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   93篇
  免费   4篇
  国内免费   2篇
林业   3篇
农学   4篇
基础科学   2篇
  10篇
综合类   42篇
农作物   12篇
水产渔业   4篇
畜牧兽医   14篇
园艺   5篇
植物保护   3篇
  2023年   2篇
  2022年   1篇
  2021年   2篇
  2020年   2篇
  2019年   1篇
  2017年   2篇
  2016年   1篇
  2015年   1篇
  2014年   4篇
  2013年   8篇
  2012年   8篇
  2011年   10篇
  2010年   5篇
  2009年   7篇
  2008年   6篇
  2007年   5篇
  2006年   13篇
  2005年   5篇
  2004年   6篇
  2003年   1篇
  1999年   1篇
  1998年   1篇
  1997年   2篇
  1996年   1篇
  1995年   1篇
  1993年   1篇
  1992年   2篇
排序方式: 共有99条查询结果,搜索用时 0 毫秒
1.
为进一步研究苦豆子生物碱对奶牛乳房炎致病菌的体外抗菌活性,选取金黄色葡萄球菌、大肠杆菌和无乳链球菌三种奶牛乳腺炎病原菌,采用苦豆子总碱、氧化苦参碱、氧化槐定碱、槐定碱等4种苦豆子生物碱进行药物敏感度试验,以试管二倍稀释法测定其最小抑菌浓度(MIC).结果表明:苦豆子总碱与槐定碱对引起奶牛乳腺炎的三种病原菌金黄色葡萄球菌、无乳链球菌及大肠杆菌均有相似的抑菌活性,其中最为敏感的为无乳链球菌,MIC为3.125 ~ 6.25 mg/mL,其次为大肠杆菌与金黄色葡萄球菌,MIC为6.25 ~ 12.5 mg/mL.氧化苦参碱与氧化槐定碱表现较弱的抑菌活性.研究为苦豆子生物碱用于奶牛乳房炎的预防与治疗提供了依据.  相似文献   
2.
In recent years the fate of human and animal pathogen microorganisms as a potential pollutant of the environment has been paid increased attention. Substantial quantities of these compounds and their metabolites are excreted, flushed down the drain, discarded as waste, or left over in animal feedlots. After passing to the sewer, several of these compounds are not adequately eliminated by the methods that are currently used in sewage treatment. Substantial quantities of biosolids and livestock manure end up on agricultural land. Effective sanitation of the environment, particularly of some of its special parts, which can be a source of spreading of diseases, plays an important role in prevention of infectious diseases. In this respect special attention should be paid to the disinfection of infected farm animal excrements. Sanitation of excrements should, on the one hand, ensure effective inhibition of infectious agents and, on the other hand, comply with the requirement of preserving the composition of the manure so it can be used in agricultural production.  相似文献   
3.
The potential negative environmental impact of manure and biological waste (BW) can be minimised at a profit by recycling plant nutrients in the food chain. Current large-scale livestock production, epizootic diseases and increasing globalisation increase the need for biosecurity, to minimise the risk of disease transmission to the food chain. Arable use of manure and BW can inadvertently spread infectious diseases; opinion differs concerning the risk levels. To obtain general acceptance for arable use, a hygienically safe end-product is needed. This paper provides a detailed discussion of treatment alternatives for co-treatment, i.e., mixture before treatment of manure and BW. Composting, anaerobic digestion and ammonia treatment are the three options given. A decision support tool is also presented and discussed. Suitable treatment methods must combine biosecurity aspects with environmental, economic and nutrient recycling aspects to create a beneficial whole-farm approach.  相似文献   
4.
为了提高板栗的贮藏保鲜效果,开发无公害的天然保鲜剂,以北京产板栗为试材,通过对板栗贮藏期间主要病害病原菌的多次分离、鉴定、接种,初步判断引起板栗贮藏病害的主要病原菌为松生厚星裂壳孢和可可毛球二孢,利用厚朴提取物洗果,可以减少板栗贮藏病害的发生,试验结果表明,在发病高峰时对照发病率为18.35%,利用厚朴提取物洗果的发病率为2.85% ̄3.03%。  相似文献   
5.
观赏植物种类繁多,在这些植物的育种、销售及栽培过程中,与植物病害相关的各种病原物也被广泛传播。因此,培育抗病品种一直是园艺育种工作者的重要目标性状之一。在粮食作物中,抗病育种方面已经投入了很大的人力物力,新的生物技术不断被用于作物新品种的培育。但对于观赏植物而言,这些新技术应用范围还极为有限。本综述对园艺植物抗病育种现状进行了总结,并对育种前景进行了预测。  相似文献   
6.
采用黑曲霉为发酵剂对活性污泥进行全程无公害处理并对各种病原菌的生长变化进行监测。结果表明病原菌总量在发酵过程中呈“马鞍型”变化。由于不同堆肥处理组合的C/N比及添加辅料的不同,导致各种病原菌的生长规律出现差异;采用黑曲霉处理城市活性污泥可使病原菌数目减少,但不能达到完全杀灭的目的;对发酵污泥进行200℃高温物理处理后,病原菌存活量为零。因而活性污泥在堆肥后必须经过高温物理处理才能达到安全化和资源化。  相似文献   
7.
Biosolids, mainly from textile industries and the rest from households, were vermicomposted with Eisenia fetida, cow manure and oat straw for 2 months at three different moisture contents (60%, 70% and 80% dry weight base) in triplicate to reduce pathogens and toxic organic compounds, and to find the best medium for growth of E. fetida. The vermicompost with the best stability and maturity and a weight loss of 18% was obtained with 1,800 g biosolid, no straw and 800 g manure at 70% water content. This vermicompost had the following properties: pH 7.9; organic C content of 163 g kg–1; an electrolytic conductivity of 11 mS cm–1; a humic-to-fulvic acid ratio of 0.5 (HA/FA); total N content of 9 g kg–1; water soluble C (Cw) less than 0.5%; cation exchange capacity of 41 cmolc kg–1; a respiration rate of 188 mg CO2-C kg–1 compost-C day–1; a NO3/CO2 ratio greater than 8; and a NH4+/NO3 ratio lower than 0.16. The vermicompost gave a germination index for cress (Lepidium sativum) of 80% after 2 months while the earthworm production increased 1.2-fold and volatile solids decreased five times. In addition, the vermicompost contained less than 3 CFU g–1Salmonella spp., no fecal coliforms and Shigella spp. and no eggs of helminths. Concentration of sodium was 152 mg kg–1 dry compost, while concentrations of chromium, copper, zinc and lead were below the limits established by the USEPA.  相似文献   
8.
There is an increasing trend to require more efficient use of water resources, both in urban and rural environments. A major mechanism that can be used to achieve greater efficiencies is the reuse of water that once would have been discarded into the environment after use. The reuse of water for agricultural irrigation is often viewed as a positive means of recycling water due to the potential large volumes of water that can be used. Recycled water can have the advantage of being a constant, reliable water source and reduces the amount of water extracted from the environment. In addition, in some cases treatment requirements may be need to be less than for water used in an urban environment due to less potential human contact. There are concerns and unknowns, however, about the impact of the quality of the recycled water, both on the crop itself and on the end users of the crops. Water quality issues that can create real or perceived problems in agriculture include nutrient and sodium concentrations, heavy metals, and the presence of contaminants such as human and animal pathogens, pharmaceuticals and endocrine disruptors. Social attitudes to the use of crops that have been irrigated with recycled waters and the resulting impact on market value of crops are also a major consideration. This paper will discuss the benefits from using different types of recycled water and outline the current knowledge and opinions relating to risks such as water quality issues.  相似文献   
9.
研究了城市污泥快速堆肥前后病原菌数量的变化。结果表明:堆肥处理后病原菌数量虽有所下降,但不能达到完全消灭病原菌的目的。  相似文献   
10.
三七细菌性叶斑病病原菌鉴定   总被引:1,自引:0,他引:1  
[目的]对引起三七细菌性叶宽病的病原菌进行系统鉴定。[方法]以2011及2012年在云南文山及石林县的三七苗圃采集的三七细菌性叶斑病病株为材料,采用柯赫氏法则,检测分离菌株致病性并重新分离得到病原菌。通过病菌形态观察、致病性测定、16SrD—NA序列分析及生理生化特性分析(Biolog系统)对其进行鉴定。[结果]确定三七细菌性叶斑病病原菌为丁香假单胞菌丁香致病变种(Pseudomonas syringae pv.syringae)。[结论]该研究为三七细菌性叶瘫病菌详细鉴定的国内首报。  相似文献   
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