全文获取类型
收费全文 | 2283篇 |
免费 | 242篇 |
国内免费 | 1篇 |
出版年
2023年 | 14篇 |
2022年 | 25篇 |
2021年 | 31篇 |
2020年 | 22篇 |
2019年 | 29篇 |
2018年 | 44篇 |
2017年 | 31篇 |
2016年 | 61篇 |
2015年 | 97篇 |
2014年 | 92篇 |
2013年 | 135篇 |
2012年 | 160篇 |
2011年 | 127篇 |
2010年 | 78篇 |
2009年 | 69篇 |
2008年 | 98篇 |
2007年 | 106篇 |
2006年 | 94篇 |
2005年 | 90篇 |
2004年 | 96篇 |
2003年 | 103篇 |
2002年 | 90篇 |
2001年 | 65篇 |
2000年 | 57篇 |
1999年 | 50篇 |
1998年 | 32篇 |
1997年 | 17篇 |
1996年 | 21篇 |
1995年 | 25篇 |
1994年 | 23篇 |
1993年 | 22篇 |
1992年 | 49篇 |
1991年 | 41篇 |
1990年 | 44篇 |
1989年 | 34篇 |
1988年 | 24篇 |
1987年 | 34篇 |
1986年 | 31篇 |
1985年 | 26篇 |
1984年 | 27篇 |
1983年 | 24篇 |
1982年 | 16篇 |
1981年 | 13篇 |
1980年 | 11篇 |
1979年 | 16篇 |
1978年 | 18篇 |
1977年 | 12篇 |
1976年 | 16篇 |
1975年 | 15篇 |
1973年 | 12篇 |
排序方式: 共有2526条查询结果,搜索用时 14 毫秒
91.
A Sánchez González J S Casas J Sordo U Russo M I Lareo B J Regueiro 《Journal of inorganic biochemistry》1990,39(3):227-235
We report the synthesis of new complexes with the general formula (R2SnX2)y.H2BiIm, where y = 1 or 2; R = Me, Et, Bun; X = Cl or Br (for R = Et) and H2BiIm = 2,2'-Biimidazole. The complexes have been characterized by elemental analysis and M?ssbauer, infra-red and 1H n.m.r. spectroscopy and tested (like the ligand, Me2SnCl2 and Et2SnCl2) against P388D1 leukemic cells. 相似文献
92.
T Galeotti A Cittadini O Dionisi M Russo T Terranova 《Biochimica et biophysica acta》1971,253(2):303-313
93.
94.
95.
96.
97.
Leonardo Ancillotto Luciano Bosso Sonia Smeraldo Emiliano Mori Giuseppe Mazza Matthias Herkt Andrea Galimberti Fausto Ramazzotti Danilo Russo 《Ecology and evolution》2020,10(12):5785-5800
Because of the high risk of going unnoticed, cryptic species represent a major challenge to biodiversity assessments, and this is particularly true for taxa that include many such species, for example, bats. Long‐eared bats from the genus Plecotus comprise numerous cryptic species occurring in the Mediterranean Region and present complex phylogenetic relationships and often unclear distributions, particularly at the edge of their known ranges and on islands. Here, we combine Species Distribution Models (SDMs), field surveys and molecular analyses to shed light on the presence of a cryptic long‐eared bat species from North Africa, Plecotus gaisleri, on the islands of the Sicily Channel, providing strong evidence that this species also occurs in Europe, at least on the islands of the Western Mediterranean Sea that act as a crossroad between the Old Continent and Africa. Species Distribution Models built using African records of P. gaisleri and projected to the Sicily Channel Islands showed that all these islands are potentially suitable for the species. Molecular identification of Plecotus captured on Pantelleria, and recent data from Malta and Gozo, confirmed the species' presence on two of the islands in question. Besides confirming that P. gaisleri occurs on Pantelleria, haplotype network reconstructions highlighted moderate structuring between insular and continental populations of this species. Our results remark the role of Italy as a bat diversity hotspot in the Mediterranean and also highlight the need to include P. gaisleri in European faunal checklists and conservation directives, confirming the usefulness of combining different approaches to explore the presence of cryptic species outside their known ranges—a fundamental step to informing conservation. 相似文献
98.
Oreto Cristina Veropalumbo Rosa Viscione Nunzio Biancardo Salvatore Antonio Botte Marilisa Russo Francesca 《The International Journal of Life Cycle Assessment》2021,26(12):2391-2407
The International Journal of Life Cycle Assessment - A challenge that the road paving sector is facing concerns the achievement of highly performing bituminous asphalt mixture solutions that do not... 相似文献
99.
Stefania Galdiero Annarita Falanga Rossella Tarallo Luigi Russo Emilia Galdiero Marco Cantisani Giancarlo Morelli Massimiliano Galdiero 《Journal of peptide science》2013,19(3):148-158
Herpes simplex virus (HSV) is a significant human pathogen causing mucocutaneous lesions primarily in the oral or genital mucosa. Although acyclovir (ACV) and related nucleoside analogs provide successful treatment, HSV remains highly prevalent worldwide and is a major cofactor for the spread of human immunodeficiency virus. Encephalitis, meningitis, and blinding keratitis are among the most severe diseases caused by HSV. ACV resistance poses an important problem for immunocompromised patients and highlights the need for new safe and effective agents; therefore, the development of novel strategies to eradicate HSV is a global public health priority. Despite the continued global epidemic of HSV and extensive research, there have been few major breakthroughs in the treatment or prevention of the virus since the introduction of ACV in the 1980s. A therapeutic strategy at the moment not fully addressed is the use of small peptide molecules. These can be either modeled on viral proteins or derived from antimicrobial peptides. Any peptide that interrupts protein–protein or viral protein–host cell membrane interactions is potentially a novel antiviral drug and may be a useful tool for elucidating the mechanisms of viral entry. This review summarizes current knowledge and strategies in the development of synthetic and natural peptides to inhibit HSV infectivity. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
100.
Cyperus polystachyos is a hygrophilous, thermophilous and heliophilous plant with a punctiform distribution in southern Italy, where it is almost exclusively found on Ischia, an island in the Bay of Naples characterized by widespread volcanic hydrothermal activity. This species is a native of tropical and subtropical areas and there is evidence for ancient isolation events in the creation of its current distribution pattern. We have studied the historical literature available for this plant since 1800 and collected temporal and spatial presence data of this species in order to develop a habitat suitability map based on a GIS approach and using a multiple linear regression model. Moreover, we have used univariate and multivariate statistical analysis. The results show the importance of the environmental mosaic around fumaroles to preserve the species; urbanization and geothermal energy use of fumaroles in the past and the combination of abandonment of the typical agricultural system and the natural occurrence of reforestation in the present are the main causes of the decline in the number of populations. 相似文献