Results 41 to 50 of about 2,849,371 (302)

The evolution of planetary nebulae [PDF]

Astronomy & Astrophysics, 2008
Fig.
Steffen, M., Schoenberner, D., Warmuth, A.   +2 more
openaire   +2 more sources

Imaging polarimetry of planetary and proto-planetary nebulae [PDF]

, 1997
Optical imaging polarimetry has been performed on a small sample of objects which are associated with that stage of stellar evolution occurring between the Asymptotic Giant Branch and full Planetary Nebula. Three such systems are considered, specifically,
Bowlzer, S.L., Bowlzer, S. L.
core  

Electrochemical Behavior of Flame‐Sprayed Sc‐Doped AlCoCrFeMo High‐Entropy Alloy Coatings in 3.5% Sodium Chloride Solution

Advanced Engineering Materials, EarlyView.
Scandium (Sc)‐doped AlCoCrFeMo HEA coatings are fabricated via flame spraying with 0.1, 0.3, and 0.5 wt% Sc additions. Among these, the HEA‐Sc0.3 coating exhibits the highest corrosion resistance, indicated by a more positive corrosion potential and lower current density.
Pankaj Kumar, Akash Vyas, Mohammad Aatif Qazi, Nashit Jalal, Maria Ophelia Jarligo, Mostafa Yakout, Jing Liu, André McDonald   +7 more
wiley   +1 more source

Phanerozoic seawater Mg/Ca variations driven by supercontinent cycles

Nature Communications
Seawater Mg/Ca has oscillated markedly over the Phanerozoic, closely associated with secular variations in sedimentation, icehouse-greenhouse fluctuations, and the evolution of calcifying invertebrates.
Pan Zhang, Mark A. Kendrick, Yigui Han, Long Ma, Kang-Jun Huang   +4 more
doaj   +1 more source

Prolonged super-orogens during Gondwana assembly contributed to the formation of a habitable Earth: Insights from big data

China Geology
Since the initiation of plate tectonics on Earth, the evolution of tectonic regime and supercontinent cycles (Nuna, Rodinia and Pangea) have been the first order factors that contributed to Earth surficial environmental changes and thus development of ...
Peng-yuan Cui, Jin-long Yao, Guo-chun Zhao, Yi-gui Han, Qian Liu, Dong-hai Zhang, Hang Yang   +6 more
doaj   +1 more source

Surges in volcanic activity on the Moon about two billion years ago

Nature Communications, 2023
The history of mare volcanism critically informs the thermal evolution of the Moon. However, young volcanic eruptions are poorly constrained by remote observations and limited samples, hindering an understanding of mare eruption flux over time. The Chang’
Heng-Ci Tian, Chi Zhang, Wei Yang, Jun Du, Yi Chen, Zhiyong Xiao, Ross N. Mitchell, Hejiu Hui, Hitesh G. Changela, Tian-Xin Zhang, Xu Tang, Di Zhang, Yangting Lin, Xianhua Li, Fuyuan Wu   +14 more
doaj   +1 more source

Impact of MgO Additions on the Oxidation Resistance and Compression Behavior of Vanadium Alloys

Advanced Engineering Materials, EarlyView.
An increase in oxidation resistance at 600 °C is achieved for alloys containing more than 2.5 wt.% MgO. It has been established that, along with V2O5, MgO6V2, and Mg2O7V2 are formed, which are presumed to enhance oxidative stability. Furthermore, the possible transformation of Mg‐vanadates through reaction with CO2, which presumably occurs in this ...
Ievgen Solodkyi, Mathias Galetz, Georg Hasemann, Fabian Lanoy, Emma White, Manja Krüger   +5 more
wiley   +1 more source

Planetary Laws and Evolution [PDF]

Surveyor, 1910
Abstract AS an introductory paper, which it is hoped will induce other members to contribute their views, the present address is intended to present briefly some of the general and striking features, of planetary Science.
openaire   +1 more source

Influence of TiC and TiN Ceramic Reinforcements on the Microstructure, Thermal Expansion Behavior, and Tensile Properties of Invar 36 Manufactured by Laser Powder Bed Fusion

Advanced Engineering Materials, EarlyView.
This study examines Invar composites reinforced with titanium carbide (TiC) and titanium nitride (TiN) using laser powder bed fusion (LPBF). It presents the influence of reinforcements on microstructure, tensile properties, and thermal expansion. Results show that TiC effectively strengthens Invar while maintaining low thermal expansion, whereas TiN ...
Ayodeji Nathaniel Oyedeji, Natasha Sacks, Johannes Pötschke, Björn Matthey   +3 more
wiley   +1 more source

Assessing Core-powered Mass Loss in the Context of Early Boil-off: Minimal Long-lived Mass Loss for the Sub-Neptune Population

The Astrophysical Journal
We develop a Python-based state-of-the-art sub-Neptune evolution model that incorporates both the post-formation boil-off at young ages ≤1 Myr and long-lived core-powered mass loss (∼Gyr) from interior cooling.
Yao Tang, Jonathan J. Fortney, Ruth Murray-Clay   +2 more
doaj   +1 more source