全文获取类型
收费全文 | 141篇 |
免费 | 24篇 |
专业分类
农学 | 2篇 |
15篇 | |
综合类 | 8篇 |
农作物 | 2篇 |
畜牧兽医 | 129篇 |
园艺 | 1篇 |
植物保护 | 8篇 |
出版年
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 1篇 |
2018年 | 10篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 11篇 |
2012年 | 1篇 |
2011年 | 4篇 |
2010年 | 6篇 |
2009年 | 4篇 |
2008年 | 4篇 |
2007年 | 7篇 |
2006年 | 6篇 |
2005年 | 4篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 7篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 8篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1992年 | 2篇 |
1990年 | 3篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1969年 | 5篇 |
1968年 | 4篇 |
1967年 | 5篇 |
1966年 | 3篇 |
排序方式: 共有165条查询结果,搜索用时 0 毫秒
161.
162.
163.
164.
Evans SJ Davies RH Binns SH Liebana E Jones TW Millar MF Threlfall EJ Ward LR Hopkins KL Mackay PH Gayford PJ 《The Veterinary record》2005,156(11):343-346
An epidemiological investigation of a calf rearing premises and a closely associated dairy herd was carried out after the isolation of Salmonella enterica serovar Paratyphi B variant Java phage type 3b variant 2 from clinically diseased calves on the premises. The isolate was resistant to ampicillin, chloramphenicol, streptomycin, sulphonamides, tetracyclines, trimethoprim and cefoperazone. The organism was widespread on the calf unit and was also recovered from the dairy premises, mainly from groups of weaned calves. The investigation was extended to 10 epidemiologically linked farms but no S Java was isolated from any of the 40 to 60 samples collected from each premises. Molecular studies showed that the S Java isolates were genetically most similar to isolates from cases of human disease associated with ornamental fish tanks or feed. Long PCR and resistance gene profiling identified a resistance island which was indistinguishable from the human 'fish tank' strain of S Java and animal and human epidemic strains of S Typhimurium DT104. The isolates were clearly distinguished from multi-resistant S Java strains commonly associated with continental poultry. This is the first report of S Java with this resistance pattern in Great Britain. 相似文献
165.
J. A. Binns R. A. Maconachie A. I. Tanko 《Land Degradation \u0026amp; Development》2003,14(5):431-444
In sub‐Saharan Africa, urban and peri‐urban food production has been identified as an important resource for meeting the challenges of rapidly growing cities, and the positive aspects of such production have been well documented in the literature. This paper examines some of the health and environmental concerns associated with urban and peri‐urban agriculture (UPA). Empirical evidence from the city of Kano in northern Nigeria suggests that there is currently much reason for concern as industrial and domestic toxins are reaching dangerously high levels. As soils and water channels become increasingly polluted, the sustainability of urban and peri‐urban food production is questioned. Since the health implications of long‐term exposure to toxins are unclear, it is suggested that coordinated longitudinal research involving urban planners, agricultural scientists and health specialists is urgently needed. In addition, it remains crucial that government and institutional actors effectively monitor and enforce both environmental and zoning by‐laws, if the health and environmental constraints of UPA are to be overcome, and the future sustainability of production is to be assured. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献