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排序方式: 共有370条查询结果,搜索用时 328 毫秒
101.
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Dipl.‐Chem. Vikas Aggarwal Dipl.‐Chem. Linus F. Reichenbach Dipl.‐Chem. Mirja Enders Dr. Thierry Muller Dipl.‐Ing. Simone Wolff Marlene Crone Prof. Dr.‐Ing. Michael Türk Prof. Dr. Stefan Bräse 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(38):12794-12799
The optimized synthesis of a range of cyclooctadiene‐stabilized Pt complexes that contained different perfluoro‐alkane chains, [Pt(cod)Me(CnF2n+1)], is presented. These metal–organic compounds were employed in the so‐called supercritical fluid reactive deposition (SFRD) in CO2 under reductive conditions to generate metallic nanoparticles on aluminum oxide as a porous support. Thus, Al2O3‐supported Pt nanoparticles with a narrow particle‐size distribution were obtained. At a reduction pressure of 15.5 MPa and a temperature of 353 K, particle diameters of d50=2.3–2.8 nm were generated. Decreasing the pressure during the reduction reaction led to slightly larger particles whilst decreasing the amount of organometallic precursor in CO2 yielded a decrease in the particle size from x50=3.2 nm to 2.6 nm and a particle‐size distribution of 2.2 nm. Furthermore, substitution of the CH3 end group by the CnF2n+1 end groups led to a significant drop in Pt loading of about 50 %. Within the series of perfluorinated end groups that were considered, the Pt complex that contained a branched perfluoro‐isopropyl group showed the most‐interesting results when compared to the control precursor, [Pt(cod)Me2] ( 1 ). 相似文献
103.
Analysis of argentinated peptide complexes using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry: Peptide = oxytocin,arg8‐vasopressin,bradykinin, bombesin,somatostatin, neurotensin 下载免费PDF全文
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Anisotropic swelling of hydrogel nanowires based on poly(vinylpyrrolidone) fabricated by single‐particle nanofabrication technique 下载免费PDF全文
Satoshi Tsukuda Masaaki Omichi Masaki Sugimoto Akira Idesaki Vikas S. Padalkar Shu Seki 《Journal of Polymer Science.Polymer Physics》2016,54(19):1950-1956
We report a hydrogel nanowire based on poly(vinylpyrrolidone) (PVP) and N,N'‐methylenebis(acrylamide) (MBA), which have anisotropic swelling ratio for radius and length direction. The PVP/MBA nanowires were fabricated by single particle nanofabrication technique, which is a technique for the fabrication of polymeric nanowires using the single ion event, that cause the crosslinking reaction of polymer chains within the ion tracks along the ion paths; furthermore the size (length and radius) of the nanowires was controlled by changing the film thickness and amount of MBA crosslinker. The swelling behaviors in air and water were observed using atomic force microscopy. The PVP/MBA nanowires exhibited anisotropic swelling along the length and radius in aqueous environments, because the hydrogel nanowires consisted of crosslinked networks with inhomogeneous crosslinking points, which reflected the initial energy distribution from incident an ion within the ion track. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1950–1956 相似文献
106.
Dongamanti Ashok Aamate Vikas Kumar Devulapally Mohan Gandhi Gundu Srinivas Balabadra Saikrishna Manga Vijjulatha Yogeeswari Perumal Sriram Dharmarajan Balasubramanian Sridhar 《Molecular diversity》2017,21(4):999-1010
Molecular Diversity - On the basis of reported antimycobacterial property of chroman-4-one pharmacophore, a series of chemically modified bis-spirochromanones were synthesized starting from... 相似文献
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Structural characterization of flavonoid C‐ and O‐glycosides in an extract of Adhatoda vasica leaves by liquid chromatography with quadrupole time‐of‐flight mass spectrometry 下载免费PDF全文
109.
Vikas Kumar J. N. Sharma P. V. Achuthan R. C. Hubli 《Journal of Radioanalytical and Nuclear Chemistry》2014,299(3):1547-1553
The 25,27-di(octyloxy)calix[4]arenebenzocrown-6 (CBC) in 1,3-alternate conformation was synthesized indigenously starting from its intermediates in good yield and purity. The extraction studies of CBC were carried out by using two different phase modifiers namely isodecyl alcohol and ortho-nitrophenyl hexyl ether. Detailed investigations on the effect of various parameters like, concentration of phase modifiers, aqueous phase acidity, ligand concentration, nitrate ion concentration and effect of temperature on extraction of cesium have been carried out. The concentration of phase modifiers was optimized to be 30 % in n-dodecane to ensure optimum extraction of cesium. Stoichiometry of the extracted complex determined by slope analysis method reveals 1:1:1 molar ratio for CsNO3:CBC:HNO3. The extraction process was found to be exothermic as determined from the plot of log K ex versus 1/T. The solvent system with a composition 0.01 M CBC/30 % phase modifier/n-dodecane was found to be effective for selective separation of cesium from simulated high level liquid waste solution. 相似文献
110.
Vikas Trivedi Priyanka A. Shah Pranav S. Shrivastav Mallika Sanyal 《Biomedical chromatography : BMC》2020,34(3):e4777
The article describes a systematic study to overcome the matrix effect during chromatographic analysis of gemfibrozil, rivastigmine, telmisartan and tacrolimus from biological fluids using LC–ESI–MS/MS. All four methods were thoroughly developed by the appropriate choice of analytical column, elution mode and pH of mobile phase for improved chromatography and overall method performance. Matrix effect was assessed by post-column analyte infusion, slope of calibration line approach and post-extraction spiking. The best chromatographic conditions established were: Acquity BEH C18 (50 × 2.1 mm, 1.7 μm) column with 5.0 mm ammonium acetate, pH 6.0–methanol as the mobile phase under gradient program for gemfibrozil; Luna CN (50 × 2.0 mm, 3 μm) column with a mobile phase consisting of acetonitrile–10 mm ammonium acetate, pH 7.0 (90:10, v/v) for rivastigmine; Inertsustain C18 (100 × 2.0 mm, 5 μm) column using methanol–2.0 mm ammonium formate, pH 5.5 (80: 20, v/v) as the mobile phase for isocratic elution of telmisartan; and Acquity BEH C18 (50 × 2.1 mm, 1.7 μm) with methanol–10 mm ammonium acetate, pH 6.0 (95:5, v/v) as mobile phase for tacrolimus. The methods were thoroughly validated as per European Medicines Agency and US Food and Drug Administration guidance and were successfully applied for pharmacokinetic studies in healthy subjects. 相似文献