全文获取类型
| 收费全文 | 596篇 |
| 免费 | 4篇 |
专业分类
| 林业 | 9篇 |
| 40篇 | |
| 综合类 | 277篇 |
| 农作物 | 23篇 |
| 水产渔业 | 8篇 |
| 畜牧兽医 | 225篇 |
| 园艺 | 2篇 |
| 植物保护 | 16篇 |
出版年
| 2012年 | 29篇 |
| 2011年 | 26篇 |
| 2010年 | 6篇 |
| 2009年 | 7篇 |
| 2008年 | 34篇 |
| 2007年 | 26篇 |
| 2006年 | 27篇 |
| 2005年 | 37篇 |
| 2004年 | 31篇 |
| 2003年 | 29篇 |
| 2002年 | 32篇 |
| 2001年 | 19篇 |
| 2000年 | 25篇 |
| 1999年 | 12篇 |
| 1996年 | 4篇 |
| 1995年 | 5篇 |
| 1994年 | 14篇 |
| 1993年 | 6篇 |
| 1992年 | 5篇 |
| 1991年 | 7篇 |
| 1990年 | 8篇 |
| 1989年 | 5篇 |
| 1988年 | 4篇 |
| 1987年 | 4篇 |
| 1986年 | 7篇 |
| 1985年 | 6篇 |
| 1984年 | 8篇 |
| 1983年 | 7篇 |
| 1982年 | 8篇 |
| 1980年 | 4篇 |
| 1979年 | 7篇 |
| 1978年 | 4篇 |
| 1977年 | 5篇 |
| 1973年 | 4篇 |
| 1970年 | 5篇 |
| 1967年 | 4篇 |
| 1963年 | 5篇 |
| 1958年 | 5篇 |
| 1956年 | 4篇 |
| 1955年 | 5篇 |
| 1954年 | 4篇 |
| 1953年 | 7篇 |
| 1940年 | 4篇 |
| 1929年 | 4篇 |
| 1920年 | 3篇 |
| 1918年 | 4篇 |
| 1912年 | 3篇 |
| 1897年 | 3篇 |
| 1888年 | 3篇 |
| 1886年 | 3篇 |
排序方式： 共有600条查询结果，搜索用时 15 毫秒
1.
2.
5.
6.
7.
The serological identity of 234 strains of Yersinia pseudotuberculosis recovered from domestic animals and birds in New Zealand was determined by slide agglutination test. Thirty strains were also examined by tube agglutination test. The strains were isolated from cattle (56), sheep (8), deer (117), goats (13), pigs (7), rabbits (6), guinea pigs (5), and aviary species of birds (22). All strains were isolated from animals or birds which had died or shown signs of ill health and amongst which diarrhoea was a common feature. Serotype I accounted for 23% (53) of strains, serotype II for 13% (30) of strains and serotype III for 64% (151) of strains. It was concluded that further investigations on the prevalence and serological identity of strains recovered from clinically healthy animals mav provide useful information in assessing the significance of various serotypes as a cause of disease in livestock. 相似文献
8.
Attempts were made to identify 900 species of staphylococci or micrococci recovered from samples of bovine milk examined for mastitis pathogens. The presence and identity of haemolysins was recorded together with results of disc diffusion antibiotic sensitivity tests. The occurrence of clinical mastitis was also noted and somatic cell counts (SCC) were performed on milk samples which were normal in appearance. Eight hundred and thirty-one coagulase positive staphylococci were obtained, of which 810 were S. aureus and 21 were S. intermedius. Of 65 coagulase negative staphylococci the species of 19 could not be determined by the identification systems used. The remainder were identified as S. hyicus sub sp. hyicus (1), S. hyicus sub sp. chromogenes (19), S. haemolyticus (17), S. hominis (3), S. epidermidis (4), S. capitis (1) and either S. hominis or S. warneri (1). Four other isolates could not clearly be assigned to the genus Staphylococcus or Micrococcus and were designated irregular strains. No micrococci were identified. The presence of alpha, beta, or delta haemolysins occurring singly or in various combinations was identified in 98.3% of coagulase positive staphylococci and in 60% of coagulase negative staphylococci. Epsilon haemolysin was detected in 47.6% of the coagulase negative staphylococci and in 9.5% of S. intermedius. All staphylococci were sensitive to tetracycline (30 microg), novobiocin (1.6 microg), nafcillin (30 microg), methicillin (10 microg) and cephalothin (30 microg) and variable numbers of each species were sensitive to penicillin (2 iu) and streptomycin (10 microg). One non-identified species of coagulase negative staphylococcus was sensitive to erythromycin (0.4 microg) the remaining staphylococci were resistant. Each of the four irregular strains was sensitive to erythromycin and novobiocin. Clinical mastitis was associated with 30.6% of coagulase positive staphylococci, 15.3% of coagulase negative staphylococci, and two of the four irregular strains (50%). Subclinical mastitis as determined by SCC of 500 x 10(3) or greater was associated with 92.7% of coagulase positive and 37.5% of coagulase negative staphylococci. 相似文献
9.
10.
Bakker RT 《Science (New York, N.Y.)》1982,217(4554):53-55
Among extant large reptiles, juveniles often occupy different habitats from those of adults or subadults and thus avoid competition with and predation from the older animals; small juveniles often choose cryptic habitats because they are vulnerable to a wide variety of predators. Evidence from fossil humeri and femora of Early Permian reptiles collected from sediments of several distinct habitats indicate that similar shifts in habitat occurred. Juvenile Dimetrodon seem to have favored cryptic habitats around swamp and swampy lake margins; adults favored open habitats on the floodplains. Similar patterns of habitat shift seem to be present in the reptile Ophiacodon and the amphibian Eryops and may have been common in fossil tetrapods of the Permian-Triassic. 相似文献