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排序方式: 共有315条查询结果,搜索用时 437 毫秒
31.
Iraj Mohammadpoor‐Baltork Majid Moghadam Shahram Tangestaninejad Valiollah Mirkhani Zohre Eskandari 《Journal of heterocyclic chemistry》2011,48(2):479-483
An efficient method for the selective synthesis of 2‐substituted oxazines and tetrahydropyrimidines by the reaction of arylnitriles with 3‐amino‐1‐propanol and 1,3‐diaminopropane in the presence of montmorillonite K‐10 and KSF as inexpensive, environmentally benign, and reusable catalysts under classical heating conditions and microwave irradiation is reported. J. Heterocyclic Chem., (2011). 相似文献
32.
Shahram Pouya Manoochehr Koochesfahani Preston Snee Moungi Bawendi Daniel Nocera 《Experiments in fluids》2005,39(4):784-786
We introduce the use of quantum dot (QD) nanoparticles for near-surface velocimetry and provide preliminary data to demonstrate its feasibility. Evanescent wave illumination is used to image the motion of water-soluble (CdSe)ZnS QDs with a core size of 6 nm within a region of order 100 nm of a surface . Results are presented for the two in-plane components of the velocity field. 相似文献
33.
A new pyridine-based diacid containing ether and imide units was synthesized via reaction of 5-amino-1-naphthol with 2,6-dichloropyridine in the presence of potassium carbonate in N-methyl-2-pyrrolidone (NMP), and subsequent reaction of the obtained diamine with 2 mol of trimellitic anhydride. A series of poly(ether imide ester)s was synthesized by the polycondensation reactions of the prepared diacid with different diols via high temperature solution polycondensation reaction method. All the products were fully characterized by common spectroscopic methods. The polymers were examined by elemental analysis, IR and 1H NMR spectra, inherent viscosity, X-ray diffraction, DSC, TGA and DMTA and their properties were studied. Polymers showed high thermal stability and good solubility in polar aprotic solvents. The Structure-property relations of the polymers were also studied. 相似文献
34.
35.
Majid Moghadam Iraj Mohammadpoor-Baltork Valiollah Mirkhani Shahram Tangestaninejad Mohammad Abdollahi-Alibeik Behrooz H. Yousefi Hadi Kargar 《Monatshefte für Chemie / Chemical Monthly》2007,33(3):579-583
Small assemblies of 2-imidazolines and bisimidazolines from appropriate nitriles and ethylenediamine with catalytic amounts
of P2S5 employing a microwave assisted protocol were prepared. Sonication of this system also led to successful synthesis of 2-imidazolines
and bisimidazolines. Another advantage of these systems is the ability to carry out large scale reactions. 相似文献
36.
Optimal piezoelectric actuator and sensor location for active vibration control, using genetic algorithm 总被引:1,自引:0,他引:1
Isabelle Bruant Laurent Gallimard Shahram Nikoukar 《Journal of sound and vibration》2010,329(10):1615-1635
This paper deals with the optimization of piezoelectric actuators and sensors locations for active vibration control. Two modified optimization criteria are used, ensuring good observability or controllability of the structure, and considering residual modes to limit the spillover effect. Two optimization variables are considered for each piezoelectric device: the location of its center and its orientation. Genetic algorithms are used to find the optimal configurations. Several simulations are presented for a simply supported plate. 相似文献
37.
Shahram Rezapour Hassan Khandani Seyyed M. Vaezpour 《Rendiconti del Circolo Matematico di Palermo》2010,59(2):185-197
Let (E, τ) be a topological vector space and P a cone in E. We shall define a topology τ
P
on E so that (E, τ
P
) is a normable topological vector space and P is a normal cone with normal constant M = 1. Then by using the norm, we shall give some results about common fixed points of two multifunctions on cone metric spaces. 相似文献
38.
Shahram Biglari 《代数通讯》2013,41(1):317-322
Using a Zariski topology associated to a finite field extensions, we give new proofs and generalize the primitive and normal basis theorems. 相似文献
39.
Ali Bahrami Shahram Mohammadnejad Saeede Soleimaninezhad 《Optical and Quantum Electronics》2013,45(2):161-197
Solar energy is one of the renewable energy resources that can be changed to the electrical energy with photovoltaic cells. This article accomplishes a comprehensive review on the emersion, underlying principles, types and performance improvements of these cells. Although there are some different categorizations about the solar cells, but in general, all of them can be divided to crystalline silicon solar cells, thin film technology, III–V multijunction cells, dye-sensitized solar cells, polymer solar cells and quantum structured solar cells. Thin film technology is investigated in two non-crystalline silicon solar cells and chalcogenide cells. We present a complete categorization of solar cells and discuss the recent developments of different types of solar cells. Indeed, this paper covers almost all of the development processes of solar cells from their emersion in 1939 up to now. Also, due to substantial effects of the light trapping techniques on the improvements of the solar cells, a comprehensive study has been carried out. 相似文献
40.
Tangestaninejad S Moghadam M Mirkhani V Mohammadpoor-Baltork I Salavati H 《Ultrasonics sonochemistry》2008,15(5):815-822
Na5PV2Mo10O40 supported on nanoporous anatase TiO2 particles, TiO2–PVMo, was used as an efficient photocatalyst for photocatalytic degradation of different dyes by visible light using oxygen as oxidant. This catalyst showed a good catalytic activity in the sonocatalytic and sonophotocatalytic decomposition of different dyes in aqueous solutions. The TiO2–PVMo composite showed higher photocatalytic and sonocatalytic activity than pure polyoxometalate or pure TiO2. 相似文献