四種樹木間輸水結(jié)構(gòu)和功能的比較研究.pdf

1、南開大學(xué)碩士學(xué)位論文四種樹木間輸水結(jié)構(gòu)和功能的比較研究姓名：張艷文申請學(xué)位級別：碩士專業(yè)：植物學(xué)指導(dǎo)教師：吳樹明羅立新19990501南開大學(xué)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