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91.
Rotich A. Benson Nader M. A. Mohamed Mohamed Soliman Mohammed Hassan Mohsen A. Abou Mandour 《Journal of Radioanalytical and Nuclear Chemistry》2017,311(1):23-27
Rapid determination of gross alpha and beta emitters in urine by liquid scintillation counting is discussed. This method is based on direct addition of urine into scintillation cocktail. 241Am, 239Pu and 90Sr were selected as model radionuclides. The LSA Hidex 300 SL equipped with Triple-Double-Coincidence-Ratio technique was used for sample measurement. The work focused on optimizing the LSC cocktail to urine volume ratio with respect to the model radionuclides. The overall efficiencies for 241Am, 239Pu and 90Sr were greater than 92 %; therefore, this method would be suitable for rapid determination of gross alpha/beta activity. 相似文献
92.
Maghsoodlou Malek Taher Habibi-Khorassani Sayyed Mostafa Heydari Reza Hazeri Nourollah Sajadikhah Seyed Sajad Rostamizadeh Mohsen 《中国化学》2010,28(2):285-288
Synthesis of α‐amino phosphonates is described under solvent‐free conditions at 100°C from reaction between aldehydes and amines in the presence of trialkyl phosphites using Al(H2PO4)3 as an efficient and reusable heterogeneous catalyst. The advantages of this procedure are short reaction time, flexibility and having high to excellent yields. 相似文献
93.
Malek Taher Maghsoodlou Sayyed Mostafa Habibi-Khorassani Zahra Shahkarami Nariman Maleki Mohsen Rostamizadeh 《中国化学快报》2010,21(6):686-689
<正>2,2'-Arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) 4l-s produced from reaction between dimedone with various aldehydes in acetonitrile using ZnO as a catalyst;whereas in the presence of ZnO-acetyl chloride catalysts the reaction is limited to give only 1,8-dioxo-octahydroxanthenes 3a-k in very good yields. 相似文献
94.
Mohsen Nikpour Hossein Eshtiagh-Hosseini Masoud Mirzaei Amir Aghaei Kaju Soroush Zarinabadi 《中国化学快报》2010,21(4):501-505
<正>A unique ionic hybrid material[C_6H_(12)N_5O]_3[(PO_4)W__(12)O_(36)]·5H_2O has been synthesized from the reaction of((1H-tetrazole-5- yl)methyl)morpholine andα-H_3[(PO_4)W_(12)O_(36)]·21H_2O.It has successfully been characterized by elemental analysis,IR and ~1H NMR spectroscopies,TGA and single-crystal X-ray diffraction method.The title compound is constructed from the three [C_6H_(12)N_5O]~+ cations andα-Keggin[(PO_4)W_(12)O_(36)]~(3-) polyoxoanion.The most remarkable structural feature of this hybrid can be described as two-dimensional inorganic infinite plane-like(2D/∞)[(PO_4)W_(12)O_(36)]~(3-)) which forming via van der Waals interactions along the x axis. 相似文献
95.
Reza Karimi Shervedani Saied Mohsen Siadat‐Barzoki Mojtaba Bagherzadeh 《Electroanalysis》2010,22(9):969-977
A new sensor, gold‐6‐amino‐2‐mercaptobenzothiazole (6A2MBT), was fabricated via a self‐assembly procedure. Electrochemical properties of the monolayer were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The modified electrode showed excellent antifouling property against the oxidation products of DA, allowed us to construct a dynamic calibration curve with two linear parts, 1.00×10?6 to 3.72×10?4 and 3.72×10?4 to 6.42×10?4 M DA, with correlation coefficients of 0.997 and 0.992 and a detection limit of 1.57×10?7 M DA by using differential pulse voltammetry (DPV), respectively. Finally, the performance of the Au‐6A2MBT modified electrode was successfully tested for electrochemical detection of DA in a pharmaceutical sample. 相似文献
96.
Khodabakhsh Niknam Dariush Saberi Mohsen Sadegheyan Abdollah Deris 《Tetrahedron letters》2010,51(4):692-694
Silica-bonded S-sulfonic acid (SBSSA) is employed as a recyclable catalyst for the condensation reaction of aromatic aldehydes with 3-methyl-l-phenyl-5-pyrazolone. This condensation reaction was performed in ethanol under refluxing conditions giving 4,4′-alkylmethylene-bis(3-methyl-5-pyrazolones) in 75-90% yields. 相似文献
97.
98.
Haghighi MG Rashidi M Nabavizadeh SM Jamali S Puddephatt RJ 《Dalton transactions (Cambridge, England : 2003)》2010,39(47):11396-11402
The cyclometalated complexes [Pt(ppy)R(SMe(2))] or [Pt(bhq)R(SMe(2))], where ppyH = 2-phenylpyridine, bhqH = benzo[h]quinoline and R = methyl or p-tolyl, react with bis(diphenylphosphino)ethane, dppe, in a 1:1 ratio to give the corresponding complexes [Pt(κ(1)-C-ppy)R(dppe)] or [Pt(κ(1)-C-bhq)R(dppe)], in which the ppy or bhq ligands are monodentate and dppe is chelating. The similar reaction in a 2:1 ratio gives the binuclear complexes [{Pt(ppy)R}(2)(μ-dppe)] or [{Pt(bhq)R}(2)(μ-dppe)], in which the dppe ligands are in the unusual bridging bidentate bonding mode. 相似文献
99.
100.
Anina Wöhl Dr. Wolfgang Müller Dr. Stephan Peitz Normen Peulecke Dr. Bhaskar R. Aluri Dr. Bernd H. Müller Dr. Detlef Heller Dr. Uwe Rosenthal Prof. Dr. Mohammed H. Al‐Hazmi Dr. Fuad M. Mosa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(26):7833-7842
In this paper we report the results of an extensive experimental kinetic study carried out on the novel ethylene trimerization catalyst system, comprising the chromium source [CrCl3(thf)3] (thf=tetrahydrofuran), a Ph2P‐N(iPr)‐P(Ph)‐N(iPr)H (PNPNH) ligand (Ph=phenyl, iPr=isopropyl), and triethylaluminum (AlEt3) as activator. It could be shown that the initial activity shows a first‐order dependency on the ethylene concentration. Also, a first‐order dependency was found for the catalyst concentration. The initial activity follows a typical Arrhenius behavior with an experimentally determined activation energy of 52.6 kJ mol?1. At elevated temperatures (ca. 80 °C), a significant deactivation was observed, which can be tentatively traced back to a ligand rearrangement in the presence of AlEt3. After a fast initial phase, a pronounced ‘kink’ in the ethylene‐uptake curve is observed, followed by a slow, almost linear, further increase of the total ethylene consumption. The catalyst composition, in particular the ligand/chromium and the cocatalyst/chromium molar ratio, has a strong impact on the catalytic performance of the trimerization of ethylene. 相似文献