简介:Anexperimentofuniaxialcompressionwascarriedoutonsamplesof8representativerocktypes.Thetemporalvariationsoftheremanentmagnetization,strainandacousticemissionofsampleswererecordedandinvestigated,especiallywhenthesampleswereunderconstantloadandwhentheyhadjustbeenunloaded.Itwasfoundthatmostsamplesstillshowedchangesoftheirremanentmagnetizationunderconstantloadandthetendencyofthesechangesremainedthesameasthatbeforetheloadhadbeenkeptconstant.Inthemeantime,similarchangesofstrainswereobservedaswell.However,inashorttimeperiodimmediatelyafterthesamplehadbeencompletelyunloaded,thevariationsofremanentmagnetizationandstrainswerestillobserved.Theabovephenomenaseemtobethereflectionofrheologicalpropertiesofrocks.Itisinterestingtonotethatsomesimilarphenomenawerealsofoundinfieldobservations,suchasaseismicgeomagneticchangesandsecularvariationinlocalgeomagneticfieldbeforeandaftere
简介:Faultisacomplexdynamicsystemcontrolledbythecouplingofrocktexture,reaction,fluidflow,stress,androckdeformationmechanism.Acoupledreaction-transport-mechanicaldynamicmodelforfaultsystemisestablishedanddescribedinthispaper.AnexampleispresentedfortheShuikoushandeposit,Hunan.Theresultsofdynamicsimulationindicatethattheevolutionandmagnitudeoffracturepermeabilityofdifferentrocksaredifferent,andthatfaultingcanenhancethespatialheterogeneityofrockpermeabilityandfacilitatefluidflowandmineralizationinlocalfaultzone.Thepressureforafaultusuallyshowsavariationmodeofaperiodicoscillationwithtime,whichreflectsthechaoticbehavioroftheevolutionofafault.
简介:StabilizedorChebyshevexplicitmethodshavebeenwidelyusedinthepasttosolvestiffordinarydifferentialequations.MakinguseofspecialpropertiesofChebyshev-likepolynomials,thesemethodshavefavorablestabilitypropertiescomparedtostandardexplicitmethodswhileremainingexplicit.Anewclassofsuchmethods,calledROCK,introducedin[Numer.Math.,90,1-18,2001]hasrecentlybeenextendedtostiffstochasticdifferentialequationsunderthenameS-ROCK[C.R.Acad.Sci.Paris,345(10),2007andCommun.Math.Sci,6(4),2008].InthispaperwediscusstheextensionoftheS-ROCKmethodstosystemswithdiscretenoiseandproposeanewclassofmethodsforsuchproblems,theT-ROCKmethods.Onemotivationforsuchmethodsisthesimulationofmulti-scaleorstiffchemicalkineticsystemsandsuchsystemsarethefocusofthispaper,butournewmethodscouldpotentiallybeinterestingforotherstiffsystemswithdiscretenoise.TwoversionsoftheT-ROCKmethodsarediscussedandtheirstabilitybehaviorisanalyzedonatestproblem.ComparedtotheT-leapingmethod,asignificantspeed-upcanbeachievedforsomestiffkineticsystems.Thebehavioroftheproposedmethodsaretestedonseveralnumericalexperiments.
简介:Geothermalenergyisapreciousresource,whichiswidelydistributed,varied,andabundant.Chinahasenteredaperiodofrapiddevelopmentofgeothermalenergysince2010.Asshallowgeothermalenergypromoting,thedepthofhydrothermalgeothermalexplorationisincreasing.ThequalityofHotDryRock(HDR)andrelatedexploratorytechnologiesarebetterdevelopedandutilized.Onthebasisofgeothermaldevelopment,thispaperreviewsthegeothermalprogressduringthe"12thFive-YearPlan",andsummarizestheachievementsofhydrothermalgeothermalandhotdryrocksfromgeothermalsurveyandevaluationaspects.Finally,theauthorspredictthedevelopmenttrendofthefuturegeothermalresearchtobenefitgeothermalandhotdryrockresearch.
简介:Theacousticemission(AE)featuresinrockfracturearesimulatednumericallywithdiscreteelementmodel(DEM).Thespecimenisconstructedbyusingsphericalparticlesbondedviatheparallelbondmodel.Asaresultoftheheterogeneityinrockspecimen,thefailurecriterionofbondedparticleiscoupledbytheshearandtensilestrengths,whichfollowanormalprobabilitydistribution.TheKaisereffectissimulatedinthefractureprocess,foracubicrockspecimenunderuniaxialcompressionwithaconstantrate.TheAEnumberisestimatedwithbreakagesofbondedparticlesusingapairofparameters,inthetemporalandspatialscale,respectively.ItisfoundthattheAEnumbersandtheelasticenergyreleasecurvescoincide.TherangefortheKaisereffectfromtheAEnumberandtheelasticenergyreleasearethesame.Furthermore,thefrequency-magnituderelationoftheAEnumbershowsthatthevalueofBdeterminedwithDEMisconsistentwiththeexperimentaldata.