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91.
We consider the two-dimensional motion of the coupled system of a viscous incompressible fluid and a rigid disc moving with
the fluid, in the whole plane. The fluid motion is described by the Navier–Stokes equations and the motion of the rigid body
by conservation laws of linear and angular momentum. We show that, assuming that the rigid disc is not allowed to rotate,
as the radius of the disc goes to zero, the solution of this system converges, in an appropriate sense, to the solution of
the Navier–Stokes equations describing the motion of only fluid in the whole plane. We also prove that the trajectory of the
centre of the disc, at the zero limit of its radius, coincides with a fluid particle trajectory. 相似文献
92.
Masoumeh Zakeri Majid M. Heravi Mina Saeedi Narges Karimi Hossein A. Oskooie Niloofar Tavakoli‐Hoseini 《中国化学》2011,29(7):1441-1445
An efficient one‐pot condensation of β‐naphthol, aldehydes and cyclic 1,3‐dicarbonyl compound has been achieved with ionic liquids as catalyst, thus a variety of 8,9,10,12‐tetrahydrobenzo[a]xanthen‐11‐one derivatives were prepared in good yields. The present approach offers several advantages such as shorter reaction times, good yields and mild reaction conditions. 相似文献
93.
Mohammad T. Baei Ali Reza Soltani Ali Varasteh Moradi Masoumeh Moghimi 《Monatshefte für Chemie / Chemical Monthly》2011,21(6):573-578
Abstract
The behavior of N2O adsorbed on the external surface of H-capped (6,0), (7,0), (8,0), and Al-doped (6,0) zigzag single-walled carbon nanotubes was studied by using density functional calculations. Geometry optimizations were carried out at the B3LYP/6-31G* level of theory using the Gaussian 03 suite of programs. We present the nature of the N2O interaction in selected sites of the nanotubes. Binding energies corresponding to adsorption of the N2O are calculated to be in the range 4–21 kJ mol−1. More efficient binding energies cannot be achieved by increasing the nanotube diameter. We also provide the effects of N2O adsorption on the electronic properties of the nanotubes. 相似文献94.
Poly(4-vinyl pyridine) supported nanoparticle of copper(Ⅰ) iodide is reported as a green and recyclable catalyst for the regioselective synthesis of 1,4-disubstituted-1H-1,2,3-triazoles from benzyl halides,sodium azide and terminal alkynes in water. This catalyst can be recovered by simple filtration and recycled up to 8 consecutive runs without any loss of its efficiency. 相似文献
95.
Tabatabaee M 《Chemistry Central journal》2012,6(1):5
Background
Various water clusters including hexamers, heptamers, octamers, decamers and 1D or 2D infinite water chains in a number of organic and inorganic-organic hybrid hosts, have been reported. 相似文献96.
In this paper, we investigate the existence of unique continuous linear extension for linear correspondences. We also give some results on cosine families of linear correspondences. 相似文献
97.
Sadjadi Samahe Malmir Masoumeh Pourmohammad Nargess Ahmadi Shervin Heravi Majid M. 《Research on Chemical Intermediates》2019,45(9):4349-4366
Research on Chemical Intermediates - A covalent hybrid of halloysite-poly(methyl methacrylate-co-maleic anhydride) was prepared and applied for the immobilization of Pd nanoparticles. The hybrid... 相似文献
98.
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
99.
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
100.
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