全文获取类型
收费全文 | 1049篇 |
免费 | 65篇 |
国内免费 | 1篇 |
专业分类
林业 | 110篇 |
农学 | 29篇 |
基础科学 | 4篇 |
277篇 | |
综合类 | 69篇 |
农作物 | 34篇 |
水产渔业 | 142篇 |
畜牧兽医 | 364篇 |
园艺 | 30篇 |
植物保护 | 56篇 |
出版年
2023年 | 8篇 |
2022年 | 15篇 |
2021年 | 14篇 |
2020年 | 27篇 |
2019年 | 22篇 |
2018年 | 35篇 |
2017年 | 34篇 |
2016年 | 31篇 |
2015年 | 33篇 |
2014年 | 37篇 |
2013年 | 83篇 |
2012年 | 65篇 |
2011年 | 88篇 |
2010年 | 65篇 |
2009年 | 31篇 |
2008年 | 61篇 |
2007年 | 48篇 |
2006年 | 33篇 |
2005年 | 46篇 |
2004年 | 39篇 |
2003年 | 47篇 |
2002年 | 37篇 |
2001年 | 31篇 |
2000年 | 18篇 |
1999年 | 9篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 9篇 |
1991年 | 11篇 |
1990年 | 10篇 |
1989年 | 4篇 |
1988年 | 10篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 7篇 |
1981年 | 3篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1971年 | 3篇 |
1969年 | 4篇 |
1967年 | 4篇 |
1966年 | 6篇 |
1965年 | 4篇 |
1964年 | 3篇 |
1950年 | 2篇 |
排序方式: 共有1115条查询结果,搜索用时 125 毫秒
1.
E A ter Laak J H Noordergraaf R P Dieltjes 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1992,39(8):553-562
The prevalence of mycoplasmas in the respiratory tracts of 148 pneumonic calves originating from 25 herds in the Netherlands is reported. Four types of culture media were used to isolate mycoplasmas: solid modified Edward medium, 2 types of Friis media, and A7B differential agar medium. Mycoplasmas were isolated both from nasal swab specimens and lung lavage fluids collected from live calves and from nasal mucosa and lung tissue specimens collected post mortem. All of the mycoplasma strains isolated could be identified as either Ureaplasma diversum (isolated from 80% of 25 herds), Mycoplasma dispar (92%), M. bovirhinis (88%), M. bovis (20%), M. bovigenitalium (4%), M. arginini (16%), or M. canis (12%). Isolation rates of M. dispar and U. diversum were considerably higher from lung lavage fluids than from nasal swab specimens. M. bovis was detected only in fattening herds and not in dairy herds. The respiratory tracts of 75% of the calves examined contained at least 2 mycoplasma species. In total, 25 different combinations of mycoplasma species were detected in specimens collected from noses and lungs. The pathogenic species U. diversum and M. dispar had not been isolated before in the Netherlands. 相似文献
2.
JaroslawOlavHorbaczuk 《中国家禽》2004,26(11):35-37
通过对全球,特别是对主要生产鸵鸟肉和皮产品的欧洲的观察发现在20世纪末人们对鸵鸟产品产生的兴趣日渐浓厚。在鸵鸟产品的总收入中肉和皮产品所占份额在不同国家和不同年份有所区别。在2000-2004年间,中欧和东欧的鸵鸟肉收入在商品鸟总收入中所占的比例为51.2%~ 相似文献
3.
Uptake of I131-labelled triiodothyronine by erythrocytes (EU test) as a test of thyroid function has been studied in cattle. The normal EU value for 141 Swedish Red-and-white cows was 6.99 ± 0.95 (range 4.45–10.23) at an incubation time of one hour. Statistically significantly higher values were obtained for newly-calved cows. The EU values for calves are significantly higher but by 12 to 18 months of age decline to the same level as for older cows.The principle of the test is described and the results obtained compared with those for human beings. The EU test is suitable for screening thyroid function for large groups of animals and for studying associations between thyroid activity and different production qualities. 相似文献
4.
5.
Ross Gordon COOPER Jaroslaw Olav HORBANCZUK Noboru FUJIHARA 《Animal Science Journal》2004,75(2):89-95
The ostrich is an important animal in many livestock industries. A significant threat to this industry is losses from diseases. Newcastle disease is a notifiable, highly contagious viral infection of ostriches. Avian influenza may be transmitted from waterfowl, shorebirds and gulls to ostriches. Borna disease virus is a viral neurotropic infection spread mainly by rodents and felines. Crimean‐Congo hemorrhagic fever is a viral disease transmitted by Hyalomma ticks to humans. Avipoxvirus afflicts ostrich chicks and is transmitted by mosquitoes or by direct contact with a pox lesion. Maintenance of a healthy and profitable enterprise requires the implementation, with assistance from the local veterinary authority, of comprehensive, practical and effective methods of health management and preventative medicine. 相似文献
6.
7.
L. N. Rønnow Kjærulff N. J. Dorch Lauritsen C. Thorn Ekstrøm S. Østergaard E. Olsen S. Hyldahl Laursen C. Lindegaard 《Equine Veterinary Education》2021,33(7):360-367
Caudal epidural analgesia is a well-established therapeutic modality for pain alleviation in horses. Additionally, epidural analgesia could potentially be a complementary diagnostic tool for confirmation of pain-related conditions in horses presenting with nonspecific signs of poor performance or rideability issues. To use the epidural as a diagnostic tool, the administered medications should provide efficient analgesia without accompanying adverse effects. Therefore, the objectives of the current study were to evaluate the analgesic properties and effects on locomotor function, mentation and physical examination parameters of caudal epidural co-administration of methadone and morphine in horses. Five mares received a caudal epidural injection of 0.1 mg/kg bwt methadone and 0.1 mg/kg bwt morphine diluted to a total volume of 4.4 mL/100 kg. Before and several times thereafter, horses were subjected to mechanical nociceptive threshold evaluation, physical examination, assessment of mentation and locomotor function examination. Horses were assigned ataxia scores (0–4) by a group of inexperienced raters (three senior-year veterinary students) and a group of experienced raters (two board-certified internal medicine specialists) that assessed the locomotor examinations either live or video-based. The epidural co-administration of methadone and morphine resulted in clinically relevant and statistically significant increases of horses’ tolerance to mechanical noxious stimuli at the coccygeal, perineal, sacral, lumbar and thoracic regions. Analgesia was evident after 4.4 h and lasted at least 5 h. Regional differences in the onset of analgesia reflected a cranial spread of the analgesic solution. No horses showed signs of gait disturbances; the overall median ataxia score was 0 at all times; and the average difference in scores between two randomly selected raters for a random horse at a random time point was 0.377 indicating high inter-rater agreement. There were no adverse changes of mentation and physical examination parameters. Observed side effects included signs of decreased frequency of defaecation, generalised sweating, and pruritus. 相似文献
8.
9.
10.