全文获取类型
| 收费全文 | 144766篇 |
| 免费 | 8078篇 |
| 国内免费 | 144篇 |
专业分类
| 林业 | 5698篇 |
| 农学 | 3947篇 |
| 基础科学 | 920篇 |
| 16107篇 | |
| 综合类 | 27352篇 |
| 农作物 | 5534篇 |
| 水产渔业 | 6676篇 |
| 畜牧兽医 | 76596篇 |
| 园艺 | 1599篇 |
| 植物保护 | 8559篇 |
出版年
| 2018年 | 1878篇 |
| 2017年 | 2106篇 |
| 2016年 | 1907篇 |
| 2015年 | 1639篇 |
| 2014年 | 2098篇 |
| 2013年 | 5160篇 |
| 2012年 | 3738篇 |
| 2011年 | 4686篇 |
| 2010年 | 2916篇 |
| 2009年 | 3083篇 |
| 2008年 | 4576篇 |
| 2007年 | 4287篇 |
| 2006年 | 4149篇 |
| 2005年 | 3766篇 |
| 2004年 | 3698篇 |
| 2003年 | 3754篇 |
| 2002年 | 3462篇 |
| 2001年 | 4489篇 |
| 2000年 | 4563篇 |
| 1999年 | 3474篇 |
| 1998年 | 1358篇 |
| 1997年 | 1375篇 |
| 1996年 | 1364篇 |
| 1995年 | 1619篇 |
| 1994年 | 1414篇 |
| 1993年 | 1421篇 |
| 1992年 | 3019篇 |
| 1991年 | 3339篇 |
| 1990年 | 3111篇 |
| 1989年 | 3148篇 |
| 1988年 | 2946篇 |
| 1987年 | 3042篇 |
| 1986年 | 3142篇 |
| 1985年 | 3009篇 |
| 1984年 | 2373篇 |
| 1983年 | 2092篇 |
| 1982年 | 1419篇 |
| 1979年 | 2244篇 |
| 1978年 | 1810篇 |
| 1977年 | 1550篇 |
| 1976年 | 1427篇 |
| 1975年 | 1563篇 |
| 1974年 | 2054篇 |
| 1973年 | 2052篇 |
| 1972年 | 2023篇 |
| 1971年 | 1893篇 |
| 1970年 | 1840篇 |
| 1969年 | 1695篇 |
| 1968年 | 1480篇 |
| 1967年 | 1509篇 |
排序方式： 共有10000条查询结果，搜索用时 546 毫秒
61.
62.
Various combinations of reoviruses and coccidia were studied to see if interactions would occur. Two reoviruses were used: virus 2035, a moderate to low pathogen, and virus 2177, a nonpathogen. Coccidia used were Eimeria acervulina, E. mitis, and E. maxima at dosages of 10(3) or 10(4) sporulated oocysts/chick and E. brunetti at 10(4) sporulated oocysts/chick. In Hubbard-Hubbard cockerels, a combination of virus 2035 and E. acervulina (10(4) oocysts/chick) or E. maxima (10(3) oocysts/chick) significantly (P less than or equal to 0.05) increased the frequency of stunting (% of chicks with body weight less than 80% of controls) and further depressed weight gain over that seen with either virus or coccidia alone. Conversely, virus 2177 ameliorated the same effects in Shaver-Arbor Acre cockerels given 10(4) oocysts/chick of E. mitis or E. maxima. The interaction could not be attributed to changes in the degree of coccidial infection based on oocyst production. Reovirus did not generally change the effect of coccidia on levels of plasma pigment and plasma protein. In Hubbard-Hubbard cockerels, coccidia-induced effects were not ameliorated by virus 2177, suggesting that breed difference in interaction can be expected. 相似文献
63.
G. L. RICHARDSON dvm T. R. O'BRIEN dvm PhD Diplomateacvr J. R. PASCOE bvsc D. M. MEAGHER dvm PhD Dipiomateacvs 《Veterinary surgery : VS》1986,15(2):156-160
The medical records of 38 horses with puncture wounds of the navicular bursa were reviewed. Only 12 horses had a satisfactory outcome (breeding or riding). Of the remaining 26 horses, 19 were euthanized, five were sold due to persistent severe lameness, one died, and one was lost to long-term follow-up. Different combinations of conservative management prior to surgical debridement and drainage of the navicular bursa were unsuccessful in resolving the condition. Horses that were treated surgically within 1 week of the injury and had a hind leg affected had the best chance of a satisfactory outcome. Additional wound debridement was necessary in 15 horses after initial surgical treatment. The most common complications encountered were navicular bone osteomyelitis and sepsis of the deep digital flexor tendon. Thirteen of 14 horses that had rupture of the deep digital flexor tendon and subluxation of the distal interphalangeal joint had an unsatisfactory outcome. One mare subsequently developed ankylosis of the distal interphalangeal joint and was a useful brood mare. Two horses that had biaxial palmar digital neurectomy because of persistent lameness were later euthanized because of navicular bone fracture and rupture of the deep digital flexor tendon. Results from limited numbers of bacterial cultures and antibiotic sensitivities suggest that penicillin and an aminoglycoside antibiotic should be used as initial antibiotic therapy. Immediate surgical debridement and appropriate antibiotic treatment are recommended as the minimum therapy for penetrating wounds of the navicular bursa in horses. 相似文献
64.
Dogs vaccinated with a Leptospira interrogans vaccine containing serogroups Canicola and Icterohaemorrhagiae and prepared from cultures grown in a protein-free medium resisted challenge with heterologous representatives of these serogroups. In contrast, control dogs were pyrexic and leptospires were isolated from the blood for nine days following Canicola challenge and six days after Icterohaemorrhagiae challenge. Leptospires were isolated from the urine of controls throughout the post challenge period and from kidneys at post mortem examination of six out of six and four out of six Canicola and Icterohaemorrhagiae challenged controls, respectively. There have been no reports of hypersensitivity reactions to this vaccine since its introduction in 1980. 相似文献
65.
Thirteen mixed-breed beef bulls, 1 to 4 years old, were used to determine the effect of live and dead filarial nematodes, Setaria labiatopapillosa, placed in the vaginal cavity of the testes. When dead worms were used, granulomatous lesions developed on the tunica vaginalis parietalis in 7 of 8 testes. The lesions were similar to those seen in some clinical cases of periorchitis. Similar lesions developed in 5 of 6 testes after live worms were implanted in the vaginal cavity of the testes and tetramisole (8 mg/kg) was injected subcutaneously 6 days after implantation. When live worms were implanted and tetramisole was not given, lesions developed in 3 of 6 testes. It was concluded that the granulomatous reaction was a local response to dead or killed S labiatopapillosa. 相似文献
66.
Wodsedalek JE 《Science (New York, N.Y.)》1917,46(1189):366-367
67.
68.
69.
70.