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Carbon Energy 2024年第3期6卷 204-214页

作者： Bin liu Jie liu Cheng Zhong Wenbin Hu Key Laboratory of Advanced Ceramics and Machining Technology(Ministry of Education) School of Materials Science and EngineeringTianjin UniversityTianjinChina Tianjin Key Laboratory of Composite and Functional Materials School of Materials Science and EngineeringTianjin UniversityTianjinChina Joint School of National University of Singapore and Tianjin University TianjinChina International Campus of Tianjin University Binhai New CityFuzhouChina

Silicon suboxide(SiO_(x),x≈1)is promising in serving as an anode material for lithium-ion batteries with high capacity,but it has a low initial Coulombic efficiency(ICE)due to the irreversible formation of lithium silicates during the first *** this work,we modify SiO_(x) by solid-phase Mg doping reaction using low-cost Mg powder as a reducing *** show that Mg reduces SiO_(2) in SiO_(x) to Si and forms MgSiO_(3) or Mg_(2)SiO_(4).The MgSiO_(3) or Mg_(2)SiO_(4) are mainly distributed on the surface of SiO_(x),which suppresses the irreversible lithium-ion loss and enhances the ICE of SiO_(x).However,the formation of MgSiO_(3) or Mg_(2)SiO_(4) also sacrifices the capacity of SiO_(x).Therefore,by controlling the reaction process between Mg and SiO_(x),we can tune the phase composition,proportion,and morphology of the Mg-doped SiO_(x) and manipulate the *** obtain samples with a capacity of 1226 mAh g^(–1) and an ICE of 84.12%,which show significant improvement over carbon-coated SiO_(x) without Mg *** the synergistical modification of both Mg doping and prelithiation,the capacity of SiO_(x) is further increased to 1477 mAh g^(–1) with a minimal compromise in the ICE(83.77%).

关键词： initial Coulombic efficiency lithium-ion batteries magnesium doping prelithiation silicon suboxide

Does the transformation of energy structure promote green technological innovation?A quasi-natural experiment based on new energy demonstration city construction

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Geoscience Frontiers 2024年第3期15卷 373-388页

作者： Chuanming liu Chang Tang Yiding liu School of Economics Shandong University of Finance and EconomicsJinan 250014China School of Economics&Management Changsha University of Science and TechnologyChangsha 410076China School of Economic and Management Southeast UniversityNanjing 211189China

New energy development is essential to achieving carbon peaks and neutrality and promoting green technological *** the causal relationship between new energy demonstration city construction and green technological innovation is crucial for the expansion and promotion of new energy demonstration *** this study,we take the construction of new energy demonstration cities as a quasi-natural experiment,study their impact on green technological innovation using difference-indifference(DID),and conduct a robustness test using DID after propensity score matching(PSM-DID).The research results indicate the following:First,energy structure optimization can significantly improve the level of urban green technological innovation(this result was shown to be valid using PSM-DID and other tests involving the effects of placebo and instrumental variables).Second,new energy demonstration city construction mainly improves the level of urban green technological innovation through technology research and development,the improvement of the industrial innovation environment,and the promotion of environmental ***,the impact of energy structure optimization on green technological innovation has regional,financial,and economic development ***,new energy demonstration city policy affects the flow of capital,labor,technology,and other production factors to pilot areas according to new energy demonstration city policy,forming a“siphon effect”.The carbon reduction effect of new energy demonstration city construction is greater than its pollution reduction *** the results of the study,policy recommendations to promote the expansion of new energy demonstration cities are proposed.

关键词： New energy demonstration city Green technological innovation Theoretical mechanism Difference-in-difference

High-performance nickel metal hydride battery anode with enhanced durability and excellent low-temperature discharge capability

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Nano Research 2024年第10期17卷 8819-8825页

作者： Zhitao Chen Huitian liu Jean Nei Nian liu School of Chemical and Biomolecular Engineering Georgia Institute of TechnologyAtlantaGA 30332USA GP Batteries HongkongChina

Current AB_(5)-type hydrogen storage alloys employed in nickel-metal hydride(NiMH)batteries exhibit exceptional low-temperature discharge performance but suffer from limited cycle life and insufficient high-temperature *** overcome these challenges,we introduce a hydrothermal synthesized LaF_(3)coating layer on the surface of the AB_(5)anode *** LaF_(3)coating layer adds a protective barrier for the active material,significantly improving the battery's cycle life and high-temperature *** findings indicate that(1)the LaF_(3)coated anode demonstrates an extended cycle life with increased specific capacity and a capacity retention of 88%after 40 cycles of abusive overcharging and rapid discharging at room temperature.(2)The synthesized anode exhibits a 97%recovery of its specific capacity of 292.7 mAh/g following 144 h of high-temperature storage.(3)The low-temperature discharge capacity of the synthesized anode remains on par with the pristine AB_(5)alloy at 230.4 mAh/g in a-40℃*** research presents a significant advancement in hydrogen storage alloy coatings and offers valuable insights for designing electrodes in NiMH batteries.

关键词： nickel metal hydride(NiMH)batteries hydrothermal synthesis lanthanum fluoride discharge capacity low temperature

Foundation models meet visualizations: Challenges and opportunities

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Computational Visual Media 2024年第3期10卷 399-424页

作者： Weikai Yang Mengchen liu Zheng Wang Shixia liu School of Software Tsinghua UniversityBeijing 100084China Microsoft Redmond 98052USA

Recent studies have indicated that foundation models, such as BERT and GPT, excel atadapting to various downstream tasks. This adaptability has made them a dominant force in buildingartificial intelligence (AI) systems. Moreover, a newresearch paradigm has emerged as visualizationtechniques are incorporated into these models. Thisstudy divides these intersections into two researchareas: visualization for foundation model (VIS4FM)and foundation model for visualization (FM4VIS).In terms of VIS4FM, we explore the primary roleof visualizations in understanding, refining, and evaluating these intricate foundation models. VIS4FMaddresses the pressing need for transparency, explainability, fairness, and robustness. Conversely, in termsof FM4VIS, we highlight how foundation models canbe used to advance the visualization field itself. Theintersection of foundation models with visualizations ispromising but also introduces a set of challenges. Byhighlighting these challenges and promising opportunities, this study aims to provide a starting point forthe continued exploration of this research avenue.

关键词： visualization artificial intelligence(AI) machine learning foundation models visualization for foundation model(VIS4FM) foundation model for visualization(FM4VIS)

Improved Double Deep Q Network-Based Task Scheduling Algorithm in Edge Computing for Makespan Optimization

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Tsinghua Science and Technology 2024年第3期29卷 806-817页

作者： Lei Zeng Qi liu Shigen Shen Xiaodong liu School of Computer Science Nanjing University of Information Science and TechnologyNanjing 210044China School of Software Nanjing University of Information Science and TechnologyNanjing 210044China School of Information Engineering Huzhou UniversityHuzhou 313000China School of Computing Edinburgh Napier UniversityEdinburghEH105DTUK

Edge computing nodes undertake an increasing number of tasks with the rise of business ***,how to efficiently allocate large-scale and dynamic workloads to edge computing resources has become a critical *** study proposes an edge task scheduling approach based on an improved Double Deep Q Network(DQN),which is adopted to separate the calculations of target Q values and the selection of the action in two networks.A new reward function is designed,and a control unit is added to the experience replay unit of the *** management of experience data are also modified to fully utilize its value and improve learning *** learning agents usually learn from an ignorant state,which is *** such,this study proposes a novel particle swarm optimization algorithm with an improved fitness function,which can generate optimal solutions for task *** optimized solutions are provided for the agent to pre-train network parameters to obtain a better cognition *** proposed algorithm is compared with six other methods in simulation *** show that the proposed algorithm outperforms other benchmark methods regarding makespan.

关键词： edge computing task scheduling reinforcement learning makespan Double Deep Q Network(DQN)

Localization−delocalization transitions in non-Hermitian Aharonov−Bohm cages

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Frontiers of physics 2024年第3期19卷 39-50页

作者： Xiang Li Jin liu Tao liu School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China

A unique feature of non-Hermitian systems is the extreme sensitivity of the eigenspectrum to boundary conditions with the emergence of the non-Hermitian skin effect (NHSE). A NHSE originates from the point-gap topology of complex eigenspectrum, where an extensive number of eigenstates are anomalously localized at the boundary driven by nonreciprocal dissipation. Two different approaches to create localization are disorder and flat-band spectrum, and their interplay can lead to the anomalous inverse Anderson localization, where the Bernoulli anti-symmetric disorder induces mobility in a full-flat band system in the presence of Aharonov−Bohm (AB) Cage. In this work, we study the localization−delocalization transitions due to the interplay of the point-gap topology, flat band and correlated disorder in the one-dimensional rhombic lattice, where both its Hermitian and non-Hermitian structures show AB cage in the presence of magnetic flux. Although it remains the coexistence of localization and delocalization for the Hermitian rhombic lattice in the presence of the random anti-symmetric disorder, it surprisingly becomes complete delocalization, accompanied by the emergence of NHSE. To further study the effects from the Bernoulli anti-symmetric disorder, we found the similar NHSE due to the interplay of the point-gap topology, correlated disorder and flat bands. Our anomalous localization−delocalization property can be experimentally tested in the classical physical platform, such as electrical circuit.

关键词： non-Hermitian skin effects disorder flat band localization−delocalization transition

Changes of China’s Status in the Global System and Its Influencing Factors:A Multiple Contact Networks Perspective

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Chinese Geographical Science 2024年第2期34卷 265-279页

作者： liu Jian liu Jibin YANG Qingshan CAI Sikai liu Jie School of Geographical Sciences Northeast Normal UniversityChangchun 130024China Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains Ministry of EducationChangchun 130024China School of Architecture and Planning Jilin Jianzhu UniversityChangchun 130118China School of Geographical Sciences Liaoning Normal UniversityDalian 116029China

Clarifying China’s position in the global system is an important logical basis for developing national *** much research has been done on China’s development status,most studies have been based on country comparisons or institutional *** today’s networked era in which the global economy,trade,personnel,and information are closely connected,studies on China’s global position and its status changes and influencing factors in multiple contact networks are still *** this study,from the perspective of diverse global contact networks,we constructed economic,cultural,and political influence indices to explore the changes and influencing factors on China’s status in the global system from 2005 to *** results show that during the study period,China’s global influence in the fields of economic ties,cultural exchanges,and political contacts increased significantly,but its influ-ence in the fields of cultural exchanges and political contacts lagged far economic *** pattern of China’s economic influence on various economies around the world has shown a transformation from an‘upright pyramid’to an‘inverted pyramid’*** proportion of these economies in low-influence zones has decreased from more than 60%in 2005 to less than 20%in ***’s cultural and political influence on various economies around the world has increased significantly;however,for the former,the percentage of high-influence areas is still less than 20%,whereas for the latter the percentage of these economies in medium-and high-influence areas is still less than 50%.Analyses such as a scatter plot matrix show that geographical proximity,economic globalization,close cooperation with developing countries,and a proactive and peaceful foreign policy are important factors in improving China’s status in the diverse global network system.

关键词： global system economic ties cultural exchanges political contacts multiple contact networks China’s status

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农药毒死蜱对小鼠肺细胞氧化损伤的研究

华中师范大学学报（自然科学版） 2013年第2期47卷 246-249页

作者：马萍焦铭刘旭东刘锋明杨旭丁书茂湖北科技学院基础医学院湖北咸宁437100 华中师范大学生命科学学院武汉430079

为了研究毒死蜱对生物体的氧化损伤,以昆明小鼠为受试体,毒死蜱按3、6和12mg/kg 3个剂量水平,灌胃染毒小鼠,每天1次,连续7d,测定小鼠肺的脏器系数比,以肺组织匀浆液测定活性氧(reactive oxygen species,ROS)、还原型谷胱甘肽(glutathion... 详细信息

为了研究毒死蜱对生物体的氧化损伤,以昆明小鼠为受试体,毒死蜱按3、6和12mg/kg 3个剂量水平,灌胃染毒小鼠,每天1次,连续7d,测定小鼠肺的脏器系数比,以肺组织匀浆液测定活性氧(reactive oxygen species,ROS)、还原型谷胱甘肽(glutathione,GSH)和丙二醛(Malondial-dehyde,MDA)的含量.实验结果表明:随着毒死蜱染毒剂量的升高,ROS和MDA含量逐渐上升,肺的脏器系数比和GSH含量逐渐降低,各指标呈一定的剂量-效应关系.染毒剂量≥6mg/kg时,GSH和MDA含量有显著差异(P<0.05);染毒剂量≥12mg/kg时,ROS含量有显著差异(P<0.05),肺的脏器系数比、GSH和MDA含量有极显著差异(P<0.01).说明较高剂量的毒死蜱可造成小鼠肺组织的氧化损伤.

关键词：毒死蜱小鼠肺脏氧化损伤

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新疆自然环境条件对公路建设的影响及其对策

公路交通技术 2007年第5期23卷 123-126页

作者：贺国佑刘锋民武汉市城市规划设计研究院武汉430014 江西省交通设计院南昌330002

结合新疆特殊的自然环境条件,深入研究新疆地貌、水文、气温、土壤、植被、常见自然病害等自然环境条件的区域差异及其对公路建设的影响,阐述相关的工程经验及治理措施,为新疆地区的公路建设提供引导和依据。

关键词：自然环境公路建设土基回弹模量干湿状态工程性质

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Skill enhancement learning with knowledge distillation

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Science China(Information Sciences) 2024年第8期67卷 206-220页

作者： Naijun liu Fuchun SUN Bin FANG Huaping liu Department of Computer Science and Technology Tsinghua University

Skill learning through reinforcement learning has significantly progressed in recent years. However, it often struggles to efficiently find optimal or near-optimal policies due to the inherent trial-and-error exploration in reinforcement learning. Although algorithms have been proposed to enhance skill learning efficacy, there is still much room for improvement in terms of skill learning performance and training stability. In this paper, we propose an algorithm called skill enhancement learning with knowledge distillation(SELKD), which integrates multiple actors and multiple critics for skill learning. SELKD employs knowledge distillation to establish a mutual learning mechanism among actors. To mitigate critic overestimation bias,we introduce a novel target value calculation method. We also perform theoretical analysis to ensure the convergence of SELKD. Finally, experiments are conducted on several continuous control tasks, illustrating the effectiveness of the proposed algorithm.

关键词： skill learning enhancement learning reinforcement learning knowledge distillation