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   238篇
  免费   13篇
林业   9篇
  9篇
综合类   18篇
农作物   5篇
水产渔业   13篇
畜牧兽医   187篇
园艺   7篇
植物保护   3篇
  2024年   5篇
  2023年   3篇
  2022年   7篇
  2021年   11篇
  2020年   7篇
  2019年   13篇
  2018年   7篇
  2017年   11篇
  2016年   3篇
  2015年   7篇
  2014年   8篇
  2013年   8篇
  2012年   29篇
  2011年   28篇
  2010年   11篇
  2009年   9篇
  2008年   8篇
  2007年   22篇
  2006年   21篇
  2005年   6篇
  2004年   4篇
  2003年   6篇
  2002年   9篇
  1999年   1篇
  1997年   2篇
  1992年   1篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1986年   1篇
排序方式: 共有251条查询结果,搜索用时 8 毫秒
11.
12.
Recall shines spotlight on pet foods   总被引:16,自引:0,他引:16  
  相似文献   
13.
14.
The impact of the mutation causing dynamin 1 (DNM1)-associated exercise-induced collapse (d-EIC) was determined in a retrospective genetic survey. The frequency of DNM1 mutant allele carriers in Labrador retrievers from conformation show, field trial/hunt test, pet or service lines ranged from 17.9% to 38.0% and the frequency of homozygous mutant (EE genotype) individuals ranged from 1.8% to 13.6%; 83.6% of these EE Labradors were reported to have collapsed by 4 years of age. DNM1 mutation carriers and EE dogs with a collapse phenotype were also detected in Chesapeake Bay retrievers, Curly-coated retrievers, Boykin spaniels, Pembroke Welsh corgis and mixed breed dogs thought to be Labrador retriever crosses. The DNM1 mutation was not identified in Golden, Flat-coated, or Nova Scotia duck tolling retrievers, or 15 other non-retrieving breeds. Veterinarians and breeders should be aware that the DNM1 EE genotype is not completely penetrant and that d-EIC is a widespread health concern in several very popular breeds, as well as breeds whose genetic similarity to retrievers is not obvious.  相似文献   
15.
16.
17.
18.
Insufficient iron (Fe) is one of the most prevalent micronutrient deficiencies in humans, with billions of people affected. Cereal grains are an important source of Fe for humans but the bioavailability of Fe in cereals is generally low. Information regarding the cellular and sub-cellular localisation of Fe in wheat grain will aid optimising nutrient delivery for human health. In this study high resolution secondary ion mass spectrometry (NanoSIMS) was used to map the distribution of Fe in the aleurone layer and in the endosperm of immature wheat grain. Iron was shown to be localised strongly in the phytin globoids in the aleurone cells and to a lesser extent in the cytoplasm around the starch granules in the endosperm.  相似文献   
19.
Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp(2)-bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.  相似文献   
20.
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