共查询到20条相似文献，搜索用时 359 毫秒
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沿长江顺流而下,可以看到千山万谷,汹涌澎湃的三峡,也可以看到九曲回肠的荆江和潮平岸阔的江苏江段。在宜昌南津关,“山随平野尽,江入大荒流”(李白《渡荆门送别诗》)。长江就在这里由山区进入平原。一般说来,天然河流都可象长江一样,分为山区和平原两段。山区河流是水流改造山谷的产物。地壳运动,增加了河床演变的复杂性。山区河流具有下列特点:(1)河床纵比降大;(2)水流湍急紊乱;(3)山谷沿程宽窄不一,河道在平面上具有藕节状外形; 相似文献
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971349 Che;19 Jie(China Universityseienees,Beijing)The MammaljanShowjng ClimatieF盆uetuat应on—ExamPle of the Early Pleistoceneof Ge。FaunaS AS anMam-malian Faunas from Zhoukoudian,Beijing,China(ESI矛,ISSN 1 005一2321,CN 11一3370/P,4(2),1997,p·275一279,1 graph,1 table,10 ref) By analyses of the four local marnmalianfaunas from Zhoukoudian,Beijing,the EarlyPleistoeene elimatie and eeologieal environ-CN 11一1 905/Q1 53,1 graph,1735(2).1997,P.145一mental ehangespaper.One of1 .90M… 相似文献
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自然河流或者处于单向演变状态,或者处于准平衡状态。这是按平均概念而言。实际河床演变就是围绕这种均衡状态或正或负地交替进行。河流一旦受到外力干扰,均衡状态被破坏之后,河床演变过程也将随之改变。有的干扰、改变甚至破坏会很强烈。这种演变开始时都比较急剧,然后逐渐衰减,最终达到新的均衡状态。干扰河床演变均衡状态的途径有二:(1)改变河道的来水来沙条件。如河段以上的水土保持工程、拦沙工程、水库枢纽工程、分流堵汊工程和引水工程等的作用。它们增减水量、沙量,改变水流过程和输沙过程以及水沙搭配关系等。(2)改变河段河床形 相似文献
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戴橦谟 《矿物岩石地球化学通报》1984,(4)
本会同位素地球化学委员会K—Ar专业组,于1984年8月2日至6日在安徽屯溪召开了Ar~(40)-Ar~((?)0)计时技术讨论会。来自全国20个单位的36位代表出席了会议。该项新兴技术方法是将快中子活化与同位素质谱测定技术结合,对在不同加温条件下的同一个样品测定一组年龄(坪龄)。利用这种技术可以开展地质体的热史及其演化史的研究。与会代表非常感兴趣地听取了利用此法研究青藏高原、三江地区的板块碰撞热史和测定 相似文献
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962135 Ma Yuzhen(The Deparrment of Ge-ograPhy,Lanzhou University,Lanzhou,730000);Tao Mingxin THE RED BEDSPORO一POLLEN ASSEMBLAGES ANDGEOLOGICAL AGE FROMZHUERZHUANG OF YAOJIE,GANSUPROVINCE(ASDS,ISSN 1000一0550,CN62一1038,13(4),1995,P.64一72,2graphs,1 table,1 plate,8 ref,with Englishabstraet)962136 Zhang Kexin(Faeulty of Earth Sei-enees,China Universiry of Geoseienees,Wuhan,卜Iubei,430074);Lai Xulong CON-ODONT SEQUENCE AND ITS GLOBALCORR… 相似文献
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962240 Li Ya(Fujian Provinee ExplorationCollege,Fuzhou,Fujian,350001)HYDRO-GEOLOGY AND ENGINEERING GEOLO-GY IN THE PROCESS COLLAPSE OF51,OPING FIELD GEOMORPHOLOGY(JCUES,ISSN 0253一6072,CN22一1151/P,25(4),1 995,p.428一434,2 graphs,4 ta-bles) ‘The distribution rule and formingmeehanism of land一slide and eollaPse indistriets where the railway,highway and hy-droeleetrie power sratio一1 were established,are summariedi:1 this paper.The at一thoreonsiders rhat … 相似文献
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980326 Chen Jianqiang(China University ofGeoseienees,Beijing)The MicroskeletalStruCtUreS ofM公k耐t勿LavruseviCh(Rugosa)(Aeta Palaeontologieal Siniea,ISSN 0001一6616,CN 32一1188,36(4),1 997,p.446一452,2 tables,2 Plates,18ref) Maikottia Lavrusevieh 1 967 15 a group ofPeeuliar fossil eystiPhyllids,usually in eerioideompound forms with eystiPhylloid septa eom-posed of eomposite rhabdaeanthines,rangingfrom Lower Silurian(Llandovery series)toUPPer Silurian(Ludlow series)in theYangtze … 相似文献
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20001589 He Chengquan(Naniing Instituteof Geology and palaeonrology,ChineseA-eademy of Seienees,Naniing,Jiangsu);SunXuekun Late Hauterivian Dinoflagellatesfrom the Lower Part of the Chengzihe For-mation in Jixi Basin,Eastern Heilongjiang,Northeast China(Aeta Palaeontologiea Sini-ea,ISSN 0001一6616,CN32一1188/Q,39(l),2000,p.46一62,1 illus.,2 tables,3Plates,67 ref) Chengzihe Formation 15 widely distribut-ed in eastern Heilongjiang Provinee.A totalof 22 dinoflagellate eyst taxa are… 相似文献
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1 937/P,30(4),1 995.p.321一328,2 graphs1 rable,8 ref,with English absrraer)962149 Yong Ruidong(In、titute of Geolo-gy,Guizhou Bureau of Geology and MineralResourees);Yang Chengxi THE CAR-BONIFEROUS TRACEF()SSILS INGUIZll0U:DISCUSSION ON DISTRIBU-TION OF ZOOPHYCOS THROUGHOUTGEOLOGIC HISTORY(GZG,ISSN 1000一5943,CN52一1059/P,12(4),1995,l,.290一297,2 graphs,1 plat。,1 2 rof) l’raee fossils臼rc abundant in fhe Cdr-bonlferous strata,esPeelally in those … 相似文献
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980302 Feng Heng(块Partment of Earth Sci-enees,Nanjing University,Nanjing,J iangsu);Yang Xiangning Study on Taxono--my of Some PSeudOSchwageri加(FusulinidForamln三fera)(Aeta MieropalaeontologieaSiniea,ISSN 1000一0674,CN32一1189,14(3),1997,p.280一294,5 graphs,1 table,2 Plates,24 ref) Morphologieal measurements of 123 thinsections and sPeeimens Published in the litera-ture have been used to study the taxonomy of厂、6心oschwagerina“dd翻1 Dunbar et Skin-ner, 1 937,P.洲烤口ris(Scher肠… 相似文献
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刁飞一ISON WITH THOSE OF NEIGHBORINGAREAS(AMCS,ISSN 1000一0674,CN32一1 1 89,12(4),1995,p.349一373,2 graPhs,4tables,35 ref,wirh English abstraet)962146 Shang Ping(Fuxin Institute of Mi-n ing and‘I’eehnology,Fuxin,Liaoning)THE NATURE AND CHARACTERS OFTHE EARLY CRETACEOUS FLORAFROM THE PINGZHUANG BASIN,IN-NER MONGOLIA(GR,ISSN 0371一5736,CN 11一1 952/P,41(6),1995,P.533一536,1table,6 ref,with English abstraer)962144 Tong Guobang(Institute o… 相似文献
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resourees eonfronted by the regional develop-ment,the PaPer studies the formation of theisland water resourees and the ways of ratio-nal development by analysing the fundamentaleharaeterisries of lslands water environment.The geologieal and geographieal environmentand regiona】elimate eondition peeuliar to theislands determine that the water environmenteapaeity 15 small,with limited water re-sourees.The regional exploitation of islandsshould follow the way of sustainable and eoor-dinated devel… 相似文献
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peldense,X.yixianenese,X.fuxinense sP.nov.and X.h:‘011,Zhe,,se sP.nov.In addi~,一on,rwo other sPeezes rePorred by prev一ousaurhors were also ldenrifled as X.‘o),ch夕l;a,,u,):and X.l;ao,,z,之ge,zse .Thepalaeoeeologieal envlronmenr model and phy-logeno51s of the genus Xeno了夕10,,aro analyzedand dlseussed irlt}115 paper.20001600 Ding Qiuhong(Shenyang Institureof Geology and Mineral Resourees,Shenyang,Liaoning);Zheng Shaolin Meso-zoic Fossil Woods of Genus Xenoxylon fromNortheast Chi… 相似文献
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working meth司and reqiuremen,of the hy-drologie reeonnaissanee for rhe wellhead fieldof the alluvial一laeustrine Pla三n are systemati-cally expounded in this PaPer too.The au-thors have indieated the imPortanee of hydro--logie reeonnaissanee in rhe light of prospeetingpraetiee of Xiaoyangzhuang wellhead field.980450 Sun Leling(Department of Geologyand Mineral Resourees of Zheiiang Provinee,Hangzhou)Management for Plaees of Natu-ral Mineral Drinking Water Resourees(Ge-ology of Zhejiang,… 相似文献