学科分类
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2 个结果
  • 简介:ThesouthcoastalplainofLaizhouBayisoneofthetypicalsalt-waterintrusionareasinChina,theoccurrenceanddevelopmentofwhichwascloselyrelatedwiththepa-laeoenvironmentevolution.Systematicanalysesofpollen,foraminiferaandgrainsizecom-positionbasedon14Candluminescencedatingfromtwosedimentcoreswereperformedforthepurposeofunderstandingthesalt-waterintrusioninthecoastalplainofLaizhouBayfromtheperspectiveofenvironmentalevolutionsincelatePleistocene.Itcouldbeclassifiedintosevenevolutionstagessince120kaBP:120–85kaBPwasatransitionperiodfromcoldtowarm;85–76kaBPwasaperiodwithwarmandwetclimatehavingswamplakesdevelopedinthelowerreachesoftheWeiheRiver,southcoastalplainofLaizhouBay;76–50kaBPwascharacterizedbygrasslandvegetationandcoarsesedimentsinterrestrialenvironment,whichwastheearlystageofDaliIce-Age;50–24kaBPwasaperiodwithalternateseadepositioninthesouthcoastalplainofLaizhouBay;24–10kaBPwasthelatestageofDaliIce-AgewithcoldestperiodofQuaternary,thesouthcoastalplainofLaizhouBaywasdrygrasslandandloessdepositionenvironment;10–4kaBPwasanotherwarmandwetclimateperiod,sealevelwashighandregressedat4kaBP;andhasbeenthemodernsedimentaryenvironmentsince4kaBP.Amongthethreewarmstages,including85–76kaBP,50–24kaBPand10–4kaBP,correspondedtolateYangkou,GuangraoandKenliseawatertransgressionrespec-tively.ThedurationofthelatteroneinsouthcoastalplainofLaizhouBaywaslongerthanthatinwestcoastofBohaiSeaandeastcoastofLaizhouBay.Thethreeperiodsofseawatertransgressionformedthefoundationofsalt-waterintrusioninthisarea.

  • 标签: environmental evolution salt-water INTRUSION late PLEISTOCENE
  • 简介:博空间是一种崭新的人类生活和交往空间,它以计算机技术、现代通讯网络技术、虚拟现实技术综合应用为基础,为人们提供了全新的经济活动场所,本文讨论了博空间的概念,以及支撑博空间的关键技术,即信息高速公路、遥感技术、地理信息系统兹术、数据库管理和虚拟现实技术等,并就其在城市规划,城市交通,商业布局及城市旅游中的若干应用进行探讨。

  • 标签: 赛博空间技术 城市地理 计算机技术 网络技术 虚拟现实技术 经济活动