The Solar Acoustic Spectrum and Eigenmode Parameters     

F Hill  PB Stark  RT Stebbins  ER Anderson  HM Antia  TM Brown  TL Duvall  DA Haber  JW Harvey  DH Hathaway  R Howe  RP Hubbard  HP Jones  JR Kennedy  SG Korzennik  AG Kosovichev  JW Leibacher  KG Libbrecht  JA Pintar  EJ Rhodes  J Schou  MJ Thompson  S Tomczyk  CG Toner  R Toussaint  WE Williams 《Science (New York, N.Y.)》1996,272(5266):1292-1296

The Global Oscillation Network Group (GONG) project estimates the frequencies, amplitudes, and linewidths of more than 250,000 acoustic resonances of the sun from data sets lasting 36 days. The frequency resolution of a single data set is 0.321 microhertz. For frequencies averaged over the azimuthal order m, the median formal error is 0.044 microhertz, and the associated median fractional error is 1.6 x 10(-5). For a 3-year data set, the fractional error is expected to be 3 x 10(-6). The GONG m-averaged frequency measurements differ from other helioseismic data sets by 0.03 to 0.08 microhertz. The differences arise from a combination of systematic errors, random errors, and possible changes in solar structure.  相似文献   

Nutritional responses in rainbow trout (Oncorhynchus mykiss) fed diets with different physical qualities at stable or variable environmental conditions     

T.S. AAS  B.F. TERJESEN  T. SIGHOLT  M. HILLESTAD  J. HOLM  S. REFSTIE  G. BAEVERFJORD  K.‐A. RØRVIK  M. SØRENSEN  M. OEHME  T. ÅSGÅRD 《Aquaculture Nutrition》2011,17(6):657-670

Rainbow trout with initial body weight 1144 g were fed two diets with high (feed A) or low (feed B) water stability for 6 weeks. During the last 2 weeks either stable or fluctuating oxygen saturation, salinity and temperature was introduced. High water stability of the feed was associated with harder pellets, less dust formation and less broken pellets compared to feed with low water stability. During the first 4 weeks, feed intake was 23% higher in trout fed diet B than in those fed diet A. Fluctuating environment resulted in a severe drop in feed intake for both dietary groups. At termination of the trial, stomachs of trout fed feed B contained mashed pellets and free water and oil. Stomachs of trout fed feed A contained more intact pellets and little fluid. The apparent digestibility of protein, starch, dry matter and energy was highest in feed A. The apparent digestibility of P and Zn was highest at stable environment, and the absorption of P was highest from feed A. In conclusion, physical quality affected the nutritional value of the feeds, and differences in nutritional value at stable or fluctuating environment appeared to be related to feed intake.  相似文献