相关实验视频
Updated: May 18, 2026
11:34
Scattering And Absorption of Light in Planetary Regoliths
Published on: July 1, 2019
黎明的元素测绘揭示了维斯塔的规流体中的外源H
Thomas H Prettyman1, David W Mittlefehldt, Naoyuki Yamashita
1Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, AZ 85719-2395, USA. prettyman@psi.edu
Science (New York, N.Y.)
|September 22, 2012
概括
维斯塔维斯塔 (Vesta Vesta) 是一个
科学领域:
- 行星科学 行星科学
- 小行星科学小行星科学
- 地质化学 地质化学
背景情况:
- 霍华德石,尤克里特石和二氧化石 (HED) 的石提供了对小行星维斯塔的组成和演变的见解.
- 之前的研究表明,HED石起源于维斯塔.
- 了解维斯塔的分化和表面成分对于小行星科学至关重要.
研究的目的:
- 用黎明任务的马射线和中子探测器的数据来测试维斯塔的进化模型.
- 调查维斯塔表面的的分布和来源.
- 为了将地表组成与地质特征和冲击历史联系起来.
主要方法:
- 从黎明的马射线和中子探测器对全球Fe/O和Fe/Si比率的分析.
- 测量中子来评估地的组成和结构.
- 在维斯塔的表面映射气度.
主要成果:
- 全球元素比率证实与HED石组成的一致性.
- 中性子数据显示,在雷亚西尔维亚盆地暴露的厚厚的二原性下层地,支持了岩分化.
- 维斯塔的规石中存在大量的气,在较古老的赤道地区度较高,在雷亚西尔维亚盆地度较低.
结论:
- 维斯塔经历了全球性岩分化,形成了一层层的地.
- 气可能通过碳状地铁石的落入逐渐积累,并因撞击而改变.
- 这些发现支持了维斯塔进化模型,该模型受内部流程和外部物质交付的影响.
相关概念视频
01:26Minerals
Minerals are essential nutrients that the human body needs in small amounts to work properly. They play a vital role in many bodily functions, such as building strong bones and transmitting nerve impulses. Some minerals are needed for hormone production or to maintain a normal heartbeat. Major minerals include calcium, phosphorus, potassium, sulfur, sodium, chlorine, and magnesium, while trace minerals include iron, manganese, copper, iodine, zinc, cobalt, fluoride, and selenium.
00:49Gravimetry: Inorganic And Organic Precipitating Agents
In gravimetry, the precipitant is chosen carefully to obtain a pure solid that can be easily filtered. Common inorganic precipitants can be used to determine several cations and anions. In some cases, the formation of the same precipitate can be used to determine the cation and the anion. For example, the reaction of barium and chromate ions to give barium chromate is used to determine both barium and chromate. However, precipitates such as hydroxides, oxalates, and metal ammonium phosphates...
02:34Water and Mineral Acquisition
Specialized tissues in plant roots have evolved to capture water, minerals, and some ions from the soil. Roots exhibit a variety of branching patterns that facilitate this process. The outermost root cells have specialized structures called root hairs that increase the root surface, thus increasing soil contact. Water can passively cross into roots, as the concentration of water in the soil is higher than that of the root tissue. Minerals, in contrast, are actively transported into root cells.
01:20Sulfur Assimilation
Sulfur is an essential element in biological systems, contributing to synthesizing key biomolecules, including amino acids such as cysteine and methionine, and cofactors such as coenzyme A and biotin. Microorganisms primarily assimilate sulfur as sulfate (SO₄²⁻) from the environment, which must undergo a series of biochemical transformations before it can be incorporated into cellular components. As sulfate is highly oxidized, it must undergo assimilatory sulfate reduction to become...
01:29Atomic Emission Spectroscopy: Lab
AES is a powerful analytical technique, especially effective when used with plasma sources, producing abundant spectra in characteristic emission lines. The Inductively Coupled Plasma (ICP), in particular, yields superior quantitative analytical data due to its high stability, low noise, low background, and minimal interferences under optimal experimental conditions. However, newer air-operated microwave sources are emerging as promising alternatives that could be more cost-effective than...
01:19Inductively Coupled Plasma–Mass Spectrometry (ICP–MS): Overview
In inductively coupled plasma–mass spectrometry (ICP–MS), an inductively coupled plasma (ICP) torch is used as an atomizer and ionizer. Solid samples are dissolved and volatilized before being introduced into the high-temperature argon plasma, while solution samples are nebulized and passed through the high-temperature argon plasma. Plasma dissociates the analytes and ionizes their component atoms to form a mixture of positive ions and molecular species. The positive ions are then passed on to...