全文获取类型
收费全文 | 852篇 |
免费 | 53篇 |
国内免费 | 1篇 |
出版年
2023年 | 3篇 |
2022年 | 15篇 |
2021年 | 18篇 |
2020年 | 7篇 |
2019年 | 12篇 |
2018年 | 17篇 |
2017年 | 15篇 |
2016年 | 21篇 |
2015年 | 54篇 |
2014年 | 57篇 |
2013年 | 62篇 |
2012年 | 87篇 |
2011年 | 72篇 |
2010年 | 49篇 |
2009年 | 46篇 |
2008年 | 52篇 |
2007年 | 50篇 |
2006年 | 44篇 |
2005年 | 40篇 |
2004年 | 25篇 |
2003年 | 31篇 |
2002年 | 22篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 6篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 3篇 |
排序方式: 共有906条查询结果,搜索用时 15 毫秒
901.
902.
Kulha Niko Pasanen Leena Holmström Lasse De Grandpré Louis Kuuluvainen Timo Aakala Tuomas 《Ecosystems》2019,22(4):709-724
Ecosystems - Identifying the scales of variation in forest structures and the underlying processes are fundamental for understanding forest dynamics. Here, we studied these scale-dependencies in... 相似文献
903.
904.
Beetle genitalia are usually described only for taxonomic purposes without considering the possible function of structures.
Exceptions are sporadic detailed studies on single species. We studied genital structures in the subfamilies of Cerambycidae
and outlined assumptions on the function of these structures and the implications for the phylogeny of the Cerambycidae. We
found that male genitalia in particular are taxon-specific on a higher taxonomic level; e.g., the parameres are widely variable
in Cerambycinae, while in most Lamiinae species they appear relatively uniform and differ from those of the Cerambycinae.
Internal sac structures are very different among the various subfamilies. Small backwards-pointing spines are the most common
armature of the internal sac. The female genitalia are less variable, although ovipositor morphology may differ among subfamilies.
In most species, the connection between the mates during copulation is achieved by the long internal sac and the ovipositor
only, whereas the median lobe and parameres are in contact with the female abdomen only at the beginning of copulation. Cerambycinae
and Lepturinae have a basal swelling of the endophallus to prevent it from sliding back into the male abdomen during copulation.
The long internal sac functions in connecting the mates and guaranteeing the sperm transfer. 相似文献
905.
Kenneth Klingenberg Barfod Lasse Smidt Karen A. Krogfelt Lars Andrup 《Biocontrol Science and Technology》2010,20(9):1001-1011
Translocation of viable cells from a Bacillus thuringiensis israelensis-based biopesticide to inner organs in a mouse model was studied. Mice were exposed to the originally formulated product through the lungs and gastrointestinal tract by intratracheal instillation. Colony forming units (CFU) were grown from lungs, caecum, spleen and liver on Bacillus cereus-specific agar (BCSA) after 24 h and finally determined to be biopesticide strain B. t. israelensis by large plasmid profile. No CFU were found in spleen or liver of the control mice or in any aerosol background or material. We have shown that viable cells from the commercial product can translocate to spleen and liver of immunocompetent mice in a dose-dependent manner. Furthermore, we discuss the methods of exposure and how bacterial translocation should be taken into consideration when evaluating the safety of novel or reintroduced biopesticides in the future. 相似文献
906.