全文获取类型
| 收费全文 | 316篇 |
| 免费 | 13篇 |
专业分类
| 林业 | 79篇 |
| 农学 | 17篇 |
| 89篇 | |
| 综合类 | 20篇 |
| 农作物 | 20篇 |
| 水产渔业 | 17篇 |
| 畜牧兽医 | 69篇 |
| 园艺 | 5篇 |
| 植物保护 | 13篇 |
出版年
| 2023年 | 2篇 |
| 2021年 | 2篇 |
| 2020年 | 5篇 |
| 2019年 | 6篇 |
| 2018年 | 7篇 |
| 2017年 | 9篇 |
| 2016年 | 6篇 |
| 2015年 | 4篇 |
| 2014年 | 3篇 |
| 2013年 | 22篇 |
| 2012年 | 12篇 |
| 2011年 | 12篇 |
| 2010年 | 6篇 |
| 2009年 | 8篇 |
| 2008年 | 7篇 |
| 2007年 | 11篇 |
| 2006年 | 17篇 |
| 2005年 | 15篇 |
| 2004年 | 18篇 |
| 2003年 | 11篇 |
| 2002年 | 15篇 |
| 2001年 | 16篇 |
| 2000年 | 9篇 |
| 1999年 | 12篇 |
| 1998年 | 5篇 |
| 1997年 | 5篇 |
| 1996年 | 5篇 |
| 1995年 | 4篇 |
| 1994年 | 6篇 |
| 1993年 | 5篇 |
| 1992年 | 5篇 |
| 1991年 | 4篇 |
| 1990年 | 2篇 |
| 1989年 | 4篇 |
| 1988年 | 3篇 |
| 1987年 | 4篇 |
| 1986年 | 4篇 |
| 1985年 | 9篇 |
| 1981年 | 2篇 |
| 1978年 | 2篇 |
| 1977年 | 2篇 |
| 1974年 | 2篇 |
| 1973年 | 2篇 |
| 1972年 | 3篇 |
| 1971年 | 5篇 |
| 1970年 | 1篇 |
| 1969年 | 2篇 |
| 1968年 | 1篇 |
| 1966年 | 1篇 |
| 1965年 | 2篇 |
排序方式： 共有329条查询结果，搜索用时 234 毫秒
1.
2.
3.
4.
5.
Herrera MR Machocho AK Nair JJ Campbell WE Brun R Viladomat F Codina C Bastida J 《Fitoterapia》2001,72(4):444-448
The alcoholic extract of the fresh bulbs of Cyrtanthus elatus yielded zephyranthine (1) and 1,2-O-diacetylzephyranthine (2), together with three other known alkaloids. Complete assignment of 1H and 13C NMR spectra of compounds 1 and 2 was done by employment of two-dimensional NMR techniques. 相似文献
6.
7.
Agroforestry Systems - Nutrient buildup in the soil caused by increased animal manure and fertilizer use in agricultural and forestry practices may increase the potential for their loss from the... 相似文献
8.
9.
10.
The Forest village scheme was introduced by the Forest Industries Organisation (FIO) of Thailand in 1967 as an attempt to stop further spread of the fast increasing shifting cultivation and deforestation in the country. The underlying princple of the scheme is to relate reforestation with social welfare of the people involved. It is essentially a modification of the traditional taungya method of plantation establishment.The salient aspect of the scheme is to induce the shifting cultivators to settle down in villages where each family is given tenure over a plot of land to construct a house and develop a homegarden around it. The farmers are required to help establish and maintain forest plantations, in which they are permitted to raise agricultural crops during the first three years of its establishment. The farmers are also given free medical and educational facilities, and technical advice on crop and livestock husbandry. They can also earn cash rewards for successful plantation establishment.Although the scheme has not achieved its full target in terms of area covered and number of families settled, it is proving to be a successful method of luring people away from destructive shifting cultivation. The approach is applicable to other countries and regions with similar land-use problems and socio-cultural background.The paper also examines the constraints to the effective working of the scheme, provides some simple suggestions for improving its functioning and identies some of the issues that can easily be tackled by research. 相似文献