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Journal of Wuhan University of Technology(Materials Science) 2024年第2期39卷 353-363页

作者：杨志强李化建 WEN Jiaxing DONG Haoliang HUANG Fali WANG Zhen YI Zhonglai Railway Engineering Research Institute China Academy of Railway Science Corporation LimitedBeijing 100081China State Key Laboratory for Track System of High-Speed Railway Beijing 100081China School of Civil Engineering Beijing Jiaotong UniversityBeijing 100044China

In order to clarify the fatigue damage evolution of concrete exposed to flexural fatigue loads,ultrasonic pulse velocity(UPV),impact-echo technology and surface electrical resistance(SR) method were *** variable based on the change of velocity of ultrasonic pulse(Du) and impact elastic wave(Di)were defined according to the classical damage *** influences of stress level,loading frequency and concrete strength on damage variable were *** experimental results show that Du and Di both present a three-stages trend for concrete exposed to fatigue *** impact elastic wave is more sensitive to the microstructure damage in stage Ⅲ,the critical damage variable,i e,the damage variable before the final fracture of concrete of Di is slightly higher than that of ***,the evolution of SR of concrete exposed to fatigue loads were analyzed and the relationship between SR and Du,SR and Di of concrete exposed to fatigue loads were *** is found that the SR of concrete was decreased with the increasing fatigue cycles,indicating that surface electrical resistance method can also be applied to describe the damage of ballastless track concrete exposed to fatigue loads.

关键词： ballastless track fatigue damage ultrasonic pulse velocity impact-echo surface electrical resistance

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Contrasting strategies of optimizing carrier concentration in bulk InSe for enhanced thermoelectric performance

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Rare Metals 2024年第9期43卷 4425-4432页

作者： Hao-Nan Shi Shu-Lin Bai Yu-Ping Wang Li-Zhong Su Qian Cao Cheng Chang Li-Dong Zhao School of Materials Science and Engineering Beihang University School of Materials Science and Engineering Taiyuan University of Science and Technology Huabei Cooling Device Co.Ltd.

Indium selenide (InSe),as a wide-bandgap semiconductor,has received extensive attention in the flexible electronics field in recent years due to its exceptional plasticity and promising thermoelectric ***,the low carrier concentration severely limits its thermoelectric performance *** this work,we conducted contrasting strategies that can be employed to increase the carrier concentration of InSe,including bandgap narrowing and heterovalent ***,the carrier concentration initially increases as a result of the reduced bandgap upon Te alloying and then slightly decreases due to the weak electronegativity of *** Br doping realizes high carrier concentration by pushing the Fermi level into the conduction bands and activating the multiple *** the other hand,both Te and Br obviously suppress the thermal conductivity due to the point defect *** contrast,Br doping realizes a higher thermoelectric performance with a maximum ZT of～0.13 at 773 K benefiting from the better optimization of carrier *** work elucidates the strategies for enhancing carrier concentration at anion sites and demonstrates the high efficiency of halogen doping in ***,the carrier concentration of InSe is promising to be further optimized,and future work should focus on employing approaches such as cation doping or secondphase compositing.

关键词： Bandgap Carrier concentration Heterovalent doping InSe Thermoelectric

A Finite-Time Convergent Analysis of Continuous Action Iterated Dilemma

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 563-565页

作者： Zhen Wang Xiaoyue Jin Tao Zhang Dengxiu Yu Northwestern Polytechnical University

Dear Editor,In this letter, a finite-time convergent analysis of continuous action iterated dilemma(CAID) is proposed. In traditional evolutionary game theory, the strategy of the player is binary(cooperation or defec... 详细信息

关键词： lemma letter convergent

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Polaron interfacial entropy as a route to high thermoelectric performance in DAE-doped PEDOT:PSS films

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National Science Review 2024年第3期11卷 259-270页

作者： Jiajia Zhang Caichao Ye Genwang Wei Liang Guo Yuhang Cai Zhi Li Xinzhi Wu Fangyi Sun Qikai Li Yupeng Wang Huan Li Yuchen Li Shuaihua Wang Wei Xu Xuefeng Guo Wenqing Zhang Weishu Liu Department of Materials Science and Engineering Southern University of Science and Technology Academy for Advanced Interdisciplinary Studies and Guangdong Provincial Key Laboratory of Computational Science and Material Design Southern University of Science and Technology Department of Mechanical and Energy Engineering Southern University of Science and Technology Beijing National Laboratory for Molecular Sciences Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences College of Chemistry and Molecular Engineering National Biomedical Imaging Centre Peking University Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices Southern University of Science and Technology

Enhancing the thermoelectric transport properties of conductive polymer materials has been a long-term challenge, in spite of the success seen with molecular doping strategies. However, the strong coupling between the thermopower and the electrical conductivity limits thermoelectric performance. Here, we use polaron interfacial occupied entropy engineering to break through this intercoupling for a PEDOT:PSS(poly（3,4-ethylenedioxythiophene）-poly（4-styrenesulfonate）) thin film by using photochromic diarylethene（DAE） dopants coupled with UV-light modulation. With a 10-fold enhancement of the thermopower from 13.5 μV K-1to 135.4 μV K-1and almost unchanged electrical conductivity, the DAE-doped PEDOT:PSS thin film achieved an extremely high power factor of 521.28 μW m-1K-2from an original value of 6.78 μW m-1K-2. The thermopower was positively correlated with the UV-light intensity but decreased with increasing temperature, indicating resonant coupling between the planar closed DAE molecule and PEDOT. Both the experiments and theoretical calculations consistently confirmed the formation of an interface state due to this resonant coupling. Interfacial entropy engineering of polarons could play a critical role in enhancing the thermoelectric performance of the organic film.

关键词： thermoelectric PEDOT: PSS interfacial occupied entropy resonant coupling UV-light modulation

Bioinspired nanofluidic iontronics for brain-like computing

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Nano Research 2024年第2期17卷 503-514页

作者： Lejian Yu Xipeng Li Chunyi Luo Zhenkang Lei Yilan Wang Yaqi Hou Miao Wang Xu Hou State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Institute of Artificial Intelligence Xiamen UniversityXiamen 361005China Department of Physics Research Institute for Biomimetics and Soft MatterFujian Provincial Key Laboratory for Soft Functional Materials ResearchJiujiang Research InstituteCollege of Physical Science and TechnologyXiamen UniversityXiamen 361005China The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province Department of BiomaterialsResearch Center of Biomedical Engineering of XiamenCollege of MaterialsXiamen UniversityXiamen 361005China The Institute of Flexible Electronics(IFE Future Technologies)Xiamen UniversityXiamen 361005China Binzhou Institute of Technology Binzhou 256600China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361102China Engineering Research Center of Electrochemical Technologies of Ministry of Education Xiamen UniversityXiamen 361005China

The human brain performs computations via a highly interconnected network of *** inspiration from the information delivery and processing mechanism of the human brain in central nervous systems,bioinspired nanofluidic iontronics has been proposed and gradually engineered to overcome the limitations of the conventional electron-based von Neumann architecture,which shows the promising potential to enable efficient brain-like *** and tunable nanofluidic ion transport behaviors and spatial confinement show promising controllability of charge carriers,and a wide range of structural and chemical modification paves new ways for realizing brain-like ***,a comprehensive framework of mechanisms and design strategy is summarized to enable the rational design of nanofluidic systems and facilitate the further development of bioinspired nanofluidic *** review provides recent advances and prospects of the bioinspired nanofluidic iontronics,including ion-based brain computing,comprehension of intrinsic mechanisms,design of artificial nanochannels,and the latest artificial neuromorphic functions ***,the challenges and opportunities of bioinspired nanofluidic iontronics in the pioneering and interdisciplinary research fields are proposed,including brain–computer interfaces and artificial neurons.

关键词： human brain ion transport nanofluidics brain-like computing memristive effect

Ensemble successor representations for task generalization in offline-to-online reinforcement learning

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Science China(Information Sciences) 2024年第7期67卷 240-255页

作者： Changhong WANG Xudong YU Chenjia BAI Qiaosheng ZHANG Zhen WANG Space Control and Inertial Technology Research Center Harbin Institute of Technology Shanghai Artificial Intelligence Laboratory Shenzhen Research Institute of Northwestern Polytechnical University School of Cybersecurity Northwestern Polytechnical University

In reinforcement learning(RL), training a policy from scratch with online experiences can be inefficient because of the difficulties in exploration. Recently, offline RL provides a promising solution by giving an initialized offline policy, which can be refined through online interactions. However, existing approaches primarily perform offline and online learning in the same task, without considering the task generalization problem in offline-to-online adaptation. In real-world applications, it is common that we only have an offline dataset from a specific task while aiming for fast online-adaptation for several tasks. To address this problem, our work builds upon the investigation of successor representations for task generalization in online RL and extends the framework to incorporate offline-to-online learning. We demonstrate that the conventional paradigm using successor features cannot effectively utilize offline data and improve the performance for the new task by online fine-tuning. To mitigate this, we introduce a novel methodology that leverages offline data to acquire an ensemble of successor representations and subsequently constructs ensemble Q functions. This approach enables robust representation learning from datasets with different coverage and facilitates fast adaption of Q functions towards new tasks during the online fine-tuning *** empirical evaluations provide compelling evidence showcasing the superior performance of our method in generalizing to diverse or even unseen tasks.

关键词： offline reinforcement learning online fine-tuning task generalization successor representations ensembles

Copper-Catalyzed Hydrogen Production through the Dehydrogenative Coupling of Methanol and Diamine

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Precision Chemistry 2024年第4期2卷 138-142页

作者： Danyang Cheng Shixiang Yu Meng Wang Ding Ma Beijing National Laboratory for Molecular Sciences New Cornerstone Science LaboratoryCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

A hydrogen storage system was developed via heterogeneous catalysis,employing the dehydrogenative coupling of methanol and N,N′-dimethylethylenediamine to efficiently produce high-purity H_(2).In this process,the Cu/ZnO/Al_(2)O_(3) catalyst displayed superior activity in hydrogen production,with Cu+identified as the major active site through comprehensive characterization.

关键词： methanol reforming hydrogen release aminocarbonylation dehydrogenative coupling Cu/ZnO/Al_(2)O_(3)catalyst

Pressure Distinguishes the Dual Emissions in Pseudohalide 2D Ruddlesden-Popper Perovskite Cs_(2)Pb(SCN)_(2)Br_(2)

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CCS Chemistry 2024年第7期6卷 1748-1756页

作者： Songhao Guo Yuhong Mao Congcong Chen Yao Zhang Guoxiang Zhao Kejun Bu Qingyang Hu Haiming Zhu Guifu Zou Wenge Yang Lingling Mao Xujie Lü Center for High Pressure Science and Technology Advanced Research(HPSTAR) Shanghai Department of Chemistry Southern University of Science and TechnologyShenzhen Department of Chemistry Zhejiang UniversityHangzhou College of Energy Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu ProvinceSoochow UniversitySuzhou

Two-dimensional(2D)Ruddlesden-Popper(RP)halide perovskites with diverse structures and properties have drawn increasing attention due to their promising optoelectronic ***,a new all-inorganic Cs_(2)Pb(SCN)_(2)Br_(2) has been reported that opens up new potential for the development of 2D RP ***,recent reports of unusual dual emissions and two-edge absorption in Cs_(2)Pb(SCN)_(2)Br_(2) have generated intense debate about its origin and remains ***,by combining continuous pressure tuning with in situ diagnostics,we have unambiguously revealed the underlying mechanisms that the 2D Cs_(2)Pb(SCN)_(2)Br_(2) exhibits an intrinsic blue emission at 2.66 eV and an absorption edge close to the emission *** the gradually formed CsPbBr_(3) is responsible for the green emission at 2.33 eV with the absorption shoulder at 2.41 ***,by fitting the temperature-dependent intensity of the intrinsic blue emission,we have determined the corrected value of exciton binding energy for 2D Cs_(2)Pb(SCN)_(2)Br_(2) to be 90 ***,an emission enhancement of 2.5 times is achieved in Cs_(2)Pb(SCN)_(2)Br_(2) under a mild pressure within 0.8 GPa,caused by the pressuresuppressed exciton-phonon *** work not only elucidates the origin of the dual emissions and two-edge absorption in Cs_(2)Pb(SCN)_(2)Br_(2),but it also provides a potential means to regulate and optimize the optoelectronic properties of 2D perovskites.

关键词： two-dimensional perovskite dual emissions two-edge absorption high pressure in situ characterization enhanced photoluminescence

Inhibition mechanisms of CRISPR-Cas9 by AcrⅡA25.1 and AcrⅡA32

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Science China(Life Sciences) 2024年第9期67卷 1781-1791页

作者： Jianlin Zheng Yuwei Zhu Tengjin Huang Wenbo Gao Jiale He Zhiwei Huang HIT Center for Life Sciences School of Life Science and TechnologyHarbin Institute of TechnologyHarbin 150080China Westlake Center for Genome Editing Westlake Laboratory of Life Sciences and BiomedicineSchool of Life SciencesWestlake UniversityHangzhou 310024China

In the ongoing arms race between bacteria and bacteriophages,bacteriophages have evolved anti-CRISPR proteins to counteract bacterial CRISPR-Cas ***,AcrⅡA25.1 and AcrⅡA32 have been found to effectively inhibit the activity of Spy Cas9 both in bacterial and human ***,their molecular mechanisms remain ***,we report the cryo-electron microscopy structures of ternary complexes formed by AcrⅡA25.1 and AcrⅡA32 bound to Spy Cas9-sg *** structural analysis and biochemical experiments,we revealed that AcrⅡA25.1 and AcrⅡA32 recognize a novel,previously-unidentified anti-CRISPR binding site on Spy *** found that both AcrⅡA25.1 and AcrⅡA32 directly interact with the WED domain,where they spatially obstruct conformational changes of the WED and PI domains,thereby inhibiting Spy Cas9 from recognizing protospacer adjacent motif(PAM)and unwinding double-stranded *** addition,they may inhibit nuclease activity by blocking the dynamic conformational changes of the Spy Cas9 surveillance *** summary,our data elucidate the inhibition mechanisms of two new anti-CRISPR proteins,provide new strategies for the modulation of Spy Cas9 activity,and expand our understanding of the diversity of anti-CRISPR protein inhibition mechanisms.

关键词： anti-CRISPR cryo-EM Spy Cas9 AcrⅡA25.1 AcrⅡA32 inhibiton

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Tuning the ferroelectricity of Hf0.5Zr0.5O2 with alloy electrodes

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Science China(Information Sciences) 2024年第8期67卷 321-330页

作者： Keqin LIU Bingjie DANG Zhiyu YANG Teng ZHANG Zhen YANG Jinxuan BAI Zelun PAN Ru HUANG Yuchao YANG Beijing Advanced Innovation Center for Integrated Circuits School of Integrated Circuits Peking University School of Electronic and Computer Engineering Peking University Center for Brain Inspired Chips Institute for Artificial Intelligence Peking University Center for Brain Inspired Intelligence Chinese Institute for Brain ResearchBeijing

Tuning ferroelectricity of Hf0.5Zr0.5O2is crucial for facilitating its practical applications in various fields, including in-memory and neuromorphic computing. Previous studies have revealed that the electrodes have a significant influence on ferroelectricity, and changing electrode materials can realize different but discrete ferroelectric polarization values. Here, we introduce an alloy-electrode method, in order to achieve gradual and accurate modulation of ferroelectric polarization, especially useful for matching the polarization charges at the interface of ferroelectric insulators and ferroelectric semiconductors. Au and W electrodes are chosen as baselines for realizing weak and strong ferroelectric polarization, where the intermediate states can be achieved by adjusting the ratio of metals in the Au-W alloy. To demonstrate the generality of this approach, the Cu-W alloy electrode is also realized for tuning ferroelectric polarization. The effect of alloy electrodes on device leakage current, endurance, and retention is evaluated. In addition, the temperature stability of ferroelectric capacitors is tested, where limited changes in both remnant polarization and coercive voltages are observed, showing the great potential of the ferroelectric hafnium oxide. Such gradual modulation of ferroelectric polarization could facilitate the application of Hf0.5Zr0.5O2in in-memory and neuromorphic computing.

关键词： ferroelectric hafnium oxide alloy electrode gradual modulation temperature stability