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Effect of ambient pressures on laser-induced breakdown spectroscopy signals

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Frontiers of physics 2024年第4期19卷 243-256页

作者： Kaifan Zhang Weiran Song Zongyu hou zhe Wang State Key Laboratory of Power System Operation and Control Tsinghua-Rio Tinto Joint Research Centre for ResourcesEnergy and Sustainable DevelopmentInternational Joint Laboratory on Low Carbon Clean Energy InnovationInstitute for Carbon NeutralityDepartment of Energy and Power EngineeringTsinghua UniversityBeijing 100084China Shanxi Research Institute for Clean Energy Tsinghua UniversityTaiyuan 030032China

Laser-induced breakdown spectroscopy(LIBS)is regarded as the future superstar for analytical chemistry and widely applied in various *** the quality of LIBS signal is fundamental to achieving accurate quantification and large-scale commercialization of *** propose control methods that improve LIBS signal quality,it is essential to have a comprehensive understanding of the influence of key parameters,such as ambient gas pressure,temperature,and sample temperature on LIBS *** date,extensive research has been carried ***,different researchers often yield significantly different experimental results for LIBS,preventing the formation of consistent *** greatly prevents the understanding of influencing laws of key parameters and the improvement of LIBS quantitative *** ambient gas pressure as an example,this paper compares the effects of ambient gas pressure under different optimization conditions,reveals the influence of spatiotemporal window caused by inherent characteristics of LIBS signal sources,i.e.,intense temporal changes and spatial non-uniformity of laser-induced plasmas,on the impact patterns of key *** the perspective of plasma spatiotemporal evolution,the paper elucidates the influence patterns of ambient gas pressure on LIBS signals,clarifying seemingly contradictory research results in the literature.

关键词： laser-induced breakdown spectroscopy spatiotemporal window pressure condition signal uncertainty plasma modulation

Output Feedback Stabilization of Switched Stochastic Nonlinear Systems Under Arbitrary Switchings

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International Journal of Automation and computing 2013年第6期10卷 571-577页

作者： Xiao-Ling Liang ming-zhe hou Guang-Ren Duan Center for Control Theory and Guidance Technology Harbin Institute of Technology

This paper is concerned with the problem of global output feedback stabilization in probability for a class of switched stochastic nonlinear systems under arbitrary switchings. The subsystems are assumed to be in output feedback form and driven by white noise. By introducing a common Lyapunov function, the common output feedback controller independent of switching signals is constructed based on the backstepping approach. It is proved that the zero solution of the closed-loop system is fourth-moment exponentially stable. An example is given to show the effectiveness of the proposed method.

关键词： Stochastic nonlinear system switched nonlinear system output feedback under arbitrary switchings moment expo-nential stability.

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Dual Frequency Transformer for Efficient SDR-to-HDR Translation

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Machine Intelligence Research 2024年第3期21卷 538-548页

作者： Gang Xu Qibin hou ming-ming Cheng Tianjin Media Computing Center College of Computer ScienceNankai UniversityTianjin300000China

The SDR-to-HDR translation technique can convert the abundant standard-dynamic-range (SDR) media resources to high-dynamic-range (HDR) ones, which can represent high-contrast scenes, providing more realistic visual experiences. While recent vision Transformers have achieved promising performance in many low-level vision tasks, there are few works attempting to leverage Transformers for SDR-to-HDR translation. In this paper, we are among the first to investigate the performance of Transformers for SDR-to-HDR translation. We find that directly using the self-attention mechanism may involve artifacts in the results due to the inappropriate way to model long-range dependencies between the low-frequency and high-frequency components. Taking this into account, we advance the self-attention mechanism and present a dual frequency attention (DFA), which leverages the self-attention mechanism to separately encode the low-frequency structural information and high-frequency detail information. Based on the proposed DFA, we further design a multi-scale feature fusion network, named dual frequency Transformer (DFT), for efficient SDR-to-HDR translation. Extensive experiments on the HDRTV1K dataset demonstrate that our DFT can achieve better quantitative and qualitative performance than the recent state-of-the-art methods. The code of our DFT is made publicly available at https://***/CS-GangXu/DFT.

关键词： Standard-dynamic-range to high-dynamic-range(SDR-to-HDR)translation Transformer dual frequency attention(DFA) frequency-aware feature decomposition efficient model

Tunable quantum anomalous Hall effects in ferromagnetic van der Waals heterostructures

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National Science Review 2024年第3期11卷 100-107页

作者： Feng Xue Yusheng hou zhe Wang Zhiming Xu Ke He Ruqian Wu Yong Xu Wenhui Duan Beijing Academy of Quantum Information Sciences State Key Laboratory of Low Dimensional Quantum Physics Department of Physics Tsinghua University Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices Center for Neutron Science and Technology School of Physics Sun Yat-sen University State Key Laboratory of Surface Physics Key Laboratory of Computational Physical Sciences and Department of PhysicsFudan University Frontier Science Center for Quantum Information Department of Physics and Astronomy University of California-Irvine Tencent Quantum Laboratory Tencent Technology(Shenzhen)Co.Ltd RIKEN Center for Emergent Matter Science(CEMS) Institute for Advanced Study Tsinghua University

The quantum anomalous Hall effect（QAHE） has unique advantages in topotronic applications, but it is still challenging to realize the QAHE with tunable magnetic and topological properties for building functional devices. Through systematic first-principles calculations, we predict that the in-plane magnetization induced QAHE with Chern numbers C = ±1 and the out-of-plane magnetization induced QAHE with high Chern numbers C = ±3 can be realized in a single material candidate, which is composed of van der Waals（vdW）coupled Bi and MnBi2Te4monolayers. The switching between different phases of QAHE can be controlled in multiple ways, such as applying strain or（weak） magnetic field or twisting the vdW materials. The prediction of an experimentally available material system hosting robust, highly tunable QAHE will stimulate great research interest in the field. Our work opens a new avenue for the realization of tunable QAHE and provides a practical material platform for the development of topological electronics.

关键词： quantum anomalous Hall effect topological quantum phase transition van der Waals heterostructures tunable Chern number high Chern number

Manufacturing task data chain-driven production logistics trajectory analysis and optimization decision making method

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Advances in Manufacturing 2024年第1期12卷 185-206页

作者： Lin Ling zhe-ming Song Xi Zhang Peng-Zhou Cao Xiao-Qiao Wang Cong-Hu Liu ming-Zhou Liu School of Mechanical Engineering Hefei University of TechnologyHefei230009People’s Republic of China Guobo Electronics Co.Ltd. Nanjing211111People’s Republic of China School of Mechanical and Electronic Engineering Suzhou UniversitySuzhou234000AnhuiPeople’s Republic of China Sino-US Global Logistics Institute Shanghai Jiao Tong UniversityShanghai200030People’s Republic of China

Production logistics(PL)is considered as a critical factor that affects the efficiency and cost of production operations in discrete manufacturing *** effectively utilize manufacturing big data to improve PL efficiency and promote job shop floor economic benefits,this study proposes a PL trajectory analysis and optimization decision making method driven by a manufacturing task data chain(MTDC).First,the manufacturing task chain(MTC)is defined to characterize the discrete production process of a *** handle manufacturing big data,the MTC data paradigm is designed,and the MTDC is ***,the logistics trajectory model is presented,where the various types of logistics trajectories are extracted using the MTC as the search engine for the *** on this,a logistics efficiency evaluation indicator system is proposed to support the optimization decision making for the ***,a case study is applied to verify the proposed method,and the method determines the PL optimization decisions for PL efficiency without changing the layout and workshop equipment,which can assist managers in implementing the optimization decisions.

关键词： Production logistics(PL) Logistics trajectory analysis Logistics optimization Data driven Manufacturing task data chain(MTDC)

Evolution of High-energy Electron Distribution in Pulsar Wind Nebulae

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Research in Astronomy and Astrophysics 2024年第7期24卷 201-217页

作者： Yi-ming Liu hou-Dun Zeng Yu-Liang Xin Si-ming Liu Yi Zhang Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of Sciences School of Astronomy and Space Science University of Science and Technology of China School of Physical Science and Technology Southwest Jiaotong University

In this paper,we analyze the spectral energy distributions of 17 powerful (with a spin-down luminosity greater than1035erg s-1) young （with an age less than 15,000 yr） pulsar wind nebulae （PWNe） using a simple timein-dependent one-zone emission *** aim is to investigate correlations between model parameters and the ages of the corresponding PWNe,thereby revealing the evolution of high-energy electron distributions within *** findings are as follows:（1） The electron distributions in PWNe can be characterized by a double power-law with a super-exponential cutoff.（2） As PWNe evolve,the high-energy end of the electron distribution spectrum becomes harder with the index decreasing from approximately 3.5 to 2.5,while the low-energy end spectrum index remains constant near 1.5.（3） There is no apparent correlation between the break energy or cutoff energy and the age of PWNe.（4） The average magnetic field within PWNe decreases with age,leading to a positive correlation between the energy loss timescale of electrons at the break energy or the high-energy cutoff and the age of the PWN.（5） The total electron energy within PWNe remains constant near 2×1048erg,while the total magnetic energy decreases with age.

关键词： gamma-rays: general ISM: general ISM: supernova remnants radiation mechanisms: non-thermal

Influences of shale microstructure on mechanical properties and bedding fractures distribution

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Petroleum Science 2024年第3期21卷 1944-1954页

作者： ming-zhe Gu Mao Sheng Shi-Zhong Cheng Fan-Hao Gong Gen-Sheng Li State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum-BeijingBeijing2249China College of Petroleum Engineering China University of Petroleum-BeijingBeijing102249China Shenyang Center of China Geological Survey ShenyangLiaoning110034China

The difference in microstructure leads to the diversity of shale mechanical properties and bedding fractures distribution *** this paper,the microstructure and mechanical properties of Longmaxi marine shale and Qingshankou continental shale were studied by X-ray diffractometer(XRD),field emission scanning electron microscope(FE-SEM)with mineral analysis system,and ***,the typical bedding layers area was properly stratified using Focused Ion Beam(FIB),and the effects of microstructure and mechanical properties on the distribution patterns of bedding fractures were *** results show that the Longmaxi marine shale sample contains more clay mineral grains,while the Qingshankou continental shale sample contains more hard brittle mineral grains such as *** Longmaxi marine shale sample,hard brittle minerals with grain sizes larger than 20μm is18.24%and those with grain sizes smaller than 20μm is 16.22%.For Qingshankou continental shale sample,hard brittle minerals with grain sizes larger than 20μm is 40.7%and those with grain sizes smaller than 20μm is 11.82%.In comparison to the Qingshankou continental shale sample,the Longmaxi marine shale sample has a lower modulus,hardness,and *** shales are formed by alternating coarse-grained and fine-grained layers during *** average single-layer thickness of Longmaxi marine shale sample is greater than Qingshankou continental shale *** two types of shale have similar bedding fractures distribution patterns and fractures tend to occur in the transition zone from coarse-grained to fine-grained *** orientation of the fracture is usually parallel to the bedding plane and detour occurs in the presence of hard brittle *** fracture distribution density of the Longmaxi marine shale sample is lower than that of the Qingshankou continental shale sample due to the strong heterogeneity of the Qingshankou continental *** current resea

关键词： Shale Nanoindentation Microstructure Mechanical property Fracture

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Composition operators on weighted Hardy spaces of polynomial growth

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Acta Mathematica Sinica,English Series 2024年

作者： Bing zhe hou Chun Lan JIANG School of Mathematics Jilin University School of Mathematics Hebei Normal University

In the present paper, we study the composition operators acting on weighted Hardy spaces of polynomial growth, which are concerned with norms, spectra and (semi-)Fredholmness. Firstly, we estimate the norms of the composition operators with symbols of disk automorphisms. Secondly, we discuss the spectra of the composition operators with symbols of disk automorphisms. In particular, it is proven of that the spectrum of a composition operator with symbol of any parabolic disk automorphism is always the unit circle. Thirdly, we consider the Fredholmness of the composition operator Cφwith symbolφwhich is an analytic self-map on the closed unit disk. We prove that Cφacting on a weighted Hardy space of polynomial growth has closed range (semi-Fredholmness) if and only ifφis a finite Blaschke product. Furthermore, it is obtained that Cφis Fredholm if and only ifφis a disk automorphism.

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Deciphering the Shared and Specific Drug Resistance Mechanisms of Anaplastic Lymphoma Kinase via Binding Free Energy Computation

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Research 2024年第1期2023卷 663-674页

作者： Yang Yu zhe Wang Lingling Wang Qinghua Wang Rongfan Tang Sutong Xiang Qirui Deng Tingjun hou Huiyong Sun Department of Medicinal Chemistry China Pharmaceutical UniversityNanjing 210009JiangsuP.R.China Innovation Institute for Artificial Intelligence in Medicine of zhejiang University College of Pharmaceutical SciencesZhejiang UniversityHangzhou 310058ZhejiangP.R.China

Anaplastic lymphoma kinase(ALK),a tyrosine receptor kinase,has been proven to be associated with the occurrence of numerous *** there have been already at least 3 generations of ALK inhibitors approved by FDA or in clinical trials,the occurrence of various mutations seriously attenuates the effectiveness of the ***,most of the drug resistance mechanisms still remain ***,it is necessary to reveal the bottom reasons of the drug resistance mechanisms caused by the *** this work,on the basis of verifying the accuracy of 2 main kinds of binding free energy calculation methodologies[end-point method of Molecular Mechanics with Poisson-Boltzmann/Generalized Born and Surface Area(MM/PB(GB)SA)and alchemical method of Thermodynamic Integration(TI)],we performed a systematic analysis on the ALK systems to explore the underlying shared and specific drug resistance mechanisms,covering the one-drug-multiple-mutation and multiple-drug-onemutation cases.

关键词： drugs Anaplastic clinical