全文获取类型
收费全文 | 218篇 |
免费 | 16篇 |
国内免费 | 8篇 |
专业分类
林业 | 6篇 |
农学 | 15篇 |
基础科学 | 1篇 |
20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 | 93篇 |
出版年
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 | 10篇 |
1999年 | 1篇 |
1998年 | 7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242条查询结果,搜索用时 15 毫秒
41.
[C8mim]Br对蚯蚓抗氧化系统的亚慢性毒性效应 总被引:1,自引:0,他引:1
以OECD标准的基质染毒法测定了离子液体溴化1-辛基-3-甲基咪唑([C8mim]Br)对蚯蚓(Eisenia foetida)的急性毒性效应和亚慢件毒性条件下蚯蚓体内CAT、SOD、GST的活性和GSH、MDA含量的变化,以期初步分析[C8mim]Br对蚯蚓抗氧化系统的作用及其毒性作用的可能机理.结果表明,[C8mim]Br对蚯蚓的7 d-LD50和14 d-LD50分别为206.8 mg·kg-1和159.4 mg·kg-1.亚慢件暴露42 d后蚯蚓体内CAT的活件受到显著抑制;SOD的活性在低浓度(1~5 mg·kg-1)受到抑制,高浓度(20~40 mg·kg-1)被激活;在高浓度处理组(20~40 mg·kg-1)GST的活性显著高于对照.10~40 mg·kg-1浓度的[C8mim]Br处理组GSH的含量显著升高,各处理组MDA含量与对照相比没有差异.推测[C8mim]Br可能通过肠道吸收进入蚯蚓体内,并诱导了蚯蚓体内抗氧化系统的反馈效应. 相似文献
42.
43.
44.
45.
46.
Experiments were carried out to investigate the influence of different modified atmospheres, low pressures alone, methyl bromide
(MB) alone, and MB in combination with CO2 or low pressure, in causing nitidulid beetles to emigrate from infested dried fruit for which dates served as a model. All
the treatments at 4 h and 16 h exposure and at 26°C, had a marked influence in causing insects to abandon the infested fruit.
The most effective treatments at the two exposures were pressures of 50 mm Hg, and 1.4% O2 in air, both of which caused over 87% of the initial insect populations to emigrate from the fruit. At 4 h exposure, 2.8%
O2 was less effective than 100 mm Hg or MB. At 16 h exposure, MB+CO2 was third in effectiveness and 100 mm Hg was one of the least effective treatments. 相似文献
47.
José M. López-Aranda Francisco Gómez Martín Puga Ricardo Zamora Marco A. Cotero 《International Journal of Fruit Science》2016,16(4):16-27
ABSTRACTWe 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
48.
Margaret Lloyd Daniel Kluepfel Thomas Gordon 《International Journal of Fruit Science》2016,16(4):84-107
ABSTRACTComposts 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
49.
Cyperus rotundus (Purple nutsedge) is the most troublesome weed of vegetable crops in the US and a major limitation to the adoption of methyl bromide alternatives due to their ineffectiveness on this weed. Thus, other effective alternatives are needed. Greenhouse studies were conducted to determine the effect of phenyl, allyl, and methyl isothiocyanate (ITC) at two concentrations (1000 and 3000 nmol g−1 in dry soil) on C. rotundus tubers under low-density polyethylene (LDPE) and virtually impermeable film (VIF) mulch. ITC treated soil containing C. rotundus tubers was filled in glass jars and covered with LDPE or VIF mulch for 21 days, followed by nutsedge tuber viability evaluations. Efficacy of all three ITCs increased with increase in concentration from 1000 to 3000 nmol g−1. All ITCs significantly reduced tuber viability, tuber dry weight, and shoot emergence, but methyl ITC was most effective followed by allyl ITC followed by phenyl ITC. Mulch type did not affect efficacy of allyl and methyl ITC, but phenyl ITC efficacy against C. rotundus was improved by using VIF mulch over LDPE mulch. Overall, methyl ITC at 3000 nmol g−1 was the most efficacious control option among three ITC tested regardless of mulch type. 相似文献
50.
用溴甲烷熏蒸松材线虫病木是目前生产上主要的检疫处理方法,本文对影响熏蒸处理效果的单因素分析表明:低温降低了熏蒸效果;增加投药量可提高效果;熏蒸时间以72h为宜;病木含水率高,熏蒸效果差;堆垛上、中下部的效果依次增高;堆垛的大小则以50-70m^3为宜;病木小头直径为6.0-17.1cm之间对熏蒸效果无显著影响,影响处理效果的多因素综合分析表明:影响熏蒸效果的顺序的温、投药量、熏蒸时间。在一定温度条 相似文献