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   396篇
  免费   12篇
林业   46篇
农学   14篇
基础科学   2篇
  67篇
综合类   45篇
农作物   36篇
水产渔业   13篇
畜牧兽医   164篇
园艺   6篇
植物保护   15篇
  2023年   4篇
  2020年   4篇
  2019年   9篇
  2018年   5篇
  2017年   3篇
  2016年   11篇
  2015年   5篇
  2014年   3篇
  2013年   9篇
  2012年   9篇
  2011年   26篇
  2010年   11篇
  2009年   13篇
  2008年   21篇
  2007年   17篇
  2006年   18篇
  2005年   11篇
  2004年   16篇
  2003年   36篇
  2002年   13篇
  2001年   10篇
  2000年   7篇
  1999年   8篇
  1997年   4篇
  1996年   4篇
  1995年   4篇
  1993年   3篇
  1991年   4篇
  1987年   3篇
  1986年   3篇
  1985年   5篇
  1983年   3篇
  1980年   3篇
  1979年   4篇
  1977年   3篇
  1974年   4篇
  1972年   4篇
  1971年   3篇
  1970年   3篇
  1968年   4篇
  1967年   5篇
  1966年   5篇
  1965年   3篇
  1955年   5篇
  1943年   2篇
  1942年   3篇
  1940年   2篇
  1936年   2篇
  1930年   2篇
  1927年   2篇
排序方式: 共有408条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
1. Sudden Death Syndrome (SDS) is a disease of well‐developed, predominandy male broiler chickens where death appears to occur because of cardiovascular failure. The role of skeletal muscle sarcoplasmic calcium regulation as a potential cause of SDS has been investigated.

2. Calcium regulation of skeletal muscle sarcoplasmic reticulum was compared between broiler and Leghorn chickens. Calcium regulation matured from the 2nd to the 11 th week and, at any age, broiler chickens showed significandy lower calcium transport rates and transport efficiencies. The mechanism of calcium transport in broiler chickens was more energy‐consuming than that of the Leghorn chickens.

3. Sarcoplasmic calcium regulation is pivotal for muscle metabolism. As in porcine malignant hyperthermia, weaker calcium regulation might lead to hyperactivation of skeletal muscle, followed by elevated lactic acid concentrations and cardiovascular failure.  相似文献   

8.
Xanthomonas fragariae spreads in symptomlessly infected strawberry plantlets and a method for detection of latent infections is necessary. It is a very slow‐growing bacterium in culture and is easily overgrown by saprophytic bacteria. Therefore, plating is not a suitable method for detecting low numbers of bacteria in symptomless plants. In addition, selective media are not available. Serological assays like immunofluorescence are useful for testing in‐vitro plants, but they are not suitable for field‐grown plants, as cross reactions are common with the available antisera. For these plants, nested PCR with primers from Pooler ( Pooler et al., 1996 ) and Zimmermann ( Zimmermann et al., 2004 ) has proved to be a valuable method. The method was successfully applied for a survey of strawberry plants from fields in Germany and for testing imported plants (frigo and green plants).  相似文献   
9.
The use of Trichogramma egg parasitoids has further increased. T. brassicae, released against the European Corn Borer Ostrinia nubilalis, holds the largest share in Germany with 11,000 hectare. For small-scale fruits crops the commercial use of T. cacoeciae and T. dendrolimi against the Codling Moth (Cydia pomonella) and the Plum Moth (Grapholita funebrana) has been expanded. Trichogramma species are also being offered for controlling the vine moths, Lobesia botrana and Eupoecilia ambiguella on grapevine in homegardens. A strain of T. evanescens is available against cabbage pests, especially noctuids. Research has been conducted on the biological control of Autographa gamma in spinach, as well as of the Pea Moth (Cydia nigricana) and the Leek Moth (Acrolepiopsis assectella) in organic farming. Trichogramma is also important for the biocontrol of exotic pests in greenhouses. These are often polyphagous pests that have been introduced together with ornamental plants, such as Duponchelia fovealis and Clepsis spectrana. The Carnation Tortrix (Cacoecimorpha pronuba) was successfully controlled by Trichogramma in the field. The use of Trichogramma has been further established for the control of storage pests. T. evanescens is used against the Indian Meal moth (Plodia interpunctella) in stored cereal products. Other target pests in storage environments are Ephestia kuehniella and Sitotroga cerealella. In addition, Trichogramma species have been tested for the control of the Common Cloths Moth (Tineola bisselliella) under laboratory conditions. The range of target pests for Trichogramma egg parasitoids has therefore increased considerably in research and commercial applications in Germany.  相似文献   
10.
Rice culture of a toxigenic strain of Aspergillus ochraceus was fed at a concentration of 25% to weanling pigs for 10 days. The clinicopathological abnormalities reflected renal damage. Activities of lactic dehydrogenase, glutamic-oxaloacetic transaminase and isocitrate dehydrogenase were increased in the urine but not in the serum. Serum concentrations of urea nitrogen and creatinine were high. Cellular and granular casts, blood, protein, and glucose were in the urine of pigs fed toxic diet. Serum concentrations of K+, Na+ and Cl- were unchanged, but concentrations of these electrolytes were reduced in the urine.  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