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381.
Alaa A. Hassan Fathy F. Abdel‐Latif Ahmed M. Nour El‐Din Mohamed Abdel‐Aziz Sara M. Mostafa Stefan Bräse 《Journal of heterocyclic chemistry》2011,48(5):1050-1055
The reaction of 3‐(dicyanomethylene)‐2‐indolone in a solution of ethanol/piperidine with 4‐substituted thiosemicarbazides forms the derivatives of 5′‐(substituted amino)‐3′H–spiro(indoline‐3,2′‐[1,3,4]thiadiazol‐2‐one. Rationales for these conversions involving the nucleophilic addition on the dicyanomethylene carbon atom are presented. The prepared compounds were evaluated each for antidepressant activity using tail suspension behavioral despair test and anticonvulsant activity against pentylenetetrazol induced seizures in mice. J. Heterocyclic Chem., (2011). 相似文献
382.
2-(芳磺酰基)-1-(2-噻吩基)乙酮的合成丁言斌樊爱龙张正*(南京大学化学系南京210093)关键词氯噻吩基乙酮,芳磺酰基噻吩基乙酮,合成,相转移催化1996-08-12收稿,1997-01-13修回砜类化合物不仅是有机合成的有用中间体[1],而... 相似文献
383.
A. M. Al‐Sabagh M. R. Noor El‐Din N. M. Nassr Khaled M. Hussein M. S. Ezaat 《Journal of Dispersion Science and Technology》2013,34(8):1190-1196
The exploration and production activities of the natural gas in Abu Madi region (in middle delta) progressed in the last decade. The condensate hydrocarbon and formation water are bi‐products produced during the natural gas industry. The accompanied water contains 10–15% condensate (gasoline). This water with gasoline was drained into the Shehab El‐Din drain. The farmers were used this water to irrigate their fields. Great areas of the fields were out of order of planting as the result of gasoline pollution. This work concentrates on washing the polluted soil using locally prepared surfactant (LABSA‐Na) in the washing process. The soil sample was picked up from the Abu Madi field and was divided into pots (four pots for each treatment). The experiment was designed on the basis of polluting the soil by gasoline (condensate) from 1 to 10%. The washing process was carried out in presence of 0.1, 0.3, and 0.5% surfactant solutions. The control and blank sample were taken in consideration. The washed and the latent oil percentages were determined using the spectrophotometric method. After polluting and washing the soil, the pots were fertilized and planted by Zea Mays. The pots were irrigated twice a week. The length of plants was followed up. The obtained results cleared that, the efficiency of washing process increases with increasing of the pollutant percentage and also with increasing of surfactant concentration. The maximum washed oil (gasoline) was obtained at 10% gasoline and 0.5% surfactant concentration. The length of plants after 21 days of planting were; 0 (no planting), 24, 34, 39, 54, and 57 cm against polluted soil and planted (control) washed soil by water only; washed soil by 0.1%; washed soil by 0.3%; washed soil by 0.5% and no polluted soil (blank) respectively. These data revealed that, removing the hydrocarbon from the soil by washing using surfactants is the most effective method as the result of solubilization and emulsification of the hydrocarbon by surfactant which make it more removable. 相似文献
384.
Sibel Demir Muharrem Dinçer Alaaddin Çukurovali ibrahim Yilmaz 《International journal of quantum chemistry》2012,112(4):1016-1028
The title compound, N′‐benzylidene‐N‐[4‐(3‐methyl‐3‐phenyl‐cyclobutyl)‐thiazol‐2‐yl]‐chloro‐acetic acid hydrazide, has been synthesized and characterized by elemental analysis, IR, 1H and 13C NMR, and X‐ray single crystal diffraction. The compound crystallizes in the orthorhombic space group P 21 21 21 with a = 5.8671 (3) Å, b = 17.7182 (9) Å, and c = 20.6373 (8) Å. Moreover, the molecular geometry from X‐ray experiment, the molecular geometry, vibrational frequencies, and gauge‐including atomic orbital 1H and 13C chemical shift values of the title compound in the ground state have been calculated by using the Hartree–Fock and density functional methods (B3LYP) with 6‐31G(d) and 6‐31G(d,p) basis sets. The results of the optimized molecular structure are exhibited and compared with the experimental X‐ray diffraction. Besides, molecular electrostatic potential, Frontier molecular orbitals, and thermodynamic properties of the title compound were determined at B3LYP/6‐31G(d) levels of theory. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012 相似文献
385.
Feng‐Ju Lai Wei‐Nien Su Loka Subramanyam Sarma Dr. Din‐Goa Liu Cheng‐An Hsieh Jyh‐Fu Lee Dr. Bing‐Joe Hwang Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(15):4602-4611
The chemical dealloying mechanism of bimetallic Pt–Co nanoparticles (NPs) and enhancement of their electrocatalytic activity towards the oxygen reduction reaction (ORR) have been investigated on a fundamental level by the combination of X‐ray absorption spectroscopy (XAS) and aberration‐corrected scanning transmission electron microscopy (STEM). Structural parameters, such as coordination numbers, alloy extent, and the unfilled d states of Pt atoms, are derived from the XAS spectra, together with the compositional variation analyzed by line‐scanning energy‐dispersive X‐ray spectroscopy (EDX) on an atomic scale, to gain new insights into the dealloying process of bimetallic Pt–Co NPs. The XAS results on acid‐treated Pt–Co/C NPs reveal that the Co–Co bonding in the bimetallic NPs dissolves first and the remaining morphology gradually transforms to a Pt‐skin structure. From cyclic voltammetry and mass activity measurements, Pt–Co alloy NPs with a Pt‐skin structure significantly enhance the catalytic performance towards the ORR. Further, it is observed that such an imperfect Pt‐skin surface feature will collapse due to the penetration of electrolyte into layers underneath and cause further dissolution of Co and the loss of Pt. The electrocatalytic activity decreases accordingly, if the dealloying process lasts for 4 h. The findings not only demonstrate the importance of appropriate treatment of bimetallic catalysts, but also can be referred to other Pt bimetallic alloys with transition metals. 相似文献
386.
Under Minisci reaction conditions, nucleophilic carbon free radicals readily substitute ferrocene (as the ferricinium ion) and protonated acetophenone, the latter reaction being highly positionally specific. 相似文献
387.
Dr. Andreas Orthaber Dr. Henrik Löfås Dr. Elisabet Öberg Dr. Anton Grigoriev Dr. Andreas Wallner Dr. S. Hassan M. Jafri Dr. Marie‐Pierre Santoni Prof. Dr. Rajeev Ahuja Prof. Dr. Klaus Leifer Prof. Dr. Henrik Ottosson Prof. Dr. Sascha Ott 《Angewandte Chemie (International ed. in English)》2015,54(36):10634-10638
Acetylenic phosphaalkenes (APAs) are used as a novel type of ligands for the stabilization of gold nanoparticles (AuNP). As demonstrated by a variety of experimental and analytical methods, both structural features of the APA, that is, the P?C as well as the C?C units are essential for NP stabilization. The presence of intact APAs on the AuNP is demonstrated by surface‐enhanced Raman spectroscopy (SERS), and first principle calculations indicate that bonding occurs most likely at defect sites on the Au surface. AuNP‐bound APAs are in chemical equilibrium with free APAs in solution, leading to a dynamic behavior that can be explored for facile place‐exchange reactions with other types of anchor groups such as thiols or more weakly binding phosphine ligands. 相似文献
388.
Zusammenfassung Bei der Sorption von Ionen an einem regenerierten Ionenaustauscher steigt die Konzentration dieser Ionen im Effluent über einen großen Teil der sogenannten Durchbruchskurve logarithmisch an. Bei konstanter Strömungsgeschwindigkeit und Säulendimension ist der Anstiegq der logarithmisch aufgetragenen Durchbruchskurve von der Konzentration der Zulauflösung abhängig. Bei niederen Strömungsgeschwindigkeiten und geringen Konzentrationen konnte eine direkte Proportionalität zwischen demq-Wert und der Konzentration nachgewiesen werden. Bei höheren Konzentrationen (bzw. Strömungsgeschwindigkeiten) tritt eine Abweichung von der Linearität auf, die durch eine Eichkurve bestimmt werden kann. Für den Fall des Strontiums wurde die Aufnahme der Durchbruchskurven und die Bestimmung der Eichkurve demonstriert. An Hand der Eichkurvenwerte kann die Konzentration einer unbekannten Lösung ermittelt werden.Die Markierung der zu bestimmenden Lösungen mit Radionukliden und die dadurch ermöglichte Auswertung des Anstiegesq durch Aktivitätsmessung ist vorteilhaft. Die beschriebene Methode eignet sich vor allem für ein automatisches Analysenverfahren.
Nach einem Vortrag bei der Fachgruppentagung Radiochemische Arbeitsmethoden im Rahmen des VI. Internationalen Symposiums für Mikrochemie im September 1970 in Graz.
Wir möchten bei dieser Gelegenheit nicht versäumen, der Internationalen Atomenergie-Organisation (IAEA), Wien, für die Gewährung eines Forsehungsstipendmms in Österreich herzlich zu danken. 相似文献
Quantitative analysis by sorption on ion exchangers
Summary In the case of the sorption of ions by a regenerated ion exchanger, the concentration of these ions increases logarithmically in the effluent over a wide range of the break-through curve. At constant flow rate and column dimensions the slopeq of the logarithmically plotted break-through curve is dependent on the concentration of the applied solution. At low flow-rates and concentrations, a direct proportionality between theq values and concentration was found. At higher concentration (or flow rates) a deviation from linearity was observed, which can be determined by a standard curve. In the case of strontium the determination of break-through curves and the standard curve is demonstrated. Using the standard curve the concentration of unknown solutions can be determined.Labelling the solution to be examined with radionuclides is favourable, because it enables the determination of the slopeq by measuring the radioactivity of the effluent. The method described is especially suitable for an automatic analytical procedure.
Nach einem Vortrag bei der Fachgruppentagung Radiochemische Arbeitsmethoden im Rahmen des VI. Internationalen Symposiums für Mikrochemie im September 1970 in Graz.
Wir möchten bei dieser Gelegenheit nicht versäumen, der Internationalen Atomenergie-Organisation (IAEA), Wien, für die Gewährung eines Forsehungsstipendmms in Österreich herzlich zu danken. 相似文献
389.
An amperometric biosensor based on catalase enzyme for alcohol determination was developed. To construct the biosensor catalase was immobilized by using gelatin and glutaraldehyde on a Clark type dissolved oxygen (DO) probe covered with a teflon membrane which is sensitive for oxygen. The working principle of the biosensor depends on two reactions, which one is related to another, catalyzed by catalase enzyme. In the first reaction catalase catalyzes the degradation of hydrogen peroxide and oxygen is produced and also a steady-state DO concentration occurs in a few minutes. When ethanol added to the medium catalase catalyzes the degradation of both hydrogen peroxide and ethanol and this results in a new steady-state DO concentration. Difference for first and the last steady-state DO concentration occurred in the interval surface of DO probe membrane, which related to ethanol concentration, are detected by the biosensor. The biosensor response depends linearly on ethanol concentration between 0.05 and 1.0 mM with a detection limit of 0.05 mM and a response time of 3 min. In the optimization studies of the biosensor phosphate buffer (pH 7.0; 50 mM) and 35 °C were established as providing the optimum working conditions. In the characterization studies of the biosensor some parameters such as reproducibility, substrate specificity, operational and storage stability were carried out. Finally, by using the biosensor developed and enzimatic-spectrophotometric method alcohol concentration of some alcoholic drinks were determined and results were compared. 相似文献
390.
Approximate natural orbitals are determined iteratively from CI expansions constructed using first-order perturbation theory in order to investigate the possibility of eliminating the complete transformation of MO integrals on each iteration. Results on LiH and H2O are compared with fully variationally determined NO's to assess questions of convergence. 相似文献