The high-alloyed wrought superalloy GH4975 tends to form coarse MC carbides and eutectic(γ+γ′)phases,which adversely affect the cogging and homogenization process.To provide theoretical guidance for control of MC c...The high-alloyed wrought superalloy GH4975 tends to form coarse MC carbides and eutectic(γ+γ′)phases,which adversely affect the cogging and homogenization process.To provide theoretical guidance for control of MC carbides and eutectic(γ+γ′)formation,differential thermal analysis(DTA)was utilized to investigate the effect of cooing rate(10-90℃·min^(-1))on solidification behavior and micro-segregation of GH4975 alloy.According to the thermodynamic calculation and distribution characteristics of precipitates,the MC carbides can act as nucleation sites forγdendrites,but the nucleation ofγdendrites becomes less dependent on the MC carbide primers at higher cooling rates.As theγdendrites grow,the elements including Ti and Nb gradually accumulate in the residual liquid and leads to the formation of more MC carbides near the interdendritic region.Finally,the solidification is terminated with the formation of eutectic(γ+γ′).With an increase in cooling rate,the liquidus temperature rises,but the solidus temperature decreases,and thus the solidification range is obviously enlarged.The dendritic structure is significantly refined by the increase of cooling rate.The secondary dendrite arm spacing,λ_(2),as a function of cooling rate,T,can be expressed asλ_(2)=216.78T^(-0.42).Moreover,the increasing cooling rate weakens the back diffusion of Al,Ti,and Nb,increases the undercooling,and limits the growth of precipitates.Consequently,the sizes of MC carbides,eutectic(γ+γ′),and primaryγ′significantly decrease,but the area fraction of eutectic(γ+γ′)linerly increases as the cooling rate rises.Thus moderate cooling rate(such as 30℃·min^(-1))should be selected during the solidification process of GH4975 alloy.展开更多
Forests exert significant biogeophysical cooling effects(CE)through processes such as increased evapotranspiration,reduced albedo,and enhanced surface roughness.However,little is known about the extent to which elevat...Forests exert significant biogeophysical cooling effects(CE)through processes such as increased evapotranspiration,reduced albedo,and enhanced surface roughness.However,little is known about the extent to which elevation-induced temperature differences bias the observed CE and how this bias interacts with the underlying biogeophysical mechanisms.In this study,we integrated multisensor remote sensing products and Shuttle Radar Topography Mission(SRTM)elevation data on the Google Earth Engine(GEE)platform,and applied a spatial-temporal window regression approach to quantify and correct the sensitivity of land surface temperature(LST)to elevation for forest pixels across China from 2001 to 2022.First,we found that forest LST exhibited a significant negative relationship with elevation,leading to systematic CE overestimation by 0.61 K during the day and 0.60 K at night compared with altitudecorrected CE values.Second,after correction,the CE showed clear spatial heterogeneity,with stronger daytime cooling in tropical(-0.54 K)and temperate forests(-0.24 K),and warming in cold(+0.11 K)and arid regions(+0.53 K),while most regions experienced nighttime warming.Among forest types,evergreen needleleaf forests(ENF)exhibited the strongest daytime cooling(-0.36 K),whereas deciduous broadleaf(DBF)and open shrublands(OS)tended to warm.Third,mechanism analysis revealed that elevation correction strengthened the correlations of CE with leaf area index(LAI)and evapotranspiration,while maintaining a significant negative correlation with albedo,indicating that both radiative and non-radiative processes jointly shape the unbiased CE.These findings provide a more accurate quantification of forest CE by eliminating elevation-induced bias,which providing a more accurate assessment of the climate mitigation potential of forests,which is crucial for developing more effective forest management and ecological restoration strategies.展开更多
An instrumental assessment and volunteer subjective evaluation method was developed to synchronously measure the actual skin temperature and evaluate the cool sensation,conducting a quantitative analysis of the percei...An instrumental assessment and volunteer subjective evaluation method was developed to synchronously measure the actual skin temperature and evaluate the cool sensation,conducting a quantitative analysis of the perceived coolness.This method was used to evaluate the effect of a self-developed hot flash spray on reducing the skin temperature and inducing the cooling sensation of menopausal individuals.31 healthy menopausal volunteers were recruited as research subjects.Using infrared thermal imaging and electroencephalogram(EEG)measurements,the skin temperature and EEG data of the subjects’cheeks were simultaneously collected at baseline(BL)immediately after simulated hot flashes(HF),1 min(T1),3 mins(T3)and 5 min(T5)after the application of the test sample.The results showed that,compared with HF,the skin temperature of cheek was significantly reduced by 8.75%,8.75%and 6.41%at T1,T3 and T5(P<0.05),respectively.And alpha-1 value of EEG was increased significantly by 59.70%,58.44%,and 51.39%at T1,T3,and T5(P<0.05),respectively.The hot flash spray effectively reduces skin temperature while also provides subjects with a feeling of coolness,which can relieve hot flashes in menopausal women.展开更多
Micro-alloying is an effective approach for improving the corrosion resistance of cast AZ91.However,the effect of micro-alloyed elements on corrosion resistance can be varied depending on the solidification rate influ...Micro-alloying is an effective approach for improving the corrosion resistance of cast AZ91.However,the effect of micro-alloyed elements on corrosion resistance can be varied depending on the solidification rate influencing the diffusion and precipitation behavior of micro-alloying elements.This study investigated the effects of the cooling rate on the microstructure and corrosion behavior of micro-Ca and-Y alloyed cast AZ91 alloy(i.e.,AZXW9100).To achieve various cooling rates,the alloys were prepared using three methods:steel mold casting(SMC),copper step mold casting(CSMC),and high-pressure die casting(HPDC).The corrosion behavior was analyzed through weight loss measurements,electrochemical impedance spectroscopy,and corrosion morphology observations.The results showed that the key microstructural factors influencing corrosion resistance differed between short-and long-term corrosion.As the cooling rate increased,the short-term corrosion rate was lowered from 0.91 mm/y(SMC)to 0.38 mm/y(HPDC),which was attributed to the decrease in the total area fractions of the eutecticαandβphases acting as galvanic corrosion sources.The long-term corrosion rate was reduced from 17.20 mm/y(SMC)to 0.71 mm/y(HPDC),which was revealed to be due to the enhanced connectivity of theβphase acting as corrosion barriers.Meanwhile,the increase in the cooling rate led to a modification of the Zn molar ratio in theβphase,reducing the Volta potential of theβphase from 101.8 m V to 66.9 m V.This reduction in the Volta potential of the main galvanic source also contributed to improved corrosion resistance.The HPDC AZXW9100 alloy produced in this study exhibited the lowest corrosion rate compared to other alloys.These findings suggest that controlling the cooling rate is a promising strategy for enhancing the corrosion resistance of AZXW9100 alloys.展开更多
The aluminum(Al)/steel transition joints used in ships are processed from composite plates,and their mechanical properties have a significant impact on the safety of ships.In this paper,the Al/steel composite plate wa...The aluminum(Al)/steel transition joints used in ships are processed from composite plates,and their mechanical properties have a significant impact on the safety of ships.In this paper,the Al/steel composite plate was prepared using rolling,with 5083 aluminum plate as the cladding plate,Q235 steel plate as the substrate,and TA1 titanium(Ti)plate and DT4 pure iron(Fe)plate as the intermediate layers.The heterothermic billet was prepared through induction heating by the magnetic effects of the steel plate and the pure Fe plate,and then the Al/steel composite plate was obtained by rolling.The impacts of post-rolling cooling process on the microstructure and properties of the Al/Ti/pure Fe/steel composite plate were studied.The results manifested that the pure Fe/steel interface had a good composite effect.With the increase in the cooling rate,the bonding strength of the Al/Ti interface was raised,and that of the Ti/Fe interface was increased first and then decreased.When the oil cooling process was adopted,the Al/Ti/pure Fe/steel composite plate exhibited the highest comprehensive performance.The shear strength of the Al/Ti interface and the Ti/Fe interface was 102 MPa and 186 MPa,respectively.The plastic fracture was determined as the mode of interface fracture.展开更多
The cooling rate of the center and edge of vacuum induction melting(VIM)or vacuum arc remelting(VAR)ingots exhibit substantial difference,leading to markedly distinct dendritic structures and precipitates.The current ...The cooling rate of the center and edge of vacuum induction melting(VIM)or vacuum arc remelting(VAR)ingots exhibit substantial difference,leading to markedly distinct dendritic structures and precipitates.The current lack of precise predictions for dendritic segregation and the distribution of precipitates in ingot makes it difficult to determine the annealing and homogenization heat treatment process.Thus,clarifying the impact of cooling rate on the solidification behavior of alloy is significantly important.The dendritic structure and precipitation characteristics of as-cast C-HRA-3 Ni–Cr–Co–Mo-based heat-resistant alloy were investigated using Thermo-Calc thermodynamic calculations,scanning electron microscopy observations,and electron probe microanalyzer.Based on high temperature observation system,the effects of cooling rate on the dendritic structure,dendritic segregation,and precipitation in this alloy were explored.The results showed that the precipitates in the as-cast C-HRA-3 alloy primarily consist of blocky Ti(C,N)phases,large-sized Ti(C,N)–M_(6)C–M_(23)C_(6) symbiotic phases and M_(6)C–M_(23)C_(6) carbides,and small-sized dispersed M_(6)C and M_(23)C_(6) carbides surronding these symbiotic phases.The primary constituent elements of these precipitates are Mo,Cr,C,and Ti,which predominantly concentrate in the interdendritic regions of the as-cast alloy.There is a clear power-law relationship between the secondary dendrite arm spacing and the cooling rate.The dendritic segregation ratio of Mo,Cr,and Ti exhibits a piecewise functional relationship with the cooling rate,under equiaxed dendritic solidification condition.These predictive models and theoretical analyses were validated using numerical simulations and experimental results from the 200 kg grade VIM electrode.展开更多
The water curtain spray system of the ship helps reduce surface thermal load and lowers thermal infrared radiation, notably enhancing the stealth and survivability of naval ships. The performance of the water curtain ...The water curtain spray system of the ship helps reduce surface thermal load and lowers thermal infrared radiation, notably enhancing the stealth and survivability of naval ships. The performance of the water curtain spray system is largely influenced by the density of the nozzles and their installation height. Therefore, a test platform was established to investigate these critical influencing factors, employing an orthogonal design methodology for the experimental study. Specifically, the study evaluated the effects of varying distances to the steel plate target and different injection heights on the cooling performance of the system. Results demonstrate that using one nozzle per 4 square meters of the ship's surface area effectively lowers the surface temperature, bringing it closer to the ambient background temperature. This nozzle configuration creates irregular infrared heat patterns, which complicate the task for infrared detectors to discern the ship's outline, thus enhancing its infrared stealth. Additionally, maintaining the nozzle installation height within 0.6 m to prevent the temperature difference between the steel plate and the background temperature from exceeding 4 K. Moreover, as the infrared imaging distance increases from 3 to 9 m, the temperature difference measured by the thermocouple and the infrared imager increases by 141.27%. Furthermore, with the increase in infrared imaging distance, the infrared temperature of the target steel plate approaches the background temperature, indicating improved detectability. These findings have significantly enhanced the stealth capabilities of naval ships, maximizing their immunity to infrared-guided weapon attacks. Moreover, their importance in improving the survivability of ships on the water surface cannot be underestimated.展开更多
The study of the spallation of thermal barrier coatings on turbine blades and its influence is of great significance for gas turbine safety operation.However,numerical simulation related to thermal barrier coatings is...The study of the spallation of thermal barrier coatings on turbine blades and its influence is of great significance for gas turbine safety operation.However,numerical simulation related to thermal barrier coatings is difficult and time-costly,which makes it hard to meet engineering demands.Therefore,this work establishes a rapid prediction model for the surface temperature and cooling efficiency of turbine blades with localized spallation of thermal barrier coatings based on a thin-wall thermal resistance model.Firstly,the influence of localized spallation of thermal barrier coatings on the cooling efficiency of typical turbine blades is numerically investigated.Then,based on the simulation data set and multi-layer perception(MLP)neural network,an intelligent prediction model for the temperature and cooling efficiency distribution of localized spallation of coatings is constructed,which can rapidly predict the surface temperature and cooling efficiency of the blade under the situation of spallation of coating at any position on the blade surface.The results show that,under a certain spallation area,the shape of localized coating spallation has little influence on the cooling efficiency,while the increase of spallation thickness will cause a linear increase in the average temperature of the blade surface.The prediction error of the proposed rapid prediction model for the average surface temperature and cooling efficiency of blades is within 2%,and the prediction error of the temperature and cooling efficiency at the spallation position is within 6%for 80%of the samples,with an overall average error within 10%.It is concluded from the rapid prediction model that when the depth of coating spallation increases,the closer the spallation position is to the leading edge of the blade,the greater the difference in cooling efficiency is,and the degree of influence of coating spallation on the cooling efficiency also increases.展开更多
The ductile-to-brittle transition temperature(DBTT)of high strength steels can be optimized by tailoring microstructure and crystallographic orientation characteristics,where the start cooling temperature plays a key ...The ductile-to-brittle transition temperature(DBTT)of high strength steels can be optimized by tailoring microstructure and crystallographic orientation characteristics,where the start cooling temperature plays a key role.In this work,X70 steels with different start cooling temperatures were prepared through thermo-mechanical control process.The quasi-polygonal ferrite(QF),granular bainite(GB),bainitic ferrite(BF)and martensite-austenite constituents were formed at the start cooling temperatures of 780℃(C1),740℃(C2)and 700℃(C3).As start cooling temperature decreased,the amount of GB decreased,the microstructure of QF and BF increased.Microstructure characteristics of the three samples,such as high-angle grain boundaries(HAGBs),MA constituents and crystallographic orientation,also varied with the start cooling temperatures.C2 sample had the lowest DBTT value(−86℃)for its highest fraction of HAGBs,highest content of<110>oriented grains and lowest content of<001>oriented grains parallel to TD.The high density of{332}<113>and low density of rotated cube{001}<110>textures also contributed to the best impact toughness of C2 sample.In addition,a modified model was used in this paper to quantitatively predict the approximate DBTT value of steels.展开更多
By combining the merits of radiative cooling(RC)and evaporation cooling(EC),radiative coupled evaporative cooling(REC)has attracted considerable attention for sub-ambient cooling purposes.However,for outdoor devices,t...By combining the merits of radiative cooling(RC)and evaporation cooling(EC),radiative coupled evaporative cooling(REC)has attracted considerable attention for sub-ambient cooling purposes.However,for outdoor devices,the interior heating power would increase the working temperature and fire risk,which would suppress their above-ambient heat dissipation capabilities and passive water cycle properties.In this work,we introduced a REC design based on an all-in-one photonic hydrogel for above-ambient heat dissipation and flame retardancy.Unlike conventional design RC film for heat dissipation with limited cooling power and fire risk,REC hydrogel can greatly improve the heat dissipation performance in the daytime with a high workload,indicating a 12.0℃lower temperature than the RC film under the same conditions in the outdoor experiment.In the nighttime with a low workload,RC-assisted adsorption can improve atmospheric water harvesting to ensure EC in the daytime.In addition,our REC hydrogel significantly enhanced flame retardancy by absorbing heat without a corresponding temperature rise,thus mitigating fire risks.Thus,our design shows a promising solution for the thermal management of outdoor devices,delivering outstanding performance in both heat dissipation and flame retardancy.展开更多
Radiative cooling textiles with spectrally selective surfaces offer a promising energy-efficient approach for sub-ambient cooling of outdoor objects and individuals.However,the spectrally selective mid-infrared emissi...Radiative cooling textiles with spectrally selective surfaces offer a promising energy-efficient approach for sub-ambient cooling of outdoor objects and individuals.However,the spectrally selective mid-infrared emission of these textiles significantly hinders their efficient radiative heat exchange with self-heated objects,thereby posing a significant challenge to their versatile cooling applicability.Herein,we present a bicomponent blow spinning strategy for the production of scalable,ultra-flexible,and healable textiles featuring a tailored dual gradient in both chemical composition and fiber diameter.The gradient in the fiber diameter of this textile introduces a hierarchically porous structure across the sunlight incident area,thereby achieving a competitive solar reflectivity of 98.7%on its outer surface.Additionally,the gradient in the chemical composition of this textile contributes to the formation of Janus infrared-absorbing surfaces:The outer surface demonstrates a high mid-infrared emission,whereas the inner surface shows a broad infrared absorptivity,facilitating radiative heat exchange with underlying self-heated objects.Consequently,this textile demonstrates multi-scenario radiative cooling capabilities,enabling versatile outdoor cooling for unheated objects by 7.8℃ and self-heated objects by 13.6℃,compared to commercial sunshade fabrics.展开更多
Radiative cooling systems(RCSs)possess the distinctive capability to dissipate heat energy via solar and thermal radiation,making them suitable for thermal regulation and energy conservation applications,essential for...Radiative cooling systems(RCSs)possess the distinctive capability to dissipate heat energy via solar and thermal radiation,making them suitable for thermal regulation and energy conservation applications,essential for mitigating the energy crisis.A comprehensive review connecting the advancements in engineered radiative cooling systems(ERCSs),encompassing material and structural design as well as thermal and energy-related applications,is currently absent.Herein,this review begins with a concise summary of the essential concepts of ERCSs,followed by an introduction to engineered materials and structures,containing nature-inspired designs,chromatic materials,meta-structural configurations,and multilayered constructions.It subsequently encapsulates the primary applications,including thermal-regulating textiles and energy-saving devices.Next,it highlights the challenges of ERCSs,including maximized thermoregulatory effects,environmental adaptability,scalability and sustainability,and interdisciplinary integration.It seeks to offer direction for forthcoming fundamental research and industrial advancement of radiative cooling systems in real-world applications.展开更多
Rechargeable Zn/Sn-air batteries have received considerable attention as promising energy storage devices.However,the electrochemical performance of these batteries is significantly constrained by the sluggish electro...Rechargeable Zn/Sn-air batteries have received considerable attention as promising energy storage devices.However,the electrochemical performance of these batteries is significantly constrained by the sluggish electrocatalytic reaction kinetics at the cathode.The integration of light energy into Zn/Sn-air batteries is a promising strategy for enhancing their performance.However,the photothermal and photoelectric effects generate heat in the battery under prolonged solar irradiation,leading to air cathode instability.This paper presents the first design and synthesis of Ni_(2)-1,5-diamino-4,8-dihydroxyanthraquinone(Ni_(2)DDA),an electronically conductiveπ-d conjugated metal-organic framework(MOF).Ni_(2)DDA exhibits both photoelectric and photothermal effects,with an optical band gap of~1.14 eV.Under illumination,Ni_(2)DDA achieves excellent oxygen evolution reaction performance(with an overpotential of 245 mV vs.reversible hydrogen electrode at 10 mA cm^(−2))and photothermal stability.These properties result from the synergy between the photoelectric and photothermal effects of Ni_(2)DDA.Upon integration into Zn/Sn-air batteries,Ni_(2)DDA ensures excellent cycling stability under light and exhibits remarkable performance in high-temperature environments up to 80℃.This study experimentally confirms the stable operation of photo-assisted Zn/Sn-air batteries under high-temperature conditions for the first time and provides novel insights into the application of electronically conductive MOFs in photoelectrocatalysis and photothermal catalysis.展开更多
Beam-tracking simulations have been extensively utilized in the study of collective beam instabilities in circular accelerators.Traditionally,many simulation codes have relied on central processing unit(CPU)-based met...Beam-tracking simulations have been extensively utilized in the study of collective beam instabilities in circular accelerators.Traditionally,many simulation codes have relied on central processing unit(CPU)-based methods,tracking on a single CPU core,or parallelizing the computation across multiple cores via the message passing interface(MPI).Although these approaches work well for single-bunch tracking,scaling them to multiple bunches significantly increases the computational load,which often necessitates the use of a dedicated multi-CPU cluster.To address this challenge,alternative methods leveraging General-Purpose computing on Graphics Processing Units(GPGPU)have been proposed,enabling tracking studies on a standalone desktop personal computer(PC).However,frequent CPU-GPU interactions,including data transfers and synchronization operations during tracking,can introduce communication overheads,potentially reducing the overall effectiveness of GPU-based computations.In this study,we propose a novel approach that eliminates this overhead by performing the entire tracking simulation process exclusively on the GPU,thereby enabling the simultaneous processing of all bunches and their macro-particles.Specifically,we introduce MBTRACK2-CUDA,a Compute Unified Device Architecture(CUDA)ported version of MBTRACK2,which facilitates efficient tracking of single-and multi-bunch collective effects by leveraging the full GPU-resident computation.展开更多
Benzalkonium chloride(BAC)is widely employed as a broad-spectrum biocide and has emerged as a significant environmental pollutant.Polymyxin B(PB)serves as the last-line defense for the treatment of Gram-negative patho...Benzalkonium chloride(BAC)is widely employed as a broad-spectrum biocide and has emerged as a significant environmental pollutant.Polymyxin B(PB)serves as the last-line defense for the treatment of Gram-negative pathogens.Previous studies reported that BAC-adapted Pseudomonas aeruginosa increased the tolerance to PB.Herein,we present the novel finding that the combination of BAC and PB exhibited synergistic antibacterial effects against P.aeruginosa.Time-killing assay demonstrated a significant reduction in bacterial cell viability.Scanning electron microscopy,zeta potential analysis,hydrophobicity measurements,and fluorescence probe analyses collectively revealed severe disruption of the cell envelope and membrane potential induced by the combination of BAC and PB.Transcriptomic analysis revealed that the BAC-PB combination notably downreg-ulated the expression of genes involved in lipid A modification and cell envelope production,including phoPQ,pmrAB,bamABCDE,lptABCDEG,lolB,yidC,and murJ.Additionally,the combination group exhibited augmented production of reactive oxygen species and diminished ATP synthesis.The expression of the genes associated with substance metabolism and energy generation was significantly impeded.This study provides significant implica-tions for the interactions of biocides and antibiotics on Gram-negative pathogens,while also addressing antibiotic resistance and developing the external treatment strategy for Pseudomonas-infected wounds and burns.展开更多
AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 group...AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 groups:Group A(implanted with the SN6CWS),Group B(implanted with the MI60),and Group C(implanted with the Aspira-aA).ELP measurements were obtained with swept-source optical coherence tomography(SS-OCT)at 1d,1wk,1mo,and 3mo postoperatively.Subjective refraction assessments were conducted at 1wk,1mo,and 3mo following surgery.RESULTS:The study included 189 eyes of 150 cataract patients(66 males).There were 77 eyes in Group A,55 eyes in Group B,and 57 eyes in Group C.The root mean square of the ELP(ELPRMS)within the initial 3mo was significantly lower for Group A than for Groups B and C.Refractive changes within Group A were not significant across the time points of 1wk,1mo,and 3mo.Conversely,both Group B and Group C demonstrated statistically significant shifts toward hyperopia from 1wk to 3mo postsurgery.CONCLUSION:Among the three IOLs examined,the SN6CWS IOL showes the greatest stability during the first 3mo postoperatively.Between 1wk and 3mo after surgery,notable hyperopic shifts are evident in eyes implanted with the MI60 and Aspira-aA IOLs,whereas refractive outcomes remain relatively constant in eyes implanted with SN6CWS IOLs.展开更多
Electrical and electronic devices face significant challenges in heatmanagement due to their compact size and high heat flux,which negatively impact performance and reliability.Conventional coolingmethods,such as forc...Electrical and electronic devices face significant challenges in heatmanagement due to their compact size and high heat flux,which negatively impact performance and reliability.Conventional coolingmethods,such as forced air cooling,often struggle to transfer heat efficiently.In contrast,thermoelectric coolers(TECs)provide an innovative active cooling solution to meet growing thermal management demands.In this research,a refrigerant based on mono ethylene glycol and distilled water was used instead of using gases,in addition to using thermoelectric cooling units instead of using a compressor in traditional refrigeration systems.This study evaluates the performance of a Peltierbased thermalmanagement systemby analyzing the effects of using two,three,and four Peltiermodules on cooling rates,power consumption,temperature reduction,and system efficiency.Experimental results indicate that increasing the number of Peltier modules significantly enhances cooling performance.The four-module system achieved an optimal balance between cooling speed and energy efficiency,reducing the temperature of a liquidmixture(30% mono ethylene glycol+70% distilled water plus laser dyes)to 8℃ in just 17 min.It demonstrated a cooling rate of 0.794℃/min and a high coefficient of performance(COP)of 1.2 while consuming less energy than the two-and three-module systems.Furthermore,the study revealed that increasing the number of modules led to faster air cooling and improved temperature reduction.These findings highlight the importance of selecting the optimal number of Peltier modules to enhance efficiency and cooling speed whileminimizing energy consumption.This makes TEC technology a sustainable and effective solution for applications requiring rapid and reliable thermal management.展开更多
The magnetic properties and Kondo effect in Ce3TiBi5 with a quasi-one-dimensional structure were investigated using in situ high-pressure resistivity measurements up to 48 GPa.At ambient pressure,Ce_(3)TiBi_(5) underg...The magnetic properties and Kondo effect in Ce3TiBi5 with a quasi-one-dimensional structure were investigated using in situ high-pressure resistivity measurements up to 48 GPa.At ambient pressure,Ce_(3)TiBi_(5) undergoes an antiferromagnetic(AFM)transition at T_(N)∼5 K.Under high pressures within 8.9 GPa,we find that Kondo scattering contributes differently to the high-temperature resistance,R(T),depending on the applied current direction,demonstrating a significantly anisotropic Kondo effect.The complete P–T phase diagram has been constructed,in which the pressure dependence of T_(N) exhibits a dome-like shape.The AFM order remains robust under pressure,even when the coherence temperature T^(*) far exceeds 300 K.We attribute the observed anisotropic Kondo effect and the robust AFM to the underlying anisotropy in electronic hybridization under high pressure.展开更多
In winter 2018,an aerosol physicochemical experiment was conducted in the Western Pacific Ocean(WPO)aboard the Research Vessel KEXUE of Chinese Academy of Sciences.This study systematically investigated both natural a...In winter 2018,an aerosol physicochemical experiment was conducted in the Western Pacific Ocean(WPO)aboard the Research Vessel KEXUE of Chinese Academy of Sciences.This study systematically investigated both natural and anthropogenic effects on marine aerosols optical properties,as well as the applicability of multi-satellite products and IMPROVE equation.The averaged aerosol optical depth(AOD500 nm)was 0.31±0.16 andÅngström exponent440–675 nm was 0.29±0.30.In offshore China,significant anthropogenic emissions affected the marine environment.In remote WPO,dust aerosols transported from northern China,Siberia,Central Asia,and those settling from the upper troposphere originating from north Africa,Arabian peninsula,and western India,were dominant.The spatial trends of AOD were opposite in the mid-latitude and southern seas of WPO.The highest AOD,0.32±0.23,appeared along the coast of South Asia at mid-latitude,decreasing from offshore seas to remote oceans.In low-latitude and equatorial seas,AOD significantly increased from coast to remote oceans.Ångström exponent dropped significantly from the coast to remote oceans as anthropogenic influence diminished across the entire WPO.Correlation analysis showed that both MODIS-C6 and Himawari AOD prod-ucts showed similar applicability in coastal urban areas,while Himawari AOD is highly recommended for coastal background and marine environment due to its finer resolution.The extinction coefficient derived from PM_(2.5) chemical compositions using IMPROVE algorithm exhibited a significant correlation(R^(2)=0.58)with the con-currently measured AOD in the absence of long-distance transport,suggesting that the IMPROVE is a reasonable proxy of the columnar average of marine aerosol extinctions free from transport influences.展开更多
This paper prepared a novel as-cast W-Zr-Ti metallic ESM using high-frequency vacuum induction melting technique.The above ESM performs a typical elastic-brittle material feature and strain rate strengthening behavior...This paper prepared a novel as-cast W-Zr-Ti metallic ESM using high-frequency vacuum induction melting technique.The above ESM performs a typical elastic-brittle material feature and strain rate strengthening behavior.The specimens exhibit violent chemical reaction during the fracture process under the impact loading,and the size distribution of their residual debris follows Rosin-Rammler model.The dynamic fracture toughness is obtained by the fitting of debris length scale,approximately 1.87 MPa·m~(1/2).Microstructure observation on residual debris indicates that the failure process is determined by primary crack propagation under quasi-static compression,while it is affected by multiple cracks propagation in both particle and matrix in the case of dynamic impact.Impact test demonstrates that the novel energetic fragment performs brilliant penetration and combustion effect behind the front target,leading to the effective ignition of fuel tank.For the brittleness of as-cast W-ZrTi ESM,further study conducted bond-based peridynamic(BB-PD)C++computational code to simulate its fracture behavior during penetration.The BB-PD method successfully captured the fracture process and debris cloud formation of the energetic fragment.This paper explores a novel as-cast metallic ESM,and provides an available numerical avenue to the simulation of brittle energetic fragment.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52474362,52174317 and 51904146)the General Project Funded by Liaoning Province Education Department(Grant No.JYTMS20230943)。
文摘The high-alloyed wrought superalloy GH4975 tends to form coarse MC carbides and eutectic(γ+γ′)phases,which adversely affect the cogging and homogenization process.To provide theoretical guidance for control of MC carbides and eutectic(γ+γ′)formation,differential thermal analysis(DTA)was utilized to investigate the effect of cooing rate(10-90℃·min^(-1))on solidification behavior and micro-segregation of GH4975 alloy.According to the thermodynamic calculation and distribution characteristics of precipitates,the MC carbides can act as nucleation sites forγdendrites,but the nucleation ofγdendrites becomes less dependent on the MC carbide primers at higher cooling rates.As theγdendrites grow,the elements including Ti and Nb gradually accumulate in the residual liquid and leads to the formation of more MC carbides near the interdendritic region.Finally,the solidification is terminated with the formation of eutectic(γ+γ′).With an increase in cooling rate,the liquidus temperature rises,but the solidus temperature decreases,and thus the solidification range is obviously enlarged.The dendritic structure is significantly refined by the increase of cooling rate.The secondary dendrite arm spacing,λ_(2),as a function of cooling rate,T,can be expressed asλ_(2)=216.78T^(-0.42).Moreover,the increasing cooling rate weakens the back diffusion of Al,Ti,and Nb,increases the undercooling,and limits the growth of precipitates.Consequently,the sizes of MC carbides,eutectic(γ+γ′),and primaryγ′significantly decrease,but the area fraction of eutectic(γ+γ′)linerly increases as the cooling rate rises.Thus moderate cooling rate(such as 30℃·min^(-1))should be selected during the solidification process of GH4975 alloy.
基金Under the auspices of National Social Sciences Foundation of China(No.21BJY114)。
文摘Forests exert significant biogeophysical cooling effects(CE)through processes such as increased evapotranspiration,reduced albedo,and enhanced surface roughness.However,little is known about the extent to which elevation-induced temperature differences bias the observed CE and how this bias interacts with the underlying biogeophysical mechanisms.In this study,we integrated multisensor remote sensing products and Shuttle Radar Topography Mission(SRTM)elevation data on the Google Earth Engine(GEE)platform,and applied a spatial-temporal window regression approach to quantify and correct the sensitivity of land surface temperature(LST)to elevation for forest pixels across China from 2001 to 2022.First,we found that forest LST exhibited a significant negative relationship with elevation,leading to systematic CE overestimation by 0.61 K during the day and 0.60 K at night compared with altitudecorrected CE values.Second,after correction,the CE showed clear spatial heterogeneity,with stronger daytime cooling in tropical(-0.54 K)and temperate forests(-0.24 K),and warming in cold(+0.11 K)and arid regions(+0.53 K),while most regions experienced nighttime warming.Among forest types,evergreen needleleaf forests(ENF)exhibited the strongest daytime cooling(-0.36 K),whereas deciduous broadleaf(DBF)and open shrublands(OS)tended to warm.Third,mechanism analysis revealed that elevation correction strengthened the correlations of CE with leaf area index(LAI)and evapotranspiration,while maintaining a significant negative correlation with albedo,indicating that both radiative and non-radiative processes jointly shape the unbiased CE.These findings provide a more accurate quantification of forest CE by eliminating elevation-induced bias,which providing a more accurate assessment of the climate mitigation potential of forests,which is crucial for developing more effective forest management and ecological restoration strategies.
文摘An instrumental assessment and volunteer subjective evaluation method was developed to synchronously measure the actual skin temperature and evaluate the cool sensation,conducting a quantitative analysis of the perceived coolness.This method was used to evaluate the effect of a self-developed hot flash spray on reducing the skin temperature and inducing the cooling sensation of menopausal individuals.31 healthy menopausal volunteers were recruited as research subjects.Using infrared thermal imaging and electroencephalogram(EEG)measurements,the skin temperature and EEG data of the subjects’cheeks were simultaneously collected at baseline(BL)immediately after simulated hot flashes(HF),1 min(T1),3 mins(T3)and 5 min(T5)after the application of the test sample.The results showed that,compared with HF,the skin temperature of cheek was significantly reduced by 8.75%,8.75%and 6.41%at T1,T3 and T5(P<0.05),respectively.And alpha-1 value of EEG was increased significantly by 59.70%,58.44%,and 51.39%at T1,T3,and T5(P<0.05),respectively.The hot flash spray effectively reduces skin temperature while also provides subjects with a feeling of coolness,which can relieve hot flashes in menopausal women.
基金supported by the Materials and Components Technology Development Program of the Ministry of Trade,Industry,and Energy(MOTIE,South Korea)(No.20024843)。
文摘Micro-alloying is an effective approach for improving the corrosion resistance of cast AZ91.However,the effect of micro-alloyed elements on corrosion resistance can be varied depending on the solidification rate influencing the diffusion and precipitation behavior of micro-alloying elements.This study investigated the effects of the cooling rate on the microstructure and corrosion behavior of micro-Ca and-Y alloyed cast AZ91 alloy(i.e.,AZXW9100).To achieve various cooling rates,the alloys were prepared using three methods:steel mold casting(SMC),copper step mold casting(CSMC),and high-pressure die casting(HPDC).The corrosion behavior was analyzed through weight loss measurements,electrochemical impedance spectroscopy,and corrosion morphology observations.The results showed that the key microstructural factors influencing corrosion resistance differed between short-and long-term corrosion.As the cooling rate increased,the short-term corrosion rate was lowered from 0.91 mm/y(SMC)to 0.38 mm/y(HPDC),which was attributed to the decrease in the total area fractions of the eutecticαandβphases acting as galvanic corrosion sources.The long-term corrosion rate was reduced from 17.20 mm/y(SMC)to 0.71 mm/y(HPDC),which was revealed to be due to the enhanced connectivity of theβphase acting as corrosion barriers.Meanwhile,the increase in the cooling rate led to a modification of the Zn molar ratio in theβphase,reducing the Volta potential of theβphase from 101.8 m V to 66.9 m V.This reduction in the Volta potential of the main galvanic source also contributed to improved corrosion resistance.The HPDC AZXW9100 alloy produced in this study exhibited the lowest corrosion rate compared to other alloys.These findings suggest that controlling the cooling rate is a promising strategy for enhancing the corrosion resistance of AZXW9100 alloys.
基金Supported by Science Research Project of Hebei Education Department(Grant No.BJK2024138)Hebei Provincial Natural Science Foundation(Grant No.E2023203129)National Natural Science Foundation of China(Grant Nos.52004242,52075472).
文摘The aluminum(Al)/steel transition joints used in ships are processed from composite plates,and their mechanical properties have a significant impact on the safety of ships.In this paper,the Al/steel composite plate was prepared using rolling,with 5083 aluminum plate as the cladding plate,Q235 steel plate as the substrate,and TA1 titanium(Ti)plate and DT4 pure iron(Fe)plate as the intermediate layers.The heterothermic billet was prepared through induction heating by the magnetic effects of the steel plate and the pure Fe plate,and then the Al/steel composite plate was obtained by rolling.The impacts of post-rolling cooling process on the microstructure and properties of the Al/Ti/pure Fe/steel composite plate were studied.The results manifested that the pure Fe/steel interface had a good composite effect.With the increase in the cooling rate,the bonding strength of the Al/Ti interface was raised,and that of the Ti/Fe interface was increased first and then decreased.When the oil cooling process was adopted,the Al/Ti/pure Fe/steel composite plate exhibited the highest comprehensive performance.The shear strength of the Al/Ti interface and the Ti/Fe interface was 102 MPa and 186 MPa,respectively.The plastic fracture was determined as the mode of interface fracture.
基金funded by the National Key R&D Program Funded Projects(No.2021YFB3704102).
文摘The cooling rate of the center and edge of vacuum induction melting(VIM)or vacuum arc remelting(VAR)ingots exhibit substantial difference,leading to markedly distinct dendritic structures and precipitates.The current lack of precise predictions for dendritic segregation and the distribution of precipitates in ingot makes it difficult to determine the annealing and homogenization heat treatment process.Thus,clarifying the impact of cooling rate on the solidification behavior of alloy is significantly important.The dendritic structure and precipitation characteristics of as-cast C-HRA-3 Ni–Cr–Co–Mo-based heat-resistant alloy were investigated using Thermo-Calc thermodynamic calculations,scanning electron microscopy observations,and electron probe microanalyzer.Based on high temperature observation system,the effects of cooling rate on the dendritic structure,dendritic segregation,and precipitation in this alloy were explored.The results showed that the precipitates in the as-cast C-HRA-3 alloy primarily consist of blocky Ti(C,N)phases,large-sized Ti(C,N)–M_(6)C–M_(23)C_(6) symbiotic phases and M_(6)C–M_(23)C_(6) carbides,and small-sized dispersed M_(6)C and M_(23)C_(6) carbides surronding these symbiotic phases.The primary constituent elements of these precipitates are Mo,Cr,C,and Ti,which predominantly concentrate in the interdendritic regions of the as-cast alloy.There is a clear power-law relationship between the secondary dendrite arm spacing and the cooling rate.The dendritic segregation ratio of Mo,Cr,and Ti exhibits a piecewise functional relationship with the cooling rate,under equiaxed dendritic solidification condition.These predictive models and theoretical analyses were validated using numerical simulations and experimental results from the 200 kg grade VIM electrode.
基金Supported by the Research Fund of Key Laboratory of Aircraft Environment Control and Life Support,MIIT,Nanjing University of Aeronautics and Astronautics (Grant No. KLAECLSE-202201)。
文摘The water curtain spray system of the ship helps reduce surface thermal load and lowers thermal infrared radiation, notably enhancing the stealth and survivability of naval ships. The performance of the water curtain spray system is largely influenced by the density of the nozzles and their installation height. Therefore, a test platform was established to investigate these critical influencing factors, employing an orthogonal design methodology for the experimental study. Specifically, the study evaluated the effects of varying distances to the steel plate target and different injection heights on the cooling performance of the system. Results demonstrate that using one nozzle per 4 square meters of the ship's surface area effectively lowers the surface temperature, bringing it closer to the ambient background temperature. This nozzle configuration creates irregular infrared heat patterns, which complicate the task for infrared detectors to discern the ship's outline, thus enhancing its infrared stealth. Additionally, maintaining the nozzle installation height within 0.6 m to prevent the temperature difference between the steel plate and the background temperature from exceeding 4 K. Moreover, as the infrared imaging distance increases from 3 to 9 m, the temperature difference measured by the thermocouple and the infrared imager increases by 141.27%. Furthermore, with the increase in infrared imaging distance, the infrared temperature of the target steel plate approaches the background temperature, indicating improved detectability. These findings have significantly enhanced the stealth capabilities of naval ships, maximizing their immunity to infrared-guided weapon attacks. Moreover, their importance in improving the survivability of ships on the water surface cannot be underestimated.
基金supported by the National Natural Science Foundation of China(No.52206090)the Jiangsu Provincial Natural Science Foundation(No.BK20220901)+2 种基金the National Major Science and Technology Projects of China(No.Y2022-Ⅲ-0004-0013)Engineering Research Center of Low-Carbon Aerospace Power Ministry of Education(No.CEPE2024020)the China Postdoctoral Science Foundation(No.2022TQ0149).
文摘The study of the spallation of thermal barrier coatings on turbine blades and its influence is of great significance for gas turbine safety operation.However,numerical simulation related to thermal barrier coatings is difficult and time-costly,which makes it hard to meet engineering demands.Therefore,this work establishes a rapid prediction model for the surface temperature and cooling efficiency of turbine blades with localized spallation of thermal barrier coatings based on a thin-wall thermal resistance model.Firstly,the influence of localized spallation of thermal barrier coatings on the cooling efficiency of typical turbine blades is numerically investigated.Then,based on the simulation data set and multi-layer perception(MLP)neural network,an intelligent prediction model for the temperature and cooling efficiency distribution of localized spallation of coatings is constructed,which can rapidly predict the surface temperature and cooling efficiency of the blade under the situation of spallation of coating at any position on the blade surface.The results show that,under a certain spallation area,the shape of localized coating spallation has little influence on the cooling efficiency,while the increase of spallation thickness will cause a linear increase in the average temperature of the blade surface.The prediction error of the proposed rapid prediction model for the average surface temperature and cooling efficiency of blades is within 2%,and the prediction error of the temperature and cooling efficiency at the spallation position is within 6%for 80%of the samples,with an overall average error within 10%.It is concluded from the rapid prediction model that when the depth of coating spallation increases,the closer the spallation position is to the leading edge of the blade,the greater the difference in cooling efficiency is,and the degree of influence of coating spallation on the cooling efficiency also increases.
基金Project(2018XK2301) supported by the Change-Zhu-Tan National Independent Innavation Demonstration Zone Special Program,China。
文摘The ductile-to-brittle transition temperature(DBTT)of high strength steels can be optimized by tailoring microstructure and crystallographic orientation characteristics,where the start cooling temperature plays a key role.In this work,X70 steels with different start cooling temperatures were prepared through thermo-mechanical control process.The quasi-polygonal ferrite(QF),granular bainite(GB),bainitic ferrite(BF)and martensite-austenite constituents were formed at the start cooling temperatures of 780℃(C1),740℃(C2)and 700℃(C3).As start cooling temperature decreased,the amount of GB decreased,the microstructure of QF and BF increased.Microstructure characteristics of the three samples,such as high-angle grain boundaries(HAGBs),MA constituents and crystallographic orientation,also varied with the start cooling temperatures.C2 sample had the lowest DBTT value(−86℃)for its highest fraction of HAGBs,highest content of<110>oriented grains and lowest content of<001>oriented grains parallel to TD.The high density of{332}<113>and low density of rotated cube{001}<110>textures also contributed to the best impact toughness of C2 sample.In addition,a modified model was used in this paper to quantitatively predict the approximate DBTT value of steels.
基金financially supported by the Science and Technology Innovation Program of Hunan Province(2024RC3003)the Central South University Innovation-Driven Research Programme(2023CXQD012)the Initiative for Sustainable Energy for its financial support。
文摘By combining the merits of radiative cooling(RC)and evaporation cooling(EC),radiative coupled evaporative cooling(REC)has attracted considerable attention for sub-ambient cooling purposes.However,for outdoor devices,the interior heating power would increase the working temperature and fire risk,which would suppress their above-ambient heat dissipation capabilities and passive water cycle properties.In this work,we introduced a REC design based on an all-in-one photonic hydrogel for above-ambient heat dissipation and flame retardancy.Unlike conventional design RC film for heat dissipation with limited cooling power and fire risk,REC hydrogel can greatly improve the heat dissipation performance in the daytime with a high workload,indicating a 12.0℃lower temperature than the RC film under the same conditions in the outdoor experiment.In the nighttime with a low workload,RC-assisted adsorption can improve atmospheric water harvesting to ensure EC in the daytime.In addition,our REC hydrogel significantly enhanced flame retardancy by absorbing heat without a corresponding temperature rise,thus mitigating fire risks.Thus,our design shows a promising solution for the thermal management of outdoor devices,delivering outstanding performance in both heat dissipation and flame retardancy.
基金financial support from the National Natural Science Foundation of China(Grant No.52273067,52233006)the Fundamental Research Funds for the Central Universities(Grant No.2232023A-03)+3 种基金the Shuguang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission(Grant No.23SG29)the Natural Science Foundation of Shanghai(Grant No.24ZR1402400)the Shanghai Scientific and Technological Innovation Project(Grant No.24520713000)Innovation Program of Shanghai Municipal Education Commission(Grant No.2021-01-07-00-03-E00108).
文摘Radiative cooling textiles with spectrally selective surfaces offer a promising energy-efficient approach for sub-ambient cooling of outdoor objects and individuals.However,the spectrally selective mid-infrared emission of these textiles significantly hinders their efficient radiative heat exchange with self-heated objects,thereby posing a significant challenge to their versatile cooling applicability.Herein,we present a bicomponent blow spinning strategy for the production of scalable,ultra-flexible,and healable textiles featuring a tailored dual gradient in both chemical composition and fiber diameter.The gradient in the fiber diameter of this textile introduces a hierarchically porous structure across the sunlight incident area,thereby achieving a competitive solar reflectivity of 98.7%on its outer surface.Additionally,the gradient in the chemical composition of this textile contributes to the formation of Janus infrared-absorbing surfaces:The outer surface demonstrates a high mid-infrared emission,whereas the inner surface shows a broad infrared absorptivity,facilitating radiative heat exchange with underlying self-heated objects.Consequently,this textile demonstrates multi-scenario radiative cooling capabilities,enabling versatile outdoor cooling for unheated objects by 7.8℃ and self-heated objects by 13.6℃,compared to commercial sunshade fabrics.
基金support from the Contract Research(“Development of Breathable Fabrics with Nano-Electrospun Membrane”,CityU ref.:9231419“Research and application of antibacterial and healing-promoting smart nanofiber dressing for children’s burn wounds”,CityU ref:PJ9240111)+1 种基金the National Natural Science Foundation of China(“Study of Multi-Responsive Shape Memory Polyurethane Nanocomposites Inspired by Natural Fibers”,Grant No.51673162)Startup Grant of CityU(“Laboratory of Wearable Materials for Healthcare”,Grant No.9380116).
文摘Radiative cooling systems(RCSs)possess the distinctive capability to dissipate heat energy via solar and thermal radiation,making them suitable for thermal regulation and energy conservation applications,essential for mitigating the energy crisis.A comprehensive review connecting the advancements in engineered radiative cooling systems(ERCSs),encompassing material and structural design as well as thermal and energy-related applications,is currently absent.Herein,this review begins with a concise summary of the essential concepts of ERCSs,followed by an introduction to engineered materials and structures,containing nature-inspired designs,chromatic materials,meta-structural configurations,and multilayered constructions.It subsequently encapsulates the primary applications,including thermal-regulating textiles and energy-saving devices.Next,it highlights the challenges of ERCSs,including maximized thermoregulatory effects,environmental adaptability,scalability and sustainability,and interdisciplinary integration.It seeks to offer direction for forthcoming fundamental research and industrial advancement of radiative cooling systems in real-world applications.
基金supported by the National Natural Science Foundation of China(No.62464010)Spring City Plan-Special Program for Young Talents(K202005007)+2 种基金Yunnan Talents Support Plan for Young Talents(XDYC-QNRC-2022-0482)Yunnan Local Colleges Applied Basic Research Projects(202101BA070001-138)Frontier Research Team of Kunming University 2023.
文摘Rechargeable Zn/Sn-air batteries have received considerable attention as promising energy storage devices.However,the electrochemical performance of these batteries is significantly constrained by the sluggish electrocatalytic reaction kinetics at the cathode.The integration of light energy into Zn/Sn-air batteries is a promising strategy for enhancing their performance.However,the photothermal and photoelectric effects generate heat in the battery under prolonged solar irradiation,leading to air cathode instability.This paper presents the first design and synthesis of Ni_(2)-1,5-diamino-4,8-dihydroxyanthraquinone(Ni_(2)DDA),an electronically conductiveπ-d conjugated metal-organic framework(MOF).Ni_(2)DDA exhibits both photoelectric and photothermal effects,with an optical band gap of~1.14 eV.Under illumination,Ni_(2)DDA achieves excellent oxygen evolution reaction performance(with an overpotential of 245 mV vs.reversible hydrogen electrode at 10 mA cm^(−2))and photothermal stability.These properties result from the synergy between the photoelectric and photothermal effects of Ni_(2)DDA.Upon integration into Zn/Sn-air batteries,Ni_(2)DDA ensures excellent cycling stability under light and exhibits remarkable performance in high-temperature environments up to 80℃.This study experimentally confirms the stable operation of photo-assisted Zn/Sn-air batteries under high-temperature conditions for the first time and provides novel insights into the application of electronically conductive MOFs in photoelectrocatalysis and photothermal catalysis.
基金supported by the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(MSIT)(No.RS-2022-00143178)the Ministry of Education(MOE)(Nos.2022R1A6A3A13053896 and 2022R1F1A1074616),Republic of Korea.
文摘Beam-tracking simulations have been extensively utilized in the study of collective beam instabilities in circular accelerators.Traditionally,many simulation codes have relied on central processing unit(CPU)-based methods,tracking on a single CPU core,or parallelizing the computation across multiple cores via the message passing interface(MPI).Although these approaches work well for single-bunch tracking,scaling them to multiple bunches significantly increases the computational load,which often necessitates the use of a dedicated multi-CPU cluster.To address this challenge,alternative methods leveraging General-Purpose computing on Graphics Processing Units(GPGPU)have been proposed,enabling tracking studies on a standalone desktop personal computer(PC).However,frequent CPU-GPU interactions,including data transfers and synchronization operations during tracking,can introduce communication overheads,potentially reducing the overall effectiveness of GPU-based computations.In this study,we propose a novel approach that eliminates this overhead by performing the entire tracking simulation process exclusively on the GPU,thereby enabling the simultaneous processing of all bunches and their macro-particles.Specifically,we introduce MBTRACK2-CUDA,a Compute Unified Device Architecture(CUDA)ported version of MBTRACK2,which facilitates efficient tracking of single-and multi-bunch collective effects by leveraging the full GPU-resident computation.
基金supported by the National Natural Science Foundation of China(No.32170121).
文摘Benzalkonium chloride(BAC)is widely employed as a broad-spectrum biocide and has emerged as a significant environmental pollutant.Polymyxin B(PB)serves as the last-line defense for the treatment of Gram-negative pathogens.Previous studies reported that BAC-adapted Pseudomonas aeruginosa increased the tolerance to PB.Herein,we present the novel finding that the combination of BAC and PB exhibited synergistic antibacterial effects against P.aeruginosa.Time-killing assay demonstrated a significant reduction in bacterial cell viability.Scanning electron microscopy,zeta potential analysis,hydrophobicity measurements,and fluorescence probe analyses collectively revealed severe disruption of the cell envelope and membrane potential induced by the combination of BAC and PB.Transcriptomic analysis revealed that the BAC-PB combination notably downreg-ulated the expression of genes involved in lipid A modification and cell envelope production,including phoPQ,pmrAB,bamABCDE,lptABCDEG,lolB,yidC,and murJ.Additionally,the combination group exhibited augmented production of reactive oxygen species and diminished ATP synthesis.The expression of the genes associated with substance metabolism and energy generation was significantly impeded.This study provides significant implica-tions for the interactions of biocides and antibiotics on Gram-negative pathogens,while also addressing antibiotic resistance and developing the external treatment strategy for Pseudomonas-infected wounds and burns.
基金Supported by the Zhejiang Medical Health Science and Technology Project(No.2021KY217)the Basic Public Welfare Research Project of Wenzhou Municipal Science and Technology Bureau(No.2024Y1221).
文摘AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 groups:Group A(implanted with the SN6CWS),Group B(implanted with the MI60),and Group C(implanted with the Aspira-aA).ELP measurements were obtained with swept-source optical coherence tomography(SS-OCT)at 1d,1wk,1mo,and 3mo postoperatively.Subjective refraction assessments were conducted at 1wk,1mo,and 3mo following surgery.RESULTS:The study included 189 eyes of 150 cataract patients(66 males).There were 77 eyes in Group A,55 eyes in Group B,and 57 eyes in Group C.The root mean square of the ELP(ELPRMS)within the initial 3mo was significantly lower for Group A than for Groups B and C.Refractive changes within Group A were not significant across the time points of 1wk,1mo,and 3mo.Conversely,both Group B and Group C demonstrated statistically significant shifts toward hyperopia from 1wk to 3mo postsurgery.CONCLUSION:Among the three IOLs examined,the SN6CWS IOL showes the greatest stability during the first 3mo postoperatively.Between 1wk and 3mo after surgery,notable hyperopic shifts are evident in eyes implanted with the MI60 and Aspira-aA IOLs,whereas refractive outcomes remain relatively constant in eyes implanted with SN6CWS IOLs.
文摘Electrical and electronic devices face significant challenges in heatmanagement due to their compact size and high heat flux,which negatively impact performance and reliability.Conventional coolingmethods,such as forced air cooling,often struggle to transfer heat efficiently.In contrast,thermoelectric coolers(TECs)provide an innovative active cooling solution to meet growing thermal management demands.In this research,a refrigerant based on mono ethylene glycol and distilled water was used instead of using gases,in addition to using thermoelectric cooling units instead of using a compressor in traditional refrigeration systems.This study evaluates the performance of a Peltierbased thermalmanagement systemby analyzing the effects of using two,three,and four Peltiermodules on cooling rates,power consumption,temperature reduction,and system efficiency.Experimental results indicate that increasing the number of Peltier modules significantly enhances cooling performance.The four-module system achieved an optimal balance between cooling speed and energy efficiency,reducing the temperature of a liquidmixture(30% mono ethylene glycol+70% distilled water plus laser dyes)to 8℃ in just 17 min.It demonstrated a cooling rate of 0.794℃/min and a high coefficient of performance(COP)of 1.2 while consuming less energy than the two-and three-module systems.Furthermore,the study revealed that increasing the number of modules led to faster air cooling and improved temperature reduction.These findings highlight the importance of selecting the optimal number of Peltier modules to enhance efficiency and cooling speed whileminimizing energy consumption.This makes TEC technology a sustainable and effective solution for applications requiring rapid and reliable thermal management.
基金supported by the National Key Research and Development Program of Chinathe National Natural Science Foundation of China (Grant Nos.2024YFA1408000,12474097,and2023YFA1406001)+2 种基金the Guangdong Provincial Quantum Science Strategic Initiative (Grant No.GDZX2201001)the Center for Computational Science and Engineering at Southern University of Science and Technology,the Major Science and Technology Infrastructure Project of Material Genome Big-science Facilities Platform supported by Municipal Development and Reform Commission of Shenzhen(for J.L.Z.and Y.L.)the Chinese funding sources applied via HPSTAR。
文摘The magnetic properties and Kondo effect in Ce3TiBi5 with a quasi-one-dimensional structure were investigated using in situ high-pressure resistivity measurements up to 48 GPa.At ambient pressure,Ce_(3)TiBi_(5) undergoes an antiferromagnetic(AFM)transition at T_(N)∼5 K.Under high pressures within 8.9 GPa,we find that Kondo scattering contributes differently to the high-temperature resistance,R(T),depending on the applied current direction,demonstrating a significantly anisotropic Kondo effect.The complete P–T phase diagram has been constructed,in which the pressure dependence of T_(N) exhibits a dome-like shape.The AFM order remains robust under pressure,even when the coherence temperature T^(*) far exceeds 300 K.We attribute the observed anisotropic Kondo effect and the robust AFM to the underlying anisotropy in electronic hybridization under high pressure.
基金supported by the CAS Strategic Priority Research Program(No.XDB0760102),the Ministry of Science and Technology of China(No.2022YFF0802501)the Major Science and Technology Infrastructure Maintenance and Transformation Project of the Chinese Academy of Sciences,Shanghai Science and Technology Innovation Action Plan-Phospherus Project(No.23YF1426200)the National Key Research and Development Program of China(No.2024YFE0212200).
文摘In winter 2018,an aerosol physicochemical experiment was conducted in the Western Pacific Ocean(WPO)aboard the Research Vessel KEXUE of Chinese Academy of Sciences.This study systematically investigated both natural and anthropogenic effects on marine aerosols optical properties,as well as the applicability of multi-satellite products and IMPROVE equation.The averaged aerosol optical depth(AOD500 nm)was 0.31±0.16 andÅngström exponent440–675 nm was 0.29±0.30.In offshore China,significant anthropogenic emissions affected the marine environment.In remote WPO,dust aerosols transported from northern China,Siberia,Central Asia,and those settling from the upper troposphere originating from north Africa,Arabian peninsula,and western India,were dominant.The spatial trends of AOD were opposite in the mid-latitude and southern seas of WPO.The highest AOD,0.32±0.23,appeared along the coast of South Asia at mid-latitude,decreasing from offshore seas to remote oceans.In low-latitude and equatorial seas,AOD significantly increased from coast to remote oceans.Ångström exponent dropped significantly from the coast to remote oceans as anthropogenic influence diminished across the entire WPO.Correlation analysis showed that both MODIS-C6 and Himawari AOD prod-ucts showed similar applicability in coastal urban areas,while Himawari AOD is highly recommended for coastal background and marine environment due to its finer resolution.The extinction coefficient derived from PM_(2.5) chemical compositions using IMPROVE algorithm exhibited a significant correlation(R^(2)=0.58)with the con-currently measured AOD in the absence of long-distance transport,suggesting that the IMPROVE is a reasonable proxy of the columnar average of marine aerosol extinctions free from transport influences.
文摘This paper prepared a novel as-cast W-Zr-Ti metallic ESM using high-frequency vacuum induction melting technique.The above ESM performs a typical elastic-brittle material feature and strain rate strengthening behavior.The specimens exhibit violent chemical reaction during the fracture process under the impact loading,and the size distribution of their residual debris follows Rosin-Rammler model.The dynamic fracture toughness is obtained by the fitting of debris length scale,approximately 1.87 MPa·m~(1/2).Microstructure observation on residual debris indicates that the failure process is determined by primary crack propagation under quasi-static compression,while it is affected by multiple cracks propagation in both particle and matrix in the case of dynamic impact.Impact test demonstrates that the novel energetic fragment performs brilliant penetration and combustion effect behind the front target,leading to the effective ignition of fuel tank.For the brittleness of as-cast W-ZrTi ESM,further study conducted bond-based peridynamic(BB-PD)C++computational code to simulate its fracture behavior during penetration.The BB-PD method successfully captured the fracture process and debris cloud formation of the energetic fragment.This paper explores a novel as-cast metallic ESM,and provides an available numerical avenue to the simulation of brittle energetic fragment.
