7,844 research outputs found
Spin Hall Effect and Spin Transfer in Disordered Rashba Model
Based on numerical study of the Rashba model, we show that the spin Hall
conductance remains finite in the presence of disorder up to a characteristic
length scale, beyond which it vanishes exponentially with the system size. We
further perform a Laughlin's gauge experiment numerically and find that all
energy levels cannot cross each other during an adiabatic insertion of the flux
in accordance with the general level-repulsion rule. It results in zero spin
transfer between two edges of the sample as each state always evolves back
after the insertion of one flux quantum, in contrast to the quantum Hall
effect. It implies that the topological spin Hall effect vanishes with the
turn-on of disorder.Comment: 4 pages, 4 figures final versio
Spin-charge separation in the single hole doped Mott antiferromagnet
The motion of a single hole in a Mott antiferromagnet is investigated based
on the t-J model. An exact expression of the energy spectrum is obtained, in
which the irreparable phase string effect [Phys. Rev. Lett. 77, 5102 (1996)] is
explicitly present. By identifying the phase string effect with spin backflow,
we point out that spin-charge separation must exist in such a system: the doped
hole has to decay into a neutral spinon and a spinless holon, together with the
phase string. We show that while the spinon remains coherent, the holon motion
is deterred by the phase string, resulting in its localization in space. We
calculate the electron spectral function which explains the line shape of the
spectral function as well as the ``quasiparticle'' spectrum observed in
angle-resolved photoemission experiments. Other analytic and numerical
approaches are discussed based on the present framework.Comment: 16 pages, 9 figures; references updated; to appear in Phys. Rev.
2-Chloro-8-methoxyquinoline-3-carbaldehyde
In the title compound, C11H8ClNO2, the quinoline fused-ring system is almost planar (r.m.s. deviation = 0.020 Å). The formyl group is slightly bent out of the quinoline plane [deviation of the O atom = 0.371 (2) Å]
Ethyl 6-chloro-2-methyl-4-phenylquinoline-3-carboxylate
In the title compound, C19H16ClNO2, the quinoline ring system is planar (r.m.s. deviation = 0.008 Å). The phenyl group and the –CO2 fragment of the ester unit form dihedral angles of 60.0 (1) and 60.5 (1)°, respectively, with the quinoline ring system
2-Chloroquinoline-3-carbaldehyde
The quinolinyl fused ring system of the title compound, C10H6ClNO, is planar (r.m.s. deviation = 0.018 Å); the formyl group is slightly bent out of the plane of the fused ring system [C—C—C—O torsion angle = 8.2 (3)°]
2-Chlorobenzo[h]quinoline-3-carbaldehyde
The benzo[h]quinolinyl fused-ring of the title compound, C14H8ClNO, is planar (r.m.s. deviation = 0.016 Å); the formyl group is slightly bent out of the plane [the C—C—C—O torsion angle is 10.7 (4)°]
2-Chloro-7,8-dimethylquinoline-3-carbaldehyde
All the non-H atoms of the title compound, C12H10ClNO, lie on a crystallographic mirror plane orientated perpendicular to the crystallographic b axis
Effect of different implant placement depths on crestal bone levels and soft tissue behavior: A 5â year randomized clinical trial
ObjectivesThis randomized clinical trial analyzed the longâ term (5â year) crestal bone changes and soft tissue dimensions surrounding implants with an internal tapered connection placed in the anterior mandibular region at different depths (equiâ and subcrestal).Materials and methodsEleven edentulous patients were randomly divided in a splitâ mouth design: 28 equicrestal implants (G1) and 27 subcrestal (1â 3 mm) implants (G2). Five implants were placed per patient. All implants were immediately loaded. Standardized intraoral radiographs were used to evaluate crestal bone (CB) changes. Patients were assessed immediately, 4, 8, and 60 months after implant placement. The correlation between vertical mucosal thickness (VMT) and soft tissue recession was analyzed. Subâ group analysis was also performed to evaluate the correlation between VMT and CB loss. Rankâ based ANOVA was used for comparison between groups (α = .05).ResultsFiftyâ five implants (G1 = 28 and G2 = 27) were assessed. Implant and prosthetic survival rate were 100%. Subcrestal positioning resulted in less CB loss (â 0.80 mm) when compared to equicrestal position (â 0.99 mm), although the difference was not statistically significant (p > .05). Significant CB loss was found within the G1 and G2 groups at two different measurement times (T4 and T60) (p  .05).ConclusionsThere was no statistically significant difference in CB changes between subcrestal and equicrestal implant positioning; however, subcrestal position resulted in higher bone levels. Neither mucosal recession nor vertical mucosa thickness was influenced by different implant placement depths.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154286/1/clr13569.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154286/2/clr13569_am.pd
2-[2-(Cyclohexylcarbonyl)phenyl]-1-phenylethanone
The title diketone, C21H22O2, features a phenylene ring having benzoylmethyl and cyclohexanoyl substituents ortho to each other. The cyclohexyl ring adopts a chair conformation with the ketonic group occupying an equatorial position; the four-atom –C(O)–C ketonic unit is twisted out of the plane of the phenylene ring by 34.9 (1)°
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