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991.
西藏申扎县木纠错地区晚三叠世海参骨片化石的发现及其地质意义 总被引:4,自引:0,他引:4
本文描述的海参骨片化石采自西藏申扎县木纠错西的多布日一带,主要有Theelia planorbicula Mostler,Theelia uariabilis alouakensis Kzour et Mock等晚三叠世诺利期标准分子。充分显示了海参骨片化石的重要的生物地层意义。该动物群的发现首次确定了西藏自治区北部冈底斯一腾冲地层区永珠蛇绿岩带以南晚三叠世海相地层的存在,并为中特提斯海的演化历史,古地理轮廓的确定,以及青藏高原的形成演变历史提供了新的资料。 相似文献
992.
Carlos Roberto A. Candeiro Adriano R. Santos Thiago S. Marinho Emerson C. Oliveira 《Geobios》2006,39(3):319
In this contribution is given a preliminary up-to-date annotated list of all fossil vertebrates from the Turonian-Santonian Adamantina Formation, Bauru Group where it occurs in the Prata paleontological district which is located 45 km to the west of Prata in Minas Gerais State, Brazil. The Adamantina Formation is a reddish sandstone in the Triângulo Mineiro region. These fluviolacustrine sediments were deposited in a semiarid environment. Three fossil vertebrate sites occur in the Prata paleontological district. The diversity of vertebrates in the Adamantina Formation is modest, and its components comprise a mixture of typical austral Gondwana taxa (such as abelisaurids, Aeolosaurus) and boreal Gondwana taxa (such as Carcharodontosauridae). The absence of Laurasian taxa in the upper part of the Bauru Group is noteworthy. Excepting some turtles, crocodylians, and one titanosaurid, most of the specimens discovered in this Group are based on fragmentary and isolated remains, which make it difficult to correctly identify the fossils. For this reason, many of the taxa have only been identified in a preliminary manner. Despite this drawback, the dinosaurs are typical Gondwana forms with no evidence of Laurasian affinities. This is concordant with the idea that the Laurasian dinosaurs entered South America at the end of the Late Cretaceous; i.e. after the Turonian-Santonian, the age of the Adamantina Formation. 相似文献
993.
Dr. Diethard Sanders 《Facies》1998,39(1):139-177
Summary The Turonian to Santonian terrestrial to neritic succession (Lower Gosau Subgroup) in the Northern Calcareous Alps of the
eastern part of the Tyrol, Austria, provides an example for deposition on a compartmentalized, narrow, microtidal to low-mesotidal,
wave-dominated, mixed siliciclastic-carbonate shelf. The shelf was situated in front of a mainland with a relatively high,
articulated relief, and underwent distinct changes in facies architecture mainly as a result of tectonism.
The investigated succession was deposited above a deeply incised, articulated truncation surface that formed when the Eo-Alpine
orogen, including the area of the future Northern Calcareous Alps, was uplifted and subaerially eroded. Distinct facies associations
were deposited from (1) alluvial fans and fan deltas, (2) rivers, (3) siliciclastic lagoonal to freshwater marsh environments,
(4) areally/temporally limited carbonate lagoons, (5) transgressive shores, (6) siliciclastic shelf environments, and (7)
an aggrading carbonate shelf. During the Turonian to Coniacian, the combination of high rates of both subsidence and sediment
accumulation, and a narrow shelf that was compartmentalized with respect to (a) morphology of the substratum, (b) fluviatile
input of siliciclastics and contemporaneous input of carbonate clasts from fan deltas, (c) deposition of shallow-water carbonates,
and (d) water energy and-depth gave rise to an exceptionally wide spectrum of facies as a distinguishing feature of the succession.
With the exception of facies association 7, which formed only once, depositional sequences in the Turonian to Coniacian interval
contain all of the facies associations 1 to 6. During Turonian to Coniacian times, the shelf was microtidal to low-mesotidal,
and was dominated by waves, storm waves and storm-induced currents. In vegetated marshes, schizohaline to freshwater marl
lakes existed. Transgressions occurred onto fan deltas and in association with estuaries, or in association with gravelly
to rocky shores. The transgressive successions, including successions deposited from transgressive rocky carbonate shores,
are overlain by regressive successions of shelf carbonates or shelf siliciclastics. Deposition of shallow-water carbonates
generally occurred within lagoons and over short intervals of time. A „catch-up” succession of shelf carbonates about 100
m thick accumulated only in an area protected from siliciclastic input.
In its preserved parts, the Turonian to Coniacian succession does not record deposition adjacent to major active faults. Lateral
changes in thickness result mainly from onlap onto the articulated basal truncation surface. Subsidence most probably was
controlled by major detachment faults outside the outcrop area, and/or was distributed over a wide area in association with
secondary faults above the major detachments.
During Coniacian to Early Santonian times, both the older substratum and the overlying Turonian-Coniacian succession were
subaerially exposed, faulted and deeply eroded. The following Early Santonian transgression ensued with rocky carbonate shores
ahead of a sandy, narrow shoreface-inner shelf environment and a deeper shelf with intermittentlydysaerobic mud. The transgression
was associated with the influx of cooler and/or nutrient-rich waters, and heralds an overall deepening. Still during the Early
Santonian, the deepening was interrupted by another phase of subaerial exposure. Subsequently, a short phase of shelf deposition
was terminated by deepening into bathyal depths. 相似文献
994.
995.
《L'Anthropologie》2022,126(1):102999
Melka Kunture is a cluster of Pleistocene sites, extending over ?100 km2 between 2000 and 2200 m asl, in the upper Awash Valley of Ethiopia. Starting around 2 million-years ago, the archaeological sequence includes sites with lithic productions of the Oldowan, Early Acheulean, middle Acheulean, final Acheulean, Early Middle Stone Age, Middle Stone Age and Late Stone Age. All over the Pleistocene, the climate was rainy and cooler than at the lower elevations of the Rift Valley, allowing the development of Afromontane vegetation. Hippopotamuses are ubiquitous and dominant in terms of biomass, but Alcelaphini are well represented, notably with genus Connochaetes and genus Damaliscus. Hominin fossils have been discovered in association with the Oldowan, the Early Acheulean, the middle Acheulean and the Early Middle Stone Age. Animal tracks and hominin footprints have also been documented, the latter ones in layers dated between 1.2 and 0.7 million-years. 相似文献
996.
Vance JE 《FEBS letters》2006,580(23):5518-5524
Niemann-Pick C (NPC) disease is a progressive neurological disorder in which cholesterol, gangliosides and bis-monoacylglycerol phosphate accumulate in late endosomes/lysosomes. This disease is caused by mutations in either the NPC1 or NPC2 gene. NPC1 and NPC2 are involved in egress of lipids, particularly cholesterol, from late endosomes/lysosomes but the precise functions of these proteins are not clear. An important question regarding the function of NPC proteins is: why do mutations in these ubiquitously expressed proteins have such dire consequences in the brain? This review summarizes the roles of NPC proteins in lipid homeostasis particularly in the central nervous system. 相似文献
997.
贵州关岭上三叠统的楯齿龙类化石 总被引:21,自引:8,他引:21
记述的新铺中国豆齿龙(Sinocyamodus xinpuensis gen. et sp. nov.)代表了齿龙目的一新属。这是齿龙类化石在我国的首次发现,也是这类特殊的海生爬行动物在欧洲、北非和中东以外地区的首次记录。标本产自贵州关岭晚三叠世瓦窑组一段的泥晶灰岩中,与鱼龙类、幻龙类及海龙类等多种海生爬行类同时产出。这一化石组合表明,贵州关岭三叠纪海生爬行动物群的性质与西特提斯动物群(wstern-Tethyan fauna)的性质极为相似,这两个地区在晚三叠世早期有广泛的动物交流。 相似文献
998.
FKBPs define a subfamily of peptidyl-prolyl cis/trans isomerases (PPIases). PPIases are known to play roles in cellular protein folding, protein interactions and signal transduction. Here we describe NcFKBP22 from Neurospora crassa, a novel type of FKBP. NcFKBP22 is synthesized as a precursor protein with a cleavable signal sequence. In addition to a typical FKBP domain in the amino-terminal part mature NcFKBP22 contains a novel second domain which is unique amongst all known FKBPs. The amino acid composition of this carboxy-terminal domain is highly biased. Secondary structure predictions suggest that this domain may form an amphipathic -helix. The carboxy-terminus of NcFKBP22 is –HNEL, a potential endoplasmic reticulum (ER) retention signal, suggesting that NcFKBP22 is a resident protein of the ER. 相似文献
999.
María Teresa Dozo Pablo Bouza Alejandro Monti Luis Palazzesi Viviana Barreda Gabriela Massaferro Roberto A. Scasso Claudia P. Tambussi 《Palaeogeography, Palaeoclimatology, Palaeoecology》2010,297(1):100-109
A new vertebrate faunal assemblage was recently discovered from the uppermost part of the late Miocene Puerto Madryn Formation. These deposits crop out along the southwestern coast of the Península Valdés area near Punta Delgada (Chubut Province, Argentina). The exhumed vertebrate fauna includes a range of fish, bird and mammal taxa, of which the latter are most varied and abundant. The new findings represent the first record of continental fossil vertebrates in the Puerto Madryn Formation and this is the first assemblage of late Miocene continental vertebrates recorded to the south of Río Negro Province. It also includes the southernmost record of Hydrochoeridae rodents, Dendrocygninae birds and Loricariidae fishes. The mammals suggest that the fossil-bearing sediments are Huayquerian in age. The climate during the accumulation of late Miocene deposits in this region is inferred to have been warmer and seasonally drier than that of today. 相似文献
1000.
N. Yu. Bragin 《Paleontological Journal》2009,43(4):356-369
When studying Late Jurassic-Early Cretaceous radiolarians from the Nordvik section (Arctic Siberia), unique morphotypes of multicyrtoid nassellarians with many horns in the apical part of the shell, which continue the rays A, V, 2l, D, and 2L of the cephalic spicule, were recorded. These morphotypes are assigned to a new family, Echinocampidae fam. nov., including three new genera (Echinocampe gen. nov., Nordvikella gen. nov., and Arctocapsula gen. nov.) and eight new species. The family Echinocampidae was probably restricted to high latitudes and belonged to the boreal fauna of the terminal Jurassic and the basal Cretaceous. 相似文献