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31.
Tahereh Ghauri Koodehi Farhad Shirini Omid Goli-Jolodar 《Journal of the Iranian Chemical Society》2017,14(2):443-456
In this work, 1,4-disulfopiperazine-1,4-diium chloride ([Piper-(SO3H)2]·2Cl), as a novel Brönsted acidic ionic catalyst is synthesized and characterized using a series of techniques including FT-IR, TGA, DTA, SEM, pH analysis and Hammett acidity function. This substance can significantly catalyze the N-Boc protection of amines without solvent interference at room temperature. The advantages of this manner are chemoselectivity, short reaction times, suitable yields, excellent yields of the products, without solvent interference and ease of preparation as well as reusability of the catalyst. 相似文献
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Hekmat D Mornhinweg R Bloch G Sun Y Jeanty P Neubert M Weuster-Botz D 《Journal of chromatography. A》2011,1218(7):944-950
The goal of the present work was to examine the hydrodynamic behavior of preparative scale packed chromatography beds during long-term cyclical operation at high loads using an experimental set-up with a high resolution measuring device of bed height. One agarose-based resin and one methacrylic-based resin were examined in a 140 mm column. Both resins exhibited hysteresis behavior during compression/relaxation cycles. The hystereses were less pronounced with decreasing hydrodynamic stress rate. The occurrence of hystereses was an indication for hydrodynamic memory behavior of the chromatography packing. During long-term cyclical operation at high loads of the column filled with methacrylic resin, oscillations of the steadily with time decreasing flow rate were observed for the first time. These oscillations were attributed to the viscoelasticity of the polymer particles network representing a system with materials with fading memory. Such nonlinear systems with feed-back are known to exhibit inherent self-oscillations. A decoupling of the two processes of bed compression and decrease of bed permeability was observed. The presented results explain why preparative packed-bed chromatography often yields unsatisfactory reproducible data and why unwanted phenomena like medium wall detachment or other symptoms of deteriorated chromatography beds are frequently observed. 相似文献
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Malekahmadi Omid Kalantar Mahdi Nouri-Khezrabad Mohsen 《Journal of Thermal Analysis and Calorimetry》2021,144(6):2109-2126
Journal of Thermal Analysis and Calorimetry - The hydroxyapatite is one of the biocompatible and insulating bioceramics, while the carbon nanotube has a high thermal conductivity potential. This... 相似文献
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Sabbagh Omid Fanaei Mohammad Ali Arjomand Alireza 《Journal of Thermal Analysis and Calorimetry》2021,145(3):851-866
Journal of Thermal Analysis and Calorimetry - A novel NGL/LNG integrated scheme based on C3MR refrigeration system is modeled by using Aspen plus® in this study. The mentioned scheme utilizes... 相似文献
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Abedini Masoumeh Shirini Farhad Mohammad-Alinejad Omran Javad Seddighi Mohadeseh Goli-Jolodar Omid 《Research on Chemical Intermediates》2016,42(5):4443-4458
Research on Chemical Intermediates - Succinimidinium N-sulfonic acid hydrogen sulfate ([SuSA-H]HSO4) as a new ionic liquid is prepared and characterized using a variety of techniques, including... 相似文献
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S.A. Safwan A.S. Asmaa Nagwa El meshed M.H. Hekmat TH.M. El-Sherbini S.H. Allam 《Superlattices and Microstructures》2010
Within the effective mass approximation, we investigated theoretically the ground-state energy of a single particle and the binding energy of the neutral donor impurity (D0) affected by a lateral electric field in a parabolic quantum dot (QD). The results show that the electron and the hole ground-state energy and the band to band transition energies shift to lower values (red shift) by increasing the field intensity. The quantum Stark shift (QSS) for the electron increases rapidly in the quasi spherical QD (QSQD) by increasing the lateral field, whereas for the hole it increases monotony. In the cylindrical QDs (CQDs), we found that the QSS for electron and hole increase monotonically. The quantum size, lateral electric field and impurity position effect on the binding energy of neutral donor (D0) is studied. Unexpected behavior of D0 in quantum well limit (QW), the binding energy of D0 is increasing (blue shift) with increasing QD radius R at the presence of a lateral electric field. It appears that for a fixed size of the QD, the off-center binding energy decreases when the impurity ion is displaced from the center to the QD borders, while it is shifted to lower energy with increasing the field. 相似文献
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We define a divisor theory for graphs and tropical curves endowed with a weight function on the vertices; we prove that the Riemann–Roch theorem holds in both cases. We extend Baker’s Specialization Lemma to weighted graphs. 相似文献
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Mahian Omid Ebrahimnia-Bajestan Ehsan Poncet Sébastien 《Journal of Thermal Analysis and Calorimetry》2019,135(1):23-28
Journal of Thermal Analysis and Calorimetry - 相似文献