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91.
A simple, low-cost, and effective cooling/heating-assisted headspace solid-phase microextraction (CHA–HS–SPME) device, capable of direct cooling the fiber to low temperatures and simultaneous heating the sample matrix to high temperatures, was fabricated and evaluated. It was able to cool down the commercial and handmade fibers for the effective tapping of volatile and semi-volatile species in the headspace of complex solid matrices, with minimal manipulation compared with conventional SPME. The CHA–HS–SPME system can create large temperature gaps (up to 200 °C) between the fiber and the sample matrix, because the cooling process is directly applied onto the fiber. 相似文献
92.
Sabbaghan Maryam Charkhan Hossein Ghalkhani Masoumeh Beheshtian Javad 《Research on Chemical Intermediates》2019,45(2):487-505
Research on Chemical Intermediates - In this study, an efficient route for graphene oxide (GO) and reduced GO (RGO) synthesis was developed by using an ultrasonic probe and bath alternatively. RGO... 相似文献
93.
Simin Nazari Mosadegh Keshavarz Bahador Karami Nasir Iravani Masoumeh Vafaee-Nezhad 《中国化学快报》2014,25(2):317-320
Imidazol-1-yl-acetic acid is introduced as a new, efficient and recyclable green bifunctional organocatalyst for the synthesis of 1,8-dioxooctahydroxanthenes under solvent-free conditions. This catalyst is water soluble and can be separated from the products by simple filtration. The filtrate can be evaporated to dryness and recrystallized from cool methanol to give the recovered catalyst. This organocatalyst was used for the synthesis of 1,8-dioxooctahydroxanthenes under solvent-flee conditions and recycled up to 8 consecutive runs without any losing of its efficiency. 相似文献
94.
Masoumeh Pirdadeh-Beiranvand Abbas Afkhami Tayyebeh Madrakian 《Journal of the Iranian Chemical Society》2018,15(7):1527-1534
Resonance light-scattering (RLS) technique was developed for studying the interaction of silver nanoparticles (Ag NPs) with bisphenol A. A simple and environmentally friendly method was developed to synthesize Ag NPs using cinnamon extract. Synthesized nanoparticles were characterized using various measurement techniques. The synthesized Ag NPs were nearly spherical, with the sizes ranging from 30 to 60 nm. Spectral analysis indicated that the cinnamon extract acted as the reducing and capping agents on the surface of Ag NPs. RLS technique was used as the detection method. Light-scattering properties of the synthesized nanoparticles in the presence or absence of bisphenol A was selected as the detection signal. Under the optimal conditions, the linear dynamic range and RSD were found to be 0.01–10.0 mg L?1 and 2.78% (n?=?3), respectively. A limit of detection of 0.005 mg L?1 was obtained for the determination of bisphenol A. The obtained results showed successful application of the method for the analysis of bisphenol A in real samples. 相似文献
95.
96.
Mehrazar Mehrdad Hassankalhori Mahdi Toolabi Mahsa Goli Fereshteh Moghimi Setareh Nadri Hamid Bukhari Syed Nasir Abbas Firoozpour Loghman Foroumadi Alireza 《Molecular diversity》2020,24(4):997-1013
Molecular Diversity - A new series of compounds based on benzodiazepine-1,2,3-triazole were synthesized and evaluated as cholinesterase inhibitors by Ellman’s method. The compounds proved to... 相似文献
97.
Abdollah Shidfar Masoumeh Mohammadi 《Numerical Methods for Partial Differential Equations》2007,23(2):456-474
In this article, we consider a nonlinear partial differential system describing two‐phase transports and try to recover the source term and the nonlinear diffusion term when the state variable is known at different profile times. To this end, we use a POD‐Galerkin procedure in which the proper orthogonal decomposition technique is applied to the ensemble of solutions to derive empirical eigenfunctions. These empirical eigenfunctions are then used as basis functions within a Galerkin method to transform the partial differential equation into a set of ordinary differential equations. Finally, the validation of the used method has been evaluated by some numerical examples. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 23: 456–474, 2007 相似文献
98.
The properties of boron nitride (BN), boron phosphide (BP), aluminum nitride (AlN), and aluminum phosphide (AlP) nanocones were investigated by density functional theory (DFT) calculations. The investigated structures were optimized and chemical shielding (CS) properties including isotropic and anisotropic CS parameters were calculated for the atoms of the optimized structures. The magnitudes of CS parameters were observed to be mainly dependent on the bond lengths of considered atoms. The results indicated that the atoms could be divided into atomic layers due to the similarities of their CS properties for the atoms of each layer. The trend means that the atoms of each layer detect almost similar electronic environments. Moreover, the atoms at the apex and mouth of nanocones exhibit different properties with respect to the other atomic layers. 相似文献
99.
100.