by lacking solid–liquid equilibrium (SLE) data for some isomers.Therefore,the SLE data of both binary and ternary mixtures of 2,3-dimethylphenol (2,3-DMP),3,5-dimethylphenol (3,5-DMP),and 3,4-dimethylphenol (3,4-DMP) were determined by using differential scanning calorimetry in this work.Additionally,crystallographic analysis was conducted to investigate the thermodynamic characteristics of these mixtures.The experimental results indicated that all the systems investigated in this research exhibited eutectic behavior.The experimentally obtained SLE data were well correlated with the Wilson and non-random two-liquid models.The excess thermodynamic functions were calculated to analyze the types and intensities of the molecular interactions occurring in the mixtures.Furthermore,this study developed a model for the correlation between the theoretical crystallization yield and the actual cooling yield and final yield in melt crystallization.This study has furnished reliable data essential for developing and optimizing the melt crystallization process of mixtures of 2,3-DMP,3,5-DMP,and 3,4-DMP.
基金jointly funded by the Strategic Priority Research Program of the Chinese Academy of Sciences(grant No.XDA0430301)the National Natural Science Foundation of China(grant Nos.42130109,41973059)。
文摘The formation of copper deposits is closely related to hydrothermal processes.Understanding the migration of copper in hydrothermal fluids aids in reconstructing mineralization processes and deciphering deposit genesis.Copper primarily exists as Cu^(+)and Cu^(2+)in hydrothermal solutions,with redox conditions governing their interconversion.In chloride-rich geological fluids,Cu-Cl complexes are considered critical for copper transport.However,the specific types and valence transitions of Cu-Cl complexes under varying hydrothermal conditions remain poorly understood.This study employed in situ Raman spectroscopy to systematically analyze Cu+HCl and CuCl_(2)+K_(2)S_(2)O_(3)/H_(2) systems under saturated vapor pressure at 25-300℃,elucidating the effects of temperature,Cl^(-)concentration,and redox conditions on copper speciation.In the Cu^(+)HCl system,copper dissolved as monovalent Cu-Cl complexes.At high temperatures(>200℃),[CuCl_(2)]^(-)is the dominated species,whereas[CuCl_(3)]^(2-)becomes prevalent at lower temperatures and higher HCl concentrations.For the Cu^(2+)-Cl system,the dominant species transitioned from[Cu(H_(2)O)n]^(2+)(<50℃)to[CuCl_(4)]^(2-)(100℃)and further to[CuCl]^(+)and[CuCl_(2)]^(0) at 300℃.The introduction of reducing agents(K_(2)S_(2)O_(3)/H_(2))facilitated Cu^(2+)→Cu^(+)reduction,thereby stabilizing Cu^(+)-Cl complexes and inducing partial copper precipitation.The behavior of copper in chloriderich hydrothermal fluids observed in this study indicates that high-temperature oxidizing fluids facilitate Cu mobilization,while cooling and redox changes promote deposition and ore minerals formation.
文摘Pediatric cancers are particularly significant due to their uncommon occurrence in children,driven by a variety of underlying factors.Because of their distinct molecular and genetic makeup,which makes early detection challenging,they are linked to problems.Diagnostic methods like imaging and tissue biopsy are only effective when the tumor has reached a size that can be identified.The liquid biopsy technique,the least intrusive and most convenient diagnostic method,is the subject of this review.It focuses on the significance of single cell analysis in examining uncommon cancer types.The many biomarkers found in bodily fluids and the cancer types they are linked to in children have been assessed,as has the potential route towards early detection and cancer recurrence forecasting.Combining the single cell liquid biopsy with the newest technologies,such as computational and multi-omics approaches,which have improved the efficiency of processing massive and unique genetic data,appears promising.This article discusses on a number of case reports for uncommon pediatric malignancies,such as Neuroblastoma,Medulloblastoma,Wilms Tumor,Rhabdomyosarcoma,Ewing Sarcoma,and Retinoblastoma,as well as their liquid biopsy profiles.Furthermore,the findings raise ethical questions regarding the therapeutic application of the technology as well as possible difficulties related to clinical translation.The likelihood that this single cell liquid biopsy will be clinically validated and eventually used as a routine diagnostic tool for uncommon pediatric cancers will rise with the realistic approach to sensitivity monitoring,specificity upgrading,and optimization.
基金supported by National Key Research and Development Program of China(2022YFB3804902,2022YFB3804900)the National Natural Science Foundation of China(52203226,52161145406,42376045)the Fundamental Research Funds for the Central Universities(2232024Y-01,2232025D-02).
文摘While desalination is a key solution for global freshwater scarcity,its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems.Solar interfacial evaporation offers sustainable management potential,yet inevitable salt nucleation at evaporation interfaces degrades photothermal conversion and operational stability via light scattering and pathway blockage.Inspired by the mangrove leaf,we propose a photothermal 3D polydopamine and polypyrrole polymerized spacer fabric(PPSF)-based upward hanging model evaporation configuration with a reverse water feeding mechanism.This design enables zero-liquiddischarge(ZLD)desalination through phase-separation crystallization.The interconnected porous architecture and the rough surface of the PPSF enable superior water transport,achieving excellent solar-absorbing efficiency of 97.8%.By adjusting the tilt angle(θ),the evaporator separates the evaporation and salt crystallization zones via controlled capillary-driven brine transport,minimizing heat dissipation from brine discharge.At an optimal tilt angle of 52°,the evaporator reaches an evaporation rate of 2.81 kg m^(−2) h^(−1) with minimal heat loss(0.366 W)under 1-sun illumination while treating a 7 wt%waste brine solution.Furthermore,it sustains an evaporation rate of 2.71 kg m^(−2) h^(−1) over 72 h while ensuring efficient salt recovery.These results highlight a scalable,energy-efficient approach for sustainable ZLD desalination.
基金supported by the National Natural Science Foundation of China(No.12372233)the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University,China(No.25GH01020005)the“111 Project”of China(No.B17037)。
文摘As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises structural concerns,and the latter is of aerodynamic interest.Thus,panel aeroelasticity in shock-dominated flow represents a vital topic for the development and optimization of supersonic vehicles and propulsion systems.This review systematically summarizes recent advances in the methodologies applied to capture structural and fluid dynamics,including theoretical models,numerical simulations,and wind tunnel experiments.The application of data-driven modal decomposition,an advanced technique to extract physically crucial features,on the topic is introduced.From the perspective of FSIs,the distinctive aeroelastic behaviors in shock-dominated flow,including hysteresis phenomena and nonlinear responses,are highlighted.From the perspective of SBLIs,the modifications in their spatial and temporal characteristics imposed by the aeroelastic responses are emphasized.Motivated by the interaction between the shock waves and structural response,different strategies have been proposed to implement aeroelastic suppression and shock control,which have the potential to enhance structural safety and aerodynamic performance in the next generation of high-speed flight vehicles.
基金co-supported by the National Key R&D Program of China(Nos.2020YFC2201103 and 2022YFB4601300)the National Natural Science Foundation of China(No.U22B20120)+1 种基金the Program of Beijing Engineering Research Center of Efficient and Green Aerospace Propulsion Technology,China(No.Lab ASP-2024-09)the Beijing Institute of Technology Research Fund Program for Young Scholars,China。
文摘Porous ionic liquid electrospray thrusters are the ideal propulsion technology for CubeSats because of their structural simplicity,high thrust accuracy and plume self-neutralization.The electrowetting technology can replenish the propellant for the emitter online,thus prolonging the lifetime of the thruster.In order to gain a deeper understanding of its operating characteristics,the changes in thruster performance before and after propellant replenishment deserve to be scrutinized.In this study,the performance changes of a porous electrowetting ionic liquid electrospray thruster are tested by voltage-current test and time-of-flight mass spectrometry over a long operating time.The experimental results show that asymmetric operation with a negative current less than positive current for a long period of time causes anions to compensate for the emission after accumulation at the emitter,resulting in a phenomenon that the negative current is much larger than positive current.The reason for the difference in emission characteristics between the positive and negative modes is that the plume in the positive mode is quite ionized while the plume in the negative mode contains liquid droplets.This study provides a reference for the selection of operating conditions for ionic liquid electrospray thrusters.
基金Project supported by the Excellence Research Group Program for Multiscale Problems in Nonlinear Mechanics of the National Natural Science Foundation of China(Grant No.12588201)the National Key R&D Program of China(Grant No.2025YFB3003603)+1 种基金the National Natural Science Foundation of China(Grant No.12135002)the Fundamental Research Funds for the Central Universities,Peking University,the Beijing Natural Science Foundation(Grant No.QY23030)。
文摘Current experimental techniques still face challenges in clarifying the structural and dynamic properties of helium(He)in liquid lithium(Li).A critical example of this technical hurdle is the formation of He bubbles,which significantly affects the transport of He within liquid Li—a vital aspect when considering liquid Li as a plasma-facing material in nuclear fusion reactors.We develop a machine-learning-based deep potential(DP)with ab initio accuracy for the Li-He system and perform molecular dynamics simulations at temperatures ranging from 470 K to 1270 K with a wide range of He concentrations.We observe that He atoms exhibit a tendency to aggregate and form clusters and bubbles in liquid Li.Notably,He clusters exhibit a significant increase in size at elevated temperatures and high concentrations of He,accompanied by the phase separation of Li and He atoms.We also observe an anomalous non-linear relationship between the diffusion coefficient of He and temperature,which is attributed to the larger cluster size at higher temperatures.Our study provides a deeper understanding of the behavior of He in liquid Li and further supports the potential application of liquid Li under extreme conditions.
