简介:Thispaperreviewsourworkonthefundamentalprinciplesofhighgravitycontrolledprecipitation(HGCP)technology,anditsapplicationsintheproductionofdrugnanoparticles,whichwascarriedoutinarotatingpackedbed(RPB).Severalkindsofdrugnanoparticleswithnarrowparticlesizedistributions(PSDs)weresuccessfullypreparedviaHGCP,includingthe300-nmCefuroximeAxetil(CFA)particles,200–400-nmcephradineparticles,500-nmsalbutamolsulfate(SS)particles(100nminwidth),and850-nmbeclomethasonedipropionate(BDP)particles,etc.Comparedtodrugsavailableinthecurrentmarket,allthedrugnanoparticlesproducedbyHGCPexhibitedadvantagesinbothformulationanddrugdelivery,thusimprovingthebioavailabilityofdrugs.HGCPisessentiallyaplatformtechnologyforthepreparationofpoorlywater-solubledrugnanoparticlesfororalandinjectiondelivery,andofinhalabledrugsforpulmonarydelivery.Consequently,HGCPofferspotentialapplicationsinthepharmaceuticalindustryduetoitscost-effectiveness,efficientprocessingandtheeaseofscaling-up.
简介:RigidFiniteElementMethod(RFEM)wasproposedtosimulatethemechanicalbehaviorofdiscontinuousstructuressuchasrockandsoilstructures.Theauthors’workonthetheoryandapplicationsofRFEMissummarizedinthispaper.BasedonthetheoryofRFEM,theElasticBody-SeamsModel(EBSM)isproposedtotakethedeformationanddamageofrockmassesintoaccount.
简介:Themulti-scalestructuresofcomplexflowsinchemicalengineeringhavebeengreatchallengestothedesignandscalingofsuchsystems,andmulti-scalemodelingisthenaturalwayinresponse.Particlemethods(PMs)areidealconstituentsandpowerfultoolsofmulti-scalemodels,owingtotheirphysicalfidelityandcomputationalsimplicity.Especially,pseudo-particlemodeling(PPM,Ge&Li,1996;Ge&Li,2003)ismostsuitableformolecularscaleflowpredictionandexplorationoftheoriginofmulti-scalestructures;macro-scalePPM(MaPPM,Ge&Li,2001)andsimilarmodelsareadvantageousformeso-scalesimulationsofflowswithcomplexanddynamicdiscontinuity,whilethelatticeBoltzmannmodelismorecompetentforhomogeneousmediaincomplexgeometries;andmeso-scalemethodssuchasdissipativeparticledynamicsareuniquetoolsforcomplexfluidsofuncertainpropertiesorflowswithstrongthermalfluctuations.Allthesemethodsarefavorableforseamlessinterconnectionofmodelsfordifferentscales.However,asPMsarenotoriginallydesignedaseithertoolsforcomplexityorconstituentsofmulti-scalemodels,furtherimprovementsareexpected.PPMisproposedformicroscopicsimulationofparticle-fluidsystemsasacombinationofmoleculardynamics(MD)anddirectsimulationMonte-Carlo(DSMC).ThecollisiondynamicsinPPMisidenticaltothatofhard-sphereMD,sothatmass,momentumandenergyareconservedtomachineaccuracy.However,thecollisiondetectionprocedure,whichismosttime-consuminganddifficulttobeparallelizedforhard-sphereMD,hasbeengreatlysimplifiedtoaprocedureidenticaltothatofsoft-sphereMD.Actually,thephysicalmodelbehindsuchatreatmentisessentiallydifferentfromMDandismoresimilartoDSMC,butanintrinsicdifferenceisthatinDSMCthecollisionsfollowdesignedstatisticalrulesthatarereflectionoftherealphysicalprocessesonlyinverylimitedcasessuchasdilutegas.PPMisidealforexploringthemechanismofcomplexflowsa