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NSF-supported scientists present research results on Earth's critical zone at 2017 AGU fall meeting（图）
NSF scientists Earth's critical zone 2017 AGU fall meeting
2017/11/24
Find related stories on NSF's Critical Zone Observatories at this link.The thin veneer of Earth's surface that stretches from the top of the forest canopy to the base of bedrock is known as the "criti...
A Critical Examination of Hypernova Remnant Candidates in M101. II. NGC 5471B
M101 kinematics and dynamics
2014/12/26
NGC 5471B has been suggested to contain a hypernova because of its extraordinarily bright X-ray emission. To assess its true nature, we have obtained high-resolution images in continuum bands and nebu...
A critical analysis of three near-infrared photometric methods of estimating distances to cataclysmic variables
Stars: novae cataclysmic variables Stars:distances parallaxes Stars:statistics
2011/10/13
A critical analysis of three methods of estimating distances to cataclysmic variables (CVs) is performed. These methods, by Ak et al., Beuermann, and Knigge, all use near-infrared (JHK or Ks) magnitud...
Can Self Organized Critical Accretion Disks Generate a Log-normal Emission Variability in AGN?
Accretion accretion disks
2011/9/29
Active Galactic Nuclei (AGN), such as Seyfert galaxies, quasars, etc., show light variations in all wavelength bands, with various amplitude and in many time scales. The variations usually look errati...
Non-convergence of the critical cooling timescale for fragmentation of self-gravitating discs
accretion accretion discs protoplanetary discs planets and satellites
2010/11/10
We carry out a resolution study on the fragmentation boundary of self-gravitating discs. We perform three-dimensional Smoothed Particle Hydrodynamics simulations of discs to determine whether the crit...
A Critical Examination of the X-Wind Model for Chondrule and Calcium-rich, Aluminum-rich Inclusion Formation and Radionuclide Production
Critical Examination Chondrule Calcium-rich Radionuclide Production
2010/11/16
Meteoritic data, especially regarding chondrules and calcium-rich, aluminumrich inclusions (CAIs), and isotopic evidence for short-lived radionuclides (SLRs)in the solar nebula, potentially can constr...
THE PROXIMITIES OF ASTEROIDS AND CRITICAL POINTS OF THE DISTANCE FUNCTION
Celestial mechanics Minor planets asteroids
2010/10/29
The proximities are important for di®erent purposes, for example to evaluate the risk of collisions of asteroids or comets with the Solar-System planets. We describe a simple and e±cient method fo...
MHD modeling of the Heliosphere：a critical evaluation of different models
Heliosphere critical evaluation
2009/5/27
The very complicated problem of the solar wind-interstellar medium interaction requires a very sophisticated numerical approach. To achieve such a goal first we need to understand very deeply the resu...
EXTRATERRESTRIAL INTELLIGENCE AND DOOMSDAY：A CRITICAL ASSESSMENT OF THE NO-OUTSIDER REQUIREMENT
extraterrestrial inteligence-history and philosophy of astronomy
2009/3/12
The so-called Doomsday Argument has attracted a lot of attention
in recent years. One of the suggested ways to make this argument ineffective is
the so-called No-Outsider requirement, indicating tha...