全文获取类型
收费全文 | 677篇 |
免费 | 28篇 |
专业分类
林业 | 11篇 |
农学 | 16篇 |
基础科学 | 2篇 |
85篇 | |
综合类 | 118篇 |
农作物 | 10篇 |
水产渔业 | 15篇 |
畜牧兽医 | 412篇 |
园艺 | 7篇 |
植物保护 | 29篇 |
出版年
2020年 | 4篇 |
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 11篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 37篇 |
2012年 | 27篇 |
2011年 | 47篇 |
2010年 | 15篇 |
2009年 | 5篇 |
2008年 | 31篇 |
2007年 | 37篇 |
2006年 | 21篇 |
2005年 | 21篇 |
2004年 | 29篇 |
2003年 | 16篇 |
2002年 | 22篇 |
2001年 | 20篇 |
2000年 | 23篇 |
1999年 | 14篇 |
1998年 | 5篇 |
1997年 | 10篇 |
1996年 | 6篇 |
1995年 | 7篇 |
1994年 | 5篇 |
1992年 | 12篇 |
1991年 | 9篇 |
1990年 | 21篇 |
1989年 | 19篇 |
1988年 | 19篇 |
1987年 | 14篇 |
1986年 | 16篇 |
1985年 | 9篇 |
1984年 | 12篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 7篇 |
1978年 | 9篇 |
1977年 | 4篇 |
1975年 | 7篇 |
1974年 | 4篇 |
1973年 | 10篇 |
1971年 | 9篇 |
1970年 | 10篇 |
1969年 | 5篇 |
1968年 | 5篇 |
1967年 | 5篇 |
1966年 | 5篇 |
排序方式: 共有705条查询结果,搜索用时 15 毫秒
21.
22.
S S Newman A F Roy D G Luther J D Hoskins H U Cox M T Kearney 《American journal of veterinary research》1985,46(1):294-297
A commercial broth microdilution system for testing the antimicrobial susceptibility of gram-positive cocci was compared with the standardized disk agar-diffusion method by testing 254 clinical strains of staphylococci and streptococci using both methods. A total of 2,794 parallel determinations were made with 92.3% complete agreement between the 2 methods; of the discrepancies encountered, 3.0% were minor, 2.5% were major, and 2.1% were very major. The results indicate that the commercial microdilution system may provide a reliable quantitative method for antimicrobial susceptibility testing of clinical isolates from animals. 相似文献
23.
Biological activity of Glechoma hederacea 总被引:2,自引:0,他引:2
The n-hexane, dichloromethane and methanol extracts of the aerial parts of Glechoma hederacea have been screened for antibacterial and free radical scavenging activity. General toxicity (brine shrimp lethality assay) of these extracts has also been assessed. 相似文献
24.
The level of indole-3-acetic acid (IAA) in shortleaf pine (Pinus echinata Mill.) roots was increased by inoculation with the ectomycorrhizal fungus Pisolithus tinctorius (Pers.) Coker and Couch. Indole-3-acetic acid oxidase activity was also increased suggesting that the increased level of IAA was the result of increased synthesis. Boron fertilization reduced IAA levels in roots inoculated with P. tinctorius but not in noninoculated roots. 相似文献
25.
26.
27.
I Kuzmenko R Buller WG Bouwman K Kjaer J Als-Nielsen M Lahav L Leiserowitz 《Science (New York, N.Y.)》1996,274(5295):2046-2049
Thin interdigitated films composed of a long-chain, water-insoluble chiral acid (p-pentadecylmandelic acid of absolute configuration R) and a water-soluble chiral base (phenylethylamine, R') were constructed at the air-solution interface. The (R, R') structure was characterized to near-atomic resolution by grazing-incidence x-ray diffraction (GIXD). The two diastereomeric systems, (R, R') and (R, S'), demonstrate similar surface pressure-molecular area isotherms, but their structures are completely different on the molecular level, as monitored by GIXD. Complementary data on these two architectures were provided by atomic force microscopy. 相似文献
28.
29.
30.
The wild tetraploid wheat species Tr$$ (Zhuk) Zhuk Var. araratieum is a source of pest resistance genes for T$$ aesti$$ L. Our objectives were to describe the breeding behaviour of T.arartuititm when backcrossed to common wheat and transfer resistance to leaf rust (caused by Pu$$) and powdery mildew (caused by Blumeria $$wheat. Crosses were made between five wheat genotypes and $$ accessions. Fertifity and chromosome numbers of BC$$; plants were determined. Resistance to leaf rust was transferred toBC2 -derived families from 10 different T’ararati$$an accessions. Leaf rust resistance genes in nine T. araratieum accessions can be assigned to at least four loci. Leaf rust resistance transferred from three accessions was inherited in the hexaploid derivatives as a single. $$ gene in each case. Resistance to powdery mildew was also detected in the T. araratie$$ backcross derivatives. Fertile hexaploid derivatives expressing T’araratieum-derived resistance genes can be recovered after two backcrosses to wheat cultivars. 相似文献