全文获取类型
收费全文 | 677篇 |
免费 | 56篇 |
国内免费 | 1篇 |
专业分类
林业 | 13篇 |
农学 | 11篇 |
45篇 | |
综合类 | 132篇 |
农作物 | 8篇 |
水产渔业 | 7篇 |
畜牧兽医 | 487篇 |
园艺 | 8篇 |
植物保护 | 23篇 |
出版年
2022年 | 6篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 10篇 |
2017年 | 11篇 |
2016年 | 17篇 |
2015年 | 14篇 |
2014年 | 18篇 |
2013年 | 38篇 |
2012年 | 17篇 |
2011年 | 27篇 |
2010年 | 13篇 |
2009年 | 27篇 |
2008年 | 30篇 |
2007年 | 31篇 |
2006年 | 18篇 |
2005年 | 15篇 |
2004年 | 19篇 |
2003年 | 27篇 |
2002年 | 11篇 |
2001年 | 13篇 |
2000年 | 12篇 |
1999年 | 13篇 |
1998年 | 8篇 |
1997年 | 14篇 |
1996年 | 7篇 |
1995年 | 9篇 |
1994年 | 5篇 |
1993年 | 11篇 |
1992年 | 16篇 |
1991年 | 14篇 |
1990年 | 23篇 |
1989年 | 14篇 |
1988年 | 11篇 |
1987年 | 12篇 |
1986年 | 15篇 |
1985年 | 10篇 |
1984年 | 7篇 |
1983年 | 12篇 |
1982年 | 9篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1975年 | 5篇 |
1974年 | 9篇 |
1973年 | 8篇 |
1972年 | 8篇 |
1971年 | 9篇 |
1970年 | 8篇 |
1969年 | 5篇 |
排序方式: 共有734条查询结果,搜索用时 15 毫秒
731.
Reproductive performance of postpartum ewes treated with insulin or progesterone hormones in association with ram effect
下载免费PDF全文
![点击此处可从《Reproduction in domestic animals》网站下载免费的PDF全文](/ch/ext_images/free.gif)
JC Ferreira‐Silva SRL Basto F Tenório Filho MT Moura ML Silva Filho MAL Oliveira 《Reproduction in domestic animals》2017,52(4):610-616
The reproductive performance of postpartum Santa Inês (SI) and Morada Nova (MN) ewes treated with insulin or progesterone hormones in association with ram effect was evaluated. Ewes from SI (n = 69) and MN (n = 69) breeds were randomly allocated to three groups of each breed (T1—ram effect only; T2—ram effect + insulin; T3—ram effect + progesterone). Progesterone concentrations (ηg/ml; mean ± SD) before and after introduction of rams (n = 6) were 0.51 ± 0.22 and 3.78 ± 0.68 (T1), 0.65 ± 0.21 and 3.77 ± 0.78 (T2) and 0.52 ± 0.21 and 3.84 ± 0.84 (T3) in SI ewes and 0.74 ± 0.19 and 3.71 ± 0.56 (T1), 0.70 ± 0.21 and 3.79 ± 0.75 (T2) and 0.81 ± 0.14 and 3.87 ± 0.80 (T3) in MN ewes, respectively. Thus, lower progesterone concentrations were found before the introduction of rams (p < .05). After the introduction of rams, preovulatory peaks of LH (ηg/ml) occurred at 28 (T1), 44 (T2) and 48 (T3) hr in SI ewes and at 64 (T1), 40 (T2) and 44 (T3) hr in MN ewes. The mean number of ovulations was similar between groups (p > .05), was 1.3 ± 0.51 (T1), 1.5 ± 0.54 (T2) and 1.6 ± 0.51 (T3) in SI ewes and 1.3 ± 0.51 (T1), 1.6 ± 0.51 (T2) and 1.6 ± 0.51 (T3) in MN ewes. In conclusion, the ram effect alone is effective at inducing and synchronizing oestrus in sheep under postpartum anoestrus, irrespective of hormone treatments. 相似文献
732.
733.
Coniine, an alkaloid of Conium maculatum (poison hemlock), was administered by gavage to immature chickens, quails, and turkeys at 0, 25, 50, and 100 mg/kg body weight. At 25 mg coniine/kg body weight, clinical signs were observed only in quails (2/10) and consisted of excitement, depression, hypermetria, seizures, opisthotonos, and flaccid paralysis. Chickens (9/10) and quails (8/10) dosed at 50 mg/kg body weight were affected, and several birds of each species died (2/10 and 5/10, respectively). Turkeys (7/10) were affected only when dosed at 100 mg/kg body weight, and quails (6/10), turkeys (4/10), and chickens (10/10) died at this dose. There were no gross or microscopic lesions. Coniine was detected in skeletal muscle and liver of birds dying after ingestion and was present in some survivors 7 days post-treatment. 相似文献
734.
M. S. Reed I. Fazey L. C. Stringer C. M. Raymond M. Akhtar‐Schuster G. Begni H. Bigas S. Brehm J. Briggs R. Bryce S. Buckmaster R. Chanda J. Davies E. Diez W. Essahli A. Evely N. Geeson I. Hartmann J. Holden K. Hubacek A. A. R. Ioris B. Kruger P. Laureano J. Phillipson C. Prell C. H. Quinn A. D. Reeves M. Seely R. Thomas M. J. van der Werff Ten Bosch P. Vergunst L. Wagner 《Land Degradation \u0026amp; Development》2013,24(4):307-322
It is increasingly recognised that land degradation monitoring and assessment can benefit from incorporating multiple sources of knowledge, using a variety of methods at different scales, including the perspectives of researchers, land managers and other stakeholders. However, the knowledge and methods required to achieve this are often dispersed across individuals and organisations at different levels and locations. Appropriate knowledge management mechanisms are therefore required to more efficiently harness these different sources of knowledge and facilitate their broader dissemination and application. This paper examines what knowledge is, how it is generated and explores how it may be stored, transferred and exchanged between knowledge producers and users before it is applied to monitor and assess land degradation at the local scale. It suggests that knowledge management can also benefit from the development of mechanisms that promote changes in understanding and efficient means of accessing and/or brokering knowledge. Broadly, these processes for knowledge management can (i) help identify and share good practices and build capacity for land degradation monitoring at different scales and in different contexts and (ii) create knowledge networks to share lessons learned and monitoring data among and between different stakeholders, scales and locations. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献