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771.
This paper presents an investigation of the resonant excitation of the electrostatic ion cyclotron wave at the difference frequency of two microwave beams propagating in a magnetoactive solid state plasma, viz. n InSb. The resonant excitation of the electrostatic ion cyclotron wave occurs when the difference frequency of the two microwave beams and the difference of their propagation vectors satisfy the dispersion relation corresponding to the electrostatic ion cyclotron wave. For typical plasma parameters of n InSb and microwave beams of power densities 1 MW cm?2, the power density of the excited ion cyclotron wave is 0.40 kW cm?2 when external magnetic field is . The power density of the excited ion cyclotron wave increases with the magnetic field. This study may provide new means for the characterisation and diagnostic of semiconductors. 相似文献
772.
Baburaj Baskar N. Ganesh Pandian Kuttikode Priya Anju Chadha 《Tetrahedron: Asymmetry》2004,15(24):3961-3966
Enantioselective bioreduction of alkyl 2-oxo-4-arylbutanoates and 2-oxo-4-arylbut-3-enoates mediated by Candida parapsilosis ATCC 7330 resulted in the formation of the corresponding (S)-2-hydroxy compounds in high enantiomeric excesses (93–99%) and good isolated yields (58–71%). The absolute configuration of enantiomerically pure ethyl 2-hydroxy-4-(p-methylphenyl)but-3-enoate obtained by the reduction of the corresponding keto ester was assigned by 1H NMR using Mosher’s method. 相似文献
773.
Solid state synthesis of tungsten carbide nanorods and nanoplatelets by a single-step pyrolysis 总被引:3,自引:0,他引:3
We report a simple and efficient single-step synthesis of tungsten carbide nanorods and nanoplatelets by direct pyrolysis of a hybrid composite material of 12-tungstophosphoric acid and hexadecyltrimethylammonium bromide in a closed Swagelok cell at 1000 degrees C. The product was characterized by XRD, TGA, SEM, TEM, XPS, and CV. The diameter of the nanorods is 30-50 nm, and the length varies from 200 to 500 nm. The size of the platelets is around 55 nm. The WC exhibits an interesting structural surface with kinks, steps, and terraces which is evidenced by HRTEM studies. 相似文献
774.
Gourishankar A Shukla S Ganesh KN Sastry M 《Journal of the American Chemical Society》2004,126(41):13186-13187
An isothermal titration calorimetric (ITC) investigation of the interaction of DNA bases and PNA base monomers with gold nanoparticles is described revealing a binding sequence in the order C > G > A > T. Direct measurement of the strength of interaction of ligands with nanogold by ITC has important implications in surface modification strategies for biomedical, catalysis, and nanoarchitecture applications. 相似文献
775.
A novel method for synthesizing hitherto unreported 3,4-dihydropyrimidin-2(1H)-ones (DHPMs) through 1,4-addition of nucleophiles on pyrimidin-2(1H)-ones is disclosed herein. 相似文献
776.
777.
P. Shanmugam P. Lakshminarayana R. Palaniappan 《Monatshefte für Chemie / Chemical Monthly》1973,104(3):633-639
Zusammenfassung Synthesen von4-Methylfuro[2,3-b]chinolin und seinen Analogen, ausgehend von den entsprechenden 3-Vinyl-2-chinolonen, werden beschrieben.
Folgende Arbeiten zählen als 1. bis 4. Mitt. dieser Veröffentlichungsreihe: Proc. Indian Acad. Sci.52, 75 (1960);54, 161 (1961);55, 227 (1962); Z. Naturforsch.27 b, 474 (1972). 相似文献
Synthesis of 4-methylfuro[2.3-b]quinoline and its analogues. Furoquinolines, part V
The syntheses of 4-methyl furo[2.3-b]quinoline and its analogues starting from the appropriate 3-vinyl-2-quinolone are described.
Folgende Arbeiten zählen als 1. bis 4. Mitt. dieser Veröffentlichungsreihe: Proc. Indian Acad. Sci.52, 75 (1960);54, 161 (1961);55, 227 (1962); Z. Naturforsch.27 b, 474 (1972). 相似文献
778.
Two tetrapeptide derivatives [peptide A (Boc–Ala–Ile–Ile–Gly–OMe) and peptide B (Boc–Ala–Ile–Leu–Ser–OMe)], that take helical turn conformation in solution, were shown to form monolayer at the air/water interface. Circular dichroism (CD) measurements indicate that peptide A has more helical turn propensity than peptide B in sodium dodecyl sulphate (SDS) micelles. Langmuir–Blodgget film study of peptides A and B suggest that both the peptides form stable monolayer at the air/water interface. Spectroscopic investigations reveal that peptide A forms helical turn assemblage on transferring the film into hydrophilic quartz and hydrophobic ZnSe surfaces. Whereas, peptide B adopts β-sheet structure on hydrophilic surface and a mixture of β-sheet and helical turn conformation on hydrophobic surface. 相似文献
779.
Dr. P. Shanmugam T. K. Thiruvengadam K. Ramasamy 《Monatshefte für Chemie / Chemical Monthly》1977,108(3):725-733
A new route to furo[2,3-b]quinolines has been developed based on the use of N-arylaconamides as starting materials. These anilides when heated with polyphosphoric acid, readily underwent intramolecular cyclization to furnish the respective 1,2-dihydro-2-oxo-quinoline-3-acetic acids which were then transformed into the corresponding dihydrofuro[2,3-b]quinolines by literature procedures. Sequential treatment of the dihydro compound withNBS andDBU afforded the corresponding furo[2,3-b]quinoline. The NMR spectra of the furoquinolines are discussed.
Mitt.: siehe Lit. 相似文献
Mitt.: siehe Lit. 相似文献
780.
Vaidya Vikas V. Menon Sasikumar N. Singh Ganesh R. Kekare Maharudra B. Choukekar Milind P. 《平面色谱法杂志一现代薄层色谱法》2007,20(2):145-147
JPC – Journal of Planar Chromatography – Modern TLC - An HPTLC method for simultaneous determination of clotrimazole and tinidazole in a pharmaceutical formulation has been developed... 相似文献