全文获取类型
收费全文 | 1501篇 |
免费 | 54篇 |
国内免费 | 75篇 |
专业分类
林业 | 140篇 |
农学 | 231篇 |
基础科学 | 51篇 |
346篇 | |
综合类 | 251篇 |
农作物 | 88篇 |
水产渔业 | 49篇 |
畜牧兽医 | 348篇 |
园艺 | 41篇 |
植物保护 | 85篇 |
出版年
2022年 | 38篇 |
2021年 | 38篇 |
2020年 | 31篇 |
2019年 | 21篇 |
2018年 | 18篇 |
2017年 | 31篇 |
2016年 | 33篇 |
2015年 | 35篇 |
2014年 | 24篇 |
2013年 | 92篇 |
2012年 | 69篇 |
2011年 | 74篇 |
2010年 | 68篇 |
2009年 | 58篇 |
2008年 | 72篇 |
2007年 | 65篇 |
2006年 | 70篇 |
2005年 | 69篇 |
2004年 | 26篇 |
2003年 | 34篇 |
2002年 | 36篇 |
2001年 | 40篇 |
2000年 | 38篇 |
1999年 | 42篇 |
1998年 | 28篇 |
1997年 | 39篇 |
1996年 | 31篇 |
1995年 | 17篇 |
1994年 | 17篇 |
1993年 | 13篇 |
1992年 | 16篇 |
1991年 | 18篇 |
1990年 | 21篇 |
1989年 | 15篇 |
1988年 | 18篇 |
1987年 | 18篇 |
1985年 | 13篇 |
1983年 | 12篇 |
1979年 | 23篇 |
1978年 | 8篇 |
1977年 | 9篇 |
1976年 | 11篇 |
1975年 | 8篇 |
1971年 | 21篇 |
1970年 | 14篇 |
1969年 | 14篇 |
1968年 | 8篇 |
1967年 | 20篇 |
1966年 | 21篇 |
1965年 | 10篇 |
排序方式: 共有1630条查询结果,搜索用时 875 毫秒
171.
1. Addition of sunflower oil (SFO) at 30 or 60 g/kg or three vegetable oils, namely SFO, soybean (SBO) or groundnut (GNO), at 30 g/kg to isocaloric and isonitrogenous broiler chicken diets were evaluated for possible counteractive effects against aflatoxin (AF) (0.3 microg B1/g diet) from 0 to 42 d of age. 2. Body weight, food intake and serum concentration of protein were lower in the AF group than in the control, whereas in the SFO and SBO supplemented groups they were comparable with those of the control. Sunflower oil at both concentrations exerted similar effects on growth. Groundnut oil did not improve growth or food intake in AF-fed birds. 3. The serum concentration of cholesterol and triglycerides decreased with AF feeding and was increased by supplementation of any of the three oils both in the control and in AF-fed groups. 4. Liver and giblet weight and liver fat content were increased by AF; these effects were countered by dietary oil inclusion, except for liver weight at 60 g/kg SFO. Weights of pancreas and gall bladder were increased by AF. Oil supplementation reduced the weight of pancreas in chickens given AF. 5. Humoral immune response was depressed by AF and dietary oil supplementation (particularly SFO or SBO) countered this effect. Other variables, namely, serum gamma glutamyl transferase activity, bone mineralisation, weights of lymphoid organs, kidney and adrenals, ready-to-cook yields and fat content in muscle and skin showed little or no effect of dietary oil supplementation. 6. It is concluded that dietary inclusion of SFO or SBO at 30 g/kg may alleviate the adverse effects of 0.3 microg/g of AF B1 in commercial broiler chickens. Groundnut oil, although showing beneficial effects on some biochemical variables, failed to improve growth performance. 相似文献
172.
Campylobacter 总被引:5,自引:0,他引:5
Moore JE Corcoran D Dooley JS Fanning S Lucey B Matsuda M McDowell DA Mégraud F Millar BC O'Mahony R O'Riordan L O'Rourke M Rao JR Rooney PJ Sails A Whyte P 《Veterinary research》2005,36(3):351-382
Species within the genus, Campylobacter, have emerged over the last three decades as significant clinical pathogens, particularly of human public health concern, where the majority of acute bacterial enteritis in the Western world is due to these organisms. Of particular concern are the species, C. jejuni and C. coli, which are responsible for most of these gastrointestinal-related infections. Although these organisms have already emerged as causative agents of zoonoses, several aspects of their epidemiology and pathophysiology are only beginning to emerge. Trends in increasing antibiotic resistance are beginning to emerge with oral antibiotics, which may be the drug of choice for when it is necessary to intervene chemotherapeutically. This review wishes to examine (i) emerging clinical aspects of the disease, such as Guillain Barre syndrome (GBS), (ii) the association between these organisms and poultry as a natural host, (iii) environmental aspects of Campylobacter epidemiology, (iv) the emergence of atypical campylobacters (v) emerging trends in antibiotic resistance, (vi) adoption of modern methods for the detection of campylobacters. 相似文献
173.
174.
175.
176.
Local application of actinomycin D does not detectably modify growth response of the chick comb to androgens. The mode of action of androgens on chick comb (a connective-tissue organ) appears to differ from their action on epithelial-tissue organs such as seminal vesicles and prostate. 相似文献
177.
178.
179.
180.