By using the non parametric least square method, the strong consistent estimations of distribution function and failure function are established,where the distribution function F(x) after logist transformation is...By using the non parametric least square method, the strong consistent estimations of distribution function and failure function are established,where the distribution function F(x) after logist transformation is assumed to be approximated by a polynomial.The performance of simulation shows that the estimations are highly satisfactory.展开更多
Marine invertebrate animal embryos and their early developmental products are of great significance to the study of taxonomy and phylogeny of early animals. A great number of phosphatized globular fossils were collect...Marine invertebrate animal embryos and their early developmental products are of great significance to the study of taxonomy and phylogeny of early animals. A great number of phosphatized globular fossils were collected fromthe early Cambrian Kuanchuanpu Member (upper Dengying Formation), southern Shaanxi, and a nearly complete develo-pmental sequence—from a fertilized egg, via blastodisc formation, blastula development, blastodisc enlargement toward gastrulae, to tissue differentiation—can be discerned in this collection. This discovery provides unmatchable material for studies on the origin, taxonomy, radiation, and ontogeny of early metazoans.展开更多
基金Fundan- Switzerland Reinsurance Fund and the National NaturalScience Foundation of China(1 0 1 71 0 79)
文摘By using the non parametric least square method, the strong consistent estimations of distribution function and failure function are established,where the distribution function F(x) after logist transformation is assumed to be approximated by a polynomial.The performance of simulation shows that the estimations are highly satisfactory.
文摘Marine invertebrate animal embryos and their early developmental products are of great significance to the study of taxonomy and phylogeny of early animals. A great number of phosphatized globular fossils were collected fromthe early Cambrian Kuanchuanpu Member (upper Dengying Formation), southern Shaanxi, and a nearly complete develo-pmental sequence—from a fertilized egg, via blastodisc formation, blastula development, blastodisc enlargement toward gastrulae, to tissue differentiation—can be discerned in this collection. This discovery provides unmatchable material for studies on the origin, taxonomy, radiation, and ontogeny of early metazoans.
