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排序方式: 共有182条查询结果,搜索用时 516 毫秒
91.
The synthesis of a novel class of N-(1H-benzo[d]imidazol-2-yl)-2-alkyl-N′-sulfonylacetamidines via a copper-catalyzed, three-component coupling reaction of 1H-benzo[d]imidazol-2-amine, sulfonyl azides, and terminal alkynes is described. 相似文献
92.
The application of a blister test for measuring the interfacial fracture energy, Ga, is demonstrated. In the designed apparatus a fluid is injected at a constant rate to the interface between a solid substrate and a deformable coating to create a blister. The necessary fluid pressure and blister diameter were measured automatically as a function of time. Based on the collected data, the adhesion energy is calculated via Gent's equation. 相似文献
93.
Mehdi Ghandi Ahmad Yari Seyed Jamal Tabatabaei Rezaei Abuzar Taheri 《Tetrahedron letters》2009,50(33):4724-8491
The one-pot, three-component condensation of sarcosine or proline Schiff bases with several aromatic aldehydes and the Knöevenagel adduct of isatin-malononitrile successfully affords spiropyrrolidine-oxindoles and spiropyrrolizine-oxindoles. 相似文献
94.
This work presented a new approach to solve the location management problem by using the location areas approach. A combination
of Genetic Algorithm and Hopfield Neural Network is used to find the optimal configuration of location areas in a mobile network.
Toward this end, the location areas configuration of the network is modeled so that the general condition of all the chromosomes
of each population improves rapidly by the help of a Hopfield Neural Network. The Hopfield Neural Network is included in the
Genetic Algorithm optimization process, to expedite its convergence, since the generic Genetic Algorithm is not fast enough.
Simulation results are very promising and they lead to network configurations that are unexpected.
相似文献
95.
Majid M. Heravi Shima Taheri Khadijeh Bakhtiari Hossein A. Oskooie 《Monatshefte für Chemie / Chemical Monthly》2006,12(2):1075-1078
Cupric sulfate pentahydrate was found to be an efficient catalyst for the protection of aldehydes as 1,1-diacetates in high
yields in a solvent-free system at room temperature. Ketones are not affected under these reaction conditions. 相似文献
96.
An efficient method for the synthesis of 14-alkyl or aryl 14H-dibenzo[a,j]xanthene derivatives by the reaction of β-naphthol,and aldehydes in the presence of a catalytic amount of bismuth(Ⅲ) chloride(BiCl3) under solvent-free conditions at 110℃is described.Aliphatic and aromatic aldehydes were used in the reaction and in all cases the desired products were synthesized successfully.This reaction was studied under different temperatures;the maximum yield was obtained in a short reaction period at 110℃.The method offers the advantages of high yields,short reaction times,simplicity and easy workup compared to the conventional method of syntheses. 相似文献
97.
Johansson PG Rowley JG Taheri A Meyer GJ Singh SP Islam A Han L 《Langmuir : the ACS journal of surfaces and colloids》2011,27(23):14522-14531
The role of low-lying π* orbitals in dye-sensitized solar cells based on mesoporous thin films of anatase TiO(2) nanocrystallites remains unknown. Herein we report three ruthenium compounds, cis-Ru(dcbq)(2)(NCS)(2), cis-Ru(dcbq)(bpy)(NCS)(2), and cis-Ru(dcb)(bq)(NCS)(2), where bpy is 2,2'-bipyridine, dcb is 4,4'-(CO(2)H)(2)-2,2'-bipyridine, bq is 2,2'-biquinoline, and dcbq is 4,4'-(CO(2)H)(2)-2,2'-biquinoline, that were synthesized, characterized, and contrasted with the well-known N3 compound (i.e., cis-Ru(dcb)(2)(NCS)(2)) in dye-sensitized solar cells. These compounds maintain the same cis-Ru(NCS)(2) core with a systematic variation in the energy of the π* orbitals of the diimine ligand: bpy > dcb > bq > dcbq. The lowered π* orbitals resulted in enhanced red absorption relative to N3. With HCl pretreated TiO(2) in regenerative solar cells, sensitization from 400 to 900 nm was realized with cis-Ru(dcb)(bq)(NCS)(2) and global power conversion efficiencies as high as 6.5% were achieved under 1 sun of AM 1.5 irradiation. The energy conversion efficiency was found to be acutely sensitive to the presence of p-tert-butylpyridine (TBP) in a 0.5 M LiI/0.05 M I(2) acetonitrile electrolyte. Nanosecond transient absorption studies revealed that the addition of TBP decreased the excited-state injection yield for the compounds with biquinoline ligands. Spectro-electrochemical studies showed that the HCl pretreatment lowered the effective density of TiO(2) acceptor states and confirmed that the presence of TBP raised them toward the vacuum level. There was no spectroscopic data to support the hypothesis that the π* levels of the diimine ligand mediate back-electron transfer to the oxidized dye or the redox mediator was found. 相似文献
98.
Singh Sandeep K. Anderson Brian D. Taheri Ehsan Junkins John L. 《Journal of Optimization Theory and Applications》2021,191(2-3):517-544
Journal of Optimization Theory and Applications - In this paper, we investigate the manifolds of three Near-Rectilinear Halo Orbits (NRHOs) and optimal low-thrust transfer trajectories using a... 相似文献
99.
A. Tohidi S. M. Hosseinalipour P. Taheri N. M. Nouri A. S. Mujumdar 《Heat and Mass Transfer》2013,49(11):1535-1548
The present work examines the role of chaotic mixing as a means of heat transfer enhancement in plate heat exchangers. In order to demonstrate the chaotic behavior, sensitivity to initial conditions and horseshoe maps are visualized. The Nusselt number and the friction factor were computed in the range of reynolds number, 1 < Re < 10. The Nusselt number increases considerably in chaotic models whereas the friction factor increases only marginally. 相似文献
100.
Homayon Ahmad Panahi Hossein Sid Kalal Elham Moniri Mahnaz Taheri Menderjani Faranak Mahmoudi 《Microchemical Journal》2009,93(1):49-54
A new chelating resin is prepared by coupling Amberlite XAD-4 with metaphenylendiamine through an azo spacer, characterized (elemental analysis, IR and thermogravimetric analysis (TGA)) and studied for preconcentration Rh (III) using Inductive Couple Plasma Atomic Emission Spectroscopy (ICP-AES) for rhodium monitoring. The optimum pH value for sorption of the metal ion was 6.5 (recovery 100%). The sorption capacity was found 0.256 mmol g− 1 of resin for Rh (III). The method has a detection limit and limit of quantification of 0.05 and 0.08 μg mL− 1 at pH 6.5, respectively. The chelating resin can be reused for 10 cycles of sorption-desorption without any significant change in sorption capacity. A recovery of 100% was obtained for the metal ion with 1.5 M HCl as eluting agent. The equilibrium adsorption data of Rh (III) on modified resin were analyzed by Langmuir and Freundlich models. Adsorption data were modeled using the pseudo-first-order, pseudo-second-order and intra-particle diffusion kinetics equations. Isotherms have also been used to obtain the thermodynamic parameters such as free energy, enthalpy and entropy of adsorption. The positive value of the enthalpy change (2.48 kJ/mol) indicates that the adsorption is an endothermic process. The method was applied for rhodium ions determination from tap water sample. 相似文献