期刊文献+
共找到110,132篇文章
< 1 2 250 >
每页显示 20 50 100
π-conjugated chromophore functionalized high-nuclearity titanium-oxo clusters containing structural unit of anatase for photocatalytic selective oxidation of sulfides 被引量:1
1
作者 Ling-Rong Liao Dong-Chun Zheng +3 位作者 Pin-Xi Ou Qi-Xin Zhao Wei-Min Xuan Qi Zheng 《Rare Metals》 SCIE EI CAS CSCD 2024年第4期1736-1746,共11页
N-doping has significant influence in manipulating the properties of TiO_(2),and this has stimulated the development of N-donor-functionalized titanium-oxo clusters(TOCs)as molecular models to study the structure-prop... N-doping has significant influence in manipulating the properties of TiO_(2),and this has stimulated the development of N-donor-functionalized titanium-oxo clusters(TOCs)as molecular models to study the structure-property relationship.However,the structural type and photoresponsive application are still limited for such TOCs,especially regarding the high-nuclearity TOCs that contain structure unit of TiO_(2)for photocatalysis.Herein,we showed the synthesis of a series of high-nuclearity TOCs 1-3 compounds usingπ-conjugated 1,10-phenanthroline(phen)as chromophore and N-donor functional ligand.Compound 1 features cocrystal structure composed of one[Ti_(26)]~(2+)and half[Ti_(22)]~(2+),which renders it as the first cocrystallized TOC containing two positively charged species and phen-functionalized TOC showing the highest nuclearity up to 37 Ti centers.By adjusting the synthetic conditions,the individual{Ti_(22)}and{Ti_(26)}clusters can also be isolated as Compounds 2 and 3,respectively.The core structure of{Ti_(22)}is mainly constructed from four lacunary{Ti_(4)}derived from pentagonal{Ti(Ti)_5}unit,while{Ti_(26)}is built from four complete{Ti(Ti)_5}unit.Notably,a{Ti_8O_(14)}structure unit of anatase TiO_(2)can be identified in{Ti_(26)}.Based on the unique structural features and proper photophysical and photochemical properties of Compounds 1-3,they are applied for photocatalytic sulfoxidation.Owing to the presence of anatase structure unit in{Ti_(26)}and the synergistic effect from{Ti_(22)}and{Ti_(26)},the catalytic performance presents in the order of Compound 1>Compound 3>Compound 2.This work provides excellent models to understand the structureproperty relationship from the perspective of cocrystallization and Ti-O binding model and will further promote the application of TOCs as functional catalysts for organic transformation. 展开更多
关键词 titanium-oxo cluster Molecular model of anatase TiO_(2) High nuclearity π-conjugated chromophore Photocatalytic sulfoxidation
原文传递
Photoactive Naphthalene Diimide Functionalized Titanium-Oxo Clusters with High Photoelectrochemical Responses 被引量:1
2
作者 杨雨 赵启新 +1 位作者 郑琦 宣为民 《Journal of Donghua University(English Edition)》 CAS 2023年第6期590-599,共10页
Photoactive functionalized titanium-oxo clusters(TOCs)are regarded as an important model compound for dye-sensitized titanium dioxide solar cells.However,the dyes used for sensitizing TOCs are still limited.Herein,two... Photoactive functionalized titanium-oxo clusters(TOCs)are regarded as an important model compound for dye-sensitized titanium dioxide solar cells.However,the dyes used for sensitizing TOCs are still limited.Herein,two cyclic TOCs are reported,namely,[Ti_(6)(μ_(3)-O)_(2)(Oi-Pr)_(8))(LA)_(2)]·i-PrOH(S1)and[Ti_(6)(μ_(3)-O)2(Oi-Pr)_(8))(LV)_(2)]·i-PrOH(S2),which are functionalized by photoactive naphthalene diimide(NDI)chromophores.Their molecular structures and photophysical and photochemical properties were systematically studied.As shown by ultraviolet-visible(UV-vis)spectra and photocurrent study results,the band gap and the photocurrent response of S1 and S2 were derived from NDI ligands which extend the absorption edge of S1 and S2 approaching 500 nm and afford high photocurrent densities of 2.12μA/cm^(2)and 1.95μA/cm^(2)for S1 and S2,respectively,demonstrating the significance of the photoactive ligand in modulating photoresponse of TOCs.This work is expected to enrich the structural library of photoactive TOCs and provide insights into understanding the structure-property relationships of sensitized clusters. 展开更多
关键词 titanium-oxo cluster naphthalene diimide photoactive photoelectrochemical response
在线阅读 下载PDF
Phenol-triggered supramolecular transformation of titanium-oxo cluster based coordination capsules
3
作者 Xi Fan Lvbing Yuan +1 位作者 Jian Zhang Lei Zhang 《Chinese Chemical Letters》 SCIE CAS CSCD 2021年第8期2415-2418,共4页
Supramolecular transformations of coordination cage or capsule have received much attention recently,which help elucidate this natural self-assembly behavior in biological systems.The current study describes the first... Supramolecular transformations of coordination cage or capsule have received much attention recently,which help elucidate this natural self-assembly behavior in biological systems.The current study describes the first supramolecular transformation of titanium-o rganic coordination capsule triggered by phenol(and H_(3) PO_(3)).The structural alterations are accompanied by the reconstruction of 5-coordinated Ti centers to 6-coordinated ones.Meanwhile,different amounts of encapsulated phenol vip molecules can be identified,dependent on the sizes of the obtained cavities.In addition,they display much better visible light absorption and air stability than the isopropanol stabilized ones. 展开更多
关键词 titanium-oxo clusters PHENOL Supramolecular transformation Post-synthesis modulation Coordination capsules
原文传递
Assembly of Homochiral Titanium-Oxo Clusters Protected by in situ Generated Chiral Ligands for Enhanced Photoelectrochemical Activity
4
作者 Nahui Huang Jinle Hou +6 位作者 Ye Wang Pengfei Fei Dongxu Zhang Zhi Wang Konggang Qu Xianxi Zhang Di Sun 《Chinese Journal of Chemistry》 2025年第7期750-758,共9页
The synthesis of titanium oxo clusters(TOCs)with both chirality and photoactivity is urgently needed to expand their applications.However,this remains a significant challenge due to synthetic difficulties and limitati... The synthesis of titanium oxo clusters(TOCs)with both chirality and photoactivity is urgently needed to expand their applications.However,this remains a significant challenge due to synthetic difficulties and limitations in chiral ligand selection.In this work,we have isolated two pairs of enantiomeric TOCs,[Ti_(3)(μ_(3)-O)(R/S-L1)_(2)(^(i)PrO)_(6)](R/S-Ti_(3);^(i)PrOH=isopropanol,R/S-L1=R/S-2'-hydroxy-[1,1'-binaphthalen]-2-yl isopropyl hydrogenphosphate)and[Ti_(4)(μ_(2)-O)(μ_(4)-O)(R/S-L2)_(2)(EtO)_(8)](R/S-Ti4;EtOH=ethanol,R/S-L2=R/S-2'-hydroxy-[1,1'-binaphthalen]-2-yl ethyl hydrogenphosphate),via an in situ ligand transformation approach.The R/S-L1 and R/S-L2 ligands were obtained by alcoholysis of R/S-L(R/S-1,1'-binaphthyl-2,2'-diyl hydrogenphosphate)in different reaction solvents.These ligands,with additional coordination sites,facilitated the formation of novel TOCs and improved their stability.Importantly,these clusters exhibited exceptional stability in solid state and maintained appreciable stability in solution.Furthermore,the introduction of chiral ligands not only imparts a homochiral nature to R/S-Ti3 and R/S-Ti4 but also confers upon them superior photoelectric properties due to ligand-to-metal charge transfer(LMCT)phenomena,as confirmed by theoretical calculations.This study offers a valuable synthetic strategy for preparing photoactive chiral TOCs,and we anticipate it will inspire new discoveries in the field of chiral metal nanoclusters. 展开更多
关键词 Chirality titanium-oxo clusters Crystal engineering Photoelectric performances Theoretical calculation| nsituligandtransformation
原文传递
Recognizing Ti-site coordination geometry in titanium-oxo clusters for enhanced photo-Fenton-like catalysis
5
作者 Zihang Wang Wenxiu Liu +4 位作者 Hui Wang Lei Li Manqin Guan Xiaodong Zhang Yi Xie 《Nano Research》 2025年第10期208-215,共8页
Titanium-based materials have emerged as promising candidates for photo-Fenton-like catalysis,whereas their structural complexities impede precise understanding of the relevant structure–activity relationships.Owing ... Titanium-based materials have emerged as promising candidates for photo-Fenton-like catalysis,whereas their structural complexities impede precise understanding of the relevant structure–activity relationships.Owing to their well-defined and tunable structures,titaniumoxo clusters appear to be facile models for looking into the photophysical and photochemical processes in Ti-H_(2)O_(2) systems.Using PTC-3 as a prototype,we interrogated the relationship between Ti-site coordination environments and photo-Fenton-like behaviors.Through integrated in-situ/exsitu spectroscopic analyses and theoretical simulations,we elucidated light-driven H_(2)O_(2) activation on hexa-coordinated and penta-coordinated Ti sites in PTC-3.The superiority of penta-coordinated Ti site was identified,where extended visible-light absorption and promoted electron transfer could synergistically boost the activation of H_(2)O_(2) into superoxide radicals.This work brightens the role of Ti-site coordination geometry in photo-Fenton-like processes and paves the way for pursuing titanium-based advanced oxidation. 展开更多
关键词 titanium-oxo clusters advanced oxidation technologies photo-Fenton-like charge transfer
原文传递
Ligand-directed construction of cobalt-oxo cluster-based organic frameworks:Structural modulation,semiconductor,and antiferromagnetic properties
6
作者 SHI Jinlian LIU Xiaoru XU Zhongxuan 《无机化学学报》 北大核心 2026年第1期45-54,共10页
Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully construct... Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully constructed by coordinatively assembling the semi-rigid multidentate ligand 5-(1-carboxyethoxy)isophthalic acid(H₃CIA)with the Nheterocyclic ligands 1,4-di(4H-1,2,4-triazol-4-yl)benzene(1,4-dtb)and 1,4-di(1H-imidazol-1-yl)benzene(1,4-dib),respectively,around Co^(2+)ions.Single-crystal X-ray diffraction analysis revealed that in both complexes HU23 and HU24,the CIA^(3-)anions adopt aκ^(7)-coordination mode,bridging six Co^(2+)ions via their five carboxylate oxygen atoms and one ether oxygen atom.This linkage forms tetranuclear[Co4(μ3-OH)2]^(6+)units.These Co-oxo cluster units were interconnected by CIA^(3-)anions to assemble into 2D kgd-type structures featuring a 3,6-connected topology.The 2D layers were further connected by 1,4-dtb and 1,4-dib,resulting in 3D pillar-layered frameworks for HU23 and HU24.Notably,despite the similar configurations of 1,4-dtb and 1,4-dib,differences in their coordination spatial orientations lead to topological divergence in the 3D frameworks of HU23 and HU24.Topological analysis indicates that the frameworks of HU23 and HU24 can be simplified into a 3,10-connected net(point symbol:(4^(10).6^(3).8^(2))(4^(3))_(2))and a 3,8-connected tfz-d net(point symbol:(4^(3))_(2)((4^(6).6^(18).8^(4)))),respectively.This structural differentiation confirms the precise regulatory role of ligands on the topology of metal-organic frameworks.Moreover,the ultraviolet-visible absorption spectra confirmed that HU23 and HU24 have strong absorption capabilities for ultraviolet and visible light.According to the Kubelka-Munk method,their bandwidths were 2.15 and 2.08 eV,respectively,which are consistent with those of typical semiconductor materials.Variable-temperature magnetic susceptibility measurements(2-300 K)revealed significant antiferromagnetic coupling in both complexes,with their effective magnetic moments decreasing markedly as the temperature lowered.CCDC:2457554,HU23;2457553,HU24. 展开更多
关键词 semi-rigid carboxylic acid ligands three-dimensional framework tetranuclear cobalt-oxo cluster semiconductor material antiferromagnetic magnetism
在线阅读 下载PDF
Equivalent Modeling with Passive Filter Parameter Clustering for Photovoltaic Power Stations Based on a Particle Swarm Optimization K-Means Algorithm
7
作者 Binjiang Hu Yihua Zhu +3 位作者 Liang Tu Zun Ma Xian Meng Kewei Xu 《Energy Engineering》 2026年第1期431-459,共29页
This paper proposes an equivalent modeling method for photovoltaic(PV)power stations via a particle swarm optimization(PSO)K-means clustering(KMC)algorithm with passive filter parameter clustering to address the compl... This paper proposes an equivalent modeling method for photovoltaic(PV)power stations via a particle swarm optimization(PSO)K-means clustering(KMC)algorithm with passive filter parameter clustering to address the complexities,simulation time cost and convergence problems of detailed PV power station models.First,the amplitude–frequency curves of different filter parameters are analyzed.Based on the results,a grouping parameter set for characterizing the external filter characteristics is established.These parameters are further defined as clustering parameters.A single PV inverter model is then established as a prerequisite foundation.The proposed equivalent method combines the global search capability of PSO with the rapid convergence of KMC,effectively overcoming the tendency of KMC to become trapped in local optima.This approach enhances both clustering accuracy and numerical stability when determining equivalence for PV inverter units.Using the proposed clustering method,both a detailed PV power station model and an equivalent model are developed and compared.Simulation and hardwarein-loop(HIL)results based on the equivalent model verify that the equivalent method accurately represents the dynamic characteristics of PVpower stations and adapts well to different operating conditions.The proposed equivalent modeling method provides an effective analysis tool for future renewable energy integration research. 展开更多
关键词 Photovoltaic power station multi-machine equivalentmodeling particle swarmoptimization K-means clustering algorithm
在线阅读 下载PDF
Aggregation of titanium-oxo clusters 被引量:1
8
作者 Yu-Long Xie Wei-Hui Fang Jian Zhang 《Aggregate》 EI CAS 2024年第3期107-126,共20页
Compared with nanoparticle-aspect relatives titanium dioxide(TiO2),titanium-oxo clusters(TOCs)are atomically structural-determined and can be further precisely modified through coordination and supramolecular chemistr... Compared with nanoparticle-aspect relatives titanium dioxide(TiO2),titanium-oxo clusters(TOCs)are atomically structural-determined and can be further precisely modified through coordination and supramolecular chemistry.Another parallel research direction is titanium-based metal-organic frameworks,and those based on TOC have attracted particular attention because of their high optical performances resulting from the cluster aggregation effect.Though challenging,assembling macro-materials from specific clusters helps establish the assembly chemistry of clusters and incorporates porous andflexible characteristics into a single bulk material.Although separate reviews are reported in these two branches,no com-prehensive review is available to highlight the bridges between them.Herein,we review and summarize the development and progress of new aggregation of TOCs,from intramolecular unique cluster aggregation to hierarchical intermolecular aggre-gation via covalent forces,coordination bonds,and non-covalent forces using the specific clusters as precursors.We hope this reviewfills the gap in the methodology of assembling particular-aggregated TOCs and their derived frameworks,providing general guidance to researchers interested in this area. 展开更多
关键词 cluster chemistry framework materials ligand engineering PHOTOCATALYSIS titanium-oxo clusters
在线阅读 下载PDF
Molecular solid solution of lanthanide-titanium-oxo clusters with enhanced photocatalytic hydrogen evolution 被引量:2
9
作者 Rong Chen Chao-Long Chen +8 位作者 Hui Zhang Zi-Han Wang Fu-Li Sun Ming-Hao Du Gui-Lin Zhuang Cheng Wang La-Sheng Long Lan-Sun Zheng Xiang-Jian Kong 《Science China Chemistry》 SCIE EI CAS CSCD 2024年第2期529-535,共7页
Molecular solid solutions of metal clusters containing different metal centers with well-defined structures can accurately regulate the HOMO-LUMO gap,but are rarely available.Herein,a series of colorless lanthanide-ti... Molecular solid solutions of metal clusters containing different metal centers with well-defined structures can accurately regulate the HOMO-LUMO gap,but are rarely available.Herein,a series of colorless lanthanide-titanium-oxo clusters Ln_(2)Ti_4(μ_(2)-O)_(2)(μ_(3)-O)_4(Piv)_(10)(THF)_(2)(Ln_(2)Ti_4,Ln = Eu,Gd,Tb,and Ce,HPiv = pivalic acid) were synthesized by the reaction of pivalic acid with Ln(Ac)_(3) and titanium isopropoxide.The light yellow crystal of cluster solid solutions Eu_(2)Ti_(4-x)Cd_(x),containing a mixture of Eu_(2)Ti_4 and Eu_(2)Ti_(3)Cd,was obtained by in situ doping Cd^(2+) and S^(2–).Eu_(2)Ti_(3.92)Cd_(0.08) displays efficient photocatalytic hydrogen evolution activity without a co-catalyst,which is up to 2.6 times that of Eu_(2)Ti_4.Femtosecond time-resolved transient absorption spectroscopy and spin-polarized density functional calculations showed that the enhanced photocatalytic performance of Eu_(2)Ti_(4-x)Cd_(x) can be attributed to the narrower HOMO-LUMO gap and lower LUMO position than that of Eu_(2)Ti_4.This studyprovides an in situ doping method to realize the simple preparation of cluster solid solution. 展开更多
关键词 molecular solid solution lanthanide-titanium-oxo clusters PHOTOCATALYTIC hydrogen evolution
原文传递
Ternary titanium-oxo cluster/CdS/MIL-101 photocatalyst for H_2 evolution
10
作者 Zhang Jian (张健) Zhang Lei (张磊) 《Science Foundation in China》 CAS 2017年第2期34-34,共1页
Subject Code:B01 Photocatalytic hydrogen evolution by water-splitting has been recognized as one of the most promising solutions to the global energy and environment crisis,owing to its renewable solar energy source a... Subject Code:B01 Photocatalytic hydrogen evolution by water-splitting has been recognized as one of the most promising solutions to the global energy and environment crisis,owing to its renewable solar energy source and clean chemical fuel product.Cadmium sulfide(CdS)and TiO2(or related polyoxo-titanium clusters)are two 展开更多
关键词 CDS MIL Ternary titanium-oxo cluster/CdS/MIL-101 photocatalyst for H2 evolution
原文传递
Cu cluster@UiO-66团簇负载型催化剂促进光催化CO_(2)加氢反应 被引量:2
11
作者 王秀林 岐少鹏 +6 位作者 周昆 邓希 姚辉超 戴若云 张雨晴 伍思达 聂锁府 《分子催化(中英文)》 北大核心 2025年第2期111-119,I0001,共10页
针对高活性Cu基团簇(Cu cluster)催化剂的稳定性问题,利用MOFs材料独特的结构限域作用,将Cu团簇锚定在UiO-66中,构建了Cu cluster@UiO-66复合材料,改善了催化剂的稳定性和催化活性.在该复合结构中,UiO-66不仅可作为吸光单元捕获太阳光... 针对高活性Cu基团簇(Cu cluster)催化剂的稳定性问题,利用MOFs材料独特的结构限域作用,将Cu团簇锚定在UiO-66中,构建了Cu cluster@UiO-66复合材料,改善了催化剂的稳定性和催化活性.在该复合结构中,UiO-66不仅可作为吸光单元捕获太阳光形成光生载流子,而且UiO-66的多孔结构可以有效稳定Cu团簇,保证其微观尺度上的高度分散和结构稳定.研究发现,在光催化反应过程中,UiO-66的光生电子可快速转移至Cu团簇,进而以Cu团簇作为催化活性位点驱动CO_(2)还原反应.得益于复合材料中高效的电荷转移和稳定的团簇活性位点结构,光催化CO_(2)加氢反应活性明显增强.本研究为合成MOFs负载型团簇材料提供了新的思路. 展开更多
关键词 复合结构 UiO-66 铜纳米簇 光催化CO_(2)还原
在线阅读 下载PDF
An Organic–Inorganic Hybrid Material Based on Benzo[ghi]perylenetri-imide and Cyclic Titanium-Oxo Cluster for Efficient Perovskite and Organic Solar Cells 被引量:4
12
作者 Zhou Zhang Faming Han +7 位作者 Jie Fang Chaowei Zhao Shuai Li Yonggang Wu Yuefeng Zhang Shengyong You Binghui Wu Weiwei Li 《CCS Chemistry》 CAS 2022年第3期880-888,共9页
Perovskite and organic solar cells usually require electron-transport interlayers to efficiently transport electrons from the photoactive layer to the metal electrode.In general,pure organic or inorganic materials are... Perovskite and organic solar cells usually require electron-transport interlayers to efficiently transport electrons from the photoactive layer to the metal electrode.In general,pure organic or inorganic materials are applied into the interlayers,but organic–inorganic hybrid materials have been rarely reported for this application.In this work,we report using the first titanium-oxo cluster-based organic–inorganic hybrid as the interlayer material by introducing largeπ-conjugated benzo[ghi]perylenetriimides as an organic part via a simple ligand-exchange reaction.This new hybrid material showed excellent solubility,well-aligned energy levels,and excellent electron mobilities,enabling its great potential application as an interlayer in solar cells such as perovskite and organic solar cells,providing high power conversion efficiencies of>20%and 16%,respectively.Therefore,we claim that our present work introduces a new class of cluster-based organic–inorganic hybrid interlayer materials that exhibit promising application in organic electronics. 展开更多
关键词 organic-inorganic hybrid material Ti-oxo clusters perylene diimide perovskite solar cells organic solar cells
在线阅读 下载PDF
Multi-View Picture Fuzzy Clustering:A Novel Method for Partitioning Multi-View Relational Data 被引量:1
13
作者 Pham Huy Thong Hoang Thi Canh +2 位作者 Luong Thi Hong Lan Nguyen Tuan Huy Nguyen Long Giang 《Computers, Materials & Continua》 2025年第6期5461-5485,共25页
Multi-view clustering is a critical research area in computer science aimed at effectively extracting meaningful patterns from complex,high-dimensional data that single-view methods cannot capture.Traditional fuzzy cl... Multi-view clustering is a critical research area in computer science aimed at effectively extracting meaningful patterns from complex,high-dimensional data that single-view methods cannot capture.Traditional fuzzy clustering techniques,such as Fuzzy C-Means(FCM),face significant challenges in handling uncertainty and the dependencies between different views.To overcome these limitations,we introduce a new multi-view fuzzy clustering approach that integrates picture fuzzy sets with a dual-anchor graph method for multi-view data,aiming to enhance clustering accuracy and robustness,termed Multi-view Picture Fuzzy Clustering(MPFC).In particular,the picture fuzzy set theory extends the capability to represent uncertainty by modeling three membership levels:membership degrees,neutral degrees,and refusal degrees.This allows for a more flexible representation of uncertain and conflicting data than traditional fuzzy models.Meanwhile,dual-anchor graphs exploit the similarity relationships between data points and integrate information across views.This combination improves stability,scalability,and robustness when handling noisy and heterogeneous data.Experimental results on several benchmark datasets demonstrate significant improvements in clustering accuracy and efficiency,outperforming traditional methods.Specifically,the MPFC algorithm demonstrates outstanding clustering performance on a variety of datasets,attaining a Purity(PUR)score of 0.6440 and an Accuracy(ACC)score of 0.6213 for the 3 Sources dataset,underscoring its robustness and efficiency.The proposed approach significantly contributes to fields such as pattern recognition,multi-view relational data analysis,and large-scale clustering problems.Future work will focus on extending the method for semi-supervised multi-view clustering,aiming to enhance adaptability,scalability,and performance in real-world applications. 展开更多
关键词 Multi-view clustering picture fuzzy sets dual anchor graph fuzzy clustering multi-view relational data
在线阅读 下载PDF
FedCPS:A Dual Optimization Model for Federated Learning Based on Clustering and Personalization Strategy 被引量:1
14
作者 Zhen Yang Yifan Liu +2 位作者 Fan Feng Yi Liu Zhenpeng Liu 《Computers, Materials & Continua》 2025年第4期357-380,共24页
Federated learning is a machine learning framework designed to protect privacy by keeping training data on clients’devices without sharing private data.It trains a global model through collaboration between clients a... Federated learning is a machine learning framework designed to protect privacy by keeping training data on clients’devices without sharing private data.It trains a global model through collaboration between clients and the server.However,the presence of data heterogeneity can lead to inefficient model training and even reduce the final model’s accuracy and generalization capability.Meanwhile,data scarcity can result in suboptimal cluster distributions for few-shot clients in centralized clustering tasks,and standalone personalization tasks may cause severe overfitting issues.To address these limitations,we introduce a federated learning dual optimization model based on clustering and personalization strategy(FedCPS).FedCPS adopts a decentralized approach,where clients identify their cluster membership locally without relying on a centralized clustering algorithm.Building on this,FedCPS introduces personalized training tasks locally,adding a regularization term to control deviations between local and cluster models.This improves the generalization ability of the final model while mitigating overfitting.The use of weight-sharing techniques also reduces the computational cost of central machines.Experimental results on MNIST,FMNIST,CIFAR10,and CIFAR100 datasets demonstrate that our method achieves better personalization effects compared to other personalized federated learning methods,with an average test accuracy improvement of 0.81%–2.96%.Meanwhile,we adjusted the proportion of few-shot clients to evaluate the impact on accuracy across different methods.The experiments show that FedCPS reduces accuracy by only 0.2%–3.7%,compared to 2.1%–10%for existing methods.Our method demonstrates its advantages across diverse data environments. 展开更多
关键词 Federated learning cluster PERSONALIZATION OVERFITTING
在线阅读 下载PDF
A novel method for clustering cellular data to improve classification
15
作者 Diek W.Wheeler Giorgio A.Ascoli 《Neural Regeneration Research》 SCIE CAS 2025年第9期2697-2705,共9页
Many fields,such as neuroscience,are experiencing the vast prolife ration of cellular data,underscoring the need fo r organizing and interpreting large datasets.A popular approach partitions data into manageable subse... Many fields,such as neuroscience,are experiencing the vast prolife ration of cellular data,underscoring the need fo r organizing and interpreting large datasets.A popular approach partitions data into manageable subsets via hierarchical clustering,but objective methods to determine the appropriate classification granularity are missing.We recently introduced a technique to systematically identify when to stop subdividing clusters based on the fundamental principle that cells must differ more between than within clusters.Here we present the corresponding protocol to classify cellular datasets by combining datadriven unsupervised hierarchical clustering with statistical testing.These general-purpose functions are applicable to any cellular dataset that can be organized as two-dimensional matrices of numerical values,including molecula r,physiological,and anatomical datasets.We demonstrate the protocol using cellular data from the Janelia MouseLight project to chara cterize morphological aspects of neurons. 展开更多
关键词 cellular data clustering dendrogram data classification Levene's one-tailed statistical test unsupervised hierarchical clustering
在线阅读 下载PDF
Mechanistic insights into cluster strengthening and grain refinement toughening in fully oxidized AgMgNi alloys 被引量:1
16
作者 Haicheng Zhu Bingrui Liu +9 位作者 Shaohong Liu Limin Zhou Hao Cui Manmen Liu Li Chen Ming Wen Haigang Dong Feng Liu Song Li Liang Zuo 《Journal of Materials Science & Technology》 2025年第20期252-263,共12页
The pursuit of Ag-based alloys with both high strength and toughness has posed a longstanding chal-lenge.In this study,we investigated the cluster strengthening and grain refinement toughening mecha-nisms in fully oxi... The pursuit of Ag-based alloys with both high strength and toughness has posed a longstanding chal-lenge.In this study,we investigated the cluster strengthening and grain refinement toughening mecha-nisms in fully oxidized AgMgNi alloys,which were internally oxidized at 800℃ for 8 h under an oxy-gen atmosphere.We found that Mg-O clusters contributed to the hardening(138 HV)and strengthening(376.9 MPa)of the AgMg alloy through solid solution strengthening effects,albeit at the expense of duc-tility.To address this limitation,we introduced Ni nanoparticles into the AgMg alloy,resulting in signifi-cant grain refinement within its microstructure.Specifically,the grain size decreased from 67.2μm in the oxidized AgMg alloy to below 6.0μm in the oxidized AgMgNi alloy containing 0.3 wt%Ni.Consequently,the toughness increased significantly,rising from toughness value of 2177.9 MJ m^(-3) in the oxidized AgMg alloy to 6186.1 MJ m^(-3) in the oxidized AgMgNi alloy,representing a remarkable 2.8-fold enhancement.Furthermore,the internally oxidized AgMgNi alloy attained a strength of up to 387.6 MPa,comparable to that of the internally oxidized AgMg alloy,thereby demonstrating the successful realization of concurrent strengthening and toughening.These results collectively offer a novel approach for the design of high-performance alloys through the synergistic combination of cluster strengthening and grain refinement toughening. 展开更多
关键词 Ag-based alloys Mg-O cluster Grain refining Internal oxidation HARDENING
原文传递
Heteronuclear lanthanide titanium-oxygen cluster luminescence thermometer with adjustable operating range and sensitivity 被引量:1
17
作者 Ting-Ting Li Jin-Zhe Liu +8 位作者 Shao-Jiang Zheng Feng Jiang Jin-Yu Liu Wei-Nan Dong Yu Zhang Shao-Ping Zheng Ya-Nan Li Zhen-Nan Wu Xue Bai 《Rare Metals》 2025年第4期2438-2449,共12页
Given customizable crystal structure and intriguing optical properties,lanthanide titanium-oxygen clusters(LTOCs)with atomic-level accuracy have gained a lot of interest.In this study,we prepared[Ln_(9)Ti_(2)(μ4-O)(... Given customizable crystal structure and intriguing optical properties,lanthanide titanium-oxygen clusters(LTOCs)with atomic-level accuracy have gained a lot of interest.In this study,we prepared[Ln_(9)Ti_(2)(μ4-O)(μ3-OH)_(14)(acac)_(17)(CH_(3)O)_(2)(CH_(3)OH)_(3)](Ln=Tb_(x)Eu_(9−x)(x=0,4,6,7,8,9),Hacac=acetylacetone),Tb^(3+)and Eu^(3+)co-doped LTOCs,to modify the optical properties for the luminescence thermometer.In detail,the serial LTOCs display dual characteristic emission peaks of ^(5)D_(4)→^(7)F_(5) for Tb^(3+)and^(5)D_(0)→^(7)F_(2) for Eu^(3+)at 548 and 616 nm,respectively,under 330 nm excitation.Effective energy transfer(ET)between Tb^(3+)ions and Eu^(3+)ions was revealed in terms of both emission spectra and luminescence lifetime.The ^(5)D_(0)→^(7)F_(2) emission intensity of Eu^(3+)ions at 616 nm is maximally enhanced(by a factor of 11.2)with a change in the relative molar ratio of Tb^(3+)to Eu^(3+),along with a change in the ET efficiency of Tb^(3+)→Eu^(3+).In addition,the luminescent color changes from red,orange,yellow,to green.This precise control of the ET process between rare-earth ions allows{Tb_(6)Eu_(3)Ti_(2)}to reach a maximum relative sensitivity of 1.241 K^(−1) at 355 K,which is an enhancement of up to 4.6-fold with respect to the previously reported homonuclear emission,holding great potential in the optical thermometers. 展开更多
关键词 Lanthanide titanium-oxygen clusters Energy transfer Color-changing luminescence Optical thermometer
原文传递
Exploring core symptoms and symptom clusters among patients with neuromyelitis optica spectrum disorder: A network analysis 被引量:1
18
作者 Hao Liang Jiehan Chen +4 位作者 Lixin Wang Zhuyun Liu Haoyou Xu Min Zhao Xiaopei Zhang 《International Journal of Nursing Sciences》 2025年第2期152-160,共9页
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
关键词 Neuromyelitis optica spectrum disorder Network analysis SYMPTOM Symptom clusters NURSING
暂未订购
Technical progress and application of global carbon dioxide capture,utilization and storage cluster 被引量:1
19
作者 WANG Guofeng LYU Weifeng +4 位作者 CUI Kai JI Zemin WANG Heng HE Chang HE Chunyu 《Petroleum Exploration and Development》 2025年第2期536-547,共12页
By systematically reviewing the development status of global carbon dioxide capture,utilization and storage(CCUS)cluster,and comparing domestic and international CCUS industrial models and successful experiences,this ... By systematically reviewing the development status of global carbon dioxide capture,utilization and storage(CCUS)cluster,and comparing domestic and international CCUS industrial models and successful experiences,this study explores the challenges and strategies for the scaled development of the CCUS industry of China.Globally,the CCUS industry has entered a phase of scaled and clustered development.North America has established a system of key technologies in large-scale CO_(2) capture,long-distance pipeline transmission,pipeline network optimization,and large-scale CO_(2) flooding for enhanced oil recovery(CO_(2)-EOR),with relatively mature cluster development and a gradual shift in industrial model from CO_(2)-EOR to geological storage.The CCUS industry of China has developed rapidly across all segments but remains in the early stage of cluster development,facing challenges such as absent business model,insufficient policy support,and technological gaps in core areas.China needs to improve the policy support system to boost enterprises participation across the entire industrial chain,strengthen top-level design and medium-to long-term planning to accelerate demonstration projects construction for whole-process CCUS clusters,advance for a full-chain technological system,including low-cost capture,pipeline optimization and EOR/storage integration technologies,and strengthen personnel training,strengthen discipline construction and university-enterprise research cooperation. 展开更多
关键词 CCUS industrial cluster business model policy guarantee entire industrial chain technology running cost
在线阅读 下载PDF
Boron cluster-based TADF emitter via through-space charge transfer enabling efficient orange-red electroluminescence 被引量:1
20
作者 Xiao Yu Dongyue Cui +8 位作者 Mengmeng Wang Zhaojin Wang Mengzhu Wang Deshuang Tu Vladimir Bregadze Changsheng Lu Qiang Zhao Runfeng Chen Hong Yan 《Chinese Chemical Letters》 2025年第3期232-238,共7页
Thermally activated delayed fluorescence(TADF)materials driven by a through-space charge transfer(TSCT)mechanism have garnered wide interest.However,access of TSCT-TADF molecules with longwavelength emission remains a... Thermally activated delayed fluorescence(TADF)materials driven by a through-space charge transfer(TSCT)mechanism have garnered wide interest.However,access of TSCT-TADF molecules with longwavelength emission remains a formidable challenge.In this study,we introduce a novel V-type DA-D-A’emitter,Trz-mCzCbCz,by using a carborane scaffold.This design strategically incorporates carbazole(Cz)and 2,4,6-triphenyl-1,3,5-triazine(Trz)as donor and acceptor moieties,respectively.Theoretical calculations alongside experimental validations affirm the typical TSCT-TADF characteristics of this luminogen.Owing to the unique structural and electronic attributes of carboranes,Trz-mCzCbCz exhibits an orange-red emission,markedly diverging from the traditional blue-to-green emissions observed in classical Cz and Trz-based TADF molecules.Moreover,bright emission in aggregates was observed for Trz-mCzCbCz with absolute photoluminescence quantum yield(PLQY)of up to 88.8%.As such,we have successfully fabricated five organic light-emitting diodes(OLEDs)by utilizing Trz-mCzCbCz as the emitting layer.It is important to note that both the reverse intersystem crossing process and the TADF properties are profoundly influenced by host materials.The fabricated OLED devices reached a maximum external quantum efficiency(EQE)of 12.7%,with an emission peak at 592 nm.This represents the highest recorded efficiency for TSCT-TADF OLEDs employing carborane derivatives as emitting layers. 展开更多
关键词 Thermally activated delayed fluorescence Through-space charge transfer CARBORANE Boron clusters Organic light-emitting diodes
原文传递
上一页 1 2 250 下一页 到第
使用帮助 返回顶部