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简介：Airtemperatureisakeyindexreflectingclimatechange.Airtemperatureextremesareveryimportantbecausetheystronglyinfluencethenaturalenvironmentandsocietalactivities.TheArcticairtemperatureextremesnorthof60°Nareinvestigatedinthewinter.Dailydatafrom238stationsatnorthof60°Nfromtheglobalsummaryofthedayfortheperiod1979–2015areusedtostudythetrendsofcolddays,coldnights,warmdaysandwarmnightsduringthewintertime.Theresultsshowadecreasingtrendofcolddaysandnights(rateof–0.2to–0.3d/a)andanincreasingtrendofwarmdaysandnights(rateof+0.2to+0.3d/a)intheArctic.Themeantemperatureincreases,whichcontributestotheincreasing(decreasing)occurrenceofwarm(cold)daysandnights.Ontheotherhand,thevarianceatmoststationsdecreased,leadingtoareducednumberofcoldevents.ApositiveAO(ArcticOscillation)indexleadstoanincreased(decreased)numberofwarm(cold)daysandnightsovernorthernEuropeandwesternRussiaandanincreased(decreased)numberofcold(warm)daysandnightsovertheBeringStraitandGreenland.ThelowerextentofArcticautumnseaiceleadstoadecreasednumberofcolddaysandnights.TheoccurrencesofabruptchangesaredetectedusingtheMann-KendallmethodforcoldnightsoccurringinCanadain1998andforwarmnightsoccurringinnorthwesternEurasiain1988.ThisabruptchangemainlyresultedfromthemeanwarminginducedbysouthwindsandanincreasedNorthAtlanticseasurfacetemperature.

简介：本文利用较长时间段的两期照相观测资料，对60颗射电星进行坐标系统和参考星表的系统统一后，求得它们在FK5系统部自行，这些射电星的平均自行精度在赤经和赤纬方向上分别为±0″.0043/yr和±0″.0042/yr，比原来SAO星表的自行精度±0″.0119／yr和±0″.0113yr高2.7倍左右。

简介：通过分析陕西省近60a来气温时空变化特征,结合GIS空间分析技术,对中国陕西省气温变化进行定量化分析,阐述其时空演变规律。结果表明：近60a来陕西省气温总体呈上升趋势,升温趋势较缓和的是关中地区,陕北地区升温趋势明显;在时间尺度上,从20世纪90年代以来陕西省气温的上升趋势特别显著;陕西省各区年均气温变化具有明显的周期性,分别以10a为第一主周期。

简介：本文选用采自辽宁某矿的天然钠基蒙脱石与两株异化铁还原菌模式菌株ShewanellaputrefaciensCN32和She-wanellaoneidensisMR-1,研究了蒙脱石与微生物之间的交互作用。结果表明这两株菌均能还原蒙脱石晶格中的三价铁,使微生物作用于蒙脱石之后的反应体系中二价铁离子浓度明显升高,反应悬浊液颜色由无色变为浅绿色。透射电子显微镜晶格条纹像显示微生物作用后的粘土矿物微结构发生明显变化,其层间距d001值从1.29nm分别减小为1.06nm（CN32）和1.02nm（MR-1）。上述结果综合指示这两株异化铁还原菌能够通过还原天然蒙脱石结构中的三价铁促进矿物发生物相转变。

简介：3种鞘脂类代谢产物N-2′-羟基十六碳酰基-1-O-β-D-吡喃葡萄糖基-9-甲基-4E-8E-十八碳二烯-1-醇（A）、N-2′-羟基-3′E-十八碳烯酰基-1-O-β-D-吡喃葡萄糖基-9-甲基-4E，8E-十八碳二烯-1-醇（B）和N-十六碳酰基二氢鞘氨醇（C）分别产生于来源于中国南海的2株海洋真菌（菌株编号为1924和3893），通过2DNMR、MS等方法测定了它们的结构。这是首次从南海红树内生真菌分离得到的3种鞘脂类代谢产物。

简介：Byusingtheupper-winddatafromJuly1980toJune1983,thevariationsofthelow-frequencyoscillation(LFO)intheatmospherebeforeandduring1982ElNinohavebeeninvestigated.BeforetheElNino,theLFOpropagatesfromwesttoeastovertheequatoroftheEasternHemisphereandfromeasttowestover20°N.TheeastwardpropagatingLFOovertheequatorconsistsofzonalwavenumber1propagatingeastwardandzonalwavenumber2withacharacterofstationarywave.Theoscillationofzonalwavenumber2canmodulatetheoscillationstrength.AftertheonsetoftheElNino,thepropagatingdirectionsoftheLFOovertheequatorand20°NoftheEasternHemispherechangetobewestwardandeastward,respectively.TheLFOoverthewesternPacificweakensrapidlyandonecomingfrommiddleandhighlatitudespropagatestotheequator.Fromthephasecompositionsofstreamlinefieldsforthezonalwavenumber1ofequatorialwestwardpropa-gatirgLFO,itisfoundthattheatmosphericheatsourceintheequatoroftheeasternPacific(EEP)excitesaseriesoftheequatorialcyclonesandanticycloneswhichmovenorthwardandwestwardandformthewestwardpropagatingLFOovertheequator.Withthewavelengthof20000km,thiskindofequatorialwaveissimilartothemixingRossby-gravitywave.Initswestwardandnorthwardmovement,thecirculationinEastAsiaismodified.ThismaybethemechanismoftheinfluenceofElNinoontheclimateofChina.

简介：WaterdischargedataoftheYellowRiveroverthepast60yearswasanalyzedusingthecontinuouswavelettransform(CWT)andMann-Kendall(MK)testmethodstoidentifyspatialandtemporalvariationpatterns.PotentialconnectionsbetweenwaterdischargeintheYellowRiverBasinandElNio/SouthernOscillation(ENSO)werealsoexaminedbythecrosswaveletandwaveletcoherencemethods.CWTresultsshowthattheperiodicoscillationsinwaterdischargeshadoccurredatthetemporalscalesof1-,2to4-,6to8and10to22-year.Itwasalsofoundthatattheannualtimescale(1-year)thephaserelationsbetweenwaterdischargeandENSOwereindistinctprobablyduetothestronginfluencebyhumandisturbances.However,overthelongertimescales,thephaserelationbecomesmuchclearerwithananti-phaserelationbeingfoundmainlyatinter-annualscale(2to8-year)andin-phaserelationatdecadalscale(16to22-year).AccordingtotheMKtestresultswaterdischargeatmoststationsexceptTangnaihaihavedecreasedsignificantlyandtheabruptchangeoccurredinthemid-1980sortheearly1990s.Thechangesinwaterdischargewerefoundtobeinfluencedbybothclimatechangesandhumanactivities.Before1970thechangeinwaterdischargewaspositivelyrelatedtoprecipitationvariationsintheriverbasin,butafter1970thedecreaseinwaterdischargehasbeenlargelycausedbyvarioushumanactivitiesincludingconstructionsofreservoirs,waterabstractionandwater-soilconservationwithwaterabstractionbeingthemaincause.

简介：Abaroclinicsemi-geostrophicmodelwithevaporation-windfeedbackmechanism(EWFM)andCISKisestablished,twonon-dimensionalparametersaandηareintroducedtorepresentEWFMandCISK,respectively.Analyticsolutionsofthemodelsystemareobtained,dynamicsanalysesandthemodelatmospherecalculationsfurtherconfirmthatEWFMandCISKareveryimportantphysicalprocessesinleadingtothelow-frequencyoscillationsinthetropics.

简介：从中国福建沿海某一污染滩涂的沉积物中筛选到一株具有较强拮抗水产病原菌的生防细菌LHB02。采用通用引物,对LHB02的16SrRNA片段进行扩增,获得1511bp的DNA系列,基于该DNA系列,结合细菌形态学、生理生化特征,鉴定LHB02为一株枯草芽孢杆菌。对LHB02进行了抗菌试验、抗菌谱检测和发酵条件优化研究,结果表明,LHB02对哈维氏弧菌、溶藻弧菌、鳗弧菌等有很强的拮抗作用,其优化后的发酵条件为：KB培养基（蛋白胨20g,丙三醇10mL,K2HPO41.5g,MgSO4.7H2O1.5g,H2O1000mL）;温度28°C,pH值7.0,培养时间36h,接种量1.5%。

简介：在在东亚上的降水之间的关系(20祣汣湯獥

简介：摘要：本文通过应用ECM低压真空渗碳Infracarb Process 热处理技术，开展了9310钢材料小模数齿轮的可控气氛渗碳与低压真空渗碳的工艺方法对比，研究了对9310钢齿轮不同位置HRC60深度的影响，分析了两种方法结果的不同及优势。

简介：BasedontheNCEP/NCARreanalysisdataandtheobservedprecipitationdatainthesouthofChinafrom1958to2000,theimpactof30to60dayoscillationofatmosphericheatsourcesonthedroughtandfloodeventsinJuneinthesouthofChinaisdiscussed.Duringtheflood(drought)events,thereexistsananomalouslow-frequencyanticyclone(cyclone)atthelowlevelofthetroposphereovertheSouthChinaSeaandthenorthwesternPacific,accompaniedwithanomalouslow-frequencyheatsinks(heatsources),whilethereexistsananomalouslow-frequencycyclone(anticyclone)withanomalousheatsources(sinks)overtheareafromthesouthofChinatothesouthofJapan.Onaverage,thephaseevolutionofthelow-frequencyindroughteventsis7to11daysaheadofthatinfloodeventsinMaytoJuneinthesouthofChina.Infloodevents,low-frequencyheatsourcesandcyclonesarepropagatednorthwardfromthesouthernSouthChinaSea,northwestwardfromthewarmpoolofthewesternPacificandwestwardfromthenorthwesternPacificaround140°E,whichhaveveryimportantimpactontheabundantrainfallinJuneinthesouthofChina.However,indroughtevents,thenorthwardpropagationsofthelow-frequencyheatsourcesandcyclonesfromtheSouthChinaSeaanditsvicinityareratherlatecomparedwiththoseinfloodevents,andthereisnoobviouswestwardpropagationoftheheatsourcesfromthenorthwesternPacific.Thetimingofthelow-frequencyheatsourcepropagationhasremarkableimpactontheJunerainfallinthesouthofChina.

简介：英国石油公司《世界能源统计评估》称，尽管全球石油已探明储量2006年小幅下降，但按照目前的消费速度，全球已探明储量依然足够使用40年。

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简介：热带降雨测量的影响结构和intraseasonal摆动(ISO)的内在的物理上的使命(TRMM)降水产品与美国国家航空学和观察系统模型版本3的空格管理戈达德土(GEOS-3)被调查数据吸收系统(DAS)。在1998夏天的强壮的ISO阶段显然位于亚洲季风区域和东方赤道的和平的区域。当向东北的繁殖是在30点的突出的ISO到超过10的60天的摆动时，东方繁殖是为在20点的热带ISO的一个主导的特征到30天的摆动

简介：摘 要 宁德站改工程施工中大胆采用常规大型工程设备，并对该部分设备进行适当的专业化改造，与以往的拨接施工相比，大大地缩减了拨接作业人员数量，提高了工效，摒弃传统拨接施工中的人海战术，在有限的封锁时间内赢得了更多的工作时间和节约了成本，保质保量的达到开通条件。

简介：甘肃省民勤县地处欧亚大陆桥的咽喉要塞。自古以来，这片绿洲就像一块绿色的宝石镶嵌在环河西、接西域、通欧亚的商贸交通枢纽上，阻隔着巴丹吉林和腾格里两大沙漠的合拢及肆虐。守护着西北乃至全国的生态安全。民勤的历史，就是一部与风沙战斗的历史。“东风吹秕田。西风打死苗”这就是对民勤恶劣风沙环境的真实写照，土地沙漠化不仅是民勤人重大的生态问题。也是民勤人面临的一个严峻的经济可持续发展问题。1950年，民勤县举行了有史以来的第一次群众性植树造林誓师动员大会。自此，一场坚持不懈、不屈不挠的防沙治沙战役在民勤大地上打响。60多年来，一代又一代民勤儿女秉承艰苦奋斗的优良传统，发扬“牢记嘱托、勤苦坚守、众志成城、绿色共享”的防沙治沙精神，始终抱定决不成为第二个罗布泊的坚定信念，始终坚守生态保护这条生命线，为了保护自己的家园，始终不渝地与荒漠风沙进行殊死搏斗，坚持一张蓝图绘到底，一代接着一代干，前赴后继、持之以恒战风斗沙，在长达408公里的风沙线上筑起了一道“绿色长城”，谱写了一曲“沙漠绿洲”的时代壮歌!

简介：利用1961～2000年辽东地区13个观测台站的逐月降水和气温资料，分析了辽东地区降水和气温的年代际变化。并利用高桥公式计算出辽东地区的蒸发量。得出了该地区蒸发量和降水蒸发差的年代际变化特征；同时利用干燥度指标研究了辽东地区气候干旱对气候变暖的响应。结果表明：近40a来辽东地区气候变化呈暖干变化趋势。即气温升高、降水减少，尤其以20世纪90年代变化最为明显。