全文获取类型
收费全文 | 878篇 |
免费 | 49篇 |
国内免费 | 1篇 |
专业分类
林业 | 65篇 |
农学 | 31篇 |
基础科学 | 4篇 |
146篇 | |
综合类 | 146篇 |
农作物 | 36篇 |
水产渔业 | 19篇 |
畜牧兽医 | 389篇 |
园艺 | 40篇 |
植物保护 | 52篇 |
出版年
2023年 | 8篇 |
2022年 | 8篇 |
2021年 | 18篇 |
2020年 | 11篇 |
2019年 | 23篇 |
2018年 | 15篇 |
2017年 | 26篇 |
2016年 | 14篇 |
2015年 | 27篇 |
2014年 | 24篇 |
2013年 | 36篇 |
2012年 | 48篇 |
2011年 | 77篇 |
2010年 | 43篇 |
2009年 | 35篇 |
2008年 | 52篇 |
2007年 | 50篇 |
2006年 | 64篇 |
2005年 | 32篇 |
2004年 | 42篇 |
2003年 | 27篇 |
2002年 | 32篇 |
2001年 | 14篇 |
2000年 | 23篇 |
1999年 | 13篇 |
1998年 | 3篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1986年 | 10篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 7篇 |
1977年 | 7篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1974年 | 7篇 |
1972年 | 7篇 |
1971年 | 3篇 |
1970年 | 5篇 |
1969年 | 6篇 |
1968年 | 7篇 |
1967年 | 8篇 |
1966年 | 8篇 |
排序方式: 共有928条查询结果,搜索用时 31 毫秒
81.
W R Hess 《Science (New York, N.Y.)》1967,158(806):1279-1283
This article is based upon data which are suitable for the correlation of behavioral research and experimental neurophysiology. Causal thinking manifests a sort of integrative activity which brings simultaneous and successive patterns of nervous excitation into a subjectively meaningful frame of reference. While neuronal patterns determine the content of consciousness, they fail to provide clues concerning the transformation of such patterns into subjective experience. 相似文献
82.
83.
84.
85.
86.
J. Tessler W. R. Hess I. C. Pan R. Trautman 《Canadian journal of veterinary research》1974,38(4):443-447
Suitably diluted cell culture adapted African swine fever virus preparations were inoculated on VERO cell monolayers and grown on coverslips. Gum tragacanth was used as an overlay. After three days incubation at 37°C the infected cultures were fixed with acetone and stained with fluorescent antibody conjugate. Fluorescing plaques consisted of 20-30 infected cells.
Three statistical criteria for a quantitatively reliable assay were met: the Poisson distribution for plaque counts, linearity of the relationship between the concentration of virus and the plaque count and reproducibility of replicate titrations. The method is suitable for counts up to at least 70 plaques per 5 cm2 coverslip and computed titers are reproducible within 0.16 log units with a total of 300 plaques enumerated.
相似文献87.
88.
89.
90.
Hess TM Kronfeld DS Williams CA Waldron JN Graham-Thiers PM Greiwe-Crandell K Lopes MA Harris PA 《American journal of veterinary research》2005,66(3):466-473
OBJECTIVE: To compare effects of oral supplementation with an experimental potassium-free sodium-abundant electrolyte mixture (EM-K) with that of oral supplementation with commercial potassium-rich mixtures (EM+K) on acid-base status and plasma ion concentrations in horses during an 80-km endurance ride. ANIMALS: 46 healthy horses. PROCEDURE: Blood samples were collected before the ride; at 21-, 37-, 56-, and 80-km inspection points; and during recovery (ie, 30-minute period after the ride). Consumed electrolytes were recorded. Blood was analyzed for pH, PvCO2, and Hct, and plasma was analyzed for Na+, K+, Cl-, Ca2+, Mg2+, lactate, albumin, phosphate, and total protein concentrations. Plasma concentrations of H+ and HCO3-, the strong ion difference (SID), and osmolarity were calculated. RESULTS: 34 (17 EM-K and 17 EM+K treated) horses finished the ride. Potassium intake was 33 g less and Na+ intake was 36 g greater for EM-K-treated horses, compared with EM+K-treated horses. With increasing distance, plasma osmolarity; H+, Na+, K+, Mg2+, phosphate, lactate, total protein, and albumin concentrations; and PvCO2 and Hct were increased in all horses. Plasma HCO3-, Ca2+, and Cl- concentrations were decreased. Plasma H+ concentration was significantly lower in EM-K-treated horses, compared with EM+K-treated horses. Plasma K+ concentrations at the 80-km inspection point and during recovery were significantly less in EM-K-treated horses, compared with EM+K-treated horses. CONCLUSIONS AND CLINICAL RELEVANCE: Increases in plasma H+ and K+ concentrations in this endurance ride were moderate and unlikely to contribute to signs of muscle fatigue and hyperexcitability in horses. 相似文献