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Thermodynamic estimation is still too much requested for scientific applications in spite of great advances in simulation methods for efficient determination of phase equilibrium of multi-component systems. In this work, thermodynamic properties of deuterium-tritium mixture in a wide range of temperatures and pressures have been predicted. Buckingham exp-6 potential has been utilized in calculations, based on statistical perturbation theory. The effects of various values of density, temperature and isotopic concentrations on pressure have been studied. Eventually, we have found out symmetrical effects of tritium concentration in deuterium-tritium mixtures. 相似文献
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A facile supported liquid membrane (SLM) system for the selective and efficient transport of silver ion is introduced. The SLM used is a thin porous polyvinyldifluoride membrane impregnated with hexathia-18-crown-6 (HT18C6) dissolved in nitrophenyloctyl ether. HT18C6 acts as a specific carrier for the uphill transport of Ag+ ion as its picrate ion paired complex through the SLM. In the presence of thiosulfate ion as a suitable stripping agent in the strip solution, transport of silver occurs almost quantitatively after 4 h. The selectivity and efficiency of silver transport from aqueous solutions containing other Mn+ cations such as Mg2+, Ca2+, Co2+, Ni2+, Cu2+, Zn2+, Pb2+, Cd2+, Hg2+, Fe3+ and Cr3+ ions were investigated. 相似文献
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A novel one-pot three-component reaction of 6-amino-uracil, isatin, and acetophenone was accomplished through a programmed pH variation for the synthesis of 5-(2-oxoindolin-3-yl)-1H-pyrrolo[2,3-d]pyrimidine-2,4(3H,7H)-dione derivatives. The reaction was conducted in a sequential tandem manner to give the oxindole substituted pyrrolo[2,3-d]pyrimidine products in good to excellent yields. Despite of timing all the processes were carried out in one pot. Most of these novel compounds show narrow to good spectrum of antimicrobial activities in vitro. 相似文献
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Seyyed Shahabeddin Azimi Mansour Kalbasi Hamidreza Sadeghifar 《Journal of Optimization Theory and Applications》2014,162(1):191-201
To solve nonlinear equations by an optimization method, scaling is very important. Two types of poor scaling where: (a) the variables differ greatly in magnitude; (b) the merit function of system is highly sensitive to small changes in certain variables and relatively insensitive to changes in other variables. If poor scaling is ignored, the algorithm may produce solutions with poor quality. To solve (a), we can change units of variables. A numerical solution of the nonlinear equations produced by the finite volume method in the forced convective heat transfer of a nanofluid, as a case study, indicates that the poor scaling (b) is solved by using the Euclidean norm of columns of the Jacobian matrix as scaling data, while some researchers proposed diagonal elements of the Hessian matrix as scaling data. 相似文献
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A novel optical sensor has been proposed for sensitive determination of Cu(II) ion in aqueous solutions. The copper sensing membrane was prepared by incorporating Qsal (2-(2-hydroxyphenyl)-3H-anthra[2,1-d]imidazole-6,11-dione) as ionophore in the plasticized PVC membrane containing tributyl phosphate (TBP) as plasticizer. The membrane responds to Cu(II) ion by changing color reversibly from yellow to dark red in acetate buffer solution at pH 4.0. The proposed sensor displays a linear range of 6.3 × 10?7?1.00 × 10?4 M with a limit of detection of 3.3 × 10?7 M. The response time of the optical sensor was about 3?C5 min, depending on the concentration of Cu(II) ions. The selectivity of the optical sensor to Cu(II) ions in acetate buffer is good. The sensor can readily be regenerated by hydrochloric acid (0.1 M). The optical sensor is fully reversible. The proposed optical sensor was applied to the determination of Cu(II) in environmental water samples. 相似文献
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Zahra Naji Azimi 《Journal of Applied Mathematics and Computing》2004,16(1-2):337-354
SA, TS, GA and ACS are four of the main algorithms for solving challenging problems of intelligent systems. In this paper we consider Examination Timetabling Problem that is a common problem for all universities and institutions of higher education. There are many methods to solve this problem, In this paper we use Simulated Annealing, Tabu Search, Genetic Algorithm and Ant Colony System in their basic frameworks for solving this problem and compare results of them with each other. 相似文献
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Fatemeh Niroomand Hosseini S. Masoud Nabavizadeh Gholamhassan Azimi 《Journal of solution chemistry》2013,42(11):2137-2148
The effect of solvent on the stability and reactivity of methyltrioxorhenium (MTO) for activation of hydrogen peroxide (H2O2) was investigated theoretically. The possible geometries for all Re complexes present in this system, MTO, monoperoxo complexes [A: MeReO2(η 2–O2) and A·H 2 O: MeReO2(η 2–O2)(H2O)], and bisperxo complexes [B: MeReO(η 2–O2)2 and B·H 2 O: MeReO(η 2–O2)2(H2O)] were calculated. Based on the theoretical calculations, species A lacks coordinated water while species B·H 2 O definitely has water coordinated to the Re. The changes of thermodynamic parameters (ΔH and ΔG) for six reactions in the MTO/H2O2, system including formation of mono- and bisperoxo complexes, were determined. 相似文献
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4H-Pyrans and coumarins were synthesized through one-pot reactions using ZnO/MgO solid sample containing ZnO nanoparticles as an efficient reusable catalyst in ionic liquid, [bmim]BF4. The catalyst is inexpensive and readily available, stable and storable, easily recycled and reused for several cycles with consistent activity. The procedure offers advantages in terms of high yields, short reaction times, and mild solvent-free reaction conditions. 相似文献
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