全文获取类型
收费全文 | 93篇 |
免费 | 9篇 |
专业分类
林业 | 1篇 |
农学 | 1篇 |
3篇 | |
综合类 | 5篇 |
农作物 | 2篇 |
畜牧兽医 | 87篇 |
植物保护 | 3篇 |
出版年
2023年 | 1篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2018年 | 1篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 14篇 |
2012年 | 7篇 |
2011年 | 7篇 |
2010年 | 4篇 |
2009年 | 6篇 |
2008年 | 4篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 7篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1968年 | 1篇 |
排序方式: 共有102条查询结果,搜索用时 359 毫秒
31.
Cox-Foster DL Conlan S Holmes EC Palacios G Evans JD Moran NA Quan PL Briese T Hornig M Geiser DM Martinson V vanEngelsdorp D Kalkstein AL Drysdale A Hui J Zhai J Cui L Hutchison SK Simons JF Egholm M Pettis JS Lipkin WI 《Science (New York, N.Y.)》2007,318(5848):283-287
In colony collapse disorder (CCD), honey bee colonies inexplicably lose their workers. CCD has resulted in a loss of 50 to 90% of colonies in beekeeping operations across the United States. The observation that irradiated combs from affected colonies can be repopulated with naive bees suggests that infection may contribute to CCD. We used an unbiased metagenomic approach to survey microflora in CCD hives, normal hives, and imported royal jelly. Candidate pathogens were screened for significance of association with CCD by the examination of samples collected from several sites over a period of 3 years. One organism, Israeli acute paralysis virus of bees, was strongly correlated with CCD. 相似文献
32.
33.
34.
KL WARD 《Australian veterinary journal》1997,75(8):558-560
Various seed diets containing chlortetracycline were fed to large and small parrots to evaluate serum chlortetracycline concentrations. The substitution of dehulled sunflower seed for whole sunflower in the seed mix may have resulted in higher chlortetracycline concentrations in cockatoos and parrots. The serum chlortetracycline concentration achieved for all diets was less than the goal of 1 μg/mL, but the concentrations attained may be useful for therapy. 相似文献
35.
36.
37.
38.
39.
SUMMARY The effects of induced parturition on calf mortality rates were studied in 24 winter-calving, pasture-fed, dairy herds in south-western Victoria. Parturition was induced when most cows were between 27 and 35 weeks of pregnancy. Control groups were selected from cows in the same herds in which calving was not induced. The incidence of mortality within 7 days of birth was much higher among calves from cows in induced groups relative to those in control groups (estimated median herd mortality incidence 72% and 7%, respectively). The incidence of calf mortality was high among groups induced at all stages of pregnancy that were investigated. However, differences in calf mortality incidence, relative to controls, were increased among groups induced at earlier stages of pregnancy. 相似文献
40.