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   205篇
  免费   17篇
  国内免费   9篇
林业   6篇
农学   15篇
基础科学   1篇
  19篇
综合类   41篇
农作物   28篇
水产渔业   3篇
畜牧兽医   25篇
园艺   10篇
植物保护   83篇
  2024年   1篇
  2023年   3篇
  2022年   3篇
  2021年   3篇
  2020年   4篇
  2019年   3篇
  2018年   4篇
  2017年   8篇
  2016年   11篇
  2015年   5篇
  2014年   13篇
  2013年   7篇
  2012年   22篇
  2011年   16篇
  2010年   11篇
  2009年   16篇
  2008年   11篇
  2007年   12篇
  2006年   14篇
  2005年   11篇
  2004年   11篇
  2003年   9篇
  2002年   5篇
  2001年   5篇
  2000年   3篇
  1998年   4篇
  1997年   1篇
  1996年   3篇
  1995年   1篇
  1994年   1篇
  1992年   2篇
  1991年   1篇
  1989年   2篇
  1987年   1篇
  1985年   2篇
  1983年   1篇
  1982年   1篇
排序方式: 共有231条查询结果,搜索用时 15 毫秒
71.
为了观察聚维酮碘消毒剂"可得福"对犬手术伤口的消毒效果,选用2~3月龄、3~5 kg的本地杂交犬10只,随机分为试验组和对照组,试验组选用1.0%~0.5%"可得福",对照组选用2%碘酊和0.1%苯扎溴铵,在相同的手术条件与伤口情形下,对比两组犬分别使用上述药液涂擦或清洗对手术伤口的影响。结果显示,使用"可得福"消毒的有效性和安全性优于2%碘酊和0.1%苯扎溴铵。  相似文献   
72.
蔬菜大棚常用土壤消毒剂   总被引:1,自引:0,他引:1  
对蔬菜大棚常用的几种土壤消毒药荆的性能、使用方法、应用领域、消毒机理及各自的特点进行了阐述.介绍了几种可以取代溴甲烷的土壤消毒剂,指出了今后用于蔬菜大棚的土壤消毒剂的发展趋势.今后土壤消毒荆的开发应朝着安全、高效、环境友好、使用方便的方向发展,以适应不同农业种植的各种要求.  相似文献   
73.
ABSTRACT

Composts can have beneficial effects on strawberry production and these benefits can be dependent on the type of compost used. Four commercial composts were evaluated: cow manure, spent mushroom, yard trimmings, and vermicompost. The nutrient composition, abundance of fungi and bacteria, and microbial activity were determined. Five field trials assessed effects on plant growth, root development, soil microbial activity, nutrient availability, and yield during one growing season. Manure and mushroom compost significantly increased soil electrical conductivity levels to 9.9 ± 1.7 dS/m and 7.3 ± 0.8 dS/m, respectively. Manure, yard trimmings, and mushroom composts shifted soil pH toward optimal levels for up to 7 months. Mushroom compost had the greatest effect on soil nitrate, which was up to 32 mg/kg of soil higher than non-amended soil. Significant effects on yield were more likely to occur where environmental conditions and management practices were less than optimal or compost was not routinely added. Several factors important to plant production were significantly affected by compost: soil salinity, plant establishment, soil nitrate, production curves, soil microbial activity, and soil pH.  相似文献   
74.
ABSTRACT

We evaluated the effectiveness of alternative fumigants on weed control and plant productivity in two nurseries located at high elevation and low latitude (Ciudad Guzman, Jalisco), during 2013 and 2014 at Driscoll’s and Lassen Canyon South nurseries. Treatments were: MB:chloropicrin (MB:CP); 1,3-dichloropropene:CP; CP alone; metam sodium (MS) alone; dimethyl disulphide (DMDS):CP; and sequentially applied CP and MS. A rotary spading machine was used for MS and CP followed by MS. All treatments produced similar pest suppression and runner-plant yields during 2013 and 2014. However, CP alone showed very poor control of the most abundant weed (barnyardgrass, Echinochloa crus-galli). Two years of work on MB alternatives were not sufficient to provide reliable recommendations on this critical need, therefore, the Methyl Bromide Technical Options Committee recommended critical use nomination for MB in 2015.  相似文献   
75.
吴敬荣 《粮食储藏》1996,25(2):13-15
大型船舶熏蒸,要求做到“安全、有效、快捷、经济”,具有要求比较高,流动性大,熏蒸人员活动范围小,货物堆放比较集中,牵涉面比较广,工作难度比较大等特点。因此,一般采用高浓度、短时间的熏蒸方法.目前,多采用溴甲烷(CH3Br)熏蒸,单位用药量50g/m3,密闭时间为48h左右.  相似文献   
76.
溴甲烷熏蒸处理鲜切花及其害虫的试验   总被引:1,自引:4,他引:1  
使用溴甲烷对16种切花及主要携带的南美斑潜蝇、棉蚜、二斑叶螨及花蓟马等害虫进行熏蒸试验。结果表明:如仅带有蚜虫或蓟马,所有供试切花均可进行熏蒸处理;如带有叶螨或斑潜蝇,金鱼草、菊花和孔雀草不宜熏蒸,玫瑰、勿忘我、康乃馨、百合、马蹄莲、情人草、非洲菊、剑兰和石斛兰可以熏蒸,满天星、天堂鸟、橙菠萝和紫罗兰在21℃下以36g/m^3,1.5h处理,对品质有轻度影响,但可100%杀死叶螨及斑潜蝇的成虫、幼虫和蛹。由于斑潜蝇卵的耐药性比其它虫态要强,对带有斑潜蝇卵而耐药性较差的切花,可以在采收后于室温下放置1~3天,待卵孵化后再进行熏蒸处理。  相似文献   
77.
木质包装松材线虫溴甲烷熏蒸处理   总被引:8,自引:0,他引:8       下载免费PDF全文
为寻求一定温度下溴甲烷熏蒸处理杀灭木质包装中松材线虫的有效浓度和时间,给国际贸易中木质包装松材线虫的熏蒸处理提供科学依据,进行了木质包装松材线虫溴甲烷熏蒸处理研究.研究分实验室基础试验和集装箱应用试验两部分,先在实验室中筛选出熏蒸有效浓度和时间,再于集装箱中进行应用试验.结果表明:11~15、16~20、≥21℃时,溴甲烷剂量分别为64、56、48g/m3,熏蒸24h,24h时浓度分别不低于32、28、24g/m3,即CT值分别为1152、1008、864 gh/m3,能够100%杀灭木质包装中松材线虫的成虫、幼虫及卵.此外,证实了国际植物检疫措施标准ISPM NO.15<国际贸易中木质包装材料控制准则>中熏蒸处理的要求偏低,不能完全杀灭木质包装中松材线虫.  相似文献   
78.
Purple and yellow nutsedge are two of the most troublesome weeds in the world. In the south-eastern USA, both weeds are common in vegetable crops and are the most difficult weeds to control in this region. A greenhouse experiment was conducted to evaluate the herbicidal activity of five liquid isothiocyanates (ITCs) (benzoyl, o -tolyl, m -tolyl, tert -octyl, and 3-fluorophenyl) on purple and yellow nutsedge. All ITCs were applied to soil in jars at 0, 100, 1000, 5000, and 10 000 nmol g−1 of soil and sealed for 72 h to prevent gaseous losses, followed by nutsedge growth evaluations after an additional 18 days. All ITCs reduced purple and yellow nutsedge shoot density and shoot biomass over the concentrations evaluated, with differences in the effectiveness on each species apparent among the compounds. Based on the lethal concentration values for shoot density, all ITCs were more effective in suppressing purple nutsedge than yellow nutsedge. Benzoyl and 3-fluorophenyl were generally the most effective of the five ITCs evaluated.  相似文献   
79.
Propargyl bromide is being investigated for its potential as a soil fumigant. Characterization of the fate of propargyl bromide in soil is important in determining both efficacy and the threat of environmental contamination. These experiments investigated some of the factors affecting the rate of propargyl bromide degradation in soil and quantified some of the products formed as a result of propargyl bromide degradation in four soils of differing composition and at three initial propargyl bromide concentrations. In all soils at all initial propargyl bromide concentrations, equimolar formation of Br- was observed during propargyl bromide degradation, but little propargyl alcohol (product of hydrolysis) was formed. The apparent first-order degradation coefficient (k) increased with decreasing initial propargyl bromide concentration in all soils, but the mass degraded per unit time increased with increasing propargyl bromide concentration. The rate of propargyl bromide degradation increased with increasing soil organic matter content, and the k value was correlated to the organic carbon content of the soil (correlation coefficient > 0.97 for all concentrations). Repeated application of propargyl bromide did not increase the rate of propargyl bromide degradation in soil. Addition of Br- did not affect the rate of propargyl bromide transformation in soil, so accumulation of Br- in the soil is not expected to impede propargyl bromide degradation.  相似文献   
80.
Many benzimidazoles are known inducers of cytochromes P4501A (CYP1A) in laboratory animals and cell lines. As flubendazole and mebendazole are benzimidazole anthelmintics often used in a pheasant, in the present study an effect of these drugs in primary cultures of pheasant (Phasianus colchicus) hepatocytes was investigated. After 48 h incubation of the hepatocytes with the benzimidazoles (0.2-5 microM), CYP1A activities -- ethoxyresorufin O-deethylation (EROD) and methoxyresorufin O-demethylation (MROD) activities were measured and the CYP1A protein levels were determined by Western blotting. None of the tested benzimidazoles influenced the CYP1A protein content. No pharmacologically significant enhancement of CYP1A after exposure of the hepatocytes to flubendazole and mebendazole was found. Inhibition of the EROD/MROD activities caused by both tested substances was observed only at the highest concentration (5 microM). From a point of view of CYP1A induction or inhibition, the treatment of pheasants by both anthelmintics tested seems to be safe. Our study demonstrates the inter-species differences in CYP1A inducibility and the importance of induction/inhibition studies on target animals.  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