全文获取类型
| 收费全文 | 115篇 |
| 免费 | 12篇 |
| 国内免费 | 1篇 |
专业分类
| 林业 | 2篇 |
| 农学 | 4篇 |
| 30篇 | |
| 综合类 | 8篇 |
| 农作物 | 6篇 |
| 水产渔业 | 12篇 |
| 畜牧兽医 | 41篇 |
| 园艺 | 1篇 |
| 植物保护 | 24篇 |
出版年
| 2023年 | 2篇 |
| 2021年 | 1篇 |
| 2020年 | 6篇 |
| 2019年 | 4篇 |
| 2018年 | 5篇 |
| 2017年 | 8篇 |
| 2016年 | 2篇 |
| 2015年 | 4篇 |
| 2014年 | 5篇 |
| 2013年 | 12篇 |
| 2012年 | 5篇 |
| 2011年 | 9篇 |
| 2010年 | 4篇 |
| 2009年 | 6篇 |
| 2008年 | 8篇 |
| 2007年 | 13篇 |
| 2006年 | 5篇 |
| 2005年 | 6篇 |
| 2004年 | 3篇 |
| 2003年 | 7篇 |
| 2002年 | 6篇 |
| 2001年 | 1篇 |
| 2000年 | 2篇 |
| 1998年 | 1篇 |
| 1995年 | 1篇 |
| 1988年 | 1篇 |
| 1985年 | 1篇 |
排序方式： 共有128条查询结果，搜索用时 203 毫秒
51.
52.
Evan A Mulligan Natalie Ferry Lise Jouanin Jörg Romeis Angharad MR Gatehouse 《Pest management science》2010,66(3):325-336
BACKGROUND: In spite of concern regarding potential non‐target effects of GM crops, few studies have compared GM pest control with conventional methods. The impacts of cypermethrin and oilseed rape expressing oryzacystatin‐1 (OC‐1) were compared in this study on the predator Chrysoperla carnea (Stephens). RESULTS: Adults fed purified rOC‐1 showed a subtle shift in digestive protease profile, with an increasing reliance on serine proteases (chymotrypsin), increase in aspartic proteases and a slight reduction in elastase activity. Although there were no effects on mortality, onset of oviposition was delayed; however, once egg production commenced, egg laying and hatching success rates were comparable with those of controls. Oryzacystatin‐1 expressed in pollen showed no detrimental effects. Cypermethrin had no effect on mortality owing to high levels of non‐specific esterase activity resulting in partial breakdown of the insecticide. In spite of this, there was a significant delay in onset of oviposition and a significant reduction in egg production and viability. CONCLUSION: This study demonstrates the potential for pest management to impact on predators, but importantly it highlights the ability of the predator to detoxify/respond to treatments with different modes of action. In this case, exposure to an insecticide carried a greater fitness cost than exposure to a protease inhibitor expressed in transgenic crops. Copyright © 2009 Society of Chemical Industry 相似文献
53.
54.
Vast areas of hardwood and mixedwood forests of eastern North America have been high-graded in the past and need silvicultural treatments to increase their value and productivity. To rehabilitate a high-graded temperate mixedwood stand, in Quebec, Canada, we used a split–split-split plot design with three replicates to assess different seed-tree and strip cutting systems, in combination with scarification and planting. The experiment consisted of three regeneration cuts in main plots: 10 seed-trees/ha, 40 seed-trees/ha and a 40-m wide strip clearcut (0 seed-tree/ha) with 60 seed-trees/ha in leave strips, thereby resulting in four levels of tree retention, and all included understory brushing. We applied two types of scarification (patch scarification or disk-trenching) to subplots, two regeneration modes (natural regeneration or planting with white spruce [Picea glauca]) to sub-subplots and two mechanical release treatments (softwood or mixedwood production) to planted sub–sub-subplots. Density of seed-trees did not affect the natural regeneration dynamics after 5 years, but disk-trenching was more efficient for the establishment of yellow birch (Betula alleghaniensis) and sugar maple (Acer saccharum). Few seed-trees of desirable white spruce were present and most died standing, confirming the importance of supplemental planting. Height growth of planted seedlings was 15% higher in the 0 and 10 (26–27 cm/year) than in the 40 and 60 (23 cm/year) seed-trees/ha treatments, and release doubled mean height growth (33.1 vs. 16.6 cm/year). Despite intensive site preparation, pre-established beaked hazel (Corylus cornuta) and mountain maple (Acer spicatum) were present at high densities in the regeneration stratum. Controlling this recalcitrant layer might be the greatest challenge for rehabilitating degraded stands of the mixedwood forest, especially since the use of herbicides is prohibited on Quebec’s public lands.
相似文献55.
Megan M. Mathey Sonali Mookerjee Lise L. Mahoney Kazim Gündüz Umesh Rosyara James F. Hancock Philip J. Stewart Vance M. Whitaker Nahla V. Bassil Thomas M. Davis Chad E. Finn 《Euphytica》2017,213(5):112
Ten seedlings from 36 crosses representing eastern and western North American short day and remontant genotypes were evaluated in 2011 and 2012 in California, Michigan, New Hampshire and Oregon, for phenology, flower related traits, plant characteristics, fruit characteristics and fruit chemistry traits. There was significant variability among genotypes, locations and evaluation year for most of the characteristics; however, few genotype × location and genotype × year interactions were detected. General combining ability variance components were significant for all traits and greater than SCA variance components for peduncle length, total flowering weeks, flowering cycles, truss size, growing degree days for harvest data, remontancy, achene position, ease of capping, fruit weight, percent soluble solids, titratable acidity and soluble solids/titratable acidity. ‘Sarian’ was identified as the best contributing parent for remontancy. Narrow-sense heritability estimates were moderate to high (0.33–0.78) for total flowering weeks, flowering cycle, truss size, remontancy, number of runners, fruit weight, pH, and titratable acidity. Having a better understanding of these attributes will provide breeders guidance on the most effective breeding strategies for incorporating superior traits from this germplasm into their programs. 相似文献
56.
Lise C. Deleuran René Gislum Birte Boelt 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(1):68-75
Seed production of spinach (Spinacea oleracea L.) is positively affected by increasing the amounts of nitrogen (N); however, regulations restrict the application rate of N in Danish agriculture. The aim of our study was to test different N application strategies in spinach seed production and their effects on N concentration, seed yield, seed weight and germination. A total amount of 100–150 kg N ha?1 was broadcast or placed at sowing or applied as a split application at sowing and pre-elongation at the Danish Institute of Agricultural Sciences, location Flakkebjerg. Seed yields were positively affected by the high N applications, but no difference was observed between 150 kg N ha?1 broadcast at sowing, and 40 kg N ha?1 broadcast at sowing with an additional late application at a rate based on soil mineral N analysis. No consistent pattern was observed between N management strategy and seed weight or N management strategy and germination. A high N concentration in the plants at the start of growth showed negative effects on final seed yield, whereas later in the season there was a significantly positive correlation between N concentration in the plants and seed yield. A soil mineral analysis can be used as a tool to adjust the N application rate when a split application strategy is chosen. 相似文献
57.
Hansen MJ Liu D Guldberg LB Feilberg A 《Journal of agricultural and food chemistry》2012,60(10):2599-2606
There is an urgent need to develop odor reduction technologies for animal production facilities, and this requires a reliable measurement technique for estimating the removal of odorants. The purpose of the present experiment was to investigate the application of proton-transfer-reaction mass spectrometry (PTR-MS) for continuous measurements at a biofilter from SKOV A/S installed at a pig production facility. PTR-MS was able to handle the harsh conditions with high humidity and dust load in a biofilter and provide reliable data for the removal of odorants, including the highly odorous sulfur compounds. The biofilter removed 80-99% of carboxylic acids, aldehydes, ketones, phenols, and indoles and ca. 75% of hydrogen sulfide. However, only ~0-15% of methanethiol and dimethyl sulfide was removed. In conclusion, PTR-MS is a promising tool that can be used to improve the development of biological air cleaning and other odor reduction technologies toward significant odorants. 相似文献
58.
59.
Wilson BD Ii M Park KW Suli A Sorensen LK Larrieu-Lahargue F Urness LD Suh W Asai J Kock GA Thorne T Silver M Thomas KR Chien CB Losordo DW Li DY 《Science (New York, N.Y.)》2006,313(5787):640-644
Axonal guidance and vascular patterning share several guidance cues, including proteins in the netrin family. We demonstrate that netrins stimulate proliferation, migration, and tube formation of human endothelial cells in vitro and that this stimulation is independent of known netrin receptors. Suppression of netrin1a messenger RNA in zebrafish inhibits vascular sprouting, implying a proangiogenic role for netrins during vertebrate development. We also show that netrins accelerate neovascularization in an in vivo model of ischemia and that they reverse neuropathy and vasculopathy in a diabetic murine model. We propose that the attractive vascular and neural guidance functions of netrins offer a unique therapeutic potential. 相似文献
60.
Proteolytic activity in byproducts from cod species caught at three different fishing grounds has been characterized and compared. The overall highest activity in the byproduct fractions was found in viscera at pH 3 (35 degrees C). Cut off and liver fractions also show maximum activity at pH 3, 35 and 50 degrees C, respectively. Proteolytic activity in viscera and cut off fractions are more affected by fishing ground than by species. Proteolytic activity at pH 3 in viscera is higher in samples from the south coast of Ireland, while viscera samples from the Icelandic Sea have the highest activity at pH 7. For cut off, the activity is higher in samples from the south coast of Ireland than the other two fishing grounds. 相似文献