收费全文 | 1818篇 |
免费 | 67篇 |
国内免费 | 97篇 |
林业 | 187篇 |
农学 | 272篇 |
基础科学 | 57篇 |
391篇 | |
综合类 | 362篇 |
农作物 | 118篇 |
水产渔业 | 54篇 |
畜牧兽医 | 369篇 |
园艺 | 61篇 |
植物保护 | 111篇 |
2023年 | 11篇 |
2022年 | 54篇 |
2021年 | 46篇 |
2020年 | 44篇 |
2019年 | 33篇 |
2018年 | 29篇 |
2017年 | 49篇 |
2016年 | 40篇 |
2015年 | 47篇 |
2014年 | 39篇 |
2013年 | 103篇 |
2012年 | 85篇 |
2011年 | 93篇 |
2010年 | 80篇 |
2009年 | 72篇 |
2008年 | 91篇 |
2007年 | 91篇 |
2006年 | 83篇 |
2005年 | 83篇 |
2004年 | 36篇 |
2003年 | 38篇 |
2002年 | 43篇 |
2001年 | 46篇 |
2000年 | 42篇 |
1999年 | 46篇 |
1998年 | 32篇 |
1997年 | 46篇 |
1996年 | 37篇 |
1995年 | 23篇 |
1994年 | 20篇 |
1993年 | 21篇 |
1992年 | 23篇 |
1991年 | 25篇 |
1990年 | 24篇 |
1989年 | 16篇 |
1988年 | 19篇 |
1987年 | 18篇 |
1985年 | 13篇 |
1983年 | 12篇 |
1979年 | 24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 |
2. Triticale 72‐S appeared to be superior to triticale 131 as a direct replacement for maize, but both grains were inferior to maize as energy sources. 相似文献
2. In one experiment, 0, 50, 100 or 200 g rabbit excreta/kg were substituted for maize in a broiler diet. Chickens receiving the diet containing 200 g rabbit excreta/kg gained significantly less weight to 8 weeks of age than those receiving other diets.
3. In a second experiment, 0, 100, 150 or 200 g rabbit excreta/kg were substituted primarily for maize in a broiler diet to provide equal energy and protein contents. Weight gains to 8 weeks of birds receiving these diets did not differ significantly. The uncorrected metabolisable energy content of the excreta was 9.15 MJ/kg.
4. There were no gross pathological changes in the birds fed on the experimental diets. 相似文献
2. Increasing proportions (0, 25, 50 or 75%) of the maize of a diet were replaced by triticale 131 to provide diets of equal energy and nitrogen contents for broilers. These diets resulted in weight gains of 1.775, 1.782, 1.713 and 1.808 kg respectively at 8 weeks and there were no significant differences among efficiencies of food conversions.
3. Dressed carcass weights as percentages of body weight were 74.38, 75.01, 73.98 and 74.50 respectively and did not differ significantly.
4. Triticale in the diet did not seem to influence the relative weights of either liver or gizzard.
5. The flavour of the meat seemed to become less acceptable as the triticale in the diet increased but there were no significant differences in tenderness and juiciness of the meat caused by the treatments. 相似文献