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141.
The main aim of this paper is to propose two semi-implicit Fourier pseudospectral schemes for the solution of generalized time fractional Burgers type equations, with an analysis of consistency, stability, and convergence. Under some assumptions, the unconditional stability of the schemes is shown. In implementation of these schemes, the fast Fourier transform (FFT) can be used efficiently to improve the computational cost. Various test problems are included to illustrate the results that we have obtained regarding the proposed schemes. The results of numerical experiments are compared with analytical solutions and other existing methods in the literature to show the efficiency of proposed schemes in both accuracy and CPU time. As numerical solution of fractional stochastic nonlinear partial differential equations driven by Brownian motions are among current related research interests, we report the performance of these schemes on stochastic time fractional Burgers equation as well. 相似文献
142.
143.
Despite its success for modeling electrolyte thermodynamics in aqueous media, the use of the Pitzer approach for the investigation
of electrolytes in nonaqueous or in mixed solvent media is still very limited. Further, a review of the literature reveals
that there are no more than a few research groups who have used the exact form of the Pitzer–Simonson–Clegg (PSC) ion-interaction
approach for the investigation of electrolytes in mixed solvent systems. As a continuation of our previous studies, the present
investigation reports modeling of HCl in the 2-propanol + water mixed solvent system with the Pitzer, PSC and an extended
form of the PSC ion-interaction approaches using the experimental potentiometric data from a cell containing pH glass membrane
and Ag/AgCl electrodes. The electrochemical measurements were performed over the HCl molality range from 0.01 to 4.5 mol⋅kg−1 in mixed 2-propanol (x%)+water (100−x%) solvents, with different solvent percent mass fractions (x%=10,20,30,40 and 50%) at 298.15±0.05 K. 相似文献
144.
Yagoub Mansoori Raana Sarvari Mohammad Reza Zamanloo Gholam Hassan Imanzadeh 《高分子科学》2010,28(1):21-28
<正>In the present work,new thermally stable polymers containing 1,3,4-oxadiazole units have been synthesized through Huisgen reaction of the aromatic bis-tetrazole compounds with the aromatic/aliphatic bis-acid chlorides in pyridine as solvent.The obtained polymers are insoluble or slightly soluble in polar aprotic solvents such as DMSO and DMF. Thermal analyses of the polymers using DSC and TGA techniques showed that the polymers had improved thermal stabilities.The model reaction was also investigated and the resulting bis-l,3,4-oxadiazole compounds were characterized by conventional spectroscopic methods. 相似文献
145.
Abdolali Alizadeh Zohreh Noaparast Hamideh Sabahno Nasrin Zohreh 《Helvetica chimica acta》2010,93(7):1401-1406
Synthesis and characterization of bis[2‐(arylimino)‐1,3‐thiazolidin‐4‐ones] are described. The one‐pot, pseudo‐five‐component reaction of an aliphatic diamine, isothiocyanatobenzene, and dialkyl but‐2‐ynedioate at room temperature in anhydrous CH2Cl2 gives the title compound in relatively high yield. Under the same conditions, aromatic 1,2‐diamines yield 2‐(arylimino)‐N‐(enaminoaryl)‐1,3‐thiazolidin‐4‐ones in a pseudo‐four‐component reaction. Their structures were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme 3). 相似文献
146.
A simple and efficient synthesis of 2‐amino‐4‐aryl thiazole derivatives was carried out through the reaction of substituted acetophenones and thiourea using three different types of catalytic systems including N,N,N′,N′‐tetrabromobenzene‐1,3‐disulfonamide [TBBDA], poly(N,N′‐dibromo‐N‐ethylbenzene‐1,3‐disulfonamide) [PBBS] and a combination of TBBDA and nano‐magnetic catalyst supported with functionalized 4‐amino‐pyridine silica (MNPs@SiO2‐Pr‐AP). The results showed that the use of TBBDA along with the MNPs@SiO2‐Pr‐AP gains the highest yields of the products in the shortest reaction time. 相似文献
147.
148.
This study was prepared for the first time the trimetallic nanocatalyst Co2-Ni-Mn/SiO2 by thermal decomposition of) [Ni(H2O)5Co(dipic)2].2H2O + [Mn(H2O)5Co(dipic)2] 2H2O)/SiO2, to study the Fischer–Tropsch reaction for conversion of the synthesis gas to light olefins. The catalytic performance of Co2-Ni-Mn/SiO2 as a nanocatalyst prepared by thermal decomposition of an inorganic precursor was compared to that of the trimetallic nanocatalysts Co2-Ni-Mn/SiO2 as reference nanocatalysts prepared by impregnation and co-precipitation. The characterization of precursor and nanocatalyst were confirmed by thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) specific surface area, and X-ray diffraction (XRD). The Fischer–Tropsch reaction for all nanocatalysts of Co2-Ni-Mn/SiO2 was studied at 280–360 °C at a gas hourly space velocity of 3600 h?1, and a H2/CO molar ratio of 1:1 at atmospheric pressure. The results showed that the Co2-Ni-Mn/SiO2 nanocatalyst prepared by thermal decomposition of an inorganic complex exhibited the higher activity than the other nanocatalysts and showed maximum selectivity to light olefins at 360 °C. 相似文献
149.
Majid M. Heravi Hamideh Alinejhad Zohreh Daroogheha Fatemeh F. Bamoharram Fatemeh Derikvand 《合成通讯》2013,43(15):2191-2200
An efficient synthesis of indeno[1,2-b]quinoline-9,11(6H,10H)-dione derivatives was reported via four-component coupling reaction of aldehydes, dimedone, 1,3-indandione, and amines in refluxing ethanol or three-component condensation of aldehydes, 1,3-indandione, and 5,5-dimethyl-3-arylamino-cyclohex-2-enone derivatives at 120 °C under solvent-free conditions in the presence of a catalytic amount of Preyssler-type heteropolyacid, H14[NaP5W30O110], as a green and reusable catalyst. 相似文献
150.
Pirsaheb Meghdad Mohammadi Somayeh Khodarahmi Reza Hoseinkhani Zohreh Mansouri Kamran Payandeh Mehrdad 《Journal of fluorescence》2022,32(5):1733-1741
Journal of Fluorescence - In this research, DNA-modified carbon dots (CDs) were exploited to construct a fluorescence assay for breast cancer genes (BRCA1, a potential marker for cancer diagnosis)... 相似文献