简介：日常生活中，人们进行交流时，免不了要谈论眼前或者未来将要发生的事情，表示“预测”的表达便自然地有了用武之地。

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简介：Weintroducethepolarizedvalondistributionstodescribethespindependenceofpartondistributions.Thepolarizedvalondistributionsintheprotonandpolarizedpartondistributionsinsidethevaloncanhelptoobtainpolarizedpartondistributioninaproton.Inordertobeabletoobtainthespincontributionofseaquarks,weneedtoimprovethevalonmodelWeemploytheBernsteinpolynomialaveragestoobtaintheunknownparameterswhichexistinourcalculations.Ourresultsforthepolarizedprotonstructurefunction,xg1p,areingoodagreementwiththeexperimentaldataforsomevaluesofQ2.

简介：ThetropicalPacifichasbeguntoexperienceanewtypeofElNio,whichhasoccurredparticularlyfrequentlyduringthelastdecade,referredtoasthecentralPacific(CP)ElNio.Variouscoupledmodelswithdifferentdegreesofcomplexityhavebeenusedtomakereal-timeElNiopredictions,buthighuncertaintystillexistsintheirforecasts.ItremainsunknownastohowmuchofthisuncertaintyisspecificallyrelatedtothenewCP-typeElNioandhowmuchiscommontoboththistypeandtheconventionalEasternPacific(EP)-typeElNio.Inthisstudy,thedeterministicperformanceofanElNio–SouthernOscillation(ENSO)ensemblepredictionsystemisexaminedforthetwotypesofElNio.EnsemblehindcastsarerunforthenineEPElNioeventsandtwelveCPElNioeventsthathaveoccurredsince1950.Theresultsshowthat(1)theskillscoresfortheEPeventsaresignificantlybetterthanthosefortheCPevents,atallleadtimes;(2)thesystematicforecastbiasescomemostlyfromthepredictionoftheCPevents;and(3)thesystematicerrorischaracterizedbyanoverlywarmeasternPacificduringthespringseason,indicatingastrongerspringpredictionbarrierfortheCPElNio.Furtherimprovementstocoupledatmosphere–oceanmodelsintermsofCPElNiopredictionshouldberecognizedasakeyandhigh-prioritytaskfortheclimatepredictioncommunity.

简介：Thestabilityofasubmarinepipelineontheseabedconcernstheflow-pipe-soilcoupling,withinfluentialfactorsrelatedtotheoceanwavesand/orcurrents,thepipelineandthesurroundingsoils.Aflow-pipe-soilcouplingsystemgenerallyhasvariousinstabilitymodes,includingtheverticalandlateralon-bottominstabilities,thetunnel-erosionoftheunderlyingsoilandthesubsequentvortex-inducedvibrations(VIVs)offree-spanningpipelines.Thispaperreviewstherecentadvancesoftheslip-linefieldsolutionstothebearingcapacity,theflow-pipe-soilcouplingmechanismandthepredictionforthelateralinstability,themulti-physicalcouplinganalysisofthetunnel-erosion,andthecouplingmechanicsbetweentheVIVsandthelocalscour.Itisrevealedthatthemechanismcompetitionalwaysexistsamongvariousinstabilitymodes,e.g.,thecompetitionbetweenthelateral-instabilityandthetunnel-erosion.Finally,theprospectsandscientificchallengesforpredictingtheinstabilityofalong-distancesubmarinepipelinearediscussedinthecontextofthedeep-wateroilandgasexploitations.

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简介：Thenumberoftropicalcyclone(TC)genesisovertheSouthChinaSeaandtheNorthwestPacificOceanin2009issignificantlylessthantheaverage(27.4).However,thenumberoflandfallTCovermainlandChinaanditsassociatedrainfallismorethantheaverage.Thispaperfocusesontheperformanceofnumericalweatherprediction(NWP)oflandfallTCprecipitationoverChinain2009.TheChinaMeteorologicalAdministration(CMA)andJapanMeteorologicalAgency(JMA)modelsarecompared.Althoughtheschemesofphysicalprocesses,thedataassimilationsystemandthedynamicframeareentirelydifferentforthetwomodels,theresultsofforecastverificationaresimilartoeachotherforTCrainfallandtrackexceptforTCGoni.Inthispaper,adaywithdailyrainfallamountgreaterthan50mmwasselectedasastormraindaywhentherewasaTCaffectingthemainland.Thereare32stormraindaysrelatedtothelandingoftyphoonsandtropicaldepressions.TherainfallforecastverificationmethodsofNationalMeteorologicalCentre(NMC)ofCMAareselectedtoverifythemodels’rainfallforecast.ObservationalprecipitationanalysesrelatedtoTCsin2009indicateaU-shapespatialdistributioninChina.Itisfoundthattherainbeltforecastedbythetwomodelswithin60hoursshowsgoodagreementwithobservations,bothinthelocationandthemaximumrainfallcenter.Beyond3days,theforecastedrainfallbeltshiftsnorthwardonaverage,andtherainfallamountofthemodelforecastsbecomesunder-predicted.TherainfallintensityofCMAmodelforecastismorereasonablethanthatofJMAmodel.Forheavyrain,theJMAmodelmademoremissingforecasts.TheTCrainfallisverifiedinGuangdong,Guangxi,FujianandHainanwhererainfallamountrelatedtoTCsisrelativelylargerthaninotherregions.TheresultsindicatethatthemodelforecastforGuangdongandGuangxiismoreskillfulthanthatforHainan.TherainfallforecastforHainanremainsdifficultforthemodelsbecauseofinsufficientobse

简介：在表金属形成形成限制的预言在面对研究人员的最重要的挑战之中。在这份报纸，一个充分联合的elastic-plastic-damage模型被开发了并且实现进明确的代码。由于飞机压力和有限紧张理论的采纳，模型能快速并且精确地预言部分的变丑和损坏。另外，在一些操作的损坏开始，繁殖，和骨折与实验被预言并且验证。与连续统损坏力学相结合的有限紧张能被用作一个快工具在形成过程的表金属预言可锻的损坏，骨折，和形成的限制，这被结束。

简介：Thevariationinload/unloadresponseratiobeforesomemoderateearthquakesisanalyzedbasedonthetheoryoftheload/unloadresponseratio.Theresultsshowthattheload-unloadresponseratioincreasesnoticeablybeforemoderateearthquakes,andtherearethreekindsofpatternsinwhichtheload/unloadresponseratiovariesandthedurationofnoticeableincreaseinload/unloadresponseratiorangesfromhalfayeartotwoyears.

简介：AbstractBackground:Gallbladder and biliary tract cancer (GBTC) has greatly damaged the health of patients and is accompanied by a dismal prognosis. The worldwide distribution of GBTC shows extensive variance and the updated data in China is lacking. This study was to determine the current status, trends, and predictions in the burden of GBTC over the past 30 years in China.Methods:This was a descriptive, epidemiological, secondary analysis of the Global Burden of Disease, Injuries, and Risk Factor Study 2019 data. Data including incidence, prevalence, mortality, and disability-adjusted life years (DALYs) of GBTC in China by year, age, and sex were assessed. Joinpoint regression analysis was conducted to evaluate trends of disease burden due to GBTC from 1990 to 2019. Nordpred age-period-cohort analysis was applied for the projection of mortality and incidence due to GBTC from 2019 to 2044.Results:Nationally, there were 38,634 (95% uncertainty interval [UI]: 27,350–46,512) new cases and 47,278 (95% UI: 32,889–57,229) patients due to GBTC, causing 34,462 (95% UI: 25,220–41,231) deaths, and 763,584 (95% UI: 566,755–920,493) DALYs in 2019. Both cases and rates of burden owing to GBTC were heavier among males and at old age. From 1990 to 2019, the age-standardized rates of incidence, prevalence, mortality, and DALYs of GBTC generally increased from 1990 to 2019, with average annual percentage change at 0.8% (95% confidential interval [CI]: 0.6–1.0%), 1.3% (95% CI: 1.1–1.5%), 0.4% (95% CI: 0.2–0.6%), and 0.2% (95% CI: 0.1–0.4%), respectively. Even though the age-standardized incidence rate and age-standardized mortality rate in both sexes were predicted to decline gradually from 2019 to 2044, the number of new cases and deaths were expected to grow steadily.Conclusions:GBTC is becoming a major health burden in China, particularly among males and older individuals. Given the aging population and increasing burden, effective strategies and measurements are urged to prevent or reduce the number of new cases and deaths of GBTC.

简介：把方法基于回响，粘滞0.2-2.0kg/m3的吸收沉积和玻璃祷告混浊的海水被测量。测量结果与用粒子尺寸分布技术的预言结果更一致而不是使用平均粒子半径技术，这被显示出。由预言的比较，用粒子的结果用平均粒子半径技术与那缩放分布技术，差异是2.3-2.6dB，这被观察为沉积的1.0kg/m3的每100米在试验性的频率的范围以内的混浊的海水。粒子尺寸分布应该在预言被考虑，这被建议粘滞沿海的混浊的水里的吸收。

简介：这份报纸为在全球规模从计量器观察，卫星估计(SE)，和数字预言合并每日的降水信息描述策略。策略被设计把全身的偏爱和随机的错误从每单个每日的降水来源移开生产通过三的全球每日的降水产品走的更好的gridded。首先，匹配过程的累积分发功能被执行在定位计量器的陆地区域上移开全身的偏爱。然后，在在海洋区域上的SE和模型预言(MP)的全面偏爱基于每月的降水用重新可伸缩的策略被改正。第三，最佳的插值(OI)基于合并计划(作为HL-OI计划参考了)被用来联合从每来源减少随机的错误并且生产一个gaugesatellite模型的不偏的计量器观察，SE，和MP合并每日的降水分析，叫的BMEP-d(北京气候中心把降水的评价与每日的分辨率合并了)，与完全的全球范围。从一个四年的时期(2011-14)的BMEP-d数据表明合并策略的能力提供实质地改进的质量的全球每日的降水。为量的错误得益于HL-OI计划的优点估计，更好的来源数据能在合并进程期间获得更多的重量。BMEP-d数据展览有在中间、低的纬度的卫星和计量器来源数据，并且与在高纬度的模型来源数据的更高的一致性。总的来说，对GPCP-1DD(GPCP一个度日报)的独立确认证明在BMEP-d和GPCP-1DD之间的一致性以空间模式，时间的可变性，概率分发，和统计降水事件比每来源数据集的那些高。

简介：Duetotheintricatestructureofporousmedia,themacroscopicpetrophysicaltransportpropertiessuchasthepermeabilityandthesaturationusedforthereservoirpredictionalsoshowaverycomplexnatureandaredifficulttoobtain.Thus,abetterunderstandingoftheinfluenceoftherockstructureonthepetrophysicaltransportpropertiesisimportant.Inthispaper,wepresentauniversalfinitevolumeelementmodelingapproachtoreconstructthethreedimensionalporemodelsfromthemicro-CTimagesbasedonthecommercialsoftwareMimicsandICEM,priortotheporenetworkmodelbasedonsomebasicassumptions.Moreover,tetrafinitevolumeelementsarepileduptorealizethegeometryreconstructionandthemeshingprocess.Comparedwiththeformermethods,thisprocessavoidsthetremendouslylargestoragerequirementforthereconstructedporousgeometryandthefailuresofmeshingthesecomplexpolygongeometries,andatthesametimeimprovesthepredictionsofpetrophysicaltransportbehaviors.ThemodelistestedontwoBereasandstones,foursandstonesamples,twocarbonatesamples,andoneSyntheticSilica.Single-andtwophaseflowsimulationsareconductedbasedontheNavier-StokesequationsintheFluentsoftware.Goodagreementsareobtainedonboththenetworkstructuresandpredictedsingle-andtwo-phasetransportpropertiesagainstbenchmarkexperimentaldata.

简介：Background:Treespeciesrecognitionisthemainbottleneckinremotesensingbasedinventoriesaimingtoproduceaninputforspecies-specificgrowthandyieldmodels.Wehypothesizedthatastratificationofthetargetdataaccordingtothedominantspeciescouldimprovethesubsequentpredictionsofspecies-specificattributesinparticularinstudyareasstronglydominatedbycertainspecies.Methods:Wetestedthishypothesisandanoperationalpotentialtoimprovethepredictionsoftimbervolumes,stratifiedtoScotspine,Norwayspruceanddeciduoustrees,inaconiferforestdominatedbythepinespecies.Wederivedpredictorfeaturesfromairbornelaserscanning(ALS)dataandusedMostSimilarNeighbor(MSN)andSeeminglyUnrelatedRegression(SUR)asexamplesofnon-parametricandparametricpredictionmethods,respectively.Results:TherelationshipsbetweentheALSfeaturesandthevolumesoftheaforementionedspecieswereconsiderablydifferentdependingonthedominantspecies.Incorporatingtheobserveddominantspeciesinthepredictionsimprovedtherootmeansquarederrorsby13.3-16.4%and12.6-28.9%basedonMSNandSUR,respectively,dependingonthespecies.Predictingthedominantspeciesbasedonalineardiscriminantanalysishadanoverallaccuracyofonly76%atbest,whichdegradedtheaccuraciesofthepredictedvolumes.Consequently,thepredictionsthatdidnotconsiderthedominantspeciesweremoreaccuratethanthoserefinedwiththepredictedspecies.TheMSNmethodgaveslightlybetterresultsthanmodelsfittedwithSUR.Conclusions:Accordingtoourresults,incorporatinginformationonthedominantspecieshasaclearpotentialtoimprovethesubsequentpredictionsofspecies-specificforestattributes.DeterminingthedominantspeciesbasedsolelyonALSdataisdeemedchallenging,butimportantinparticularinareaswherethespeciescompositionisotherwiseseeminglyhomogeneousexceptbeingdominatedbycertainspecies.