全文获取类型
收费全文 | 457篇 |
免费 | 12篇 |
专业分类
农学 | 10篇 |
基础科学 | 8篇 |
16篇 | |
综合类 | 204篇 |
农作物 | 9篇 |
水产渔业 | 11篇 |
畜牧兽医 | 188篇 |
园艺 | 7篇 |
植物保护 | 16篇 |
出版年
2021年 | 4篇 |
2019年 | 7篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 10篇 |
2012年 | 10篇 |
2011年 | 16篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 14篇 |
2007年 | 15篇 |
2006年 | 13篇 |
2005年 | 11篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 5篇 |
2001年 | 11篇 |
2000年 | 6篇 |
1999年 | 10篇 |
1998年 | 5篇 |
1997年 | 8篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 7篇 |
1992年 | 13篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 8篇 |
1977年 | 23篇 |
1976年 | 25篇 |
1975年 | 17篇 |
1974年 | 26篇 |
1973年 | 22篇 |
1972年 | 30篇 |
1971年 | 27篇 |
1970年 | 7篇 |
1963年 | 2篇 |
1955年 | 2篇 |
排序方式: 共有469条查询结果,搜索用时 0 毫秒
51.
Since 1966, teams of new graduates from the Royal (Dick) School of Veterinary Studies have organised eight veterinary research expeditions to Africa, tropical America and the Seychelles. The expeditions are now a regular feature of the school's activities. It is now possible to look back, learn and advise on future expeditions regarding timing, research and funding. 相似文献
52.
S B Mohanty M G Lillie A L Ingling R C Hammond 《Journal of the American Veterinary Medical Association》1972,161(9):1008-1011
53.
Hammond AL 《Science (New York, N.Y.)》1977,195(4274):164-166
54.
Effect of pH on in vitro ruminal conversion of L-tryptophan to 3-methylindole and indole 总被引:1,自引:0,他引:1
A C Hammond L L Slyter J R Carlson L P Wong R G Breeze 《American journal of veterinary research》1984,45(11):2247-2250
Three in vitro experiments were conducted to determine the effects of pH on ruminal conversion of L-tryptophan (TRP) to 3-methylindole (3-MI) and indole (IND). Experiment 1 involved 2 closed-system incubations, each with triplicate replications of buffered ruminal fluid at initial pH of 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, and 8.0. Highest molar conversions of TRP to 3-MI were 61.5 +/- 2.7% and 64.3 +/- 0.8% at initial pH treatments of 7.5 and 7.0 (final pH 7.3 and 6.9) for the 2 incubations, respectively. Experiment 2 used duplicate continuous cultures at each of 4 pH treatments. Following a common 5-day pretreatment period, effluent pH averaged 5.6, 6.1, 6.5, and 6.9 for the respective treatments. Data for 4 subsequent 5-day time periods showed production of 3-MI was affected by pH treatment (P less than 0.01), time (P greater than 0.01), and treatment X time (P less than 0.01); conversion of TRP to 3-MI reached 78% at pH 6.9 and decreased to less than 1% at pH 5.6. Production of IND was not related to pH treatment (P greater than 0.10). Total moles of volatile fatty acid (VFA) carbon produced showed a pH treatment X time interaction (P less than 0.01) which reflected a trend toward decreasing VFA production at lower pH and increasing VFA production at higher pH. Experiment 3 consisted of 2 pH treatments with additional continuous culture fermenters.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
55.
56.
A C Hammond G B Huntington R G Breeze 《American journal of veterinary research》1983,44(11):2195-2199
The time course and quantity of 3-methylindole (3MI) and indole absorbed after oral administration of L-tryptophan (TRP) was determined in 2 steers. The relationship between the appearance of 3MI and indole in the rumen and blood plasma to absorption of 3MI and indole was also studied. Two Hereford X Angus steers with portal vein, mesenteric vein, and femoral (steer 1) or iliac (steer 2) artery catheters were used. Absorption rates from the portal drained viscera (net absorption) of 3MI and indole were determined by the product of portal and arterial concentration difference and blood flow. Blood flow was determined by primed continuous infusion of p-aminohippuric acid into a mesenteric vein. Three absorption measurements 30 minutes apart were taken at midpoint times of 0, 12, 24, 36, and 48 hours after oral administration of 0.4 g of TRP/kg of body weight. Steer 1 was dosed twice resulting in a total of 45 absorption measurements. Net absorption of 3MI and indole peaked at an average of 1.05 and 0.81 g/hr, respectively. By 48 hours, 29.2% and 15.3% of the TRP dose were accounted for by 3MI and indole absorption, respectively. Closed system in vitro incubations of TRP with ruminal fluid from the same 2 steers resulted in a TRP to 3MI conversion of 23.2% and a TRP to indole conversion of 10.7%. Net absorption of 3MI and indole closely followed and was correlated with concentration of 3MI and indole in ruminal fluid and blood plasma.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
57.
L Maggio-Price C L Emerson T R Hinds F F Vincenzi W R Hammond 《American journal of veterinary research》1988,49(7):1020-1025
Three Beagles with chronic anemia and reticulocytosis were studied. The dogs originated from a large breeding colony and appeared clinically normal with the exception of splenomegaly. The PCV ranged from 30 to 39% (normal, 46 to 56%), with reticulocyte indices of 2.3 to 9.9. Red blood cells were morphologically normal, and examination of marrow aspirates revealed erythroid hyperplasia. Shortened chromium-51 RBC life-spans (7.2 to 15.4 days in anemic dogs; 22.2 to 25.2 days in control dogs) documented a hemolytic anemia. Acquired causes of hemolytic anemia were ruled out. Red blood cells had normal glycolytic enzyme activities, no evidence of unstable or abnormal hemoglobin, and had altered osmotic fragility curves. The breeding of 2 anemic dogs resulted in offspring with anemia and reticulocytosis. Polyacrylamide gel electrophoresis revealed no abnormalities in RBC membrane cytoskeletal proteins in all anemic adult dogs and in 3 offspring. 相似文献
58.
Hammond AL 《Science (New York, N.Y.)》1972,176(4033):391-393
59.
Hammond AL 《Science (New York, N.Y.)》1973,181(4098):428-430
60.
Hammond AL 《Science (New York, N.Y.)》1975,187(4179):823-825