全文获取类型
收费全文 | 2072篇 |
免费 | 138篇 |
出版年
2024年 | 3篇 |
2023年 | 15篇 |
2022年 | 48篇 |
2021年 | 68篇 |
2020年 | 58篇 |
2019年 | 62篇 |
2018年 | 78篇 |
2017年 | 69篇 |
2016年 | 87篇 |
2015年 | 151篇 |
2014年 | 137篇 |
2013年 | 150篇 |
2012年 | 145篇 |
2011年 | 136篇 |
2010年 | 102篇 |
2009年 | 79篇 |
2008年 | 126篇 |
2007年 | 99篇 |
2006年 | 87篇 |
2005年 | 60篇 |
2004年 | 64篇 |
2003年 | 53篇 |
2002年 | 74篇 |
2001年 | 41篇 |
2000年 | 30篇 |
1999年 | 28篇 |
1998年 | 19篇 |
1997年 | 16篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 15篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 9篇 |
1990年 | 12篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1980年 | 3篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1967年 | 2篇 |
排序方式: 共有2210条查询结果,搜索用时 31 毫秒
41.
42.
43.
Marcos A. L. Teixeira Pedro E. Vieira Fredrik Pleijel Bruno R. Sampieri Ascensão Ravara Filipe O. Costa Arne Nygren 《Zoologica scripta》2020,49(2):222-235
We report on two new lineages of the Eumida sanguinea complex from Great Britain and describe one of them as a new species using a multilocus approach, including the mitochondrial DNA COI-5P and the nuclear markers ITS (ITS1, 5.8S rRNA and ITS2) and 28S rRNA. The molecular analysis placed Eumida mackiei sp. nov. in a monophyletic clade with 19.1% (COI), 10.1% (ITS) and 1.7% (28S) mean distance to its nearest neighbour. Molecular diagnoses were also applied to nine lineages within the E. sanguinea complex. This was complemented with morphometric data employing multivariate statistical analysis and the incorporation of statistical dissimilarities against three other described species from the complex. Eumida mackiei sp. nov. can be distinguished from E. notata and E. maia by the larger distance between the eyes and differences in morphometric proportions mainly in the dorsal and ventral cirri as well as in the prostomial appendages. E. sanguinea sensu stricto failed to produce a cluster of its own in the morphometric analysis, probably due to juvenile bias. Integrative taxonomy provided strong evidence to formally describe a new cryptic species that can now be used in biomonitoring or other relevant ecological research. 相似文献
44.
Ogaki Mayara B. Coelho Lívia C. Vieira Rosemary Neto Arthur A. Zani Carlos L. Alves Tânia M. A. Junior Policarpo A. S. Murta Silvane M. F. Barbosa Emerson C. Oliveira Jaquelline G. Ceravolo Isabela P. Pereira Patrícia O. Cota Betania B. Viana Roberta O. Alves Viviane S. Rosa Luiz H. 《Extremophiles : life under extreme conditions》2020,24(2):227-238
Extremophiles - We accessed the culturable mycobiota present in marine sediments at different depths in Antarctica Ocean. Acremonium fusidioides, Penicillium allii-sativi, Penicillium chrysogenum,... 相似文献
45.
Thdia Evelyn de Araújo Iliana Claudia Balga Milin Guilherme de Souza Rafaela Jos da Silva Alessandra Monteiro Rosini Pmela Mendona Guirelli Priscila Silva Franco Bellisa Freitas Barbosa Eloisa Amlia Vieira Ferro Idessania Nazareth da Costa 《Cell biology international》2020,44(1):36-50
During pregnancy, the placenta regulates the transfer of oxygen, nutrients, and residual products between the maternal and fetal bloodstreams and is a key determinant of fetal exposure to xenobiotics from the mother. To study the disposition of substances through the placenta, various experimental models are used, especially the perfused placenta, placental villi explants, and cell lineage models. In this context, nanotechnology, an area of study that is on the rise, enables the creation of particles on nanometric scales capable of releasing drugs aimed at specific tissues. An important reason for furthering the studies on transplacental transfer is to explore the potential of nanoparticles (NPs), in new delivery strategies for drugs that are specifically aimed at the mother, the placenta, or the fetus and that involve less toxicity. Due to the fact that the placental barrier is essential for the interaction between the maternal and fetal organisms as well as the possibility of NPs being used in the treatment of various pathologies, the aim of this review is to present the main experimental models used in studying the maternal–fetal interaction and the action of NPs in the placental environment. 相似文献
46.
47.
Systematic Parasitology - The proteocephalid genus Pseudoendorchis (Cestoda: Onchoproteocephalidea) has recently been proposed to accommodate seven species/species-level lineages of tapeworm... 相似文献
48.
Martinelli L. A. Nardoto G. B. Soltangheisi A. Reis C. R. G. Abdalla-Filho A. L. Camargo P. B. Domingues T. F. Faria D. Figueira A. M. Gomes T. F. Lins S. R. M. Mardegan S. F. Mariano E. Miatto R. C. Moraes R. Moreira M. Z. Oliveira R. S. Ometto J. P. H. B. Santos F. L. S. Sena-Souza J. Silva D. M. L. Silva J. C. S. S. Vieira S. A. 《Biogeochemistry》2021,154(2):425-426
Biogeochemistry - The initial online publication contained typesetting mistakes in the author information. The original article has been corrected. 相似文献
49.
Patrícia Barros Pinheiro Igor Da Mata-Oliveira Mariana Gomes do Rêgo Bruno Mourato Fábio Hissa Vieira Hazin 《Zeitschrift fur angewandte Ichthyologie》2021,37(4):523-533
The present work describes the reproductive biology of the white marlin (Kajikia albida) caught in the southwestern and equatorial Atlantic Ocean. The gonads of 924 fish were collected by observers on board Brazilian tuna longliners, between November 2004 and December 2006. The spawning season was assessed by the monthly frequency distribution of distinct stages of maturity and monthly mean female gonadosomatic index GSI. Sixty-one percent (n = 656) of the fish examined were female, with a Lower Jaw Fork Length (LJFL) between 83 and 236 cm (mean = 155.5 ± 16.63). The 268 males had a LJFL between 90 and 220 cm (mean = 152.3 ± 34.62). Although the northeastern region of Brazil does not appear to be a significant spawning area for the species, the results suggest a higher reproductive activity in the third quarter of the year. Using a Bayesian logistic model approach, length at 50% maturity was estimated at 145.04 cm (credibility interval of 95%, 143.94–146.09 cm), for females, and at 140.03 cm (credibility interval of 95%, 137.28–142.52 cm), for males. 相似文献
50.
Joana Romero Carolina Vieira Susana Garrido Margarida Hermida Paulo Catry Graça Faria José Pedro Granadeiro 《Journal of fish biology》2021,99(3):831-843
The Atlantic chub mackerel Scomber colias and the blue jack mackerel Trachurus picturatus are two abundant species in the Macaronesia region which includes the archipelago of Madeira, Portugal. Both are key species in the trophic web, being important prey for several local top predators, such as seabirds and marine mammals. Nonetheless, little is known about their feeding ecology in oceanic environments. In this study, the authors describe the seasonal variation in the diet of S. colias and T. picturatus in the oceanic region of Madeira throughout a year. Visual inspection of stomach contents revealed that S. colias fed on a broader range of prey groups than T. picturatus, but for both species, zooplankton (particularly calanoid copepods) and fish were the most important food items. The diet of S. colias included a higher proportion of fish, namely Atlantic saury Scomberesox saurus and S. colias, than that of T. picturatus, that included mostly the longspine snipefish Macroramphosus scolopax. T. picturatus consumed a higher proportion of decapods and other copepods. Seasonal variation was found in the diet of both species, with zooplanktonic species being more important in colder months (February to April) for S. colias and during warm months (May to October) for T. picturatus. Their diet in other seasons was dominated by fish. Although they consume similar prey, carbon and nitrogen stable isotope analysis of muscle of S. colias and T. picturatus showed little overlap in their diets, and T. picturatus showed higher δ15N and a narrower isotopic niche. 相似文献