全文获取类型
收费全文 | 460篇 |
免费 | 43篇 |
专业分类
林业 | 7篇 |
农学 | 2篇 |
基础科学 | 1篇 |
57篇 | |
综合类 | 51篇 |
农作物 | 12篇 |
水产渔业 | 19篇 |
畜牧兽医 | 348篇 |
园艺 | 3篇 |
植物保护 | 3篇 |
出版年
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 10篇 |
2020年 | 17篇 |
2019年 | 19篇 |
2018年 | 16篇 |
2017年 | 9篇 |
2016年 | 9篇 |
2015年 | 14篇 |
2014年 | 14篇 |
2013年 | 23篇 |
2012年 | 34篇 |
2011年 | 38篇 |
2010年 | 25篇 |
2009年 | 11篇 |
2008年 | 32篇 |
2007年 | 39篇 |
2006年 | 35篇 |
2005年 | 38篇 |
2004年 | 22篇 |
2003年 | 14篇 |
2002年 | 6篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1993年 | 4篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1983年 | 2篇 |
1981年 | 3篇 |
1979年 | 4篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1970年 | 3篇 |
1969年 | 2篇 |
1966年 | 1篇 |
1963年 | 1篇 |
1961年 | 1篇 |
1948年 | 1篇 |
1942年 | 1篇 |
1940年 | 1篇 |
1939年 | 1篇 |
1933年 | 1篇 |
1931年 | 1篇 |
1928年 | 1篇 |
排序方式: 共有503条查询结果,搜索用时 5 毫秒
501.
Edson Ferreira da Silva Luiz Sergio Costa Duarte Filho Ana Kelly dos Santos Maia Allison Vieira da Silva Ana Carolina Borges Lins e Silva 《Genetic Resources and Crop Evolution》2018,65(6):1551-1557
In this study, we describe three populations of the wild cotton Gossypium mustelinum Miers ex Watt in the coastal plain to the north of the State of Pernambuco, Northeast Brazil. These populations occur in urban areas in current expansion and under imminent risks of extinction, due to land use changes for house constructions. Distances between these new occurrences and the populations already mapped in the Northeast semiarid Caatinga (Rio Grande do Norte, Ceará, and Bahia) range from approximately 270–950 km. Besides distant, the populations on the coastal plain of Pernambuco also occur in very distinct climatic and edaphic conditions. Aiming at allowing the ex situ conservation of these genetic resources, branches of 66 plants were collected, propagated by the asexual breeding method cutting to regenerate an accession of each plant. These now constitute a germplasm collection in the Department of Agronomy of the Federal Rural University of Pernambuco (UFRPE), in Recife, Pernambuco, Brazil. 相似文献
502.
对猪肉加工者而言,免疫去势可提供较高质量的胴体,且胴体脂肪较少,浪费也少,因此胴体价值较高. 肉品生产行业当然属于竞争激烈的行业,并且易受二个重要的因素影响:新的法律法规和技术革新.肉品生产行业的专业人员不得不留意最近正在发生的潜在变化和由这些变化产生的机会. 相似文献
503.
Krzysztof Nowacki Maciej Galiski Andriy Fursov Alona Voronkina Heike Meissner Iaroslav Petrenko Allison L. Stelling Hermann Ehrlich 《Marine drugs》2022,20(11)
Three-dimensional chitinous scaffolds often used in regenerative medicine, tissue engineering, biomimetics and technology are mostly isolated from marine organisms, such as marine sponges (Porifera). In this work, we report the results of the electrochemical isolation of the ready to use chitinous matrices from three species of verongiid demosponges (Aplysina archeri, Ianthella basta and Suberea clavata) as a perfect example of possible morphological and chemical dimorphism in the case of the marine chitin sources. The electrolysis of concentrated Na2SO4 aqueous solution showed its superiority over the chemical chitin isolation method in terms of the treatment time reduction: only 5.5 h for A. archeri, 16.5 h for I. basta and 20 h for the S. clavata sample. Further investigation of the isolated scaffolds by digital microscopy and SEM showed that the electrolysis-supported isolation process obtains chitinous scaffolds with well-preserved spatial structure and it can be competitive to other alternative chitin isolation techniques that use external accelerating factors such as microwave irradiation or atmospheric plasma. Moreover, the infrared spectroscopy (ATR-FTIR) proved that with the applied electrochemical conditions, the transformation into chitosan does not take place. 相似文献