全文获取类型
收费全文 | 527篇 |
免费 | 38篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 7篇 |
2019年 | 10篇 |
2018年 | 8篇 |
2017年 | 8篇 |
2016年 | 12篇 |
2015年 | 23篇 |
2014年 | 22篇 |
2013年 | 43篇 |
2012年 | 34篇 |
2011年 | 34篇 |
2010年 | 22篇 |
2009年 | 12篇 |
2008年 | 26篇 |
2007年 | 38篇 |
2006年 | 30篇 |
2005年 | 34篇 |
2004年 | 24篇 |
2003年 | 26篇 |
2002年 | 26篇 |
2001年 | 7篇 |
2000年 | 12篇 |
1999年 | 5篇 |
1998年 | 8篇 |
1997年 | 11篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 10篇 |
1990年 | 7篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 7篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 5篇 |
1968年 | 2篇 |
排序方式: 共有565条查询结果,搜索用时 0 毫秒
561.
562.
563.
Katsuhiro Nishiyama Jiro Okada Yoshihiro Toh 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2007,193(9):963-971
The behavioral responses to attractive and aversive odors were examined in blinded adult male cockroaches under tethered-walking
conditions. A sex pheromone-like stimulant derived from adult virgin females and artificially synthesized limonene were used
as attractive and aversive odor sources, respectively. When a searching animal was stimulated with the attractive female-derived
odor, the horizontal deflections of both the antennae were increased, and in most cases the vertical antennal positions were
shifted downward. The stimulation also significantly decreased the walking speed of the animal. These behavioral changes imply
a careful search in the immediate surroundings. The aftereffect of the sex pheromone was more pronounced on locomotion than
on antennal movement. On the other hand, stimulation with the aversive odor (limonene) tended to suppress active antennal
movement, and also increased the walking speed. Immediately after the withdrawal of the aversive odor, the active movement
of the antennae was resumed, and the walking speed rapidly decreased to a level approximately the same as that of the control
period. These results indicate that the responses to the qualitatively opposite types of odor are reciprocal to each other
with regard to both antennal movement and locomotion. 相似文献
564.
Takashi Masaki Katsuhiro Osumi Kazunori Takahashi Kazuhiko Hoshizaki Kenji Matsune Wajirou Suzuki 《Ecological Research》2007,22(5):724-734
In a temperate riparian forest, the effects of substrate types, canopy gaps and conspecific seedfall density were investigated
on the seed-to-seedling process for the five dominant species (Aesculus turbinata, Fagus crenata, Acer mono, Pterocarya rhoifolia and Cercidiphyllum japonicum). Densities of seedfall and subsequent seedling recruits were measured in the stand over a period of 6 years. A model assuming
that local density of seedling recruits is proportional to seedfall density in the preceding year significantly explained
a spatial variation in seedling recruits for all species. Several environmental factors were then added. Substrate composition
had a positive effect on P. rhoifolia and C. japonicum. P. rhoifolia was favored by gravel substrate, which also explained the adult distribution of this species in this forest. C. japonicum appeared to be facilitated by a mineral-soil substrate. However, the distributions of this substrate and adults of C. japonicum did not follow each other closely. A. mono was negatively affected by gaps, and F. crenata was negatively affected by conspecific seedfall density. In contrast, A. turbinata was not significantly affected by any of the environmental factors tested. The microenvironmental heterogeneity in this forest
explained species coexistence to a limited extent in the context of seed-to-seedling processes. Performances at later stages
of the life-cycle and/or catastrophic disturbances (e.g. landslides) might have a stronger influence on species coexistence
in this forest. 相似文献
565.
Molecular analysis of the deletion mutants in the E homeotic complex of the silkworm Bombyx mori. 总被引:5,自引:0,他引:5
The E loci in Bombyx mori are expected to contain a homeotic gene complex specifying the identities of the larval abdominal segments. However, the molecular structure of this complex remains to be determined. We have started to analyze the structural changes in the E complex mutations. We used three newly isolated Bombyx homeobox genes as probes. These genes are probably homologues of the Ultrabithorax (Ubx), abdominal-A (abd-A) and Abdominal-B (Abd-B) in the Drosophila bithorax complex, because the amino-acid sequences of the homeobox regions in these Bombyx genes are almost identical to those of Drosophila genes. We found that the Bombyx Ubx and abd-A genes are deleted in the EN chromosome, and the Bombyx abd-A gene is deleted in the ECa chromosome. From these results, we conclude that the Bombyx E complex consists of the Ubx, abd-A and possibly Abd-B genes, which may play similar roles to their homologues in the Drosophila bithorax complex. 相似文献