Results 31 to 40 of about 7,480 (167)

Studies on optical properties of tip-enhanced Raman/fluorescence system [PDF]

open access: yes, 2015
针尖增强拉曼光谱(Tip-enhancedRamanspectroscopy,TERS)和针尖增强荧光(Tip-enhancedfluorescence,TEF)具有极高的检测灵敏度和空间分辨率,已经成为表面科学研究中强大的表征手段。尽管TERS及TEF在近年取得了重大的进步,但依然存在许多重大的科学问题尚待解决。如TERS实验中实现的亚纳米空间分辨理论机制已不能用常规的局域电场增强理论来加以解释;进展迅速的STM-TERS技术受到样品和基底导电的严重限制而急需发展普适性更广泛的针尖增强拉曼体系 ...
孟令雁
core  

CHINA’S LAND FINANCE AS ACTIVE MODE OF LAND DEVELOPMENT AND INFRASTRUCTURE DELIVERY: Reality, History and Prospects

open access: yesInternational Journal of Urban and Regional Research, Volume 50, Issue 1, Page 191-220, January 2026.
Abstract Henry George advocated for capturing land value increases for public ends. The active approach of public authorities organizing and financing land development can help capture higher land value increases, as Hartman and Spit indicate. However, this approach hardly happens in developing countries, where the coalition of private developers and ...
Nannan Xu
wiley   +1 more source

RBFEM在电场快速优化设计中的应用

open access: yesGaoya dianqi, 2010
针对高压电器设备电场优化设计常用有限元法(FEM)结合非线性规划法,设计变量改变后需要不断重复FEM的一系列计算过程,存在着大量的重复计算,从而引起计算量大大增加。为此,笔者引入了缩减基有限元法(RBFEM),推导了基于缩减基法的有限元方程。RBFEM通过计算维数大大减小的缩减基矩阵,使得整个优化过程的计算量大大减小。利用该算法,对500 kV电力变压器设备的绝缘结构进行了优化设计,每计算一次有限元方程,缩减基法需要的时间是FEM的1/4,可大大提高优化效率 ...
马爱清, 江秀臣, 贾一凡
doaj  

Design and Simulation of Contact Fatigue Testing System of Flexspline and Circular Spline in Harmonic Drive [PDF]

open access: yes, 2016
谐波齿轮传动是随着空间技术的发展而诞生的一种新型传动方式,其工作原理是利用柔轮的弹性变形波来实现运动或者动力传递,因其具有结构简单、传动精度高、传动比大等诸多优点,在航空、航天、机器人等领域得到了广泛应用。在谐波齿轮传动过程中,柔轮的运动情况比较复杂,作为弹性薄壁构件需承载交变应力,容易造成齿面磨损和疲劳断裂。因此,建立合适的模型对谐波齿轮传动过程中柔轮的错齿运动进行模拟分析具有重要意义。 本文首先针对谐波齿轮传动过程中柔轮的错齿运动设计了一种新的接触疲劳试验装置 ...
吴泽林
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Integrating Plant Tissue Culture and DNA Barcoding: Cutting‐Edge Technologies for Plant Conservation in Sri Lanka 整合植物组织培养与dna条形码技术:斯里兰卡植物保护的前沿技术

open access: yesIntegrative Conservation, Volume 4, Issue 4, Page 555-568, December 2025.
Sri Lanka's biodiversity is threatened by habitat loss, climate change, and ineffective traditional conservation methods. Integrating plant tissue culture and DNA barcoding offers scalable, precise tools for conserving rare and endemic species. This review emphasizes the potential of biotechnological approaches to enhance conservation accuracy and ...
Mylange Dona Kasundi Mekhala Gunasena   +2 more
wiley   +1 more source

The Efficient Mixed Spectral Element Method and the Mixed Finite Element Method for Maxwell’s Eigenvalue Problem [PDF]

open access: yes, 2017
电磁场本征值问题求解是计算电磁学的一个重要部分。本文的主要工作是研究电磁场本征值问题的快速高效数值方法。依照基函数选取不同分为两部分内容。第一部分研究了高精度混合谱元法,第二部分发展了混合有限元法,提出可质量矩阵对角化混合有限元法及传输阻抗边界混合有限元法。第一部分具体包括以下两方面工作: 一、运用Kikuchi混合变分格式耦合高斯定律提出了混合谱元法,用于求解二维及三维非均匀介质、耗散介质、及各向异性介质的电磁场本征值问题。该方法使用Gauss-Lobatto-Legendre(GLL ...
刘娜
core  

Prospects and perils in the geospatial turn of conservation

open access: yesConservation Biology, Volume 39, Issue 6, December 2025.
Abstract Conservation has embraced advances in big data and related digital technologies as key to preventing biodiversity loss, especially in the identification of areas of conservation priority based on spatial data, which we call the big geospatial data turn.
Jocelyne Shimin Sze, Laura Aileen Sauls
wiley   +1 more source

高压电气支柱法兰胶装结点等效弯曲模量研究

open access: yesDianci bileiqi, 2016
结合我国电力设施抗震设计规范(GB 50260—2013),试验数据及有限元模型,对高压电气设备法兰胶装节点弯曲刚度进行研究。采用有限元方法对500kV氧化锌避雷器建立三种不同模型,计算对比三种模型,研究法兰节点弯曲刚度。提出法兰节点刚度EI的修正系数,提供一种新的建立法兰胶装节点有限元模型的方法。
陈巍, 范荣全, 曹枚根, 卓越
doaj  

Understanding Student Preparedness to Handle L2 Writing Curriculum Transitions: A Hidden Curriculum Perspective

open access: yesInternational Journal of Applied Linguistics, Volume 35, Issue 4, Page 2063-2077, November 2025.
ABSTRACT Despite the efforts devoted to improving L2 writing pedagogy to promote student writing development, students’ dissatisfactory writing development and outcomes are still reported. Investigating student learning preparedness to navigate L2 writing curriculum transitions may generate new understandings and provide an alternative explanation for ...
Yu Zhou, Shulin Yu
wiley   +1 more source

Research on Eddy Current Testing of Damages in Carbon Fiber Reinforced Polymers [PDF]

open access: yes, 2015
碳纤维增强树脂基复合材料因其优异的性能已被广泛应用于飞行器制造、汽车制造、化学工业、造船与电气设备等各个行业,尤其是在航空航天、船舰以及核能设备等领域受到高度重视。然而,复合材料结构件在制造和使用过程中不可避免的会因为冲击等原因产生各种类型的缺陷。此外,复合材料结构件在损坏之前几乎没有先兆,其破坏具有突然性,这一点往往造成严重的后果。因此对碳纤维增强树脂基复合材料损伤的无损检测研究具有极其重要的意义。 目前应用较多的检测碳纤维增强树脂基复合材料损伤的方法有红外检测、X射线检测以及超声检测等 ...
杜飞
core  

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