全文获取类型
收费全文 | 1332篇 |
免费 | 94篇 |
专业分类
林业 | 46篇 |
农学 | 45篇 |
基础科学 | 11篇 |
163篇 | |
综合类 | 262篇 |
农作物 | 126篇 |
水产渔业 | 37篇 |
畜牧兽医 | 675篇 |
园艺 | 15篇 |
植物保护 | 46篇 |
出版年
2017年 | 13篇 |
2016年 | 25篇 |
2015年 | 13篇 |
2014年 | 22篇 |
2013年 | 53篇 |
2012年 | 31篇 |
2011年 | 45篇 |
2010年 | 26篇 |
2009年 | 40篇 |
2008年 | 42篇 |
2007年 | 46篇 |
2006年 | 45篇 |
2005年 | 42篇 |
2004年 | 41篇 |
2003年 | 40篇 |
2002年 | 40篇 |
2001年 | 29篇 |
2000年 | 38篇 |
1999年 | 23篇 |
1998年 | 22篇 |
1997年 | 13篇 |
1995年 | 14篇 |
1993年 | 15篇 |
1992年 | 18篇 |
1991年 | 18篇 |
1990年 | 29篇 |
1989年 | 19篇 |
1988年 | 19篇 |
1987年 | 15篇 |
1986年 | 13篇 |
1985年 | 11篇 |
1984年 | 16篇 |
1983年 | 22篇 |
1982年 | 21篇 |
1979年 | 20篇 |
1978年 | 24篇 |
1977年 | 21篇 |
1976年 | 13篇 |
1975年 | 16篇 |
1974年 | 24篇 |
1973年 | 19篇 |
1972年 | 14篇 |
1971年 | 18篇 |
1970年 | 26篇 |
1969年 | 18篇 |
1968年 | 17篇 |
1948年 | 10篇 |
1945年 | 12篇 |
1944年 | 14篇 |
1943年 | 14篇 |
排序方式: 共有1426条查询结果,搜索用时 15 毫秒
151.
D L Knudson W K Butterfield R E Shope T E Walton C H Campbell 《Veterinary microbiology》1982,7(4):285-293
The genomes of U.S. bluetongue viruses, an Australian bluetongue virus, and three other related orbiviruses were analyzed by polyacrylamide gel electrophoresis. The genomes were comprised of ten segments of double-stranded (ds) RNA. Estimates of the molecular weights of the dsRNA segments revealed that the U.S. bluetongue serotypes were remarkably similar. Although the dsRNA profiles of the viruses exhibited common segments, each virus had a distinct dsRNA profile. The usefulness of the genome analysis as a diagnostic tool for identification and for epidemiologic studies is discussed. 相似文献
152.
W. C. Campbell 《Veterinary research communications》1981,5(1):251-262
The avermectins are macrocyclic lactones produced byStreptomyces
avermitilis. One of them has been chemically modified and given the non-proprietary name invermectin. The compounds have shown efficacy against various stages of filarial parasites. With respect to pre-adult stages in the mammalian host, activity has been observed againstDirofilaria
immitis in ferrets and dogs, andDipetalonema
viteae andLitomosoides
carinii in jirds (Meriones); but activity has not been observed against the developing stages ofBrugia spp. in jirds orOnchocerca spp. in cattle. The compounds have not shown activity against adult filarial worms, except in the case ofSetaria
equina in horses and possiblyDipetalonema
viteae in jirds. With respect to the first stage larva (microfilaria) in the mammalian host, efficacy has been observed againstDirofilaria
immitis in dogs,Brugia
malayi in multimammate rats (Mastomys),Dipetalonema
viteae andLitomosoides
carinii in jirds andOnchocerca spp. in horses and cattle; but activity has not been observed against microfilariae ofBrugia
pahangi in jirds or cats. Efficacy against filarial parasites has been observed following oral or parenteral administration of drug, sometimes at extremely low dosage. For example, a single oral dosage of 0.05 mg/kg was highly active against the third and fourth larval stages and microfilariae ofD.
immitis in dogs. 相似文献
153.
L D Campbell 《British poultry science》1979,20(3):239-246
1. There was a marked strain difference in the incidence of hepatic haemorrhage in White Leghorn hens receiving dietary rapeseed meal (RSM). 2. Tolerance to high dietary contents of RSM also varied between individual birds within a strain. 3. Glucosinolates were implicated in the development of hepatic haemorrhage among hens receiving dietary RMS but the exact relationship was not clear. 相似文献
154.
Eighteen pony foals were experimentally infected with 500 third stage larvae of Strongylus vulgaris at 2 weeks, and at 2, 4, 6 and 8 months after birth. For the duration of the study, all foals were kept in the same pasture with their mothers to allow natural infection with other parasites by exposure to a contaminated environment. Twelve of the foals were utilized in groups of 3 and treated orally five times at two month intervals starting at one month of age with closantel at doses of 5, 10, 20 or 40 mg kg-1. Ten months after birth the foals were necropsied to determine the parasitic burdens in the gastrointestinal tracts and the cranial mesenteric arteries. The results indicate a high antiparasitic activity of closantel against larval stages of Gasterophilus intestinalis and S. vulgaris, as well as against adult S. vulgaris, S. edentatus, Anoplocephala perfoliata and Triodontophorus spp., when used at doses of 20 or 40 mg kg-1. 相似文献
155.
Further studies on the effect of total nephrectomy in the bovine 总被引:2,自引:0,他引:2
156.
157.
Some kinetic data on the inactivation of equine herpesvirus type 1 (EHV1) and equine rhinovirus type 1 (ERhV1) by betapropiolactone (BPL) and ultraviolet (UV) irradiation are reported. 0.25% BPL at 37 degrees C for 1 h reduced the titre of EHV1 by greater than 10(3 . 4) and of ERhV1 by greater than 10(4 . 1) TCID50/ml. UV irradiation (334 microW/cm2) produced similar reductions in titre after 2 min. These data were used as a basis for inactivating EHV1 and ERhV1 by the combined action of BPL and UV irradiation. Viruses were exposed to 0.1% BPL for 1 h at 4 degrees C with constant stirring, followed by UV irradiation for 2 min, followed by incubation for 3 h at 37 degrees C. Inactivated EHV1 elicited secondary immune responses only in horses whereas ERhV1 produced primary immune responses in mice (including athymic nu/nu mice), rabbits and probably in horses. 相似文献
158.
159.
Milk allergy, an autoallergic disease of cattle 总被引:3,自引:0,他引:3
S G Campbell 《The Cornell veterinarian》1970,60(4):684-721
160.