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排序方式: 共有269条查询结果,搜索用时 8 毫秒
51.
Tapio Salmi Henrik GrénmanJohan Wärnå Dmitry Yu. Murzin 《Chemical Engineering Research and Design》2013
Typical features of liquid–solid reactions were reviewed: reaction kinetics, mass transfer effects and particle morphology. It was concluded that classical liquid–solid models based on ideal, non-porous geometries (sphere, infinite cylinder, slab) cannot satisfactorily describe real reactive solid particles with various surface defects, such as cracks, craters and limited porosity. Typically a too low reaction order for the reactive solid is predicted by the classical models. The surface morphology can be revealed by electron microscopy, which gives inspiration to develop new mathematical models for reactive solids. 相似文献
52.
Heikki Käsnänen Mikko J. Myllymäki Anna Minkkilä Antti O. Kataja Susanna M. Saario Dr. Tapio Nevalainen Dr. Ari M. P. Koskinen Prof. Dr. Antti Poso Prof. Dr. 《ChemMedChem》2010,5(2):213-231
Carbamates are a well‐established class of fatty acid amide hydrolase (FAAH) inhibitors. Here we describe the synthesis of meta‐substituted phenolic N‐alkyl/aryl carbamates and their in vitro FAAH inhibitory activities. The most potent compound, 3‐(oxazol‐2yl)phenyl cyclohexylcarbamate ( 2 a ), inhibited FAAH with a sub‐nanomolar IC50 value (IC50=0.74 nM ). Additionally, we developed and validated three‐dimensional quantitative structure–activity relationships (QSAR) models of FAAH inhibition combining the newly disclosed carbamates with our previously published inhibitors to give a total set of 99 compounds. Prior to 3D‐QSAR modeling, the degree of correlation between FAAH inhibition and in silico reactivity was also established. Both 3D‐QSAR methods used, CoMSIA and GRID/GOLPE, produced statistically significant models with coefficient of correlation for external prediction (R2PRED) values of 0.732 and 0.760, respectively. These models could be of high value in further FAAH inhibitor design. 相似文献
53.
Tapio Eeva Samuli Helle Juha-Pekka Salminen Harri Hakkarainen 《Journal of chemical ecology》2010,36(6):608-613
Dietary carotenoids are important pigments, antioxidants, and immune-stimulants for birds. Despite recent interest in carotenoids in bird ecology, we know surprisingly little about the carotenoid content of invertebrates consumed by birds. We compared carotenoid (lutein, β-carotene, and total) concentrations in invertebrates brought to nestlings by two insectivorous passerines, the great tit, Parus major and the pied flycatcher, Ficedula hypoleuca. We also compared carotenoid levels between environments that were either polluted by heavy metals or were not polluted, because the carotenoid-based plumage color of P. major nestlings is affected by environmental pollution. Lepidopterans were the most carotenoid-rich food items and contained the largest proportion of lutein. There were no differences in carotenoid concentrations in the food items of the two bird species but P. major nestlings obtained more carotenoids from their invertebrate diet than F. hypoleuca nestlings because the P. major diet had a higher proportion of lepidopteran larvae. In polluted areas, P. major nestlings consumed lower levels of dietary carotenoids than in unpolluted areas because of temporal differences in caterpillar abundance between polluted and unpolluted sites. Our study suggests that pollution-related difference in nestling plumage color in P. major is related to varying dietary proportion of lutein-rich food items rather than pollution-related variation in insect carotenoid levels. 相似文献
54.
Abstract Experimental observations of the power transfer effect between two writing beams in dry methylene-blue-sensitized gelatin films are presented. A low-power He-Ne laser is used for the realization of two-wave mixing. The influences of the writing angles and the polarization of the writing beams on the holographic enhancement coefficient, which shows the magnitude of the power transfer, are demonstrated. The diffraction efficiency was 0.4% and the holographic enhancement coefficient 0.16. 相似文献
55.
Combination of Reaction and Separation in Heterogeneous Catalytic Hydrogenation of Ethylformate 下载免费PDF全文
Gerson Martin Carla Pereira Frank Pettersson Henrik Saxén Dmitry Y. Murzin Alírio Rodrigues Tapio Salmi 《化学工程与技术》2015,38(5):804-812
Continuous hydrogenation reaction of ethyl benzoylformate was studied over a (–)‐cinchonidine (CD)‐modified Pt/Al2O3 catalyst. The catalyst showed a good stability, and high enantioselectivity was achieved in the fixed‐bed reactor. Chromatographic separation of (R)‐ and (S)‐ethyl mandelate originating from a post‐continuous hydrogenation reaction of ethyl benzoylformate over the (–)‐CD‐modified Pt/Al2O3 catalyst was investigated in the same reaction mixture. A commercial column filled with a chiral selector resin was chosen as a perspective preparative‐scale adsorbent. Since adsorption equilibrium isotherms were linear within the entire investigated range of concentrations, they were determined by pulse experiments for the isomers present in a post‐reaction mixture. Breakthrough curves were measured and described successfully by the dispersive plug‐flow model with linear driving force approximation. 相似文献
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The International Flow of Television Programs 总被引:2,自引:1,他引:1
Tapio Varis 《The Journal of communication》1984,34(1):143-152
60.
Mats Söderlund Päivi Mäki-Arvela Kari Eränen Tapio Salmi Risto Rahkola Dmitry Yu. Murzin 《Catalysis Letters》2005,105(3-4):191-202
Both thermal and catalytic decomposition of diborane resulting in borane as the main product were investigated under the pressure
and temperature ranges of 2–15 bar and 100–300 °C, respectively over Al2O3 and Pt/Al2O3 in a fixed bed reactor. Catalytic decomposition rate was essentially higher than the thermal decomposition, however the catalyst
deactivation was substantial. 相似文献