全文获取类型
收费全文 | 1008篇 |
免费 | 85篇 |
专业分类
林业 | 29篇 |
农学 | 12篇 |
基础科学 | 8篇 |
114篇 | |
综合类 | 231篇 |
农作物 | 50篇 |
水产渔业 | 57篇 |
畜牧兽医 | 510篇 |
园艺 | 28篇 |
植物保护 | 54篇 |
出版年
2020年 | 20篇 |
2019年 | 16篇 |
2018年 | 24篇 |
2017年 | 23篇 |
2016年 | 20篇 |
2015年 | 19篇 |
2014年 | 19篇 |
2013年 | 53篇 |
2012年 | 28篇 |
2011年 | 55篇 |
2010年 | 26篇 |
2009年 | 28篇 |
2008年 | 33篇 |
2007年 | 38篇 |
2006年 | 21篇 |
2005年 | 37篇 |
2004年 | 29篇 |
2003年 | 33篇 |
2002年 | 23篇 |
2001年 | 21篇 |
2000年 | 27篇 |
1999年 | 21篇 |
1998年 | 13篇 |
1997年 | 8篇 |
1996年 | 7篇 |
1995年 | 12篇 |
1993年 | 7篇 |
1992年 | 21篇 |
1991年 | 18篇 |
1990年 | 8篇 |
1989年 | 19篇 |
1988年 | 18篇 |
1986年 | 14篇 |
1985年 | 11篇 |
1984年 | 14篇 |
1983年 | 9篇 |
1981年 | 8篇 |
1980年 | 13篇 |
1979年 | 11篇 |
1978年 | 7篇 |
1977年 | 7篇 |
1974年 | 11篇 |
1973年 | 15篇 |
1972年 | 22篇 |
1971年 | 16篇 |
1970年 | 12篇 |
1969年 | 7篇 |
1968年 | 9篇 |
1967年 | 9篇 |
1912年 | 6篇 |
排序方式: 共有1093条查询结果,搜索用时 0 毫秒
131.
Combinations of detomidine (mean dose rate 13 micrograms/kg) and butorphanol (mean dose rate 26 micrograms/kg) were used to sedate 61 horses for a variety of surgical or diagnostic procedures in general equine practice. Three horses were sedated on more than one occasion. The degree of sedation was graded from 3 to 0 (deep sedation to no effect) and any side effects were recorded. Forty-three per cent of the horses were graded 3, 46 per cent were graded 2, 8 per cent were graded 1 and 3 per cent were graded 0. Bradycardia and ataxia were the major side effects. The combination was judged to be effective and safe for use in general practice. In 56 horses (92 per cent) the necessary procedure was carried out under excellent conditions and in only one horse was the degree of sedation considered to be totally unsatisfactory. 相似文献
132.
Toxicity of polychlorinated biphenyls in poultry 总被引:4,自引:0,他引:4
133.
134.
135.
The harvesting, storing and utilisation in tissue culture of lung alveolar macrophages from 2–3 weeks old piglets were investigated. An average yield of 4×108 cells was obtained, which in culture usually remained healthy for at least 8 days. In liquid nitrogen at –173°C about 50% of the cells were still viable after 3 months. Pig cells sustained the growth of ovineChlamydia
psittaci and a rising titre was demonstrated over 4 passages. 相似文献
136.
Alternative approaches to eliminating endemic diseases and improving performance of pigs 总被引:2,自引:0,他引:2
D L Harris 《The Veterinary record》1988,123(16):422-423
137.
Atypical myoglobinuria: an acute myopathy in grazing horses 总被引:1,自引:0,他引:1
Four out of 12 horses grazing a field in Berkshire, England, suffered a prostrating illness and died within 12 to 72 h. Serum biochemical abnormalities, including markedly elevated muscle enzymes, were demonstrated and at post mortem widespread myodegeneration was found in both skeletal muscle and myocardium. Urine analysis revealed myoglobinuria, and renal changes were seen histologically. Although similar pathologically, the clinical syndrome and circumstances of the outbreak were not typical of equine exertional rhabdomyolysis (EER). The outbreak bore a striking resemblance to other reported sporadic outbreaks of an atypical myoglobinuria occurring in grazing horses. A number of potential aetiological and contributory factors (including herbicide toxicity) were considered, but the aetiology remains unresolved. 相似文献
138.
Five thousand oocysts of each of two species of coccidia, Eimeria crandallis and E ovinoidalis or 30,000 infective larvae of Nematodirus battus, given as single infections to three- to five-week-old lambs, caused only transient diarrhoea and had no effect on growth. Lambs infected first with coccidia and two weeks later with N battus suffered severe diarrhoea, weight loss and some deaths. Simultaneous administration of the coccidia and the nematodes increased the clinical severity of the syndrome and increased the numbers of nematode eggs produced. 相似文献
139.
D. J. Harris 《Australian veterinary journal》1981,57(8):357-361
SUMMARY: In a study of 64 dairy herds in south-western Victoria it was found that pasture and animal management practices were associated with the incidence of parturient paresis. The incidence was higher when pastures were treated with higher rates of superphosphate and potash and when longer pasture was available to cows during the preparturient period. When pasture available was in limited supply, the incidence was inversely related to the amount of hay fed to cows. The incidence was also influenced by age, breed and body condition of cows. 相似文献
140.
The Effects of Cesarean Section Anesthesia on Heat Loss and Heat Production in the Newborn Rabbit 下载免费PDF全文
The newborn of some smaller animals rely upon heat produced by nonshivering thermogenesis in the brown fat to prevent a fall in body temperature after birth. Because of their pharmacological properties, some drugs may affect nonshivering thermogenesis. Therefore, in this study, the ability of newborn rabbits delivered under Innovar-Vet, ketamine hydrochloride, methoxyflurane and epidural anesthesia to maintain the rectal, subcutaneous interscapular and lumbar temperature was investigated at an ambient temperature of 35°C or 22°C and the results compared with control newborns delivered without anesthesia. When the newborns were exposed to 35°C, the anesthetics studied had no effect on the ability of the newborn to maintain the rectal temperature and the subcutaneous temperature over the interscapular fat pad was similar to the lumbar subcutaneous temperature thereby indicating that nonshivering thermogenesis was not activated. However, at an ambient temperature of 22°C Innovar-Vet or methoxyflurane reduced the temperature difference between interscapular and lumbar temperatures to 1.6°C compared to 2.5°C in controls and the difference between core temperature and ambient temperature to 3.5°C greater compared to 7.5°C in controls. Ketamine hydrochloride or lidocaine hydrochloride plus meperidine has less effect because these compounds lack adrenergic blocking properties. These data suggest that newborns delivered under anesthetics or tranquillizers that have adrenergic blocking properties require a warm (35°C) environment to prevent a fall in core temperature. 相似文献