Background:The study aimed to investigate the protective effect and mechanism of total flavonoids of Scutellaria baicalensis(TFSB)on acute myocardial ischemia(AMI)rats by using functional metabonomics.Methods:Rats wer...Background:The study aimed to investigate the protective effect and mechanism of total flavonoids of Scutellaria baicalensis(TFSB)on acute myocardial ischemia(AMI)rats by using functional metabonomics.Methods:Rats were divided into the Control,Model,AMI positive control(Propranolol hydrochloride,30 mg/kg),low dose TFSB(50 mg/kg),and high dose TFSB(100 mg/kg)groups.Rats received the corresponding treatment by intragastric administration once daily for 10 consecutive days.Electrocardiogram,myocardial enzyme,triphenyltetrazolium chloride staining,hematoxylin-eosin,and enzyme-linked immunosorbent assay were performed to evaluate the protective effect of TFSB on AMI rats.Then,the UHPLC-Q-Orbitrap MS method based on serum metabolomics was utilised to search for metabolic biomarkers and metabolic pathways.Subsequently,Western blot and RT-PCR techniques were employed to identify the respective genes and proteins.Results:Pharmacodynamics revealed that TFSB could ameliorate AMI in rats.The results of the metabolomics analysis indicated that the alterations in metabolic profile observed in rats with AMI were partially improved by treatment with TFSB.Moreover,the mRNA expression levels of 5-lipoxygenase(5-LOX)and 15-lipoxygenase(15-LOX)and the protein expression levels of 5-LOX,15-LOX,interleukin-1β(IL-1β),and NF-κB p65 were reduced following treatment with TFSB.Conclusion:The potential treatment of TFSB in AMI may be ascribed to its ability to regulate arachidonic acid metabolism.展开更多
Segregation of solute atoms in the center of thick plates of the tempered steel can cause an inhomogeneous structural transformation and generate micron-sized inclusions,which leads to lamellar tearing of thick plate ...Segregation of solute atoms in the center of thick plates of the tempered steel can cause an inhomogeneous structural transformation and generate micron-sized inclusions,which leads to lamellar tearing of thick plate and decreases the plasticity and toughness.The formation and fragmentation mechanisms of micron-sized inclusions,like MnS and(Nb,Ti)C,in the center of thick plates were investigated by using thermodynamic calculations,finite element simulations,and electron backscatter diffraction characterization techniques.The results show that micron-sized inclusions nucleate and grow in the liquid phase,and under tensile loading,they exhibit three fragmentation mechanisms.The local stress during the fragmentation of inclusions is lower than the critical fracture stress of adjacent grains,and phase boundaries can effectively impede crack propagation into the matrix.The existence of a low proportion of high-angle grain boundaries(58.1%)and high Kernel average misorientation value(0.534°)in the segregation band promotes inclusions fragmentation and crack propagation.The difference in crack initiation and propagation direction caused by the morphology of inclusions and physical properties,as well as different matrix arrest abilities,is the main reasons for the diversity of inclusion fragmentation.展开更多
This study investigated the effect of pressure,pre-charge time,punch velocity and oxygen content on the mechanical properties of X42 pipeline steel in gaseous hydrogen environment by using small punch test.When expose...This study investigated the effect of pressure,pre-charge time,punch velocity and oxygen content on the mechanical properties of X42 pipeline steel in gaseous hydrogen environment by using small punch test.When exposed to nitrogen,the fracture mode of X42 pipeline steel undergoes ductile fracture,but in the presence of hydrogen,it shifts to brittle fracture.Moreover,an increase in hydrogen pressure or a decrease in punch velocity is found to enhance the hydrogen embrittlement susceptibility of X42 pipeline steel,as evidenced by the decrease of maximal load,displacement at failure onset and small punch energy.But the effect of pre-charge time on the hydrogen embrittlement susceptibility of X42 pipeline steel is not very obvious.Meanwhile,the presence of oxygen has been found to effectively inhibit hydrogen embrittlement.As the oxygen content in hydrogen increases,the hydrogen embrittlement susceptibility of X42 pipeline steel decreases.展开更多
To study the volatile organic compounds(VOCs)emission characteristics of industrial enterprises in China,6 typical chemical industries in Yuncheng City were selected as research objects,including the modern coal chemi...To study the volatile organic compounds(VOCs)emission characteristics of industrial enterprises in China,6 typical chemical industries in Yuncheng City were selected as research objects,including the modern coal chemical industry(MCC),pharmaceutical industry(PM),pesticide industry(PE),coking industry(CO)and organic chemical industry(OC).The chemical composition of 91 VOCs was quantitatively analyzed.The results showed that the emission concentration of VOCs in the chemical industry ranged from 1.16 to 155.59 mg/m^(3).Alkanes were the main emission components of MCC(62.0%),PE(55.1%),and OC(58.5%).Alkenes(46.5%)were important components of PM,followed by alkanes(23.8%)and oxygenated volatile organic compounds(OVOCs)(21.2%).Halocarbons(8.6%-71.1%),OVOCs(9.7%-37.6%)and alkanes(11.2%-27.0%)were characteristic components of CO.The largest contributor to OFP was alkenes(0.6%-81.7%),followed by alkanes(9.3%-45.9%),and the lowest onewas alkyne(0%-0.5%).Aromatics(66.9%-85.4%)were the largest contributing components to SOA generation,followed by alkanes(2.6%-28.5%),and the lowest one was alkenes(0%-4.1%).Ethylene and BTEX were the key active species in various chemical industries.The human health risk assessment showed workers long-term exposed to the air in the chemical industrial zone had a high cancer and non-cancer risk during work,and BTEX and dichloromethane were the largest contributors.展开更多
Carbon-based foams with a three-dimensional structure can serve as a lightweight template for the rational design and control-lable preparation of metal oxide/carbon-based composite microwave absorption materials.In t...Carbon-based foams with a three-dimensional structure can serve as a lightweight template for the rational design and control-lable preparation of metal oxide/carbon-based composite microwave absorption materials.In this study,a flake-like nickel cobaltate/re-duced graphene oxide/melamine-derived carbon foam(FNC/RGO/MDCF)was successfully fabricated through a combination of solvo-thermal treatment and high-temperature pyrolysis.Results indicated that RGO was evenly distributed in the MDCF skeleton,providing ef-fective support for the load growth of FNC on its surface.Sample S3,the FNC/RGO/MDCF composite prepared by solvothermal method for 16 h,exhibited a minimum reflection loss(RL_(min))of-66.44 dB at a thickness of 2.29 mm.When the thickness was reduced to 1.50 mm,the optimal effective absorption bandwidth was 3.84 GHz.Analysis of the absorption mechanism of FNC/RGO/MDCF revealed that its excellent absorption performance was primarily attributed to the combined effects of conduction loss,multiple reflection,scattering,in-terface polarization,and dipole polarization.展开更多
4-Nonylphenol(NP)is a kind of estrogen belonging to the endocrine disrupter,widely used in various agricultural and industrial goods.However,extensive use of NP with direct release to environment poses high risks to b...4-Nonylphenol(NP)is a kind of estrogen belonging to the endocrine disrupter,widely used in various agricultural and industrial goods.However,extensive use of NP with direct release to environment poses high risks to both human health and ecosystems.Herein,for the first time,we developed near-infrared(NIR)responsive upconversion luminescence nanosensor for NP detection.The Förster resonance energy transfer based upconversion nanoparticles(UCNPs)-graphene oxide sensor offers highly selective and sensitive detection of NP in linear ranges of 5−200 ng/mL and 200−1000 ng/mL under 980 nm and 808 nm excitation,respectively,with LOD at 4.2 ng/mL.The sensors were successfully tested for NP detection in real liquid milk samples with excellent recovery results.The rare-earth fluoride based upconversion luminescence nanosensor with NIR excitation wavelength,holds promise for sensing food,environmental,and biological samples due to their high sensitivity,specific recognition,low LOD,negligible autofluorescence,along with the deep penetration of NIR excitation sources.展开更多
In this work,the Si@reduced graphene oxide/ZrO_(2)(Si@rGO/ZrO_(2))with the shelled structures is prepared for the high-capacity and stable lithium-ion batteries.The shelled structure not only significantly improves th...In this work,the Si@reduced graphene oxide/ZrO_(2)(Si@rGO/ZrO_(2))with the shelled structures is prepared for the high-capacity and stable lithium-ion batteries.The shelled structure not only significantly improves the electrical conductivity of the whole electrode,but also protects the inner Si nanoparticles(Si NPs)from rupturing and being damaged by undesired side reactions with the electrolyte.As a result,the Si@rGO/ZrO_(2) anode delivers high initial discharge capacity of 3046 mAh·g^(−1) at 1.0 A·g^(−1).After 100 cycles,it can be maintained at 613 mAh·g^(−1),which is much higher than that of either the pure Si NPs(31 mAh·g^(−1))or the Si@rGO(261 mAh·g^(−1)).Even at 2 A·g^(−1),it still provides superior specific capacity of 834 mAh·g^(−1),while the pure Si anode merely possesses the capacity of 41 mAh·g^(−1).Moreover,the density functional theory calculations point out that ZrO_(2) layer can effectively enhance the adsorption energy of Li+and optimize the migration paths of Li+,ensuring the electrochemical performance of Si@rGO/ZrO_(2) composite anode.Furthermore,the Li+storage mechanism and low volume expansion of Si@rGO/ZrO_(2) anode is investigated by ex-situ X-ray photoelectron spectroscopy and morphological evolution upon cycling,respectively.展开更多
The complexity of living environment system demands higher requirements for the sensitivity and selectivity of the probe.Therefore,it is of great importance to develop a universal strategy for highperformance probe op...The complexity of living environment system demands higher requirements for the sensitivity and selectivity of the probe.Therefore,it is of great importance to develop a universal strategy for highperformance probe optimization.Herein,we propose a novel“Enrichment-enhanced Detection”strategy and use carbon dots-dopamine detection system as a representative model to evaluate its feasibility.The composite probe carbon dots (CDs)-encapsulated in glycol-chitosan (GC)(i.e.,CDs@GC) was obtained by simply mixing GC and CDs through noncovalent interactions,including electrostatic interactions and hydrogen bonding.Dopamine (DA) could be detected through internal filter effect (IFE)-induced quenching of CDs.In the case of CDs@GC,noncovalent interactions (electrostatic interactions) between GC and the formed quinone (oxide of DA) could selectively extract and enrich the local concentration of DA,thus effectively improving the sensitivity and selectivity of the sensing system.The nanosensor had a low detection limit of 3.7 nmol/L,which was a 12-fold sensitivity improvement compared to the bare CDs probes with similar fluorescent profiles,proving the feasibility of the“Enrichment-enhanced Detection”strategy.Further,to examine this theory in real case,we designed a highly portable sensing platform to realize visual determination of DA.Overall,our work introduces a new strategy for accurately detecting DA and provides valuable insights for the universal design and optimization of superior nanoprobes.展开更多
Mercury ions(Hg^(2+))and bacteria are widely spread in water pollution and pose a great threat to human health and the environment.Herein,a multifunctional COF Dmta Tph with significant Hg^(2+)adsorption capability an...Mercury ions(Hg^(2+))and bacteria are widely spread in water pollution and pose a great threat to human health and the environment.Herein,a multifunctional COF Dmta Tph with significant Hg^(2+)adsorption capability and continuous sunlight-driven sterilization property is designed and synthesized by introducing thioether and photosensitive porphyrin in a single molecule.The obtained COF displays a high Hg^(2+)adsorption capacity of 657.9 mg/g at 298 K and a superior antibacterial effect toward Escherichia coli and Staphylococcus aureus under sunlight irradiation.Mechanistic studies reveal that the strong coordination between S species and Hg^(2+)is the main driving force for high Hg^(2+)adsorption capability.The sterilization mechanism clarifies that the inactivation of bacteria is caused by1O_(2)produced from Dmta Tph with the assistance of light irradiation.Noteworthy,when Dmta Tph is applied in the treatment of wastewater,it displays high Hg^(2+)removal efficiency and remarkable antibacterial effect under complex conditions.This study has demonstrated a promising strategy for designing multifunctional COF-based materials,offering great potential in tackling the problem of heavy metal ions and bacteria pollution in water.展开更多
The discharge of effluents containing uranium(U)ions into aquatic ecosystems poses significant risks to both human health and marine organisms.This study investigated the biosorption of U(VI)ions from aqueous solution...The discharge of effluents containing uranium(U)ions into aquatic ecosystems poses significant risks to both human health and marine organisms.This study investigated the biosorption of U(VI)ions from aqueous solutions using corncob-sodium alginate(SA)-immobilized Trichoderma aureoviride hyphal pellets.Experimental parameters,including initial solution pH,initial concentration,temperature,and contact time,were systematically examined to understand their influence on the bioadsorption process.Results showed that the corncob-SA-immobilized T.aureoviride hyphal pellets exhibited maximum uranium biosorption capacity at an initial pH of 6.23 and a contact time of 12 h.The equilibrium data aligned with the Langmuir isotherm model,with a maximum biosorption capacity of 105.60 mg/g at 301 K.Moreover,biosorption kinetics followed the pseudo-second-order kinetic model.In terms of thermodynamic parameters,the changes in Gibbs-free energy(△G°)were determined to be-4.29 kJ/mol at 301 K,the changes in enthalpy(△H°)were 46.88 kJ/mol,and the changes in entropy(△S°)was 164.98 J/(mol·K).Notably,the adsorbed U(VI)could be efficiently desorbed using Na_(2)CO_(3),with a maximum readsorption efficiency of 53.6%.Scanning electron microscopic(SEM)analysis revealed U(VI)ion binding onto the hyphal pellet surface.This study underscores the efficacy of corncob-SA-immobilized T.aureoviride hyphal pellets as a cost-effective and environmentally favorable biosorbent material for removing U(VI)from aquatic ecosystems.展开更多
To efficiently diminish the Pt consumption while concurrently enhancing the anodic reaction kinetics,a straightforward synthesis for PtPdAg nanotrees(NTs)with exceedingly low Pt content is presented,utilizing the galv...To efficiently diminish the Pt consumption while concurrently enhancing the anodic reaction kinetics,a straightforward synthesis for PtPdAg nanotrees(NTs)with exceedingly low Pt content is presented,utilizing the galvanic replacement reaction between the initially prepared PdAg NTs and Pt ions.Due to the multilevel porous tree-like structure and the incorporation of low amounts of Pt,the electrocatalytic activity and stability of PtPdAg NTs are markedly enhanced,achieving 1.65 and 1.69 A·mg^(-1)Pt+Pd for the anodic reactions of formic acid oxidation(FAOR)and methanol oxidation(MOR)within DLFCs,surpassing the performance of PdAg NTs,as well as that of commercial Pt and Pd black.Density functional theory(DFT)calculations reveal that the addition of low amounts of Pt leads to an increase in the d-band center of PtPdAg NTs and lower the COads adsorption energy to-1.23 eV,enhancing the anti-CO toxicity properties optimally.This approach offers an effective means for designing low Pt catalysts as exceptional anodic electrocatalysts for direct liquid fuel cells.展开更多
Exploiting high-performance electrolyte holds the key for realization practical application of rechargeable magnesium batteries(RMBs).Herein,a new non-nucleophilic mononuclear electrolyte was developed and its electro...Exploiting high-performance electrolyte holds the key for realization practical application of rechargeable magnesium batteries(RMBs).Herein,a new non-nucleophilic mononuclear electrolyte was developed and its electrochemical active species was identified as[Mg(DME)_(3)][GaCl_(4)]_(2) through single-crystal X-ray diffraction analysis.The as-synthesized Mg(GaCl_(4))_(2)-IL-DME electrolyte could achieve a high ionic conductivity(9.85 m S cm^(-1)),good anodic stability(2.9 V vs.Mg/Mg^(2+)),and highly reversible Mg plating/stripping.The remarkable electrochemical performance should be attributed to the in-situ formation of Mg^(2+)-conducting Ga_(5)Mg_(2)alloy layer at the Mg/electrolyte interface during electrochemical cycling,which not only efficiently protects the Mg anode from passivation,but also allows for rapid Mg-ion transport.Significantly,the Mg(GaCl_(4))_(2)-IL-DME electrolyte showed excellent compatibility with both conversion and intercalation cathodes.The Mg/S batteries with Mg(Ga Cl_(4))_(2)-IL-DME electrolyte and KB/S cathode showed a high specific capacity of 839 m Ah g^(-1)after 50 cycles at 0.1 C with the Coulombic efficiency of~100%.Moreover,the assembled Mg|Mo_6 S_8 batteries delivered a reversible discharge capacity of 85 m Ah g^(-1)after 120 cycles at 0.2 C.This work provides a universal electrolyte for the realization of high-performance and practical RMBs,especially Mg/S batteries.展开更多
Mixed polyanion phosphate Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_(7)(NFPP)is regarded as the most promising cathode material for sodium-ion batteries(SIBs),due to its high structural stability and low-cost environmental frien...Mixed polyanion phosphate Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_(7)(NFPP)is regarded as the most promising cathode material for sodium-ion batteries(SIBs),due to its high structural stability and low-cost environmental friendliness.However,its intrinsic low conductivity and sluggish Na^(+)diffusion restricted the fast-charge and low-temperature sodium storage.Herein,an NFPP composite encapsulated by in-situ pyrolytic carbon and coupled with expanded graphite(NFPP@C/EG)was constructed via a sol-gel method followed by a ballmill procedure.Due to the dual-carbon modified strategy,this NFPP@C/EG only enhanced the electronic conductivity,but also endowed more channels for Na^(+)diffusion.As cathode for SIBs,the optimized NFPP(M-NFPP@C/EG)delivers excellent rate capability(capacity of~80.5 mAh/g at 50 C)and outstanding cycling stability(11000 cycles at 50 C with capacity retention of 89.85%).Additionally,cyclic voltammetry(CV)confirmed that its sodium storage behavior is pseudocapacitance-controlled,with in-situ electrochemical impedance spectroscopy(EIS)further elucidating improvements in electrode reaction kinetics.At lower temperatures(0℃),M-NFPP@C/EG demonstrated exceptional cycling performance(8800 cycles at 10 C with capacity retention of 95.81%).Moreover,pouch cells also exhibited excellent stability.This research demonstrates the feasibility of a dual carbon modification strategy in enhancing NFPP and proposes a low-cost,high-rate,and ultra-stable cathode material for SIBs.展开更多
Organophosphorus pesticides(OPPs)in foods pose a serious threat to human health,motivating the development of novel analytical methods for their rapid detection and quantification.A magnetic covalent organic framework...Organophosphorus pesticides(OPPs)in foods pose a serious threat to human health,motivating the development of novel analytical methods for their rapid detection and quantification.A magnetic covalent organic framework(M-COF)adsorbent for the magnetic solid-phase extraction(MSPE)of OPPs from foods was reported.M-COF was synthesized by the Schiff base condensation reaction of 1,3,5-tris(4-aminophenyl)benzene and 4,4-biphenyldicarboxaldehyde on the surface of amino-functionalized magnetic nanoparticles.Density functional theory(DFT)calculations showed that adsorption of OPPs onto the surface of M-COF involved hydrophobic effects,van der Waals interactions,π-πinteractions,halogen-N bonding,and hydrogen bonding.Combined with gas chromatography-mass spectrometry(GC-MS)technology,the MSPE method features low limits of detection for OPPs(0.002-0.015μg/L),good reproducibility(1.45%-6.14%),wide linear detection range(0.01-1μg/L,R≥0.9935),and satisfactory recoveries(87.3%-110.4%).The method was successfully applied for the trace analysis of OPPs in spiked fruit juices.展开更多
The biomass electrochemical oxidation coupled with hydrogen evolution reaction has received widespread attention due to its carbon-neutral and sustainable properties.The electrosynthesis of 2,5-furanodicarboxylic acid...The biomass electrochemical oxidation coupled with hydrogen evolution reaction has received widespread attention due to its carbon-neutral and sustainable properties.The electrosynthesis of 2,5-furanodicarboxylic acid(FDCA)from 5-hydroxymethylfurfural(HMF)oxidation is one of the most promising means for the production of bioplastic monomers.In this work,we constructed a novel P-doped Ni_(3)S_(2)and Ni heterojunction on nickel foam(P-Ni_(3)S_(2)/Ni/NF)using electrodeposition methods and thermal sulfuration techniques as a bifunctional catalyst for the simultaneous anodic oxidation of HMF to FDCA(HMFOR)and the cathodic hydrogen evolution reaction(HER).On one hand,the synergistic promotion of P doping and the heterojunction of Ni_(3)S_(2)and Ni accelerated electron transfer,and on the other hand,the structure of three-dimensional microsphere stacking on NF surface to form macropores enhances the exposure of catalytically active sites.The prepared P-Ni_(3)S_(2)/Ni/NF exhibited remarkable performance with high HMF conversion(99.2%),FDCA yield(98.1%),and Faraday efficiency(98.8%),and excellent stability with good product selectivity for 7 consecutive cycles,which stands at a higher level than majority of previously published electrocatalysts.Furthermore,P-Ni_(3)S_(2)/Ni/NF also shows a significant response in HER.By using HMFOR and HER as the anodic reaction and cathodic reaction,respectively,the biomass upgrading and hydrogen production can be carried out simultaneously.The synthesized P-Ni_(3)S_(2)/Ni/NF only need a voltage of 1.31V to achieve a current density of 10mA/cm^(2)in a two-electrode system of HMFOR and HER,which is much lower than that of 1.48 V in OER and HER process,thus potentially reducing the cost of this process.展开更多
Transition metal selenides are considered promising electrochemical energy storage materials due to their excellent rate properties and high capacity based on multi-step conversion reactions.However,its practical appl...Transition metal selenides are considered promising electrochemical energy storage materials due to their excellent rate properties and high capacity based on multi-step conversion reactions.However,its practical applications are hampered by poor conductivity and large volume variation for Na^(+)storage,which resulting fast capacity decay.Herein,a facile metal-organic framework(MOF)derived method is explored to embed Cu_(2-x)Se@C particles into a carbon nanobelts matrix.Such carbon encapsulated nanobelts'structural moderate integral electronic conductivity and maintained the structure from collapsing during Na^(+)insertion/extraction.Furthermore,the porous structure of these nanobelts endows enough void space to mitigate volume stress and provide more diffusion channels for Na^(+)/electrons transporting.Due to the unique structure,these Cu_(2-x)Se@C nanobelts achieved ultra-stable cycling performance(170.7 m Ah/g at1.0 A/g after 1000 cycles)and superior rate capability(94.6 m Ah/g at 8 A/g)for sodium-ion batteries.The kinetic analysis reveals that these Cu_(2-x)Se@C nanobelts with considerable pesoudecapactive contribution benefit the rapid sodiation/desodiation.This rational design strategy broadens an avenue for the development of metal selenide materials for energy storage devices.展开更多
Recent advancements in nanotechnology have spotlighted the catalytic potential of nanozymes, particularly single-atom nanozymes(SANs), which are pivotal for innovations in biosensing and medical diagnostics. Among oth...Recent advancements in nanotechnology have spotlighted the catalytic potential of nanozymes, particularly single-atom nanozymes(SANs), which are pivotal for innovations in biosensing and medical diagnostics. Among others, DNA stands out as an ideal biological regulator. Its inherent programmability and interaction capabilities allow it to significantly modulate nanozyme activity. This study delves into the dynamic interplay between DNA and molybdenum-zinc single-atom nanozymes(Mo-Zn SANs). Using molecular dynamics simulations, we uncover how DNA influences the peroxidase-like activities of Mo-Zn SANs, providing a foundational understanding that broadens the application scope of SANs in biosensing.With these insights as a foundation, we developed and demonstrated a model aptasensor for point-ofcare testing(POCT), utilizing a label-free colorimetric approach that leverages DNA-nanozyme interactions to achieve high-sensitivity detection of lysozyme. Our work elucidates the nuanced control DNA exerts over nanozyme functionality and illustrates the application of this molecular mechanism through a smartphone-assisted biosensing platform. This study not only underscores the practical implications of DNA-regulated Mo-Zn SANs in enhancing biosensing platforms, but also highlights the potential of single-atom nanozyme technology to revolutionize diagnostic tools through its inherent versatility and sensitivity.展开更多
In this study,low-field nuclear magnetic resonance(LF-NMR)was used to collect the transverse relaxation signals of camphor seeds that had been dried at different temperatures and for different durations.The transverse...In this study,low-field nuclear magnetic resonance(LF-NMR)was used to collect the transverse relaxation signals of camphor seeds that had been dried at different temperatures and for different durations.The transverse relaxation time of the hydrogen nucleus was obtained by SIRT(Simultaneous Iterative Reconstruction Technique)inversion,and the correlation between the moisture content on dry basis and the amplitude of NMR signal of camphor seeds sampled at different drying stages was analyzed.The results showed that water existed in three main forms strongly bound water,weakly bound water and free water in camphor seeds.During the drying process,the peak position of strongly bound water remained unchanged,but the peak positions of weakly bound water and free water fluctuated.Drying rate increased with drying temperature increasing.In addition,there was a very significant linear relationship between the total NMR signal amplitude and moisture content on dry basis,and the correlation coefficient reached 0.984 4.展开更多
During aging at a temperature ranging from 650 -950 ℃,the ferric matrix in duplex stainless steels undergoes various decomposition processes which could form the precipitates of the Sigma （σ） and Chi （X） phases,...During aging at a temperature ranging from 650 -950 ℃,the ferric matrix in duplex stainless steels undergoes various decomposition processes which could form the precipitates of the Sigma （σ） and Chi （X） phases, as well as nitrides. It is well known that these precipitates lead to a reduction in creep ductility and adversely affect toughness and corrosion properties of steel. This experiment carded out qualitative and quantitative analyses of intermetallic phases and nitrides and established an analytical procedure, including specimen preparation, the choosing of the electrolyte and electrolytic systems,electrolytic isolation,wet chemical separation, and physical and chemical analysis, etc. The residues were collected by ultrasonic cleaning and filtration after galvanostatic electrolysis. Dynamic laser scattering sizer （DLS- sizer） ,scanning electron microscope （SEM） and transmission electron microscope （TEM） were used to examine their structure,modality and size. Qualitative and quantitative analyses were performed by using X-ray diffraction （XRD）, oxygen-nitrogen analyzer and wet chemical analysis. Furthermore, there is a discussion on the effect of isothermal treatment on precipitation that occurs at different temperatures for different periods of time.展开更多
Objective:To clone and express Rv3265c gene of Mycobacterium tuberculosis in Escherichia coli (E.coli) under optimistic conditions,obtain and identify protein expressed,analyze the structure and characteristics of the...Objective:To clone and express Rv3265c gene of Mycobacterium tuberculosis in Escherichia coli (E.coli) under optimistic conditions,obtain and identify protein expressed,analyze the structure and characteristics of the protein using bioinformatics methods for future applications.Methods: Rv3265c gene from Mycobacterium tuberculosis H37Rv was amplified by polymerase chain reaction,and was cloned into the pET-30a vector after purification and recovery.The recombinant plasmid was sequenced and expressed in E.coli BL21(DE3),and then purified and identified by western blotting.The essential physical-chemical properties of the protein were predicated by bioinformatics tools,including subcellular location,secondary structure,domains,antigenic epitopes,etc.Tertiary structure of the protein based on homology modeling was estabUshed,while multi-sequence homological alignment and phylogenetic analysis were preformed.Results:The recombinant protein was obtained in soluble fraction from expression system in E.coli B121(DE3) carrying pET30- Rv3265c plasmid,and Rv3265c gene was expressed correctly.Bioinformatics analysis showed the protein contained no signal peptide and transmembrane helices,located outside of membrane.Secondary structure analysis revealed it containedα-helix,extended strand and random coil,46.8%,14.6%,38.6%,respectively.Furthermore,it possessed six potential antigenic epitopes,one glycosyl transferase domain.A simple three-dimensional model of this protein was constructed by Swiss-model sever.Both sequences and structures were conservative and especial either in gene or in protein.Conclusions:Rv3265c gene might be a desirable molecular target for anti-tuberculosis drug and vaccine.The purified protein from expression will be utilized to study the kinetics of L-rhamnosyltransferase and to develope an enzyme assay for screening vaccine or drug.展开更多
基金sponsored by Shandong Provincial Key Research and Development Program(Major Technological Innovation Project)([2021]CXGC010508)Guizhou Province Youth Science and Technology Talent Plan(YQK[2023]038)+1 种基金Science and Technology Department of Zunyi City of Guizhou province of China([2020]7)Key project at central government level:the ability establishment of sustainable use for valuable Chinese medicine resources(2060302).
文摘Background:The study aimed to investigate the protective effect and mechanism of total flavonoids of Scutellaria baicalensis(TFSB)on acute myocardial ischemia(AMI)rats by using functional metabonomics.Methods:Rats were divided into the Control,Model,AMI positive control(Propranolol hydrochloride,30 mg/kg),low dose TFSB(50 mg/kg),and high dose TFSB(100 mg/kg)groups.Rats received the corresponding treatment by intragastric administration once daily for 10 consecutive days.Electrocardiogram,myocardial enzyme,triphenyltetrazolium chloride staining,hematoxylin-eosin,and enzyme-linked immunosorbent assay were performed to evaluate the protective effect of TFSB on AMI rats.Then,the UHPLC-Q-Orbitrap MS method based on serum metabolomics was utilised to search for metabolic biomarkers and metabolic pathways.Subsequently,Western blot and RT-PCR techniques were employed to identify the respective genes and proteins.Results:Pharmacodynamics revealed that TFSB could ameliorate AMI in rats.The results of the metabolomics analysis indicated that the alterations in metabolic profile observed in rats with AMI were partially improved by treatment with TFSB.Moreover,the mRNA expression levels of 5-lipoxygenase(5-LOX)and 15-lipoxygenase(15-LOX)and the protein expression levels of 5-LOX,15-LOX,interleukin-1β(IL-1β),and NF-κB p65 were reduced following treatment with TFSB.Conclusion:The potential treatment of TFSB in AMI may be ascribed to its ability to regulate arachidonic acid metabolism.
基金the financial support to the National Natural Science Foundation of China(U20A20279)the technical support provided by Analysis and Test Center of Wuhan University of Science and Technology,China.
文摘Segregation of solute atoms in the center of thick plates of the tempered steel can cause an inhomogeneous structural transformation and generate micron-sized inclusions,which leads to lamellar tearing of thick plate and decreases the plasticity and toughness.The formation and fragmentation mechanisms of micron-sized inclusions,like MnS and(Nb,Ti)C,in the center of thick plates were investigated by using thermodynamic calculations,finite element simulations,and electron backscatter diffraction characterization techniques.The results show that micron-sized inclusions nucleate and grow in the liquid phase,and under tensile loading,they exhibit three fragmentation mechanisms.The local stress during the fragmentation of inclusions is lower than the critical fracture stress of adjacent grains,and phase boundaries can effectively impede crack propagation into the matrix.The existence of a low proportion of high-angle grain boundaries(58.1%)and high Kernel average misorientation value(0.534°)in the segregation band promotes inclusions fragmentation and crack propagation.The difference in crack initiation and propagation direction caused by the morphology of inclusions and physical properties,as well as different matrix arrest abilities,is the main reasons for the diversity of inclusion fragmentation.
基金supported by the National Key R&D Program of China(2021YFB4001601)the Youth Innovation Promotion Association CAS(2022187).
文摘This study investigated the effect of pressure,pre-charge time,punch velocity and oxygen content on the mechanical properties of X42 pipeline steel in gaseous hydrogen environment by using small punch test.When exposed to nitrogen,the fracture mode of X42 pipeline steel undergoes ductile fracture,but in the presence of hydrogen,it shifts to brittle fracture.Moreover,an increase in hydrogen pressure or a decrease in punch velocity is found to enhance the hydrogen embrittlement susceptibility of X42 pipeline steel,as evidenced by the decrease of maximal load,displacement at failure onset and small punch energy.But the effect of pre-charge time on the hydrogen embrittlement susceptibility of X42 pipeline steel is not very obvious.Meanwhile,the presence of oxygen has been found to effectively inhibit hydrogen embrittlement.As the oxygen content in hydrogen increases,the hydrogen embrittlement susceptibility of X42 pipeline steel decreases.
基金supported by the National Natural Science Foundation of China(No.41905108)the National Research Program for Key Issues in Air Pollution Control(No.DQ GG0532).
文摘To study the volatile organic compounds(VOCs)emission characteristics of industrial enterprises in China,6 typical chemical industries in Yuncheng City were selected as research objects,including the modern coal chemical industry(MCC),pharmaceutical industry(PM),pesticide industry(PE),coking industry(CO)and organic chemical industry(OC).The chemical composition of 91 VOCs was quantitatively analyzed.The results showed that the emission concentration of VOCs in the chemical industry ranged from 1.16 to 155.59 mg/m^(3).Alkanes were the main emission components of MCC(62.0%),PE(55.1%),and OC(58.5%).Alkenes(46.5%)were important components of PM,followed by alkanes(23.8%)and oxygenated volatile organic compounds(OVOCs)(21.2%).Halocarbons(8.6%-71.1%),OVOCs(9.7%-37.6%)and alkanes(11.2%-27.0%)were characteristic components of CO.The largest contributor to OFP was alkenes(0.6%-81.7%),followed by alkanes(9.3%-45.9%),and the lowest onewas alkyne(0%-0.5%).Aromatics(66.9%-85.4%)were the largest contributing components to SOA generation,followed by alkanes(2.6%-28.5%),and the lowest one was alkenes(0%-4.1%).Ethylene and BTEX were the key active species in various chemical industries.The human health risk assessment showed workers long-term exposed to the air in the chemical industrial zone had a high cancer and non-cancer risk during work,and BTEX and dichloromethane were the largest contributors.
基金support of the Key Science Research Project in Colleges and Universities of Anhui Province,China(No.2022AH050813)the Medical Special Cultivation Project of Anhui University of Science and Technology,China(No.YZ2023H2A002).
文摘Carbon-based foams with a three-dimensional structure can serve as a lightweight template for the rational design and control-lable preparation of metal oxide/carbon-based composite microwave absorption materials.In this study,a flake-like nickel cobaltate/re-duced graphene oxide/melamine-derived carbon foam(FNC/RGO/MDCF)was successfully fabricated through a combination of solvo-thermal treatment and high-temperature pyrolysis.Results indicated that RGO was evenly distributed in the MDCF skeleton,providing ef-fective support for the load growth of FNC on its surface.Sample S3,the FNC/RGO/MDCF composite prepared by solvothermal method for 16 h,exhibited a minimum reflection loss(RL_(min))of-66.44 dB at a thickness of 2.29 mm.When the thickness was reduced to 1.50 mm,the optimal effective absorption bandwidth was 3.84 GHz.Analysis of the absorption mechanism of FNC/RGO/MDCF revealed that its excellent absorption performance was primarily attributed to the combined effects of conduction loss,multiple reflection,scattering,in-terface polarization,and dipole polarization.
文摘4-Nonylphenol(NP)is a kind of estrogen belonging to the endocrine disrupter,widely used in various agricultural and industrial goods.However,extensive use of NP with direct release to environment poses high risks to both human health and ecosystems.Herein,for the first time,we developed near-infrared(NIR)responsive upconversion luminescence nanosensor for NP detection.The Förster resonance energy transfer based upconversion nanoparticles(UCNPs)-graphene oxide sensor offers highly selective and sensitive detection of NP in linear ranges of 5−200 ng/mL and 200−1000 ng/mL under 980 nm and 808 nm excitation,respectively,with LOD at 4.2 ng/mL.The sensors were successfully tested for NP detection in real liquid milk samples with excellent recovery results.The rare-earth fluoride based upconversion luminescence nanosensor with NIR excitation wavelength,holds promise for sensing food,environmental,and biological samples due to their high sensitivity,specific recognition,low LOD,negligible autofluorescence,along with the deep penetration of NIR excitation sources.
基金supported by the Natural Science Foundation of Ningxia(No.2022AAC05014).
文摘In this work,the Si@reduced graphene oxide/ZrO_(2)(Si@rGO/ZrO_(2))with the shelled structures is prepared for the high-capacity and stable lithium-ion batteries.The shelled structure not only significantly improves the electrical conductivity of the whole electrode,but also protects the inner Si nanoparticles(Si NPs)from rupturing and being damaged by undesired side reactions with the electrolyte.As a result,the Si@rGO/ZrO_(2) anode delivers high initial discharge capacity of 3046 mAh·g^(−1) at 1.0 A·g^(−1).After 100 cycles,it can be maintained at 613 mAh·g^(−1),which is much higher than that of either the pure Si NPs(31 mAh·g^(−1))or the Si@rGO(261 mAh·g^(−1)).Even at 2 A·g^(−1),it still provides superior specific capacity of 834 mAh·g^(−1),while the pure Si anode merely possesses the capacity of 41 mAh·g^(−1).Moreover,the density functional theory calculations point out that ZrO_(2) layer can effectively enhance the adsorption energy of Li+and optimize the migration paths of Li+,ensuring the electrochemical performance of Si@rGO/ZrO_(2) composite anode.Furthermore,the Li+storage mechanism and low volume expansion of Si@rGO/ZrO_(2) anode is investigated by ex-situ X-ray photoelectron spectroscopy and morphological evolution upon cycling,respectively.
基金the financial support from the National Natural Science Foundation of China(No.21904007)the Fundamental Research Funds for the Central Universities(China,No.2412022QD008)+1 种基金the Jilin Provincial Department of Education(China),the Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province(China)the Analysis and Testing Center of Northeast Normal University(China)。
文摘The complexity of living environment system demands higher requirements for the sensitivity and selectivity of the probe.Therefore,it is of great importance to develop a universal strategy for highperformance probe optimization.Herein,we propose a novel“Enrichment-enhanced Detection”strategy and use carbon dots-dopamine detection system as a representative model to evaluate its feasibility.The composite probe carbon dots (CDs)-encapsulated in glycol-chitosan (GC)(i.e.,CDs@GC) was obtained by simply mixing GC and CDs through noncovalent interactions,including electrostatic interactions and hydrogen bonding.Dopamine (DA) could be detected through internal filter effect (IFE)-induced quenching of CDs.In the case of CDs@GC,noncovalent interactions (electrostatic interactions) between GC and the formed quinone (oxide of DA) could selectively extract and enrich the local concentration of DA,thus effectively improving the sensitivity and selectivity of the sensing system.The nanosensor had a low detection limit of 3.7 nmol/L,which was a 12-fold sensitivity improvement compared to the bare CDs probes with similar fluorescent profiles,proving the feasibility of the“Enrichment-enhanced Detection”strategy.Further,to examine this theory in real case,we designed a highly portable sensing platform to realize visual determination of DA.Overall,our work introduces a new strategy for accurately detecting DA and provides valuable insights for the universal design and optimization of superior nanoprobes.
基金financially supported by the National Natural Science Foundation of China(Nos.22106078,62105175)High-end Foreign Experts Recruitment Plan(No.G2023024007L)+1 种基金Shandong Provincial Natural Science Foundation(Nos.ZR2022YQ12,ZR2021QB031,ZR2021QF058)the Science,Education,and Industry Integration Pilot Project for Talent Research at Qilu University of Technology(Shandong Academy of Sciences)(No.2024RCKY028)。
文摘Mercury ions(Hg^(2+))and bacteria are widely spread in water pollution and pose a great threat to human health and the environment.Herein,a multifunctional COF Dmta Tph with significant Hg^(2+)adsorption capability and continuous sunlight-driven sterilization property is designed and synthesized by introducing thioether and photosensitive porphyrin in a single molecule.The obtained COF displays a high Hg^(2+)adsorption capacity of 657.9 mg/g at 298 K and a superior antibacterial effect toward Escherichia coli and Staphylococcus aureus under sunlight irradiation.Mechanistic studies reveal that the strong coordination between S species and Hg^(2+)is the main driving force for high Hg^(2+)adsorption capability.The sterilization mechanism clarifies that the inactivation of bacteria is caused by1O_(2)produced from Dmta Tph with the assistance of light irradiation.Noteworthy,when Dmta Tph is applied in the treatment of wastewater,it displays high Hg^(2+)removal efficiency and remarkable antibacterial effect under complex conditions.This study has demonstrated a promising strategy for designing multifunctional COF-based materials,offering great potential in tackling the problem of heavy metal ions and bacteria pollution in water.
基金supported by the National Natural Science Foundation of China(Grant No.21968001).
文摘The discharge of effluents containing uranium(U)ions into aquatic ecosystems poses significant risks to both human health and marine organisms.This study investigated the biosorption of U(VI)ions from aqueous solutions using corncob-sodium alginate(SA)-immobilized Trichoderma aureoviride hyphal pellets.Experimental parameters,including initial solution pH,initial concentration,temperature,and contact time,were systematically examined to understand their influence on the bioadsorption process.Results showed that the corncob-SA-immobilized T.aureoviride hyphal pellets exhibited maximum uranium biosorption capacity at an initial pH of 6.23 and a contact time of 12 h.The equilibrium data aligned with the Langmuir isotherm model,with a maximum biosorption capacity of 105.60 mg/g at 301 K.Moreover,biosorption kinetics followed the pseudo-second-order kinetic model.In terms of thermodynamic parameters,the changes in Gibbs-free energy(△G°)were determined to be-4.29 kJ/mol at 301 K,the changes in enthalpy(△H°)were 46.88 kJ/mol,and the changes in entropy(△S°)was 164.98 J/(mol·K).Notably,the adsorbed U(VI)could be efficiently desorbed using Na_(2)CO_(3),with a maximum readsorption efficiency of 53.6%.Scanning electron microscopic(SEM)analysis revealed U(VI)ion binding onto the hyphal pellet surface.This study underscores the efficacy of corncob-SA-immobilized T.aureoviride hyphal pellets as a cost-effective and environmentally favorable biosorbent material for removing U(VI)from aquatic ecosystems.
基金supported by the National Natural Science Foundation of China(Nos.22202104,22279062,22232004 and 22072067)the Natural Science Foundation of Jiangsu Province(No.BK20220933)Shuangchuang Doctor Plan of Jiangsu Province(No.JSSCBS20220273).
文摘To efficiently diminish the Pt consumption while concurrently enhancing the anodic reaction kinetics,a straightforward synthesis for PtPdAg nanotrees(NTs)with exceedingly low Pt content is presented,utilizing the galvanic replacement reaction between the initially prepared PdAg NTs and Pt ions.Due to the multilevel porous tree-like structure and the incorporation of low amounts of Pt,the electrocatalytic activity and stability of PtPdAg NTs are markedly enhanced,achieving 1.65 and 1.69 A·mg^(-1)Pt+Pd for the anodic reactions of formic acid oxidation(FAOR)and methanol oxidation(MOR)within DLFCs,surpassing the performance of PdAg NTs,as well as that of commercial Pt and Pd black.Density functional theory(DFT)calculations reveal that the addition of low amounts of Pt leads to an increase in the d-band center of PtPdAg NTs and lower the COads adsorption energy to-1.23 eV,enhancing the anti-CO toxicity properties optimally.This approach offers an effective means for designing low Pt catalysts as exceptional anodic electrocatalysts for direct liquid fuel cells.
基金financially supported by National Natural Science Foundation of China(21773291,52303130,62205231,61904118,22002102)Natural Science Foundation of the Jiangsu Higher Education Institutions of China(19KJA210005)+1 种基金Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX23_1710)Postgraduate Research&Practice Innovation Program of Suzhou University of Science and Technology(CLKYCX23_06)。
文摘Exploiting high-performance electrolyte holds the key for realization practical application of rechargeable magnesium batteries(RMBs).Herein,a new non-nucleophilic mononuclear electrolyte was developed and its electrochemical active species was identified as[Mg(DME)_(3)][GaCl_(4)]_(2) through single-crystal X-ray diffraction analysis.The as-synthesized Mg(GaCl_(4))_(2)-IL-DME electrolyte could achieve a high ionic conductivity(9.85 m S cm^(-1)),good anodic stability(2.9 V vs.Mg/Mg^(2+)),and highly reversible Mg plating/stripping.The remarkable electrochemical performance should be attributed to the in-situ formation of Mg^(2+)-conducting Ga_(5)Mg_(2)alloy layer at the Mg/electrolyte interface during electrochemical cycling,which not only efficiently protects the Mg anode from passivation,but also allows for rapid Mg-ion transport.Significantly,the Mg(GaCl_(4))_(2)-IL-DME electrolyte showed excellent compatibility with both conversion and intercalation cathodes.The Mg/S batteries with Mg(Ga Cl_(4))_(2)-IL-DME electrolyte and KB/S cathode showed a high specific capacity of 839 m Ah g^(-1)after 50 cycles at 0.1 C with the Coulombic efficiency of~100%.Moreover,the assembled Mg|Mo_6 S_8 batteries delivered a reversible discharge capacity of 85 m Ah g^(-1)after 120 cycles at 0.2 C.This work provides a universal electrolyte for the realization of high-performance and practical RMBs,especially Mg/S batteries.
基金supported by the National Key Research and Development Program of China(No.2022YFB2502000)the National Natural Science Foundation of China(Nos.U21A20332,51771076,U21A200970,52301266)the Science and Technology Planning Project of Guangzhou(No.2024A04J3332)。
文摘Mixed polyanion phosphate Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_(7)(NFPP)is regarded as the most promising cathode material for sodium-ion batteries(SIBs),due to its high structural stability and low-cost environmental friendliness.However,its intrinsic low conductivity and sluggish Na^(+)diffusion restricted the fast-charge and low-temperature sodium storage.Herein,an NFPP composite encapsulated by in-situ pyrolytic carbon and coupled with expanded graphite(NFPP@C/EG)was constructed via a sol-gel method followed by a ballmill procedure.Due to the dual-carbon modified strategy,this NFPP@C/EG only enhanced the electronic conductivity,but also endowed more channels for Na^(+)diffusion.As cathode for SIBs,the optimized NFPP(M-NFPP@C/EG)delivers excellent rate capability(capacity of~80.5 mAh/g at 50 C)and outstanding cycling stability(11000 cycles at 50 C with capacity retention of 89.85%).Additionally,cyclic voltammetry(CV)confirmed that its sodium storage behavior is pseudocapacitance-controlled,with in-situ electrochemical impedance spectroscopy(EIS)further elucidating improvements in electrode reaction kinetics.At lower temperatures(0℃),M-NFPP@C/EG demonstrated exceptional cycling performance(8800 cycles at 10 C with capacity retention of 95.81%).Moreover,pouch cells also exhibited excellent stability.This research demonstrates the feasibility of a dual carbon modification strategy in enhancing NFPP and proposes a low-cost,high-rate,and ultra-stable cathode material for SIBs.
基金supported by Key Research and Development Project of Shandong Province(2021ZDSYS12)National Natural Science Foundation of China(22076086,21777089)+3 种基金Taishan Scholar Program of Shandong Province(ts20190948)Shandong Province Science and Technology Small and Medium Enterprises Innovation Ability Enhancement Project(2023TSGC0689,2023TSGC0055)Natural Science Foundation of Shandong Province(ZR2021MB086,ZR2023QB035)Jinan City University and Institute Innovation Team Project(2021GXRC061,20228045,202333027)。
文摘Organophosphorus pesticides(OPPs)in foods pose a serious threat to human health,motivating the development of novel analytical methods for their rapid detection and quantification.A magnetic covalent organic framework(M-COF)adsorbent for the magnetic solid-phase extraction(MSPE)of OPPs from foods was reported.M-COF was synthesized by the Schiff base condensation reaction of 1,3,5-tris(4-aminophenyl)benzene and 4,4-biphenyldicarboxaldehyde on the surface of amino-functionalized magnetic nanoparticles.Density functional theory(DFT)calculations showed that adsorption of OPPs onto the surface of M-COF involved hydrophobic effects,van der Waals interactions,π-πinteractions,halogen-N bonding,and hydrogen bonding.Combined with gas chromatography-mass spectrometry(GC-MS)technology,the MSPE method features low limits of detection for OPPs(0.002-0.015μg/L),good reproducibility(1.45%-6.14%),wide linear detection range(0.01-1μg/L,R≥0.9935),and satisfactory recoveries(87.3%-110.4%).The method was successfully applied for the trace analysis of OPPs in spiked fruit juices.
基金financially supported by Natural Science Foundation of Shandong Province(No.ZR2024QB415)。
文摘The biomass electrochemical oxidation coupled with hydrogen evolution reaction has received widespread attention due to its carbon-neutral and sustainable properties.The electrosynthesis of 2,5-furanodicarboxylic acid(FDCA)from 5-hydroxymethylfurfural(HMF)oxidation is one of the most promising means for the production of bioplastic monomers.In this work,we constructed a novel P-doped Ni_(3)S_(2)and Ni heterojunction on nickel foam(P-Ni_(3)S_(2)/Ni/NF)using electrodeposition methods and thermal sulfuration techniques as a bifunctional catalyst for the simultaneous anodic oxidation of HMF to FDCA(HMFOR)and the cathodic hydrogen evolution reaction(HER).On one hand,the synergistic promotion of P doping and the heterojunction of Ni_(3)S_(2)and Ni accelerated electron transfer,and on the other hand,the structure of three-dimensional microsphere stacking on NF surface to form macropores enhances the exposure of catalytically active sites.The prepared P-Ni_(3)S_(2)/Ni/NF exhibited remarkable performance with high HMF conversion(99.2%),FDCA yield(98.1%),and Faraday efficiency(98.8%),and excellent stability with good product selectivity for 7 consecutive cycles,which stands at a higher level than majority of previously published electrocatalysts.Furthermore,P-Ni_(3)S_(2)/Ni/NF also shows a significant response in HER.By using HMFOR and HER as the anodic reaction and cathodic reaction,respectively,the biomass upgrading and hydrogen production can be carried out simultaneously.The synthesized P-Ni_(3)S_(2)/Ni/NF only need a voltage of 1.31V to achieve a current density of 10mA/cm^(2)in a two-electrode system of HMFOR and HER,which is much lower than that of 1.48 V in OER and HER process,thus potentially reducing the cost of this process.
基金supported by the National Key Research and Development Program of China(No.2022YFB2502000)the National Natural Science Foundation of China(Nos.U21A2033251771076,52301266,42203047)+2 种基金R&D Program in Key Areas of Guangdong Province(No.2020B0101030005)Science and Technology Planning Project of Guangzhou(No.2024A04J9999)GDUT Large-Scale Instruments Open Foundation(No.ATC2022201)。
文摘Transition metal selenides are considered promising electrochemical energy storage materials due to their excellent rate properties and high capacity based on multi-step conversion reactions.However,its practical applications are hampered by poor conductivity and large volume variation for Na^(+)storage,which resulting fast capacity decay.Herein,a facile metal-organic framework(MOF)derived method is explored to embed Cu_(2-x)Se@C particles into a carbon nanobelts matrix.Such carbon encapsulated nanobelts'structural moderate integral electronic conductivity and maintained the structure from collapsing during Na^(+)insertion/extraction.Furthermore,the porous structure of these nanobelts endows enough void space to mitigate volume stress and provide more diffusion channels for Na^(+)/electrons transporting.Due to the unique structure,these Cu_(2-x)Se@C nanobelts achieved ultra-stable cycling performance(170.7 m Ah/g at1.0 A/g after 1000 cycles)and superior rate capability(94.6 m Ah/g at 8 A/g)for sodium-ion batteries.The kinetic analysis reveals that these Cu_(2-x)Se@C nanobelts with considerable pesoudecapactive contribution benefit the rapid sodiation/desodiation.This rational design strategy broadens an avenue for the development of metal selenide materials for energy storage devices.
基金supported by the Science and Technology Research Project from Education Department of Jilin Province (No. JJKH20231296KJ)the Natural Science Foundation of Science and Technology Department of Jilin Province (Joint Fund Project) (No. YDZJ202201ZYTS340)+9 种基金the Fundamental Research Funds for the Central Universities (No. 2412022ZD013)the Science and Technology Development Plan Project of Jilin Province (Nos. SKL202302030, SKL202402017, 20210204126YY, 20230204113YY, 20240602003RC, 20210402059GH)the National Natural Science Foundation of China (Nos. 22174137, 22322410, 92372102 and 22073094)the Cooperation Funding of Changchun with Chinese Academy of Sciences (No. 22SH13)the Capital Construction Fund Projects within the Budget of Jilin Province (No. 2023C042–5)the University Level Scientific Research Projects of Ordinary Universities in Xinjiang Uygur Autonomous Region (No. 2022YQSN002)the State Key Laboratory of Molecular Engineering of Polymers (Fudan University) (No. K2024–11)the Program for Young Scholars in Regional Development of CASthe essential support of the Network and Computing Center, CIAC, CASthe Computing Center of Jilin Province。
文摘Recent advancements in nanotechnology have spotlighted the catalytic potential of nanozymes, particularly single-atom nanozymes(SANs), which are pivotal for innovations in biosensing and medical diagnostics. Among others, DNA stands out as an ideal biological regulator. Its inherent programmability and interaction capabilities allow it to significantly modulate nanozyme activity. This study delves into the dynamic interplay between DNA and molybdenum-zinc single-atom nanozymes(Mo-Zn SANs). Using molecular dynamics simulations, we uncover how DNA influences the peroxidase-like activities of Mo-Zn SANs, providing a foundational understanding that broadens the application scope of SANs in biosensing.With these insights as a foundation, we developed and demonstrated a model aptasensor for point-ofcare testing(POCT), utilizing a label-free colorimetric approach that leverages DNA-nanozyme interactions to achieve high-sensitivity detection of lysozyme. Our work elucidates the nuanced control DNA exerts over nanozyme functionality and illustrates the application of this molecular mechanism through a smartphone-assisted biosensing platform. This study not only underscores the practical implications of DNA-regulated Mo-Zn SANs in enhancing biosensing platforms, but also highlights the potential of single-atom nanozyme technology to revolutionize diagnostic tools through its inherent versatility and sensitivity.
文摘In this study,low-field nuclear magnetic resonance(LF-NMR)was used to collect the transverse relaxation signals of camphor seeds that had been dried at different temperatures and for different durations.The transverse relaxation time of the hydrogen nucleus was obtained by SIRT(Simultaneous Iterative Reconstruction Technique)inversion,and the correlation between the moisture content on dry basis and the amplitude of NMR signal of camphor seeds sampled at different drying stages was analyzed.The results showed that water existed in three main forms strongly bound water,weakly bound water and free water in camphor seeds.During the drying process,the peak position of strongly bound water remained unchanged,but the peak positions of weakly bound water and free water fluctuated.Drying rate increased with drying temperature increasing.In addition,there was a very significant linear relationship between the total NMR signal amplitude and moisture content on dry basis,and the correlation coefficient reached 0.984 4.
文摘During aging at a temperature ranging from 650 -950 ℃,the ferric matrix in duplex stainless steels undergoes various decomposition processes which could form the precipitates of the Sigma （σ） and Chi （X） phases, as well as nitrides. It is well known that these precipitates lead to a reduction in creep ductility and adversely affect toughness and corrosion properties of steel. This experiment carded out qualitative and quantitative analyses of intermetallic phases and nitrides and established an analytical procedure, including specimen preparation, the choosing of the electrolyte and electrolytic systems,electrolytic isolation,wet chemical separation, and physical and chemical analysis, etc. The residues were collected by ultrasonic cleaning and filtration after galvanostatic electrolysis. Dynamic laser scattering sizer （DLS- sizer） ,scanning electron microscope （SEM） and transmission electron microscope （TEM） were used to examine their structure,modality and size. Qualitative and quantitative analyses were performed by using X-ray diffraction （XRD）, oxygen-nitrogen analyzer and wet chemical analysis. Furthermore, there is a discussion on the effect of isothermal treatment on precipitation that occurs at different temperatures for different periods of time.
基金Supported by Research Program in higher educational institutes of The Education Department of Hainan Province(No.Hj2010-21)Research Program of The Health Department of Hainan Province(No.2007-44)+1 种基金Natural Science Fund of Hainan Province(No.2008-30837)Cultivation Program of Hainan Medical University (HY2010-006)
文摘Objective:To clone and express Rv3265c gene of Mycobacterium tuberculosis in Escherichia coli (E.coli) under optimistic conditions,obtain and identify protein expressed,analyze the structure and characteristics of the protein using bioinformatics methods for future applications.Methods: Rv3265c gene from Mycobacterium tuberculosis H37Rv was amplified by polymerase chain reaction,and was cloned into the pET-30a vector after purification and recovery.The recombinant plasmid was sequenced and expressed in E.coli BL21(DE3),and then purified and identified by western blotting.The essential physical-chemical properties of the protein were predicated by bioinformatics tools,including subcellular location,secondary structure,domains,antigenic epitopes,etc.Tertiary structure of the protein based on homology modeling was estabUshed,while multi-sequence homological alignment and phylogenetic analysis were preformed.Results:The recombinant protein was obtained in soluble fraction from expression system in E.coli B121(DE3) carrying pET30- Rv3265c plasmid,and Rv3265c gene was expressed correctly.Bioinformatics analysis showed the protein contained no signal peptide and transmembrane helices,located outside of membrane.Secondary structure analysis revealed it containedα-helix,extended strand and random coil,46.8%,14.6%,38.6%,respectively.Furthermore,it possessed six potential antigenic epitopes,one glycosyl transferase domain.A simple three-dimensional model of this protein was constructed by Swiss-model sever.Both sequences and structures were conservative and especial either in gene or in protein.Conclusions:Rv3265c gene might be a desirable molecular target for anti-tuberculosis drug and vaccine.The purified protein from expression will be utilized to study the kinetics of L-rhamnosyltransferase and to develope an enzyme assay for screening vaccine or drug.
