n a toxic nonmetallic element related to sulfur and tellurium; occurs in several allotropic forms; a stable grey metallike allotrope conducts electricity better in the light than in the dark and is used in photocells; occurs in sulfide ores (as pyrite)
n the compass point midway between south and east; at 135 degrees
n 1/60 of a minute; the basic unit of time adopted under the Systeme International d'Unites
n an abundant tasteless odorless multivalent nonmetallic element; best known in yellow crystals; occurs in many sulphide and sulphate minerals and even in native form (especially in volcanic regions)
n the cardinal compass point that is at 180 degrees
n a unit of conductance equal to the reciprocal of an ohm
n the 19th letter of the Roman alphabet
n (thermodynamics) a thermodynamic quantity representing the amount of energy in a system that is no longer available for doing mechanical work
abbr. (美)工程科学学会(Society of Engineering Science);(美)太阳能学会(Solar Energy Society)