Results 21 to 30 of about 2,447 (151)

The oxic degradation of sedimentary organic matter 1400 Ma constrains atmospheric oxygen levels [PDF]

Biogeosciences, 2017
We studied sediments from the ca. 1400 million-year-old Xiamaling Formation from the North China block. The upper unit of this formation (unit 1) deposited mostly below storm wave base and contains alternating black and green-gray shales with very ...
S. Zhang, X. Wang, H. Wang, E. U. Hammarlund, J. Su, Y. Wang, D. E. Canfield   +6 more
doaj   +1 more source

A new type of solar-system material recovered from Ordovician marine limestone

Nature Communications, 2016
Meteorites falling on Earth today are believed to represent 100–150 parent bodies. Within 470 Myr ago sediments at a limestone quarry in Sweden, Schmitz et al.
B. Schmitz, Q. -Z. Yin, M. E. Sanborn, M. Tassinari, C. E. Caplan, G. R. Huss   +5 more
doaj   +1 more source

Paternal occupational exposures and infant congenital heart defects in the Japan Environment and Children’s Study

Environmental Health and Preventive Medicine, 2023
Background: Few prospective studies have investigated the association between paternal occupational exposures and risk of infant congenital heart defects (CHDs).
Mina Hayama-Terada, Yuri Aochi, Satoyo Ikehara, Takashi Kimura, Kazumasa Yamagishi, Takuyo Sato, Hiroyasu Iso   +6 more
doaj   +1 more source

NEUTRON-RICH CHROMIUM ISOTOPE ANOMALIES IN SUPERNOVA NANOPARTICLES [PDF]

The Astrophysical Journal, 2010
Neutron-rich isotopes with masses near that of iron are produced in type Ia and II supernovae. Traces of such nucleosynthesis are found in primitive meteorites in the form of variations in the isotopic abundance of 54Cr, the most neutron-rich stable isotope of chromium. The hosts of these isotopic anomalies must be presolar grains that condensed in the
Dauphas, N., Remusat, L., Chen, J. H., Roskosz, M., Papanastassiou, D. A., Stodolna, J., Guan, Y., Ma, C., Eiler, J. M.   +8 more
openaire   +3 more sources

Discovery of chromium, manganese, nickel, and copper isotopes [PDF]

Atomic Data and Nuclear Data Tables, 2012
Twenty-seven chromium, twenty-five manganese, thirty-one nickel and twenty-six copper isotopes have so far been observed and the discovery of these isotopes is discussed. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.
Garofali, K., Robinson, R., Thoennessen, M.   +2 more
openaire   +2 more sources

Chromium isotopic composition of core‐top planktonic foraminifera

Geobiology, 2016
AbstractThe chromium isotope system (53Cr/52Cr expressed as δ53Cr relative to NIST SRM 979) is potentially a powerful proxy for the redox state of the ocean–atmosphere system, but a lack of temporally continuous, well‐calibrated archives has limited its application to date. Marine carbonates could potentially serve as a common and continuous Cr isotope
Wang, Xiangli, Planavsky, N. J., Hull, P. M., Tripati, A. E., Zou, H. J., Elder, L., Henehan, M.   +6 more
openaire   +5 more sources

Investigating nuclear deformation and longitudinal form factors in some fp-shell nuclei using the shell model and Hartree - Fock approximation [PDF]

Ядерна фізика та енергетика
The current study examined the nuclear deformation of certain Titanium and Chromium isotopes using the shell model and Hartree - Fock approximation within the fp-shell model space.
A. A. Alzubadi, R. T. Mahdi
doaj   +1 more source

Measurement of (n,α) cross section for set of structural material isotopes

EPJ Web of Conferences, 2017
A novel spectrometer was developed and used to measure the cross section for the (n,α) reaction at IPPE. Direct measurements of the α-particles yield from solid isotopic pure targets of 50, 52 and 53 chromium, 54 and 57 iron, 60 nickel, and 64 zinc were ...
Khryachkov Vitaly, Gurbich Alexander, Khromyleva Tatiana, Bondarenko Ivan, Ketlerov Vladimir, Prusachenko Pavel   +5 more
doaj   +1 more source

High-density element concentrations in fish from subtidal to hadal zones of the Pacific Ocean

Heliyon, 2018
Anthropogenic use of high density, toxic elements results in marine pollution which is bio-accumulating throughout marine food webs. While there have been several studies in various locations analyzing such elements in fish, few have investigated ...
Connor J. Welty, Matthew L. Sousa, Frank M. Dunnivant, Paul H. Yancey   +3 more
doaj   +1 more source

Provision of optimum requirements for preparation of thin free targets from isotopes of chromium, scandium, zirconium, iron, copper [PDF]

Ядерна фізика та енергетика, 2008
Free films (targets) from high-melting chromium, scandium, zirconium, iron, copper isotopes of textured structures are prepared and explored by the method of thermal sputtering. About 2 sm2 films of ≤ 0,5 mg/sm2 thickness with homogeneity about 1 % and
Yu. V. Kibkalo, V. P. Tokarev
doaj