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351.
V. Parthasarathy S. K. Sarkar N. V. Iyer K. V. S. Rama Rao J. P. Mittal 《Applied physics. B, Lasers and optics》1993,56(5):321-325
IR laser chemistry of (CF3Br/Cl2) mixture and neat CF2HCl are examined in the context of 13C enrichment. Decomposition extent, enrichment factor and energy absorbed are measured for both systems at their respective optimum conditions. A direct comparison is obtained by keeping extraneous factors such as laser, its pulse duration, cell, irradiation geometry etc. the same. The halogen scavenged CF3Br MPD requires lower fluence compared to neat CF2HCl irradiation. Overall throughput for a product with 60–65% 13C content in a single stage is the same for both systems requiring a similar amount of energy. However, at lower enrichment levels, CF2HCl MPD is better than (CF3Br/Cl2) photolysis in terms of both product yield and energy absorption. 相似文献
352.
Ashok Mittal Virpal Singh K. D. Nayak 《International Journal of Infrared and Millimeter Waves》1999,20(10):1803-1808
This paper describes the design and development of Integrated Finline Trans-receiver at Ka-Band. Integrated trans-receiver has been designed for Simplex Voice Communication System. The trans-receiver includes a modulator, duplexer and a mixer integrated together on a single substrate RT Duroid 5880. Two Millimeter Wave Gunn sources, one as transmit source and the other one as Local Oscillator source, in Waveguide are connected externally. The system has been realised and tested with the integrated trans-receiver unit for ASK voice Communication System for a range of 2.5 KM LOS. The system is highly useful for short-range communication systems such as Hand-held Millimeter Wave Radio. 相似文献
353.
K. P. Madhusudanan Raka Jain Shubhra Mittal Susheel Durani R. S. Kapil 《Journal of mass spectrometry : JMS》1986,21(12):781-784
From a study of the reactions of nucleophiles with 1,2,3-triaryl-propenones and-butenones in a chemical ionization source it has been found that stronger nucleophiles, such as, MeO?, EtO? and MeS?, attack the α,β-unsaturated system at the β-carbon (Michael addition) or the carbonyl carbon giving rise to tetrahedral adducts, while weaker nucleophiles, such as, Cl? form the adduct ion by H-bonding with the β-hydrogen. The effect of substituents and source temperature supports the operation of these processes. The triaryl butenone did not give the adduct ion with MeO? as deprotonation leads to a stable [M ? H]? ion. 相似文献
354.
Jérôme JP. Leon 《Letters in Mathematical Physics》1981,5(1):75-80
We establish a transformation which connects the potentials of the one-dimensional Dirac and Klein-Gordon operators. This transformation links the solutions of the nonlinear evolution equations solvable by means of the two inverse spectral transforms which use the Dirac and Klein-Gordon direct and inverse spectral problems. 相似文献
355.
356.
Zusammenfassung Durch potentiometrische und konduktometrische Titrationen wird die genaue Zusammensetzung des Komplexes untersucht, der sich aus Thallium(I) und -Mercaptopropionsäure in wäßriger 0,1m-KNO3-Lösung bildet. Es zeigt sich, daß Thallium nur einen einzigen Komplex bildet. Er ist farblos, hat die Molzusammensetzung 11 und liegt besonders im pH-Bereich 9,0–10,5 vor. Durch Anwendung der vonCalvin undMelchior erweiterten Meßmethode vonBjerrum wird für drei verschiedene Temperaturen der Wert der Komplexbildungskonstante bestimmt. Als Werte für logK ergaben sich bei 20° 2,775, bei 30° 2,850 und bei 40° 2,935. Die Werte der thermodynamischen Zustandsfunktionen berechnen sich für die Komplexbildung zu G=–3,95 kcal/Mol, H=–3,34 kcal/Mol und S=+2,01 cal/grad.
Mit 3 Abbildungen 相似文献
The precise nature of the complex formation between Thallium(I) and -mercaptopropionic acid in aqueous 0.1M-KNO3 has been investigated by potentiometric and conductometric titration techniques. It was found that Tl(I) forms only one, 11, colourless complex predominating at pH 9.0–10.5. The stability constant of the complex has been determined by applyingCalvin andMelchior's extention ofBjerrum's method at three different temperatures. The logK values were found to be 2.775, 2.850 and 2.935 at 20, 30 and 40° C respectively. The thermodynamic functions of complexation, G, H and S were also evaluated at 30° C and found to be –3.95 K-cal/mole, –3.34 K-cal/mole and +2.01 Cal/deg. respectively.
Mit 3 Abbildungen 相似文献
357.
M. A. Palafox V. K. Rastogi Lalit Mittal W. Kiefer H. P. Mital 《International journal of quantum chemistry》2006,106(8):1885-1901
Geometry, vibrational wavenumbers, and several thermodynamic parameters have been calculated using ab initio quantum chemical methods for the 3‐aminobenzonitrile molecule for the first time. The results were compared with experimental values. With the help of specific scaling procedures, the observed vibrational wavenumbers were analyzed and assigned to different normal modes of the molecule. In general, the error obtained was very low. Using potential energy distribution (PED), the contributions of the different modes to each wavenumber were determined. Other general conclusions were also deduced. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 相似文献
358.
The transient optical absorption bands formed at λmax=340 and 435 nm, on reaction of √OH radicals in aerated acidic aqueous solutions of 1,1,1-trifluoro-2-iodoethane at low and high solute concentration, have been assigned to monomer and dimer radical cations, respectively. The deprotonation of the solute radical cations is the rate-determining step for the decay of the dimer radical cations. The stability constant for the dimer radical cation is determined to be 50 dm3 mol−1 at 25°C. The dimer radical cation is a strong one-electron oxidant. Quantum chemical calculations and experimental results confirm that fluorine reduces the electron density at iodine and the √OH-radical-induced oxidation of fluoroiodoalkanes becomes a difficult process compared to iodoalkanes. 相似文献
359.
In an attempt to synthesise azuleno[2,1-a]azulene (1), Cu+ ion-catalysed reaction of diazomethane with 3,6,7,8-tetrahydrodibenzopentalene (4) has been investigated. Addition occurred to only one of the aromatic rings to give chiefly 1,2-benzo-4,5-cycloheptatrieno-3,6,7,8-tetrahydropentalene (13/14). Dehydrogenation of 13/14 to 11H-indeno[2.1-a]azulene has been carried out. 相似文献
360.
P. K. R. Nair A. Mittal S. V. Kadamne K. Srinivasulu 《Reaction Kinetics and Catalysis Letters》1982,19(1-2):201-205
Oscillatory behavior in the uncatalyzed aqueous acidic bromate oxidation of 3,4-dimethoxybenzaldehyde (veratraldehyde) is reported. The generally used H2SO4 can be substituted by HNO3, HClO4, CCl3 COOH and H3PO4 in this system. The length of the induction period is found to be dependent on the initial concentrations of the reagents and this effect is more prominent in the case of acidity. The precipitate accumulated in the reaction during oscillations has been identified. A plausible mechanism is also suggested. Experiments with allyl alcohol, a bromine scavenger, suggest that elemental bromine formed in the reaction has a role in the mechanism together with or besides bromide inons.
3,4- () . H2SO4 HNO3, HClO4, CCl3 COOH H3PO4 . . , , . . , , , , , .相似文献