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991.
A collection of 9089 spectroscopic LiH line positions, of widely varying precision, which sample 84.9% and 98.6% of the A and X state well depths, respectively, have been employed in a direct least-squares fit of the effective potential energy and Born-Oppenheimer breakdown functions for the two states. For the four isotopomers (6)LiH, (7)LiH, (6)LiD, and (7)LiD, the data comprise both pure rotational and vibration-rotational transitions within the ground state, as well as rotationally resolved transitions in the A-X system. Despite the unusual shape and associated anomalous properties of the A state potential, no special features or considerations were required in the direct potential fitting approach. The reduced standard deviation of the fit was close to unity, indicating that the quantum mechanical eigenvalues calculated from the fully analytical functions of the Hamiltonians of the two states, which are characterized by a total of only 53 fitted parameters, represent the line positions, on average, to within the estimated uncertainties. A quantum mechanical calculation of the molecular constants G(nu), B(nu), D(nu), H(nu), L(nu), M(nu), N(nu), and O(nu) from the fitted potential for the A state of (7)LiH confirms that the usual polynomial expansion in J(J+1) is an unsatisfactory representation for the rotational terms of the lowest vibrational levels. 相似文献
992.
Naik RR Tomczak MM Luckarift HR Spain JC Stone MO 《Chemical communications (Cambridge, England)》2004,(15):1684-1685
Entrapment of enzymes and nanoparticles using biosilicification reactions. 相似文献
993.
994.
Silicon and tin substituents surprisingly have only a moderate directing effect on the Tiffeneau-Demjanov reaction. The low selectivity is rationalised as being due to the reactive nature of the diazonium ion leaving group, the weaker oxydiazene leaving group was found to give better yields of the silicon-directed ring expanded product. 相似文献
995.
Condick PN Fox MA Greatrex R Jones C Ormsby DL 《Chemical communications (Cambridge, England)》2002,(14):1448-1449
The gas-phase reaction of the phosphaalkyne P identical to CtBu with tetraborane(10), B4H10, yields the nido five-vertex phosphacarbaborane cluster compound 2-tBu-1,2-PCB3H5 2 with an unusual 31P NMR peak shift of -500.5 ppm. 相似文献
996.
Cameron KS Clark JK Cooper A Fielding L Palin R Rutherford SJ Zhang MQ 《Organic letters》2002,4(20):3403-3406
A series of per-6-substituted cyclodextrin derivatives was synthesized as synthetic host molecules for rocuronium, a steroidal muscle relaxant. By forming host-guest complexes with rocuronium, these cyclodextrin derivatives reverse the muscle relaxation induced by rocuronium in vitro and in vivo. The isothermal microcalorimetry data are consistent with the biological data supporting the encapsulation mechanism of action. Binary and biphasic complexes are reported with NMR experiments clearly showing free and bound rocuronium. [structure: see text] 相似文献
997.
998.
Toroidal and Annular Dehn Fillings 总被引:4,自引:0,他引:4
Suppose that M is a hyperbolic 3-manifold which admits two Dehnfillings M(r1) and M(r2) such that M(r1) contains an essentialannulus, and M(r2) contains an essential torus. It is knownthat = (r1, r2) 5. We will show that if = 5 then M is theWhitehead sister link exterior, and if = 4 then M is the exteriorof either the Whitehead link or the 2-bridge link associatedto the rational number . There are infinitely many examples with = 3. 1991 Mathematics SubjectClassification: 11D25, 11G05, 14G05. 相似文献
999.
Gerard Anderson Donald W. Cameron Geoffrey I. Feutrill Roger W. Read 《Tetrahedron letters》1981,22(43):4347-4348
Trialkylsilyl ethers of 1,1-dioxygenated butadienes, substituted at position 3 by electron releasing substituents, undergo thermal rearrangement with 1,5-migration of the silyl group from oxygen to carbon. 相似文献
1000.
Fine ML Schrinel J Cameron TM 《The Journal of the Acoustical Society of America》2004,116(2):1271-1275
Physiological work on fish sound production may require exposure of the swimbladder to air, which will change its loading (radiation mass and resistance) and could affect parameters of emitted sounds. This issue was examined in Atlantic croaker Micropogonius chromis by recording sounds from the same individuals in air and water. Although sonograms appear relatively similar in both cases, pulse duration is longer because of decreased damping, and sharpness of tuning (Q factor) is higher in water. However, pulse repetition rate and dominant frequency are unaffected. With appropriate caution it is suggested that sounds recorded in air can provide a useful tool in understanding the function of various swimbladder adaptations and provide reasonable approximation of natural sounds. Further, they provide an avenue for experimentally manipulating the sonic system, which can reveal details of its function not available from intact fish underwater. 相似文献