四種樹木間輸水結構和功能的比較研究.pdf

1、南開大學碩士學位論文四種樹木間輸水結構和功能的比較研究姓名：張艷文申請學位級別：碩士專業(yè)：植物學指導教師：吳樹明羅立新19990501南開大學碩士論文ThecomparativestudyontherelationshipbetweenstructureandfunctionofstemsapflowinthefourintactplantsAbstractTheadvancedheatpulsevelocityrecorderwasu

2、sedtomeasureflowvelocityandrateofstemsapflowinfourintactplants(RobiniaPseudoacaciaL.，Ailanthusaltissima(Mill.)SwinglePopulustomentosaCarr.，Salixha妙lonicaL.)undernaturalconditions.Thentherelationshipbetweenthestructureofv

3、esselsandtheflowrateandvelocitywasstudiedindetails.Theresultsareinteresting:Undernaturalconditionsthelocationsofthefastestvelocityareallundercambiumof5mmandthechangeofthefastestvelocitywhichisthesameasthechangeofflowrate

4、inonedayshowslowinthemorninghighestinthenoonandlowagainintheafternoonThemosttransportfunctionlargelydependsontheoutermostringintheringporoustrees(RobiniaPseudoacaciaL.，Ailanthusaltissima(Mill)Swinglewhileonmanyringsinthe

5、diffuseporoustrees(PopulustomentosaCarrSalixba勿lonicaL.)ThefastestvelocityindiffuseporoustreesishigherthanthatinringporoustreesThedensitiesofvesselsaffecttheflowvelocity:themoredensitiesthefastervelocityTherelationshipbe

6、tweenvelocityanddiameterofpitsispositive:thelargerdiameterofpitsthefastervelocityandlargediameterofpitswithlowfrequencyshowslowresistancetoflownorelationshipbetweenthevelocityandthelengthandwidthofpits.Keywords:heatpulse