The 3CL protease, a highly conserved enzyme in the coronavirus, plays a crucial role in the viral life cycle by facilitating viral replication through precise cleavage of polyproteins. Beyond its proteolytic function,...The 3CL protease, a highly conserved enzyme in the coronavirus, plays a crucial role in the viral life cycle by facilitating viral replication through precise cleavage of polyproteins. Beyond its proteolytic function, the 3CL protease also engages in intricate interactions with host cell proteins involved in critical cellular processes such as transcription, translation, and nuclear-cytoplasmic transport, effectively hijacking cellular machinery to promote viral replication. Additionally, it disrupts innate immune signaling pathways, suppresses interferon activity and cleaves antiviral proteins. Furthermore, it modulates host cell death pathways including pyroptosis and apoptosis, interferes with autophagy and inhibits stress granule formation to maintain viral infection and exacerbate viral pathogenesis. This review highlights the molecular mechanisms by which the 3CL protease orchestrates virus-host interactions, emphasizing its central role in coronavirus pathogenesis and highlighting potential therapeutic targets for future interventions.展开更多
A γ-TiAl alloy with nominal composition of Ti-47%Al（molar fraction） was directionally solidified in an alumina mould with an Y2O3 protective coating.The effects of processing parameters（melting temperature and int...A γ-TiAl alloy with nominal composition of Ti-47%Al（molar fraction） was directionally solidified in an alumina mould with an Y2O3 protective coating.The effects of processing parameters（melting temperature and interaction time） on the metal-coating interface,microstructure and chemical composition of the alloy were evaluated.The result shows that the Y2O3 protective coating exhibits an effective barrier capability to avoid direct contact between the mould base material and the TiAl melt,although the Y2O3 coating is found to suffer some erosion and be slightly dissolved by the molten TiAl due to the coating-metal interactions.The directionally solidified alloys were contaminated with Y and O,and Y2O3 inclusions were dispersed in the metal matrix.The reason for this metal contamination is the Y2O3 coating dissolution by the TiAl melt.One mode of the interaction between Y2O3 and the TiAl melt is dissolution of yttrium and atomic oxygen in the melt by reaction Y2O3（s）=2Y（in TiAl melt）＋3O（in TiAl melt）.Both the extent of alloy contamination and the volume fractions of Y2O3 inclusions depend on the melting temperature and the interaction time.展开更多
With the help of a modified mapping method and a new mapping method, we re-study the （3＋1）-dimensional Burgers equation, and derive two families of variable separation solutions. By selecting appropriate functions ...With the help of a modified mapping method and a new mapping method, we re-study the （3＋1）-dimensional Burgers equation, and derive two families of variable separation solutions. By selecting appropriate functions in the variable separation solution, we discuss the interaction behaviors among taper-like, plateau-type rings, and rectangle-type embed-solitons in the periodic wave background. All the interaction behaviors are completely elastic, and no phase shift appears after interaction.展开更多
The mechanical properties and microstructures of Al_(2)O_(3)whiskers and graphene nano-platelets(GNPs)co-reinforced Cu-matrix composites were studied.Cu-matrix composites with a variation of GNPs amount were fabricate...The mechanical properties and microstructures of Al_(2)O_(3)whiskers and graphene nano-platelets(GNPs)co-reinforced Cu-matrix composites were studied.Cu-matrix composites with a variation of GNPs amount were fabricated by mechanical alloying followed by vacuum hot-pressing sintering and hot isostatic pressing.The Cu-matrix composite with 0.5 wt.%GNPs(GNPs-0.5)suggests a good interfacial bonding of both Cu/C and Cu/Al_(2)O_(3)interfaces.Both the hardness and compressive strength of Cu-matrix composites show a consistent tendency that firstly increases to a critical value and then decreases with increasing GNPs amount.It is suggested that the most possible strengthening mechanisms of both GNPs and Al_(2)O_(3)whisker working in the Cu-matrix composites involve energy dissipating and load transfer,as well as grain refinements for GNPs.The synergetic effect of GNPs and Al_(2)O_(3)whiskers is highlighted that the embedded GNPs would hinder the crack path generated at the Al_(2)O_(3)/Cu interface and enhance the already outstanding strengthening effect that Al_(2)O_(3)whiskers provide.展开更多
In this paper, a 3D time domain technique is adopted to calculate the coupled hydrodynamic interaction between two bodies without flare in waves. For verifying the code, two same cylinders are selected to calculate co...In this paper, a 3D time domain technique is adopted to calculate the coupled hydrodynamic interaction between two bodies without flare in waves. For verifying the code, two same cylinders are selected to calculate coupled hydrodynamic effects by comparison with the results obtained by 3D frequency method which has been proved to be efficient for solving such problems. In order to improve efficiency of calculation, the effect of history time has been discussed, and an improved method is presented. Moreover, the effect of lateral separation distance is also discussed in detail. The technique developed here may serve as a more rigorous tool to analyze the related transient problems of two ships doing underway replenishment in waves.展开更多
In this work,we fabricated three kinds of Ag/Fe2O3 model catalysts with different morphologies to study the interfacial interactions between Ag and Fe2O3,and how they affected the catalytic activity in hydrogenation o...In this work,we fabricated three kinds of Ag/Fe2O3 model catalysts with different morphologies to study the interfacial interactions between Ag and Fe2O3,and how they affected the catalytic activity in hydrogenation of p-nitrophenol was explored.The hydrothermal method was used to synthesize the metal oxide supported silver catalyst,with various morphologies including nanoplates(NPs),nanospheres(NSs),and nanocubes(NCs).The crystal structure,morphology and surface elements of the composite were investigated by various measurements,such as X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS).The catalytic activity was also evaluated by the reduction of p-nitrophenol to p-aminophenol.It was found that the activities of the above catalysts varied with the morphology of the support.Among them,Ag/Fe2O3 NPs promoted the highest performance,Ag/Fe2O3 NSs were slightly inferior,and Ag/Fe2O3 NCs were the worst.At last,we ascribed the remarkable activity of Ag/Fe2O3 NPs to the strong metal-support interactions between Ag and Fe2O3.展开更多
Tuning metal-support interactions(MSIs)is an important strategy in heterogeneous catalysis to realize the desirable metal dispersion and redox ability of metal catalysts.Herein,we use pre-reduced Co_(3)O_(4)nanowires(...Tuning metal-support interactions(MSIs)is an important strategy in heterogeneous catalysis to realize the desirable metal dispersion and redox ability of metal catalysts.Herein,we use pre-reduced Co_(3)O_(4)nanowires(Co-NWs)in situ grown on monolithic Ni foam substrates to support Ag catalysts(Ag/Co-NW-R)for soot combustion.The macroporous structure of Ni foam with crossed Co_(3)O_(4)nanowires remarkably increases the soot-catalyst contact effi ciency.Our characterization results demonstrate that Ag species exist as Ag 0 because of the equation Ag^(+)+Co^(2+)=Ag^(0)+Co^(3+),and the pre-reduction treatment enhances interactions between Ag and Co_(3)O_(4).The number of active oxygen species on the Ag-loaded catalysts is approximately twice that on the supports,demonstrating the signifi cant role of Ag sites in generating active oxygen species.Additionally,the strengthened MSI on Ag/Co-NW-R further improves this number by increasing metal dispersion and the intrinsic activity determined by the turnover frequency of these oxygen species for soot oxidation compared with the catalyst without pre-reduction of Co-NW(Ag/Co-NW).In addition to high activity,Ag/Co-NW-R exhibits high catalytic stability and water resistance.The strategy used in this work might be applicable in related catalytic systems.展开更多
^1H and ^13C NMR chemical shifts were determined to investigate the interactions of acetone with a room temperature ionic liquid 1-hexyl-3- methylimidazolium bromide [C6mim]Br at various mole fractions. Changes in che...^1H and ^13C NMR chemical shifts were determined to investigate the interactions of acetone with a room temperature ionic liquid 1-hexyl-3- methylimidazolium bromide [C6mim]Br at various mole fractions. Changes in chemical shifts of hydrogen nuclei and of carbon nuclei with the acetone concentration indicated the formation of hydrogen bond between anion of the ionic liquid and methyl protons of acetone. The NMR results were in good agreement with the ab initio computational results.展开更多
Supported metal oxide catalysts have garnered significantattention in oxidative dehydrogenation(ODH)due to their tunable metal-support interactions.The pentacoordinate Al^(3+)(Al_(V)^(3+))in γ-Al_(2)O_(3)supports pla...Supported metal oxide catalysts have garnered significantattention in oxidative dehydrogenation(ODH)due to their tunable metal-support interactions.The pentacoordinate Al^(3+)(Al_(V)^(3+))in γ-Al_(2)O_(3)supports plays a pivotal role in modulating metal-support interaction.This study investigates oxalic acid(OA)pretreatment as a defect engineering strategy to enhance the catalytic performance of CeO_(2)/γ-Al_(2)O_(3)in cyclohexane ODH.Through integrated characterization(XRD,27Al MAS NMR,H_(2)-TPR,TPRO,MS,XPS)and catalytic testing,we demonstrate that optimal OA treatment(1:10 ratio)eliminates 100%of surface Al_(V)^(3+)defects while enhancing CeO_(2)crystallinity and interfacial oxygen mobility.The removal of Al_(V)^(3+)species restructures metal-support interaction,accelerating interfacial oxygen mobility.In oxidation dehydrogenation of cyclohexane,the modified CeO_(2)/γ-Al_(2)O_(3)achieves 29%of cyclohexane conversion with stable selectivity of 49%cyclohexene.These findingsprovide an initial framework for designing redox-active catalysts via targeted support modificationin CeO_(2)/γ-Al_(2)O_(3)systems,emphasizing the relationship between metal-support interaction and oxygen mobility.展开更多
In the context of the prevalent winter air quality issues in China marked by declining PM_(2.5)and rising O_(3),this study employed amodified WRF-Chem model to examine the aerosol radiation interaction(ARI),heterogene...In the context of the prevalent winter air quality issues in China marked by declining PM_(2.5)and rising O_(3),this study employed amodified WRF-Chem model to examine the aerosol radiation interaction(ARI),heterogeneous chemistry(AHC),and their combined impact(ALL)on the variations in O_(3)and PM_(2.5)during the 2014–2020 in eastern China.Our analysis confirmed that ARI curtailed O_(3)while elevating PM_(2.5).AHC reduced O_(3)through heterogeneous absorption of NOx and hydroxideswhile notably fostering fine-grained sulfate,resulting in a PM_(2.5)increase.Emission reductions mitigated the inhibitory impact of ARI on meteorological fields and photolysis rates.Emission reduction individually without aerosol feedback led to a 5.43 ppb O_(3)increase and a 22.89μg/m^(3)PM_(2.5)decrease.ARI and AHC amplified the emission-reduction-induced(ERI)O_(3)rise by 1.83 and 0.31 ppb,respectively.The response of ARI to emission diminution brought about a modest PM_(2.5)increase of 0.31μg/m^(3).Conversely,AHC,acting as the primary contributor,caused a noteworthy PM_(2.5)decrease of 4.60μg/m^(3).As efforts concentrate on reducing PM_(2.5),the promotion of ARI on PM_(2.5)counterbalanced the efficacy of emission reduction and the AHC-induced strengthening of PM_(2.5)decrease.The ALL magnified the ERI O_(3)increase by 38.9%and PM_(2.5)decrease by 18.7%.Sensitivity experiments with different degrees of emission reduction demonstrated a consistent linear relationship between the ALL-induced enhancement of O_(3)increase and PM_(2.5)decrease to the ERI PM_(2.5)decline.Our investigation revealed the complex connection between emissions and aerosol feedback in influencing air quality.展开更多
The study of ligand-receptor interactions is of great significance in food flavor perception.In this study,a computer simulation method was used to investigate the mechanism of interaction between umami peptides and T...The study of ligand-receptor interactions is of great significance in food flavor perception.In this study,a computer simulation method was used to investigate the mechanism of interaction between umami peptides and T1R1/T1R3-Venus-flytrap domain(VFT)receptor.The binding site,conformational changes,and binding free energy between umami peptides and T1R1/T1R3-VFT were analyzed through molecular modeling,molecular docking,and molecular dynamics simulations.The receptor model constructed using AlphaFold2 has the best rationality.The molecular docking results showed that umami peptides primarily bound to T1R1-VFT through hydrogen bonding,with key binding residues such as Thr149,Arg151,and Asp108.The binding of umami peptides led to a more stable complex system,and the positively charged amino acids contributed positively to the overall binding free energy.This study provides theoretical support for the development of a better understanding of the interaction between umami substances and the umami receptor.展开更多
Herein,an oxygen-doped porous g-C_(3)N_(4)photocatalyst modified with atomically dispersed Fe(Fe_(1)/OPCN)issuccessfully prepared and exhibits significant superiority in removing refractory sulfonic azo contaminants f...Herein,an oxygen-doped porous g-C_(3)N_(4)photocatalyst modified with atomically dispersed Fe(Fe_(1)/OPCN)issuccessfully prepared and exhibits significant superiority in removing refractory sulfonic azo contaminants fromwater via catalyst-contaminant interaction.The elimination performance of Fe_(1)/OPCN towards acid red 9,acidred 13 and amaranth containing similar azonaphthalene structure and increasing sulfonic acid groups increasesgradually.The amaranth degradation rate of Fe_(1)/OPCN is 17.7 and 6.1 times as that of homogeneous Fenton andOPCN,respectively.In addition,Fe_(1)/OPCN also has more outstanding removal activities towards other con-taminantswith sulfonic acid and azo groups alone.The considerable enhancement for removing sulfonic azocontaminants of Fe_(1)/OPCN is mainly ascribed to the following aspects:(1)The modified Fe could enhance theadsorption towards sulfonic azo compounds to accelerate the mass transfer,act as e^(-)acceptor to promoteinterfacial charge separation,and trigger the self-Fenton reaction to convert in-situ generated H_(2)O_(2)into·OH.(2)Fe(Ⅲ)could coordinate with-N=N-to form d-πconjugation,which could attract e^(-)transfer to attack-N=N-bond.Meanwhile,the inhibited charge recombination could release more free h^(þ)to oxidize sulfonicacid groups into SO4^(-)·.(3)Under the cooperation of abundant multiple active species(·O_(2)^(-),h^(þ),e^(-),·OH,SO4^(-)·)formed during the degradation reaction,sulfonic azo compounds could be completely mineralized into harmlesssmall molecules(CO_(2),H_(2)O,etc.)by means of-N=N-cleavage,hydroxyl substitution,and aromatic ringopening.This work offers a novel approach for effectively eliminating refractory sulfonic azo compounds fromwastewater.展开更多
As the“fourth messenger”of epigenetic regulation,metabolites playa spatiotemporally specific regulatory role in kidney regeneration by dynamically reshaping the state of chromatin modifications.This review systemati...As the“fourth messenger”of epigenetic regulation,metabolites playa spatiotemporally specific regulatory role in kidney regeneration by dynamically reshaping the state of chromatin modifications.This review systematically expounds the coordinated mechanism of the dual axes of succinate/H3K9ac andα-ketoglutarate(α-KG)/TET enzymes:Succinate activates regeneration-related genes by regulating histone acetylation(H3K9ac),whileα-KG relieves the epigenetic repression of the Wnt pathway through TET-mediated DNA demethylation.The dynamic balance between the two maintains epigenetic plasticity.Multi-omics integration strategies(such as Gaussian graphical models and deep learning frameworks)and single-cell epigenetic tracking technologies(such as spatial metabolomics)have revealed the regulation of metabolite gradients on cellular heterogeneity and the immune microenvironment.The coordinated application of metabolite precursor supplementation(such as NAD precursors)and dynamic monitoring systems(such as isotope tracing and artifi cial intelligence models)has promoted the shift of metabolic medicine from the“static replacement”paradigm to the“dynamic reshaping”paradigm.However,technical bottlenecks(such as insuffi cient multimodal integration)and clinical translation pitfalls(such as challenges in standardized production)still need to be overcome.In the future,through the development of“metabolism-immunity”co-regulatory strategies and intelligent closed-loop systems,it is expected to achieve precise interventions for kidney regeneration and disease treatment.展开更多
We propose the exact solution of the equation in separated variable which appears in the process of constructing solutions to the quantum Calogero-Moser three-particle problem with elliptic two-particle potential . Th...We propose the exact solution of the equation in separated variable which appears in the process of constructing solutions to the quantum Calogero-Moser three-particle problem with elliptic two-particle potential . This solution is found for special values of coupling constants . It can be used for solving three-particle Calogero-Moser problem under the appropriate boundary conditions.展开更多
The human genome can be demarcated into domains based on distinct epigenetic states.The trimethylation of histone H3 lysine 9(H3K9me3)is essential for the formation of constitutive heterochromatin nanodomains.However,...The human genome can be demarcated into domains based on distinct epigenetic states.The trimethylation of histone H3 lysine 9(H3K9me3)is essential for the formation of constitutive heterochromatin nanodomains.However,the extent to which genomic regions require specific densities or degrees of H3K9me3 for stable interactions remains unclear.Here,we utilize CRISPR-based DNA imaging to investigate the role of endogenous or ectopic H3K9me3 in chromatin dynamics and genomic interactions.We select three loci(IDR3,TCF3,and PR1)with distinct levels of H3K9me3 to examine the genomic interactions and association with endogenous Heterochromatin Protein 1(HP1α)condensates.Our results demonstrate a positive correlation between the levels of H3K9me3 at the loci and their association with HP1αcondensates.By dual-color labeling and long-term tracking of IDR3 and PR1 loci,we find a periodical association between the two ranging from one to three hours.Epigenetic perturbation-induced Genome organization(EpiGo)-KRAB introduces∼20 kilobases of H3K9me3 at the TCF3 locus,which is sufficient to establish a stable association between TCF3 and HP1αcondensates.In addition,EpiGo-mediated H3K9me3 also leads to stable genomic interaction between IDR3 and TCF3.Briefly,these data suggest that the density of H3K9me3 could dictate the stability of interactions between genomic loci and HP1αcondensates.展开更多
In this paper,2D asynchronous spectra generated by using the DAOSD approach was utilized to probe interactions between Nd^3＋ and pyridinium dissolved in aqueous solution.A series of cross peaks in the resultant 2D as...In this paper,2D asynchronous spectra generated by using the DAOSD approach was utilized to probe interactions between Nd^3＋ and pyridinium dissolved in aqueous solution.A series of cross peaks in the resultant 2D asynchronous spectrum confirms the occurrence of intermolecular interaction between Nd^3＋and pyridinium.However,no coordination occurs between Nd^3＋ and pyridinium.Interaction between πelectron from aromatic system and/electron from lanthanide ions account for the appearance of cross peaks in 2D asynchronous spectra.Because of the interaction,the emission spectrum of pyridinium exhibits a significant change when neodymium perchlorate was introduced into the system.展开更多
Accurate description of potential energy curves driven by nonbonded interactions remains a great challenge for pure density functional approximations(DFAs).It is because the Rdecay behavior of dispersion cannot be int...Accurate description of potential energy curves driven by nonbonded interactions remains a great challenge for pure density functional approximations(DFAs).It is because the Rdecay behavior of dispersion cannot be intrinsically captured by the(semi)-local ingredients and the exact-exchange used in the popular hybrid DFAs.Overemphasizing the accuracy on the equilibrium region for the functional construction would likely deteriorate the overall performance on the other regions of potential energy surfaces.In consequence,the empirical dispersion correction becomes the standard component in DFAs to treat the non-bonded interactions.In this Letter,we demonstrate that without the use of empirical dispersion correction,doubly hybrid approximations,in particular two recently proposed rev XYG3 and XYG7 functionals,hold the promise to have a balanced description of non-bonded interactions on the whole potential energy curves for several prototypes ofπ-π,CH/π,and SH/πinteractions.The error of rev XYG3 and XYG7 for non-bonded interactions is around 0.1 kcal/mol,and their potential energy curves almost coincide with the accurate CCSD(T)/CBS curves.展开更多
Interactions between vacancies and Σ3 prismatic screw-rotation grain boundary in α-Al2O3 are investigated by the first principles projector-augmented wave method.It turns out that the vacancy formation energy decrea...Interactions between vacancies and Σ3 prismatic screw-rotation grain boundary in α-Al2O3 are investigated by the first principles projector-augmented wave method.It turns out that the vacancy formation energy decreases with reducing the distance between vacancy and grain boundary（GB） plane and reaches the minimum on the GB plane（at the atomic layer next to the GB） for an O（Al） vacancy.The O vacancy located on the GB plane can attract other vacancies nearby to form an O–O di-vacancy while the Al vacancy cannot.Moreover,the O–O di-vacancy can further attract other O vacancies to form a zigzag O vacancy chain on the GB plane,which may have an influence on the diffusion behavior of small atoms such as H and He along the GB plane of α-Al2O3.展开更多
In order to explore the effect mechanism of solvent on the synthesis of the metal organic framework materials, the microscopic interaction between solvent and framework and the effects of N,N-dimethyl-formamide(DMF) o...In order to explore the effect mechanism of solvent on the synthesis of the metal organic framework materials, the microscopic interaction between solvent and framework and the effects of N,N-dimethyl-formamide(DMF) or N-methyl- 2-pyrrolidone(NMP) on solvothermal synthesis of [Zn4O(BDC)3]8 were investigated through a combined DFT and experimental study. XRD and SEM showed that the absorbability of NMP in the pore of [Zn4O(BDC)3]8 was weaker than that of DMF. The thermal decomposition temperature of [Zn4O(BDC)3]8 synthesized in DMF was higher than that in NMP according to TG and FT-IR. In addition, the nitrogen sorption isotherms indicated that NMP improved gas sorption property of [Zn4O(BDC)3]8. The COSMO optimized calculations indicated that the total energy of Zn4O(BDC)3 in NMP was higher than that in DMF, and compared with non-solvent system, the charge of zinc atoms decreased and the charge value was the smallest in NMP. Furthermore, the interaction of DMF, NMP or DEF in [Zn4O(BDC)3]8 crystal model was calculated by DFT method. The results suggested that NMP should be easier to be removed from pore of materials than DMF from the point of view of energy state. It can be concluded that NMP was a favorable solvent to synthesize [Zn4O(BDC)3]8 and the microscopic mechanism was that the binding force between Zn4O(BDC)3 and NMP molecule was weaker than DMF.展开更多
基金supported by the National Natural Science Foundation of China(grant no.82370015).
文摘The 3CL protease, a highly conserved enzyme in the coronavirus, plays a crucial role in the viral life cycle by facilitating viral replication through precise cleavage of polyproteins. Beyond its proteolytic function, the 3CL protease also engages in intricate interactions with host cell proteins involved in critical cellular processes such as transcription, translation, and nuclear-cytoplasmic transport, effectively hijacking cellular machinery to promote viral replication. Additionally, it disrupts innate immune signaling pathways, suppresses interferon activity and cleaves antiviral proteins. Furthermore, it modulates host cell death pathways including pyroptosis and apoptosis, interferes with autophagy and inhibits stress granule formation to maintain viral infection and exacerbate viral pathogenesis. This review highlights the molecular mechanisms by which the 3CL protease orchestrates virus-host interactions, emphasizing its central role in coronavirus pathogenesis and highlighting potential therapeutic targets for future interventions.
文摘A γ-TiAl alloy with nominal composition of Ti-47%Al（molar fraction） was directionally solidified in an alumina mould with an Y2O3 protective coating.The effects of processing parameters（melting temperature and interaction time） on the metal-coating interface,microstructure and chemical composition of the alloy were evaluated.The result shows that the Y2O3 protective coating exhibits an effective barrier capability to avoid direct contact between the mould base material and the TiAl melt,although the Y2O3 coating is found to suffer some erosion and be slightly dissolved by the molten TiAl due to the coating-metal interactions.The directionally solidified alloys were contaminated with Y and O,and Y2O3 inclusions were dispersed in the metal matrix.The reason for this metal contamination is the Y2O3 coating dissolution by the TiAl melt.One mode of the interaction between Y2O3 and the TiAl melt is dissolution of yttrium and atomic oxygen in the melt by reaction Y2O3（s）=2Y（in TiAl melt）＋3O（in TiAl melt）.Both the extent of alloy contamination and the volume fractions of Y2O3 inclusions depend on the melting temperature and the interaction time.
基金Project supported by the National Natural Science Foundation of China (Grant No. 11005092)the Undergraduate Scientific and Technological Innovation Project of Zhejiang Province of China (Grant No. 2012R412018)the Undergraduate Innovative Base Program of Zhejiang A & F University
文摘With the help of a modified mapping method and a new mapping method, we re-study the （3＋1）-dimensional Burgers equation, and derive two families of variable separation solutions. By selecting appropriate functions in the variable separation solution, we discuss the interaction behaviors among taper-like, plateau-type rings, and rectangle-type embed-solitons in the periodic wave background. All the interaction behaviors are completely elastic, and no phase shift appears after interaction.
基金the financial supports from the National Natural Science Foundation of China (No. 52101183)China Postdoctoral Science Foundation (Nos. 2017M623054, 2018T110993)
文摘The mechanical properties and microstructures of Al_(2)O_(3)whiskers and graphene nano-platelets(GNPs)co-reinforced Cu-matrix composites were studied.Cu-matrix composites with a variation of GNPs amount were fabricated by mechanical alloying followed by vacuum hot-pressing sintering and hot isostatic pressing.The Cu-matrix composite with 0.5 wt.%GNPs(GNPs-0.5)suggests a good interfacial bonding of both Cu/C and Cu/Al_(2)O_(3)interfaces.Both the hardness and compressive strength of Cu-matrix composites show a consistent tendency that firstly increases to a critical value and then decreases with increasing GNPs amount.It is suggested that the most possible strengthening mechanisms of both GNPs and Al_(2)O_(3)whisker working in the Cu-matrix composites involve energy dissipating and load transfer,as well as grain refinements for GNPs.The synergetic effect of GNPs and Al_(2)O_(3)whiskers is highlighted that the embedded GNPs would hinder the crack path generated at the Al_(2)O_(3)/Cu interface and enhance the already outstanding strengthening effect that Al_(2)O_(3)whiskers provide.
文摘In this paper, a 3D time domain technique is adopted to calculate the coupled hydrodynamic interaction between two bodies without flare in waves. For verifying the code, two same cylinders are selected to calculate coupled hydrodynamic effects by comparison with the results obtained by 3D frequency method which has been proved to be efficient for solving such problems. In order to improve efficiency of calculation, the effect of history time has been discussed, and an improved method is presented. Moreover, the effect of lateral separation distance is also discussed in detail. The technique developed here may serve as a more rigorous tool to analyze the related transient problems of two ships doing underway replenishment in waves.
基金financially supported by the 111 Project of the Ministry of Science and Technology of China(No.B17019)Talent Project of Southwest University of the Ministry of Education of China(No.SWU115034)。
文摘In this work,we fabricated three kinds of Ag/Fe2O3 model catalysts with different morphologies to study the interfacial interactions between Ag and Fe2O3,and how they affected the catalytic activity in hydrogenation of p-nitrophenol was explored.The hydrothermal method was used to synthesize the metal oxide supported silver catalyst,with various morphologies including nanoplates(NPs),nanospheres(NSs),and nanocubes(NCs).The crystal structure,morphology and surface elements of the composite were investigated by various measurements,such as X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS).The catalytic activity was also evaluated by the reduction of p-nitrophenol to p-aminophenol.It was found that the activities of the above catalysts varied with the morphology of the support.Among them,Ag/Fe2O3 NPs promoted the highest performance,Ag/Fe2O3 NSs were slightly inferior,and Ag/Fe2O3 NCs were the worst.At last,we ascribed the remarkable activity of Ag/Fe2O3 NPs to the strong metal-support interactions between Ag and Fe2O3.
基金supported by the National Natu-ral Science Foundation of China(Nos.21878213,21808211)the open foundation of the State Key Laboratory of Chemical Engineer-ing(SKL-ChE-20B01)Authors are also grateful to the Program of Introducing Talents of Disciplines to China Universities(BP0618007).
文摘Tuning metal-support interactions(MSIs)is an important strategy in heterogeneous catalysis to realize the desirable metal dispersion and redox ability of metal catalysts.Herein,we use pre-reduced Co_(3)O_(4)nanowires(Co-NWs)in situ grown on monolithic Ni foam substrates to support Ag catalysts(Ag/Co-NW-R)for soot combustion.The macroporous structure of Ni foam with crossed Co_(3)O_(4)nanowires remarkably increases the soot-catalyst contact effi ciency.Our characterization results demonstrate that Ag species exist as Ag 0 because of the equation Ag^(+)+Co^(2+)=Ag^(0)+Co^(3+),and the pre-reduction treatment enhances interactions between Ag and Co_(3)O_(4).The number of active oxygen species on the Ag-loaded catalysts is approximately twice that on the supports,demonstrating the signifi cant role of Ag sites in generating active oxygen species.Additionally,the strengthened MSI on Ag/Co-NW-R further improves this number by increasing metal dispersion and the intrinsic activity determined by the turnover frequency of these oxygen species for soot oxidation compared with the catalyst without pre-reduction of Co-NW(Ag/Co-NW).In addition to high activity,Ag/Co-NW-R exhibits high catalytic stability and water resistance.The strategy used in this work might be applicable in related catalytic systems.
基金Ⅴ. ACKN0WLEDGMENTS This work was supported Science Foundation of China by the National Natural （No.20273019）.
文摘^1H and ^13C NMR chemical shifts were determined to investigate the interactions of acetone with a room temperature ionic liquid 1-hexyl-3- methylimidazolium bromide [C6mim]Br at various mole fractions. Changes in chemical shifts of hydrogen nuclei and of carbon nuclei with the acetone concentration indicated the formation of hydrogen bond between anion of the ionic liquid and methyl protons of acetone. The NMR results were in good agreement with the ab initio computational results.
基金support from Zhejiang Provincial Natural Science Foundation of China(LZ23B060001).
文摘Supported metal oxide catalysts have garnered significantattention in oxidative dehydrogenation(ODH)due to their tunable metal-support interactions.The pentacoordinate Al^(3+)(Al_(V)^(3+))in γ-Al_(2)O_(3)supports plays a pivotal role in modulating metal-support interaction.This study investigates oxalic acid(OA)pretreatment as a defect engineering strategy to enhance the catalytic performance of CeO_(2)/γ-Al_(2)O_(3)in cyclohexane ODH.Through integrated characterization(XRD,27Al MAS NMR,H_(2)-TPR,TPRO,MS,XPS)and catalytic testing,we demonstrate that optimal OA treatment(1:10 ratio)eliminates 100%of surface Al_(V)^(3+)defects while enhancing CeO_(2)crystallinity and interfacial oxygen mobility.The removal of Al_(V)^(3+)species restructures metal-support interaction,accelerating interfacial oxygen mobility.In oxidation dehydrogenation of cyclohexane,the modified CeO_(2)/γ-Al_(2)O_(3)achieves 29%of cyclohexane conversion with stable selectivity of 49%cyclohexene.These findingsprovide an initial framework for designing redox-active catalysts via targeted support modificationin CeO_(2)/γ-Al_(2)O_(3)systems,emphasizing the relationship between metal-support interaction and oxygen mobility.
基金supported by the National Natural Science Foundation of China(No.42077192)the National Key Basic Research&Development Program of China(No.2020YFA0607802).
文摘In the context of the prevalent winter air quality issues in China marked by declining PM_(2.5)and rising O_(3),this study employed amodified WRF-Chem model to examine the aerosol radiation interaction(ARI),heterogeneous chemistry(AHC),and their combined impact(ALL)on the variations in O_(3)and PM_(2.5)during the 2014–2020 in eastern China.Our analysis confirmed that ARI curtailed O_(3)while elevating PM_(2.5).AHC reduced O_(3)through heterogeneous absorption of NOx and hydroxideswhile notably fostering fine-grained sulfate,resulting in a PM_(2.5)increase.Emission reductions mitigated the inhibitory impact of ARI on meteorological fields and photolysis rates.Emission reduction individually without aerosol feedback led to a 5.43 ppb O_(3)increase and a 22.89μg/m^(3)PM_(2.5)decrease.ARI and AHC amplified the emission-reduction-induced(ERI)O_(3)rise by 1.83 and 0.31 ppb,respectively.The response of ARI to emission diminution brought about a modest PM_(2.5)increase of 0.31μg/m^(3).Conversely,AHC,acting as the primary contributor,caused a noteworthy PM_(2.5)decrease of 4.60μg/m^(3).As efforts concentrate on reducing PM_(2.5),the promotion of ARI on PM_(2.5)counterbalanced the efficacy of emission reduction and the AHC-induced strengthening of PM_(2.5)decrease.The ALL magnified the ERI O_(3)increase by 38.9%and PM_(2.5)decrease by 18.7%.Sensitivity experiments with different degrees of emission reduction demonstrated a consistent linear relationship between the ALL-induced enhancement of O_(3)increase and PM_(2.5)decrease to the ERI PM_(2.5)decline.Our investigation revealed the complex connection between emissions and aerosol feedback in influencing air quality.
基金funded by the National Natural Science Foundation of China(32001824,31972198)supported by the Startup Fund for Young Faculty at SJTU(Shanghai Jiao Tong University)High Level Innovation Team and Distinguished Scholar Project of Guangxi Universities and Colleges(2020[6]).
文摘The study of ligand-receptor interactions is of great significance in food flavor perception.In this study,a computer simulation method was used to investigate the mechanism of interaction between umami peptides and T1R1/T1R3-Venus-flytrap domain(VFT)receptor.The binding site,conformational changes,and binding free energy between umami peptides and T1R1/T1R3-VFT were analyzed through molecular modeling,molecular docking,and molecular dynamics simulations.The receptor model constructed using AlphaFold2 has the best rationality.The molecular docking results showed that umami peptides primarily bound to T1R1-VFT through hydrogen bonding,with key binding residues such as Thr149,Arg151,and Asp108.The binding of umami peptides led to a more stable complex system,and the positively charged amino acids contributed positively to the overall binding free energy.This study provides theoretical support for the development of a better understanding of the interaction between umami substances and the umami receptor.
基金supported by the Natural Science Foundation of Jiangsu Province(BK20221541)National Natural Science Foundation of China(21707052)Jiangsu Agriculture Science and Technology Innovation Fund(CX(20)3108).
文摘Herein,an oxygen-doped porous g-C_(3)N_(4)photocatalyst modified with atomically dispersed Fe(Fe_(1)/OPCN)issuccessfully prepared and exhibits significant superiority in removing refractory sulfonic azo contaminants fromwater via catalyst-contaminant interaction.The elimination performance of Fe_(1)/OPCN towards acid red 9,acidred 13 and amaranth containing similar azonaphthalene structure and increasing sulfonic acid groups increasesgradually.The amaranth degradation rate of Fe_(1)/OPCN is 17.7 and 6.1 times as that of homogeneous Fenton andOPCN,respectively.In addition,Fe_(1)/OPCN also has more outstanding removal activities towards other con-taminantswith sulfonic acid and azo groups alone.The considerable enhancement for removing sulfonic azocontaminants of Fe_(1)/OPCN is mainly ascribed to the following aspects:(1)The modified Fe could enhance theadsorption towards sulfonic azo compounds to accelerate the mass transfer,act as e^(-)acceptor to promoteinterfacial charge separation,and trigger the self-Fenton reaction to convert in-situ generated H_(2)O_(2)into·OH.(2)Fe(Ⅲ)could coordinate with-N=N-to form d-πconjugation,which could attract e^(-)transfer to attack-N=N-bond.Meanwhile,the inhibited charge recombination could release more free h^(þ)to oxidize sulfonicacid groups into SO4^(-)·.(3)Under the cooperation of abundant multiple active species(·O_(2)^(-),h^(þ),e^(-),·OH,SO4^(-)·)formed during the degradation reaction,sulfonic azo compounds could be completely mineralized into harmlesssmall molecules(CO_(2),H_(2)O,etc.)by means of-N=N-cleavage,hydroxyl substitution,and aromatic ringopening.This work offers a novel approach for effectively eliminating refractory sulfonic azo compounds fromwastewater.
基金funded by Medical Science Research Project of Hebei(No.20220364).
文摘As the“fourth messenger”of epigenetic regulation,metabolites playa spatiotemporally specific regulatory role in kidney regeneration by dynamically reshaping the state of chromatin modifications.This review systematically expounds the coordinated mechanism of the dual axes of succinate/H3K9ac andα-ketoglutarate(α-KG)/TET enzymes:Succinate activates regeneration-related genes by regulating histone acetylation(H3K9ac),whileα-KG relieves the epigenetic repression of the Wnt pathway through TET-mediated DNA demethylation.The dynamic balance between the two maintains epigenetic plasticity.Multi-omics integration strategies(such as Gaussian graphical models and deep learning frameworks)and single-cell epigenetic tracking technologies(such as spatial metabolomics)have revealed the regulation of metabolite gradients on cellular heterogeneity and the immune microenvironment.The coordinated application of metabolite precursor supplementation(such as NAD precursors)and dynamic monitoring systems(such as isotope tracing and artifi cial intelligence models)has promoted the shift of metabolic medicine from the“static replacement”paradigm to the“dynamic reshaping”paradigm.However,technical bottlenecks(such as insuffi cient multimodal integration)and clinical translation pitfalls(such as challenges in standardized production)still need to be overcome.In the future,through the development of“metabolism-immunity”co-regulatory strategies and intelligent closed-loop systems,it is expected to achieve precise interventions for kidney regeneration and disease treatment.
文摘We propose the exact solution of the equation in separated variable which appears in the process of constructing solutions to the quantum Calogero-Moser three-particle problem with elliptic two-particle potential . This solution is found for special values of coupling constants . It can be used for solving three-particle Calogero-Moser problem under the appropriate boundary conditions.
基金This work was funded by the National Natural Science Foundation of China(No.31970591 to H.Ma),the Shanghai Pujiang Program(19PJ1408000 to H.Ma)the Shanghai Science and Technology Innovation Action Plan(21JC1404800 to H.Ma)We thank Luke Lavis(Janelia Research Campus,Howard Hughes Medical Institute,Ashburn,VA,USA)for providing the HaloTag JF-549.U2OS Genomic DNA was a gift from Xingxu Huang.We thank Pengwei Zhang and Shuangli Zhang for their help with cell sorting.
文摘The human genome can be demarcated into domains based on distinct epigenetic states.The trimethylation of histone H3 lysine 9(H3K9me3)is essential for the formation of constitutive heterochromatin nanodomains.However,the extent to which genomic regions require specific densities or degrees of H3K9me3 for stable interactions remains unclear.Here,we utilize CRISPR-based DNA imaging to investigate the role of endogenous or ectopic H3K9me3 in chromatin dynamics and genomic interactions.We select three loci(IDR3,TCF3,and PR1)with distinct levels of H3K9me3 to examine the genomic interactions and association with endogenous Heterochromatin Protein 1(HP1α)condensates.Our results demonstrate a positive correlation between the levels of H3K9me3 at the loci and their association with HP1αcondensates.By dual-color labeling and long-term tracking of IDR3 and PR1 loci,we find a periodical association between the two ranging from one to three hours.Epigenetic perturbation-induced Genome organization(EpiGo)-KRAB introduces∼20 kilobases of H3K9me3 at the TCF3 locus,which is sufficient to establish a stable association between TCF3 and HP1αcondensates.In addition,EpiGo-mediated H3K9me3 also leads to stable genomic interaction between IDR3 and TCF3.Briefly,these data suggest that the density of H3K9me3 could dictate the stability of interactions between genomic loci and HP1αcondensates.
基金financially supported by the National Natural Science Foundation of China(No.51373003)Beijing Natural Science Foundation(No.2122059)
文摘In this paper,2D asynchronous spectra generated by using the DAOSD approach was utilized to probe interactions between Nd^3＋ and pyridinium dissolved in aqueous solution.A series of cross peaks in the resultant 2D asynchronous spectrum confirms the occurrence of intermolecular interaction between Nd^3＋and pyridinium.However,no coordination occurs between Nd^3＋ and pyridinium.Interaction between πelectron from aromatic system and/electron from lanthanide ions account for the appearance of cross peaks in 2D asynchronous spectra.Because of the interaction,the emission spectrum of pyridinium exhibits a significant change when neodymium perchlorate was introduced into the system.
基金supported by the National Natural Science Foundation of China(No.21973015,No.22125301,No.91427301)the Science Challenge Project(TZ2018004)+1 种基金Innovative Research Team of High-Level Local universities in Shanghaia Key Laboratory Program of the Education Commission of Shanghai Municipality(ZDSYS14005)。
文摘Accurate description of potential energy curves driven by nonbonded interactions remains a great challenge for pure density functional approximations(DFAs).It is because the Rdecay behavior of dispersion cannot be intrinsically captured by the(semi)-local ingredients and the exact-exchange used in the popular hybrid DFAs.Overemphasizing the accuracy on the equilibrium region for the functional construction would likely deteriorate the overall performance on the other regions of potential energy surfaces.In consequence,the empirical dispersion correction becomes the standard component in DFAs to treat the non-bonded interactions.In this Letter,we demonstrate that without the use of empirical dispersion correction,doubly hybrid approximations,in particular two recently proposed rev XYG3 and XYG7 functionals,hold the promise to have a balanced description of non-bonded interactions on the whole potential energy curves for several prototypes ofπ-π,CH/π,and SH/πinteractions.The error of rev XYG3 and XYG7 for non-bonded interactions is around 0.1 kcal/mol,and their potential energy curves almost coincide with the accurate CCSD(T)/CBS curves.
基金Project supported by the National Key Basic Research and Technology Program,China(Grant No.2010CB731601)the National Natural Science Foundation of China(Grant No.50871057)
文摘Interactions between vacancies and Σ3 prismatic screw-rotation grain boundary in α-Al2O3 are investigated by the first principles projector-augmented wave method.It turns out that the vacancy formation energy decreases with reducing the distance between vacancy and grain boundary（GB） plane and reaches the minimum on the GB plane（at the atomic layer next to the GB） for an O（Al） vacancy.The O vacancy located on the GB plane can attract other vacancies nearby to form an O–O di-vacancy while the Al vacancy cannot.Moreover,the O–O di-vacancy can further attract other O vacancies to form a zigzag O vacancy chain on the GB plane,which may have an influence on the diffusion behavior of small atoms such as H and He along the GB plane of α-Al2O3.
基金Project(51104185)supported by the National Natural Science Foundation of ChinaProject(2010QZZD003)supported by the Key Project of Central South University of Fundamental Research Funds for the Central Universities of China
文摘In order to explore the effect mechanism of solvent on the synthesis of the metal organic framework materials, the microscopic interaction between solvent and framework and the effects of N,N-dimethyl-formamide(DMF) or N-methyl- 2-pyrrolidone(NMP) on solvothermal synthesis of [Zn4O(BDC)3]8 were investigated through a combined DFT and experimental study. XRD and SEM showed that the absorbability of NMP in the pore of [Zn4O(BDC)3]8 was weaker than that of DMF. The thermal decomposition temperature of [Zn4O(BDC)3]8 synthesized in DMF was higher than that in NMP according to TG and FT-IR. In addition, the nitrogen sorption isotherms indicated that NMP improved gas sorption property of [Zn4O(BDC)3]8. The COSMO optimized calculations indicated that the total energy of Zn4O(BDC)3 in NMP was higher than that in DMF, and compared with non-solvent system, the charge of zinc atoms decreased and the charge value was the smallest in NMP. Furthermore, the interaction of DMF, NMP or DEF in [Zn4O(BDC)3]8 crystal model was calculated by DFT method. The results suggested that NMP should be easier to be removed from pore of materials than DMF from the point of view of energy state. It can be concluded that NMP was a favorable solvent to synthesize [Zn4O(BDC)3]8 and the microscopic mechanism was that the binding force between Zn4O(BDC)3 and NMP molecule was weaker than DMF.
