首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   96篇
  免费   2篇
  国内免费   1篇
林业   3篇
农学   3篇
基础科学   1篇
  10篇
综合类   31篇
农作物   3篇
水产渔业   4篇
畜牧兽医   43篇
植物保护   1篇
  2023年   3篇
  2022年   1篇
  2020年   4篇
  2019年   4篇
  2018年   3篇
  2017年   1篇
  2015年   1篇
  2014年   3篇
  2013年   3篇
  2012年   4篇
  2011年   3篇
  2010年   2篇
  2009年   7篇
  2008年   6篇
  2007年   2篇
  2006年   2篇
  2005年   6篇
  2003年   1篇
  2002年   5篇
  2001年   2篇
  1999年   1篇
  1996年   1篇
  1991年   1篇
  1987年   2篇
  1986年   1篇
  1984年   1篇
  1981年   1篇
  1971年   1篇
  1970年   2篇
  1965年   1篇
  1954年   1篇
  1943年   1篇
  1939年   1篇
  1935年   1篇
  1929年   1篇
  1928年   1篇
  1924年   2篇
  1923年   1篇
  1922年   1篇
  1918年   1篇
  1917年   1篇
  1916年   1篇
  1915年   2篇
  1913年   1篇
  1912年   2篇
  1911年   1篇
  1909年   2篇
  1903年   1篇
  1900年   1篇
  1886年   1篇
排序方式: 共有99条查询结果,搜索用时 250 毫秒
91.
OBJECTIVE: To assess a ready-to-use formulation of dicyclanil to prevent blowfly strike on Merino sheep under Australian conditions. DESIGN: Randomised clinical trials conducted in an environment house and in the field. PROCEDURE: Two environment house trials were used to measure the protection against flystrike provide by a jetting or a ready-to-use 5% spray-on formulation of dicyclanil over 22 and 31 weeks respectively. Oviposition and strikes were recorded weekly for each sheep. In two field trials the occurrence of strike in Merino sheep treated off-shears or in long wool with dicyclanil or with cyromazine was compared for up to 38 weeks after treatment. Efficacy was assessed by calculating the cumulative percentage of sheep struck. RESULTS: Under environment house conditions, sheep jetted with dicyclanil at 1.50, 0.75 and 0.30 g per sheep developed 0, 8 and 9 strikes respectively during the 22 weeks of the trial, whereas there were 358 strikes present in the placebo group. Sheep sprayed with dicyclanil at 2.25, 1.50 and 0.75 g per sheep developed 5, 11 and 29 strikes respectively between weeks 15 and 31 after treatment, whereas there were 185 strikes present in the untreated controls. In field trials the cumulative percentage of sheep struck reached 1% between weeks 12 to 13 after sheep had been treated with cyromazine. Sheep treated with dicyclanil reached the 1% limit at week 21 after treatment. CONCLUSION: Under Australian field conditions, a ready-to-use 5% spray-on formulation of dicyclanil applied off-shears or to long wool protected Merino sheep from blowfly strike for a period of at least 20 weeks.  相似文献   
92.
93.
This study investigated the performance of steers grazing rhizomatous birdsfoot trefoil (Lotus corniculatus L.) (RBFT) compared to nonrhizomatous birdsfoot trefoil (BFT) in pure stands or when interseeded with endophyte-free tall fescue (Festuca arundinacea Schreb.; TF). Five forage treatments of RBFT, BFT, TF, RBFT+TF, and BFT+TF (four replicate paddocks per treatment) were continuously stocked in spring and fall of 1998 and spring of 1999. Grazing for individual treatments was terminated when pasture mass fell below 900 kg/ha. Average daily gain was greatest (P < 0.10) in pure stands of BFT and RBFT, but total forage production, and thus grazing days, for these treatments was low. Average daily gain for steers grazing BFT+TF and RBFT+TF treatments was not different from (spring and fall 1998) or greater (P < 0.10) (spring 1999) than that for TF. Total forage production of BFT+TF and RBFT+TF was greater (P < 0.10) than that of TF in spring 1998. In fall 1998, BFT+TF produced more (P < 0.10) total forage than either RBFT+TF or TF, and in spring 1999, RBFT+TF had less (P < 0.10) total forage than TF or BFT+TF. Total steer days on mixed pastures were greater (P < 0.10) than that for TF in spring and fall 1998 but not different from those for TF in spring 1999. In all three trials total weight gain/hectare was greater (P < 0.10) for RBFT+TF and BFT+TF than for TF. The RBFT+TF and BFT +TF had greater (P < 0.05) CP than TF in spring and fall 1998 and less (P < 0.05) NDF and ADF in fall 1998. We concluded that either RBFT or BFT could be interseeded with tall fescue to enhance ADG and total steer days.  相似文献   
94.
通过对兽药生产企业GMP的考察验收,发现兽药生产企业在实施GMP过程中存在着诸多共性问题.笔者汇总分析了企业在兽药GMP硬件、软件建设和验收准备中普遍存在的问题,对这些问题进行了讨论,以期使企业减少在实施GMP建设中的返工现象和不必要的损失,并做好兽药GMP检查验收的各项准备工作.  相似文献   
95.
Schoolyards and suburban parks are two environments where active tick surveillance may inform local management approaches. Even in a state such as New York with a robust active tick surveillance programme operated by the state Department of Health, these settings are not routinely covered. The goal of this study was to highlight the importance of active surveillance for tick‐borne pathogens by describing their prevalence in ticks collected from schoolyards and suburban parks and to guide the use of integrated pest management in these settings. Tick dragging was performed in three regions of New York State: Long Island, the Lower Hudson Valley and the Capital Region. A total of 19 schoolyards and 32 parks were sampled. The location, habitat and weather at the time of tick collection were recorded. Ticks were speciated and tested for the presence of 17 pathogens with a novel application of nanoscale real‐time PCR. The causative agents of Lyme disease, anaplasmosis, babesiosis and Powassan virus disease were all detected from Ixodes scapularis in various sites throughout the capital region and south‐eastern counties of New York state. The most common agent detected was Borrelia burgdorferi, and coinfection rates were as high as 36%. This surveillance study also captured the first of the invasive Asian longhorned tick species, Haemaphysalis longicornis, in New York state (collected 2 June 2017). Results from this study highlight the importance of collaborative efforts and data sharing for improvement of surveillance for tick‐borne disease agents.  相似文献   
96.
97.
98.
99.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号