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排序方式: 共有196条查询结果,搜索用时 281 毫秒
91.
92.
Amira Zaouak Ahlem Noomen Haikel Jelassi 《Journal of Radioanalytical and Nuclear Chemistry》2018,316(1):37-47
Cesium uptake by natural zeolite clinoptilolite from Bulgaria was studied using batch technique and model solutions. The optimal conditions of interaction were determined. The pseudo-second-order rate model better describes the kinetic data obtained at different concentrations. The intraparticle diffusion and the surface diffusion models were tested to identify the rate-controlling step. The sites in the structure of clinoptilolite that are preferable for exchange were studied by application of Rietveld structural approach and the sequence of site occupation by cesium was followed. The Langmuir isotherm model provides a good fit of the equilibrium experimental data. The thermodynamic parameters for the system were calculated. 相似文献
93.
Norbani Abdullah Suhana Mohd Said Yanti Yana Halid Megat Muhammad Ikhsan Megat Hasnan Naima Sharmin Siti Amira Mat Hussin 《Journal of Coordination Chemistry》2016,69(19):2954-2971
Nickel(II) carboxylates [Ni(CH3(CH2)14COO)2(H2O)2] (1) and [Ni(C6H5COO)2(H2O)2] (2) were obtained from reactions of NiCl2·6H2O with CH3(CH2)14COONa and C6H5COONa, respectively. Complex 1 reacted with pyridine (pyr) to form [Ni(CH3(CH2)14COO)2(pyr)2(H2O)2] (3) and [Ni2(μ2-H2O)(CH3(CH2)14COO)4(pyr)4] (4) in the same reaction mixture, and reacted with cyclam to form an ionic complex, [Ni(CH3(CH2)14COO)(cyclam)(H2O)]CH3(CH2)14COO·4H2O (5). In contrast, 2 reacted with cyclam to form [Ni(C6H5COO)2(cyclam)] (6). Finally, 6 reacted with p-(hexadecyloxy)pyridine (L) to form an ionic complex, [Ni(cyclam)(L)2](C6H5COO)2 (7). Complexes 3–6 were single crystals. All complexes have octahedral Ni(II) center(s) and were magnetic. Complexes with cyclam as co-ligand were more thermally stable than those with pyridine and its derivative, L. Complexes 3 and 4 were mesomorphic after partial loss of water and/or pyridine ligands on heating. The ionic complexes 5 and 7 were not mesomorphic, but showed good thermoelectrical behavior with negative Se values in CHCl3 (?0.28 mV K?1 for 5; -0.39 mV K?1 for 7) and positive Se values in C2H5OH (+0.25 mV K?1 for 5; +0.20 mV K?1 for 7). 相似文献
94.
Helwa Amira A. Gedawy Ehab M. Abou-Seri Sahar M. Taher Azza T. El-Ansary Afaf K. 《Research on Chemical Intermediates》2018,44(4):2685-2702
Research on Chemical Intermediates - New series of pyrimidinone-5-carbonitriles 3a–i, 4a–e, 5a–c, 6 and 7 have been synthesized and explored for their activities as anticancer,... 相似文献
95.
Chrif Sada Fatma Amor Rym Ben Chrif Amira Zid Mohamed Faouzi 《Journal of Solid State Electrochemistry》2021,25(7):1987-1997
Journal of Solid State Electrochemistry - Crystals of Ag0.2K0.8Nb4AsO13 (I) and Ag0.62K0.38Nb4AsO13 (II) were synthesized by a solid-state reaction. Both of them crystallize in the orthorhombic... 相似文献
96.
S.P. AltintasA. Amira A. VarilciC. Terzioglu 《Journal of magnetism and magnetic materials》2012,324(7):1331-1336
Bulk samples of gadolinium doped manganites with compositional formula La0.7−xGdxCa0.3MnO3 (x=0.0 and 0.1) were prepared by conventional solid state reaction method. After characterizing the samples by X-ray diffraction, scanning electron microscope and energy dispersive X-ray spectrometer, a systematic investigation of electrical and magneto-transport properties has been investigated. The replacement of La ion by Gd results in a decrease of the metal-insulator transition temperature TMI and the magnetoresistance as well as the resistivity are found to increase. The electrical resistivity in the entire temperature range fit well with the phenomenological percolation model, which is based upon an approach that the system consists of the phase separated ferromagnetic metallic and paramagnetic insulating regions. 相似文献
97.
98.
Ashraf A. Aly Alan B. Brown Mohamed Abdel‐Aziz Gamal El‐Din A. A. Abuo‐Rahma Mohamed F. Radwan Mohamed Ramadan Amira M. Gamal‐Eldeen 《Journal of heterocyclic chemistry》2012,49(4):726-731
Reaction of 3‐aroyl‐1‐arylthioureas with dimethyl but‐2‐ynedioate in dichloromethane and catalyzed by triphenylphosphine at ?5°C led to (Z)‐methyl 2‐[(Z)‐2‐(4‐aroylimino)‐4‐oxo‐3‐aryl‐1,3‐thiazolidin‐5‐ylidene]acetates in good yields. The mechanism is discussed. X‐ray structure analysis of one thiazolidine derivative is described. Antitumor and antioxidant activities have been investigated. One derivative of 1,3‐thiazolidine showed moderate antiproliferative in vitro activity against hepatocellular carcinoma Hep‐G2, whereas another 1,3‐thiazolidine introduced effective antioxidant activity compared to ascorbic acid. 相似文献
99.
100.
Najeh Tka Jamil Kraïem Yakdhane Kacem Amira Hajri Bchir Ben Hassine 《Comptes Rendus Chimie》2009,12(9):1066-1071
New enantiomerically pure N-methyl-N-arylsulfonyl-α-aminonitriles were prepared starting from the corresponding α-amino acids by way of N-methyl-N-arylsulfonyl-α-amino amides. The key step of this sequence consists of the dehydration of amides by thionyl chloride which proceeded without a significant racemization. Enantiomeric purity of nitriles was determined by HPLC analysis. 相似文献