简介:<正>Since1980s,participatoryapproach,asatoolandmajortechnology,hasbeenreceivedbymanycountriesandinternationalorgans,andhasbeenusedextensivelyintheprojectsofsurvey,povertyrelief,resourcedevelopmentandresourceprotection.Indeed,thesedevelopmentactions,supportedby
简介:Inthispaper,tenwoodyplantsgrewonthecampusoftheBeijingForestryUniversitywereselectedformeasuringhydraulicarchitectureparametersandwaterpotentialofone-year-oldtwigs.Theresultsshowthatdayandnightchangeofwaterpotentialandhydraulicarchitectureparametersappeartobeobviouslyconvextrend.Therelationshipmodelsbetweenwaterpotentialandhydraulicconductivity,specialconductivityandleafspecialconductivitywererespectivelyestablished,whichweresimulatedb...
简介:Inthepaper,thehydraulicarchitectureparametersofPinustabulaeformisseedlings(4yearsold)weremeasuredbyimprovedflushingmethodundernormalwaterconditioninthegreenhouseandthebasictheoryofhydraulicarchitectureisusedtodiscusstherationalityofthepipemodel.Theresultsoftheexperimentandsimulationshowthatthedifferencesofhydraulicconductivity,specificconductivityandleafspecificconductivityisgreatindifferentstemsandbranchesofPinustabulaeformisseedlings.Thehydraulicconductivityofnon-constrictionareaishigherthanthatofconstrictionarea.Thedevotionoffunctionalxylemofstemtounitleafgrowthisnotaconstant,namely,theHubervalueisdiverse.Eventhoughthepipemodelhasbeenacceptedinsomeareas,itspreconditionisnotperfect,anditishelplessincorrectlyunderstandingtheessenceofwatertransportinseedlingsfromtheprospectiveofwaterphysiology.
简介:仔猪咬耳朵、咬尾巴是由于个体本身代谢机能紊乱,味觉异常而引起的一种非常复杂的综合症,主要表现在仔猪到处舔食、啃咬甚至互相攻击对方.咬耳朵、咬尾巴的发生一般认为是由于仔猪机体内蛋白质或某些氨基酸缺乏和不全的一种表现.仔猪间互相啃咬对方耳朵、尾巴,并可引发群猪攻击其中的某一头,如不能采取有效措施及时制止并隔开,被咬的仔猪一般都造成严重的伤残甚至死亡,是影响养猪生产的不利原因之一.咬耳朵、咬尾巴的发生一般无明显的规律性,多发于断奶后至50公斤体重的猪群,炎热天气、圈舍内饮水缺乏、环境条件潮湿、闷热时发生较多,几窝不同群的仔猪合群饲养时也见多发.笔者认为,采取以下七条措施,可有效降低仔猪咬耳朵、咬尾巴现象的发生: