全文获取类型
收费全文 | 227篇 |
免费 | 3篇 |
专业分类
林业 | 10篇 |
农学 | 8篇 |
14篇 | |
综合类 | 28篇 |
农作物 | 2篇 |
水产渔业 | 35篇 |
畜牧兽医 | 100篇 |
园艺 | 1篇 |
植物保护 | 32篇 |
出版年
2023年 | 2篇 |
2016年 | 2篇 |
2013年 | 8篇 |
2012年 | 2篇 |
2011年 | 5篇 |
2010年 | 5篇 |
2009年 | 8篇 |
2008年 | 6篇 |
2007年 | 5篇 |
2006年 | 3篇 |
2005年 | 4篇 |
2002年 | 2篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 10篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1994年 | 6篇 |
1993年 | 9篇 |
1991年 | 8篇 |
1990年 | 11篇 |
1989年 | 9篇 |
1988年 | 8篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1966年 | 1篇 |
1963年 | 3篇 |
1962年 | 1篇 |
1961年 | 2篇 |
1959年 | 6篇 |
1958年 | 5篇 |
1957年 | 6篇 |
1956年 | 7篇 |
1955年 | 1篇 |
1954年 | 4篇 |
1953年 | 8篇 |
1952年 | 1篇 |
1948年 | 2篇 |
1946年 | 3篇 |
1945年 | 1篇 |
排序方式: 共有230条查询结果,搜索用时 15 毫秒
31.
SUMMARY: An outbreak of sarcoptic mange in a colony of koalas was effectively controlled by the topical application of amitraz as a 0.025% aqueous suspension. Several koalas died in the 9 months preceding treatment, with lesions suggestive of Sarcoptes scabiei ; however, no further deaths occurred following treatment and there was complete recovery of all affected animals. 相似文献
32.
Plasma and urine disposition and dose proportionality of ceftiofur and metabolites in dogs after subcutaneous administration of ceftiofur sodium 总被引:2,自引:0,他引:2
S.A. BROWN T.S. ARNOLD P.J. HAMLOW A.K. SPEEDY N.L. DELEEUW V.L. HUBBARD J.K. CALLAHAN S.D. FOLZ R.L. JANOSE T.F. FLOOK T.D. COX 《Journal of veterinary pharmacology and therapeutics》1995,18(5):363-369
Nine male dogs (10.3–13.5 kg body weight) were randomly assigned to three groups of three dogs each and administered ceftiofur sodium subcutaneously as a single dose of 0.22, 2.2, or 4.4 mg ceftiofur free acid equivalents/kg body weight. Plasma and urine samples were collected serially for 72 h and assayed for ceftiofur and metabolites (derivatized to desfuroylceftiofur acetamide) using high-performance liquid chromatography. Urine concentrations remained above the MIC 90 for Escherichia coll (4.0 μg/mL) and Proteus mirabilis (1.0 μg/mL) for over 24 h after doses of 2.2 mg/kg (8.1 μg/mL) and 4.4 mg/kg (29.6 μg/mL), the interval between treatments for ceftiofur sodium in dogs, whereas urine concentrations 24 h after dosing at 0.22 mg/kg (0.1 mg/Ib) were below the MIC 90 for E.coli and P. mirabills (0.6 μg/mL). Plasma concentrations were dose-proportional, with peak concentrations of 1.66 ± 0.0990 μg/mL, 8.91 ± 6.42 μg/mL, and 26.7 ± 1.07 μg/mL after doses of 0.22, 2.2, and 4.4 mg/kg, respectively. The area under the plasma concentration versus time curve, when normalized to dose, was similar across all dosage groups. 相似文献
33.
R. A. Ll. BROWN A. MORROW I. HERON S. N. CHONG 《The Journal of small animal practice》1987,28(9):845-851
Immunofluorescent staining of epithelial cells present in urine of early clinical cases of canine distemper confirmed the presumptive diagnosis by revealing fluorescing intracytoplasmic inclusions. Positive results were not obtained in urine samples from control dogs nor from samples from dogs ill for more than three weeks. The urine samples, with added preservative, still yielded positive results after 5 days storage at 37°C or 21 days storage at 18°C. 相似文献
34.
35.
Human rhodopsin in aqueous solution has lambda(max). of 493 mmicro and is lower in the spectrum than the rhodopsins of all other known vertebrates, with the exception of certain deep-sea fishes. Its molar extinction is 40,000 +/- 800. Like other rhodopsins, it bleaches to a mixture of opsin and all-trans retinene and is resynthesized by incubating opsin with neo-b (11-cis) retinene. The regenerated rhodopsin has the same lambda(max). as the extracted pigment; this is due, therefore, not to an unusual retinene but to a characteristic human opsin. The regeneration in solution from opsin and neo-b retinene is a second-order reaction with a half-time, at 29.5 degrees C, of about 2.5 minutes. This is much faster than the synthesis of rhodopsin in the living human eye, and faster than human rod dark-adaptation; the rate of both processes in vivo must be limited by reactions which precede the union of neo-b retinene with opsin, the final step in rhodopsin synthesis. In the rods, rhodopsin is virtually in the solid state-highly oriented in close relation with other highly oriented molecules. In this situation its spectrum is displaced toward the red (lambda(max) 500 mmicro) and is narrower than in solution. For light entering the rods axially, rhodopsin has also a considerably increased extinction, some 1.5 times higher than when randomly oriented. The spectrum of rhodopsin in rods agrees well in form and position with the spectral sensitivity of human rod vision, measured at the retinal surface. 相似文献
36.
37.
38.
BROWN CW 《Science (New York, N.Y.)》1958,127(3312):1432-1433
39.
40.
Eight experimental diets were formulated for rainbow trout using agricultural byproducts as major ingredients. Each experimental diet contained varying amounts of corn grain, corn gluten meal, corn gluten feed and one of the following: 200 g kg?1 peanut meal, 200 or 400 g kg?1 soybean meal (SBM), 390 g kg?1 low-allergen soy flour, 310 g kg?1 soy protein concentrate, 300 g kg?1 low-allergen soy protein concentrate or 200 g kg?1 SBM + 110 g kg?1 blood meal. One diet contained 200 g kg?1 SBM and canola oil as the main lipid source. The remaining diets contained 95 g kg?1 menhaden oil. Fish fed a commercial trout diet exhibited significantly greater weight gain (322%), and a lower feed conversion ratio (0.89) but significantly lower protein efficiency ratio (2.18) than fish fed the experimental diets. Within the experimental diets, fish fed the 400 g kg?1 soy flour diet and the 400 g kg?1 soybean meal diet had significantly higher weight gains (276% and 268%) and protein efficiency ratios (2.58 and 2.52), and lower feed conversion ratios (1.02 and 1.03) than fish fed other experimental diets. Fillet flavour varied between treatments. Most notable was the lower fishy flavour and higher chicken flavour of fish fed the diet that contained canola oil rather than menhaden oil. Microscopic evaluation of the liver and five sections of the gastrointestinal tract failed to demonstrate any differences between treatment groups. The ingredient costs of several experimental diets were lower than the estimated cost of a standard commercial trout diet. However, the superior feed conversion ratios of fish fed the control diet resulted in lower feed costs per unit of fish produced. 相似文献