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141.
The structures of the modulated phases of K2SeO4, Rb2ZnCl4, Rb2ZnCl4 and Cs2CdBr4 are compared. Both commensurate and incommensurate modulations are considered. Clear common features can be derived between the polarization vectors of their primary harmonic modulations. Even distortions with very different modulation wavevectors present a clear correlation. 相似文献
142.
In this paper, we derive the exact solution of the cubic-quintic Duffing oscillator based on the use of Jacobi elliptic functions. We also showed that the exact angular frequency of this cubic-quintic Duffing equation is given in terms of the complete elliptic integral of the first kind. 相似文献
143.
A right module M over a ring R is said to be retractable if Hom R (M, N) ≠ 0 for each nonzero submodule N of M. We show that M ? R RG is a retractable RG-module if and only if M R is retractable for every finite group G. The ring R is (finitely) mod-retractable if every (finitely generated) right R-module is retractable. Some comparisons between max rings, semiartinian rings, perfect rings, noetherian rings, nonsingular rings, and mod-retractable rings are investigated. In particular, we prove ring-theoretical criteria of right mod-retractability for classes of all commutative, left perfect, and right noetherian rings. 相似文献
144.
A. González Ureña A. Requena A. Bastida J. Zúñiga 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,49(3):297-303
A molecular beam interference model is presented based on a two-state interaction between a polar molecule and a resonant
RF field as it occurs in the so-called C-field of a typical molecular beam electric resonant spectrometer. The treatment shows the onset of interferences in the beam
transmission spectra as well as in its transverse profile. It is demonstrated how the molecular interferences are originated
by the wavefunction phase shift introduced by the resonant RF field. Furthermore it is shown that for a given beam velocity
and oscillating field frequency the fringes’ visibility depends on the strength of the RF field, i.e. the Rabi frequency,
in the transmission spectra. Likewise the presence of a RF field gradient in the perpendicular beam direction gives rise to
a peak structure in the transverse beam profile. The theoretical model was applied to simulate a variety of beam transmission
spectra under resonant conditions as well as some experimental data already published by our group showing a satisfactory
agreement between experimental and simulated data. Finally, the potentiality of this internal state molecular interferometer
to carry out studies in matter-wave interferometry is remarked. 相似文献
145.
Ćilerdžić Jasmina Galić Milica Ivanović Žarko Brčeski Ilija Vukojević Jelena Stajić Mirjana 《Applied biochemistry and biotechnology》2019,187(4):1371-1383
Applied Biochemistry and Biotechnology - Biological pretreatment of the lignocellulosic residues, in which white-rot fungi have a crucial role, has many advantages compared to the chemical,... 相似文献
146.
Bajuk-Bogdanović Danica Holclajtner-Antunović Ivanka Jovanović Zoran Mravik Željko Krstić Jugoslav Uskoković-Marković Snežana Vujković Milica 《Journal of Solid State Electrochemistry》2019,23(9):2747-2758
Journal of Solid State Electrochemistry - The synergistic effects between two Keggin-type heteropoly acids (HPAs) and carbon surface were examined and elucidated. An improved high rate capability... 相似文献
147.
Baronėnas Žygimantas Manstavičius Eugenijus Šapokaitė Patricija 《Lithuanian Mathematical Journal》2021,61(3):289-300
Lithuanian Mathematical Journal - We examine the variance of a linear statistic defined on the symmetric group endowed with the Ewens probability. Despite the dependence of the summands, it can be... 相似文献
148.
D. Živković N. Štrbac M. Sokić V. Andrić I. Jovanović M. Jovičić B. Andjelić S. Radosavljević 《Journal of Thermal Analysis and Calorimetry》2014,118(2):1369-1373
Preliminary results of physicochemical investigation of some archaeometallurgical findings from Kmpije locality in vicinity of Bor (Serbia) are presented in this paper. Ancient samples of prehistoric origin were investigated using different instrumental analytic methods—chemical, differential thermal, X-ray diffraction, and energy dispersive X-ray fluorescence analysis. Obtained results indicate to the presence of ancient metallurgical activities, so locality Kmpije may be considered as an archaeometallurgical site, which should be investigated more in future for more precise details. 相似文献
149.
Synthesis of poly(ester‐amide) dendrimers based on 2,2‐Bis(hydroxymethyl) propanoic acid and glycine
David Pahovnik Anja Čusak Sebastjan Reven Ema Žagar 《Journal of polymer science. Part A, Polymer chemistry》2014,52(22):3292-3301
Water‐soluble, biodegradable, and biocompatible poly(ester‐amide) dendrimers with hydroxyl functional groups are synthesized from previously prepared AB2 adduct of 2,2‐bis(hydroxymethyl) propanoic acid (bis‐MPA) and glycine as a repeating unit. Two esterification procedures using different coupling reagent/catalyst systems (DCC/DPTS or EDC/DMAP) are studied with respect to efficiency, ease of products purification, and quality of the final products. Both procedures have their own benefits and drawbacks, depending on dendrimer generation. The synthesized poly(ester‐amide) dendrimers as well as commercially available bis‐MPA dendrimers, poly(ester‐amide) hyperbranched polymer, and poly(vinyl alcohol) are used for preparation of solid dispersions of sulfonylurea antidiabetic drug glimepiride to improve its poor water‐solubility. In vitro dissolution studies show in comparison with pure glimepiride in crystalline or amorphous form, to the same extent improved glimepiride solubility for solid dispersions based on dendritic polymers, but not for poly(vinyl alcohol). The amount of glimepiride complexed with both dendrimer types increases with dendrimer generation. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3292–3301 相似文献
150.
Elías-Zúñiga Alex Palacios-Pineda Luis Manuel Olvera-Trejo Daniel Martínez-Romero Oscar 《Nonlinear dynamics》2020,102(3):1239-1270
Nonlinear Dynamics - In this paper, the dynamics response of a finite extensibility nonlinear elastic (FENE) absorber attached to a nonlinear primary system is investigated by writing the modal... 相似文献