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61.
A fossil-bearing locality near Padhri village, Dhok Pathan, 55 km away from the tehsil Dina, Jhelum District, in the Potwar Plateau, Middle Siwaliks, Punjab, northern Pakistan, is significantly rich in mammalian fossils. This site has provided an abundant mammalian fossil fauna of Late Miocene age from the Dhok Pathan Formation (Fm.). The recovered material belongs to four families: Equidae (horses), Rhinocerotidae (rhinos), Bovidae (cows), and Suidae (pigs). We discovered a new skull of hipparionine Hipparion theobaldi from this locality along with 22 specimens from the associated assemblage of fossil mammals. The recovered material includes seven other species: the aceratheriine Chilotherium intermedium, boselaphines Tragoportax punjabicus, Selenoportax vexillarius, Pachyportax latidens, the antelope Gazella lydekkeri and suinine Propotamochoerus hysudricus. The specimens are isolated teeth, fragments of maxilla, mandibles and horn cores. The Dhok Pathan Fm. is generally composed of claystone, siltstone and sandstone beds and, based on the mammalian fauna, the Padhri fossil locality is dated as Late Miocene. Thi99s formation was deposited in a subtropical paleoenvironment and the predominance of fossil bovids indicates extremely moist conditions with small but frequent standing water bodies.  相似文献   
62.
This study employs Structural Equation Models (SEMs) to systematically analyze the components of a multi-stakeholder negotiation in an applied setting. It characterizes participant perceptions of a multi-stakeholder, consensus-based negotiation process used to reduce harmful interactions between marine mammals and fishing gear in U.S. waters (marine mammal Take Reduction Teams). From April to July 2013, 234 current and former participants of eight Take Reduction Teams received a survey with 15 questions about the negotiation process, outputs (Take Reduction Plans), and outcomes. The SEMs depict relationships among the latent variables of social capital and shared learning, fairness, stakeholder satisfaction with the Take Reduction Plans, and their perceived outcomes. The SEMs also explain the influence of independent predictors of team identity and age, geographic region, and stakeholder affiliation on the latent variables. Results indicate that stakeholder views of fairness significantly influenced their satisfaction with the Take Reduction Plans, which in turn, significantly affected their opinions of the outcomes. While the majority of participants believed the plans were at least slightly successful at reducing marine mammal bycatch, this varied among teams and was significantly influenced by stakeholder affiliation, region, and Take Reduction Team age.  相似文献   
63.
This study aimed to identify the occurrence and spatial distribution of cetaceans in Mauritanian waters (eastern Atlantic). A geophysical survey was conducted over 92 days between September and December 2012. Over 967 km was surveyed, with 1 017 h of observer effort recorded. Visual watches for marine mammals resulted in 228 cetacean sightings of 16 different species, including 12 odontocetes and 4 mysticetes. The short-finned pilot whale Globicephala macrorhynchus was the most frequently encountered odontocete, followed by the Atlantic spotted dolphin Stenella frontalis. Of the mysticetes, the sei whale Balaenoptera borealis and blue whale B. musculus were encountered most frequently. We used generalised additive models and generalised linear models to examine the relationships between environmental factors and cetacean distribution. The results showed depth had a significant influence on presence of the short-finned pilot whale, which preferred waters deeper than 1 800 m. The model for mysticetes identified bathymetry as a significant environmental predictor, whereas slope of the ocean floor had a positive effect but was not significant. This study contributes to our understanding of cetaceans in Mauritanian waters, using data from a platform of opportunity.  相似文献   
64.
Geografisk Tidsskrift—Danish Journal of Geography 110(2):175–200, 2010

The GeoArk project conducted interdisciplinary studies between 2003 and 2008 to investigate the Thule culture (c. 1400 AD until c. 1850 AD) in the Wollaston Forland- Clavering Ø region (74°N). Faunal remains of recent excavations and re-analyses of previous excavations of Thule culture seasonal features, winter houses and middens are presented, with an emphasis on the two winter sites of Fladstrand and Dødemandsbugten. The faunal assemblages showed ringed seal (Phoca hispida) to be the key game species, although, with important contingents of narwhal (Monodon monocerosj and caribou (Rangifer tarandus) Thule subsistence was highly dependent on having a well developed procurement system and the sea- and landscape was used differentially during the annual cycle. Hvalros Ø, located at the recurring Sirius Water Polynya, was used as a seasonal aggregation site especially for hunting walrus (Odobenus rosmarusj) throughout the entire Thule culture era. Being a predictable source of meat and blubber, the walrus was of fundamental importance to the Thule Inuit in order to cope with a harsh high arctic environment. The site locations of the study area revealed a continued similar usage of the sea- and landscape for centuries and the analyses documented only minor temporal changes in subsistence patterns.  相似文献   
65.
在晚白垩世期间,哈萨克斯坦东部的斋桑盆地形成了一个湖盆,一直延续到现在。古斋桑湖中最老的沉积是Tayzhuzgen组,由厚达136m的泥岩、粉砂岩、页岩、石英砂岩、砾岩和淡水石灰岩红层组成。按照当地的地层名称,Tayzhuzgen组包括Manrak、Tayzhuzgen、Aulisbulak、Aktobe、Dysum bay和Kiin Kerish层。在斋桑湖以南的Tayzhuzgen河附近一个地点的Tayzhuzgen组下部,发现了恐龙蛋壳碎片,蛋壳至少包括有两个主要类型:圆形蛋类和长形蛋类。恐龙蛋壳指示了Tayzhuzgen组下部的时代为晚白垩世(可能是马斯特里赫特期)。在本组的较高层位,发现了晚?古新世的植物化石,因此斋桑盆地的白垩系-古近系界线在Tayzhuzgen组内部。在Tayzhuzgen组中,白垩纪与古新世化石层之间的地层间隔只有约50m,由此推测在Tayzhuzgen组内部可能存在一个或多个不整合,或是本组的中部为凝缩沉积,即在白垩系-古近系界线处的沉积速率非常缓慢。Tayzhuzgen组顶部有一个显著的不整合,那里中或晚始新世(Arshantan,Irdinmanhan或Egilian陆生哺乳动物"期")的地层存在于含哺乳动物化石剖面的底部。斋桑盆地的白垩系-古近系界线位于古斋桑湖沉积剖面的下部。这不是一个完整的界线剖面,可能是一个包含有一个或多个不整合和/或一个由慢速沉积造成的凝缩剖面。  相似文献   
66.
The study of British Pleistocene mammal faunas has been hampered by the difficulty of telling the difference between the postcranial elements of the often abundant remains of the large bovids Bos primigenius Bojanus, 1827 and Bison priscus Bojanus, 1827. Here I present qualitative and morphometric criteria whereby Bos primigenius and Bison priscus radii, metacarpals, tibiae, astragali and metatarsals can be told apart using British Pleistocene material.  相似文献   
67.
辽西首次发现保存毛发和软件的中生代哺乳动物化石   总被引:3,自引:2,他引:3  
季强 《地质通报》2002,21(1):29-34
中国辽西地区素以产出丰富多彩的中生代热河生物群闻名于世。特别是近几年来,该区大量长羽毛的恐龙、原始鸟类、原始哺乳类和被子植物化石的发现更加引起了国际科学界的极大关注。1997年秋,作者在辽宁北票四合屯地区发现了一块完整的保存有毛发和软体印痕的对齿兽类哺乳动物化石。身体保存有手发和软体印痕的中生代哺乳动物化石在世界上也是罕见的。对对于研究对齿兽形态结构、生物习性、系统关系等方面均具有重要意义。  相似文献   
68.
A New Symmetrodont Mammal with Fur Impressions from the Mesozoic of China   总被引:3,自引:0,他引:3  
Western Liaoning of northeastern China is world-renowned for the Mesozoic Jehol biota, especially for yielding many feathered dinosaurs, primitive birds, mammals and fossil angiosperm. This paper describes a complete specimen of a symmetrodont mammal with well-preserved hairs and soft tissue from the basal part of the Yixian Formation in the Sihetun area, Beipiao, western Liaoning. It is significant for understanding the morphology, osteology, phylogeny and life habits of Mesozoic symmetrodont mammals.  相似文献   
69.
The ‘algarrobo’Prosopis flexuosais an important food resource in the Monte Desert of Argentina. Native, domestic, and exotic mammals consume the fruit of this legume and disperse the seed through faeces. In the present study we analyse the effect that different dispersal agents (cattle, horse, European wild boar, rodents, gray fox) have on seed damage, viability, and germination. Cattle increase germination at the expense of reduced viability, whereas horses maintain viability but do not contribute to a prompt germination response. Among native mammals, the gray fox maintains seed viability without increasing germination, whereas rodents affect seed viability but enhance germination rates. The European wild boar, however, damages all of the seeds it consumes.  相似文献   
70.
Mercury concentrations in fish, faeces and exhaled air were investigated in order to evaluate total mercury exposure through the gut in captive bottlenose dolphin and excretion via intestine and pulmonary routes. Results showed that faeces account for elimination of 34-48% of dietary mercury; while only 0.9-1.2% of alimentary mercury is eliminated through exhaled air. The remaining 51.2-65.3% of ingested mercury, ranging approximately between 266 and 339 microg per day, is retained within the organism. The complexation of mercury with selenium, forming insoluble tiemannite granules, is discussed as an important mechanism, complementary to excretion, by which odontocetes are able to cope with elevated alimentary exposure to mercury.  相似文献   
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