We present an incorporation of the kinetic Monte Carlo(kMC)simulation with the adjacency matrix(AM)method to investigate structural parameters of randomly branched polymers.The AMs of branched polymers are obtained by...We present an incorporation of the kinetic Monte Carlo(kMC)simulation with the adjacency matrix(AM)method to investigate structural parameters of randomly branched polymers.The AMs of branched polymers are obtained by the growth generation model,which is employed in the kMC simulation based on Gillespie’s algorithm.Of particular interest is the effect of the branched units on the relevant structural parameters.As an application in randomly hyperbranched polymers formed by AB_(2)type of monomers,average maximum span length,average length of sub-chains,number distribution of branched units,and meansquare radius of gyration are calculated.It is shown that the branched units can give rise to a significant effect on these physical quantities,whereby such a structure-property relationship can be employed to optimize reaction conditions and implement material designs.展开更多
The sulfation and decomposition process has proven effective in selectively extracting lithium from lepidolite.It is essential to clarify the thermochemical behavior and kinetic parameters of decomposition reactions.A...The sulfation and decomposition process has proven effective in selectively extracting lithium from lepidolite.It is essential to clarify the thermochemical behavior and kinetic parameters of decomposition reactions.Accordingly,comprehensive kinetic study by employing thermalgravimetric analysis at various heating rates was presented in this paper.Two main weight loss regions were observed during heating.The initial region corresponded to the dehydration of crystal water,whereas the subsequent region with overlapping peaks involved complex decomposition reactions.The overlapping peaks were separated into two individual reaction peaks and the activation energy of each peak was calculated using isoconversional kinetics methods.The activation energy of peak 1 exhibited a continual increase as the reaction conversion progressed,while that of peak 2 steadily decreased.The optimal kinetic models,identified as belonging to the random nucleation and subsequent growth category,provided valuable insights into the mechanism of the decomposition reactions.Furthermore,the adjustment factor was introduced to reconstruct the kinetic mechanism models,and the reconstructed models described the kinetic mechanism model more accurately for the decomposition reactions.This study enhanced the understanding of the thermochemical behavior and kinetic parameters of the lepidolite sulfation product decomposition reactions,further providing theoretical basis for promoting the selective extraction of lithium.展开更多
Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the k...Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the kinetics and selectivity of each reaction step.1H NMR monitoring revealed equilibrated positional isomerization among acylglycerols:sn-1 monoolein comprised 97.3%of total monoacylglycerols,and sn-1,3 diolein comprised 73.3%of total diacylglycerols.Acyl migration(isomer equilibration)occurred faster than overall esterification.The observed rate constants for successive esterification steps(glycerol→monoacylglycerol,monoacylglycerol→diacylglycerol,diacylglycerol→triacylglycerol)were 0.01068,0.00615,and 0.00304 min^(-1),respectively,indicating progressively slower reaction rates for larger acylglycerol species.Furthermore,molecular distillation at 200–220℃ purified the DAG without altering its fatty acid profile.These findings establish a kinetic model of the three-step esterification and highlight the importance of acyl migration in enzymatic DAG synthesis.展开更多
Kinetic impact is the most practical planetary-defense technique,with momentum-transfer efficiency central to deflection design.We present a Monte Carlo photometric framework that couples ejecta sampling,dynamical evo...Kinetic impact is the most practical planetary-defense technique,with momentum-transfer efficiency central to deflection design.We present a Monte Carlo photometric framework that couples ejecta sampling,dynamical evolution,and image synthesis to compare directly with HST,LICIACube,ground-based and Lucy observations of the DART impact.Decomposing ejecta into(1)a highvelocity(~1600 m/s)plume exhibiting Na/K resonance,(2)a low-velocity(~1 m/s)conical component shaped by binary gravity and solar radiation pressure,and(3)meter-scale boulders,we quantify each component’s mass and momentum.Fitting photometric decay curves and morphological evolution yields size-velocity distributions and,via scaling laws,estimates of Dimorphos’bulk density,cratering parameters,and cohesive strength that agree with dynamical constraints.Photometric ejecta modeling therefore provides a robust route to constrain momentum enhancement and target properties,improving predictive capability for kinetic-deflection missions.展开更多
The volatilization characteristics and kinetic mechanisms of arsenic were investigated in the temperature range of 623−773 K and pressure ranges of 10−10000 Pa.The experimental results reveal that the evaporation rate...The volatilization characteristics and kinetic mechanisms of arsenic were investigated in the temperature range of 623−773 K and pressure ranges of 10−10000 Pa.The experimental results reveal that the evaporation rate increases with increasing temperature and decreasing pressure.Surface reaction control dominates at low pressures(<100 Pa),whereas diffusion control dominates at high pressures(>5000 Pa).The evaporation behavior is successfully described by an Arrhenius-type model for temperature dependence and Logistic model for pressure dependence.Key kinetic parameters,including the critical pressure,maximum evaporation rate and evaporation coefficient,were calculated.The evaporation coefficient varies between 0.010 and 0.223,and the critical pressures vary between 281 and 478 Pa with temperature.展开更多
Hepatocellular carcinoma presents with three distinct immune phenotypes,including immune-desert,immune-excluded,and immune-inflamed,indicating various treatment responses and prognostic outcomes.The clinical applicati...Hepatocellular carcinoma presents with three distinct immune phenotypes,including immune-desert,immune-excluded,and immune-inflamed,indicating various treatment responses and prognostic outcomes.The clinical application of multi-omics parameters is still restricted by the expensive and less accessible assays,although they accurately reflect immune status.A comprehensive evaluation framework based on“easy-to-obtain”multi-model clinical parameters is urgently required,incorporating clinical features to establish baseline patient profiles and disease staging;routine blood tests assessing systemic metabolic and functional status;immune cell subsets quantifying subcluster dynamics;imaging features delineating tumor morphology,spatial configuration,and perilesional anatomical relationships;immunohistochemical markers positioning qualitative and quantitative detection of tumor antigens from the cellular and molecular level.This integrated phenomic approach aims to improve prognostic stratification and clinical decision-making in hepatocellular carcinoma management conveniently and practically.展开更多
The hydrogen reduction kinetics of tungsten trioxide(WO_(3))was investigated via non-isothermal thermogravimetric analysis.Under the local gas-solid reduction conditions,the particle morphology of tungsten powders was...The hydrogen reduction kinetics of tungsten trioxide(WO_(3))was investigated via non-isothermal thermogravimetric analysis.Under the local gas-solid reduction conditions,the particle morphology of tungsten powders was found to be consistent with that of raw material WO_(3).The removal of oxygen from tungsten oxide during hydrogen reduction led to the formation of porous structures between the reduced particles,which were obviously different from the polyhedral single-crystal configuration of tungsten powders obtained via chemical vapor deposition.Moreover,the two-stage hydrogen reduction mechanisms of WO_(3) under the local gas-solid reduction conditions can be described using the composite autocatalytic function.The activation energies of the first and second stages of the hydrogen reduction of WO_(3) were determined to be 121 and 135 kJ/mol,respectively.展开更多
The crystallization and aggregation characteristics of the active layer components in organic solar cells(OSCs)are one of the core factors determining photovoltaic performance,influencing the entire process from light...The crystallization and aggregation characteristics of the active layer components in organic solar cells(OSCs)are one of the core factors determining photovoltaic performance,influencing the entire process from light absorption to charge separation,transport,and ultimately charge collection.Dynamic changes in crystallization and aggregation states can also disrupt the microstructure of the active layer,thus shortening the lifetime of the cell.In this study,a morphology modulation strategy is proposed to regulate the crystallization kinetics of non-fullerene acceptors by employing the polymer molecule PYIT as a nucleating agent.An appropriate amount of PYIT was first completely dissolved with the non-fullerene acceptor Y6 and left to stand for 24 h,followed by the fabrication of layer-by-layer processed OSCs.Experiments demonstrated that high crystallinity of PYIT allows it to act as a crystallization nucleus,promoting the crystallization,orientation consistency,and ordered stacking of the acceptor.These nanoscale structural optimizations facilitate efficient charge transport,enhance exciton dissociation efficiency,and suppress unfavorable energetic disorder.Consequently,not only was the power conversion efficiency(PCE)of D18-Cl/Y6-based layer-by-layer processed OSC increased from 18.08%to 19.13%,but the atmospheric stability and long-term lifetime of the OSCs were also significantly improved.Notably,this strategy is also applicable to indoor OSCs,and the PYIT-optimized device can achieve a PCE of 27.0%under 1000 lux light-emitting diode(LED,3200K)irradiation,which is superior to that of the control device(24.2%).This work develops a crystal engineering strategy that is able to simultaneously optimize the microscopic morphology and charge dynamics properties in OSCs,thereby achieving simultaneous improvement in efficiency and stability.展开更多
Presented in this study is a novel method for estimating the depth of single underwater source in shallow water,utilizing vector sensors.The approach leverages the depth distribution of the broadband Stokes parameters...Presented in this study is a novel method for estimating the depth of single underwater source in shallow water,utilizing vector sensors.The approach leverages the depth distribution of the broadband Stokes parameters to estimate source depth accurately.Unlike traditional matched field processing(MFP)and matched mode processing(MMP),the proposed approach can estimate source depth directly from the data received by sensors without requiring complete environmental information.Firstly,the broadband Stokes parameters(BSP)are established using the normal mode theory.Then the nonstationary phase approximation is used to simplify the theoretical derivation,which is necessary when dealing with broadband integrals.Additionally,range terms of the BSP are eliminated by normalization.By analyzing the depth distribution of the normalized broadband Stokes parameters(NBSP),it is found that the NBSP exhibit extreme values at the source depth,which can be used for source depth estimation.So the proposed depth estimation method is based on searching the peaks of the NBSP.Simulations show that this method is effective in relatively simple shallow water environments.Finally,the effect of source range,frequency bandwidth,sound speed profile(SSP),water depth,and signal-to-noise ratio(SNR)are studied.The findings indicate that the proposed method can accurately estimate the source depth when the SNR is greater than-5 d B and does not need to consider model mismatch issues.Additionally,variations in environmental parameters have minimal impact on estimation accuracy.Compared to MFP,the proposed method requires a higher SNR,but demonstrates superior robustness against fluctuations in environmental parameters.展开更多
In order to explore the effects of CaO,lignite dust and sawdust on the drying characteristics ofmunicipal sludge at different concentrations,a three-factor three-level regression experiment was carried out based on th...In order to explore the effects of CaO,lignite dust and sawdust on the drying characteristics ofmunicipal sludge at different concentrations,a three-factor three-level regression experiment was carried out based on the results of thermogravimetric experiment and single factor experiment.By fitting three common mathematical models,the Page model with the highest fitting degree was selected to determine the most suitable mathematical model to describe the municipal sludge drying process.In addition,the Box-Behnken design principle in the response surface method was used to analyze the interaction of three factors on the drying characteristics of municipal sludge.The results of the study show that below 100℃is the optimal drying temperature range for municipal sludge.The results of single factor experiments showed that the order of influence of the three factors on sludge drying time was CaO concentration>sawdust concentration>lignite dust concentration.In the single factor experiment,the optimal process parameterswere CaOconcentration 3%,lignite powder concentration 7%,and sawdust concentration 7%.In themulti-factor interaction analysis,the interaction between CaO and sawdust had the most significant effect on the reduction of drying time,and the order of influence was as follows:CaO interaction with sawdust>lignite dust interaction with sawdust>CaO interaction with lignite powder.Further analysis showed that the optimal process ratio was 3%CaO concentration and 3%sawdust concentration.展开更多
This study explores the thin-layer convective solar drying of Marrubium vulgare L.leaves under conditions typical of sun-rich semi-arid climates.Drying experiments were conducted at three inlet-air temperatures(40℃,5...This study explores the thin-layer convective solar drying of Marrubium vulgare L.leaves under conditions typical of sun-rich semi-arid climates.Drying experiments were conducted at three inlet-air temperatures(40℃,50℃,60℃)and two air velocities(1.5 and 2.5 m·s^(-1))using an indirect solar dryer with auxiliary temperature control.Moisture-ratio data were fitted with eight widely used thin-layer models and evaluated using correlation coefficient(r),root-mean-square error(RMSE),and Akaike information criterion(AIC).A complementary heattransfer analysis based on Reynolds and Prandtl numbers with appropriate Nusselt correlations was used to relate flow regime to drying performance,and an energy balance quantified the relative contributions of solar and auxiliary heat.The logarithmic model consistently achieved the lowest RMSE/AIC with r>0.99 across all conditions.Higher temperature and air velocity significantly reduced drying time during the decreasing-rate period,with no constantrate stage observed.On average,solar input supplied the large majority of the thermal demand,while the auxiliary heater compensated short irradiance drops to maintain setpoints.These findings provide a reproducible dataset and a modelling benchmark for M.vulgare leaves,and they support energy-aware design of hybrid solar dryers formedicinal plants in sun-rich regions.展开更多
The synthesis of propylene carbonate(PC)from CO_(2) and propylene oxide(PO)is a typical gas-liquid biphasic system,where gas-liquid mass transfer efficiency significantly influences CO_(2) cycloaddition reactions.Here...The synthesis of propylene carbonate(PC)from CO_(2) and propylene oxide(PO)is a typical gas-liquid biphasic system,where gas-liquid mass transfer efficiency significantly influences CO_(2) cycloaddition reactions.Here,we proposed a microchannel reaction system for the CO_(2) cycloaddition reaction catalyzed by ionic liquid within an aqueous environment.The effect of liquid flow rate,temperature and residence time on gas-liquid flow pattern,catalytic performance and mass transfer were systematically investigated.The results revealed that the PC generation rate reached 560.11 mmol·ml^(−1)·h^(−1)at a 50 cm of flow distance under reaction conditions of 105℃,2.5 MPa,QG=176 ml·min^(−1) and QL=0.3 ml·min^(−1).Variations in mass transfer rate and reaction rate at different flow distances were experimentally studied.The reaction efficiency gradually decreased with increasing flow distance,which were attributed to the reduction of mass transfer caused by decreasing bubble velocity.Optimizing bubble velocity at an appropriate position enhanced reaction efficiency by improving mass transfer,achieving a 97.7%PC yield within 2.85 min.Furthermore,a kinetic model coupling intrinsic kinetics with gas-liquid mass transfer was developed for CO_(2) cycloaddition reaction.The kinetic model was applied to predict PC reaction rates in microchannel reactors at various temperatures and liquid flow rates,achieving an average relative error of 9.6%.展开更多
The increasing production and release of synthetic organic chemicals,including pharmaceuticals,into our envi-ronment has allowed these substances to accumulate in our surface water systems.Current purification technol...The increasing production and release of synthetic organic chemicals,including pharmaceuticals,into our envi-ronment has allowed these substances to accumulate in our surface water systems.Current purification technolo-gies have been unable to eliminate these pollutants,resulting in their ongoing release into aquatic ecosystems.This study focuses on cloperastine(CPS),a cough suppressant and antihistamine medication.The environmental impact of CPS usage has become a concern,mainly due to its increased detection during the COVID-19 pandemic.CPS has been found in wastewater treatment facilities,effluents from senior living residences,river waters,and sewage sludge.However,the photosensitivity of CPS and its photodegradation profile remain largely unknown.This study investigates the photodegradation process of CPS under simulated tertiary treatment conditions using UV photolysis,a method commonly applied in some wastewater treatment plants.Several transformation prod-ucts were identified,evaluating their kinetic profiles using chemometric approaches(i.e.,curve fitting and the hard-soft multivariate curve resolution-alternating least squares(HS-MCR-ALS)algorithm)and calculating the reaction quantum yield.As a result,three different transformation products have been detected and correctly identified.In addition,a comprehensive description of the kinetic pathway involved in the photodegradation process of the CPS drug has been provided,including observed kinetic rate constants.展开更多
In this study,copper extraction from low-grade oxide-sulfide ores was investigated using a leaching method combined with response surface methodology(RSM)to optimize operational conditions and assess leaching kinetics...In this study,copper extraction from low-grade oxide-sulfide ores was investigated using a leaching method combined with response surface methodology(RSM)to optimize operational conditions and assess leaching kinetics.Given copper's extensive industrial applications,sustainable recovery from low-grade ores is critical.Five key parameters-acid concentration,leaching time,particle size,temperature,and solids percentage-were identified as major influences on copper recovery.The results revealed that leaching time and solids percentage,along with interactions between temperature-time and temperature-solids percentage,had the most significant effects.Optimal conditions for 80% copper recovery while minimizing iron recovery below 3% included an acid concentration of 1.21 mol L^(-1),a leaching time of 108 min,a particle size of 438μm,a temperature of 45℃,and a solids percentage of 18.2%.Leaching kinetics were analyzed using shrinking core models,with the Dickinson model best describing the process,showing an activation energy of 32.63 kJ mol^(-1),indicative of mixed diffusion and chemical reaction control.The final kinetic model effectively predicted the influence of key parameters.These findings highlight the importance of optimizing process variables and selecting suitable kinetic models to enhance extraction efficiency,reduce costs,and improve sustainability in copper recovery.展开更多
Layered double hydroxides(LDHs)hold great promise as cathode materials for aqueous zinc-ion batteries(AZIBs).Nevertheless,they also face challenges of sluggish kinetics and rapid capacity loss.Herein,a conformational ...Layered double hydroxides(LDHs)hold great promise as cathode materials for aqueous zinc-ion batteries(AZIBs).Nevertheless,they also face challenges of sluggish kinetics and rapid capacity loss.Herein,a conformational entropy regulation strategy has been applied to surmount the shortcomings.A medium-entropy iron-based metal organic framework(MIL-88)derived NiCoFeInZnV-based layered double hydroxide with carbon loaded(ME-NiCoFeInZnV-LDH/C)has been first proposed and prepared with a designed method.The increased entropy optimizes electron conductivity and alleviates structure alteration and diffusion barrier during interactions with charge carriers,due to electron-induced effect and“cocktail”effect.Moreover,the nanosheet assembled hollow prismatic structures could homogenize flux distribution and electric field distribution.Therefore,the electrochemical kinetics,crystal structure stability,and activity could be dramatically improved.Leveraging the advantages of structure and composition regulation,Zn||ME-NiCoFeInZnV-LDH/C zinc battery delivers high specific capacities,rate performance,and cycling stability.This work proposes a novel and feasible medium-entropy strategy to prepare a high-performance cathode for advanced AZIBs,which is of prominent significance for the development of charge storage devices.展开更多
Single-pass and double-pass high-temperature deformation experiments were conducted on 40Cr10Si2Mo steel using a Gleeble-3500 thermal simulator.The static recrystallization(SRX)behavior and recrystallization mechanism...Single-pass and double-pass high-temperature deformation experiments were conducted on 40Cr10Si2Mo steel using a Gleeble-3500 thermal simulator.The static recrystallization(SRX)behavior and recrystallization mechanisms of 40Cr10Si2Mo steel were investigated under deformation temperatures of 900-1100℃,deformation strains of 10%,20%,and 30%,and inter-pass times of 1-120 s.A static recrystallization fraction model was developed.The results showed that the SRX volume fraction increased with higher deformation temperature,larger deformation amount,and longer inter-pass time,with the deformation temperature having the most significant effect on SRX.During the deformation process,different process parameters led to different internal deformation mechanisms of the material.Static recovery and continuous static recrystallization(CSRX)dominated deformation at lower temperatures through progressive lattice rotation.In comparison,at higher temperatures,the deformation mechanism was dominated by CSRX and discontinuous static recrystallization(DSRX).The nucleation mechanisms of the SRX process were grain boundary bulging nucleation and subgrain merging nucleation,with grain boundary bulging present under all conditions.Subgrain merging nucleation could provide an additional nucleation mode at lower deformation temperatures or lower deformation amounts.Based on the traditional Avarmi equation,a modified model coefficient was used to establish the SRX kinetic model for 40Cr10Si2Mo steel.The linear correlation coefficient R^(2) between the predicted and experimental static recrystallization volume fraction was 0.96702,indicating high prediction accuracy.展开更多
The effects of acid surface dissolution on the flotation kinetics of ilmenite(IL)and its common accompanied gangue minerals including olivine-pyroxene(Ol-Px),tremolite-clinochlore(Tr-Cch)and quartz were investigated.T...The effects of acid surface dissolution on the flotation kinetics of ilmenite(IL)and its common accompanied gangue minerals including olivine-pyroxene(Ol-Px),tremolite-clinochlore(Tr-Cch)and quartz were investigated.The results show that through the surface dissolution the adsorption rate constant for ilmenite increases from 5.272 to 8.441 mol/(g·min)while it decreases for Ol-Px,Tr-Cch and quartz from 6.332,7.309 and 7.774 mol/(g·min)to 5.034,6.223 and 7.371 mol/(g·min),respectively.Also,the flotation experiments on a binary mixture of minerals indicate that after surface dissolution the values of modified rate constant for ilmenite flotation from Ol-Px,Tr-Cch and quartz are enhanced from 36.15,36.52 and 47.86 min-1 to 41.72,45.78 and 56.24 min-1,respectively.This results in the improvement of kinetic selectivity index(SI)in the separation of treated ilmenite from gangue minerals.As evidenced by ICP-MS analysis,the decrease of kinetic parameters for gangue minerals can be due to the removal of Fe^2+,Ca^2+and Mg^2+ions from their surfaces,which results in the lack of enough active sites to interact with collector species.As confirmed by contact angle measurements,this prevents the formation of a stable hydrophobic layer on the minerals surfaces for creating stable attachments between minerals and bubbles.Generally,the improvement of ilmenite flotation kinetics has a negative correlation with the iron content in its accompanied gangue minerals.展开更多
Determination of probable mechanism function and kinetic parameters is important to hydrometallurgical kinetics.In this work,the most probable mechanism function and kinetic parameters of gibbsite dissolution in NaOH ...Determination of probable mechanism function and kinetic parameters is important to hydrometallurgical kinetics.In this work,the most probable mechanism function and kinetic parameters of gibbsite dissolution in NaOH solution are studied.The sample,the mixture of synthetic gibbsite and sodium hydroxide solution,was scanned in high-pressure differential scanning calorimetry(DSC) equipment with the heating rate of 10 K·min-1. Integral equation and differential equation of non-isothermal kinetics were solved to fit the data related to DSC curve.According to the calculation results,the most probable mechanism function for pure synthetic gibbsite dissolution in sodium hydroxide solution is presented based on the optimum procedure in the database of the mechanism function.The apparent activation energy obtained is(75±1) kJ·mol-1,the frequency factor is 10 8±1mol·s-1,and the reaction is a second order reaction.展开更多
The thermal behavior,non-isothermal thermal decomposition reaction kinetics and specific heat capacity of hexanitro-hexaazaisowurtzitane(HNIW)were studied by differential scanning calorimeter(DSC)and Micro-DSCIapparat...The thermal behavior,non-isothermal thermal decomposition reaction kinetics and specific heat capacity of hexanitro-hexaazaisowurtzitane(HNIW)were studied by differential scanning calorimeter(DSC)and Micro-DSCIapparatus,The kinetic parameters of the thermal decomposition reaction(the apparent activation energy(E,)and pre-exponential factor(A))were calcu-lated by non-isothermal DSC curves.The results show that the differential mlechanism function and values of E,and A of the ther-mal decomposition reaction of HNIW are 3(1-a)[-ln(1-a)]"·,155.04 kJ·mol^(-1)and 10""s^(-1),respectively.The critical tem-perature of thermal explosion of the title compound is 226.60℃.The entropy of activation(AS·),enthalpy of activation(AH·)and free energy of activation(AG·)of this reaction are 11.60J·mol·K^(-1),152.04 kJ·mol^(-1)and 146.29 kJ·mol^(-1),respec-tively.The equation of specific heat capacity of HNIW with temperature is C,=0.2472+0.002705992Tin the temperature range of 283 K to 343K.The values of self-accelerating decomposition temperature,adiabatic time-to-maximum decomposition rate and adiabatic time-to-explosion are 486.5K,54.81s and 54.31s,respectively.Thermal sensitivity probability density distribution curve of HNIW is constructed.展开更多
In this paper,Dy^(3+)incorporated BaSi_(2)O_(5)phosphors were synthesized by gel co mbustion method and characterized by X-ray diffraction(XRD).The effects of various heating rate s on thermoluminescence(TL)kinetics a...In this paper,Dy^(3+)incorporated BaSi_(2)O_(5)phosphors were synthesized by gel co mbustion method and characterized by X-ray diffraction(XRD).The effects of various heating rate s on thermoluminescence(TL)kinetics and glow peak temperatures of Dy^(3+)incorporated BaSi_(2)O_(5)phosphors exposed toβirradiation at room temperature were investigated.The glow curves of the phosphor exposed toβ-irradiation(0.1-100 Gy)consist of four main peaks located at 87,130,271,and 327℃and exhibit a good linearity between 0.1 and100 Gy.Three experimental techniques including variable heating rate(VHR),repeated initial rise(RIR),peak shape(PS)and computerized glow curve deconvolution(CGCD)were employed to determine TL kinetic parameters.Our findings indicate that the TL glow peaks of the phosphor obey first-order kinetics.Analysis of the main dosimetric peaks through the techniques mentio ned above indicates that activation energies(E)and pre-exponential factor(s)are in the range of 0.80-1.50 eV and 1.15×10^(8)-3.28×10^(13)s^(-1).Additionally,it is found that the temperature of the glow peaks shifts toward the higher temperatures and the TL intensity smoothly decreases as the heating rate increases.The effect on the TL intensities and glow peak temperatu res of the heating rate is discussed in terms of thermal quenching.展开更多
基金supported by the Central Guidance on Local Science and Technology Development Fund of Hebei Province (No.236Z7601G)the Interdisciplinary Research Program of Natural Science of Hebei University, China (No.DXK202112)。
文摘We present an incorporation of the kinetic Monte Carlo(kMC)simulation with the adjacency matrix(AM)method to investigate structural parameters of randomly branched polymers.The AMs of branched polymers are obtained by the growth generation model,which is employed in the kMC simulation based on Gillespie’s algorithm.Of particular interest is the effect of the branched units on the relevant structural parameters.As an application in randomly hyperbranched polymers formed by AB_(2)type of monomers,average maximum span length,average length of sub-chains,number distribution of branched units,and meansquare radius of gyration are calculated.It is shown that the branched units can give rise to a significant effect on these physical quantities,whereby such a structure-property relationship can be employed to optimize reaction conditions and implement material designs.
基金financially supported by the National Natural Science Foundation of China(Nos.52034002 and U2202254)the Fundamental Research Funds for the Central Universities,China(No.FRF-TT-19-001)。
文摘The sulfation and decomposition process has proven effective in selectively extracting lithium from lepidolite.It is essential to clarify the thermochemical behavior and kinetic parameters of decomposition reactions.Accordingly,comprehensive kinetic study by employing thermalgravimetric analysis at various heating rates was presented in this paper.Two main weight loss regions were observed during heating.The initial region corresponded to the dehydration of crystal water,whereas the subsequent region with overlapping peaks involved complex decomposition reactions.The overlapping peaks were separated into two individual reaction peaks and the activation energy of each peak was calculated using isoconversional kinetics methods.The activation energy of peak 1 exhibited a continual increase as the reaction conversion progressed,while that of peak 2 steadily decreased.The optimal kinetic models,identified as belonging to the random nucleation and subsequent growth category,provided valuable insights into the mechanism of the decomposition reactions.Furthermore,the adjustment factor was introduced to reconstruct the kinetic mechanism models,and the reconstructed models described the kinetic mechanism model more accurately for the decomposition reactions.This study enhanced the understanding of the thermochemical behavior and kinetic parameters of the lepidolite sulfation product decomposition reactions,further providing theoretical basis for promoting the selective extraction of lithium.
基金Bureau of Science and Information of Guangzhou under grant 2024A04J3254the National Key Research and Development Program of China under grant 2024YFE0214900+2 种基金the National Natural Science Foundation of China under grant 32272341,he National Key Research and Development Program of China under grant 2023YFD2100401the Opening Project of Hubei Key Laboratory of Lipid Chemistry and Nutrition under grant 202401,are gratefully acknowledged.
文摘Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the kinetics and selectivity of each reaction step.1H NMR monitoring revealed equilibrated positional isomerization among acylglycerols:sn-1 monoolein comprised 97.3%of total monoacylglycerols,and sn-1,3 diolein comprised 73.3%of total diacylglycerols.Acyl migration(isomer equilibration)occurred faster than overall esterification.The observed rate constants for successive esterification steps(glycerol→monoacylglycerol,monoacylglycerol→diacylglycerol,diacylglycerol→triacylglycerol)were 0.01068,0.00615,and 0.00304 min^(-1),respectively,indicating progressively slower reaction rates for larger acylglycerol species.Furthermore,molecular distillation at 200–220℃ purified the DAG without altering its fatty acid profile.These findings establish a kinetic model of the three-step esterification and highlight the importance of acyl migration in enzymatic DAG synthesis.
基金supported by the National Natural Science Foundation of China(Grant No.12272018)the National Key Basic Research Project(2022JCJQZD20600).
文摘Kinetic impact is the most practical planetary-defense technique,with momentum-transfer efficiency central to deflection design.We present a Monte Carlo photometric framework that couples ejecta sampling,dynamical evolution,and image synthesis to compare directly with HST,LICIACube,ground-based and Lucy observations of the DART impact.Decomposing ejecta into(1)a highvelocity(~1600 m/s)plume exhibiting Na/K resonance,(2)a low-velocity(~1 m/s)conical component shaped by binary gravity and solar radiation pressure,and(3)meter-scale boulders,we quantify each component’s mass and momentum.Fitting photometric decay curves and morphological evolution yields size-velocity distributions and,via scaling laws,estimates of Dimorphos’bulk density,cratering parameters,and cohesive strength that agree with dynamical constraints.Photometric ejecta modeling therefore provides a robust route to constrain momentum enhancement and target properties,improving predictive capability for kinetic-deflection missions.
基金Yunnan Fundamental Research Project,China(No.202201BE070001-056)。
文摘The volatilization characteristics and kinetic mechanisms of arsenic were investigated in the temperature range of 623−773 K and pressure ranges of 10−10000 Pa.The experimental results reveal that the evaporation rate increases with increasing temperature and decreasing pressure.Surface reaction control dominates at low pressures(<100 Pa),whereas diffusion control dominates at high pressures(>5000 Pa).The evaporation behavior is successfully described by an Arrhenius-type model for temperature dependence and Logistic model for pressure dependence.Key kinetic parameters,including the critical pressure,maximum evaporation rate and evaporation coefficient,were calculated.The evaporation coefficient varies between 0.010 and 0.223,and the critical pressures vary between 281 and 478 Pa with temperature.
文摘Hepatocellular carcinoma presents with three distinct immune phenotypes,including immune-desert,immune-excluded,and immune-inflamed,indicating various treatment responses and prognostic outcomes.The clinical application of multi-omics parameters is still restricted by the expensive and less accessible assays,although they accurately reflect immune status.A comprehensive evaluation framework based on“easy-to-obtain”multi-model clinical parameters is urgently required,incorporating clinical features to establish baseline patient profiles and disease staging;routine blood tests assessing systemic metabolic and functional status;immune cell subsets quantifying subcluster dynamics;imaging features delineating tumor morphology,spatial configuration,and perilesional anatomical relationships;immunohistochemical markers positioning qualitative and quantitative detection of tumor antigens from the cellular and molecular level.This integrated phenomic approach aims to improve prognostic stratification and clinical decision-making in hepatocellular carcinoma management conveniently and practically.
基金supported by the National Key Research&Development Program of China(No.2022YFC2904905)the National Natural Science Foundation of China(No.52274400)+1 种基金the Project of Zhongyuan Critical Metals Laboratory,China(No.GJJSGFZD202302)the Science and Technology Project of Henan Province,China(No.232102230044)。
文摘The hydrogen reduction kinetics of tungsten trioxide(WO_(3))was investigated via non-isothermal thermogravimetric analysis.Under the local gas-solid reduction conditions,the particle morphology of tungsten powders was found to be consistent with that of raw material WO_(3).The removal of oxygen from tungsten oxide during hydrogen reduction led to the formation of porous structures between the reduced particles,which were obviously different from the polyhedral single-crystal configuration of tungsten powders obtained via chemical vapor deposition.Moreover,the two-stage hydrogen reduction mechanisms of WO_(3) under the local gas-solid reduction conditions can be described using the composite autocatalytic function.The activation energies of the first and second stages of the hydrogen reduction of WO_(3) were determined to be 121 and 135 kJ/mol,respectively.
基金supported by the National Natural Science Foundation of China (NSFC grant no. 62474028, 52130304, and62222503)the Natural Science Foundation of Sichuan Province(2025ZNSFSC0037, 2025ZNSFSC1460, and 2024NSFSC1447)+1 种基金the National Key R and D Program of China (2023YFB2604101)sponsored by the Sichuan Province Key Laboratory of Display Science and Technology
文摘The crystallization and aggregation characteristics of the active layer components in organic solar cells(OSCs)are one of the core factors determining photovoltaic performance,influencing the entire process from light absorption to charge separation,transport,and ultimately charge collection.Dynamic changes in crystallization and aggregation states can also disrupt the microstructure of the active layer,thus shortening the lifetime of the cell.In this study,a morphology modulation strategy is proposed to regulate the crystallization kinetics of non-fullerene acceptors by employing the polymer molecule PYIT as a nucleating agent.An appropriate amount of PYIT was first completely dissolved with the non-fullerene acceptor Y6 and left to stand for 24 h,followed by the fabrication of layer-by-layer processed OSCs.Experiments demonstrated that high crystallinity of PYIT allows it to act as a crystallization nucleus,promoting the crystallization,orientation consistency,and ordered stacking of the acceptor.These nanoscale structural optimizations facilitate efficient charge transport,enhance exciton dissociation efficiency,and suppress unfavorable energetic disorder.Consequently,not only was the power conversion efficiency(PCE)of D18-Cl/Y6-based layer-by-layer processed OSC increased from 18.08%to 19.13%,but the atmospheric stability and long-term lifetime of the OSCs were also significantly improved.Notably,this strategy is also applicable to indoor OSCs,and the PYIT-optimized device can achieve a PCE of 27.0%under 1000 lux light-emitting diode(LED,3200K)irradiation,which is superior to that of the control device(24.2%).This work develops a crystal engineering strategy that is able to simultaneously optimize the microscopic morphology and charge dynamics properties in OSCs,thereby achieving simultaneous improvement in efficiency and stability.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12274348 and 12004335)the National Key Research and Development Program of China(Grant No.2024YFC2813800)。
文摘Presented in this study is a novel method for estimating the depth of single underwater source in shallow water,utilizing vector sensors.The approach leverages the depth distribution of the broadband Stokes parameters to estimate source depth accurately.Unlike traditional matched field processing(MFP)and matched mode processing(MMP),the proposed approach can estimate source depth directly from the data received by sensors without requiring complete environmental information.Firstly,the broadband Stokes parameters(BSP)are established using the normal mode theory.Then the nonstationary phase approximation is used to simplify the theoretical derivation,which is necessary when dealing with broadband integrals.Additionally,range terms of the BSP are eliminated by normalization.By analyzing the depth distribution of the normalized broadband Stokes parameters(NBSP),it is found that the NBSP exhibit extreme values at the source depth,which can be used for source depth estimation.So the proposed depth estimation method is based on searching the peaks of the NBSP.Simulations show that this method is effective in relatively simple shallow water environments.Finally,the effect of source range,frequency bandwidth,sound speed profile(SSP),water depth,and signal-to-noise ratio(SNR)are studied.The findings indicate that the proposed method can accurately estimate the source depth when the SNR is greater than-5 d B and does not need to consider model mismatch issues.Additionally,variations in environmental parameters have minimal impact on estimation accuracy.Compared to MFP,the proposed method requires a higher SNR,but demonstrates superior robustness against fluctuations in environmental parameters.
基金the National Natural Science Foundation of China,grant number 52406074the China Postdoctoral Science Foundation under Grant Number 2025T180171+1 种基金the Natural Science Foundation of Guangdong Province(2025A1515011270)the China Southern Power Grid Technology Project(GDKJXM20231415/030100KC23120104).
文摘In order to explore the effects of CaO,lignite dust and sawdust on the drying characteristics ofmunicipal sludge at different concentrations,a three-factor three-level regression experiment was carried out based on the results of thermogravimetric experiment and single factor experiment.By fitting three common mathematical models,the Page model with the highest fitting degree was selected to determine the most suitable mathematical model to describe the municipal sludge drying process.In addition,the Box-Behnken design principle in the response surface method was used to analyze the interaction of three factors on the drying characteristics of municipal sludge.The results of the study show that below 100℃is the optimal drying temperature range for municipal sludge.The results of single factor experiments showed that the order of influence of the three factors on sludge drying time was CaO concentration>sawdust concentration>lignite dust concentration.In the single factor experiment,the optimal process parameterswere CaOconcentration 3%,lignite powder concentration 7%,and sawdust concentration 7%.In themulti-factor interaction analysis,the interaction between CaO and sawdust had the most significant effect on the reduction of drying time,and the order of influence was as follows:CaO interaction with sawdust>lignite dust interaction with sawdust>CaO interaction with lignite powder.Further analysis showed that the optimal process ratio was 3%CaO concentration and 3%sawdust concentration.
文摘This study explores the thin-layer convective solar drying of Marrubium vulgare L.leaves under conditions typical of sun-rich semi-arid climates.Drying experiments were conducted at three inlet-air temperatures(40℃,50℃,60℃)and two air velocities(1.5 and 2.5 m·s^(-1))using an indirect solar dryer with auxiliary temperature control.Moisture-ratio data were fitted with eight widely used thin-layer models and evaluated using correlation coefficient(r),root-mean-square error(RMSE),and Akaike information criterion(AIC).A complementary heattransfer analysis based on Reynolds and Prandtl numbers with appropriate Nusselt correlations was used to relate flow regime to drying performance,and an energy balance quantified the relative contributions of solar and auxiliary heat.The logarithmic model consistently achieved the lowest RMSE/AIC with r>0.99 across all conditions.Higher temperature and air velocity significantly reduced drying time during the decreasing-rate period,with no constantrate stage observed.On average,solar input supplied the large majority of the thermal demand,while the auxiliary heater compensated short irradiance drops to maintain setpoints.These findings provide a reproducible dataset and a modelling benchmark for M.vulgare leaves,and they support energy-aware design of hybrid solar dryers formedicinal plants in sun-rich regions.
基金supported by the National Key Projects for Fundamental Research and development of China(2020YFA0710202)the China Postdoctoral Science Foundation(2024M761567)Shandong Postdoctoral Science Foundation(SDCX-ZG-202400271).
文摘The synthesis of propylene carbonate(PC)from CO_(2) and propylene oxide(PO)is a typical gas-liquid biphasic system,where gas-liquid mass transfer efficiency significantly influences CO_(2) cycloaddition reactions.Here,we proposed a microchannel reaction system for the CO_(2) cycloaddition reaction catalyzed by ionic liquid within an aqueous environment.The effect of liquid flow rate,temperature and residence time on gas-liquid flow pattern,catalytic performance and mass transfer were systematically investigated.The results revealed that the PC generation rate reached 560.11 mmol·ml^(−1)·h^(−1)at a 50 cm of flow distance under reaction conditions of 105℃,2.5 MPa,QG=176 ml·min^(−1) and QL=0.3 ml·min^(−1).Variations in mass transfer rate and reaction rate at different flow distances were experimentally studied.The reaction efficiency gradually decreased with increasing flow distance,which were attributed to the reduction of mass transfer caused by decreasing bubble velocity.Optimizing bubble velocity at an appropriate position enhanced reaction efficiency by improving mass transfer,achieving a 97.7%PC yield within 2.85 min.Furthermore,a kinetic model coupling intrinsic kinetics with gas-liquid mass transfer was developed for CO_(2) cycloaddition reaction.The kinetic model was applied to predict PC reaction rates in microchannel reactors at various temperatures and liquid flow rates,achieving an average relative error of 9.6%.
基金supported by the grants PID2020-113371RA-C22 and TED2021-130845A-C32,funded by MCIN/AEI/10.13039/501100011033.M.Marín-García,R.González-OlmosC.Gómez-Canela are members of the GESPA group(Grup d’Enginyeria i Simulacióde Processos Ambientals)at IQS-URL,which has been acknowledged as a Consolidated Research Group by the Government of Catalonia(No.2021-SGR-00321)+1 种基金In addition,M.Marín-García has been awarded a public grant for the Investigo Programme,aimed at hiring young job seekers to undertake research and innovation projects under the Recovery,Transformation,and Resilience Plan(PRTR),European Union Next Generation,for the year 2022,through the Government of Catalonia and the Spanish Ministry for Work and Social Economy(No.100045ID16)Ana Belén Cuenca for her support and expertise,which helped to confirm the proposed reaction mechanism involved in the UV photolysis of cloperastine.
文摘The increasing production and release of synthetic organic chemicals,including pharmaceuticals,into our envi-ronment has allowed these substances to accumulate in our surface water systems.Current purification technolo-gies have been unable to eliminate these pollutants,resulting in their ongoing release into aquatic ecosystems.This study focuses on cloperastine(CPS),a cough suppressant and antihistamine medication.The environmental impact of CPS usage has become a concern,mainly due to its increased detection during the COVID-19 pandemic.CPS has been found in wastewater treatment facilities,effluents from senior living residences,river waters,and sewage sludge.However,the photosensitivity of CPS and its photodegradation profile remain largely unknown.This study investigates the photodegradation process of CPS under simulated tertiary treatment conditions using UV photolysis,a method commonly applied in some wastewater treatment plants.Several transformation prod-ucts were identified,evaluating their kinetic profiles using chemometric approaches(i.e.,curve fitting and the hard-soft multivariate curve resolution-alternating least squares(HS-MCR-ALS)algorithm)and calculating the reaction quantum yield.As a result,three different transformation products have been detected and correctly identified.In addition,a comprehensive description of the kinetic pathway involved in the photodegradation process of the CPS drug has been provided,including observed kinetic rate constants.
基金Open Access funding enabled and organized by Projekt DEAL.
文摘In this study,copper extraction from low-grade oxide-sulfide ores was investigated using a leaching method combined with response surface methodology(RSM)to optimize operational conditions and assess leaching kinetics.Given copper's extensive industrial applications,sustainable recovery from low-grade ores is critical.Five key parameters-acid concentration,leaching time,particle size,temperature,and solids percentage-were identified as major influences on copper recovery.The results revealed that leaching time and solids percentage,along with interactions between temperature-time and temperature-solids percentage,had the most significant effects.Optimal conditions for 80% copper recovery while minimizing iron recovery below 3% included an acid concentration of 1.21 mol L^(-1),a leaching time of 108 min,a particle size of 438μm,a temperature of 45℃,and a solids percentage of 18.2%.Leaching kinetics were analyzed using shrinking core models,with the Dickinson model best describing the process,showing an activation energy of 32.63 kJ mol^(-1),indicative of mixed diffusion and chemical reaction control.The final kinetic model effectively predicted the influence of key parameters.These findings highlight the importance of optimizing process variables and selecting suitable kinetic models to enhance extraction efficiency,reduce costs,and improve sustainability in copper recovery.
基金the funding support from the National Natural Science Foundation of China(Grant No.52202217,52471222)the Natural Science Foundation of Jilin Province(Grant No.YDZJ202201ZYTS375).
文摘Layered double hydroxides(LDHs)hold great promise as cathode materials for aqueous zinc-ion batteries(AZIBs).Nevertheless,they also face challenges of sluggish kinetics and rapid capacity loss.Herein,a conformational entropy regulation strategy has been applied to surmount the shortcomings.A medium-entropy iron-based metal organic framework(MIL-88)derived NiCoFeInZnV-based layered double hydroxide with carbon loaded(ME-NiCoFeInZnV-LDH/C)has been first proposed and prepared with a designed method.The increased entropy optimizes electron conductivity and alleviates structure alteration and diffusion barrier during interactions with charge carriers,due to electron-induced effect and“cocktail”effect.Moreover,the nanosheet assembled hollow prismatic structures could homogenize flux distribution and electric field distribution.Therefore,the electrochemical kinetics,crystal structure stability,and activity could be dramatically improved.Leveraging the advantages of structure and composition regulation,Zn||ME-NiCoFeInZnV-LDH/C zinc battery delivers high specific capacities,rate performance,and cycling stability.This work proposes a novel and feasible medium-entropy strategy to prepare a high-performance cathode for advanced AZIBs,which is of prominent significance for the development of charge storage devices.
基金supported by the National Natural Science Foundation of China(Grant No.52174371)the National Key Research and Development Program of China(Grant No.2021YFB3501003)the Shaanxi Provincial Science and Technology Department Enterprise Joint Fund(Grant No.2021JLM-33).
文摘Single-pass and double-pass high-temperature deformation experiments were conducted on 40Cr10Si2Mo steel using a Gleeble-3500 thermal simulator.The static recrystallization(SRX)behavior and recrystallization mechanisms of 40Cr10Si2Mo steel were investigated under deformation temperatures of 900-1100℃,deformation strains of 10%,20%,and 30%,and inter-pass times of 1-120 s.A static recrystallization fraction model was developed.The results showed that the SRX volume fraction increased with higher deformation temperature,larger deformation amount,and longer inter-pass time,with the deformation temperature having the most significant effect on SRX.During the deformation process,different process parameters led to different internal deformation mechanisms of the material.Static recovery and continuous static recrystallization(CSRX)dominated deformation at lower temperatures through progressive lattice rotation.In comparison,at higher temperatures,the deformation mechanism was dominated by CSRX and discontinuous static recrystallization(DSRX).The nucleation mechanisms of the SRX process were grain boundary bulging nucleation and subgrain merging nucleation,with grain boundary bulging present under all conditions.Subgrain merging nucleation could provide an additional nucleation mode at lower deformation temperatures or lower deformation amounts.Based on the traditional Avarmi equation,a modified model coefficient was used to establish the SRX kinetic model for 40Cr10Si2Mo steel.The linear correlation coefficient R^(2) between the predicted and experimental static recrystallization volume fraction was 0.96702,indicating high prediction accuracy.
文摘The effects of acid surface dissolution on the flotation kinetics of ilmenite(IL)and its common accompanied gangue minerals including olivine-pyroxene(Ol-Px),tremolite-clinochlore(Tr-Cch)and quartz were investigated.The results show that through the surface dissolution the adsorption rate constant for ilmenite increases from 5.272 to 8.441 mol/(g·min)while it decreases for Ol-Px,Tr-Cch and quartz from 6.332,7.309 and 7.774 mol/(g·min)to 5.034,6.223 and 7.371 mol/(g·min),respectively.Also,the flotation experiments on a binary mixture of minerals indicate that after surface dissolution the values of modified rate constant for ilmenite flotation from Ol-Px,Tr-Cch and quartz are enhanced from 36.15,36.52 and 47.86 min-1 to 41.72,45.78 and 56.24 min-1,respectively.This results in the improvement of kinetic selectivity index(SI)in the separation of treated ilmenite from gangue minerals.As evidenced by ICP-MS analysis,the decrease of kinetic parameters for gangue minerals can be due to the removal of Fe^2+,Ca^2+and Mg^2+ions from their surfaces,which results in the lack of enough active sites to interact with collector species.As confirmed by contact angle measurements,this prevents the formation of a stable hydrophobic layer on the minerals surfaces for creating stable attachments between minerals and bubbles.Generally,the improvement of ilmenite flotation kinetics has a negative correlation with the iron content in its accompanied gangue minerals.
基金Supported by the Research Fund for the Doctoral Program of Higher Education(20050145029)the Science and Technology Talents Fund for Excellent Youth of Liaoning Province(2005221012)
文摘Determination of probable mechanism function and kinetic parameters is important to hydrometallurgical kinetics.In this work,the most probable mechanism function and kinetic parameters of gibbsite dissolution in NaOH solution are studied.The sample,the mixture of synthetic gibbsite and sodium hydroxide solution,was scanned in high-pressure differential scanning calorimetry(DSC) equipment with the heating rate of 10 K·min-1. Integral equation and differential equation of non-isothermal kinetics were solved to fit the data related to DSC curve.According to the calculation results,the most probable mechanism function for pure synthetic gibbsite dissolution in sodium hydroxide solution is presented based on the optimum procedure in the database of the mechanism function.The apparent activation energy obtained is(75±1) kJ·mol-1,the frequency factor is 10 8±1mol·s-1,and the reaction is a second order reaction.
基金The National Nature Science Foundation of China(21173163)
文摘The thermal behavior,non-isothermal thermal decomposition reaction kinetics and specific heat capacity of hexanitro-hexaazaisowurtzitane(HNIW)were studied by differential scanning calorimeter(DSC)and Micro-DSCIapparatus,The kinetic parameters of the thermal decomposition reaction(the apparent activation energy(E,)and pre-exponential factor(A))were calcu-lated by non-isothermal DSC curves.The results show that the differential mlechanism function and values of E,and A of the ther-mal decomposition reaction of HNIW are 3(1-a)[-ln(1-a)]"·,155.04 kJ·mol^(-1)and 10""s^(-1),respectively.The critical tem-perature of thermal explosion of the title compound is 226.60℃.The entropy of activation(AS·),enthalpy of activation(AH·)and free energy of activation(AG·)of this reaction are 11.60J·mol·K^(-1),152.04 kJ·mol^(-1)and 146.29 kJ·mol^(-1),respec-tively.The equation of specific heat capacity of HNIW with temperature is C,=0.2472+0.002705992Tin the temperature range of 283 K to 343K.The values of self-accelerating decomposition temperature,adiabatic time-to-maximum decomposition rate and adiabatic time-to-explosion are 486.5K,54.81s and 54.31s,respectively.Thermal sensitivity probability density distribution curve of HNIW is constructed.
基金Project supported by the Deanship of Scientific Research at Jazan University,the Kingdom of Saudi Arabia(W41-032).
文摘In this paper,Dy^(3+)incorporated BaSi_(2)O_(5)phosphors were synthesized by gel co mbustion method and characterized by X-ray diffraction(XRD).The effects of various heating rate s on thermoluminescence(TL)kinetics and glow peak temperatures of Dy^(3+)incorporated BaSi_(2)O_(5)phosphors exposed toβirradiation at room temperature were investigated.The glow curves of the phosphor exposed toβ-irradiation(0.1-100 Gy)consist of four main peaks located at 87,130,271,and 327℃and exhibit a good linearity between 0.1 and100 Gy.Three experimental techniques including variable heating rate(VHR),repeated initial rise(RIR),peak shape(PS)and computerized glow curve deconvolution(CGCD)were employed to determine TL kinetic parameters.Our findings indicate that the TL glow peaks of the phosphor obey first-order kinetics.Analysis of the main dosimetric peaks through the techniques mentio ned above indicates that activation energies(E)and pre-exponential factor(s)are in the range of 0.80-1.50 eV and 1.15×10^(8)-3.28×10^(13)s^(-1).Additionally,it is found that the temperature of the glow peaks shifts toward the higher temperatures and the TL intensity smoothly decreases as the heating rate increases.The effect on the TL intensities and glow peak temperatu res of the heating rate is discussed in terms of thermal quenching.
