| 11. |
|
|
| 12. |
- Cederwall, Bo, 1964-, et al.
(författare)
-
Lifetime Measurements of Excited States in Pt-172 and the Variation of Quadrupole Transition Strength with Angular Momentum
- 2018
-
Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 121:2
-
Tidskriftsartikel (refereegranskat)abstract
- Lifetimes of the first excited 2(+) and 4(+) states in the extremely neutron -deficient nuclide Pt-172 have been measured for the first time using the recoil-distance Doppler shift and recoil-decay tagging techniques. An unusually low value of the ratio B(E2: 4(1)(+) -> 2(1)(+)/B(E2: 2(1)(+) -> 0(gs)(+)) = 0.55(19) was found, similar to a handful of other such anomalous cases observed in the entire Segre chart. The observation adds to a cluster of a few extremely neutron -deficient nuclides of the heavy transition metals with neutron numbers N approximate to 90-94 featuring the effect. No theoretical model calculations reported to date have been able to explain the anomalously low B(E2: 4(1)(+) -> 2(1)(+)/B(E2: 2(1)(+) -> 0(gs)(+)) ratios observed in these cases. Such low values cannot, e.g., be explained within the framework of the geometrical collective model or by algebraic approaches within the interacting boson model framework. It is proposed that the group of B(E2: 4(1)(+) -> 2(1)(+)/B(E2: 2(1)(+) -> 0(gs)(+)) ratios in the extremely neutron-deficient even-even W, Os, and Pt nuclei around neutron numbers N approximate to 90-94 reveal a quantum phase transition from a seniority-conserving structure to a collective regime as a function of neutron number. Although a system governed by seniority symmetry is the only theoretical framework for which such an effect may naturally occur, the phenomenon is highly unexpected for these nuclei that are not situated near closed shells.
|
|
| 13. |
|
|
| 14. |
|
|
| 15. |
- Kabiri Samani, Majid, 1976, et al.
(författare)
-
Thermal conductivity enhancement of carbon@ carbon nanotube arrays and bonded carbon nanotube network
- 2019
-
Ingår i: Materials Research Express. - : IOP Publishing. - 2053-1591. ; 6:8
-
Tidskriftsartikel (refereegranskat)abstract
- Carbon nanotubes (CNTs) are long considered as a promising material for thermal applications. However, problems such as low volume CNT fraction abhorrent to practical applications have been raising the demand for novel architecture of this material. Here we demonstrate two fabrication methods, in which a self-assembly method for fabricating covalent-bonded CNT network (3D CNT) and another method for covalent-bonded C to CNTs (C@CNT) network, and presented both as a potential method to enhance thermal conductivity of CNT arrays. We utilized pulsed photothermal reflectance technique and using new four-layer heat conduction model based on the transmission-line theory to measure thermal conductivity of the samples. The 3D CNT with thermal conductivity of 21 W mK(-1) and C@CNT with thermal conductivity of 26 W mK(-1) turn out to be an excellent candidate for thermal interface material as the thermal conductivity increased by 40% and 70% respectively as compared to conventional CNT arrays. The improvement is attributed to the efficient thermal routines constructed between CNTs and secondary CNTs in 3D CNT and between C layer and CNTs in C@CNT. The other factor to improve thermal conductivity of the samples is decreasing air volume fraction in CNT arrays. Our fabrication methods provide a simple method but effective way to fabricate 3D CNT and C@CNT and extend the possibility of CNTs towards TIM application.
|
|
| 16. |
- Kato, Norihiro, et al.
(författare)
-
Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation
- 2015
-
Ingår i: Nature Genetics. - : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 47:11, s. 1282-1293
-
Tidskriftsartikel (refereegranskat)abstract
- We carried out a trans-ancestry genome-wide association and replication study of blood pressure phenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 × 10−11 to 5.0 × 10−21). The sentinel blood pressure SNPs are enriched for association with DNA methylation at multiple nearby CpG sites, suggesting that, at some of the loci identified, DNA methylation may lie on the regulatory pathway linking sequence variation to blood pressure. The sentinel SNPs at the 12 new loci point to genes involved in vascular smooth muscle (IGFBP3, KCNK3, PDE3A and PRDM6) and renal (ARHGAP24, OSR1, SLC22A7 and TBX2) function. The new and known genetic variants predict increased left ventricular mass, circulating levels of NT-proBNP, and cardiovascular and all-cause mortality (P = 0.04 to 8.6 × 10−6). Our results provide new evidence for the role of DNA methylation in blood pressure regulation.
|
|
| 17. |
- Kristan, Matej, et al.
(författare)
-
The Visual Object Tracking VOT2016 Challenge Results
- 2016
-
Ingår i: COMPUTER VISION - ECCV 2016 WORKSHOPS, PT II. - Cham : SPRINGER INT PUBLISHING AG. - 9783319488813 - 9783319488806 ; , s. 777-823
-
Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge VOT2016 aims at comparing short-term single-object visual trackers that do not apply pre-learned models of object appearance. Results of 70 trackers are presented, with a large number of trackers being published at major computer vision conferences and journals in the recent years. The number of tested state-of-the-art trackers makes the VOT 2016 the largest and most challenging benchmark on short-term tracking to date. For each participating tracker, a short description is provided in the Appendix. The VOT2016 goes beyond its predecessors by (i) introducing a new semi-automatic ground truth bounding box annotation methodology and (ii) extending the evaluation system with the no-reset experiment.
|
|
| 18. |
- Li, Hongjie J., et al.
(författare)
-
Collective band structures in the Tc-99 nucleus
- 2015
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 91:5
-
Tidskriftsartikel (refereegranskat)abstract
- Excited states in Tc-99 with energies up to 6 MeV have been populated using the Zr-96(Li-7, 4n)Tc-99 reaction with a laboratory beam energy of 35 MeV. Coincident gamma rays from excited nuclei produced in the reactions were detected using an array of coaxial, planar, and clover-type high-purity germanium detectors. A total of 60 new gamma-ray transitions and 21 new levels are identified and placed into a new level scheme. Two collective bands assigned to be built on the pi g(9/2)[422]5/2(+) and pi p(1/2)[301]1/2(-) Nilsson configurations have been extended with spins up to 35/2 and 33/2 h, respectively. Backbending and signature inversion have been observed in the yrast band. The large signature splitting of the positive-parity band in Tc-99 may be caused by a triaxial deformation, which agrees well with the electromagnetic properties, theoretical calculations based on total Routhian surface, and triaxial particle-rotor model calculations.
|
|
| 19. |
- Li, Hongjie, et al.
(författare)
-
Reinvestigation of the collective band structures in odd-odd Pm-138 nucleus
- 2015
-
Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 51:5
-
Tidskriftsartikel (refereegranskat)abstract
- The high-spin states in the odd-odd Pm-138 nucleus have been reinvestigated via the Te-124(F-19, 5n) reaction at the beam energy of 103MeV. Most of the known transitions and levels are confirmed. A number of bands are revised and one new band has been established. For the yrast pi h(11/2) circle times nu h(11/2) band based on 8(+) state, no evidence supporting the occurence of signature inversion is found. The experimental and theoretical B(M1)/B(E2) ratios have been calculated for band (2), which support the pi g(7/2)[413]5/2(+) circle times nu h(11/2)[514]9/2(-) Nilsson configuration assignment. Four bands with Delta I = 2 transitions are tentatively assigned as doubly decoupled bands. The other three bands are proposed as oblate-triaxial bands. The possible configuration assignments for these bands are also discussed under the calculations of total Routhian surface and particle-rotor model.
|
|
| 20. |
- Liu, Chong, et al.
(författare)
-
Microstructural refinement in spark plasma sintering 3Y-TZP nanoceramics
- 2016
-
Ingår i: Journal of the European Ceramic Society. - : Elsevier BV. - 0955-2219 .- 1873-619X. ; 36:10, s. 2565-2571
-
Tidskriftsartikel (refereegranskat)abstract
- A commercial 3Y-TZP nanopowder was consolidated by spark plasma sintering (SPS) techniques. By special die-upset designs, each possible influence from the electric field, uniaxial pressure and heating rate was peeled to identify its contribution. Besides density and grain growth, the evolution of pore structure was consulted to clarify the relationships between microstructural development and densification kinetics. The results showed that neither electric current nor fast heating had no decisive contributions while external force was a necessity for the microstructural refinement. The authors proposed that the essentially underlying mechanism was the intensive particle rearrangement, which involves no grain growth but particle close-packing through grain rotation and sliding. The full advantages of this mechanism can be taken in rapid heating conditions, which combined with the application of higher pressures, make the SPS family of techniques to have advancement in the preparations of nanoceramics over their conventional counterparts characterized by slow heating features.
|
|
