00000nz  a2200000n  4500
001  KSH1998025545
005  19990503184334
008  980429 n azknn|abn          |a a|a    | 
150  ▼a대기 희석▲
550  ▼a음향 흡수[音響吸收]▲
550  ▼a전자기 산란[電磁氣散亂]▲