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122 个结果
  • 简介:DE200/LE200和DE245/LE245都是行星和月球的精密历表。DE200/LE200已在很多领域(例如SLR和GPS)中得到了广泛应用,DE245/LE245却是刚发表不久的新历表。DE245/LE245中增加了DE200/LE200中没有同时提供的月亮天平动。本文主要比较DE245/LE245和DE200/LE200的差别对月球探测器着月点位置的影响,得到的结论是如果要使着月点位置满足一定的精度要求,采用DE245/LE245历表比DE200/LE200历表更好。

  • 标签: 行星星历表 月球运动 月球探测器 登月轨道 飞行轨道
  • 简介:本文介绍了利用美国喷气推进实验室(JPL)的星历磁带DE303,在计算机内存在中创建DE303/LE303星历表和月球天平动LLB303文件的过程,并应用这一最新历表处理了1987年10月至1990年12月的全球4个测月站的观测资料,求得了UT0-UTC序列SHA90M01。同时,对不同历表解逄的UT0-UTC结果也作了比较,计算结果表明,采用DE303/LE303星历表LLB303天平动历表照片得到的UT0-UTC序列的外部精度略好于用DE200/LE200星历表及LLB200天平动历表归算所得结果序列的外部精度。

  • 标签: 激光测月 历书 天平动 星历表 磁带
  • 简介:Itisnecessarytoestimateheavymetalconcentrationswithinsoilsforunderstandingheavymetalcontaminationsandforkeepingthesustainabledevelopmentsofecosystems.Thisstudy,withthefloodplainalongLe'anRiveranditstwobranchesinJiangxiProvinceofChinaasacasestudy,aimedtoexplorethefeasibilityofestimatingconcentrationsofheavymetallead(Pb),copper(Cu)andzinc(Zn)withinsoilsusinglaboratory-basedhyperspectraldata.Thirtysoilsampleswerecollected,andtheirhyperspectraldata,soilorganicmattersandPb,CuandZnconcentrationsweremeasuredinthelaboratory.Thepotentialrelationsamonghyperspectraldata,soilorganicmatterandPb,CuandZnconcentrationswereexploredandfurtherusedtoestimatePb,CuandZnconcentrationsfromhyperspectraldatawithsoilorganicmatterasabridge.Theresultsshowedthattheratioofthefirst-orderderivativesofspectralabsorbanceatwavelengths624and564nmcouldexplain52%ofthevariationofsoilorganicmatter;thesoilorganicmattercouldex-plain59%,51%and50%ofthevariationofPb,CuandZnconcentrationswithestimatedstandarderrorsof1.41,48.27and45.15mg·kg-1;andtheabsoluteestimationerrorswere8%-56%,12%-118%and2%-22%,and50%,67%and100%ofthemwerelessthan25%forPb,CuandZnconcentrationestimations.Weconcludedthatthelaboratory-basedhyperspectraldataholdpotentialsinesti-matingconcentrationsofheavymetalPb,CuandZninsoils.Moresamplingpointsorotherpotentiallinearandnon-linearregressionmethodsshouldbeusedforimprovingthestabilitiesandaccuraciesoftheestimationmodels.

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  • 简介:ThebvaluespectrumandηvaluebythemomentmethodToruOuchi(大内)DepartmentofEarthSciences,FacultyofScience,KobeUniversity,Kobe,657,...

  • 标签: b VALUE SPECTRUM MOMENT METHOD η
  • 简介:摘要:本文介绍了对 B市债务情况进行描述性统计分析。整理了 B市 10个县区 2014-2018年 5年的地方债务数据,基于经济增长速度这一角度,通过面板协整回归模型系统分析了地方政府债务对经济增长速度的影响。

  • 标签: 政府债务 经济增长 债务风险
  • 简介:CalculationofbvalueanditsapplicationinearthquakepredictionHua-ChenDUAN(段华琛);Chang-QingFAN(范长青)andYue-MinXU(许跃敏)(Seismological...

  • 标签: b VALUE standardizing time DENSITY FACTOR
  • 简介:Intheestimationofseismictendency,usingGutenberg-Richter¢sb-valueandusingHurstexponentaretwocom-monlyusedmethods.Basedonthefractalgeometryofearthquaketimeseries,wepointoutthatthesetwomethodscorrelatetoeachother.IntheperspectiveoffractionalBrownianmotion(FBM),anearthquakesequencewithb>3/4andthatwithb<3/4havedifferentdynamicproperties.

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  • 简介:本文讨论可信的历史地震资料和现代化仪器记录资料的统一使用问题。

  • 标签: 历史地震 检验 b值统计
  • 简介:介绍了基于B/S结构的网上考试系统应用于气象部门的理论研究,并分析了系统总体结构,提供了一种应用SQL数据库以及ASP编程实现的网络考试系统,详细阐述了科目管理、随机生成试卷等模块的设计与实现,以及相关数据库表的结构。

  • 标签: B/S ASP 网上考试 科目管理 随机生成试卷
  • 简介:WeusedearthquakecatalogsrecordedbyGuangdongSeismologicalNetworkfrom2008to2014toresolvethespatialvariationsofb-valuesinthecoastalareaofGuangdong,particularlyinthreekeyresearchareas(Yangjiang,Heyuan,andoffshoreNanaoIsland)withstrongseismicity.Ourresultsrevealedthatb-valuesexhibitedsignificantspatialvariations,andzoneswithlowb-valuescouldindicatethemostlikelyseismogenicareaoflargeearthquakes.Weobservedthreeclearlowb-valuepatchesintheoffshoreNanaoIsland.Wefoundadistincthighb-valuepeakatthedepthof11kmandtwominimumpeaksatabout14and7–8kmintheYangjiangarea.Theoverallb-valuesgenerallydecreasewithdepthintheHeyuanarea.Thespatialvariationsofb-valuesreflecttectonicanomalies;thatis,the‘low-high-low’distributionofb-valuesintheoffshoreNanaoIslandandtheYangjiangareamayindicatetheanomalyofthecrustalstructurewithaweaklayer.Theb-valuesofreservoir-inducedseismicityareobviouslylowerthanthatinducedbytectonism.Thisfindingindicatesthatthereservoirareaisgenerallyathighstressstateundertheconditionofhighporepressure.Weinferredthatlargeearthquakesmightbepronetooccurat10–12kmdepthintheoffshoreNanaoIsland,at12–15kmdepthintheYangjiangarea,andatthelowerpartoftheseismicactivityzoneintheHeyuanarea.Moreover,theupstreamareaoftheXinfengjiangreservoiristhemostlikelyareaoffuturelargeearthquakesintheHeyuanarea.

  • 标签: B-VALUES EARTHQUAKE GUANGDONG SEISMOGENIC area STRESS
  • 简介:SequencevariationofpartialcytochromebgenesbetweentwoCoiliaspecies,C.ectenesandC.mystus,wasinvestigated.Ofthe402nucleotides,twenty-seven(6.72%)arepolymorphicandallaresynonymoussubstitutions.Atthethirdpositionsofgeneticcondonofcytochromebgene,thetwospeciesshowanextremeanti-Gbias(<4%)andapronouncedbiastowardsAandC(>68%).Thereisnoaminoacidsequencedivergencebetweenthepartialcytochromebgenesofthetwospecies,indicatingaclosegeneticrelationshipbetweenthem.Thek-2pgeneticdistanceofpartialcytochromebsegmentofthetwospeciesis0.072,suggestingthatthespecieswereseparated3.6Maago,inthemiddlePliocene.Ourresultrevealsthatthecytochromebgeneisanappropriatemarkerforstudiesofpopulationgeneticstructuresandphylogeographicpatternsofthetwospecies.

  • 标签: 细胞色素 B基因 基因转化 线粒体DNA 凤尾鱼
  • 简介:宝浪油田宝中区块油藏类型为含气顶的环状凝析油气藏,地温梯度高,油藏埋藏深、压力高(压力梯度为1.07MPa/100m左右),地层微裂缝发育.在此情况下,通过深入进行串漏机理分析,有针对性地优选封串工艺技术,优选油井封串水泥,优选隔离液,优化工艺设计与运行,在B208井封串一次成功,为井下工艺技术状况复杂井修井作业提供了可资借鉴的成功经验.

  • 标签: 宝浪油田 环状凝析油气田 水泥环窜槽 封串工艺 选择性封堵
  • 简介:本实验根据B9在土豆叶面喷洒的规定,对叶面喷洒B9的土豆与叶面不喷洒B9的土豆进行了对比观测,且采用中国农科院关于科技成果效益计算方法从新增产量、新增产值、新增生产费用、新增纯收益、新增投资收益率等方面进行了经济效益分析,实验结果经济效益比较显著。

  • 标签: 土豆叶面 喷洒 B9 实验 经济效益
  • 简介:摘要:2015年国家颁发了《水污染防治行动计划》,其中要求全国加油站地下油罐应于2017年底前全部更新为双层罐或完成防渗池设置。按此要求,全国10万多座在运营加油站需在规定时间完成此项技术改造。但是截止目前,全国尚有大批加油站未完成改造。本文以B公司为例,从项目进度控制角度出发,分析了B公司双层罐项目进度控制在计划阶段和实施过程中存在的问题,并对原因进行分析,最后对B公司双层罐项目进度控制提出完善计划、明确流程、保障资源投入等对策建议。

  • 标签: 双层罐 进度计划 进度控制
  • 简介:Effectsofthemixtureofβ-ecdysoneandpolypodine-B(2:1W/W)onthemoultingandgrowthofprawn,Penaeusorientalisswerestudiedinlaboratorybyrearingtheanimalwiththeaddedcompounddiets.Theresultsshowedthattheadditionofthemoultinghormone(M.H)mixturetocompounddiets,from1.33×10-6to30×10-6,couldincreasemoultingactivityandgrowthrateoftheprawntodifferentextents,amongwhichthe5.33×10-6-10.67×10-6additionhadstatisticallysignificanteffects.However,60×10-6addeddietscausedmoultingandgrowthinhibitionsandcuticlethickening.Theanalysesofprotein,waterandashcontentsoftheprawnshowednoremarkabledifferencesbetweenhormonedosedanimalsandthecontrol.

  • 标签: PENAEUS EFFECTS of statistically larvae remarkable