全文获取类型
收费全文 | 845篇 |
免费 | 37篇 |
专业分类
林业 | 29篇 |
农学 | 17篇 |
基础科学 | 6篇 |
93篇 | |
综合类 | 154篇 |
农作物 | 30篇 |
水产渔业 | 31篇 |
畜牧兽医 | 469篇 |
园艺 | 17篇 |
植物保护 | 36篇 |
出版年
2021年 | 8篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 14篇 |
2017年 | 7篇 |
2016年 | 13篇 |
2015年 | 14篇 |
2014年 | 18篇 |
2013年 | 60篇 |
2012年 | 23篇 |
2011年 | 33篇 |
2010年 | 19篇 |
2009年 | 23篇 |
2008年 | 25篇 |
2007年 | 42篇 |
2006年 | 23篇 |
2005年 | 25篇 |
2004年 | 23篇 |
2003年 | 30篇 |
2002年 | 21篇 |
2001年 | 28篇 |
2000年 | 16篇 |
1999年 | 18篇 |
1998年 | 15篇 |
1996年 | 8篇 |
1992年 | 19篇 |
1991年 | 20篇 |
1990年 | 13篇 |
1989年 | 16篇 |
1988年 | 10篇 |
1987年 | 9篇 |
1986年 | 20篇 |
1985年 | 15篇 |
1984年 | 13篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1979年 | 18篇 |
1978年 | 10篇 |
1976年 | 14篇 |
1975年 | 7篇 |
1974年 | 15篇 |
1973年 | 10篇 |
1972年 | 10篇 |
1970年 | 9篇 |
1969年 | 9篇 |
1968年 | 7篇 |
1967年 | 13篇 |
1966年 | 9篇 |
1958年 | 5篇 |
排序方式: 共有882条查询结果,搜索用时 109 毫秒
261.
262.
Misalliance and mummification are two indications for treatment with cloprostenol. Of 56 animals mated accidentally that were treated with 0-5 mg cloprostenol, 12 were more than 150 days pregnant and of those, nine required more than one treatment. The animals treated early in pregnancy aborted promptly and completely whereas two, considered to be 200 days pregnant at the first treatment, failed to respond at all. There were no reports of retained fetal membranes or any adverse side effects. Eight cases of fetal mummification were also submitted for treatment. All aborted within three to five days, the fetus being removed manually per vaginam in each case. Serial blood progesterone assays indicated that successful treatment was associated with leutolysis in all cases. It was concluded that cloprostenol may successfully be used for the treatment of misalliance and mummification of the fetus. 相似文献
263.
264.
Herold FC De Haas K Cooper D Colenbrander B Nöthling JO Theunisen W Spillings B Gerber D 《The Onderstepoort journal of veterinary research》2004,71(3):203-210
Assisted reproductive techniques might prove themselves useful tools in producing buffaloes free of specific diseases (BFSD), which are in demand in South Africa. Freezing protocols for African buffalo semen must not only result in good post-thaw qualities, but must also be practical. Epididymal sperm from six mature African buffalo bulls was collected, diluted with three different semen extenders and frozen. Pre-freezing equilibration times between 2 and 9 h were tested. Total and progressive motility, longevity and acrosomal integrity were measured and compared. The use of Triladyl proved to result in better post-thaw parameters than the other two diluents. Equilibration times of between 4 and 9 h did not influence post-thaw sperm qualities significantly. For some of the treatments, exposure to semen extenders before freezing for less than 4 h resulted in inferior post-thaw semen parameters. 相似文献
265.
Wyse CA Preston T Yam PS Sutton DG Christley RM Hotchkiss JW Mills CA Glidle A Cumming DR Cooper JM Love S 《The Veterinary record》2004,154(12):353-360
The analysis of exhaled breath is a potentially useful method for application in veterinary diagnostics. Breath samples can be easily collected from animals by means of a face mask or collection chamber with minimal disturbance to the animal. After the administration of a 13C-labelled compound the recovery of 13C in breath can be used to investigate gastrointestinal and digestive functions. Exhaled hydrogen can be used to assess orocaecal transit time and malabsorption, and exhaled nitric oxide, carbon monoxide and pentane can be used to assess oxidative stress and inflammation. The analysis of compounds dissolved in the aqueous phase of breath (the exhaled breath condensate) can be used to assess airway inflammation. This review summarises the current status of breath analysis in veterinary medicine, and analyses its potential for assessing animal health and disease. 相似文献
266.
Systemic erysipelas infection was seen in 2-to-4-day-old poults from three separate ranches owned by the same company. The affected poults were all from the same breeder source; poults from other breeder sources were seemingly unaffected. Mortality increased on days 2 and 3, ranging from 2% to 8.5%. Birds submitted were dehydrated and very weak, with one half of the poults submitted having died during transport to the lab. Gross lesions included swollen, congested livers and spleens, as well as hemorrhagic breast muscle in one case. Toes were swollen and reddish-purple in color. The poults had been toe-trimmed during hatchery processing using a commercial microwave. Histologically, periportal inflammation with heterophilic infiltration in the liver was noted. Spleens showed hyalinization of arteries, lymphoid depletion, and necrosis. Toe joints showed purulent synovitis and cellulitis. Gram stains done on impression smears of liver and spleen showed rare to moderate numbers of small gram-positive rods. Erysipelothrix rhusiopathiae was isolated from 18 of 22 livers cultured, five of six toe joints cultured, and from the yolk sac in two birds. 相似文献
267.
268.
Specific in situ hybridization of Haemobartonella felis with a DNA probe and tyramide signal amplification 总被引:2,自引:0,他引:2
Haemobartonella felis is an epierythrocytic bacterium suspected to be the causative agent of feline infectious anemia. Previous studies with a polymerase chain reaction assay have identified a mycoplasmal 16S rRNA gene sequence that coincides with clinical disease and the presence of organisms in the blood. Tissues from a cat experimentally infected with H. felis were used for in situ hybridization studies to physically link this 16S rRNA gene to the organisms on the red cells. A biotin-labeled probe was used in conjunction with tyramide signal amplification to visualize the hybridization signal. This study clearly demonstrates a specific hybridization signal on the red cells in the tissues of the H. felis-infected cat. This in situ hybridization study is the final step in fulfilling the molecular guidelines for disease causation and proves that H. felis, a mycoplasmal organism, is the causative agent of feline infectious anemia. 相似文献
269.
Red pine (Pinus resinosia Ait) and southern pine (Pinus spp.) sapwood blocks were pressure treated with CCA-C at retention of 6.4, 2.0, 1.5 kg?m-3 followed by fixation using 11 post-treatment schedules ranging from 50-70 °C and 5 different relative humidity conditions. The effect of these post-treatment schedules on fixation rate, chemical leachability and decay resistant once were evaluated to better understand the effects of fixation/drying conditions on leachability and biodeterioration. Southern pine blocks fixes slightly slower than red pine. Fixation of CCA at high temperature high humidity, essential initially fixation at high humidity for fixation/drying schedules, resulted in lower leaching of chromium and arsenic elements than high temperature low humidity or initially fixation at the high temperature low humidity conditions. Copper leaching was indicated no significant difference under 11 fixation/drying conditions for both species. Weight losses for southern pine by Chaetomium globosum was lower than red pine by Gloeophyllom trabeum. There were some different capacities of decay resistance for both species under those post treatment conditions. 相似文献
270.