检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

自激式电感耦合等离子体光源设计及光谱分析

光谱学与光谱分析 2025年第1期45卷 66-71页

作者：卢思贤龙开红詹陈锐李明北方工业大学电气与控制工程学院北京100144 益阳职业技术学院电子与信息工程学院湖南益阳413055

电感耦合等离子体(ICP)光谱仪是一种应用范围很广的元素分析仪,主要用于元素定性与定量的分析。ICP光源是光谱仪的核心部件,它在光谱仪中扮演着至关重要的角色。目前主流的ICP光源有两种:自激式和他激式,各自具有优缺点。他激式光源电... 详细信息

电感耦合等离子体(ICP)光谱仪是一种应用范围很广的元素分析仪,主要用于元素定性与定量的分析。ICP光源是光谱仪的核心部件,它在光谱仪中扮演着至关重要的角色。目前主流的ICP光源有两种:自激式和他激式,各自具有优缺点。他激式光源电路复杂、体积庞大、阻抗匹配速度较慢、最大输出功率有限。设计了一种基于镀金工艺的高功率MOSFET和变频实现阻抗匹配的自激式ICP光源,该光源采用射频放大和阻抗匹配一体化的设计,把从负载线圈采样的频率信号f_(1)以及功率放大电路放大后的频率相位f_(0)进行相位比较,再根据两者相位差的变化,进而控制频率的变化,实现阻抗匹配;设计上采用了镀金工艺的金属化硅n通道型高功率的MOSFET实现功率放大,具有更大的功率密度、更小的体积,最大输出功率超过2400 W。对研制的ICP光源进行了电学静态测试,给出了鉴相器、压控振荡器以及功率的输出特性,验证了各电路在相应工作状态下的性能表现;同时结合光谱仪进行了包含Ba、na和Li元素标准溶液的测试,获得了目标元素的光谱信号;另外,对获得的光谱信号进行了处理,使用了基于EEMD特征增强的方法对目标元素光谱信号进行有效增强,信号的线性决定系数(R^(2))从0.97降至0.99,相对标准偏差(RSD)从6.47%降至1.07%,增强了信号的准确性和可用性。本文所研制的自激式ICP光源,通过射频放大和阻抗匹配一体化设计缩小了体积,变频技术使阻抗匹配速度从毫秒级提升到纳秒级,镀金工艺的MOSFET技术使最大输出功率从原来的1800 W增加到2400 W,为ICP光源的进一步优化和应用奠定了基础,具有重要的科学研究和工程实践意义。

关键词：自激式ICP光源阻抗匹配光谱信号 EEMD算法

An atomistic approach for the structural and electronic properties of twisted bilayer graphene-boron nitride heterostructures

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2022年第1期8卷 687-696页

作者： Min Long Pierre A.Pantaleón Zhen zhan Francisco Guinea JoseÁngel Silva-Guillén Shengjun Yuan Key Laboratory of Artificial Micro-and nano-structures of Ministry of Education and School of Physics and Technology Wuhan UniversityWuhan430072China Imdea nanoscience C/Faraday 928015MadridSpain Donostia International Physics Center Paseo Manuel de Lardizábal 420018San SebastiánSpain Ikerbasque Basque Foundation for Science48009BilbaoSpain Wuhan Institute of Quantum Technology Wuhan430206China

Twisted bilayer graphene(TBG)has taken the spotlight in the condensed matter community since the discovery of correlated *** this work,we study heterostructures of TBG and hexagonal boron nitride(hBn)using an atomistic tight-binding model together with semi-classical molecular dynamics to consider relaxation *** hBn substrate has significant effects on the band structure of TBG even in the case where TBG and hBn are not ***,the substrate induces a large mass gap and strong pseudo-magnetic fields that break the layer ***,such degeneracy can be recovered with a second hBn ***,we develop a continuum model that describes the tight-binding band *** results show that a real-space tight-binding model in combination with semi-classical molecular dynamics is a powerful tool to study the electronic properties of moiréheterostructures,and to explain experimental results in which the effect of the substrate plays an important role.

关键词： boron electronic twisted

Solution to nonlinear Parabolic Equations Related to P-Laplacian

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2012年第5期33卷 767-782页

作者： Huashui zhan School of Sciences Jimei University Xiamen 361021 Fujian China. E-mail: hszhan@***

Consider the following Cauchy problem：where 1 〈 p 〈 2, 1 〈 m 〈 p_~11, and # is a a-finite measure in n. By the Moser＇s iteration method, the existence of the weak solution is obtained, provided that （M＋1）n 〈 P. In mn＋l contrast, if 〉 p, there is no solution to the Cauchy problem with an initial value δ（X）, where 5（x） is the classical Dirac function.

关键词： nonlinear parabolic equation Cauchy problem Existence a-Finite measure

Evolutionary p(x)-Laplacian Equation with a Convection Term

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2019年第3期35卷 655-670页

作者： Hua-shui zhan School of Applied Mathematics Xiamen University of Technology

The paper studies an evolutionary p(x)-Laplacian equation with a convection term ut=div(ρα|■u|p(x)-2■u)+∑n i=1■bi(u)/■xi,whereρ(x)=dist(x,■Ω),ess inf p(x)=p^->*** assure the well-posedness of the solutions,the paper shows only a part of the boundary,Σp■■Ω,on which we can impose the boundary value.Σp is determined by the convection term,in particular,when 1ni(x)n essential difference between the equation and the usual evolutionary p-Laplacian *** last,the existence and the stability of weak solutions are proved under the additional conditionsαndΣp=■Ω.

关键词： Evolutionary p(x)-Laplacian equation week solution Fichera-Oleinik theory boundary degeneracy

On Tensor Spaces for Rook Monoid Algebras

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2016年第5期32卷 607-620页

作者： zhan Kui XIAO School of Mathematical Sciences Huaqiao University

Let m, n ∈ n, and V be an m-dimensional vector space over a field F of characteristic 0. Let U = F ＋ V and Rn be the rook monoid. In this paper, we construct a certain quasi-idempotent in the annihilator of U^×n in FRn, which comes from some one-dimensional two-sided ideal of rook monoid algebra. We show that the two-sided ideal generated by this element is indeed the whole annihilator of U^×n in FR^n.

关键词： Rook monoid tensor space general linear group symmetric group

Gelfand–Kirillov Dimensions of the Z^2-graded Oscillator Representations of sl(n)

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2015年第6期31卷 921-937页

作者： zhan Qiang BAI Institute of Mathematics Academy of Mathematics and System SciencesChinese Academy of Sciences

We find an exact formula of Gelfand-Kirillov dimensions for the infinite-dimensional explicit irreducible sl（n,F）-modules that appeared in the Z2-graded oscillator generalizations of the classical theorem on harmonic polynomials established by Luo and Xu. Three infinite subfamilies of these modules have the minimal Gelfand-Kirillov dimension. They contain weight modules with unbounded weight multiplicities and completely pointed modules.Service E-mail this articleAdd to my bookshelfAdd to citation managerE-mail AlertRSSArticles by authors

关键词： Gelfand-Kirillov dimension highest-weight module associated variety minimal GKdimension module universal enveloping algebra

Multi-Objective Optimization Analysis of Auxiliary Flux Modulator Magnetic Gear with Unequal Magnetic Poles

在线全文

学校读者我要写书评

暂无评论

CES Transactions on Electrical Machines and Systems 2023年第4期7卷 372-378页

作者： zhan Su Libing Jing the College of Electrical Engineering and new Energy Hubei Provincial Engineering Technology Research Center for MicrogridChina Three Gorges UniversityYichang 443002China

To enhance the output torque and minimize the torque ripple of coaxial magnetic gear(CMG),a novel auxiliary flux modulator CMG with unequal magnetic poles is *** design incorporates an inner rotor with an asymmetric sector and a trapezoidal combined n-S pole structure,featuring Halbach arrays for the arrangement of permanent magnets(PMs).The outer rotor PMs adopt a Spoke-type *** optimize the CMG for high output torque and low torque ripple,a sensitivity analysis is conducted to identify key size parameters that significantly influence the optimization *** on the sensitivity hierarchy of these parameters,a multi-objective optimization analysis is performed using a genetic algorithm(GA)to determine the optimal structural parameter values of the *** addition,a coaxial magnetic gear(CMG)topology with 4 inner and 17 outer pole pairs is adopted,and the parametric model is ***,the electromagnetic properties of the CMG are evaluated using the finite element *** results indicate a remarkable reduction in torque ripple,specifically by 46.15%.

关键词： Auxiliary flux modulator CMG Torque Multi-objective optimization Parameter sensitivity

Reducing energy barriers of chemical reactions with a nanomicrocell catalyst consisting of integrated active sites in conductive matrices

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2019年第6期64卷 385-390页

作者： Guo-Peng zhan Chuan-De State Key Laboratory of Silicon Materials Center for Chemistry of High-Performance&Novel MaterialsDepartment of ChemistryZhejiang University

Reducing energy barriers of chemical reactions is the never-ending endeavor of *** by the high reactivity of primary cells,we develop a nanosized fuel cell catalyst(denoted as nanomicrocell catalyst),consisting of integrated electrode pairs,conductive matrices and electrolytes,to improve the chemical ***,the anodes are Pd species which is combining with the electron-rich n atoms in B-and-n co-doped carbon dots;the cathodes are electron-deficient B atoms;and the conductive matrices are B-and-n co-doped carbon dots which are connecting with the electrode *** to the reactivity of primary cells,the catalytic properties of the nanomicrocell catalyst in hydrogenation of benzaldehyde are depending on the properties of electrode pairs,conductive matrices and *** unique catalytic properties are attributed to the different substrate adsorption capability and catalytic properties of paired electrodes,and the easy migration of electrons and charge carriers,which could improve the synergetic effect between paired active ***,this work may open up a new window for designed synthesis of advanced catalysts which could highly lower the energy barriers of chemical reactions.

关键词： nanomicrocell catalysts Conductive matrices Electrode pairs Electrolytes Primary cells

On the Well-Posedness Problem of the Anisotropic Porous Medium Equation with a Variable Diffusion Coefficient

在线全文

学校读者我要写书评

暂无评论

Journal of Partial Differential Equations 2024年第2期37卷 135-149页

作者： zhan Huashui School of Mathematics and Statistics Xiamen University of TechnologyXiamen 361024China

The initial-boundary value problem of an anisotropic porous medium equation■is *** with the usual porous medium equation,there are two different characteristics in this *** lies in its anisotropic property,another one is that there is a nonnegative variable diffusion coefficient a(x,t)*** a(x,t)may be degenerate on the parabolic boundary∂Ω×(0,T),instead of the boundedness of the gradient|∇u|for the usual porous medium,we can only show that∇u∈L^(∞)(0,T;L^(2)_(loc)(Ω)).Based on this property,the partial boundary value conditions matching up with the anisotropic porous medium equation are discovered and two stability theorems of weak solutions can be proved naturally.

关键词： Anisotropic porous medium equation variable diffusion coefficient stability partial boundary condition