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81.
Mössbauer and X-ray spectra for taenite lamellae from the iron meteorite Cape York show that the lamellae contain an ordered phase with the composition FeNi, and with the structure L10. This phase has not previously been detected in meteorites. 相似文献
82.
Funda Aydin Erkan Yilmaz 《International journal of environmental analytical chemistry》2016,96(14):1356-1366
A separation-preconcentration method based on supramolecular solvent ultrasonic-assisted liquid-phase microextraction (Ss-USA-LPME) for spectrophotometric determination of mercury as 1-(2-pyridylazo)-2-naphthol (PAN) chelates has been established. Red coloured Hg(II)-PAN hydrophobic complex was extracted into the supramolecular phase (1-decanol/THF) at pH 9.5. The extract was separated from aqueous phase by centrifugation, diluted with ethanol and determined by UV–Vis spectrophotometer at λmax = 560 nm. The influences of important analytical parameters such as pH, amount of PAN, 1-decanol and THF, sample volume and matrix effects for the quantitative recoveries were examined and optimised. Under the optimised experimental conditions, the amount of ligand, 1-decanol and THF were 1.0 × 10–4 M, 200 µL and 300 µL, respectively. The optimum time of ultrasonic bath and centrifugation were found as 2 min and 5 min. A linear calibration graph was obtained linearly in the concentration ranges of 8.3–1000 µg L?1. The preconcentration factor was obtained as 20. The limit of detection (LOD) was 2.6 µg L?1 with the relative standard deviation (RSD) of 2.4% for mercury (C = 100 µg L?1, n = 7). The validity of the developed Ss-USA-LPME technique was checked with a certified reference material of NIST 1641d. The presented method has been successfully applied to the determination of mercury in water samples. 相似文献
83.
Aydin J Kumar KS Sayah MJ Wallner OA Szabó KJ 《The Journal of organic chemistry》2007,72(13):4689-4697
New easily accessible 1,1'-bi-2-naphthol- (BINOL-) and biphenanthrol-based chiral pincer complex catalysts were prepared for selective (up to 85% enantiomeric excess) allylation of sulfonimines. The chiral pincer complexes were prepared by a flexible modular approach allowing an efficient tuning of the selectivity of the catalysts. By employment of the different enantiomeric forms of the catalysts, both enantiomers of the homoallylic amines could be selectively obtained. Both allyl stannanes and allyl trifluoroborates can be employed as allyl sources in the reactions. The biphenanthrol-based complexes gave higher selectivity than the substituted BINOL-based analogues, probably because of the well-shaped chiral pocket generated by employment of the biphenanthrol complexes. The enantioselective allylation of sulfonimines presented in this study has important implications for the mechanism given for the pincer complex-catalyzed allylation reactions, confirming that this process takes place without involvement of palladium(0) species. 相似文献
84.
Composites of poly(vinyl chloride) (PVC) filled with micron‐ and nanosized calcium carbonate (CaCO3) particles were prepared by solution blending. The influences of particle size and CaCO3 content on the microstructure and mechanical properties of the PVC composites were investigated by means of polarized optical microscopy and mechanical testing. The polarized optical microscope images revealed that nanosized CaCO3 particles were more agglomerated than micron‐sized CaCO3 particles and the amount of agglomerates increased with increasing particle content. PVC/CaCO3‐0.22 composites (PVC nanocomposite filled with 220‐nm‐particle‐sized CaCO3) 5 phr CaCO3 content had the maximum tensile strength. The Young's modulus of all composites increased with increasing particle content. The energy at break of all composites showed a decreasing trend as a function of CaCO3 content and varied with particle size. 相似文献
85.
The formation of iridium clusters from supported mononuclear iridium complexes in H(2) at 300 K and 1 bar was investigated by spectroscopy and atomic-resolution scanning transmission electron microscopy. The first steps of cluster formation from zeolite-supported Ir(C(2)H(4))(2) complexes are triggered by the activation of H(2) and the formation of iridium hydride, accompanied by the breaking of iridium-support bonds. This reactivity can be controlled by the choice of ligands on the iridium, which include the support. 相似文献
86.
F. Aydin Akgun 《Applied mathematics and computation》2012,218(12):6677-6683
We show that the generalized Hölder and Cesáro matrices of order α > −1 are equivalent. We also show that the corresponding is true for doubly infinite generalized Hölder and Cesáro matrices. 相似文献
87.
88.
Majid Soolaki Iraj Mahdavi Nezam Mahdavi-Amiri Reza Hassanzadeh Aydin Aghajani 《Applied Mathematical Modelling》2012
The airline industry is under intense competition to simultaneously increase efficiency and satisfaction for passengers and profitability and internal system benefit for itself. The boarding process is one way to achieve these objectives as it tends itself to adaptive changes. In order to increase the flying time of a plane, commercial airlines try to minimize the boarding time, which is one of the most lengthy parts of a plane’s turn time. To reduce boarding time, it is thus necessary to minimize the number of interferences between passengers by controlling the order in which they get onto the plane through a boarding policy. Here, we determine the passenger boarding problem and examine the different kinds of passenger boarding strategies and boarding interferences in a single aisle aircraft. We offer a new integer linear programming approach to reduce the passenger boarding time. A genetic algorithm is used to solve this problem. Numerical results show effectiveness of the proposed algorithm. 相似文献
89.
90.
Bianisotropic metamaterials including Ω-shaped metallic elements are investigated experimentally and theoretically. A passband is observed for a composite metamaterial (CMM) based on an Ω-medium below the plasmonic frequency of the corresponding closed CMM. The effective parameters (refractive index, impedances, permittivity, permeability, and magnetoelectric coupling coefficient) are retrieved for the Ω-medium and the CMM based on it. Our retrieval results show that the passband observed for the CMM is a band with positive refractive indices. Our retrieval results confirm the deductions of our previous reports. 相似文献