全文获取类型
收费全文 | 1076篇 |
免费 | 81篇 |
国内免费 | 4篇 |
专业分类
林业 | 66篇 |
农学 | 14篇 |
基础科学 | 3篇 |
128篇 | |
综合类 | 193篇 |
农作物 | 19篇 |
水产渔业 | 106篇 |
畜牧兽医 | 534篇 |
园艺 | 41篇 |
植物保护 | 57篇 |
出版年
2023年 | 12篇 |
2022年 | 9篇 |
2021年 | 28篇 |
2020年 | 34篇 |
2019年 | 40篇 |
2018年 | 44篇 |
2017年 | 23篇 |
2016年 | 39篇 |
2015年 | 35篇 |
2014年 | 27篇 |
2013年 | 89篇 |
2012年 | 62篇 |
2011年 | 82篇 |
2010年 | 49篇 |
2009年 | 37篇 |
2008年 | 49篇 |
2007年 | 63篇 |
2006年 | 61篇 |
2005年 | 54篇 |
2004年 | 43篇 |
2003年 | 37篇 |
2002年 | 42篇 |
2001年 | 13篇 |
2000年 | 10篇 |
1999年 | 8篇 |
1998年 | 16篇 |
1997年 | 10篇 |
1996年 | 10篇 |
1995年 | 9篇 |
1994年 | 8篇 |
1993年 | 12篇 |
1992年 | 6篇 |
1991年 | 10篇 |
1990年 | 11篇 |
1989年 | 8篇 |
1988年 | 7篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1980年 | 4篇 |
1978年 | 5篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1969年 | 2篇 |
1963年 | 2篇 |
1942年 | 2篇 |
排序方式: 共有1161条查询结果,搜索用时 15 毫秒
1.
Frdrick G. Sunstrum Wubishet A. Bekele Charlene P. Wight Weikai Yan Yuanhong Chen Nicholas A. Tinker 《Plant Breeding》2019,138(1):82-94
We developed 178 recombinant inbred lines from a southern‐by‐spring oat population designated as “TxH.” These lines were genotyped to generate a high‐quality linkage map that resolved 6,902 markers into 21 linkage groups that matched closely with the latest hexaploid oat consensus map. Three major quantitative trait loci (QTLs) affecting heading date were found in locations that are consistent with known QTLs and candidate genes, and two other QTLs affecting heading date were found in novel locations. Five QTLs affecting plant height were found. Both sets of QTLs are responsible for transgressive segregation observed for these two traits. Four QTLs affecting resistance to crown rust, caused by the pathogen Puccinia coronata f. sp. avenae, were identified. Two of these QTLs are consistent with known clusters of rust resistance genes, while two may represent new locations of novel rust resistance genes. A complete set of SNP sequences suitable for generating markers for molecular selection is provided. 相似文献
2.
3.
4.
Comparative,multidimensional imaging of patent ductus arteriosus and a proposed update to the morphology classification system for dogs 下载免费PDF全文
5.
6.
7.
8.
AIM: To compare, in cows treated with an internal teat sealant, the effect of short-acting and long-acting cloxacillin-based dry-cow therapy on somatic cell counts (SCC) after calving.METHODS: Cows from a spring-calving, pasture-based dairy farm in the Manawatu-Whanganui region of New Zealand were randomly allocated to receive either a short-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=291) or a long-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=288) at the end of lactation. Cows were managed on-farm with routine husbandry procedures through the dry period and following calving. A multivariable logistic regression model was used to determine the association between length of action of dry-cow therapy and the proportion of cows with a SCC >150,000?cells/mL at the first herd test after calving.RESULTS: Age of cow, mean SCC for the preceding season and interval from calving to the first post-calving herd test were all associated with the proportion of cows with an individual SCC >150,000?cells/mL at the first herd test (p<0.001) Treatment with the short-acting dry-cow therapy was not associated with decreased odds of cows having a SCC >150,000?cells/mL at the first herd test compared with treatment with long-acting dry-cow therapy (OR=0.724; 95% CI=0.40–1.30).CONCLUSIONS AND CLINICAL RELEVANCE: In this herd, which routinely used internal teat sealants, the use of short-acting cloxacillin-based dry-cow therapy did not result in an increased proportion of cows with elevated SSC post-calving. This was a single farm, single year study but indicates that in this herd, changing from a long-acting to a short-acting antimicrobial may have no impact on the prevalence of subclinical mastitis. 相似文献
9.
Krystina D. Mossop Nicholas P. Moran David G. Chapple Bob B. M. Wong 《Landscape Ecology》2017,32(5):1065-1078