相关概念视频
01:10Detection of Black Holes
Although black holes were theoretically postulated in the 1920s, they remained outside the domain of observational astronomy until the 1970s.
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
01:05Total Internal Reflection Fluorescence Microscopy
Total internal reflection fluorescence microscopy or TIRF is an advanced microscopic technique used to visualize fluorophores in samples close to a solid surface with a higher refractive index, such as a glass coverslip. TIRF only allows fluorophores in proximity to the solid surface to be excited. When light from a medium with a lower refractive index (such as air) hits the glass coverslip at a critical angle, the light undergoes total internal reflection stead of passing through the glass.
01:22Atomic Emission Spectroscopy: Instrumentation
The instrumentation of atomic emission spectrometry (AES) involves various components, including atomization devices that convert samples into gas-phase atoms and ions. There are two main types of atomization devices: continuous and discrete atomizers. Continuous atomizers, like plasmas and flames, introduce samples in a constant stream, while discrete atomizers inject individual samples using syringes or autosamplers. The most common discrete atomizer is the electrothermal atomizer.
01:02Flame Photometry: Overview
Flame photometry, also known as flame emission spectrometry, is a technique used for the qualitative and quantitative analysis of elements present in a sample using a flame as the source of excitation energy. The concept of flame photometry was realized in the early 1860s by Kirchhoff and Bunsen, who discovered that specific elements emit characteristic radiation when excited in flames. The first instrument developed for this purpose was used to measure sodium (Na) in plant ash using a Bunsen...
01:16Flame Photometry: Lab
In a flame photometer, when a solution like potassium chloride is aspirated into the flame, the solvent evaporates, leaving behind dehydrated salt. This salt dissociates into free gaseous atoms in their ground state. Some of these atoms absorb energy from the flame, leading to their excitation. The excited atoms return to the ground state, emitting photons at characteristic wavelengths. Because only electronic transitions are involved, the resulting emission lines are very narrow. The intensity...
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相关实验视频
Updated: Jun 30, 2026
10:35
Bringing the Visible Universe into Focus with Robo-AO
Published on: February 12, 2013
用FAUST望远镜进行天文学观测.
J Bixler1, S Bowyer, J M Deharveng
1Department of Physics, University of California, Berkeley 94720, USA.
Science (New York, N.Y.)
|July 13, 1984
概括
远紫外太空望远镜 (FAUST) 提供了诸如天环这样的宇宙天体的广场图像. 数据分析将使用这些紫外线观测来搜索热白矮星.
科学领域:
- 天文学和天体物理学
- 太空科学 太空科学
- 紫外线天文学 紫外线天文学
背景情况:
- 远紫外太空望远镜 (FAUST) 任务旨在捕获广场图像.
- 在1300至1800安格斯特罗姆波长范围内进行了观测.
研究的目的:
- 使用远紫外光对天体进行成像.
- 为了确定进一步天文学研究的潜在目标,包括热白矮星.
主要方法:
- 利用太空实验室1号上的FAUST仪器进行成像.
- 处理的摄影薄膜用于分析紫外线暴露.
主要成果:
- 大多数片呈现高背景曝光,限制了数据质量.
- 可用的包括Cygnus Loop超新星残骸和星系团Abell 2634.4的图像.
结论:
- 尽管存在背景挑战,但获得了有价值的数据.
- 选定的曝光率将促进对热白矮星的搜索.
