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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

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

Enhanced structural damage behavior of liquid-filled tank by reactive material projectile impact

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Defence Technology（防务技术） 2024年第1期31卷 211-229页

作者： Jianwen Xie Yuanfeng Zheng Zhenyang liu Chengzhe liu Aoxin liu Pengwan Chen Haifu Wang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

A series of ballistic experiments were performed to investigate the damage behavior of high velocity reactive material projectiles(RMPs) impacting liquid-filled tanks,and the corresponding hydrodynamic ram(HRAM) was studied in ***/Al/W RMPs with steel-like and aluminum-like densities were prepared by a pressing/sintering *** projectiles impacted a liquid-filled steel tank with front aluminum panel at approximately 1250 m/*** corresponding cavity evolution characteristics and HRAM pressure were recorded by high-speed camera and pressure acquisition system,and further compared to those of steel and aluminum *** different from the conical cavity formed by the inert metal projectile,the cavity formed by the RMP appeared as an ellipsoid with a conical *** RMPs were demonstrated to enhance the radial growth velocity of cavity,the global HRAM pressure amplitude and the front panel damage,indicating the enhanced HRAM and structural damage ***,combining the impact-induced fragmentation and deflagration characteristics,the cavity evolution of RMPs under the combined effect of kinetic energy impact and chemical energy release was *** mechanism of enhanced HRAM pressure induced by the RMPs was further revealed based on the theoretical model of the initial impact wave and the impulse ***,the linear correlation between the deformation-thickness ratio and the non-dimensional impulse for the front panel was obtained and *** was determined that the enhanced near-field impulse induced by the RMPs was the dominant reason for the enhanced structural damage behavior.

关键词： Reactive material projectile Hydrodynamic ram Enhanced structural damage Liquid-filled tank Impact

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

Non-contact and full-field online monitoring of curing temperature during the in-situ heating process based on deep learning

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Advances in Manufacturing 2024年第1期12卷 167-176页

作者： Qiang-Qiang liu Shu-Ting liu Ying-Guang Li Xu liu Xiao-Zhong Hao College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing210016People’s Republic of China School of Mechanical and Power Engineering Nanjing Tech UniversityNanjing211816People’s Republic of China

Online monitoring of the curing temperature field is essential to improving the quality and efficiency of the manufacturing process of composite *** embedded sensor-based technologies have difficulty monitoring the full temperature field or have to introduce heterogeneous items that could have an undesired impact on the *** this paper,a non-contact,full-field monitoring method based on deep learning that predicts the internal temperature field of composite parts in real time using surface temperature measurements of auxiliary materials is *** the proposed method,an average temperature monitoring accuracy of 97%is achieved in various heating *** addition,this method also demonstrates satisfying feasibility when a stronger thermal barrier covers the *** method was experimentally validated during the self-resistance electric heating process,in which the monitoring accuracy reached 93.1%.This method can potentially be applied to automated manufacturing and process control in the composites industry.

关键词： Online monitoring Curing temperature field Deep learning(DL) In-situ heating

Shock Raman spectra and structural transformation of powdered TKX-50 by the plate impact experiments combined with real-time Raman detection

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Defence Technology（防务技术） 2024年第1期31卷 158-162页

作者： Xue Yang Qijun liu Yundan Gan Lei Yang Zhengtang liu Fusheng liu Bond and Band Engineering Group School of Physical Science and TechnologySouthwest Jiaotong UniversityChengdu 610031People's Republic of China Xi'an Modern Chemistry Research Institute Xi'an 710065People's Republic of China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072People's Republic of China

As an energetic material of great interest,the work capacity of dihydroxylammonium 5,5’-bistetrazole-1,1’-diolate(TKX-50)has been questioned *** some research groups have explored the reasons for the low working ability of TKX-50,the plane impact experiment on powdered TKX-50 is obviously closer to the practical application,and the conclusions based on this are more ***,we performed shock Hugoniot measurements of powdered TKX-50 between 5.65 and 16.29 *** plane impact experiments of powdered TKX-50 were carried out and the shocked Raman spectra were *** Raman spectroscopy analysis,a new peak of powdered TKX-50 was found between19.47 GPa and 24.96 GPa,which may be caused by decomposition/phase transition and was related with the low work capacity.

关键词： Powdered TKX-50 Hugoniot Raman Decomposition Phase transition

A visible-light-assisted Pd/TiO_(2)gas sensor with carbon nanotubes electrodes for trace formaldehyde detection

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Rare Metals 2024年第1期43卷 257-266页

作者： Can liu Qiao-Qiao Zou Bin liu Yong Zhang School of Physics and Optoelectronics Xiangtan UniversityXiangtan 411105China Hunan Institute of Advanced Sensing and Information Technology Xiangtan UniversityXiangtan 411105China School of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China

Owing to the ppb-level detection standard toward the toxic and harmful gas,the detection of trace gases has become an important subject in the field of indoor environment ***,the traditional resistive gas sensors hardly meet the requirement due to the weak signal generated by trace gas molecules that are difficult to ***,a visible-light-assisted Pd/TiO_(2)gas sensor is proposed to endow the effective detection of trace formaldehyde(HCHO)gas without heating *** from the enhanced photocatalytic properties of TiO_(2)by Pd decoration,the visible-light-assisted Pd/TiO_(2)gas sensor can detect the HCHO gas as low as80×10^(–9)at room *** successful preparation of nanoscale TiO_(2)sensing layer is facilitated by the ultrathin carbon nanotube interdigital electrode in the gas sensor,which avoids the discontinuity of the sensing layer caused by the excessive thickness of the traditional metal *** addition,the whole preparation process of the Pd/TiO_(2)gas sensor with carbon nanotube electrodes is compatible with mainstream CMOS fabrication technology,which is expected to realize the batch fabrication and micro-integrated application of gas *** is expected that our work can provide a new strategy for the batch preparation of high-performance trace HCHO gas sensors and their future applications in portable electronic devices such as smartphones.

关键词： Visible-light-assisted gas sensor Pd/TiO_(2) Trace HCHO detection Carbon nanotubes electrodes

Characteristics and sources of peroxyacetyl nitrate(PAN)in the rural North China Plain:Results from1-year continuous observations

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Journal of Environmental Sciences 2024年第4期138卷 719-731页

作者： Xin liu Xiaowei He Chenglong Zhang Yifei Song Shuyang Xie Chengtang liu Pengfei liu Yuanyuan Zhang Yujing Mu Junfeng liu Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

Peroxyacetyl nitrate(PAN)is an important photochemical pollutant in the troposphere,whereas long-term measurements are scarce in rural areas in North China Plain(NCP),resulting in unclear seasonal variations and sources of PAN in rural *** this study,we conducted a 1-year observation of PAN during 2021-2022 at the rural NCP *** average concentrations of PAN were 1.10,0.75,0.65,and 0.88 ppbv in spring,summer,autumn,and winter,respectively,with a 1-year average of 0.81±0.60 *** indicate that the loss of PAN through thermal decomposition in summer accounts for 43.2% of the total formed PAN,which is an important reason for the low concentration of PAN in *** speculate that since the correlation between PAN and O_(3) in winter is significantly lower than that in other seasons,the observed regional transport of PAN cannot be ignored in *** budget analysis,regional transport accounted for 12.8% and 55.9% of the observed PAN on the spring and winter pollution days,respectively,which showed that regional transport played key roles during the photochemical pollution of the rural NCP in *** potential source contribution function revealed that the transported PAN mainly comes from southern Hebei in *** winter,the transported PAN was mainly from Langfang,Hengshui,and southern *** findings may aid in understanding PAN variations in different seasons in rural areas and highlight the impact of regional transport on the PAN budget.

关键词： Photochemical pollution Peroxyacetyl nitrate(PAN) Seasonal variations Regional transport Rural area

Input-to-State Stability of Impulsive Switched Systems Involving Uncertain Impulse-Switching Moments

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1515-1517页

作者： Chang liu Wenlu liu Tengda Wei Xiaodi Li School of Mathematical and Statistics Shandong Normal UniversityJinan 250014China

Dear Editor,This letter studies the input-to-state stability(ISS)for a class of impulsive switched systems,where uncertain impulse-switching moments are *** robustness of ISS with respect to the perturbations of the occurrence time of impulse-switching moments is revealed by several less conservative dwell-time conditions for the uncertain impulse-switching moments combined with Lyapunov ***,the Lyapunov conditions have multiple coefficients at discrete time so as to handle the hybrid effect of impulse-switching moments,and the case that time derivative of Lyapunov function is indefinite is also taken into ***,a numerical example is proposed to illustrate the effectiveness of the theoretical results.

关键词： letter conservative derivative