Chitosan(CTS)was grafted onto the surface of amino‑functionalized silver chloride silicon dioxide(AgCl@SiO_(2)‑NH_(2))cores to obtain AgCl@SiO_(2)/CTS hybrid nanoparticles.The as‑obtained AgCl@SiO_(2)/CTS nanoparticle...Chitosan(CTS)was grafted onto the surface of amino‑functionalized silver chloride silicon dioxide(AgCl@SiO_(2)‑NH_(2))cores to obtain AgCl@SiO_(2)/CTS hybrid nanoparticles.The as‑obtained AgCl@SiO_(2)/CTS nanoparticles were chlorinated by NaClO solution to get AgCl@SiO_(2)/CTS‑based chloramine nano‑hybrid materials,denoted as AgCl@SiO_(2)/CTS‑Cl.A transmission electron microscope was used to observe the morphology of the as‑prepared samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.At the same time,an X‑ray diffractometer and an infrared spectroscope were utilized to characterize their crystal and chemical structures.Besides,ζpotentials were measured to elucidate the surface modification of AgCl nanoparticles by—NH_(2),the antibacterial mechanism of AgCl@SiO_(2)/CTS‑Cl was investigated by scanning electron microscopy,and Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)were used as the to‑be‑tested strains to evaluate the antimicrobial activity of samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.Findings demonstrate that sample AgCl@SiO_(2)/CTS exhibits a chain‑like structure ascribed to the interaction between—NH_(2),and each AgCl@SiO_(2)/CTS hybrid nanoparticle contains several AgCl cores.In the meantime,sample AgCl@SiO_(2)/CTS‑Cl exhibits excellent antibacterial activity against E.coli and S.aureus,which is attributed to the synergistic antibacterial effect of Ag^(+)and Cl^(-).Sample AgCl@SiO_(2)/CTS‑Cl with a dosage of 640.00μg·mL^(-1) could completely kill the two kinds of tested bacteria in 12 h of incubation;it retains a high antibacterial efficiency even after 10 cycles of antibacterial tests.展开更多
Benzalkonium chloride(BAC)is widely employed as a broad-spectrum biocide and has emerged as a significant environmental pollutant.Polymyxin B(PB)serves as the last-line defense for the treatment of Gram-negative patho...Benzalkonium chloride(BAC)is widely employed as a broad-spectrum biocide and has emerged as a significant environmental pollutant.Polymyxin B(PB)serves as the last-line defense for the treatment of Gram-negative pathogens.Previous studies reported that BAC-adapted Pseudomonas aeruginosa increased the tolerance to PB.Herein,we present the novel finding that the combination of BAC and PB exhibited synergistic antibacterial effects against P.aeruginosa.Time-killing assay demonstrated a significant reduction in bacterial cell viability.Scanning electron microscopy,zeta potential analysis,hydrophobicity measurements,and fluorescence probe analyses collectively revealed severe disruption of the cell envelope and membrane potential induced by the combination of BAC and PB.Transcriptomic analysis revealed that the BAC-PB combination notably downreg-ulated the expression of genes involved in lipid A modification and cell envelope production,including phoPQ,pmrAB,bamABCDE,lptABCDEG,lolB,yidC,and murJ.Additionally,the combination group exhibited augmented production of reactive oxygen species and diminished ATP synthesis.The expression of the genes associated with substance metabolism and energy generation was significantly impeded.This study provides significant implica-tions for the interactions of biocides and antibiotics on Gram-negative pathogens,while also addressing antibiotic resistance and developing the external treatment strategy for Pseudomonas-infected wounds and burns.展开更多
The UV-2600 ultraviolet(UV)spectrophotometer and the UV sunscreen index analyzer SolarLight Model 601 were used to test the UV absorption capacity and the UV damage alleviating effect of commonly used raw materials,an...The UV-2600 ultraviolet(UV)spectrophotometer and the UV sunscreen index analyzer SolarLight Model 601 were used to test the UV absorption capacity and the UV damage alleviating effect of commonly used raw materials,and the Hen’s Egg Test-Chorioallantoic Membrane were also processed to assess the mildness.As a result,bisabolol,pongamia pinnata seed extract,pterocarpus marsupium bark extract and other materials were screened as the effective and gentle sunscreen synergistic ingredients.展开更多
Freeze–thaw(F–T)cycle-induced cracking in silty clays poses a significant risk to engineering stability.Although the individual addition of fly ash(FA)or sisal fiber(SF)provides partial solutions,their simultaneous ...Freeze–thaw(F–T)cycle-induced cracking in silty clays poses a significant risk to engineering stability.Although the individual addition of fly ash(FA)or sisal fiber(SF)provides partial solutions,their simultaneous application may result in a synergistic effect to compensate for their respective shortcomings.In this study,the effects of SF and FA on the mechanical properties,crack resistance,water retention,and erosion resistance of improved soil were systematically investigated through unconfined compressive strength(UCS)tests,crack evolution analysis,simulated rainfall erosion tests,and microscopic characterization(laser particle size analysis and nitrogen adsorption).The results reveal that the volumetric stability of FA particles significantly inhibits cracking in soil after F–T cycles.However,FA contributes only slightly to soil strength and erosion resistance.SF,on the other hand,plays a substantial role in increasing both soil strength and erosion resistance.The synergy between FA and SF results in the simultaneous increase in crack resistance,erosion resistance,and strength.FA improves the aggregate stability during F–T cycles,whereas SF reinforces the bonds between these aggregates.A comprehensive evaluation of the improved soil during F–T cycles using the entropy weight-TOPSIS method reveal that the combination of 10%FA+18 mm SF performed the best,achieving a 246%higher composite score than the unmodified soil did.With respect to this optimal combination,compared with the unmodified soil,the SF–FA-improved soil exhibits a 30%reduction in the average crack width,a 30%reduction in the erosion rate,and a 46%increase in strength.The findings of this study provide a scientific basis for the design of soil improvement in disaster mitigation engineering in seasonally frozen soil regions.展开更多
Attaining the selective oxidation of isochroman into isochromanone in a molecular oxygen(O_(2))environment without any additives,via a heterogeneous oxidation process,is highly desirable and challenging work.Herein,we...Attaining the selective oxidation of isochroman into isochromanone in a molecular oxygen(O_(2))environment without any additives,via a heterogeneous oxidation process,is highly desirable and challenging work.Herein,we prepare two mixed-addendum polyoxometalate-based coordination polymers of the general formula[H_(x)M_(1-x)(i-PrIm)_(4)][H_(2)N(CH_(3))_(2)]_(4)[HPMo_(8)V_(6)O_(42)](M=Co 1,Ni,2;i-PrIm=1-isopropyl-1H-imidazole).Needing no additives,they can catalyze the selective oxidation of isochroman to isochromanone with O_(2)as an oxidant,with yields of 91.5%(1)and 46.8%(2),respectively.Mechanistic studies indicate that the excellent performance of catalyst 1 is attributed to the synergistic operation of[Co(i-Pr-Im)_(4))]complex and PMo_(8)V_(6)unit,and that the catalytic reaction is a radical pathway involving superoxide radicals.Additionally,the catalyst 1 can be recycled and reused at least four times with uncompromised performance.These results provide fundamental guidelines for designing efficient and multi-site heterogeneous catalysts for the selective oxidation of benzyl C(sp^(3))-H bonds by activating O_(2).展开更多
The synergistic effect of low Gd+Mn additions on the evolution of microstructure and mechanical properties of Mg−xGd−0.8Mn alloy was investigated.Gd addition shows a strong grain refinement effect on the extruded Mg−x...The synergistic effect of low Gd+Mn additions on the evolution of microstructure and mechanical properties of Mg−xGd−0.8Mn alloy was investigated.Gd addition shows a strong grain refinement effect on the extruded Mg−xGd−0.8Mn alloy,and leads to a continuous decrease in the area fraction of basal texture grains and the corresponding maximum density of texture components.However,the maximum density of the basal texture components grows abruptly as Gd content increases to 6 wt.%.When the Gd content is below 6 wt.%,the asymmetry of the tensile and compressive yield of the alloy is negatively correlated to the Gd content due to grain refinement and texture weakening effects.Besides,the contribution of grain refinement to higher alloy yield strength is more significant than that of grain orientation.Compared with the extruded Mg−xGd alloy,the extruded Mg−xGd−0.8Mn alloy shows a lower limit composition point that corresponds to solid solution strengthening and plasticizing effect(2 wt.%and 4 wt.%).Finally,the trend of basal slip and prismatic slip resistance variations of the extruded Mg−xGd−0.8Mn alloys was predicted.展开更多
Electrodeposition of acid copper plating on mild steel substrate is tedious due to the galvanic displacement reaction ofcopper on mild steel.This can be avoided by using a proper complexing agent,because the complexin...Electrodeposition of acid copper plating on mild steel substrate is tedious due to the galvanic displacement reaction ofcopper on mild steel.This can be avoided by using a proper complexing agent,because the complexing agent tuned the potential ofnoble direction to less noble direction by complex formation.In this paper,environment friendly electrodeposition of copper fromnon-cyanide electrolyte using sodium gluconate as complexing agent was investigated in alkaline medium.The effects of additivessuch as1,2,3-benzotriazole,sodium lauryl sulphate,PEG8000and saccharin were studied.These additives are found to reduce thegrain size,grain boundaries and improve surface morphology of the copper deposits.Also they improve the throwing power of thedepositing electrolytes and hardness of deposits.The electrodeposited copper coatings were characterized by X-ray diffractiontechnique.XRD results indicate that the electrodeposited copper shows polycrystalline and face centered cubic structure.The crystalsize was calculated by XRD and AFM analysis.Among these additives studied,the mixture of benzotriazole and sodium laurylsulphate acts as the best additive.A uniform pore-free surface observed under SEM and AFM results reveal the grain refining broughtabout by the additives.展开更多
The major solving ways for the material wear are surface modification and lubrication. Currently, the researches at home and abroad are all limited to the single study of either nano-lubricating oil additive or electr...The major solving ways for the material wear are surface modification and lubrication. Currently, the researches at home and abroad are all limited to the single study of either nano-lubricating oil additive or electroless deposited coating. The surface coating has high hardness and high wear resistance, however, the friction reduction performance of the coating with high hardness is not good, the thickness of the coating is limited, and the coating can not regenerate after wearing. The nano-lubricating additives have good tribological performance and self-repair function, but under heavy load, the self-repair rate to the worn surface with the nano-additives is smaller than the wearing rate of the friction pair. To solve the above problems, the Ni-W-P alloy coating and deposition process with excellent anti-wear, and suitable for industrial application were developed, the optimum bath composition and process can be obtained by studying the influence of the bath composition, temperature and PH value to the deposition rate and the plating solution stability. The tribological properties as well as anti-wear and friction reduction mechanism of wear self-repair nano-ceramic lubricating additives are also studied. The ring-block abrasion testing machine and energy dispersive spectrometer are used to explore the internal relation between the coating and the nano-lubricating oil additives, and the tribology mechanism, to seek the synergetic effect between the two. The test results show that the wear resistance of Ni-W-P alloy coating （with heat treatment and in oil with nano-ceramic additives） has increased hundreds times than 45 steel as the metal substrate in basic oil, the friction reduction performance is improved. This research breaks through the bottleneck of previous separate research of the above-mentioned two methods, and explores the combination use of the two methods in industrial field.展开更多
Background: The radiosensitizing effect of Photofrin II has been demonstrated in vitro and in animal models, even in tumor models known to be highly radioresistant, such as glioblastoma and bladder carcinoma. Radio-ad...Background: The radiosensitizing effect of Photofrin II has been demonstrated in vitro and in animal models, even in tumor models known to be highly radioresistant, such as glioblastoma and bladder carcinoma. Radio-adaptive doses are also known to lead to an augmented cell or tissue reaction. The aim of this study was to investigate potential synergistic or additive effects when combining the two methods in vitro for an improved therapeutic concept in bladder cancer. Material and Methods: RT4 human bladder carcinoma cell line and HCV29 human bladder epithelium cells were seeded and incubated with various concentrations of Photofrin II. The cells were additionally irradiated with ionizing radiation (0.05 Gy/2 Gy/0.05 Gy + 2 Gy). Cells without Photofrin II incubation and irradiation served as controls. The cell survival was evaluated. Results: The survival rate of both cell lines, RT4 and HCV29, did not differ significantly when incubated with a non-toxic concentration of Photofrin II and exposed to a pre-irradiation dose of 0.05 Gy prior to the 2 Gy radiation fraction, compared to cells exposed to Photofrin II plus a 2 Gy ionizing radiation. Conclusion: The combination of both methods did neither demonstrate a synergistic or additive effect nor did it lead to a negative influence of both modulating factors in an in vitro setting.展开更多
Autumn rain in western China(ARWC)is a unique and significant precipitation phenomenon that occurs during the summer-to-winter transition of the atmospheric circulation.Using the fifth generation of global climate and...Autumn rain in western China(ARWC)is a unique and significant precipitation phenomenon that occurs during the summer-to-winter transition of the atmospheric circulation.Using the fifth generation of global climate and weather reanalysis data from the European Centre for Medium-Range Weather Forecasts and CN05.1 grid precipitation data,this study examined the anomalous characteristics and mechanisms of ARWC by combining the synergistic effect of the westerly jet and meridional wind.Over the past 60 years,ARWC has exhibited significant interdecadal and interannual variations,as well as a north-south seesaw pattern.The westerly jet index(meridional wind index)exhibited a negative(positive)correlation with precipitation in the northern autumn rain zone(NARZ),and a positive(negative)correlation with precipitation in the southern autumn rain zone(SARZ).The coupling of a weak meridional southerly wind with a southward westerly jet and a strong meridional southerly wind with a northward westerly jet are the two primary modes that synergistically influence the ARWC.These synergistic effects cause significant atmospheric changes throughout the troposphere.The contrasting circulation structure,temperature advection,vertical motion,and water vapor flux contributed to the opposite precipitation anomalies observed in the NARZ and SARZ.A new comprehensive index that reflects the coupled synergistic effect is proposed to characterize the anomalous changes in ARWC.This study improves the understanding of the anomalous characteristics and mechanisms of ARWC.展开更多
This study developed a novel heterogeneous Vis-Photo+Fenton-like system by integrating visible-light-responsive Co_(3)O_(4)/TiO_(2) photocatalysis with peroxymonosulfate(PMS)activation for efficient atrazine(ATZ)degra...This study developed a novel heterogeneous Vis-Photo+Fenton-like system by integrating visible-light-responsive Co_(3)O_(4)/TiO_(2) photocatalysis with peroxymonosulfate(PMS)activation for efficient atrazine(ATZ)degradation.The synergistic process achieved complete ATZ removal within 60 min under near-neutral pH(6.9),outperform-ing individual Fenton-like(39%)and photocatalytic(24%)processes.Key factors influencing the degradation efficiency included light sources(UV>visible),pH(optimal at 6.9),catalyst dosage(0.01 g Co_(3)O_(4)/TiO_(2)),and PMS:ATZ molar ratio(1:2).The system exhibited a synergistic coefficient of 5.03(degradation)and 1.97(miner-alization),attributed to enhanced radical generation and accelerated Co^(3+)/Co^(2+)redox cycling through photoin-duced electron transfer.Intermediate analysis revealed dealkylation,dechlorination,and oxidation pathways,with reduced toxicity of by-products(e.g.,CEAT,CIAT)confirmed by ecotoxicity assessments.The mineralization efficiency(Vis-Photo+Fenton-like)reached 83.1%,significantly higher than that of standalone processes(Fenton-like:43.2%;photocatalysis:30.5%).The catalyst demonstrated excellent stability(nearly 90%recov-ery,<1μg/L Co leaching)and practical applicability.This study provides an efficient,sludge-free,and solar-compatible strategy for eliminating persistent herbicides in water treatment.展开更多
Formulating oil-based drilling fluids(OBDFs)with an ultra-low oil-to-water ratio(OWR≤60:40)presents a formidable stability challenge due to the maximized interfacial area and intensified stress on the interfacial fil...Formulating oil-based drilling fluids(OBDFs)with an ultra-low oil-to-water ratio(OWR≤60:40)presents a formidable stability challenge due to the maximized interfacial area and intensified stress on the interfacial film under high-temperature,high-density conditions.To address this,we engineered a synergistic stabilization system through molecular and colloidal design.A novel hyperbranched polyamide emulsifier(epoxidized soybean oil polyamide)(ESOP),synthesized from epoxidized soybean oil,exhibits superior thermal stability and interfacial activity due to its hyperbranched architecture.Combined with calcium petroleum sulfonate(CPS)and hydrophobic nanosilica(HNs),it enables a high-performance OBDF with an ultra-low OWR of 60:40.The results show that the optimized formula achieves an excellent demulsification voltage of 1290 V,an ultra-low HTHP fluid loss of 1.5 mL,a yield point of 12.9 Pa,and a superior sag factor(SF)of 0.504,outperforming both base and commercial systems.Mechanistic studies reveal a multiscale stabilization strategy involving a dense composite interfacial film,Pickering stabilization,a 3D network,and a unique thermally triggered self-reinforcement effect.This work not only provides a cost-effective OBDF formulation but,more importantly,establishes a molecular topology engineering paradigm for stabilizing complex industrial fluids under extreme conditions.展开更多
As a key low-carbon energy source,nuclear power plays a vital role in the global transition toward sustainable energy.Photocatalytic uranium extraction from seawater(UES)offers a promising solution to ensure long-term...As a key low-carbon energy source,nuclear power plays a vital role in the global transition toward sustainable energy.Photocatalytic uranium extraction from seawater(UES)offers a promising solution to ensure long-term uranium supply but is challenged by ultra-low uranium concentrations and ion interference.To overcome these issues,we design three diketopyrrolopyrrole-based covalent organic frameworks(COFs)via a synergisticπ-extended lock and carboxyl-functionalized anchor molecular engineering strategy.Among them,TPy-DPP-COF features a covalently lockedπ-conjugated structure that enhances planarity,optimizes energy alignment,and minimizes exciton binding energy,thereby promoting charge transfer and suppressing recombination.Concurrently,carboxyl groups enable uranyl-specific coordination and create local electric fields to facilitate charge separation.These features contribute to the outstanding performance of TPy-DPP-COF,which achieves a high uranium adsorption capacity of 16.33 mg g−1 in natural seawater under irradiation,with only 29.3%capacity loss after 10 cycles,surpassing industrial benchmarks.Density functional theory(DFT)calculations and experimental studies reveal a synergistic photocatalysis-adsorption pathway,with DPP units acting as active sites for uranium reduction.This work highlights a molecular design strategy for developing efficient COF-based photocatalysts for practical marine uranium recovery.展开更多
Tetrahydrofuran-2,5-dicarboxylic acid(THFDCA)is a bio-based cyclic dicarboxylic acid with greater flexibility and biosafety than the renowned 2,5-furandicarboxylic acid(FDCA),but its synthesis is limited to thermochem...Tetrahydrofuran-2,5-dicarboxylic acid(THFDCA)is a bio-based cyclic dicarboxylic acid with greater flexibility and biosafety than the renowned 2,5-furandicarboxylic acid(FDCA),but its synthesis is limited to thermochemical methods with only several reports.This study pioneers an electrocatalytic strategy for the efficient synthesis of THFDCA via the oxidation of tetrahydrofuran dimethanol(THFDM).By constructing NiCo bimetallic oxides micron sheets on nickel foam(NiCoMS/NF)through controlled pyrolysis of a metal-organic framework(MOF)-like precursor,we achieved a remarkable THFDM conversion of 99.0%and THFDCA yield up to 98.2%,surpassing all reports on thermocatalytic oxidation as we know.In-depth analysis revealed that the synergistic effect between NiO and Co_(3)O_(4) contributes to the high catalytic performance.In-situ Raman and rotating ring-disk electrode(RRDE)techniques were employed to discuss the reaction mechanism and the inhibitory effect on oxygen evolution reaction(OER).This study not only provides a paradigm-shifting,groundbreaking strategy for the synthesis of the flexible cyclic dicarboxylic acid derived from furanic biomass but also offers deep insights into the synergistic effects of electrocatalysts.展开更多
In this paper,we study a predator-prey model with additional food for predator.By using white noise to perturb the natural growth rates and introduce a jump process,we model the corresponding stochastic differential e...In this paper,we study a predator-prey model with additional food for predator.By using white noise to perturb the natural growth rates and introduce a jump process,we model the corresponding stochastic differential equations.The effect of fear and prey refuge on population dynamics is also considered.First,we use Itô's formula to prove the existence and uniqueness of a global positive solution and its boundedness.Next,sufficient conditions for the extinction and persistence of both species have been given.Then the stochastic permanence of our system is investigated under some conditions.Our main results demonstrate that sufficiently large white noise could drive both species to extinction.However,Lévy noise enhances the survival of both prey and predator species.Our analytical derivations are justified through numerical simulations which show the reliability of the model from the ecological point of view.In addition,we have investigated the impact of fear effect,prey refuge and the additional food biomass on this model by numerical simulation.展开更多
Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In t...Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In this work,six bis-β-ketoimine binuclear titanium complexes4a-4f containing different alkylthio sidearms and configurations were synthesized and characterized by nuclear magnetic resonance hydrogen spectrum(~1H-NMR),nuclear magnetic resonance carbon spectrum(^(13)C-NMR),Fourier transform infrared spectrum(FTIR),and elemental analysis.The intermetallic distances of isomeric complexes 4a,4d,4e and 4f determined through density functional theory(DFT)optimization were in the order 4a<4d<4e<4f and were found to significantly influence the catalytic performance for ethylene(co)polymerization.These complexes could efficiently catalyze ethylene polymerization and ethylene/1-hexene or ethylene/1-octene copolymerization with high activity to produce highmolecular-weight ethylene homo-and co-polymers.Among the three binuclear titanium complexes 4a-4c with similar structures but different lengths of alkylthio sidearms,complex 4a,which contained the shortest methylthio sidearm,exhibited the highest activity for ethylene polymerization and copolymerization with 1-hexene or 1-octene.Additionally,for ethylene/1-hexene or ethylene/1-octene copolymerization,it showed the highest comonomer incorporation compared with propylthio(4b)and octylthio(4c)derivatives because of the smaller steric hindrance of the methyl group in 4a and the more open coordination space for vinyl monomers.Furthermore,among the isomeric complexes 4a,4d,4e and4f,complex 4a with the shortest bimetallic distance also exhibited the highest activity towards ethylene(co)polymerization,and the highest 1-hexene or 1-octene incorporation in comparison with its regioisomeric counterparts 4d,4e and p-phenyl-bridged analog 4f,owing to a more appropriate bimetallic distance that is conducive to a synergistic effect.展开更多
The role of catalysts in enhancing the hydrogen storage kinetics of the Mg/MgH_(2)system is pivotal.However,the exploration of efficient catalysts and the underlying principles of their design remain both a prominent ...The role of catalysts in enhancing the hydrogen storage kinetics of the Mg/MgH_(2)system is pivotal.However,the exploration of efficient catalysts and the underlying principles of their design remain both a prominent focus and a significant challenge in current research.In this study,we present a bimetallic oxide of Bi_(2)Ti_(2)O_(7)hollow sphere as a highly effective catalyst for MgH_(2).As a result,the Bi_(2)Ti_(2)O_(7)-catalyzed Mg/MgH_(2)system lowers the hydrogen desorption initiation temperature to 194.3℃,reduces the peak desorption temperature to 245.6℃,decreases the dehydrogenation activation energy to 82.14 kJ·mol^(−1),and can absorb 5.4 wt.%of hydrogen within 60 s at 200℃,demonstrating outstanding hydrogen ab/desorption kinetics,compared to pure MgH_(2).Additionally,it can maintain a high hydrogen capacity of 5.2 wt.%,even after 50 dehydrogenation cycles,showing good cycle stability.The characterization results show that the high-valent Bi and Ti in Bi_(2)Ti_(2)O_(7)are reduced to their low-valent or even zero-valent metallic states during the dehydrogenation and hydrogenation process,thus establishing an in-situ multivalent and multi-element catalytic environment.Density functional theory calculations further reveal that the synergistic effects between Bi and Ti in the Bi-Ti mixed oxide facilitate the cleavage of Mg-H bonds and lower the kinetic barrier for the dissociation of hydrogen molecules,thereby substantially enhancing the kinetics of the Mg/MgH_(2)system.This study presents a strategic method for developing efficient catalysts for hydrogen storage materials by harnessing the synergistic effects of metal elements.展开更多
Ulcerative colitis(UC)is a chronic inflammatory disorder with a complex etiology,characterized by intestinal inflammation and barrier dysfunction.Platycodon grandiflorus polysaccharides(PGP),the primary component of P...Ulcerative colitis(UC)is a chronic inflammatory disorder with a complex etiology,characterized by intestinal inflammation and barrier dysfunction.Platycodon grandiflorus polysaccharides(PGP),the primary component of Platycodon grandiflorus,and hesperidin(Hesp),a prominent active component in Citrus aurantium L.(CAL),have both demonstrated anti-inflammatory properties.This study aims to elucidate the underlying mechanism of the synergistic effect of PGP combined with Hesp on UC,focusing on the coordinated interaction between the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)and Janus kinase 2(JAK2)/signal transducer and activator of transcription 3(STAT3)signaling pathways.A mouse model of UC induced by dextran sulfate sodium(DSS)and a cell model using lipopolysaccharide(LPS)-induced RAW264.7/IEC6 cells were employed to investigate the in vitro and in vivo anti-inflammatory effects of PGP combined with Hesp on UC and its potential mechanism of action.The results indicated that compared to the effects of either drug alone,the combination of PGP and Hesp significantly modulated inflammatory factor levels,inhibited oxidative stress,regulated colonic mucosal immunity,suppressed apoptosis,and restored intestinal barrier function in vitro and in vivo.Further in vitro studies revealed that PGP significantly inhibited the PI3K/AKT signaling pathway,while Hesp significantly inhibited the JAK2/STAT3 signaling pathway.The use of inhibitors and activators targeting both pathways validated the synergistic effects of PGP combined with Hesp on the PI3K/AKT and JAK2/STAT3 signaling pathways.These findings suggest that PGP combined with Hesp exhibits a synergistic effect on DSS-induced colitis,potentially mediated through the phosphatase and tensin homolog(PTEN)/PI3K/AKT and interleukin-6(IL-6)/JAK2/STAT3 signaling pathways.展开更多
Bulk metallic glasses(BMGs)are typically characterized by high strength and elasticity.However,they generally demonstrate a deficiency in plastic deformation capability at room temperatures.In this work,Cu_(50-x)Zr_(4...Bulk metallic glasses(BMGs)are typically characterized by high strength and elasticity.However,they generally demonstrate a deficiency in plastic deformation capability at room temperatures.In this work,Cu_(50-x)Zr_(46)Al4Agx(x=0,1,2,3,4)alloys were prepared by arc melting and copper mold casting to investigate their structure,glass-forming ability,and mechanical properties.The results show that the addition of Ag can increase the parameter of DTx and g in Cu_(50)Zr_(46)Al_(4)alloy by 116%and 1.5%respectively,effectively enhancing its thermal stability and glass-forming ability.Compressive fracture tests reveal that the addition of Ag can significantly improve the yield strength,ultimate strength,and plasticity of the Cu_(50)Zr_(46)Al_(4)alloy.Specifically,with the Ag addition of 1 at.%,the alloy’s ultimate strength and plasticity increased by 71.8%and 21 times,respectively.Furthermore,the introduction of Ag can effectively control the free volume content in the Cu_(50)Zr_(46)Al_(4)alloy,thereby tuning the hardness of the material.This work provides valuable insights into improving the mechanical performance of BMGs through micro-alloying approaches.展开更多
The introduction of metal single atoms(SAs)and nanoparticles(NPs)are effective approaches to mod-ify electronic configuration of semiconductors,whereas recognizing the synergistic effects of metal SAs and NPs are stil...The introduction of metal single atoms(SAs)and nanoparticles(NPs)are effective approaches to mod-ify electronic configuration of semiconductors,whereas recognizing the synergistic effects of metal SAs and NPs are still challenging in photocatalytic water purification.Herein,a general strategy is achieved by subsequentially anchoring Fe SAs and Fe NPs in graphitic carbon nitride.The modification of Fe SAs and Fe NPs improves the energy band structure and constructs a gradient charge polarization,directly expanding the optical absorption range and facilitating the efficient separation and transfer of charge car-riers.With the assistance of the gradient charge polarization,pollutants are readily oxidated by h+,which strengthens the continuous reduction of O2 on Fe NPs for pollutant oxidation in water.This work rein-forces the synergistic effect of SAs and NPs on electronic configuration modulation at the atomic level,which exhibits great potential for the construction of an efficient and sustainable water purification sys-tem.展开更多
文摘Chitosan(CTS)was grafted onto the surface of amino‑functionalized silver chloride silicon dioxide(AgCl@SiO_(2)‑NH_(2))cores to obtain AgCl@SiO_(2)/CTS hybrid nanoparticles.The as‑obtained AgCl@SiO_(2)/CTS nanoparticles were chlorinated by NaClO solution to get AgCl@SiO_(2)/CTS‑based chloramine nano‑hybrid materials,denoted as AgCl@SiO_(2)/CTS‑Cl.A transmission electron microscope was used to observe the morphology of the as‑prepared samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.At the same time,an X‑ray diffractometer and an infrared spectroscope were utilized to characterize their crystal and chemical structures.Besides,ζpotentials were measured to elucidate the surface modification of AgCl nanoparticles by—NH_(2),the antibacterial mechanism of AgCl@SiO_(2)/CTS‑Cl was investigated by scanning electron microscopy,and Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)were used as the to‑be‑tested strains to evaluate the antimicrobial activity of samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.Findings demonstrate that sample AgCl@SiO_(2)/CTS exhibits a chain‑like structure ascribed to the interaction between—NH_(2),and each AgCl@SiO_(2)/CTS hybrid nanoparticle contains several AgCl cores.In the meantime,sample AgCl@SiO_(2)/CTS‑Cl exhibits excellent antibacterial activity against E.coli and S.aureus,which is attributed to the synergistic antibacterial effect of Ag^(+)and Cl^(-).Sample AgCl@SiO_(2)/CTS‑Cl with a dosage of 640.00μg·mL^(-1) could completely kill the two kinds of tested bacteria in 12 h of incubation;it retains a high antibacterial efficiency even after 10 cycles of antibacterial tests.
基金supported by the National Natural Science Foundation of China(No.32170121).
文摘Benzalkonium chloride(BAC)is widely employed as a broad-spectrum biocide and has emerged as a significant environmental pollutant.Polymyxin B(PB)serves as the last-line defense for the treatment of Gram-negative pathogens.Previous studies reported that BAC-adapted Pseudomonas aeruginosa increased the tolerance to PB.Herein,we present the novel finding that the combination of BAC and PB exhibited synergistic antibacterial effects against P.aeruginosa.Time-killing assay demonstrated a significant reduction in bacterial cell viability.Scanning electron microscopy,zeta potential analysis,hydrophobicity measurements,and fluorescence probe analyses collectively revealed severe disruption of the cell envelope and membrane potential induced by the combination of BAC and PB.Transcriptomic analysis revealed that the BAC-PB combination notably downreg-ulated the expression of genes involved in lipid A modification and cell envelope production,including phoPQ,pmrAB,bamABCDE,lptABCDEG,lolB,yidC,and murJ.Additionally,the combination group exhibited augmented production of reactive oxygen species and diminished ATP synthesis.The expression of the genes associated with substance metabolism and energy generation was significantly impeded.This study provides significant implica-tions for the interactions of biocides and antibiotics on Gram-negative pathogens,while also addressing antibiotic resistance and developing the external treatment strategy for Pseudomonas-infected wounds and burns.
文摘The UV-2600 ultraviolet(UV)spectrophotometer and the UV sunscreen index analyzer SolarLight Model 601 were used to test the UV absorption capacity and the UV damage alleviating effect of commonly used raw materials,and the Hen’s Egg Test-Chorioallantoic Membrane were also processed to assess the mildness.As a result,bisabolol,pongamia pinnata seed extract,pterocarpus marsupium bark extract and other materials were screened as the effective and gentle sunscreen synergistic ingredients.
基金supported by the Jilin Science and Technology Program(20230203130SF)。
文摘Freeze–thaw(F–T)cycle-induced cracking in silty clays poses a significant risk to engineering stability.Although the individual addition of fly ash(FA)or sisal fiber(SF)provides partial solutions,their simultaneous application may result in a synergistic effect to compensate for their respective shortcomings.In this study,the effects of SF and FA on the mechanical properties,crack resistance,water retention,and erosion resistance of improved soil were systematically investigated through unconfined compressive strength(UCS)tests,crack evolution analysis,simulated rainfall erosion tests,and microscopic characterization(laser particle size analysis and nitrogen adsorption).The results reveal that the volumetric stability of FA particles significantly inhibits cracking in soil after F–T cycles.However,FA contributes only slightly to soil strength and erosion resistance.SF,on the other hand,plays a substantial role in increasing both soil strength and erosion resistance.The synergy between FA and SF results in the simultaneous increase in crack resistance,erosion resistance,and strength.FA improves the aggregate stability during F–T cycles,whereas SF reinforces the bonds between these aggregates.A comprehensive evaluation of the improved soil during F–T cycles using the entropy weight-TOPSIS method reveal that the combination of 10%FA+18 mm SF performed the best,achieving a 246%higher composite score than the unmodified soil did.With respect to this optimal combination,compared with the unmodified soil,the SF–FA-improved soil exhibits a 30%reduction in the average crack width,a 30%reduction in the erosion rate,and a 46%increase in strength.The findings of this study provide a scientific basis for the design of soil improvement in disaster mitigation engineering in seasonally frozen soil regions.
基金financially supported by the National Natural Science Foundation of China(Nos.22171122 and 22201123)Liaoning Revitalization Talents Program(No.XLYC 2007130)+1 种基金Fundamental Research Project(No.LJ212410148038)of the Educational Department of Liaoning ProvinceTalent Scientific Research Fund of Liaoning Petrochemical University(No.2016XJJL–019)。
文摘Attaining the selective oxidation of isochroman into isochromanone in a molecular oxygen(O_(2))environment without any additives,via a heterogeneous oxidation process,is highly desirable and challenging work.Herein,we prepare two mixed-addendum polyoxometalate-based coordination polymers of the general formula[H_(x)M_(1-x)(i-PrIm)_(4)][H_(2)N(CH_(3))_(2)]_(4)[HPMo_(8)V_(6)O_(42)](M=Co 1,Ni,2;i-PrIm=1-isopropyl-1H-imidazole).Needing no additives,they can catalyze the selective oxidation of isochroman to isochromanone with O_(2)as an oxidant,with yields of 91.5%(1)and 46.8%(2),respectively.Mechanistic studies indicate that the excellent performance of catalyst 1 is attributed to the synergistic operation of[Co(i-Pr-Im)_(4))]complex and PMo_(8)V_(6)unit,and that the catalytic reaction is a radical pathway involving superoxide radicals.Additionally,the catalyst 1 can be recycled and reused at least four times with uncompromised performance.These results provide fundamental guidelines for designing efficient and multi-site heterogeneous catalysts for the selective oxidation of benzyl C(sp^(3))-H bonds by activating O_(2).
基金National Natural Science Foundation of China(No.U2241231)National Key Research and Development Program of China(No.2021YFB3701100)+1 种基金Scientific Research Project of Jiangxi Provincial Department of Education,China(No.GJJ211038)Doctoral Research Project of Jinggangshan University,China(No.JZB2110)。
文摘The synergistic effect of low Gd+Mn additions on the evolution of microstructure and mechanical properties of Mg−xGd−0.8Mn alloy was investigated.Gd addition shows a strong grain refinement effect on the extruded Mg−xGd−0.8Mn alloy,and leads to a continuous decrease in the area fraction of basal texture grains and the corresponding maximum density of texture components.However,the maximum density of the basal texture components grows abruptly as Gd content increases to 6 wt.%.When the Gd content is below 6 wt.%,the asymmetry of the tensile and compressive yield of the alloy is negatively correlated to the Gd content due to grain refinement and texture weakening effects.Besides,the contribution of grain refinement to higher alloy yield strength is more significant than that of grain orientation.Compared with the extruded Mg−xGd alloy,the extruded Mg−xGd−0.8Mn alloy shows a lower limit composition point that corresponds to solid solution strengthening and plasticizing effect(2 wt.%and 4 wt.%).Finally,the trend of basal slip and prismatic slip resistance variations of the extruded Mg−xGd−0.8Mn alloys was predicted.
文摘Electrodeposition of acid copper plating on mild steel substrate is tedious due to the galvanic displacement reaction ofcopper on mild steel.This can be avoided by using a proper complexing agent,because the complexing agent tuned the potential ofnoble direction to less noble direction by complex formation.In this paper,environment friendly electrodeposition of copper fromnon-cyanide electrolyte using sodium gluconate as complexing agent was investigated in alkaline medium.The effects of additivessuch as1,2,3-benzotriazole,sodium lauryl sulphate,PEG8000and saccharin were studied.These additives are found to reduce thegrain size,grain boundaries and improve surface morphology of the copper deposits.Also they improve the throwing power of thedepositing electrolytes and hardness of deposits.The electrodeposited copper coatings were characterized by X-ray diffractiontechnique.XRD results indicate that the electrodeposited copper shows polycrystalline and face centered cubic structure.The crystalsize was calculated by XRD and AFM analysis.Among these additives studied,the mixture of benzotriazole and sodium laurylsulphate acts as the best additive.A uniform pore-free surface observed under SEM and AFM results reveal the grain refining broughtabout by the additives.
文摘The major solving ways for the material wear are surface modification and lubrication. Currently, the researches at home and abroad are all limited to the single study of either nano-lubricating oil additive or electroless deposited coating. The surface coating has high hardness and high wear resistance, however, the friction reduction performance of the coating with high hardness is not good, the thickness of the coating is limited, and the coating can not regenerate after wearing. The nano-lubricating additives have good tribological performance and self-repair function, but under heavy load, the self-repair rate to the worn surface with the nano-additives is smaller than the wearing rate of the friction pair. To solve the above problems, the Ni-W-P alloy coating and deposition process with excellent anti-wear, and suitable for industrial application were developed, the optimum bath composition and process can be obtained by studying the influence of the bath composition, temperature and PH value to the deposition rate and the plating solution stability. The tribological properties as well as anti-wear and friction reduction mechanism of wear self-repair nano-ceramic lubricating additives are also studied. The ring-block abrasion testing machine and energy dispersive spectrometer are used to explore the internal relation between the coating and the nano-lubricating oil additives, and the tribology mechanism, to seek the synergetic effect between the two. The test results show that the wear resistance of Ni-W-P alloy coating （with heat treatment and in oil with nano-ceramic additives） has increased hundreds times than 45 steel as the metal substrate in basic oil, the friction reduction performance is improved. This research breaks through the bottleneck of previous separate research of the above-mentioned two methods, and explores the combination use of the two methods in industrial field.
文摘Background: The radiosensitizing effect of Photofrin II has been demonstrated in vitro and in animal models, even in tumor models known to be highly radioresistant, such as glioblastoma and bladder carcinoma. Radio-adaptive doses are also known to lead to an augmented cell or tissue reaction. The aim of this study was to investigate potential synergistic or additive effects when combining the two methods in vitro for an improved therapeutic concept in bladder cancer. Material and Methods: RT4 human bladder carcinoma cell line and HCV29 human bladder epithelium cells were seeded and incubated with various concentrations of Photofrin II. The cells were additionally irradiated with ionizing radiation (0.05 Gy/2 Gy/0.05 Gy + 2 Gy). Cells without Photofrin II incubation and irradiation served as controls. The cell survival was evaluated. Results: The survival rate of both cell lines, RT4 and HCV29, did not differ significantly when incubated with a non-toxic concentration of Photofrin II and exposed to a pre-irradiation dose of 0.05 Gy prior to the 2 Gy radiation fraction, compared to cells exposed to Photofrin II plus a 2 Gy ionizing radiation. Conclusion: The combination of both methods did neither demonstrate a synergistic or additive effect nor did it lead to a negative influence of both modulating factors in an in vitro setting.
基金National Natural Science Foundation of China(42030611)Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(2019QZKK0103)。
文摘Autumn rain in western China(ARWC)is a unique and significant precipitation phenomenon that occurs during the summer-to-winter transition of the atmospheric circulation.Using the fifth generation of global climate and weather reanalysis data from the European Centre for Medium-Range Weather Forecasts and CN05.1 grid precipitation data,this study examined the anomalous characteristics and mechanisms of ARWC by combining the synergistic effect of the westerly jet and meridional wind.Over the past 60 years,ARWC has exhibited significant interdecadal and interannual variations,as well as a north-south seesaw pattern.The westerly jet index(meridional wind index)exhibited a negative(positive)correlation with precipitation in the northern autumn rain zone(NARZ),and a positive(negative)correlation with precipitation in the southern autumn rain zone(SARZ).The coupling of a weak meridional southerly wind with a southward westerly jet and a strong meridional southerly wind with a northward westerly jet are the two primary modes that synergistically influence the ARWC.These synergistic effects cause significant atmospheric changes throughout the troposphere.The contrasting circulation structure,temperature advection,vertical motion,and water vapor flux contributed to the opposite precipitation anomalies observed in the NARZ and SARZ.A new comprehensive index that reflects the coupled synergistic effect is proposed to characterize the anomalous changes in ARWC.This study improves the understanding of the anomalous characteristics and mechanisms of ARWC.
基金supported by the Financial Supports of the National Natural Science Foundation of China(Nos.51508056,52370030 and 42007352)the Chongqing Postgraduate Joint Training Base Project(No.JDLHPYJD2022005)the special fund of Henan Key Labora-tory of Water Pollution Control and Rehabilitation Technology(No.CJSZ2024001).
文摘This study developed a novel heterogeneous Vis-Photo+Fenton-like system by integrating visible-light-responsive Co_(3)O_(4)/TiO_(2) photocatalysis with peroxymonosulfate(PMS)activation for efficient atrazine(ATZ)degradation.The synergistic process achieved complete ATZ removal within 60 min under near-neutral pH(6.9),outperform-ing individual Fenton-like(39%)and photocatalytic(24%)processes.Key factors influencing the degradation efficiency included light sources(UV>visible),pH(optimal at 6.9),catalyst dosage(0.01 g Co_(3)O_(4)/TiO_(2)),and PMS:ATZ molar ratio(1:2).The system exhibited a synergistic coefficient of 5.03(degradation)and 1.97(miner-alization),attributed to enhanced radical generation and accelerated Co^(3+)/Co^(2+)redox cycling through photoin-duced electron transfer.Intermediate analysis revealed dealkylation,dechlorination,and oxidation pathways,with reduced toxicity of by-products(e.g.,CEAT,CIAT)confirmed by ecotoxicity assessments.The mineralization efficiency(Vis-Photo+Fenton-like)reached 83.1%,significantly higher than that of standalone processes(Fenton-like:43.2%;photocatalysis:30.5%).The catalyst demonstrated excellent stability(nearly 90%recov-ery,<1μg/L Co leaching)and practical applicability.This study provides an efficient,sludge-free,and solar-compatible strategy for eliminating persistent herbicides in water treatment.
基金supported by the Key Research and Development Program Project of Hubei Province(2023BCB070).
文摘Formulating oil-based drilling fluids(OBDFs)with an ultra-low oil-to-water ratio(OWR≤60:40)presents a formidable stability challenge due to the maximized interfacial area and intensified stress on the interfacial film under high-temperature,high-density conditions.To address this,we engineered a synergistic stabilization system through molecular and colloidal design.A novel hyperbranched polyamide emulsifier(epoxidized soybean oil polyamide)(ESOP),synthesized from epoxidized soybean oil,exhibits superior thermal stability and interfacial activity due to its hyperbranched architecture.Combined with calcium petroleum sulfonate(CPS)and hydrophobic nanosilica(HNs),it enables a high-performance OBDF with an ultra-low OWR of 60:40.The results show that the optimized formula achieves an excellent demulsification voltage of 1290 V,an ultra-low HTHP fluid loss of 1.5 mL,a yield point of 12.9 Pa,and a superior sag factor(SF)of 0.504,outperforming both base and commercial systems.Mechanistic studies reveal a multiscale stabilization strategy involving a dense composite interfacial film,Pickering stabilization,a 3D network,and a unique thermally triggered self-reinforcement effect.This work not only provides a cost-effective OBDF formulation but,more importantly,establishes a molecular topology engineering paradigm for stabilizing complex industrial fluids under extreme conditions.
基金the Young Elite Scientists Sponsorship Program by JXAST(2024QT11)the National Natural Science Foundation of China(22465001,22309003)the Jiangxi Provincial Natural Science Foundation(20232BAB203042,20242BAB22002).
文摘As a key low-carbon energy source,nuclear power plays a vital role in the global transition toward sustainable energy.Photocatalytic uranium extraction from seawater(UES)offers a promising solution to ensure long-term uranium supply but is challenged by ultra-low uranium concentrations and ion interference.To overcome these issues,we design three diketopyrrolopyrrole-based covalent organic frameworks(COFs)via a synergisticπ-extended lock and carboxyl-functionalized anchor molecular engineering strategy.Among them,TPy-DPP-COF features a covalently lockedπ-conjugated structure that enhances planarity,optimizes energy alignment,and minimizes exciton binding energy,thereby promoting charge transfer and suppressing recombination.Concurrently,carboxyl groups enable uranyl-specific coordination and create local electric fields to facilitate charge separation.These features contribute to the outstanding performance of TPy-DPP-COF,which achieves a high uranium adsorption capacity of 16.33 mg g−1 in natural seawater under irradiation,with only 29.3%capacity loss after 10 cycles,surpassing industrial benchmarks.Density functional theory(DFT)calculations and experimental studies reveal a synergistic photocatalysis-adsorption pathway,with DPP units acting as active sites for uranium reduction.This work highlights a molecular design strategy for developing efficient COF-based photocatalysts for practical marine uranium recovery.
基金supported by the National Natural Science Foundation of China(22072170,U23A20125)the President Foundation of Ningbo Institute of Materials Technology and Engineering。
文摘Tetrahydrofuran-2,5-dicarboxylic acid(THFDCA)is a bio-based cyclic dicarboxylic acid with greater flexibility and biosafety than the renowned 2,5-furandicarboxylic acid(FDCA),but its synthesis is limited to thermochemical methods with only several reports.This study pioneers an electrocatalytic strategy for the efficient synthesis of THFDCA via the oxidation of tetrahydrofuran dimethanol(THFDM).By constructing NiCo bimetallic oxides micron sheets on nickel foam(NiCoMS/NF)through controlled pyrolysis of a metal-organic framework(MOF)-like precursor,we achieved a remarkable THFDM conversion of 99.0%and THFDCA yield up to 98.2%,surpassing all reports on thermocatalytic oxidation as we know.In-depth analysis revealed that the synergistic effect between NiO and Co_(3)O_(4) contributes to the high catalytic performance.In-situ Raman and rotating ring-disk electrode(RRDE)techniques were employed to discuss the reaction mechanism and the inhibitory effect on oxygen evolution reaction(OER).This study not only provides a paradigm-shifting,groundbreaking strategy for the synthesis of the flexible cyclic dicarboxylic acid derived from furanic biomass but also offers deep insights into the synergistic effects of electrocatalysts.
基金Supported by Guangxi Natural Science Foundation(2026GXNSFAA00641039)。
文摘In this paper,we study a predator-prey model with additional food for predator.By using white noise to perturb the natural growth rates and introduce a jump process,we model the corresponding stochastic differential equations.The effect of fear and prey refuge on population dynamics is also considered.First,we use Itô's formula to prove the existence and uniqueness of a global positive solution and its boundedness.Next,sufficient conditions for the extinction and persistence of both species have been given.Then the stochastic permanence of our system is investigated under some conditions.Our main results demonstrate that sufficiently large white noise could drive both species to extinction.However,Lévy noise enhances the survival of both prey and predator species.Our analytical derivations are justified through numerical simulations which show the reliability of the model from the ecological point of view.In addition,we have investigated the impact of fear effect,prey refuge and the additional food biomass on this model by numerical simulation.
基金financially supported by the National Natural Science Foundation of China(No.21172269)the Fundamental Research Funds for the Central Universities,SouthCentral Minzu University(No.CZH24005)。
文摘Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In this work,six bis-β-ketoimine binuclear titanium complexes4a-4f containing different alkylthio sidearms and configurations were synthesized and characterized by nuclear magnetic resonance hydrogen spectrum(~1H-NMR),nuclear magnetic resonance carbon spectrum(^(13)C-NMR),Fourier transform infrared spectrum(FTIR),and elemental analysis.The intermetallic distances of isomeric complexes 4a,4d,4e and 4f determined through density functional theory(DFT)optimization were in the order 4a<4d<4e<4f and were found to significantly influence the catalytic performance for ethylene(co)polymerization.These complexes could efficiently catalyze ethylene polymerization and ethylene/1-hexene or ethylene/1-octene copolymerization with high activity to produce highmolecular-weight ethylene homo-and co-polymers.Among the three binuclear titanium complexes 4a-4c with similar structures but different lengths of alkylthio sidearms,complex 4a,which contained the shortest methylthio sidearm,exhibited the highest activity for ethylene polymerization and copolymerization with 1-hexene or 1-octene.Additionally,for ethylene/1-hexene or ethylene/1-octene copolymerization,it showed the highest comonomer incorporation compared with propylthio(4b)and octylthio(4c)derivatives because of the smaller steric hindrance of the methyl group in 4a and the more open coordination space for vinyl monomers.Furthermore,among the isomeric complexes 4a,4d,4e and4f,complex 4a with the shortest bimetallic distance also exhibited the highest activity towards ethylene(co)polymerization,and the highest 1-hexene or 1-octene incorporation in comparison with its regioisomeric counterparts 4d,4e and p-phenyl-bridged analog 4f,owing to a more appropriate bimetallic distance that is conducive to a synergistic effect.
基金supported by the National Key Research and Development Program of China(No.2024YFB4007204,2022YFB4004301)the National Natural Science Founda-tion of China(Grant Nos.52477220,52301287,22005353)+2 种基金the Two-chain Integration Key Project of Shaanxi Province(2021LLRH-09)the Key Research and Development Program of Shaanxi Province(No.2024CY2-GJHX-44,2024CY2-GJHX-53,2024GX-ZDCYL-04-06)the Key Industrial Chain Technology Research Program of Xi’an city(23LL-RHZDZX0017).
文摘The role of catalysts in enhancing the hydrogen storage kinetics of the Mg/MgH_(2)system is pivotal.However,the exploration of efficient catalysts and the underlying principles of their design remain both a prominent focus and a significant challenge in current research.In this study,we present a bimetallic oxide of Bi_(2)Ti_(2)O_(7)hollow sphere as a highly effective catalyst for MgH_(2).As a result,the Bi_(2)Ti_(2)O_(7)-catalyzed Mg/MgH_(2)system lowers the hydrogen desorption initiation temperature to 194.3℃,reduces the peak desorption temperature to 245.6℃,decreases the dehydrogenation activation energy to 82.14 kJ·mol^(−1),and can absorb 5.4 wt.%of hydrogen within 60 s at 200℃,demonstrating outstanding hydrogen ab/desorption kinetics,compared to pure MgH_(2).Additionally,it can maintain a high hydrogen capacity of 5.2 wt.%,even after 50 dehydrogenation cycles,showing good cycle stability.The characterization results show that the high-valent Bi and Ti in Bi_(2)Ti_(2)O_(7)are reduced to their low-valent or even zero-valent metallic states during the dehydrogenation and hydrogenation process,thus establishing an in-situ multivalent and multi-element catalytic environment.Density functional theory calculations further reveal that the synergistic effects between Bi and Ti in the Bi-Ti mixed oxide facilitate the cleavage of Mg-H bonds and lower the kinetic barrier for the dissociation of hydrogen molecules,thereby substantially enhancing the kinetics of the Mg/MgH_(2)system.This study presents a strategic method for developing efficient catalysts for hydrogen storage materials by harnessing the synergistic effects of metal elements.
基金supported by the Major Fund Project of Anhui Province Department of Education(No.2022AH040077)the Academic Funding for Top Talents in Disciplines(Specialities)of Anhui Provincial High Education Institutes(No.gxbjzD2021056)the Program for New Era Cultivate Talents of Anhui province(Postgraduate Education)(No.2022xscx099).
文摘Ulcerative colitis(UC)is a chronic inflammatory disorder with a complex etiology,characterized by intestinal inflammation and barrier dysfunction.Platycodon grandiflorus polysaccharides(PGP),the primary component of Platycodon grandiflorus,and hesperidin(Hesp),a prominent active component in Citrus aurantium L.(CAL),have both demonstrated anti-inflammatory properties.This study aims to elucidate the underlying mechanism of the synergistic effect of PGP combined with Hesp on UC,focusing on the coordinated interaction between the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)and Janus kinase 2(JAK2)/signal transducer and activator of transcription 3(STAT3)signaling pathways.A mouse model of UC induced by dextran sulfate sodium(DSS)and a cell model using lipopolysaccharide(LPS)-induced RAW264.7/IEC6 cells were employed to investigate the in vitro and in vivo anti-inflammatory effects of PGP combined with Hesp on UC and its potential mechanism of action.The results indicated that compared to the effects of either drug alone,the combination of PGP and Hesp significantly modulated inflammatory factor levels,inhibited oxidative stress,regulated colonic mucosal immunity,suppressed apoptosis,and restored intestinal barrier function in vitro and in vivo.Further in vitro studies revealed that PGP significantly inhibited the PI3K/AKT signaling pathway,while Hesp significantly inhibited the JAK2/STAT3 signaling pathway.The use of inhibitors and activators targeting both pathways validated the synergistic effects of PGP combined with Hesp on the PI3K/AKT and JAK2/STAT3 signaling pathways.These findings suggest that PGP combined with Hesp exhibits a synergistic effect on DSS-induced colitis,potentially mediated through the phosphatase and tensin homolog(PTEN)/PI3K/AKT and interleukin-6(IL-6)/JAK2/STAT3 signaling pathways.
基金supported by the National Natural Science Foun-dation of China(Grant Nos.12404228 and 52371148)the Science and Technology Research Program of Chongqing Ed-ucation Commission of China(Grant No.KJQN202200510).
文摘Bulk metallic glasses(BMGs)are typically characterized by high strength and elasticity.However,they generally demonstrate a deficiency in plastic deformation capability at room temperatures.In this work,Cu_(50-x)Zr_(46)Al4Agx(x=0,1,2,3,4)alloys were prepared by arc melting and copper mold casting to investigate their structure,glass-forming ability,and mechanical properties.The results show that the addition of Ag can increase the parameter of DTx and g in Cu_(50)Zr_(46)Al_(4)alloy by 116%and 1.5%respectively,effectively enhancing its thermal stability and glass-forming ability.Compressive fracture tests reveal that the addition of Ag can significantly improve the yield strength,ultimate strength,and plasticity of the Cu_(50)Zr_(46)Al_(4)alloy.Specifically,with the Ag addition of 1 at.%,the alloy’s ultimate strength and plasticity increased by 71.8%and 21 times,respectively.Furthermore,the introduction of Ag can effectively control the free volume content in the Cu_(50)Zr_(46)Al_(4)alloy,thereby tuning the hardness of the material.This work provides valuable insights into improving the mechanical performance of BMGs through micro-alloying approaches.
基金the National Natural Science Foundation of China(Nos.52100032 and 52350005)the Basic and Applied Basic Research Project of Guangzhou(Nos.2024A04J3679, 2024A03J0088)+2 种基金the Introduced Innovative Research and Development Team Project under the“The Pearl River Talent Recruitment Program”of Guangdong Province(No.2019ZT08L387)the Special Basic Research Fund for Central Public Research Institutes of China(No.PMzx703-202204-152)the Research Fund Program of Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology(No.2023B1212060016).
文摘The introduction of metal single atoms(SAs)and nanoparticles(NPs)are effective approaches to mod-ify electronic configuration of semiconductors,whereas recognizing the synergistic effects of metal SAs and NPs are still challenging in photocatalytic water purification.Herein,a general strategy is achieved by subsequentially anchoring Fe SAs and Fe NPs in graphitic carbon nitride.The modification of Fe SAs and Fe NPs improves the energy band structure and constructs a gradient charge polarization,directly expanding the optical absorption range and facilitating the efficient separation and transfer of charge car-riers.With the assistance of the gradient charge polarization,pollutants are readily oxidated by h+,which strengthens the continuous reduction of O2 on Fe NPs for pollutant oxidation in water.This work rein-forces the synergistic effect of SAs and NPs on electronic configuration modulation at the atomic level,which exhibits great potential for the construction of an efficient and sustainable water purification sys-tem.
