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641.
Mohammad Reza Ganjali Mohammad Reza Pourjavid Mojtaba Shamsipur Taherh Poursaeri Morteza Rezapour Mehran Javanbakht Hashem Sharghi 《Analytical sciences》2003,19(7):995-999
Poly(vinyl chloride) (PVC) based membranes of zinc-phthalocyanine (ZPC) with hexadecyltrimethylammonium bromide (HTAB) as a cation excluder, and dibutyl phthalate (DBP) and benzyl acetate (BA) as plasticizing solvent mediators were prepared and investigated as a SO4(2-) selective electrode. The best performance was observed with a membrane having a composition of ZPC-PVC-HTAB-BA in a ratio of 5%:32%:3%:60%, which works well over a wide concentration range (1.0 x 10(-2) - 1.0 x 10(-6) M) with a Nemstian slope of -29.2 mV per decade of activity, between the pH values of 2.0 to 7.0. This sensor shows a very fast response time of 10 s, and can be used over a period of 2 months with good reproducibility. The proposed sensor displays excellent selectivity for SO4(2-) over a large number of common inorganic anions. The sensor has been successfully applied for the direct and indirect determination of sulfate and zinc in zinc sulfate tablets, respectively. It was also used as an indicator electrode in the potentiometric titration of sulfate ions with barium ions. 相似文献
642.
Narges Sharifi Mahdi Ardjmand Morteza Ghorbanzadeh Ahangari Masoud Darvish Ganji 《Structural chemistry》2013,24(5):1473-1483
The characteristics of lithium adsorption on Si-decorated graphene are investigated using first-principles density functional theory calculations. It is found that the Si atom is strongly adsorbed at the bridge site of the C–C bond with binding energy of about ?26.75 kcal/mol. We show that Si decorating turns Si:graphene complex into an electron-deficient system and significantly enhances the Li-storage capacity on the graphene. The obtained results indicate that up to eight Li-ions being adsorbed onto the Si-decorated graphene can form the stable complex. It is found, interestingly, that two Si atoms coated onto double-side of the graphene can strongly adsorb sixteen Li-ions. The analyses of electronic structures show a strong interaction between Li-ions and Si-decorated graphene leading to a high exothermicity. The stability of the sixteen Li-ions adsorbed on the Si:graphene system was evaluated with ab initio molecular dynamics simulation which have been carried out at room temperature. Our first-principles results are relevant to identify the potential applications of Si-decorated graphene as superior media for Li-ions storage. 相似文献
643.
Bahador Karami Morteza Montazerozohori Mohammad Hossein Habibi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2825-2831
Tungstate sulfuric acid in combination with various oxidants was found to be an efficient reagent for the conversion of thiols to disulfides at r.t. in good to excellent yields. The selective oxidative deprotection of 1,3-dithianes to their parent carbonyl compounds at r.t. was also observed with this reagent. 相似文献
644.
Morteza Rahimian Ali A. Orouji Amirhossein Aminbeidokhti 《Current Applied Physics》2013,13(4):779-784
In this paper, we present the unique features exhibited by a novel nanoscale SiGe-on-insulator metal-oxide-semiconductor field-effect transistor (MOSFET) with modified channel band energy. The key idea in this work is to modify the band energy in the channel for improving electrical performances. Graded Ge composition profile is employed in the channel that leads to call the proposed structure as GC-SGOI structure. Using two-dimensional two-carrier simulation we demonstrate that the GC-SGOI structure has higher saturation velocity in comparison with stepped (SC-SGOI) and uniform (UC-SGOI) germanium composition due to the high conduction and valence bands slopes by using graded Ge composition profile. Also, our results show that the GC-SGOI exhibit excellent properties not only higher mobility, drain current and saturation velocity but also hot electron degradation improvement and better reliability. Therefore, refer to the results, the GC-SGOI structure has superior performances in comparison with the SC- and UC-SGOI structures which leads to be a good candidate for VLSI circuits. 相似文献
645.
Morteza Maghrebi Abbas Ali Khodadadi Yadollah Mortazavi Ali Sane Mohsen Rahimi Yaser Shirazi Zviad Tsakadze Subodh Mhaisalkar 《Applied Physics A: Materials Science & Processing》2009,97(2):417-424
The mm-long carbon nanotube (CNT) arrays were grown in a floating catalyst reactor, using xylene-ferrocene and a small amount
of acetic acid as the feed. The CNT arrays deposited on a quartz substrate at several positions along the reactor were extensively
characterized using Raman spectroscopy, scanning electron microscopy, X-ray diffraction, high-resolution transmission electron
microscopy, and optical microscopy. Various characterization methods consistently reveal that the acetic acid additive to
the feed alleviates deposition of amorphous carbon layer, which gradually thickens CNTs along the reactor. The acetic acid
also resulted in a higher growth rate along the so-called growth window, where CNT arrays are deposited on the quartz substrate.
High-performance liquid chromatography of extracted byproducts (PAHs) confirmed the presence of some polycyclic aromatic hydrocarbons.
The solid weight of PAHs decreased upon addition of ferrocene as the catalyst precursor, as well as of acetic acid to xylene
feed. The results suggest that primary light products of xylene pyrolysis can be competitive reactants for both catalytic
and subsequent pyrolytic reactions. They may also be more efficient feeds for CNT growth than xylene itself. 相似文献
646.
647.
Ali Khalaj Morteza Pirali Hogatollah Matloubi Reza Dowlatabadi 《Monatshefte für Chemie / Chemical Monthly》2001,39(12):747-752
Several novel N-(2,3-dihydro-2-oxo-5-phenyl-1H-1,4-benzodiazepin-3-yl)-2-carboxamides were prepared by acyl coupling of 2-aminobenzophenones with α-(benzotriazol-1-yl)-N-acylglycines followed by displacement of the benzotriazole ring with ammonia and cyclization of the resulting monoacyl aminals. In addition to high yields and shorter reaction sequences due to avoiding deprotection and acylation of the protected 3-amino-1,4-benzodiazepin-2-one intermediates, the present approach did not involve the use of toxic and odoriferous materials as is the case with other methods. 相似文献
648.
Amir Alaei Morteza Hasanzadeh Kafshgari Shahab Kashani Rahimi 《Heat and Mass Transfer》2013,49(2):285-290
New experimental results present the effects of low-frequency vibrations in a vertical heat pipe. The thermal resistance was investigated under different heat transfer rates, filling ratios and frequencies, increase of which improved the thermal performance. The vibrations were effective 33.83 % on the performance, and the best performance was estimated using the L16 array of Taguchi method, and it was achieved with the thermal resistance 0.064 K/W in the frequency 30 Hz. 相似文献
649.
ABSTRACTThe current work reports an experimental study on hydrothermal improvement in a chevron plate-fin heat exchanger combined with holes and winglets. The experiments are performed for water flow through a test square duct fitted with enhanced chevron plate-fins for the Reynolds number from 4000 to 10000. Characteristics of the enhanced chevron plate-fins include three waviness aspect ratios and four different arrangements of holes and winglets at a constant diameter of holes and width/height of winglets. An overall performance factor is applied to obtain the optimal geometry. Then, only the optimal geometries are applied to find out the effect of Al2O3/water nanofluid flow on the performance of a plate-fin heat exchanger. In comparison to simple chevron plate-fins, the enhanced ones would increase the Nusselt number by a factor between 1.05% and 1.6%. In addition, simultaneous application of the optimal enhanced chevron plate-fins and the nanofluid could increase the Nusselt number. The best working conditions of this system are detected for the nanofluid at a weight fraction of 0.3%. 相似文献
650.
Morteza Yavari 《理论物理通讯》2013,59(1):125-130
In this letter,we are going to use a geometrical approach to describe the free energy of DNA structures.The exact solutions of the equilibrium shape equations in a general WLC model for DNA forms by using the Feoli's formalism [A.Feoli,et al.,Nucl.Phys.B 705(2005) 577] are studied.Then,the free energy of transition between Band Z-DNA is calculated in this formalism. 相似文献