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21.
H-ZSM5 is applied as an efficient, highly reusable, and heterogeneous catalyst for the oxidation of sulfides to sulfoxides using 30% H2O2 under solvent-free conditions at room temperature. A variety of aromatic and aliphatic sulfides with different functional groups were successfully oxidized with good to excellent yields in short reaction times. The catalyst can be easily recovered by simple filtration and recycled for several consecutive runs without any significant loss of its catalytic activity. 相似文献
22.
Nitrogen doped nano porous graphene was used as an efficient sorbent in solid‐phase extraction process for simultaneous separation and pre‐concentration of metal ions lead (II), cadmium(II), and chromium(III)) in biological samples. Ultrasonic assisted in‐syringe dispersive micro solid phase extraction coupled with micro sampling atomic absorption spectrometry was utilized for the determination of metal ions. Nitrogen doped nano porous graphene was synthesized as a nano sorbent by chemical vapour deposition method. Methane and aniline were used as carbon and nitrogen sources. The characterization of sorbent was performed by field emission scanning electron microscope, transmission electron microscopy, atomic force microscope, fourier transform infrared, chemical element analysis and raman analysis. Effective parameters on the extraction efficiency such as pH, sorbent dosage, eluent volume and eluent concentration were optimized by central composite design and desirability function. Experimental results indicate that the optimal conditions for this extraction were pH = 6.4, 1.42 mg of sorbent, 100 μL of eluent, and 0.84 mol L‐1 of eluent concentration. The detection limits are as low as 1.5, 0.3 and 0.9 μg L‐1 for lead, cadmium, and chromium, respectively. The intra‐day precisions were 3.6, 4.38 and 2.94 and Inter‐day precision were 4.83, 5.26 and 4.52 for lead, cadmium, and chromium, respectively. Method performance was investigated by determination of mentioned heavy metals in complicated biological matrixes such as human plasma, urine and saliva samples with good recoveries. 相似文献
23.
Zeinab Ansari-Asl Tahereh Sedaghat Abbas Tarassoli Hossein Motamedi Elham Hoveizi 《Phosphorus, sulfur, and silicon and the related elements》2017,192(5):538-543
Three new water-soluble organotin complexes R2Sn(5-BrSalGT)Cl [R = Ph, Me] and Ph2Sn(2-OHNaphGT)Cl have been synthesized by the reaction of R2SnCl2 (R = Ph or Me) with Schiff bases derived from condensation of Girard-T reagent with 5-bromosalicylaldehyde and 2-naphthaldehyde, (5-BrH2SalGT)Cl (1) and (2-OHH2NaphGT)Cl (2). The synthesized compounds have been investigated by elemental analysis, conductometric measurements, IR, 1H NMR, and 119Sn NMR spectroscopy. These data show that the deporotonated ligand is coordinated to Sn(IV) via ONO atoms and six-coordinate zwitterionic complexes are formed. The ligands and their complexes were investigated for their in vitro toxicity against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. The results show remarkable antibacterial activity against the studied bacteria. All complexes exhibit more inhibitory effects than the parent ligand. The anticancer activity of all compounds were also performed on HN5 cell line and (2-OHH2NaphGT)Cl with concentration of 1 mg mL?1 was found to show higher anticancer activity than other compounds. 相似文献
24.
Mehdi Rimaz Hossein Mousavi Laya Nikpey Behzad Khalili 《Research on Chemical Intermediates》2017,43(7):3925-3937
25.
Song and Mason equation of state (EOS) with a simple modification has been extended to modelling PVT properties of ionic liquids (ILs). The considered ILs are [C1mim][MeSO4], [C1mim][CH3OC2H5SO4], [C1mim][(CH3)2PO4], [C2mim][MeSO4], [C2mim][BF4], [C2mim][SCN], [C2eim][NTf2], [C4mim][C(CN)3], [C4mim][CF3SO3], [C4mim][SCN], [C5mim][NTf2], [C8mim][NTf2], [(C6H13)3P(C14H29)][Cl], [(C6H13)3P(C14H29)][NTf2], [(C6H13)3P(C14H29)][Ac], [C3mpyr][NTf2], [C4mpyr][NTf2] and [Py][C2H5OC2H4SO4]. Three temperature-dependent parameters in the proposed EOS have been scaled as functions of reduced temperature with the use of the law of corresponding states. It is shown that the knowledge of just critical temperature and critical density is sufficient to predict the PVT properties of these ILs. The overall average absolute deviation of calculated densities from literature values for 1347 data points of 18 ILs was found to be 0.58%. The predicted density of ILs from proposed EOS has been compared with those obtained by other literature work. Moreover, we indicate that the Zeno line regularity can well be predicted by proposed model for ILs. 相似文献
26.
Welch K Mousavi S Lundberg B Strømme M 《The European physical journal. E, Soft matter》2005,18(1):105-112
A newly developed method for determining the frequency-dependent complex Young's modulus was employed to analyze the mechanical
response of compacted microcrystalline cellulose, sorbitol, ethyl cellulose and starch for frequencies up to 20 kHz. A Debye-like
relaxation was observed in all the studied pharmaceutical excipient materials and a comparison with corresponding dielectric
spectroscopy data was made. The location in frequency of the relaxation peak was shown to correlate to the measured tensile
strength of the tablets, and the relaxation was interpreted as the vibrational response of the interparticle hydrogen and
van der Waals bindings in the tablets. Further, the measured relaxation strength, holding information about the energy loss
involved in the relaxation processes, showed that the weakest material in terms of tensile strength, starch, is the material
among the four tested ones that is able to absorb the most energy within its structure when exposed to external perturbations
inducing vibrations in the studied frequency range. The results indicate that mechanical relaxation analysis performed over
relatively broad frequency ranges should be useful for predicting material properties of importance for the functionality
of a material in applications such as, e.g., drug delivery, drug storage and handling, and also for clarifying the origin of hitherto unexplained molecular processes. 相似文献
27.
A new colorimetric method for the determination of carboxylic acids using bromocresol green reagent is established. The formed color follows Beer's Lambert law and is stable for 24 hr. The method is successfully applied for measuring the disappearance of volatile fatty acids in P. oxalicum culture media. The method is reproducable and is used also for the quantitative determination of carboxylic acids in Dowex 1-X8 eluates. A linear relationship between the pK1 of different carboxylic acids and the calculated molar extinction coefficients of the color formed at 440 nm is demonstrated. 相似文献
28.
René Carmona Jean-Pierre Fouque Seyyed Mostafa Mousavi Li-Hsien Sun 《Journal of Optimization Theory and Applications》2018,179(2):366-399
We propose a model of inter-bank lending and borrowing which takes into account clearing debt obligations. The evolution of log-monetary reserves of banks is described by coupled diffusions driven by controls with delay in their drifts. Banks are minimizing their finite-horizon objective functions which take into account a quadratic cost for lending or borrowing and a linear incentive to borrow if the reserve is low or lend if the reserve is high relative to the average capitalization of the system. As such, our problem is a finite-player linear–quadratic stochastic differential game with delay. An open-loop Nash equilibrium is obtained using a system of fully coupled forward and advanced-backward stochastic differential equations. We then describe how the delay affects liquidity and systemic risk characterized by a large number of defaults. We also derive a closed-loop Nash equilibrium using a Hamilton–Jacobi–Bellman partial differential equation approach. 相似文献
29.
Mohammad Abbasi Mohammad Reza Mohammadizadeh Zeinab Khatoon Taghavi 《Journal of the Iranian Chemical Society》2013,10(2):201-205
An efficient and odorless synthesis of disulfides from alkyl halides using thiourea and elemental sulfur in the presence of sodium carbonate in wet polyethylene glycol (PEG 200) at 40 °C without contamination by higher polysulfides has been developed. This procedure was then extended to preparation of disulfides from alkyl tosylates at 70 °C. 相似文献
30.
Seyyed Mahmoud Mousavi Hamed Tavakoli Mohammad Samadfam Fatemeh Semnani Zahra Asadi Hamid Sepehrian 《Research on Chemical Intermediates》2013,39(3):951-959
Adsorption and recovery of uranium by nanoporous MCM-41 from aqueous solutions (synthetic solution and uranium conversion facility liquid waste) were investigated by use of a fixed-bed column (1.2 cm diameter and 3.0 cm height). Adsorption was carried out at flow rates 0.2 and 0.5 mL min?1, which correspond to retention times of 10 and 6 min. The maximum breakthrough capacity for uranium ions was achieved by use of nanoporous MCM-41 at the optimum pH of 3.6 and flow rate 0.2 mL min?1 (61.95 μg g?1). The Thomas and Yan models were applied to the experimental data, by use of linear regression, to determine the characteristics of the column for process design. The breakthrough curves calculated from the models were in good agreement with the experimental data. The elution behavior of uranium on nanoporous MCM-41 was studied with different eluents; the results showed that 0.1 M HCl is good eluent for uranium recovery. The regenerated column could be used in a multitude of adsorption–desorption cycles. 相似文献