排序方式: 共有16条查询结果,搜索用时 15 毫秒
1.
2.
F. Mollaamin M. T. Baei M. Monajjemi R. Zhiani B. Honarparvar 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2008,82(13):2354-2361
In this study, hydrogen adsorption on the surface of vanadium at various positions (top, bridge, and central sites) was studied,
and the binding energies of hydrogen species adsorbed on vanadium were calculated using density functional theory (DFT) within
the generalized gradient approximation (GGA). The potential of the adsorption of hydrogen on vanadium was examined as a function
of both surface coverage and adsorption site. Our results were in excellent agreement with the experimental values reported
in the literature. The relative stabilities of hydrogen chemisorption were independent of both the transition metal surface
and surface coverage. That is, hydrogen exhibited insignificant selectivity with respect to positions on the metal surface.
Our data on H2/V surface chemisorption revealed that the stablest model for hydrogen adsorption was that on the vertical bridge site. The
adsorption energy for this model was lower than for the other sites. However, adsorption on bridge-hydrogen vacancies was
strong. 相似文献
3.
4.
Novel heterogeneous catalyst systems comprised of a fibrous nanosilica‐supported nano‐Ni@Pd‐based ionic liquid (KCC‐1/IL/Ni@Pd) are described for the cyclization of propargylic amines with CO2 to provide 2‐oxazolidinones. KCC‐1 with high surface area was functionalized with IL acting as a robust anchor so that the nano‐Ni@Pd was well dispersed on the fibres of the KCC‐1 microspheres, without aggregation. Because of the amplification effect of IL, high loading capacities of the nanocatalysts were achieved. The reported synthesis includes several advantages like solvent‐free conditions, operational simplicity, short reaction times, environmentally benign reaction conditions, cost effectiveness, high atom economy and excellent yields, making it a genuinely green protocol. 相似文献
5.
We have found that fibrous nanosilica (KCC‐1) can used as a excellent support for the synthesis of highly sparse nanoparticles and has high surface area that was functionalized with Tetrathia‐azacyclopentadecane (TTACP) groups acting as the strong performers so that the Ag nanoparticles were well‐dispersed without aggregation on the fibers of the KCC‐1 microspheres (KCC‐1/TTACP/Ag). We enthusiasm to report one‐pot synthesis of 3‐Acyloxylindolines for first time from N‐tosyl‐2‐vinylaniline, and benzoic acid in the presence of KCC‐1/TTACP/Ag as a catalyst. 相似文献
6.
F. Rezai Balf H. Zhiani RezaiG.R. Jahanshahloo F. Hosseinzadeh Lotfi 《Applied Mathematical Modelling》2012,36(1):46-56
One problem that has been discussed frequently in data envelopment analysis (DEA) literature has been lack of discrimination in DEA applications, in particular when there are insufficient DMUs or the number of inputs and outputs is too high relative to the number of units. This is an additional reason for the growing interest in complete ranking techniques. In this paper a method for ranking extreme efficient decision making units (DMUs) is proposed. The method uses L∞(or Tchebycheff) Norm, and it seems to have some superiority over other existing methods, because this method is able to remove the existing difficulties in some methods, such as Andersen and Petersen [2] (AP) that it is sometimes infeasible. The suggested model is always feasible. 相似文献
7.
Abolghasem Davoodnia Rahele Zhiani Niloofar Tavakoli-Hoseini 《Monatshefte für Chemie / Chemical Monthly》2008,81(2):1405-1407
Starting from 1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-ones, a synthesis pathway to the tricyclic pyrazolo[4,3-e][1,2,4]triazolo[4,3-c]pyrimidines is described. Reaction of 1,5-dihydro-4H-pyrazolo[3,4-d] pyrimidin-4-ones with phosphoryl chloride afforded the corresponding 4-chloro-1H-pyrazolo[3,4-d]pyrimidines. Treatment of these compounds with hydrazine hydrate at reflux temperature gave the hydrazino derivatives, which
were subsequently cyclized to the titled compounds on heating with orthoesters in ethanol. 相似文献
8.
Structural Chemistry - The detection methods used to analyze abused drugs should be sensitive sufficiently. Here in, we propose carbon nanotube (CNT) functionalized with COOH and CONHCH3 groups as... 相似文献
9.
Abolghasem Davoodnia Rahele Zhiani Niloofar Tavakoli-Hoseini 《Monatshefte für Chemie / Chemical Monthly》2008,139(11):1405-1407
Starting from 1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-ones, a synthesis pathway to the tricyclic pyrazolo[4,3-e][1,2,4]triazolo[4,3-c]pyrimidines is described. Reaction of 1,5-dihydro-4H-pyrazolo[3,4-d] pyrimidin-4-ones with phosphoryl chloride afforded the corresponding 4-chloro-1H-pyrazolo[3,4-d]pyrimidines. Treatment of these compounds with hydrazine hydrate at reflux temperature gave the hydrazino derivatives, which
were subsequently cyclized to the titled compounds on heating with orthoesters in ethanol.
Correspondence: Abolghasem Davoodnia, Department of Chemistry, School of Sciences, Islamic Azad University, Mashhad Branch,
Mashhad 91735-413, Iran. 相似文献
10.
Russian Journal of Organic Chemistry - Novel Fe3O4/SiO2/PPA nanoparticles were used as solid acid support in the solvent-free synthesis of... 相似文献