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排序方式: 共有375条查询结果,搜索用时 15 毫秒
1.
Fernandes Joo Lucas Ribeiro e de Souza Altair Lcio de Faria Geraldo Lcio 《Journal of Thermal Analysis and Calorimetry》2022,147(12):6593-6603
Journal of Thermal Analysis and Calorimetry - The hot coil slump is a recurrent problem in the manufacturing process of medium and high equivalent carbon steel plates. Even with the success of the... 相似文献
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New di‐ and triorganotin(IV) carboxylates derived from a Schiff base: synthesis,characterization and in vitro antimicrobial activities 下载免费PDF全文
Letícia C. Dias Geraldo M. de Lima Jacqueline A. Takahashi José D. Ardisson 《应用有机金属化学》2015,29(5):305-313
A new carboxylic acid, 2‐{[5‐(2‐nitrophenyl)furan‐2‐yl]methyleneamino}benzoic acid (HOBZ), has been produced by reacting 5‐(2‐nitrophenyl)furfural with 2‐aminobenzoic acid. Reactions of NaOBZ with organotin chlorides led to formation of [Me3Sn(OBZ)] ( 1 ), [Bu3Sn(OBZ)] ( 2 ), [Me2Sn(OBZ)2] ( 3 ) and [Bu2Sn(OBZ)2] ( 4 ). Complexes 1 , 2 , 3 , 4 have been characterized using elemental analyses and infrared, 1H NMR, 13C NMR, 119Sn NMR and 119Sn Mössbauer spectroscopies. In the solid state, the OBZ ligands might coordinate to tin in an anisobidentate fashion via the carboxylate group. The in vitro antimicrobial activity of all compounds has been screened against the following fungi: Aspergillus niger, A. flavus, A. parasiticus, Penicillium citrinum, Candida dubliniensis, C. lusitaniae, C. albicans, C. tropicalis, C. parapsilosis and C. glabrata; and against the following bacteria: Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Streptococcus sanguinis, Escherichia coli, Citrobacter frendii, Salmonella typhimurium and Pseudomonas aeruginosa. Complexes 2 and 4 exhibited higher biocide activity in comparison to 1 and 3 and to the control drugs nystatin and miconazole nitrate for the yeasts, and chloramphenicol and ampicillin for the bacteria. The biological activity of 2 was superior to that of 4 . In addition, the toxicity of HOBZ, NaOBz and 1 , 2 , 3 , 4 were determined using Chlorella vulgaris, revealing low toxicity of the complexes at MIC50 concentrations. We also performed cell viability studies, using XTT assay, displaying no change in the mitochondrial function after 2–4 h of exposure of the microorganism to the complexes at MIC50 concentrations. The butyl‐containing complexes 2 and 4 display greater lipophilicities than do the methyl analogues 1 and 3 , thereby endowing 2 and 4 with superior abilities to cross the microbe cell membrane, the possible mechanism of action. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Giuseppe Vacca Lourenco Beirão da Veiga 《Numerical Methods for Partial Differential Equations》2015,31(6):2110-2134
The virtual element method (VEM) is a recent technology that can make use of very general polygonal/polyhedral meshes without the need to integrate complex nonpolynomial functions on the elements and preserving an optimal order of convergence. In this article, we develop for the first time, the VEM for parabolic problems on polygonal meshes, considering time‐dependent diffusion as our model problem. After presenting the scheme, we develop a theoretical analysis and show the practical behavior of the proposed method through a large array of numerical tests. © 2015 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 31: 2110–2134, 2015 相似文献
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Growth under Visible Light Increases Conidia and Mucilage Production and Tolerance to UV‐B Radiation in the Plant Pathogenic Fungus Colletotrichum acutatum 下载免费PDF全文
Henrique D. de Menezes Nelson S. Massola Jr Stephan D. Flint Geraldo J. Silva Jr Luciano Bachmann Drauzio E. N. Rangel Gilberto U. L. Braga 《Photochemistry and photobiology》2015,91(2):397-402
Light conditions can influence fungal development. Some spectral wavebands can induce conidial production, whereas others can kill the conidia, reducing the population size and limiting dispersal. The plant pathogenic fungus Colletotrichum acutatum causes anthracnose in several crops. During the asexual stage on the host plant, Colletototrichum produces acervuli with abundant mucilage‐embedded conidia. These conidia are responsible for fungal dispersal and host infection. This study examined the effect of visible light during C. acutatum growth on the production of conidia and mucilage and also on the UV tolerance of these conidia. Conidial tolerance to an environmentally realistic UV irradiance was determined both in conidia surrounded by mucilage on sporulating colonies and in conidial suspension. Exposures to visible light during fungal growth increased production of conidia and mucilage as well as conidial tolerance to UV. Colonies exposed to light produced 1.7 times more conidia than colonies grown in continuous darkness. The UV tolerances of conidia produced under light were at least two times higher than conidia produced in the dark. Conidia embedded in the mucilage on sporulating colonies were more tolerant of UV than conidia in suspension that were washed free of mucilage. Conidial tolerance to UV radiation varied among five selected isolates. 相似文献
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Pedro Rocha ngela Vilas‐Boas Natacha Fontes Dulce Geraldo Ftima Bento 《Electroanalysis》2020,32(1):159-165
The electrochemical oxidation processes that occur during a voltammetric assay in wine samples lead to the formation of species that obstructs the surface and reduce their active area. This effect is critical for screen printed carbon electrodes (SPCE) and leads to abnormal low values of the total polyphenols content of wines, ca. 72 % lower than those obtained with glassy carbon electrodes. This effect was examined using 10 red and Port wine samples. Mechanical polishing and electrochemical‐based treatments for the removal of this fouling layer were tested. The best results were obtained by electrochemical activation in at a constant potential of 1.2 V during 100 s Na2CO3 saturated solution, and by polishing. The success of some of these treatments brings an added value to SPCE, as it opens the possibility of their reuse in the wine analysis. This outcome is particularly relevant for quality control where a huge number of analysis is performed and the reduction of cost may dictates the choice of the analytical method. 相似文献
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Cristiane P. de Macedo Charles A. B. Negrão Luiz G. M. de Macedo José R. Zamian Geraldo N. da Rocha Filho Carlos E. F. da Costa 《Journal of Thermal Analysis and Calorimetry》2014,115(1):31-36
The Al-MCM-41 molecular sieve with Si/Al = 20 molar ratio was synthesized at room temperature and characterized by X-ray diffractometry, surface area, thermogravimetry, and infrared spectroscopy. The kinetic study was conducted by Vyazovkin and Ozawa method, in order to verify the activation energy during the Hofmann degradation between 130 and 370 °C, in which most of surfactant removal occurs. The results suggest that the activation energy for template removal is close to 80 kJ mol?1 lower in Al-MCM-41 synthesized at room temperature, when compared to results obtained for mesopores Al-MCM-41 and MCM-41 synthesized by hydrothermal method. This lower activation energy may be understood as consequence of textural properties, such as higher pore size. 相似文献