Chemical looping methane steam reforming(CL-MSR)has garnered significant attention owing to its ability to sequentially produce syngas with high selectivity and high-purity hydrogen through redox cycling.To overcome t...Chemical looping methane steam reforming(CL-MSR)has garnered significant attention owing to its ability to sequentially produce syngas with high selectivity and high-purity hydrogen through redox cycling.To overcome the limitations of single ironbased oxygen carriers,including poor cycling stability,low reactivity and susceptibility to sintering,this study employed a dipcoating method to modify Fe_(2)O_(3)/Al_(2)O_(3)oxygen carriers by incorporating three distinct metal additives:Cu,La and Ce.The composite oxygen carriers were systematically characterized and evaluated under redox conditions to investigate the structure-activity relationships between the physicochemical properties,reactivity,and hydrogen production performance.Results revealed that the spinel-phase CuFe_(2)O_(4)exhibited higher reactivity than the perovskite-phase LaFeO_(3)and CeO_(2),promoting the deeper reduction of Fe_(2)O_(3).Fe58Cu2Al exhibited an oxygen storage capacity as high as 6.5 mmol/g.During the CH4 reaction stage,Fe58Cu2Al achieved the highest oxygen loss of 12.1 g/100 g oxygen carrier,accompanied by a syngas yield of 5.15 mmol/g-1.33 times and 1.59 times greater than that of Fe60Al.In the hydrogen production stage,the 2%Cu-modified oxygen carrier demonstrated optimal performance,yielding 5.13 mmol/g of hydrogen,which was 1.51 times that of the pristine sample.Even after ten cycles,the H_(2)yield remained at 3.61 mmol/g,surpassing the single-cycle output of the pristine sample and the H2 purity consistently exceeded 98%.展开更多
Optically pure chiral chemicals are important building blocks with widespread applications across mul-tiple scientific and industrial do-mains such as in pharmaceuticals,agrochemicals,and food,especially acting as pre...Optically pure chiral chemicals are important building blocks with widespread applications across mul-tiple scientific and industrial do-mains such as in pharmaceuticals,agrochemicals,and food,especially acting as precursors to synthesize biodegradable polymers.As an al-ternative to fossil resources,renew-able lignocellulosic biomass has been used to access chiral chemicals,due to the versatile inherent stere-ostructures and multiple functional groups,such as hydroxyl,carbonyl,and phenyl ether groups.Typically,as the two main units of(hemi)cel-lulose components in lignocellulosic biomass,D-xylose and D-glucose bear multiple chiral centers(e.g.,2R-3S-4R for D-xylose and 2R-3S-4R-5R for D-glucose).Lignin bearsβ-O-4 linkages,exhibiting(R,S/S,R)or(R,R/S,S)stereocenters at the side-chainαandβcarbon atoms.The valorization of biomass into optical-ly pure chiral chemicals is vital for developing a more sustainable future.This review discuss-es the production of typical chiral chemicals derived from biomass through chemocatalysis,including lactones(e.g.,R/S-valerolactone),carboxylic acids(e.g.,D/L-glyceric acid,D/L-lactic acid),polyols(e.g.,tetrose),furans,oligosaccharides,and others.Two strategies are generally employed.One approach involves first producing achiral platform chemicals from biomass,followed by the introduction of asymmetric catalysts to reconstruct stereocenters.The second relates to selectively preserving one or more inherent stereocenters in the natural biomass structure during complex cascade reactions in which biomass feedstock acts as a“chi-ral pool",thus eliminating the establishment of stereocenter.The feedstock,methods em-ployed,and enantioselectivity and applications of the target chiral chemicals are discussed.Despite these advances,the synthesis of optically pure chemicals from biomass is still in its in-fancy.The coming decade presents both extraordinary challenges and opportunities in biomass-derived chiral chemistry.Future research should be focused on:(1)integrating well-established asymmetric catalysis techniques and methods with biomass’s inherent chiral pools,presenting an unprecedented opportunity to expand the chemical space of sustainable chiral compounds;(2)mastering polyfunctional complexity of chiral chemicals through holis-tic utilization of biomass’multichiral centers;(3)unlocking lignin’s stereochemical treasury that represents the next frontier in biomass valorization.展开更多
The dried fruit of Forsythia suspensa(Oleaceae),also known as Forsythia,is a traditional Chinese medicinal herb known for its heat-clearing and detoxifying properties.It is used to disperse nodules,reduce swelling,rem...The dried fruit of Forsythia suspensa(Oleaceae),also known as Forsythia,is a traditional Chinese medicinal herb known for its heat-clearing and detoxifying properties.It is used to disperse nodules,reduce swelling,remove toxins,clear heat,and alleviate wind-heat syndromes.It also has hepatoprotective,anti-inflammatory,antiviral,antibacterial,anticancer,antioxidant,antiaging,and anti-obesity effects,as well as potential therapeutic effects on Alzheimer’s disease and diabetic nephropathy.It is used to treat scrofula,mastitis,wind-heat common cold,and other ailments.The review summarizes the chemical constituents and pharmacological effects of F.suspensa,aiming to provide a scientific foundation for its future development,research,and clinical utilization.展开更多
Panax notoginseng(P.notoginseng),a valuable traditional Chinese medicine,is the dried root of plants in Acanthopanax gracilistylus family,with the effect of dispersing blood stasis,eliminating swelling and relieving p...Panax notoginseng(P.notoginseng),a valuable traditional Chinese medicine,is the dried root of plants in Acanthopanax gracilistylus family,with the effect of dispersing blood stasis,eliminating swelling and relieving pain.With the development of modern medicine,the active ingredients and mechanisms of P.notoginseng have been gradually revealed.The present paper systematically reviews the chemical composition and biological activities of P.nologinseng,to provide a scientific basis and reference for detailed research on P.nologinseng.展开更多
The development of intrinsically conductive piezoresistive sensors with high strain tolerance has garnered significant interest.While elastomeric polymers exhibit excellent strain capabilities,their utility in sensing...The development of intrinsically conductive piezoresistive sensors with high strain tolerance has garnered significant interest.While elastomeric polymers exhibit excellent strain capabilities,their utility in sensing applications has been limited by inherent challenges such as high electrical resistivity,poor aging resistance,and interfacial incompatibility.To address these limitations,hydroxyl-terminated polybutadiene(HTPB)-based polyurethane was chemically modified with acetylferrocene-polyaniline conductive moieties to enhance charge transport properties.Remarkably,this covalent functionalization endowed the resulting ferrocene-polyaniline hybrid polyurethane(FPHP)with a conductivity of2.33 n A at 1 V bias while preserving piezoresistive functionality.The FPHP demonstrated exceptional mechanical-electrical performance,achieving 254% elongation at break with strain-dependent gauge factors of 7.28(0%-12.5% strain,R^(2)=0.9504)and 19.66(12.5%-35.0% strain,R^(2)=0.9929).Further characterization revealed a rapid 0.60 s response time and stability over 3500 strain-release cycles at compression strain,underscoring its durability under repetitive loading.The FPHP sensor was capable of monitoring various human movements and recognizing writing signals.These advances establish a materials design paradigm for fabricating flexible sensors that synergistically integrate high deformability,tunable sensitivity,and robust operational stability,positioning FPHP as a promising candidate for next-generation wearable electronics and soft robotics.展开更多
Solar-driven H_(2) production coupled with selective organic transformation represents a promising strategy for co-generation of green hydrogen and high-value chemicals,yet its feasibility relies critically on effecti...Solar-driven H_(2) production coupled with selective organic transformation represents a promising strategy for co-generation of green hydrogen and high-value chemicals,yet its feasibility relies critically on effective bifunctional photocatalysts.Herein,we report the synthesis of ultrafine Cd_(x)Zn_(1-x)S nanocrystals derived from a zeolitic imidazolate framework(ZIF),featuring high surface area,shortened charge diffusion path,and enhanced H_(2) evolution activity.Anchoring amorphous Pt sub-nanoclusters onto these nanocrystals created a bifunctional catalyst(Pt-Cd_(x)Zn_(1-x)S)for efficient lactic acid photoreforming,enabling coproduction of H_(2) with switchable selectivity toward pyruvic acid(PA)or 2,3-dihydroxy-2,3-dimethylsuccinic acid(DTA).The optimized 0.5Pt-Cd_(0.3)Zn_(0.7)S catalyst achieved an exceptional H_(2) production rate of 270.6 mmol h^(-1) g^(-1),73.1%PA selectivity,and 62.8% apparent quantum efficiency at 400 nm.Mechanistic studies revealed that lactic acid undergoes C-H cleavage to form carbon-centered radicals.Pt sub-nanoclusters served as electron sinks to facilitate O-H dissociation and PA formation,whereas pristine Cd_(0.3)Zn_(0.6)7S promoted direct C-C coupling of radicals to predominantly yield DTA.This work offers critical insights for designing advanced bifunctional photocatalysts to integrate solar hydrogen and value-added chemical synthesis.展开更多
The aerosolization and diffusion of radioactive materials caused by chemical explosions represent a typical nuclear accident scenario that poses severe radioactive hazards to human health and the environment.This stud...The aerosolization and diffusion of radioactive materials caused by chemical explosions represent a typical nuclear accident scenario that poses severe radioactive hazards to human health and the environment.This study examines the diffusion of plutonium aerosol generated by a chemical explosion within a typical representative underground facility.The state of explosion products following a single-point detonation of explosives was simulated.Subsequently,a numerical simulation of plutonium aerosol diffusion using the discrete phase model(DPM)was conducted based on the outcomes of the chemical explosion simulation.The simulation results indicate that plutonium aerosols diffuse throughout underground facilities after a chemical explosion;small particle size aerosols primarily accumulate in the upper part of the room after the accident;the concentrations of plutonium aerosol in the room and tunnel are significantly higher than those in the other areas;and the temporal variations in aerosol concentration in each area were quantified.Based on the particle concentration distribution and the effective dose computation approach,the study computes the internal irradiation dose received by personnel in seven areas over various time periods post-accident.Recommendations for emergency decision-making were derived from these calculations.These findings provide important theoretical insight and practical engineering application value for understanding the diffusion of radioactive aerosol in confined spaces following chemical explosions and for evaluating personnel radiation dose.展开更多
Conventional error cancellation approaches separate molecules into smaller fragments and sum the errors of all fragments to counteract the overall computational error of the parent molecules.However,these approaches m...Conventional error cancellation approaches separate molecules into smaller fragments and sum the errors of all fragments to counteract the overall computational error of the parent molecules.However,these approaches may be ineffective for systems with strong localized chemical effects,as fragmenting specific substructures into simpler chemical bonds can introduce additional errors instead of mitigating them.To address this issue,we propose the Substructure-Preserved Connection-Based Hierarchy(SCBH),a method that automatically identifies and freezes substructures with significant local chemical effects prior to molecular fragmentation.The SCBH is validated by the gas-phase enthalpy of formation calculation of CHNO molecules.Therein,based on the atomization scheme,the reference and test values are derived at the levels of Gaussian-4(G4)and M062X/6-31+G(2df,p),respectively.Compared to commonly used approaches,SCBH reduces the average computational error by half and requires only15%of the computational cost of G4 to achieve comparable accuracy.Since different types of local effect structures have differentiated influences on gas-phase enthalpy of formation,substituents with strong electronic effects should be retained preferentially.SCBH can be readily extended to diverse classes of organic compounds.Its workflow and source code allow flexible customization of molecular moieties,including azide,carboxyl,trinitromethyl,phenyl,and others.This strategy facilitates accurate,rapid,and automated computations and corrections,making it well-suited for high-throughput molecular screening and dataset construction for gas-phase enthalpy of formation.展开更多
Polymer-modified bentonite(PMB)is much more effective at containing chemically aggressive liquids than conventional bentonite.The PMB manufacturing process typically utilizes natural,high-quality sodium bentonite(NaB)...Polymer-modified bentonite(PMB)is much more effective at containing chemically aggressive liquids than conventional bentonite.The PMB manufacturing process typically utilizes natural,high-quality sodium bentonite(NaB)owing to its excellent hydrophilicity and swelling capacity.However,calcium bentonite(CaB),which is much more abundant worldwide,is rarely used for containment applications owing to its poor hydrophilicity.This study proposed a polymerization method that transforms sodium-activated calcium bentonite(NCB)into PMB to achieve low hydraulic conductivity(k)to aggressive liquids.The mechanism for its low k was revealed through characterization techniques and analyses(e.g.X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM),and Brunauer-Emmett-Teller(BET)).The results showed that the PMB had a small amount of polymer elution(indicating better interface stability)and thus exhibited excellent barrier properties under chemically aggressive conditions,with the k of<10^(-11) m/s for 0.6 mol/L NaCl solution,which is four orders of magnitude lower than that of the NCB(k=3×10^(-7) m/s).Various microscopic analyses indicated that the selected monomers were successfully polymerized,and intercalated into and grafted onto the montmorillonite layers of bentonite.The formed polymer network increased the swelling capability of PMB granules,decreased the pore size,and created narrow and tortuous flow pathways leading to a very low k to aggressive liquids.展开更多
Photocatalytic C-N coupling reactions using waste plastic-and biomass-based feedstocks with nitrogen-containing species have emerged as a promising route for the synthesis of high-value chemicals such as amides and am...Photocatalytic C-N coupling reactions using waste plastic-and biomass-based feedstocks with nitrogen-containing species have emerged as a promising route for the synthesis of high-value chemicals such as amides and amino acids.However,the complexity of multistep reaction routes and the presence of competing side reactions pose significant challenges,often leading to low yield and poor selectivity of target products.To substantially enhance the efficiency and selectivity of C-N coupling reactions,it is imperative to gain a thorough understanding of the underlying reaction mechanisms and to develop highly active photocatalysts.Such catalysts must be capable of effectively activating diverse substrates while maintaining an appropriate balance between the adsorption and desorption of carbon-and nitrogen-containing intermediates or radical species.In this review,we systematically summarize recent advances in photocatalytic C-N coupling for the production of amides and amino acids from waste plastic-and biomass-based feedstocks,with particular focus on catalyst selection,process design,control of reaction intermediates,and catalytic mechanisms.Furthermore,the technoeconomic feasibility and environmental impact of these C-N coupling reactions are evaluated using technoeconomic analysis and life-cycle assessment.Lastly,the current challenges and future prospects in this field are also discussed.This review aims to provide valuable insights for the development of high-efficiency photocatalytic C-N coupling reactions and to deepen the understanding of their catalytic mechanisms.展开更多
Space exploration and manufacturing are of critical importance for scientific advancement,technological innovation,national security,and the acquisition of extraterrestrial resources.In view of this,chemical and biolo...Space exploration and manufacturing are of critical importance for scientific advancement,technological innovation,national security,and the acquisition of extraterrestrial resources.In view of this,chemical and biological nano-/micro-/meso-scale manufacturing provide complementary approaches to overcome key space exploration challenges by enabling the in-situ production of essential life-support materials,propellants,and other resources.This review examines the origin and historical evolution of space manufacturing and the latest advances across different environments—from orbital space stations and the lunar surface to Mars and asteroids.It is structured to present the current state of research,outline key manufacturing strategies and technologies,assess the technical and environmental challenges,and discuss emerging trends and future directions.Besides,the potential applications of emerging technologies such as synthetic biology and artificial intelligence in overcoming the limitations of microgravity,limited resources,and extreme conditions are discussed.Ultimately,this integrative review could serve to guide future development,from advancing space science and disruptive manufacturing to enabling interdisciplinary and application-level innovations.展开更多
Molecular dynamics simulations were carried out to study the effect of chemical short-range order(CSRO)on the primary radiation damage in TiVTaNb high-entropy alloys(HEAs).We have performed displacement cascade simula...Molecular dynamics simulations were carried out to study the effect of chemical short-range order(CSRO)on the primary radiation damage in TiVTaNb high-entropy alloys(HEAs).We have performed displacement cascade simulations to explore the CSRO effect on the generation and evolution behaviors of irradiation defects.The results demonstrate that CSRO can suppress the formation of Frenkel pairs in TiVTaNb HEAs,with the suppression effect becoming more pronounced as the degree of CSRO increases.CSRO can change the types of interstitial defects generated during cascade collisions.Specifically,as the degree of CSRO increases,the proportion of Ti-related interstitials shows a marked enhancement,primarily evidenced by a significant rise in Ti–Ti dumbbells accompanied by a corresponding decrease in Ti–V dumbbells.CSRO exhibits negligible influence on defect clustering and the nucleation and evolution of dislocation loops.Regardless of CSRO conditions,TiVTaNb HEAs preserve exceptional radiation tolerance throughout the cascade damage process,suggesting that the intrinsic properties of this multi-principal element system dominate its radiation response.These findings provide fundamental insights into the CSRO effect on defect formation and evolution behaviors in HEAs,which may provide new design strategies for high-entropy alloys.展开更多
Pseudomonas aeruginosa is an opportunistic pathogen responsible for severe nosocomial infections.This multidrug-resistant bacterium can cause pneumonia and cystic fibrosis,both of which are associated with high morbid...Pseudomonas aeruginosa is an opportunistic pathogen responsible for severe nosocomial infections.This multidrug-resistant bacterium can cause pneumonia and cystic fibrosis,both of which are associated with high morbidity and mortality rates.The lipopolysaccharide of P.aeruginosa serves as an attractive target for the development of effective glycoconjugate vaccines.In this article,we report the first chemical synthesis of the highly challenging tetrasaccharide repeating unit of the P.aeruginosa serotype O3 O-antigen using a two-directional[1+(2+1)]glycosylation strategy.The synthesis is particularly challenging due to the poor nucleophilicity of the axial C4 hydroxyl group of l-galactose and the steric hindrance imposed by the 3S-hydroxybutyryl(Hb)chain.Furthermore,the presence of an acetyl group at the ortho position relative to the glycosylation site on l-galactose can lead to undesirable acetyl migration.Additionally,it is noteworthy that the selective removal of a 2-naphthylmethyl ether(Nap)during the late stages of synthesis,particularly in the presence of multiple benzyl groups,can be somewhat challenging to predict.Through the careful selection of synthetic strategies,building blocks,and optimized reaction conditions,we achieved the stereoselective glycosylations,selective oxidation of primary alcohols,remarkable enhancement of acceptor activity,and efficient introduction of the 3S-Hb group.The synthetic methodology presented in this work serves as a valuable reference for the preparation of structurally related oligosaccharides.By incorporating an aminopropyl linker,the target tetrasaccharide facilitates glycan microarray preparation and in vivo immunological assessments,thereby accelerating progress toward a synthetic glycoconjugate vaccine for P.aeruginosa.展开更多
The physicochemical properties of SUS304 foil surfaces are crucial to their applications.Pulsed laser modification was applied to 30μm thick SUS304 foils to systematically investigate the influence of laser energy on...The physicochemical properties of SUS304 foil surfaces are crucial to their applications.Pulsed laser modification was applied to 30μm thick SUS304 foils to systematically investigate the influence of laser energy on surface characteristics.Through multidimensional characterization of surface morphology,three-dimensional profiles and roughness,contact angle,and chemical composition,the structure-function correlation between laser energy and the physicochemical properties of steel surface was revealed.With increasing laser energy,the surface morphology of the steel transitions from a directional rolling-marked structure to a uniform sponge-like isotropic structure,accompanied by increased peak density and an expanded interfacial area.Additionally,the chemical state on the metal surface gradually stabilizes from unstable redox reactions,forming a stable oxide layer and significantly increasing active hydroxyl groups,thereby effectively improving surface wettability.Single lap shear tests reveal an enhancement in the bonding strength of steel/carbon fiber reinforced composites joints after laser modification,which is attributed to the synergistic effects of mechanical interlocking,enhanced wettability,and chemical bonding at the interface.The demonstrated potential of laser surface treatment for modifying SUS304 ultra-thin foils provides theoretical support and technical reference for its application in fiber metal laminates.展开更多
Chemical warfare agents(CWAs)remain a persistent hazard in many parts of the world,necessitating a deeper exploration of their chemical and physical characteristics and reactions under diverse conditions.Diisopropyl m...Chemical warfare agents(CWAs)remain a persistent hazard in many parts of the world,necessitating a deeper exploration of their chemical and physical characteristics and reactions under diverse conditions.Diisopropyl methylphosphonate(DIMP),a commonly used CWA surrogate,is widely studied to enhance our understanding of CWA behavior.The prevailing thermal decomposition model for DIMP,developed approximately 25 years ago,is based on data collected in nitrogen atmospheres at temperatures ranging from 700 K to 800 K.Despite its limitations,this model continues to serve as a foundation for research across various thermal and reactive environments,including combustion studies.Our recent experiments have extended the scope of decomposition analysis by examining DIMP in both nitrogen and zero air across a lower temperature range of 175℃ to 250℃.Infrared spectroscopy results under nitrogen align well with the established model;however,we observed that catalytic effects,stemming from decomposition byproducts and interactions with stainless steel surfaces,alter the reaction kinetics.In zero air environments,we observed a novel infrared absorption band.Spectral fitting suggests this band may represent a combination of propanal and acetone,while GCMS analysis points to vinyl formate and acetone as possible constituents.Although the precise identity of these new products remains unresolved,our findings clearly indicate that the existing decomposition model cannot be reliably extended to lower temperatures or non-nitrogen environments without further revisions.展开更多
The rapid increase in traffic loads and frequencies has rendered conventional asphalt pavement inadequate to maintain its durability under tropical climates.This challenge has necessitated the exploration of new sourc...The rapid increase in traffic loads and frequencies has rendered conventional asphalt pavement inadequate to maintain its durability under tropical climates.This challenge has necessitated the exploration of new sources of modified asphalt with enhanced stiffness and superior performance at high temperatures.Natural rubber(NR)is a renewable biopolymer that has received growing interest as a modifier for asphalt binders.Cup lump rubber(CLR),a type of NR,is used to enhance asphalt properties and improve the performance of road pavements.This study evaluates the influence of wax-based surfactants(WS)on CLR-modified asphalt binder(CMB).The assessment focuses on changes in chemical characteristics,rheological behaviour,activation energy,and morphology.Four concentrations of WS(0.1%,0.15%,0.2%,and 0.25%)were incorporated into CMB.Analysis of CMB chemical changes showed that viscosity increased due to higher sulfoxide,carbonyl,and aromatic bond indices.These chemical modifications contributed to improved resistance of the binder to heat-induced deterioration.In both unaged and aged CMB samples,the incorporation of WS reduced the sulfoxide index of the binder.Rheological analysis indicated that CMB improved rutting resistance and anti-ageing performance,while WS further enhanced fatigue resistance.Activation energy analysis suggested that the combination of CMB with 0.15%WS produced the most favourable enhancement.Micrograph results showed that WS improved binder homogeneity and interconnectivity.In conclusion,the findings indicated that incorporating 0.15%WS into CMB enhanced the performance and durability of the asphalt pavement.展开更多
The chemical industry plays a critical role in supporting global economic development,yet its traditional production paradigms are associated with high resource consumption,energy demand,and environmental impact.To de...The chemical industry plays a critical role in supporting global economic development,yet its traditional production paradigms are associated with high resource consumption,energy demand,and environmental impact.To deal with the growing regulatory burden,societal demands,and environmental targets,eco-friendly processes in chemicals have become one of the major approaches to ensuring industrialization with environmental safety.This review includes an overall summary of the recent developments of green chemical processes with the focus on the basic principles,facilitating structures,and technologies that form the basis of sustainable chemical production.The most important advances in sustainable feedstocks,green catalysis,environmentally benign solvents,energy-efficient and intensified process technologies are also essential introductions,and the importance of digitalization,artificial intelligence,and life cycle-informed assessment tools in environmental performance optimization is also increasing.The review also discusses some of the barriers related to industry implementation,such as scalability,economic viability,and the necessity of having strong sustainability verification.Using chosen industrial case studies of China,South Korea,and Vietnam,various ways of integrating eco-friendly processes are demonstrated,including the adoption of renewable energy and low-carbon hydrogen,the adoption of circular plastics,and refinery energy optimization.Such examples demonstrate the significance of regional settings,system-level integration,and open environmental assessment in achieving significant sustainability results.The presented insights should guide the way future research proceeds and facilitate the shift toward the low-impact chemical manufacturing systems that are resilient.展开更多
Groundwater is a key part of the terrestrial ecosystem,but it is vulnerable to pollution in the context of chemical industry development.Treating contaminated groundwater is challenging due to its stable water quality...Groundwater is a key part of the terrestrial ecosystem,but it is vulnerable to pollution in the context of chemical industry development.Treating contaminated groundwater is challenging due to its stable water quality,hidden contamination,and complex treatment requirements.Current research focuses on advanced treatment technologies,among which the advanced oxidation process(AOPs) of peroxomonosulfate(PMS) has great potential.Although there are many reviews of PMS-based AOP,most of them focus on surface water.This review aims to explore the activation reaction of PMS to groundwater by in-situ chemical oxidation(ISCO) technology,further study the reaction mechanism,compare the treatment effect of characteristic pollutants in the groundwater of the chemical industry park,propose new activation methods and catalyst selection,and provide guidance for future groundwater treatment research.展开更多
[Objectives]To determine the optimal concentration of topping agents applied by unmanned aerial vehicles(UAVs)to effectively regulate cotton growth and improve production efficiency.[Methods]A field experiment was con...[Objectives]To determine the optimal concentration of topping agents applied by unmanned aerial vehicles(UAVs)to effectively regulate cotton growth and improve production efficiency.[Methods]A field experiment was conducted in Shihezi City,Xinjiang,employing a randomized block design.Five UAV-based chemical topping treatments were applied at dosages of 0.300,0.525,0.750,0.975,and 1.200 L/hm 2,designated as H1,H2,H3,H4,and H5,respectively.Additionally,manual topping(CK1)and tractor topping(CK2)treatments,both at a concentration of 0.750 L/hm 2,were included as control treatments.During the first 20 d following topping,parameters including primary agronomic traits of cotton(plant height,leaf age,number of fruit branches),dry matter accumulation and distribution,leaf area boll load(LAB),root-to-shoot ratio(RSR),leaf mass area(LMA),and leaf area index(LAI)were examined.At harvest,yield components,lint cotton yield,harvest index,and fiber quality were evaluated.[Results]Twenty days after topping,the concentration of the topping agent applied via UAV did not significantly affect cotton leaf age or the number of fruit branches.Additionally,no significant differences in plant height were observed among the five concentration treatments compared to CK2.However,plants treated with H1 exhibited significantly greater height compared to those treated with H5 and CK1,indicating that H1 was the least effective in controlling vegetative growth.Total dry matter accumulation(TDM),boll dry matter accumulation(BDM),LAB,and LMA all demonstrated an initial increase followed by a decrease as the spraying concentration increased.The highest TDM and reproductive organ dry matter ratio(RRDM)were observed in the H3 treatment.No significant differences were found among treatments for LMA,RSR,or LAI;however,LAB and single boll weight were greatest in the H3 treatment.Fiber quality parameters,including fiber length uniformity,micronaire(MIC),specific strength,and fiber maturity,initially increased and then decreased with increasing spraying concentration,whereas fiber elongation rate exhibited the opposite trend.The H3 treatment yielded the highest average fiber length uniformity and specific strength.[Conclusions]At optimal spraying concentrations,UAV-based application more effectively controls vegetative growth,promotes dry matter accumulation and distribution in cotton bolls,increases single boll weight,and enhances the MIC,specific strength,and fiber elongation rate of cotton fibers compared to manual and tractor spraying of topping agents.In summary,the use of UAVs for spraying chemical topping agents is recommended,with a suggested dosage range of 0.750 and 0.975 L/hm 2.展开更多
The generation of human induced pluripotent stem cell-derived motor neurons overcomes limited access to human tissues and offers an unprecedented approach to modeling motor neuron diseases such as dystonia and amyotro...The generation of human induced pluripotent stem cell-derived motor neurons overcomes limited access to human tissues and offers an unprecedented approach to modeling motor neuron diseases such as dystonia and amyotrophic lateral sclerosis.Motor neurons generated through different strategies may exhibit substantial differences in purity,maturation,characterization,and even neuronal identity,leading to variable outcomes in disease modeling and drug screening.However,very few comparative studies have been conducted to determine the similarities and differences among motor neurons prepared via different protocols.In this study,we prepared human induced pluripotent stem cell-derived motor neurons via lentiviral delivery of transcription factors and chemical induction and performed a systematic comparative analysis.We found that motor neurons generated by both approaches showed typical motor neuron morphology and robustly expressed motor neuron-specific markers,such as nuclear homeobox transcription factor 9 and choline acetyltransferase.The chemical induction protocol utilizes a combination of small molecules to induce motor neuron differentiation,offering a significantly faster maturation time of 35 days compared to 46 days with lentiviral delivery of transcription factors.Additionally,while lentiviral delivery of transcription factors are suitable for downstream biochemical analysis,chemical induction are more applicable for therapeutic approaches as they avoid the use of lentiviruses.Both approaches produce motor neurons with high purity(>95%)and yield.No significant differences were found between chemical induction and lentiviral delivery of transcription factors in terms of motor neuron markers and maturation markers.These robust methodologies offer researchers powerful tools for investigating motor neuron diseases and potential therapeutic strategies.展开更多
基金Supported by the National Natural Science Foundation of China(52266008,52464057)Applied Basic Research Program of Yunnan Province(202301AT070067)the Yunnan Revitalization Talent Support Program Young Talent Project(XDYC-QNRC-2022-0060)。
文摘Chemical looping methane steam reforming(CL-MSR)has garnered significant attention owing to its ability to sequentially produce syngas with high selectivity and high-purity hydrogen through redox cycling.To overcome the limitations of single ironbased oxygen carriers,including poor cycling stability,low reactivity and susceptibility to sintering,this study employed a dipcoating method to modify Fe_(2)O_(3)/Al_(2)O_(3)oxygen carriers by incorporating three distinct metal additives:Cu,La and Ce.The composite oxygen carriers were systematically characterized and evaluated under redox conditions to investigate the structure-activity relationships between the physicochemical properties,reactivity,and hydrogen production performance.Results revealed that the spinel-phase CuFe_(2)O_(4)exhibited higher reactivity than the perovskite-phase LaFeO_(3)and CeO_(2),promoting the deeper reduction of Fe_(2)O_(3).Fe58Cu2Al exhibited an oxygen storage capacity as high as 6.5 mmol/g.During the CH4 reaction stage,Fe58Cu2Al achieved the highest oxygen loss of 12.1 g/100 g oxygen carrier,accompanied by a syngas yield of 5.15 mmol/g-1.33 times and 1.59 times greater than that of Fe60Al.In the hydrogen production stage,the 2%Cu-modified oxygen carrier demonstrated optimal performance,yielding 5.13 mmol/g of hydrogen,which was 1.51 times that of the pristine sample.Even after ten cycles,the H_(2)yield remained at 3.61 mmol/g,surpassing the single-cycle output of the pristine sample and the H2 purity consistently exceeded 98%.
基金supported by the National Natural Sci-ence Foundation of China(Nos.22478263,22308230)Natural Science Foundation of Sichuan(No.2024NSF-SC1134)+2 种基金China Postdoctoral Science Foundation(No.2024T170612)111 center(B17030)the Fun-damental Research Funds for the Central Universities.
文摘Optically pure chiral chemicals are important building blocks with widespread applications across mul-tiple scientific and industrial do-mains such as in pharmaceuticals,agrochemicals,and food,especially acting as precursors to synthesize biodegradable polymers.As an al-ternative to fossil resources,renew-able lignocellulosic biomass has been used to access chiral chemicals,due to the versatile inherent stere-ostructures and multiple functional groups,such as hydroxyl,carbonyl,and phenyl ether groups.Typically,as the two main units of(hemi)cel-lulose components in lignocellulosic biomass,D-xylose and D-glucose bear multiple chiral centers(e.g.,2R-3S-4R for D-xylose and 2R-3S-4R-5R for D-glucose).Lignin bearsβ-O-4 linkages,exhibiting(R,S/S,R)or(R,R/S,S)stereocenters at the side-chainαandβcarbon atoms.The valorization of biomass into optical-ly pure chiral chemicals is vital for developing a more sustainable future.This review discuss-es the production of typical chiral chemicals derived from biomass through chemocatalysis,including lactones(e.g.,R/S-valerolactone),carboxylic acids(e.g.,D/L-glyceric acid,D/L-lactic acid),polyols(e.g.,tetrose),furans,oligosaccharides,and others.Two strategies are generally employed.One approach involves first producing achiral platform chemicals from biomass,followed by the introduction of asymmetric catalysts to reconstruct stereocenters.The second relates to selectively preserving one or more inherent stereocenters in the natural biomass structure during complex cascade reactions in which biomass feedstock acts as a“chi-ral pool",thus eliminating the establishment of stereocenter.The feedstock,methods em-ployed,and enantioselectivity and applications of the target chiral chemicals are discussed.Despite these advances,the synthesis of optically pure chemicals from biomass is still in its in-fancy.The coming decade presents both extraordinary challenges and opportunities in biomass-derived chiral chemistry.Future research should be focused on:(1)integrating well-established asymmetric catalysis techniques and methods with biomass’s inherent chiral pools,presenting an unprecedented opportunity to expand the chemical space of sustainable chiral compounds;(2)mastering polyfunctional complexity of chiral chemicals through holis-tic utilization of biomass’multichiral centers;(3)unlocking lignin’s stereochemical treasury that represents the next frontier in biomass valorization.
文摘The dried fruit of Forsythia suspensa(Oleaceae),also known as Forsythia,is a traditional Chinese medicinal herb known for its heat-clearing and detoxifying properties.It is used to disperse nodules,reduce swelling,remove toxins,clear heat,and alleviate wind-heat syndromes.It also has hepatoprotective,anti-inflammatory,antiviral,antibacterial,anticancer,antioxidant,antiaging,and anti-obesity effects,as well as potential therapeutic effects on Alzheimer’s disease and diabetic nephropathy.It is used to treat scrofula,mastitis,wind-heat common cold,and other ailments.The review summarizes the chemical constituents and pharmacological effects of F.suspensa,aiming to provide a scientific foundation for its future development,research,and clinical utilization.
文摘Panax notoginseng(P.notoginseng),a valuable traditional Chinese medicine,is the dried root of plants in Acanthopanax gracilistylus family,with the effect of dispersing blood stasis,eliminating swelling and relieving pain.With the development of modern medicine,the active ingredients and mechanisms of P.notoginseng have been gradually revealed.The present paper systematically reviews the chemical composition and biological activities of P.nologinseng,to provide a scientific basis and reference for detailed research on P.nologinseng.
文摘The development of intrinsically conductive piezoresistive sensors with high strain tolerance has garnered significant interest.While elastomeric polymers exhibit excellent strain capabilities,their utility in sensing applications has been limited by inherent challenges such as high electrical resistivity,poor aging resistance,and interfacial incompatibility.To address these limitations,hydroxyl-terminated polybutadiene(HTPB)-based polyurethane was chemically modified with acetylferrocene-polyaniline conductive moieties to enhance charge transport properties.Remarkably,this covalent functionalization endowed the resulting ferrocene-polyaniline hybrid polyurethane(FPHP)with a conductivity of2.33 n A at 1 V bias while preserving piezoresistive functionality.The FPHP demonstrated exceptional mechanical-electrical performance,achieving 254% elongation at break with strain-dependent gauge factors of 7.28(0%-12.5% strain,R^(2)=0.9504)and 19.66(12.5%-35.0% strain,R^(2)=0.9929).Further characterization revealed a rapid 0.60 s response time and stability over 3500 strain-release cycles at compression strain,underscoring its durability under repetitive loading.The FPHP sensor was capable of monitoring various human movements and recognizing writing signals.These advances establish a materials design paradigm for fabricating flexible sensors that synergistically integrate high deformability,tunable sensitivity,and robust operational stability,positioning FPHP as a promising candidate for next-generation wearable electronics and soft robotics.
基金supported by the National Natural Science Foundation of China(Grant 52276212)the National Key Research and Development Program of China(Grant 2022YFB3803600)+1 种基金the Natural Science Foundation of Jiangsu Province(Grant BK20231211)the China Fundamental Research Funds for the Central Universities.
文摘Solar-driven H_(2) production coupled with selective organic transformation represents a promising strategy for co-generation of green hydrogen and high-value chemicals,yet its feasibility relies critically on effective bifunctional photocatalysts.Herein,we report the synthesis of ultrafine Cd_(x)Zn_(1-x)S nanocrystals derived from a zeolitic imidazolate framework(ZIF),featuring high surface area,shortened charge diffusion path,and enhanced H_(2) evolution activity.Anchoring amorphous Pt sub-nanoclusters onto these nanocrystals created a bifunctional catalyst(Pt-Cd_(x)Zn_(1-x)S)for efficient lactic acid photoreforming,enabling coproduction of H_(2) with switchable selectivity toward pyruvic acid(PA)or 2,3-dihydroxy-2,3-dimethylsuccinic acid(DTA).The optimized 0.5Pt-Cd_(0.3)Zn_(0.7)S catalyst achieved an exceptional H_(2) production rate of 270.6 mmol h^(-1) g^(-1),73.1%PA selectivity,and 62.8% apparent quantum efficiency at 400 nm.Mechanistic studies revealed that lactic acid undergoes C-H cleavage to form carbon-centered radicals.Pt sub-nanoclusters served as electron sinks to facilitate O-H dissociation and PA formation,whereas pristine Cd_(0.3)Zn_(0.6)7S promoted direct C-C coupling of radicals to predominantly yield DTA.This work offers critical insights for designing advanced bifunctional photocatalysts to integrate solar hydrogen and value-added chemical synthesis.
文摘The aerosolization and diffusion of radioactive materials caused by chemical explosions represent a typical nuclear accident scenario that poses severe radioactive hazards to human health and the environment.This study examines the diffusion of plutonium aerosol generated by a chemical explosion within a typical representative underground facility.The state of explosion products following a single-point detonation of explosives was simulated.Subsequently,a numerical simulation of plutonium aerosol diffusion using the discrete phase model(DPM)was conducted based on the outcomes of the chemical explosion simulation.The simulation results indicate that plutonium aerosols diffuse throughout underground facilities after a chemical explosion;small particle size aerosols primarily accumulate in the upper part of the room after the accident;the concentrations of plutonium aerosol in the room and tunnel are significantly higher than those in the other areas;and the temporal variations in aerosol concentration in each area were quantified.Based on the particle concentration distribution and the effective dose computation approach,the study computes the internal irradiation dose received by personnel in seven areas over various time periods post-accident.Recommendations for emergency decision-making were derived from these calculations.These findings provide important theoretical insight and practical engineering application value for understanding the diffusion of radioactive aerosol in confined spaces following chemical explosions and for evaluating personnel radiation dose.
基金the support of the National Natural Science Foundation of China(22575230)。
文摘Conventional error cancellation approaches separate molecules into smaller fragments and sum the errors of all fragments to counteract the overall computational error of the parent molecules.However,these approaches may be ineffective for systems with strong localized chemical effects,as fragmenting specific substructures into simpler chemical bonds can introduce additional errors instead of mitigating them.To address this issue,we propose the Substructure-Preserved Connection-Based Hierarchy(SCBH),a method that automatically identifies and freezes substructures with significant local chemical effects prior to molecular fragmentation.The SCBH is validated by the gas-phase enthalpy of formation calculation of CHNO molecules.Therein,based on the atomization scheme,the reference and test values are derived at the levels of Gaussian-4(G4)and M062X/6-31+G(2df,p),respectively.Compared to commonly used approaches,SCBH reduces the average computational error by half and requires only15%of the computational cost of G4 to achieve comparable accuracy.Since different types of local effect structures have differentiated influences on gas-phase enthalpy of formation,substituents with strong electronic effects should be retained preferentially.SCBH can be readily extended to diverse classes of organic compounds.Its workflow and source code allow flexible customization of molecular moieties,including azide,carboxyl,trinitromethyl,phenyl,and others.This strategy facilitates accurate,rapid,and automated computations and corrections,making it well-suited for high-throughput molecular screening and dataset construction for gas-phase enthalpy of formation.
基金supported by the National Natural Science Foundation of China(Grant Nos.52478351,52208329)the Shenzhen Science and Technology Innovation Commission(Grant No.JCYJ20240813143306009)support is gratefully acknowledged.
文摘Polymer-modified bentonite(PMB)is much more effective at containing chemically aggressive liquids than conventional bentonite.The PMB manufacturing process typically utilizes natural,high-quality sodium bentonite(NaB)owing to its excellent hydrophilicity and swelling capacity.However,calcium bentonite(CaB),which is much more abundant worldwide,is rarely used for containment applications owing to its poor hydrophilicity.This study proposed a polymerization method that transforms sodium-activated calcium bentonite(NCB)into PMB to achieve low hydraulic conductivity(k)to aggressive liquids.The mechanism for its low k was revealed through characterization techniques and analyses(e.g.X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM),and Brunauer-Emmett-Teller(BET)).The results showed that the PMB had a small amount of polymer elution(indicating better interface stability)and thus exhibited excellent barrier properties under chemically aggressive conditions,with the k of<10^(-11) m/s for 0.6 mol/L NaCl solution,which is four orders of magnitude lower than that of the NCB(k=3×10^(-7) m/s).Various microscopic analyses indicated that the selected monomers were successfully polymerized,and intercalated into and grafted onto the montmorillonite layers of bentonite.The formed polymer network increased the swelling capability of PMB granules,decreased the pore size,and created narrow and tortuous flow pathways leading to a very low k to aggressive liquids.
基金supported by the National Natural Science Foundation of China(Nos.22572141,22178266)Talent Program Fund of Tianjin University(Nos.0701321039,0903074107)supported by a grant from the Key Laboratory of Recycling and Eco-Treatment of Waste Biomass of Zhejiang Province(No.2024HZYB02)。
文摘Photocatalytic C-N coupling reactions using waste plastic-and biomass-based feedstocks with nitrogen-containing species have emerged as a promising route for the synthesis of high-value chemicals such as amides and amino acids.However,the complexity of multistep reaction routes and the presence of competing side reactions pose significant challenges,often leading to low yield and poor selectivity of target products.To substantially enhance the efficiency and selectivity of C-N coupling reactions,it is imperative to gain a thorough understanding of the underlying reaction mechanisms and to develop highly active photocatalysts.Such catalysts must be capable of effectively activating diverse substrates while maintaining an appropriate balance between the adsorption and desorption of carbon-and nitrogen-containing intermediates or radical species.In this review,we systematically summarize recent advances in photocatalytic C-N coupling for the production of amides and amino acids from waste plastic-and biomass-based feedstocks,with particular focus on catalyst selection,process design,control of reaction intermediates,and catalytic mechanisms.Furthermore,the technoeconomic feasibility and environmental impact of these C-N coupling reactions are evaluated using technoeconomic analysis and life-cycle assessment.Lastly,the current challenges and future prospects in this field are also discussed.This review aims to provide valuable insights for the development of high-efficiency photocatalytic C-N coupling reactions and to deepen the understanding of their catalytic mechanisms.
基金supported by National Natural Science Foundation of China(22278241)a grant from the Institute Guo Qiang,Tsinghua University(2021GQG1016).
文摘Space exploration and manufacturing are of critical importance for scientific advancement,technological innovation,national security,and the acquisition of extraterrestrial resources.In view of this,chemical and biological nano-/micro-/meso-scale manufacturing provide complementary approaches to overcome key space exploration challenges by enabling the in-situ production of essential life-support materials,propellants,and other resources.This review examines the origin and historical evolution of space manufacturing and the latest advances across different environments—from orbital space stations and the lunar surface to Mars and asteroids.It is structured to present the current state of research,outline key manufacturing strategies and technologies,assess the technical and environmental challenges,and discuss emerging trends and future directions.Besides,the potential applications of emerging technologies such as synthetic biology and artificial intelligence in overcoming the limitations of microgravity,limited resources,and extreme conditions are discussed.Ultimately,this integrative review could serve to guide future development,from advancing space science and disruptive manufacturing to enabling interdisciplinary and application-level innovations.
基金Project supported by the Youth Program of the National Natural Science Foundation of China(Grant No.12405324)the CNNC Science Fund for Talented Young Scholars(Grant No.24940)the CNNC Basic Science Fund(Grant No.24851)。
文摘Molecular dynamics simulations were carried out to study the effect of chemical short-range order(CSRO)on the primary radiation damage in TiVTaNb high-entropy alloys(HEAs).We have performed displacement cascade simulations to explore the CSRO effect on the generation and evolution behaviors of irradiation defects.The results demonstrate that CSRO can suppress the formation of Frenkel pairs in TiVTaNb HEAs,with the suppression effect becoming more pronounced as the degree of CSRO increases.CSRO can change the types of interstitial defects generated during cascade collisions.Specifically,as the degree of CSRO increases,the proportion of Ti-related interstitials shows a marked enhancement,primarily evidenced by a significant rise in Ti–Ti dumbbells accompanied by a corresponding decrease in Ti–V dumbbells.CSRO exhibits negligible influence on defect clustering and the nucleation and evolution of dislocation loops.Regardless of CSRO conditions,TiVTaNb HEAs preserve exceptional radiation tolerance throughout the cascade damage process,suggesting that the intrinsic properties of this multi-principal element system dominate its radiation response.These findings provide fundamental insights into the CSRO effect on defect formation and evolution behaviors in HEAs,which may provide new design strategies for high-entropy alloys.
基金the National Key R&D Program of China(No.2023YFC2308000)the National Natural Science Foundation of China(Nos.22478153,22477046,22177041)+3 种基金the Max Planck Society International Partner Group Programthe China Scholarship Council(CSC)the Fundamental Research Funds for the Central Universities for fundingthe Max-Planck Society for generous financial support.
文摘Pseudomonas aeruginosa is an opportunistic pathogen responsible for severe nosocomial infections.This multidrug-resistant bacterium can cause pneumonia and cystic fibrosis,both of which are associated with high morbidity and mortality rates.The lipopolysaccharide of P.aeruginosa serves as an attractive target for the development of effective glycoconjugate vaccines.In this article,we report the first chemical synthesis of the highly challenging tetrasaccharide repeating unit of the P.aeruginosa serotype O3 O-antigen using a two-directional[1+(2+1)]glycosylation strategy.The synthesis is particularly challenging due to the poor nucleophilicity of the axial C4 hydroxyl group of l-galactose and the steric hindrance imposed by the 3S-hydroxybutyryl(Hb)chain.Furthermore,the presence of an acetyl group at the ortho position relative to the glycosylation site on l-galactose can lead to undesirable acetyl migration.Additionally,it is noteworthy that the selective removal of a 2-naphthylmethyl ether(Nap)during the late stages of synthesis,particularly in the presence of multiple benzyl groups,can be somewhat challenging to predict.Through the careful selection of synthetic strategies,building blocks,and optimized reaction conditions,we achieved the stereoselective glycosylations,selective oxidation of primary alcohols,remarkable enhancement of acceptor activity,and efficient introduction of the 3S-Hb group.The synthetic methodology presented in this work serves as a valuable reference for the preparation of structurally related oligosaccharides.By incorporating an aminopropyl linker,the target tetrasaccharide facilitates glycan microarray preparation and in vivo immunological assessments,thereby accelerating progress toward a synthetic glycoconjugate vaccine for P.aeruginosa.
基金supported by Major Program of National Natural Science Foundation of China(U22A20188)National Science Fund for Distinguished Young Scholars(52425504).
文摘The physicochemical properties of SUS304 foil surfaces are crucial to their applications.Pulsed laser modification was applied to 30μm thick SUS304 foils to systematically investigate the influence of laser energy on surface characteristics.Through multidimensional characterization of surface morphology,three-dimensional profiles and roughness,contact angle,and chemical composition,the structure-function correlation between laser energy and the physicochemical properties of steel surface was revealed.With increasing laser energy,the surface morphology of the steel transitions from a directional rolling-marked structure to a uniform sponge-like isotropic structure,accompanied by increased peak density and an expanded interfacial area.Additionally,the chemical state on the metal surface gradually stabilizes from unstable redox reactions,forming a stable oxide layer and significantly increasing active hydroxyl groups,thereby effectively improving surface wettability.Single lap shear tests reveal an enhancement in the bonding strength of steel/carbon fiber reinforced composites joints after laser modification,which is attributed to the synergistic effects of mechanical interlocking,enhanced wettability,and chemical bonding at the interface.The demonstrated potential of laser surface treatment for modifying SUS304 ultra-thin foils provides theoretical support and technical reference for its application in fiber metal laminates.
基金sponsored by the Department of Defense,Defense Threat Reduction Agency under the Materials Science in Extreme Environments University Research Alliance,HDTRA1-20-2-0001。
文摘Chemical warfare agents(CWAs)remain a persistent hazard in many parts of the world,necessitating a deeper exploration of their chemical and physical characteristics and reactions under diverse conditions.Diisopropyl methylphosphonate(DIMP),a commonly used CWA surrogate,is widely studied to enhance our understanding of CWA behavior.The prevailing thermal decomposition model for DIMP,developed approximately 25 years ago,is based on data collected in nitrogen atmospheres at temperatures ranging from 700 K to 800 K.Despite its limitations,this model continues to serve as a foundation for research across various thermal and reactive environments,including combustion studies.Our recent experiments have extended the scope of decomposition analysis by examining DIMP in both nitrogen and zero air across a lower temperature range of 175℃ to 250℃.Infrared spectroscopy results under nitrogen align well with the established model;however,we observed that catalytic effects,stemming from decomposition byproducts and interactions with stainless steel surfaces,alter the reaction kinetics.In zero air environments,we observed a novel infrared absorption band.Spectral fitting suggests this band may represent a combination of propanal and acetone,while GCMS analysis points to vinyl formate and acetone as possible constituents.Although the precise identity of these new products remains unresolved,our findings clearly indicate that the existing decomposition model cannot be reliably extended to lower temperatures or non-nitrogen environments without further revisions.
基金the financial support provided under the Fundamental Research Grant Scheme(FRGS),Project Code:FRGS/1/2021/TK01/USM/02/1,which made this research possible,The kind assistance and collaboration of all material suppliers were also gratefully acknowledged.Additional appreciation is extended to the Public Works Department Malaysia for the scholarship provided through the Hadiah Latihan Persekutuan programme for professional and managerial officers pursuing doctoral studies(JPA-1-840622086040)The APC was funded by Prof.Hui Yao from Beijing University of Technology.
文摘The rapid increase in traffic loads and frequencies has rendered conventional asphalt pavement inadequate to maintain its durability under tropical climates.This challenge has necessitated the exploration of new sources of modified asphalt with enhanced stiffness and superior performance at high temperatures.Natural rubber(NR)is a renewable biopolymer that has received growing interest as a modifier for asphalt binders.Cup lump rubber(CLR),a type of NR,is used to enhance asphalt properties and improve the performance of road pavements.This study evaluates the influence of wax-based surfactants(WS)on CLR-modified asphalt binder(CMB).The assessment focuses on changes in chemical characteristics,rheological behaviour,activation energy,and morphology.Four concentrations of WS(0.1%,0.15%,0.2%,and 0.25%)were incorporated into CMB.Analysis of CMB chemical changes showed that viscosity increased due to higher sulfoxide,carbonyl,and aromatic bond indices.These chemical modifications contributed to improved resistance of the binder to heat-induced deterioration.In both unaged and aged CMB samples,the incorporation of WS reduced the sulfoxide index of the binder.Rheological analysis indicated that CMB improved rutting resistance and anti-ageing performance,while WS further enhanced fatigue resistance.Activation energy analysis suggested that the combination of CMB with 0.15%WS produced the most favourable enhancement.Micrograph results showed that WS improved binder homogeneity and interconnectivity.In conclusion,the findings indicated that incorporating 0.15%WS into CMB enhanced the performance and durability of the asphalt pavement.
文摘The chemical industry plays a critical role in supporting global economic development,yet its traditional production paradigms are associated with high resource consumption,energy demand,and environmental impact.To deal with the growing regulatory burden,societal demands,and environmental targets,eco-friendly processes in chemicals have become one of the major approaches to ensuring industrialization with environmental safety.This review includes an overall summary of the recent developments of green chemical processes with the focus on the basic principles,facilitating structures,and technologies that form the basis of sustainable chemical production.The most important advances in sustainable feedstocks,green catalysis,environmentally benign solvents,energy-efficient and intensified process technologies are also essential introductions,and the importance of digitalization,artificial intelligence,and life cycle-informed assessment tools in environmental performance optimization is also increasing.The review also discusses some of the barriers related to industry implementation,such as scalability,economic viability,and the necessity of having strong sustainability verification.Using chosen industrial case studies of China,South Korea,and Vietnam,various ways of integrating eco-friendly processes are demonstrated,including the adoption of renewable energy and low-carbon hydrogen,the adoption of circular plastics,and refinery energy optimization.Such examples demonstrate the significance of regional settings,system-level integration,and open environmental assessment in achieving significant sustainability results.The presented insights should guide the way future research proceeds and facilitate the shift toward the low-impact chemical manufacturing systems that are resilient.
基金supported by the National Key Research and Development Program of China (No.2023YFC3708005)the National Natural Science Foundation of China (Nos.21872102,22172080)the Fundamental Research Funds for the Central Universities (Nankai University,No.63241208)。
文摘Groundwater is a key part of the terrestrial ecosystem,but it is vulnerable to pollution in the context of chemical industry development.Treating contaminated groundwater is challenging due to its stable water quality,hidden contamination,and complex treatment requirements.Current research focuses on advanced treatment technologies,among which the advanced oxidation process(AOPs) of peroxomonosulfate(PMS) has great potential.Although there are many reviews of PMS-based AOP,most of them focus on surface water.This review aims to explore the activation reaction of PMS to groundwater by in-situ chemical oxidation(ISCO) technology,further study the reaction mechanism,compare the treatment effect of characteristic pollutants in the groundwater of the chemical industry park,propose new activation methods and catalyst selection,and provide guidance for future groundwater treatment research.
基金Supported by Xinjiang"Tianshan Talents"Program Project"Research and Demonstration of Key Technologies for Precise Monitoring and Pesticide Application by Unmanned Aerial Vehicle during the Cotton Topping Stage"(2023TSYCCX0126)Xinjiang Production and Construction Corps Science and Technology Innovation Project"Innovation Team Project for Intelligent Information Collection and Smart Management in Cotton Fields"(NCG202304).
文摘[Objectives]To determine the optimal concentration of topping agents applied by unmanned aerial vehicles(UAVs)to effectively regulate cotton growth and improve production efficiency.[Methods]A field experiment was conducted in Shihezi City,Xinjiang,employing a randomized block design.Five UAV-based chemical topping treatments were applied at dosages of 0.300,0.525,0.750,0.975,and 1.200 L/hm 2,designated as H1,H2,H3,H4,and H5,respectively.Additionally,manual topping(CK1)and tractor topping(CK2)treatments,both at a concentration of 0.750 L/hm 2,were included as control treatments.During the first 20 d following topping,parameters including primary agronomic traits of cotton(plant height,leaf age,number of fruit branches),dry matter accumulation and distribution,leaf area boll load(LAB),root-to-shoot ratio(RSR),leaf mass area(LMA),and leaf area index(LAI)were examined.At harvest,yield components,lint cotton yield,harvest index,and fiber quality were evaluated.[Results]Twenty days after topping,the concentration of the topping agent applied via UAV did not significantly affect cotton leaf age or the number of fruit branches.Additionally,no significant differences in plant height were observed among the five concentration treatments compared to CK2.However,plants treated with H1 exhibited significantly greater height compared to those treated with H5 and CK1,indicating that H1 was the least effective in controlling vegetative growth.Total dry matter accumulation(TDM),boll dry matter accumulation(BDM),LAB,and LMA all demonstrated an initial increase followed by a decrease as the spraying concentration increased.The highest TDM and reproductive organ dry matter ratio(RRDM)were observed in the H3 treatment.No significant differences were found among treatments for LMA,RSR,or LAI;however,LAB and single boll weight were greatest in the H3 treatment.Fiber quality parameters,including fiber length uniformity,micronaire(MIC),specific strength,and fiber maturity,initially increased and then decreased with increasing spraying concentration,whereas fiber elongation rate exhibited the opposite trend.The H3 treatment yielded the highest average fiber length uniformity and specific strength.[Conclusions]At optimal spraying concentrations,UAV-based application more effectively controls vegetative growth,promotes dry matter accumulation and distribution in cotton bolls,increases single boll weight,and enhances the MIC,specific strength,and fiber elongation rate of cotton fibers compared to manual and tractor spraying of topping agents.In summary,the use of UAVs for spraying chemical topping agents is recommended,with a suggested dosage range of 0.750 and 0.975 L/hm 2.
基金National Institute of Health(NIH)National Institute of Neurological Disorders and Stroke(NINDS),Nos.NS112910,NS133252(to BD)Department of Defense(DoD)Peer Reviewed Medical Research Program(PRMRP)Discovery Award,No.W81XWH2010186(to BD).
文摘The generation of human induced pluripotent stem cell-derived motor neurons overcomes limited access to human tissues and offers an unprecedented approach to modeling motor neuron diseases such as dystonia and amyotrophic lateral sclerosis.Motor neurons generated through different strategies may exhibit substantial differences in purity,maturation,characterization,and even neuronal identity,leading to variable outcomes in disease modeling and drug screening.However,very few comparative studies have been conducted to determine the similarities and differences among motor neurons prepared via different protocols.In this study,we prepared human induced pluripotent stem cell-derived motor neurons via lentiviral delivery of transcription factors and chemical induction and performed a systematic comparative analysis.We found that motor neurons generated by both approaches showed typical motor neuron morphology and robustly expressed motor neuron-specific markers,such as nuclear homeobox transcription factor 9 and choline acetyltransferase.The chemical induction protocol utilizes a combination of small molecules to induce motor neuron differentiation,offering a significantly faster maturation time of 35 days compared to 46 days with lentiviral delivery of transcription factors.Additionally,while lentiviral delivery of transcription factors are suitable for downstream biochemical analysis,chemical induction are more applicable for therapeutic approaches as they avoid the use of lentiviruses.Both approaches produce motor neurons with high purity(>95%)and yield.No significant differences were found between chemical induction and lentiviral delivery of transcription factors in terms of motor neuron markers and maturation markers.These robust methodologies offer researchers powerful tools for investigating motor neuron diseases and potential therapeutic strategies.
