全文获取类型
收费全文 | 2021篇 |
免费 | 99篇 |
专业分类
林业 | 51篇 |
农学 | 58篇 |
基础科学 | 3篇 |
336篇 | |
综合类 | 286篇 |
农作物 | 252篇 |
水产渔业 | 142篇 |
畜牧兽医 | 861篇 |
园艺 | 25篇 |
植物保护 | 106篇 |
出版年
2022年 | 23篇 |
2021年 | 38篇 |
2020年 | 23篇 |
2019年 | 26篇 |
2018年 | 52篇 |
2017年 | 45篇 |
2016年 | 45篇 |
2015年 | 44篇 |
2014年 | 56篇 |
2013年 | 109篇 |
2012年 | 101篇 |
2011年 | 137篇 |
2010年 | 61篇 |
2009年 | 51篇 |
2008年 | 96篇 |
2007年 | 107篇 |
2006年 | 64篇 |
2005年 | 77篇 |
2004年 | 72篇 |
2003年 | 72篇 |
2002年 | 51篇 |
2001年 | 33篇 |
2000年 | 43篇 |
1999年 | 37篇 |
1998年 | 17篇 |
1997年 | 18篇 |
1996年 | 17篇 |
1994年 | 14篇 |
1992年 | 26篇 |
1991年 | 39篇 |
1990年 | 33篇 |
1989年 | 29篇 |
1988年 | 20篇 |
1987年 | 28篇 |
1986年 | 27篇 |
1985年 | 27篇 |
1984年 | 20篇 |
1983年 | 19篇 |
1979年 | 20篇 |
1978年 | 11篇 |
1977年 | 19篇 |
1976年 | 11篇 |
1974年 | 17篇 |
1973年 | 23篇 |
1972年 | 18篇 |
1971年 | 14篇 |
1970年 | 18篇 |
1969年 | 19篇 |
1968年 | 12篇 |
1966年 | 11篇 |
排序方式: 共有2120条查询结果,搜索用时 78 毫秒
231.
Young NJ Thomas CJ Thompson I Collins ME Brownlie J 《Preventive veterinary medicine》2005,72(1-2):115-20; discussion 215-9
Immune responses to non-structural protein 3 (NS3) of bovine viral diarrhoea virus (BVDV) were investigated. cDNA encoding NS3 from type 1a BVDV was used to vaccinate five calves, another five calves remained unvaccinated. Three weeks after final vaccination animals were challenged intranasally with heterologous type 1a BVDV. Anti-NS3 antibodies were detected in only one animal post-vaccination. Partial protection from virus challenge was observed in the vaccinates. Virus was not isolated from nasal mucosa of two vaccinates, and virus clearance from nasal mucosa was faster in the vaccinates compared to the controls. While elevated rectal temperatures were evident in both groups 7 days post-challenge, the mean increase in the controls was twice that observed in the vaccinates. In conclusion, NS3 DNA vaccination induced humoral immunity in one calf, and prevented fever and virus establishment in the nasal mucosa in 2/5 calves, demonstrating the efficacy of NS3 vaccination, which may benefit future development of pestivirus and flavivirus vaccines. 相似文献
232.
Friedrichs KR Young KM 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2005,34(3):218-223
BACKGROUND: Comprehensive quality control (QC) procedures are necessary to ensure accurate analytic method performance. Highly automated systems typically have inherent QC programs that facilitate performance and maintenance of QC procedures; however, for bench-top analyzers that lack internal systems, independent QC programs must be used. OBJECTIVE: The goal of this study was to evaluate the adaptability of an independent QC program, EZ Runs (Westgard QC Inc, Madison, WI, USA), to the maintenance of QC procedures for a mechanical, bench-top coagulation unit and to compare the results with our current, manual, QC method in a qualitative way. METHODS: A QC application file for activated partial thromboplastin time (aPTT) performed on a STart4 (Diagnostica Stago, Parsippany, NJ) was created in EZ Runs. Results were recorded and interpreted using this software package as well as the current, manual, QC method. RESULTS: EZ Runs was adaptable to QC monitoring for the bench-top analyzer, and the program permitted identification of both random and systematic errors not detected by the manual QC system. CONCLUSIONS: EZ Runs improved the performance and maintenance of QC procedures for this bench-top coagulation analyzer. The results indicated the need to improve staff training in assay performance and QC interpretation. In addition, use of the software program indicated that a multirule QC design was needed to monitor assay performance. 相似文献
233.
Kim DY Mauldin GE Hosgood G Cho DY 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2005,19(4):610-612
Melanocytic tumors are relatively common in dogs and most often occur in the oral cavity, lip, skin, digit, and eye. There are notable differences in the behavior of these tumors, depending on their anatomical location. The majority of oral melanomas and two-thirds of melanomas arising from the digit are malignant, whereas most of melanomas originating from the haired skin are benign. The anus and perianal areas are very uncommon sites for melanocytic tumors in domestic animals except horses, and most of those tumors in horses are malignant. To our knowledge, perianal malignant melanoma has not been reported in the dog and its prognosis is unknown. 相似文献
234.
235.
236.
237.
Calcitonin activity in ultimobranchial neoplasms from bulls 总被引:1,自引:0,他引:1
238.
Forty-four elements were determined in crown vetch sampled along a heavily travelled highway in Virginia. Twenty-four elements including Ba, Br, Cr, Pb, Sn, and Sr were higher in this vegetation than in control vetch. When the highway-grown vetch was fed as 45% (dry weight) of the diet to guinea pigs for 100 days, Ba, Br, Cr, Pb, Sn and Sr were found at higher concentrations in the various animal tissues than in those of guinea pigs similarly fed the control crown vetch. 相似文献
239.
Ketamine anaesthesia in the pregnant sheep 总被引:1,自引:0,他引:1
240.