umbral

adj.

有荫影的，阴暗的；

Umbral Moonshine
Umbral moonshine and the Niemeier lattices
Umbral oscillations as resonant modes of magneto-atmospheric waves
Applications of umbral algebra to some special polynomials
More on the umbral calculus, with emphasis on the q-umbral calculus
Umbral Fine Structures in Sunspots Observed with Hinode Solar Optical Telescope
Selecciones nacionales, el umbral de la independencia
Temporal Changes in Sunspot Umbral Magnetic Fields and Temperatures
Umbral oscillations in sunspots: Absorption of p-modes and active region heating by mode conversion
La Generalitat eleva el umbral de las licencias comerciales de 800 a 1.300 metros