Results 61 to 70 of about 60,044 (291)

NITROGEN ISOTOPE ABUNDANCE MEASUREMENTS

, 1958
The abundance of the nitrogen isotopes in several source of nitrogen has been determined. In atmospheric nitrogen the absolute ratio, N/sup 14//N/sup 15/ , is 272.0 plus or minus 0.3. Small variations were observed for various sources of compressed gas, but the isotopic composition of the nitrogen isotopes of the atmosphere was constant (to 1 part in ...
G Junk, H Svec
openaire   +2 more sources

ISOTOPIC TITANIUM ABUNDANCES IN LOCAL M DWARFS [PDF]

The Astrophysical Journal, 2009
Relative abundances of the five stable isotopes of titanium (^46Ti to ^50Ti) are measured for 11 M dwarfs belonging to the thin disk (four stars), thick disk (three stars), the halo (one star), and either the thick or the thin disk (three stars).
Chavez, Joy, Lambert, David L.
openaire   +3 more sources

Dual‐Site Ru Single‐Atoms and RuP Nanoclusters on N, P, and B Co‐Doped Porous Carbon for Efficient Alkaline HER and AEM Water Electrolysis

Advanced Functional Materials, EarlyView.
Ru single atoms and RuP nanoclusters are co‐anchored in N, P, and B co‐doped porous carbon nanospheres via in situ carbonization/phosphidation of a boronate polymer precursor. RuP activates water, while nearby Ru single atoms accelerate H2 formation through H* transfer. The catalyst delivers low overpotential and high durability in alkaline HER and AEM
Xiaohong Wang, Juguo Dai, Dongxu Li, Jianghua Wu, Hucheng Fu, Yiting Xu, Xueqiang Qi, Qian Xue, Yanbin Shen, Xiaoqing Pan, Conghui Yuan, Shuifen Xie, Andreu Cabot, Lizong Dai   +13 more
wiley   +1 more source

Noble Gas Planetology and the Xenon Clouds of Uranus

The Planetary Science Journal
Noble gases provide tracers of cosmic provenance that are accessible to a future Uranus atmospheric probe. Argon and krypton are expected to be well mixed on Uranus with respect to H _2 and He, although condensation at the winter pole may be possible ...
Kevin Zahnle
doaj   +1 more source

A Systematic Observational Study on Galactic Interstellar Ratio 18O/17O. II. C18O and C17O J = 2–1 Data Analysis

The Astrophysical Journal Supplement Series, 2023
To investigate the relative amount of ejecta from high-mass versus intermediate-mass stars and to trace the chemical evolution of the Galaxy, we have performed a systematic study of Galactic interstellar ^18 O/ ^17 O ratios toward a sample of 421 ...
Y. P. Zou, J. S. Zhang, C. Henkel, D. Romano, W. Liu, Y. H. Zheng, Y. T. Yan, J. L. Chen, Y. X. Wang, J. Y. Zhao   +9 more
doaj   +1 more source

The temperature and chronology of heavy-element synthesis in low-mass stars [PDF]

, 2015
Roughly half of the heavy elements (atomic mass greater than that of iron) are believed to be synthesized in the late evolutionary stages of stars with masses between 0.8 and 8 solar masses. Deep inside the star, nuclei (mainly iron) capture neutrons and
A Jorissen, A. Jorissen, B Gustafsson, B. Plez, CB Stephenson, DA Garcìa-Hernàndez, DL Lambert, E Biémont, E Vassiliadis, F Kupka, F Käppeler, F Käppeler, G Raskin, G Tagliente, G Wallerstein, GJ Mathews, K Takahashi, K-P Schröder, L Siess, L. Siess, M Asplund, MR Savina, O Straniero, O Trippella, P de Laverny, P. Neyskens, PW Merrill, R Alvarez, S Cristallo, S Goriely, S Goriely, S Van Eck, S Van Eck, S Van Eck, S Van Eck, S. Goriely, S. Van Eck, VV Smith, Y Kashiv, ZY Bao   +39 more
core   +2 more sources

The Terminal Domains of Collagen‐Like Silk Direct Molecular Interactions and Liquid–Liquid Phase Separation‐Mediated Material Assembly

Advanced Functional Materials, EarlyView.
Terminal domains of recombinant collagen‐like silk regulate hierarchical self‐assembly across molecular and material scales. We show that terminal domains of collagen‐like silk enhance triple‐helix stability and drive liquid–liquid phase separation, enabling reversible formation of fibers and self‐healing films.
Mengjie Shen, Daniil Astapov, Nur Alia Oktaviani, Mami Goto, Keiji Numata, A. Sesilja Aranko   +5 more
wiley   +1 more source

Fluorescent Nanosensor for Indole‐3‐Propionic Acid Detection in Gut Health Monitoring

Advanced Healthcare Materials, EarlyView.
This work introduces a fluorescent nanosensor system with two optical modalities for detection of indole‐3‐propionic acid (IPA) gut metabolite: (1) blue‐emitting cationic conjugated polyelectrolyte (CP3) and (2) near‐infrared (NIR)‐emitting CP3‐wrapped single‐walled carbon nanotube (SWNT).
Mervin Chun‐Yi Ang, Jonathan Wei Jie Lee, Sayyid Mohaideen, Gabriel Sánchez‐Velázquez, Song Wang, Yangyang Han, Liu Lin, Germaine Yong, Raju Cheerlavancha, Duc Thinh Khong, Jianhong Ching, Sharon Hong Yu Han, Jun Yu Yeo, Lian Xu, Gajendra Pratap Singh, Michael S. Strano   +15 more
wiley   +1 more source

Magnesium isotopic detection in cool stars: Tracing nucleosynthetic signatures from MgH features

Astronomy & Astrophysics
Context. Magnesium isotopic ratios offer valuable insights into stellar nucleosynthesis and Galactic chemical evolution, particularly in distinguishing between contributions from supernovae and asymptotic giant branch (AGB) stars.
Aicken Davies Q., Worley C. C.
doaj   +1 more source

Presolar Grains from Novae: Evidence from Neon and Helium Isotopes in Comet Dust Collections

, 2011
Presolar grains in meteorites and interplanetary dust particles (IDPs) carry non-solar isotopic signatures pointing to origins in supernovae, giant stars, and possibly other stellar sources. There have been suggestions that some of these grains condensed
Amari, Anders, Becker, Bode, Eberhardt, Gehrz, Heck, Heck, Helton, Helton, Joswiak, José, Lodders, Love, Mabry, Nakamura-Messenger, Nier, Nittler, Nittler, Owen, Palma, Petz, Rauscher, Rho, Robert D. Gehrz, Robert O. Pepin, Russell L. Palma, Shore, Smith, Starrfield, Starrfield, Sumner Starrfield, Zinner, Zolensky   +33 more
core   +1 more source