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141.
Hamid Amini Moghadam Ali A. Orouji 《Physica E: Low-dimensional Systems and Nanostructures》2011,43(10):1779-1782
In this paper, we report a novel Super Junction Metal Semiconductor Field Effect Transistor (SJ-MESFET) where the drift region consists of a p-type pillar in order to improve breakdown voltage. We demonstrate that the depletion region in the drift region can be extended entirely by the p-type pillar leading to a uniform electric field. Therefore breakdown voltage significantly improves. Using two-dimensional and two-carrier device simulation, we have analyzed the various performance and design considerations of the SJ-MESFET. Also we have explained the reasons for improving the performance of the SJ-MESFET when compared to a Conventional Bulk MESFET (CB-MESFET). Detailed numerical simulations demonstrate that for the proposed structure due to decrease in parasitic gate-to-drain capacitor, maximum oscillation frequency increases with respect to CB-MESFET. 相似文献
142.
Ammonia modification of activated carbon to enhance carbon dioxide adsorption: Effect of pre-oxidation 总被引:5,自引:0,他引:5
Mohammad Saleh Shafeeyan Wan Mohd Ashri Wan Daud Amirhossein HoushmandArash Arami-Niya 《Applied Surface Science》2011,257(9):3936-3942
A commercial granular activated carbon (GAC) was subjected to thermal treatment with ammonia for obtaining an efficient carbon dioxide (CO2) adsorbent. In general, CO2 adsorption capacity of activated carbon can be increased by introduction of basic nitrogen functionalities onto the carbon surface. In this work, the effect of oxygen surface groups before introduction of basic nitrogen functionalities to the carbon surface on CO2 adsorption capacity was investigated. For this purpose two different approaches of ammonia treatment without preliminary oxidation and amination of oxidized samples were studied. Modified carbons were characterized by elemental analysis and Fourier Transform Infrared spectroscopy (FT-IR) to study the impact of changes in surface chemistry and formation of specific surface groups on adsorption properties. The texture of the samples was characterized by conducting N2 adsorption/desorption at −196 °C. CO2 capture performance of the samples was investigated using a thermogravimetric analysis (TGA). It was found that in both modification techniques, the presence of nitrogen functionalities on carbon surface generally increased the CO2 adsorption capacity. The results indicated that oxidation followed by high temperature ammonia treatment (800 °C) considerably enhanced the CO2 uptake at higher temperatures. 相似文献
143.
Suzuki–Miyaura cross-coupling reactions in water using in situ generated palladium(II)–phosphazane complexes 总被引:1,自引:1,他引:0
Mojtaba Amini Abbas Tarassoli Saeed Yousefi Sepideh Delsouz-Hafshejani Mina Bigdeli Mahnaz Salehifar 《中国化学快报》2014,25(1):166-168
The phosphazane derivatives(L1–3) were readily obtained by reaction of different ratios of PCl3 and PhNH2. The L1–3 derivatives were found to be efficient ligands in the palladium-catalyzed Suzuki C–C coupling reactions in water. It was determined that with the use of L1–3 /Pd(OAc)2 system as a catalyst, aryl halides undergo Suzuki cross-couplings with arylboronic acids to give the desired products in moderate to excellent yields. 相似文献
144.
Application of a magnetic molecularly imprinted polymer for the selective extraction and trace detection of lamotrigine in urine and plasma samples
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Mohammad Behbahani Saman Bagheri Mostafa M. Amini Hamid Sadeghi Abandansari Hamid Reza Moazami Akbar Bagheri 《Journal of separation science》2014,37(13):1610-1616
Magnetic molecularly imprinted polymers have been synthesized for the selective preconcentration and trace determination of lamotrigine (LTG) in urine and plasma samples. The magnetic nanoparticles were modified by tetraethyl orthosilicate and 3‐methacryloxypropyl trimethoxysilane before imprinting. The magnetic molecularly imprinted polymers were prepared via surface molecular imprinting technique, using Fe3O4 as a magnetic component, LTG as template molecule, methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross‐linker, and 2,2′‐azobisisobutyronitrile as a radical initiator in methanol/acetonitrile (50:50, v/v) as the porogen. The obtained sorbent was characterized using scanning electron microscopy, Fourier‐transform infrared spectroscopy, X‐ray diffraction, and thermal analysis. Separation of the sorbent from the sample solution was simply achieved by applying an external magnetic field. Determination of the extracted drug was performed by high‐performance liquid chromatography with UV detection. Under the optimum extraction conditions, the method detection limits were 0.7 μg/L (based on S/N of 3) for urine samples and 0.5 μg/L for plasma samples. A linear dynamic range of 1–1000 μg/L was obtained for LTF in plasma and urine samples. Finally, the applicability of the proposed method was evaluated by extraction and determination of LTG in urine and plasma samples. 相似文献
145.
Mojtaba Bagherzadeh Mojtaba Amini Parviz Gohari Derakhshandeh Mohammad Mehdi Haghdoost 《Journal of the Iranian Chemical Society》2014,11(2):441-446
The glucose-based ligand, N-salicylidene-d-glucosamine (Sal-d-glsmN), was readily obtained by reaction of salicylaldehyde (Hsal) with the d-glucosamine hydrochloride. Ligand Sal-d-glsmN was found to be an efficient ligand in the palladium-catalyzed Suzuki and Heck C–C coupling reactions in aqueous medium under aerobic condition. It was found that the use of Sal-d-glsmN/Pd(OAc)2 system as a catalyst, aryl halides undergo Suzuki and Heck cross-couplings, respectively, with arylboronic acids and olefins to give the desired products in moderate to excellent yields. 相似文献
146.
Homeira Ebrahimzadeh Elahe Moazzen Mostafa M.Amini Omid Sadeghi 《Mikrochimica acta》2013,180(5-6):445-451
We have developed a gold ion-imprinted polymer (GIP) by incorporating a dipyridyl ligand into an ethylene glycol dimethacrylate matrix which then was coated onto porous silica particles. The material was used for the selective extraction of ultratrace quantities of gold ion from mine stones, this followed by its quantitation by FAAS. The effects of concentration and volume of eluent, pH of the solution, flow rates of sample and eluent, and effect of potentially interfering ions, especially palladium and platinum, was investigated. The limit of detection is <0.2 ng?mL?1, the precision (RSD%) is 1.03 %, and recoveries are >99 %. In order to show the high selectivity and efficiency of the new sorbent, the results were compared to those obtained with more simple sorbents possessing the same functional groups. The accuracy of the method was demonstrated by the accurate determination of gold ions in a certified reference material. To the best of our knowledge, there is no report so far on an imprint for gold ions that has such a selectivity over Pd(II) and Pt(II) ions. Figure
Coating of gold ion imprinted polymer on nanoporous silica 相似文献
147.
Hero Modares Amirhossein Moravejosharieh Rosli Bin Salleh Jaime Lloret 《ETRI Journal》2014,36(1):51-61
In the Mobile IPv6 (MIPv6) protocol, a mobile node (MN) is a mobile device with a permanent home address (HoA) on its home link. The MN will acquire a care‐of address (CoA) when it roams into a foreign link. It then sends a binding update (BU) message to the home agent (HA) and the correspondent node (CN) to inform them of its current CoA so that future data packets destined for its HoA will be forwarded to the CoA. The BU message, however, is vulnerable to different types of security attacks, such as the man‐in‐the‐middle attack, the session hijacking attack, and the denial‐of‐service attack. The current security protocols in MIPv6 are not able to effectively protect the BU message against these attacks. The private‐key‐based BU (PKBU) protocol is proposed in this research to overcome the shortcomings of some existing MIPv6 protocols. PKBU incorporates a method to assert the address ownership of the MN, thus allowing the CN to validate that the MN is not a malicious node. The results obtained show that it addresses the security requirements while being able to check the address ownership of the MN. PKBU also incorporates a method to verify the reachability of the MN. 相似文献
148.
Dr. Hashem Amini Dr. Nancy Weisbach Dr. Sébastien Gauthier Dr. Helene Kuhn Dr. Nattamai Bhuvanesh Dr. Frank Hampel Dr. Joseph H. Reibenspies Prof. Dr. John A. Gladysz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(49):12619-12634
The silylated hexatriynyl complex trans-(C6F5)(p-tol3P)2Pt(C≡C)3SiEt3 ( PtC6TES ) is converted in situ to PtC6H (wet n-Bu4N+ F−, THF) and cross coupled with the diyne H(C≡C)2SiEt3 ( HC4TES ; CuCl/TMEDA, O2) to give PtC10TES (71 %). This sequence is repeated twice to afford PtC14TES (65 %) and then PtC18TES (27 %). An analogous series of reactions starting with PtC8TES gives PtC12TES (60 %), then PtC16TES (43 %), and then PtC20TES (17 %). Similar cross couplings with H(C≡C)2Si(i-Pr)3 ( HC4TIPS ) give PtC12TIPS (68 %), PtC14TIPS (68 %), and PtC16TIPS (34 %). The trialkylsilyl species (up to PtC18TES ) are converted to 3+2 “click” cycloadducts or 1,4-disubstituted 1,2,3-triazoles trans-(C6F5)(p-tol3P)2Pt(C≡C)n-1C=CHN(CH2C6H5)N=N (29–92 % after workups). The most general procedure involves generating the terminal polyynes PtC x H (wet n-Bu4N+ F−, THF) in the presence of benzyl azide in DMF and aqueous CuSO4/ascorbic acid. All of the preceding complexes are crystallographically characterized and the structural and spectroscopic properties analyzed as a function of chain length. Two pseudopolymorphs of PtC20TES are obtained, both of which feature molecules with parallel sp carbon chains in a pairwise head/tail packing motif with extensive sp/sp van der Waals contacts. 相似文献
149.
Hajibashi F. Amini Arabkoohsar A. Babaelahi M. 《Journal of Thermal Analysis and Calorimetry》2021,144(3):955-961
Journal of Thermal Analysis and Calorimetry - The paper focused on an analytical analysis of the main features of heat transfer in incompressible steady-state flow in a microconfusor with account... 相似文献
150.
Efficient quadrature rules with a priori error estimates for integrands with end point singularities
In this paper we present details of an efficient numerical integration rule based upon error function transformation of the integration variable. We also derive an a priori error estimate for our method and present numerical results to highlight various features of the rule as applied to integrals with end point singularities in the low order derivatives of their integrands. 相似文献