简介:本文在L^1空间上,研究了种群细胞中一类具总转变规则的Rotenberg模型,讨论了这类模型相应的迁移算子生成正C0半群,并且证明了该正C0半群是不可约的等结果.
简介:<正>案情:已经快下午六点了,李某又像往常一样蹬上那辆陪伴她风风雨雨的自行车下乡去检查工作。当行至一偏僻的山路,突然从山上跳出一男子,拦住李某,企图抢车。李某环顾四周旷无人烟,又天近黄昏,便对这名男子说:"车你拿走吧,不要伤害我!"男子同意了便上前推车。这时,李又说:"能否把车上的气筒还我,那是借别人的,必须要还给人家啊。"男子想了一下也答应了。李就开始动手卸气筒。这时,这名男子也弯下身子检查车况,正好背对着李某,于是李灵机一动,用气筒朝男子的后脑猛击一下,将其打昏,赶忙骑车到附近报案。当李某来到最近的一个屯子时,整个屯子一片漆黑,只有一户人家从门缝露出一线灯
简介:FromGreenhorntoGreenEarthBySHILIHONGPROBABLYNOanchorpersonsare"greener"thanLiaoXiaoyi,awomanproduenvironmentalTVprograms."Gre...
简介:INa2005NewYorkTunesreporttitled:'ChinaIsBrightSpotinDarkReportontheWorld'sDiminishingForests,'Ms.MetteL.Wilkie,forestofficeroftheUNFoodandAgricultureOrganization(FAO),wasquotedassaying:'Asialostabout3,000squaremilesofforestayearinthe90s,butgainednearly4,000annuallysince2000.AlmostallofthatchangehasoccurredbecauseofChina'snewforestpolicy.'ThearticleconcludedthatwidespreadtreeplantinginChinahasslowedtherateatwhichtheearth'sforestedlandisdwindling.Sowhat'sbeenhappeningontheground?