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31.
In this paper, we study the braneworld scenarios in the presence of two real scalar fields coupled by gravity. The first-order formalism for the bent brane (for both de Sitter and anti-de Sitter geometry), leads us to discuss the shape invariance method in the bent brane systems. So, by using the fluctuations of metric and fields we obtain the Schrödinger equation. Then we factorize the corresponding Hamiltonian in terms of multiplication of the first-order differential operators. These first-order operators lead us to obtain the energy spectrum with the help of shape invariance method. 相似文献
32.
J. Sadeghi 《International Journal of Theoretical Physics》2007,46(3):492-502
We obtain the exact bound states of the generalized of Hulthén potential with negative energy levels using an analytic approach.
In order to obtain bound states, we use the associated Jacobi differential equation. Using the supersymmetry approach to quantum
mechanics, we show that these bound states, via four pairs of first order differential operators, represent four types of
ladder equations. Two types of these supersymmetric structures suggest derivation of algebric solutions for the bound states
using two different approaches.
PACS 21.60.Cs; 21.60.Fw; 21.60.-n; 03.65.Fd; 03.65.Ge; 03.65.-w 相似文献
33.
Susan Sadeghi Fatemeh Fathi 《Journal of inclusion phenomena and macrocyclic chemistry》2010,67(1-2):91-98
A new PVC membrane coated graphite electrode for cesium ion based on 4′,4″(5′)di–tert-butyl di-benzo-18-crown-6 (DTBDB18C6) as ionophore was prepared. The electrode shows a near Nernstian response of 57.0 ± 1.8 mV decade?1 over a wide activity range of 6.0 × 10?6–1.0 × 10?1 mol L?1 with a limit of detection 4.0 × 10?6 mol L?1. The proposed electrode is suitable for use in aqueous solution in the pH range of 3.0–9.5. It has a fast response time of 10 s and can be used for at least 1 month without any considerable divergence in potential. The selectivity coefficients for Cs+ ion with respect to ammonium, alkali, alkaline earth and some selected transition metal ions were determined and showed a superior selectivity over Li+, Na+ and alkaline earth metal ions. The new electrode was applied for determination of Cs+ in spiked tap water. The electrode was also used as indicator electrode in potentiometric titration of Cs+ with sodium tetraphenyl borate. 相似文献
34.
Mahdi Sadeghi Zahra Alipoor Abbas Majdabadi 《Journal of Radioanalytical and Nuclear Chemistry》2011,288(3):745-751
The 82Sr/82Rb radionuclide generator is used very commonly in positron emission tomography. ALICE/ASH and TALYS 1.0 codes were used to calculate excitation functions for proton, alpha and 3He induced on various targets that lead to produce 82Sr radioisotope using intermediate energy accelerators. Recommended thickness of the targets according to SRIM code was premeditated. The application of those data, particularly in the calculation of integral yields, is discussed and theoretical integral yields for any reaction were computed. To consider precision of TALYS 1.0 code calculations, 85Rb(p,4n)82Sr process was determined as most interesting one due to radionuclide purity. The TALYS 1.0 code predicts a maximum cross-section of about 130 mb at 47 MeV for this reaction. Rubidium chloride deposition on copper substrate was carried out via sedimentation method in order to produce 82Sr. 2.98 g RbCl, 1.043 g ethyl cellulose, 10 mL acetone were used to prepare a layer of enriched rubidium chloride of 11.69 cm2 area and 0.34 g/cm2 thickness. 相似文献
35.
In this research, we combined ionic liquid-based dispersive liquid-liquid micro-extraction (IL-based DLLME) with stopped-flow spectrofluorometry (SFS) to evaluate the concentration of aluminum in different real samples at trace level. 1-Hexylpyridinium hexafluorophosphate [Hpy][PF6] ionic liquid and 8-hydroxyquinoline (oxine), which forms a highly fluorescent complex with Al3+, were chosen as the extraction solvent and chelating agent, respectively. The hydrophobic Al-oxine complex was extracted into the [Hpy][PF6] and separated from the aqueous phase. Then, the concentration of the enriched aluminum in the sediment phase was determined by SFS. Some effective parameters that influence the SFS signals and the micro-extraction efficiency, such as the suction and sending time, the concentration of the chelating agent, pH, the amount of the ionic liquid, the type of disperser solvent and diluting agent, ionic strength, extraction time, equilibration temperature and centrifugation time were investigated and optimized. In the optimum experimental conditions, the limit of detection (3 s) and enrichment factor were 0.05 μg L−1 and 100, respectively. The relative standard deviation (RSD) for six replicate determinations of 6 μg L−1 Al was 1.7%. The calibration graph using the pre-concentration system was linear in the range of 0.06-15 μg L−1 with a correlation coefficient of 0.9989. The developed method was validated by the analysis of certified reference materials and applied successfully to the determination of aluminum in several water, fruit juice and food samples. 相似文献
36.
In this paper, we consider locally dually flat (??, ??)-metrics with isotropic S-curvature and find some necessary and sufficient conditions under which these metrics reduce to locally Minkowskian metrics. 相似文献
37.
In this paper the superstability of the Cauchy equation can be proved for complex valued functions on commutative semigroup under some suitable conditions. Furthermore, in this note, we give a partial affirmative answer to problem 18, in the 31st ISFE. 相似文献
38.
In this paper, we present a fixed point method to prove generalized Hyers–Ulam stability of derivations in modular spaces. 相似文献
39.
In this paper, we study generalized Douglas–Weyl(α, β)-metrics. Suppose that a regular(α, β)-metric F is not of Randers type. We prove that F is a generalized Douglas–Weyl metric with vanishing S-curvature if and only if it is a Berwald metric. Moreover, by ignoring the regularity, if F is not a Berwald metric, then we find a family of almost regular Finsler metrics which is not Douglas nor Weyl. As its application, we show that generalized Douglas–Weyl square metric or Matsumoto metric with isotropic mean Berwald curvature are Berwald metrics. 相似文献
40.
Abdalghani Daaoub James M. F. Morris Vanessa A. Béland Paul Demay-Drouhard Amaar Hussein Simon J. Higgins Hatef Sadeghi Richard J. Nichols Andrea Vezzoli Thomas Baumgartner Sara Sangtarash 《Angewandte Chemie (International ed. in English)》2023,62(24):e202302150
Most studies in molecular electronics focus on altering the molecular wire backbone to tune the electrical properties of the whole junction. However, it is often overlooked that the chemical structure of the groups anchoring the molecule to the metallic electrodes influences the electronic structure of the whole system and, therefore, its conductance. We synthesised electron-accepting dithienophosphole oxide derivatives and fabricated their single-molecule junctions. We found that the anchor group has a dramatic effect on charge-transport efficiency: in our case, electron-deficient 4-pyridyl contacts suppress conductance, while electron-rich 4-thioanisole termini promote efficient transport. Our calculations show that this is due to minute changes in charge distribution, probed at the electrode interface. Our findings provide a framework for efficient molecular junction design, especially valuable for compounds with strong electron withdrawing/donating backbones. 相似文献