首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   127448篇
  免费   6381篇
  国内免费   58篇
林业   5134篇
农学   3668篇
基础科学   856篇
  15379篇
综合类   23510篇
农作物   5047篇
水产渔业   5486篇
畜牧兽医   65866篇
园艺   1448篇
植物保护   7493篇
  2018年   1654篇
  2017年   1828篇
  2016年   1714篇
  2015年   1362篇
  2014年   1683篇
  2013年   4975篇
  2012年   3204篇
  2011年   3999篇
  2010年   2706篇
  2009年   2656篇
  2008年   4005篇
  2007年   3742篇
  2006年   3455篇
  2005年   3150篇
  2004年   3269篇
  2003年   3171篇
  2002年   3057篇
  2001年   3804篇
  2000年   3819篇
  1999年   2834篇
  1998年   1251篇
  1995年   1438篇
  1994年   1329篇
  1993年   1273篇
  1992年   2625篇
  1991年   2804篇
  1990年   2735篇
  1989年   2796篇
  1988年   2508篇
  1987年   2609篇
  1986年   2732篇
  1985年   2631篇
  1984年   2152篇
  1983年   1993篇
  1982年   1312篇
  1981年   1274篇
  1979年   2138篇
  1978年   1679篇
  1977年   1422篇
  1976年   1478篇
  1975年   1540篇
  1974年   1921篇
  1973年   1962篇
  1972年   1881篇
  1971年   1743篇
  1970年   1665篇
  1969年   1587篇
  1968年   1358篇
  1967年   1444篇
  1966年   1341篇
排序方式: 共有10000条查询结果,搜索用时 812 毫秒
991.
992.
993.
994.
995.
996.
997.
Cotts RM 《Science (New York, N.Y.)》1993,261(5124):1063-1064
  相似文献   
998.
999.
1. To improve the influence of variation of ME intake, an experiment was carried out using equalised feeding to investigate the comparative effects on protein and energy utilisation in chicks of diets containing medium chain triglyceride (MCT) and long chain triglyceride (LCT). Experimental diets were given at 3 different food intakes, namely, 100, 120 or 147 g/bird/10 d. The diets contained MCT or LCT on an isoenergetic basis. Maize oil and caprylic acid triglyceride respectively, were used as LCT and MCT sources.

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   

1000.
1. The effect of dietary medium chain triglyceride (MCT) on short‐term food intake was compared with the effect of long chain triglyceride (LCT) in chickens. Maize oil was used as the LCT while glyceryl tricaprylate (C 8) and glyceryl tricaprate (C 10) were used as MCT. Cumulative food intake was determined during the 6 h after the start of feeding.

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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号