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311.
312.
Maryam?Ghaemi Ghodratollah?AbsalanEmail author 《Journal of the Iranian Chemical Society》2015,12(1):1-7
Adsorption characteristics and doxycycline (DC) removal efficiency of Fe3O4 magnetic nanoparticles as adsorbents have been determined by investigating the effects of pH, concentration of the DC, amount of adsorbents, contact time, ionic strength and temperature. The mechanism of adsorption was also studied. The adsorption of DC to the Fe3O4 magnetic nanoparticles could be described by Langmuir-type adsorption isotherms. Short contact time between the reagents, reusability of Fe3O4 for three times after recycling of the nanoparticles, good precision and accuracy, wide working pH range and high breakthrough volume are among the highlights of this procedure. The proposed extraction and determination procedure based on magnetic nanoparticles as adsorbent was successfully applied to the determination of DC spiked in honey and various water samples. The method presented here is fast, simple, cheap and robust, and it does not require the use of organic solvents. Also, the method needs only a magnet and can be performed in any laboratory without sophisticated equipment. 相似文献
313.
Mehrnoosh?Kangani Nourallah?HazeriEmail author Malek?Taher?Maghsoodlou Khatereh?Khandan-Barani Maryam?Kheyrollahi Fereshteh?Nezhadshahrokhabadi 《Journal of the Iranian Chemical Society》2015,12(1):47-50
Saccharose was applied as an efficient and homogeneous catalyst for one-pot, four-component synthesis of 1,4-dihydropyrano[2,3-c]pyrazole derivatives from aromatic aldehydes, malononitrile, ethyl acetoacetate and hydrazine monohydrate under thermal solvent-free conditions. This protocol has a considerable number of advantages including mild condition, high yields, operational simplicity, environmentally benign and simple work-up procedures. 相似文献
314.
Elaheh K. Goharshadi Maryam Imani Rayhaneh Rahimi-Zarei Fahimeh Razghandi Maryam Abareshi Ali R. Berenji 《European Polymer Journal》2010,46(3):587-591
In this work, the excess thermodynamic properties, namely excess molar Gibbs energy, excess molar enthalpy, excess molar entropy, excess molar internal energy, and excess molar Helmholtz energy for four polymer mixtures and blends at different temperatures, pressures, and compositions have been calculated using the GMA equation of state. We have also calculated the activity coefficient for these polymeric mixtures using the GMA equation of state. The values of statistical parameters between experimental and calculated properties show the ability of this equation of state in reproducing and predicting the excess thermodynamic functions and activity coefficients for studied polymeric mixtures. 相似文献
315.
Mukhles Sowwan Maryam Faroun Elad Mentovich Imad Ibrahim Shayma Haboush Fikri Emrah Alemdaroglu Minseok Kwak Shachar Richter Andreas Herrmann 《Macromolecular rapid communications》2010,31(14):1242-1246
In this study, DNA block copolymer (DBC) micelles with a polystyrene (PS) core and a single‐stranded (ss) DNA shell were doped with ferrocene (Fc) molecules. Tapping mode atomic force microscopy (AFM) was used to study the morphology of the doped and undoped block copolymer aggregates. We show that introducing Fc molecules into the hydrophobic core does not affect the structural properties such as shape or size. In contrast, doping with Fc significantly changes the micelles' electrical properties, namely their polarizability. Electrostatic force microscopy (EFM) measurements reveal that the undoped micelles show no significant polarization signal, while the Fc‐doped aggregates exhibit strongly enhanced polarizability. Furthermore, the nucleic acid moieties were utilized in combination with complementary ssDNA strands to assemble single particles into linear arrays of DBC nanoobjects. The ability to tune the electrostatic properties of the polymer core and the presence of nucleic acids might open the way for using these bioorganic nanoparticles as building blocks for nanoelectronic or biosensing devices.
316.
Azadeh Farahzadi Maryam Beigmohamadi Stephan Kremers Michael Heuken 《Applied Surface Science》2010,256(22):6612-14284
The optical properties of tris(8-hydroxyquinoline) aluminum (Alq3), N,N′-diphenyl-N,N′-bis(1-naphthyl)-1-1′biphenyl-4,4″diamine (α-NPD) and other amorphous organic materials for OLEDs application, e.g. 4,4-bis(2,2-diphenyl vinyl)-1,1-biphenyl (DPVBI) and Spiro-DPVBI have been studied by multi-angle spectroscopic ellipsometry (SE). The thin films of these materials have been deposited by organic vapor phase deposition (OVPD). The structural characterization has been performed using atomic force microscopy (AFM) and X-ray reflectometry (XRR). Comparison of the measurements using these different independent techniques enables the precise determination of the optical model for dielectric function of these thin films. The detail analyses on Alq3 and α-NPD show that the Kim model with Gaussian broadening provides a significantly better fit to the ellipsometry data than the frequently used harmonic oscillator model. This conclusion is further proved by performing similar measurements on other amorphous organic samples for OLEDs application, e.g. DPVBI and Spiro-DPVBI. This result can be explained by the characteristic features of electronic states in organic molecules. 相似文献
317.
Abedien Zabardasti Saeid Amani Mohammad Solimannejad Maryam Salehnassaj 《Structural chemistry》2009,20(6):1087-1092
Abstract
Ab initio and density functional calculations were used to analyze the interaction between a molecule of the isocyanic acid with 1 up to 4 molecules of ammonia at the B3LYP/6-311++G(d,p) and MP2/6-311++G(d,p) computational levels. The cooperative effect is increased with the increasing size of studied clusters. Red shifts of the H–N stretching frequency for complexes involving the isocyanic acid as an H-donor were predicted. Atom in molecules was used to analyze cooperative effects on topological parameters. 相似文献318.
Chekin F Bordbar M Fathollahi Y Alizadeh N 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2006,63(2):370-376
1H NMR spectroscopy was used to investigate the stoichiometry and stability of the drug ketamine cation complexes with some crown ethers, such as 15-crown-5 (15C5), aza-15-crown-5 (A15C5), 18-crown-6 (18C6), aza-18-crown-6 (A18C6), diaza-18-crown-6 (DA18C6), dibenzyl-diaza-18-crown-6 (DBzDA18C6) and cryptant [2,2,2] (C222) in acetonitrile (AN), dimethylsulfoxide (DMSO) and methanol (MeOH) at 27 degrees C. In order to evaluate the formation constants of the ketamine cation complexes, the CH3 protons chemical shift (on the nitrogen atom of ketamine) was measured as function of ligand/ketamine mole ratio. The formation constant of resulting complexes were calculated by the computer fitting of chemical shift versus mole ratio data to appropriate equations. A significant chemical shift variation was not observed for 15C5 and 18C6. The stoichiometry of the mono aza and diaza ligands are 1:1 and 1:2 (ligand/ketamine), respectively. In all of the solvents studied, DA18C6 formed more stable complexes than other ligands. The solvent effect on the stability of these complexes is discussed. 相似文献
319.
Jouyban A Chan HK Chew NY Khoubnasabjafari M Acree WE 《Chemical & pharmaceutical bulletin》2006,54(4):428-431
The Jouyban-Acree model has been used to predict the solubility of paracetamol in water-ethanol-propylene glycol binary and ternary mixtures based on model constants computed using a minimum number of solubility data of the solute in water-ethanol, water-propylene glycol and ethanol-propylene glycol binary mixtures. Three data points from each binary solvent system and solubilities in neat solvents were used to calculate the binary interaction parameters of the model. Then the solubility at other binary solvent compositions as well as in a number of ternary solvents were predicted, and the mean percentage deviation (+/-S.D.) of predicted values from experimental solubilities was 7.4(+/-6.1)%. 相似文献
320.
María D. Acosta Mieczysław Mastyło Maryam Soleimani-Mourchehkhorti 《Journal of Functional Analysis》2018,274(9):2673-2699
We study the Bishop–Phelps–Bollobás property for operators between Banach spaces. Sufficient conditions are given for generalized direct sums of Banach spaces with respect to a uniformly monotone Banach sequence lattice to have the approximate hyperplane series property. This result implies that Bishop–Phelps–Bollobás theorem holds for operators from into such direct sums of Banach spaces. We also show that the direct sum of two spaces with the approximate hyperplane series property has such property whenever the norm of the direct sum is absolute. 相似文献