193 research outputs found
Quantum chaos with spin-chains in pulsed magnetic fields
Recently it was found that the dynamics in a Heisenberg spin-chain subjected
to a sequence of periodic pulses from an external, parabolic, magnetic field
can have a close correspondence with the quantum kicked rotor (QKR). The QKR is
a key paradigm of quantum chaos; it has as its classical limit the well-known
Standard Map. It was found that a single spin excitation could be converted
into a pair of non-dispersive, counter-propagating spin coherent states
equivalent to the accelerator modes of the Standard Map. Here we consider how
other types of quantum chaotic systems such as a double-kicked quantum rotor or
a quantum rotor with a double-well potential might be realized with spin
chains; we discuss the possibilities regarding manipulation of the one-magnon
spin waves.Comment: 10 pages, 4 figures. Submitted to PTP special issue for QMC200
Doubly excited ferromagnetic spin-chain as a pair of coupled kicked rotors
We show that the dynamics of a doubly-excited 1D Heisenberg ferromagnetic
chain, subject to short pulses from a parabolic magnetic field may be analyzed
as a pair of quantum kicked rotors. By focusing on the two-magnon dynamics in
the kicked XXZ model we investigate how the anisotropy parameter - which
controls the strength of the magnon-magnon interaction - changes the nature of
the coupling between the two "image" coupled Kicked Rotors. We investigate
quantum state transfer possibilities and show that one may control whether the
spin excitations are transmitted together, or separate from each other.Comment: 8 pages, 4 figures; extended appendix and corrected typo
Intra-and inter-group perceptions of Chinese and Tanzanian employees in intercultural cooperation
The cooperation between Chinese and Tanzanian employees and organisations has a very long tradition in Tanzanian history. The purpose of this paper is to explore and understand how Chinese and Tanzanian employees see themselves and “the other” while cooperating. This research presents a study of a single case, conducted in a selected Chinese organisation in Tanzania. It uses a hermeneutical research paradigm. Data was collected using semi-structured interviews and observation and analysed through content analysis, following Terre Blanche’s model. Findings demonstrate and explain the perspectives which Chinese and Tanzanian employees hold mutually with regard to the group image of self and other within the organisation, as well as perceptions of self and other in terms of organisational, environmental and cultural contexts. Since this is a qualitative single organisational case study, the findings are limited to this single organisation and are not generalisable. Conclusions drawn from the new research insights are provided and recommendations are given in terms of how Chinese and Tanzanian perceptions present themselves and how organisations could work with self-image and counter images to improve intercultural cooperation
Mineralogical characterization of protolith and fault rocks from the SAFOD Main Hole
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94865/1/grl22060.pd
Intra-and inter-group perceptions of Chinese and Tanzanian employees in intercultural cooperation
The cooperation between Chinese and Tanzanian employees and organisations has a very long tradition in Tanzanian history. The purpose of this paper is to explore and understand how Chinese and Tanzanian employees see themselves and “the other” while cooperating. This research presents a study of a single case, conducted in a selected Chinese organisation in Tanzania. It uses a hermeneutical research paradigm. Data was collected using semi-structured interviews and observation and analysed through content analysis, following Terre Blanche’s model. Findings demonstrate and explain the perspectives which Chinese and Tanzanian employees hold mutually with regard to the group image of self and other within the organisation, as well as perceptions of self and other in terms of organisational, environmental and cultural contexts. Since this is a qualitative single organisational case study, the findings are limited to this single organisation and are not generalisable. Conclusions drawn from the new research insights are provided and recommendations are given in terms of how Chinese and Tanzanian perceptions present themselves and how organisations could work with self-image and counter images to improve intercultural cooperation
Basic kinetic wealth-exchange models: common features and open problems
We review the basic kinetic wealth-exchange models of Angle [J. Angle, Social
Forces 65 (1986) 293; J. Math. Sociol. 26 (2002) 217], Bennati [E. Bennati,
Rivista Internazionale di Scienze Economiche e Commerciali 35 (1988) 735],
Chakraborti and Chakrabarti [A. Chakraborti, B. K. Chakrabarti, Eur. Phys. J. B
17 (2000) 167], and of Dragulescu and Yakovenko [A. Dragulescu, V. M.
Yakovenko, Eur. Phys. J. B 17 (2000) 723]. Analytical fitting forms for the
equilibrium wealth distributions are proposed. The influence of heterogeneity
is investigated, the appearance of the fat tail in the wealth distribution and
the relaxation to equilibrium are discussed. A unified reformulation of the
models considered is suggested.Comment: Updated version; 9 pages, 5 figures, 2 table
Bayesian paternity analysis and mating patterns in a parasitic nematode, Trichostrongylus tenuis
Mating behaviour is a fundamental aspect of the evolutionary ecology of sexually reproducing species, but one that has been under-researched in parasitic nematodes. We analysed mating behaviour in the parasitic nematode Trichostrongylus tenuis by performing a paternity analysis in a population from a single red grouse host. Paternity of the 150 larval offspring of 25 mothers (sampled from one of the two host caeca) was assigned among 294 candidate fathers (sampled from both caeca). Each candidate father's probability of paternity of each offspring was estimated from 10-locus microsatellite genotypes. Seventy-six (51%) offspring were assigned a father with a probability of >0.8, and the estimated number of unsampled males was 136 (95% credible interval (CI) 77-219). The probability of a male from one caecum fathering an offspring in the other caecum was estimated as 0.024 (95% CI 0.003-0.077), indicating that the junction of the caeca is a strong barrier to dispersal. Levels of promiscuity (defined as the probability of two of an adult's offspring sharing only one parent) were high for both sexes. Variance in male reproductive success was moderately high, possibly because of a combination of random mating and high variance in post-copulatory reproductive success. These results provide the first data on individual mating behaviour among parasitic nematodes
Water Rights in Wilderness: The Influence of Reserved Rights Language on Protection of Wilderness Water in Arizona and Colorado
1 v. (various pagings) : ill. (some color), color maps ; 29 cm
Executive summary -- Introduction -- Background and scope -- Compilation and analysis of water rights data -- Protection of wilderness water : federal agency response to statutory language -- Final observations -- Appendix A. Legislative history of Arizona and Colorado wilderness legislation -- Appendix B. State water law : Arizona and Colorado -- Appendix C. Study methods -- Appendix D. Agency policies.https://scholar.law.colorado.edu/books_reports_studies/1015/thumbnail.jp
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