全文获取类型
收费全文 | 156篇 |
免费 | 3篇 |
专业分类
林业 | 13篇 |
农学 | 2篇 |
基础科学 | 2篇 |
36篇 | |
综合类 | 22篇 |
农作物 | 13篇 |
水产渔业 | 3篇 |
畜牧兽医 | 54篇 |
园艺 | 3篇 |
植物保护 | 11篇 |
出版年
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 4篇 |
2012年 | 8篇 |
2011年 | 12篇 |
2010年 | 9篇 |
2009年 | 14篇 |
2008年 | 14篇 |
2007年 | 11篇 |
2006年 | 20篇 |
2005年 | 6篇 |
2004年 | 6篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1974年 | 1篇 |
1965年 | 1篇 |
1959年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有159条查询结果,搜索用时 31 毫秒
61.
Dariusz Piwczyski Beata Sitkowska Magdalena Kolenda Marcin Brzozowski Joanna Aerts Pamela M. Schork 《Animal Science Journal》2020,91(1)
The purpose of this paper was to utilize the decision trees technique to determine the factors responsible for high monthly milk yield in Polish Holstein‐Friesian cows from 27 herds equipped with milking robots. The applied statistical method—the decision tree technique—showed that the most important factors responsible for monthly milk yield of dairy cows using robots were, in descending order of importance: milking frequency, lactation number, month of milking, and type of lying stall. At the same time, it has been ascertained that the highest monthly milk yield (47.24 kg) can be expected from multiparous cows kept in barns with a deep bedding that were milked more frequently than three times per day. On the other hand, the lowest milk production (13.56 kg) was observed among dairy cows milked less frequently than two times a day, with an average number of milked quarters lower than 3.97. The application of the decision trees technique allows a breeder to select appropriate levels of environmental factors and parameters that will help to ensure maximized milk production. 相似文献
62.
63.
L A Hoogenboom A Pijpers P W van de Steeg M M Aerts J H Verheijden H A Kuiper 《The Veterinary quarterly》1988,10(2):136-139
The in vivo interaction of sulphadimidine (SDM) with nitrite and nitrate has been investigated in pigs. It was shown that the combined oral treatment with SDM and nitrite but not nitrate leads to the formation of a deaminated compound, which becomes the major metabolite in plasma soon after cessation of the treatment. The major in vitro reaction product, 1,3-di(4-[N(4,6-dimethyl-2-pyrimidinyl)]-sulphamoylphenyl)-triazen e, DDPSPT as has been reported previously, could not be detected in blood, urine or faeces of the exposed animals. No effect of nitrite or nitrate could be observed on the acetylation of SDM. 相似文献
64.
Liquid chromatographic determination of chloramphenicol residues in meat: interlaboratory study 总被引:2,自引:0,他引:2
R M Aerts H J Keukens G A Werdmuller 《Journal of the Association of Official Analytical Chemists》1989,72(4):570-576
A liquid chromatographic (LC) method for the determination of chloramphenicol (CAP) residues in meat at the 10 microgram/kg level was tested in an interlaboratory study. The method used, based on aqueous extraction and sample cleanup with a cartridge containing Extrelut, was published earlier. A prestudy to familiarize collaborators with the method was performed before the actual interlaboratory precision study. The meat samples used in the precision study were prepared by diluting dosed chicken and pig muscle tissues with blank tissues from other species. Fourteen laboratories received 20 meat samples; 13 laboratories actually participated in the study. Two blank samples and 2 positive samples each of pig, calf, chicken, lamb, and cow meat were tested. The chloramphenicol concentrations in the positive samples ranged from 6.5 to 21 micrograms/kg. The overall mean reproducibility coefficient of variation was 17.9% after the results per laboratory were corrected for the mean recovery obtained within each sample series. The overall mean recovery was 55.1% with a coefficient of variation of 18.0% at the 10 micrograms/kg level. The limit of detection, based on chromatograms of blank samples, was estimated to be 1.5 micrograms/kg of chloramphenicol. No false positives or false negatives were observed in the concentration range tested; only 2 false positive results above the detection limit (1.7 and 6 micrograms/kg) on a total number of 60 blank analyses (3.3%) were observed. 相似文献
65.
Batsi Germain Sonwa Denis Jean Mangaza Lisette Ebuy Jérôme Kahindo Jean-Marie 《Agroforestry Systems》2021,95(8):1505-1517
Agroforestry Systems - In the perspective of using cocoa as a response to climate change, a preliminary carbon stock assessment was conducted in cocoa agroforests of the Bengamisa-Yangambi forest... 相似文献
66.
67.
Diane Lefebvre Eric Depiereux Jean-Marie Giffroy Claire Diederich 《Journal of Veterinary Behavior: Clinical Applications and Research》2010,5(1):2-6
We quantified the behavioral perturbation induced in kenneled dogs using a classical procedure of video equipment installation. Using 14-minute sessions of videorecording, 136 hours of recordings were collected from 14 healthy, individually housed Malinois shepherds. Our results show that dogs trotted, jumped, and ran more during the first 2 minutes of recording. These behaviors suggest an intense but brief agitation following installation of the video equipment. These results lead us to advise researchers, when studying the behavior of kenneled dogs by videotaping, to evaluate the duration of perturbations stemming from their particular experimental procedure and to carefully examine it. 相似文献
68.
Jean-Marie Denoix DVM PhD Nathalie Crevier DVM MSc Bernard Roger MD Jean-Francois Lebas MD PhD 《Veterinary radiology & ultrasound》1993,34(6):405-411
The purpose of this study was to assess the ability of magnetic resonance imaging to depict abnormalities of the equine foot. MRI was performed on isolated limbs which had lesions of the foot. These images were made in 3 perpendicular planes (sagittal, transverse and frontal) using a T1 weighted sequence and were 5mm thick. Images accurately depicted normal and pathologic structures in the foot and proved to be very precise for documenting degenerative joint disease, navicular disease and laminitis lesions. This preliminary study demonstrates the considerable potential of MRI in the diagnosis of locomotor problems in the horse. 相似文献
69.
Namata H Méroc E Aerts M Faes C Abrahantes JC Imberechts H Mintiens K 《Preventive veterinary medicine》2008,83(3-4):323-336
Since the 1980s, the prevalence of Salmonella in Belgian poultry layers and broilers has greatly fluctuated with a rise observed in 2003 and a significant decrease in 2005. In order to alleviate the risk at egg consumer level, it is crucial to understand the factors which influence the contamination and the spread of Salmonella in laying hens. To study such determinants we explored the Belgian data from the 2005 baseline study on the prevalence of Salmonella in laying flocks of Gallus gallus in the European Union. The response variables corresponded to presence or absence of Salmonella from dust and faecal samples taken from the environment of a Belgian layer flock. The explanatory variables included: region of Belgium, sampling time (month the flock was sampled), production type (cage or barn and free range), Salmonella vaccination status, flock age and flock size. Analyses of these data were performed using a bivariate logistic regression model assuming independence between the two responses and bivariate generalized estimating equations model, which incorporates the correlation between the two responses on the same flock. The main risk factor that was identified was rearing flocks in cages compared to barns and free-range systems. The results also showed a significant higher risk for Salmonella for a 1 week increase in flocks’ age as well as with a unit increase in the size of the flock. 相似文献
70.
Three dogs with presumptive cardiogenic pulmonary edema underwent a thoracic ultrasonographic examination. Multiple ring-down artifacts involving both sides of the thorax emanating from the pleural-lung interface were detected. When clinical and radiographic signs of pulmonary edema were resolved, ring-down artifacts were not observed. The ring-down artifact may be a useful diagnostic sign for screening the lung of animals with acute respiratory distress where radiographs are not feasible. 相似文献