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   725篇
  免费   27篇
  国内免费   2篇
林业   49篇
农学   56篇
  208篇
综合类   49篇
农作物   96篇
水产渔业   25篇
畜牧兽医   212篇
园艺   11篇
植物保护   48篇
  2023年   3篇
  2022年   2篇
  2021年   14篇
  2020年   13篇
  2019年   17篇
  2018年   21篇
  2017年   16篇
  2016年   15篇
  2015年   23篇
  2014年   29篇
  2013年   35篇
  2012年   54篇
  2011年   50篇
  2010年   26篇
  2009年   28篇
  2008年   52篇
  2007年   49篇
  2006年   39篇
  2005年   31篇
  2004年   24篇
  2003年   29篇
  2002年   32篇
  2001年   26篇
  2000年   17篇
  1999年   17篇
  1998年   6篇
  1997年   8篇
  1996年   3篇
  1993年   3篇
  1992年   6篇
  1991年   8篇
  1990年   7篇
  1989年   6篇
  1988年   2篇
  1987年   5篇
  1986年   4篇
  1985年   3篇
  1983年   2篇
  1980年   2篇
  1977年   1篇
  1974年   3篇
  1973年   1篇
  1972年   1篇
  1971年   1篇
  1970年   4篇
  1969年   2篇
  1968年   1篇
  1965年   2篇
  1964年   2篇
  1963年   3篇
排序方式: 共有754条查询结果,搜索用时 265 毫秒
751.
Magnaporthe grisea is a fungal pathogen of rice that forms appressoria that penetrate the outer cuticle of the rice plant. Data from recent studies indicate that M. grisea isocitrate lyase (ICL), a key enzyme in the glyoxylate cycle, is highly expressed during appressorium-mediated plant infection. Bromophenols isolated from the red alga Odonthalia corymbifera exhibited potent ICL inhibitory activity and blocked appressoria formation by M. grisea in a concentration-dependent manner. In addition, these compounds protected the rice plants from infection by M. grisea. Rice plants infected with wild-type M. grisea Guy 11 exhibited significantly lower disease severity with bromophenol treatment than without, and the treatment effect was comparable to the behavior of the Deltaicl knockout mutant I-10. The protective effect of bromophenols and their strong inhibition of appressorium formation on rice plants suggest that ICL inhibitors may be promising candidates for crop protection, particularly to protect rice plants against M. grisea.  相似文献   
752.
Acupuncture analgesia is an important issue in veterinary medicine. This study was designed to elucidate central modulation effects in response to electroacupuncture (EA) at different acupoints. Manganese-enhanced functional magnetic resonance imaging was performed in Sprague-Dawley rats after sham acupuncture, sham EA, or true EA at somatic acupoints. The acupoints were divided into 3 groups: group 1, analgesic acupoints commonly used for pain relief, such as Hegu (LI 4); group 2, nonanalgesic acupoints rarely used for analgesic effect, such as Neiguan (PC 6); and group 3, acupoints occasionally used for analgesia, such as Zusanli (ST 36). Image acquisition was performed on a 1.5-T superconductive clinical scanner with a circular polarized extremity coil. The results showed that there was no neural activation caused by EA at a true acupoint with shallow needling and no electric current (sham acupuncture). When EA at a true acupoint was applied with true needling but no electric current (sham EA), there was only a slight increase in brain activity at the hypothalamus; when EA was applied at a true acupoint with true needling and an electric current (true EA), the primary response at the hypothalamus was enhanced. Also, there was a tendency for the early activation of pain-modulation areas to be prominent after EA at analgesic acupoints as compared with nonanalgesic acupoints. In conclusion, understanding the linkage between peripheral acupoint stimulation and central neural pathways provides not only an evidence-based approach for veterinary acupuncture but also a useful guide for clinical applications of acupuncture.  相似文献   
753.
The objectives of this research were to study the effects of slurry specific gravity, starch table slope, slurry pumping rate, and their interactions on starch recovery and purity; and to propose a small‐scale laboratory wet‐milling procedure for wheat. First‐order and second‐order response surface regression models were developed to study the effects and interactions of slurry specific gravity, starch table slope, and slurry pumping rate on starch and gluten separation for a 100‐g wheat wet‐milling procedure. The starch and starch protein content data fit the first‐order models (R2 = 0.99 and 0.96) better than the second‐order models (R2 = 0.98 and 0.93). Regression results from the first‐order models indicated that specific gravity, table slope, pumping rate, and their interactions all had a significant effect on starch yield and purity. However, these effects could be simplified as the effect of the resident time of starch and gluten slurry on the starch table and the specific gravity. Starch yield increased as resident time increased and specific gravity decreased. Protein content in starch decreased as the resident time decreased and the specific gravity increased. The separation condition with specific gravity of 3 Bé, table slope of 1.04 cm/m, and pumping rate of 50 mL/min was recommended. Under this condition, starch recovery was 85.6% and protein content of starch was 0.42%, which was similar to the 1.5‐kg laboratory methods in starch recovery. Total solids recovery was 98.1%, which is similar to that from 1.5‐kg laboratory methods. These results indicated that precision of the 100‐g wheat wet‐milling procedure was similar to that of the 1.5‐kg laboratory methods.  相似文献   
754.
Mung bean, potato, and rice starch solutions (5%, w/w) were sonicated for up to 5 min after heating, and their physicochemical properties were investigated. Alkaline viscosities, including the apparent and inherent viscosities of starches, decreased. The residues of the swollen starch granules after pasting and centrifugation were also reduced prominently by sonication. Average degree of polymerization did not change with sonication. The starch paste became more transparent, and the hot paste viscosity measured at 70°C decreased remarkably. Results indicate that changes in the physicochemical properties of starch were induced by the disruption of swollen granules rather than the breakage of glucosidic linkages with sonication.  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