In this study,the approximate and exact solutions for the stationary-state of the solids model with neglecting reactant consumption for both non-uniform and uniform temperature systems were applied on gas ignition und...In this study,the approximate and exact solutions for the stationary-state of the solids model with neglecting reactant consumption for both non-uniform and uniform temperature systems were applied on gas ignition under a constant pressure condition.The criticality conditions for a slab,an infinite cylinder,and a sphere are determined and discussed using dimensionless temperatures under constant ambient and surface temperatures for a non-uniform temperature system.Exact solution for a Semenov model with convection heat loss was also presented.The solution of the Semenov problem for constant volume or density as a solid and constant pressure were compared.The critical parameterδis calculated and compared with those of Frank-Kamenetskii solution values.The validation of the calculated ignition temperatures with other exact solution and experimental results were offered.The relation between critical parameters form Semenov and F.K.models solution was introduced.展开更多
Archroma becomes the exclusive global distributor of Fibre52®'s patented chemistry-advancing a new standard in sustainable processing.Combined with Archroma's AVITERA®SE dyes,the partnership delivers...Archroma becomes the exclusive global distributor of Fibre52®'s patented chemistry-advancing a new standard in sustainable processing.Combined with Archroma's AVITERA®SE dyes,the partnership delivers the industry's most resource-efficient bleach-and-dye sys-tems.Archroma,a leading global specialty chemicals company committed to sus-tainable innovation,and Innovo Fiber LLC,owner of the patented Fibre52®system,today announced an exclusive global dis-tribution partnership to expand the reach of Fibre52®'s proven low-temperature,bleaching technology with innovative dyeing application to textile mills and brands worldwide.展开更多
Purpose–This study solves the key problem that the static level monitoring is susceptible to temperature interference and affects the accuracy in slope instability/deformation monitoring.The purpose is to develop a r...Purpose–This study solves the key problem that the static level monitoring is susceptible to temperature interference and affects the accuracy in slope instability/deformation monitoring.The purpose is to develop a reliable temperature compensation method for the system,improve the accuracy of slope stability monitoring and provide support for improving the safety and safety monitoring of engineering spoil slope and other projects.Design/methodology/approach–Combined with theoretical analysis and experimental verification,the temperature compensation method is explored.The working principle of the hydrostatic leveling monitoring system is analyzed and the data processing formula,the temperature error calculation formula and the calculation formula for eliminating the error settlement value are derived.The temperature compensation method is established and verified by the field test of the engineering spoil slope which is disturbed by a debris flow.Findings–The experimental results show that this method can reduce the error of the static level monitoring system by about 40%.The field test shows that the fluctuation of slope settlement monitoring value is reduced after temperature compensation and the monitoring value is consistent with the actual situation,which has certain practicability.Originality/value–The originality of this study is to derive a theoretical formula for quantifying/eliminating temperature errors in static leveling and to establish a practical temperature compensation method.The accuracy of the system is improved,which provides a reference for slope stability monitoring under complex environment(especially railway geotechnical engineering)and promotes the development of precision monitoring technology.展开更多
Numerical thermodynamic models are proposed for the quaternary fluid system H_(2)O-CO_(2)-NaCl-CaCl_(2)and its ternary subsystems H_(2)O-NaCl-CaCl_(2),H_(2)O-CO_(2)-NaCl,and H_(2)O-CO_(2)-CaCl_(2).The models are valid...Numerical thermodynamic models are proposed for the quaternary fluid system H_(2)O-CO_(2)-NaCl-CaCl_(2)and its ternary subsystems H_(2)O-NaCl-CaCl_(2),H_(2)O-CO_(2)-NaCl,and H_(2)O-CO_(2)-CaCl_(2).The models are valid for temperatures from 150℃to 350℃,pressures from 0.2 to 1.4 kbar,and for arbitrary concentrations of salts.The latter feature is inherited from the earlier developed models of binary systems H_(2)O-NaCl and H_(2)O-CaCl_(2).All the models are formulated in terms of the Gibbs free energy.The entropy term in the equation for the Gibbs free energy of mixing is introduced in a general form,based on the number of different ways of arranging particles in the system that lead to the same total energy.The parameters of the energy terms corresponding to the interactions of particles in binary and ternary subsystems are obtained by fitting published experimental data.The concentrations of salts in the gas phase are simulated based on the salt evaporation free energy.Our model,also available as a computer code,makes it possible to predict the physicochemical properties of fluids involved in hydrothermal processes in the upper crust:the phase state of the system(homogeneous or two-phase fluid),activities of the components,densities,and compositions of the(coexisting)fluid phases.The model offers a numerical tool for analyzing fluid inclusion data and better understanding of metamorphic and metasomatic processes in the upper crust.Fluids at studied P-T conditions play a decisive role in the formation of hydrothermal ore deposits,including most of the world's gold deposits.展开更多
Optically detected magnetic resonance(ODMR)has emerged as a powerful technique for quantum sensing,enabling high-sensitivity detection of physical quantities even at room temperature.Solid-state defects,such as nitrog...Optically detected magnetic resonance(ODMR)has emerged as a powerful technique for quantum sensing,enabling high-sensitivity detection of physical quantities even at room temperature.Solid-state defects,such as nitrogen-vacancy(NV)centers in diamond,have demonstrated remarkable capabilities in this domain[1–4].However,these systems are limited by their rigid lattice structures and lack tunability.展开更多
To address the temperature cross-talk issue in detecting heavy metal ions in natural waters, a highly-integrated and fully fiber-optic metal ion sensing system capable of temperature-concentration decoupling measureme...To address the temperature cross-talk issue in detecting heavy metal ions in natural waters, a highly-integrated and fully fiber-optic metal ion sensing system capable of temperature-concentration decoupling measurement has been designed. This system integrates a fluidic detection structure assisted by side-polished fibers(SPFs) with a Sagnac interferometer.展开更多
Thermal barrier coating(TBC)is crucial for the performance of turbine blades at high temperatures;however,it degrades the microstructure of single-crystal superalloy(SX),thereby reducing creep life.Despite this,the de...Thermal barrier coating(TBC)is crucial for the performance of turbine blades at high temperatures;however,it degrades the microstructure of single-crystal superalloy(SX),thereby reducing creep life.Despite this,the degradation mechanisms associated with the complex multi-layer damage and inter-layer diffusion behavior for TBC/SX systems have not yet been fully elucidated.In this study,using integrated experimental efforts and multiscale characterization techniques,the creep degradation mechanisms of TBC/SX systems at 900℃/500 MPa,980℃/300 MPa,and 1050℃/160 MPa are systematically investigated.Results demonstrate that the creep degradation from TBC intensifies with increasing temperature(T)and stress(σ)ratio(T/σ),exhibiting significant dependency on these two factors,and primarily reduces lifespan of the steady-state stage,with minimal effects on the accelerating stage.During creep deformation,the cracking behavior caused by thermally grown oxide(TGO)beneath the top coat(TC)layer,voids resulting from internal oxidation and interdiffusion in the bond coat(BC)layer,and the recrystallization growth driven by the sandblasting process in the secondary reaction zone(SRZ)are temperature-sensitive damages.In contrast,the initiation and propagation of cracks associated with the topologically close-packed(TCP)phases in the SRZ exhibit pronounced stress sensitivity.Furthermore,the formation of the substrate diffusion zone(SDZ)and the decomposition ofγ/γ′interfacial dislocation networks driven by the Cr-Ru diffusion,as well as the increased stacking fault energy in theγ′phase due to Co loss,are responsible for the acceleration of steady-state creep rate at 1050℃/160 MPa.This work provides a comprehensive and in-depth understanding of the degradation mechanisms under thermal-mechanical coupling in TBC/SX systems,offering new insights into targeted design optimization for multilayered coatings.展开更多
Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materi...Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.展开更多
In recent years,the research on superconductivity in one-dimensional(1D)materials has been attracting increasing attention due to its potential applications in low-dimensional nanodevices.However,the critical temperat...In recent years,the research on superconductivity in one-dimensional(1D)materials has been attracting increasing attention due to its potential applications in low-dimensional nanodevices.However,the critical temperature(T_(c))of 1D superconductors is low.In this work,we theoretically investigate the possible high T_(c) superconductivity of(5,5)carbon nanotube(CNT).The pristine(5,5)CNT is a Dirac semimetal and can be modulated into a semiconductor by full hydrogenation.Interestingly,by further hole doping,it can be regulated into a metallic state with the sp^(3)-hybridized σ electrons metalized,and a giant Kohn anomaly appears in the optical phonons.The two factors together enhance the electron–phonon coupling,and lead to high-T_(c) superconductivity.When the hole doping concentration of hydrogenated-(5,5)CNT is 2.5 hole/cell,the calculated T_(c) is 82.3 K,exceeding the boiling point of liquid nitrogen.Therefore,the predicted hole-doped hydrogenated-(5,5)CNT provides a new platform for 1D high-T_(c) superconductivity and may have potential applications in 1D nanodevices.展开更多
Lin Wei is a hiking enthusiast.At six o'clock on the last Saturday morning,the temperature at the foot of the mountain was only 2℃,so she put on her thickest fleece jacket.However,after only half an hour of climb...Lin Wei is a hiking enthusiast.At six o'clock on the last Saturday morning,the temperature at the foot of the mountain was only 2℃,so she put on her thickest fleece jacket.However,after only half an hour of climbing,the heat left her drenched in sweat,making her feel very cold.By midday,the temperature was approaching 20℃,and her heavy jacket had to be tied around her waist,becoming a burden during her hike.This outdoor adventure allowed her to appreciate the beautiful scenery,but also subjected her to repeated changes in temperature.展开更多
Following over 20 years of research,a direct measurement of the QGP temperature has been achieved at Relativistic Heavy-Ion Collider(RHIC),free from the blue-shift effect and contamination from strong interactions.Thi...Following over 20 years of research,a direct measurement of the QGP temperature has been achieved at Relativistic Heavy-Ion Collider(RHIC),free from the blue-shift effect and contamination from strong interactions.This viewpoint discusses a recent measurement of the QGP temperature at different stages at the Solenoidal Tracker at RHIC(STAR),which used e^(+)e^(-)pairs as penetrating probes.展开更多
Prolonged exposure to n-butanol, a common hazardous volatile organic compound(VOC) in the environment, can lead to a broad range of adverse health effects. Therefore, detecting n-butanol safely and efficiently at low ...Prolonged exposure to n-butanol, a common hazardous volatile organic compound(VOC) in the environment, can lead to a broad range of adverse health effects. Therefore, detecting n-butanol safely and efficiently at low concentrations becomes critical for both environmental monitoring and human health. In this study, a novel Eu/Ce-codoped MOF-ZnO gas sensor was developed for the sensitive detection of n-butanol gas under ultraviolet activation at ambient temperature. A series of Eu/Ce-ZnO nanomaterials were synthesized via a simple co-precipitation route, by carefully designing the varied mass ratios of Eu and Ce incorporated into pristine ZnO derived from MOF precursors. The gas testing results revealed that introducing an appropriate amount of Eu and Ce would enlarge the specific surface area and enrich the oxygen vacancy content compared to pristine MOF-ZnO. Upon UV irradiation, the 0.03 wt% Eu 0.04 wt% Ce-ZnO sensor achieved a superior response of 611 for100 ppm n-butanol at room temperature, 15.28 times higher than that of pristine MOF-ZnO(40). Furthermore, the sensor presented rapid response/recovery times(15 s/28 s) and excellent selectivity. The above contributions pave the way for the promising development of highly sensitive, ultraviolet-enhanced gas sensors for ambient temperature detection of VOCs.展开更多
Root-zone temperature(RZT)strongly affects plant growth,nutrient uptake and tolerance to environmental stress,making its regulation a key challenge in greenhouse cultivation in cold climates.This study aimed to assess...Root-zone temperature(RZT)strongly affects plant growth,nutrient uptake and tolerance to environmental stress,making its regulation a key challenge in greenhouse cultivation in cold climates.This study aimed to assess the potential of passive techniques,namely black polyethylene mulch and row covers,for modifying RZT dynamics in lettuce(Lactuca sativa L.)production and to evaluate the predictive performance of the eXtreme Gradient Boosting(XGBoost)algorithm.Experiments were conducted in Iğdır,Türkiye,over a 61-day period,with soil temperature continuously monitored at depths of 1-30 cm under mulched and non-mulched conditions,alongside measurements of greenhouse air temperature both with and without row covers.The application of row covers increased internal air temperature by 5.8℃,while mulching raised RZT by 0.6-1.3℃,with effects diminishing at deeper layers.XGBoost modeling achieved high predictive accuracy,with RMSE values of 0.150-0.189◦C and R^(2)values above 0.99,and feature-importance analysis indicated that neighboring soil depths were the strongest predictors of RZT.These findings show that integrating row covers and mulching can stabilize the root-zone microclimate without active heating.The XGBoost model provides a robust tool for forecasting soil temperature and supports sustainable greenhouse production in cold regions.展开更多
This study presents a numerical investigation of the transient relaxation dynamics of a near-critical CO_(2)droplet immersed in a warmer supercritical environment composed of the same fluid.Three thermodynamic regimes...This study presents a numerical investigation of the transient relaxation dynamics of a near-critical CO_(2)droplet immersed in a warmer supercritical environment composed of the same fluid.Three thermodynamic regimes were analysed:quasi-critical(T_(r)=1.01,P_(r)=1.01),transitional(T_(r)=2.01,P_(r)=1.01),and deep supercritical(T_(r)=5.01,P_(r)=3.01).Theevolution of density,temperature,and velocity fieldswas examined to characterize the internal structure and stability of the interfacial transition layer.The evolution of density,temperature,and velocity fields highlights the competition between thermal diffusion,compressibility,andmass confinement in shaping the stability of the interfacial transition layer.Near the critical point,strong gradients and flux discontinuities emerge,consistent with known instabilities,whereas higher reduced conditions promote homogenization and stabilized transport.In the deep supercritical regime,smooth and nearly uniform fields indicate robust thermal stability.The model is validated against prior studies on droplet evaporation under supercritical and trans-critical conditions.Beyond theoretical insights,the results underline practical implications for advanced propulsion,heat transfer,and evaporation systems as well as for safe CO_(2)supercritical storage and extraction processes in energy,aerospace,pharmaceutical,and materials industries.展开更多
For red pear,the anthocyanin content is a crucial factor determining the fruit skin color,which affects consumer preferences.Low overnight temperatures promote anthocyanin accumulation,but the molecular mechanism resp...For red pear,the anthocyanin content is a crucial factor determining the fruit skin color,which affects consumer preferences.Low overnight temperatures promote anthocyanin accumulation,but the molecular mechanism responsible is unclear.In this study,‘Hongzaosu’pear(Pyrus pyrifolia×Pyrus communis)fruit were treated with a low nighttime temperature(LNT,16℃)or a warm nighttime temperature(WNT,26℃),with sampling conducted within two diurnal cycles.The results showed that LNT promoted anthocyanin accumulation in the fruit skin.The structural anthocyanin biosynthetic genes PpCHS,PpF3H,and PpUFGT exhibited a rhythmic increase in expression at night under LNT.To examine the underlying mechanism,RNA sequencing was conducted using pear calli exposed to LNT and WNT for different durations(24,48,72,or 96 h).Transcriptome analysis revealed 285 differentially expressed genes(DEGs)common to all pairwise comparisons of LNT-and WNT-treated calli of‘Clapp's Favorite’(P.communis)at the sampling time points.KEGG pathway and gene ontology enrichment analyses indicated that the common DEGs were enriched in secondary metabolic processes and phenylpropanoid metabolic processes,which are associated with anthocyanin biosynthesis.The transcription factor PpCDF5,which was responsive to LNT,was selected for further study.Dual-luciferase assays showed that PpCDF5 activated the transcription of anthocyanin biosynthetic genes PpMYB10,PpCHS,PpF3H,PpDFR,PpANS,and PpUFGT.The yeast one-hybrid and EMSA assays demonstrated that PpCDF5 directly binds to the PpF3H promoter,which contains an AAAG motif.Overexpression of PpCDF5 in pear calli and transient overexpression in pear fruit both increased anthocyanin accumulation.The results indicate that PpCDF5 is involved in LNT-induced anthocyanin biosynthesis in pear fruit and provide insights into the molecular regulation of commercial fruit coloration.展开更多
Understanding the temperature dependent deformation behavior of Mg alloys is crucial for their expanding use in the aerospace sector.This study investigates the deformation mechanisms of hot-rolled AZ61 Mg alloy under...Understanding the temperature dependent deformation behavior of Mg alloys is crucial for their expanding use in the aerospace sector.This study investigates the deformation mechanisms of hot-rolled AZ61 Mg alloy under uniaxial tension along rolling direction(RD)and transverse direction(TD)at-50,25,50,and 150℃.Results reveal a transition from high strength with limited elongation at-50℃ to significant softening and maximum ductility at 150℃.TD samples consistently showed 2%-6%higher strength than RD;however,this yield anisotropy diminished at 150℃ due to the shift from twinning to thermally activated slip and recovery.Fractography indicated a change from semi-brittle to fully ductile fracture with increasing temperature.Electron backscattered diffraction(EBSD)analysis confirmed twinning-driven grain refinement at low temperatures,while deformation at high temperatures involved grain elongation along shear zones,enabling greater strain accommodation before material failure.展开更多
As underground mining advances to greater depths,cemented paste backfill(CPB)is increasingly subjected to complex thermo-mechanical loading conditions,including multiaxial stress states and elevated temperatures.This ...As underground mining advances to greater depths,cemented paste backfill(CPB)is increasingly subjected to complex thermo-mechanical loading conditions,including multiaxial stress states and elevated temperatures.This study investigates the coupled effects of field-representative vertical self-weight and horizontal rockwall closure stresses,along with in-situ temperatures,on the mechanical behavior and pore water pressure(PWP)evolution of CPB.Experiments were conducted using a novel apparatus capable of controlling multiaxial stress and temperature during curing,replicating in-situ stress paths and thermal profiles typical of deep mine environments.Results show that multiaxial stress enhances CPB strength and stiffness by promoting denser particle packing,reducing porosity,and increasing frictional resistance.Elevated temperatures independently accelerate early-age cement hydration,further improving bond strength and stiffness.When combined,multiaxial stress and elevated temperature produce a synergistic enhancement in unconfined compressive strength(UCS)and elastic modulus,as confirmed by two-way ANOVA and synergy index analysis.PWP responses were also highly sensitive to thermo-mechanical conditions.The evolution of positive and negative PWP was governed by the interplay of thermal expansion,hydration-induced desaturation,and mechanical compaction.Multiaxial stress amplified early positive PWP and delayed its dissipation,whereas elevated temperature accelerated hydration and reduced pore pressure,leading to enhanced suction at later ages.A transient“stress-induced resaturation”effect was observed under late-stage excessive horizontal stress but was mitigated by elevated temperatures.These findings provide critical insights into the coupled mechanical and hydraulic behavior of CPB under realistic field conditions and offer guidance for optimizing backfill design,binder content,and barricade stability in deep mining applications.展开更多
The effect of real-time high temperature and thermal treatment on the mechanical characteristics and crack evolution of granite with different grain sizes(i.e.,0.5 mm,0.7 mm and 1.0 mm)is investigated by numerical sim...The effect of real-time high temperature and thermal treatment on the mechanical characteristics and crack evolution of granite with different grain sizes(i.e.,0.5 mm,0.7 mm and 1.0 mm)is investigated by numerical simulation employing a grain-based model,and the impact of initial cracks on thermal-induced strengthening is also examined by integrating random cracks within the model before tests.The results revealed that thermal stress,induced by the mismatch in thermal expansion coefficient between various minerals,is the primary distinction between rock specimens in real-time high temperature and thermal treatment.With increasing temperature,the thermal stress gradually accumulates in quartz minerals under real-time high temperature but releases after thermal treatment.The high local contact force significantly affects the peak stress and crack evolution.Uniaxial compression simulation results demonstrate that progressive accumulation of thermal stress induces degradation in macroscopic peak strength and increase of microcrack density.The grain size controls the ratio of intergranular contacts to intragranular contacts,and leads to an increase in strong contact number in the intragrain and a decrease in strong contact number in the intergrain.The strengthening of uniaxial compression strength in the experiment can be well simulated by controlling the number of pre-existing initial cracks in the numerical model.Our conclusions are beneficial to a better understanding of the underlying mechanisms of thermal damage and thermal strengthening of granite for deep geological engineering.展开更多
Thermal-mechanical damage and deformation at the interface between shotcrete linings and the surrounding rock of tunnels under high-temperature and variable-temperature conditions are critical to the safe construction...Thermal-mechanical damage and deformation at the interface between shotcrete linings and the surrounding rock of tunnels under high-temperature and variable-temperature conditions are critical to the safe construction and operation of tunnel engineering.This study investigated the thermo-mechanical damage behavior of the composite interface between alkali-resistant glass fiber-reinforced concrete(ARGFRC)and granite,focusing on a plateau railway tunnel.Laboratory triaxial tests,laser scanning,XRD analysis,numerical simulations,and theoretical analyses were employed to investigate how different initial curing temperatures and joint roughness coefficient(JRC)influence interfacial damage behavior.The results indicate that an increase in interface roughness exacerbates the structural damage at the interface.At a JRC of 19.9 and a temperature of 70℃,crack initiation in granite was notably restrained when the confining pressure rose from 7 MPa to 10 MPa.Roughness-induced stress distribution at the interface was notably altered,although this effect became less pronounced under high confining pressure conditions.Additionally,during high-temperature curing,thermal stress concentration at the tips of micro-convex protrusions on the granite surface induced microcracks in the adjacent ARGFRC matrix,followed by deformation.These findings provide practical guidelines for designing concrete support systems to ensure tunnel structural safety in high-altitude regions with harsh thermal environments.展开更多
With the growing global demand for energy,deep underground salt caverns are emerging as a potential solution for large-scale energy storage.In this study,multistage cyclic loading tests were conducted on rock salt at ...With the growing global demand for energy,deep underground salt caverns are emerging as a potential solution for large-scale energy storage.In this study,multistage cyclic loading tests were conducted on rock salt at different temperatures in combination with real-time acoustic emission(AE)monitoring.The results show that the cumulative AE count increases stepwise with increasing cyclic stress.The peak frequency is concentrated primarily in the medium-frequency range,exhibiting a band distribution across low-,medium-,and high-frequency ranges.As the temperature increases,the proportion of low-frequency signals decreases from 14.32%to 5.76%,whereas the proportion of medium-frequency signals increases from 85.48%to 94.1%.The proportion of high-frequency signals remains relatively constant between 0.1%and 0.2%.The amplitude-count relationship of the AE signals demonstrates a strong negative power-law correlation.Furthermore,with increasing temperature,the negative power-law exponent of the amplitude gradually decreases,with the b value decreasing from 1.096 to 0.837 and the a value decreasing from 7.4871 to 6.6982.Under all four temperature conditions,the dominant failure mode in rock salt is tensile cracking.However,as the temperature increases,the proportion of tensile cracks decreases from 88.59%to 75.12%,whereas the proportion of shear cracks at 80℃is nearly double that at 20℃.This finding indicates that as the temperature increases,the ductility of the material increases,and the crack propagation mode shifts from tensile to shear.This research provides valuable insights for the design and stability assessment of salt cavern reservoirs for deep underground energy storage systems.展开更多
文摘In this study,the approximate and exact solutions for the stationary-state of the solids model with neglecting reactant consumption for both non-uniform and uniform temperature systems were applied on gas ignition under a constant pressure condition.The criticality conditions for a slab,an infinite cylinder,and a sphere are determined and discussed using dimensionless temperatures under constant ambient and surface temperatures for a non-uniform temperature system.Exact solution for a Semenov model with convection heat loss was also presented.The solution of the Semenov problem for constant volume or density as a solid and constant pressure were compared.The critical parameterδis calculated and compared with those of Frank-Kamenetskii solution values.The validation of the calculated ignition temperatures with other exact solution and experimental results were offered.The relation between critical parameters form Semenov and F.K.models solution was introduced.
文摘Archroma becomes the exclusive global distributor of Fibre52®'s patented chemistry-advancing a new standard in sustainable processing.Combined with Archroma's AVITERA®SE dyes,the partnership delivers the industry's most resource-efficient bleach-and-dye sys-tems.Archroma,a leading global specialty chemicals company committed to sus-tainable innovation,and Innovo Fiber LLC,owner of the patented Fibre52®system,today announced an exclusive global dis-tribution partnership to expand the reach of Fibre52®'s proven low-temperature,bleaching technology with innovative dyeing application to textile mills and brands worldwide.
基金funded by the Scientific Research Project of China Academy of Railway Sciences Group Co.,Ltd(No.2024YJ332 and No.2024QT005)Scientific Research Special Project of China State Railway Group Co.,Ltd(No.TICSTR-2024-Ⅳ-007).
文摘Purpose–This study solves the key problem that the static level monitoring is susceptible to temperature interference and affects the accuracy in slope instability/deformation monitoring.The purpose is to develop a reliable temperature compensation method for the system,improve the accuracy of slope stability monitoring and provide support for improving the safety and safety monitoring of engineering spoil slope and other projects.Design/methodology/approach–Combined with theoretical analysis and experimental verification,the temperature compensation method is explored.The working principle of the hydrostatic leveling monitoring system is analyzed and the data processing formula,the temperature error calculation formula and the calculation formula for eliminating the error settlement value are derived.The temperature compensation method is established and verified by the field test of the engineering spoil slope which is disturbed by a debris flow.Findings–The experimental results show that this method can reduce the error of the static level monitoring system by about 40%.The field test shows that the fluctuation of slope settlement monitoring value is reduced after temperature compensation and the monitoring value is consistent with the actual situation,which has certain practicability.Originality/value–The originality of this study is to derive a theoretical formula for quantifying/eliminating temperature errors in static leveling and to establish a practical temperature compensation method.The accuracy of the system is improved,which provides a reference for slope stability monitoring under complex environment(especially railway geotechnical engineering)and promotes the development of precision monitoring technology.
基金the Research Program of the IPGG RAS FMUW-2021-0002.
文摘Numerical thermodynamic models are proposed for the quaternary fluid system H_(2)O-CO_(2)-NaCl-CaCl_(2)and its ternary subsystems H_(2)O-NaCl-CaCl_(2),H_(2)O-CO_(2)-NaCl,and H_(2)O-CO_(2)-CaCl_(2).The models are valid for temperatures from 150℃to 350℃,pressures from 0.2 to 1.4 kbar,and for arbitrary concentrations of salts.The latter feature is inherited from the earlier developed models of binary systems H_(2)O-NaCl and H_(2)O-CaCl_(2).All the models are formulated in terms of the Gibbs free energy.The entropy term in the equation for the Gibbs free energy of mixing is introduced in a general form,based on the number of different ways of arranging particles in the system that lead to the same total energy.The parameters of the energy terms corresponding to the interactions of particles in binary and ternary subsystems are obtained by fitting published experimental data.The concentrations of salts in the gas phase are simulated based on the salt evaporation free energy.Our model,also available as a computer code,makes it possible to predict the physicochemical properties of fluids involved in hydrothermal processes in the upper crust:the phase state of the system(homogeneous or two-phase fluid),activities of the components,densities,and compositions of the(coexisting)fluid phases.The model offers a numerical tool for analyzing fluid inclusion data and better understanding of metamorphic and metasomatic processes in the upper crust.Fluids at studied P-T conditions play a decisive role in the formation of hydrothermal ore deposits,including most of the world's gold deposits.
文摘Optically detected magnetic resonance(ODMR)has emerged as a powerful technique for quantum sensing,enabling high-sensitivity detection of physical quantities even at room temperature.Solid-state defects,such as nitrogen-vacancy(NV)centers in diamond,have demonstrated remarkable capabilities in this domain[1–4].However,these systems are limited by their rigid lattice structures and lack tunability.
基金supported by the National Natural Science Foundation of China(Nos.61705027,62375031 and 52075131)the Chongqing Science and Technology Commission Basic Research Project(No.CSTC-2020jcyj-msxm0603)the Chongqing Municipal Education Commission Science and Technology Research Program(No.KJQN202000609)。
文摘To address the temperature cross-talk issue in detecting heavy metal ions in natural waters, a highly-integrated and fully fiber-optic metal ion sensing system capable of temperature-concentration decoupling measurement has been designed. This system integrates a fluidic detection structure assisted by side-polished fibers(SPFs) with a Sagnac interferometer.
基金supported by the National Science and Technology Major Project of China(No.J2019-Ⅲ-0008-0051)the National Natural Science Foundation of China(Nos.52201140,52375225,and 92360307)the Natural Science Foundation for Youths of Shaanxi Province(No.2023-JC-QN-0521).
文摘Thermal barrier coating(TBC)is crucial for the performance of turbine blades at high temperatures;however,it degrades the microstructure of single-crystal superalloy(SX),thereby reducing creep life.Despite this,the degradation mechanisms associated with the complex multi-layer damage and inter-layer diffusion behavior for TBC/SX systems have not yet been fully elucidated.In this study,using integrated experimental efforts and multiscale characterization techniques,the creep degradation mechanisms of TBC/SX systems at 900℃/500 MPa,980℃/300 MPa,and 1050℃/160 MPa are systematically investigated.Results demonstrate that the creep degradation from TBC intensifies with increasing temperature(T)and stress(σ)ratio(T/σ),exhibiting significant dependency on these two factors,and primarily reduces lifespan of the steady-state stage,with minimal effects on the accelerating stage.During creep deformation,the cracking behavior caused by thermally grown oxide(TGO)beneath the top coat(TC)layer,voids resulting from internal oxidation and interdiffusion in the bond coat(BC)layer,and the recrystallization growth driven by the sandblasting process in the secondary reaction zone(SRZ)are temperature-sensitive damages.In contrast,the initiation and propagation of cracks associated with the topologically close-packed(TCP)phases in the SRZ exhibit pronounced stress sensitivity.Furthermore,the formation of the substrate diffusion zone(SDZ)and the decomposition ofγ/γ′interfacial dislocation networks driven by the Cr-Ru diffusion,as well as the increased stacking fault energy in theγ′phase due to Co loss,are responsible for the acceleration of steady-state creep rate at 1050℃/160 MPa.This work provides a comprehensive and in-depth understanding of the degradation mechanisms under thermal-mechanical coupling in TBC/SX systems,offering new insights into targeted design optimization for multilayered coatings.
文摘Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.
基金supported by the National Natural Science Foundation of China (Grant Nos.12074213 and 11574108)the Major Basic Program of Natural Science Foundation of Shandong Province (Grant No.ZR2021ZD01)the Natural Science Foundation of Shandong Province (Grant No.ZR2023MA082)。
文摘In recent years,the research on superconductivity in one-dimensional(1D)materials has been attracting increasing attention due to its potential applications in low-dimensional nanodevices.However,the critical temperature(T_(c))of 1D superconductors is low.In this work,we theoretically investigate the possible high T_(c) superconductivity of(5,5)carbon nanotube(CNT).The pristine(5,5)CNT is a Dirac semimetal and can be modulated into a semiconductor by full hydrogenation.Interestingly,by further hole doping,it can be regulated into a metallic state with the sp^(3)-hybridized σ electrons metalized,and a giant Kohn anomaly appears in the optical phonons.The two factors together enhance the electron–phonon coupling,and lead to high-T_(c) superconductivity.When the hole doping concentration of hydrogenated-(5,5)CNT is 2.5 hole/cell,the calculated T_(c) is 82.3 K,exceeding the boiling point of liquid nitrogen.Therefore,the predicted hole-doped hydrogenated-(5,5)CNT provides a new platform for 1D high-T_(c) superconductivity and may have potential applications in 1D nanodevices.
文摘Lin Wei is a hiking enthusiast.At six o'clock on the last Saturday morning,the temperature at the foot of the mountain was only 2℃,so she put on her thickest fleece jacket.However,after only half an hour of climbing,the heat left her drenched in sweat,making her feel very cold.By midday,the temperature was approaching 20℃,and her heavy jacket had to be tied around her waist,becoming a burden during her hike.This outdoor adventure allowed her to appreciate the beautiful scenery,but also subjected her to repeated changes in temperature.
文摘Following over 20 years of research,a direct measurement of the QGP temperature has been achieved at Relativistic Heavy-Ion Collider(RHIC),free from the blue-shift effect and contamination from strong interactions.This viewpoint discusses a recent measurement of the QGP temperature at different stages at the Solenoidal Tracker at RHIC(STAR),which used e^(+)e^(-)pairs as penetrating probes.
基金supported by the National Natural Science Foundation of China (Grant No. 12304467)the China Postdoctoral Science Foundation (Grant No. 2023M732175)。
文摘Prolonged exposure to n-butanol, a common hazardous volatile organic compound(VOC) in the environment, can lead to a broad range of adverse health effects. Therefore, detecting n-butanol safely and efficiently at low concentrations becomes critical for both environmental monitoring and human health. In this study, a novel Eu/Ce-codoped MOF-ZnO gas sensor was developed for the sensitive detection of n-butanol gas under ultraviolet activation at ambient temperature. A series of Eu/Ce-ZnO nanomaterials were synthesized via a simple co-precipitation route, by carefully designing the varied mass ratios of Eu and Ce incorporated into pristine ZnO derived from MOF precursors. The gas testing results revealed that introducing an appropriate amount of Eu and Ce would enlarge the specific surface area and enrich the oxygen vacancy content compared to pristine MOF-ZnO. Upon UV irradiation, the 0.03 wt% Eu 0.04 wt% Ce-ZnO sensor achieved a superior response of 611 for100 ppm n-butanol at room temperature, 15.28 times higher than that of pristine MOF-ZnO(40). Furthermore, the sensor presented rapid response/recovery times(15 s/28 s) and excellent selectivity. The above contributions pave the way for the promising development of highly sensitive, ultraviolet-enhanced gas sensors for ambient temperature detection of VOCs.
文摘Root-zone temperature(RZT)strongly affects plant growth,nutrient uptake and tolerance to environmental stress,making its regulation a key challenge in greenhouse cultivation in cold climates.This study aimed to assess the potential of passive techniques,namely black polyethylene mulch and row covers,for modifying RZT dynamics in lettuce(Lactuca sativa L.)production and to evaluate the predictive performance of the eXtreme Gradient Boosting(XGBoost)algorithm.Experiments were conducted in Iğdır,Türkiye,over a 61-day period,with soil temperature continuously monitored at depths of 1-30 cm under mulched and non-mulched conditions,alongside measurements of greenhouse air temperature both with and without row covers.The application of row covers increased internal air temperature by 5.8℃,while mulching raised RZT by 0.6-1.3℃,with effects diminishing at deeper layers.XGBoost modeling achieved high predictive accuracy,with RMSE values of 0.150-0.189◦C and R^(2)values above 0.99,and feature-importance analysis indicated that neighboring soil depths were the strongest predictors of RZT.These findings show that integrating row covers and mulching can stabilize the root-zone microclimate without active heating.The XGBoost model provides a robust tool for forecasting soil temperature and supports sustainable greenhouse production in cold regions.
文摘This study presents a numerical investigation of the transient relaxation dynamics of a near-critical CO_(2)droplet immersed in a warmer supercritical environment composed of the same fluid.Three thermodynamic regimes were analysed:quasi-critical(T_(r)=1.01,P_(r)=1.01),transitional(T_(r)=2.01,P_(r)=1.01),and deep supercritical(T_(r)=5.01,P_(r)=3.01).Theevolution of density,temperature,and velocity fieldswas examined to characterize the internal structure and stability of the interfacial transition layer.The evolution of density,temperature,and velocity fields highlights the competition between thermal diffusion,compressibility,andmass confinement in shaping the stability of the interfacial transition layer.Near the critical point,strong gradients and flux discontinuities emerge,consistent with known instabilities,whereas higher reduced conditions promote homogenization and stabilized transport.In the deep supercritical regime,smooth and nearly uniform fields indicate robust thermal stability.The model is validated against prior studies on droplet evaporation under supercritical and trans-critical conditions.Beyond theoretical insights,the results underline practical implications for advanced propulsion,heat transfer,and evaporation systems as well as for safe CO_(2)supercritical storage and extraction processes in energy,aerospace,pharmaceutical,and materials industries.
基金supported by the National Natural Science Foundation of China(Grant Nos.32072545,32272639 and 32260745)Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LTGN23C150009 and LY22C150003)Zhejiang University Experimental Technology Research Project(Grant No.SYBJS202217).
文摘For red pear,the anthocyanin content is a crucial factor determining the fruit skin color,which affects consumer preferences.Low overnight temperatures promote anthocyanin accumulation,but the molecular mechanism responsible is unclear.In this study,‘Hongzaosu’pear(Pyrus pyrifolia×Pyrus communis)fruit were treated with a low nighttime temperature(LNT,16℃)or a warm nighttime temperature(WNT,26℃),with sampling conducted within two diurnal cycles.The results showed that LNT promoted anthocyanin accumulation in the fruit skin.The structural anthocyanin biosynthetic genes PpCHS,PpF3H,and PpUFGT exhibited a rhythmic increase in expression at night under LNT.To examine the underlying mechanism,RNA sequencing was conducted using pear calli exposed to LNT and WNT for different durations(24,48,72,or 96 h).Transcriptome analysis revealed 285 differentially expressed genes(DEGs)common to all pairwise comparisons of LNT-and WNT-treated calli of‘Clapp's Favorite’(P.communis)at the sampling time points.KEGG pathway and gene ontology enrichment analyses indicated that the common DEGs were enriched in secondary metabolic processes and phenylpropanoid metabolic processes,which are associated with anthocyanin biosynthesis.The transcription factor PpCDF5,which was responsive to LNT,was selected for further study.Dual-luciferase assays showed that PpCDF5 activated the transcription of anthocyanin biosynthetic genes PpMYB10,PpCHS,PpF3H,PpDFR,PpANS,and PpUFGT.The yeast one-hybrid and EMSA assays demonstrated that PpCDF5 directly binds to the PpF3H promoter,which contains an AAAG motif.Overexpression of PpCDF5 in pear calli and transient overexpression in pear fruit both increased anthocyanin accumulation.The results indicate that PpCDF5 is involved in LNT-induced anthocyanin biosynthesis in pear fruit and provide insights into the molecular regulation of commercial fruit coloration.
基金supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)the Ministry of Trade,Industry&Energy(MOTIE)of the Republic of Korea Program(No.RS-2025-02603127,Innovation Research Center for Zero-carbon Fuel Gas Turbine Design,Manufacture,and Safety)。
文摘Understanding the temperature dependent deformation behavior of Mg alloys is crucial for their expanding use in the aerospace sector.This study investigates the deformation mechanisms of hot-rolled AZ61 Mg alloy under uniaxial tension along rolling direction(RD)and transverse direction(TD)at-50,25,50,and 150℃.Results reveal a transition from high strength with limited elongation at-50℃ to significant softening and maximum ductility at 150℃.TD samples consistently showed 2%-6%higher strength than RD;however,this yield anisotropy diminished at 150℃ due to the shift from twinning to thermally activated slip and recovery.Fractography indicated a change from semi-brittle to fully ductile fracture with increasing temperature.Electron backscattered diffraction(EBSD)analysis confirmed twinning-driven grain refinement at low temperatures,while deformation at high temperatures involved grain elongation along shear zones,enabling greater strain accommodation before material failure.
基金the University of Ottawa, the China Scholarship Council and the Natural Sciences and Engineering Research Council of Canada (NSERC) for their financial support.
文摘As underground mining advances to greater depths,cemented paste backfill(CPB)is increasingly subjected to complex thermo-mechanical loading conditions,including multiaxial stress states and elevated temperatures.This study investigates the coupled effects of field-representative vertical self-weight and horizontal rockwall closure stresses,along with in-situ temperatures,on the mechanical behavior and pore water pressure(PWP)evolution of CPB.Experiments were conducted using a novel apparatus capable of controlling multiaxial stress and temperature during curing,replicating in-situ stress paths and thermal profiles typical of deep mine environments.Results show that multiaxial stress enhances CPB strength and stiffness by promoting denser particle packing,reducing porosity,and increasing frictional resistance.Elevated temperatures independently accelerate early-age cement hydration,further improving bond strength and stiffness.When combined,multiaxial stress and elevated temperature produce a synergistic enhancement in unconfined compressive strength(UCS)and elastic modulus,as confirmed by two-way ANOVA and synergy index analysis.PWP responses were also highly sensitive to thermo-mechanical conditions.The evolution of positive and negative PWP was governed by the interplay of thermal expansion,hydration-induced desaturation,and mechanical compaction.Multiaxial stress amplified early positive PWP and delayed its dissipation,whereas elevated temperature accelerated hydration and reduced pore pressure,leading to enhanced suction at later ages.A transient“stress-induced resaturation”effect was observed under late-stage excessive horizontal stress but was mitigated by elevated temperatures.These findings provide critical insights into the coupled mechanical and hydraulic behavior of CPB under realistic field conditions and offer guidance for optimizing backfill design,binder content,and barricade stability in deep mining applications.
基金Project(51879135)supported by the Taishan Scholars Program,ChinaProject(52309130)supported by the National Natural Science Foundation of China+1 种基金Project(SKLGME023003)supported by the Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering Safety,ChinaProject(2022AH051754)supported by the Natural Science Research Project of Anhui Universities,China。
文摘The effect of real-time high temperature and thermal treatment on the mechanical characteristics and crack evolution of granite with different grain sizes(i.e.,0.5 mm,0.7 mm and 1.0 mm)is investigated by numerical simulation employing a grain-based model,and the impact of initial cracks on thermal-induced strengthening is also examined by integrating random cracks within the model before tests.The results revealed that thermal stress,induced by the mismatch in thermal expansion coefficient between various minerals,is the primary distinction between rock specimens in real-time high temperature and thermal treatment.With increasing temperature,the thermal stress gradually accumulates in quartz minerals under real-time high temperature but releases after thermal treatment.The high local contact force significantly affects the peak stress and crack evolution.Uniaxial compression simulation results demonstrate that progressive accumulation of thermal stress induces degradation in macroscopic peak strength and increase of microcrack density.The grain size controls the ratio of intergranular contacts to intragranular contacts,and leads to an increase in strong contact number in the intragrain and a decrease in strong contact number in the intergrain.The strengthening of uniaxial compression strength in the experiment can be well simulated by controlling the number of pre-existing initial cracks in the numerical model.Our conclusions are beneficial to a better understanding of the underlying mechanisms of thermal damage and thermal strengthening of granite for deep geological engineering.
基金funded by the National Natural Science Foundation of China(Nos.52209130 and 52379100)Shandong Provincial Natural Science Foundation(No.ZR2024ME112).
文摘Thermal-mechanical damage and deformation at the interface between shotcrete linings and the surrounding rock of tunnels under high-temperature and variable-temperature conditions are critical to the safe construction and operation of tunnel engineering.This study investigated the thermo-mechanical damage behavior of the composite interface between alkali-resistant glass fiber-reinforced concrete(ARGFRC)and granite,focusing on a plateau railway tunnel.Laboratory triaxial tests,laser scanning,XRD analysis,numerical simulations,and theoretical analyses were employed to investigate how different initial curing temperatures and joint roughness coefficient(JRC)influence interfacial damage behavior.The results indicate that an increase in interface roughness exacerbates the structural damage at the interface.At a JRC of 19.9 and a temperature of 70℃,crack initiation in granite was notably restrained when the confining pressure rose from 7 MPa to 10 MPa.Roughness-induced stress distribution at the interface was notably altered,although this effect became less pronounced under high confining pressure conditions.Additionally,during high-temperature curing,thermal stress concentration at the tips of micro-convex protrusions on the granite surface induced microcracks in the adjacent ARGFRC matrix,followed by deformation.These findings provide practical guidelines for designing concrete support systems to ensure tunnel structural safety in high-altitude regions with harsh thermal environments.
基金supported by the Major Research Development Program of Hubei Province,China(Grant Nos.2022BAA093 and 2022BAD163)the Open Research Fund of the State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences(Grant No.SKLGME023008).
文摘With the growing global demand for energy,deep underground salt caverns are emerging as a potential solution for large-scale energy storage.In this study,multistage cyclic loading tests were conducted on rock salt at different temperatures in combination with real-time acoustic emission(AE)monitoring.The results show that the cumulative AE count increases stepwise with increasing cyclic stress.The peak frequency is concentrated primarily in the medium-frequency range,exhibiting a band distribution across low-,medium-,and high-frequency ranges.As the temperature increases,the proportion of low-frequency signals decreases from 14.32%to 5.76%,whereas the proportion of medium-frequency signals increases from 85.48%to 94.1%.The proportion of high-frequency signals remains relatively constant between 0.1%and 0.2%.The amplitude-count relationship of the AE signals demonstrates a strong negative power-law correlation.Furthermore,with increasing temperature,the negative power-law exponent of the amplitude gradually decreases,with the b value decreasing from 1.096 to 0.837 and the a value decreasing from 7.4871 to 6.6982.Under all four temperature conditions,the dominant failure mode in rock salt is tensile cracking.However,as the temperature increases,the proportion of tensile cracks decreases from 88.59%to 75.12%,whereas the proportion of shear cracks at 80℃is nearly double that at 20℃.This finding indicates that as the temperature increases,the ductility of the material increases,and the crack propagation mode shifts from tensile to shear.This research provides valuable insights for the design and stability assessment of salt cavern reservoirs for deep underground energy storage systems.
