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31.
Alisdair O. G. Wallis Edward J. J. Longdon Piotr S. Żuchowski Jeremy M. Hutson 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,65(1-2):151-160
We calculate the quartet potential energy surface for Li+NH and use it to calculate elastic and spin-relaxation cross sections for collisions in magnetically trappable spin-stretched states. The potential is strongly anisotropic but spin-relaxation collisions are still suppressed by centrifugal barriers when both species are in spin-stretched states. In the ultracold regime, both the elastic and inelastic cross sections fluctuate dramatically as the potential is varied because of Feshbach resonances. The potential-dependence is considerably reduced at higher energies. The major effect of using an unconverged basis set in the scattering calculations is to shift the resonances without changing their general behaviour. We have calculated the ratio of elastic and spin-relaxation cross sections, as a function of collision energy and magnetic field, for a variety of potential energy surfaces. Most of the surfaces produce ratios that are favorable for sympathetic cooling, at temperatures below about 20 mK. 相似文献
32.
Sylwia Narkowicz ?aneta Polkowska Jacek Namie?nik 《Central European Journal of Chemistry》2013,11(1):16-24
Environmental tobacco smoke (ETS) contains many toxic compounds which include substances classified as aldehydes (e.g. formaldehyde) and inorganic substances such as cyanide ions. The information on the determination of these compounds in water is available, but the monitoring data on the level of these substances in human body fluids are still lacking. In this work the procedure for determining cyanide ions and formaldehyde in samples of human nasal discharge by simple spectrophotometric technique is presented. 相似文献
33.
The synthesis of both enantiomers of TEI-9826 has been accomplished in seven steps with an overall yield of 44% starting from diastereomeric camphor protected 3-[(dimethoxyphosphoryl)methyl]-4,5-dihydroxycyclopent-2-enones. The key steps include a fully diastereoselective hydrogenation of the endocyclic carbon–carbon double bond in the cyclopentenone ring controlled with a chiral diol moiety and the conversion of the latter into a new transposed olefinic bond. 相似文献
34.
35.
Honey produced by honeybees is a valuable food product. The presence of xenobiotics in honey may harm its quality and constitute a danger to human health. Antibiotics are commonly applied by beekeepers to eliminate disease among honeybees. Moreover, ubiquitous administration of antibiotics may cause bacteria to become resistant to many drugs and spread antibiotic-resistant strains of bacteria. Appropriate sample preparation and determination of antibiotics at very low concentrations in foodstuffs are real analytical challenges. This article reviews analytical methods used for determination of residues of different sorts of antibiotic in honey and other honeybee products. 相似文献
36.
TPR method was used to elucidate the status of nickel ions in chrysoprase. Temperature profiles of chrysoprase samples were
interpreted by comparing them with TPR curves of references. Two kinds of nickel species were identified in the studied samples.
The first one is nickel in 2:1 layer silicates while the other is nickel in the extra-framework positions. Apparent activation
energies (85±3 and 20±5 kJ mol−1) which were obtained from TPR data support the above attribution.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
37.
Szymon Żeberski 《Mathematical Logic Quarterly》2007,53(1):38-42
Assume that there is no quasi-measurable cardinal not greater than 2ω . We show that for a c. c. c. σ -ideal 𝕀 with a Borel base of subsets of an uncountable Polish space, if 𝒜 is a point-finite family of subsets from 𝕀, then there is a subfamily of 𝒜 whose union is completely nonmeasurable, i.e. its intersection with every non-small Borel set does not belong to the σ -field generated by Borel sets and the ideal 𝕀. This result is a generalization of the Four Poles Theorem (see [1]) and a result from [3]. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
38.
P. Żenczykowski 《International Journal of Theoretical Physics》1990,29(8):835-852
The octonion algebra seems to constitute the natural underlying algebra of nonrelativistic phase-space. A correspondence between the imaginary unit of quantum mechanics and the seventh imaginary unit of octonion algebra is proposed. Conjectures as to the possible physical meaning of some particular transformations from the automorphism group of octonions are presented. 相似文献
39.