Jove
Visualize
联系我们
JoVE
x logofacebook logolinkedin logoyoutube logo
关于 JoVE
概览领导团队博客JoVE 帮助中心
作者
出版流程编辑委员会范围与政策同行评审常见问题投稿
图书馆员
用户评价订阅访问资源图书馆顾问委员会常见问题
研究
JoVE JournalMethods CollectionsJoVE Encyclopedia of Experiments存档
教育
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab Manual教师资源中心教师网站
使用条款与条件
隐私政策
政策

相关概念视频

Influence of Earth's Curvature and Atmospheric Refraction on Leveling01:26

Influence of Earth's Curvature and Atmospheric Refraction on Leveling

92
During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance.
92
Focusing of Light in the Eye01:16

Focusing of Light in the Eye

2.7K
Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...
2.7K
Adjusting a Traverse01:12

Adjusting a Traverse

56
In the site survey of a four-sided traverse, internal angles are essential to ensure geometric accuracy. The survey revealed that the sum of the measured internal angles was 359 degrees and 48 minutes, which is 12 minutes less than the expected 360 degrees. This discrepancy signals an error likely arising from measurement inaccuracies during the fieldwork.To rectify this error, the adjustment process involved distributing the 12-minute shortfall equally across the four internal angles. By...
56
Equation of the Elastic Curve01:23

Equation of the Elastic Curve

500
The concept of curvature in plane curves, crucial in structural engineering, defines how sharply a beam bends under load. This curvature is determined using the curve's first and second derivatives.
Consider a cantilever beam with a point load at its free end (for instance, a diving board). When analyzing beam deflection with small slopes, the shape of the beam's elastic curve becomes key. The governing equation for this analysis involves the bending moment and the beam's flexural...
500
Bending of Curved Members - Strain Analysis01:14

Bending of Curved Members - Strain Analysis

136
The mechanics of deformation in curved members, such as beams or arches, under bending moments, involve complex responses. When such a member, symmetric about the y-axis and shaped like a segment of a circle centered at point C, is subjected to equal and opposite forces, its curvature and surface lengths change significantly. This alteration results in the shift of the curvature's center from C to C', indicating a tighter curve.
The important part of bending analysis for such a member...
136
Beams with Unsymmetric Loadings01:17

Beams with Unsymmetric Loadings

118
Analyzing a supported beam under unsymmetrical loadings is essential in structural engineering to understand how beams respond to varied force distributions. This analysis involves calculating the deflection and identifying points where the slope of the beam is zero, which are crucial for ensuring structural stability and functionality.
The first moment-area theorem determines the slope at any point on the beam. This theorem indicates that the change in slope between two points on a beam...
118

您也可能阅读

相关文章

通过共同作者、期刊和引用图与本文相关的文章。

排序
Same author

Critical slowing down of semiarid vegetation resilience is amplified by intensifying heatwaves.

Nature communications·2026
Same author

Ultra flash cold events under global warming.

Nature communications·2026
Same author

Application and Evaluation of a NOAA GFS-Driven Air Quality Model Using CMAQv5.4 and High-Resolution Emissions: FIREX-AQ 2019.

Journal of geophysical research. Atmospheres : JGR·2026
Same author

In tune with AI: Singing as a social surrogate to ease loneliness and foster social connection.

Applied psychology. Health and well-being·2026
Same author

Experimental Determination of Isothermal Sections in the Ni-Al-Cr-Ru Quaternary System: Implications for Ni-Based Superalloys and High-Entropy Alloys.

Materials (Basel, Switzerland)·2026
Same author

Dust storms: Hidden drivers of extreme rainfall and global precipitation shifts.

Science advances·2026

相关实验视频

Updated: Jun 26, 2025

Cell-based Assay Protocol for the Prognostic Prediction of Idiopathic Scoliosis Using Cellular Dielectric Spectroscopy
08:08

Cell-based Assay Protocol for the Prognostic Prediction of Idiopathic Scoliosis Using Cellular Dielectric Spectroscopy

Published on: October 16, 2013

10.7K

折射误差是影响脊柱形的因素吗?

Jianru Cai1, Yue Zhou1, Xiaojuan Chen1

  • 1Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China.

PloS one
|May 13, 2024
PubMed
概括

像近视这样的折射误差不会影响儿童的脊椎病发育. 然而,较低的身体质量指数,农村生活和年龄较大与脊柱结石风险增加有关.

更多相关视频

Minimally Invasive Treatment for Thoracolumbar Burst Fracture Using Sagittal Alignment Screws and A Trauma Reduction Device
04:19

Minimally Invasive Treatment for Thoracolumbar Burst Fracture Using Sagittal Alignment Screws and A Trauma Reduction Device

Published on: November 8, 2024

405
Subjective Refraction Test Using a Smartphone for Vision Screening
05:36

Subjective Refraction Test Using a Smartphone for Vision Screening

Published on: October 18, 2024

662

相关实验视频

Last Updated: Jun 26, 2025

Cell-based Assay Protocol for the Prognostic Prediction of Idiopathic Scoliosis Using Cellular Dielectric Spectroscopy
08:08

Cell-based Assay Protocol for the Prognostic Prediction of Idiopathic Scoliosis Using Cellular Dielectric Spectroscopy

Published on: October 16, 2013

10.7K
Minimally Invasive Treatment for Thoracolumbar Burst Fracture Using Sagittal Alignment Screws and A Trauma Reduction Device
04:19

Minimally Invasive Treatment for Thoracolumbar Burst Fracture Using Sagittal Alignment Screws and A Trauma Reduction Device

Published on: November 8, 2024

405
Subjective Refraction Test Using a Smartphone for Vision Screening
05:36

Subjective Refraction Test Using a Smartphone for Vision Screening

Published on: October 18, 2024

662

科学领域:

  • 儿科整形外科 儿科整形外科
  • 眼科医生 眼科 眼科
  • 流行病学 流行病学

背景情况:

  • 脊柱病是一种常见的儿科脊柱疾病,需要手术干预.
  • 折射误差在全球普遍存在,影响视力.
  • 折射误差和脊椎病的发展之间的关系尚未得到充分证实.

研究的目的:

  • 调查各种折射误差与学龄儿童脊椎病的发展之间的相关性.
  • 为了确定其他潜在的风险因素,与这群人群的脊椎病相关.

主要方法:

  • 一项截面研究于2023年在中国南通市进行.
  • 分层集群采样包括学龄学生.
  • 单变量和多变量逻辑回归分析检查了脊椎病和参数之间的相关性,包括折射误差,体重指数 (BMI),居住面积和年龄.

主要成果:

  • 在学生中,脊椎病的患病率为2.2%.
  • 近视,近视,眼,眼和异观眼没有与脊椎病的发展有显著的相关性 (p≥0.05).
  • 较低的BMI (aOR=0.92),农村居住 (aOR=1.40) 和较高的年龄 (aOR=1.32) 与更高的脊柱结石风险有显著的关联.

结论:

  • 折射误差与儿科脊柱病的发展没有相关性.
  • 较低的BMI,居住在农村地区,以及年龄较大被确定为脊柱结石症的重要危险因素.