739 research outputs found
Stretched exponential behavior in remanent lattice striction of a (La,Pr)SrMnO bilayer manganite single crystal
We have investigated the time dependence of remanent magnetostriction in a
(La,Pr)SrMnO single crystal, in order to examine
the slow dynamics of lattice distortion in bilayered manganites. A competition
between double exchange and Jahn-Teller type orbital-lattice interactions
results in the observed lattice profile following a stretched exponential
function. This finding suggests that spatial growth of the local lattice
distortions coupled with e-electron orbital strongly correlates with the
appearance of the field-induced CMR effect.Comment: 3 figure
Resistive relaxation in field-induced insulator-metal transition of a (LaPr)SrMnO bilayer manganite single crystal
We have investigated the resistive relaxation of a
(LaPr)SrMnO single crystal, in
order to examine the slow dynamics of the field-induced insulator to metal
transition of bilayered manganites. The temporal profiles observed in remanent
resistance follow a stretched exponential function accompanied by a slow
relaxation similar to that obtained in magnetization and magnetostriction data.
We demonstrate that the remanent relaxation in magnetotransport has a close
relationship with magnetic relaxation that can be understood in the framework
of an effective medium approximation by assuming that the first order parameter
is proportional to the second order one.Comment: 6 pages,5 figure
Highly reflective distributed Bragg reflectors using a deeply etched semiconductor/air grating for InGaN/GaN laser diodes
2002-2003 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Taming C60 fullerene: Tuning intramolecular photoinduced electron transfer process with subphthalocyanines
Two subphthalocyanine-C60 conjugates have been prepared by means of the 1,3-dipolar cycloaddition reaction of (perfluoro) or hexa(pentylsulfonyl) electron deficient subphthalocyanines to C60. Comprehensive assays regarding the electronic features-in the ground and excited state-of the resulting conjugates revealed energy and electron transfer processes upon photoexcitation. Most important is the unambiguous evidence-in terms of time-resolved spectroscopy-of an ultrafast oxidative electron transfer evolving from C60 to the photoexcited subphthalocyanines. This is, to the best of our knowledge, the first case of an intramolecular oxidation of C60 within electron donor-acceptor conjugates by means of only photoexcitationFinancial support from the MICINN and MEC, Spain (CTQ- 2011-24187/BQU and PRI-PIBUS-2011-1128) is acknowledged. D.M.G. appreciates funding by the DFG (GU 517/14-1) and “Solar Technologies Go Hybrid” – an initiative of the Bavarian State Ministry for Science, Research, and Ar
Higgs production in association with top quark pair at e+e- colliders in theories of higher dimensional gravity
The models of large extra compact dimensions, as suggested by Arkani-Hamed,
Dimopoulos and Dvali, predict exciting phenomenological consequences with
gravitational interactions becoming strong at the TeV scale. Such theories can
be tested at the existing and future colliders. In this paper, we study the
contribution of virtual Kaluza-Klein excitations in the process at future linear collider (NLC). We find that the virtual exchange
KK gravitons can modify the cross-section
significantly from its Standard Model value and will allow the effective string
scale to be probed up to 7.9 TeV.Comment: 10 pages, Latex, 4 postscript figure
Single phase a-plane MgZnO epilayers for UV optoelectronics: substitutional behaviour of Mg at large contents
High quality 1 μm thick a-plane MgxZn1−xO layers were produced by molecular beam epitaxy with Mg contents higher than 50%. Resonant Rutherford backscattering spectrometry combined with ion channeling revealed a uniform growth in both composition and atomic order. The lattice-site location of Mg, Zn and O elements was determined independently, proving the substitutional behaviour of Mg in Zn-sites of the wurtzite lattice. X-Ray diffraction pole figure analysis also confirms the absence of phase separation. Optical properties at such high Mg contents were studied in Schottky photodiodes
The impact of inpatient suicide on psychiatric nurses and their need for support
<p>Abstract</p> <p>Background</p> <p>The nurses working in psychiatric hospitals and wards are prone to encounter completed suicides. The research was conducted to examine post-suicide stress in nurses and the availability of suicide-related mental health care services and education.</p> <p>Methods</p> <p>Experiences with inpatient suicide were investigated using an anonymous, self-reported questionnaire, which was, along with the Impact of Event Scale-Revised, administered to 531 psychiatric nurses.</p> <p>Results</p> <p>The rate of nurses who had encountered patient suicide was 55.0%. The mean Impact of Event Scale-Revised (IES-R) score was 11.4. The proportion of respondents at a high risk (≥ 25 on the 88-point IES-R score) for post-traumatic stress disorder (PTSD) was 13.7%. However, only 15.8% of respondents indicated that they had access to post-suicide mental health care programmes. The survey also revealed a low rate of nurses who reported attending in-hospital seminars on suicide prevention or mental health care for nurses (26.4% and 12.8%, respectively).</p> <p>Conclusions</p> <p>These results indicated that nurses exposed to inpatient suicide suffer significant mental distress. However, the low availability of systematic post-suicide mental health care programmes for such nurses and the lack of suicide-related education initiatives and mental health care for nurses are problematic. The situation is likely related to the fact that there are no formal systems in place for identifying and evaluating the psychological effects of patient suicide in nurses and to the pressures stemming from the public perception of nurses as suppliers rather than recipients of health care.</p
- …