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41.
A.?N.?WilsonEmail author G.?D.?Dracoulis A.?P.?Byrne P.?M.?Davidson G.?J.?Lane R.?M.?Clark P.?Fallon A.?G?rgen A.?O.?Macchiavelli D.?Ward 《The European Physical Journal A - Hadrons and Nuclei》2005,24(2):179-183
A superdeformed band has been observed in the N = 108 isotope 190Pb. This is the most neutron-deficient Pb isotope in which superdeformed states have been observed. Several theoretical approaches have predicted that N = 108 will mark the limit of observable superdeformation in the Pb isotopes. The band, which consists of five (possibly six) transitions, is observed to feed at least one isomeric level in its decay to the ground state. This decay pattern supports a spin assignment of 10 for the lowest observed level. 相似文献
42.
Pattison LK Cullen DM Smith JF Fletcher AM Walker PM El-Masri HM Podolyák Z Wood RJ Scholey C Wheldon C Mukherjee G Balabanski D Djongolov M Dalsgaard T Thisgaard H Sletten G Kondev F Jenkins D Lane GJ Lee IY Macchiavelli AO Frauendorf S Almehed D 《Physical review letters》2003,91(18):182501
Evidence is presented for multiphonon excitations based on a high-spin (25 Planck) intrinsic state in the deformed nucleus 182 Os. Angular momentum generation by this mode competes with collective rotation. The experimental data are compared with tilted-axis cranking calculations, supporting the vibrational interpretation. However, the lower experimental energies provide evidence that more complex interactions of states are playing a role. 相似文献
43.
[reaction: see text]. A new method was developed for the stereoselective synthesis of alpha-substituted serine amino acids. The strategy utilizes a common enantiomerically enriched intermediate obtained through an enzymatic desymmetrization. A variety of amino acids were synthesized in good ee's through nucleophilic acetylide addition reactions and palladium-catalyzed Sonogashira couplings. 相似文献
44.
N. S. Kelsall C. E. Svensson S. Fischer D. E. Appelbe R. A. E. Austin D. P. Balamuth G. C. Ball J. A. Cameron M. P. Carpenter R. M. Clark M. Cromaz M. A. Deleplanque R. M. Diamond P. Fallon D. F. Hodgson R. V. F. Janssens D. G. Jenkins G. J. Lane C. J. Lister A. O. Macchiavelli C. D. O’Leary D. G. Sarantities F. S. Stephens D. C. Schmidt D. Seweryniak K. Vetter J. C. Waddington R. Wadsworth D. Ward A. N. Wilson A. V. Afanasjev S. Frauendorf I. Ragnarsson 《The European Physical Journal A - Hadrons and Nuclei》2003,20(1):131-132
High-spin states have been studied in 72Kr and 72Br using the 40Ca + 40Ca and 36Ar + 40Ca reactions at 164 and 145 MeV, respectively. The properties and configurations of the high-spin bands observed have been interpreted using unpaired cranked Nilsson-Strutinsky (CNS), and for 72Kr, paired cranked relativistic Hartree-Bogoliubov (CRHB) calculations. In 72Kr a new band has been identified that has the properties expected for the doubly aligned S-band configuration. In 72Br the previously known bands have been extended to higher spin. This has lead to a re-interpretation of the configurations.Received: 31 October 2002, Published online: 24 February 2004PACS:
21.10.Re Collective levels - 23.20.Lv
transitions and level energies - 27.50. + e
相似文献
45.
Trout AL Prasad R Coffin D DiMartini A Lane T Blessum C Khatter N Landers JP 《Electrophoresis》2000,21(12):2376-2383
Transferrin, an iron transport protein found in serum and cerebrospinal fluid, is known to be microheterogeneous with respect to its carbohydrate and sialic acid content. The forms of transferrin deficient in sialic acid and/or carbohydrate, termed carbohydrate-deficient transferrin (CDT), have been of clinical interest for almost two decades as a result of the initial finding that elevated CDT concentrations are associated with chronic, excessive alcohol abuse. We demonstrate the utility of capillary electrophoresis for examining the CDT sialoform profile via the direct electrophoresis of serum. The need for negligible preelectrophoresis sample preparation and absence of postelectrophoresis processing dramatically decreases analysis time compared to slab gel-based separations. Using a fluorocarbon-coated capillary containing a hydroxyethyl cellulose/borate buffer, the high resolution separation of serum components is effected in less than 30 min. Under these conditions, the beta region proteins (including transferrin) are well resolved from the alpha-2 and gamma zone proteins in a window where the individual transferrin sialoforms can be detected. The usefulness of this method is demonstrated with the electrophoresis of serum from subjects known to be either non-alcoholic and alcoholic. 相似文献
46.
47.
Lane W. Martin 《Surface science》2011,605(15-16):1388-1389
This perspective briefly reviews the recent developments in the study of exotic phenomena at complex oxide heterointerfaces – with special attention to results published by L. Qiao, et al. in this edition – on the LaAlO3/SrTiO3 heterointerface. The fundamental mechanisms of the observed phenomena are discussed and the results of the current study are placed in context. The importance of rigorous materials characterization and insight into fundamental limitations of modern synthesis techniques are probed. 相似文献
48.
Jane S. Murray Pat Lane Anian Nieder Thomas M. Klapötke Peter Politzer 《Theoretical chemistry accounts》2010,127(4):345-354
Si-pentaerythritol tetranitrate (PETN), Si[CH2ONO2]4, is a silicon analog of the widely used explosive PETN, C[CH2ONO2]4. Si-PETN is extremely sensitive to impact, much more so than PETN. This was attributed by Liu et al. to Si-PETN having a
much lower activation barrier to decomposition, via a facile rearrangement that is not as readily available to PETN, and which
releases considerable energy that can promote further steps. We have investigated computationally why the barrier to the rearrangement
is so much lower for Si-PETN than for PETN, using 5, (H3C)3C–CH2ONO2, and 6, (H3C)3Si–CH2ONO2, as models for PETN and Si-PETN. Reaction force analysis shows that most of the difference between the rearrangement barriers
for 5 and 6 comes about in the initial (reactant) stages of the processes, in which 6 benefits from a 1,3 electrostatic interaction involving a positive σ–hole on the silicon and the negative linking oxygen.
The analogous interaction is weaker in 5, since the central carbon does not have positive σ–holes; furthermore, this carbon is less able than silicon to temporarily
expand its coordination sphere. A similar explanation involving a positive silicon σ–hole and a linking oxygen is proposed
for Si-PETN. The greater exothermicity of the rearrangement of 6 (and also Si-PETN) can be rationalized, following Liu et al., in terms of the formation of the strong Si–O bond. 相似文献
49.
Stephen M. Lipson Ashley J. Cadby Paul A. Lane Diarmuid F. O’Brien Anna Drury Donald D. C. Bradley Werner J. Blau 《Monatshefte für Chemie / Chemical Monthly》2001,132(1):151-158
Summary. We have investigated the effect of film preparation procedures on the photoluminescence efficiency of the luminescent co-polymer
poly-(m-phenylene-co-2,5-dioctoxy-p-phenylenevinylene) (PmPV). The photoluminescence efficiency of PmPV films improved by up to 50% when the solution was degassed by bubbling argon gas through it prior to spin casting in an inert
atmosphere and baking under vacuum. Photoinduced absorption and doping measurements show that this preparation method reduces
polaron photogeneration, which reduces the photoluminescence (PL) yield through exciton quenching and excited state absorption.
It is proposed that this sample preparation method increases interchain separation, reducing the formation of polarons and
non-radiative quenching routes, thus resulting in increased PL efficiency.
Received June 23, 2000. Accepted (revised) August 3, 2000 相似文献
50.
Department of Health staff wished to use systems modelling to discuss acute patient flows with groups of NHS staff. The aim was to assess the usefulness of system dynamics (SD) in a healthcare context and to elicit proposals concerning ways of improving patient experience. Since time restrictions excluded simulation modelling, a hybrid approach using stock/flow symbols from SD was created. Initial interviews and hospital site visits generated a series of stock/flow maps. A ‘Conceptual Framework’ was then created to introduce the mapping symbols and to generate a series of questions about different patient paths and what might speed or slow patient flows. These materials formed the centre of three workshops for NHS staff. The participants were able to propose ideas for improving patient flows and the elicited data was subsequently employed to create a finalized suite of maps of a general acute hospital. The maps and ideas were communicated back to the Department of Health and subsequently assisted the work of the Modernization Agency. 相似文献