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10 个结果
  • 简介:TomoreindepthunderstandthedopingeffectsofoxygenonSiGealloys,boththemicro-structureandpropertiesofO-dopedSiGe(including:bulk,(001)surface,and(110)surface)arecalculatedbyDFT+Umethodinthepresentwork.Thecalculatedresultsareasfollows.(i)The(110)surfaceisthemainexposingsurfaceofSiGe,inwhichOimpuritypreferstooccupythesurfacevacancysites.(ii)ForOinterstitialdopingonSiGe(110)surface,theexistencesofenergystatescausedbyOdopinginthebandgapnotonlyenhancetheinfraredlightabsorption,butalsoimprovethebehaviorsofphoto-generatedcarriers.(iii)ThefindingaboutdecreasedsurfaceworkfunctionofO-dopedSiGe(110)surfacecanconfirmpreviousexperimentalobservations.(iv)Inallcases,Odoingmainlyinducestheelectronicstructuresnearthebandgaptovary,butisnotdirectlyinvolvedinthesevariations.Therefore,thesefindingsinthepresentworknotonlycanprovidefurtherexplanationandanalysisforthecorrespondingunderlyingmechanismforsomeoftheexperimentalfindingsreportedintheliterature,butalsoconducetothedevelopmentofμc-SiGe-basedsolarcellsinthefuture.

  • 标签: SIGE 计算结果 电子结构 掺杂 O型 锗硅合金
  • 简介:AfewCT-basedvoxelphantomswereproducedtoinvestigatethesensitivityofMonteCarlosimulationsofX-raybeamandelectronbeamtotheproportionsofelementsandthemassdensitiesofthematerialsusedtoexpressthepatient'sanatomicalstructure.Thehumanbodycanbewelloutlinedbyair,lung,adipose,muscle,softboneandhardbonetocalculatethedosedistributionwithMonteCarlomethod.TheeffectsofthecalibrationcurvesestablishedbyusingvariousCTscannersarenotclinicallysignificantbasedonourinvestigation.ThedeviationfromthevaluesofcumulativedosevolumehistogramderivedfromCT-basedvoxelphantomsislessthan1%forthegiventarget.

  • 标签: 蒙特卡洛法 核辐射 临界分布计算 标定曲线 计算机断层摄影
  • 简介:Theintermolecularinteractionpotentialformethane-argoncomplexiscalculatedbylocaldensityapproximation(LDA)approaches.Thecalculatedpotentialhasaminimumwhentheintermoleculardistanceofmethane-argoncomplexis6.75a.u.;thecorrespondingdepthofthepotentialis0.0163eVwhichhasgoodagreementwithexperimentaldata.WealsohavemadeanonlinearfittingofourresultsfortheLennard-Jones(12-6)potentialfunctionandobtainthatV(R)=143794365.332/R^12-3032.093/R^6(Rina.u.andV(R)ineV).

  • 标签: 局部密度近似 分子间相互势 分子力学 蒙特卡罗模拟 分子物理学 甲烷-氩复合
  • 简介:自从模仿波浪的风波浪模型,Nearshore(天鹅)不能有效地包括波浪高度在侧面的边界,变化特征和计算波浪因素的失真范围附近模仿波浪地,时期,方向,并且计算领域的侧面的边界附近的长度小心地分别地在不同的水深度和风速度的情况中被学习。水深度和风的变化的效果在侧面的边界附近在建模的不同波浪因素上加速的计算结果表演是不同的。在某个风速度的情况中,水深度越大,失真范围是越多greater。在某个水深度的情况中,波浪高度,时期,和长度的相对错误定义的失真范围与相应波浪因素的绝对错误定义的那些不同。而且,相对错误减少随风的增加定义的失真范围加速;而绝对错误定义的失真范围随着风速度的变化有点变化。有风速度的增加的波浪方向减少的失真范围。与SWAN一起的侧面的边界附近的计算波浪因素在实际物理区域当模特儿,例如在这研究考虑的泰胡湖和达恩尚湖,如果计算领域没根据实际物理区域被扩大,确实被弄歪。因此,当天鹅被采用计算风波浪时,地接近海或内陆湖的海岸线,适当途径必须被采用减少计算错误。

  • 标签: 模型模拟 计算域 侧边界 特征和 天鹅 风场
  • 简介:Langevinsimulationoftheparticlesmulti-passingoverthesaddlepointisproposedtocalculatethermalfissionrate.Duetofinitefrictionandthecorrespondingthermalflutuation,abackstreamingexistsintheprocessoftheparticledescentfromthesaddletothescissio.Thisleadstothatthediffusionbehindthesaddlepointhasinfluenceuponthestationaryflowacrossthesaddlepoint.Adynamicalcorrectionfactor,asaratiooftheflowsofmulti-andfirstoverpassingthesaddlepoint,isevaluatedanalytically.Theresultsshowthatthefissionratecalculatedbytheparticlesmulti-passingoverthesaddlepointislowerthantheonecalculatedbytheparticlefirstlypassingoverthesaddlepoint,andthefomerapproachestheresultsatthescissionpoint.

  • 标签: Langevin模拟 热裂变率 粒子多通道支座点 稳态流 动力学修正因素 粒子物理
  • 简介:Tungstenisregardedasanimportantcandidateofplasmafacingmaterialininternationalthermonuclearexperimentalreactor(ITER),sothedeterminationandmodelingofspectraoftungstenplasma,especiallythespectraathightemperaturewereintenselyfocusedonrecently.Inthiswork,usingtheatomicstructurecodeofCowan,acollisionalradiativemodel(CRM)basedonthespin-orbit-split-arraysisdeveloped.Basedonthismodel,thechargestatedistributionoftungstenionsisdeterminedandthesoftX-rayspectrafromhighchargedionsoftungstenatdifferenttemperaturesarecalculated.Theresultsshowthatboththeaverageionizationchargeandlinepositionsarewellagreedwithotherscalculationsandmeasurementswithdiscrepanciesoflessthan0.63%and1.26%,respectively.Thespectraathighertemperaturesarealsoreportedandtherelationshipbetweenionabundanceandtemperatureispredictedinthiswork.

  • 标签: 面向等离子体材料 碰撞辐射模型 X射线光谱 分布计算 钨离子 高温
  • 简介:AbstractBackground:Since the diagnostic value of aldosterone to renin ratio (ARR) calculated by plasma renin concentration (PRC) or plasma renin activity (PRA) is still inconclusive, we conducted a meta-analysis by systematically reviewing relevant literature to explore the difference in the diagnostic efficacy of ARR calculated by PRC or PRA, so as to provide guidance for clinical diagnosis.Methods:We searched PubMed, Embase, and Cochrane Library from the establishment of the database to March 2021. We included studies that report the true positive, false positive, true negative, and false negative values for the diagnosis of primary aldosteronism, and we excluded duplicate publications, research without full text, incomplete information, or inability to conduct data extraction, animal experiments, reviews, and systematic reviews. STATA 15.1 was used to analyze the data.Results:The pooled results showed that ARR (plasma aldosterone concentration [PAC]/PRC) had a sensitivity of 0.82 (95% confidence interval [CI]: 0.78-0.86), a specificity of 0.94 (95% CI: 0.92-0.95), a positive-likelihood ratio (LR) of 12.77 (95% CI: 7.04-23.73), a negative LR of 0.11 (95% CI: 0.07-0.17), and symmetric area under the curve (SAUC) of 0.982, respectively. Furthermore, the diagnostic odds ratio (DOR) of ARR (PAC/PRC) was 180.21. Additionally, the pooled results showed that ARR (PAC/PRA) had a sensitivity of 0.91 (95% CI: 0.86-0.95), a specificity of 0.91 (95% CI: 0.90-0.93), a positive LR of 7.30 (95% CI: 2.99-17.99), a negative LR of 0.10 (95% CI: 0.04-0.26), and SAUC of 0.976, respectively. The DOR of ARR (PAC/PRA) was 155.52. Additionally, we conducted a subgroup analysis for the different thresholds (<35 or ≥35) of PAC/PRC. The results showed that the DOR of the cut-off ≥35 groups was higher than the cut-off <35 groups (DOR = 340.15, 95% CI: 38.32-3019.66; DOR= 116.40, 95% CI = 23.28-581.92).Conclusions:The research results suggest that the determination of ARR (PAC/PRC) and ARR (PAC/PRA) was all effective screening tools for PA. The diagnostic accuracy and diagnostic value of ARR (PAC/PRC) are higher than ARR (PAC/PRA). In addition, within a certain range, the higher the threshold, the better the diagnostic value.

  • 标签: Primary aldosteronism Aldosterone to renin ratio Plasma renin activity Plasma renin concentration Diagnostic value Meta-analysis
  • 简介:Inthispaper,usingthe1999~2007GPSvelocityfielddata,andbychoosingtheoptimalblockmodel,weobtainedthedeformationmodelsapplicabletotheboundaryzonesofmajorblocksandtheslipratesofblockboundaryfaultsonthemid-southernsegmentoftheNorth-SouthSeismicBelt.Theresultsshowthat:ontheLongmenshanfaultzone,thetensionalandcompressivesliprateissmallontheBaoxing-Wenchuansegment,about0.5~1.8mm·a-1,andtherateisrelativelysignificantonthesegmentoftheWenchuan-Maoxian,as1.8~3.8mm·a-1;ontheXianshuihefaultbelt,thereisacertaindifferenceinspatialdistributionbetweenthetensionalsliprateandstrike-sliprate:thetensionalsliprate(8.1mm·a-1)isbiggerthanthesinistralstrike-sliprate(4.8mm·a-1)atthenorthoftheLuhuoregion;thetensionandcompressionsliprateisbasicallythesameasthestrike-sliprateatLuhuo-Dawu;theDawu-Kangdingsectionpresentsatrendofdecreasedstrike-sliprateandincreasedtensionalsliprate;theKangding-Shimiansegmentshowsastrike-slipnature;thestrike-sliprateissignificantlygreaterthanthetension/compressionrateontheXiaojiangfaultzone;thesliprateontheRedRiverfaultzoneshowsobviousspatialsegmentation,thesliprateissmallerinitsnorthwestpart,butwithacertainamountoftensional/compressioncomponent,4.7mm·a-1ontheJingdongsegment.ThesegmenteastofJingdong(westernGejiu)ismainlyofstrike-slip,withasliprateof4.5mm·a-1.

  • 标签: 断裂滑动速率 南北地震带 块体理论 左旋走滑速率 GPS速度场 计算