関連する実験動画

Updated: Jul 12, 2026

Sampling and Pretreatment of Tooth Enamel Carbonate for Stable Carbon and Oxygen Isotope Analysis
07:57

Sampling and Pretreatment of Tooth Enamel Carbonate for Stable Carbon and Oxygen Isotope Analysis

Published on: August 15, 2018

南ネバダ州で発生する現代のカタツムリの殻の主要な炭素14欠乏症は,ネバダ州南部から発生する

A C Riggs

    Science (New York, N.Y.)
    |April 6, 1984
    PubMed
    まとめ

    ネバダ州の泉から採取された淡水カタツムリの殻は,非常に低い炭素14濃度を示しており,死体から生じたものではないことを示唆しています. この発見は,水生炭酸塩の正確な放射性炭素年代測定に極めて重要です.

    さらに関連する動画

    Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses11:19

    Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses

    Published on: October 21, 2016

    Characterization of Calcification Events Using Live Optical and Electron Microscopy Techniques in a Marine Tubeworm15:39

    Characterization of Calcification Events Using Live Optical and Electron Microscopy Techniques in a Marine Tubeworm

    Published on: February 28, 2017

    関連する概念動画

    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.
    Minerals01:26

    Minerals

    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.
    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...
    Carbon Skeletons01:12

    Carbon Skeletons

    Life on Earth is carbon-based, as all macromolecules that make up living organisms contain carbon atoms. All organic compounds have a carbon backbone. Each carbon atom is tetravalent and can bond with four other atoms, making it an extraordinarily flexible component of biological molecules. Because carbon’s valence electrons are stable, it rarely becomes an ion. As the carbon chain increases in length, structural modifications such as ring structures, double bonds, and branching side chains...
    Skeleton and Calcium Homeostasis01:21

    Skeleton and Calcium Homeostasis

    Calcium is not only the most abundant mineral in bone but also the most abundant mineral in the human body. Calcium ions are needed for bone mineralization, tooth health, heart rate regulation and strength of contraction, blood coagulation, the contraction of smooth and skeletal muscle cells, and the regulation of nerve impulse conduction. The average calcium level in the blood is about 10 mg/dL. When the body cannot maintain this level, a person will experience hypo or hypercalcemia.
    Essential Minerals for Bone Health01:31

    Essential Minerals for Bone Health

    The minerals contained in all of the food we consume are essential for our organ systems. However, certain essential minerals, such as calcium, phosphorus, magnesium, manganese, and fluoride, largely affect bone health.
    Calcium and Phosphorus
    Calcium is a critical component of bones, especially in the form of calcium phosphate and calcium carbonate. Since the body cannot make calcium, it must be obtained from the diet. However, calcium cannot be absorbed from the small intestine without...