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排序方式: 共有170条查询结果,搜索用时 31 毫秒
21.
Azadi Mahboobeh Olya Mohammad Javad Vahedi Samaneh Sangani Neda Fazeli 《Russian Journal of Applied Chemistry》2017,90(7):1181-1187
Russian Journal of Applied Chemistry - Titanium dioxide (TiO2) is widely used in the paint industry as a white pigment. To reduce the high cost of TiO2, mineral fillers such as different calcites... 相似文献
22.
Zahra Najafi Mohammad Mahdavi Maliheh Safavi Mina Saeedi Heshmatollah Alinezhad Mahboobeh Pordeli Sussan Kabudanian Ardestani Abbas Shafiee Alireza Foroumadi Tahmineh Akbarzadeh 《Journal of heterocyclic chemistry》2015,52(6):1743-1747
New derivatives of triazole‐isoxazole were synthesized through a four‐step reaction starting from various ethyl 4‐aryl‐2,4‐dioxobutanoate derivatives. Finally, all compounds were examined by MTT assays for cytotoxic activity in two human breast cancer cell lines (MCF‐7 and T‐47D). 相似文献
23.
A modified pseudospectral method for solving trajectory optimization problems with singular arc 下载免费PDF全文
Zahra Foroozandeh Mostafa Shamsi Vadim Azhmyakov Masoud Shafiee 《Mathematical Methods in the Applied Sciences》2017,40(5):1783-1793
This paper presents a direct method based on Legendre–Radau pseudospectral method for efficient and accurate solution of a class of singular optimal control problems. In this scheme, based on a priori knowledge of control, the problem is transformed to a multidomain formulation, in which the switching points appear as unknown parameters. Then, by utilizing Legendre‐Radau pseudospectral method, a nonlinear programming problem is derived which can be solved by the well‐developed parameter optimization algorithms. The main advantages of the present method are its superior accuracy and ability to capture the switching times. Accuracy and performance of the proposed method are examined by means of some numerical experiments. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
24.
Heshmatollah Alinezhad Mahmood Tajbakhsh Mahboobeh Zare 《Journal of fluorine chemistry》2011,132(11):995-1000
A simple, efficient and three component one-pot synthesis of 1,4,5-trisubstituted pyrazoles by condensation of β-dicarbonyls, N,N-dimethylformamide dimethyl acetal (DMFDMA) and hydrazine derivatives in 2,2,2-trifluoroethanol without using any catalyst and activation, is described. 相似文献
25.
Mohammed K. Almoaeet Mostafa Shamsi Hassan Khosravian‐Arab Delfim F. M. Torres 《Mathematical Methods in the Applied Sciences》2019,42(10):3465-3480
We present the method of lines (MOL), which is based on the spectral collocation method, to solve space‐fractional advection‐diffusion equations (SFADEs) on a finite domain with variable coefficients. We focus on the cases in which the SFADEs consist of both left‐ and right‐sided fractional derivatives. To do so, we begin by introducing a new set of basis functions with some interesting features. The MOL, together with the spectral collocation method based on the new basis functions, are successfully applied to the SFADEs. Finally, four numerical examples, including benchmark problems and a problem with discontinuous advection and diffusion coefficients, are provided to illustrate the efficiency and exponentially accuracy of the proposed method. 相似文献
26.
Shahrokh Esmaeili Mostafa Shamsi Mehdi Dehghan 《Central European Journal of Physics》2013,11(10):1470-1481
The main focus of this paper is to present a numerical method for the solution of fractional differential equations. In this method, the properties of the Caputo derivative are used to reduce the given fractional differential equation into a Volterra integral equation. The entire domain is divided into several small domains, and by collocating the integral equation at two adjacent points a system of two algebraic equations in two unknowns is obtained. The method is applied to solve linear and nonlinear fractional differential equations. Also the error analysis is presented. Some examples are given and the numerical simulations are also provided to illustrate the effectiveness of the new method. 相似文献
27.
Houshmand Mahboobeh Mohammadi Zahra Zomorodi-Moghadam Mariam Houshmand Monireh 《International Journal of Theoretical Physics》2020,59(4):1315-1329
International Journal of Theoretical Physics - Distributed quantum computing has been well-known for many years as a system composed of a number of small-capacity quantum circuits. Limitations in... 相似文献
28.
Maryam Sohaniyan Mahboobeh Manoochehri Maryam Daghighi Asli 《Journal of separation science》2019,42(23):3528-3534
An efficient and fast dispersive magnetic solid phase extraction method was developed using MIL‐101(Cr)/poly (mercaptobenzothiazole)@magnetite nanoparticles for the preconcentration and determination of nitrophenols in river and rain water samples. High‐performance liquid chromatography‐Ultraviolet instrument was applied for the analysis of target nitrophenols. The effect of several variables on the extraction performance was explored via design of experiment approach. Limits of detection and linear dynamic ranges were attained in the range of 0.05–0.10 µg/L and 0.2–250 µg/L, respectively. The enrichment factors were in the range of 317–363. The precision (n = 3) of dispersive magnetic solid phase extraction method was in the range of 5.3–6.8%. Eventually, the method was utilized for the analysis of target nitrophenols in river and rain water samples. 相似文献
29.
Hossein Tavallali Hossein Malekzadeh Mohammad Ali Karimi Mahmood Payehghadr Gohar Deilamy-Rad Mahboobeh Tabandeh 《Arabian Journal of Chemistry》2019,12(7):1487-1495
Multi-walled carbon nanotubes (MWCNTs) were chemically functionalized by glutaric dihydrazide (GDH) and characterized with FT-IR technique. This new sorbent was used for enrichment and preconcentration of Co(II), Cd(II), Pb(II), and Pd(II) ions. The adsorption was achieved quantitatively on MWCNTs at pH 4.0, and then the retained metal ions on the adsorbent were eluted with 1.5 mol L?1 HNO3. The effects of analytical parameters including pH of the solution, eluent type, sample volume, and matrix ions were investigated for optimization of the presented procedure. The adsorption capacity of the adsorbent at optimum conditions was found to be 33.6, 29.2, 22.1, and 36.0 mg g?1 for Co(II), Cd(II), Pb(II), and Pd(II), respectively. The LOD values of the method were 0.16, 0.19, 0.17, and 0.12 ng mL?1 (3Sb, n = 10) for Co(II), Cd(II), Pb(II), and Pd(II), respectively. The RSDs values of the method were 0.75, 0.85, 1.16, and 1.30 ng mL?1 for Co(II), Cd(II), Pb(II), and Pd(II), respectively. The method was applied for the determination of analytes in soil, well water, and wastewater samples with satisfactory results. 相似文献
30.
Faezeh Farzaneh Yasaman Sadeghi Mahboobeh Maghami Zeinab Asgharpour 《Journal of Cluster Science》2016,27(5):1701-1718
In this study, magnetically recoverable vanadium complexs designated as VO(Sal-Tryp)/AmpSCMNPs and VO(Sal-His)/AmpSCMNPs were prepared through immobilization of Schiff bases of histidine or tryptophan with salicylaldehyde on the surface of modified silica coated iron oxide magnetite nanoparticles with (3-aminopropyl) trimethoxysilane as aminopropyl (Amp) spacer followed by complexation with VOSO4. Characterization was carried out by chemical analysis, Fourier transform infrared spectroscopy, XRD, scanning electron microscopy and vibrating sample magnetometry techniques. VO(Sal-Tryp)/AmpSCMNPs and VO(Sal-His)/AmpSCMNP were found to catalyze the epoxidation of allyl alcohols and olefins with tert-butyl hydroperoxide with excellent conversions and selectivities. Investigation of the stability and reusability revealed the heterogeneity character of the catalyst with no desorption during the course of epoxidation reactions. High yields, clean reactions, easily catalyst separation and recyclability of the solid catalyst are some advantages of this method. 相似文献