排序方式: 共有62条查询结果,搜索用时 62 毫秒
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Claudia Dussaubat Alban Maisonnasse Cedric Alaux Sylvie Tchamitchan Jean-Luc Brunet Erika Plettner Luc P. Belzunces Yves Le Conte 《Journal of chemical ecology》2010,36(5):522-525
Pheromones in social insects play a key role in the regulation of group homoeostasis. It is well-established that parasites
can modify hormone signaling of their host, but less is known about the effect of parasites on pheromone signaling in insect
societies. We, thus, tested in honey bees (Apis mellifera) the effect of the widespread parasite Nosema spp. on the production of ethyl oleate (EO), the only identified primer pheromone in honey bee workers. Since environmental
stressors like pesticides also can weaken honey bees, we also analyzed the effect of imidacloprid, a neonicotinoid widely
used in agriculture, on EO production. We show that, contrary to imidacloprid, Nosema spp. significantly altered EO production. In addition, the level of Nosema infection was correlated positively with the level of EO production. Since EO is involved in the regulation of division of
labor among workers, our result suggests that the changes in EO signaling induced by parasitism have the potential to disturb
the colony homoeostasis. 相似文献
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Vincent Sobotka Alban Agazzi Nicolas Boyard Didier Delaunay 《Applied Thermal Engineering》2013,50(1):416-421
This work presents an efficient method to quickly calculate with good accuracy (to 5%) the solidification time of an injected semi-crystalline polymer slab. Under some hypotheses this polymer can be considered as a phase change material with a constant phase change temperature. We use a noteworthy property established as the ratio between the thickness of a solidifying phase change finite medium and the solidified thickness in a semi-infinite medium. The knowledge of this ratio enables to predict analytically the solidification time in a 1D finite medium. This ratio can be parameterized as a function of characteristic numbers in phase change problems: Stefan numbers and the ratio of thermal diffusivities of both phases. The results are compared with those given by a complete model integrating the physics of the coupling between heat transfer and crystallization kinetics. The solidification times computed from both models are very close, demonstrating the relevance of the simplified model. Finally, we also get a very good accuracy in calculating the total cooling time, from injection to ejection. 相似文献
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In the setting of program algebra (PGA), a projection from PGAu, i.e., PGA extended with a unit instruction operator, into PGA is defined. This is done via a composition that employs backward jumps and (labeled) goto's. 相似文献
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Naouel Moha Yann-Gaël Guéhéneuc Anne-Françoise Le Meur Laurence Duchien Alban Tiberghien 《Formal Aspects of Computing》2010,22(3-4):345-361
Code and design smells are recurring design problems in software systems that must be identified to avoid their possible negative consequences on development and maintenance. Consequently, several smell detection approaches and tools have been proposed in the literature. However, so far, they allow the detection of predefined smells but the detection of new smells or smells adapted to the context of the analysed systems is possible only by implementing new detection algorithms manually. Moreover, previous approaches do not explain the transition from specifications of smells to their detection. Finally, the validation of the existing approaches and tools has been limited on few proprietary systems and on a reduced number of smells. In this paper, we introduce an approach to automate the generation of detection algorithms from specifications written using a domain-specific language. This language is defined from a thorough domain analysis. It allows the specification of smells using high-level domain-related abstractions. It allows the adaptation of the specifications of smells to the context of the analysed systems. We specify 10 smells, generate automatically their detection algorithms using templates, and validate the algorithms in terms of precision and recall on Xerces v2.7.0 and GanttProject v1.10.2, two open-source object-oriented systems. We also compare the detection results with those of a previous approach, iPlasma. 相似文献
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R.M. Calderón-Olvera E.A. Albanés-Ojeda M. García-Hipólito J.M. Hernández-Alcántara M.A. Álvarez-Perez C. Falcony O. Álvarez-Fregoso 《Ceramics International》2018,44(7):7917-7925
SrAl2O4, SrAl2O4:Tb3+ and SrAl2O4:Eu3+:Eu2+ films were synthesized by means of the ultrasonic spray pyrolysis technique. These samples, characterized by X-Ray Diffraction, showed the monoclinic phase of the strontium aluminate. Images of the surface morphology of these films were obtained by SEM and the chemical composition was measured by EDS and XPS. The photoluminescence and cathodoluminescence characteristics of the films were studied as a function of the terbium and europium concentrations. The optimal PL emission intensities were reached at 8?at% for terbium doped films and 6?at% for europium doped samples. The CL emission spectra for europium doped films showed the typical bands of Eu3+ ions and also a broadband centered at 525?nm which is attributed to Eu2+ ions. XPS measurements confirm the presence of Eu3+ and Eu2+ in europium doped SrAl2O4 films, without having been subjected to a reducing atmosphere. Chromatic diagrams exhibited green color for SrAl2O4:Tb3+ films, red and yellow colors for SrAl2O4:Eu3+:Eu2+ films. The PL decay curves were also obtained: the averaged decay time was 2.7?ms for SrAl2O4:Tb3+ films and 1.9?ms for SrAl2O4:Eu3+ films. Similar results were obtained by the stretched exponential model. 相似文献
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Granular Matter - Compressed frictional granular matter cannot flow without dilation. Upon forced shearing to generate flow, the amount of dilation may depend on the initial preparation and a host... 相似文献
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Grard Cahiez Alban Moyeux Olivier Gager Maël Poizat 《Advanced Synthesis \u0026amp; Catalysis》2013,355(4):790-796
The copper‐catalyzed decarboxylation of carboxylic aromatic acids has been advantageously achieved by using aliphatic amines like tetramethylethylenediamine (TMEDA) or hexamethylenetetraamine (HMTA) as ligands instead of the aromatic heterocyclic amines (quinoline, phenanthroline) used until now. The improvement is significant since the reaction can be performed at a lower temperature (ca. 50 °C less) and the reaction time is clearly shorter (15 min instead of 12 to 24 h). 相似文献
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