Results 51 to 60 of about 60,044 (291)

ISOTOPIC ABUNDANCES OF MAGNESIUM - ²⁴Mg, ²⁵ Mg, ²⁶ Mg IN THE ATMOSPHERES OF G-K - GIANTS

Odessa Astronomical Publications, 2017
The isotopic abundances of magnesium in the star of thin disk of Galaxy with various chromospheric activity were studied. We use the new data about molecular constants of radiation for isotopes 24Mg, 25Mg, and 26Mg.
V. V. Kovtyukh, N. S. Komarov, S. M. Andrievsky, I. F. Dulapchi   +3 more
doaj   +1 more source

Geochemical support for a climbing habit within the Paleozoic seed fern genus Medullosa [PDF]

, 2011
A long-standing problem in paleobotany is the accurate identification of the growth habits and statures of fossil plants. Tissue-specific analysis of stable carbon isotope ratios in plant fossils can provide an independent perspective on this issue ...
Fischer, Woodward W., Wilson, Jonathan P.   +1 more
core   +2 more sources

Absolute isotopic abundance of terrestrial silver

Journal of Research of the National Bureau of Standards Section A: Physics and Chemistry, 1962
Isotopic abundance ratios are reported for a commercial silver nitrate, 13 samples of native silver, and 11 silver minerals of various compositions and from widely distributed deposits. Collateral measurements of known mixtures of nearly pure silver isotopes permit the determination of absolute abundance ratios.
Shields, William R., Garner, Ernest L., Dibeler, Vernon H.   +2 more
openaire   +1 more source

Electroactive Metal–Organic Frameworks for Electrocatalysis

Advanced Functional Materials, EarlyView.
Electrocatalysis is crucial in sustainable energy conversion as it enables efficient chemical transformations. The review discusses how metal–organic frameworks can revolutionize this field by offering tailorable structures and active site tunability, enabling efficient and selective electrocatalytic processes.
Irena Senkovska, Yutong Luo, Ruyan Zhao, Jianjun Zhang, Mingchao Wang, Xinliang Feng, Eike Brunner, Stefan Kaskel   +7 more
wiley   +1 more source

Isotopic Ratios in the Disk of HD 163296

The Astrophysical Journal Letters
Isotopic abundance ratios in protoplanetary disks are critical for understanding volatile inheritance and chemical evolution in planet-forming environments. We present Atacama Large Millimeter/submillimeter Array observations of the rare isotopologue ^13
Chunhua Qi, David J. Wilner, Catherine C. Espaillat   +2 more
doaj   +1 more source

Auto‐Generated Valence States in Electrocatalysts for Boosting Oxygen and Hydrogen Evolution Kinetics in Alkaline Water/Alkaline Seawater/Simulated Seawater/Natural Seawater

Advanced Functional Materials, EarlyView.
This review systematically highlights the latest achievements in mixed‐valence states relevant to hydrogen and oxygen evolution reactions, providing essential insights into future directions and methods for large‐scale practical implementation. This critical review is expected to provide an overview of recent advancements in diverse valence‐state metal
Jitendra N. Tiwari, Gokul Bhaskaran, Krishan Kumar, Yun Suk Huh, Young‐Kyu Han   +4 more
wiley   +1 more source

Galactic R Coronae Borealis Stars: The C-2 Swan Bands, The Carbon Problem, And The C-12/C-13 Ratio [PDF]

, 2012
Observed spectra of R Coronae Borealis (RCB) and hydrogen-deficient carbon (HdC) stars are analyzed by synthesizing the C-2 Swan bands (1, 0), (0, 0), and (0, 1) using our detailed line list and the Uppsala model atmospheres.
Hema, B. P., Lambert, David L., Pandey, Gajendra   +2 more
core   +1 more source

Shaping Ti3C2 MXene Nanospheres for Precision Near‐Infrared Photothermal Therapy

Advanced Functional Materials, EarlyView.
In this study, we report producing spherical MXenes via fs laser fragmentation of Ti3C2 flakes in liquid medium. The nanoparticles demonstrated pronounced light absorption and high photothermal conversion efficiencies of 68% and 63% under heating with NIR‐I and NIR‐II lasers, respectively.
Julia S. Babkova, Ivan V. Zelepukin, Konstantin G. Shevchenko, Gleb V. Tikhonowski, Lyubov V. Gorelik, Anton A. Popov, Anna S. Sogomonyan, Alina Yu. Kapitannikova, Ivan S. Kazantsev, Dmitry V. Dyubo, Daria A. Panova, Daniil I. Tselikov, Anton A. Minnekhanov, Aziz B. Mirkasymov, Georgy A. Ermolaev, Alexander V. Syuy, Gleb I. Tselikov, Aleksey V. Arsenin, Andrei V. Kabashin, Kostya S. Novoselov, Sergey M. Deyev, Valentyn S. Volkov   +21 more
wiley   +1 more source

Iron Isotope Constraints on the Structure of the Early Solar System

The Astrophysical Journal Letters, 2023
The recent advent of nontraditional isotopic systems has revealed that meteorites display a fundamental isotopic dichotomy between noncarbonaceous (NC) and carbonaceous (C) groups, which represent material from the inner and outer solar system ...
Yves Marrocchi, Maxime Piralla, François L. H. Tissot   +2 more
doaj   +1 more source

Near infrared spectroscopy of M dwarfs. IV. A preliminary survey on the carbon isotopic ratios in M dwarfs

, 2016
Based on the medium resolution near infrared spectra of 13CO (3,1) band, carbon isotopic ratios are estimated in 48 M dwarfs, for which we had determined the carbon and oxygen abundances from CO and H2O lines, respectively. We find clear evidence for the
Tsuji, Takashi
core   +1 more source