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71.
Statistical equilibrium states for a linear transport equation were defined in a previous work. We consider here the two-dimensional case: we show that under some mild assumptions these equilibrium states actually describe the long-time dynamics of the system. 相似文献
72.
All steps involved in the determination of tributyltin in sediments by anhydrous acetic acid extraction, hydride generation, cold trapping, gas chromatographic separation and quartz furnace atomic absorption spectrometry are critically examined. Detection limits (1.8 ng Sn.g–1) and reproducibility at representative concentration levels (6–12%) are satisfying for practical purposes. 相似文献
73.
Stévigny C Jiwan JL Rozenberg R de Hoffmann E Quetin-Leclercq J 《Rapid communications in mass spectrometry : RCM》2004,18(5):523-528
This work reports a detailed study of the fragmentations of aporphine alkaloids by electrospray ionization with multistage mass spectrometry (ESI-MS(n)) in positive mode. In a first step the loss of the amino group and its substituent is observed. Further steps display the loss of the peripheral groups. Losses of methanol and CO are observed if an OH is vicinal to an OCH(3) on the aromatic ring. Otherwise the spectra show radical losses of CH(3)* or CH(3)O* as the main fragmentations. If a methylenedioxy group is present losses of formaldehyde followed by CO are observed. These fragmentations yield important information on the structures of aporphines. 相似文献
74.
Frédéric?Gressent Julie?V?Cullimore Raoul?Ranjeva Jean-Jacques?BonoEmail author 《BMC biochemistry》2004,5(1):4
Background
The NodH sulfotransferase from Sinorhizobium meliloti has been used to radiolabel lipochitooligosaccharidic (LCO) Nod factor signals with 35S from inorganic sulfate in a two-step enzymatic procedure. The first step involved the production of 3'-phosphoadenosine 5'-phosphosulfate (PAPS), a sulphate donor, using enzymes contained in a yeast extract, and the second step used the NodH enzyme. However with this established procedure, only a low incorporation of the initial inorganic sulfate into the Nod factors was obtained (about 7% after purification of the labeled compounds). The aim of this work was to optimize the radiolabelling of Nod factors with 35S. 相似文献75.
Cloud point of aqueous solutions of tetrabutylammonium dodecyl sulfate is a function of the concentration of counterions in the aqueous phase 总被引:1,自引:0,他引:1
The cloud point of the surfactant tetrabutylammonium dodecyl sulfate is shown to be a function of the tetrabutylammonium counterion concentration in the aqueous phase whether the counterions are provided by the surfactant or both the surfactant and added tetrabutylammonium bromide. The micellized surfactant dissociates 17% of its counterions to aqueous phase. 相似文献
76.
77.
Raoul Mens Fatma Demir Guy Van Assche Bruno Van Mele Dirk Vanderzande Peter Adriaensens 《Journal of polymer science. Part A, Polymer chemistry》2012,50(5):1037-1041
In this article, it is demonstrated that doctor blading of thin poly‐3‐hexylthiophene/phenyl‐C61‐butyric acid methyl ester (1/1) bulk‐hetero junction films from toluene leads to an improved nanocrystallinity, when compared with their unannealed chlorobenzene processed counterparts. This difference in morphology was demonstrated by solid‐state NMR and Rapid Heating Cooling Calorimetry (RHC), being useful complementary techniques to investigate the active layer morphology of photovoltaic devices. An increased PC60BM nanocrystallinity is indicated by several NMR relaxation decay times (T1C, T1H, and T1ρH) and confirmed by an increase of the melting enthalpy in RHC experiments. An improved solar cell performance further strengthens this conclusion. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
78.
Phuoc Dien Pham Vincent Lapinte Yann Raoul Jean‐Jacques Robin 《Journal of polymer science. Part A, Polymer chemistry》2014,52(11):1597-1606
Oleic acid and α,ω‐diacid were converted into propargylic esters followed by thiol‐ene/yne coupling (TEC/TYC) functionalization in presence of mercaptoethanol. The multiradical addition on fatty esters leads to the formation of lipidic polyols (OH1 and OH2), as judged by 1H NMR and mass spectroscopies as well as by size exclusion chromatography. The crosslinking reaction between TEC/TYC‐based polyols and 4,4′‐methylene bis(phenylisocyanate) isocyanate reactant was monitored by FTIR experiment and reaction parameters were optimized. By differential scanning calorimetry, relatively high glass transitions are measured corresponding to structure with little or without dangling chain. Moreover, the thermal stability of the resulting plant oil‐based polyurethane materials (PU1 and PU2) were found to be fully consistent with that of other lipidic PUs respecting a three‐step process. Thanks to TYC methodology, fatty α,ω‐diacid produces lipidic polyol without dangling chain and lipidic thermoset PU with relatively high Tg. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1597–1606 相似文献
79.
Andrew I. Stipetic John W. Goodby Yann M. Raoul Helen F. Gleeson 《Liquid crystals》2013,40(7):819-828
Novel liquid crystalline esters have been synthesized with a perfluorocarbonyloxy terminal chain and lateral fluoro substituents in order to determine their influence on mesomorphic behaviour, tilt angle and spontaneous polarization. Certain locations of lateral fluoro substituents provide for very low melting points and reasonably wide temperature ranges of the antiferroelectric phase, and can generate enhanced tilt angles of up to 45°, although spontaneous polarization is always lower than for the parent system without lateral fluoro substituents. Thus, these novel materials, particularly as components in mixtures, should be useful in high tilt antiferroelectric (orthoconic) applications. 相似文献
80.
Cristina-Mihaela Băleanu Raoul R. Nigmatullin Saime Sebnem Cetin Dumitru Băleanu Suleyman Ozcelik 《Central European Journal of Physics》2011,9(3):729-739
In this paper we presented a new method (Eigen-Coordinates (ECs)) that can be used for calculations of the critical points
(CPs) energy of the interband-transition edges of the heterostructures. This new method is more accurate and complete in comparison
with conventional ones and has a wide range of application for the calculation of the fitting parameters related to nontrivial
functions that initially have nonlinear fitting parameters that are difficult to evaluate. The new method was applied to determine
the CPs energies from the dielectric functions of the MBE grown GaAs1−xP
x
ternary alloys obtained using spectroscopic ellipsometry (SE) measurements at room temperature in the 0.5-5 eV photon energy
region. The obtained results are in good agreement with the results of the other methods. 相似文献