全文获取类型
收费全文 | 209篇 |
免费 | 5篇 |
专业分类
林业 | 46篇 |
农学 | 20篇 |
基础科学 | 1篇 |
45篇 | |
综合类 | 31篇 |
农作物 | 2篇 |
畜牧兽医 | 56篇 |
园艺 | 4篇 |
植物保护 | 9篇 |
出版年
2022年 | 2篇 |
2021年 | 3篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 4篇 |
2013年 | 8篇 |
2012年 | 7篇 |
2011年 | 16篇 |
2010年 | 4篇 |
2009年 | 6篇 |
2008年 | 11篇 |
2007年 | 8篇 |
2006年 | 14篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 6篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1998年 | 2篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1986年 | 3篇 |
1982年 | 2篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1969年 | 2篇 |
1953年 | 2篇 |
1939年 | 2篇 |
1938年 | 2篇 |
1936年 | 2篇 |
1934年 | 2篇 |
1933年 | 4篇 |
1932年 | 1篇 |
1931年 | 4篇 |
1929年 | 1篇 |
1928年 | 2篇 |
1926年 | 1篇 |
排序方式: 共有214条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
95.
Albrecht Hase 《Journal of pest science》1954,27(4):59-60
Ohne Zusammenfassung 相似文献
96.
97.
98.
Jadwiga Andrzejewska Francisco E. Contreras‐Govea Anna Pastuszka Karol Kotwica Kenneth A. Albrecht 《Grass and Forage Science》2019,74(1):97-103
Spring‐sown oat (Avena sativa L.) is well adapted for forage production in Central Europe; however, environmental conditions make this crop susceptible to crown rust disease (Puccinia coronata) when grown in summer. The objective of this study was to assess oat cultivars sown in late summer, when conditions for crown rust are less favourable, and harvest in autumn for forage with potential use for feeding lactating dairy cows. Three oat cultivars: Berdysz, Zuch and ForagePlus, the first two from Poland and the latter from United States, were sown 1 and 15 August, and 1 September, over three consecutive years, and harvested for forage in late October. The two Polish cultivars had 61% leaf area affected by rust with 1 August sowing, but ForagePlus was not affected by rust with any sowing date. Sowing 15 August significantly reduced crown rust incidence and increased DM yield of the Polish cultivars 21% relative to the 1 August sowing date, but decreased ForagePlus DM yield by 35%. Sowing 1 September resulted in best forage nutritive value, but the lowest DM yields for all cultivars. Calculated milk production per ton of forage for all cultivars was lowest with the 1 August sowing date. Calculated milk production per hectare was greatest for Berdysz sown in mid‐August. Oat can be sown 15 August and harvested in autumn for forage production, avoiding crown rust disease during summer in Poland. Nutritive value of autumn oat forage is adequate to meet forage requirements of lactating dairy cows. 相似文献
99.
100.
Estrada A Samper JC Lillich JD Rathi RR Brault LS Albrecht BB Imel MM Senne EM 《Journal of the American Veterinary Medical Association》2003,222(12):1740-2, 1707
A 3-year-old Quarter Horse halter stallion was referred for routine semen evaluation. Physically, the stallion's reproductive organs appeared normal. Repeated semen evaluations did not reveal any spermatozoa. Because high activities of alkaline phosphatase are detected in the epididymal fluid and indicative of complete ejaculation, alkaline phosphatase activities were analyzed in several samples, which yielded activities far less than reference values and suggested a blockage of the reproductive tract. Endoscopic evaluation of the urethra and the bulbourethral, prostate, and urethral gland ducts did not reveal abnormalities. The left ductus deferens was exposed surgically, and attempts to pass a catheter through it in a normograde direction met resistance after 20 cm. Laparoscopic abdominal surgery revealed the ductus deferens tapered to a thin structure just cranial to the entrance in the urogenital fold, cranial and lateral to the bladder. Both ductus deferentia were similarly affected. The symmetry and bilateral nature of the abnormalities were strong indications of a possible congenital defect. 相似文献