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缺陷对单层硅烯纳米梁振动频率的影响

原子与分子物理学报 2025年第6期42卷 76-82页

作者：张文博王静新疆大学物理科学与技术学院乌鲁木齐830017

由于硅纳米谐振器在量子计算、传感器、医学等方面存在广泛的应用,使其物理性质的研究具有重要意义.本文通过分子动力学模拟方法研究了掺杂元素、空位缺陷、掺杂浓度对单层硅烯纳米梁振动特性的影响.研究结果表明,单层硅烯纳米梁的振动... 详细信息

由于硅纳米谐振器在量子计算、传感器、医学等方面存在广泛的应用,使其物理性质的研究具有重要意义.本文通过分子动力学模拟方法研究了掺杂元素、空位缺陷、掺杂浓度对单层硅烯纳米梁振动特性的影响.研究结果表明,单层硅烯纳米梁的振动频率随着纳米梁长度的增加而减小.单元素、双元素掺杂均会导致单层硅烯纳米梁的振动频率的增加,且随着掺杂浓度的增加纳米梁的振动频率整体呈现增大的趋势.此外,单空位缺陷会导致单层硅烯纳米梁的振动频率随着缺陷浓度的增加而减小.掺杂-单空位缺陷的单层硅烯纳米梁的振动频率则呈现了随着掺杂浓度的增加先减小后增加的变化趋势.这些变化规律均是由掺杂元素、空位缺陷以及它们共同作用的结果.此研究结果对硅烯纳米谐振器,振荡器等纳米器件的设计具有一定的理论指导意义.

关键词：硅烯掺杂振动频率分子动力学

Measuring the value of water quality improvements in Lake Tai, China

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第9期12卷 710-719页

作者： Wei-wen zhang Department of Land Management Zhejiang University Hangzhou 310029 China

Despite widespread concerns and elevated policy debates, little is known about the Chinese public＇s perceptions of water pollution and willingness to cooperate with government policies. Based on survey data, this study examined Lake Tai resident perception of water pollution, willingness to pay （WTP） for water quality improvements, and its influencing factors. Contingent valuation （CV） results showed that respondents would prefer to pay 141 CNY per household a year, approximately 0.70% of their annual per capita disposable income, as an environmental fee to improve water quality in Lake Yai. Aggregate WTP for all five lakeside cities of Lake Tai was estimated at about 3.8 billion CNY, without discounts, in the next ten years. WTP was found to increase with income and female respondents were willing to pay more than males. Those respondents who were dissatisfied with water quality were more likely to pay more. The usage of Lake Tai did not strongly affect WTE

关键词： Water quality Willingness to pay (WTP) Contingent valuation (CV) Lake Tai

WAVELET METHOD FOR BOUNDARY INTEGRALEQUATIONS

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Journal of Computational Mathematics 2000年第1期18卷 25-42页

作者： Pin-wen zhang Yu zhang School of Mathematical Sciences Peking UniversityBeliing 100871China Institute of Computational Mathematics and Scientific/Engineering Computing ChineseAcademy if SciencesBeijing 100080China

Presents a study which showed how to use wavelet to discretize the boundary integral equations. Application of wavelets to signal and image processing; Kinds of boundary reduction; Sparsity of the matrices in the stan... 详细信息

关键词： wavelet bases boundary integral equation preconditioning

Characterizations of Universal Finite Representability and B-convexity of Banach Spaces via Ball Coverings

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Acta Mathematica Sinica,English Series 2012年第7期28卷 1369-1374页

作者： wen zhang School of Mathematical Sciences Xiamen University

By a ball-covering B of a Banach space X, we mean that B is a collection of open （or closed） balls off the origin whose union contains the unit sphere of X; and X is said to have the ball-covering property provided it admits a ball-covering of countably many balls. This paper shows that universal finite representability and B-convexity of X can be characterized by properties of ball-coverings of its finite dimensional subspaces.

关键词： Ball-covering finite representability convexity universal space Banach space

Recovering Unbounded Rough Surfaces with a Direct Imaging Method

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Acta Mathematicae Applicatae Sinica 2020年第1期36卷 119-133页

作者： Hai-wen zhang NCMIS and Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China

In this paper,we consider the inverse acoustic scattering problem by an unbounded rough surface.A direct imaging method is proposed to reconstruct the rough surfaces from scattered-field data for incident plane waves and the performance analysis is also *** reconstruction method is very robust to noises of measured data and does’t need to know the type of the boundary conditions of the surfaces in ***,numerical examples are carried out to illustrate that our method is fast,accurate and stable even for the case of multiple-scale profiles.

关键词： direct imaging method inverse scattering problem unbounded rough surface incident plane wave near-field data

Construction of solitonary and periodic solutions to some nonlinear equations using EXP-function method

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第4期8卷 660-664页

作者： zhang Mei zhang wen-jing Department of Applied Physics College of Science Donghua University Shanghai 201620 China

This paper applies the EXP-function method to find exact solutions of various nonlinear equations. Tzitzeica- Dodd-Bullough (TDB) equation was selected to illustrate the effectiveness and convenience of the suggested method. More generalized solitonary solutions with free parameters were obtained by suitable choice of the free parameters, and also the obtained solitonary solutions can be converted into periodic solutions.

关键词： Soliton Periodic solution Nonlinear equation EXP-function method

Secondary Frequency Control Considering Optimized Power Support From Virtual Power Plant Containing Aluminum Smelter Loads Through VSC-HVDC Link

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Journal of Modern Power Systems and Clean Energy 2023年第1期11卷 355-367页

作者： Peng Bao wen zhang Yuxi zhang Key Laboratory of Power System Intelligent Dispatch and Control of the Ministry of Education Shandong UniversityJinan 250061China

The growing number of renewable energy replacing conventional generators results in a loss of the reserve for frequency control in power systems,while many industrial power grids often have excess energy supply due to abundant wind and solar energy *** paper proposes a secondary frequency control(SFC)strategy that allows industrial power grids to provide emergency high-voltage direct current(HVDC)power support(EDCPS)for emergency to a system requiring power support through a voltage source converter(VSC)HVDC *** architecture including multiple model predictive control(MPC)controllers with periodic communication is designed to simultaneously obtain optimized EDCPS capacity and minimize adverse effects on the providing power support(PPS)***,a model of a virtual power plant(VPP)containing aluminum smelter loads(ASLs)and a high penetration of wind power is established for the PPS *** flexibility and controllability of the VPP are improved by the demand response of the *** uncertainty associated with wind power is considered by chance *** effectiveness of the proposed strategy is verified by simulation results using the data of an actual industrial power grid in Inner Mongolia,*** DC voltage of the VSCs and the DC in the potlines of the ASLs are also investigated in the simulation.

关键词： Secondary frequency control power support voltage source converter(VSC) high-voltage direct current(HVDC) model predictive control(MPC) virtual power plant(VPP) demand response

Stability and guaranteed cost control for uncertain time-delay Lur'e systems

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Journal of Systems Engineering and Electronics 2008年第3期19卷 546-554页

作者： zhang Dongmei Yu Li zhang wen'an Coll. of Science Zhejiang Uinv. of Technology Hangzhou 310032 P. R. China Dept. of Automation Zhejiang Uinv. of Technology Hangzhou 310032 P. R. China

The problem of delay-dependent stability and guaranteed cost control （GCC） for a class of uncertain time-delay Lur＇e systems are studied. By using an improved integral inequality,a less conservative delay-dependent stability criterion is formulated as the feasibility problem of the linear matrix inequality （LMI）. The criterion is proved theoretically to be less conservative than some existing results for linear time-delay systems. Because of the fact that the matrices in the LMI-based stability criteria usually have different dimensions, different structures, and different variables, the conservatism analysis of the criteria is difficult. This study brings about a new insight into the comparison of conservatism among different stability criteria, which are expressed in certain LMI forms. The existence of the guaranteed cost controller is given in terms of matrix inequalities. The condition can be solved by using an iterative procedure and does not need any parameter tuning. A numerical example is given to illustrate the effectiveness of the proposed method.

关键词： guaranteed cost control absolute stability LMI delay-dependent.

Formation mechanism of interface reaction layer between microporous magnesia refractories and molten steel and its effect on steel cleanliness

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Journal of Iron and Steel Research International 2023年第9期30卷 1743-1754页

作者： wen-wen zhang Wan Zheng wen Yan Guang-qiang Li The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina Hubei Provincial Key Laboratory for New Process of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081HubeiChina

The ceramic filter in continuous casting tundish can effectively improve the cleanliness of high-performance steel by regulating tundish flow field to promote the removal of inclusions and adsorbing or blocking fine inclusions in the molten steel into the *** interaction between microporous magnesia refractories used as tundish filter and molten interstitial-free(IF)steel at 1873 K was investigated to reveal the formation mechanism of their interface layer and its effect on steel cleanliness by laboratory research and thermodynamic *** results show that the magnesium–aluminum spinel layer at the interface between the molten IF steel and the microporous magnesia refractories is formed mainly by the reaction of MgO in the refractory with the[Al]and[O]in the molten steel,significantly reducing the total O content,the size and amount of inclusions of the molten *** addition,the interparticle phases of microporous magnesia refractories at high temperature can adsorb Al_(2)O_(3) and TiO_(2) inclusions in the molten steel into interparticle channels of the refractories to form high melting point spinel,impeding the further penetration of the molten *** a result,the consecutive interface layer of high melting point spinel between microporous magnesia refractories and molten steel can improve the cleanliness of the molten steel by adsorbing inclusions in the molten steel and avoid the direct dissolution of refractories of the tundish ceramic filter immersed in the molten steel,increasing their service life.

关键词： Tundish metallurgy Microporous magnesia refractory Interstitial-free steel Formation mechanism Interface reaction layer Inclusion removal