Results 51 to 60 of about 22,750 (171)

The Research on Multi-Sensors Calibration of Mobile Mapping Systems [PDF]

open access: yes, 2014
人们从外界获取的信息绝大部分来源于视觉。人们通过眼睛将获取的信息传入到大脑,再由大脑对其进行相应的处理与分析。随着传感器与计算机技术的迅速发展,计算机视觉逐渐实现了替代人眼与大脑实现对周围环境的简单识别与理解。计算机视觉的研究目标是让计算机能像人那样通过视觉观察和理解世界,这不仅要求计算机能够感知三维环境中物体的几何信息(物体的形状、位置、姿态等),还需要对它们进行存储、描述、识别与理解。相比于直接在三维环境中通过各种机械量测工具、测角和测距设备等实现三维环境信息的描述、存储等 ...
李迪龙
core  

Systematic Study of Fermi‐Level Pinning at Crystalline Metal/GaN Interfaces: First‐Principles Calculations and Diode Characterization

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT The Schottky barrier height (SBH), which serves as a pivotal determinant of charge carrier injection efficiency in electronic devices, critically governs electrical behavior at metal/semiconductor interfaces. However, pronounced metal‐induced gap states at metal contact interfaces induce Fermi‐level pinning, which constrains the ...
Xiaofei Liu   +10 more
wiley   +1 more source

用于特高压电晕笼分裂导线的集成化光电式电晕损失测量系统设计

open access: yesGaoya dianqi, 2017
为了研究高海拔地区特高压分裂导线的起晕特性和电晕损失特性,研制了一套集成化光电式电晕损失测量系统。测量系统由远端光通信采集模块,本地合并单元和上位机软件组成。远端光通信采集模块与本地合并单元之间采用光纤传输,通过光脉冲触发保证导线电晕电流和电压的精确同步采集。采用Labview开发了上位机软件,本地合并单元与上位机之间以UDP通信协议通讯。在实验室用信号发生器对测量系统进行角差、比差测定,测量结果表明 ...
刘云鹏   +5 more
doaj  

Study on Measurement and Data Processing of High Precision Optical Aspheric Surface [PDF]

open access: yes, 2005
现代光学设计中,广泛采用高精度的光学非球面元件。采用非球面光学器件,不仅可以消除球差、像差、场曲,减少光能损失。从而获得高质量的图像效果和高品质的光学特性,而且减少了光学元件的数量,简化系统的结构。影响非球面加工精度的不仅是机床和刀具,而且与制造系统所采用的测量系统和测量精度密切相关。本文针对光学非球面制造系统的测量特点,利用激光位移传感器和数据采集卡搭建非接触式非球面测量系统。测量系统的精度是本课题研究的核心内容。测量系统的精度不仅取决于系统的硬件结构,而且与数据处理算法密切相关 ...
范剑红
core  

Landscape Composition and Proximity to Water Affect American Badger Occupancy in Shortgrass Prairies 景观组成和与水的距离影响矮草草原中美洲獾的占域率

open access: yesWildlife Letters, Volume 4, Issue 1, Page 23-31, March 2026.
American badgers, a medium‐sized carnivore occurring in much of North America, are important predators in prairie landscapes though our understanding of their habitat use requirements in these areas is unclear. We used a multi‐scale approach to understand American badger habitat use at both local and landscape scales.
Colleen W. Piper   +5 more
wiley   +1 more source

Study on Measurement System of High Precision Axisymmetrical Aspheric Surface and its Tools [PDF]

open access: yes, 2004
高精度非球面制造技术是精密加工和超精密加工领域的热点问题。一直以来,非球面元件制造难,测量技术更是非球面制造技术中的瓶颈,各国专家和学者投入大量的人力和物力全方位地研究非球面的加工和测量问题。本课题来源于国家863科技计划项目“大型光学非球面透镜数控高效加工技术”。基于补偿加工的在线测量技术是目前大口径非球面加工制造采用的主流测量技术之一,本课题的研究目的就是建立一个基于补偿加工的在线测量系统,用于:1.进行非球面工件在线测量,为非球面补偿加工提供补偿数据。2.提供对非球面加工砂轮表面的测量 ...
谢仁宁
core  

Factors That Influenced Coping With COVID‐19 During the Pandemic in Botswana

open access: yesWorld Medical &Health Policy, Volume 18, Issue 1, March 2026.
ABSTRACT This paper forms part of the broader Global South study, Personal and Family Coping with COVID‐19 in the Global South, which examines psychosocial and behavioral responses to the COVID‐19 pandemic. In Sub‐Saharan Africa, the pandemic posed significant psychological, social, and economic challenges, with important implications for preparedness ...
Magen Mhaka‐Mutepfa   +3 more
wiley   +1 more source

油纸绝缘局部放电超高频检测方法的研究

open access: yesGaoya dianqi, 2011
针对传统的局部放电检测方法在线测量时易受外界干扰的问题,笔者在实验室建立了变压器中典型局部放电的模拟系统,并用超高频宽带和窄带测量系统对其测量,分析比较两种测量系统性能上的不同。经测量分析得出,超高频窄带检测方法对检测信号的中心频率和带宽可调,可以选择合适的频带来避开干扰测量,抗干扰能力很强;超高频宽带检测方法检测频带宽,可以检测到更丰富的局部放电信息。
李梅
doaj  

微型铣刀外径视觉测量系统的照明设计 [PDF]

open access: yes, 2015
为了满足微型铣刀外径视觉测量系统的照明需求,设计并制作了一种基于柯勒照明原理的平行光源。平行光源由白光lEd、孔径光阑和3组组合透镜组成,使用zEMAX对光路进行了仿真。设计并加工了多级可调金属圆筒机械结构,将光源各部分器件固定组合,光源总长为142 MM。搭建了微型铣刀外径视觉测量系统,并分别使用漫射背光光源和平行背光光源对铣刀进行照明成像。实验结果表明,平行背光照明提高了铣刀测量系统的测量精度 ...
夏添艺   +4 more
core  

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