全文获取类型
收费全文 | 227篇 |
免费 | 9篇 |
专业分类
林业 | 97篇 |
农学 | 4篇 |
基础科学 | 4篇 |
48篇 | |
综合类 | 37篇 |
农作物 | 5篇 |
水产渔业 | 2篇 |
畜牧兽医 | 31篇 |
园艺 | 2篇 |
植物保护 | 6篇 |
出版年
2023年 | 2篇 |
2021年 | 2篇 |
2018年 | 3篇 |
2016年 | 6篇 |
2014年 | 5篇 |
2013年 | 14篇 |
2012年 | 7篇 |
2011年 | 19篇 |
2010年 | 7篇 |
2009年 | 8篇 |
2008年 | 13篇 |
2007年 | 9篇 |
2006年 | 9篇 |
2005年 | 12篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1991年 | 3篇 |
1989年 | 3篇 |
1986年 | 2篇 |
1980年 | 2篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1974年 | 2篇 |
1973年 | 6篇 |
1972年 | 2篇 |
1971年 | 5篇 |
1970年 | 4篇 |
1967年 | 3篇 |
1966年 | 4篇 |
1963年 | 2篇 |
1956年 | 3篇 |
1954年 | 2篇 |
1953年 | 2篇 |
1941年 | 1篇 |
1940年 | 1篇 |
1938年 | 1篇 |
1937年 | 2篇 |
1936年 | 1篇 |
1935年 | 1篇 |
1934年 | 3篇 |
1931年 | 1篇 |
1930年 | 4篇 |
1929年 | 3篇 |
1928年 | 1篇 |
排序方式: 共有236条查询结果,搜索用时 15 毫秒
1.
Ohne Zusammenfassung
Schweitzerbartsche Veriagsbuchhandlung, Stuttgart 相似文献
2.
Erwin Otten 《Journal of pest science》1948,21(4):59-60
Ohne Zusammenfassung 相似文献
3.
4.
5.
Lea Middendorf Marion Schmicke Kristian Düngelhoef Erwin Sieverding Heinrich Windhaus Dieter Mischok Dimitri Radko Christian Visscher 《Journal of animal physiology and animal nutrition》2021,105(Z2):70-78
The hepatic lipidosis (HL) in fattening turkeys is a disease has been known for a long time, but the cause and pathogenesis is still not clarified. A recent study reported unexplained high levels of iron in liver tissue of fattening turkeys suffering from HL. In this study, the iron status, possible infectious or inflammatory influences in form of an acute phase reaction and the analysis of fatty acid pattern in liver tissue of turkeys affected by HL were examined. Three cases of HL on three different fattening turkey farms were investigated during the outbreak of the disease. Clinically affected and non-affected animals were subjected to a pathological examination, where the diagnosis HL or non-affected was made. In total, 70 birds were examined (40 with HL, 30 without HL) and blood and liver samples were taken. Additionally, samples from 15 slaughtered birds were taken as a further control group. In liver tissue, the iron content and the content of long-chain fatty acids were determined; in blood samples, ferritin and transferrin were measured. The iron content in liver tissue was more than three times higher for animals with HL than among non-affected animals and the control group. The transferrin levels were lowest for animals with HL, highest in the control group and in between for non-affected animals. The fatty acid pattern in liver tissue of affected animals indicated a shift from polyunsaturated fatty acids to saturated fatty acids and monounsaturated fatty acids compared to the control group and the non-affected animals. Overall, the non-affected animals of a flock affected by HL were similar to the healthy animals of the abattoir. The low acute phase protein levels for animals with HL together with high iron contents could indicate a previous malnutrition/starvation period and/or severe liver damage for those animals suffering from HL. 相似文献
6.
7.
Dwarf shrub litter is thought to be of poor quality and palatability for macro-decomposers. In laboratory feeding experiments, however, it was found that this litter type represents a potential food source for earthworms and millipedes. Here we tested whether this is true under natural conditions by conducting a 1 year field experiment on an abandoned alpine pasture in Tyrol (Austria). As the natural isotopic signatures of plant litter do not allow discriminating between different plant species, dwarf shrub litter, artificially enriched in 15N, was offered in experimental plots to the macro-decomposer community. Both the earthworm Lumbricus rubellus and the millipede Cylindrojulus fulviceps fed on dwarf shrub litter as indicated by their increased δ15N signatures, but IsoError analysis indicated a clear preference for grass litter for all macro-decomposer species investigated.Soil δ15N signatures were only marginally affected by the experimental provision of 15N-enriched dwarf shrub litter, whereas litter from other, unlabelled, plants became enriched by the isotopic tracer to some extent. Except for one grass species, plants harvested at the end of the experiment were not enriched in 15N, suggesting that the N-uptake from decomposing litter material by plants on abandoned alpine pastureland is slow. 相似文献
8.
9.
Nöckler K Kutzer P Reif S Rosenberger N Draeger A Bahn P Göllner C Erlbeck C 《Berliner und Münchener tier?rztliche Wochenschrift》2003,116(9-10):368-372
Brucella (B.) canis was isolated from ejaculate of a 4-year old Korthals-Griffon male dog after occurrence of epididymitis and orchitis. Despite several trials of therapy with different antibiotics relapes occurred, with B. canis being isolated from ejaculate, blood and urine samples, respectively. Bacteriological examinations were added by serological testing over a period of about 1.5 years. During the study SAT serum titre steadily dropped from 1:200 to 1:50. By CFT, B. canis antibodies were detectable at the beginning with a titre of 1:320 and to the end of the study with titres between 1:80 and 1:160. 相似文献
10.