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51.
Hamid Sepehrian Syed Javad Ahmadi Syed Waqif‐Husain Ahmad Reza Zolfaghari‐Daryani Mortaza Azadmousavi 《中国化学》2010,28(4):561-566
A new adsorbent, modified mesoporous lanthanum(III) silicate, has been prepared with various molar ratios of Si/La (10, 20, 40, 80) and cethyltrimethylammonium bromide (CTAB) as structure directing agent. XRD, nitrogen sorption, SEM, IR, thermogravimetry and sorption of radionuclides and toxic metal ions have been studied. The results show that adsorption amount of some element such as Pb(II) and Th(IV) has been increased significantly by incorporation of lanthanum ions in the framework of adsorbent. Separation of Co(II)‐Th(IV), Co(II)‐U(VI) and Mo(VI)‐U(VI) has been developed on columns of this adsorbent. 相似文献
52.
Kalbasi Roozbeh Javad Massah Ahmad Reza Zamani Farzad Javaherian Naghash Hamid 《中国化学》2010,28(3):397-403
TiO2‐ZrO2 (1/1)‐surf with Ti and Zr molar ratio of 1/1 was prepared with surfactant through a sol‐gel method. The optimum experimental condition was investigated for nitration of salicylic acid. Then, a number of nitration reactions were carried out with a variety of aromatic compounds in the optimum condition. The 25 wt% H3PO4/TiO2‐ZrO2 (1/1)‐surf catalyst showed good selectivity and yield in a short time for the nitration of salicylic acid and some other aromatic compounds. 相似文献
53.
Comparative study of kinetic modeling for the oxidative coupling of methane by genetic and marquardt algorithms 总被引:1,自引:0,他引:1
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Overall kinetic studies on the oxidative coupling of methane, OCM, have been conducted in a tubular fixed bed reactor, using perovskite titanate as the reaction catalyst. The appropriate operating conditions were found to be: temperature 750-775 ℃, total feed flow rate of 160 ml/min, CH4/O2 ratio of 2 and GHSV of 100 min-1. Under these conditions, C2 yield of 28% was achieved. Correlations of the kinetic data have been performed with lumped rate equations for C2 and COx formation as functions of temperature, O2 and CH4 partial pressures. Six models have been selected among the common lumped kinetic models. The selected models have been regressed with the experimental data which were obtained from the Catatest system by genetic algorithm in order to obtain optimized parameters. The kinetic coefficients in the overall reactions were optimized by different numerical optimization methods such as: the Levenberg-Marquardt and genetic algorithms and the results were compared with one another. It has been found that the Santamaria model is in good agreement with the experimental data. The Arrhenius parameters of this model have been obtained by linear regression. It should be noted that the Marquardt algorithm is sensitive to the first guesses and there is possibility to trap in the relative minimum. 相似文献
54.
Javad Safaei-Ghomi Tayebeh Ahmadi Hossein Batooli 《Chemistry of Natural Compounds》2010,46(5):816-818
55.
Amir Reza Jalilian Mahdokht Jouiaei Alireza Doroudi Javad Garousi Sedigheh Moradkhani 《Journal of Radioanalytical and Nuclear Chemistry》2010,285(3):555-561
In this work, recently prepared 67Ga-labeled glucagon (67Ga-DTPA-GCG) for imaging studies (radiochemical purity >94%; HPLC, S.A. 296–370 GBq/mM) was used in biological studies. The wild-type rat biodistribution results, 2 h post injection, demonstrated high tissue:muscle ratios for target tissues (liver, kidney, heart, spleen, fat intestine stomach and pancreas), 234, 18.45, 7.12, 1.75, 128.7, 4.9, 6.3 and 1.11, respectively. The tracer binding capacity using freshly prepared rat brain homogenate demonstrated significant specific binding of the tracer to neuronal GCG receptors (67Ga-DTPA-GCG/67Ga:3 and 67Ga-DTPA-GCG/67GaDTPA:2.2 at 90 min). SPECT images also demonstrated target specific binding of the tracer at 4 h. The data suggests the tracer is accumulated in GCGR rich tissues 2–4 h post injection, suggesting potentials of the tracer for future imaging studies in glocagonoma models. 相似文献
56.
A. A. Karimi Zarchi N. Mokhtari M. Arfan T. Rehman M. Ali M. Amini R. Faridi Majidi A. R. Shahverdi 《Applied Physics A: Materials Science & Processing》2011,103(2):349-353
In this study a sunlight-induced method for rapid synthesis of silver nanoparticles using an ethanol extract of Andrachnea chordifolia is described. The silver nitrate solutions (1 mM) containing the ethanol extract of Andrachnea chordifolia were irradiated by both sunlight radiation and by sunlight radiation passed through different colored filters (red, yellow
or green). The smallest size of silver nanoparticles was obtained when a silver ion solution was irradiated for 5 minutes
by direct sunlight radiation. Further examination of the shape and size and of the surface chemistry of these biogenic silver
nanoparticles, which were prepared under sunlight radiation, was carried out using transmission electron microscopy and infrared
spectroscopy, respectively. Transmission electron microscopy images show spherical particles with an average size of 3.4 nm.
Hydroxyl residues were also detected on the surface of these biogenic silver nanoparticles fabricated using plant extract
of Andrachnea chordifolia under sunlight radiation. Our study on the reduction of silver ions by this plant extract in darkness shows that the synthesis
process can take place under dark conditions at much longer incubations (48 hours). Larger silver polydispersed nanoparticles
ranging in size from 3 to 30 nm were obtained when the silver ions were treated with the ethanol extract of Andrachnea chordifolia under dark conditions for 48 hours. 相似文献
57.
Javad Sharifi 《Physics letters. A》2011,375(3):522-528
The quantum trajectory renders the optimal estimation of quantum state. It is a classical Itô stochastic differential equation. The Lyapunov global stabilization problem is solved for squeezed noise quantum trajectory. Lyapunov control stabilizes the quantum system toward one eigenstate. A two-level bistable quantum system is simulated as an example. 相似文献
58.
Robabeh Baharfar Mohammad Javad Taghizadeh Majid Ahmadian Seyed Meysam Baghbanian 《中国化学快报》2010,21(2):175-178
<正>The addition of 2,4-dihydroxyaceto(and benzo)phenone to propiolic ester is catalyzed by triphenylphosphine or tert-butyl isocyanide to form O-vinyl aryl derivatives in fairly good yields. 相似文献
59.
M. G. Dekamin N. Yazdaninia J. Mokhtari M. R. Naimi-Jamal 《Journal of the Iranian Chemical Society》2011,8(2):537-544
Tetrabutylammonium phthalimide-N-oxyl (TBAPINO) was found to be an effective organocatalyst for rapid, simple and chemoselective protection of the hydroxyl group of alcohols and phenols using hexamethyldisilazane (HMDS) under mild conditions. The low catalyst loading, high to quantitative yields and simple removal of the catalyst from the reaction mixture illustrate the other attractive features of this protocol. 相似文献
60.
Using Auslander’s G-dimension, we assign a numerical invariant to any group Γ. It provides a refinement of the cohomological dimension and fits well into the well-known hierarchy of dimensions assigned already to Γ. We study this dimension and show its power in reflecting the properties of the underlying group. We also discuss its connections to relative and Tate cohomology of groups. 相似文献