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The breaking of spin symmetry in the single-particle resonances in deformed nuclei

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Nuclear Science and Techniques 2024年第3期35卷 237-245页

作者： Zhen-Yu zheng Shou-Wan Chen Quan liu School of Physics and Optoelectronic Engineering Anhui UniversityHefei 230601China

The exploration of spin symmetry (SS) in nuclear physics has been instrumental in identifying atomic nucleus *** this study,we solve the Dirac equation from the relativistic mean field (RMF) in complex momentum *** investigated SS and its breaking in single-particle resonant states within deformed nuclei,with a focus on the illustrative *** was the initial discovery of a resonant spin doublet in a deformed nucleus,with the expectation of the SS approaching the continuum *** increasing single-particle energy,the splitting of the resonant spin doublets widened *** escalating splitting implies diminishing adherence to the SS,indicating a departure from the expected behavior as the energy levels *** also analyzed the width of the resonant states,showing that lower orbital angular momentum resonances possess shorter decay times and that SS is preserved within broad resonant doublets,as opposed to narrow resonant *** the radial density of the upper components for the bound-state and resonant-state doublets,it becomes evident that while SS is well-preserved in the bound states,it deteriorates in the resonant *** impact of nuclear deformation (β_(2)) on SS was examined,demonstrating that an increase in β_(2) resulted in higher energy and width splitting in the resonant spin doublets,which is attributed to increased component ***,the sensitivity of spin doublets to various potential parameters such as surface diffuseness (a),radius (R),and depth (Σ0) is discussed,emphasizing the role of these parameters in *** study provides valuable insights into the behavior of spin doublets in deformed nuclei and their interplay with the nuclear structure,thereby advancing our understanding of SS in the resonance state.

关键词： Spin symmetry Resonant states Deformed nuclei Complex-momentum representation

Performance Limits and Advancements in Single 2D Transition Metal Dichalcogenide Transistor

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Nano-Micro Letters 2024年第12期16卷 134-188页

作者： Jing Chen Ming-Yuan Sun Zhen-Hua Wang zheng Zhang Kai Zhang Shuai Wang Yu Zhang Xiaoming Wu Tian-Ling ren Hong liu Lin Han Institute of Marine Science and Technology Shandong UniversityQingdao 266237ShandongPeople’s Republic of China School of Integrated Circuits and Beijing National Research Center for Information Science and Technology(BNRist) Tsinghua UniversityBeijing 100084People’s Republic of China BNRist Tsinghua UniversityBeijing 100084People’s Republic of China State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100ShandongPeople’s Republic of China Shenzhen Research Institute of Shandong University Shenzhen 518057People’s Republic of China Shandong Engineering Research Center of Biomarker and Artificial Intelligence Application Jinan 250100People’s Republic of China

Two-dimensional(2D)transition metal dichalcogenides(TMDs)allow for atomic-scale manipulation,challenging the conventional limitations of semiconductor *** capability may overcome the short-channel effect,sparking significant advancements in electronic devices that utilize 2D *** the dimension and performance limits of transistors based on 2D TMDs has gained substantial *** review provides a comprehensive investigation into these limits of the single 2D-TMD *** delves into the impacts of miniaturization,including the reduction of channel length,gate length,source/drain contact length,and dielectric thickness on transistor operation and *** addition,this review provides a detailed analysis of performance parameters such as source/drain contact resistance,subthreshold swing,hysteresis loop,carrier mobility,on/off ratio,and the development of p-type and single logic *** review details the two logical expressions of the single 2D-TMD logic transistor,including current and *** also emphasizes the role of 2D TMD-based transistors as memory devices,focusing on enhancing memory operation speed,endurance,data retention,and extinction ratio,as well as reducing energy consumption in memory devices functioning as artificial *** review demonstrates the two calculating methods for dynamic energy consumption of 2D synaptic *** review not only summarizes the current state of the art in this field but also highlights potential future research directions and *** underscores the anticipated challenges,opportunities,and potential solutions in navigating the dimension and performance boundaries of 2D transistors.

关键词： Two-dimensional transistors Dimension limits Performance limits Memory devices Artificial synapses

Electrospinning-derived functional carbon-based materials for energy conversion and storage

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Chinese Chemical Letters 2024年第6期35卷 3-13页

作者： Xinyu ren Hong liu Jingang Wang Jiayuan Yu Institute for Advanced Interdisciplinary Research(iAIR) School of Chemistry and Chemical EngineeringUniversity of JinanJi’nan 250022China State Key Laboratory of Crystal Materials Shandong UniversityJi’nan 250100China

The over-exploitation of fossil fuel energy has brought about serious environmental *** would be of great significance to construct efficient energy conversion and storage system to maximize utilize renewable energy,which contributes to reducing environmental *** the past few years,in terms of electrocatalysis and energy storage,carbon fiber materials show great advantages due to its outstanding electrical conductivity,good flexibility and mechanical *** a simple and low-cost technique,electrospinning can be employed to prepare various *** is noted that the functional fiber materials with different special structure and composition can be obtained for energy conversion and storage by combining electrospinning with other *** this paper,the structural design,controllable synthesis and multifunctional applications of electrospinning-derived functional carbon-based materials(EFCMs)is ***,we briefly introduce the history,basic principle and typical equipment of *** we discuss the strategies for preparing EFCMs with different structures and composition in *** addition,we show recently the application of advanced EFCMs in energy conversion and storage,such as nitrogen species reduction reaction,CO_(2) reduction reaction,oxygen reduction reaction,water-splitting,supercapacitors and ion *** the end,we propose some perspectives on the future development direction of EFCMs.

关键词： Electrospinning Carbon materials Functional fiber Energy conversion Energy storage Electrocatalysis

Modulation of zeolite surface realizes dynamic copper species redispersion

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Chinese Journal of Structural Chemistry 2024年第6期43卷 6-7页

作者： Guoliang liu Zhiqiang liu Anmin zheng Interdisciplinary Institute of NMR and Molecular Sciences School of Chemistry and Chemical EngineeringThe State Key Laboratory of Refractories and MetallurgyWuhan University of Science and TechnologyWuhan430081PR China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan430071PR China

Zeolite-based metal nanoparticles(NPs)catalysts have shown promising applications in fuel production,petro-and fine-chemical manufacture,biomass refinery,and so *** of hydroxyl groups on the zeolite surface has proven to be effective in boosting catalytic reactions over metal-zeolite *** example,modifying the wettability of ZSM-5 and titanium silicalite-1(TS-1)crystals by surface hydrophobization drastically enhances catalytic performance of zeolites encapsulated AuPd[1]and Pt[2]NPs in methane oxidation and aldehydes/ketones hydrogenation,*** fact,two kinds of hydroxyl groups are present in zeolite materials,which refers to bridged hydroxyls[Si-O(H)-Al]and silanols[Si-O(H)].Both hydroxyl groups are defects of zeolite framework structures,which provides anchor points in dispersing metals[3].The former hydroxyl group is tunable to control acidity by adjusting Si/Al ratio in zeolite,whereas the role of silanols is not fully understood[4],particularly in the dispersion of metal NPs.

关键词： zeolite dispersion aldehydes

Secure state estimation for cyber-physical systems with unknown input sliding mode observer

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Control Theory and Technology 2024年第2期22卷 244-253页

作者： Panpan Zhang Yuwei ren Yixian Fang Ang liu School of Information Science and Engineering Shandong Normal UniversityJinan250358ShandongChina School of Information Engineering Shandong Management UniversityJinan250357ShandongChina

In recent years, cyber attacks have posed great challenges to the development of cyber-physical systems. It is of great significance to study secure state estimation methods to ensure the safe and stable operation of the system. This paper proposes a secure state estimation for multi-input and multi-output continuous-time linear cyber-physical systems with sparse actuator and sensor attacks. First, for sparse sensor attacks, we propose an adaptive switching mechanism to mitigate the impact of sparse sensor attacks by filtering out their attack modes. Second, an unknown input sliding mode observer is designed to not only observe the system states, sensor attack signals, and measurement noise present in the system but also counteract the effects of sparse actuator attacks through an unknown input matrix. Finally, for the design of an unknown input sliding mode state observer, the feasibility of the observing system is demonstrated by means of Lyapunov functions. Additionally, simulation experiments are conducted to show the effectiveness of this method.

关键词： Sparse attacks Cyber-physical systems Unknown input sliding mode Secure state estimation Adaptive switching mechanism

Co/Fe Dual Catalysis for Sequential Hydrosilylation-Isomerization:Access to Trisubstituted(E)-Alkenyl Silanes from Terminal Alkynes

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Chinese Journal of Chemistry 2024年第16期42卷 1860-1866页

作者： Zhihao Guo Guixia liu zheng Huang Chang-Kung Chuang Institute East China Normal UniversityShanghai 200062China The State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChineseAcademyof SciencesShanghai200032China School of Chemistry and Materials Science Hangzhou Institute of Advanced StudyUniversity of Chinese Academy of SciencesHangzhouZhejiang310024China

By rational modification of electronic and steric properties of pincer ligands,a Co/Fe dual catalyst system is developed for one-pot sequential Markovnikov alkyne hydrosilylation and stereoselective alkene *** protocol provides an atom-economical and efficient approach to trisubstituted(E)-alkenyl silanes from widely accessible terminal alkynes with high regio-and stereoselectivities under mild *** utility of this reaction was demonstrated by gram-scale synthesis and derivatization of bioactive *** radical clock and trapping experiments indicated that radical pathway might be operative in the alkene isomerization step.

关键词： Cobalt Dual catalysis Hydrosilylation Iron Isomerization Trisubstituted alkenyl silanes

Skull and vertebral bone marrow in central nervous system inflammation

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Fundamental Research 2024年第2期4卷 246-250页

作者： Honglei ren Qiang liu Department of Neurology Tianjin Neurological InstituteTianjin Institute of ImmunologyState Key Laboratory of Experimental HematologyInternational Joint Laboratory of Ocular DiseasesMinistry of EducationHaihe Laboratory of Cell EcosystemTianjin Medical University General HospitalTianjin 300052China

Emerging evidence has highlighted the capacity of hematogenous cells in skull and vertebral bone marrow to enter the meningeal borders via ossified vascular channels and maintain immune homeostasis in the central nervous system(CNS).CNS-adjacent skull and vertebral bone marrow comprises hematopoietic niches that can sense CNS injury and supply specialized immune cells to fine-tune inflammatory ***,we review recent advances in our understanding of skull and vertebral bone marrow-derived immune cells in homeostasis and inflammatory CNS ***,we discuss the implications for future development of therapies to mitigate CNS inflammation and its detrimental sequelae in neurological disorders.

关键词： Central nervous system Bone marrow Hematopoiesis Immune cells Neuroinflammation Stroke Multiple sclerosis

Influence of Vanes and Blades on Ingress in Axial Rim Seal for Turbine Stages

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Journal of Thermal Science 2024年第3期33卷 833-846页

作者： ren Ran DU Qiang liu Guang ZENG Yanlian XIE Lei Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China National Key Laboratory of Science and Technology on Advanced Light-duty Gas-turbine Beijing100190China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing100190China

Hot gas ingestion refers to the phenomenon of mainstream hot gas flowing into the space cavity of a turbine *** studies have found that mainstream annulus pressure distribution plays an important role in hot gas ingestion,but due to its complexity,the mechanism of the interaction between mainstream flow and hot gas ingestion remains *** paper adopts the URANS method,and three sealing flow rates are considered,named C_(w)=0,C_(w)=500,and C_(w)=*** time-averaged annulus pressure distribution shows that an increase in the sealing flow decreases the pressure value,and the effects of the sealing flow on the pressure distribution of the leading edge of the blade are much more influential than that of the trailing edge of the *** unsteady pressure time-space distribution in the annulus indicates that a time-space tilted distribution of pressure at the rim exits when the sealing flow *** phenomenon is mainly due to the strong feedback mechanism of the sealing flow to the annulus pressure field.A comparison of the pressure and mean radial velocity distribution of the mainstream shows that the ingestion mainly occurs on the blade side,where the pressure is lower than on the vane *** flow characteristics at the wheel rim are analyzed with a sealing flow rate C_(w)=5000,and under these conditions,both pressure-induced ingestion and ingestion caused by a passage vortex can be *** three-dimensional and inertial effects of the mainstream at the wheel rim lead to the generation of separation vortices on the blade side,and the presence of separation vortices leads to ingestion along the blade *** the same time,pressure on the blade side will cause the fluid to have a radial inward flow tendency,which will promote the formation of separation vortices,leading to more serious ingestion in the high-pressure region on the blade *** blade pressure field can be more significant than the vane trailing pressure field in the rim sea

关键词： separation vortex unsteady rim seal the effect of blade on ingestion

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