Results 41 to 50 of about 17,392 (258)

Detection of Radio Emission from Fireballs

open access: yes, 2014
We present the findings from the Prototype All-Sky Imager (PASI), a backend correlator of the first station of the Long Wavelength Array (LWA1), which has recorded over 11,000 hours of all-sky images at frequencies between 25 and 75 MHz.
Dowell, J.   +11 more
core   +1 more source

Embodied, Enacted, and Multimodal: Exploring Science Teachers’ Metaphors in Authentic Classroom Contexts

open access: yesScience Education, EarlyView.
ABSTRACT Over the past decades, science education research has extensively examined the role of metaphors in teaching and learning science. However, much of the existing research has focused on verbal manifestations of metaphors, thereby overlooking aspects of metaphors that may occur in non‐verbal form. This study reconceptualises metaphors as dynamic
Magdalena Kersting   +2 more
wiley   +1 more source

Meteor Statistics. I. The Distribution of Instrumental Magnitudes

open access: yesThe Astronomical Journal
The distribution of meteor magnitudes is known to follow an exponential distribution, where the base of this distribution is called the population index.
Althea V. Moorhead   +4 more
doaj   +1 more source

Key Technical Fields and Future Outlooks of Space Manipulators: A Survey

open access: yesSmartBot, EarlyView.
This paper systematically reviews the technological development of space manipulators, emphasizing the unique challenges posed by space environments. It examines four areas: structural design, modeling, planning, and control, while introducing typical ground test platforms.
Gang Chen   +12 more
wiley   +1 more source

Radar and optical leonids [PDF]

open access: yesAtmospheric Chemistry and Physics, 2004
We present joint optical-radar observations of meteors collected near the peak of the Leonid activity in 2002. We show four examples of joint detections with a large, phased array L-band radar and with intensified video cameras.
N. Brosch   +4 more
doaj  

Resource reallocation across successive systemic innovations: How Rolls‐Royce shaped the evolution of the turbojet, turboprop, and turbofan

open access: yesStrategic Management Journal, EarlyView.
Abstract Research Summary Despite the importance of resource reallocation in shaping a variety of strategic outcomes, strategy scholars have paid only limited attention to the processes by which firms reallocate their resources across successive systemic innovations.
Gino Cattani   +2 more
wiley   +1 more source

A Curated Dataset of Regional Meteor Events with Simultaneous Optical and Infrasound Observations (2006–2011)

open access: yesData
We present a curated, openly accessible dataset of 71 regional meteor events simultaneously recorded by optical and infrasound instrumentation between 2006 and 2011. These events were captured during an observational campaign using the all-sky cameras of
Elizabeth A. Silber   +3 more
doaj   +1 more source

Quasi‐BIC and Reflective Mode Coupling Drives SHG Beyond the Q Factor Limit

open access: yesSmall, EarlyView.
An analytical expression is developed to relate second‐harmonic generation to both the resonance Q factor and absorptance. Simulations and experiments on a dual‐resonance 3R‐MoS2 metasurface validate the formula, showing that absorptance engineering provides an effective route to enhance SHG beyond conventional Q‐only design.
Wenkai Yang   +8 more
wiley   +1 more source

The stellar origins of 96Zr excesses in presolar graphites from the Murchison meteorite

open access: yesAstronomy & Astrophysics
Context. Zirconium-96 is a stable isotope that can be synthesized under different neutron-rich nucleosynthetic conditions. Astrophysical models predict its production to occur in various stellar environments: from low-to-intermediate-mass asymptotic ...
Pal I.   +16 more
doaj   +1 more source

Seeding the Solar System with Life: Mars, Venus, Earth, Moon, Protoplanets

open access: yesOpen Astronomy, 2020
In the space of the entire universe, the only conclusive evidence of life, is found on Earth. Although the ultimate source of all life is unknown, many investigators believe Earth, Mars, and Venus may have been seeded with life when these planets, and ...
Joseph Rhawn G.   +3 more
doaj   +1 more source

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