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121.
van Eis MJ Wijsman GW de Wolf WH Bickelhaupt F Rogers DW Kooijman H Spek AL 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(9):1537-1546
The course of the hydrogenation of [5]- and [6]metacyclophane (1b and 1c) and their thermochemistry is described. Both compounds are hydrogenated rapidly (within 10 s) to furnish the bridgehead olefins 13b and 12c. The accompanying hydrogenation enthalpies are -220 and -141 kJmol(-1), respectively. Strain energies (SE) and olefinic strains (OS) of a number of bridgehead olefins have been evaluated by DFT calculations; it was concluded that 13b belongs to the class of hyperstable olefins which correlates nicely with its reluctance to undergo hydrogenation. By combining experimental hydrogenation enthalpies and DFT calculations, SE of 187 and 121 kJmol(-1) were derived for 1b and 1c. 相似文献
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Peter Köhler Thomas Meixner Michael Wester 《Journal of Combinatorial Theory, Series A》1985,38(2):203-209
A certain “free” group U is constructed that is generated by three elements of order 3 which pairwise generate a Frobenius group of order 21 and it is shown that U operates regularly on the affine building of type over the field of 2-adic numbers. As a result an infinite series of finite rank 3 geometries is obtained whose rank 2 residues are projective planes of order 2, and which possess a regular automorphism group isomorphic to SL3(p) or SU3(p) for some prime p. 相似文献
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126.
Geer S Marriner J Martens M Ray RE Streets J Wester W Hu M Snow GR Armstrong T Buchanan C Corbin B Lindgren M Muller T Gustafson R 《Physical review letters》2000,84(4):590-593
A search for antiproton decay has been made at the Fermilab Antiproton Accumulator. Limits are placed on fifteen antiproton decay modes. The results are used to place limits on the characteristic mass scale m(X) that could be associated with CPT violation accompanied by baryon number violation. 相似文献
127.
Speech production knowledge in automatic speech recognition 总被引:1,自引:0,他引:1
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129.
Prof. Dr. Stanka Jerosimić Assist. Prof. Dr. Milan Milovanović Assist. Dr. Marko Mitić Univ.-Prof. Dr. Roland Wester Prof. Dr. Dr. h. c. Francesco A. Gianturco 《Chemphyschem》2023,24(22):e202300248
We present results of quantum structure calculations aimed at demonstrating the possible existence of dipole-bound states (DBS) for the anion , a species already detected in the Interstellar medium (ISM). The positive demonstration of DBS existence using ab initio studies is an important step toward elucidating possible pathways for the formation of the more tightly bound valence bound states (VBS) in environments where free electrons from starlight ionization processes are known to be available to interact with the radical partner of the title molecule. Our current calculations show that such excited DBS states can exist in , in agreement with what we had previously found for the smallercyanopolyyne in the series: the anion. This system has a very weakly bound anion with binding energies of about 3 and 9 cm−1 for the and DBS, respectively. 相似文献