Previous X-ray and optical studies of the galaxy cluster pair A222/223 suggested the possible presence of a=lamentary structure connecting the two clusters,a result that appears to be supported by subsequent weak-lens...Previous X-ray and optical studies of the galaxy cluster pair A222/223 suggested the possible presence of a=lamentary structure connecting the two clusters,a result that appears to be supported by subsequent weak-lensing analyses.This=lament has been reported to host a primordial warm-hot intergalactic medium,which existed prior to being heated by the interactions of the clusters.In this study,we made an attempt to examine the reported emission feature with data from an archival Suzaku observation,taking advantage of its low detector background.Because the emission is expected to be very weak,we=rst carefully examined all potential sources of“contamination,”and then modeled the residual emission.Due to large uncertainties,unfortunately,our results can neither con=rm the presence of the reported emission feature nor rule it out.We discuss the sources of uncertainties.展开更多
The 11th data release of the LAMOST survey provides fundamental stellar parameters but lacks detailed abundance measurements forα-elements,which are crucial for understanding stellar populations and Galactic chemical...The 11th data release of the LAMOST survey provides fundamental stellar parameters but lacks detailed abundance measurements forα-elements,which are crucial for understanding stellar populations and Galactic chemical evolution.In this study,we derive the abundances of oxygen(O),magnesium(Mg),silicon(Si),calcium(Ca),and titanium(Ti)for over 6.8 million stars using LAMOST DR11 low-resolution spectra.To ensure reliable measurements,we select 760 open clusters spanning a broad range of ages and apply Monte Carlo sampling for accurate abundance estimates.Additionally,we utilize over 30,000 stars from the GALAH DR4 catalog to train an XGBoost model for extractingα-element abundances from LAMOST DR11 spectra.Bayesian linear regression is employed to analyze the compositional distribution across the Galactic disk and infer chemical gradients as a function of Galactocentric distance.Our results indicate a general increase in chemical abundances with Galactocentric distance,with oxygen showing the steepest gradient.Our results confirm the overall increase ofα-element abundances with Galactocentric distance,consistent with previous studies,while minor discrepancies in Mg,Ca,and Ti gradients likely arise from differences in sample selection,observational sensitivity,or Galactic enrichment processes.展开更多
LiNO_(3) is known to significantly enhance the reversibility of lithium metal batteries;however,the modification of solvation structures in various solvents and its further impact on the interface have not been fully ...LiNO_(3) is known to significantly enhance the reversibility of lithium metal batteries;however,the modification of solvation structures in various solvents and its further impact on the interface have not been fully revealed.Herein,we systematically studied the evolution of solvation structures with increasing LiNO_(3) concentration in both carbonate and ether electrolytes.The results from molecular dynamics simulations unveil that the Li^(+)solvation structure is less affected in carbonate electrolytes,while in ether electrolytes,there is a significant decrease of solvent molecules in Li^(+)coordination,and a larger average size of Li^(+)solvation structure emerges as LiNO_(3) concentration increases.Notably,the formation of large ion aggregates with size of several nanometers(nano-clusters),is observed in ether-based electrolytes at conventional Li^(+)concentration(1 M)with higher NO_(3)^(-) ratio,which is further proved by infrared spectroscopy and small-angle X-ray scattering experiments.The nano-clusters with abundant anions are endowed with a narrow energy gap of molecular orbitals,contributing to the formation of an inorganic rich electrode/electrolyte interphase that enhances the reversibility of lithium stripping/plating with Coulombic efficiency up to 99.71%.The discovery of nano-clusters elucidates the underlying mechanism linking ions/solvent aggregation states of electrolytes to interfacial stability in advanced battery systems.展开更多
Two-dimensional(2D)materials loaded with single atoms and clusters are being set at the forefront of catalysis due to their distinctive geometric and electronic features.However,the usually-complicated synthesis proce...Two-dimensional(2D)materials loaded with single atoms and clusters are being set at the forefront of catalysis due to their distinctive geometric and electronic features.However,the usually-complicated synthesis procedures impede in-depth clarification of their catalytic mechanisms.To this end,herein we developed an efficient one-step dimension-reduction carbonization strategy,with which we successfully architected a highly-efficient catalyst for oxygen reduction reaction(ORR),featured with symbiotic cobalt single atoms and clusters decorated in two-dimensional(2D)ultra-thin(3.5 nm thickness)nitrogen-carbon nanosheets.The synergistic effects of the two components afford excellent oxygen reduction activity in alkaline media(E_(1/2)=0.823 V vs.RHE)and thereof a high power density(146.61 mW cm^(-2))in an assembled Zn-air battery.As revealed by theoretical calculations,the cobalt clusters can regulate electrons surrounding those individual atoms and affect the adsorption of intermediate species.As a consequence,the derived active sites of single cobalt atoms lead to a significant improvement of the ORR performance.Thus,our work may fuel interests to delicate architectu re of single atoms and clusters coexisting 2D support toward optimal electrocatalytic performance.展开更多
Objectives To identify core symptoms and symptom clusters in patients with neuromyelitis optica spectrum disorder(NMOSD)by network analysis.Methods From October 10 to 30,2023,140 patients with NMOSD were selected to p...Objectives To identify core symptoms and symptom clusters in patients with neuromyelitis optica spectrum disorder(NMOSD)by network analysis.Methods From October 10 to 30,2023,140 patients with NMOSD were selected to participate in this online questionnaire survey.The survey tools included a general information questionnaire and a self-made NMOSD symptoms scale,which included the prevalence,severity,and distress of 29 symptoms.Cluster analysis was used to identify symptom clusters,and network analysis was used to analyze the symptom network and node characteristics and central indicators including strength centrality(r_(s)),closeness centrality(r_(c))and betweeness centrality(r_(b))were used to identify core symptoms and symptom clusters.Results The most common symptom was pain(65.7%),followed by paraesthesia(65.0%),fatigue(65.0%),easy awakening(63.6%).Regarding the burden level of symptoms,pain was the most burdensome symptom,followed by paraesthesia,easy awakening,fatigue,and difficulty falling asleep.Six clusters were identified:somatosensory,motor,visual,and memory symptom clusters,bladder and rectum symptom clusters,sleep symptoms clusters,and neuropsychological symptom clusters.Fatigue(r_(s)=12.39,r_(b)=68.00,r_(c)=0.02)was the most central and prominent bridge symptom,and motor symptom cluster(r_(s)=2.68,r_(c)=0.10)was the most central symptom cluster among the six clusters.Conclusions Our study demonstrated the necessity of symptom management targeting fatigue,pain,and motor symptom cluster in patients with NMOSD.展开更多
Dispersing metals from nanoparticles to clusters is often achieved using ligand protection methods,which exhibit unique properties such as suppressing structure-sensitive side reactions.However,this method is limited ...Dispersing metals from nanoparticles to clusters is often achieved using ligand protection methods,which exhibit unique properties such as suppressing structure-sensitive side reactions.However,this method is limited by the use of different metal precursor salts corresponding to different ligands.An alternative approach,the ion exchange(IE)method,can overcome this limitation to some extent.Nevertheless,there is still an urgent need to address the stabilization of metals(especially precious metals)by using IE method.Here,we reported a Pt cluster catalyst prepared mainly by anchoring Pt atoms via O located near the framework Zn in zincosilicate zeolites and riveted by zeolite surface rings after reduction(reduced Pt/Zn-3-IE).The catalyst can achieve an initial propane conversion of 26%in a pure propane atmosphere at 550℃and shows little deactivation even after 7.5 d of operation.Moreover,the alteration of catalyst by the introduction of framework Zn was also highlighted and interpreted.展开更多
The atomic-level exploration of structure-property correlations poses significant challenges in establishing precise design principles for electrocatalysts targeting efficient CO_(2)conversion.This study demonstrates ...The atomic-level exploration of structure-property correlations poses significant challenges in establishing precise design principles for electrocatalysts targeting efficient CO_(2)conversion.This study demonstrates how controlled exposure of metal sites governs CO_(2)electroreduction performance through two octanuclear bismuth-oxo clusters with distinct architectures.The Bi_(8)-DMF cluster,constructed using tert–butylthiacalix[4]arene(TC4A)as the sole ligand,features two surface-exposed Bi active sites,while the dual-ligand Bi_(8)-Fc(with TC4A/ferrocene carboxylate)forms a fully encapsulated structure.Electrocatalytic tests reveal Bi_(8)-DMF achieves exceptional formate selectivity(>90%Faradaic efficiency)across a broad potential window(-0.9 V to-1.6 V vs.RHE)with 20 h stability,outperforming Bi_(8)-Fc(60%efficiency at-1.5 V).Theoretical calculations attribute Bi_(8)-DMF's superiority to exposed Bi sites that stabilize the critical*OCHO intermediate via optimized orbital interactions.This work provides crucial guidance for polynuclear catalyst design:moderate exposure of metal active sites significantly enhances CO_(2)reduction performance.展开更多
Surface-supported clusters forming by aggregation of excessive adatoms could be the main defects of 2D materials after chemical vapor deposition.They will significantly impact the electronic/magnetic properties.Moreov...Surface-supported clusters forming by aggregation of excessive adatoms could be the main defects of 2D materials after chemical vapor deposition.They will significantly impact the electronic/magnetic properties.Moreover,surface supported atoms are also widely explored for high active and selecting catalysts.Severe deformation,even dipping into the surface,of these clusters can be expected because of the very active edge of clusters and strong interaction between supported clusters and surfaces.However,most models of these clusters are supposed to simply float on the top of the surface because ab initio simulations cannot afford the complex reconstructions.Here,we develop an accurate graph neural network machine learning potential(MLP)from ab initio data by active learning architecture through fine-tuning pre-trained models,and then employ the MLP into Monte Carlo to explore the structural evolutions of Mo and S clusters(1-8 atoms)on perfect and various defective MoS2 monolayers.Interestingly,Mo clusters can always sink and embed themselves into MoS2 layers.In contrast,S clusters float on perfect surfaces.On the defective surface,a few S atoms will fill the vacancy and rest S clusters float on the top.Such significant structural reconstructions should be carefully taken into account.展开更多
Correction to:Rare Met.https://doi.org/10.1007/s12598-021-01815-z In the original publication,Fig.5 was published with few mistakes.The correct version of Fig.5 is given in this correction.
Correction to:Nano-Micro Letters(2025)17:123 https://doi.org/10.1007/s40820-025-01654-y Following publication of the original article[1],the authors reported that Dr.Mohamed Bououdina’s affiliation needed to be corre...Correction to:Nano-Micro Letters(2025)17:123 https://doi.org/10.1007/s40820-025-01654-y Following publication of the original article[1],the authors reported that Dr.Mohamed Bououdina’s affiliation needed to be corrected from 1 to 2.The correct author affiliation has been provided in this Correction and the original article[1]has been corrected.展开更多
Atomically precise palladium(Pd)clusters are emerging as versatile nanomaterials with applications in catalysis and biomedicine.This study explores the synthesis,structure evolution,and catalytic properties of Pd clus...Atomically precise palladium(Pd)clusters are emerging as versatile nanomaterials with applications in catalysis and biomedicine.This study explores the synthesis,structure evolution,and catalytic properties of Pd clusters stabilized by cyclohexanethiol(HSC_(6)H_(11))ligands.Using electrospray ionization mass spectrometry(ESI-MS)and single-crystal X-ray diffraction(SXRD),structures of the Pd clusters ranging from Pd4(SC_(6)H_(11))8 to Pd18(SC_(6)H_(11))36 were determined.This analysis revealed a structure evolution from polygonal to elliptical geometries of the PdnS2n frameworks as the cluster size increased.UV-Vis-NIR spectroscopy,combined with quantum chemical calculations,elucidated changes in the electronic structure of the clusters.Catalytic studies on the Sonogashira cross-coupling reactions demonstrated a size-dependent decline in activity attributed to variations in structural arrangements and electronic properties.Mechanistic insights proposed a distinctive Pd(Ⅱ)-Pd(Ⅳ)catalytic cycle.This research underscores how ligands and cluster size influence the structures and properties of Pd clusters,offering valuable insights for the future design and application of Pd clusters in advanced catalysis and beyond.展开更多
CO_(2) conversion to CO via the reverse water-gas shift(RWGS)reaction is limited by a low CO_(2) conversion rate and CO selectivity.Herein,an efficient RWGS catalyst is constructed through Enteromorpha prolifera–deri...CO_(2) conversion to CO via the reverse water-gas shift(RWGS)reaction is limited by a low CO_(2) conversion rate and CO selectivity.Herein,an efficient RWGS catalyst is constructed through Enteromorpha prolifera–derived N-rich mesoporous biochar(EPBC)supported atomic-level Cu-Mo_(2)C clusters(Cu-Mo_(2)C/EPBC).Unlike traditional acti-vated carbon(AC)supported Cu-Mo_(2)C particles(Cu-Mo_(2)C/AC),the Cu-Mo_(2)C/EPBC not only presents the better graphitization degree and larger specific surface area,but also uniformly andfirmly anchors atomic-level Cu-Mo_(2)C clusters due to the existence of pyridine nitrogen.Furthermore,the pyridine N of Cu-Mo_(2)C/EPBC strengthens an unblocked electron transfer between Mo_(2)C and Cu clusters,as verified by X-ray absorption spectroscopy.As a result,the synergistic effect between pyridinic N anchoring and the clusters interaction in Cu-Mo_(2)C/EPBC facilitates an improved CO selectivity of 99.95%at 500℃ compared with traditional Cu-Mo_(2)C/AC(99.60%),as well as about 3-fold CO_(2) conversion rate.Density functional theory calculations confirm that pyr-idine N-modified carbon activates the local electronic redistribution at Cu-Mo_(2)C clusters,which contributes to the decreased energy barrier of the transition state of CO^(*)+O^(*)+2H^(*),thereby triggering the transformation of rate-limited step during the redox pathway.This biomass-derived strategy opens perspective on producing sustain-able fuels and building blocks through the RWGS reaction.展开更多
As part of the LAMOST medium-resolution spectroscopic survey,the LAMOST-MRS-O is a non-time domain survey that aims to perform medium-resolution spectral observations for member stars in the open cluster areas.This su...As part of the LAMOST medium-resolution spectroscopic survey,the LAMOST-MRS-O is a non-time domain survey that aims to perform medium-resolution spectral observations for member stars in the open cluster areas.This survey plans to obtain the spectroscopic parameters such as radial velocity and metal abundances of member stars and provide data support for further study on the chemical and dynamical characteristics and evolution of open clusters in combination with Gaia data.We have completed the observations on ten open cluster fields and obtained 235184 medium-resolution spectra of 133792 stars.Based on the data analyzed of LAMOST DR11v1.1,for some clusters of particular concern,it is found that the sampling ratio of members stars with Gmag<15 mag can reach 70%,which indicates that the LAMOST-MRS-O has reached our initial design goal.展开更多
Recent studies have increasingly identified extended main sequence turn-off(e MSTO)phenomena in Galactic open clusters,yet the number of such clusters with sufficient spectroscopic information for member stars remains...Recent studies have increasingly identified extended main sequence turn-off(e MSTO)phenomena in Galactic open clusters,yet the number of such clusters with sufficient spectroscopic information for member stars remains limited.Unlike most studies that rely on fitting isochrones based on color–magnitude diagram(CMD)morphology to account for varying rotational velocities,our approach leverages LAMOST spectral data to compute actual rotational velocity distributions for confirmed cluster members,along with parameters such as metallicity,differential extinction,and rotational inclination,to utilize PARSEC isochrones for fitting the cluster CMDs.We systematically surveyed all known Galactic open clusters and selected 12 clusters where rotational velocity distributions could be reliably calculated for detailed fitting.Our results successfully reproduced the eMSTO phenomenon observed in these clusters.For the majority of clusters,considering only differential extinction and variations in rotational velocity adequately explains the position and morphology of the MSTO.For some intermediate-age clusters,incorporating rotational inclination additionally accounts for the broadening of the MSTO.This study underscores the importance of spectroscopic data in understanding eMSTO phenomena and provides a probable explanation for interpreting the combined effects of differential extinction,rotation,and inclination on the CMDs of Galactic open clusters.展开更多
Ultrafine,highly dispersed Pt clusters were immobilized onto the Co nanoparticle surfaces by one-step pyrolysis of the precursor Pt(Ⅱ)-encapsulating Co-MOF-74.Owing to the small size effects of Pt clusters as well as...Ultrafine,highly dispersed Pt clusters were immobilized onto the Co nanoparticle surfaces by one-step pyrolysis of the precursor Pt(Ⅱ)-encapsulating Co-MOF-74.Owing to the small size effects of Pt clusters as well as the strongly enhanced synergistic interactions between Pt and Co atoms,the obtained Pt-on-Co/C400 catalysts exhib-ited excellent catalytic activity toward the hydrolysis of ammonia borane with an extremely high turnover frequency(TOF)value of 3022 min^(-1)at 303 K.Durability test indicated that the obtained Pt-on-Co/C400 catalysts possessed high catalytic stability,and there were no changes in the catalyst structures and catalytic activities after 10 cycles.展开更多
An aluminoborate,Na_(2.5)Rb[Al{B_(5)O_(10)}{B_(3)O_(5)}]·0.5NO_(3)·H_(2)O(1),was synthesized under hydrothermal condition,which was built by mixed oxoboron clusters and AlO_(4)tetrahedra.In the structure,the...An aluminoborate,Na_(2.5)Rb[Al{B_(5)O_(10)}{B_(3)O_(5)}]·0.5NO_(3)·H_(2)O(1),was synthesized under hydrothermal condition,which was built by mixed oxoboron clusters and AlO_(4)tetrahedra.In the structure,the[B_(5)O_(10)]^(5-)and[B_(3)O_(7)]^(5-)clusters are alternately connected to form 1D[B_(8)O_(15)]_(n)^(6n-)chains,which are further linked by AlO_(4)units to form a 2D monolayer with 7‑membered ring and 10‑membered ring windows.Two adjacent monolayers with opposite orientations further form a porous‑layered structure with six channels through B—O—Al bonds.Compound 1 was characterized by single crystal X‑ray diffraction,powder X‑ray diffraction(PXRD),IR spectroscopy,UV‑Vis diffuse reflection spectroscopy,and thermogravimetric analysis(TGA),respectively.UV‑Vis diffuse reflectance analysis indicates that compound 1 shows a wide transparency range with a short cutoff edge of 201 nm,suggesting it may have potential application in UV regions.CCDC:2383923.展开更多
Accurate description of noncova-lent interactions in large systems is challenging due to the require-ment of high-level electron corre-lation methods.The generalized energy-based fragmentation(GEBF)approach,in conjunc...Accurate description of noncova-lent interactions in large systems is challenging due to the require-ment of high-level electron corre-lation methods.The generalized energy-based fragmentation(GEBF)approach,in conjunc-tion with the domain-based local pair natural orbital(DLPNO)method,has been applied to assess the average binding energies(ABEs)of large benzene clus-ters,specifically(C6H6)13,at the coupled cluster singles and doubles with perturbative triples correction[CCSD(T)]level and the complete basis set(CBS)limit.Utilizing GEBF-DLPNO-CCSD(T)/CBS ABEs as benchmarks,various DFT functionals were evaluated.It was found that several functionals with empirical dispersion correction,including M06-2X-D3,B3LYP-D3(BJ),and PBE-D3(BJ),provide accurate descriptions of the ABEs for(C6H6)13 clusters.Additionally,the M06-2X-D3 functional was used to calculate the ABEs and relative stabili-ties of(C6H6)n clusters for n=11,12,13,14,and 15 revealing that the(C6H6)13 cluster ex-hibits the highest relative stability.These findings align with experimental evidence suggest-ing that n=13 is one of the magic numbers for benzene clusters(C6H6)n,with n≤30.展开更多
Objective This study aimed to investigate the prevalence of HIV pretreatment drug resistance(PDR)and the transmission clusters associated with PDR-related mutations in newly diagnosed,treatmentnaive patients between 2...Objective This study aimed to investigate the prevalence of HIV pretreatment drug resistance(PDR)and the transmission clusters associated with PDR-related mutations in newly diagnosed,treatmentnaive patients between 2020 and 2023 in Dehong prefecture,Yunnan province,China.Methods Demographic information and plasma samples were collected from study participants.PDR was assessed using the Stanford HIV Drug Resistance Database.The Tamura-Nei 93 model within HIVTRACE was employed to compute pairwise matches with a genetic distance of 0.015 substitutions per site.Results Among 948 treatment-naive individuals with eligible sequences,36 HIV subtypes were identified,with unique recombinant forms(URFs)being the most prevalent(18.8%,178/948).The overall prevalence of PDR was 12.4%(118/948),and resistance to non-nucleotide reverse transcriptase inhibitors(NNRTIs),nucleotide reverse transcriptase inhibitors(NRTIs),and protease inhibitors(PIs)was10.7%,1.3%,and 1.6%,respectively.A total of 91 clusters were identified,among which eight showed evidence of PDR strain transmission.The largest PDR-associated cluster consisted of six CRF01_AE drugresistant strains carrying K103N and V179T mutations;five of these individuals had initial CD4^(+)cell counts<200 cells/μL.Conclusion The distribution of HIV subtypes in Dehong is diverse and complex.PDR was moderately prevalent(12.4%)between 2020 and 2023.Evidence of transmission of CRF01_AE strains carrying K103N and V179T mutations was found.Routine surveillance of PDR and the strengthening of control measures are essential to limit the spread of drug-resistance HIV strains.展开更多
Objective:This study aims to investigate the patterns of symptom occurrence in patients experiencing acute exacerbations of chronic obstructive pulmonary disease(AECOPD).It will explore the composition of symptom clus...Objective:This study aims to investigate the patterns of symptom occurrence in patients experiencing acute exacerbations of chronic obstructive pulmonary disease(AECOPD).It will explore the composition of symptom clusters and analyze the correlation between these clusters and health-related quality of life(HRQoL).Methods:A total of 207 patients with AE-COPD were surveyed from a tertiary grade A hospital.Data collection was conducted using three validated instruments:the Basic Information Questionnaire(BIQ),Disease Symptom Survey Questionnaire(MSAS),and Quality of Life Questionnaire(CAT).Statistical software SPSS 22.0 was used to analyze the correlation between symptom clusters and quality of life.Results:Exploratory factor analysis showed that five major symptom clusters existed in the patients,including the psycho-emotional symptom cluster,the sleep-related symptom cluster,the other side effects symptom cluster,the energy deficiency symptom cluster and the cough-loss of appetite symptom cluster,and the severity of the symptom clusters showed a significant negative correlation with the quality of life of the patients(P<0.05).Conclusion:Strengthening the comprehensive management of symptom clusters in patients with AE-COPD can help to effectively reduce the symptom burden of patients,and then significantly improve their quality of life.展开更多
Metal nanoclusters with well-defined atomic structures offer significant promise in the field of catalysis due to their sub-nanometer size and tunable organic-inorganic hybrid structural features.Herein,we successfull...Metal nanoclusters with well-defined atomic structures offer significant promise in the field of catalysis due to their sub-nanometer size and tunable organic-inorganic hybrid structural features.Herein,we successfully synthesized an 11-core copper(Ⅰ)-alkynyl nanocluster(Cu11),which is stabilized by alkynyl ligands derived from a photosensitive rhodamine dye molecule.Notably,this Cu11cluster exhibited excellent photocatalytic hydrogen evolution activity(8.13 mmol g-1h-1)even in the absence of a mediator and noble metal co-catalyst.Furthermore,when Cu11clusters were loaded onto the surface of TiO_(2)nanosheets,the resultant Cu11@TiO_(2)nanocomposites exhibited a significant enhancement in hydrogen evolution efficiency,which is 60 times higher than that of pure TiO_(2)nanosheets.The incorporation of Cu11clusters within the Cu11@TiO_(2)effectively inhibits the recombination of photogenerated electrons and holes,thereby accelerating the charge separation and migration in the composite material.This work introduces a novel perspective for designing highly active copper cluster-based photocatalysts.展开更多
基金supported in part by the National Natural Science Foundation of China through Grant 11821303by the Ministry of Science and Technology of China through Grant 2018YFA0404502+1 种基金support from the China Scholarship Councilthe nancial support of the GA?R EXPRO grant No.21-13491X.
文摘Previous X-ray and optical studies of the galaxy cluster pair A222/223 suggested the possible presence of a=lamentary structure connecting the two clusters,a result that appears to be supported by subsequent weak-lensing analyses.This=lament has been reported to host a primordial warm-hot intergalactic medium,which existed prior to being heated by the interactions of the clusters.In this study,we made an attempt to examine the reported emission feature with data from an archival Suzaku observation,taking advantage of its low detector background.Because the emission is expected to be very weak,we=rst carefully examined all potential sources of“contamination,”and then modeled the residual emission.Due to large uncertainties,unfortunately,our results can neither con=rm the presence of the reported emission feature nor rule it out.We discuss the sources of uncertainties.
基金supported by the National Natural Science Foundation of China under program Nos.12090040,12090043,12473031,and 12003025as well as the Basic Research Program of Yunnan Province(No.202401AT070142)+2 种基金the International Center of Supernovae,Yunnan Key Laboratory(No.202302AN360001)the Natural Science Foundation of Yunnan Province(No.202201BC070003)the support of the Postdoctoral Fellowship Program of CPSF under grant Nos.GZC20240124 and 2024M760242.
文摘The 11th data release of the LAMOST survey provides fundamental stellar parameters but lacks detailed abundance measurements forα-elements,which are crucial for understanding stellar populations and Galactic chemical evolution.In this study,we derive the abundances of oxygen(O),magnesium(Mg),silicon(Si),calcium(Ca),and titanium(Ti)for over 6.8 million stars using LAMOST DR11 low-resolution spectra.To ensure reliable measurements,we select 760 open clusters spanning a broad range of ages and apply Monte Carlo sampling for accurate abundance estimates.Additionally,we utilize over 30,000 stars from the GALAH DR4 catalog to train an XGBoost model for extractingα-element abundances from LAMOST DR11 spectra.Bayesian linear regression is employed to analyze the compositional distribution across the Galactic disk and infer chemical gradients as a function of Galactocentric distance.Our results indicate a general increase in chemical abundances with Galactocentric distance,with oxygen showing the steepest gradient.Our results confirm the overall increase ofα-element abundances with Galactocentric distance,consistent with previous studies,while minor discrepancies in Mg,Ca,and Ti gradients likely arise from differences in sample selection,observational sensitivity,or Galactic enrichment processes.
基金supported by the National Natural Science Foundation of China(No.22372083,52201259)the National Key R&D Program of China(2021YFB2500300)+2 种基金the Fundamental Research Funds for the Central Universities:Nankai University(63241607)the Natural Science Foundation of Tianjin(No.22JCZDJC00380)the Young Elite Scientist Sponsorship Program by CAST.
文摘LiNO_(3) is known to significantly enhance the reversibility of lithium metal batteries;however,the modification of solvation structures in various solvents and its further impact on the interface have not been fully revealed.Herein,we systematically studied the evolution of solvation structures with increasing LiNO_(3) concentration in both carbonate and ether electrolytes.The results from molecular dynamics simulations unveil that the Li^(+)solvation structure is less affected in carbonate electrolytes,while in ether electrolytes,there is a significant decrease of solvent molecules in Li^(+)coordination,and a larger average size of Li^(+)solvation structure emerges as LiNO_(3) concentration increases.Notably,the formation of large ion aggregates with size of several nanometers(nano-clusters),is observed in ether-based electrolytes at conventional Li^(+)concentration(1 M)with higher NO_(3)^(-) ratio,which is further proved by infrared spectroscopy and small-angle X-ray scattering experiments.The nano-clusters with abundant anions are endowed with a narrow energy gap of molecular orbitals,contributing to the formation of an inorganic rich electrode/electrolyte interphase that enhances the reversibility of lithium stripping/plating with Coulombic efficiency up to 99.71%.The discovery of nano-clusters elucidates the underlying mechanism linking ions/solvent aggregation states of electrolytes to interfacial stability in advanced battery systems.
基金supported by the National Natural Science Foundation of China(51872115 and 12234018)Beijing Synchrotron Radiation Facility(BSRF)4B9A.
文摘Two-dimensional(2D)materials loaded with single atoms and clusters are being set at the forefront of catalysis due to their distinctive geometric and electronic features.However,the usually-complicated synthesis procedures impede in-depth clarification of their catalytic mechanisms.To this end,herein we developed an efficient one-step dimension-reduction carbonization strategy,with which we successfully architected a highly-efficient catalyst for oxygen reduction reaction(ORR),featured with symbiotic cobalt single atoms and clusters decorated in two-dimensional(2D)ultra-thin(3.5 nm thickness)nitrogen-carbon nanosheets.The synergistic effects of the two components afford excellent oxygen reduction activity in alkaline media(E_(1/2)=0.823 V vs.RHE)and thereof a high power density(146.61 mW cm^(-2))in an assembled Zn-air battery.As revealed by theoretical calculations,the cobalt clusters can regulate electrons surrounding those individual atoms and affect the adsorption of intermediate species.As a consequence,the derived active sites of single cobalt atoms lead to a significant improvement of the ORR performance.Thus,our work may fuel interests to delicate architectu re of single atoms and clusters coexisting 2D support toward optimal electrocatalytic performance.
基金supported by the Specific Research Fund for Top-notch Talents of Guangdong Provincial Hospital of Chinese Medicine(No.2022KT1188).
文摘Objectives To identify core symptoms and symptom clusters in patients with neuromyelitis optica spectrum disorder(NMOSD)by network analysis.Methods From October 10 to 30,2023,140 patients with NMOSD were selected to participate in this online questionnaire survey.The survey tools included a general information questionnaire and a self-made NMOSD symptoms scale,which included the prevalence,severity,and distress of 29 symptoms.Cluster analysis was used to identify symptom clusters,and network analysis was used to analyze the symptom network and node characteristics and central indicators including strength centrality(r_(s)),closeness centrality(r_(c))and betweeness centrality(r_(b))were used to identify core symptoms and symptom clusters.Results The most common symptom was pain(65.7%),followed by paraesthesia(65.0%),fatigue(65.0%),easy awakening(63.6%).Regarding the burden level of symptoms,pain was the most burdensome symptom,followed by paraesthesia,easy awakening,fatigue,and difficulty falling asleep.Six clusters were identified:somatosensory,motor,visual,and memory symptom clusters,bladder and rectum symptom clusters,sleep symptoms clusters,and neuropsychological symptom clusters.Fatigue(r_(s)=12.39,r_(b)=68.00,r_(c)=0.02)was the most central and prominent bridge symptom,and motor symptom cluster(r_(s)=2.68,r_(c)=0.10)was the most central symptom cluster among the six clusters.Conclusions Our study demonstrated the necessity of symptom management targeting fatigue,pain,and motor symptom cluster in patients with NMOSD.
文摘Dispersing metals from nanoparticles to clusters is often achieved using ligand protection methods,which exhibit unique properties such as suppressing structure-sensitive side reactions.However,this method is limited by the use of different metal precursor salts corresponding to different ligands.An alternative approach,the ion exchange(IE)method,can overcome this limitation to some extent.Nevertheless,there is still an urgent need to address the stabilization of metals(especially precious metals)by using IE method.Here,we reported a Pt cluster catalyst prepared mainly by anchoring Pt atoms via O located near the framework Zn in zincosilicate zeolites and riveted by zeolite surface rings after reduction(reduced Pt/Zn-3-IE).The catalyst can achieve an initial propane conversion of 26%in a pure propane atmosphere at 550℃and shows little deactivation even after 7.5 d of operation.Moreover,the alteration of catalyst by the introduction of framework Zn was also highlighted and interpreted.
基金supported by the Natural Science Foundation of Hunan Province(No.2023JJ30650)the Central South University Innovation-Driven Research Programme(No.2023CXQD061)。
文摘The atomic-level exploration of structure-property correlations poses significant challenges in establishing precise design principles for electrocatalysts targeting efficient CO_(2)conversion.This study demonstrates how controlled exposure of metal sites governs CO_(2)electroreduction performance through two octanuclear bismuth-oxo clusters with distinct architectures.The Bi_(8)-DMF cluster,constructed using tert–butylthiacalix[4]arene(TC4A)as the sole ligand,features two surface-exposed Bi active sites,while the dual-ligand Bi_(8)-Fc(with TC4A/ferrocene carboxylate)forms a fully encapsulated structure.Electrocatalytic tests reveal Bi_(8)-DMF achieves exceptional formate selectivity(>90%Faradaic efficiency)across a broad potential window(-0.9 V to-1.6 V vs.RHE)with 20 h stability,outperforming Bi_(8)-Fc(60%efficiency at-1.5 V).Theoretical calculations attribute Bi_(8)-DMF's superiority to exposed Bi sites that stabilize the critical*OCHO intermediate via optimized orbital interactions.This work provides crucial guidance for polynuclear catalyst design:moderate exposure of metal active sites significantly enhances CO_(2)reduction performance.
基金supported by the National Natural Science Foundation of China(Grant No.12374253,12074053,12004064)J.G.thanks the Foreign talents project(G2022127004L),The authors also acknowledge computer support from the Shanghai Supercomputer Center,the DUT Supercomputing Center,and the Tianhe supercomputer of Tianjin Center.
文摘Surface-supported clusters forming by aggregation of excessive adatoms could be the main defects of 2D materials after chemical vapor deposition.They will significantly impact the electronic/magnetic properties.Moreover,surface supported atoms are also widely explored for high active and selecting catalysts.Severe deformation,even dipping into the surface,of these clusters can be expected because of the very active edge of clusters and strong interaction between supported clusters and surfaces.However,most models of these clusters are supposed to simply float on the top of the surface because ab initio simulations cannot afford the complex reconstructions.Here,we develop an accurate graph neural network machine learning potential(MLP)from ab initio data by active learning architecture through fine-tuning pre-trained models,and then employ the MLP into Monte Carlo to explore the structural evolutions of Mo and S clusters(1-8 atoms)on perfect and various defective MoS2 monolayers.Interestingly,Mo clusters can always sink and embed themselves into MoS2 layers.In contrast,S clusters float on perfect surfaces.On the defective surface,a few S atoms will fill the vacancy and rest S clusters float on the top.Such significant structural reconstructions should be carefully taken into account.
文摘Correction to:Rare Met.https://doi.org/10.1007/s12598-021-01815-z In the original publication,Fig.5 was published with few mistakes.The correct version of Fig.5 is given in this correction.
文摘Correction to:Nano-Micro Letters(2025)17:123 https://doi.org/10.1007/s40820-025-01654-y Following publication of the original article[1],the authors reported that Dr.Mohamed Bououdina’s affiliation needed to be corrected from 1 to 2.The correct author affiliation has been provided in this Correction and the original article[1]has been corrected.
基金supported by the Start-Up Research Funding of Fujian Normal University(No.Y0720326K13)the National Natural Science Foundation of China(Nos.22103035 and 22033005)+2 种基金the National Key R&D Program of China(No.2022YFA1503900)Shenzhen Science and Technology Program(No.RCYX20231211090357078)Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002).
文摘Atomically precise palladium(Pd)clusters are emerging as versatile nanomaterials with applications in catalysis and biomedicine.This study explores the synthesis,structure evolution,and catalytic properties of Pd clusters stabilized by cyclohexanethiol(HSC_(6)H_(11))ligands.Using electrospray ionization mass spectrometry(ESI-MS)and single-crystal X-ray diffraction(SXRD),structures of the Pd clusters ranging from Pd4(SC_(6)H_(11))8 to Pd18(SC_(6)H_(11))36 were determined.This analysis revealed a structure evolution from polygonal to elliptical geometries of the PdnS2n frameworks as the cluster size increased.UV-Vis-NIR spectroscopy,combined with quantum chemical calculations,elucidated changes in the electronic structure of the clusters.Catalytic studies on the Sonogashira cross-coupling reactions demonstrated a size-dependent decline in activity attributed to variations in structural arrangements and electronic properties.Mechanistic insights proposed a distinctive Pd(Ⅱ)-Pd(Ⅳ)catalytic cycle.This research underscores how ligands and cluster size influence the structures and properties of Pd clusters,offering valuable insights for the future design and application of Pd clusters in advanced catalysis and beyond.
基金support from National Natural Science Foundation of China(32101474 and 42377249)National Key Research and Development Program of China(2023YFD2201605).
文摘CO_(2) conversion to CO via the reverse water-gas shift(RWGS)reaction is limited by a low CO_(2) conversion rate and CO selectivity.Herein,an efficient RWGS catalyst is constructed through Enteromorpha prolifera–derived N-rich mesoporous biochar(EPBC)supported atomic-level Cu-Mo_(2)C clusters(Cu-Mo_(2)C/EPBC).Unlike traditional acti-vated carbon(AC)supported Cu-Mo_(2)C particles(Cu-Mo_(2)C/AC),the Cu-Mo_(2)C/EPBC not only presents the better graphitization degree and larger specific surface area,but also uniformly andfirmly anchors atomic-level Cu-Mo_(2)C clusters due to the existence of pyridine nitrogen.Furthermore,the pyridine N of Cu-Mo_(2)C/EPBC strengthens an unblocked electron transfer between Mo_(2)C and Cu clusters,as verified by X-ray absorption spectroscopy.As a result,the synergistic effect between pyridinic N anchoring and the clusters interaction in Cu-Mo_(2)C/EPBC facilitates an improved CO selectivity of 99.95%at 500℃ compared with traditional Cu-Mo_(2)C/AC(99.60%),as well as about 3-fold CO_(2) conversion rate.Density functional theory calculations confirm that pyr-idine N-modified carbon activates the local electronic redistribution at Cu-Mo_(2)C clusters,which contributes to the decreased energy barrier of the transition state of CO^(*)+O^(*)+2H^(*),thereby triggering the transformation of rate-limited step during the redox pathway.This biomass-derived strategy opens perspective on producing sustain-able fuels and building blocks through the RWGS reaction.
基金supported by the National Natural Science Foundation of China(NSFC)through grants 12090040,12090042,and 12073060the National Key R&D Program of China No.2019YFA0405501+2 种基金J.Z.acknowledges the Youth Innovation Promotion Association CASthe Science and Technology Commission of Shanghai Municipality(grant No.22dz1202400)the Program of Shanghai Academic/Technology Research Leader。
文摘As part of the LAMOST medium-resolution spectroscopic survey,the LAMOST-MRS-O is a non-time domain survey that aims to perform medium-resolution spectral observations for member stars in the open cluster areas.This survey plans to obtain the spectroscopic parameters such as radial velocity and metal abundances of member stars and provide data support for further study on the chemical and dynamical characteristics and evolution of open clusters in combination with Gaia data.We have completed the observations on ten open cluster fields and obtained 235184 medium-resolution spectra of 133792 stars.Based on the data analyzed of LAMOST DR11v1.1,for some clusters of particular concern,it is found that the sampling ratio of members stars with Gmag<15 mag can reach 70%,which indicates that the LAMOST-MRS-O has reached our initial design goal.
基金supported by the National Natural Science Foundation of China,No.12261141689。
文摘Recent studies have increasingly identified extended main sequence turn-off(e MSTO)phenomena in Galactic open clusters,yet the number of such clusters with sufficient spectroscopic information for member stars remains limited.Unlike most studies that rely on fitting isochrones based on color–magnitude diagram(CMD)morphology to account for varying rotational velocities,our approach leverages LAMOST spectral data to compute actual rotational velocity distributions for confirmed cluster members,along with parameters such as metallicity,differential extinction,and rotational inclination,to utilize PARSEC isochrones for fitting the cluster CMDs.We systematically surveyed all known Galactic open clusters and selected 12 clusters where rotational velocity distributions could be reliably calculated for detailed fitting.Our results successfully reproduced the eMSTO phenomenon observed in these clusters.For the majority of clusters,considering only differential extinction and variations in rotational velocity adequately explains the position and morphology of the MSTO.For some intermediate-age clusters,incorporating rotational inclination additionally accounts for the broadening of the MSTO.This study underscores the importance of spectroscopic data in understanding eMSTO phenomena and provides a probable explanation for interpreting the combined effects of differential extinction,rotation,and inclination on the CMDs of Galactic open clusters.
文摘Ultrafine,highly dispersed Pt clusters were immobilized onto the Co nanoparticle surfaces by one-step pyrolysis of the precursor Pt(Ⅱ)-encapsulating Co-MOF-74.Owing to the small size effects of Pt clusters as well as the strongly enhanced synergistic interactions between Pt and Co atoms,the obtained Pt-on-Co/C400 catalysts exhib-ited excellent catalytic activity toward the hydrolysis of ammonia borane with an extremely high turnover frequency(TOF)value of 3022 min^(-1)at 303 K.Durability test indicated that the obtained Pt-on-Co/C400 catalysts possessed high catalytic stability,and there were no changes in the catalyst structures and catalytic activities after 10 cycles.
文摘An aluminoborate,Na_(2.5)Rb[Al{B_(5)O_(10)}{B_(3)O_(5)}]·0.5NO_(3)·H_(2)O(1),was synthesized under hydrothermal condition,which was built by mixed oxoboron clusters and AlO_(4)tetrahedra.In the structure,the[B_(5)O_(10)]^(5-)and[B_(3)O_(7)]^(5-)clusters are alternately connected to form 1D[B_(8)O_(15)]_(n)^(6n-)chains,which are further linked by AlO_(4)units to form a 2D monolayer with 7‑membered ring and 10‑membered ring windows.Two adjacent monolayers with opposite orientations further form a porous‑layered structure with six channels through B—O—Al bonds.Compound 1 was characterized by single crystal X‑ray diffraction,powder X‑ray diffraction(PXRD),IR spectroscopy,UV‑Vis diffuse reflection spectroscopy,and thermogravimetric analysis(TGA),respectively.UV‑Vis diffuse reflectance analysis indicates that compound 1 shows a wide transparency range with a short cutoff edge of 201 nm,suggesting it may have potential application in UV regions.CCDC:2383923.
基金supported by the National Key R&D Program of China(No.2023YFB3712504)the National Natural Science Foundation of China(Nos.22273038,22073043,and 22033004)。
文摘Accurate description of noncova-lent interactions in large systems is challenging due to the require-ment of high-level electron corre-lation methods.The generalized energy-based fragmentation(GEBF)approach,in conjunc-tion with the domain-based local pair natural orbital(DLPNO)method,has been applied to assess the average binding energies(ABEs)of large benzene clus-ters,specifically(C6H6)13,at the coupled cluster singles and doubles with perturbative triples correction[CCSD(T)]level and the complete basis set(CBS)limit.Utilizing GEBF-DLPNO-CCSD(T)/CBS ABEs as benchmarks,various DFT functionals were evaluated.It was found that several functionals with empirical dispersion correction,including M06-2X-D3,B3LYP-D3(BJ),and PBE-D3(BJ),provide accurate descriptions of the ABEs for(C6H6)13 clusters.Additionally,the M06-2X-D3 functional was used to calculate the ABEs and relative stabili-ties of(C6H6)n clusters for n=11,12,13,14,and 15 revealing that the(C6H6)13 cluster ex-hibits the highest relative stability.These findings align with experimental evidence suggest-ing that n=13 is one of the magic numbers for benzene clusters(C6H6)n,with n≤30.
基金supported by the National Key Research and Development Program of China(2022YFC2305201)National Natural Science Foundation of China(71874168)。
文摘Objective This study aimed to investigate the prevalence of HIV pretreatment drug resistance(PDR)and the transmission clusters associated with PDR-related mutations in newly diagnosed,treatmentnaive patients between 2020 and 2023 in Dehong prefecture,Yunnan province,China.Methods Demographic information and plasma samples were collected from study participants.PDR was assessed using the Stanford HIV Drug Resistance Database.The Tamura-Nei 93 model within HIVTRACE was employed to compute pairwise matches with a genetic distance of 0.015 substitutions per site.Results Among 948 treatment-naive individuals with eligible sequences,36 HIV subtypes were identified,with unique recombinant forms(URFs)being the most prevalent(18.8%,178/948).The overall prevalence of PDR was 12.4%(118/948),and resistance to non-nucleotide reverse transcriptase inhibitors(NNRTIs),nucleotide reverse transcriptase inhibitors(NRTIs),and protease inhibitors(PIs)was10.7%,1.3%,and 1.6%,respectively.A total of 91 clusters were identified,among which eight showed evidence of PDR strain transmission.The largest PDR-associated cluster consisted of six CRF01_AE drugresistant strains carrying K103N and V179T mutations;five of these individuals had initial CD4^(+)cell counts<200 cells/μL.Conclusion The distribution of HIV subtypes in Dehong is diverse and complex.PDR was moderately prevalent(12.4%)between 2020 and 2023.Evidence of transmission of CRF01_AE strains carrying K103N and V179T mutations was found.Routine surveillance of PDR and the strengthening of control measures are essential to limit the spread of drug-resistance HIV strains.
文摘Objective:This study aims to investigate the patterns of symptom occurrence in patients experiencing acute exacerbations of chronic obstructive pulmonary disease(AECOPD).It will explore the composition of symptom clusters and analyze the correlation between these clusters and health-related quality of life(HRQoL).Methods:A total of 207 patients with AE-COPD were surveyed from a tertiary grade A hospital.Data collection was conducted using three validated instruments:the Basic Information Questionnaire(BIQ),Disease Symptom Survey Questionnaire(MSAS),and Quality of Life Questionnaire(CAT).Statistical software SPSS 22.0 was used to analyze the correlation between symptom clusters and quality of life.Results:Exploratory factor analysis showed that five major symptom clusters existed in the patients,including the psycho-emotional symptom cluster,the sleep-related symptom cluster,the other side effects symptom cluster,the energy deficiency symptom cluster and the cough-loss of appetite symptom cluster,and the severity of the symptom clusters showed a significant negative correlation with the quality of life of the patients(P<0.05).Conclusion:Strengthening the comprehensive management of symptom clusters in patients with AE-COPD can help to effectively reduce the symptom burden of patients,and then significantly improve their quality of life.
基金supported by the National Natural Science Foundation of China(Nos.22371263 and U2004193)Natural Science Foundation of Henan Province(No.232300421225)。
文摘Metal nanoclusters with well-defined atomic structures offer significant promise in the field of catalysis due to their sub-nanometer size and tunable organic-inorganic hybrid structural features.Herein,we successfully synthesized an 11-core copper(Ⅰ)-alkynyl nanocluster(Cu11),which is stabilized by alkynyl ligands derived from a photosensitive rhodamine dye molecule.Notably,this Cu11cluster exhibited excellent photocatalytic hydrogen evolution activity(8.13 mmol g-1h-1)even in the absence of a mediator and noble metal co-catalyst.Furthermore,when Cu11clusters were loaded onto the surface of TiO_(2)nanosheets,the resultant Cu11@TiO_(2)nanocomposites exhibited a significant enhancement in hydrogen evolution efficiency,which is 60 times higher than that of pure TiO_(2)nanosheets.The incorporation of Cu11clusters within the Cu11@TiO_(2)effectively inhibits the recombination of photogenerated electrons and holes,thereby accelerating the charge separation and migration in the composite material.This work introduces a novel perspective for designing highly active copper cluster-based photocatalysts.
