全文获取类型
收费全文 | 131906篇 |
免费 | 6781篇 |
国内免费 | 96篇 |
专业分类
林业 | 5111篇 |
农学 | 3616篇 |
基础科学 | 901篇 |
14104篇 | |
综合类 | 26785篇 |
农作物 | 5054篇 |
水产渔业 | 5714篇 |
畜牧兽医 | 68270篇 |
园艺 | 1411篇 |
植物保护 | 7817篇 |
出版年
2018年 | 1429篇 |
2017年 | 1586篇 |
2016年 | 1500篇 |
2015年 | 1295篇 |
2014年 | 1584篇 |
2013年 | 4513篇 |
2012年 | 3052篇 |
2011年 | 3788篇 |
2010年 | 2378篇 |
2009年 | 2401篇 |
2008年 | 3649篇 |
2007年 | 3425篇 |
2006年 | 3438篇 |
2005年 | 3182篇 |
2004年 | 3077篇 |
2003年 | 3140篇 |
2002年 | 2999篇 |
2001年 | 3735篇 |
2000年 | 3780篇 |
1999年 | 2962篇 |
1995年 | 1456篇 |
1994年 | 1324篇 |
1993年 | 1276篇 |
1992年 | 2797篇 |
1991年 | 3061篇 |
1990年 | 2960篇 |
1989年 | 2977篇 |
1988年 | 2847篇 |
1987年 | 2921篇 |
1986年 | 2981篇 |
1985年 | 2863篇 |
1984年 | 2328篇 |
1983年 | 2047篇 |
1982年 | 1429篇 |
1981年 | 1313篇 |
1980年 | 1246篇 |
1979年 | 2190篇 |
1978年 | 1820篇 |
1977年 | 1574篇 |
1976年 | 1501篇 |
1975年 | 1630篇 |
1974年 | 2128篇 |
1973年 | 2066篇 |
1972年 | 2105篇 |
1971年 | 1998篇 |
1970年 | 1896篇 |
1969年 | 1691篇 |
1968年 | 1423篇 |
1967年 | 1570篇 |
1966年 | 1321篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
H.S. Cameron D.V.M. Ph.D. 《New Zealand veterinary journal》2013,61(3):41-44
Extract First let me express my appreciation of being the recipient of a Fulbright Fellowship for research in New Zealand and also for the privilege of discussing brucellosis before the New Zealand Veterinary Association. 相似文献
942.
Extract Whenever disease is discussed in terms of beef production, in New Zealand it is certain to include infertility (brucellosis, vibriosis), metabolic diseases (bloat, staggers) and possibly exotic diseases and their prevention. On the rare occasion that parasitism is considered it tends somehow to find itself, along with selenium and other deficiency diseases, under a general heading of nutrition or management. This is probably because, while parasitism is still recognized as an infectious disease with clear clinical signs in severe cases, the tendency is to ignore its presence unless nutritional or management changes force a confrontation. 相似文献
943.
944.
Evaluation of a screening programme for identification of mannosidosis heterozygotes in angus cattle
R.D. Jolly B.V.Sc Ph.D. M.A.C.V.Sc. K.G. Thompson B.V.Sc C.A. Tse B.Sc. 《New Zealand veterinary journal》2013,61(10):185-190
Sir, — In recent years, much research effort has been directed towards identifying the cause of Ryegrass staggers (RGS). Many promising leads have been investigated, including studies of fungi in soil, ryegrass leaves, and dead leaf litter that could produce tremorgenic mycotoxins(3). Several groups of fungi produce tremorgens(4) which, when injected into sheep, produce symptoms similar to those in field outbreaks of RGS. However, under field conditions, populations of these fungi have not been shown to differ significantly between toxic and non-toxic pasture(7) (McKenzie &; Byford, unpublished data). 相似文献
945.
Extract Madam:— Members of the public have brought to my attention that there are some within our profession performing laparoscopic A.I. in goats in an unsatisfactory fashion. 相似文献
946.
B. M. Buddle M. Herceg M. J. Ralston H. D. Pulford K. R. Millar D. C. Elliott 《New Zealand veterinary journal》2013,61(4):167-170
A study was undertaken to indicate the importance of different causes of death in goats and to investigate the management factors which influence these problems. Over a 15 month period, 324 dead goats were received from 67 farms in the Horowhenua, Wairarapa, Wanganui and Wellington regions. Although a wide range of diseases was encountered in the study, the major causes of mortality could be divided into 4 groups: problems directly related to management, microbial diseases, nematode parasitism, and trace element related deficiencies and toxicities. The highest proportion of deaths related directly to management problems and included deaths from hypothermia, mismothering, premature birth, ruminal acidosis, pregnancy toxaemia, trauma, and plant and chemical toxicities. In larger flocks, microbial diseases including Pasteurella pneumonia and yersiniosis were major problems. Deaths from nematode parasitism were predominantly observed in goats 12 months of age and older. White muscle disease (selenium/vitamin E deficiency) was the major trace element deficiency causing death in goats. The influence of factors including age of goat, flock size and management practices on the major causes of death are discussed. 相似文献
947.
F. YANG N. SUN Y. X. SUN Q. SHAN H. Y. ZHAO D. P. ZENG Z. L. ZENG 《Journal of veterinary pharmacology and therapeutics》2013,36(2):192-200
Yang, F., Sun, N., Sun, Y. X., Shan, Q., Zhao, H. Y., Zeng, D. P., Zeng, Z. L. A physiologically based pharmacokinetics model for florfenicol in crucian carp and oral‐to‐intramuscular extrapolation. J. vet. Pharmacol. Therap. 36 , 192–200. In this study, an oral physiologically based pharmacokinetics (PBPK) model was developed for florfenicol in crucian carp (Carassius auratus). Subsequently, oral‐to‐intramuscular extrapolation was performed and the two models were used to predict florfenicol concentrations in the edible tissues of crucian carp. The oral model gave good predictions in most tissues, except for kidney and liver in which the florfenicol concentrations were underestimated at the later time points. In contrast, using the intramuscular model, the concentrations in the kidney were overestimated at the later time points. Both models had the best predictive ability in the main edible tissue, the muscle. The oral model also accurately predicted the florfenicol concentrations in the muscle after multiple doses. The present study demonstrated the feasibility of predicting florfenicol concentrations in the edible tissues of crucian carp using a route‐to‐route extrapolation method. 相似文献
948.
949.
950.