学科分类
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219 个结果
  • 简介:关于在在中国的纵贯的地震的带和基于地理信息,系统(GIS)被做了的中央orogenic带的连接区域的差错和seismicity之间的关系的研究。为每在这个区域的16个差错,我们造一个25km缓冲区地区和使用覆盖分析在每个差错上调查seismicity和它的特征。结果作为follows:the揭开主要地震差错西方的片断西方Qinling差错,Lixian-Luojiabao差错的西南的片断,Lintan-Dangchang差错的东南的片断,Wenxian差错的西南的片断,Huya差错,和Xueshan差错北边。最活跃的差错是Huya和Xueshan差错,然后,Tazang差错,Lixian-Luojiabao差错和Guanggaishan-Dieshan的北山麓指责。研究地区能根据焦点的深度被划分成四个区域,它向南向北变得更深从到。焦点的深度的侧面显示几何学和差错的机械性质,并且进一步揭示西藏的高原的东方挤出和群众的向东南的逃跑的运动模型,因此在这个区域对地震和危险缓解为保护提供基础。

  • 标签: 南北地震带 中央造山带 活断层 GIS 交界地区 中国
  • 简介:通过从CMIP3和CMIP5收集的联合模型模拟和设计的整体的分析,我们证明基本空间规模限制可能在气候模型预言和设计的有用另外的精炼不能在哪个下面是可能的下面存在。那限制在气候变量之中并且从区域变化到区域。我们证明在表面温度预言的无常(噪音)(在全球气候模型模拟的一个整体之中由传播代表了)通常在整个北美洲在1000km下面在水平规模超过整体平均数(信号),在那些规模暗示差的可预测性。更多的有限技巧为地区性的降水的可预测性被显示出。在这种情况中的整体传播趋于在2000km下面为规模超过或等于整体平均数。这些调查结果热点在预言地区性特定的未来气候异例的挑战,为特别,hydroclimatic影响例如干旱和湿。

  • 标签: 可预测性 模型模拟 区域气候 美国 集合 耦合模型
  • 简介:Background:Themainobjectiveofthisstudywastoexaminetheclimaticsensitivityoftheradialgrowthresponseof13easternwhitepine(PinusstrobusL.)provenancesplantedatseventestsitesthroughoutthenorthernpartofthespecies’nativedistributionineasternNorthAmerica.Methods:Thetestsites(i.e.,Wabeno,Wisconsin,USA;Manistique,Michigan,USA;PineRiver,Michigan,USA;Newaygo,Michigan,USA;TurkeyPoint,Ontario,Canada;Ganaraska,Ontario,Canada;andOrono,Maine,USA)examinedinthisstudywerepartofarange-widewhitepineprovenancetrialestablishedintheearly1960sintheeasternUnitedStatesandCanada.Principalcomponentsanalysis(PCA)wasusedtoexaminethemainmodesofvariation[first(PC1)andsecond(PC2)principalcomponentaxes]inthestandardizedradialgrowthindicesoftheprovenancesateachtestsite.TheyearscoresforPC1andPC2wereexaminedinrelationtoanarrayoftestsiteclimatevariablesusingmultipleregressionanalysistoexaminethecommonalityofgrowthresponseacrossallprovenancestotheclimateofeachtestsite.ProvenanceloadingsonPC1andPC2werecorrelatedwithgeographicparameters(i.e.,latitude,longitude,elevation)andasuiteofbiophysicalparametersassociatedwithprovenanceoriginlocation.Results:TheamountofvariationinradialgrowthexplainedbyPC1andPC2rangedfrom43.4%to89.6%.Dendroclimaticmodelsrevealedthatwhitepineradialgrowthresponsestoclimatewerecomplexanddifferedamongsites.Thekeydendroclimaticrelationshipsobservedincludedsensitivitytohightemperatureinwinterandsummer,coldtemperatureinthespringandfal(i.e.,beginningandendofthegrowingseason),summermoisturestress,potentialsensitivitytostorminduceddamageinspringandfal,andbothpositiveandnegativeeffectsofhigherwintersnowfal.Separationoftheloadingsofprovenancesonprincipalcomponentaxeswasmainlyassociatedwithtemperature-relatedbioclimaticparametersofprovenanceoriginat5ofth

  • 标签: ADAPTATION CLIMATE change Dendrochronology SEED source
  • 简介:热带气旋(TC)的可能的变化未来上的轨道和他们的影响在西方的诺思太平洋(WNP)上的TC的盆宽的紧张基于从CMIP5(联合模型Intercomparison工程阶段5)的一种选择导出的投射大规模环境被检验模型。特定的注意对气候在在WNP上为TC开发模仿大规模环境建模的CMIP5的表演被给予。包括为模仿TC磁道和紧张的单个模型的一个downscaling系统被用来选择CMIP5模型并且以后模仿TC活动。

  • 标签: 热带气旋活动 西北太平洋 全流域 热带气旋路径 气候模型 模式模拟
  • 简介:Fivesetsofmodelsensitivityexperimentsareconductedtoinvestigatetheinfluenceoftropicalcyclone(TC)genesislocationandatmosphericcirculationoninterannualvariabilityofTCintensityinthewesternNorthPacific(WNP).Ineachexperiment,bogusTCsareplacedatdifferentinitiallocations,andsimulationsareconductedwithidenticalinitialandboundaryconditions.Inthefirstthreeexperiments,thespecifiedatmosphericandSSTconditionsrepresentthemeanconditionsofElNio,LaNia,andneutralyears.TheothertwoexperimentsareconductedwiththespecifiedatmosphericconditionsofElNioandLaNiayearsbutwithSSTsexchanged.ThemodelresultssuggestthatTCsgeneratedinthesoutheasternWNPincurredmorefavorableenvironmentalconditionsfordevelopmentthanTCsgeneratedelsewhere.ThedifferentTCintensitiesbetweenElNioandLaNiayearsarecausedbydifferenceinTCgenesislocationandlow-levelvorticity(VOR).VORplaysasignificantroleintheintensitiesofTCswiththesamegenesislocationsbetweenElNioandLaNiayears.

  • 标签: 热带气旋强度 西北太平洋 敏感性试验 厄尔尼诺 模型 南方涛动
  • 简介:有CO2的高内容的天然气水池在探索Hailar-Tamtsag盆的中间的差错地区期间被发现。到目前为止有有碳同位素的特征的CO2的这种煤气的水库是特殊的。在学习区域的CO2的稳定的碳同位素与13$C_是相对轻的{CO_2}$C_{CO_2}价值从13.1~8.2。联系的氩气体的40Ar/36Ar价值从916~996,与1.201.26的R/Ra。基于全面分析,在这个学习区域的CO2气体具有外壳披风来源,这被相信。

  • 标签: 二氧化碳气体 断裂带 海拉尔 天然气 盆地 起源
  • 简介:AbstractBackground:Blood glucose control is closely related to type 2 diabetes mellitus (T2DM) prognosis. This multicenter study aimed to investigate blood glucose control among patients with insulin-treated T2DM in North China and explore the application value of combining an elastic network (EN) with a machine-learning algorithm to predict glycemic control.Methods:Basic information, biochemical indices, and diabetes-related data were collected via questionnaire from 2787 consecutive participants recruited from 27 centers in six cities between January 2016 and December 2017. An EN regression was used to address variable collinearity. Then, three common machine learning algorithms (random forest [RF], support vector machine [SVM], and back propagation artificial neural network [BP-ANN]) were used to simulate and predict blood glucose status. Additionally, a stepwise logistic regression was performed to compare the machine learning models.Results:The well-controlled blood glucose rate was 45.82% in North China. The multivariable analysis found that hypertension history, atherosclerotic cardiovascular disease history, exercise, and total cholesterol were protective factors in glycosylated hemoglobin (HbA1c) control, while central adiposity, family history, T2DM duration, complications, insulin dose, blood pressure, and hypertension were risk factors for elevated HbA1c. Before the dimensional reduction in the EN, the areas under the curve of RF, SVM, and BP were 0.73, 0.61, and 0.70, respectively, while these figures increased to 0.75, 0.72, and 0.72, respectively, after dimensional reduction. Moreover, the EN and machine learning models had higher sensitivity and accuracy than the logistic regression models (the sensitivity and accuracy of logistic were 0.52 and 0.56; RF: 0.79, 0.70; SVM: 0.84, 0.73; BP-ANN: 0.78, 0.73, respectively).Conclusions:More than half of T2DM patients in North China had poor glycemic control and were at a higher risk of developing diabetic complications. The EN and machine learning algorithms are alternative choices, in addition to the traditional logistic model, for building predictive models of blood glucose control in patients with T2DM.

  • 标签: Type 2 diabetes Blood glucose HbA1c Elastic network Machine learning
  • 简介:OnOctober18,2018,theChinaGeologicalSurveylaunchedaprojectoftheNationalKeyResearchandDevelopmentProgramofChina,entitled"PredictionandDeepExplorationDemonstrationofGoldPolymetallicDepositsintheJiaodongandLiaodongAreaswithintheNorthChinaCraton".Forthisproject,WulongandBaiyun-XiaotongjiapuyiinJiaodong,aswellasthenorthernZhaopingbeltsofLiaodong,werechosenasoreprospectingdemonstrationareas(Fig.1).

  • 标签: China HAS launched PROSPECTING DEMONSTRATION evaluate
  • 简介:与在中间的最好、古典的剖面图Trans北方ChinaOrogen分割的邻近的Fuping和HengshanComplexesrepresents联系的Wutai建筑群,通常划分了成东方、西方的块。UnconformablyoverlyingWutaiandFuping建筑群Hutuo组在这个区域被看作最年轻的岩石地层单位并且为解释前寒武纪的历史以及theTrans北方中国造山带的全面进化重要。在这个组的沉积岩的起源的知识的缺乏妨碍了depositional和构造意义的理解。LA-ICP-MS被使用为花岗石的卵石获得U-Pb锆石年龄,Hutuo组的最低岩石层位学的岩石,它,与结合了以前的岩石层位学,geochronological,结构、变形的数据,在沉积起源和这个区域的构造进化上提供新限制。Hutuo的顺序从更低的底砾岩andvolcaniclastic岩石(Doucun亚群)向上组织范围,通过碎屑沉积物,板岩,白云石和云石(Dongye亚群),到在顶(Guojiazhai亚群)的沙岩和集团企业。从在Doucun亚群底砾岩保存的花岗石的卵石的锆石给加权的mean~(207)在2517妈和2566妈之间的Pb/~(206)Pb年龄,它与为迟了的ArcheanWutaiGranitoids的那些一样,显示卵石从Wutai花岗石的侵入(2566-2515妈)被导出。基于新数据和以前的研究,与在Hutuo组为volcanics获得的2087±9妈的火的锆石结晶化年龄结合了,Hutuo组在在东方块的西方的边缘下面在西方的块的东方指导俯冲期间在theWutai弧后面发展了的subduction相关的制动火箭弧低岬盆环境被扔。这盆经历了长寿沉积并且最后在~1期间关上了导致了北方中国古地台的最后的合并的850妈collisional事件。

  • 标签: 地质年代学 锆石 花岗岩 聚结 岩石层位学 前寒武纪
  • 简介:AbstractBackground:Real-time polymerase chain reaction (PCR) is a sensitive and specific method for diagnosing schistosomiasis. However, this method should be performed in a laboratory, usually located distant from the sample collection site. Therefore, it is important to have fast sampling preservation methods, which allow simple transport prior to DNA extraction and amplification. The aim of this study was to verify if blood samples applied to filter paper are suitable for analysis of Schistosoma mansoni DNA by real-time PCR.Methods:A cross-sectional study was conducted among 100 study participants aged 17 to 70 years in a fishing village on the southern shore of Lake Victoria, Tanzania. Serum samples and ethylenediaminetetraacetic acid (EDTA)-anticoagulated whole blood for preparation of dried blood spots (DBS) were collected to test for Schistosoma mansoni infection by real-time PCR. A combined diagnostic reference of positive results of serum-based real-time PCR and the Kato-Katz (KK) method was used for analysis. Sensitivity and negative predictive value (NPV) were calculated. The Wilcoxon signed-rank test was chosen to compare the mean cycle threshold (Ct) values from serum and DBS.Results:According to the reference, 92.5% S. mansoni positive samples were determined. The serum-based real-time PCR performed excellently with 95.4% sensitivity, whereas the DBS-based real-time PCR showed a low sensitivity (45.4%). The Ct-values were significantly higher in DBS (median: 37.3) than in serum samples (median: 27.5, P < 0.001), reflecting a lower parasite-specific DNA load on the filter cards. With increasing egg counts, an increase in sensitivity was observed for all methods. The POC-CCA test and the serum-based real-time PCR showed a sensitivity of 100% for medium and severe infections. The DBS real-time PCR showed a sensitivity of only 85.7% even for severe infections.Conclusions:DBS-based real-time PCR did not provide good results in our study and therefore should not be recommended or must be tested concerning temperature of storage, storage duration, use of different filter papers and extraction methods before it is used in future studies. In contrast, our results showed that the POC-CCA test is a sensitive and precise test for detecting S. mansoni infections.

  • 标签: Schistosoma mansoni Real-time PCR Circulating DNA Dried blood spots Tanzania
  • 简介:Previousstudiesemphasizetheimportantroleofa'north-ridgeversussouth-trough'dipole(affectingthelatitudesfrom20°to75°NaroundtheTibetanPlateau)ofanomalousgeopotentialheight(Z)intheearly-2008abnormalcryogenicfreezing-rain-and-snoweventsinthesouthernpartofChina.ThepresentstudyintendstoextracttheleadingsignalfacilitatingthedipolebasedonthenumericaloutputsofafullZ-linearmodelfordiagnosingtheglobalZ.Usingthismodelbuiltonfullprimitiveequationsinspherical-isobariccoordinates,wecanfurthersplittheanomalyofZ-Zfζ-uβ(representingtheZcomponentnotexplicitlyassociatedwiththeCoriolisparameterfanditsmeridionalderivativeβ)into15components.Withthemodel-outputZfζ-uβ(mainlyaccountingforthedipoleunderthegeostrophicbalance)andZ-Zfζ-uβmatricesastheleftandrightsingularvectorsrespectively,amaximumcovarianceanalysis(MCA)isperformedtoextractthesignificant2-4-dayleadingsignalcarriedbytheMCAZ-Zfζ-uβmodeintheupstreamareaofthedipole.Thisleadingsignalismainlyattributedto1)theabnormallystrongwesterliescenteredaroundtheexitregionoftheAtlanticjet-streamand2)thecorrespondinganomalous950-300hPaanticyclonetothesouthoftheabnormallystrongcenterofwesterlies.Theenergyofthepositivewavecenteraroundthisjetexitregionfavorsthedownstreamnorth-ridgewhiletheenergyofthenegativewavecenterassociatedwiththeanomalousanticyclonefavorsthedownstreamsouth-trough.

  • 标签: 堵住系统 结冰的雨 数字诊断 领先的信号
  • 简介:在Trans北方中国造山带的中间的片断定位了,FupingComplex在理解北方ChinaCraton(NCC)的进化历史被看作一个批评区域。建筑群由各种各样的高级、多样地使变形的岩石组成,包括灰色的片麻岩,基本granulite,角闪岩,有细密纹理的片麻岩和大理石,变形了到上面的角闪岩或granulite外形。它能被划分成四个岩石单位:FupingTTG片麻岩,Longquanguanaugen,Wanzi在上crustals,和Nanying花岗石的片麻岩。从FupingComplex的Wanzi在上crustals的大约200由岩屑形成的锆石的U-Pb年龄和Hfisotope作文被分析了。边界给的变形锆石上的数据1.82-1.84Ga变老,相应于NCC的最后的合并事件为在~2.10和~2.51Ga的火的锆石核心产量二年龄人口的数据,与在第2.5a2.9Ga之间散布的一些继承年龄。这些结果建议Wanzi在上crustals从FupingTTGgneisses(~2.5Ga)和Nanying花岗石的片麻岩(2.0-2.1Ga)被导出并且在2.10and1.84Ga之间扔了。有~2.51Ga年龄的所有锆石有起始的ε_(Hf)从+1.4珍视到+10.9的positive,建议在通过从披风的少年材料的增加的~2.5Ga的一个重要外壳的生长事件。为由岩屑形成的锆石的Hf同位素数据进一步暗示2.8Ga岩石是在下地壳的重要部件,它与从为东方块的Nd同位素数据的一个建议一致。2.10Ga人口的锆石有起始的ε_(Hf)-4.9to+6.1的价值,作为在2.1Ga.These结果与次要的少年材料贡献外壳的再融化混合解释了为西方的块从那是不同的,支持Fuping建筑群是在在东方块的西方的边缘的构造活跃环境的emplaced。

  • 标签: 地球化学 同位素 岩屑 岩石
  • 简介:【摘 要】教学反思是教师对所授课堂中教学活动过程和课堂教学设计进行全面、深入思考和总结,教师可以通过复盘课堂、切片式观察教学过程,从细微处认识到自己教学中存在的问题,有助于在接下来的教学中不断改进,提高自己的教学技能。

  • 标签: 复盘式 切片式 教学反思
  • 简介:TheShihugolddeposit,situatedintheTaihangMesozoicorogenoftheNorthChinaCraton(NCC),ishostedbyductile-brittlefaultswithinArcheanmetamorphiccorecomplex.Thedepositischaracterizedbygold-bearingquartz-polymetallicsulfidesveins.TheMapenggranitoidsstockandintermediate-basicdikesintrudedthemetamorphicbasementrocks,andarespatiallyrelatedtogoldmineralization.Detailedlaserablationinductivelycoupledplasmamassspectrometry(LAICP-MS)U-Pbzirconagesofthegraniticrocks,dykesandmineralizedquartzveinsinthestudiedarearevealitsmagmaticandmineralizedhistory.Themineralizedquartzveinscontaininheritedzirconswithagesofabout2.55Gaand1.84Ga,probablycomingfromthebasement.ThesetwoPrecambrianeventsarecoevalwiththoseinotherpartsoftheNCC.TheMapenggranitoidstock,thelargestintrusioninthearea,wasemplacedatca.130Ma,andiscoevalwithmagmaticzirconpopulationsfromdioritesandquartzdioritepophyritesinthesameregion.Theca.130MamagmatismandgoldmineralizationweremostlikelyrelatedtoanunderplatingeventthattookplaceintheTaihangorogenatLateMesozoic.Thetimingofgoldmineralizationwithrespecttofelsicmagmatismintheareaissimilartothoseobservedinothermajorgold-producingprovincesintheNCC.ThisepisodeissimultaneouswiththoseintheeasternmarginofNCC,indicativeofawidespreadlateYanshanianmetallogeniceventthatwasaresponsetotheEarlyCretaceouslithosphereintheeasternNCC,inwhichthemesothermalgolddepositswereformedfromsimilartectono-magmaticenvironments.

  • 标签: 锆石U-PB同位素年龄 ICP-MS 金成矿作用 花岗岩类 激光烧蚀 构造意义
  • 简介:In1997,IGCPProjectNo.410wasestablishedtoappraiseknownrecordsofOrdovicianbiotas,inordertoevaluateoneofthegreatest-everdiversificationsoflifeonEarth,between489and443millionyearsago.Datacollectionandanalysisofbiodiversitywerecoordinatedthroughsevenregionalteams,andaglobal“clade”team.

  • 标签: 奥陶纪 生物多样化 物种大爆发 古生物化石