简介:Inthiswork,thefactorsandparametersofatestmethodonabrasionresistanceatelevatedtemperatureswerediscussedandresearched.Firstofall,theprecisiontestsofthetestmethodonabrasionresistanceatelevatedtemperatureswereconductedin8laboratories.Theresultssuchasthestandarddeviationandreproducibilityshowgoodrepeatabilityandreliability.Therelationshipbetweenthestabilityofrefractoryperformanceandthestandarddeviationoftheirwearvaluewasanalyzed.ThentheimpactoftheheattreatmentconditionofunshapedrefractoriesandoxidationofSiCsandasabrasiveonthelostvolumeofthetestedspecimenswasresearched.
简介:TheConductorandHardwareResearchDivisionoftheElectricPowerConstructionResearchInstitute,MinistyofEnergy,isascientificresearchandtestbaseforstudyofmechanicalpropertiesoftransmissionlineconductorandhardwareinChina,whichhasahistoryof32yearslong.TheDivisionnowpossessesastaffofabout20,including5seniorengineersand5engineers.TheDivisionpossessesalsoalab,itmainlydealsWiththetestandre-
简介:TheCET4writingtestiswidelyusedinChina,butwhetheritisamorereliableandvalidtestofwritingforCET4thanothermethodsofevaluationisstillnotclear.Thepurposeofthisstudywastoexaminethereliabilityandthevalidityofamodificationofthistest.Incarryingoutthestudy,atotalof60Band4studentsinZhejiangUniversitytookthemodifiedtest,aCET4testandaFirstCertificatePracticeTest.TheresultsofthisstudydemonstratethatthemodifiedversionisasignificantlymorereliableandvalidwritingtestthanthepresentCET4writingtest.TheseresultssuggestthattheCET4writingtestneedsmodification.
简介:Onthebasisofthetheoryofthermalshockresistanceinthescienceofmaterialsandthetestmethodofairquenchingwhichisgenerallyrec-ognizedinternationally,especiallyinEurope,thepresenttestmethodsfordeterminationofthermalshockresistanceinChinahavebeenanalysed,Experimentstudyonthermalshockresis-tanceofsilicaandbasicrefractoryproductshasbeenconducted,andanewtestmethodofthermalshockresistance-airquenchingmethodhasbeenputforward.
简介:Inthispaper,anewhybridcontroltechnique,basedonacombinationofbase-isolationandsemi-activevariablestiffness/dampinginasuperstructure,ispresented.Toillustratetheefficiencyoftheproposedcontrolsystem,modeltestsonamini-electromagneticshakingtableandanumericalsimulationwereperformed.Thetestandnumericalcalculationresultsindicatethatthisnewhybridcontrolmodewithadditionaldampingandsmalleradditionalstiffnesscanachieveabettercontrolefficiency.
简介:Determiningtheinterfacialpropertiesofthermalbarriercoatings(TBCs)isimperativefortheirdurabilityevaluationandfurtherimprovements.Aceramiccoating(topcoat)andaNiCoCrALYbondcoatwereatmospheric-plasma-sprayed(APS)onastainlesssteelsubstrate.Amodifiedthree-pointbendingtestwasadoptedtoinitiateandpropagatethetopcoat/bondcoat(TC/BC)interfacialcrack.Afteracompletedelamination,thefracturesurfaceswereexaminedbyanopticalmicroscope,whichshowsthatthecrackingplanewasmerelyontheTC/BCinterface.Basedontheexperimentalresultsofload–displacementandcracklength–displacement,thestrainenergyreleaserateGforcrackpropagationwascalculated,andtheaveragedmagnitudewas77.1J/m2.Repeatableresultshaveindicatedthatthemethodcanbeusedfortheevaluationofinterfacialfracturetoughnessinthermalbarriercoatingsandothermulti-layerstructures.
简介:Liquefactiontestingatasaturatedloesssitewasperformedunderthesimulatedearthquakegroundmotioninducedbyartificialexplosionswithmicro-timeintervals.Thetimehistoriesofgroundacceleration,porewaterpressureandtheultimatevalueofresidualstrainwererecordedandmeasured.ThemodifiedFEQdraincomputationsoftwarewasusedtoanalyzetheliquefaction.Boththetestandtheanalysisconfumtheobjectiveoccurrenceofloessliquefaction.Furthermore,thereliabilityofthemethodoftheloessliquefactionanalysisbasedonFEQdrainandthemodelofporewaterpressuredevelopmentofsaturatedloessareexamined.
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简介:AbstractIntroduction:Erosive pustular dermatosis of the scalp (EPDS) is an uncommon condition with unknown etiology. The clinical exclusive diagnosis needs to be differentiated from similar diseases.Here, we present a case of EPDS after surgical treatment of scalp squamous cell carcinoma.Case presentation:A 68-year-old woman presented with an eight-month history of a chronic scalp eruption. She had been diagnosed as squamous cell carcinoma by biopsy nine months ago, and had been treated by surgical excision and skin grafting. One month later, she was referred for evaluation of the newly enlarged lesion which was observed at the skin grafting site. She was diagnosed of EPDS based on characteristics of lesions, clinicopathological findings and laboratory data. The condition had clinically improved with systemic steroid therapy and topical tacrolimus for two weeks. Relapses occurred after complete withdrawal of both treatments. After repeating the above therapy and applying topical tacrolimus as maintenance therapy, the condition was well controlled at the one-year follow-up.Discussion:EPDS is an uncommon inflammatory dermatosis with main incidence rate of elderly patients and female predominance. The diagnosis of EPDS cant be made only by histopathological examination, which is helpful for differential diagnosis. Microbiological investigations commonly remain negative. For the high risk of relapse, it is important for clinicians to be aware of maintenance treatment and a long-term management.Conclusion:It should be recognized by clinicians that EPDS is an uncommon and relapse disease, leading to serious cosmetic problems. The treatment lacks evidence-based medicine data, clinician should choose the appropriate therapy according to the condition of patients.
简介:AbstractCurrent treatment of vitiligo is still a great challenge, since most cases of vitiligo have variable re-pigmentation outcomes due to their unpredictable responses to existing therapeutic regimens. There is an urgent need to identify this re-pigmentation process and to develop novel therapies. This review illustrates the most current research and latest understanding of vitiligo skin re-pigmentation and related regulatory mechanisms. Literature was collected from PubMed until January 2020, using the search terms including "vitiligo," "re-pigmentation," "phototherapy," "narrow-band ultraviolet B, " "excimer," "fractional carbon dioxide laser," and "melanocyte stem cells." Literature was mainly derived from English articles. Article type was not limited. Emerging evidence suggests that patients with vitiligo present various re-pigmentation patterns following ultraviolet B phototherapy, which relies on different cell reservoirs from the perilesional margins and/or from uninvolved hair follicles to replenish functional melanocytes that are lost in vitiliginous skin. The following events are likely to be involved in this re-pigmentation process, including: 1) changes in the paracrine secretion and distribution of transforming growth factor-β1 in the bulge area and in the epidermis; 2) the enhanced transfer of dermal pro-melanogenic growth factors to the epidermis; and 3) the induction of a C-X-C motif chemokine ligand (CXCL) 12-enriched micro-environment that efficiently recruits CXCR4-or CXCR7-positive melanocytes. Ongoing studies on the cellular and molecular events underlying vitiligo re-pigmentation will help design new therapeutic strategies to improve treatment outcomes.
简介:Forty-threepatientswithchronicspinalcordinjuryforover6monthsweretransplantedwithembryonicolfactoryensheathingcells,2–4×106,intomultiplesitesintheinjuredareaunderthesurgicalmicroscope.Thesympatheticskinresponseinpatientswasmeasuredwithanelectromyography/evokedpotentialinstrument1daybeforetransplantationand3–8weeksaftertransplantation.SpinalnervefunctionofpatientswasassessedusingtheAmericanSpinalInjuryAssociationimpairmentscale.Thesympatheticskinresponsewaselicitedin32casesbeforeolfactoryensheathingcelltransplantation,whileitwasobservedin34casesaftertransplantation.Concomitantly,sympatheticskinresponselatencydecreasedsignificantlyandamplitudeincreasedsignificantlyaftertransplantation.TransplantationofolfactoryensheathingcellsalsoimprovedAmericanSpinalInjuryAssociationscoresformovement,painandlighttouch.Ourfindingsindicatethatolfactoryensheathingcelltransplantationimprovesmotor,sensoryandautonomicnervefunctionsinpatientswithchronicspinalcordinjury.