简介：Thepaperdealswiththebackgroundfeatures,formationanddistributionofthechemicalel-ementsK,Na,Ca,Mg,Si,Fe,Mn,Cr,Ni,V,Co,Ti,Mo,Cu,Pb,Zn,As,Hg,Cd,Be,Li,Sr,B,F,Cl,BrandIinthegroundwaterintheregionofthemiddleandlowerreachesoftheYangtzeRiverandtheirrelationstothecompositionofthewater-bearingmedia,propertiesoftheoverly-ingrocksandsoils,redoxenvironment,andgroundwaterflowcondition,mineralizationandpHofgroundwater.

简介：Stiffnessdegradationwilloccurduetothegenerationofaccumulatedporepressureinsaturatedsoftclaysundercyclicloading.Thesoilstatic-dynamicmulti-purposetriaxialandtorsionalshearapparatusinDalianUniversityofTechnologywasemployedtoperformdifferenttypesoftestonthesaturatedsoftmarineclayintheYangtzeEstuary.Undisturbedsamplesoftheclayweresubjectedtoundrainedcyclicverticalandtorsionalcouplingshearandcyclictorsionalshearafterthree-directionalanisotropicconsolidationwithdifferentinitialconsolidationparameters.Investigatedweretheeffectsoftheinitialorientationangleofthemajorprincipalstress,initialratioofdeviatoricstress,initialcoefficientofintermediateprincipalstressandcontinuousrotationofprincipalstressaxesonthestiffnessdegradation.Itisfoundthatthedegradationindexdecreases(ordegradationdegreeincreases)significantlywithincreasinginitialorientationangleofthemajorprincipalstressandinitialratioofdeviatoricstress.Comparedwiththeeffectsoftheinitialorientationangleofthemajorprincipalstressandinitialratioofdeviatoricstress,theeffectofinitialcoefficientofintermediateprincipalstressislessevidentandthistrendismoreclearlyreflectedbytheresultsofthecyclictorsionalshearteststhanthoseofthecycliccouplingsheartests.Atthesamecyclenumber,thedegradationindexobtainedfromthecyclictorsionalsheartestishigherthanthatfromthecycliccouplingsheartest.Themainreasonisthatthecontinuousrotationinprincipalstressdirectionsduringcycliccouplingsheardamagestheoriginalstructureofthesoilmorethanthecyclictorsionalsheardoes.Basedonaseriesofexperiments,amathematicalmodelforstiffnessdegradationisproposedandtherelevantparametersaredetermined.

简介：TobetterunderstandclimatevariationsofMeiyu,somenewindicatorsfortheonsetandretreatdates,duration,andMeiyuprecipitationintheYangtze-HuaiheRivervalleyareobjectivelydevelopedbyusingobserveddailyprecipitationdatafrom230stationsineasternChinaduring1954-2003.Therainyseasononsetandretreatdatesineachstationcanbedefinedintermsofthresholdsforrainfallintensityandpersistence.Then,theonsetandretreatdatesoftheMeiyufortheYangtze-HuaiheRiverbasinhavebeendeterminedwhenmorethan40%ofstationsreachthefirstrainyseasonthresholdsinthestudyregion.BasedontheindicatorsofMeiyuintheYangtze-HuaiheRiverbasin,variationsofMeiyurainfallduring1954-2003areanalyzed.TheresultssuggestthatMeiyurainfallintheYangtze-HuaiheRiverbasinhasincreasedinrecent50years.Inaddition,interannualandinterdecadalvariabilityofMeiyuisalsoobvious.Alltheindicatorsdisplayapredominantperiodofabout3years.

简介：TheUpperSinianbeddedchertsarewidelydistributedonthesoutheastcontinentalmarginoftheYangtzeplate,withatotalthicknessrangingfrom20to150m,Thechertsareverysimpleinchemicalcomposition,withthecontentsofsiliceousmineralsexceeding90%andthoseofothermineralspeciesbeingverylow.Thetotalcontentoftraceelementsisconsiderablyvarialbe,Thecontentsofmosttraceelementsarelowascomparedwiththeircrustclarkevalues.ButthesechertsareveryrichinthetraceelementsBa,As,Ab,AgandU,coupledwithrelativelyhighcontentsofFe,MnandlowcontentsofAl,Ti,andMg,ItcanbeidentifiedasthechertsofhydrothermaloriginintermsofthevaluesofFe/Ti,(Fe+Mn)/Ti,Al/(Al+Fe+Mn)andU/Th,IntheAl-Fe-Mn,andFe-Mn-(Cu+Ni+Co)×10diagramsandlg[U]-lg[Th],Cr-Zrdiagrams.allthesamplesfromtheareastudiedfallwithinthehydrothermalsedimentfield.Allthesecharacteristicsshowthatthechertsaremainlytheproductofhydrothermalprocesses.Thefactthattheδ30Sivaluesofthechertrangefrom0.0‰to0.7‰withδ18Ofrom20.1‰to23.6‰cleralymanifeststhatthesubmarinehydrothermalwateristhemainsourceofsilica.

简介：摘要：广泛有机物(OM)富有的外形(黑页岩)在Yangtze区域发生在Ordo志留纪边界继任，华南。为了在Ordo志留纪期间调查Yangtze海的氧化还原作用变化，转移，二OM节(在在Zhangjiajie的Yichang，湖北省，和Sanjiaguan的Wangjiawan，湖南省)跨骑Ordo志留纪边界被学习。在这研究完成的大小包括总数的内容Fe的器官的碳(TOC)，黄铁矿硫，和不同种类，包括dithionite可引出的Fe(喂)，黄铁矿Fe(FeP)，HCI可引出的Fe(FeH)，和全部的Fe(FeT)在黑页岩，象另外的氧化还原作用代理一样，例如S/C比率，在高度反应的Fe之间的比率(FeHR=喂了+FeP)并且FeT，和Fep/(FeP+FeH)比率，作为pyritization(DOP)的度知道。在Wangjiawan节，中间的Ashgill沉积有高FeHR/FeT比率(0.20-0.77；avg。0.45)，高DOP价值(0.21-0.72；avg。0.54)，并且器官的碳内容的一个相对经常的硫内容独立人士。由对比，中间早，Hirnantian存款通常有低FeHR/FeT比率(0.10-0.35；avg。0.21)，低DOP价值(0.11-0.40；avg。0.28)，并且S/C价值在正常海洋的价值上正在聚类(S/C=0.36)。迟了的Hirnantian和早Rhuddanian存款，类似于那些中间的Ashgill存款，被高FeHR/FeT比率描绘(0.32-0.49；avg。0.41)，高DOP价值(0.46-0.68；avg。0.53)并且相当经常的硫内容。这些数据在间隔期间在Yangtze海架上建议海洋的血缺氧的出现中间的Ashgill，迟了的Hirnantian和早Rhuddanian，和通气并且氧化的水兵调节在期间中间早Hirnantian时间。中间早，Hirnantian通气了事件是有全球冰川的经期的伴随物，多半在架海床之上源于glacio海面升降的海平面的秋天和冷、稠密的氧化的水的随后的循环。因此，突然的变化从从迟了的Hirnantian氧化了到缺氧的海洋的水，早Rhuddanian从海面升降的海水平的冰期后的上升被结果。在subemergent高地附

简介：ThisstudyexaminedtherainfallaroundthemiddleandlowerreachesoftheYangtzeRiverandrelatedatmosphericcirculationbyusingNCEPreanalysisdata.Thepurposeofthisstudyistoanalyzetheirdecadalvariationandtherelationshipamongrainfall,atmosphericcirculationaroundEastAsiaandtheENSOepisodes.Currentresultsarepresentedasfollows:(1)VeryclearincreasingtrendoftherainfallaroundthemiddleandlowreachesoftheYangtzeRiverduringtheMeiyuperiodandJunetoJulyisfoundintherecent15years.Meanwhile,thegeopotentialheightat500hPaaroundtheOkhotskSeaalsoholdssimilarincreasingtrend.ItisnoticeablethatENSOepisodestendtooccurmorefrequentlyintherecent15years.(2)AnindexdescribingEastAsiansummermonsooniswellcorrelatedwiththeSSTintheNino-3regioninprecedingautumnintherecent20yearsbutisnotpriortotheperiod.ThismeansthattheElNinophenomenonexertsmoreimpactsonEastAsiansummermonsoonrecently.(3)ThewarmphaseofPDOintherecent20yearsbasicallycoincideswiththeincreasingtrendoftheatmosphericcirculationinEastAsia.

简介：Publicwillingnesstopay(WTP)forurbanriversrestorationwasinvestigatedinShanghai,NanjingandHangzhouinChinawithasampleof1,285.ThefactorsinfluencingpositiveWTPagainstzeroWTPareanalyzedusingabinarylogitmodel.Theresultsindicatethatincome,Huji(residentialregistration)status,householdsize,homepropertyownership,riverfrontaccess,andattitudestowardcurrentwaterqualityarestatisticallysignificantinthelikelihoodofpositiveWTP.ItisalsofoundthatrespondentswithoutlocalHujiarelesswillingnesstopaypositivelyinpooledsampleandShanghaisample.InthegroupholdingpropertyrightofhousebutwithoutlocalHujiislesswillingnesstopaypositivelyinHangzhou.RespondentsinNanjingaremorewillingnesstopaypositivelythanthoseinHangzhou.Mostcommonargumentsagainsttopayfortherestorationare"government’sduty","lowincome","non-local-Huji"and"lackoftrustinthegovernmentinhowitspendsmoney".TheresultsaregenerallyconsistentwiththehypothesisandspecificsituationsinChina.Thefindingsmakesomecontributionstothenon-marketvaluationstudiesaswellasprovideusefulinformationforpublicpolicymakinginChina.

简介：Typhoon-generatedwavesaresimulatedwithtwonumericalwavemodels,theSWANmodelforthecoastalandYangtzeEstuarydomain,nestedwithintheWAVEWATCHIII(WW3)forthebasin-scaleEastChinaSeadomain.TyphoonNo.8114ischosenbecauseitwasverystrong,andgeneratedhighwavesintheEstuary.WW3wasimplementedfortheEastChinaSeacoarse-resolutioncomputationaldomain,tosimulatethewavesoveralargespatialscaleandprovideboundaryconditionsforSWANmodelsimulations,implementedonafine-resolutionnesteddomainfortheYangtzeEstuaryarea.TheTakahashiwindmodelisappliedtothesimulationoftheEastChinaSeascale(3-hourly)andYangtzeEstuaryscale(1-hourly)winds.SimulationsofsignificantwaveheightsintheEastChinaSeashowthatthehighestwavesareontherightsideofthestormtrack,andmaximatendtooccurattheeasterndeep-wateropenboundaryoftheYangtzeEstuary.IntheYangtzeEstuary,incomingswellisdominantoverlocallygeneratedwavesbeforethetyphoonapproachestheEstuary.AsthetyphoonapproachestheEstuary,windwavesandswellcoexist,andthewavedirectionismainlyinfluencedbytheswelldirectionandthecomplextopography.

简介：AbstractBackground:Due to sustained control activities, the prevalence of Schistosoma japonicum infection in humans, livestock and snails has decreased significantly in P. R. China, and the target has shifted from control to elimination according to the Outline of Healthy China 2030 Plan. Applying highly sensitive methods to explore the presence of S. japonicum infection in its intermediate host will benefit to assess the endemicity or verify the transmission interruption of schistosomiasis accurately. The aim of this study was to access the presence of S. japonicum infection by a loop-mediated isothermal amplification (LAMP) method through a 5-year longitudinal study in five lake provinces along the Yangtze River.Methods:Based on previous epidemiological data, about 260 villages with potential transmission risk of schistosomiasis were selected from endemic counties in five lake provinces along the Yangtze River annually from 2015 to 2019. Snail surveys were conducted in selected villages by systematic sampling method and/or environmental sampling method each year. All live snails collected from field were detected by microscopic dissection method, and then about one third of them were detected by LAMP method to assess the presence of S. japonicum infection with a single blind manner. The infection rate and nucleic acid positive rate of schistosomes in snails, as well as the indicators reflecting the snails’ distribution were calculated and analyzed. Fisher’s exact test was used to examine any change of positive rate of schistosomes in snails over time.Results:The 5-year survey covered 94,241 ha of environment with 33,897 ha of snail habitats detected accumulatively. Totally 145.3 ha new snail habitats and 524.4 ha re-emergent snail habitats were found during 2015-2019. The percentage of frames with snails decreased from 5.93% [45,152/761,492, 95% confidence intervals (CI): 5.88-5.98%] in 2015 to 5.25% (30,947/589,583, 95% CI: 5.19-5.31%) in 2019, while the mean density of living snails fluctuated but presented a downward trend generally from 0.20 snails/frame (155,622/761,492, 95% CI: 0.17-0.37) in 2015 to 0.13 snails/frame (76,144/589,583, 95% CI: 0.11-0.39) in 2019. A total of 555,393 live snails were collected, none of them was positive by dissection method. Totally 17 pooling snail samples were determined as positives by LAMP method among 8716 pooling samples with 174,822 of living snails, distributed in 12 villages of Hubei, Hunan, Jiangxi and Anhui provinces. The annual average positive rate was 0.41% (95% CI: 0.13-0.69%) in 2015, 0% in 2016, 0.36% (95% CI: 0.09-0.63%) in 2017, 0.05% (95% CI: 0-0.16%) in 2018, 0.05% (95% CI: 0-0.15%) in 2019, respectively, presenting a downward trend from 2015 to 2019 with statistical significance (χ2 = 11.64, P < 0.05).Conclusions:The results suggest that S. japonicum infection still persisted in nature along the Yangtze River and traditional techniques might underestimate the prevalence of schistosomiasis in its intermediate hosts. Exploring and integrating molecular techniques into national surveillance programme could improve the sensitivity of surveillance system and provide guidance on taking actions against schistosomiasis.

简介：InordertodiscussthecontentdistributionsandfluxesofheavymetalsinsuspendedmattersduringatidalcycleintheturbiditymaximumaroundtheChangjiang(Yangtze)Estuary,thecontentsofheavymetals(Zn,Pb,Cd,CoandNi)havebeenanalyzed.Duringatidalcycle,theaveragecontentsofheavymetalsareintheorderofZn>Ni>Pb>CoàCd.Theaveragecontentsinebbtidearegenerallyhigherthanthatinfloodtide.However,attheinshoreSta.11,influencedbythecontaminationfromthenearbywastetreatmentplant,theaveragecontentsofZnandNiinfloodtidearehigherthanthoseinebbtideandattheoffshoreSta.10,thecontentofCdinfloodtidehigherthanthatinebbtideduetomarine-derivedmaterials.Thefiveheavymetals,mainlyterrigenous,aretransportedtowardseast-northeast,andsettledownwithsuspendedmattersintheareabetweenSta.11andSta.10.Influencedbymarine-derivedmaterials,thefluxvalueofCddoesnotaltersignificantlywithobviouslychanginginfluxdirectiontowardsnorthwest.Thesourceofheavymetals,thesalinityofwaterandtheconcentrationofsuspendedmattersarethemainfactorscontrollingthecontentdistributionsofheavymetalsduringatidalcycle.Thereisapositivecorrelationbetweenthecontentsofheavymetals(Zn,Pb,CoandNi)andthesalinityofwater,whiletheoppositecorrelationbetweenthecontentsandtheconcentrationsofsuspendedmatters.Becauseofmarine-derivedmaterials,thecontentofCdisnotcorrelatedwiththeconcentrationofsuspendedmattersandthesalinityofwater.

简介：AbstractBackground:China has experienced rapid urbanization in the past 30 years. We aimed to report blood cadmium level (BCL) in the rapidly urbanized Yangtze Plain of China, and explore the association between BCL and 25-hydroxyvitamin D (25(OH)D).Methods:Our data source was the Survey on Prevalence in East China for Metabolic Diseases and Risk Factors (SPECT-China) cross-sectional study (ChiCTR-ECS-14005052, www.chictr.org). We enrolled 3234 subjects from 12 villages in the Yangtze Plain. BCLs were measured by atomic absorption spectrometry. 25(OH)D was measured with a chemiluminescence assay.Results:A total of 2560 (79.2%) subjects were diagnosed with vitamin D deficiency. The median (interquartile range) BCL was 1.80 μg/L (0.60-3.42) for men and 1.40 μg/L (0.52-3.10) for women. In women, mean 25(OH)D concentrations were inversely associated with BCL (0.401, 95% confidence interval: -0.697 to -0.105 nmol/L lower with each doubling of the BCL) after adjustment for age, educational status, current smoking, body mass index, diabetes, and season. However, there was no significant difference in 25(OH)D across the BCL tertiles for men.Conclusions:BCL in Chinese residents in the Yangtze Plain were much higher than that in developed countries. An inverse association between BCL and 25(OH)D was found in general Chinese women after multivariable adjustment. Future prospective cohort and animal studies are warranted to resolve the direction and temporality of these relationships, and to elucidate the exact mechanisms involved.

简介：Preferentialflowistheordinaryphenomenonofrapidandnon-equilibriumtransportofwaterandsolutesoccurringinmostsoil.Itcauseslatentpollutionofgroundandsurfacewatersandaffectsrunoffyieldandflowconcentration.ThispaperstudiespreferentialflowforadarkconiferousecosystemintheupperreachareaoftheYangtzeRiver,establishesaclassificationforthepreferentialflowanddiscussestypesofpreferentialflowwithasoilcolumnexperimentusingahomemadeapparatusanddye-traceranalysis.Thepreferentialflowismainlyunsaturatedgravitationalflowintheupperlayeroftheslopedepositformatureforestsoil,whichisdominatedbyawetnessfront,andtheflowgraduallytransformstomacroporousflowasthesoillayerdeepens.Theobservedpreferentialflowintheyoung,middle-agedandover-matureforeststhathavegrownonglaciallateralmorainesismacroporousflow.ThepurposeofthisresearchistoanalyzesystemicallythebehaviorofsoilwatermovementforadarkconiferousforestecosystemintheupperreachareaoftheYangtzeRiverandtoprovideatheoreticalbasisforeffectivewatershedmanagement.

简介：摘要：除了以前报导的小壳的石块(SSF)，一个宏观的石块集合，包括的丰富的水藻，锥形的管状的石块形式，和可能的印象一放大了后生动物，在西方的湖北省的Yangtze峡区域来自更低的寒武纪的Yanjiahe形成，华南。可见石块在thinlaminatedsiltstone被保存或泥泞siltstone在815公里厚的碳酸盐存款之间设置了，浅水里的抑制本地消沉的可能代表的沉积背景在早寒武纪的Meishucunian阶段期间焦化站台。宏观的石块协会关于生活的进化提供重要石块证据从对寒武纪的爆炸间隔晚前寒武纪。

简介：ThedeforestationonlargescaleintheupperreachesofYangtzeRiverhascausedseriousproblemsofecosystemandenvironment.Restorationofthedegeneratedforestecosystemsisoneofthemainresearchfields.TakingGonggaMountainasanexample,degenerationfeaturesandexistingproblemsofforestecosystemsareanalyzedinthispaper,andthemeasuresarealsoproposed.

简介：我们进行了孵化试验在中国在Changjiang河河口和它的邻近的水在不同磷酸盐集中和发光下面在浮游植物的滋养的举起调查变化的舷侧。在100%天赋发光下面，磷酸盐，硅酸盐，和硝酸盐的举起率在高磷酸盐层次(1.84亩M)被加速，当在低发光(大约50%自然发光)下面他们的举起率在高度被制止，但是在中间的磷酸盐集中极大地刺激了时(1.26嗯)作为浮游植物的生长，在亚硝酸根和铵举起的变化没跟随一个明显的模式。我们的结果也证明在在低、高的发光下面的不同磷酸盐集中在硝酸盐，硅酸盐和磷酸盐举起之间有线性关系，并且浮游植物的生长时期在低发光下面在高发光下面并且在中间的集中在高磷酸盐集中两个都被延长，建议浮游植物生长的限制主要在它的生长时期反映了变化，并且因为如此的环境(低发光和低磷酸盐集中)都实际上没在一个高混浊地区存在，浮游植物花蕾几乎没发生在那里。当发光不在时，脱氮乐意地发生了，浮游植物被作为减少，它导致了磷酸盐新生。

简介：

简介：RecentbathymetricchangesintheChangjiangEstuaryundertheinfluenceofartificialregulationengineeringsandbasinreservoirshavebeenanalyzedbasedonthemaritimechartssince1997andrecentfieldworks.Theresultsindicateaslighterosionofthechannelsintheupperandmiddleestuary,continuingdepositionandseawardmoveofthemouthbarcrestandintensifyingerosionatthenearshoreseabed.Itisnoteworthythatthemorphologicalevolutioncausedbyintensivehumanactivitiesdominatesoverthechangesfromnatureprocess.First,theriverbesareerodedoverallintheSouthBranch(SB),theSouthChannel(SC)andtheupperandmiddlereachesoftheNorthChannel(NC).Thenearshoreseabedoutsidetherivermouthisbeingerodedslightly,whichisattributedtothedecliningsedimentsupplyfromtheChangjiangBasinduetotheconstructionoftheThreeGorgesDamupstream.Thesedimentabovetheseabedisveryactiveandcoarsened,meanwhile,sandwavesarebecomingmoredistinct.Second,adepositionoccursintheNorthBrach(NB),themouthoftheNC,themouthbarsoftheNorthPassage(NP)andtheSouthPassage(SP)andespeciallythemainchanneloftheNP,whereitshowsamassivesiltationafterthedeepwaterwayproject.Thereasonsfortherecentchangesarenotonlythedynamicstructureinestuarinemouthbars,butalsothesupplyofsedimentresuspensioninalocalandoffshorearea.Meanwhile,thesevereerosionandsiltationinsomereachesisrelatedtotheconstructionofestuarineengineerings.ItisindicatedthattheChangjiangEstuaryisgraduallyself-adjustedandadaptingtothevaryingnaturalfactorsandintensivehumanactivities.Thestudyonthemechanismofself-regulationoftherecentbathymetricchangesintheChangjiangEstuaryhasimportantandpracticalsignificance.

简介：在No.1，No.3和No.4南京长江桥附近切入山谷的长江的地层学的剖面图与各自的讨厌的人日期和文件一起被建立。由四把钻的样品的14C年龄分析，核心接近No.4桥(被造)，我们能发现paleo山谷的时间范围在在深度的LGM是过时的?60m到?南京附近的90m。深切入山谷的隧道是狭窄的，河迅速流动了，这也被显示。部分并且深深地介绍的古老的长江深隧道在No.1桥附近切入特征。根据以前的出版物，许多研究在长江的主要paleo隧道上被做了，但是很少结果在分泌物评价上被完成了。在这篇论文，早期的速度和LGM的平均速度被计算与，等等以河形状，沉积谷物尺寸和序列接近No.3和No.1桥。而且，在长江的南京活动范围的分泌物在LGM期间被估计了根据分泌物的关系在12,00016,000m3/s附近，流动和剖面图的速度。

简介：1.TheregionincludesavastpartofSE.China,NW.Burma,N.VietnamandN.Laos’Itisaheterogeneousandverycomplicatedtectonicprovince.TheretookplaceactiveintracontinentalgeodynamieproccsscsofIndosinianYanshanianandHimalagunteetoniccycles.Assupposed,Varicdirectedmovementsoflithosphericblocks,aswellastheirinteracti

简介：