The biology and functional morphology of the high-energy beach dwelling Paphies elongata (Bivalvia: Mactroidea: Mesodesmatidae). Convergence with the surf clams (Donax: Tellinoidea: Donacidae)

The biology and functional morphology of the Australian endemic Paphies elongata (shell length <20 mm) from wave-exposed beaches are described. On Middleton Bay Beach, Albany, Western Australia, the species co-occurs with the smaller (shell length <13 mm) Donax columbella. Both make tidally regulated migrations up and down the shore in the swash and backwash of waves, respectively. Emergence from and re-burrowing into the beach sand in concordance with the waves is fast in both taxa (5–10 s). Adaptations to such a life on these high-energy beaches include an anteriorly elongate and posteriorly reduced shell and a mesh of tentacles within the inhalant siphon that screens out sand grains from the mantle cavity but allows entry for particles of detritus that P. elongata suspension feeds on when they are raised into the water column with each breaking wave. Internally, relatively large ctenidia, small labial palps, a stomach with many sorting areas and a short intestine equip P. elongata for life in such a dynamic habitat. Strong rejectory currents in the mantle cavity keep it clean of sand. Paphies elongata is dioecious, as are species of Donax, which throughout its Australian range P. elongata is sympatric with. These donacid and mesodesmatid taxa have both evolved to exploit the niche and the food resource of detritus held in suspension by breaking waves of high-energy sandy beaches within their respective ranges. Of interest, however, is that the original and sole occupants of such beaches – the Mesozoic Upper Cretaceous Donacidae – have been joined subsequently by representatives of the Mesodesmatidae, such as P. elongata, the adoption of this habitat taking place in the Eocene of the Cenozoic, some 50 million years later.     

线性结构关系模型参数估计的强收敛速度

该文讨论了线性结构关系模型｛β’ｘｋ＋α＝０ ζｋ＝ｘｋ＋εｋ ｛εｋ，ｋ＝１，２，…，ｎ｝，ｉ，ｉ，ｄ。ｋ＝１，２，…，ｎ，Ｅ（ε１）＝０ ｖａｒ（ε１）＝σ＾２Ｉｍ式中，｛ｘｋ，ｋ＝１，２，…，ｎ｝为一组ｉ．ｉ．ｄ。的不可观测的ｍ维随机向量，｛ｘｋ，ｋ＝１，２，…，｝，与｛εｋ，１，２，…，ｎ｝相互独立。     

Gauss－Seidel迭代法收敛的新准则

给出了当一般迭代矩阵Ａ的Ｆｒｏｂｅｎｉｕｓ范数‖Ａ‖Ｆ＝　＜１时，Ｇａｕｓｓ—Ｓｅｉｄｅｌ迭代法收敛的充分条件。该条件易于检验，适用范围广，证明方法独特。     

广义积分收敛性的新判别法

本文引进新的系统的广义积分判别法,它不仅比传统的判别法更加精细,而且避免了传统判别法需要寻找参照函数的困难。只要研究被积函数自身的性态,即可知其敛散性。     

一类具有分形特征的函数

应用Mathemiatica 4．0研究了一类处处连续处处不可导函数的图形，并在局部范围内与可导函数进行对比分析，发现这类函数在局部范围内具有明显的分形特征．     

向量值函数的叶果洛夫定理及等价性

本文给出了强可测向量值函数列的几个收敛定理，并证明了它们与全有限测度空间上的лузнн定理，叶果洛夫定理是等价的．     

浅析解析函数的充要条件与主要性质

讨论了解析函数四个充要条件与主要性质的关系,同时辩证地分析了产生这些充要条件与主要性质的逻辑基础与思想方法,提出了复变函数教学内容、教学方法改革的建议。     

巷道三点收敛观测法测点布置的复变函数解析

针对均质岩体巷道两帮或圆弧段上的三点收敛观测法的测点布置主要依靠工程师经验确定,随意性较强,缺乏可靠的理论依据,采用复变函数方法对均质岩体巷道两帮与圆弧段竖直方向的位移进行精确解析,确定出竖向位移为零而水平位移值最大的形变特征点,并将其作为巷道两帮或圆弧段上的测点布置位置,从而解决了测点布置的理论依据问题。研究成果可为均质岩体巷道围岩稳定性收敛观测工作提供了科学依据。     

Molecular phylogenetic analysis of three groups of Asian epilachnine ladybird beetles recognized by the female internal reproductive organs and modes of sperm transfer

We determined partial sequences of the nuclear 28S ribosomal RNA gene (717 base pairs) and mitochondrial DNA NADH-dehydrogenase subunit 2 gene (535 base pairs) of 25 species of phytophagous ladybird beetles from Asia that comprise 16 species of the genus Henosepilachna and nine species of the genus Epilachna, and reconstructed the phylogenetic trees for each gene by the maximum parsimony and maximum likelihood methods. The estimated phylogenetic relationships were consistent with those obtained by the mode of sperm transfer and female internal reproductive system, and supported an earlier assumption that very similar elytral spot patterns of some sympatric members of epilachnine beetles evolved independently.     

弱闭与*弱闭等价的一个充分条件

引入赋范线性空间的一种性质,得到对偶空间中弱闭与＊弱闭等价的一个充分条件,并研究具有这种性质的赋范线性空间的对偶空间中凸集的最佳逼近元存在性问题。