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91.
92.
M. Popescu V. Matei A. Simion A. Danet 《Journal of Thermal Analysis and Calorimetry》1983,26(1):65-72
The TG curves obtained for various temperatures and evaporation times allowed establishment of the thermodiffusive characterics of the solvents frequently used in adhesive and film-forming materials. Determinations were carried out in air with a flow rate of 51/h, on pure solvents, on mixtures with solvent ratios corresponding to those in the final products, and on the final products. The temperature range of the study was 17–35°, the evaporation period for most cases at each temperature being 25 minutes. The method leads to the evaporation rates of such solvents with an average standard deviation of 4 per cent. 相似文献
93.
94.
Hunter M Backman V Popescu G Kalashnikov M Boone CW Wax A Gopal V Badizadegan K Stoner GD Feld MS 《Physical review letters》2006,97(13):138102
Light scattered from biological tissues can exhibit an inverse power law spectral component. We develop a model based on the Born approximation and von Karman (self-affine) spatial correlation of submicron tissue refractive index to account for this. The model is applied to light scattering spectra obtained from excised esophagi of normal and carcinogen-treated rats. Power law exponents used to fit dysplastic tissue site spectra are significantly smaller than those from normal sites, indicating that changes in tissue self-affinity can serve as a potential biomarker for precancer. 相似文献
95.
Varga Zsolt Wallenius Maria Nicholl Adrian Mayer Klaus Balan Ionel Benea Vasile 《Journal of Radioanalytical and Nuclear Chemistry》2019,322(3):1585-1591
JRC-Karlsruhe obtained a swipe sample from a highly enriched uranium seizure, which had taken place in 2011. Due to the very low amount of uranium (nanograms) a new method needed to be developed to determine the U production date (age). The particles on the swipe were collected on a pyrolytic graphite planchet using a vacuum impactor and they were subsequently leached with ccHNO3. The “bulk” U isotopic composition (235U: 72.51?±?0.03 wt%) and the production date (December 1992?±?1 year) determined by MC-ICP-MS indicated that the material showed similarity with two other HEU cases seized earlier in Europe.
相似文献96.
Leulescu Marian Pălărie Ion Moanţă Anca Cioateră Nicoleta Popescu Mariana Morîntale Emilian Văruţ Marius Ciprian Rotaru Petre 《Journal of Thermal Analysis and Calorimetry》2019,136(3):1249-1268
Journal of Thermal Analysis and Calorimetry - Thermal behavior of Brown HT food dye was studied in correlation with the physical and biological antioxidant properties. Brown HT’s structure... 相似文献
97.
Carla Alice Carabet Anca Moan Ion Plrie Gabriela Iacobescu Andrei Rotaru Marian Leulescu Mariana Popescu Petre Rotaru 《Molecules (Basel, Switzerland)》2020,25(23)
Two yellow bis-azo dyes containing anthracene and two azodiphenylether groups (BPA and BTA) were prepared, and an extensive investigation of their physical, thermal and biological properties was carried out. The chemical structure was confirmed by the FTIR spectra, while from the UV–Vis spectra, the quantum efficiency of the laser fluorescence at the 476.5 nm was determined to be 0.33 (BPA) and 0.50 (BTA). The possible transitions between the energy levels of the electrons of the chemical elements were established, identifying the energies and the electronic configurations of the levels of transition. Both crystals are anisotropic, the optical phenomenon of double refraction of polarized light (birefringence) taking place. Images of maximum illumination and extinction were recorded when the crystals of the bis-azo compounds rotated by 90° each, which confirms their birefringence. A morphologic study of the thin films deposited onto glass surfaces was performed, proving the good adhesion of both dyes. By thermal analysis and calorimetry, the melting temperatures were determined (~224–225 °C for both of them), as well as their decomposition pathways and thermal effects (enthalpy variations during undergoing processes); thus, good thermal stability was exhibited. The interaction of the two compounds with collagen in the suede was studied, as well as their antioxidant activity, advocating for good chemical stability and potential to be safely used as coloring agents in the food industry. 相似文献
98.
In the recent decade, the meshless methods have been handled for solving most of PDEs due to easiness of the meshless methods. One of the popular meshless methods is the element-free Galerkin (EFG) method that was first proposed for solving some problems in the solid mechanics. The test and trial functions of the EFG are based on the special basis. Recently, some modifications have been developed to improve the EFG method. One of these improvements is the variational multiscale EFG procedure. In the current article, the shape functions of interpolation moving least squares approximation have been applied to the variational multiscale EFG technique for solving the incompressible magnetohydrodynamics flow. In order to reduce the elapsed CPU time of simulation, we employ a reduced-order model based on the proper orthogonal decomposition technique. The current combination can be referred to as the reduced-order variational multiscale EFG technique. To illustrate the reduction in CPU time used as well as the efficiency of the proposed method, we applied it for the two-dimensional cases. 相似文献
99.
Liviu Horia Popescu 《Integral Equations and Operator Theory》2014,79(3):355-375
The present paper is devoted to the study of some qualitative properties of C 0-groups via topological equivalence, also called conjugacy. The special case of the evolution groups is analysed. We show that hyperbolicity implies structural stability. Our constructions improve existing similar results for groups with bounded generators, and apply to linear differential equations with unbounded coefficient operator. 相似文献
100.
Leulescu Marian Rotaru Andrei Pălărie Ion Moanţă Anca Cioateră Nicoleta Popescu Mariana Morîntale Emilian Bubulică Maria Viorica Florian Gabriel Hărăbor Ana Rotaru Petre 《Journal of Thermal Analysis and Calorimetry》2018,134(1):209-231
Journal of Thermal Analysis and Calorimetry - The food-colouring dye tartrazine is a significant additive and in the same time a biologically active material. Thermal behaviour of trisodium... 相似文献