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Plate tectonics in the Archean:Observations versus interpretations

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Science China Earth Sciences 2024年第1期67卷 1-30页

作者： YongFei ZHENG School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China Key Laboratory of Crust-Mantle Materials and Environment Chinese Academy of SciencesHefei 230026China Center of Excellence for Comparative Planetology Chinese Academy of SciencesHefei 230026China

Plate tectonics theory,established in the 1960s,has been successful in explaining many geological phenomena,processes and events that occurred in the ***,the theory has often struggled to provide a coherent framework in interpreting geological records in continental interior and Precambrian *** dealing with the relationship between plate tectonics and continental geology,continental interior tectonics was often separated from continental margin tectonics in the inheritance and development of their structure and *** separation led to the illusion that the plate tectonics theory is not applicable to Precambrian geology,particularly in explaining the fundamental geological characteristics of Archean *** this illusion does not mean that the Archean continental crust did not originate from a regime of plate tectonics,it led to the development of alternative tectonic models,often involving vertical movements under a regime of stagnant lid tectonics,including not only endogenous processes such as gravitational sagduction,mantle plumes and heat pipes but also exogenous processes such as bolide *** vertical processes were not unique to the Archean but persisted into the *** result from mantle poloidal convection at different depths,not specific to any particular *** the plate tectonics theory from the traditional kinematic model in the 20th century to a holistic kinematic-dynamic model in the 21st century and systematically examining the vertical transport of matter and energy at plate margins,it is evident that plate tectonics can explain the common geological characteristics of Archean cratons,such as lithological associations,structural patterns and metamorphic *** deciphering the structure and composition of convergent plate margins as well as their dynamics,the formation and evolution of continental crust since the Archean can be divided into ancient plate tectonics in the Preca

关键词： Plate tectonics Archean geology Continental origin Crustal reworking Plate interior Plate margin

Online Nonstop Task Management for Storm-Based Distributed Stream Processing Engines

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Journal of Computer Science & Technology 2024年第1期39卷 116-138页

作者：张洲金培权谢希科王晓亮刘睿诚万寿红 School of Computer Science and Technology University of Science and Technology of ChinaHefei 230026China Key Laboratory of Electromagnetic Space Information Chinese Academy of SciencesHefei 230026China

Most distributed stream processing engines(DSPEs)do not support online task management and cannot adapt to time-varying data ***,some studies have proposed online task deployment algorithms to solve this ***,these approaches do not guarantee the Quality of Service(QoS)when the task deployment changes at runtime,because the task migrations caused by the change of task deployments will impose an exorbitant *** study one of the most popular DSPEs,Apache Storm,and find out that when a task needs to be migrated,Storm has to stop the resource(implemented as a process of Worker in Storm)where the task is *** will lead to the stop and restart of all tasks in the resource,resulting in the poor performance of task *** to solve this problem,in this pa-per,we propose N-Storm(Nonstop Storm),which is a task-resource decoupling DSPE.N-Storm allows tasks allocated to resources to be changed at runtime,which is implemented by a thread-level scheme for task ***,we add a local shared key/value store on each node to make resources aware of the changes in the allocation ***,each resource can manage its tasks at *** on N-Storm,we further propose Online Task Deployment(OTD).Differ-ing from traditional task deployment algorithms that deploy all tasks at once without considering the cost of task migra-tions caused by a task re-deployment,OTD can gradually adjust the current task deployment to an optimized one based on the communication cost and the runtime states of *** demonstrate that OTD can adapt to different kinds of applications including computation-and communication-intensive *** experimental results on a real DSPE cluster show that N-Storm can avoid the system stop and save up to 87%of the performance degradation time,compared with Apache Storm and other state-of-the-art *** addition,OTD can increase the average CPU usage by 51%for computation-intensive application

关键词： distributed stream processing engine(DSPE) Apache Storm online task migration online task deployment

Efficient synthesis of bottle-brush polymers enabled by selective photoactivation strategy in NIR-induced PET-RAFT polymerization

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Science China Chemistry 2024年第7期67卷 2353-2361页

作者： Hao Zha Lin Cheng Zuowei Wang Chao Liu Chunyan Hong Department of Polymer Science and Engineering University of Science and Technology of ChinaHefei 230026China hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China

Bottle-brush polymers possessing densely grafted side chains have special properties that are distinct from linear ***,an efficient method for preparing bottle-brush polymers based on a selective photoactivation strategy in the photoinduced electron/energy transfer reversible addition-fragmentation chain transfer(PET-RAFT)polymerization was developed.A methacrylate monomer 2-(2-(dodecylthiocarbonothioylthio)propionate)ethyl methacrylate(DTPEMA)containing a 2-(dodecylthiocarbonothioylthio)propionate(DTP)unit with a secondary R group was *** the unique selectivity of metal naphthalocyanine photocatalyst zinc 2,11,20,29-tetra-tert-butyl-2,3-naphthalocyanine(ZnTtBNc)toward trithiocarbonate with tertiary R group,the PET-RAFT polymerization of DTPEMA catalyzed by ZnTtBNc was performed under near infrared(NIR)light(λ_(max)=760 nm)irradiation at room temperature,using 4-cyano-4-[(dodecylsulfanylthiocarbonyl)-sulfanyl]pentanoic acid(CDTPA)with a tertiary R group as a chain transfer agent(CTA).Proton nuclear magnetic resonance(1H NMR)and gel permeation chromatography(GPC)results demonstrated that the DTP units in the side chains were inert during the *** grafting poly(methyl acrylate)(PMA)from PDTPEMA via thermal-initiated RAFT polymerization,welldefined P(DTPEMA-g-PMA)bottle-brush polymers could be ***,the film prepared from the bottle-brush polymer exhibited excellent scratch self-healing property due to the interlocking of side chains.

关键词： bottle-brush polymers PET-RAFT polymerization selective photoactivation scratch self-healing

Two-dimensional semiconductor heterostructures for photocatalytic CO_(2)conversion

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Science China Chemistry 2024年第8期67卷 2434-2447页

作者： Yang Wu Mingyu Wu Yongfu Sun Yi Xie hefei National Research Center for Physical Sciences at Microscale University of Science and Technology of ChinaHefei 230026China

The CO_(2)reduction into carbon-contained fuel via solar energy offers the powerful tools to realize the zero-emission carbon *** to the intriguing features of the two-dimensional(2D)heterostructures,it is susceptible to modulate the electronic structure as well as the surface geometry for optimizing the photocatalytic CO_(2)*** this perspective,we surveyed the fundamental insights of 2D semiconductor heterostructures,involving the fabrication strategies and classification of the 2D semiconductor ***,we have detailly discussed the overview of 2D semiconductor heterostructure for optimizing CO_(2)photocatalytic influenced factors,including the solar energy utilization,photogenerated carriers separation,and redox reaction ***,we showed the significant advantages of 2D heterostructures in elevating CO_(2)photoreduction performance,focusing on activity,selectivity and *** analyzing the limitations and developments,we ended by putting forward insights into the further researches about the CO_(2)photocatalysts and reactor design,even industrial applications.

关键词： two-dimensional semiconductor heterostructures photocatalysis CO_(2)conversion

Preparing cyclic polymers at high concentrations via self-folding cyclization technique by adjusting the contents of hydrophilic units in linear precursors

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Chinese Chemical Letters 2024年第2期35卷 283-288页

作者： Hao Zha Zuowei Wang Chao Liu Chunyan Hong Department of Polymer Science and Engineering University of Science and Technology of ChinaHefei 230026China hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China

Cyclic polymers are a class of polymers that feature endless topology,and the synthesis of cyclic polymers has attracted the attention of many ***,cyclic polymers were efficiently constructed by self-folding cyclization technique at high *** poly((oligo(ethylene glycol)acrylate)-co-(dodecyl acrylate))(P(OEGA-co-DDA))precursors with different ratios of hydrophilic and hydrophobic moieties were synthesized by reversible addition-fragmentation chain transfer(RAFT)polymerization using a bifunctional chain transfer agent with two anthryl end *** amphiphilic linear precursors underwent the self-folding process to generate polymeric nanoparticles in *** irradiating the aqueous solution of the nanoparticles with 365 nm UV light,cyclic polymers were synthesized successfully via coupling of anthryl *** effects of the ratios of hydrophilic and hydrophobic moieties in linear P(OEGA-co-DDA)copolymers and polymer concentration on the purity of the obtained cyclic polymers were explored in detail via ^(1)H nuclear magnetic resonance(^(1)H NMR),dynamic light scattering(DLS),UV‒visible(vis)analysis,three-detection size exclusion chromatography(TD-SEC)and transmission electron microscopy(TEM).It was found that by adjusting the content of the hydrophilic segments in linear precursors,single chain polymeric nanoparticles(SCPNs)can be generated at high polymer ***,cyclic polymers with high purity can be constructed *** method overcomes the limitation of traditional ring-closure method,which is typically conducted in highly dilute conditions,providing an efficient method for the scalable preparation of cyclic polymers.

关键词： Cyclic polymers Self-folding cyclization technique Single chain polymeric nanoparticles RAFT polymerization Direct visualization

Room-temperature ferrimagnetism and size-modulated electronic structures in two-dimensional cluster-based metal-organic frameworks

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Science China Chemistry 2024年第4期67卷 1334-1340页

作者： Jing Cheng Xingxing Li Jinlong Yang Key Laboratory of Precision and Intelligent Chemistry University of Science and Technology of ChinaHefei 230026China Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

Cluster-assembled materials have attracted particular attention for their complex hierarchical structures and unique ***,the majority of cluster-based assemblies developed so far are either non-magnetic or only exhibit magnetic ordering with a relatively low Curie temperature,limiting their applications in ***,two-dimensional(2D)cluster-assembled materials with room-temperature magnetism remain highly *** this purpose,based on first principles calculations,we design a series of thermodynamically stable 2D cluster-based metal-organic frameworks(MOFs)Fe_(n)-(pyz)(n=1-6)by utilizing Fenmetal clusters as nodes and nitrogen-containing pyrazine ligands as organic *** 2D cluster-based MOFs exhibit robust ferrimagnetic ordering due to the strong d-p direct exchange interaction between d-electron spin of Fe_(n)(n=1-6)clusters and charge transfer-induced p-electron spin of pyrazine *** particular,the ferrimagnetic Curie temperatures are well above room temperature(up to 836 K).Additionally,altering the size of Fe_(n)clusters in Fe_(n)-(pyz)(n=1-6)MOFs results in diverse functional spintronic properties,including bipolar magnetic semiconductors,half semiconductors and Dirac half ***,these 2D assembled MOFs possess sizable magnetic anisotropy energies,up to 9.16 me V per formula.

关键词： metal-organic framework two-dimensional material half metal bipolar magnetic semiconductor magnet

An improved analysis method for assessing the nuclear-heating impact on the stability of toroidal field magnets in fusion reactors

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Nuclear Science and Techniques 2024年第6期35卷 163-176页

作者： Yu-Dong Lu Jin-Xing Zheng Xu-Feng Liu Huan Wu Jian Ge Kun Xu Ming Li Hai-Yang Liu Lei Zhu Fei Liu Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China

The superconducting magnet system of a fusion reactor plays a vital role in plasma confinement,a process that can be dis-rupted by various operational factors.A critical parameter for evaluating the temperature margin of superconducting magnets during normal operation is the nuclear heating caused by D-T *** study investigates the impact of nuclear heat-ing on a superconducting magnet system by employing an improved analysis method that combines neutronics and thermal *** the magnet system,toroidal field(TF)magnets are positioned closest to the plasma and bear the highest nuclear-heat load,making them prime candidates for evaluating the influence of nuclear heating on *** enhance the modeling accuracy and facilitate design modifications,a parametric TF model that incorporates heterogeneity is established to expedite the optimization design process and enhance the accuracy of the computations.A comparative analysis with a homogeneous TF model reveals that the heterogeneous model improves accuracy by over 12%.Considering factors such as heat load,magnetic-field strength,and cooling conditions,the cooling circuit facing the most severe conditions is selected to calculate the temperature of the *** selection streamlines the workload associated with thermal-hydraulic *** approach enables a more efficient and precise evaluation of the temperature margin of TF ***,it offers insights that can guide the optimization of both the structure and cooling strategy of superconducting magnet systems.

关键词： Superconducting magnet Nuclear heating Neutronics Thermal hydraulics

Synthesis of hierarchically porous carbon materials by zinc salts-assisted carbonization of biomass and organic solid wastes

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Particuology 2024年第1期84卷 45-52页

作者： Le-Le Zhang Lei Tong Yanwei Ding Wanqun Zhang Hai-Wei Liang hefei National Research Center for Physical Sciences at the Microscale Department of ChemistryUniversity of Science and Technology of ChinaHefei230026China

Hierarchically porous carbons(HPCs)with multimodal pores have attracted considerable attention due to their unique physical and chemical properties and various application potentials in heterogeneous catalysis,environmental treatment,and energy storage and ***,we report a general and simple zinc salts-assisted method for the synthesis of HPCs with varied porosity and chemical func-tionalities by the direct carbonization of diverse biomass and *** the carbonization,zinc salts are thermally decomposed into nanoparticles that serve as in-situ templates to introduce nanopores in *** prepared HPCs exhibit high specific surface areas(up to 2432 m2 g-1),large pore volumes(up to 4.30 cm^(3)g^(-1)),and broad pore size ***,the zinc salts can be recovered and recycled,supporting the sustainable production of HPCs on large *** prepared HPCs-supported catalysts with atomically dispersed metal sites exhibit promising electrocatalytic performance for the oxygen reduction reaction.

关键词： Hierarchical porous carbon Zinc salts Biomass Wastes Electrocatalysis

A Multi-Constraint Path Optimization Scheme Based on Information Fusion in Software Defined Network

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Computers, Materials & Continua 2024年第4期79卷 1399-1418页

作者： Jinlin Xu Wansu Pan Longle Cheng Haibo Tan Munan Yuan Xiaofeng Li hefei Institutes of Physical Science Chinese Academy of SciencesHefei230031China University of Science and Technology of China Hefei230026China

The existingmultipath routing in Software Defined Network (SDN) is relatively blind and inefficient, and there is alack of cooperation between the terminal and network sides, making it difficult to achieve dynamic adaptationof service requirements and network resources. To address these issues, we propose a multi-constraint pathoptimization scheme based on information fusion in SDN. The proposed scheme collects network topology andnetwork state information on the network side and computes disjoint paths between end hosts. It uses the FuzzyAnalytic Hierarchy Process (FAHP) to calculate the weight coefficients of multiple constrained parameters andconstructs a composite quality evaluation function for the paths to determine the priority of the disjoint paths. TheSDN controller extracts the service attributes by analyzing the packet header and selects the optimal path for flowrule forwarding. Furthermore, the service attributes are fed back to the path composite quality evaluation function,and the path priority is dynamically adjusted to achieve dynamic adaptation between service requirements andnetwork status. By continuously monitoring and analyzing the service attributes, the scheme can ensure optimalrouting decisions in response to varying network conditions and evolving service demands. The experimentalresults demonstrated that the proposed scheme can effectively improve average throughput and link utilizationwhile meeting the Quality of Service (QoS) requirements of various applications.

关键词： SDN multi-constraint path information fusion FAHP