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排序方式: 共有133条查询结果,搜索用时 671 毫秒
31.
Rahmatallah Saboori Shahriar Osfouri Samad Sabbaghi Alireza Bahramian 《Journal of Dispersion Science and Technology》2018,39(6):767-776
Wettability alteration is an important mechanism to increase recovery from oil and gas reservoirs. In this study, effect of fluorine-doped silica coated by fluorosilane nanofluid on wettability alteration of carbonate rock was investigated. The nanoparticle synthesized by sol-gel method was characterized using XRD, FTIR, SEM, and DLS. Adsorption of nanoparticle on rock was characterized by FESEM, and composition of rock after treatment was determined by EDXA. Effect of nanofluid on wettability was investigated by measuring static, advancing, and receding contact angle and surface free energy, imbibition of water, crude oil, and condensate of untreated and treated carbonate rock. Also, stability of contact angle and thermal stability of nanofluid were studied. ?Results show that contact angles for water, condensate, and crude oil were altered from 37.95°, 0°, ?and 0° to 146.47°, 145.59°, and 138.24°. In addition, water, condensate, and oil imbibition ?decreased more than 87, 88, and 80%, indicating that wettability was altered from strongly oil wet, ?condensate wet, and water wet to strongly gas wet. The ultraoleophobic and ultrahydrophobic stability were >48 hours and 120 minutes. Surface free energy of treated rock for water, crude oil, and condensate was ?2.24, 1.17, and 1.47mN/m. Thermal stability of nanofluids and adsorbed nanoparticle was up to 150°C. 相似文献
32.
Abbas?ShockraviAbbas_Shockravi@yahoo.co.uk" title="Shockravi@saba.tmu.ac.ir Abbas_Shockravi@yahoo.co.uk" itemprop="email" data-track="click" data-track-action="Email author" data-track-label="">Email author T.?Samad?Bavili 《Journal of inclusion phenomena and macrocyclic chemistry》2005,52(3-4):223-227
Some new dibenzosulfide macrocyclic diamides (6–12) are synthesized. The macrocyclization process is performed by reaction of the dimethyl ester (5) and diacid chloride (4) with appropriate diamines by two methods. Also the results of two methods are discussed and compared.This revised version was published online in July 2005 with a corrected issue number. 相似文献
33.
A novel, one-pot reductive mono-alkylation method of amines (primary and secondary), 1,2-phenylenediamine, O-trimethylsilylhydroxylamine, and N,N-dimethylhydrazine was developed using LiClO4 (5 mol %) as a source for in situ generation of imine, iminium ion, oxime, and hydrazone, and zirconium borohydride-piperazine complex as reducing agent. This condition is especially useful for situations in which it is not practical to use the amine in excess (as is typically the case under acid-catalyzed conditions) or for acid-sensitive compounds. 相似文献
34.
Dr. Abdus Samad Dr. Aamir Shafique Prof. Udo Schwingenschlögl Dr. ZongWei Ji Prof. Guangfu Luo 《Chemphyschem》2022,23(10):e202200041
Monolayer, bilayer, and bulk BSi are studied to explore their application potential as anode materials of Li-ion batteries. Structural stability and metallicity are obtained in each case. The Li storage capacities of monolayer and bilayer BSi are 1378 and 689 mAh g−1, respectively, with average open circuit voltages of 1.30 and 0.47 V as well as Li diffusion barriers of 0.48 and 0.27 eV. Bulk BSi realizes a layered structure in the presence of a small amount of Li and its Li diffusion barrier of 0.48 eV is identical to that of graphite and lower than that of bulk Si (0.58 eV). The Li storage capacity of bulk BSi is found to be 689 mAh g−1, i. e., much higher than that of graphite (372 mAh g−1). The volume expansion turns out to be 33 % and the chemical bonds remain intact at full lithiation, outperforming the 72 % volume expansion of bulk Si at the same capacity and thus pointing to excellent cyclability. 相似文献
35.
We have achieved the synthesis of C15-C27 fragment of venturicidine X using desymmetrization protocol, substrate-controlled Grignard reaction, Barton-McCombie reaction, Sharpless epoxidation, and TBSOTf-mediated rearrangement to produce the aldol product through a non-aldol route as the key step following 23 longest linear sequences with 6.4% overall yield starting from a known intermediate 11. 相似文献
36.
A simple and efficient protocol for the chemoselective mono-N-Boc protection of various structurally diverse amines with di-tert-butyl dicarbonate using thioglycoluril as the catalyst is described. The catalyst can be readily separated from the reaction products by simple filtration and recovered for reuse. No competitive side reactions, such as formation of isocyanate, urea, oxazolidinone, and N,N-di-Boc derivatives were observed. 相似文献
37.
Ricardo Elgul Samad Lilia Coronato Courrol Ademar Benévolo Lugão Anderson Zanardi de Freitas Nilson Dias Vieira 《Radiation Physics and Chemistry》2010,79(3):355-357
We report here the creation of color centers in commercial, transparent PMMA samples by ultrashort pulses from a Ti:Sapphire laser emitting at 800 nm, with spatial control. Although the 800 nm photon energy is not sufficient to ionize the polymer, the centers are created following a multiphotonic absorption that causes the ionization. We propose that the free electrons quivering motion on the pulse electric field displaces atoms from its equilibrium positions, creating free radicals and double bonds that coalesce into color centers. The absorption and emission spectra of the centers were measured, but a dose-like curve could not be built due to the presence of damages created along with the centers that scatter the excitation and emission lights due to the commercial sample's poor optical quality. 相似文献
38.
S. Mustafa Samad Yar Hussain A. Naeem Khan 《Reaction Kinetics and Catalysis Letters》1992,47(1):125-131
The kinetics of phosphate sorption on Amberlite IRA-400 has been studied as a function of temperature, nature of counterions, at two different concentrations. The film and particle diffusion coefficients and the activation parameters of the process are calculated.
IRA-400 , . .相似文献
39.
A novel, chemoselective mono-N-Boc protection of various structurally diverse amines with di-tert-butoxypyrocarbonate (Boc)2O is described that relies on selective carbonyl activation by hydrogen bond formation. This mild, acid- and metal-free process requires only catalytic amounts of thiourea as hydrogen bond donor. 相似文献
40.