数学 外文翻译 外文文献 英文文献 真空压力播种机的数学建模Word格式.docx

数学 外文翻译 外文文献 英文文献 真空压力播种机的数学建模Word格式.docx

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结果与讨论……………………………………………………21

4.Conclusions……………………………………………………13

结论…………………………………………………………26

5.Acknowledgements…………………………………………13

鸣谢………………………………………………………26

MathematicalModellingofVacuumPressureonaPrecisionSeeder

D.Karayel1,Z.B.Barut2andA.Ö

zmerzi1

1AkdenizUniversity,FacultyofAgriculture,DepartmentofAgriculturalMachinery,07070,Antalya,Turkey

2Ç

ukurovaUniversity,FacultyofAgriculture,DepartmentofAgriculturalMachinery,Adana,Turkey;

e-mailofcorrespondingauthor:

dkarayel@akdeniz.edu.tr

Received9July2003;

accepted19January2004. 

Availableonline13April2004.

Abstract

Thepurposeofthisresearchwastodeterminetheoptimumvacuumpressureofaprecisionvacuumseederandtodevelopmathematicalmodelsbyusingsomephysicalpropertiesofseedssuchasonethousandkernelmass,projectedarea,sphericityandkerneldensity.Maize,cotton,soyabean,watermelon,melon,cucumber,sugarbeetandonionseedswereusedinlaboratorytests.Onethousandkernelmass,projectedarea,sphericityandkerneldensityofseedsvariedfrom4.3to372.5 

g,5–77 

mm2,38.4–85.8%and440–1310 

kg 

m−3,respectively.Theoptimumvacuumpressurewasdeterminedas4.0 

kPaformaizeIandII;

3.0 

kPaforcotton,soyabeanandwatermelonI;

2.5 

kPaforwatermelonII,melonandcucumber;

2.0 

kPaforsugarbeet;

and1.5 

kPaforonionseeds.

Thevacuumpressurewaspredictedbymathematicalmodels.Accordingtotheresults,thefinalmodelcouldsatisfactorilydescribethevacuumpressureoftheprecisionvacuumseederwithachi-squareof2.51×

10−3,rootmeansquareerrorof2.74×

10−2andmodellingefficiencyof0.99.

Nomenclature

a,b,c,d,eregressioncoefficients

Emmodellingefficiency

Ermsrootmeansquareerror

kexpexperimentalvacuumpressure,kPa

kexp,meanmeanvalueofexperimentalvacuumpressure,kPa

kprepredictedvacuumpressure,kPa

Llength,mm

m1000onethousandkernelmass,g

Nnumberofobservation

nnumberofconstantsinthemodel

Pprojectedarea,mm2

Pvvacuumpressure,kPa

pprobability

R2coefficientofdetermination

Tthickness,mm

Wwidth,mm

φsphericity,%

χ2chi-square

ρkkerneldensity,kg 

m−3

ArticleOutline

1.Introduction

2.Literaturereview

3.Materialsandmethods

4.Resultsanddiscussion

5.Conclusions

Acknowledgements

References

1.Introduction

Precisionsowinghasbeenamajorthrustofagriculturalengineeringresearchformanyyears;

however,mostoftheresearchanddevelopmentworkhasdealtwithseedersforagronomiccrops.

Themainpurposeofsowingistoplacetheseedtoacertainspaceandadepthintheseedbed.Precisionseedersplaceseedsattherequiredspacingandprovideabettergrowingareaperseed.Therearetwocommontypesofprecisionseeders:

beltandvacuum.Precisionvacuumseedershaveameteringplatewithmeteringholesonapredeterminedradius.Avacuumisappliedtothesemeteringholesbymeansofaracemachinedinabackingplate.Astheplaterotates,thevacuumappliedtothemeteringholesenablesthemtopickupseedsfromtheseedhopper.Precisionvacuumseedershavethefollowingadvantagesoverthemechanicalseeders:

betterworkingquality,morepreciseseedrateswithlowerrateofseeddamage,bettercontrolandadjustmentofupkeepanddriftofseeds,andbroaderspectrumofapplicability（Soosetal.,1989）.

Aseedershouldplaceaseedinanenvironmentinwhichtheseedwillreliablygerminateandemerge.Anumberoffactorsaffectthespacingofplants.Theseedselectionmechanismmayfailtoselectordropaseedresultinginlargespacingbetweenseeds.Themechanismmayselectanddropmultipleseedsresultinginsmallspacingsbetweenseeds.Seedquality,soilconditions,seederdesignandtheskilloftheoperatorallplayapartindeterminingthefinalplantstand.

Thephysicalpropertiesofseedsareessentialforthedesignofequipmentforhandling,processing,storingandsowingthekernels.Varioustypesofcleaning,grading,separationandsowingequipmentaredesignedonthebasisofthephysicalpropertiesofseeds.However,nomodelhasbeenfoundtodescribeseederparameterssuchasvacuumpressurerelatedwithphysicalpropertiesofseeds.

Thephysicalpropertiesoftheseedsarethemostimportantfactorsindeterminingtheoptimumvacuumpressureoftheprecisionvacuumseeder.Inthisstudy,usingsomeofthese,e.g.onethousandkernelmass,projectedarea,sphericityandkerneldensity,mathematicalmodelsweredevelopedtopredictoptimumvacuumpressure.Theexperimentalvaluesofvacuumpressureweredeterminedfromlaboratorytestproce