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   331篇
  免费   10篇
  国内免费   4篇
林业   15篇
农学   21篇
基础科学   6篇
  75篇
综合类   50篇
农作物   22篇
水产渔业   11篇
畜牧兽医   103篇
园艺   10篇
植物保护   32篇
  2023年   1篇
  2022年   4篇
  2021年   8篇
  2020年   10篇
  2019年   11篇
  2018年   7篇
  2017年   5篇
  2016年   13篇
  2015年   7篇
  2014年   7篇
  2013年   12篇
  2012年   16篇
  2011年   34篇
  2010年   16篇
  2009年   20篇
  2008年   16篇
  2007年   22篇
  2006年   20篇
  2005年   29篇
  2004年   12篇
  2003年   13篇
  2002年   18篇
  2001年   5篇
  1999年   4篇
  1998年   2篇
  1997年   2篇
  1996年   1篇
  1995年   1篇
  1994年   6篇
  1992年   2篇
  1991年   2篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1985年   1篇
  1984年   1篇
  1983年   3篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1975年   1篇
  1971年   2篇
  1966年   3篇
  1955年   1篇
  1863年   1篇
排序方式: 共有345条查询结果,搜索用时 139 毫秒
341.
Epidemiological studies have linked whole grain consumption to prevention of several chronic diseases. Whole grain is a source of important phytochemicals, such as ferulic acid (FA). FA is the most abundant phenolic and major contributor to the in vitro antioxidant capacity of wheat grain. Several studies have reported highly variable results on FA bioavailability (0.4–98%). The binding of FA to polysaccharides may limit its bioavailability. Therefore, our study aimed at monitoring release features of FA during gastrointestinal (GI) transit. This was termed bioaccessibility. The bioaccessibility of FA was studied from different wheat fractions and breads with the use of a dynamic in vitro system that simulates the upper GI transit and digestion. The results showed low bioaccessibility of FA from the wheat fractions and breads (<1%). However, the bioaccessibility was high when free FA was added to flour (∼60%). The bioaccessibility of FA appeared to be determined by the percentage of free FA. In wheat grain, most of FA is bound to arabinoxylans and other indigestible polysaccharides restricting its release in the small intestine. New processing developments should be considered to increase free FA in the cereal matrix in order to improve its bioavailability and systemic health effect.  相似文献   
342.
Satellite tracking was used to follow the movements of a problematic top-order carnivore, the wild dog (Canis lupus dingo, C. lupus familiaris and their hybrids), in contiguous forested landscapes in south-eastern mainland Australia. Home range sizes of wild dogs were much larger than previously determined using conventional telemetry methods, averaging 10,000 ha with a maximum size of 59,000 ha over approximate 3-month periods. Wild dogs at sites with high abundance of kangaroos, wallabies and rabbits had smaller areas of occupancy than did dogs at sites with low availability of these preys. Despite mostly large home ranges, tracked animals were loyal to publicly-owned tenure and there were few instances where individuals moved large distances on to adjacent private tenure. Instead, movement behaviours of most tracked animals were characterised by repeated short distance forays, often at acute angles from previous locations. Consequently, home ranges were stable and otherwise well defined. Analysis of DNA from our study animals indicated that most individuals were of ‘dingo’ ancestry, but otherwise considered hybrids because of the presence of domestic dog genes. Only two of 24 animals could be considered as ‘pure’ dingo. Contemporary wild dog management demarcates lands where control is or is not undertaken, with the latter notionally acting to ‘conserve’ dingoes. Due to the large scale of movement of animals, existing control efforts likely impact over a greater area than previously suspected. Furthermore, our genetic findings suggest that conservation of dingoes in south-eastern mainland Australia is difficult to achieve. A modified approach to wild dog management is needed, taking account of the extent of range of individual animals and the existing genetic characteristics of populations.  相似文献   
343.
In this work the effect on hair of two types of keratin samples obtained from wool, was investigated. Fiber surface changes were evaluated by contact angle measurements. The effectiveness of these keratin ingredients to restore the mechanical properties and the moisture content of the fibers was also determined. Modifications of hair properties due to some conventional chemical treatments were demonstrated with lower values of contact angle and detrimental effects on the mechanical properties. Application of keratin peptides and proteins to pretreated hair improved the fibers’ moisture content and their mechanical properties.  相似文献   
344.
345.
A wide variety of enzyme‐linked immunosorbent assays (ELISAs) are commercially available for gluten detection in food, including new formats and assays with antibodies against relevant gluten epitopes. Nevertheless, problems persist to accurately determine the gluten content of products. In this study, the performance of a set of 14 ELISA kits for gluten detection, representative of the current ELISA methods available on the market, was evaluated. These tests were used to determine gluten content in a series of relevant food matrices varying in complexity. Our results show that, currently, there is no single ELISA method that can accurately detect and quantify gluten in all different matrices. This includes the current type I method R5 as recommended by Codex Alimentarius. We conclude that further improvements are urgently needed and recommend focusing on competitive formats, improving extraction methods, and the detection of relevant gluten peptides (in order of priority).  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