排序方式: 共有163条查询结果,搜索用时 15 毫秒
91.
Mahsa Majidian Jahan Bakhsh Raoof Sayed Reza Hosseini Reza Ojani 《Journal of the Iranian Chemical Society》2017,14(6):1263-1270
In this work, an antimony trioxide-modified multi-walled carbon nanotube paste electrode (Sb2O3/CNTPE) was employed for determination of Cu2+ ions by using square wave anodic stripping voltammetry (SWASV) in the presence of 8-hydroxy-7-iodo-5-quinoline sulfonic acid (HIQSA) as a chelating agent. The field emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS) and electrochemical impedance spectroscopy (EIS) methods were applied to estimate the morphology and properties of the modified electrode. Measurements related to SWASV were taken in 0.6 M HCl at ?1.0 V versus Ag|AgCl|KCl (3 M) for 90 s (deposition step). After equilibrium time of 15 s, an ASV appeared at 0.0 V versus Ag|AgCl|KCl (3 M) (stripping step). The sensor depicted a fairly linear response for Cu2+ in the concentration range of 2–100 ppb with appropriate detection limit about 0.39 ppb and limit of quantification about 1.3 ppb. The stability of the modified electrode during 7 weeks and its behavior in the presence of some metal ions was evaluated. The practical applicability of the Sb2O3/CNTPE was established on the voltammetric determination of Cu2+ in tap water as a sample. 相似文献
92.
Sulfonic acid groups were grafted onto three different types of synthesized magnetic nanoparticles, namely Fe3O4, Fe3O4@SiO2, and Fe3O4@MCM‐48. The sulfonic acid‐functionalized nanoparticles were evaluated as catalysts for the synthesis of 5‐aryl‐1H‐benzo[f]chromeno[2,3‐d]pyrimidine‐2,4(3H,5H)‐dione derivatives in terms of activity and recyclability. Their catalytic activities were compared with that of the homogeneous acid catalyst 1‐methylimidazolium hydrogen sulfate ([HMIm][HSO4]). The activity of Fe3O4@MCM‐48–SO3H was comparable to those of the other heter‐ogeneous and homogeneous catalysts. 相似文献
93.
Synthesis and Cytotoxic Activity of Some Novel Dihyrobenzo[h]pyrano[3,2‐c]chromene Derivatives 下载免费PDF全文
Nasim Esmati Mahsa Foroughian Mina Saeedi Mohammad Mahdavi Mehdi Khoshneviszadeh Omidreza Firuzi Nader Tanideh Ramin Miri Najmeh Edraki Abbas Shafiee Alireza Foroumadi 《Journal of heterocyclic chemistry》2015,52(1):97-104
Three‐component reaction of 4‐hydroxy‐2H‐benzo[h]chromen‐2‐one, aromatic aldehydes, and malononitrile in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) in ethanol at room temperature affords good yields of novel dihyrobenzo[h]pyrano[3,2‐c]chromene derivatives. The synthesized compounds examined by MTT assays for cytotoxic activity in two human cancer cell lines (MOLT‐4, HL‐60). Most of the evaluated compounds showed low inhibitory activity against tumor cell line at micromolar concentrations. 相似文献
94.
Ahmadi Mostafa Rashedi Reza Ahmadjo Saeid Karimi Mahsa Zahmaty Majid Mortazavi Seyed Mohammad Mahdi 《Journal of Thermal Analysis and Calorimetry》2018,131(3):2523-2533
Journal of Thermal Analysis and Calorimetry - Development of olefin block copolymers (OBCs) based on new catalytic systems is challenging. We evaluate the performance of rac-ethylenebis(1-η... 相似文献
95.
Corrigendum: Vicinal Disulfide Constrained Cyclic Peptidomimetics: a Turn Mimetic Scaffold Targeting the Norepinephrine Transporter 下载免费PDF全文
96.
Alireza?KhataeeEmail author Mahsa?Haddad Irani-nezhad Javad?Hassanzadeh 《Mikrochimica acta》2018,185(3):190
It is reported that a mixture of WS2 nanosheets (WS2 NS) and silver nanoclusters (AgNCs) displays strongly enhanced peroxidase-mimicking activity. The catalytic effect of the mixture was studied by colorimetry, fluorometry, chemiluminescence (CL) and electrochemistry. The effect is interpreted in terms of a difference between the Fermi energy level of the two nanomaterials. This leads to the formation of charge separation regions which act as active sites for enzyme mimetic interaction with the substrates. The mixture of WS2 NS and AgNCs was exploited for the non-enzymatic determination of H2O2 and glucose. A stopped-flow method was applied as a sensitive CL detection system using the bicarbonate-H2O2 reaction. The mixture has a powerful peroxidase mimicking activity on the bicarbonate-H2O2 CL reaction, and this effect is much larger than that of any single constituent. In addition, the CL emission is improved several times by using the stopped-flow technique. Under optimum condition, H2O2 can be determined in the 2.5–1500 nM concentration range. Moreover, glucose levels in human serum can be quantified via glucose oxidase based oxidation which leads to the generation of H2O2. Using this CL assay, a linear relationship was obtained between the intensity of the CL emission and glucose concentration in the range of 0.03–20 μM, with a limit of detection (3S) of 13 nM. 相似文献
97.
Mahsa Kangazian Kangazi Ali Akbar Gharehaghaji Majid Montazer 《Journal of Sol-Gel Science and Technology》2018,87(3):528-536
Multiferroic materials based on lead-free ferroelectric materials have potential applications in the fabrication of next-generation devices. Herein, the sol–gel method is used to synthesize pristine and Cr-doped Bi0.5K0.5TiO3 nanocrystals. Density functional theory simulation is performed to elucidate the mechanism underlying the observed electronic and magnetic properties of the nanocrystals. In materials doped with 9?mol% Cr, the substitution of Cr in the Ti site decreases the optical band gap from 3.09?eV to 2.26?eV and induces ferromagnetism at room temperature. The saturation magnetization of the materials is approximately 0.18?μB/Cr at 5?K and can be attributed to the interplay of the unpaired electron counts of Cr3+ ions in the crystal field mechanism and Jahn–Teller effect. Pristine Bi0.5K0.5TiO3 samples exhibit weak ferromagnetism at room temperature, given the existence of the mixed valence states of Ti4+ and Ti3+ and the formation of O or Ti vacancies during sample growth. The present study provides deep insight into the induction of magnetism in ferroelectric materials doped with transition metals. Such materials have potential spintronic applications. 相似文献
98.
Mohammad Mahdavi Mehdi Asadi Mahsa Khoshbakht Mina Saeedi Mohammad Bayat Alireza Foroumadi Abbas Shafiee 《Helvetica chimica acta》2016,99(5):378-383
A series of novel quinazolin‐4(3H)‐one derivatives were efficiently synthesized starting from isatoic anhydride. First, reaction of isatoic anhydride and amines in H2O at room temperature afforded 2‐aminobenzamides. Then, CuBr/Et3N promoted reaction of 2‐aminobenzamides and different aryl isothiocyanates in DMF at 80° afforded the title compounds in good yield. 相似文献
99.
Torabizadeh Mahsa Tabar-Heydar Kourosh Ahmadi Seyyed Hamid 《Journal of Analytical Chemistry》2022,77(8):1047-1056
Journal of Analytical Chemistry - In this study, an online solid-phase extraction-thermal desorption method coupled with gas chromatography-flame ionization detection was used to extract seven... 相似文献
100.
A new magnetically recoverable nanocatalyst was prepared by functionalization of mesoporous silica (SBA‐15) with a Schiff base ligand, and then immobilization of palladium nanoparticles on it using a simple procedure. This heterogeneous catalyst was fully characterized using appropriate analyses and its catalytic efficiency was investigated in Heck reaction using iodo‐, bromo‐ and chlorobenzene derivatives and styrene, with the aim of synthesizing stilbene derivatives, a class of compounds with a variety of pharmacological properties. Some of the characteristics of this nanocatalyst include good dispersion of palladium nanoparticles on the SBA‐15 support, easy separation, catalyses the production of stilbene derivatives in a short time with excellent yields even for bromo‐ and chlorobenzene, and preservation of its catalytic activity after eight reaction cycles. 相似文献