收费全文 | 133718篇 |
免费 | 7209篇 |
国内免费 | 331篇 |
林业 | 5524篇 |
农学 | 4069篇 |
基础科学 | 965篇 |
16077篇 | |
综合类 | 24954篇 |
农作物 | 5393篇 |
水产渔业 | 6023篇 |
畜牧兽医 | 68500篇 |
园艺 | 1568篇 |
植物保护 | 8185篇 |
2018年 | 1807篇 |
2017年 | 1967篇 |
2016年 | 1855篇 |
2015年 | 1580篇 |
2014年 | 1874篇 |
2013年 | 5299篇 |
2012年 | 3524篇 |
2011年 | 4267篇 |
2010年 | 2876篇 |
2009年 | 2883篇 |
2008年 | 4286篇 |
2007年 | 3936篇 |
2006年 | 3738篇 |
2005年 | 3410篇 |
2004年 | 3460篇 |
2003年 | 3399篇 |
2002年 | 3269篇 |
2001年 | 4130篇 |
2000年 | 4122篇 |
1999年 | 3087篇 |
1998年 | 1371篇 |
1997年 | 1377篇 |
1995年 | 1524篇 |
1994年 | 1419篇 |
1993年 | 1326篇 |
1992年 | 2840篇 |
1991年 | 3063篇 |
1990年 | 2946篇 |
1989年 | 2977篇 |
1988年 | 2746篇 |
1987年 | 2778篇 |
1986年 | 2933篇 |
1985年 | 2804篇 |
1984年 | 2240篇 |
1983年 | 2049篇 |
1982年 | 1354篇 |
1981年 | 1360篇 |
1979年 | 2183篇 |
1978年 | 1763篇 |
1977年 | 1430篇 |
1976年 | 1426篇 |
1975年 | 1472篇 |
1974年 | 1886篇 |
1973年 | 1993篇 |
1972年 | 1905篇 |
1971年 | 1766篇 |
1970年 | 1686篇 |
1969年 | 1570篇 |
1968年 | 1293篇 |
1967年 | 1370篇 |
2. Body weight gain and food efficiency of chicks significantly increased with the supplement of dietary MCT compared with dietary LCT at all food intakes. Protein retention and the efficiency of protein utilisation (protein retained/protein intake) at all food intakes also significantly increased with dietary MCT, while body fat and fat retention were significantly reduced. Chicks fed the LCT‐supple‐mented diet, on the other hand, had a lower protein retention, but significantly higher fat retention. The value for energy retention and the efficiency of energy utilisation (energy retained/ME intake) were not significantly different between MCT‐ and LCT‐supplemented diets.
3. It was concluded that supplementing MCT to the chick diet would improve body weight gain and protein utilisation while regulating fat deposition compared to the LCT supplemented diet, under equalised feeding conditions. 相似文献
2. Chicks were given diets containing 200 g C 8/kg diet, 200 g C 10/kg diet or 200 g LCT/kg diet in experiment 1. As early as 30 min after feeding, cumulative food intake in both MCT‐supplemented diets decreased significantly compared with the diet containing LCT.
3. To determine if endogenous cholecystokinin (CCK) was responsible for the decrease in food intake caused by MCT, birds were injected with the CCK‐A receptor antagonist devazepide (DVZ, 1 mg/kg BW) before diet presentation. DVZ had no effect on food intake with either LCT‐ or MCT‐supplemented diets.
4. In experiment 3, chicks were given a choice between either diets containing LCT and C 8, LCT and C 10, or C 8 and C 10 to confirm whether or not the palatability of the diets was influenced by the dietary fat sources. There was no difference in food intake between C 8 and C 10‐supplemented diets. However, chicks preferred the LCT‐supplemented diet compared with either of the diets containing MCT. 相似文献