2,550 research outputs found
New class of 3D topological insulator in double perovskite
We predict a new class of three-dimensional topological insulators (TIs) in
which the spin-orbit coupling (SOC) can more effectively generate a large band
gap at point. The band gap of conventional TI such as BiSe is
mainly limited by two factors, the strength of SOC and, from electronic
structure perspective, the band gap when SOC is absent. While the former is an
atomic property, we find that the latter can be minimized in a generic
rock-salt lattice model in which a stable crossing of bands {\it at} the Fermi
level along with band character inversion occurs for a range of parameters in
the absence of SOC. Thus, large-gap TI's or TI's comprised of lighter elements
can be expected. In fact, we find by performing first-principle calculations
that the model applies to a class of double perovskites ABiXO (A = Ca,
Sr, Ba; X = Br, I) and the band gap is predicted up to 0.55 eV. Besides, more
detailed calculations considering realistic surface structure indicate that the
Dirac cones are robust against the presence of dangling bond at the boundary
with a specific termination.Comment: submitted; title changed and new references added; see DOI for
published versio
Gapless topological Fulde-Ferrell superfluidity in spin-orbit coupled Fermi gases
Topological superfluids usually refer to a superfluid state which is gapped
in the bulk but metallic at the boundary. Here we report that a gapless,
topologically non-trivial superfluid with inhomogeneous Fulde-Ferrell pairing
order parameter can emerge in a two-dimensional spin-orbit coupled Fermi gas,
in the presence of both in-plane and out-of-plane Zeeman fields. The
Fulde-Ferrell pairing - induced by the spin-orbit coupling and in-plane Zeeman
field - is responsible for this gapless feature. This exotic superfluid has a
significant Berezinskii-Kosterlitz-Thouless (BKT) transition temperature and
has robust Majorana edge modes against disorder owing to its topological
nature.Comment: 5 pages, 5 figures; add the results on the critical BKT temperature
and superfluid density, as well as the discussion on the robustness of the
chiral edge states against disorde
Dynamic Evolution of Eukaryotic Mitochondrial and Nuclear Genomes: A Case Study in the Gourmet Pine Mushroom Tricholoma matsutake
Fungi, as eukaryotic organisms, contain two genomes, the mitochondrial genome and the nuclear genome, in their cells. How the two genomes evolve and correlate to each other is debated. Herein, taking the gourmet pine mushroom Tricholoma matsutake as an example, we performed comparative mitogenomic analysis using samples collected from diverse locations and compared the evolution of the two genomes. The T. matsutake mitogenome encodes 49 genes and is rich of repetitive and non-coding DNAs. Six genes were invaded by up to 11 group I introns, with one cox1 intron cox1P372 showing presence/absence dynamics among different samples. Bioinformatic analyses suggested limited or no evidence of mitochondrial heteroplasmy. Interestingly, hundreds of mitochondrial DNA fragments were found in the nuclear genome, with several larger than 500 nt confirmed by PCR assays and read count comparisons, indicating clear evidence of transfer of mitochondrial DNA into the nuclear genome. Nuclear DNA of T. matsutake showed a higher mutation rate than mitochondrial DNA. Furthermore, we found evidence of incongruence between phylogenetic trees derived from mitogenome and nuclear DNA sequences. Together, our results reveal the dynamic genome evolution of the gourmet pine mushroom.Peer reviewe
CUSTOMER READINESS, MARKET ORIENTATION AND TRANSACTION FREQUENCY IN MOBILE BANKING SERVICE RECOVERY
This study investigates the effect of internet banking service recovery satisfaction on future intention toward using mobile banking, and examines transaction frequency as a moderator of this relationship. Moreover, this study applies customer participation in service recovery and service recovery experience as the influential factors of service recovery satisfaction. Questionnaires were obtained 419 respondents with internet banking and service recovery experience. The results of SEM analysis illustrate that both role clarity and ability of service recovery can affect the level of service recovery participation. Additionally, the internet banking service provider’s responsive and proactive customer orientation can influence customer service recovery experience, which further increases service recovery satisfaction. Recovery satisfaction can thus affect future intention toward using mobile banking. The moderating effect of transaction frequency was also confirmed. Theoretical and managerial implications are discussed
Expanded CURB-65: A new score system predicts severity of community-acquired pneumonia with superior efficiency
Aim of this study was to develop a new simpler and more effective severity score for communityacquired pneumonia (CAP) patients. A total of 1640 consecutive hospitalized CAP patients in Second
Affiliated Hospital of Zhejiang University were included. The effectiveness of different pneumonia
severity scores to predict mortality was compared, and the performance of the new score was validated
on an external cohort of 1164 patients with pneumonia admitted to a teaching hospital in Italy.
Using age≥ 65 years, LDH>230u/L, albumin<3.5g/dL, platelet count<100×109/L, confusion,
urea>7mmol/L, respiratory rate≥30/min, low blood pressure, we assembled a new severity score
named as expanded-CURB-65. The 30-day mortality and length of stay were increased along with
increased risk score. The AUCs in the prediction of 30-day mortality in the main cohort were 0.826
(95%CI, 0.807–0.844), 0.801 (95%CI, 0.781–0.820), 0.756 (95%CI, 0.735–0.777), 0.793 (95%CI,
0.773–0.813) and 0.759 (95%CI, 0.737–0.779) for the expanded-CURB-65, PSI, CURB-65, SMART-COP
and A-DROP, respectively. The performance of this bedside score was confirmed in CAP patients of
the validation cohort although calibration was not successful in patients with health care-associated
pneumonia (HCAP). The expanded CURB-65 is objective, simpler and more accurate scoring system for
evaluation of CAP severity, and the predictive efficiency was better than other score systems
2-(MethylÂsulfanÂyl)cycloÂdodecaÂnone tosylÂhydrazone
The title compound, C20H32N2O2S2, has been synthesized by the reaction of α-methylÂsulfanylcycloÂdodecaÂnone and p-tolueneÂsulfonylÂhydrazine. In the crystal structure, the conformation of the non-benzenoid ring is [3333] and the methylÂsulfanyl group is in the α-side exo position. The molÂecules are linked by interÂmolecular N—H⋯S hydrogen bonds
Spin-Neutral Tunneling Anomalous Hall Effect
Anomalous Hall effect (AHE) is a fundamental spin-dependent transport property that is widely used in spintronics. It is generally expected that currents carrying net spin polarization are required to drive the AHE. Here we demonstrate that, in contrast to this common expectation, a spin-neutral tunneling AHE (TAHE), i.e. a TAHE driven by spin-neutral currents, can be realized in an antiferromagnetic (AFM) tunnel junction where an AFM electrode with a non-spin-degenerate Fermi surface and a normal metal electrode are separated by a non-magnetic barrier with strong spin-orbit coupling (SOC). The symmetry mismatch between the AFM electrode and the SOC barrier results in an asymmetric spin-dependent momentum filtering of the spin-neutral longitudinal current generating the transverse Hall current in each electrode. We predict a sizable spin-neutral TAHE in an AFM tunnel junction with a RuO2-type AFM electrode and a SnTe-type SOC barrier and show that the Hall currents are reversible by the Néel vector switching. With the Hall angle being comparable to that in conventional AHE bulk materials, the predicted spin-neutral TAHE can be used for the Néel vector detection in antiferromagnetic spintronics
Examining resilience in local adaptation policies – pilot studies in Taipei and Tainan, Taiwan
Resilience has gained considerable attention over recent years in both theories and decision-making practices. In Taiwan, the term resilience is generally considered as a synonym for adaptation. This may limit the use of the notion. By understanding resilience in terms of adaptation and mitigation, we identify six attributes for assessment. The assessment is addressed in local level climate change adaptation policies in two selected cities. The city of Taipei represents places where local adaptation policies were directed mainly by the national government. The city of Tainan represents places where the municipal government plays a more critical role in framing these policies. This can result in different policymaking considerations. The assessment points out that the proposed actions of these policies are broader than a general understanding of adaptation. Mitigation strategies are addressed and sometimes highly recommended. Because of this, we can interpret these actions as resilience strategies covered under the use of the term adaptation. The notion of resilience does not stay on the rhetorical level alone. It is happening in shaping decisions – without using the terminology directly. The broadness of the resilience notion, in spite of being abstract, can provide a more general framework for cross-sectorial discussion and collaboration in policy-making. This is particularly important for dealing with complex issues, such as climate-related disturbances, which cannot be managed by a single group of professions
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