全文获取类型
收费全文 | 257篇 |
免费 | 15篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 6篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 18篇 |
2013年 | 12篇 |
2012年 | 21篇 |
2011年 | 19篇 |
2010年 | 9篇 |
2009年 | 11篇 |
2008年 | 26篇 |
2007年 | 23篇 |
2006年 | 19篇 |
2005年 | 21篇 |
2004年 | 12篇 |
2003年 | 5篇 |
2002年 | 16篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 7篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有272条查询结果,搜索用时 15 毫秒
271.
M. Sujatha M. Lakshminarayana M. Tarakeswari P. K. Singh Rakesh Tuli 《Plant cell reports》2009,28(6):935-946
Castor (cv. DCS-9) has been transformed through Agrobacterium-mediated and particle gun bombardment methods using appropriate vectors containing the Bt chimeric gene cry1EC driven by enhanced 35S promoter. About 81 and 12 putative transformants were regenerated following selection on hygromycin
and kanamycin, respectively. Southern analysis of DNA extracted from T0 plants confirmed integration of the introduced gene in castor genome. The integration and inheritance of the introduced genes
was demonstrated up to T4 generation by PCR and Southern analysis. Southern analysis of two events having single and two copies showed the same pattern
of integration in the subsequent generations. Insect feeding experiments conducted in the laboratory by releasing neonate
larvae of castor semilooper and S. litura on leaf tissues excised from transgenic and control plants showed varying degrees of larval mortality and slow growth in
larvae fed on transgenic leaf tissue. Field bioassays against Spodoptera litura and castor semilooper conducted for eight events in T1–T4 generations under net confinement were more informative and events conferring resistance to the two major defoliators were
identified. 相似文献
272.
Natural hazards like landslides, earthquakes, and floods are a major deterrent to the development of mountain regions of the world. Recently, there has been a rise in the number of landslides in Western Ghats, India. Several factors cause landslides and they depend on the local geo-environmental set-up of the region. This study attempts to map the spatial distribution of landslide hazard and analyze the risk for a typical hill town, Kodaikkanal in the Western Ghats, India, facing rapid urbanization and infra-structure growth, using a weighted linear combination model in a geographic information system platform. Landslides in the region are triggered by rainfall and it is fairly uniform throughout the area. Hence, the susceptibility map is used as the hazard map. Validation of the weighted linear combination model using landslide hazard index shows that landslide density increases with the hazard class. The risk assessment matrix (RAM) is used to evaluate risk based on the land use and landslide hazard category. The land use map is reclassified by assigning damage potential for each land use feature. The risk map is classified into low, moderate, and high risk categories. Suitable control measures are suggested for various risk categories. 相似文献