| 1. |
|
|
| 2. |
- Feuerbacher, M., et al.
(författare)
-
The Samson phase, β-Mg2Al3, Revisited
- 2007
-
Ingår i: Zeitschrift für Kristallographie. - 0044-2968. ; 222:6, s. 259-288
-
Tidskriftsartikel (refereegranskat)
|
|
| 3. |
- Euchner, H., et al.
(författare)
-
Anomalous vibrational dynamics in the Mg(2)Zn(11) phase
- 2011
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 83:14, s. 144202-
-
Tidskriftsartikel (refereegranskat)abstract
- We present a combined experimental and theoretical study of the structure and the lattice dynamics in the complex metallic alloy Mg(2)Zn(11), by means of neutron and x-ray scattering, as well as ab initio and empirical potential calculations. Mg(2)Zn(11) can be seen as an intermediate step in structural complexity between the simple Laves-phase MgZn(2) on one side, and the complex 1/1 approximants and quasicrystals ZnMgAl and Zn(Mg)Sc on the other. The structure can be described as a cubic packing of a triacontahedron whose center is partially occupied by a Zn atom. This partially occupied site turned out to play a major role in understanding the lattice dynamics. Data from inelastic neutron scattering evidence a Van Hove singularity in the vibrational spectrum of Mg(2)Zn(11) for an energy as low as 4.5 meV, which is a unique feature for a nearly-close-packed metallic alloy. This corresponds to a gap opening at the Brillouin zone boundary and an interaction between a low-lying optical branch and an acoustic one, as could be deduced from the dispersion relation measured by inelastic x-ray scattering. Second, the measured phonon density of states exhibits many maxima, indicating strong mode interactions across the whole energy range. The origin of the low-energy modes in Mg(2)Zn(11) and other features of the vibrational spectra are studied, using both ab initio and empirical potential calculations. A detailed analysis of vibrational eigenmodes is presented, linking features in the vibrational spectrum to atomic motions within structural building blocks.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Euchner, H., et al.
(författare)
-
Anomalous vibrational dynamics in the Mg2Zn11 phase
- 2011
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 83:14, s. 144202-
-
Tidskriftsartikel (refereegranskat)abstract
- We present a combined experimental and theoretical study of the structure and the lattice dynamics in the complex metallic alloy Mg2Zn11, by means of neutron and x-ray scattering, as well as ab initio and empirical potential calculations. Mg2Zn11 can be seen as an intermediate step in structural complexity between the simple Laves-phase MgZn2 on one side, and the complex 1/1 approximants and quasicrystals ZnMgAl and Zn(Mg)Sc on the other. The structure can be described as a cubic packing of a triacontahedron whose center is partially occupied by a Zn atom. This partially occupied site turned out to play a major role in understanding the lattice dynamics. Data from inelastic neutron scattering evidence a Van Hove singularity in the vibrational spectrum of Mg2Zn11 for an energy as low as 4.5 meV, which is a unique feature for a nearly-close-packed metallic alloy. This corresponds to a gap opening at the Brillouin zone boundary and an interaction between a low-lying optical branch and an acoustic one, as could be deduced from the dispersion relation measured by inelastic x-ray scattering. Second, the measured phonon density of states exhibits many maxima, indicating strong mode interactions across the whole energy range. The origin of the low-energy modes in Mg2Zn11 and other features of the vibrational spectra are studied, using both ab initio and empirical potential calculations. A detailed analysis of vibrational eigenmodes is presented, linking features in the vibrational spectrum to atomic motions within structural building blocks.
|
|
| 7. |
- Jacob, M, et al.
(författare)
-
Synthesis of structurally controlled nanocarbons – in particular the nanobarrel carbon
- 2003
-
Ingår i: Solid State Sciences. - 1293-2558 .- 1873-3085. ; 5, s. 133-137
-
Tidskriftsartikel (refereegranskat)abstract
- Nanoporous carbons have been prepared through a selective etching reaction, performed by halogenisation of aluminum carbide. The structures obtained can be controlled by varying the chlorination temperature. The unique set of nanocarbons obtained include nanoporous amorphous structures, the nanobarrel structure and a nanographitic structure as chlorination temperatures were increased from 400 °C to 1000 °C. The synthesis process gives a pure product with high yield, and may be scaled up to produce bulk amounts
|
|
| 8. |
- Rodmar, M., et al.
(författare)
-
Electrical resistivity of one-dimensional quasiperiodic η8-Cu5Sn4
- 1999
-
Ingår i: Physical Review B - Condensed Matter and Materials Physics. - 1098-0121. ; 60:6, s. 3908-3911
-
Tidskriftsartikel (refereegranskat)abstract
- The electrical resistivity, ρ, of one-dimensional quasiperiodic η8-Cu5Sn4 has been studied, and compared with crystalline Cu6Sn5 of identical basic structure (B8) and closely related atomic structure. ρ was measured between 1.5 and 300 K on needle-shaped crystals with their axes along the base lattice c direction, corresponding to the quasiperiodic direction in η8-Cu5Sn4. ρ (4 K) was found to be nine times larger in η8-Cu5Sn4 compared to Cu6Sn5, and the residual ratio R [=ρ(4K)/ρ(300K)<1] was larger by a factor of 3. The similar structures and these large differences in transport properties indicate that the effect of quasiperiodic ordering has been observed in the resistivity of a one-dimensional metal.
|
|
| 9. |
- Berg, Rand Wilcox Vanden, et al.
(författare)
-
Brain tissue saving effects by single-dose intralesional administration of Neuroprotectin D1 on experimental focal penetrating brain injury in rats
- 2019
-
Ingår i: Journal of Clinical Neuroscience. - : Elsevier BV. - 0967-5868 .- 1532-2653. ; 64, s. 227-233
-
Tidskriftsartikel (refereegranskat)abstract
- Traumatic brain injury (TBI)is followed by a secondary inflammation in the brain. Neuroprotectin D1 (NPD1)is synthesized from docosahexaenoic acid (DHA)and has anti-inflammatory and antiapoptotic effects in experimental models of neurodegenerative disease and brain ischemia-reperfusion. It is not known whether intralesional administration of NPD1 ameliorates inflammation and cell death after severe TBI. We therefore investigated the effects of NPD1 following a severe form of focal penetrating TBI. A total of 30 male Sprague-Dawley rats weighing between 350 and 450 g were exposed to focal penetrating TBI or sham surgery. The rats were randomized to NPD1 treatment (50 ng intralesionally, immediately following TBI)or no treatment. The rats were sacrificed at 24 or 72 h. All subgroups consisted of 5 rats. Brains were removed, fresh frozen, cut in 14-µm coronal sections and subjected to Fluoro-Jade, TUNEL, MnSOD, 3-NT, COX-2, Ox-42 and NF-κB immuno-staining and lesion size analyses. NPD1 decreased the lesion area at 72 h compared to no treatment with a mean change 42% (NPD1 14.1 mm 2 ; no treatment 24.5 mm 2 )(p < 0.01). No difference was detected in markers for neuronal degeneration, apoptosis, anti-inflammatory or antioxidative enzymes, or immune cells. In conclusion, single-dose intralesional administration of NPD1 had brain tissue sparing effects after focal penetrating TBI, which may be beneficial in preventing brain tissue damage, making NPD1 a potential candidate for further clinical applications. Exact mechanisms of action could not be determined and it is possible that continuous or multiple administration regimens may increase efficacy in sequential preclinical studies.
|
|
| 10. |
|
|
