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951.
Ali Z. Abu-Zuhri 《Monatshefte für Chemie / Chemical Monthly》1984,115(1):57-64
A sensitive procedure for spectrophotometric determination of cerium(III) has been developed. AtpH 10.2 cerium reacts with 1-(2-pyridylazo)-2-naphthol in 40% ethanol to form a red complex which has an absorption maximum at 545 nm. The molar absorptivity at 545 is 3.95·103 mol–1. Maximum stability of the complex was attained in pure ethanol. The stoichiometries and structures of the chelates were studied applying conductometric titration, visible spectrophotometry and IR spectrophotometry. The IR spectra revealed that coordination takes place through the N=N, C-OH and pyridyl group.
Spektrophotometrische Untersuchungen und analytische Anwendung von Ce(III)-Chelaten mit 1-(2-Pyridylazo)-2-naphthol (PAN)
Zusammenfassung Es wurde eine empfindliche Methode zur spektrophotometrischen Bestimmung von Cer(III) entwickelt. Bei einempH von 10,2 reagiert Cer mit 1-(2-Pyridylazo)-2-naphthol in 40% Ethanol unter Bildung eines roten Komplexes mit einem Absorptionsmaximum bei 545 nm (=3 950). Der Komplex besitzt in reinem Ethanol ein Maximum an Stabilität. Die Stöchiometrien und Strukturen der gebildeten 1:1- und 1:2-Chelate wurden mittels konduktometrischer Titration, Elektronen- und IR-Spektrometrie untersucht. Die IR-Daten zeigen, daß die Koordination über N=N, C-OH und Pyridyl erfolgt.相似文献
952.
An adsorptive differential pulse stripping method for the simultaneous determination of lead and tin is proposed. The procedure involves an adsorptive accumulation of lead and tin on a hanging mercury drop electrode (HMDE), followed by oxidation of adsorbed lead and tin by voltammetric scan using differential pulse modulation. The optimum experimental conditions are: 0.2 mol L?1 HNO3, accumulation potential of ?900 mV versus Ag/AgCl, accumulation time of 200 s, scan rate of 20 mV s?1 and pulse height of 80 mV. Lead and tin peak currents were observed in the same potential region at about ?400 mV. The simultaneous determination of lead and tin by using voltammetry is a difficult problem in analytical chemistry, due to voltammogram interferences. The resolution of a mixture of lead and tin by the application of orthogonal signal correction‐partial least squares (OSC‐PLS) was performed. The linear dynamic ranges were 0.003‐0.35 and 0.008‐0.50 μg mL?1 and detection limits were land 3 ng mL?1 for lead and tin, respectively. The RMSEP for lead and tin with OSC and without OSC were 2.8737, 6.0557 and 8.0941, 9.5151, respectively. The capability of the method for the analysis of real samples was evaluated by the determination of lead and tin in water samples with satisfactory results. 相似文献
953.
This article discusses on the solution of the regularized long wave (RLW) equation, which is introduced to describe the development of the undular bore, has been used for modeling in many branches of science and engineering. A numerical method is presented to solve the RLW equation. The main idea behind this numerical simulation is to use the collocation and approximating the solution by radial basis functions (RBFs). To avoid solving the nonlinear system, a predictor‐corrector scheme is proposed. Several test problems are given to validate the new technique. The numerical simulation, includes the propagation of a solitary wave, interaction of two positive solitary waves, interaction of a positive and a negative solitary wave, the evaluation of Maxwellian pulse into stable solitary waves and the development of an undular bore. The three invariants of the motion are calculated to determine the conservation properties of the algorithm. The results of numerical experiments are compared with analytical solution and with those of other recently published methods to confirm the accuracy and efficiency of the presented scheme.© 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010 相似文献
954.
955.
Ismail M. Ali 《Journal of Radioanalytical and Nuclear Chemistry》2010,285(2):263-270
A series of rare-earth-doped sodium titanates with the chemical formula R
x
H
y
Na4 − (x+y)TiO4·nH2O (where R = Ce3+, Nd3+ and Sm3+) were grown employing solid-state fusion reaction technique. The physico-chemical investigations indicated that the new materials
were self engineered into large particles enough to be used in sorption process and having crystalline structures containing
localized Na+ ions. Equilibrium studies revealed that an enhancement in sorption efficiency of sodium titanate after rare-earth doping.
The neodymium-rich sodium titanate exhibited a better exchange affinity for Cs+ compared to the other studied series. Data on the kinetics of cesium exchange fit well to pseudo-second order and intra-particle
diffusion models. In a separate experiment, it was reported that the R-HNaTi series showed responsible sorption affinity toward
Ce, Nd and Sm ions in their solution mixture with insignificant selectivity trend which reflects the high stability of titanate
matrices. 相似文献
956.
Ali A. Abdel Hafez Ibrahim M. A. Awad Khairy M. Hassan 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4):219-225
Abstract Some new derivatives containing both 8-hydroxyquinoline and sulphonylamino β-lactams and thiazolidinones have been prepared. These compounds were synthesized from the corresponding 8-hydroxyquinoline sulphonylhydrazide (1) by converting it to hydrazones (2). The latter hydrazones (2) were easily transformed to β-lactams (3) and thiazolidinones (4) by cyclocondensation reaction with chloroacetyl chloride and/or mercaptoacetic acid. Some metal chelates with Fe3+. Co2++, Ni2+, Cu2+ and Cd2+ have been prepared for some of the compounds and screened in vitro for their biological activity. 相似文献
957.
Ali Soleyman Jahan 《manuscripta mathematica》2009,130(4):533-550
In this paper we study how prime filtrations and squarefree Stanley decompositions of squarefree modules over the polynomial
ring and over the exterior algebra behave with respect to Alexander duality. The results which we obtained suggest a lower
bound for the regularity of a
\mathbb Zn{\mathbb {Z}^n}-graded module in terms of its Stanley decompositions. For squarefree modules this conjectured bound is a direct consequence
of Stanley’s conjecture on Stanley decompositions. We show that for pretty clean rings of the form R/I, where I is a monomial ideal, and for monomial ideals with linear quotient our conjecture holds. 相似文献
958.
Özge Dağlı Dursun Ali Köse Onur Şahin Zarife Sibel Şahin 《Journal of Thermal Analysis and Calorimetry》2017,128(3):1373-1383
The coumarilate (coum?) complexes of CoII(1), NiII(2) CuII(3) and ZnII(4) were synthesized and characterized by elemental analysis, magnetic susceptibility, solid-state UV–Vis, FTIR spectra, thermoanalytical TG–DTG/DTA and single-crystal X-ray diffraction methods. It was found that all of the complex structures have 2 mol (coum?) ligand bonded as monoanionic monodentate in the structures of 1 and 2 while they were coordinated to metal cations as monoanionic bidentate in the complexes 3 and 4. There was not any hydrate water in the metal complexes. The complexes of 1 and 2 have four moles of aqua ligand, and the other complexes have two moles. Thermal decomposition of each complex starts with dehydration, and then the decomposition of organic parts goes. The thermal dehydration of the complexes takes place in one (for the compounds of 2, 3, 4) or two (for the compound 1) steps. The decomposition mechanism and the thermal stability of the complexes under investigation were determined on the basis of their structures. Metal oxides were obtained as the final decomposition product. 相似文献
959.
Abdelmalek Zahra Khan Sami Ullah Waqas Hassan Riaz Arshad Khan Israr Ali Tlili Iskander 《Journal of Thermal Analysis and Calorimetry》2021,144(1):205-217
Journal of Thermal Analysis and Calorimetry - The significant bioconvection phenomenon with the utilization of nanoparticles encountered fundamental industrial and technological applications in... 相似文献
960.
Mohammad Hossein Mashhadizadeh Mahnaz Pesteh Mahzad Talakesh Iran Sheikhshoaie Mohammad Mazloum Ardakani Mohammad Ali Karimi 《Spectrochimica Acta Part B: Atomic Spectroscopy》2008
A simple, selective and reliable method for rapid extraction and determination of trace amounts of Cu (II) ions from aqueous samples using octadecyl-bonded silica membrane disks modified with bis-(3-methoxy salicylaldehyde)-1,6-diaminohexane and flame atomic absorption spectrometry (FAAS) is presented. Extraction efficiency, the influence of pH, flow rates, amount of ligand, and type and least amount of eluant were investigated. The linear dynamic range of the proposed method for Cu (II) ions was found in a wide concentration range of 1.0 (± 0.2)–150 (± 2) μg l− 1. The detection limit and preconcentration factor of this method were found 30.0 (± 0.7) ng l− 1 and 100 respectively. The reproducibility of the procedure is at the most 2.0%. The effects of various cationic interferences on the percent recovery of copper ion were studied. The method was used to the recovery of copper ion from different synthetic, alloys and biological samples. 相似文献