全文获取类型
收费全文 | 459篇 |
免费 | 24篇 |
专业分类
林业 | 16篇 |
农学 | 18篇 |
82篇 | |
综合类 | 91篇 |
农作物 | 17篇 |
水产渔业 | 33篇 |
畜牧兽医 | 180篇 |
园艺 | 24篇 |
植物保护 | 22篇 |
出版年
2021年 | 7篇 |
2020年 | 6篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 10篇 |
2016年 | 5篇 |
2015年 | 14篇 |
2014年 | 12篇 |
2013年 | 30篇 |
2012年 | 24篇 |
2011年 | 23篇 |
2010年 | 15篇 |
2009年 | 14篇 |
2008年 | 38篇 |
2007年 | 35篇 |
2006年 | 30篇 |
2005年 | 40篇 |
2004年 | 24篇 |
2003年 | 32篇 |
2002年 | 28篇 |
2001年 | 4篇 |
2000年 | 7篇 |
1999年 | 4篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 9篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1986年 | 3篇 |
1984年 | 4篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1967年 | 1篇 |
1963年 | 1篇 |
1958年 | 1篇 |
1948年 | 1篇 |
1940年 | 1篇 |
排序方式: 共有483条查询结果,搜索用时 0 毫秒
481.
Nancy Tierranegra-García Patricia Salinas-Soto Irineo Torres-Pacheco Rosalia V. Ocampo-Velázquez Enrique Rico-García Sandra O. Mendoza-Diaz Ana A. Feregrino-Pérez Adán Mercado-Luna Marcela Vargas-Hernandez Genaro M. Soto-Zarazúa Ramón G. Guevara-González 《Phytoparasitica》2011,39(2):137-144
The effects were examined of plant-response signaling compounds, salicylic acid (SA) and methyl jasmonate (MeJA), on resistance to pill-bugs (Armadillidium vulgare) attack in lettuce plants. Foliar SA and MeJA applications were made at weekly intervals from the emergence of the plant until one week before harvesting. SA and MeJA induced detectable levels of hydrogen peroxide (H2O2) at least during 5 days post-application in these plants throughout their cultivation. On the whole, SA and MeJA in the concentrations and application scheme evaluated in this research did not significantly influence the dry and fresh weight matter of plants, or the chlorophyll and nitrate contents. In addition, both signal elicitors significantly diminished lettuce mortality due to pill-bugs, which was positively correlated with phenolics and flavonoids contents. Our results suggest that SA and MeJA, especially in low concentrations, should be further evaluated in lettuce production and priming resistance. 相似文献
482.
Diapause eggs of Centropages hamatus were used to investigate the effect of temperature and duration of incubation on egg hatching. Eggs were incubated for 10, 12, 14, 16, 20, 24, 28, 32, 36 and 40 h at 15°C and 14L–10D. After incubation for the designated period, eggs were transferred to 25°C and monitored periodically to determine egg hatching. Control eggs were incubated solely at 15°C and monitored for egg hatching. The greatest daily hatching success of eggs occurred within 1 or 2 days after transfer from 15°C to 25°C, while the controls required 3–4 days. The cumulative hatching success of eggs was significantly lower than the control, with the exception of eggs held for at least 36 h at 15°C before transfer to 25°C. These results indicate that overall time to hatching of diapause eggs of C. hamatus can be reduced by transferring the eggs to a higher temperature, for example, 25°C, following a minimum period of time (36 h) at reduced temperature, for example, 15°C. Exposure to 15°C for only 10 h does not appear to be sufficient to result in any subsequent hatching at higher temperature. 相似文献
483.