关于南雄盆地K/T界线问题的讨论──与D.A.拉塞尔,D.E.拉塞尔,A.R.斯威特商榷

陆相山间盆地的沉积过程远比某些海相的沉积过程复杂。评述了当今流行的利用沉积速率来检验、甚至推断陆相磁性地层极性时序列方法的可靠性。南雄盆地地层及哺乳动物化石的分布研究表明,前人所定Ｋ／Ｔ界线上下地层连续,并不象一些学者认为的在上湖组底部缺失了数百万年的沉积。     

A taxonomic study on the genus LeptolepidiumK. H. Shing et S. K. Wu

A taxonomic study is made on the genus Leptolepidium K. H. Shing et S. K. Wu （Sinopteridaceae） on the basis of field work and specimen examination. Two species （L. caesium (Christ) K. H. Shing et S. K. Wu and L. tenellum Ching et S. K. Wu） and two va     

Gentamicin resistance among salmonellae. A ten-year study, 1973–1982

A total of 8579 Salmonella strains received during 1973–1982 were tested for their antibiogram patterns against nine routinely used antibiotics including gentamicin. Of these, 380 strains (4.4%) showed resistance to gentamicin at levels of 10 g/ml and above. A high degree of resistance to gentamicin was recorded in 1979 (18.7%) and 1980 (9.4%). M.I.C. levels of strains received during 1982 were determined and it was found that some strains had levels as high as 160 g/ml. The comparative results of gentamicin resistance from 1973 to 1982 are presented and the public health significance of the alarming increase in two years (1979–1980) is discussed.