Results 71 to 80 of about 9,499,304 (290)

EFTE-SOAR: Two Giant M Dwarf Flares with Rapid Spectroscopic Follow-up

open access: yesThe Astronomical Journal
We present time-series optical spectroscopy of two stellar flares with complex multi-peaked light curves: a $2.{1}_{-.3}^{+.4}\times 1{0}^{34}$ erg flare from an M8 ultra-cool dwarf, and a $1.{5}_{-.2}^{+.2}\times 1{0}^{35}$ erg superflare from an M4 ...
Hank Corbett   +8 more
doaj   +1 more source

Selective N‐Functionalization of Pyrazoles

open access: yesEuropean Journal of Organic Chemistry, EarlyView.
This review traces the evolution of regioselective N‐functionalization strategies for pyrazoles, a key class of nitrogen heterocycles widely used in medicinal chemistry. Due to rapid tautomerism, N‐functionalization often lacks selectivity, leading to poor and unpredictable regioisomeric outcomes.
Lucas Popek   +2 more
wiley   +1 more source

Adaptive Detection of Fast-moving Celestial Objects Using a Mixture-of-experts and Physical-inspired Neural Network

open access: yesThe Astronomical Journal
Fast-moving celestial objects are characterized by velocities across the celestial sphere that significantly differ from the motions of background stars.
Peng Jia   +4 more
doaj   +1 more source

Study of Damage to Shutters Exposed to a Vegetation Fire: Definition of Vulnerability Thresholds

open access: yesFire and Materials, EarlyView.
ABSTRACT This study examines the fire behavior of wooden, PVC, and aluminum shutters through laboratory and large‐scale experiments. Laboratory tests were conducted using a cone calorimeter to assess the ignitability of the PVC and wooden shutters, focusing on the critical heat flux of ignition, ignition time and critical Flux Time Product (FTP ...
C. Luciani   +5 more
wiley   +1 more source

Offline assembly of the lobster-eye x-ray telescope based on optical reference transfer [PDF]

open access: yesAIP Advances
To address the difficulty of focal alignment and optical axis calibration of lobster-eye x-ray telescopes in the absence of an x-ray vacuum environment, an offline visible-light alignment method based on optical reference transfer under atmospheric ...
Yifan Chen   +13 more
doaj   +1 more source

Wide-field and large aperture optical system design for ground-based photoelectric detection

open access: yes, 2019
Detection and recognition of space objects with ground-based photoelectric systems is one of the major technical ways for space situational awareness. During the past thirty years, there has been significant development of optical telescopes dedicated to
She, Wenji   +13 more
core   +1 more source

Drivers and Challenges of Micro‐Irrigation Adoption and Intensity in India: A Study of Four States

open access: yesIrrigation and Drainage, EarlyView.
ABSTRACT India's food security relies substantially on groundwater, but inefficient irrigation is seriously depleting this resource. Micro‐irrigation (MI) improves irrigation application efficiency and productivity, yet adoption remains low. This study examines MI adoption across four major Indian states—Uttar Pradesh, Maharashtra, Madhya Pradesh and ...
Gurpreet Singh   +2 more
wiley   +1 more source

Advances in Active Surface Shape Control for Segmented Primary Reflectors in Radio Telescopes

open access: yesGalaxies
Active surface shape control is a key engineering technology enabling high-frequency operation and high-performance observations in modern large-aperture radio telescopes.
Rui Wang, Lei Ding
doaj   +1 more source

VLBI2010 - The TWIN radio telescope project at Wettzell, Germany [PDF]

open access: yes, 2010
The Twin Telescope Wettzell (TTW) Project is funded to be exec uted during the period of 2008-2011. The design of the TTW was based on the VLBI2010 vision of the corresponding IVS Working Group.
Hase, H   +5 more
core  

Overview of the medium and high frequency telescopes of the LiteBIRD space mission [PDF]

open access: yes, 2020
LiteBIRD is a JAXA-led Strategic Large-Class mission designed to search for the existence of the primordial gravitational waves produced during the inflationary phase of the Universe, through the measurements of their imprint onto the polarization of the
Borrill, J   +762 more
core   +1 more source

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