We investigated the phase behavior of diblock copolymer AB/homopolymer C blends in concentrated aqueous solutions using a simulated annealing method.Phase diagrams were constructed as a function of the concentration o...We investigated the phase behavior of diblock copolymer AB/homopolymer C blends in concentrated aqueous solutions using a simulated annealing method.Phase diagrams were constructed as a function of the concentration of all polymers(Φ)and the volume fraction of homopolymer(fC).Rich phase transition sequences were observed,especially reentrant phase transitions,such as lamellae→inverted cylinders→gyroids→lamellae→disorder,for a givenΦwith increasing fC.By analyzing the variations in the average contact numbers between different components and the effective volume fractions of B-domains,we elucidated the mechanisms of the reentrant phase transitions.We found that the strong attraction between B and C leads to the swelling of B-domains upon addition of homopolymer.Concurrently,the solvent preferentially swells the A-domains over the B+C-domains.The competing swelling effects of the solvent and homopolymer on the A-domains and B-domains,respectively,triggered the reentrant phase behavior in the symmetric AB copolymer system upon addition of homopolymer.展开更多
A polylactide(PLA)blend with simultaneous enhancement of strength,toughness,and heat resistance was successfully achieved by adding biodegradable poly(propylene carbonate)(PPC)and uniaxial pre-stretching.The effects o...A polylactide(PLA)blend with simultaneous enhancement of strength,toughness,and heat resistance was successfully achieved by adding biodegradable poly(propylene carbonate)(PPC)and uniaxial pre-stretching.The effects of the PPC content(0 wt%-50 wt%)on the phase morphology and performance of the blends before and after pre-stretching were systematically investigated.Blending PPC initially reduced the strength,modulus,and heat resistance,but pre-stretching significantly enhanced these properties.In blends containing≤30 wt%PPC,where PPC formed a well-dispersed island-like phase within the PLA matrix,pre-stretching simultaneously enhanced strength,toughness,and heat resistance.The optimized pre-stretched 70/30 PLA/PPC(ps-70/30)blend achieved exceptional performance:tensile strength increased from 66.9MPa to 84.5 MPa,elongation at break dramatically improved from 6.8%to 115.1%,impact strength reached 55.1 k J/m^(2)(far exceeding neat PLA's 3.5 k J/m^(2)),and Vicat softening temperature(VST)increased by 60.6%to 101.8℃.Notably,the ps-70/30 blend retained excellent mechanical properties even after six months of aging.These improvements were attributed to the synergistic effects of the PPC incorporation and prestretching.PPC not only promoted the high orientation of the PLA molecular chains but also facilitated the formation of a stable crystalline phase during pre-stretching,thereby enhancing both the mechanical properties and heat resistance.However,when the PPC content exceeded 30wt%,phase inversion occurred,resulting in a continuous amorphous PPC phase that degraded the overall performance.This study demonstrated that a combination of controlled PPC incorporation and pre-stretching can effectively overcome PLA's brittleness of PLA while improving its heat resistance,offering a promising strategy for developing high-performance,fully biodegradable PLA materials suitable for industrial applications.展开更多
To explore the best preparation process for terminal blend(TB)composite-modified asphalt and to filter its formulation with excellent performance,this study evaluates the performance of TB composite modified asphalt b...To explore the best preparation process for terminal blend(TB)composite-modified asphalt and to filter its formulation with excellent performance,this study evaluates the performance of TB composite modified asphalt by physical property index,microscopic morphology,rheological testing,and infrared spectroscopy on multiple scales.The results show that the best preparation process for TB-modified asphalt is stirring at 260℃ for 4 h at 400 rpm,which significantly reduces the modification time of the asphalt.From a physical property viewpoint,the TB composite-modified asphalt sample with 5% styrene-butadiene-styrene(SBS)+1% aromatics+0.1% sulfur exhibits high-comprehensive,high-and low-temperature properties.More-over,its crosslinked mesh structure comprises black rubber particles uniformly interwoven in the middle,which further enhances the performance of the asphalt and results in an excellent performance formulation.In addition,the sample with 5%SBS content has a higher G*value and smaller δ value than that with 3%SBS content,indicating that its high-temperature resistance is improved.The effect of adding 3%SBS content on the viscoelastic ratio is,to some extent,less than that caused by 20% rubber powder.展开更多
A new principle for producing fire-resistant polymer materials with increased deformation properties using a flame retardant not as a heterogeneous additive,but as a thermoplastic flame retardant in a hybrid polymer m...A new principle for producing fire-resistant polymer materials with increased deformation properties using a flame retardant not as a heterogeneous additive,but as a thermoplastic flame retardant in a hybrid polymer mixture with a polyhydrocarbon is considered.Hybrid polymer blends of low-molecular ammonium polyphosphate(APP)with an ethylene-vinyl acetate copolymer(EVA)with an APP content of 80 wt%with enhanced deformation properties were obtained by extrusion mixing at various temperatures in the range from 200°C to 250°C.A chemical scheme for the transformations of the components during the formation of the composite is proposed.X-ray diffraction analysis showed the formation of new crystalline structures of APP.The phase structure of the systems corresponding to the model of a dispersed-filled composite in which EVA plays the role of a matrix,determining the deformation of the mixture,and the filler is ammonium polyphosphate,was studied by scanning electron microscopy(SEM).The method of FTIR microscopy showed chemical interactions between EVA and APP with the formation of amide groups.The conditions for obtaining compositions characterized by heat resistance of 210°C,oxygen index of 55 and ultimate elongation at drawing of 213%were established.展开更多
Rubber-toughened thermoplastic materials have become ubiquitous in modern society owing to their lightweight nature and desirable combination of advantageous performances.Despite the ever-increasing demand,the develop...Rubber-toughened thermoplastic materials have become ubiquitous in modern society owing to their lightweight nature and desirable combination of advantageous performances.Despite the ever-increasing demand,the development of polymer alloys that are lightweight,high-strength,and high-toughness remains an ongoing challenge.Inspired by the unique“salami”microstructure from commercial acrylonitrile butadiene styrene copolymer(ABS)and high-impact polystyrene(HIPS),a facile approach was developed to overcome the trade-off between enhancing the toughness and rigidity of fully polymer-based alloys by virtue of elastomeric salami particles.This strategy entails pre-grafting rigid poly(lactic acid)(PLLA)chains with glycidyl methacrylate-grafted octene ethylene copolymer(POE-g-GMA)using complementary reactive groups.It can be envisaged that the PLLA grafts featuring strong incompatibility with polypropylene(PP)remain fixed in elastomer phase upon the subsequent melt compounding,facilitating the in situ formation of“hard core(PLLA)-soft shell(polyolefin elastomer,POE)”particles in polypropylene(PP)matrix.The all-polymer alloys containing elastomeric salami particles demonstrated unprecedented performance combinations,including upper notched impact strengths(56.8 kJ/m2),even higher tensile strength(36.8 MPa),and Young’s modulus(0.93 GPa)than that of the PP matrix.Furthermore,these materials are lightweight without the incorporation of reinforcing nano-fillers,which is competitive with industrial engineering plastics.It is highly anticipated that this universal and highly efficient protocol will be appropriate for arbitrary rubber toughened/reinforced systems,offering a paradigm in the design of advanced all-polymer alloys.展开更多
In mixture experiments,the observed response is determined by the relative proportions of the components,consequently rendering the experimental region a simplex.This paper focuses primarily on the optimal designs of ...In mixture experiments,the observed response is determined by the relative proportions of the components,consequently rendering the experimental region a simplex.This paper focuses primarily on the optimal designs of mixture experiments that involve process variables.Prior research has extensively delved into optimal orthogonal block designs for some classic mixture models with process variables.Based on the framework of general blending models,this paper proposes a class of symmetric linear mixture models,which can be regarded as a generalization of many existing ones.Under the orthogonal blocking conditions,orthogonal block designs are devised through Latin squares in the presence of process variables.TheD-,A-,and E-optimality criteria are utilized to obtain optimal designs at the boundary of the simplex in the case of 3 components.As the values of the exponents change,numerically derived optimal design points are presented to illustrate the pattern of their variations,and to verify the consistency of the results with previous research on some specific symmetric general blending models.展开更多
The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behav...The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behavior of dispersed long chains.Using molecular dynamics simulations based on the Kremer-Grest model,we systematically explore the N_(S)-dependence of static conformations,equilibrium dynamics,and nonlinear shear responses in unentangled long-chain/short-chain polymer blends.Our results demonstrate a decoupling between the static and dynamic sensitivity to N_(S):while the static chain size,R_g,follows Flory theory with slight swelling at small N_(S) due to incomplete excluded volume screening,the diffusion coefficient,D,and the relaxation time,τ_(0),exhibit a strong,non-monotonic N_(S)-dependence,transitioning from monomeric friction dominance at small N_(S) to collective segmental rearrangement at large N_(S).Additionally,we observe partial decoupling between the viscous and normal stress responses:while the zero-shear viscosity,η,is strongly N_(S)-dependent,the first and second normal stress coefficients,Ψ_(1) and Ψ_(2),collapse onto universal curves when scaled by the dimensionless shear rate,γτ_(0),suggesting a common mechanism of orientation and stretching.Under shear,long chains compress in the vorticity direction λ_(z)~Wi^(-0.2),which reduces collision frequency and contributes to shear thinning,while the scaling of weaker orientation resistance m_(G)~Wi^(0.35)reflects hydrodynamic screening by the short-chain matrix.These findings highlight the limitations of single-chain models and emphasize the necessity of considering N_(S)-dependent matrix dynamics and flow-induced structural changes in understanding the rheology of unentangled polymer blends.展开更多
High-entropy polymer blends composed of polypropylene(PP),polystyrene(PS),polyamide 6(PA6),poly(lactic acid)(PLA),and styrene-ethylene-butylene-styrene(SEBS)were successfully fabricated using maleic anhydride-grafted ...High-entropy polymer blends composed of polypropylene(PP),polystyrene(PS),polyamide 6(PA6),poly(lactic acid)(PLA),and styrene-ethylene-butylene-styrene(SEBS)were successfully fabricated using maleic anhydride-grafted SEBS(SEBS-g-MAH)as a compatibilizer.Dynamic mechanical analysis(DMA),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),and mechanical testing demonstrated that SEBS-g-MAH significantly enhanced the compatibility between the polar(PA6,PLA)and nonpolar(PP,PS,SEBS)components.The compatibilizer effectively refined the microstructure,substantially reduced the domain sizes,and blurred the phase boundaries,indicating enhanced interfacial interactions among all the components.The optimal compatibilizer content(15 wt%)notably increased tensile ductility(elongation at break from 5.0%to 23.7%)while maintaining balanced crystallization behavior,despite slightly decreasing modulus.This work not only demonstrates the broad applicability of high-entropy polymer blends as a sustainable strategy for converting complex,unsorted plastic waste into high-performance value-added materials that significantly contribute to plastic upcycling efforts,but also highlights intriguing physical phenomena emerging from such complex polymer systems.展开更多
While artificial intelligence(AI)shows promise in education,its real-world effectiveness in specific settings like blended English as a Foreign Language(EFL)learning needs closer examination.This study investigated th...While artificial intelligence(AI)shows promise in education,its real-world effectiveness in specific settings like blended English as a Foreign Language(EFL)learning needs closer examination.This study investigated the impact of a blended teaching model incorporating AI tools on the Superstar Learning Platform for Chinese university EFL students.Using a mixed-methods approach,60 first-year students were randomized into an experimental group(using the AI-enhanced model)and a control group(traditional instruction)for 16 weeks.Data included test scores,learning behaviors(duration,task completion),satisfaction surveys,and interviews.Results showed the experimental group significantly outperformed the control group on post-tests and achieved larger learning gains.These students also demonstrated greater engagement through longer study times and higher task completion rates,and reported significantly higher satisfaction.Interviews confirmed these findings,with students attributing benefits to the model’s personalized guidance,structured content presentation(knowledge graphs),immediate responses,flexibility,and varied interaction methods.However,limitations were noted,including areas where the platform’s AI could be improved(e.g.,for assessing speaking/translation)and ongoing challenges with student self-discipline.The study concludes that this AI-enhanced blended model significantly improved student performance,engagement,and satisfaction in this EFL context.The findings offer practical insights for educators and platform developers,suggesting AI integration holds significant potential while highlighting areas for refinement.展开更多
Current mix design practices typically assume total blending and use the white curve of reclaimed asphalt pavement(RAP)to determine the gradation and optimum asphalt content(OAC)of recycled hot mix asphalt(HMA),often ...Current mix design practices typically assume total blending and use the white curve of reclaimed asphalt pavement(RAP)to determine the gradation and optimum asphalt content(OAC)of recycled hot mix asphalt(HMA),often overlooking the effects of RAP agglomeration and partial blending.This oversight can result in unsatisfactory performance,particularly when higher RAP content is used.Therefore,this paper reviews and discusses strategies for adjusting the mix design of recycled HMA to enhance its in-service performance.The discussion begins with RAP particle agglomeration,a significant phenomenon that significantly impacts the aggregate gradation of recycled HMA.Subsequently,detection methods to clarify the blending between virgin and RAP binders are described.Partial blending between RAP and virgin binders is common,and various indexes have been proposed to quantify the blending degree.Finally,the adjusted mix design method of recycled HMA is presented,emphasizing gradation optimization and corrected OAC.Gradation optimization should account for RAP agglomeration,while the corrected OAC should consider particle blending.Recycled HMA using the adjusted mix design exhibits improved crack resistance and fatigue life without substantially impairing rutting performance.This review aims to help both academics and highway agencies maximize the utilization of RAP materials within sustainable pavement frameworks.展开更多
Background Small-scale research or individual seed cotton samples from breeders and geneticists are ginned using laboratory saws or roller gins.The objective of this study was to examine the effects of two different l...Background Small-scale research or individual seed cotton samples from breeders and geneticists are ginned using laboratory saws or roller gins.The objective of this study was to examine the effects of two different laboratory saw ginning(SG)rates and subsequent mechanical blending on fiber high volume instrument(HVI)and advanced fiber information system(AFIS)quality measurement.Seed cottons from diverse upland cotton cultivars,years,and locations were evaluated.Results As the SG rate was increased,HVI results for uniformity index(UI),short fiber index(SFI),and two non-lint parameters(area%,particle count),as well as AFIS results for some properties,were impacted,with significant effects on HVI UI and AFIS short fiber content(SFC).Apparent fiber blending impacts were observed for HVI UI,strength(STR),reflectance(Rd),SFI,and two trashes as well as for all AFIS parameters,with significant effects on HVI Rd and two trashes and all AFIS parameters except the length and maturity measurements.A combination of ginning and blending processes indicated statistically significant interactions for HVI STR,Rd,SFI,and two trashes,and also for AFIS neps,L(w)CV,UQL(w),L(n)CV,SFC(n),L5%(n),immature fiber content(IFC),fineness,total count,dust count,particle count,and visible foreign matter(VFM).Further analysis implied a few impacts of ginning and blending on correlations between HVI and relevant AFIS qualities.Conclusion Despite the observation,the laboratory saw gin and blending methods should continue to be a practical tool to study the differences when all samples are processed identically.展开更多
Fuel injection properties,including the injection rate(temporal aspects)and spray behavior(spatial aspects),play a crucial role in the combustion efficiency and emissions of diesel engines.This study investigates the ...Fuel injection properties,including the injection rate(temporal aspects)and spray behavior(spatial aspects),play a crucial role in the combustion efficiency and emissions of diesel engines.This study investigates the effects of different ethanol-biodiesel-diesel(EBD)blends on the injection performance in diesel engines.Experimental tests are conducted to examine key injection parameters,such as spray penetration distance,spray cone angle,and droplet size,alongside an analysis of coupling leakage.The main findings are as follows:(1)The injection behavior of ethanol and diesel differs significantly.The addition of ethanol reduces the density,viscosity,and modulus of elasticity of the fuel mixture.While the injection advance angle,penetration distance,and Sauter mean diameter show minimal changes,the spray cone angle and coupling leakage increase notably.These alterations may disrupt the“fuelair-chamber”matching characteristics of the original engine,potentially affecting performance.(2)In contrast,the injection performance of biodiesel ismore similar to that of diesel.As biodiesel content increases,the density,viscosity,and modulus of elasticity of the blended fuel also grow.Though changes in injection timing,penetration distance,and spray cone angle remain minimal,the Sauter mean diameter experiences a slight increase.The“air-fuel chamber”compatibility of the original engine is largely unaffected,though fuel atomization slightly deteriorates.Blending up to 20%biodiesel and 30%ethanol with diesel effectively compensates for the shortcomings of using single fuels,maintaining favorable injection dynamics while enhancing lubrication and sealing performance of engine components.展开更多
College students’safety education is an important part of the fundamental task of fostering virtue through education in colleges and universities.A questionnaire survey at J University shows that the popularization d...College students’safety education is an important part of the fundamental task of fostering virtue through education in colleges and universities.A questionnaire survey at J University shows that the popularization degree and teaching satisfaction of college students’safety education are relatively high,but the teaching content and teaching forms still need improvement.With the rapid development of artificial intelligence technology and considering the char-acteristics of college students’online learning in the new era,carrying out the SPOC+PBL blended teaching reform not only helps to enhance the effectiveness of theoretical and practical teaching but also contributes to optimizing the teach-ing evaluation and feedback mechanism and strengthening students’problem-solving abilities.Therefore,we should adhere to the goal orientation,meticulously design the teaching plan,highlight the student-centered approach,focus on integrating teaching resources,strengthen process management,promptly provide feedback and guidance,empower with data,and continuously improve teaching evaluation.Thus,a student-centered SPOC+PBL blended teaching sys-tem can be constructed to empower the transformation and innovation of talent cultivation in higher education.展开更多
This article explores in-class practice of blended teaching of Chinese-English(C-E)translation for English as a Foreign Language(EFL)majors in the era of artificial intelligence(AI).It examines the opportunities and c...This article explores in-class practice of blended teaching of Chinese-English(C-E)translation for English as a Foreign Language(EFL)majors in the era of artificial intelligence(AI).It examines the opportunities and challenges AI presents in enhancing translation education,particularly in fostering student engagement,improving teaching efficiency,and promoting self-motivated learning.Case study suggests that AI can enhance the flexibility of teaching and motivate students,yet challenges such as over-reliance on AI and diminished critical thinking need to be addressed.While acknowledging the indispensability of human translators,the article concludes that effective blended teaching requires purposeful curriculum design,proper integration of AI,and a collaborative effort of teachers and students to maximize the potential of AI while ensuring high-quality,independent learning outcomes.展开更多
Wet flue gas desulfurization(WFGD)could effectively reduce sulfur dioxide emission.However,magnesium sulfite(MgSO_(3)),a by-product of desulfurization,was easy to result in secondary pollution.In this study,the solid ...Wet flue gas desulfurization(WFGD)could effectively reduce sulfur dioxide emission.However,magnesium sulfite(MgSO_(3)),a by-product of desulfurization,was easy to result in secondary pollution.In this study,the solid catalyst Co-Bent(bentonite supported cobalt)was prepared by blending method for MgSO_(3) oxidation with bentonite as the carrier and cobalt as the active component.At the calcination temperature of 550℃ and the Co loading level of 3 wt.%,the catalyst showed excellent catalytic performance for the oxidation of high concentration MgSO_(3) slurry,and the oxidation rate of MgSO_(3) was 0.13 mol/(L·h).The research indicated that the active component was uniformly distributed within porous structure of the catalyst as Co_(3)O_(4),which facilitated the oxidation of SO_(3)^(2-) catalyzed by Co_(3)O_(4).Kinetic researches indicated the oxidation rate of MgSO_(3) was influenced by the catalyst dosage,the reaction temperature,the solution pH,the airflow rate,and the SO_(3)^(2-) concentration.Additionally,after recycling experiments,the regenerated catalyst retained its high catalytic performance for the MgSO_(3) oxidation.The reaction mechanism for the catalytic oxidation of MgSO_(3) by Co-Bent catalyst was also proposed.The generation of active free radicals(OH·,SO_(4)^(-)·,SO_(3)^(-)·,SO_(5)^(-)·)accelerated the MgSO_(3) oxidation.These results provide theoretical support for the treatment of MgSO_(3) and the development of durable catalyst.展开更多
The current work includes a numerical investigation of the effect of biodiesel blends with different aluminum oxide nanoparticle concentrations on the combustion process in the cylinder of a diesel engine.IC Engine Fl...The current work includes a numerical investigation of the effect of biodiesel blends with different aluminum oxide nanoparticle concentrations on the combustion process in the cylinder of a diesel engine.IC Engine Fluent,a specialist computational tool in the ANSYS software,was used to simulate internal combustion engine dynamics and combustion processes.Numerical analysis was carried out using biodiesel blends with three Al_(2)O_(3) nanoparticles in 50,100,and 150 ppm concentrations.The tested samples are called D100,B20,B20A50,B20A100,and B20A150 accordingly.The modeling runs were carried out at various engine loads of 0,100,and 200 Nm at a rated speed of 1800 rpm.The combustion characteristics are improved due to the catalytic effect and higher surface area of nano additives.The results showed the improvements in the combustion process as the result of nanoparticle addition,which led to the higher peak cylinder pressure.The increases in the peak cylinder pressures for B20A50,B20A100,and B20A150 about B20 were 3%,5%,and 8%,respectively,at load 200 Nm.The simulation found that the maximum temperature for biodiesel blends diesel was higher than pure diesel;this was due to higher hydrocarbon values of B20.Also,nano-additives caused a decrease in temperatures in the combustion of biofuels.展开更多
Polymeric materials have emerged as a promising alternative to electrolytic solutions in energy storage applications.However,high crystallinity and poor ionic conductivity are the main barriers restricting their daily...Polymeric materials have emerged as a promising alternative to electrolytic solutions in energy storage applications.However,high crystallinity and poor ionic conductivity are the main barriers restricting their daily application.In this study,we propose a polymer electrolyte system consisting of methylcellulose-polyvinyl alcohol(MC-PVA)blend as host material and lithium trifluoromethanesulfonate(LiCF_(3)SO_(3))as dopant,which was prepared using the solution-casting method.The electrochemical impedance spectroscopy(EIS)analysis revealed a maximum conductivity of 5.42×10^(−6) S cm^(−1) with 40 wt.%LiCF_(3)SO_(3).The key findings demonstrated that the variation in the dielectric loss(εi)and dielectric constant(εr)was significantly correlated with the variation in ionic conductivity.Fourier-transform infrared spectroscopy(FTIR)analysis was done to analyse the salt-polymer interaction by observing the shifting of selected bands.By deconvoluting FTIR spectra in the wavenumber range of 970–1100 cm^(−1),transport properties of electrolytes were investigated and found to be improved when the salt concentration was increased to 40 wt.%.Results from the X-ray diffraction(XRD)study suggested that the higher salt concentration promoted the formation of an amorphous phase,which is favourable for ionic conduction.Field emission scanning electron microscopy(FESEM)study demonstrated that the addition of salt altered the surface morphology of MC-PVA.展开更多
Artificial Intelligence is profoundly transforming innovation and development in healthcare and education.In this study,we developed an AI-empowered blended learning model for disaster medicine.Leveraging the Rain Cla...Artificial Intelligence is profoundly transforming innovation and development in healthcare and education.In this study,we developed an AI-empowered blended learning model for disaster medicine.Leveraging the Rain Classroom platform,we established a comprehensive intelligent teaching support system covering the entire learning cycle-pre-class,in-class,and post-class.Through AI-driven enhancements,the model enables intelligent resource allocation,personalized learning paths,and high-fidelity simulation of practical training scenarios.Moreover,it addresses key challenges in traditional disaster medicine education,including fragmented knowledge delivery,insufficient practical training environments,and limited evaluation methods.Ultimately,the model enhances both the efficiency and effectiveness of disaster medicine education.展开更多
基金financially supported by the Natural Science Foundation of Shandong Province(Nos.ZR2023QA136,ZR2021MA073 and ZR2024QA235)the National Natural Science Foundation of China(No.22173051).
文摘We investigated the phase behavior of diblock copolymer AB/homopolymer C blends in concentrated aqueous solutions using a simulated annealing method.Phase diagrams were constructed as a function of the concentration of all polymers(Φ)and the volume fraction of homopolymer(fC).Rich phase transition sequences were observed,especially reentrant phase transitions,such as lamellae→inverted cylinders→gyroids→lamellae→disorder,for a givenΦwith increasing fC.By analyzing the variations in the average contact numbers between different components and the effective volume fractions of B-domains,we elucidated the mechanisms of the reentrant phase transitions.We found that the strong attraction between B and C leads to the swelling of B-domains upon addition of homopolymer.Concurrently,the solvent preferentially swells the A-domains over the B+C-domains.The competing swelling effects of the solvent and homopolymer on the A-domains and B-domains,respectively,triggered the reentrant phase behavior in the symmetric AB copolymer system upon addition of homopolymer.
基金supported by the Science and Technology Development Plan of Jilin Province(No.YDZJ202403009CGZH)Engineering Research Center of Coalbased Ecological Carbon Sequestration Technology of the Ministry of Education(No.MJST2025-1)+2 种基金Chinese Academy of Sciences(Changchun Branch)(No.2024SYHZ0038)Development and Reform Commission of Jilin Province of China(No.2024C019-5)Science and Technology Bureau of Changchun City of China(No.23SH08)。
文摘A polylactide(PLA)blend with simultaneous enhancement of strength,toughness,and heat resistance was successfully achieved by adding biodegradable poly(propylene carbonate)(PPC)and uniaxial pre-stretching.The effects of the PPC content(0 wt%-50 wt%)on the phase morphology and performance of the blends before and after pre-stretching were systematically investigated.Blending PPC initially reduced the strength,modulus,and heat resistance,but pre-stretching significantly enhanced these properties.In blends containing≤30 wt%PPC,where PPC formed a well-dispersed island-like phase within the PLA matrix,pre-stretching simultaneously enhanced strength,toughness,and heat resistance.The optimized pre-stretched 70/30 PLA/PPC(ps-70/30)blend achieved exceptional performance:tensile strength increased from 66.9MPa to 84.5 MPa,elongation at break dramatically improved from 6.8%to 115.1%,impact strength reached 55.1 k J/m^(2)(far exceeding neat PLA's 3.5 k J/m^(2)),and Vicat softening temperature(VST)increased by 60.6%to 101.8℃.Notably,the ps-70/30 blend retained excellent mechanical properties even after six months of aging.These improvements were attributed to the synergistic effects of the PPC incorporation and prestretching.PPC not only promoted the high orientation of the PLA molecular chains but also facilitated the formation of a stable crystalline phase during pre-stretching,thereby enhancing both the mechanical properties and heat resistance.However,when the PPC content exceeded 30wt%,phase inversion occurred,resulting in a continuous amorphous PPC phase that degraded the overall performance.This study demonstrated that a combination of controlled PPC incorporation and pre-stretching can effectively overcome PLA's brittleness of PLA while improving its heat resistance,offering a promising strategy for developing high-performance,fully biodegradable PLA materials suitable for industrial applications.
基金Funded by the National Natural Science Foundation of China(No.52278446)。
文摘To explore the best preparation process for terminal blend(TB)composite-modified asphalt and to filter its formulation with excellent performance,this study evaluates the performance of TB composite modified asphalt by physical property index,microscopic morphology,rheological testing,and infrared spectroscopy on multiple scales.The results show that the best preparation process for TB-modified asphalt is stirring at 260℃ for 4 h at 400 rpm,which significantly reduces the modification time of the asphalt.From a physical property viewpoint,the TB composite-modified asphalt sample with 5% styrene-butadiene-styrene(SBS)+1% aromatics+0.1% sulfur exhibits high-comprehensive,high-and low-temperature properties.More-over,its crosslinked mesh structure comprises black rubber particles uniformly interwoven in the middle,which further enhances the performance of the asphalt and results in an excellent performance formulation.In addition,the sample with 5%SBS content has a higher G*value and smaller δ value than that with 3%SBS content,indicating that its high-temperature resistance is improved.The effect of adding 3%SBS content on the viscoelastic ratio is,to some extent,less than that caused by 20% rubber powder.
基金financially supported by Ministry of Science and Higher Education of the Russian Federation.
文摘A new principle for producing fire-resistant polymer materials with increased deformation properties using a flame retardant not as a heterogeneous additive,but as a thermoplastic flame retardant in a hybrid polymer mixture with a polyhydrocarbon is considered.Hybrid polymer blends of low-molecular ammonium polyphosphate(APP)with an ethylene-vinyl acetate copolymer(EVA)with an APP content of 80 wt%with enhanced deformation properties were obtained by extrusion mixing at various temperatures in the range from 200°C to 250°C.A chemical scheme for the transformations of the components during the formation of the composite is proposed.X-ray diffraction analysis showed the formation of new crystalline structures of APP.The phase structure of the systems corresponding to the model of a dispersed-filled composite in which EVA plays the role of a matrix,determining the deformation of the mixture,and the filler is ammonium polyphosphate,was studied by scanning electron microscopy(SEM).The method of FTIR microscopy showed chemical interactions between EVA and APP with the formation of amide groups.The conditions for obtaining compositions characterized by heat resistance of 210°C,oxygen index of 55 and ultimate elongation at drawing of 213%were established.
基金financially supported by the National Natural Science Foundation of China(Nos.52373070,52273071 and U25A20255)the Special Support Plan for High-Level Talents in Zhejiang Province(No.2022R51008)the HZNU scientific research and innovation team project(No.TD2025004).
文摘Rubber-toughened thermoplastic materials have become ubiquitous in modern society owing to their lightweight nature and desirable combination of advantageous performances.Despite the ever-increasing demand,the development of polymer alloys that are lightweight,high-strength,and high-toughness remains an ongoing challenge.Inspired by the unique“salami”microstructure from commercial acrylonitrile butadiene styrene copolymer(ABS)and high-impact polystyrene(HIPS),a facile approach was developed to overcome the trade-off between enhancing the toughness and rigidity of fully polymer-based alloys by virtue of elastomeric salami particles.This strategy entails pre-grafting rigid poly(lactic acid)(PLLA)chains with glycidyl methacrylate-grafted octene ethylene copolymer(POE-g-GMA)using complementary reactive groups.It can be envisaged that the PLLA grafts featuring strong incompatibility with polypropylene(PP)remain fixed in elastomer phase upon the subsequent melt compounding,facilitating the in situ formation of“hard core(PLLA)-soft shell(polyolefin elastomer,POE)”particles in polypropylene(PP)matrix.The all-polymer alloys containing elastomeric salami particles demonstrated unprecedented performance combinations,including upper notched impact strengths(56.8 kJ/m2),even higher tensile strength(36.8 MPa),and Young’s modulus(0.93 GPa)than that of the PP matrix.Furthermore,these materials are lightweight without the incorporation of reinforcing nano-fillers,which is competitive with industrial engineering plastics.It is highly anticipated that this universal and highly efficient protocol will be appropriate for arbitrary rubber toughened/reinforced systems,offering a paradigm in the design of advanced all-polymer alloys.
基金supported by the National Natural Science Foundation of China[grant numbers 12071329,12471246].
文摘In mixture experiments,the observed response is determined by the relative proportions of the components,consequently rendering the experimental region a simplex.This paper focuses primarily on the optimal designs of mixture experiments that involve process variables.Prior research has extensively delved into optimal orthogonal block designs for some classic mixture models with process variables.Based on the framework of general blending models,this paper proposes a class of symmetric linear mixture models,which can be regarded as a generalization of many existing ones.Under the orthogonal blocking conditions,orthogonal block designs are devised through Latin squares in the presence of process variables.TheD-,A-,and E-optimality criteria are utilized to obtain optimal designs at the boundary of the simplex in the case of 3 components.As the values of the exponents change,numerically derived optimal design points are presented to illustrate the pattern of their variations,and to verify the consistency of the results with previous research on some specific symmetric general blending models.
基金financially supported by the National Natural Science Foundation of China(Nos.22341304,22303100 and 12205270)the National Key R&D Program of China(Nos.2023YFA1008800 and 2020YFA0713601)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDC0180303)。
文摘The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behavior of dispersed long chains.Using molecular dynamics simulations based on the Kremer-Grest model,we systematically explore the N_(S)-dependence of static conformations,equilibrium dynamics,and nonlinear shear responses in unentangled long-chain/short-chain polymer blends.Our results demonstrate a decoupling between the static and dynamic sensitivity to N_(S):while the static chain size,R_g,follows Flory theory with slight swelling at small N_(S) due to incomplete excluded volume screening,the diffusion coefficient,D,and the relaxation time,τ_(0),exhibit a strong,non-monotonic N_(S)-dependence,transitioning from monomeric friction dominance at small N_(S) to collective segmental rearrangement at large N_(S).Additionally,we observe partial decoupling between the viscous and normal stress responses:while the zero-shear viscosity,η,is strongly N_(S)-dependent,the first and second normal stress coefficients,Ψ_(1) and Ψ_(2),collapse onto universal curves when scaled by the dimensionless shear rate,γτ_(0),suggesting a common mechanism of orientation and stretching.Under shear,long chains compress in the vorticity direction λ_(z)~Wi^(-0.2),which reduces collision frequency and contributes to shear thinning,while the scaling of weaker orientation resistance m_(G)~Wi^(0.35)reflects hydrodynamic screening by the short-chain matrix.These findings highlight the limitations of single-chain models and emphasize the necessity of considering N_(S)-dependent matrix dynamics and flow-induced structural changes in understanding the rheology of unentangled polymer blends.
基金supported by the National Natural Science Foundation of China(No.52173017)the Project of Introducing Urgently Needed and Scarce Talents in Key Supported Regions of Shandong Province in 2024.
文摘High-entropy polymer blends composed of polypropylene(PP),polystyrene(PS),polyamide 6(PA6),poly(lactic acid)(PLA),and styrene-ethylene-butylene-styrene(SEBS)were successfully fabricated using maleic anhydride-grafted SEBS(SEBS-g-MAH)as a compatibilizer.Dynamic mechanical analysis(DMA),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),and mechanical testing demonstrated that SEBS-g-MAH significantly enhanced the compatibility between the polar(PA6,PLA)and nonpolar(PP,PS,SEBS)components.The compatibilizer effectively refined the microstructure,substantially reduced the domain sizes,and blurred the phase boundaries,indicating enhanced interfacial interactions among all the components.The optimal compatibilizer content(15 wt%)notably increased tensile ductility(elongation at break from 5.0%to 23.7%)while maintaining balanced crystallization behavior,despite slightly decreasing modulus.This work not only demonstrates the broad applicability of high-entropy polymer blends as a sustainable strategy for converting complex,unsorted plastic waste into high-performance value-added materials that significantly contribute to plastic upcycling efforts,but also highlights intriguing physical phenomena emerging from such complex polymer systems.
基金supported by the 2024“Special Research Project on the Application of Artificial Intelligence in Empowering Teaching and Education”of Zhejiang Province Association of Higher Education(KT2024165).
文摘While artificial intelligence(AI)shows promise in education,its real-world effectiveness in specific settings like blended English as a Foreign Language(EFL)learning needs closer examination.This study investigated the impact of a blended teaching model incorporating AI tools on the Superstar Learning Platform for Chinese university EFL students.Using a mixed-methods approach,60 first-year students were randomized into an experimental group(using the AI-enhanced model)and a control group(traditional instruction)for 16 weeks.Data included test scores,learning behaviors(duration,task completion),satisfaction surveys,and interviews.Results showed the experimental group significantly outperformed the control group on post-tests and achieved larger learning gains.These students also demonstrated greater engagement through longer study times and higher task completion rates,and reported significantly higher satisfaction.Interviews confirmed these findings,with students attributing benefits to the model’s personalized guidance,structured content presentation(knowledge graphs),immediate responses,flexibility,and varied interaction methods.However,limitations were noted,including areas where the platform’s AI could be improved(e.g.,for assessing speaking/translation)and ongoing challenges with student self-discipline.The study concludes that this AI-enhanced blended model significantly improved student performance,engagement,and satisfaction in this EFL context.The findings offer practical insights for educators and platform developers,suggesting AI integration holds significant potential while highlighting areas for refinement.
基金sponsored by the National Natural Science Foundation of China(52178420,52408476)Special subsidy from Heilongjiang Provincial People's Government(HITTY-20190028)+1 种基金Postdoctoral Fellowship Program of CPSF(GZC20242207)the Fundamental Research Funds for the Central Universities(HIT.DZJJ.2023086).
文摘Current mix design practices typically assume total blending and use the white curve of reclaimed asphalt pavement(RAP)to determine the gradation and optimum asphalt content(OAC)of recycled hot mix asphalt(HMA),often overlooking the effects of RAP agglomeration and partial blending.This oversight can result in unsatisfactory performance,particularly when higher RAP content is used.Therefore,this paper reviews and discusses strategies for adjusting the mix design of recycled HMA to enhance its in-service performance.The discussion begins with RAP particle agglomeration,a significant phenomenon that significantly impacts the aggregate gradation of recycled HMA.Subsequently,detection methods to clarify the blending between virgin and RAP binders are described.Partial blending between RAP and virgin binders is common,and various indexes have been proposed to quantify the blending degree.Finally,the adjusted mix design method of recycled HMA is presented,emphasizing gradation optimization and corrected OAC.Gradation optimization should account for RAP agglomeration,while the corrected OAC should consider particle blending.Recycled HMA using the adjusted mix design exhibits improved crack resistance and fatigue life without substantially impairing rutting performance.This review aims to help both academics and highway agencies maximize the utilization of RAP materials within sustainable pavement frameworks.
基金supported by the USDA-ARS Research Project(#6054–44000-080-00D)。
文摘Background Small-scale research or individual seed cotton samples from breeders and geneticists are ginned using laboratory saws or roller gins.The objective of this study was to examine the effects of two different laboratory saw ginning(SG)rates and subsequent mechanical blending on fiber high volume instrument(HVI)and advanced fiber information system(AFIS)quality measurement.Seed cottons from diverse upland cotton cultivars,years,and locations were evaluated.Results As the SG rate was increased,HVI results for uniformity index(UI),short fiber index(SFI),and two non-lint parameters(area%,particle count),as well as AFIS results for some properties,were impacted,with significant effects on HVI UI and AFIS short fiber content(SFC).Apparent fiber blending impacts were observed for HVI UI,strength(STR),reflectance(Rd),SFI,and two trashes as well as for all AFIS parameters,with significant effects on HVI Rd and two trashes and all AFIS parameters except the length and maturity measurements.A combination of ginning and blending processes indicated statistically significant interactions for HVI STR,Rd,SFI,and two trashes,and also for AFIS neps,L(w)CV,UQL(w),L(n)CV,SFC(n),L5%(n),immature fiber content(IFC),fineness,total count,dust count,particle count,and visible foreign matter(VFM).Further analysis implied a few impacts of ginning and blending on correlations between HVI and relevant AFIS qualities.Conclusion Despite the observation,the laboratory saw gin and blending methods should continue to be a practical tool to study the differences when all samples are processed identically.
基金supported by Innovation Research Project for the training of high-level scientific and technological talents(Technical expert talents)of the Armed Police Force ZZKY20222415“13th Five-Year Plan”military key colleges and key disciplines-Equipment Engineering(Power)-17.
文摘Fuel injection properties,including the injection rate(temporal aspects)and spray behavior(spatial aspects),play a crucial role in the combustion efficiency and emissions of diesel engines.This study investigates the effects of different ethanol-biodiesel-diesel(EBD)blends on the injection performance in diesel engines.Experimental tests are conducted to examine key injection parameters,such as spray penetration distance,spray cone angle,and droplet size,alongside an analysis of coupling leakage.The main findings are as follows:(1)The injection behavior of ethanol and diesel differs significantly.The addition of ethanol reduces the density,viscosity,and modulus of elasticity of the fuel mixture.While the injection advance angle,penetration distance,and Sauter mean diameter show minimal changes,the spray cone angle and coupling leakage increase notably.These alterations may disrupt the“fuelair-chamber”matching characteristics of the original engine,potentially affecting performance.(2)In contrast,the injection performance of biodiesel ismore similar to that of diesel.As biodiesel content increases,the density,viscosity,and modulus of elasticity of the blended fuel also grow.Though changes in injection timing,penetration distance,and spray cone angle remain minimal,the Sauter mean diameter experiences a slight increase.The“air-fuel chamber”compatibility of the original engine is largely unaffected,though fuel atomization slightly deteriorates.Blending up to 20%biodiesel and 30%ethanol with diesel effectively compensates for the shortcomings of using single fuels,maintaining favorable injection dynamics while enhancing lubrication and sealing performance of engine components.
基金“Research on Mental Health Education of Poor College Students-Based on the Perspective of‘New Campus’”Philosophy and Social Science Research Project of Universities in Jiangsu Province(2019SJB912)“Research on Mental Health Education of Poor College Students-Based on the Perspective of‘New Campus’”Special Topic of Ideological and Political Education for College Students in 2018(JDXGXB201801)“Research on College English Teaching Strategies from the Perspective of the Theory of Multiple Intelligences”Jiangsu Provincial University Philosophy and Social Sciences Research Project(2023SJYB2216)。
文摘College students’safety education is an important part of the fundamental task of fostering virtue through education in colleges and universities.A questionnaire survey at J University shows that the popularization degree and teaching satisfaction of college students’safety education are relatively high,but the teaching content and teaching forms still need improvement.With the rapid development of artificial intelligence technology and considering the char-acteristics of college students’online learning in the new era,carrying out the SPOC+PBL blended teaching reform not only helps to enhance the effectiveness of theoretical and practical teaching but also contributes to optimizing the teach-ing evaluation and feedback mechanism and strengthening students’problem-solving abilities.Therefore,we should adhere to the goal orientation,meticulously design the teaching plan,highlight the student-centered approach,focus on integrating teaching resources,strengthen process management,promptly provide feedback and guidance,empower with data,and continuously improve teaching evaluation.Thus,a student-centered SPOC+PBL blended teaching sys-tem can be constructed to empower the transformation and innovation of talent cultivation in higher education.
基金supported by the Industry-Academia Collaboration Project of the Ministry of Education:A Study on the Blended Teaching Model of Chinese-English Translation in the Era of Artificial Intelligence(Project Fund No.231001363084506).
文摘This article explores in-class practice of blended teaching of Chinese-English(C-E)translation for English as a Foreign Language(EFL)majors in the era of artificial intelligence(AI).It examines the opportunities and challenges AI presents in enhancing translation education,particularly in fostering student engagement,improving teaching efficiency,and promoting self-motivated learning.Case study suggests that AI can enhance the flexibility of teaching and motivate students,yet challenges such as over-reliance on AI and diminished critical thinking need to be addressed.While acknowledging the indispensability of human translators,the article concludes that effective blended teaching requires purposeful curriculum design,proper integration of AI,and a collaborative effort of teachers and students to maximize the potential of AI while ensuring high-quality,independent learning outcomes.
基金supported by the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology (No. 2022TS10)the Taishan Industrial Experts Programthe Natural Science Foundation of Shandong Province of China (No. ZR2023ME212).
文摘Wet flue gas desulfurization(WFGD)could effectively reduce sulfur dioxide emission.However,magnesium sulfite(MgSO_(3)),a by-product of desulfurization,was easy to result in secondary pollution.In this study,the solid catalyst Co-Bent(bentonite supported cobalt)was prepared by blending method for MgSO_(3) oxidation with bentonite as the carrier and cobalt as the active component.At the calcination temperature of 550℃ and the Co loading level of 3 wt.%,the catalyst showed excellent catalytic performance for the oxidation of high concentration MgSO_(3) slurry,and the oxidation rate of MgSO_(3) was 0.13 mol/(L·h).The research indicated that the active component was uniformly distributed within porous structure of the catalyst as Co_(3)O_(4),which facilitated the oxidation of SO_(3)^(2-) catalyzed by Co_(3)O_(4).Kinetic researches indicated the oxidation rate of MgSO_(3) was influenced by the catalyst dosage,the reaction temperature,the solution pH,the airflow rate,and the SO_(3)^(2-) concentration.Additionally,after recycling experiments,the regenerated catalyst retained its high catalytic performance for the MgSO_(3) oxidation.The reaction mechanism for the catalytic oxidation of MgSO_(3) by Co-Bent catalyst was also proposed.The generation of active free radicals(OH·,SO_(4)^(-)·,SO_(3)^(-)·,SO_(5)^(-)·)accelerated the MgSO_(3) oxidation.These results provide theoretical support for the treatment of MgSO_(3) and the development of durable catalyst.
文摘The current work includes a numerical investigation of the effect of biodiesel blends with different aluminum oxide nanoparticle concentrations on the combustion process in the cylinder of a diesel engine.IC Engine Fluent,a specialist computational tool in the ANSYS software,was used to simulate internal combustion engine dynamics and combustion processes.Numerical analysis was carried out using biodiesel blends with three Al_(2)O_(3) nanoparticles in 50,100,and 150 ppm concentrations.The tested samples are called D100,B20,B20A50,B20A100,and B20A150 accordingly.The modeling runs were carried out at various engine loads of 0,100,and 200 Nm at a rated speed of 1800 rpm.The combustion characteristics are improved due to the catalytic effect and higher surface area of nano additives.The results showed the improvements in the combustion process as the result of nanoparticle addition,which led to the higher peak cylinder pressure.The increases in the peak cylinder pressures for B20A50,B20A100,and B20A150 about B20 were 3%,5%,and 8%,respectively,at load 200 Nm.The simulation found that the maximum temperature for biodiesel blends diesel was higher than pure diesel;this was due to higher hydrocarbon values of B20.Also,nano-additives caused a decrease in temperatures in the combustion of biofuels.
基金Universiti Teknologi PETRONAS for the financial support provided through the YUTP-FRG grant(015LC0-631).
文摘Polymeric materials have emerged as a promising alternative to electrolytic solutions in energy storage applications.However,high crystallinity and poor ionic conductivity are the main barriers restricting their daily application.In this study,we propose a polymer electrolyte system consisting of methylcellulose-polyvinyl alcohol(MC-PVA)blend as host material and lithium trifluoromethanesulfonate(LiCF_(3)SO_(3))as dopant,which was prepared using the solution-casting method.The electrochemical impedance spectroscopy(EIS)analysis revealed a maximum conductivity of 5.42×10^(−6) S cm^(−1) with 40 wt.%LiCF_(3)SO_(3).The key findings demonstrated that the variation in the dielectric loss(εi)and dielectric constant(εr)was significantly correlated with the variation in ionic conductivity.Fourier-transform infrared spectroscopy(FTIR)analysis was done to analyse the salt-polymer interaction by observing the shifting of selected bands.By deconvoluting FTIR spectra in the wavenumber range of 970–1100 cm^(−1),transport properties of electrolytes were investigated and found to be improved when the salt concentration was increased to 40 wt.%.Results from the X-ray diffraction(XRD)study suggested that the higher salt concentration promoted the formation of an amorphous phase,which is favourable for ionic conduction.Field emission scanning electron microscopy(FESEM)study demonstrated that the addition of salt altered the surface morphology of MC-PVA.
基金supported by the Anesthesiology Department Teaching Development Foundation of Naval Medical University(2024MZQN03)the Teaching Research and Reform Project of Naval Medical University(JYG2024B24).
文摘Artificial Intelligence is profoundly transforming innovation and development in healthcare and education.In this study,we developed an AI-empowered blended learning model for disaster medicine.Leveraging the Rain Classroom platform,we established a comprehensive intelligent teaching support system covering the entire learning cycle-pre-class,in-class,and post-class.Through AI-driven enhancements,the model enables intelligent resource allocation,personalized learning paths,and high-fidelity simulation of practical training scenarios.Moreover,it addresses key challenges in traditional disaster medicine education,including fragmented knowledge delivery,insufficient practical training environments,and limited evaluation methods.Ultimately,the model enhances both the efficiency and effectiveness of disaster medicine education.
