関連する実験動画

Updated: Jun 21, 2026

Low-energy Cathodoluminescence for (Oxy)Nitride Phosphors
07:03

Low-energy Cathodoluminescence for (Oxy)Nitride Phosphors

Published on: November 15, 2016

低宇宙線被曝率の鉄隕石は老化しています

J C Cobb

    Science (New York, N.Y.)
    |March 25, 1966
    PubMed
    まとめ

    鉄隕石の宇宙射線分析は,異常に短い曝露時間を明らかにし,その一部はコンドライトに似ています. これは,鉄隕石の大部分が短期間の宇宙線被曝を経験した可能性があることを示唆しています.

    さらに関連する動画

    Carrier Lifetime Measurements in Semiconductors through the Microwave Photoconductivity Decay Method07:38

    Carrier Lifetime Measurements in Semiconductors through the Microwave Photoconductivity Decay Method

    Published on: April 18, 2019

    Resource Recycling of Red Soil to Synthesize Fe2O3/FAU-type Zeolite Composite Material for Heavy Metal Removal05:52

    Resource Recycling of Red Soil to Synthesize Fe2O3/FAU-type Zeolite Composite Material for Heavy Metal Removal

    Published on: June 2, 2022

    関連する概念動画

    Corrosion02:49

    Corrosion

    The degradation of metals due to natural electrochemical processes is known as corrosion. Rust formation on iron, tarnishing of silver, and the blue-green patina that develops on copper are examples of corrosion. Corrosion involves the oxidation of metals. Sometimes it is protective, such as the oxidation of copper or aluminum, wherein a protective layer of metal oxide or its derivatives forms on the surface, protecting the underlying metal from further oxidation. In other cases, corrosion is...
    Nuclear Stability03:18

    Nuclear Stability

    Protons and neutrons, collectively called nucleons, are packed together tightly in a nucleus. With a radius of about 10−15 meters, a nucleus is quite small compared to the radius of the entire atom, which is about 10−10 meters. Nuclei are extremely dense compared to bulk matter, averaging 1.8 × 1014 grams per cubic centimeter. If the earth’s density were equal to the average nuclear density, the earth’s radius would be only about 200 meters.
    To hold positively charged protons together in the...
    Radioactive Decay and Radiometric Dating02:48

    Radioactive Decay and Radiometric Dating

    Radioactivity is a spontaneous disintegration of an unstable nuclide and is a random process, as all the nuclei in the sample do not decay simultaneously. The number of disintegrations per unit time is called the activity (A), which is directly proportional to the number of nuclei in the sample. The decay constant (λ) is an average probability of decay per nucleus in unit time.
    Imperfections in Crystal Structure: Non-Stoichiometric Defects01:29

    Imperfections in Crystal Structure: Non-Stoichiometric Defects

    Non-stoichiometric defects refer to a type of defect in the crystal structure of a compound where the ratio of its constituent elements deviates from the ideal stoichiometric ratio. There are two main types of non-stoichiometric defects: metal excess defects and metal deficiency defects.Metal excess defects occur when there is a slight surplus of metal ions than what is required by the stoichiometric ratio of the compound. For example, heating a sodium chloride crystal in sodium vapor results...
    Deleterious Substances in Aggregate01:25

    Deleterious Substances in Aggregate

    Deleterious substances in aggregates can be detrimental to the quality and durability of concrete. These substances include organic impurities like loam, which interfere with cement hydration and are usually present in the sand. These prevent a good bond between aggregate and cement paste. Organic impurities can be detected using the colorimetric test, where the darkness of a solution after agitation indicates the level of organic content.
    Another type of impurity is clay and fine material that...
    Corrosion of Reinforcement01:27

    Corrosion of Reinforcement

    The corrosion of steel reinforcement within concrete is a process influenced by the material's inherent properties and external factors. The high pH level of around 13, provided by calcium hydroxide present in concrete, initially protects the steel reinforcement by promoting the formation of a passive iron oxide layer on its surface.
    However, over time and under certain conditions like carbonation, chloride ingress, and cracking this protective state can be compromised. Steel has areas with...