标题（Title） 一般不超过80个字符
NASS
（4 个字符）
关键词（KeyWords）一般不超过100个字符
NASS, sundials, gnomonics, cadrans, cadrans solaires, sol cadrans, orologi solari e meridiane, sonnenuhr, sonnenuhren, slunecni hodiny, horizontal dial, vertical dial, equatorial dial, polar dial, ring dial, armillary, analemma, equinox, solstice, analemmatic, equation of time
（277 个字符）
描述（Description）一般不超过200个字符
NASS North American Sundial Society for sundials, gnomonics, history of sundials, theory of sundials, making sundials, using sundials, sundial education, teaching sundials, sundial curriculum, sundial construction, sundial design, sun and shadows, solar analemma, analemma calculation, equinox, solstice, and computing equation of time
（335 个字符）
