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101.
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103.
The frequency of radiation from Ta(superconducting)-Al(normal) point contacts has been measured as a function of temperature. The dependence agrees with the Bardeen-Cooper-Schrieffer (BCS) gap equation for Ta. 相似文献
104.
Leopold Jirovetz Alexej Nikiforov Gerhard Buchbauer Dieter Braun 《Mikrochimica acta》1989,99(1-2):1-6
The results of the densitometric and the capillary gas chromatographic investigations of numerous lavender oils of different origin and of essential oils of the woody group were correlated. Especially the main components, the monoterpenes linalool (¯1) and linalyl acetate (¯2), were quantified by densitometry with an average standard deviation of 6–7% in the examined oils. The use of TLC in combination with densitometry in the quantification of the main components to essential oils is thus a valuable addition to capillary gas chromatographic investigation. In addition to this, a useful and efficient alternative is given to groups specialized in TLC/densitometry to obtain data on such volatile compounds of essential oils during quantification. The use of TLC/densitometry thus combines the advantage of LC-with detection of also less volatile compounds—and the possibility of the parallel investigation of more samples in one step in a very efficient way. 相似文献
105.
We study the parity-violating neutral current effects in muonic atoms which might result from an interference between E1 and E2 amplitudes in 3D → 1S transitions. We conclude that polarization asymmetries may be measurable in heavy atoms (Z ~ 70) exhibiting large nuclear deformations. 相似文献
106.
Characteristics of p-terphenyl and PBD, the most efficient uv dyes, have been investigated under high intensity pumping by a multi-atmosphere KrF1 discharge laser at 248 nm wavelength. Energy conversion efficiencies, spectral features and temporal behaviour of the dyes were studied parametrically. A maximum powerof 2 MW uv emission with a bandwidth of ~2×10-2 nm was obtained for PBD. It was found that a mixture of both dyes provided higher (by a factor of 1.3) output in the range 348–366 nm than either of the dyes alone. Significant pump intensity dependent conversion efficiency and pulse shape variations were observed for the most efficient uv dye, p-terphenyl and were related to triplet-triplet adsorption processes in the dye. 相似文献
107.
Leopold Laitem Leon Christiaens Marcel Renson 《Magnetic resonance in chemistry : MRC》1980,13(5):319-322
An important 13C NMR shielding effect on carbons bearing a heavy chalcogen is demonstrated. This effect is parallel to that induced by iodine, but to a lesser extent. For acyclic compounds and for partially saturated heterocycles, there is an excellent linear correlation between the 13C chemical shifts of carbons bearing a chalcogen and carbons bearing a halogen atom in the corresponding compound. The linearity of the relationship is less satisfactory with heteroaromatic compounds. 相似文献
108.
A new phthalic acid ester 1,2-benzenedicarboxylic acid bis(2S-methyl heptyl) ester (1) was isolated from the hexane extract of the whole plant of Ajuga bracteosa. In addition, chloroform and methanol extracts yielded neo-clerodane diterpene ajugarin-I and two iridoid glycosides, reptoside and 8-O-acetyl harpagide. The structures of all the compounds were confirmed by extensive spectroscopic analysis. From the two oily fractions nine and six volatile constituents respectively were identified by GCMS. Linalyl acetate was found to be common in both the oil fractions. This plant is a new source of linalyl acetate, a valuable perfumery compound. 相似文献
109.
Brauer CS Craddock MB Kilian J Grumstrup EM Orilall MC Mo Y Gao J Leopold KR 《The journal of physical chemistry. A》2006,110(33):10025-10034
The Stark effect has been observed in the rotational spectra of several gas-phase amine-hydrogen halide complexes and the following electric dipole moments have been determined: H(3)(15)N-H(35)Cl (4.05865 +/- 0.00095 D), (CH(3))(3)(15)N-H(35)Cl (7.128 +/- 0.012 D), H(3)(15)N-H(79)Br (4.2577 +/- 0.0022 D), and (CH(3))(3)(15)N-H(79)Br (8.397 +/- 0.014 D). Calculations of the binding energies and electric dipole moments for the full set of complexes R(n)()(CH(3))(3)(-)(n)()N-HX (n = 0-3; X = F, Cl, Br) at the MP2/aug-cc-pVDZ level are also reported. The block localized wave function (BLW) energy decomposition method has been used to partition the binding energies into contributions from electrostatic, exchange, distortion, polarization, and charge-transfer terms. Similarly, the calculated dipole moments have been decomposed into distortion, polarization, and charge-transfer components. The complexes studied range from hydrogen-bonded systems to proton-transferred ion pairs, and the total interaction energies vary from 7 to 17 kcal/mol across the series. The individual energy components show a much wider variation than this, but cancellation of terms accounts for the relatively narrow range of net binding energies. For both the hydrogen-bonded complexes and the proton-transferred ion pairs, the electrostatic and exchange terms have magnitudes that increase with the degree of proton transfer but are of opposite sign, leaving most of the net stabilization to arise from polarization and charge transfer. In all of the systems studied, the polarization terms contribute the most to the induced dipole moment, followed by smaller but still significant contributions from charge transfer. A significant contribution to the induced moment of the ion pairs also arises from distortion of the HX monomer. 相似文献
110.