排序方式: 共有73条查询结果,搜索用时 45 毫秒
11.
Elham Moosazadeh Enayatollah Sheikhhosseini Dadkhoda Ghazanfari Shahla Soltaninejad 《Journal of heterocyclic chemistry》2020,57(5):2271-2278
In the present study, a group of polysubstituted furopyran derivatives possessing ether spacer groups were synthesized under good-to-exceptional yields via cycloaddition of bisarylidene Meldrum's acid derivatives (1 mmol) with isocyanides (6 mmol) within dichloromethane (CH2Cl2) for 3 to6 hours at room temperature with no assistance from any type of catalysts. The structure of the products was then confirmed by Fourier Transform-infrared spectroscopy, 1H-nuclear magnetic resonance spectroscopy, 13C-nuclear magnetic resonance spectroscopy, and elemental analysis. Moreover, the 5c , 5d , and 5f compounds exhibited favorable pharmaceutical behavior as antibacterial. 相似文献
12.
Denis Liyu Shahla H. Nemati Andreas E. Vasdekis 《Journal of Polymer Science.Polymer Physics》2016,54(17):1681-1686
Due to their low‐cost and processing simplicity, polymers have made a substantial impact on everyday life and scientific discoveries. Such discoveries include the use of microanalysis and optical microsystems, which—albeit simpler to prototype than their inorganic counterparts—still require dedicated procedures at high temperatures and pressures. Here, recent developments in microsystem prototyping are highlighted, based on solvent‐assisted polymer stimulation. These developments—largely inspired by the earlier demonstration of solvent‐assisted micromolding (SAMIM) for nanoimprinting—enable micronscale imprinting, but also bonding to substrates and three‐dimensional chemical functionalization via strict benchtop procedures. These solvent‐assisted strategies are categorized into two groups: those based on solvent immersion and those based on complete polymer dissolution. Recent embodiments within each group are discussed and compared in performance. Solvent‐assisted prototyping further narrows the gap of processing complexity and costs between the PDMS elastomer and thermoplastic polymer microfluidics, and also enables novel architectures and thus new opportunities in microscale Life Sciences and Chemistry investigations. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1681–1686 相似文献
13.
Polyimide‐coated magnetic nanoparticles as a sorbent in the solid‐phase extraction of polycyclic aromatic hydrocarbons in seawater samples 下载免费PDF全文
Magnetic polyimide poly(4,4′‐oxydiphenylene‐pyromellitimide) nanoparticles were successfully synthesized and developed for the solid‐phase extraction of polycyclic aromatic hydrocarbons in seawater samples. The aromatic rings of polyimide coating provided a good adsorption capacity (28.3–42.5 mg/g) for polycyclic aromatic hydrocarbons because of the π–π stacking interaction. The developed method was used as a simple, fast, and efficient extraction and preconcentration technique for the trace analysis of polycyclic aromatic hydrocarbons. The high chemical, physical and thermal stability, excellent reusability, and good magnetic properties are the merits of the sorbent. High preconcentration factors (41–63) were obtained. The sorbent was also characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X‐ray spectrometry, transmission electron microscopy, and vibrating sample magnetometry. After optimizing several appropriate extraction parameters, the results indicated that the extraction recoveries of polycyclic aromatic hydrocarbons were in the range of 61.6–94.7%, with relative standard deviations between 2.9 and 5.4%, the calibration graph was linear in the concentration range of 1–100 μg/L (r > 0.9991) with limit of detection in the range of 0.15–0.19 μg/L (n = 3). Seawater samples were analyzed as real samples and good recoveries (68.5–99.5%) were obtained at different spiked values. 相似文献
14.
Hamzavi Seyedeh Fazileh Jamili Shahla Yousefzadi Morteza Mashinchian Moradi Ali Amrollahi Biuki Narges 《Molecular diversity》2020,24(4):985-995
Molecular Diversity - In this work, we reported a facile synthesis of Pt nanoparticles (NPs) on proline-functionalized cross-linked chitosan particles to catalyze the reduction of R-NO2 to R-NH2 in... 相似文献
15.
Zafar Ahmad Siddiqi Shahla Nusrat Qidwai Maimoona Jaria Mohd Shakir 《Transition Metal Chemistry》1988,13(4):244-246
Summary Reactions ofN-trimethylsilylimidazole andN-trimethyl-silyl-2-methylimidazole with CoCl2 yield chloro(imidazolato)cobalt(II), (1), or chloro(2-methylimidazolato)-cobalt(II), (2). However, the corresponding reactions of [Co(Ph3P)2Cl2] cause total removal of Ph3P along with the substitution of both the chlorine atoms yielding bis(imidazolato)cobalt(II), (3), or bis(2-methylimidazolato)cobalt(II), (4), in the form of light blue microcrystalline solids. The complexes have been characterized by elemental analysis, molecular weight, and magnetic susceptibility measurements, and i.r., reflectance and electronic spectra. The results are consistent with formulations as rare examples of two-coordinate cobalt(II) derivatives.Author to whom all correspondence should be directed 相似文献
16.
Freites JA Ali S Rosengarth A Luecke H Dennin MB 《Langmuir : the ACS journal of surfaces and colloids》2004,20(26):11674-11683
We present the results of a fluorescence microscopy study of the interaction of annexin A1 with dipalmitoylphosphatidylcholine (DPPC) monolayers as a function of the lipid monolayer phase and the pH of the aqueous subphase. We show that annexin A1-DPPC interaction depends strongly on the domain structure of the DPPC monolayer and only weakly on the subphase pH. Annexin A1 is found to be line active, with preferential adsorption at phase boundaries. Also, annexin A1 is found to form networks in the presence of a domain structure in the monolayer. Our results point toward an important contribution of the unique N-terminal domain to the organization of the protein at the interface. 相似文献
17.
Shahla Khalili Saied Nouri Khorasani Niloufar Saadatkish Khadije Khoshakhlagh 《Polymer Science Series A》2016,58(3):399-408
Gelatin/cellulose acetate electrospun nanofibers are a good candidates for simulation of extracellular matrix (ECM). Electrospinning of the blend is controlled by many parameters such as applied voltage, gap distance, solvent composition, polymer composition and solution concentration. The individual and interactive effects of these parameters on pH, electrical conductivity (EC) and viscosity of solutions, and diameter and quality of fibers were investigated. Response surface methodology (RSM) and artificial neural networks (ANNs) were considered to model and optimize the responses. EC, pH and viscosity of solutions were dependent on the solution parameters. The solvent composition and solution concentration had an influence on the fiber diameter and quality. The optimum conditions for fabricating qualified nanofibers with minimum diameter were 16.9 kV, 15.3 cm, 77.5 wt % of gelatin, 88.9 vol % of acetic acid and solution concentration of 20 wt %/vol %. Uniform beadless nanofibers with a diameter of 284 nm were attained at this optimum condition. 相似文献
18.
19.
In this study, an efficient and green procedure is explained for the preparation of 1‐amidoalkyl‐2‐naphthols applying one‐pot condensation reaction of 2‐naphthol, amide and aromatic nanoparticles (Fe3O4@SiO2@IL‐PVP) as a novel solid acid catalyst under solvent‐free conditions. The remarkable features of this method are short reaction time, high conversions, and high yield of product, easy workup procedures and solvent‐free conditions. The Fe3O4@SiO2@IL‐PVP catalyst was characterized via Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction patterns (XRD), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), vibrating sample magnetometer (VSM), and energy‐dispersive X‐ray spectroscopy (EDS). Also, nanocatalysts could be easily recovered by a simple magnet and reused for the next reactions without significant loss of its catalytic activity. 相似文献
20.