全文获取类型
收费全文 | 6712篇 |
免费 | 3466篇 |
国内免费 | 1篇 |
专业分类
林业 | 191篇 |
农学 | 462篇 |
基础科学 | 7篇 |
1407篇 | |
综合类 | 27篇 |
农作物 | 220篇 |
水产渔业 | 2562篇 |
畜牧兽医 | 4016篇 |
园艺 | 15篇 |
植物保护 | 1272篇 |
出版年
2022年 | 20篇 |
2021年 | 149篇 |
2020年 | 488篇 |
2019年 | 1050篇 |
2018年 | 929篇 |
2017年 | 980篇 |
2016年 | 972篇 |
2015年 | 835篇 |
2014年 | 828篇 |
2013年 | 1022篇 |
2012年 | 491篇 |
2011年 | 508篇 |
2010年 | 621篇 |
2009年 | 261篇 |
2008年 | 262篇 |
2007年 | 70篇 |
2006年 | 94篇 |
2005年 | 83篇 |
2004年 | 87篇 |
2003年 | 83篇 |
2002年 | 97篇 |
2001年 | 66篇 |
2000年 | 99篇 |
1999年 | 6篇 |
1997年 | 11篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1991年 | 1篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 9篇 |
1977年 | 5篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1970年 | 4篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
31.
M. M. Sloet van Oldruitenborgh‐Oosterbaan G. C. M. Grinwis 《Equine Veterinary Education》2018,30(10):558-563
The most common viral skin problems are discussed in the third article in our equine dermatology series. 相似文献
32.
33.
34.
35.
36.
Mitchell D Stamm Tiffany M Heng‐Moss Frederick P Baxendale Blair D Siegfried Roch E Gaussoin Daniel D Snow David A Cassada 《Pest management science》2013,69(2):285-291
BACKGROUND: Neonicotinoid insecticides are generally efficacious against many turfgrass pests, including several important phloem‐feeding insects. However, inconsistencies in control of western chinch bugs, Blissus occiduus, have been documented in field efficacy studies. This research investigated the efficacy of three neonicotinoid insecticides (clothianidin, imidacloprid and thiamethoxam) against B. occiduus in buffalograss under field conditions and detected statistically significant differences in B. occiduus numbers among treatments. A subsequent study documented the relative quantity and degradation rate of these insecticides in buffalograss systemic leaf tissues, using HPLC. RESULTS: Neonicotinoid insecticides initially provided significant reductions in B. occiduus numbers, but mortality diminished over the course of the field studies. Furthermore, while all three neonicotinoids were present in the assayed buffalograss leaf tissues, imidacloprid concentrations were significantly higher than those of clothianidin and thiamethoxam. Over the course of the 28 day study, thiamethoxam concentrations declined 700‐fold, whereas imidacloprid and clothianidin declined only 70‐fold and 60‐fold respectively. CONCLUSIONS: Field studies continued to verify inconsistencies in B. occiduus control with neonicotinoid insecticides. This is the first study to document the relative concentrations of topically applied neonicotinoid insecticides in buffalograss systemic leaf tissues. Copyright © 2012 Society of Chemical Industry 相似文献
37.
Allelopathy and the active metabolites of the endophytic fungus,Alternaria J46, from Platycladus orientalis
下载免费PDF全文
![点击此处可从《Weed Biology and Management》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The endophytic fungus, Alternaria J46, was isolated from the stem of the medicinal plant, Platycladus orientalis. A suspension of Alternaria J46 mycelial segments and the culture filtrates of the fungi exhibited marked seed germination inhibition against the monocot wheat, large crabgrass, bromegrass, rice and barnyardgrass and weak inhibition against the dicot redroot pigweed and morning glory, but it was safe for use on soybean, rape, cucumber, tomato, lettuce and radish crops. It is possible to use J46 culture filtrates in order to prevent monocot weeds in dicot cropland. Three active metabolites were isolated from an extract of the fungus cultures and elucidated as 3‐acetyl‐5‐sec‐butyltetramic acid (1, tenuazonic acid), 3‐acetyl‐5‐iso‐butyltetramic acid (2, vivotoxin II) and cyclo‐(L‐leucyl‐L‐proline) (3). Among these three compounds, compounds 1 and 2 showed significant phytotoxic effects on the seed germination of large crabgrass, while compound 3 exhibited weak activity, and all were safe for lettuce at 100 μg mL?1. Accordingly, compounds 1 and 2 were the main active metabolites that were responsible for endophytic fungus Alternaria J46's strong seed germination inhibition against monocotyledons. 相似文献
38.
39.
40.
Reducing copper use in the environment: the use of larixol and larixyl acetate to treat downy mildew caused by Plasmopara viticola in viticulture
下载免费PDF全文
![点击此处可从《Pest management science》网站下载免费的PDF全文](/ch/ext_images/free.gif)