全文获取类型
收费全文 | 880篇 |
免费 | 62篇 |
国内免费 | 83篇 |
专业分类
林业 | 170篇 |
农学 | 145篇 |
基础科学 | 49篇 |
104篇 | |
综合类 | 252篇 |
农作物 | 70篇 |
水产渔业 | 39篇 |
畜牧兽医 | 133篇 |
园艺 | 20篇 |
植物保护 | 43篇 |
出版年
2024年 | 2篇 |
2023年 | 10篇 |
2022年 | 27篇 |
2021年 | 36篇 |
2020年 | 32篇 |
2019年 | 37篇 |
2018年 | 25篇 |
2017年 | 36篇 |
2016年 | 23篇 |
2015年 | 28篇 |
2014年 | 26篇 |
2013年 | 37篇 |
2012年 | 42篇 |
2011年 | 49篇 |
2010年 | 57篇 |
2009年 | 51篇 |
2008年 | 49篇 |
2007年 | 56篇 |
2006年 | 49篇 |
2005年 | 42篇 |
2004年 | 15篇 |
2003年 | 21篇 |
2002年 | 21篇 |
2001年 | 24篇 |
2000年 | 21篇 |
1999年 | 27篇 |
1998年 | 22篇 |
1997年 | 24篇 |
1996年 | 31篇 |
1995年 | 14篇 |
1994年 | 11篇 |
1993年 | 14篇 |
1992年 | 10篇 |
1991年 | 14篇 |
1990年 | 15篇 |
1989年 | 13篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有1025条查询结果,搜索用时 4 毫秒
81.
Amplified fragment length polymorphism- and simple sequence repeat-based molecular tagging and mapping of greenbug resistance gene Gb3 in wheat 总被引:3,自引:0,他引:3
The greenbug, Schizaphis graminum (Rondani), is the most economically damaging aphid pest of wheat in the southern Great Plains of the USA. In this study, the single, dominant greenbug resistance gene, Gb3, was molecularly tagged and genetically mapped using amplified fragment length polymorphism (AFLP) and simple sequence repeat(SSR) markers. Three AFLP loci were associated with the Gb3 locus in linkage analysis with 75 F2:3 families from the cross between two near‐isogenic lines (NILs) for Gb3,‘TXGBE273’ and ‘TXGBE281′. Two of these loci, XMgcc Pagg and Xmagg Patg cosegregate with Gb3 in the population analysed. Further analysis indicated that XMgcc Pagg and Xmagg Patg are specific for the Gb3 locus in diverse genetic backgrounds. Two SSR markers, Xgwm111 and Xgwm428 previously mapped in wheat chromosome 7D, were shown to be linked with Gb3, 22.5 cM and 33.1 cM from Gb3, respectively, in an F2 population of ‘Largo’בTAM 107’, suggesting that Gb3 is located in the long arm of chromosome 7D. The two AFLP markers cosegregating with Gb3 are valuable tools in developing molecular markers for marker‐assisted selection of greenbug resistance in wheat breeding. 相似文献
82.
83.
水稻白叶枯病抗性基因的聚合及其遗传效应 总被引:19,自引:3,他引:19
以全生育期抗水稻白叶枯病的早粳G38为抗源供体,以成株期抗性的晚粳品种秀水11为轮回亲本,通过连续回交转育出全生育期抗白叶枯病的晚粳品系D601、D602和D603。遗传研究表明,3个晚粳品系都聚合了来自双亲的xa-5和Xa-3抗性基因,聚合的抗性基因可能具有抗性累加效应,其抗性水平和抗扩展能力强于双亲,抗谱宽于秀水11。同时评价了3个晚粳稻抗病品系对我甸白叶枯病病原型的抗性及主要农艺性状。认为D 相似文献
84.
85.
旱地玉米双相覆盖技术在太原地区的增产效果与机理 总被引:1,自引:0,他引:1
玉米双相覆盖技术在太原生态区增产率为14.48%。具有苗期适宜增温促发、中期保墒促长的土壤环境效应。增产机理是:玉米地上部和地下部协调增长,叶面积大,茎秆还原糖贮量多,干物质积累也多;具持续高强度灌浆特性,加快了物质运转速度 相似文献
86.
Wei BL Weng JR Chiu PH Hung CF Wang JP Lin CN 《Journal of agricultural and food chemistry》2005,53(10):3867-3871
The antiinflammatory activities of the isolated flavonoids, including cycloartomunin (1), cyclomorusin (2), dihydrocycloartomunin (3), dihydroisocycloartomunin (4), cudraflavone A (5), cyclocommunin (6), and artomunoxanthone (7), and cycloheterohyllin (8), artonins A (9) and B (10), artocarpanone (11), artocarpanone A (12), and heteroflavanones A (13), B (14), and C (15) from Artocarpus communis and A. heterophyllus, were assessed in vitro by determining their inhibitory effects on the chemical mediators released from mast cells, neutrophils, and macrophages. Compound 4 significantly inhibited the release of beta-glucuronidase and histamine from rat peritoneal mast cells stimulated with P-methoxy-N-methylphenethylamine (compound 48/80). Compound 11 significantly inhibited the release of lysozyme from rat neutrophils stimulated with formyl-Met-Leu-Phe (fMLP). Compounds 8, 10, and 11 significantly inhibited superoxide anion formation in fMLP-stimulated rat neutrophils while compounds 2, 3, 5, and 6 evoked the stimulation of superoxide anion generation. Compound 11 exhibited significant inhibitory effect on NO production and iNOS protein expression in RAW 264.7 cells. The potent inhibitory effect of compound 11 on NO production in lipopolysaccharide (LPS)-activated macrophages, probably through the suppression of iNOS protein expression. 相似文献
87.
88.
89.
Yuhui Weng Yill-Sung Park Marek J. Krasowski T. J. Mullin 《Annals of Forest Science》2011,68(1):129-138