Mixed gels of chitosan-pectin were prepared by varying the ratio of constituents in the presence of NaCl. Mixed gel at 3%of total polysaccharide concentration with addtion of 12%NaCl showed a synergistic maximum when ...Mixed gels of chitosan-pectin were prepared by varying the ratio of constituents in the presence of NaCl. Mixed gel at 3%of total polysaccharide concentration with addtion of 12%NaCl showed a synergistic maximum when the ratio of chitosan to pectin was 60: 40. The effect of the polysaccharide concentration, the preparation temperature (T p), the time of incubation, balk salt concentration, the molecular weight and the degree of deacetylation of chitosan on gelation have been studied. Interaction mechanism between molecules of both polysaccharides was investigated by FT-IR spectrometry.展开更多
1. Introduction The increasing global demand for sustainable energy sources and emerging environmental issues have pushed the development of energy conversion and storage technologies to the forefront of chemical rese...1. Introduction The increasing global demand for sustainable energy sources and emerging environmental issues have pushed the development of energy conversion and storage technologies to the forefront of chemical research [1,2]. In particular, electrochemical CO_(2) reduction(CO_(2) R) to value-added fuels and chemicals presents a feasible pathway for renewable energy storage and could help mitigate the ever-increasing CO_(2) emissions [3].展开更多
In this paper,the adsorption behaviors of phenol on polymeric adsorbents(Amberlite XAD4,NDA101,and D301) were investigated in batch system at 293,303,and 313 K,respectively.As the results shown,the adsorption isotherm...In this paper,the adsorption behaviors of phenol on polymeric adsorbents(Amberlite XAD4,NDA101,and D301) were investigated in batch system at 293,303,and 313 K,respectively.As the results shown,the adsorption isotherms of phenol on all adsorbents can be well fitted by Langmuir and Freundlich equations,which indicate a favorable and exothermic process.The adsorption capacity on a newly developed aminated adsorbent,NDA101,on which adsorption could be achieved by both hydrogen bonding interaction and π-π interaction,are higher than that on a weak base adsorbent,D301,on which adsorption could be achieved by hydrogen bonding interaction only,and on a nonpolar adsorbent,XAD4,on which adsorption could be achieved by π-π interaction only.The results of this paper indicate that the synergistic effect of some weak interactions,which occur simultaneously would contribute more to the adsorption than that occur individually.展开更多
Multiple viral infections in insect vectors with synergistic effects are common in nature,but the underlying mechanism remains elusive.Here,we find that rice gall dwarf reovirus(RGDV)facilitates the transmission of ri...Multiple viral infections in insect vectors with synergistic effects are common in nature,but the underlying mechanism remains elusive.Here,we find that rice gall dwarf reovirus(RGDV)facilitates the transmission of rice stripe mosaic rhabdovirus(RSMV)by co-infected leafhopper vectors.RSMV nucleoprotein(N)alone activates complete anti-viral autophagy,while RGDV nonstructural protein Pns11 alone induces pro-viral incomplete autophagy.In co-infected vectors,RSMVexploits Pns11-induced autophagosomes to assemble enveloped virions via N-Pns11-ATG5 interaction.Furthermore,RSMV could effectively propagate in Sf9 cells.Expression of Pns11 in Sf9 cells or leafhopper vectors causes the recruitment of N from the ER to Pns11-induced autophagosomes and inhibits N-induced complete autophagic flux,finally facilitating RSMV propagation.In summary,these results demonstrate a previously unappreciated role of autophagy in the regulation of the direct synergistic interaction during co-transmission of two distinct arboviruses by insect vectors and reveal the functional importance of virus-induced autophagosomes in rhabdovirus assembly.展开更多
Inflorescences are flower-bearing shoots that originate from pools of stem cells in shoot apical meristems (SAM).Inflorescence architecture is determined by a process of meristem maturation,during which stem cell fate...Inflorescences are flower-bearing shoots that originate from pools of stem cells in shoot apical meristems (SAM).Inflorescence architecture is determined by a process of meristem maturation,during which stem cell fate switches from a vegetative to a reproductive growth program.A major factor in plant reproductive success in nature and yield in agriculture is the number of branches and flowers on inflorescences (Kobayashi and Weigel,2007;展开更多
The development of efficient single-atom catalysts(SACs) for the oxygen reduction reaction(ORR)remains a formidable challenge,primarily due to the symmetric charge distribution of metal singleatom sites(M-N_(4)).To ad...The development of efficient single-atom catalysts(SACs) for the oxygen reduction reaction(ORR)remains a formidable challenge,primarily due to the symmetric charge distribution of metal singleatom sites(M-N_(4)).To address such issue,herein,Fe-N_(x) sites coupled synergistic catalysts fabrication strategy is presented to break the uniform electronic distribution,thus enhancing the intrinsic catalytic activity.Precisely,atomically dispersed Fe-N_(x) sites supported on N/S-doped mesoporous carbon(NSC)coupled with FeS@C core-shell nanoparticles(FAS-NSC@950) is synthesized by a facile hydrothermal reaction and subsequent pyrolysis.Due to the presence of an in situ-grown conductive graphitic layer(shell),the FeS nanoparticles(core) effectively adjust the electronic structure of single-atom Fe sites and facilitate the ORR kinetics via short/long-range coupling interactions.Consequently,FAS-NSC@950displays a more positive half-wave potential(E_(1/2)) of 0.871 V with a significantly boosted ORR kinetics(Tafel slope=52.2 mV dec^(-1)),outpacing the commercial Pt/C(E_(1/2)=0.84 V and Tafel slope=54.6 mV dec^(-1)).As a bifunctional electrocatalyst,it displays a smaller bifunctional activity parameter(ΔE) of 0.673 V,surpassing the Pt/C-RuO_(2) combination(ΔE=0.724 V).Besides,the FAS-NSC@950-based zincair battery(ZAB) displays superior power density,specific capacity,and long-term cycling performance to the Pt/C-Ir/C-based ZAB.This work significantly contributes to the field by offering a promising strategy to enhance the catalytic activity of SACs for ORR,with potential implications for energy conversion and storage technologies.展开更多
Korean spruce （Picea koraiensis Sieb. E1 Zucc.） is one of the main afforestation species in northern China. Seedling quality is a critical factor at planting time. To test whether the synergistic growth enhancement ...Korean spruce （Picea koraiensis Sieb. E1 Zucc.） is one of the main afforestation species in northern China. Seedling quality is a critical factor at planting time. To test whether the synergistic growth enhancement of Scotch pine （P. sylvestris var. mongolica） seedlings brought by the plant beneficial fungus Trichoderma virens （J.H. Mill., Giddens and A.A. Foster） Arx and ectomycorrhizal fungus （Suillus luteus （L.） Roussel.） can also benefit Korean spruce seed- lings, we examined the effects of S. luteus and T. virens on the growth of P. koraiensis seedlings and drought resistance of P. sylvestris var. mongolica in peat soils. The two fungi were added to sterilized peat soil in pots, and the plants were grown for 4 months. Seedling growth and physiological variables, including mycorrhizal colonization rate of roots, biomass, and chlorophyll content, were examined. The colonization rate of the mycorrhizal fungus on P. koraiensis exceeded 65 %, and the synergism between S. luteus and T. virens enhanced most of the variables for P. koraiensis seedlings after inoculation with S. luteus then 30 days later with T. virens as in our published results for seedlings of P. sylvestris var. mongolica. When seedlings of P. sylvestris var. mongolica were inoculated with this sequence, they became more drought tolerant. T. virens also induced S. luteus to produce -l,3-glucanase and chitinase. This inocu- lation sequence at planting can thus improve the quality of P. sylvestris var. mongolica and P. koraiensis seedlings and substantiates our previous results.展开更多
The aim of this work was to investigate the possible synergistic interaction between monopalmitate(MP)and carnauba wax(CW)on the properties and crystallization behavior of oleogels.The soybean oleogels were prepared f...The aim of this work was to investigate the possible synergistic interaction between monopalmitate(MP)and carnauba wax(CW)on the properties and crystallization behavior of oleogels.The soybean oleogels were prepared from MP and CW,and were characterized by oil binding capacity(OBC),solid fat content(SFC)and isothermal crystallization.The results showed that the OBC of the prepared oleogels changed in a W-shape trend with the increase of CW content.The mass ratio of MP and CW greatly affected the SFC.At 40,50 and 60°C,the SFC of these oleogels showed a slight deep eutectic effect with the increase of CW content in the gelators.The mass ratio of MP to CW also apparently affected the peak temperature and enthalpy during the crystallization and melting process analyzed by differential scanning calorimeter.The hysteresis occurring in the study indicated that crystallization temperature was lower than melting temperature and crystallization enthalpy was higher than melting enthalpy.The isothermal crystallization of these oleogels was characterized by Avrami equation,the Avrami exponent(n)and the apparent crystallization constant(k)of these oleogels were affected by the mass ratio of MP to CW as well as the crystallization temperature.Great difference in the values of n and k between the MP(or CW)oleogel and these oleogels suggested that the crystal growth mechanism had changed.However,the factor k for the oleogel formed of MP and CW with a mass ratio of 2:8 was about 1,unaffected by the crystallization temperature.From these results,we could deduce that the synergistic interaction between MP and CW did happen and affect the properties and crystallization behavior of these oleogels.展开更多
Sulfur redox reactions render lithium–sulfur(Li–S)batteries with an energy density of>500Whkg−1 but suffer a low practical capacity and fast capacity fade due to sluggish sulfur redox reaction(SRR)kinetics,which ...Sulfur redox reactions render lithium–sulfur(Li–S)batteries with an energy density of>500Whkg−1 but suffer a low practical capacity and fast capacity fade due to sluggish sulfur redox reaction(SRR)kinetics,which lies in the complex reaction process that involves a series of reaction intermediates and proceeds via a cascade reaction.Here,we present a Pt–Cu dual-atom catalyst(Pt/Cu-NG)as an electrocatalyst for sulfur redox reactions.Pt/Cu-NG enabled the rapid conversion of soluble polysulfide intermediates into insoluble Li2S2/Li2S,and consequently,it prevented the accumulation and shuttling of lithium polysulfides,thus outperforming the corresponding single-atom catalysts(SACs)with individual Pt or Cu sites.Operando X-ray absorption spectroscopy and density functional theory calculations revealed that a synergistic effect between the paired Pt and Cu atoms modifies the electronic structure of the Pt site through d-orbital interactions,resulting in an optimal moderate interaction of the metal atom with the different sulfide species.This optimal interaction enhanced charge transfer kinetics and promoted sulfur redox reactions.Our work thus provides important insights on the atomic scale into the synergistic effects operative in dual-atom catalysts and will thus pave the way to electrocatalysts with enhanced efficiency for high-performance Li–S batteries.展开更多
The hydrogen evolution reaction(HER) through electrocatalysis is promising for the production of clean hydrogen fuel. However,designing the structure of catalysts,controlling their electronic properties,and manipulati...The hydrogen evolution reaction(HER) through electrocatalysis is promising for the production of clean hydrogen fuel. However,designing the structure of catalysts,controlling their electronic properties,and manipulating their catalytic sites are a significant challenge in this field. Here,we propose an electrochemical surface restructuring strategy to design synergistically interactive phosphorus-doped carbon@MoP electrocatalysts for the HER. A simple electrochemical cycling method is developed to tune the thickness of the carbon layers that cover on MoP core,which significantly influences HER performance. Experimental investigations and theoretical calculations indicate that the inactive surface carbon layers can be removed through electrochemical cycling,leading to a close bond between the MoP and a few layers of coated graphene. The electronsdonated by the MoP core enhance the adhesion and electronegativity of the carbon layers;the negatively charged carbon layers act as an active surface. The electrochemically induced optimization of the surface/interface electronic structures in the electrocatalysts significantly promotes the HER. Using this strategy endows the catalyst with excellent activity in terms of the HER in both acidic and alkaline environments(current density of 10 mA cm^(-2) at low overpotentials,of 68 mV in 0.5 M H_(2)SO_(4) and 67 mV in 1.0 M KOH).展开更多
A field experiment was conducted at Kpongu in the Upper West region of Ghana to determine the added benefits in grain yield of maize derived from the concurrent use of manure and mineral fertilizer, and their cost eff...A field experiment was conducted at Kpongu in the Upper West region of Ghana to determine the added benefits in grain yield of maize derived from the concurrent use of manure and mineral fertilizer, and their cost effectiveness. Factorial combinations of cattle manure and mineral fertilizer each at 0, 50 and 100% of their recommended rates were evaluated in both the field and the laboratory studies. The treatments were applied in a randomized complete block design with three replications on the field. The same treatments were applied in the incubation study in a completely randomized design. The use of 100% NPK （Nitrogen, Phosphorus, Potassium） ＋ 5 t manure gave the highest grain yield of 4,678 kg·ha^-1. Synergistic interactions resulting in added benefits in grain yield were observed in all the combined nutrient inputs except 50% NPK ＋ 2.5 t manure which accrued an added disadvantage of 44 kg·ha^-1. Economic analysis proved that 100% NPK ＋ 2.5 t manure and 50% NPK ＋ 5 t manure were the most economically viable combined treatments in terms of grain yield. Based on the results from this study, resource poor farmers in the Upper West region of Ghana may reduce mineral fertilizer recommended rates by 50% and supplement it with 5 t quality （N 〉2.5%） cattle manure without compromising yield and profit.展开更多
Hormonal crosstalk is central for tailoring plant responses to the nature of challenges encountered. The role of antagonism between the two major defense hormones, salicylic acid （SA） and jasmonic acid （JA）, and m...Hormonal crosstalk is central for tailoring plant responses to the nature of challenges encountered. The role of antagonism between the two major defense hormones, salicylic acid （SA） and jasmonic acid （JA）, and modulation of this interplay by ethylene （ET） in favor of JA signaling pathway in plant stress responses is well recognized, but the underlying mechanism is not fully understood. Here, we show the opposing function of two transcription factors, ethylene insensitive3 （EIN3） and EIN3-Like1 （EIL1）, in SA-mediated suppression and JA- mediated activation of PLANT DEFENSINI.2 （PDFI.2）. This functional duality is mediated via their effect on protein, not transcript levels of the PDF1.2 transcriptional activator octadecanoid-responsive Arabidopsis59 （ORA59）. Specifically, JA induces ORA59 protein levels independently of EIN3/EIL1, whereas SA reduces the protein levels dependently of EIN3/EIL1. Co-infiltration assays revealed nuclear co-localization of ORA59 and EIN3, and split- luciferase together with yeast-two-hybrid assays established their physical interaction. The functional ramification of the physical interaction is EIN3-dependent degradation of ORA59 by the 26S proteasome. These findings allude to SA-responsive reduction of ORA59 levels mediated by EIN3 binding to and targeting of ORA59 for degrada4tion, thus nominating ORA59 pool as a coordination node for the antagonistic function of ET/JA and SA.展开更多
Hydrogen evolution electrocatalysts derived from metal-organic crystalline frameworks can inherit the merits of ordered and adjustable structures with high surface area.In this paper,organic-octamolybdate crystalline ...Hydrogen evolution electrocatalysts derived from metal-organic crystalline frameworks can inherit the merits of ordered and adjustable structures with high surface area.In this paper,organic-octamolybdate crystalline superstructures(OOCS)with a fixed stoichiometric ratio of Mo_(8)(L)_(2) and high Mo content(>40 wt%)were synthesized using flexible ligands with controllable lengths(named as OOCS-1-3).Then,molybdenum carbides coated with carbon layers as electrocatalysts(Mo_(2)C@C-1-3)can be obtained directly from a one-step high-temperature carbonization process using OOCS-1-3 as precursors.As a typical example,Mo_(2)C@C-3 exhibits satisfactory hydrogen evolution activity with a low overpotential of 151 m V(1.0 mol/L KOH)at 10 m A/cm^(2) and stability for 24 h.The electrocatalytic activity is mainly from the synergistic interactions between the carbon layers and molybdenum carbide species.Furthermore,compared with the initial content of C,N,Mo in OOCS and Mo_(2)C@C,the catalytic activity increases with the N amount.This work makes organic-octamolybdate crystalline superstructures used as general precursors to product high Mo content electrocatalysts applied in energy storage and conversion fields.展开更多
Developing industrially moldable catalysts with harmonized redox performance and acidity is of great significance for the efficient disposal of chlorinated volatile organic compounds(CVOCs)in actual exhaust gasses.Her...Developing industrially moldable catalysts with harmonized redox performance and acidity is of great significance for the efficient disposal of chlorinated volatile organic compounds(CVOCs)in actual exhaust gasses.Here,commercial TiO_(2),typically used for molding catalysts,was chosen as the carrier to fabricate a series of Ce_(0.02)Mn_(0-0.24)TiO_(x) materials with different Mn doping ratios and employed for chlorobenzene(CB)destruction.The introduction of Mn remarkedly facilitated the synergistic effect of each element via the electron transfer processes:Ce^(3+)+Mn^(4+/3+)■Ce^(4+)+Mn^(3+/2+)and Mn^(4+/3+)+Ti^(4+)■Mn^(3+/2+)+Ti^(3+).These synergistic interactions in Ce_(0.02)Mn_(0.04-0.24)TiO_(x),especially Ce_(0.02)Mn_(0.16)TiO_(x),significantly elevated the active oxygen species,oxygen vacancies and redox properties,endowing the superior catalytic oxidation of CB.When the Mn doping amount increased to 0.24,a separate Mn_(3)O_(4) phase appeared,which in turn might weaken the synergistic effect.Furthermore,the acidity of Ce_(0.02)Mn_(0.04-0.24)TiO_(x) was decreased with the Mn doping,regulating the balance of redox property and acidity.Notably,Ce_(0.02)Mn_(0.16)TiO_(x) featured relatively abundant B-acid sites.Its coordinating redox ability and moderate acidity promoted the deep oxidation of CB and RCOOH-intermediates,as well as the rapid desorption of Cl species,thus obtaining sustainable reactivity.In comparison,CeTiO_(x) owned the strongest acidity,however,its poor redox property was not sufficient for the timely oxidative decomposition of the easier adsorbed CB,resulting in its rapid deactivation.This finding provides a promising strategy for the construction of efficient commercial molding catalysts to decompose the industrial-scale CVOCs.展开更多
Ce1-xZrxO_(2) composite oxides(molar,x=0-1.0,interval of 0.2)were prepared by a cetyltrimethylammonium bromide-assisted precipitation method.The enhancement of silver-species modification and catalytic mechanism of ad...Ce1-xZrxO_(2) composite oxides(molar,x=0-1.0,interval of 0.2)were prepared by a cetyltrimethylammonium bromide-assisted precipitation method.The enhancement of silver-species modification and catalytic mechanism of adsorption-transformationdesorption process were investigated over the Ag-impregnated catalysts for lowtemperature selective catalytic oxidation of ammonia(NH_(3)-SCO).The optimal 5 wt.%Ag/Ce_(0.6)Zr_(0.4)O_(2) catalyst presented good NH_(3)-SCO performancewith>90% NH_(3) conversion at temperature(T)≥250°C and 89% N_(2) selectivity.Despite the irregular block shape and underdeveloped specific surface area(∼60m2/g),the naked and Ag-modified Ce_(0.6)Zr_(0.4)O_(2) solid solution still obtained highly dispersed distribution of surface elements analyzed by scanning electron microscope-energy dispersive spectrometer(SEM-EDS)(mapping),N_(2) adsorptiondesorption test and X-ray diffraction(XRD).H2 temperature programmed reduction(H2-TPR)and X-ray photoelectron spectroscopy(XPS)results indicated that Ag-modification enhanced the mobility and activation of oxygen-species leading to a promotion on CeO_(2) reducibility and synergistic Ag0/Ag+and Ce^(4+)/Ce^(3+)redox cycles.Besides,Ag+/Ag_(2)O clusters could facilitate the formation of surface oxygen vacancies that was beneficial to the adsorption and activation of ammonia.NH3-temperature programmed desorption(NH_(3)-TPD)showed more adsorption-desorption capacity to ammoniawere provided by physical,weakandmedium-strong acid sites.Diffused reflectance infrared Fourier transform spectroscopy(DRIFTS)experiments revealed the activation of ammonia might be the control step of NH3-SCO procedure,during which NH3 dehydrogenation derived from NHx-species and also internal selective catalytic reduction(i-SCR)reactions were proposed.展开更多
Supported atomically dispersed metal catalysts(ADMCs)have received enormous attention due to their high atom utilization efficiency,mass activity and excellent selectivity.Single-atom site catalysts(SACs)with monometa...Supported atomically dispersed metal catalysts(ADMCs)have received enormous attention due to their high atom utilization efficiency,mass activity and excellent selectivity.Single-atom site catalysts(SACs)with monometal-center as the quintessential ADMCs have been extensively studied in the catalysis-related fields.Beyond SACs,novel atomically dispersed metal catalysts(NADMCs)with flexible active sites featuring two or more catalytically centers including dual-atom and triple-atom catalysts have drawn ever-increasing attention recently.Owing to the presence of multiple neighboring active sites,NADMCs could exhibit much higher activity and selectivity compared with SACs,especially in those complicated reactions with multi-step intermediates.This review comprehensively outlines the recent exciting advances on the NADMCs with emphasis on the deeper understanding of the synergistic interactions among multiple metal atoms and underlying structure-performance relationships.It starts with the systematical introduction of principal synthetic approaches for NADMCs highlighting the key issues of each fabrication method including the atomically precise control in the design of metal nuclearity,and then the state-of-the-art characterizations for identifying and monitoring the atomic structure of NADMCs are explored.Thereafter,the recent development of NADMCs in energy-related applications is systematically discussed.Finally,we provide some new insights into the remaining challenges and opportunities for the development of NADMCs.展开更多
A series of CeO2-ZrO2-WO3 catalysts for the selective catalytic reduction （SCR） of NO with NH3 were prepared by hydrothermal method. The influence of calcination temperature on the catalytic activity, microstructure...A series of CeO2-ZrO2-WO3 catalysts for the selective catalytic reduction （SCR） of NO with NH3 were prepared by hydrothermal method. The influence of calcination temperature on the catalytic activity, microstructure, surface acidity and redox behavior of CeO2-ZrO2-WO3 catalyst was investigated using various characterization methods. It was found that the CeO2-ZrO2-WO3 catalyst calcined at 600 ℃ showed the best catalytic performance and excellent N2 selectivity, and yielded more than 90% NO conversion in a wide temperature range of 250-500 ℃ with a space velocity （GHSV） of 60000 131. As the calcination temperature was increased from 400 to 600 ℃, the NO conversion obviously increased, but decreased at higher calcination temperature. The results implied that the higher surface area, the strongest synergistic interaction, the superior redox property and the highly dispersed or amorphous WO3 species contributed to the excellent SCR activity of the CeO2-ZrO2-WO3 catalyst calcined at 600℃.展开更多
Designing cost-effective and high-performance carbon-based oxygen reduction reaction(ORR)electrocatalysts is crucial in the development of Zn-air batteries(ZABs).In this study,a facile one-pot synthesis approach is en...Designing cost-effective and high-performance carbon-based oxygen reduction reaction(ORR)electrocatalysts is crucial in the development of Zn-air batteries(ZABs).In this study,a facile one-pot synthesis approach is engineered to construct Zn/Co-N-C carbonaceous polyhedrons interconnected with self-catalyzed-grown carbon nanotubes(CNTs)from zeolitic imidazolium frameworks linked with graphene oxide nanosheets.The special N-doped threedimensional(3 D)carbon matrix allows manipulating the exposure of active sites and the synergistic interaction between metal nanoparticles and CNTs.The as-synthesized catalyst features impressive ORR activity in 0.1 mol L^(-1)KOH(E_(1/2)=0.83 V)and 0.5 mol L^(-1)H_(2)SO_(4)(E_(1/2)=0.73 V),satisfactory cycling stability and methanol resistance comparable to those of the benchmark Pt/C catalyst(E_(1/2)=0.80 V in 0.1 mol L^(-1)KOH,E_(1/2)=0.75 V in 0.5 mol L^(-1)H_(2)SO_(4)).Furthermore,the asestablished ZAB demonstrates a competitive peak power density(90 mW cm^(-2))and prominent long-term stability,which are better than those of devices based on the commercial Pt/C catalyst(82 mW cm^(-2)).This work provides promising guidance for fabricating highly effective ORR catalysts with in situ formed CNTs,which can be applied in portable ZABrelated devices.展开更多
The assembly of hybrid nanomaterials has opened up a new direction for the construction of high-performance anodes for lithium-ion batteries （LIBs）. In this work, we present a straightforward, eco-friendly, one-step...The assembly of hybrid nanomaterials has opened up a new direction for the construction of high-performance anodes for lithium-ion batteries （LIBs）. In this work, we present a straightforward, eco-friendly, one-step hydrothermal protocol for the synthesis of a new type of Fe2OB-SnO2/graphene hybrid, in which zero-dimensional （0D） SnO2 nanoparticles with an average diameter of 8 nm and one-dimensional （1D） Fe203 nanorods with a length of -150 nm are homogeneously attached onto two-dimensional （2D） reduced graphene oxide nanosheets, generating a unique point-line-plane （0D-1D-2D） architecture. The achieved Fe203-SnO2/graphene exhibits a well-defined morphology, a uniform size, and good monodispersity. As anode materials for LIBs, the hybrids exhibit a remarkable reversible capacity of 1,530 mA·g^-1 at a current density of 100 ma·g^-1 after 200 cycles, as well as a high rate capability of 615 mAh·g^-1 at 2,000 mA·g^-1 Detailed characterizations reveal that the superior lithium-storage capacity and good cycle stability of the hybrids arise from their peculiar hybrid nanostructure and conductive graphene matrix, as well as the synergistic interaction among the components.展开更多
Compression coated tablets for oral colon specific delivery systems were developed with a mixture polysaccharide of konjac glucomannan(KGM)and xanthan gum(XG)as the compression coat.Diffusion of cimetidine from compre...Compression coated tablets for oral colon specific delivery systems were developed with a mixture polysaccharide of konjac glucomannan(KGM)and xanthan gum(XG)as the compression coat.Diffusion of cimetidine from compression coated tablets was investigated by release experiment in Vitro.0.22U/mLβ-mannanase was applied in the mimic colon solution.The structure of the mixture polysaccharide was studied by an atomic force microscope(AFM).The experimental results indicate that a KGM70 tablet with a 0.4 g coat is of good design,due to a less than 5%drug loss in the mimic upper gastrointestinal solution by the synergistic interaction between XG and KGM,and due to about 50%cumulative release in the mimic colon solution by degradation after 24 hours.The release mechanism and model are discussed based on different periods of drug release including the delay of the drug,the constant release without an enzyme and the delay of degradation.Under hydrolysis byβ-mannanase,drug release from the tablet with KGM coat shows an exponential increase,while that from the dosage with the mixture polysaccharide coat is an approximately zero-order process in which the constant release rate relates to the release velocity of a non-degraded system,the content of KGM within the coat and the average molecular weight ratio of KGM to XG.It was found that XG was the framework of the polysaccharide mixtures by AFM,which is similar to the analysis results from experiments on drug release.展开更多
基金Supported by the National Natural Science Foundation of China ( No.2 95 74173)
文摘Mixed gels of chitosan-pectin were prepared by varying the ratio of constituents in the presence of NaCl. Mixed gel at 3%of total polysaccharide concentration with addtion of 12%NaCl showed a synergistic maximum when the ratio of chitosan to pectin was 60: 40. The effect of the polysaccharide concentration, the preparation temperature (T p), the time of incubation, balk salt concentration, the molecular weight and the degree of deacetylation of chitosan on gelation have been studied. Interaction mechanism between molecules of both polysaccharides was investigated by FT-IR spectrometry.
基金supported by the National Natural Science Foundation of China(Grants 21872039,22072030 and 52025023)the Science and Technology Commission of Shanghai Municipality(Grants 18JC1411700 and 19DZ2270100)+3 种基金the Key R&D Program of Guangdong Province(Grant 2020B010189001)funding support from the original personalized project of Fudan Universityfunding support from China Postdoctoral Science Foundation(2021M700810)。
文摘1. Introduction The increasing global demand for sustainable energy sources and emerging environmental issues have pushed the development of energy conversion and storage technologies to the forefront of chemical research [1,2]. In particular, electrochemical CO_(2) reduction(CO_(2) R) to value-added fuels and chemicals presents a feasible pathway for renewable energy storage and could help mitigate the ever-increasing CO_(2) emissions [3].
基金This study was funded by the National Natural Science Foundation of China(No.20274017)the Natural Science Foundation of Jiangsu Province(No.BK2004415)
文摘In this paper,the adsorption behaviors of phenol on polymeric adsorbents(Amberlite XAD4,NDA101,and D301) were investigated in batch system at 293,303,and 313 K,respectively.As the results shown,the adsorption isotherms of phenol on all adsorbents can be well fitted by Langmuir and Freundlich equations,which indicate a favorable and exothermic process.The adsorption capacity on a newly developed aminated adsorbent,NDA101,on which adsorption could be achieved by both hydrogen bonding interaction and π-π interaction,are higher than that on a weak base adsorbent,D301,on which adsorption could be achieved by hydrogen bonding interaction only,and on a nonpolar adsorbent,XAD4,on which adsorption could be achieved by π-π interaction only.The results of this paper indicate that the synergistic effect of some weak interactions,which occur simultaneously would contribute more to the adsorption than that occur individually.
基金supported by the National Natural Science Foundation of China(31920103014,31970160)the Natural Science Foundation of Fujian Province(2020J06015)。
文摘Multiple viral infections in insect vectors with synergistic effects are common in nature,but the underlying mechanism remains elusive.Here,we find that rice gall dwarf reovirus(RGDV)facilitates the transmission of rice stripe mosaic rhabdovirus(RSMV)by co-infected leafhopper vectors.RSMV nucleoprotein(N)alone activates complete anti-viral autophagy,while RGDV nonstructural protein Pns11 alone induces pro-viral incomplete autophagy.In co-infected vectors,RSMVexploits Pns11-induced autophagosomes to assemble enveloped virions via N-Pns11-ATG5 interaction.Furthermore,RSMV could effectively propagate in Sf9 cells.Expression of Pns11 in Sf9 cells or leafhopper vectors causes the recruitment of N from the ER to Pns11-induced autophagosomes and inhibits N-induced complete autophagic flux,finally facilitating RSMV propagation.In summary,these results demonstrate a previously unappreciated role of autophagy in the regulation of the direct synergistic interaction during co-transmission of two distinct arboviruses by insect vectors and reveal the functional importance of virus-induced autophagosomes in rhabdovirus assembly.
基金supported by startup funding to C.X.from State Key Laboratory of Plant Genomics and Institute of Genetics and Developmental Biology,Chinese Academy of Sciences,and a National Science Foundation grant(IOS-1556171)to Z.B.L
文摘Inflorescences are flower-bearing shoots that originate from pools of stem cells in shoot apical meristems (SAM).Inflorescence architecture is determined by a process of meristem maturation,during which stem cell fate switches from a vegetative to a reproductive growth program.A major factor in plant reproductive success in nature and yield in agriculture is the number of branches and flowers on inflorescences (Kobayashi and Weigel,2007;
基金financially supported by the National Natural Science Foundation of China(21773024)the Natural Science Foundation of Sichuan Province of China(2023NSFC0084)the China Postdoctoral Science Foundation(2019M663469)。
文摘The development of efficient single-atom catalysts(SACs) for the oxygen reduction reaction(ORR)remains a formidable challenge,primarily due to the symmetric charge distribution of metal singleatom sites(M-N_(4)).To address such issue,herein,Fe-N_(x) sites coupled synergistic catalysts fabrication strategy is presented to break the uniform electronic distribution,thus enhancing the intrinsic catalytic activity.Precisely,atomically dispersed Fe-N_(x) sites supported on N/S-doped mesoporous carbon(NSC)coupled with FeS@C core-shell nanoparticles(FAS-NSC@950) is synthesized by a facile hydrothermal reaction and subsequent pyrolysis.Due to the presence of an in situ-grown conductive graphitic layer(shell),the FeS nanoparticles(core) effectively adjust the electronic structure of single-atom Fe sites and facilitate the ORR kinetics via short/long-range coupling interactions.Consequently,FAS-NSC@950displays a more positive half-wave potential(E_(1/2)) of 0.871 V with a significantly boosted ORR kinetics(Tafel slope=52.2 mV dec^(-1)),outpacing the commercial Pt/C(E_(1/2)=0.84 V and Tafel slope=54.6 mV dec^(-1)).As a bifunctional electrocatalyst,it displays a smaller bifunctional activity parameter(ΔE) of 0.673 V,surpassing the Pt/C-RuO_(2) combination(ΔE=0.724 V).Besides,the FAS-NSC@950-based zincair battery(ZAB) displays superior power density,specific capacity,and long-term cycling performance to the Pt/C-Ir/C-based ZAB.This work significantly contributes to the field by offering a promising strategy to enhance the catalytic activity of SACs for ORR,with potential implications for energy conversion and storage technologies.
基金the National Natural Science Foundation of China (31170597, 31200484)the National Fiveyear Science and Technology Research Project (2012BAD19B0801)+1 种基金the Fundamental Research Funds for the Central Universities (2572014AA30)the National Forestry Bureau ‘‘948’’ Project (2009-4-39) for financial support
文摘Korean spruce （Picea koraiensis Sieb. E1 Zucc.） is one of the main afforestation species in northern China. Seedling quality is a critical factor at planting time. To test whether the synergistic growth enhancement of Scotch pine （P. sylvestris var. mongolica） seedlings brought by the plant beneficial fungus Trichoderma virens （J.H. Mill., Giddens and A.A. Foster） Arx and ectomycorrhizal fungus （Suillus luteus （L.） Roussel.） can also benefit Korean spruce seed- lings, we examined the effects of S. luteus and T. virens on the growth of P. koraiensis seedlings and drought resistance of P. sylvestris var. mongolica in peat soils. The two fungi were added to sterilized peat soil in pots, and the plants were grown for 4 months. Seedling growth and physiological variables, including mycorrhizal colonization rate of roots, biomass, and chlorophyll content, were examined. The colonization rate of the mycorrhizal fungus on P. koraiensis exceeded 65 %, and the synergism between S. luteus and T. virens enhanced most of the variables for P. koraiensis seedlings after inoculation with S. luteus then 30 days later with T. virens as in our published results for seedlings of P. sylvestris var. mongolica. When seedlings of P. sylvestris var. mongolica were inoculated with this sequence, they became more drought tolerant. T. virens also induced S. luteus to produce -l,3-glucanase and chitinase. This inocu- lation sequence at planting can thus improve the quality of P. sylvestris var. mongolica and P. koraiensis seedlings and substantiates our previous results.
基金surpported by the National Natural Science Foundation of China(31772003,31801461)the Science Research Foundation of Henan University of Technology(2017RCJH07)。
文摘The aim of this work was to investigate the possible synergistic interaction between monopalmitate(MP)and carnauba wax(CW)on the properties and crystallization behavior of oleogels.The soybean oleogels were prepared from MP and CW,and were characterized by oil binding capacity(OBC),solid fat content(SFC)and isothermal crystallization.The results showed that the OBC of the prepared oleogels changed in a W-shape trend with the increase of CW content.The mass ratio of MP and CW greatly affected the SFC.At 40,50 and 60°C,the SFC of these oleogels showed a slight deep eutectic effect with the increase of CW content in the gelators.The mass ratio of MP to CW also apparently affected the peak temperature and enthalpy during the crystallization and melting process analyzed by differential scanning calorimeter.The hysteresis occurring in the study indicated that crystallization temperature was lower than melting temperature and crystallization enthalpy was higher than melting enthalpy.The isothermal crystallization of these oleogels was characterized by Avrami equation,the Avrami exponent(n)and the apparent crystallization constant(k)of these oleogels were affected by the mass ratio of MP to CW as well as the crystallization temperature.Great difference in the values of n and k between the MP(or CW)oleogel and these oleogels suggested that the crystal growth mechanism had changed.However,the factor k for the oleogel formed of MP and CW with a mass ratio of 2:8 was about 1,unaffected by the crystallization temperature.From these results,we could deduce that the synergistic interaction between MP and CW did happen and affect the properties and crystallization behavior of these oleogels.
基金This work was supported by the Natural Science Foundation of China(22125902,21975243,U2032202,and U1932201)the National Program for Support of Topnotch Young Professionals,the DNL Cooperation Fund,CAS(DNL202020)+2 种基金the Anhui Science Fund for Distinguished Young Scholars(2208085J15)the National Key R&D Program of China(2022YFA1504101)Users with Excellence Program of Hefei Science Center CAS(2021HSC-UE002).
文摘Sulfur redox reactions render lithium–sulfur(Li–S)batteries with an energy density of>500Whkg−1 but suffer a low practical capacity and fast capacity fade due to sluggish sulfur redox reaction(SRR)kinetics,which lies in the complex reaction process that involves a series of reaction intermediates and proceeds via a cascade reaction.Here,we present a Pt–Cu dual-atom catalyst(Pt/Cu-NG)as an electrocatalyst for sulfur redox reactions.Pt/Cu-NG enabled the rapid conversion of soluble polysulfide intermediates into insoluble Li2S2/Li2S,and consequently,it prevented the accumulation and shuttling of lithium polysulfides,thus outperforming the corresponding single-atom catalysts(SACs)with individual Pt or Cu sites.Operando X-ray absorption spectroscopy and density functional theory calculations revealed that a synergistic effect between the paired Pt and Cu atoms modifies the electronic structure of the Pt site through d-orbital interactions,resulting in an optimal moderate interaction of the metal atom with the different sulfide species.This optimal interaction enhanced charge transfer kinetics and promoted sulfur redox reactions.Our work thus provides important insights on the atomic scale into the synergistic effects operative in dual-atom catalysts and will thus pave the way to electrocatalysts with enhanced efficiency for high-performance Li–S batteries.
基金supported by the National Natural Science Foundation of China (Grant Nos. 21975286 and 21473254)the Special Project Fund of “Taishan Scholar” of Shandong Province (Grant No. ts201511017)+2 种基金the QLUT Special Funding for Distinguished Scholars (Grant No. 2419010420)the project ZR2020QE058 supported by Shandong Provincial Natural Science Foundationthe Fundamental Research Funds for the Central Universities (Grant Nos. YCX2020050,18CX06030A,and 17CX02039A)。
文摘The hydrogen evolution reaction(HER) through electrocatalysis is promising for the production of clean hydrogen fuel. However,designing the structure of catalysts,controlling their electronic properties,and manipulating their catalytic sites are a significant challenge in this field. Here,we propose an electrochemical surface restructuring strategy to design synergistically interactive phosphorus-doped carbon@MoP electrocatalysts for the HER. A simple electrochemical cycling method is developed to tune the thickness of the carbon layers that cover on MoP core,which significantly influences HER performance. Experimental investigations and theoretical calculations indicate that the inactive surface carbon layers can be removed through electrochemical cycling,leading to a close bond between the MoP and a few layers of coated graphene. The electronsdonated by the MoP core enhance the adhesion and electronegativity of the carbon layers;the negatively charged carbon layers act as an active surface. The electrochemically induced optimization of the surface/interface electronic structures in the electrocatalysts significantly promotes the HER. Using this strategy endows the catalyst with excellent activity in terms of the HER in both acidic and alkaline environments(current density of 10 mA cm^(-2) at low overpotentials,of 68 mV in 0.5 M H_(2)SO_(4) and 67 mV in 1.0 M KOH).
文摘A field experiment was conducted at Kpongu in the Upper West region of Ghana to determine the added benefits in grain yield of maize derived from the concurrent use of manure and mineral fertilizer, and their cost effectiveness. Factorial combinations of cattle manure and mineral fertilizer each at 0, 50 and 100% of their recommended rates were evaluated in both the field and the laboratory studies. The treatments were applied in a randomized complete block design with three replications on the field. The same treatments were applied in the incubation study in a completely randomized design. The use of 100% NPK （Nitrogen, Phosphorus, Potassium） ＋ 5 t manure gave the highest grain yield of 4,678 kg·ha^-1. Synergistic interactions resulting in added benefits in grain yield were observed in all the combined nutrient inputs except 50% NPK ＋ 2.5 t manure which accrued an added disadvantage of 44 kg·ha^-1. Economic analysis proved that 100% NPK ＋ 2.5 t manure and 50% NPK ＋ 5 t manure were the most economically viable combined treatments in terms of grain yield. Based on the results from this study, resource poor farmers in the Upper West region of Ghana may reduce mineral fertilizer recommended rates by 50% and supplement it with 5 t quality （N 〉2.5%） cattle manure without compromising yield and profit.
基金supported by National Institutes of Health(R01GM107311)National Science Foundation(IOS-1036491and IOS1352478) grants awarded to K.D.
文摘Hormonal crosstalk is central for tailoring plant responses to the nature of challenges encountered. The role of antagonism between the two major defense hormones, salicylic acid （SA） and jasmonic acid （JA）, and modulation of this interplay by ethylene （ET） in favor of JA signaling pathway in plant stress responses is well recognized, but the underlying mechanism is not fully understood. Here, we show the opposing function of two transcription factors, ethylene insensitive3 （EIN3） and EIN3-Like1 （EIL1）, in SA-mediated suppression and JA- mediated activation of PLANT DEFENSINI.2 （PDFI.2）. This functional duality is mediated via their effect on protein, not transcript levels of the PDF1.2 transcriptional activator octadecanoid-responsive Arabidopsis59 （ORA59）. Specifically, JA induces ORA59 protein levels independently of EIN3/EIL1, whereas SA reduces the protein levels dependently of EIN3/EIL1. Co-infiltration assays revealed nuclear co-localization of ORA59 and EIN3, and split- luciferase together with yeast-two-hybrid assays established their physical interaction. The functional ramification of the physical interaction is EIN3-dependent degradation of ORA59 by the 26S proteasome. These findings allude to SA-responsive reduction of ORA59 levels mediated by EIN3 binding to and targeting of ORA59 for degrada4tion, thus nominating ORA59 pool as a coordination node for the antagonistic function of ET/JA and SA.
基金financially supported by Joint Fund Project of the Natural Science Foundation of Jilin Province(No.YDZJ202301ZYTS290)。
文摘Hydrogen evolution electrocatalysts derived from metal-organic crystalline frameworks can inherit the merits of ordered and adjustable structures with high surface area.In this paper,organic-octamolybdate crystalline superstructures(OOCS)with a fixed stoichiometric ratio of Mo_(8)(L)_(2) and high Mo content(>40 wt%)were synthesized using flexible ligands with controllable lengths(named as OOCS-1-3).Then,molybdenum carbides coated with carbon layers as electrocatalysts(Mo_(2)C@C-1-3)can be obtained directly from a one-step high-temperature carbonization process using OOCS-1-3 as precursors.As a typical example,Mo_(2)C@C-3 exhibits satisfactory hydrogen evolution activity with a low overpotential of 151 m V(1.0 mol/L KOH)at 10 m A/cm^(2) and stability for 24 h.The electrocatalytic activity is mainly from the synergistic interactions between the carbon layers and molybdenum carbide species.Furthermore,compared with the initial content of C,N,Mo in OOCS and Mo_(2)C@C,the catalytic activity increases with the N amount.This work makes organic-octamolybdate crystalline superstructures used as general precursors to product high Mo content electrocatalysts applied in energy storage and conversion fields.
基金supported by the National Key R&D Program of China(No.2020YFC1910100)the National Natural Science Foundation of China(Nos.22006156 and 21876193)+1 种基金the Chengdu Science and Technology Bureau(No.2018-ZM01-00019-SN)the Youth Innovation Promotion Association CAS。
文摘Developing industrially moldable catalysts with harmonized redox performance and acidity is of great significance for the efficient disposal of chlorinated volatile organic compounds(CVOCs)in actual exhaust gasses.Here,commercial TiO_(2),typically used for molding catalysts,was chosen as the carrier to fabricate a series of Ce_(0.02)Mn_(0-0.24)TiO_(x) materials with different Mn doping ratios and employed for chlorobenzene(CB)destruction.The introduction of Mn remarkedly facilitated the synergistic effect of each element via the electron transfer processes:Ce^(3+)+Mn^(4+/3+)■Ce^(4+)+Mn^(3+/2+)and Mn^(4+/3+)+Ti^(4+)■Mn^(3+/2+)+Ti^(3+).These synergistic interactions in Ce_(0.02)Mn_(0.04-0.24)TiO_(x),especially Ce_(0.02)Mn_(0.16)TiO_(x),significantly elevated the active oxygen species,oxygen vacancies and redox properties,endowing the superior catalytic oxidation of CB.When the Mn doping amount increased to 0.24,a separate Mn_(3)O_(4) phase appeared,which in turn might weaken the synergistic effect.Furthermore,the acidity of Ce_(0.02)Mn_(0.04-0.24)TiO_(x) was decreased with the Mn doping,regulating the balance of redox property and acidity.Notably,Ce_(0.02)Mn_(0.16)TiO_(x) featured relatively abundant B-acid sites.Its coordinating redox ability and moderate acidity promoted the deep oxidation of CB and RCOOH-intermediates,as well as the rapid desorption of Cl species,thus obtaining sustainable reactivity.In comparison,CeTiO_(x) owned the strongest acidity,however,its poor redox property was not sufficient for the timely oxidative decomposition of the easier adsorbed CB,resulting in its rapid deactivation.This finding provides a promising strategy for the construction of efficient commercial molding catalysts to decompose the industrial-scale CVOCs.
基金financially supported by National Natural Science Foundation of China (No.U20A20130)Fundamental Research Funds for the Central Universities (No.06500152)
文摘Ce1-xZrxO_(2) composite oxides(molar,x=0-1.0,interval of 0.2)were prepared by a cetyltrimethylammonium bromide-assisted precipitation method.The enhancement of silver-species modification and catalytic mechanism of adsorption-transformationdesorption process were investigated over the Ag-impregnated catalysts for lowtemperature selective catalytic oxidation of ammonia(NH_(3)-SCO).The optimal 5 wt.%Ag/Ce_(0.6)Zr_(0.4)O_(2) catalyst presented good NH_(3)-SCO performancewith>90% NH_(3) conversion at temperature(T)≥250°C and 89% N_(2) selectivity.Despite the irregular block shape and underdeveloped specific surface area(∼60m2/g),the naked and Ag-modified Ce_(0.6)Zr_(0.4)O_(2) solid solution still obtained highly dispersed distribution of surface elements analyzed by scanning electron microscope-energy dispersive spectrometer(SEM-EDS)(mapping),N_(2) adsorptiondesorption test and X-ray diffraction(XRD).H2 temperature programmed reduction(H2-TPR)and X-ray photoelectron spectroscopy(XPS)results indicated that Ag-modification enhanced the mobility and activation of oxygen-species leading to a promotion on CeO_(2) reducibility and synergistic Ag0/Ag+and Ce^(4+)/Ce^(3+)redox cycles.Besides,Ag+/Ag_(2)O clusters could facilitate the formation of surface oxygen vacancies that was beneficial to the adsorption and activation of ammonia.NH3-temperature programmed desorption(NH_(3)-TPD)showed more adsorption-desorption capacity to ammoniawere provided by physical,weakandmedium-strong acid sites.Diffused reflectance infrared Fourier transform spectroscopy(DRIFTS)experiments revealed the activation of ammonia might be the control step of NH3-SCO procedure,during which NH3 dehydrogenation derived from NHx-species and also internal selective catalytic reduction(i-SCR)reactions were proposed.
基金the Beijing Natural Science Foundation(No.2224096)the National Key R&D Program of China(No.2018YFA0702003)+3 种基金the Science and Technology Key Project of Guangdong Province,China(No.2020B010188002)the China Postdoctoral Science Foundation(Nos.2021M690086 and 2021TQ0170)X.B.Z.acknowledges funding support from the Office of China Postdoctoral Council(No.YJ20200277)the“Shuimu Tsinghua Scholar Program"(No.2020SM109)of Tsinghua University,China.
文摘Supported atomically dispersed metal catalysts(ADMCs)have received enormous attention due to their high atom utilization efficiency,mass activity and excellent selectivity.Single-atom site catalysts(SACs)with monometal-center as the quintessential ADMCs have been extensively studied in the catalysis-related fields.Beyond SACs,novel atomically dispersed metal catalysts(NADMCs)with flexible active sites featuring two or more catalytically centers including dual-atom and triple-atom catalysts have drawn ever-increasing attention recently.Owing to the presence of multiple neighboring active sites,NADMCs could exhibit much higher activity and selectivity compared with SACs,especially in those complicated reactions with multi-step intermediates.This review comprehensively outlines the recent exciting advances on the NADMCs with emphasis on the deeper understanding of the synergistic interactions among multiple metal atoms and underlying structure-performance relationships.It starts with the systematical introduction of principal synthetic approaches for NADMCs highlighting the key issues of each fabrication method including the atomically precise control in the design of metal nuclearity,and then the state-of-the-art characterizations for identifying and monitoring the atomic structure of NADMCs are explored.Thereafter,the recent development of NADMCs in energy-related applications is systematically discussed.Finally,we provide some new insights into the remaining challenges and opportunities for the development of NADMCs.
基金Project supported by the National Natural Science Foundation of China(21377048,21307047)the Opening Project of Key Laboratory of Green Catalysis of Sichuan Institutes of High Education(LYJ1309)
文摘A series of CeO2-ZrO2-WO3 catalysts for the selective catalytic reduction （SCR） of NO with NH3 were prepared by hydrothermal method. The influence of calcination temperature on the catalytic activity, microstructure, surface acidity and redox behavior of CeO2-ZrO2-WO3 catalyst was investigated using various characterization methods. It was found that the CeO2-ZrO2-WO3 catalyst calcined at 600 ℃ showed the best catalytic performance and excellent N2 selectivity, and yielded more than 90% NO conversion in a wide temperature range of 250-500 ℃ with a space velocity （GHSV） of 60000 131. As the calcination temperature was increased from 400 to 600 ℃, the NO conversion obviously increased, but decreased at higher calcination temperature. The results implied that the higher surface area, the strongest synergistic interaction, the superior redox property and the highly dispersed or amorphous WO3 species contributed to the excellent SCR activity of the CeO2-ZrO2-WO3 catalyst calcined at 600℃.
基金supported by the National Natural Science Foundation of China(51872076 and U1804255)the Program for Innovative Research Team of Henan Scientific Committee(CXTD2014033)+1 种基金the Project of Central Plains Science and Technology Innovation Leading Talents of Henan Province(194200510001)the Scientific and Technological Research Project of Henan province(212102210651)。
文摘Designing cost-effective and high-performance carbon-based oxygen reduction reaction(ORR)electrocatalysts is crucial in the development of Zn-air batteries(ZABs).In this study,a facile one-pot synthesis approach is engineered to construct Zn/Co-N-C carbonaceous polyhedrons interconnected with self-catalyzed-grown carbon nanotubes(CNTs)from zeolitic imidazolium frameworks linked with graphene oxide nanosheets.The special N-doped threedimensional(3 D)carbon matrix allows manipulating the exposure of active sites and the synergistic interaction between metal nanoparticles and CNTs.The as-synthesized catalyst features impressive ORR activity in 0.1 mol L^(-1)KOH(E_(1/2)=0.83 V)and 0.5 mol L^(-1)H_(2)SO_(4)(E_(1/2)=0.73 V),satisfactory cycling stability and methanol resistance comparable to those of the benchmark Pt/C catalyst(E_(1/2)=0.80 V in 0.1 mol L^(-1)KOH,E_(1/2)=0.75 V in 0.5 mol L^(-1)H_(2)SO_(4)).Furthermore,the asestablished ZAB demonstrates a competitive peak power density(90 mW cm^(-2))and prominent long-term stability,which are better than those of devices based on the commercial Pt/C catalyst(82 mW cm^(-2)).This work provides promising guidance for fabricating highly effective ORR catalysts with in situ formed CNTs,which can be applied in portable ZABrelated devices.
基金Acknowledgements The authors gratefully thank the financial support from the National Natural Science Foundation of China （Nos. 11275121, 21471096, and 21371116）, and Program for Innovative Research Team in University （No. IRT13078）.
文摘The assembly of hybrid nanomaterials has opened up a new direction for the construction of high-performance anodes for lithium-ion batteries （LIBs）. In this work, we present a straightforward, eco-friendly, one-step hydrothermal protocol for the synthesis of a new type of Fe2OB-SnO2/graphene hybrid, in which zero-dimensional （0D） SnO2 nanoparticles with an average diameter of 8 nm and one-dimensional （1D） Fe203 nanorods with a length of -150 nm are homogeneously attached onto two-dimensional （2D） reduced graphene oxide nanosheets, generating a unique point-line-plane （0D-1D-2D） architecture. The achieved Fe203-SnO2/graphene exhibits a well-defined morphology, a uniform size, and good monodispersity. As anode materials for LIBs, the hybrids exhibit a remarkable reversible capacity of 1,530 mA·g^-1 at a current density of 100 ma·g^-1 after 200 cycles, as well as a high rate capability of 615 mAh·g^-1 at 2,000 mA·g^-1 Detailed characterizations reveal that the superior lithium-storage capacity and good cycle stability of the hybrids arise from their peculiar hybrid nanostructure and conductive graphene matrix, as well as the synergistic interaction among the components.
基金the financial support from Grand project of Tianjin City,China(No.07ZCZDGX19600).
文摘Compression coated tablets for oral colon specific delivery systems were developed with a mixture polysaccharide of konjac glucomannan(KGM)and xanthan gum(XG)as the compression coat.Diffusion of cimetidine from compression coated tablets was investigated by release experiment in Vitro.0.22U/mLβ-mannanase was applied in the mimic colon solution.The structure of the mixture polysaccharide was studied by an atomic force microscope(AFM).The experimental results indicate that a KGM70 tablet with a 0.4 g coat is of good design,due to a less than 5%drug loss in the mimic upper gastrointestinal solution by the synergistic interaction between XG and KGM,and due to about 50%cumulative release in the mimic colon solution by degradation after 24 hours.The release mechanism and model are discussed based on different periods of drug release including the delay of the drug,the constant release without an enzyme and the delay of degradation.Under hydrolysis byβ-mannanase,drug release from the tablet with KGM coat shows an exponential increase,while that from the dosage with the mixture polysaccharide coat is an approximately zero-order process in which the constant release rate relates to the release velocity of a non-degraded system,the content of KGM within the coat and the average molecular weight ratio of KGM to XG.It was found that XG was the framework of the polysaccharide mixtures by AFM,which is similar to the analysis results from experiments on drug release.
