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41.
S. Mustafa Samad Yar Hussain A. Naeem Khan 《Reaction Kinetics and Catalysis Letters》1992,47(1):125-131
The kinetics of phosphate sorption on Amberlite IRA-400 has been studied as a function of temperature, nature of counterions, at two different concentrations. The film and particle diffusion coefficients and the activation parameters of the process are calculated.
IRA-400 , . .相似文献
42.
L. C. Courrol R. E. Samad L. Gomes I. M. Ranieri S. L. Baldochi A. Z. Freitas S. P. Morato N. D. Vieira Jr. 《Laser Physics》2006,16(2):331-335
Color centers are lattice vacancy defects trapping electrons or holes. They are easily created in single crystals by irradiation with ionizing radiation. We report the production of color centers in LiF and LiYF4 single crystals by ultrashort high-intensity laser pulses (60 fs, 12.5 GW). An intensity threshold for color center creation of 1.9 and 2 TW/cm2 was determined in YLF and LiF, respectively, which is slightly smaller than the continuum generation threshold. Due to the high energy density of the coherent radiation of the focused laser beam, we were able to identify a large amount of F centers, which gave rise to aggregates such as F2, F 2 + , and F 3 + . The proposed mechanism of formation is based on multiphoton excitation, which also produces short-lived F 2 + centers. It is also shown that it is possible to write tracks in the LiF crystals with dimensional control. 相似文献
43.
A novel, chemoselective mono-N-Boc protection of various structurally diverse amines with di-tert-butoxypyrocarbonate (Boc)2O is described that relies on selective carbonyl activation by hydrogen bond formation. This mild, acid- and metal-free process requires only catalytic amounts of thiourea as hydrogen bond donor. 相似文献
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二氧化钛纳米粒子催化合成Hantzsch酯和多氢喹啉衍生物(英文) 总被引:2,自引:0,他引:2
Mahmood TAJBAKHSH Ehsan ALAEE Heshmatollah ALINEZHAD Mohammad KHANIAN Fatemeh JAHANI Samad KHAKSAR Parizad REZAEE Mahgol TAJBAKHSH 《催化学报》2012,(9):1517-1522
1,4-Dihydropyridine and polyhydroquinoline derivatives have been prepared efficiently in a one-pot synthesis via Hantzsch condensation using nanosized titanium dioxide as a heterogeneous catalyst.The present methodology offers several advantages such as excellent yields,short reaction times (30-120 min),environmentally benign,and mild reaction conditions.The catalyst can be readily separated from the reaction products and recovered in excellent purity for direct reuse. 相似文献
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A simple, diastereoselective, inexpensive, and efficient route for the synthesis of highly functionalized piperidines by the condensation of β-keto-esters, aromatic aldehydes and anilines using cerium(IV) triflate as a catalyst is described. In most cases, the piperidine precipitates out of the solution. 相似文献
48.
Farhang Mizani Abbas Shockravi Mehdi Taghdiri Samad Bavili Tabrizi Faezeh Azmoodeh Kamal Alizadeh Mojtaba Shamsipur 《Journal of inclusion phenomena and macrocyclic chemistry》2014,79(1-2):83-94
A novel thia-aza substituted macrocyclic diamide 7,10,13-triaza-1-thia-4,16-dioxa-20,24-dimethyl-2,3;17,18-dibenzo-cyclooctadecane-6,14-dione (L) was synthesized and stability of its complexes with several alkaline earth, transition and heavy metal ions were studied conductometrically in methanol solution. The resulting 1:1 Ag+–L complex found to be the most stable one among all cation complexes studied. The optimized structures of the ligand and its Ag+ complex were also investigated. Based on the preliminary results thus obtained, L was used as an excellent sensing material to prepare polymeric membrane (PME) and coated graphite (CGE) silver-selective electrodes. The electrodes revealed a Nernstian behavior over wide Ag+ ion concentration ranges (i.e., 2.0 × 10?6–1.0 × 10?2 M for PME and 5.0 × 10?7–1.0 × 10?2 M for CGE). The potentiometric responses were independent of pH of the test solution in the range 2.9–6.8. The electrodes possessed advantages of low resistance, relatively fast response time, long lifetimes and, especially, good selectivity relative to a wide variety of other cations. The electrodes were used, as indicator electrodes, in the potentiometric titration of silver ion and in the determination of Ag+ ion in waste water, photographic emulsion, radiographic and photographic films and dental amalgams. 相似文献
49.
Abbas Shockravi T. Samad Bavili 《Journal of inclusion phenomena and macrocyclic chemistry》2005,52(3):223-227
Some new dibenzosulfide macrocyclic diamides (6–12) are synthesized. The macrocyclization process is performed by reaction of the dimethyl ester (5) and diacid chloride (4) with appropriate diamines by two methods. Also the results of two methods are discussed and compared. 相似文献
50.
Nejatolahi Mostafa Golneshan Ali Akbar Kamali Reza Sabbaghi Samad 《Journal of Thermal Analysis and Calorimetry》2021,144(4):1467-1481
Journal of Thermal Analysis and Calorimetry - Both equilibrium and nonequilibrium molecular dynamics (EMD and NEMD, respectively) methods have been used to predict the thermal conductivity of... 相似文献