1,623 research outputs found
Structure of the cuspidal rational torsion subgroup of J_1(p^n)
In this article, we determine the structure of the -primary subgroup of
the cuspidal rational torsion subgroup of the Jacobian of the
modular curve for a regular prime .Comment: 26 page
Two distinct topological phases in the mixed valence compound YbB6 and its differences from SmB6
We discuss the evolution of topological states and their orbital textures in
the mixed valence compounds SmB6 and YbB6 within the framework of the
generalized gradient approximation plus onsite Coulomb interaction (GGA+U)
scheme for a wide range of values of U. In SmB6, the topological Kondo
insulator (TKI) gap is found to be insensitive to the value of U, but in sharp
contrast, Kondo physics in isostructural YbB6 displays a surprising sensitivity
to U. In particular, as U is increased in YbB6, the correlated TKI state in the
weak-coupling regime transforms into a d-p-type topological insulator phase
with a band inversion between Yb-5d and B-2p orbitals in the intermediate
coupling range, without closing the insulating energy gap throughout this
process. Our theoretical predictions related to the TKI and non-TKI phases in
SmB6 and YbB6 are in substantial accord with recent angle-resolved
photoemission spectroscopy (ARPES) experiments.Comment: 6 pages, 4 figures URL:
http://link.aps.org/doi/10.1103/PhysRevB.91.15515
Voice pitch elicited frequency following response in Chinese elderlies
Background: Perceptual and electrophysiological studies have found reduced speech discrimination in quiet and noisy environment, delayed neural timing, decreased neural synchrony, and decreased temporal processing ability in elderlies, even those with normal hearing. However, recent studies have also demonstrated that language experience and auditory training enhance the temporal dynamics of sound encoding in the auditory brainstem response (ABR). The purpose of this study was to explore the pitch processing ability at the brainstem level in an aging population that has a tonal language background. Method: Mandarin speaking younger (n = 12) and older (n = 12) adults were recruited for this study. All participants had normal audiometric test results and normal suprathreshold click-evoked ABR. To record frequency following responses (FFRs) elicited by Mandarin lexical tones, two Mandarin Chinese syllables with different fundamental frequency pitch contours (Flat Tone and Falling Tone) were presented at 70 dB SPL. Fundamental frequencies (f0) of both the stimulus and the responses were extracted and compared to individual brainstem responses. Two indices were used to examine different aspects of pitch processing ability at the brainstem level: Pitch Strength and Pitch Correlation. Results: Lexical tone elicited FFR were overall weaker in the older adult group compared to their younger adult counterpart. Measured by Pitch Strength and Pitch Correlation, statistically significant group differences were only found when the tone with a falling f0 (Falling Tone) were used as the stimulus. Conclusion: Results of this study demonstrated that in a tonal language speaking population, pitch processing ability at the brainstem level of older adults are not as strong and robust as their younger counterparts. Findings of this study are consistent with previous reports on brainstem responses of older adults whose native language is English. On the other hand, lexical tone elicited FFRs have been shown to correlate with the length of language exposure. Older adults\u27 degraded responses in our study may also be due to that, the Mandarin speaking older adults\u27 long term exposure somewhat counteracted the negative impact on aging and helped maintain, or at least reduced, the degradation rate in their temporal processing capacity at the brainstem level
Consistency between ARPES and STM measurements on SmB
Strongly correlated topological surface states are promising platforms for
next-generation quantum applications, but they remain elusive in real
materials. The correlated Kondo insulator SmB is one of the most promising
candidates, with theoretically predicted heavy Dirac surface states supported
by transport and scanning tunneling microscopy (STM) experiments. However, a
puzzling discrepancy appears between STM and angle-resolved photoemission
(ARPES) experiments on SmB. Although ARPES detects spin-textured surface
states, their velocity is an order of magnitude higher than expected, while the
Dirac point -- the hallmark of any topological system -- can only be inferred
deep within the bulk valence band. A significant challenge is that SmB
lacks a natural cleavage plane, resulting in ordered surface domains limited to
10s of nanometers. Here we use STM to show that surface band bending can shift
energy features by 10s of meV between domains. Starting from our STM spectra,
we simulate the full spectral function as an average over multiple domains with
different surface potentials. Our simulation shows excellent agreement with
ARPES data, and thus resolves the apparent discrepancy between large-area
measurements that average over multiple band-shifted domains and
atomically-resolved measurements within a single domain
Application of Digitizing Methods to Urban Area with an Example-- Zong-Ye Historic District, Tainan City
This article attempts to apply digitizing methods to historic assets in old downtown by map overlaying analysis after map rectifying, and then taking textual method through surveying images. After proving and conform through research, townscape could be connected with real historic traces by reality digitizing approach, and it will make a reality aura of formerly district for visitors. In this way the abundant, definite and impressive content of district can be the valuable materials in region development, and the time and space of this district could continue the history and culture of the city. Consequently, this article aims to set up a feasibility proposal applied to it concretely. This article puts forward 1.the district analysis through historic map rectifying 2.the reality digital reconstruction of streets digital archives elements 3.the application on AR(Augmented Reality) in historic district, and brings forward an technological approach which could respond to the challenge of losing regional characteristics in redevelopment process with an example of Zong-Ye historic district in traditional Tainan City. Therefore, this proposal which places great emphasis on local history and culture is equipped with applying value for European cities based on plentiful culture in cultural industries and regional development issues.
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