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Anomalous Hall effect and electronic correlation in a spin-reoriented kagome antiferromagnet LuFe_(6)Sn_(6)

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chinese Physics B 2024年第10期33卷 46-51页

作者： Meng Lyu Yang Liu Shen Zhang Junyan Liu Jinying Yang Yibo Wang Yiting Feng Xuebin Dong Binbin Wang Hongxiang Wei Enke Liu Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China University of chinese academy of sciences Beijing 100049China Ningbo Institute of Materials Technology&Engineering Chinese Academy of SciencesNingbo 315201China

The kagome lattice system has been identified as a fertile ground for the emergence of a number of new quantumstates,including superconductivity,quantum spin liquids,and topological electronic *** has attracted significantinterest within the field of condensed matter ***,we present the observation of an anomalous Hall effect in aniron-based kagome antiferromagnet LuFe_(6)Sn_(6),which implies a non-zero Berry curvature in this *** means ofextensive magnetic measurements,a high Neel temperature,T_(N)=552 K,and a spin reorientation behavior were identifiedand a simple temperature-field phase diagram was ***,this compound was found to exhibit a largeSommerfeld coefficient ofγ=87 mJ·mol^(-1)·K^(-2),suggesting the presence of a strong electronic correlation *** indicates that LuFe_(6)Sn_(6)is an intriguing compound that may exhibit magnetism,strong correlation,and topologicalstates.

关键词： kagome lattice anomalous Hall effect magnetism electronic correlation

Non-B-form DNA is associated with centromere stability in newly-formed polyploid wheat

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Science China(Life sciences) 2024年第7期67卷 1479-1488页

作者： Congyang Yi Qian Liu Yuhong Huang Chang Liu Xianrui Guo Chaolan Fan Kaibiao Zhang Yang Liu Fangpu Han Institute of Genetics and Developmental Biology Chinese Academy of SciencesBeijing 100101China University of chinese academy of sciences Beijing 100049China

Non-B-form DNA differs from the classic B-DNA double helix structure and plays a crucial regulatory role in replication and ***,the role of non-B-form DNA in centromeres,especially in polyploid wheat,remains ***,we systematically analyzed seven non-B-form DNA motif profiles(A-phased DNA repeat,direct repeat,G-quadruplex,inverted repeat,mirror repeat,short tandem repeat,and Z-DNA)in hexaploid *** found that three of these non-B-form DNA motifs were enriched at centromeric regions,especially at the CENH3-binding sites,suggesting that non-B-form DNA may create a favorable loading environment for the CENH3 *** investigate the dynamics of centromeric non-B form DNA during the alloploidization process,we analyzed DNA secondary structure using CENH3 ChIP-seq data from newly formed allotetraploid wheat and its two diploid *** found that newly formed allotetraploid wheat formed more non-B-form DNA in centromeric regions compared with their parents,suggesting that non-B-form DNA is related to the localization of the centromeric regions in newly formed ***,non-B-form DNA enriched in the centromeric regions was found to preferentially form on young LTR retrotransposons,explaining CENH3's tendency to bind to younger ***,our study describes the landscape of non-B-form DNA in the wheat genome,and sheds light on its potential role in the evolution of polyploid centromeres.

关键词： non-B-form DNA polyploid wheat centromere retrotransposon

Decoupling of Rattling Mode and Superconductivity in Filled-Skutterudite Ba_(x)Ir_(4)Sb_(12)

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chinese Physics Letters 2024年第7期41卷 132-139页

作者：刘辉于同旭张志华应天平 School of Materials Science and Engineering Dalian Jiaotong UniversityDalian 116028China Institute of Physics Chinese Academy of SciencesBeijing 100190China University of chinese academy of sciences Chinese Academy of SciencesBeijing 100190China Suzhou Laboratory Suzhou 215123China

The rattling mode,an anharmonic vibrational phonon,is widely recognized as a critical factor in the emergence of superconductivity in caged ***,we present a counterexample in a filled-skutterudite superconductor Ba_(x)Ir_(4)Sb_(12)(x=0.8,0.9,1.0),synthesized via a high-pressure *** measurements down to liquid 3He temperatures reveal a transition temperature(T_(c))of 1.2 K and an upper critical field(H_(c2))of 1.3 *** other superconductors with caged structures,the Ba_(x)Ir_(4)Sb_(12)(X=P,As,Sb)family exhibits a monotonic decreasing T_(c) with the enhancement of the rattling mode,as indicated by fitting the Bloch–Grüneisen *** analysis suggests that electron doping from Ba transforms the direct bandgap IrSb3 into a metal,with the Fermi surface dominated by the hybridization of Ir 5d and Sb 5p *** findings of decoupled rattling modes and superconductivity distinguish the Ba_(x)Ir_(4)Sb_(12) family from other caged superconductors,warranting further exploration into the underlying mechanism.

关键词： mechanism materials superconductivity

Engineering FeOOH/Ni(OH)_(2) heterostructures on Ni_(3)S_(2)surface to enhance seawater splitting

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Rare Metals 2024年第5期43卷 1989-1998页

作者： Chen Yang Ya-Dong Li Li-Juan Cao Xi-Long Wang Han-Pu Liang Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of SciencesQingdao 266101China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Sino-Danish College University of Chinese Academy of SciencesBeijing 100049China

The construction of highly stable and efficient electrocatalysts is desirable for seawater splitting but remains challenging due to the high concentration of Cl-in ***,FeOOH/Ni(OH)_(2)heterostructure supported on Ni_(3)S_(2)-covered nickel foam(Fe–Ni/Ni_(3)S_(2)/NF)was fabricated by hydrothermal and etching methods,as well as anodic oxidation *** electronic structure of FeOOH and Ni(OH)_(2)could be modulated after depositing FeOOH nanoparticles on Ni(OH)_(2)nanosheet,which greatly boosted the catalytic *** the catalyst used as an electrode for oxygen evolution reaction(OER),it needed low overpotentials of 266 and 368 m V to achieve current densities of 100 and 800 m A·cm^(-2),respectively,in 1 mol·L^(-1)KOH+seawater *** can operate continuously at 100 m A·cm^(-2)for 400 h without obvious ***,in situ generated SO_(4)^(2-)from inner Ni_(3)S_(2)during electrolysis process would accumulate on the surface of active sites to form passivation layers to repel Cl^(-),which seemed to be responsible for superior *** study not only synthesizes an OER catalyst for highly selective and stable seawater splitting,but also gives a novel approach for industrial hydrogen production.

关键词： Anodic oxidation Heterostructure Oxygen evolution reaction Seawater splitting

Learning Top-K Subtask Planning Tree Based on Discriminative Representation Pretraining for Decision-making

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Machine Intelligence Research 2024年第4期21卷 782-800页

作者： Jingqing Ruan Kaishen Wang Qingyang Zhang Dengpeng Xing Bo Xu Institute of Automation Chinese Academy of SciencesBeijing 100190China School of Future Technology University of Chinese Academy of SciencesBeijing 100049China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China

Decomposing complex real-world tasks into simpler subtasks and devising a subtask execution plan is critical for humans to achieve effective ***,replicating this process remains challenging for AI agents and naturally raises two questions:(1)How to extract discriminative knowledge representation from priors?(2)How to develop a rational plan to decompose complex problems?To address these issues,we introduce a groundbreaking framework that incorporates two main ***,our multiple-encoder and individual-predictor regime goes beyond traditional architectures to extract nuanced task-specific dynamics from datasets,enriching the feature space for ***,we innovate in planning by introducing a top-K subtask planning tree generated through an attention mechanism,which allows for dynamic adaptability and forward-looking *** framework is empirically validated against challenging benchmarks BabyAI including multiple combinatorially rich synthetic tasks(e.g.,GoToSeq,SynthSeq,BossLevel),where it not only outperforms competitive baselines but also demonstrates superior adaptability and effectiveness incomplex task decomposition.

关键词： Reinforcement learning representation learning subtask planning task decomposition pretraining.

Identifying malicious traffic under concept drift based on intraclass consistency enhanced variational autoencoder

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Science China(Information sciences) 2024年第8期67卷 238-252页

作者： Xiang LUO Chang LIU Gaopeng GOU Gang XIONG Zhen LI Binxing FANG Institute of Information Engineering Chinese Academy of Sciences School of Cyber Security University of Chinese Academy of Sciences School of Computer Science and Technology Harbin Institute of Technology (Shenzhen)

Accurate identification of malicious traffic is crucial for implementing effective defense countermeasures and has led to extensive research efforts. However, the continuously evolving techniques employed by adversaries have introduced the issues of concept drift, which significantly affects the performance of existing methods. To tackle this challenge, some researchers have focused on improving the separability of malicious traffic representation and designing drift detectors to reduce the number of false ***, these methods often overlook the importance of enhancing the generalization and intraclass consistency in the representation. Additionally, the detectors are not sufficiently sensitive to the variations among different malicious traffic classes, which results in poor performance and limited robustness. In this paper, we propose intraclass consistency enhanced variational autoencoder with Class-Perception detector(ICE-CP) to identify malicious traffic under concept drift. It comprises two key modules during training:intraclass consistency enhanced(ICE) representation learning and Class-Perception(CP) detector construction. In the first module, we employ a variational autoencoder(VAE) in conjunction with Kullback-Leibler(KL)-divergence and cross-entropy loss to model the distribution of each input malicious traffic flow. This approach simultaneously enhances the generalization, interclass consistency, and intraclass differences in the learned representation. Consequently, we obtain a compact representation and a trained classifier for nondrifting malicious traffic. In the second module, we design the CP detector, which generates a centroid and threshold for each malicious traffic class separately based on the learned representation, depicting the boundaries between drifting and non-drifting malicious traffic. During testing, we utilize the trained classifier to predict malicious traffic classes for the testing samples. Then, we use the CP det

关键词： concept drift malicious traffic identification variational autoencoder intrusion detection cyberspace security

Using restored two-dimensional X-ray images to reconstruct the three-dimensional magnetopause

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Earth and Planetary Physics 2024年第1期8卷 133-154页

作者： RongCong Wang JiaQi Wang DaLin Li TianRan Sun XiaoDong Peng YiHong Guo National Space Science Center Chinese Academy of SciencesBeijing 100190China University of chinese academy of sciences Beijing100049China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China

Astronomical imaging technologies are basic tools for the exploration of the universe,providing basic data for the research of astronomy and space *** Soft X-ray Imager(SXI)carried by the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)aims to capture two-dimensional(2-D)images of the Earth’s magnetosheath by using soft X-ray ***,the observed 2-D images are affected by many noise factors,destroying the contained information,which is not conducive to the subsequent reconstruction of the three-dimensional(3-D)structure of the *** analysis of SXI-simulated observation images shows that such damage cannot be evaluated with traditional restoration *** makes it difficult to establish the mapping relationship between SXIsimulated observation images and target images by using mathematical *** propose an image restoration algorithm for SXIsimulated observation images that can recover large-scale structure information on the *** idea is to train a patch estimator by selecting noise–clean patch pairs with the same distribution through the Classification–Expectation Maximization algorithm to achieve the restoration estimation of the SXI-simulated observation image,whose mapping relationship with the target image is established by the patch *** Classification–Expectation Maximization algorithm is used to select multiple patch clusters with the same distribution and then train different patch estimators so as to improve the accuracy of the *** results showed that our image restoration algorithm is superior to other classical image restoration algorithms in the SXI-simulated observation image restoration task,according to the peak signal-to-noise ratio and structural *** restoration results of SXI-simulated observation images are used in the tangent fitting approach and the computed tomography approach toward magnetospheric reconstruction techniques,significantly improving

关键词： Solar wind Magnetosphere Ionosphere Link Explorer(SMILE) soft X-ray imager magnetopause image restoration

MTCR-CR Routing Strategy for Connection-Oriented Routing over Satellite Networks

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China Communications 2024年第5期21卷 280-296页

作者： Li Changhao Sun Xue Yan Lei Cao Suzhi The University of chinese academy of sciences Beijing 100094China Key Laboratory of Space Utilization Chinese Academy of SciencesBeijing 100094China Technology and Engineering Center for Space Utilization Chinese Academy of SciencesBeijing 100094China

The high-speed movement of satellites makes it not feasible to directly apply the mature routing scheme on the ground to the satellite ***-DVTR in the snapshot-based connectionoriented routing strategy is one of the representative solutions,but it still has room for improvement in terms of routing *** this paper,we propose an improved scheme for connection-oriented routing strategy named the minimal Topology Change Routing based on Collaborative Rules(MTCR-CR).The MTCR-CR uses continuous time static topology snapshots based on satellite status to search for intersatellite link(ISL)construction solutions that meet the minimum number of topology changes to avoid route *** simulation results in Beidou-3 show that compared with DT-DVTR,MTCR-CR reduces the number of routing changes by about 92%,the number of path changes caused by routing changes is about38%,and the rerouting time is reduced by approximately 47%.At the same time,in order to show our algorithm more comprehensively,the same experimental index test was also carried out on the Globalstar satellite constellation.

关键词： ISL routing stability satellite networks satellite routing dynamic strategy

Enhancing Multi-agent Coordination via Dual-channel Consensus

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Machine Intelligence Research 2024年第2期21卷 349-368页

作者： Qingyang Zhang Kaishen Wang Jingqing Ruan Yiming Yang Dengpeng Xing Bo Xu Institute of Automation Chinese Academy of SciencesBeijing 100190China School of Future Technology University of Chinese Academy of SciencesBeijing 100049China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China

Successful coordination in multi-agent systems requires agents to achieve *** works propose methods through information sharing,such as explicit information sharing via communication protocols or exchanging information implicitly via behavior ***,these methods may fail in the absence of communication channels or due to biased *** this work,we propose to develop dual-channel consensus(DuCC)via contrastive representation learning for fully cooperative multi-agent systems,which does not need explicit communication and avoids biased *** comprises two types of consensus:temporally extended consensus within each agent(inner-agent consensus)and mutual consensus across agents(inter-agent consensus).To achieve DuCC,we design two objectives to learn representations of slow environmental features for inner-agent consensus and to realize cognitive consistency as inter-agent *** DuCC is highly general and can be flexibly combined with various MARL *** extensive experiments on StarCraft multi-agent challenge and Google research football demonstrate that our method efficiently reaches consensus and performs superiorly to state-of-the-art MARL algorithms.

关键词： Multi-agent reinforcement learning contrastive representation learning consensus multi-agent cooperation cognitive consistency