简介：ForarelativisticHamiltoniansystem,twonewtypesoftheLiesymmetriesandconservationlawsaregivenunderinfinitesimaltransformaitonsofgroups.OnthebasisofthetheoryofinvarianceoftherelativisticHamiltonianequationsunderinfinitesimaltransformationsandintroducinginfinitesimaltransformationsfortimet,generalizedcoordinatesqsandgeneralizedmonentaps,weobtainthedetermingingequations,thestructureequationsandtheconservedquantitiesoftheLiesymmetries.Introducinginfinitesimaltransformationforgeneralizedcoordinatesqsandgeneralizedmomentaps,weconstructtheLiesymmetricaltransformationsofthesystem,whichonlydependonthecanonicalvariables.AsetofconservedquantitiesaredirectlyobtainedfromtheLiesymmetriesofthesyste.Anexampleisgiventoillustrantetheapplicationoftheresults.

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.

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简介：TheprobabilityoffractaldeterminationofcoastaltypesbasedonGISispreliminarilydiscussedwithChinaasanexample.Finally,somesignificantconclusionsaredrawn:(1)Thefractaldimensionofcoastlineofthebedrockcoastislargerthanthatoftheplaincoastonthesamescalemap;(2)Asfarasthebedrockcoastisconcerned,thelargerfractaldimensionofcoastlineofthebedrockcoastonthesamescalemapindicatesthatthebedrockcoastisprobablynottypical;(3)Asfarastheplaincoastisconcerned,thesmallerfractaldimensionofcoastlineoftheplaincoastonthesamescalemapindicatesthatitisprobablythesiltplaincoast;(4)Thedifferentsubstantialcompositionsaffectthefractaldimensionsofcoastlinesofdifferentcoastaltypes.Ingeneral,thecoastwhichliesinthenorthoftheHangzhouBayconsistsofsandmainly,itssurfaceisflat,anditisconnectedwiththecoastalplain,itslandformisbroadshoal,itstotalchangeiscomparativelyhomogenousinthetidaldynamicprocess,andthus,therelativelysmallerfractaldimensionofcoastlineresultsfromthis.Forthebedrockcoast,thereismorebedrock,thecoastlineiscomparativelysmoothandstraight,beingaffectedbythefaultsandoceandynamicprocess,whichresultinthelargerfractaldimension.

简介：与51的数据在1954-2003期间在珍珠河盆在4月9月驻扎的降雨，我们使用了主要部件分析方法研究4月9月降雨的空间分发特征。结果揭示下列。在珍珠河盆，有不同降水，在4月9月从600公里变化到1900公里，降水从东南逐渐地减少到西北。标准差分发总体上从东方逐渐地减少到西方。珍珠河盆的降雨分发有五种主要类型：类型:在整个区域有洪水(干旱)，类型：在南方在北方和干旱(洪水)有洪水(干旱)，类型：在西方在东方和干旱(洪水)有洪水(干旱)，类型：在那里在在东方和西方的中央部分和干旱(洪水)的标志洪水(干旱)，和类型：在北方和南方在中心和干旱(洪水)有洪水(干旱)。在整个区域的洪水(干旱)和在在南方的北方和干旱(洪水)的洪水(干旱)的类型就多于其它出现，是64%总数。从10年的移动一般水准，在在珍珠河盆区域的4月和9月之间的降雨在1983-1992主要是干燥的，这被看见，并且主要在东方弄干并且在1967-1971在西方弄湿并且在东方弄湿并且在1979在西方弄干。

简介：Thisstudydevelopedasequentialcouplingfiniteelementproceduretopredictresidualstressesofsteelpipeswithlongitudinalwela\circumferentialweldandspiralweld.Theresultsshowthattheresidualstressinheataffectedzone(HAZ)ishigherthanthatinweldforspiralweldpipe.Forthecircumferentialweldpipeandspiralweldpipe,theresidualstressininnersurfaceishigherthanthatinoutersurface.However,forthespiralweldpipe,theresidualstressininnersurfaceissmallerthanthatinoutersurface.Thehoopresidualstressofcircumferentialweldpipeishigherthanthatoflongitudinalweldpipe,whiletheaxialresidualstressofcircumferentialweldpipeissmallerthanthatoflongitudinalweldpipe.Thehoopstressesforcircumferentialweldpipeandaxialstressforlongitudinalweldpipehaveexceededtheyieldstrengthofbasemetal.Withtheincreaseofhelixangle,thehoopstressdecreaseswhiletheaxialstressincreases.Forthespiralpipe(α=30°to50°),boththehoopstressandaxialstressarerelativelysmall.Thespiralpipe(helixanglerangingfrom30°to50°)ishelpfultoreducestresscorrosioncracking(SCC)anditisrecommendedtomanufacturethesteelpipe.

简介：Inthepaper,generalizedordersandgeneralizedtypesofDirichletseriesintherighthalf-planearegiven.Someinterestingrelationshipsonmaximummodulus,themaximumtermandthecoefficientsofentirefunctiondefinedbyDirichletseriesofintherighthalf-planeareobtained.

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简介：AbstractPurpose:The increasing number of deaths due to road traffic accidents (RTAs) has attracted global attention. However, the influence of road types is rarely considered in the study of RTAs. This study evaluates the influence of different road types in RTAs in northern Guizhou to provide a basis for the formulation of evidence-based policies and measures.Methods:We obtained the data from the Zunyi Traffic Management Data Platform for the years 2009-2018. The mortality rates of RTAs were calculated. Descriptive methods and Chi-square tests were used to analyze the characteristics of road traffic collisions on different road types. We also examined the associations between the mortality rate per 10,000 vehicles and the growth of per capital gross domestic product (GDP) with Spearman's rank correlation analysis. According to the passing volume and the infrastructure, we defined different types of roads, like administrative road, functional road, general urban road and urban expressway.Results:In 2012, the traffic mortality rate of administrative roads was 8.9 per 100,000 people, and the mortality rate of functional roads was 7.4 per 100,000 people, which decreased in 2018 to 6.1 deaths per 100,000 people and 5.2 deaths per 100,000 people, respectively. The mortality rate per 10,000 vehicles reached the highest level in 2011 (28.8 per 10,000 vehicles and 22.5 per 10,000 vehicles on administrative and functional roads, respectively). The death rate of county roads was the highest among administrative roads (χ2= 17.389, p < 0.05) and that of fourth-class roads was the highest among functional roads (χ2= 21.785, p < 0.05). The mortality rate per 10,000 vehicles was negatively correlated with per capital GDP.Conclusion:Although our research shows that RTAs in northern Guizhou have steadily declined in recent years, the range of decline is relatively small. Many measures and sustainable efforts are needed to control road traffic death and accelerate the progress in road traffic safety in northern Guizhou.

简介：Fishfindershavealreadybeenwidelyavailableinthefishingmarketforanumberofyears.However,thesizesofthesefishfindersaretoobigandtheirpricesareexpensivetosuitfortheresearchofroboticfishormini-submarine.Thegoalofthisresearchistoproposealow-costfishdetectorandclassifierwhichsuitsforunderwaterrobotorsubmarineasaproximitysensor.Withsomepre-conditioninhardwareandalgorithms,theexperimentalresultsshowthattheproposeddesignhasgoodper-formance,withadetectionrateof100%andaclassificationrateof94%.Boththeexistingtypeoffishandthegroupbehaviorcanberevealedbystatisticalinterpretationssuchashoveringpassionandsparseswimmingmode.

简介：Inthispaper,avariationalmethodispresentedforsolvingtheclassicalgravimetric,satellitegravimetricandsatellitealtimetricmixedtypeboudaryvalueproblemtoobtainthepotentialcoefficients.Accordingtothisprinciple,classicalgravimetricdata（heightmeasuredbygeometriclevellingorheighttriangulation）,satellitegravimetricdata（heightmeasuredbysatellitegeodesytechnique）andsatellitealtimetricdatacanbeusedjointlytocalculatethepotentialcoefficients.

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简介：Thispapertriestodeterminetheeconomicaltypeofreinforcedconcretechimneystructurebasedonthesameeffectiveheightofchimney.Thesimulatedexperimentsofwindtunnelareperformedforthestudy,whichcomparemulti-tubechimneywithsingletubechimneybasedonthesamebuoyancyfluxofplume.Accordingtothecomparisonamongtheexperimentresultsandthepreviousstudyofplumerise,thepaperdefinessomefinalplumerisemodels.Finally,thepapergivesthecost-benefitanalysisaftermakingcostestimationfordifferenttypesofchimneystructureandrecommendstheeconomicalandreasonabletypeofchimneystructureinlightofthesameenvironmentalbenefits.

简介：AbstractMilitary training is intense, difficult and often dangerous, so all kinds of injuries or diseases frequently occur during training. Most of the previous studies and reviews on military training-related injuries focused on musculoskeletal system, whereas there are no reviews of abdominal injuries and diseases. Although the incidence of military training-related abdominal injuries and diseases is relatively low, the patients’ condition is often critical especially in the presence of abdominal organ injury, leading to multi-organ dysfunction syndrome and even death. This paper elaborates on common types of military training-related abdominal injuries and diseases as well as the prevention and treatment measures, which provides some basis for scientific and reasonable training and improvement of medical security.

简介：Thisstudyprovidesbasisinformationforestimatingthefeasibilityoftheenvironmentalandecologicalforestryconstructionprojectinthearea.ThroughthesurveyinMiyunwatershed,theeconomicalbenefitsofcarbonsequestrationinfivetypicalforesttypeshavebeenstudiedbycalculatingthebiomassfromthetimberaccumulationdataandconvertingtothemoneyvalue.Theresultsshowthat:inthedurationof100years,atadiscountrateof5%,and197RMByuan/tasthepriceofthecarbonsequestration,thepresentvalue(PV)ofthecarbonsequestrationindifferentforestsare:6900-9300yuan/hainChinesepineforest,6100-8200yuan/hainoakforest,4500-6100yuan/hainotherbroadleafforests,2300-3200yuan/hainshrubsand1300-1800yuan/haincypressforest.Theannualmeaneconomicbenefitofcarbonsequestrationis770-1040yuan/ha.Thepineforesthasthehighestcarbonsequestrationbenefit,followedbyoakforest,otherbroadleafforest,shrubs,andcypressforest.Ifthelandissuitableforallforests,pineforestandoakforestshouldbeplantedinordertosequestratemorecarbon.

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简介：0vcrl00pyrophylliteoccurrcnccs(dcposits,orcsp0tsandmincralisedsp0ts)havebeenfuul1dinChina-Am0ngthemab0ut90%arerelatcdtotbeacti0nofv0lcanicgas-1iquidandaccountf0rabout87Koftbcprovcdrcserves.ManylargcandsuperlarScpyr0phy1litedcp0sitsbclongtothistype.Thercf0re,pyr0phyllitedep0sitsofv0lcanicgas-1iquida1

简介：Oneofmanyinterestingresearchactivitiesinbiofluidmechanicsisdedicatedtoinvestigationsoflocomotioninwater.Someofpropulsionmechanismsobservedintheunderwaterworldareusedinthedevelopmentprocessofunderwaterauto-nomicvehicles(AUV).Inordertocharacteriseseveralsolutionsaccordingtotheirmanoeuvrability,influenceonthesur-roundingfluidandenergeticefficiency,adetailedanalysisoffin-likemovementisindispensable.Inthecurrentpaperananalysisofundulatory,oscillatoryandcombinedfin-likemovementsbymeansofnumericalsimulationiscarriedout.TheconservationequationofmassandtheconservationequationofmomentumaresolvedwiththeFiniteVolumeMethod(FVM)byuseofthesoftwareCFX-10.0.Theundulatoryandoscillatoryfinmovementsaremodelledwithanequationthatisimplementedwithinanadditionalsubroutineandjoinedwiththemainsolver.Numericalsimulationsarecarriedoutinthecomputationaldomain,inwhichonefinisfixedinaflow-throughwaterduct.SimulationsarecarriedoutintherangeoftheRenumberupto105.Theresultsshowsignificantinfluenceofappliedfinmotiononthevelocitydistributioninthesurroundingfluid.