Periodica Mathematica Hungarica - Two new asymmetric generalizations of the Filbert and Lilbert matrices constructed by the products of two Fibonacci and Lucas numbers are considered, with... 相似文献
It is found that additional illumination by photons with energies above the band gap width in barrier layers leads to a strong (up to 40% in depth at the values of the illumination power used in this work) modulation of the light intensity elastically scattered upon resonant excitation of exciton states in quantum wells of GaAs/AlGaAs structures. Evidently, the effect observed is associated with the redistribution of oscillator strengths of exciton transitions due to the formation of three-particle exciton complexes (trions). These complexes arise through preferred capture of nonequilibrium like charge carriers (in our case, holes). 相似文献
A function is said to be bi-Bazilevic? in the open unit disk U if both the function and its inverse are Bazilevic? there. Making use of the Hankel determinant, in this work, we obtain coefficient expansions for Bi-Bazilevic? functions. 相似文献
We study Poletsky–Stessin Hardy spaces on complex ellipsoids in \(\mathbb {C}^{n}\). Different from one variable case, classical Hardy spaces are strictly contained in Poletsky–Stessin Hardy spaces on complex ellipsoids so boundary values are not automatically obtained in this case. We have showed that functions belonging to Poletsky–Stessin Hardy spaces have boundary values and they can be approached through admissible approach regions in the complex ellipsoid case. Moreover, we have obtained that polynomials are dense in these spaces. We also considered the composition operators acting on Poletsky–Stessin Hardy spaces on complex ellipsoids and gave conditions for their boundedness and compactness. 相似文献
In the proposed work, the simultaneous analysis of amlodipine–rosuvastatin and amlodipine–atorvastatin in their dosage forms was achieved. Simultaneous dissolution profiles of the amlodipine–rosuvastatin and amlodipine–atorvastatin tablets are realized using Apparatus II with a simple, accurate and precise RP-LC method. The mobile phase consisting of 0.2 % H3PO4 and pH 5:methanol:acetonitrile (46:27:27) was used. The samples of 10 µL were injected onto a Zorbax SB C18 (100 mm, 4.6 mm, 3.5 µm particle size) column with 1.2 µL min−1 flow rate. The samples were detected at 236 nm. By plotting peak area ratios vs. concentration, the linearity for amlodipine–rosuvastatin and amlodipine–atorvastatin was determined. With the developed RP-LC method, AML, ROS and ATOR were detected within the range of 0.25–10, 0.5–10 and 0.25–25 µg mL−1, respectively. LOD and LOQ values were also calculated as 0.028, 0.058, 0.021 and 0.095 µg mL−1, 0.195 µg mL−1, 0.070 µg mL−1 for AML, ROS and ATOR, respectively. System suitability tests parameters, such as capacity factor, selectivity to previous peak, selectivity to next peak, resolution to previous peak, resolution to next peak, tailing factor, theoretical number of plates, were performed and found coherent with the ICH guideline parameters. The proposed method has been extensively validated in terms of recovery, and recovery results were between 99 and 101 %. For proving the precision, between-day and within-day repeatability results of the method were proposed. The method can be used for the simultaneous determination of amlodipine–rosuvastatin and amlodipine–atorvastatin.
The lead (II) biosorption potential of Aspergillus parasiticus fungal biomass has been investigated in a batch system. The initial pH, biosorbent dosage, contact time, initial metal ion
concentrations and temperature were studied to optimize the biosorption conditions. The maximum lead (II) biosorption capacity
of the fungal biosorbent was found as 4.02 × 10−4 mol g−1 at pH 5.0 and 20°C. The biosorption equilibrium was reached in 70 min. Equilibrium biosorption data were followed by the
Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models. In regeneration experiments, no significant loss of sorption
performance was observed during four biosorption-desorption cycles. The interactions between lead (II) ions and biosorbent
were also examined by FTIR and EDAX analysis. The results revealed that biosorption process could be described by ion exchange
as dominant mechanism as well as complexation for this biosorbent. The ion exchange mechanism was confirmed by E value obtained from D-R isotherm model as well. 相似文献
The interactions of cationic surfactants with anionic dyes were studied by conductometric method. Benzyltrimethylammonium chloride (BTMACl), benzyltriethylammonium chloride (BTEACl) and benzyltributylammonium chloride (BTBACl) were used as cationic surfactants and indigo carmine (IC) and amaranth (Amr) were chosen as anionic dyes. The specific conductance of dye–surfactant mixtures was measured at 25, 35 and 45 °C. A decrease in measured specific conductance values of dye–surfactant mixture was caused by the formation of non-conducting or less-conducting dye–surfactant complex. The equilibrium constants, K1, the standard free energy changes, ΔG1°, the standard enthalpy changes, ΔH1° and the standard entropy changes, ΔS1° for the first association step of dye–surfactant complex formation were calculated by a theoretical model. The results showed that the equilibrium constants and the negative standard free energy change values for all systems decreased as temperature increased. Also these values decreased for all systems studied with increasing alkyl chains of surfactants due to the steric effect. When the equilibrium constant values, K1, for the first association step of IC–surfactant and Amr–surfactant systems with the same surfactant were compared, the values of K1 for IC–surfactant system were higher than that of Amr–surfactant system. 相似文献
A spherical polyacrylonitrile–TiO2 composite adsorbent was prepared and its strontium removal potential was investigated. The Langmuir equation fixed well the
equilibrium data. The value of ∆H° = 8.943 kJ/mol and ∆G° = 6.291 kJ/mol at 298 K indicate that the adsorption of strontium onto TiO2/PAN composite adsorbent is an endothermic and non-spontaneous reaction. The kinetic process was described by a pseudo-second-order
rate model very well. 相似文献