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   930篇
  免费   69篇
林业   50篇
农学   25篇
  117篇
综合类   112篇
农作物   34篇
水产渔业   43篇
畜牧兽医   539篇
园艺   7篇
植物保护   72篇
  2023年   12篇
  2022年   12篇
  2021年   30篇
  2020年   37篇
  2019年   29篇
  2018年   26篇
  2017年   22篇
  2016年   25篇
  2015年   19篇
  2014年   27篇
  2013年   37篇
  2012年   56篇
  2011年   70篇
  2010年   28篇
  2009年   33篇
  2008年   58篇
  2007年   50篇
  2006年   50篇
  2005年   45篇
  2004年   37篇
  2003年   33篇
  2002年   27篇
  2001年   11篇
  2000年   15篇
  1999年   15篇
  1998年   4篇
  1997年   6篇
  1996年   4篇
  1993年   6篇
  1992年   13篇
  1990年   13篇
  1989年   9篇
  1988年   12篇
  1986年   7篇
  1985年   12篇
  1983年   4篇
  1982年   6篇
  1981年   3篇
  1980年   4篇
  1979年   5篇
  1978年   10篇
  1977年   6篇
  1974年   9篇
  1973年   3篇
  1972年   3篇
  1970年   3篇
  1969年   8篇
  1968年   7篇
  1967年   3篇
  1966年   3篇
排序方式: 共有999条查询结果,搜索用时 46 毫秒
1.
In 11 dogs with nasal adenocarcinoma, IV treatment with 2 to 8 cycles of cisplatin at a dosage of 60 mg/m2 of body surface, given at 3-week intervals, resulted in a survival time of 8 to 128 weeks (mean, 32.7 weeks; median, 20 weeks). Radiography revealed complete remission in 2 dogs and partial remission in 1 dog, for an overall response rate of 27%. Clinical problems such as nasal discharge (n = 11), sneezing (n = 6), and epistaxis (n = 4) resolved in 1 to 2 weeks in all dogs after beginning chemotherapy.  相似文献   
2.
New biotechnical methods in reproduction have been introduced in animal breeding via embryo transfer. There are no serious objections against these methods as long as the variety of species is reassured and the animal protection law is considered. More substantial objections exist against genetic engineering methods which alter the genome of animals. Beside for legal protection there is a strong public demand for the adequete awareness and responsibility of scientists who are active in this field. Comprehensive information on such research projects can lead to a better understanding of the aims and methods and might, therefore, help to reduce inadequate apprehensions.  相似文献   
3.
4.
5.
6.
7.
An outbreak of perinatal foal mortality associated with a herpesvirus is described. Twenty two foals either were still-born, or died soon after birth, or were weak and soon developed severe respiratory signs, or were normal at birth and developed respiratory symptoms 18 to 24 hours later. Elevated temperatures, heart and respiratory rates were constant features. The animals were severely leucopaenic, and showed an absolute neutropaenia. At autopsy the lungs were enlarged, and showed varying degrees of aeration and moderate to severe oedema and congestion. Histopathology showed an acute focal necrotising bronchiolitis with the presence of intranuclear eosinophilic inclusion bodies. Herpesvirus was recovered from 9 foals in cell culture and identified by electron microscopy.  相似文献   
8.
1. The electrophoretic patterns of water‐soluble proteins of avian muscle showed differences due both to species and to muscle type.

2. Each muscle pattern within a species showed a unique protein band which distinguished that species from other species.  相似文献   

9.
10.
This study evaluated the influence of calcium and magnesium ions on the empirical rheological properties of wheat flour to verify possible effects of these ions on processing because, in addition to their nutritional importance, they are also responsible for water hardness. Calcium (0–1.30 g/100 g) and magnesium (0–0.34 g/100 g) ions from sulfate salts were added to wheat flour, according to a central composite rotatable design. The farinograph and extensigraph properties of wheat flour and its mixtures were evaluated. The results were analyzed by response surface methodology. Calcium ions stood out for increasing water absorption, decreasing mixing stability, and producing a delayed effect on dough extensibility (reduced at 135 min). Magnesium ions influenced most flour rheological properties in a similar manner to oxidizing agents (increased dough stability, increased resistance to extension, and reduced extensibility), thus proving to be a possible replacement agent for these additives. An interaction effect of the combined calcium and magnesium ions was observed on dough development time. The results showed that effects on processing can occur when wheat flour fortification is made, and adaptations on wheat flour specifications, product formulation, and processing parameters may be required.  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