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911.
Reihaneh Malakooti Zeinab Parsaee Rahele Hosseinabadi Hossein A. Oskooie Majid M. Heravi Mina Saeedi Maryam Amrollah Akram Fallah 《Comptes Rendus Chimie》2013,16(9):799-806
A novel [Cu(bpdo)2·2H2O]2+-supported SBA-15 catalyst (bpdo = 2,2′-bipyridine,1,1′-dioxide) was prepared by the impregnation method. The catalyst was characterized by XRD, TEM, and BET nitrogen adsorption–desorption method, FT-IR, UV–vis, and chemical analysis. XRD patterns and TEM analysis of [Cu(bpdo)2·2H2O]2+/SBA-15 showed highly ordered hexagonal mesoporous silica, even after immobilization. Also, nitrogen adsorption–desorption isotherms exhibited type-IV isotherms and H1 hysteresis loops according to the IUPAC classification of mesoporous materials. This green support was tested for the synthesis of benzoxanthenone and benzochromene derivatives under solvent-free conditions, with high yield of products via a simple experimental and work-up procedure. 相似文献
912.
We study the entanglement between the internal electronic and the external vibrational degrees of freedom of a trapped atom which is driven by two lasers into electromagnetically induced transparency. It is shown that basic features of the intricate entanglement dynamics can be traced to Landau-Zener splittings (avoided crossings) in the spectrum of the atom-laser field Hamiltonian. We further construct an effective Hamiltonian that describes the behavior of entanglement under dissipation induced by spontaneous emission processes. The proposed approach is applicable to a broad range of scenarios for the control of entanglement between electronic and translational degrees of freedom of trapped atoms through suitable laser fields. 相似文献
913.
914.
Arash Ghorbani‐Choghamarani Hamid Goudarziafshar Maryam Hajjami Jinoos Soltani 《中国化学会会志》2008,55(6):1191-1194
Various types of sulfides are chemoselectively oxidized to the corresponding sulfoxides by treatment of Al(NO3)3.9H2O, silica sulfuric acid and a catalytic amount of NaBr in the presence of wet SiO2 (50% w/w) in CH2Cl2 at room temperature. The catalytic oxidation procedure is very simple and the products are easily isolated in good yields. 相似文献
915.
Mirzaei-Mosbat Maryam Ghorbani-Vaghei Ramin Karamshahi Zahra 《Research on Chemical Intermediates》2020,46(2):1613-1628
Research on Chemical Intermediates - In this research, the synthesis route of ZnCr-layered double hydroxides functionalized with poly(p-phenylenediamine) and Cu(II) was described. LDHs@PpPDA@Cu was... 相似文献
916.
Majid M. Heravi Khadijeh Bakhtiari Tina Benmorad Fatemeh F. Bamoharram Hossein A. Oskooie Maryam H. Tehrani 《Monatshefte für Chemie / Chemical Monthly》2007,41(10):449-452
The nitration of aromatic compounds was carried out in the presence of divanadium-substituted molybdophosphoric acid, H5PMo10V2O40, as catalyst and a mixture of nitric acid and acetic anhydride as nitrating agent. In the presence of this heteropolyacid
the ortho- and para-nitro compounds were obtained in good to excellent yields under mild reaction conditions. 相似文献
917.
We have investigated the switching performance of a gained (nonlinear directional coupler) NLDC switch in the presence of
both 2nd and 4th order gain nonlinearities. In this system, we have achieved a nearly complete pulse switching at half beat
length of the coupler which implies about 40% reduction in the switching length as compared to the switching length reported
in Trillo et al. (1988). We have shown that at the half beat length the output energy of each branch is equal to that of the
input energy and hence the gained NLDC switches have ability to be cascaded. Our initial investigations reveal that this gained
NLDC switch has remarkable performance and potential to be used in ultra-fast optical communication systems. 相似文献
918.
Three aza‐aromatic base adducts of cadmium(II) furoyltrifluoroacetonate, [Cd(4,4′‐bpy)(ftfa)2]n ( 1 ), [Cd(2,2′‐bpy)(ftfa)2] ( 2 ) and [Cd(dmp)(ftfa)2] ( 3 ) (“4,4′‐bpy”, “2,2′‐bpy”, “dmp” and “ftfa” are the abbreviations of 4,4′‐bipyridine, 2,2′‐bipyridine, 2,9‐dimethyl‐1,10‐phenanthroline and furoyltrifluoroacetonate, respectively) have been synthesized and characterized by elemental analysis and IR, 1H NMR and 13C NMR spectroscopy and studied by thermal as well as X‐ray crystallography. The single‐crystal structure of these complexes shows that the coordination number of the CdII ions are six with two N‐donor atoms from aza‐aromatic base ligands and four O‐donors from two the furoyltrifluoroacetonates. The supramolecular features in these complexes are guided/controlled by weak directional intermolecular interactions. 相似文献
919.
In the present study, chemometric analysis of visible spectral data of phospho-and silico-molybdenum blue complexes was used to develop artificial neural networks (ANNs) for the simultaneous determination of the phosphate and silicate. Combinations of principal component analysis (PCA) with feed-forward neural networks (FFNNs) and radial basis function networks (RBFNs) were built and investigated. The structures of the models were simplified by using the corresponding important principal components as input instead of the original spectra. Number of inputs and hidden nodes, learning rate, transfer functions and number of epochs and SPREAD values were optimized. Performances of methods were tested with root mean square errors prediction (RMSEP, %), using synthetic solutions. The obtained satisfactory results indicate the applicability of this ANN approach based on PCA input selection for determination in highly spectral overlapping. The results obtained by FFNNs and by RBF networks were compared. The applicability of methods was investigated for synthetic samples, for detergent formulations, and for a river water sample. 相似文献
920.
Ramin Ghahremanzadeh Somayyeh Ahadi Maryam Sayyafi Ayoob Bazgir 《Tetrahedron letters》2008,49(29-30):4479-4482
Some new phthalazine derivatives were prepared by reaction of phthalhydrazide and dialkyl acetylenedicarboxylates in the presence of N-heterocycles. 相似文献