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Numerical simulation of a truncated cladding negative curvature fiber sensor based on the surface plasmon resonance effect
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作者 张志超 苑金辉 +6 位作者 邱石 周桂耀 周娴 颜玢玢 吴强 王葵如 桑新柱 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第3期262-269,共8页
A refractive index(RI)sensor based on the surface plasmon resonance effect is proposed using a truncated cladding negative curvature fiber(TC-NCF).The influences of the TC-NCF structure parameters on the sensing perfo... A refractive index(RI)sensor based on the surface plasmon resonance effect is proposed using a truncated cladding negative curvature fiber(TC-NCF).The influences of the TC-NCF structure parameters on the sensing performances are investigated and compared with the traditional NCF.The simulation results show that the proposed TC-NCF RI sensor has an ultra-wide detection range from 1.16 to 1.43.The maximum wavelength sensitivity reaches 12400 nm/RIU,and the corresponding R^(2)of the polynomial fitting equation is 0.9999.The maximum and minimum resolutions are 2.56×10^(-5)and 8.06×10^(-6),respectively.In addition,the maximum amplitude sensitivity can reach-379.1 RIU^(-1)when the RI is chosen as 1.43.The proposed TC-NCF RI sensor could be useful in biochemical medicine,environmental monitoring,and food safety. 展开更多
关键词 truncated cladding negative curvature fiber refractive index sensor surface plasmon resonance
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Single-polarization single-mode hollow-core negative curvature fiber with nested U-type cladding elements
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作者 Qi-Wei Wang Shi Qiu +9 位作者 Jin-Hui Yuan Gui-Yao Zhou Chang-Ming Xia Yu-Wei Qu Xian Zhou Bin-Bin Yan Qiang Wu Kui-Ru Wang Xin-Zhu Sang Chong-Xiu Yu 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第6期422-428,共7页
Hollow-core negative curvature fibers(HC-NCFs)have become one of the research hotspots in the field of optical fiber because of their potential applications in the data and energy transmissions.In this work,a new kind... Hollow-core negative curvature fibers(HC-NCFs)have become one of the research hotspots in the field of optical fiber because of their potential applications in the data and energy transmissions.In this work,a new kind of single-polarization single-mode HC-NCF with nested U-type cladding elements is proposed.To achieve the single-polarization single-mode transmission,we use two different silica tubes in thickness,which satisfy the resonance and anti-resonance conditions on the U-type cladding elements and the cladding tubes,respectively.Besides,the elliptical elements are introduced to achieve good single-mode performance.By studying the influences of the structure parameters on the propagation characteristics,the optimized structure parameters are obtained.The simulation results show that when the wavelength is fixed at 1550 nm,the single-polarization single-mode transmission is achieved,with the polarization extinction ratio of 25749 and minimum high-order mode extinction ratio of 174.Furthermore,the confinement loss is only 0.0015 dB/m. 展开更多
关键词 hollow-core negative curvature fiber single-polarization SINGLE-MODE finite element method
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An Interpolation of Hardy Inequality and Moser–Trudinger Inequality on Riemannian Manifolds with Negative Curvature 被引量:2
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作者 Yan Qing DONG Qiao Hua YANG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2016年第7期856-866,共11页
Let M be a complete, simply connected Riemannian manifold with negative curvature. We obtain an interpolation of Hardy inequality and Moser-Trudinger inequality on M. Furthermore, the constant we obtain is sharp.
关键词 Moser-Trudinger inequality Hardy inequality Riemannian manifold negative curvature
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Existence and Uniqueness for the Non-Compact Yamabe Problem of Negative Curvature Type
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作者 Joseph Hogg Luc Nguyen 《Analysis in Theory and Applications》 2024年第1期57-91,共35页
We study existence and uniqueness results for the Yamabe problem on non-compact manifolds of negative curvature type.Ourfirst existence and uniqueness result concerns those such manifolds which are asymptotically local... We study existence and uniqueness results for the Yamabe problem on non-compact manifolds of negative curvature type.Ourfirst existence and uniqueness result concerns those such manifolds which are asymptotically locally hyperbolic.In this context,our result requires only a partial C2 decay of the metric,namely the full decay of the metric in C1 and the decay of the scalar curvature.In particular,no decay of the Ricci curvature is assumed.In our second result we establish that a local volume ratio condition,when combined with negativity of the scalar curvature at infinity,is sufficient for existence of a solution.Our volume ratio condition appears tight.This paper is based on the DPhil thesis of thefirst author. 展开更多
关键词 Yamabe problem non-compact manifolds negative curvature asymptotically locally hyperbolic asymptotically warped product relative volume comparison non-smooth conformal compactification
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Teichmller space of negatively curved metrics on complex hyperbolic manifolds is not contractible
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作者 FARRELL F. Thomas SORCAR Gangotryi 《Science China Mathematics》 SCIE CSCD 2017年第4期569-580,共12页
We prove that for all n = 4k- 2 and k 2 there exists a closed smooth complex hyperbolic manifold M with real dimension n having non-trivial π1(T<0(M)). T<0(M) denotes the Teichm¨uller space of all negative... We prove that for all n = 4k- 2 and k 2 there exists a closed smooth complex hyperbolic manifold M with real dimension n having non-trivial π1(T<0(M)). T<0(M) denotes the Teichm¨uller space of all negatively curved Riemannian metrics on M, which is the topological quotient of the space of all negatively curved metrics modulo the space of self-diffeomorphisms of M that are homotopic to the identity. 展开更多
关键词 space of Riemannian metrics negative curvature complex hyperbolic space
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On the Negativity of Ricci Curvatures of Complete Conformal Metrics
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作者 Qing Han Weiming Shen 《Peking Mathematical Journal》 2021年第1期83-117,共35页
A version of the singular Yamabe problem in bounded domains yields complete conformal metrics with negative constant scalar curvatures.In this paper,we study whether these metrics have negative Ricci curvatures.Affirm... A version of the singular Yamabe problem in bounded domains yields complete conformal metrics with negative constant scalar curvatures.In this paper,we study whether these metrics have negative Ricci curvatures.Affirmatively,we prove that these metrics indeed have negative Ricci curvatures in bounded convex domains in the Euclidean space.On the other hand,we provide a general construction of domains in compact manifolds and demonstrate that the negativity of Ricci curvatures does not hold if the boundary is close to certain sets of low dimension.The expansion of the Green’s function and the positive mass theorem play essential roles in certain cases. 展开更多
关键词 Negativity of Ricci curvatures The singular Yamabe problem negative sectional curvatures
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A NONMONOTONE SECOND-ORDER STEPLENGTH METHOD FOR UNCONSTRAINED MINIMIZATION 被引量:5
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作者 Qun-yan Zhou Wen-yu Sun 《Journal of Computational Mathematics》 SCIE EI CSCD 2007年第1期104-112,共9页
In this paper, a nonmonotone method based on McCormick's second-order Armijo's step-size rule [7] for unconstrained optimization problems is proposed. Every limit point of the sequence generated by using this proced... In this paper, a nonmonotone method based on McCormick's second-order Armijo's step-size rule [7] for unconstrained optimization problems is proposed. Every limit point of the sequence generated by using this procedure is proved to be a stationary point with the second-order optimality conditions. Numerical tests on a set of standard test problems are presented and show that the new algorithm is efficient and robust. 展开更多
关键词 Nonmonotone method Armijo's line search Direction of negative curvature Unconstrained optimization.
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Harmonic maps between compact Hermitian manifolds 被引量:1
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作者 LIU KeFeng YANG XiaoKui 《Science China Mathematics》 SCIE 2008年第12期2149-2160,共12页
In this paper, we generalize the Bochner-Kodaira formulas to the case of Hermitian complex (possibly non-holomorphic) vector bundles over compact Hermitian (possibly non-K?hler) manifolds. As applications, we get the ... In this paper, we generalize the Bochner-Kodaira formulas to the case of Hermitian complex (possibly non-holomorphic) vector bundles over compact Hermitian (possibly non-K?hler) manifolds. As applications, we get the complex analyticity of harmonic maps between compact Hermitian manifolds. 展开更多
关键词 Bochner-Kodaira formulas harmonic maps strongly negative curvature 53C40
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