全文获取类型
收费全文 | 7512篇 |
免费 | 3510篇 |
国内免费 | 8篇 |
专业分类
林业 | 268篇 |
农学 | 462篇 |
基础科学 | 10篇 |
1616篇 | |
综合类 | 207篇 |
农作物 | 150篇 |
水产渔业 | 2549篇 |
畜牧兽医 | 4356篇 |
园艺 | 37篇 |
植物保护 | 1375篇 |
出版年
2023年 | 8篇 |
2022年 | 15篇 |
2021年 | 146篇 |
2020年 | 483篇 |
2019年 | 1035篇 |
2018年 | 907篇 |
2017年 | 957篇 |
2016年 | 953篇 |
2015年 | 830篇 |
2014年 | 817篇 |
2013年 | 1004篇 |
2012年 | 531篇 |
2011年 | 558篇 |
2010年 | 651篇 |
2009年 | 293篇 |
2008年 | 326篇 |
2007年 | 147篇 |
2006年 | 174篇 |
2005年 | 165篇 |
2004年 | 168篇 |
2003年 | 182篇 |
2002年 | 189篇 |
2001年 | 83篇 |
2000年 | 111篇 |
1999年 | 22篇 |
1998年 | 9篇 |
1997年 | 26篇 |
1996年 | 15篇 |
1995年 | 12篇 |
1994年 | 13篇 |
1993年 | 11篇 |
1992年 | 7篇 |
1991年 | 14篇 |
1990年 | 11篇 |
1989年 | 12篇 |
1988年 | 4篇 |
1987年 | 8篇 |
1986年 | 12篇 |
1985年 | 10篇 |
1984年 | 8篇 |
1983年 | 9篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 4篇 |
1978年 | 12篇 |
1977年 | 11篇 |
1976年 | 6篇 |
1974年 | 6篇 |
1970年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
211.
212.
Pei‐Yi Wang Meng Xiang Min Luo Hong‐Wu Liu Xiang Zhou Zhi‐Bing Wu Li‐Wei Liu Zhong Li Song Yang 《Pest management science》2020,76(8):2746-2754
213.
214.
Philippe Desbordes Bernd Essigmann Stephanie Gary Oliver Gutbrod Michael Maue Hans‐Georg Schwarz 《Pest management science》2020,76(10):3340-3347
Succinate dehydrogenase inhibitors (SDHIs) have played a crucial role in disease control to protect cereals as well as fruit and vegetables for more than a decade. Isoflucypram, the first representative of a newly installed subclass of SDHIs inside the Fungicide Resistance Action Committee (FRAC) family of complex II inhibitors, offers unparalleled long‐lasting efficacy against major foliar diseases in cereals. Herein we report the chemical optimization from early discovery towards isoflucypram and the first hypothesis of its altered binding mode in the ubiquinone binding site of succinate dehydrogenase. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. 相似文献
215.
216.
217.
218.
219.
Wardatou Boukari Denis Filloux Jean Heinrich Daugrois Emmanuel Fernandez Dimitre Mollov Claudia Kaye Martha Hincapie Alexander Sanchez Jianping Wang Philippe Roumagnac Philippe Rott 《Plant pathology》2020,69(6):1060-1069
Viruses in the genus Mastrevirus (family Geminiviridae), including those infecting sugarcane, have natural geographical ranges almost exclusively restricted to Africa and the Indian Ocean islands off the African coast. Only sugarcane white streak virus (SWSV) in Barbados and sugarcane striate virus (SStrV) in Florida and Guadeloupe are known to infect a few sugarcane varieties in the Western Hemisphere. In this study, PCR assays were developed to detect these two viruses in sugarcane. Five hundred and seventy-one DNA samples from Saccharum species and interspecific hybrids from the Miami World Collection of sugarcane and related grasses were tested for the presence of SStrV and SWSV by PCR. No variety was found infected by SWSV but SStrV was detected in 19 varieties. PCR data were confirmed by sequencing amplified fragments (248 bp). These fragments shared 93%–100% nucleotide identity with SStrV sequences from the GenBank database. SStrV isolates were distributed in six phylogenetic groups, including the four strains of the virus. Most varieties infected by SStrV originated from Asia, thus confirming a previous hypothesis stating that this virus originated from this continent. Absence of SStrV in commercial sugarcane in Florida also suggested that this virus has not been spread in this location, while infected plants have been present for several decades. 相似文献
220.
Analysing the agricultural sectors of Taiwan, Malaysia and Singapore, this paper examines the capability‐building process that encourages productivity and innovation. It describes and explains the origins and subsequent evolution of three forms of agricultural production system, each generating different farming capabilities and distinct forms of competitive advantages. The paper argues that Taiwan's rice‐oriented agricultural production system stimulates both productivity and innovation, helping Taiwanese farmers raise their income level and living standards. The active deployment of state institutions and a malleable labour force, evidenced in the Malaysian palm oil industry, is effective in raising farming productivity but not the ability to innovate. Singapore's aquaculture‐oriented agricultural production system is somewhat useful in stimulating productivity and innovation. Yet the city‐state's inherent lack of space and open international trade regime have circumscribed the potential of its aquaculture industry. It now relies on the regional ethnic Chinese business networks to expand the aquaculture industry's knowledge base and its industrial commons. The principles discussed in this paper provide policy lessons, or at least some initial guidance, for other developing economies aspiring to modernise their agricultural sector. 相似文献