期刊文献+
共找到145,356篇文章
< 1 2 250 >
每页显示 20 50 100
Interscale analysis of sediment clusters amid turbulence 被引量:1
1
作者 Wai Hong Ronald Chan Ahmed Elnahhas +3 位作者 Hanul Hwang Lucy J.Brown Andrew J.Banko S.Balachandar 《Acta Mechanica Sinica》 2026年第1期73-80,共8页
Noncohesive particle clusters are identified and tracked in turbulent flows to determine the breakdown and time evolution of cluster statistics and their implications for interscale mass transfer,which has connections... Noncohesive particle clusters are identified and tracked in turbulent flows to determine the breakdown and time evolution of cluster statistics and their implications for interscale mass transfer,which has connections to the classical turbulent energy cascade and its mass cascade counterpart running in parallel.In particular,the formation and dynamics of sediment and larvae clusters are of interest to coral larvae settlement in coastal regions and particularly the resilience of green-gray coastal protection solutions.Analogous cluster behavior is relevant to cloud microphysics and precipitation initiation,radiation transport and light transmission through colloids and suspensions,heat and mass transfer in particle-laden flows,and viral and pollutant transmission.Following a comparison between various clustering techniques,we adopt a density-based cluster identification algorithm based on its simplicity and efficiency,where particles are clustered based on the number of neighboring particles in their individual spheres of influence.We establish parallels with lattice-based percolation theory,as evident in the power-law scaling of the cluster size distribution near the percolation threshold.The degree of discontinuity of the phase transition associated with this percolation threshold is observed to broaden with larger Stokes numbers and thereby large-scale clustering.The sensitivity of our findings to the employed clustering algorithm is discussed.A novel cluster tracking algorithm is deployed to determine the interscale transfer rate along the particle-number phase-space dimension via accounting of cluster breakup and merger events,extending previous work on the bubble breakup cascade beneath surface breaking waves.Our findings shed light on the interaction between particle clusters and their carrier turbulent flows,with an eye toward transport models incorporating cluster characteristics and dynamics. 展开更多
关键词 Particle-laden flows Particle-laden turbulence Sediment transport Computational fluid dynamics Multiphase turbulence Particle clustering Percolation theory
原文传递
The Impact of Depression and Anxiety on Negative Ideation Among Standardized Residency Trainees:The Moderating Role of Individual Resilience Dimensions
2
作者 Jie Zhang Xiaoxu Zhi +3 位作者 Jiahui Chen Paerhati Halisa Lihai Chen Minhao Zhang 《International Journal of Mental Health Promotion》 2026年第2期171-184,共14页
Objectives:Although standardized residency trainees are at high risk for depression,anxiety,and suicidal ideation,the psychological pathways connecting depression and anxiety to suicidal ideation,especially the modera... Objectives:Although standardized residency trainees are at high risk for depression,anxiety,and suicidal ideation,the psychological pathways connecting depression and anxiety to suicidal ideation,especially the moderating role of resilience,remain elusive.This study aimed to examine the associations between depression,anxiety,and suicidal ideation among physicians undergoing standardized residency training,and to investigate the moderating roles of different dimensions of individual resilience,namely tenacity,strength,and optimism.Methods:A convenience sampling method was adopted to recruit 133 resident physicians.Validated instruments assessing individual resilience,depressive symptoms,anxiety levels,and suicidal ideation were administered.Spearman correlation analysis was used to evaluate the relationships among the variables.Hierarchical regression analysis was conducted to assess the moderating roles of tenacity,strength,and optimism in the associations between depression,anxiety,and suicidal ideation.Results:Depressive symptoms and anxiety levels were both positively associated with suicidal ideation(p<0.001).All three resilience dimensions were negatively correlated with suicidal ideation(tenacity:r=−0.504,strength:r=−0.477,optimism:r=−0.440,all p<0.001).Tenacity,strength,and optimism significantly moderated the associations between depression and suicidal ideation(all p<0.05).When resilience levels in these dimensions were high,the associations between depression and suicidal ideation were weaker.Strength and optimism also moderated the associations between anxiety and suicidal ideation(strength:p=0.028,optimism:p=0.028).When the resiliences(strength and optimism)were high,the associations between anxiety and suicidal ideation were weaker.Conclusion:Individual resilience,particularly in the dimensions of tenacity,strength,and optimism,may serve as protective correlates for physicians in training,being associated with weaker relationships between depression,anxiety,and suicidal ideation.These findings highlight the potential value of resilience-enhancing strategies in clinical training settings,although causal inferences cannot be drawn due to the cross-sectional design. 展开更多
关键词 Depression anxiety resident physicians individual resilience
暂未订购
Latent Risk-Protection Profiles of Suicidal Ideation in Chinese Adolescents:A Gender-Specific Analysis of Environmental Vulnerability and Individual Resilience
3
作者 Xiaoyin Li Ruixiang Gao +2 位作者 Jiaxian Luo Yongxing Guo Pinchao Luo 《International Journal of Mental Health Promotion》 2026年第2期48-67,共20页
Background:Exposure to environmental vulnerability poses significant threats to adolescent suicidal ideation,while individual resilience can mitigate these adverse effects with notable gender commonalities and differe... Background:Exposure to environmental vulnerability poses significant threats to adolescent suicidal ideation,while individual resilience can mitigate these adverse effects with notable gender commonalities and differences.However,research examining how these factors co-configure at the individual level remains limited,particularly from a gender-specific perspective.Thus,the present study aims to adopt a person-centered analytic approach to identify gender-specific configurations of environmental vulnerability and individual resilience associated with suicidal ideation among Chinese adolescents.Methods:Data were collected from 2616 Chinese primary and secondary school students(aged 10–17;1223 girls).Participants completed validated scales measuring environmental vulnerability,individual resilience,and suicidal ideation.Latent profile analysis(LPA)was conducted separately by gender.Results:Gender differences were prominent:males exhibited higher resilience and lower suicidal ideation,while females reported higher environmental vulnerability and elevated levels of suicidal ideation.LPA identified three distinct profiles for males:Low Vulnerable–High Protective–Low Risk(LHL),Medium Vulnerable–Low Protective–Low Risk(MLL),and High Vulnerable–Low Protective–High Risk(HLH).Four profiles emerged for females:LHL,MLL,Medium Vulnerable–Low Protective–Medium Risk(MLM),and HLH.Crucially,within the HLH profile,males exhibited particularly deficient humor(η^(2)=0.19)and confidence(η^(2)=0.16),while females formed a distinct subgroup characterized by severe academic and family stressors(η^(2)=0.30–0.36).Conclusion:The study underscores developing gender-specific mental health interventions using a nuanced,person-centered approach that considers both environmental risk and individual resilience factors,which allows for targeted suicide prevention strategies addressing the unique needs of male and female adolescents. 展开更多
关键词 Environmental vulnerability individual resilience suicidal ideation gender difference latent profile analysis
暂未订购
Evolution Characteristics and Driving Mechanism of‘Bottom-up’and‘Top-down’Endogenous Automobile Industry Clusters:A Comparative Study in Taizhou and Wuhu,China
4
作者 JIANG Haining ZHANG Jun +1 位作者 CHEN Jiaqi JIN Xingxing 《Chinese Geographical Science》 2026年第1期34-49,共16页
Bottom-up and top-down endogenous automobile clusters exhibit distinct evolutionary traits and driving mechanisms,yet their comparative analysis remains understudied.Therefore,using Taizhou automobile industry cluster... Bottom-up and top-down endogenous automobile clusters exhibit distinct evolutionary traits and driving mechanisms,yet their comparative analysis remains understudied.Therefore,using Taizhou automobile industry cluster(TAIC)and Wuhu automobile industry cluster(WAIC)as cases,using historical statistical data and field interview data from the 1980s to 2023,combined with qualitative research methods of thematic and diachronic analysis,and quantitative research methods of social network analysis,we compare both endogenous automobile clusters’evolutionary traits and driving mechanisms.The results confirm both clusters undergo multi-scale spatial reconfiguration,organizational complexification,and intelligent networking technological transformation,yet diverge fundamentally:TAIC evolves through market-driven progressive expansion,transitioning from single to dual-core structures via private enterprise networking,with innovation following market-integrated logic and institutional thickness built on demand-driven evolution.Conversely,WAIC follows planned expansion,maintaining state-led hierarchical single-core stability through policy-driven breakthrough innovation and supply-dominated institutional construction-though both ultimately require formal-informal system synergy.Their coevolution is driven by dynamic interactions of path dependence(weakening influence),learning-innovation(strengthening influence),and relationship selection(inverted U-shaped trajectory),with divergent development paths rooted in TAIC’s grassroots self-organization genes versus WAIC’s top-level design genes,amplified by core enterprises’strategic disparities.The research findings can not only provide decision-making support for China’s industrial upgrading,but also contribute China’s insights to global economic governance. 展开更多
关键词 endogenous automobile industrial clusters evolutionary characteristics driving mechanism Taizhou Wuhu China
在线阅读 下载PDF
Growing Together——Villages in Zhejiang form clusters for common development
5
作者 LIU TING 《ChinAfrica》 2026年第2期22-24,共3页
Villager Pan Chunlin is witnessing a boom in his homestay business.More and more visitors are coming to his village,Yucun Village in Anji County,Huzhou City,Zhejiang Province.
关键词 Huzhou city Zhejiang province VILLAGES VISITORS Yucun village clusters common development homestay business
原文传递
The five major textile and apparel industry clusters in Xinjiang have achieved an output value exceeding 220 billion yuan
6
作者 Qiu Shuchen 《China Textile》 2026年第1期34-35,共2页
In the Tianshan region,a complete textile industry chain has been established,covering the entire process from cotton cultivation and chemical fiber production,through spinning,weaving,dyeing,and finishing,and further... In the Tianshan region,a complete textile industry chain has been established,covering the entire process from cotton cultivation and chemical fiber production,through spinning,weaving,dyeing,and finishing,and further extending to apparel,home textiles,and industrial textiles.In November 2025,the first list of five characteristic textile and apparel industry clusters in Xinjiang was officially announced,marking a new stage in the clustering of Xinjiang's textile and apparel industry.Data shows that the total output value of Xinjiang's cotton and textile and apparel industry chain has exceeded 220 billion yuan.With the nation's largest cotton production,a complete industrial chain system,and strong synergistic effects,Xinjiang has become a leading and highly competitive textile industry hub in China. 展开更多
关键词 clustering XINJIANG cotton production apparel industry chemical fiber industrial chain textile industry output value
在线阅读 下载PDF
Multimodal artificial intelligence integrates imaging,endoscopic,and omics data for intelligent decision-making in individualized gastrointestinal tumor treatment
7
作者 Hui Nian Yi-Bin Wu +5 位作者 Yu Bai Zhi-Long Zhang Xiao-Huang Tu Qi-Zhi Liu De-Hua Zhou Qian-Cheng Du 《Artificial Intelligence in Gastroenterology》 2026年第1期1-19,共19页
Gastrointestinal tumors require personalized treatment strategies due to their heterogeneity and complexity.Multimodal artificial intelligence(AI)addresses this challenge by integrating diverse data sources-including ... Gastrointestinal tumors require personalized treatment strategies due to their heterogeneity and complexity.Multimodal artificial intelligence(AI)addresses this challenge by integrating diverse data sources-including computed tomography(CT),magnetic resonance imaging(MRI),endoscopic imaging,and genomic profiles-to enable intelligent decision-making for individualized therapy.This approach leverages AI algorithms to fuse imaging,endoscopic,and omics data,facilitating comprehensive characterization of tumor biology,prediction of treatment response,and optimization of therapeutic strategies.By combining CT and MRI for structural assessment,endoscopic data for real-time visual inspection,and genomic information for molecular profiling,multimodal AI enhances the accuracy of patient stratification and treatment personalization.The clinical implementation of this technology demonstrates potential for improving patient outcomes,advancing precision oncology,and supporting individualized care in gastrointestinal cancers.Ultimately,multimodal AI serves as a transformative tool in oncology,bridging data integration with clinical application to effectively tailor therapies. 展开更多
关键词 Multimodal artificial intelligence Gastrointestinal tumors individualized therapy Intelligent diagnosis Treatment optimization Prognostic prediction Data fusion Deep learning Precision medicine
在线阅读 下载PDF
Selective heterometal doping in isostructural clusters converts phosphorescence to TADF with over 100-fold enhancing
8
作者 Xu-Yang Ding Jin-Yun Wang +3 位作者 Lin-Xi Shi Zhi-Ping Kang Hao Zeng Zhong-Ning Chen 《Science China Chemistry》 2026年第2期716-722,共7页
Precise heterometal doping or substitution of specific metal sites in isostructural metal clusters remains a formidable synthetic challenge,despite its transformative potential for modulating excited-state characteris... Precise heterometal doping or substitution of specific metal sites in isostructural metal clusters remains a formidable synthetic challenge,despite its transformative potential for modulating excited-state characteristics and customizing optical properties.In this work,we achieved the precise synthesis of isostructural alloy clusters R/S-Ag_(3)Cu([Ag_(3)Cu(tppm)(R/S-IPTT)]ClO_(4),R/S-IPTT=R/S-4-isopropylthiazolidine-2-thiolate,tppm=tris(diphenylphosphino)methane)in high yield(89%-91%)through selective doping of a Cu(Ⅰ)atom into chiral homometallic cluster enantiomers R/S-Ag_(4)([Ag_(4)(tppm)(R/S-IPTT)]ClO_(4)).In stark contrast to R/S-Ag_(4)(Φ_(em)<0.5%)that displays weak circularly polarized luminescence(CPL)with phosphorescence characteristic,R/S-Ag_(3)Cu(Φ_(em)≈70%)demonstrates strong CPL properties featured with thermally activated delay fluorescence(TADF)at ambient temperature.The selective substitution of the apical Ag(Ⅰ)atom in Ag_(4)triangular pyramid with a Cu(Ⅰ)atom not only gives rise to beyond 100-fold boosting of photoluminescence quantum yield(PLQY),but also leads to more pronounced optically chiral activity of alloy clusters in excited states in view of the larger photoluminescence dissymmetry factors(g_(PL))of R/S-Ag_(3)Cu(-3.5×10^(-3)/3.4×10^(-3))than that of R/S-Ag_(4)(-2.7×10^(-3)/2.6×10^(-3)).Furthermore,compared with chiral homometallic clusters R/S-Cu_(4)([Cu_(4)(tppm)(R/S-IPTT)]ClO_(4))with the same TADF characteristic at ambient temperature,R/S-Ag_(3)Cu manifests 1.7-fold PLQY and 6-fold g_(PL)due to faster reverse intersystem crossing(RISC)and more effective coupling of electric and magnetic transition moments in alloy clusters.This work not only presents a typical example of selective heterometal doping to modulate excited-state properties of isostructural metal clusters,but also gets deeper insight into the doping chemistry of dissimilar metals at the molecular level. 展开更多
关键词 heterometal doping alloy cluster PHOTOLUMINESCENCE thermally activated delay fluorescence circularly polarized luminescence
原文传递
CeO_(2)-supported bi-layer Pt clusters for anti-Markovnikov alkene hydrosilylation
9
作者 Sunpei Hu Haofan Lei +7 位作者 Junlong Shi Yongjie Ye Fenglin Peng Wenlong Wu Jian Zhang Han Yan Chao Ma Jie Zeng 《Science China Chemistry》 2026年第2期946-952,共7页
Precisely identifying the atomic structure of reducible oxide-supported metal clusters remains challenging yet critical for understanding their catalytic behavior.Herein,we report the preparation of CeO_(2)-supported ... Precisely identifying the atomic structure of reducible oxide-supported metal clusters remains challenging yet critical for understanding their catalytic behavior.Herein,we report the preparation of CeO_(2)-supported bi-layer Pt clusters(Pt_(n)/CeO_(2))via a deposition-reduction strategy,with Pt cluster sizes ranging from 0.8 to 1.2 nm(9–30 atoms).Through combined aberration-corrected high-angle annular dark field scanning transmission electron microscope(HAADF-STEM)imaging,quantitative STEM simulations,and X-ray fine structure(XAFS)analysis,we reveal the bi-layer configuration featuring coordinatively unsaturated Pt^(0) sites on the top layer while maintaining Pt-CeO_(2)interfacial bonding at the bottom.When applied to anti-Markovnikov alkene hydrosilylation,Pt_(n)/CeO_(2)achieves 99.9%silane conversion with a mass-specific activity 2.0×and 8.8×higher than single-atom site(Pt_(1)/CeO_(2))and nanoparticle(Pt_(NP)/CeO_(2))counterparts,respectively.The bi-layer structure endows exceptional cycling stability and anti-leaching properties.This work establishes a multi-scale characterization paradigm to resolve atomic-precision structures of supported clusters,opening avenues for designing robust catalysts with tailored metal-oxide interfaces. 展开更多
关键词 Pt/CeO_(2)catalyst bi-layer Pt clusters metal-support interaction size effect alkene hydrosilylation
原文传递
Comprehensive influence of individualized nutrition support and nursing strategy on rehabilitation of patients with liver cancer after operation 被引量:2
10
作者 Xue-Li Zhang Hai-Yan Ma 《World Journal of Gastrointestinal Surgery》 2025年第2期136-144,共9页
BACKGROUND Hepatocellular carcinoma ranks among the most prevalent malignant neoplasms.Surgical intervention constitutes a critical therapeutic approach for this condition.Nonetheless,postoperative recovery is frequen... BACKGROUND Hepatocellular carcinoma ranks among the most prevalent malignant neoplasms.Surgical intervention constitutes a critical therapeutic approach for this condition.Nonetheless,postoperative recovery is frequently influenced by the patient's nutritional status and the quality of nursing care provided.AIM To examine the comprehensive impact of personalized nutritional support and nursing strategies on the postoperative rehabilitation of patients with liver cancer.METHODS In this study,a retrospective comparative analysis was conducted involving 60 post-operative liver cancer patients.The subjects were selected as subjects and divided into two groups based on differing nursing interventions,with each group comprising 30 patients.The control group received standard nutritional support and care,whereas the experimental group received individualized nutritional support and nursing strategies.The study aimed to evaluate the impact of individualized nutrition by comparing the rehabilitation indices,nutritional status,quality of life(QoL),and complication rates between the two groups.RESULTS The results showed that the recovery index of the experimental group was significantly better than that of the control group 2 weeks after surgery,and the average liver function recovery index of the experimental group was 85.significantly higher than that of the control group(73.67±7.19).In terms of nutritional status,the serum albumin level and body weight stabilization rate of the experimental group were also significantly higher than those of the control group,which were 42.33±2.4 g/L and 93.3%,respectively,compared with 36.01±3.85 g/L and 76.7%of the control group.In addition,the average QoL score of the experimental group was 84.66±3.7 points,which was significantly higher than that of the control group(70.92±4.28 points).At the psychological level,the average anxiety score of the experimental group was 1.17±0.29,and the average depression score was 1.47±0.4,which were significantly lower than the 2.26±0.42 and 2.57±0.45 of the control group.This showed that patients in the experimental group were better relieved of anxiety and depression under the individualized nutrition support and nursing strategy.More importantly,the complication rate in the experimental group was only 10%,much lower than the 33.3%in the control group.CONCLUSION Personalized nutritional support and tailored nursing strategies significantly enhance the postoperative rehabilitation of liver cancer patients.Consequently,it is recommended to implement and advocate for these individualized approaches to improve both the recovery outcomes and QoL for these patients. 展开更多
关键词 Liver cancer After surgery individualized nutritional support Nursing strategy Rehabilitation effect
暂未订购
Exploring core symptoms and symptom clusters among patients with neuromyelitis optica spectrum disorder: A network analysis 被引量:1
11
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
A porous⁃layered aluminoborate built by mixed oxoboron clusters and AlO_(4)tetrahedra
12
作者 CHEN Juan YANG Guoyu 《无机化学学报》 北大核心 2025年第1期193-200,共8页
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
关键词 hydrothermal synthesis aluminoborate mixed oxoboron cluster porous layer
在线阅读 下载PDF
Ultrafine platinum clusters achieved by metal‑organic framework derived cobalt nanoparticle/porous carbon:Remarkable catalytic performance in dehydrogenation of ammonia borane
13
作者 XIE Xinnan ZHANG Boyu +4 位作者 YANG Jianxun ZHONG Yi Osama Younis YANG Jianxiao YANG Xinchun 《无机化学学报》 北大核心 2025年第10期2095-2102,共8页
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
关键词 ammonia borane hydrogen generation Pt cluster porous carbon metal-organic framework
在线阅读 下载PDF
Evaporation-Processed X-Ray Imaging Scintillation Screen Based on Copper Clusters
14
作者 Xie Gaozhan Chen Cheng +9 位作者 Zhang Jingru Xiao Dongjie Cai Minyue Gao Qiya Gao Zhisheng Sun Chengxi Li Hui Li Huanhuan Chen Runfeng Tao Ye 《有机化学》 北大核心 2025年第11期4219-4226,共8页
Organic-inorganic hybrid clusters with strong X-ray radioluminescence have exhibited great potential in scintillator field.However,fabricating the X-ray imaging screens of the clusters without sacrificing the scintill... Organic-inorganic hybrid clusters with strong X-ray radioluminescence have exhibited great potential in scintillator field.However,fabricating the X-ray imaging screens of the clusters without sacrificing the scintillation performance is challenging.Herein,we report an effective way to prepare high-quality scintillation films of two synthesized Cu(Ⅰ)clusters through vacuum evaporation deposition.The developed Cu(Ⅰ)clusters with rigid molecular structures show excellent scintillation performance with a high light yield of up to 19356.7 photons/MeV and a low detection limit of 158 nGy/s.The scintillation film based on the Cu(Ⅰ)clusters made by vacuum evaporation deposition is highly uniform with a small surface roughness value of 1.04 nm,which can be applied to X-ray imaging for various objects.These results not only provide important guidance to develop high-performance organic-inorganic hybrid scintillators,but also pave a straightforward way to prepare non-doped scintillation screens for remarkable X-ray imaging applications. 展开更多
关键词 scintillator RADIOLUMINESCENCE Cu(Ⅰ)clusters vacuum evaporation deposition X-ray imaging
原文传递
Research on the Principle Comparison and Comprehensive Application of High-Availability Clusters and Load-Balancing Clusters
15
作者 Yue Yang 《Journal of Electronic Research and Application》 2025年第6期294-301,共8页
In modern distributed systems and cloud computing architectures,high availability and high scalability are core requirements to ensure the continuous and stable operation of services.As key technologies for achieving ... In modern distributed systems and cloud computing architectures,high availability and high scalability are core requirements to ensure the continuous and stable operation of services.As key technologies for achieving these two goals,high-availability clusters and load-balancing clusters have significant differences in their design concepts and application scenarios,while also maintaining close connections.This paper aims to conduct an in-depth analysis of the core objectives,working principles,technical advantages and disadvantages,and typical application cases of high-availability clusters and load-balancing clusters.By introducing an analogical model of a“restaurant kitchen,”the differences between the two are intuitively explained,and their technical characteristics are compared in detail.Additionally,a detailed practical case is included to specifically demonstrate the collaborative work of high-availability and load-balancing technologies through the construction process of Keepalived and HAProxy.Finally,taking the architecture of a typical e-commerce website as an example,this paper demonstrates the best practice of organically combining the two cluster technologies in a production environment to build a robust and high-performance distributed system.Research shows that understanding the differences between the two and implementing collaborative deployment is the cornerstone of designing modern IT infrastructure. 展开更多
关键词 High-availability cluster Load-balancing cluster Failover Distributed system Architecture design Performance optimization
在线阅读 下载PDF
Extracting fuzzy clusters from massive attributed graphs using Markov lumpability optimization
16
作者 Kai-Yue Jiang Li-Heng Xu +3 位作者 Shi-Pei Lin Li-Yang Zhou Hui-Jia Li Ge Gao 《Chinese Physics B》 2025年第10期609-617,共9页
Attributed graph clustering plays a vital role in uncovering hidden network structures,but it presents significant challenges.In recent years,various models have been proposed to identify meaningful clusters by integr... Attributed graph clustering plays a vital role in uncovering hidden network structures,but it presents significant challenges.In recent years,various models have been proposed to identify meaningful clusters by integrating both structural and attribute-based information.However,these models often emphasize node proximities without adequately balancing the efficiency of clustering based on both structural and attribute data.Furthermore,they tend to neglect the critical fuzzy information inherent in attributed graph clusters.To address these issues,we introduce a new framework,Markov lumpability optimization,for efficient clustering of large-scale attributed graphs.Specifically,we define a lumped Markov chain on an attribute-augmented graph and introduce a new metric,Markov lumpability,to quantify the differences between the original and lumped Markov transition probability matrices.To minimize this measure,we propose a conjugate gradient projectionbased approach that ensures the partitioning closely aligns with the intrinsic structure of fuzzy clusters through conditional optimization.Extensive experiments on both synthetic and real-world datasets demonstrate the superior performance of the proposed framework compared to existing clustering algorithms.This framework has many potential applications,including dynamic community analysis of social networks,user profiling in recommendation systems,functional module identification in biological molecular networks,and financial risk control,offering a new paradigm for mining complex patterns in high-dimensional attributed graph data. 展开更多
关键词 attributed clustering Markov chain lumped random walk fuzzy clusters OPTIMIZATION
原文传递
Chiral europium-organotin oxo-clusters with dual-emission circularly polarized luminescence
17
作者 Gui-Xin Yan Er-Xia Chen +2 位作者 Jin-Xia Yang Jian Zhang Qipu Lin 《Chinese Journal of Structural Chemistry》 2025年第12期90-94,共5页
Chiral metal-organic clusters(MOCs)integrating lanthanide ions(Ln^(3+))and organic luminophores present a promising platform for modulating circularly polarized luminescence(CPL).However,achieving dual-wavelength CPL ... Chiral metal-organic clusters(MOCs)integrating lanthanide ions(Ln^(3+))and organic luminophores present a promising platform for modulating circularly polarized luminescence(CPL).However,achieving dual-wavelength CPL in discrete cluster systems constitutes a considerable challenge.Herein,two enantiomeric pairs of heterometallic EuSn oxo clusters,designated as Sn_(2)EuL_(2)-R/S and Sn_(2)EuL_(4)-R/S,were strategically synthesized using axially chiral binaphthol-phosphonate ligands.These hybrid clusters exhibit dual emission,characterized by a broad ligand-derived fluorescence band superimposed with sharp,characteristic Eu^(3+)f-f transitions,which enables excitation-dependent luminescence color tuning.Their emission profiles and quantum yields are found to be exquisitely adjusted by the distinct coordination environments of Sn^(4+)centers.Notably,Sn_(2)EuL_(2)-R/S demonstrates CPL activity in both near-UV(|g_(lum)|=1.7×10^(-3))and visible(|g_(lum)|=3.1×10^(-2))regions.This work not only reports the first instance of dual-wavelength CPL in a lanthanide/tin oxo complex but also establishes a robust design strategy for fabricating color-tunable chiral photonic materials. 展开更多
关键词 Heterometallic oxo clusters Organotin clusters Chirality Circularly polarized luminescence Dual emission
原文传递
Tracking toads from dusk till dawn:linking inter-and intra-individual variation in movement behavior
18
作者 Nathalie Jreidini David M.Green 《Current Zoology》 2025年第3期320-328,共9页
Animals can differ in their individual movement behaviors during their daily displacements.Studies of animal movement patterns often disregard the need to understand individual variation in these patterns and the role... Animals can differ in their individual movement behaviors during their daily displacements.Studies of animal movement patterns often disregard the need to understand individual variation in these patterns and the role of this variation in shaping population distributions of movements.To assess the link between individual movements and population distributions,we radio-tracked 13 Fowler's Toads Anaxyrus fowleri in Long Point,Ontario,Canada,after their breeding season.We recorded individual coordinates every 30 min,from the moment they emerged from their burrows around dusk until they burrowed in the morning,and obtained a total of 157 movements.We used the resulting series of step lengths and turning angles in a Hidden Markov Model to estimate movement type as"directed"or"non-directed"We also assigned to each encounter one of 3 space-dependent movement states:"foraging""in transit'or"searching"and found that movement type and state switched within individuals irrespective of time during a single night.We find that switching between movement types varied throughout the night,leading to stochastic within-individual variation in movements,and the distribution of movement distances differed significantly among individuals.Movement states,however,were time-dependent,suggesting displacement routines were similar across individuals.Variation in movement behavior within individuals scales up to result in variation among individuals which,in turn,was found to shape the distribution of the sampled population.Our findings therefore underline the importance of a multi-scale approach in the study of movement. 展开更多
关键词 AMPHIBIAN individualITY RADIO-TRACKING step length turning angle.
原文传递
Generalized Energy-Based Fragmentation DLPNO-CCSD(T)Approach at Complete Basis Set Limit and Its Application to Benzene Clusters
19
作者 Yan Sun Benkun Hong +1 位作者 Wei Li Shuhua Li 《Chinese Journal of Chemical Physics》 2025年第3期347-355,I0061-I0105,I0109,共55页
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
关键词 Generalized energy-based fragmentation approach Coupled cluster Complete basis set limit Benzene cluster Dispersion interactions
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部