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Cleaning of two mirrors in the first mirror unit using radiofrequency capacitively coupled plasma

Plasma Science and Technology 2024年第9期26卷 165-171页

作者： Chenxue WANG Rong YAN Yuming LIU Su XU Lei MU Wei ZHENG Rui DING Junling CHEN Institute of Plasma physics Chinese Academy of SciencesHefei 230031People’s Republic of China University of Science and Technology of China Hefei 230026People’s Republic of China School of Computer Engineering Anhui Sanlian UniversityHefei 230601People’s Republic of China

First mirror(FM)cleaning,using radio frequency(RF)plasma,has been proposed to recover FM reflectivity in nuclear fusion reactors such as the International Thermonuclear Experimental Reactor(ITER).To investigate the influence of simultaneous cleaning of two mirrors on mirror cleaning efficiency and uniformity,experiments involving single-mirror cleaning and dual-mirror cleaning were conducted using RF capacitively coupled plasma in the *** the test and simultaneous cleaning of two mirrors,the FM and second mirror(SM),both measuring 1.0 mm×80 mm,were placed inside the first mirror unit(FMU).They were composed of 1. mirror samples,each with a dimension of 27.5 mm×20 *** mirror samples consist of a titanium-zirconium-molybdenum alloy substrate,a 500 nm Mo intermediate layer and a 30 nm Al_(2)O_(3) surface coating as a proxy for Be *** cleaning of a single first mirror(SFM)and the simultaneous cleaning of the FM and SM(DFM and DSM)lasted for 9 h using Ar plasma at a pressure of 1.*** total reflectivity of mirror samples on the DSM did not fully recover and varied with location,with a self-bias of−1.0 *** a self-bias of−300 V,the total reflectivity of mirror samples on the SFM and DFM was fully *** energy dispersive spectrometer results demonstrated that the Al_(2)O_(3) coating had been completely removed from these mirror ***,the mass loss of each mirror sample on the SFM and DFM before and after cleaning varied depending on its location,with higher mass loss observed for mirror samples located in the corners and lower loss for those in the *** with SM cleaning,the simultaneous cleaning of two mirrors reduced the difference between the highest and lowest mass ***,this mass loss for the mirror samples of the DFM facing the DSM was *** indicated that mirror samples cleaned face to face in the FMU simultaneously could influence each other,highlighting the need for special attention in

关键词： first mirror unit dual-mirror cleaning reflectivity sputtering rate

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CPT-Frames for Non-Hermitian Hamiltonians

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Communications in Theoretical physics 2013年第9期60卷 328-334页

作者：曹怀信郭志华陈峥立 college of {1. and Information Science Shaanxi Normal University

Based on the PT-symmetric quantum theory, the concepts of PT-frame, PT-symmetric operator and CPT-frame on a Hilbert space K and for an operator on K are proposed. It is proved that the spectrum and point spectrum of a PT-symmetric linear operator are both symmetric with respect to the real axis and the eigenvalues of an unbroken PT-symmetric operator are real. For a linear operator H on Cd, it is proved that H has unbroken PT- symmetry if and only if it has d different eigenvalues and the corresponding eigenstates are eigenstates of PT. Given a CPT-frame on K, a new positive inner product on K is induced and called CPT-inner product. Te relationship between the CPT-adjoint and the Dirac adjoint of a densely defined linear operator is derived, and it is proved that an operator which has a bounded CPT-frame is CPT-Hermitian if and only if it is T-symmetric, in that case, it is similar to a Hermitian operator. The existence of an operator C consisting of a CPT-frame is discussed, These concepts and results will serve a mathematical discussion about PT-symmetric quantum mechanics.

关键词： CPT-frame PT-frame PT-symmetry operator

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Comparison of band structure and superconductivity in FeSe_(0.5)Te_(0.5) and FeS

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Chinese physics B 2017年第12期26卷 526-532页

作者：杨阳冯世全向圆圆路洪艳王万胜 college of {1. and Electronic Engineering Zhengzhou University of Light Industry college of Science Hohai University School of physics and Electronic Information Huaibei Normal University Department of physics Ningbo University

The isovalent iron chalcogenides, FeSe0.5Te0.5 and FeS, share similar lattice structures but behave very differently in superconducting properties. We study the underlying mechanism theoretically. By first principle calculations and tight-binding fitting, we find the spectral weight of the dX2-Y2 orbital changes remarkably in these compounds. While there are both electron and hole pockets in FeSe0.5Te0.5 and FeS, a small hole pocket with a mainly dX2-Y2 character is absent in FeS. We find the spectral weights of dX2-Y2 orbital change remarkably, which contribute to electron and hole pockets in FeSe0.5Te0.5 but only to electron pockets in FeS. We then perform random-phase-approximation and unbiased singular-mode functional renormalization group calculations to investigate possible superconducting instabilities that may be triggered by electron-electron interactions on top of such bare band structures. For FeSe0.5Te0.5, we find a fully gapped s-wave pairing that can be associated with spin fluctuations connecting electron and hole pockets. For FeS, however, a nodal dxy （or dx2-y2 in an unfolded Broullin zone） is favorable and can be related to spin fluctuations connecting the electron pockets around the corner of the Brillouin zone. Apart from the difference in chacogenide elements, we propose the main source of the difference is from the dX2-Y2 orbital, which tunes the Fermi surface nesting vector and then influences the dominant pairing symmetry.

关键词： iron-based superconductors theories and models of superconducting state pairing symmetry

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Large-scale boron nanowire nanojunctions and their highly-oriented arrays

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Science China(physics,Mechanics & Astronomy) 2004年第5期47卷 621-632页

作者： CAO Limin1.2, ZHANG Ze2 & WANG Wenkui1.2 1. Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China 2. Institute of physics, Chinese Academy of Sciences, Beijing 1.0080, China 1. Key Laboratory of Metastable Materials Science and Technology Yanshan University 066004 Qinhuangdao China 2. Institute of physics Chinese Academy of Sciences 100080 Beijing China

Highly oriented multiple boron nanowire nanojunctions with unilateral feather- like morphology were first successfully prepared using a radio-frequency magnetron sputtering method. The branched boron nano-feathers always nucleate and grow on the same sidewall of the stems, and align in parallel to form multiple T- and/or Y-type nanojunctions. The diameters of the branches and the stems are in the range of 20—40 and 60—80 nm, respectively. The thinner branches and thicker stems of the boron nanowires self-assembled into large-scale, highly ordered arrays on various substrates. During the formation and self-assembly of the arrays, no template or catalyst was needed. We believe that the approach presented here can be used to fabricate heterostructures with bottom-up assembly of a wide variety of one-dimensional nanostructures via the rational design of targets and the proper control of the experimental conditions.

关键词： boron nanowires, nanojunctions, self-assembly, magnetron sputtering.

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Controlling Chaos in Hénon Map by the Constant Feedback Method

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Communications in Theoretical physics 2007年第2X期48卷 279-287页

作者： HAO Jian-Hong XU Hai-Bo YU Jin-Jiang Department of Information Engineering North China Electric Power University. Beijing 102206 China Institute of Applied physics and Computational {1. Beijing 100088 China Department of physics Shijiazhuang College Shijiazhuang 050801 China

We demonstrate the constant feedback and the modified constant feedback method to the Hénon map. Using the convergence of the chaotic orbit in finite time, we can control the system from chaos to the stable fixed point, and even to the stable period-2 orbit or higher periodic orbit by the action of a proper feedback strength and pulse interval. We also find that the multi-steady solutions appear with the same control strength and different initial conditions. The aim of this control method is explicit and the feedback strength is easy to determine. The method is robust under the presence of weak external noise.

关键词： constant feedback modified constant feedback finite time convergence zone Hénon map multisteady solutions

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A Survey on an Emerging Safety Challenge for Autonomous Vehicles:Safety of the Intended Functionality

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Engineering 2024年第2期33卷 17-34页

作者： Hong Wang Wenbo Shao Chen Sun Kai Yang Dongpu Cao Jun Li Tsinghua Intelligent Vehicle Design and Safety Research Institute School of Vehicle and MobilityTsinghua UniversityBeijing 100084China CogDrive Lab Department of Mechanical and Mechatronics EngineeringUniversity of WaterlooWaterlooON N2L3G1Canada college of Mechanical and Vehicle Engineering Chongqing UniversityChongqing 400044China

As the complexity of autonomous vehicles(AVs)continues to increase and artificial intelligence algorithms are becoming increasingly ubiquitous,a novel safety concern known as the safety of the intended functionality(SOTIF)has emerged,presenting significant challenges to the widespread deployment of *** focuses on issues arising from the functional insufficiencies of the AVs’intended functionality or its implementation,apart from conventional safety *** the systems engineering standpoint,this study offers a comprehensive exploration of the SOTIF landscape by reviewing academic research,practical activities,challenges,and perspectives across the development,verification,validation,and operation *** research encompasses system-level SOTIF studies and algorithm-related SOTIF issues and ***,it encapsulates practical SOTIF activities undertaken by corporations,government entities,and academic institutions spanning international and Chinese contexts,focusing on the overarching methodologies and practices in different ***,the paper presents future challenges and outlook pertaining to the development,verification,validation,and operation phases,motivating stakeholders to address the remaining obstacles and challenges.

关键词： Safety of the intended functionality Autonomous vehicles Artificial intelligence Uncertainty Verification Validation

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SVOM gamma ray monitor

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Science China(physics,Mechanics & Astronomy) 2010年第S1期53卷 40-42页

作者： DONG YongWei,WU BoBing,LI YanGuo,ZHANG YongJie & ZHANG ShuangNan Key Laboratory of Particle Astrophysics,Institute of High Energy physics,Chinese Academy of Sciences,Beijing 1.0049,China 1. Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

The space-based multi-band astronomical Variable Object Monitor(SVOM) mission is dedicated to the detection,localization and broad-band study of gamma-ray bursts(GRBs) and other high-energy transient *** gamma ray monitor(GRM) onboard is designed to observe GRBs up to 5 *** this instrument,one of the key GRB parameters,Epeak,can be easily measured in the hard X-ray *** can achieve a detection rate of 1.0 GRBs per year which ensures the scientific output of SVOM.

关键词： gamma-ray burst Epeak triple phoswich

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First-principles study of orbital ordering in cubic fluoride KCrF_3

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Chinese physics B 2014年第3期23卷 514-517页

作者：明星熊良斌徐火希杜菲王春忠陈岗 college of {1. and Electronic Information Huanggang Normal University college of {1. State Key Laboratory of Superhard Materials Jilin University

Comprehensive first-principles calculations are performed to provide insight into the intriguing physical properties of the ternary cubic fluoride KCrF3. The electronic structures exhibit a prominent dependence on the effective local Coulomb interaction parameter Ueff. The ground state of the cubic phase is a ferromagnetic （FM） half-metal with Ueff equal to 0, 2, and 4 eV, whereas the insulating A-type antiferromagnetic （A-AFM） state with concomitant homogeneous orbital ordering is more robust than the FM state for Ueff exceeding 4 eV. We propose that the origin of the orbital ordering is purely electronic when the cooperative Jahn-Teller distortions are absent in cubic KCrF3.

关键词： electron density of states band structure orbital ordering first-principles calculations

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Simulation of Haloxylon Ammodendron Stand Basic Diameter Structure Based on Fuzzy Distribution Function

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Agricultural Sciences 2024年第1期15卷 132-145页

作者： Shaohua Wang Chuanqiang Liu Ting Yang college of Economics and Management Hunan University of Arts and Science Changde China college of Agricultural Shihezi University Shihezi China

Based on the investigation data of 1. Haloxylon ammodendron plots in the south edge of Gurbantunggut Desert, Fuzzy distribution was introduced into the study of Haloxylon ammodendron base diameter structure fitting according to the consistency between the characteristics of Fuzzy distribution function and the distribution series of cumulative percentage of stand base diameter, and the fitting precision and effect of Fuzzy distribution function were discussed. The root mean square error RMSE and determination coefficient R2 values showed that Fuzzy-Γ1./sub>, Fuzzy-Γ2, Fuzzy-Γ3, Fuzzy-Γ4 had good fitting performance, among which Fuzzy-Γ1./sub> had relatively high fitting precision, and its parameters were closely related to stand age and density, Fuzzy-Γ2 distribution function was the second, and Fuzzy-Γ4 distribution function had the worst fitting effect. By introducing a parameter c from the similarity of four distribution function formulas, a generalized Fuzzy distribution function Fuzzy-Γ5 is obtained. This function shows the highest fitting accuracy. Most of the values of parameter c are near 1.or 2, which shows that the diameter distribution is mainly approximate to Fuzzy-Γ1./sub> and Fuzzy-Γ2.

关键词： Fuzzy Distribution Function Haloxylon Ammodendron Base Diameter Distribution Stand Factor

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APPROXIMATIONS OF HYPERSINGULAR INTEGRALS FOR NEGATIVE FRACTIONAL EXPONENT

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Journal of Computational mathematics 2018年第5期36卷 627-643页

作者： Chaolang Hu Tao Lu college of {1. Sichuan University Chengdu 610064 China

This article presents approximations of the hypersingular integrals fa^b g（x）（x- t）^adx and fa^b g（x）｜x- t｜dx with arbitrary singular point t C （a, b） and negative fraction number 〈 -1. These general expansions are applicable to a large range of hypersingular inte- grals, including both popular hypersingular integrals discussed in the literature and other important ones which have not been addressed yet. The corresponding mid-rectangular formulas and extrapolations, which can be calculated in fairly straightforward ways, are investigated. Numerical examples are provided to illustrate the features of the numerical methods and verify the theoretical conclusions.

关键词： Hypersingular integral Negative fractional exponent Mid-rectangular quadrature formula Extrapolation.

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