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   145篇
  免费   23篇
林业   3篇
农学   2篇
  16篇
综合类   21篇
农作物   5篇
水产渔业   35篇
畜牧兽医   75篇
园艺   1篇
植物保护   10篇
  2023年   1篇
  2022年   2篇
  2020年   7篇
  2019年   6篇
  2018年   9篇
  2017年   12篇
  2016年   8篇
  2015年   4篇
  2014年   4篇
  2013年   11篇
  2012年   7篇
  2011年   10篇
  2010年   3篇
  2009年   9篇
  2008年   10篇
  2007年   8篇
  2006年   14篇
  2005年   7篇
  2004年   6篇
  2003年   2篇
  2002年   5篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
  1998年   2篇
  1994年   1篇
  1992年   2篇
  1990年   1篇
  1986年   2篇
  1983年   1篇
  1979年   2篇
  1978年   1篇
  1974年   1篇
  1969年   1篇
  1945年   1篇
  1942年   1篇
  1931年   1篇
  1928年   1篇
  1921年   2篇
排序方式: 共有168条查询结果,搜索用时 31 毫秒
1.
2.
3.
Plant Foods for Human Nutrition - The effects of cocoa-derived polyphenols on cognitive functions have been analyzed through numerous studies using different interventions (doses, vehicles, time...  相似文献   
4.
Plant Foods for Human Nutrition - The evaluation of the level of alkaloids in edible Lupinus species is crucial from a food safety point of view. Debittering of lupin seeds has a long history;...  相似文献   
5.
6.
7.
8.
9.
The genetic relationship among individuals at one locus is characterized by nine coefficients of identity. The coefficients of inbreeding, coancestry and dominance (or fraternity) are just linear functions of them. Here, it is shown how they can be estimated using biallelic and triallelic markers using the method of moments, and comparisons are made with other methods based on molecular coancestry or molecular covariance. It is concluded that in the general case of dominance and inbreeding with biallelic markers, only the coefficients of inbreeding and coancestry can be estimated, but neither the single coefficients of identity nor the coefficient of dominance can be estimated. More than two alleles are required for a full estimation as illustrated with the triallelic situation.  相似文献   
10.
This work focuses on the development of dendrometric algorithms to calculate the volume and total biomass contained in olive trees. This laid the foundation for the use of this methodology as a tool to manage resources from orchards, establishing adequate prediction models for assessing other parameters such as income from raw materials from the cultivation, fruit production, CO2 sinks, and waste materials (residual wood) used for energy or industry. Dendrometry has traditionally been applied to forest trees. However, little research has been conducted on fruit trees because of their heterogeneous structure. This issue was the first step of this research. For this, the form factors were calculated. This relates to the actual volume of the branch with a model volume, calculated as a revolution solid from the base diameter and length. The shape more approximated to 1 was the cylinder model with a mean value of 0.76 and standard deviation (SD) of 0.23. On the other hand, volume equations were obtained for the branches. The distribution of biomass in the tree was analyzed. It is estimated that 40 % of biomass is located in the stem and 60 % in the crown, and most of the crown biomass is concentrated in the first branches (60 %). Afterwards, occupation factors were calculated to relate the wood volume in the crown to its apparent volume, the mean being 0.005 dm3/m3 and SD 0.0025 dm3/m3. Also, equations for predicting the whole wood in the crown were obtained. In this regard, the best results were obtained when the crown diameter was used (R 2 = 0.74). These results could be correlated with the production and quality of the fruit, amount of residual biomass coming from pruning, and LIDAR data, which may indicate a simple, quick, and accurate method for predicting biomass.  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