Two new species of Leymus (Poaceae : Triticeae) from Qinghai, China

Two new species of Leymus, L. pendulus and L. obvipodus, are described and illustrated. These two species are endemic to Qinghai province, China, occurring at the margins of woodlands, wastelands, mountain valleys, and the bases of walls, at 2280-2400 m elevation. Leymus pendulus is unusual in its lax, long, pendent spikes. It is closely related to L. flexus, but differs from that species by pendent spikes, longer rachis internodes, and shorter glumes and lemmas. Leymus obvipodus is unique in the genus in having all spikelets pedicellate. It resembles both L. divaricatus (Drobow) Tzvelev and L. aristiglumus L. B. Cai but differs from the former by lanceolate glumes with 1 to 3 nerves, longer spike-like panicles, taller culms, and lanceolate lemmas with 5 obscure nerves and pubescent margins, and from the latter by lax, longer spike-like panicles, pedicellate spikelets with 4 to 8 florets, narrower glumes, and longer, lustrous lemmas.

石油储集层评价专家系统

本文扼要地介绍了石油储集层评价专家系统。该系统是以人工智能理论为基础,结合模糊数学、概率统计等方法,系统地总结测井资料解释专家的知识和经验,给出了一种新的储集层评价专家系统结构。具体内容有知识模型、知识表达、控制机构、说明能力及其在计算机上的实现。另外,我们设计了一种NFA专用语言来描述石油储集层评价专家的知识和经验。