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181.
1. Syclinal warping at the end of the Cretaceous time?(Phase Ⅲof Yenshan Movement?).Intermont sedimentation.Deposition of the lowerand middle portions of the Kuanchuang Series during the Eocene(and earlyOligocene?)time. 2. Block-faulting and progressive tilting during the late Oligocenetime(Nanling Movement).Accumulation of the "bajada breccias" in con-nection with the faulting and the inauguration of the Tanghsien consequentdrainage system. 3. Tanghsien erosion to full maturity during the Miocene time. 4. Prolonged period of chemical weathering.Fossil soils withmanganese-iron pisolites and karst surfaces formed(Pliocene). 5. Deposition of gravels(Late Pliocene?). 6. "Z erosion" of moderate dissection followed by the accumula-tion of the Concretionary Reddish Loams (Lower Pleis cene). 7. Chingshui dissection along old lines,followed by the deposition ofbrownish-gray loams and loess of the Malan epoch(Upper Pleistocene). 8. Present cycle of erosion and deposition. 相似文献
182.
大别山超高压变质岩的地球动力学意义 总被引:54,自引:3,他引:54
超高压变质岩因其在岩性与原岩上的多样性,以及其岩块与基质混杂的构造特征而具变质混杂岩属性,其顺时针型P-T轨迹表明,超高压岩石的形成与演化与碰撞造山作用有关,年代学研究表明,峰期超高压变质作用发生于中-晚三叠世,几个不同地点的超高压岩石的P-T-t轨迹已被归纳,并据之计算了超高压岩石的折返速率.计算表明,大别山超高压岩石的折返具多阶段性,即中-晚三叠世的快速折返(3.3~3.6mm/a),早侏罗世的中速折返(0.7~1.1mm/a),以及中侏罗世至早白垩世的极慢速折返(0.15mm/a).以上述资料为约束条件,提出了一个大别山造山带的柱状模型. 相似文献
183.
中国合肥盆地新生代火山岩成因岩石学研究 总被引:19,自引:4,他引:19
古新世和渐新世(可能至中新世)玄武岩质岩石的零星露头产在中国东部的合肥盆地中。前者是拉班玄武岩质,而后者是碱性玄武岩质。对它们进行了详细的岩石学以及微量元素和同位素地球化学研究,古新世拉斑玄武岩浆应该来源于一个老地幔楔的部分熔融,而这个地幔楔是由早中生代扬子板块向华北板块之下消减而形成的。自渐新世,中国东部大陆进入了张裂的大陆边缘阶段。该阶段的碱性玄武岩浆可能来源于软流圈。 相似文献
184.
一年以來,關於新生代骨化石之採集與研究,續有進展。除賈蘭坡在四川,技工王存義在河北邢台西所獲標本爲前所採集,新經研究者外;關於第三紀初期者,李悅言在河南盧氏,卞美年在雲南曲靖及魯南,均獲有確切無疑之始新統或漸新統 相似文献
185.
在地質研究中,新生代地質,向來是最易被人忽略的一部分,早年的地质報告中,提到第三纪第四纪地層,每以数十字成十餘字了之,最普遍的無非是紅色岩系或第三紀初期砂岩,三趾馬紅土或黄土等而已。一般的地质调查,多注意新生代以前地層,故此等现象,本無足怪。 相似文献
186.
187.
188.
A MIOCENE FOSSIL FROG FROM SHANTUNG. 总被引:1,自引:0,他引:1
Among a large collection of plants,insects,fishes,turtles andmammals recently collected by the author near Lingchühsien,Shantung,a well preserved fossil frog and numerous impressions of tadpoles are 相似文献
189.
THE CENOZOIC SEQUENCE IN THE YANGTZE VALLEY 总被引:3,自引:0,他引:3
On the whole the sequence of the Cenozoic formations in the Yangtzebasin and its provisional correlation with the Cenozoic sequence in North China,can be expressed in the following table: ON THE POSSIBILITY OF PREHISTORIC FINDS IN THE YANGTZE VALLEY (1) Generally speaking,possibilities of discovering traces of PalaeolithicMan in the Yangtze basin are rather limited,either on account of the poordevelopment of the Late Pleistocene beds,or on account of their unpromisingfacies(silt or mud). Nevertheless,methodical researches should be started in the extensivepits opened for brick industry in the lower terraces of the Yangtze,for instance,near Nanking in the Hsiasu Loam.Fig.12.An artifact collected on the ground west of Wanshien.Natural size. (2) An attractive field for the search of stony implements would bethe superficial deposits capping the 30-meter terrace developed so extensivelyalong the Yangtze.The Yuhuatai gravels,composing this terrace,contain alarge amount of siliceous pebbles remarkably fitted for the development of astony industry. (3) West of lchang,there is still a better material for stony implementsrepresented by the large pebbles of hard quartzite forming the gold-bearing gravel of the Yangtze.Most probably,if the Red Basin of Szechuan wascovered by loess,palaeolithic flakes would be common in its basal gravel.Un-fortunately,the Mesozoic ground is exposed almost everywhere,in a barrenand cultivated condition,this fact rendering researches difficult,and eventually,interpretation of finds rather difficult.Our figure 12 illustrates a retouchedflake of siliceous pebble collected along the Yangtze,some 10 kilometers westof Wanhsien(nght bank of the river).The specimen was picked up from theground,at a point a little higher than the loamy terrace 1 represented in ourfigure 11.The piece is distinctly incrusted,and differs by its shape from theNeolithic implements(mostly polished celts)commonly observed along theYangtze banks.But its pre-Neolithic age is impossible to prove. (4) As the most promising field for Palaeoanthropology still remainthe fossiliferous dissolution pits spread over the karstic plateaus of the Wanhsienarea.As observed by Granger,those pits have most been worked as naturaltraps,and never represented a dwelling place for animals.Yet the possibilityof discovering somewhere(as in Kwangsi,cf.Teilhard,...Chang,1935)anhabitated cave is not excluded. (5) A special re-investigation is necessary of the Tatsienlu area inwhich quartzite flakes associated with pot sherds have been collected in a kindof loess by Edgar and Bowles.Our own suspicion is that the Tatsionlu loessreally is Late Pleistocene,and the fragments of pottery secondary additions inthe deposits. 相似文献
190.
INTRODUCTION The Dinosaur beds of Mengyin are one of the localities known to con-tain fossil reptiles in China.This site was surveyed about ten years ago byTan and Zdansky and the material studied by Professors C.Wiman~1 and 相似文献