排序方式: 共有140条查询结果,搜索用时 15 毫秒
101.
Siyavash Kazemi Movahed Parinaz Salari Melika Kasmaei Mahsa Armaghan Minoo Dabiri Mostafa M. Amini 《应用有机金属化学》2018,32(1)
Cu nanoparticles with average particles size around 10 nm were incorporated on the surface of a mesoporous carbon nitride support. The XRD and N2 adsorption isotherms show that it maintains a hexagonal mesoporous structure with a high surface area (600.03 m2 g?1). The embedded Cu nanoparticles exhibit extremely high catalytic performance in two different kinds of organic reactions. The Huisgen 1,3‐dipolar cycloaddition and N‐arylation of N‐heterocycles were all accomplished. 相似文献
102.
Structural Chemistry - The interplay among two important noncovalent interactions involving aromatic ring is studied by means of density functional theory (DFT) calculations on complexes of methyl... 相似文献
103.
Torabizadeh Mahsa Tabar-Heydar Kourosh Ahmadi Seyyed Hamid 《Journal of Analytical Chemistry》2022,77(8):1047-1056
Journal of Analytical Chemistry - In this study, an online solid-phase extraction-thermal desorption method coupled with gas chromatography-flame ionization detection was used to extract seven... 相似文献
104.
Mahsa Khoshbakht Jason Srey Donovon A. Adpressa Annika Jagels Sandra Loesgen 《Molecules (Basel, Switzerland)》2021,26(15)
The plant endophyte Chalara sp. is able to biotransform the epigenetic modifier vorinostat to form unique, aniline-containing polyketides named chalanilines. Here, we sought to expand the chemical diversity of chalaniline A-type molecules by changing the aniline moiety in the precursor vorinostat. In total, twenty-three different vorinostat analogs were prepared via two-step synthesis, and nineteen were incorporated by the fungus into polyketides. The highest yielding substrates were selected for large-scale precursor-directed biosynthesis and five novel compounds, including two fluorinated chalanilines, were isolated, purified, and structurally characterized. Structure elucidation relied on 1D and 2D NMR techniques and was supported by low- and high-resolution mass spectrometry. All compounds were tested for their bioactivity but were not active in antimicrobial or cell viability assays. Aminofulvene-containing natural products are rare, and this high-yielding, precursor-directed process allows for the diversification of this class of compounds. 相似文献
105.
Moosavi-Zare Ahmad Reza Rezaei-Gohar Mohammad Tavasoli Mahsa Goudarziafshar Hamid 《Research on Chemical Intermediates》2021,47(7):2689-2700
Research on Chemical Intermediates - 4-Carboxy-1-sulfopyridin-1-ium monozinc(II) trichloride {[4CSPy]ZnCl3} as a new acidic catalyst was designed and tested on the synthesis of... 相似文献
106.
Payam Molla-Abbasi Mahsa Sadat Asgari Mohammad Mahdi Hassani Sadrabadi 《Journal of Macromolecular Science: Physics》2017,56(4):234-244
A new polymer nanocomposite membrane based on Nafion and functionalized carbon nanotubes (CNTs) was developed for proton exchange membrane fuel cell (PEMFC) applications. Histidine, an imidazole-based amino acid, was used for modifying the surface of CNTs. The modification of CNTs was characterized by means of Fourier transform infrared spectroscopy (FTIR) and their Zeta potential. The imidazole groups, due to forming and breaking of hydrogen bonding, can facilitate proton transport across the polymer matrix by the Grotthuss mechanism. The final structure of the Nafion/CNT nanocomposites was investigated by small angle X-ray scattering (SAXS). The results confirm that the transport properties of the fabricated new membranes were significantly improved in comparison with unmodified and conventional Nafion® membranes. The power density of the imidazole-CNT (Im-CNT) Nafion® composite membranes was about three times more than Nafion® membranes. Also, the experimental results showed that the proton conductivity for the conventional Nafion® membranes decreased over 100°C but the conductivity for the Nafion®/Im-CNT remained at a nearly constant value above 100°C up to 120°C. Thus, the nanocomposite based on Nafion/imidazole functionalized CNT can be considered as an anhydrous PEMFC membrane for high-temperature applications. 相似文献
107.
A hydrothermal method was successfully used for synthesis of CuO/ZnO/Al2O3 (CZA) nanopowder with atomic ratio of 6:3:1. The effect of crystallization time (3, 6, 9, and 12 h) on physicochemical properties of nanopowder was investigated. Nanopowders were characterized using XRD, FESEM, EDX, FTIR, TG, and BET techniques. The XRD patterns confirmed metal oxides formation and their good crystallinity with average crystallite size of 20 nm as obtained by the Scherrer equation. Relative crystallinity was shown to increase with increasing crystallization time. In agreement with XRD results, FESEM images also illustrated nanosized particles. EDX mapping indicated homogenous dispersion of elements. BET specific surface area analysis showed acceptable surface area for CZA nanopowder. FTIR spectroscopy confirmed metal oxides formation during hydrothermal and calcination processing. TG results illustrated high thermal stability of the synthesized nanopowders. TG-DTG and FTIR analyses were used to propose a reaction mechanism for nanopowder formation during processing. Physicochemical characterization showed optimal crystallization time to be 6 h. 相似文献
108.
Yue Sun Mahsa Gharibi Marzancola Jonathan Lee Naveed Gulzar Jamie K. Scott 《Analytical letters》2019,52(5):839-851
A bioarray chip was developed for the rapid and sensitive detection of the antibody (Ab) in nanoliter volumes of biological fluids. The chip was used to detect the anti-hemagglutinin (anti-HA) Ab from mouse ascites fluids. On the bioarray chip, lanes of antigens (i.e., a 13-amino acid peptide, HA, that is bound by anti-HA Ab) were printed in one dimension on the chip surface. The antigens probed the protein samples (i.e., mouse anti-HA) obtained from biological fluids flowing in channels arranged in the perpendicular dimension. To determine if the detection sensitivity was increased by using different fluorescent labeling methods, two types of labeling reagents were compared, namely AlexaFluor 647-labeled goat anti-mouse Ab (AxIgG), and biotin-labeled anti-mouse Ab (BioIgG) followed by cyanine 5-tagged streptavidin (SA-Cy5). In addition, the assay procedure was shortened by omitting the reduction and blocking steps, while maintaining the sensitivity. In conclusion, a bioarray chip was adopted to detect as low as 10?pM mouse monoclonal antibody (anti-HA) in 500 nL of biological fluids (i.e., corresponding to 5 attomoles of antibody). Our results demonstrate that on-chip detection using this bioarray format is more sensitive and less time-consuming than traditional analyses. 相似文献
109.
Mahsa Fayazi 《Journal of Dispersion Science and Technology》2019,40(1):112-118
Two samples of nanostructured CuS were synthesized by two different methods, and were used for degradation of Bismarck Brown, as an azo dye. The first sample consists an assembly of nanosheets, and the second one has prolat-like spheroid structure. It is shown that CuS nanosheets have higher catalytic activity than the second sample for degradation of Bismarck Brown in the presence of H2O2. The catalytic activity of the CuS nanosheets was investigated by different variables such as reaction time, solution temperature, volume of H2O2, catalyst mass, dye concentration and presence of NaCl. CuS nanosheets have high degradation efficiency under mild conditions and in the dark medium. It was found that the rate of dye degradation by H2O2 is fast in the presence of CuS nanosheets, and most of the reactant molecules are degraded within 10?minute. As the main products of dye degradation by the CuS nanosheet, and in presence of H2O2 are CO2 and CO, it is a good catalyst for water purification. Another advantage of this catalyst is its reusability and recyclability, which maintains its stability after several cycles. Finally, the catalytic performance of CuS nanosheets was investigated for degradation of dye mixture (Bismarck Brown and Methyl violet). 相似文献
110.
Mojtaba Hadi Mahsa Bayat Hossein Mostaanzadeh Ali Ehsani Ali Yeganeh-Faal 《International journal of environmental analytical chemistry》2018,98(3):197-214
This study describes the utilisation of a glassy carbon electrode modified with a composite of multi-walled carbon nanotube and Cr-based metal-organic framework (MIL-101, Cr-BDC, BDC = 1,4-benzenedicarboxylate) for the sensitive, simple and fast voltammetric determination of picloram in environmental samples. Under optimum conditions, additions of picloram using square wave voltammetry showed linear ranges of picloram concentrations from 24.15 to 3018 µg?L?1 (0.1–12.5 μM) and from 3018 to 9658 µg?L?1 (12.5–40 μM) with a detection limit of 14.49 µg?L?1 (0.06 µM). The method was successfully applied to the determination of picloram in tap and river water samples spiked with picloram without any purification step by the standard addition method. The good recovery values obtained ranging from 97.5% to 105.0% revealed the reliability and accuracy of the method. 相似文献