全文获取类型
收费全文 | 685篇 |
免费 | 49篇 |
国内免费 | 1篇 |
出版年
2023年 | 6篇 |
2022年 | 11篇 |
2021年 | 33篇 |
2020年 | 14篇 |
2019年 | 24篇 |
2018年 | 21篇 |
2017年 | 19篇 |
2016年 | 20篇 |
2015年 | 46篇 |
2014年 | 50篇 |
2013年 | 50篇 |
2012年 | 55篇 |
2011年 | 59篇 |
2010年 | 36篇 |
2009年 | 29篇 |
2008年 | 30篇 |
2007年 | 37篇 |
2006年 | 28篇 |
2005年 | 21篇 |
2004年 | 27篇 |
2003年 | 16篇 |
2002年 | 24篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 8篇 |
1998年 | 7篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1968年 | 1篇 |
1960年 | 1篇 |
1950年 | 1篇 |
1944年 | 1篇 |
排序方式: 共有735条查询结果,搜索用时 15 毫秒
711.
Justine L. Larrouy Manpreet K. Dhami Eirian E. Jones Hayley J. Ridgway 《Environmental microbiology》2023,25(3):766-771
Flowers are an important niche for microbes, and microbes in turn influence plant fitness. As flower morphology and biology change rapidly over time, dynamic niches for microbes are formed and lost. Floral physiology at each life stage can therefore influence arrival, persistence and loss of microbial species; however, this remains little understood despite its potential consequences for host reproductive success. Through internal transcribed spacer 1 (ITS1) community profiling, we characterized the effect of transitioning through five floral stages of mānuka (Leptospermum scoparium), from immature bud to spent flower, and subsequent allocation to seed, on the flower-inhabiting fungal community. We found nectar-consuming yeasts from Aureobasidium and Vishniacozyma genera and functionally diverse filamentous fungi from the Cladosporium genus dominated the anthosphere. The candidate core microbiota persisted across this dynamic niche despite high microbial turnover, as observed in shifts in community composition and diversity as flowers matured and senesced. The results demonstrated that floral stages are strong drivers of anthosphere fungal community assembly and dynamics. This study represents the first detailed exploration of fungi through floral development, building on fundamental knowledge in microbial ecology of healthy flowers. 相似文献
712.
713.
Diplozoon is known to display an exceptional biology of reproduction: the hermaphroditic adults are permanently fused together and their genital ducts communicate. In contrast to all other polyopisthocotylean monogeneans in which the spermatozoa show an homogeneous biflagellate structure, the spermatozoon of Diplozoon is aflagellate. It is filiform, and composed of a cytoplasmic region and a nuclear region. The cytoplasmic region exhibits mitochondria, a well-developed smooth endoplasmic reticulum, and up to 450 longitudinal singlet microtubules. The microtubules show links between them; seen in cross section, they are arranged as rows or polygons. The spermatozoon nuclear region contains the nucleus surrounded by cortical longitudinal microtubules. The spermiogenesis shows no zone of differentiation, a typical structure found in all other parasitic Platyhelminthes. Diplozoon is the first case of aflagellate spermatozoon found in the parasitic Platyhelminthes. The atypical sperm structure is not linked with phylogeny, but is well correlated with the atypical biology of reproduction. 相似文献
714.
Fischhoff Ilya R.; Sundaresan Siva R.; Cordingley Justine; Rubenstein DI 《Behavioral ecology》2007,18(4):725-729
Prey species must adapt their behavior to avoid predation. Asa key prey item for lions (Panthera leo), plains zebras (Equusburchelli) were expected to respond to immediate threats posedby lions in their area. In addition, zebras were predicted toexhibit behavior tuned to reduce the potential for encounterswith lions, by modifying their movement patterns in the timesof day and habitats of greatest lion danger. We studied a populationof approximately 600 plains zebra living in Ol Pejeta Conservancy,Kenya. We found that zebra abundance on or near a grasslandpatch was lower if lions had also been observed on that patchduring the same day. Predation danger was highest in grasslandhabitat during the night, when lions were more active. Zebrasightings and global positioning system radio collar data indicatedthat zebras also reduced their use of grassland at night, insteadusing more woodland habitat. Zebras moved faster and took sharperturns in grassland at night. It is hypothesized that these moreerratic movements assist zebras in avoiding detection or captureby lions. 相似文献
715.
716.
717.
718.
719.
Jean-Lou Justine 《Systematic parasitology》2009,74(1):59-63
Triloculotrema chisholmae n. sp. is described from three specimens collected from the nasal tissues of a deep-sea shark, the blacktailed spurdog Squalus melanurus Fourmanoir & Rivaton, caught off New Caledonia, South Pacific. The new species is distinguished from the only other and type-species
of the genus, T. japanicae Kearn, 1993, by the morphology of the sclerotised male copulatory organ (shorter and straight versus curved) and shorter hamuli.
Résumé Triloculotrema chisholmae n. sp. est décrit à partir de trois spécimens récoltés dans les tissus nasaux d’un requin de profondeur, l’aiguillat à queue noire Squalus melanurus Fourmanoir & Rivaton, pêché au large de la Nouvelle-Calédonie, Pacifique Sud. La nouvelle espèce est distinguée de l’espèce-type et seule autre espèce du genre, T. japanicae Kearn, 1993, par la morphologie de l’appareil copulateur male sclérifié (plus court, et droit au lieu de courbe), et par des hamuli plus courts.相似文献
720.
Alcicornis haroldi n. sp. is described from Carangoides fulvoguttatus from off New Caledonia, South Pacific. It differs from all other Alcicornis spp. in its large protuberant pharynx, and from the most similar species, A. baylisi Nagaty, 1937, in its broader rhynchus, indistinct withdrawn tentacles and vitelline distribution. 相似文献