全文获取类型
收费全文 | 269篇 |
免费 | 28篇 |
专业分类
农学 | 1篇 |
3篇 | |
综合类 | 21篇 |
农作物 | 6篇 |
水产渔业 | 7篇 |
畜牧兽医 | 250篇 |
园艺 | 7篇 |
植物保护 | 2篇 |
出版年
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 10篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 4篇 |
2014年 | 11篇 |
2013年 | 19篇 |
2012年 | 7篇 |
2011年 | 14篇 |
2010年 | 8篇 |
2009年 | 7篇 |
2008年 | 13篇 |
2007年 | 18篇 |
2006年 | 12篇 |
2005年 | 13篇 |
2004年 | 11篇 |
2003年 | 7篇 |
2002年 | 8篇 |
2001年 | 8篇 |
2000年 | 3篇 |
1999年 | 7篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1981年 | 4篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1975年 | 5篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 6篇 |
1971年 | 5篇 |
1970年 | 7篇 |
1969年 | 5篇 |
1968年 | 1篇 |
1963年 | 1篇 |
1954年 | 1篇 |
1953年 | 1篇 |
1927年 | 1篇 |
1922年 | 2篇 |
排序方式: 共有297条查询结果,搜索用时 265 毫秒
291.
J. J. Pavek D. L. Corsini D. R. Douglas R. E. Ohms J. G. Garner H. C. McKay C. Stanger G. E. Vogt W. C. Sparks R. Kunkel J. R. Davis A. J. Walz C. E. Dallimore J. Augustin 《American Journal of Potato Research》1978,55(12):685-690
‘BUTTE’, a new long russet potato variety, was released by the Agricultural Research Service, U. S. Department of Agriculture and the Idaho, Oregon, and Washington Agricultural Experiment Stations in April, 1977. Its tubers are similar to those of ‘Russet Burbank’ but BUTTE offers several advantages to growers and processors. BUTTE has averaged 7% more total yield and 25% more U.S. No. 1’s than Russet Burbank over 51 location-years of testing across southern Idaho, eastern Oregon, and in the Columbia Basin. Its specific gravity in these trials averaged .004 higher than that of Russet Burbank. Dehydrating quality of BUTTE is superior to that of Russet Burbank and the product has longer shelf life. BUTTE french fries well although it accumulates slightly more sugars in storage than does Russet Burbank. Its vitamin C content has averaged 58% higher and protein content 20% higher than that of Russet Burbank. BUTTE is hypersensitive to virus X and resistant to net necrosis. Other disease reactions are similar to those of Russet Burbank. 相似文献
292.
Sharon E. Roche Naomi Cogger M. Graeme Garner Anak Agung Gde Putra Jenny-Ann L.M.L. Toribio 《Preventive veterinary medicine》2014
Indonesia continues to report the highest number of human and poultry cases of highly pathogenic avian influenza H5N1. The disease is considered to be endemic on the island of Bali. Live bird markets are integral in the poultry supply chain on Bali and are important, nutritionally and culturally, for the rural and urban human populations. Due to the lack of biosecurity practiced along the supply chain from producer to live bird markets, there is a need to understand the risks associated with the spread of H5N1 through live bird movements for effective control. Resources to control H5N1 in Indonesia are very limited and cost effective strategies are needed. We assessed the probability a live bird market is infected through live poultry movements and assessed the effects of implementing two simple and low cost control measures on this risk. Results suggest there is a high risk a live bird market is infected (0.78), and risk mitigation strategies such as detecting and removing infected poultry from markets reduce this risk somewhat (range 0.67–0.76). The study demonstrates the key role live poultry movements play in transmitting H5N1 and the need to implement a variety of control measures to reduce disease spread. 相似文献
293.
This study examined the effect of acute bull exposure around the time of artificial insemination (AI) on oxytocin and progesterone concentrations, and pregnancy rates in dairy cows. Ninety six dairy cows, stratified according to parity into primiparous and pluriparous, were divided into three groups; short bull exposure (SBE; 10 min, n = 32), long bull exposure (LBE; 4 h, n = 32) or no bull exposure (NBE; n = 32). On day 45 post‐partum, all cows were treated with PGF2α on three occasions 11–14 days apart to synchronize oestrus. They were submitted to fixed time AI 80 h after the third PGF2α injection. Cows in the SBE and LBE groups were artificially inseminated 5 min after the introduction of the bull. From a subset of cows (n = 6 per group; three primiparous and three pluriparous), blood samples were collected once every 5 min starting 15 min before AI until 15 min after AI and analysed for oxytocin concentrations. Additional blood samples were collected for measurements of progesterone (P4) concentrations once daily for 4 days starting on the day of AI and once every 3 days thereafter until day 22. The effects of bull exposure, time, parity, difficulty of AI, and pregnancy on oxytocin and P4 concentrations were analysed using the mixed linear model procedure. Mean oxytocin concentrations or change in oxytocin concentrations after bull exposure or AI were not different among groups. Pregnancy rates for the NBE, SBE and LBE groups were 55.5%, 33.3% and 44.4%, respectively, and were not different among groups. In conclusion, acute bull exposure around the time of AI did not affect oxytocin and progesterone concentrations and did not improve pregnancy rates in dairy cattle under these farms conditions. 相似文献
294.
Relatively unoxidized black uranium ores from sandstone deposits in the western United States show deviations in the uranium-235 to uranium-234 ratio throughout a range from 40 percent excess uranium-234 to 40 percent deficient uranium-234 with respect to a reference uranium-235 to uranium-234 ratio. The deficient uranium-234 is leached preferentially to uranium-238 and the excess uranium-234 is believed to result from deposition of uranium-234 enriched in solutions from leached deposits. 相似文献
295.
296.
Garner EC Bernard R Wang W Zhuang X Rudner DZ Mitchison T 《Science (New York, N.Y.)》2011,333(6039):222-225
Rod-shaped bacteria elongate by the action of cell wall synthesis complexes linked to underlying dynamic MreB filaments. To understand how the movements of these filaments relate to cell wall synthesis, we characterized the dynamics of MreB and the cell wall elongation machinery using high-precision particle tracking in Bacillus subtilis. We found that MreB and the elongation machinery moved circumferentially around the cell, perpendicular to its length, with nearby synthesis complexes and MreB filaments moving independently in both directions. Inhibition of cell wall synthesis by various methods blocked the movement of MreB. Thus, bacteria elongate by the uncoordinated, circumferential movements of synthetic complexes that insert radial hoops of new peptidoglycan during their transit, possibly driving the motion of the underlying MreB filaments. 相似文献
297.
Carles Juan-Sallés Rui Patrício Joseba Garrido Michael M. Garner 《Journal of Exotic Pet Medicine》2009,18(4):306-310
Although mycobacteria have been isolated from rodents, overt mycobacteriosis is rare in any rodent species. A pet adult male Richardson's ground squirrel (Spermophilus richardsonii) died after a short course of alopecia, anorexia, and weight loss. Necropsy and subsequent histopathological examination of tissue samples revealed disseminated granulomatous inflammation involving the lungs, lymph nodes, liver, intestine, adrenal gland, spleen, pleura, and peritoneum. Ziehl-Neelsen stain revealed high numbers of acid-fast bacilli within the cytoplasm of macrophages and multinucleated giant cells. Polymerase chain reaction performed on paraffin-embedded tissues was positive for Mycobacterium avium subsp. avium and negative for M. bovis-tuberculosis complex. Three females housed with this squirrel remained clinically healthy, and mycobacterial cultures of pooled feces from these animals were negative. To the authors' knowledge, this is the second report of disseminated mycobacteriosis in squirrels involving M. avium subsp. avium, with both cases described recently in the Iberian Peninsula. 相似文献