简介:本文利用图的独立数和任意3个独立点集中距离2的点对邻域交,给出了图为Hamilton和Hamilton连通的新的充分条件
简介:Anopen-endedcoaxiallinereflectionmethodespeciallysuitableformeas-uringthedielectricpropertiesofbiologicaltissueinvivoisdescribed.Thismethodofferstheadvantageofnotrequiringanyspecialpreparationofthesamplestobemeasuredbutaclosecontactwiththeopenendofacoaxialline.Itis,therefore,veryconvenienttoacquirealargenumberofmeasurementdatainbroadbandrapidly.Themethodmayalsobeusedtomeasurethepropertiesofothersubstances.ThemeasuringsystemconsistsofanetworkanalyzercontrolledbyamicrocomputerandcalibratedbyusingANAproceduretoelimi-hatetheinflunceoferrornetworkintroducedbytheadapter,someconnectors,etc.Inor-dertoreachhigheraccuracy,theiterativemethodisusedtodeterminetheparametersoftheequivalentcircuit.Measurementsofpermeativitiesofsomelivingtissueshavebeenper-formedinthefrequencybandof0.5-2GHz.Comparedwiththeresultsknowninsomepapers,thevalidityofthismethodhasbeenconfirmed.Thedifferenceindielectricproper-tiesbetweenlivinganddeadtissues,andthetissuepermeativites(ε)versusfrequencyanddurationofmeasurementafterdeathhavealsobeenmeasured.
简介:在这个工作,在dodecyl-benzenesulfonic酸和钠碳酸盐之间的使成粒状高在实验室规模被调查砍混合器。包括主要碳酸盐尺寸,文件夹内容,impeller速度,和操作温度,明确的表达参数和过程变量的效果被相关到产品小粒的性质。实验的设计和变化的分析被联合分析试验性的数据,并且结果证明有更少好粒子的更大的小粒尺寸能被采用更高的文件夹内容和更大的钠碳酸盐尺寸获得。impeller的shear力量能广泛地打破oversized小粒。文件夹内容在与二种钠碳酸盐形成的小粒的flowability上施加了形成对照的效果,因为在固体的液体浸透的差别可能。同轴的尺寸分析决定的溶解率证明高文件夹内容对溶解性能,和在亨特之间的关系有益颜色和测试参数被评估。这个工作的结果能在粉末为过程控制和优化被用作可靠指导净化的生产。
简介:Background:Artificialturfisconsideredafeasibleglobalalternativetonaturalturfbymanysportsgoverningbodies.Consequently,itsabilitytoprovideasafeandconsistentplayingsurfaceregardlessofclimatebecomesessential.Theaimsofthisstudyweretodeterminetheeffectsofartificialsurfacetemperatureon:(1)mechanicalpropertiesoftheturfand(2)thekinematicsofaturf-sportrelatedmovement.Methods:Twoidenticalartificialturfpitchesweretested:onewithacoldsurfacetemperature(1.8°C–2.4°C)andonewithawarmsurfacetemperature(14.5°C–15.2°C).Mechanicaltestingwasperformedtomeasurethesurfaceproperties.Fouramateursoccerplayersperformedahurdlejumptosprintaccelerationmovement,withdata(contacttime,steplengthandhip,kneeandanklekinematics)collectedusingCODASport(200Hz).Results:Thetemperaturedifferencehadasignificantinfluenceonthemechanicalpropertiesoftheartificialturf,includingforceabsorption,energyrestitution,rotationalresistance,andtheheightwheretheheadinjurycriterionwasmet.Bothsteplength(p=0.008)andcontacttime(p=0.002)oftheinitialstepafterthelandingweresignificantlylongeronthewarmsurface.Inaddition,significantrangeofmotionandjointangularvelocitydifferenceswerefound.Conclusion:Thesefindingshighlightdifferentdemandsplacedonplayersduetothesurfacetemperatureandsuggestaneedforcoaches,practitioners,andsportsgoverningbodiestobeawareofthesedifferences.
简介:Topreventexpandedpolystyrene(EPS)beadsfromrisinguptothesurfaceinthemoldingprocessofEPSlightweightconcrete,vibrationwithpressurewasappliedandthepolyvinylacetate(PVA)emulsionwasadoptedtoimproveitsmechanicalproperties.Themechanicalproperties,thermalpropertiesanddurabilityofEPSlightweightconcreteweretested.ThemicrostructuresofEPSlightweightconcretewereobservedbyscanningelectronmicroscope(SEM).Vibrationwithpressurereducesthenumberofsmallcracks.The180dcompressivestrengthandflexuralstrengthincreaseobviouslyasalargeamountofPVAwasadded.ThemixedamountofPVAhasnoobviousinfluenceonthethermalperformancewhenitisnotmorethan10%ofthecement.VibrationwithpressureandsurfacemodificationofEPSbeadsbyPVAimprovethecombinationofEPSbeadswithcementstoneandthemechanicalpropertiesofEPSlightweightconcrete.
简介:TheeffectofMnsubstitutionforpartialFeinRFe11Tionstructureandmagneticpropertiesofcompoundswasresearched.RFe7Mn4Tisamples(R=Y,Tb,Dy,Ho,Er)werepreparedbymeansofvacuumarc-meltingandsubsequentvacuumannealing.ThestructureandmagneticpropertiesofRFe7Mn4TicompoundswereinvestigatedbyX-raypowderdiffractionandmagneticmeasurements.Thefollowingconclusionswereobtained:alltheRFe7Mn4TicompoundscrystallizeintheThMn12-typestructure.Thelatticeconstantsandtheunit-cellvolumechangedwiththeincreaseofatomicnumberforR=Y,Th,Dy,Ho,andEr.ThecompensationcharactersappearfortheDyFe7Mn4TiandHoFe7Mn4Ticompounds,andthecompensationtemperatureswereabout123Kand90K,respectively.TheCurietemperature,thesaturationmagnetization,andsaturationmomentofRFe7Mn4Ticompoundsweregiven.
简介:ZrO_2-SnO_2-TiO_2(ZST)系统陶艺的微波电介质性质作为Sb_2O_5掺杂物的数量的功能被学习。与0-0的增加。5%Sb_2O_5(臼齿的比率),有Sb~(5+)离子的Ti~(4+)离子的替换减少了sintering温度并且由于氧空缺的减小增加了优秀因素Q。当Sb~(5+)的数量进一步增加了时(超过0.5%)。Q被增加电子浓度减少。当与0.5%Sb_2O_5做的系统是在为6h的1150℃的sintered时,相对的绝缘的经常的ε,Qf_0,和反响的频率(TCF)的温度系数是38.46,44500GHz,20.0x10~(-6)/℃,分别地,在6GHz。