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871.
Nguyêñ Quôć Thǎńg 《Mathematische Zeitschrift》2008,259(2):457-467
We treat a case that was omitted from consideration in our article [2] in Math Zeit, 2007. 相似文献
872.
873.
874.
Complete 1H and 13C NMR assignments of an uncommon 2,3‐dihydroxynaphthoquinone isolated from Cordia multispicata (Cham.)
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875.
Út V. Lê 《Nonlinear Analysis: Real World Applications》2011,12(1):702-722
The main goal of this paper is to study with continuous dependence and a low-frequency asymptotic expansion of a unique weak solution to an initial-boundary value problem. This problem is arisen from a general mathematical model for the collision between the free-fall hammer of a pile-driver and an elastic pile whose ends are furnished with a bearing. 相似文献
876.
Audrey Hernoux-Villière Ulla Lassi Jean-Marc Lévêque 《Ultrasonics sonochemistry》2013,20(6):1341-1344
An advanced dual frequency ultrasonic coaxial reactor enabling simultaneously low and high frequencies irradiating in the same direction was developed to focus both mechanical and chemical effects on a concentrated area. The prototype was straightforward employed for the conversion of a starch-based industrial waste into sugars. 相似文献
877.
Olivier Alévêque Pierre-Yves Blanchard Christelle Gautier Marylène Dias Tony Breton Eric Levillain 《Electrochemistry communications》2010,12(11):1462-1466
The Laviron's interaction model, dedicated to randomly distributed electroactive adsorbed species, was extended to a non-random distribution in order to extract the current–voltage characteristics from any surface distribution of electroactive centers on self-assembled monolayer (SAM). Confronted to electrochemical behaviour of nitroxyl radical SAMs, the agreement observed between theory and experiments provides evidence of a distribution independence of the interaction parameters. 相似文献
878.
Anderson dos Reis Albuquerque Jefferson Maul Antônio Francisco Fernandes Vasconcelos José Rodrigues Carvalho Filho Iêda Maria Garcia dos Santos Antônio Gouveia de Souza 《Journal of Thermal Analysis and Calorimetry》2014,117(2):799-806
The radical abstraction reaction of (bis)-allylic hydrogen in biodiesel fatty acid chains is the first step of autoxidation, being the rate-determining one. Some intrinsic features of the intermediary radicals can determine the oxidative stability (OS) under thermodynamic control. In the present study, some common fatty acid methyl esters present in biodiesel (stearate, oleate, ricinoleate, and linoleate) were oxidized in non-isothermal conditions, using differential scanning calorimetry, and the results were compared with quantum chemical calculations at the density functional theory level. The OS order (saturated > monounsaturated > polyunsaturated) was observed in both approaches (experimental and theoretical). A slight deviation observed between oleate and ricinoleate OS’s was explained based on their allylic radicals resonance and the influence of vicinal hydroxyl group. A linear relationship was found between oxidation temperature by pressurized differential scanning calorimetry and the calculated bond dissociation energy (C–H) for the first step of autoxidation. 相似文献
879.
We report instrumental neutron activation analysis results for 15 elements (K, Fe, Sc, Cr, Co, Zn, As, Rb, Sb, Cs, Ba, Hf, Ta, Th, and U) in 16 geochemical reference samples, namely SDC-1, SCo-1, SGR-1, STM-1, RGM-1, BIR-1, MAG-1 and BHVO-1 from USGS (United States Geological Survey, Reston), Soil-5, Soil-7 and SL-1 from IAEA (International Atomic Energy Agency, Vienna), and GSS-1, GSS-4, GSS-7, GSR-2 and GSR-3 from IGGE Institute of Geophysical and Geochemical Prospecting, People's Republic of China), The results are compared with literature values. In general our results agree well with recommended or proposed values. 相似文献
880.
Alves C Fernandes C Dos Santos Neto AJ Rodrigues JC Costa Queiroz ME Lanças FM 《Journal of chromatographic science》2006,44(6):340-346
Solid-phase microextraction (SPME)-liquid chromatography (LC) is used to analyze tricyclic antidepressant drugs desipramine, imipramine, nortriptyline, amitriptyline, and clomipramine (internal standard) in plasma samples. Extraction conditions are optimized using a 2(3) factorial design plus a central point to evaluate the influence of the time, temperature, and matrix pH. A Polydimethylsiloxane-divinylbenzene (60-mum film thickness) fiber is selected after the assessment of different types of coating. The chromatographic separation is realized using a C(18) column (150 x 4.6 mm, 5-microm particles), ammonium acetate buffer (0.05 mol/L, pH 5.50)-acetonitrile (55:45 v/v) with 0.1% of triethylamine as mobile phase and UV-vis detection at 214 nm. Among the factorial design conditions evaluated, the best results are obtained at a pH 11.0, temperature of 30 degrees C, and extraction time of 45 min. The proposed method, using a lab-made SPME-LC interface, allowed the determination of tricyclic antidepressants in in plasma at therapeutic concentration levels. 相似文献