排序方式: 共有166条查询结果,搜索用时 0 毫秒
31.
Alireza Aslani Mohammadreza Arefi Khalil Beyki-Shuraki Aziz Babapoor 《Journal of Saudi Chemical Society》2013,17(4):403-407
Lead iodide, bromide and chloride nanoparticles (NP-PbX2, X = I, Br and Cl) with various morphologies were successfully prepared through a simple hydrothermal method without any additives or stabilizers. By treating the PbX2 in EtOH/CH2Cl2 solution at 170 °C for 12 h, the corresponding PbX2 nanoparticles were synthesized. The average sizes of PbX2 nanoparticles were between 30 and 80 nm. The structure, morphology, surface and size of PbX2 nanoparticles were determined by X-ray diffraction powder, Scanning Electron Microscopy, solid state Photo Luminescent, BET surface area and solid state UV. 相似文献
32.
33.
Hassan Ghavidel Behrooz Mirza Somayeh Soleimani-Amiri Mohammadreza Manafi 《中国化学会会志》2020,67(10):1856-1876
A green synthesis of functionalized 4H-chromenes using one-pot, three-component reaction of salicylaldehyde ( 1 ), active methylene ( 2 ), and carbon-based nucleophile ( 3 ) using Fe3O4@CONa nanoparticles in water has been performed at 60°C. The Fe3O4@CONa nanoparticle as an efficient, green, and magnetically reusable heterogeneous catalyst was applied in these reactions up to the nine runs. Green catalyst and solvent, short reaction time, high product yields, as well as simple work-up procedure were found as some advantages of this methodology. The density functional theory calculations were applied to all-inclusive perception of the one-pot, three-component reaction mechanism. The most reactions progressed through the following route: (a) nucleophilic addition of 2 to 1 ; (b) ring closing, dehydration; (c) nucleophilic substitution of 3 (2-naphtol, 4-hydroxycumarin) to intermediate. Sometimes mechanism mutated to: (a) nucleophilic addition of 3 (indole, 2-methylindole) to 1 , and dehydration; (b) nucleophilic addition of 2 to intermediate; and (c) ring closing, and dehydration. The frontier molecular orbitals, NBO analyses, molecular electrostatic potential of reactants, and intermediates confirmed the proposal mechanisms. Theoretical study could be so helpful to pick out suitable reactants of the reaction. 相似文献
34.
Mohammadreza Shariatgorji Juan Astorga-Wells Leopold L. Ilag 《Analytical and bioanalytical chemistry》2011,399(1):191-195
Downscaled analytical tools for sample preparation have offered benefits such as higher throughput, easier automation and
lower sample/reagent consumption. Microfluidic electrocapture, which is a newly developed sample preparation/manipulation
system, uses an electric field to trap and separate charged species without using any solid sorbent. The feasibility of using
microfluidic electrocapture is reported for separation, clean-up, concentration, microreactions and complexation studies of
proteins, peptides and other biologically important biomolecules. The instrumentation and applications of microfluidic electrocapture
are reviewed and an overview is provided of future perspectives offered by the current and envisaged platforms. 相似文献
35.
36.
Mohammadreza Khanmohammadi 《光谱学快报》2013,46(4):269-272
An accurate and stable algorithm, QR Decomposition Algorithm (QRDA) is initially presented into the chemistry field. The basic principle of QR Multivariate Calibration Algorithm (QRMCA) is investigated, and the complexes system of sodium tripolyphosphate (STPP), sodium sulfate (SS), and sodium Carbonate (SC) with serious overlapping absorption peaks is analyzed by QRMCA. According to our survey, QRDA can avoid matrix inverting, reduce the orders of matrixes, and speed up the operation of matrices. So, it has bright prospects in chemometrics. The process of the QR Decomposition Algorithm (QRDA) was implemented by an orthogonal and upper triangular matrix decomposition that is robust and convenient. Then it was applied to overcome the problem of overlapping spectra of different components in detergent-washing powder. 相似文献
37.
Mohammadreza Khanmohammadi Amir Bagheri Garmarudi Nafiseh Khoddami Keyvan Shabani Mohammadreza Khanlari 《Microchemical Journal》2010,95(2):337-340
Determination of particle size is one of the critical parameters in nanotechnology. The relationship between particle size and diffuse reflectance (DR) spectra in near-infrared region has been applied to introduce a method for estimation of particle size. Back-propagation artificial neural network (BP-ANN) as a nonlinear model was applied to estimate average particle size based on near-infrared diffuse reflectance spectra. Thirty five different nano TiO2 samples with different particle size were analyzed by DR-FTNIR spectrometry and the obtained data were processed by BP-ANN. The network was trained by 30 samples and was evaluated by the remaining 5 samples. In order to establish whether the new method is applicable for estimation of particle size of nano structured samples, the optimized model was applied to analyze 44 nano TiO2 samples. It was observed that ANN using the back-propagation algorithm is capable of generalization and could correctly predict the average particle size of nano-sized particles. 相似文献
38.
Bardajee Ghasem Rezanejade Zamani Mohammadreza Sharifi Mahdieh Rezanejad Habib Motallebi Mostafa 《Journal of fluorescence》2022,32(5):1959-1967
Journal of Fluorescence - A novel cyanine 3 (Cy3)-based bio-conjugated sensor has been developed to detect target DNA or extracted RNA from COVID -19 samples using the fluorescence resonance energy... 相似文献
39.
Yousef Shafieyan Shahriar Sharifi Mohammad Imani Mohammad Ali Shokrgozar Neda Aboudzadeh Mohammad Atai 《先进技术聚合物》2011,22(12):2182-2190
Fabrication of biodegradable composites applicable as hard tissue substitutes consisting of poly(ε‐caprolactone fumarate) (PCLF), methacrylic acid (MAA), and hydroxyapatite (HA) was investigated. PCLF macromers were synthesized by reaction of PCL diol with fumaryl chloride in the presence of propylene oxide and characterized by gel permeation chromatography, FTIR, and 1H NMR spectroscopy. Composites were fabricated by incorporating HA as inorganic filler in PCLF matrix which followed by thermal curing of the composition using benzoyl peroxide and MAA as a free radical initiator and reactive diluent, respectively. Uniform distribution of the fine ceramic phase in the polymer matrix was elucidated by scanning electron microscopy. The effects of the initial macromer molecular weight and the filler volume fraction on mechanical properties and cytotoxicity of the composites were also examined. Significant enhancement in the mechanical properties was observed upon increasing HA content and/or initial PCLF molecular weight. The biocompatibility of the specimens was also improved with increasing ceramic phase. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
40.
Anna M. Fyhn Xiaodong Yang Mohammadreza Nematollahi John C. Walmsley Ursula J. Gibson 《Journal of Solid State Electrochemistry》2014,18(1):13-18
We demonstrate the anodic electrodeposition of copper-doped AgO at high pH using a silver counter-electrode. Precipitates from a mixture of nitrates and NaOH provided source material for the deposition, and application of a moderate anodic voltage (0.9 V) to the substrate led to deposition of crystalline nanoparticles with incorporated copper. Further increase of the NaOH concentration reduced the amount of copper in the crystals, and higher voltages degraded the crystal quality. XRD confirms the underlying structure to be that of AgO, and Auger and energy dispersive x-ray analyses confirm copper concentrations of approximately 3 % in the crystals. 相似文献