全文获取类型
收费全文 | 12414篇 |
免费 | 574篇 |
国内免费 | 888篇 |
专业分类
林业 | 1118篇 |
农学 | 894篇 |
基础科学 | 1091篇 |
1414篇 | |
综合类 | 5687篇 |
农作物 | 754篇 |
水产渔业 | 156篇 |
畜牧兽医 | 1973篇 |
园艺 | 302篇 |
植物保护 | 487篇 |
出版年
2024年 | 74篇 |
2023年 | 212篇 |
2022年 | 379篇 |
2021年 | 423篇 |
2020年 | 413篇 |
2019年 | 454篇 |
2018年 | 261篇 |
2017年 | 465篇 |
2016年 | 533篇 |
2015年 | 423篇 |
2014年 | 760篇 |
2013年 | 692篇 |
2012年 | 1025篇 |
2011年 | 1027篇 |
2010年 | 754篇 |
2009年 | 774篇 |
2008年 | 632篇 |
2007年 | 786篇 |
2006年 | 690篇 |
2005年 | 600篇 |
2004年 | 517篇 |
2003年 | 393篇 |
2002年 | 257篇 |
2001年 | 252篇 |
2000年 | 217篇 |
1999年 | 148篇 |
1998年 | 136篇 |
1997年 | 104篇 |
1996年 | 98篇 |
1995年 | 49篇 |
1994年 | 56篇 |
1993年 | 52篇 |
1992年 | 55篇 |
1991年 | 31篇 |
1990年 | 31篇 |
1989年 | 28篇 |
1988年 | 22篇 |
1987年 | 21篇 |
1986年 | 11篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1973年 | 1篇 |
1963年 | 1篇 |
1962年 | 3篇 |
1956年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
This case report describes tuberculosis (TB) due to infection with Mycobacterium bovis (M. bovis) in alpaca (Lama pacos) on a farm in Ireland. Two severely debilitated alpaca were presented to the University Veterinary Hospital, University College Dublin in November 2004. Bloods were taken, and haematology and biochemistry results were indicative of chronic infection. Radiological examination showed evidence of diffuse granulomatous pneumonia suggestive of tuberculosis. On necropsy there were granulomatous lesions present throughout many body organs including lung, liver, kidney, intestine as well on peritoneum and mesentery. Culture of acid-fast bacilli from lesions led to a diagnosis of tuberculosis due to M. bovis. The use of intradermal skin testing proved inefficient and unreliable for ante mortem diagnosis of tuberculosis in alpaca. Infection due to M. bovis should be considered among the differential diagnoses of debilitating diseases in alpaca, particularly those farmed in areas known to be traditional black spots for tuberculosis in cattle. 相似文献
72.
73.
74.
B. Matharoo‐Ball A. K. Miles C. S. Creaser G. Ball R. Rees 《Veterinary and comparative oncology》2008,6(4):224-247
Companion animals are exposed to similar environmental conditions and carcinogens as humans. In some animal cancers, there also appears to be the same genetic changes associated as in humans. However, little work has been carried out in cancer biomarker identification in animals. The recent dramatic advances in molecular medicine, genomics, proteomics and translational research will allow biomarker identification, which may provide the best strategies for veterinarians and clinicians to combat disease by early diagnosis and administration of effective treatments. Proteomics may have important applications in cancer diagnosis, prognosis and predictive clinical outcome that could directly change clinical practice by affecting critical elemen‐ts of care and management. This review summarizes the advances in proteomics that has propelled us to this exciting age of clinical proteomics, and highlights the future work that is required for this to become a reality. In this review, we will discuss the available proteomic technologies and their limitations, and highlight the key areas of research and how they have been used to discover cancer biomarkers. The principles described here are equally applicable to human and animal disease, but implementation of ‘omic’ technologies requires stringent guidelines for collection of clinical material, the application of analytical techniques and interpretation of the data. 相似文献
75.
76.
77.
79.
Effect of feeding different levels of wheat roti on nutrient utilization and blood metabolite profile in semi‐captive Asian elephants (Elephas maximus) 下载免费PDF全文
A. Das M. Saini S. Katole S. S. Kullu D. Swarup A. K. Sharma 《Journal of animal physiology and animal nutrition》2015,99(2):367-378
This experiment was conducted to study the effect of different levels of wheat roti (WR) on nutrient utilization and blood metabolites in Asian elephants fed roughages ad libitum. Nine (3 M, 6 F) Asian elephants (14–52 years of age, 1909–3968 kg BW) were used in an experiment based on replicated Latin square design. Animals in each group (n = 3) were assigned to one of the three dietary treatments in a manner that animals in all the three groups were exposed to all the three treatments in three different periods. Each feeding trial comprised 30 days (25 days of adaptation and 5 days collection period). The amount of WR fed to the elephants was 0.18, 0.12 and 0.06% of BW in groups I, II and III, respectively. They were allowed to forage in the nearby forests for 6 h/day and to bathe for 2 h/day. The animals had ad libitum access to cut Rohini (Mallotus philippensis) trees in their night shelter. Intake and apparent digestibility of dry matter (DM), crude protein (CP), gross energy (GE), Ca, P, Fe, Cu and Zn were measured. Feed consumption was not significantly different among the groups. Significant (p < 0.01) decrease in digestibility of DM and GE and blood glucose concentration was observed with decreased level of WR in the diet. Feeding of WR at 0.06% of BW supplied adequate amount of DE, CP, Ca, P, Fe, Cu and Zn to meet requirement for adult maintenance. Feeding of WR in excess of 0.06% of BW supplied DE in excess of requirement, increased blood glucose concentration which may cause obesity and other associated health problems. It was concluded that the amount of WR should be restricted to 0.06% of BW in the diet of captive Asian elephants. 相似文献
80.
Isolation of faecal chlamydia from sheep in Britain andtheir characterization by cultural properties
Faeces samples were taken per rectum from sheep on 26 farms in England and Wales and examined for thepresence of chlamydia by culture McCoy cell monolayers. Thirteen of the fars were known to have had abortion outbreaks associated with Chlamydia psittaci (enzootic abortion) and 13 were free of this infection. The chlamydia isolated were characterized by cultural techniques. Chlamydia were isolated from the faeces of lambs on all 26 farms and the prevalence of infection varied from 5–50% on individual farms. There was no significant difference between the proportion of infected lambs on farms where enzootic abortion was present or absent. Lambs first showed infection when they were 3 months old and the prevalence rate of infection increased up to 9 months old. No chlamydia were isolated from the faeces of 316 adult ewes. The chlamydia were identified as enteric rather than abortion type and thus were C. pecorum rather than C. psittaci. 相似文献