Physics & Astronomy
ions
100%
astrophysics
82%
electron impact
71%
planetary nebulae
57%
collisions
53%
line spectra
45%
universe
38%
Far UV Spectroscopic Explorer
37%
electronics
37%
excitation
34%
electron-ion recombination
34%
interstellar gas
32%
stellar atmospheres
31%
H II regions
29%
supernova remnants
27%
XMM-Newton telescope
26%
accretion disks
24%
active galactic nuclei
24%
newton
23%
proposals
22%
chemical composition
21%
electrons
20%
anomalies
19%
flow velocity
19%
galaxies
17%
physics
15%
estimates
13%
trends
13%
photons
13%
coefficients
12%
molecules
12%
spectroscopy
12%
temperature
12%
atoms
12%
wavelengths
11%
expansion
11%
x rays
10%
configurations
9%
Earth & Environmental Sciences
electronics
59%
electron
49%
ion
45%
matrix
42%
collision
30%
calculation
19%
shell
13%
trend
8%
comparison
7%
temperature
6%