65 research outputs found
Recommended from our members
Favoritism Toward Foreign and Domestic Brands: A Comparison of Different Theoretical Explanations
Five theoretical approaches can predict favoritism toward domestic and foreign brands. This article applies a contrastive perspective to examine social identity, personal identity, cultural identity, system justification, and categorical cognition theories and their attendant constructs. The authors propose a set of main-effects hypotheses as well as hypotheses related to both product and country moderation effects on attitudes toward and loyalty to domestic and foreign brands. They test the hypotheses on a sample of Chinese consumers with respect to salient brands from 12 product categories. The results indicate that three of the theoretical approaches examined can explain only one side of favoritism—most commonly favoritism toward domestic brands—but not favoritism toward both domestic and foreign brands. Consumer xenocentrism, a concept rooted in system justification theory, seems to provide more consistent predictions for both domestic- and foreign-brand bias
Observation of electronic nematicity driven by three-dimensional charge density wave in kagome lattice KVSb
Kagome superconductors AVSb (A = K, Rb, Cs) provide a fertile
playground for studying various intriguing phenomena such as non-trivial band
topology, superconductivity, giant anomalous Hall effect, and charge density
wave (CDW). Remarkably, the recent discovery of symmetric nematic phase
prior to the superconducting state in AVSb has drawn enormous
attention, as the unusual superconductivity might inherit the symmetry of the
nematic phase. Although many efforts have been devoted to resolve the charge
orders using real-space microscopy and transport measurements, the direct
evidence on the rotation symmetry breaking of the electronic structure in the
CDW state from the reciprocal space is still rare. The underlying mechanism is
still ambiguous. Here, utilizing the micron-scale spatially resolved
angle-resolved photoemission spectroscopy, we observed the fingerprint of band
folding in the CDW phase of KVSb, which yet demonstrates the
unconventional unidirectionality, and is indicative of the rotation symmetry
breaking from to . We then pinpointed that the interlayer coupling
between adjacent planes with -phase offset in the 222 CDW
phase would lead to the preferred twofold symmetric electronic structure.
Time-reversal symmetry is further broken at temperatures below 40 K as
characterized by giant anomalous Hall effect triggered by weak magnetic fields.
These rarely observed unidirectional back-folded bands with time-reversal
symmetry breaking in KVSb may provide important insights into its
peculiar charge order and superconductivity
Observation of nonrelativistic plaid-like spin splitting in a noncoplanar antiferromagnet
Spatial, momentum and energy separation of electronic spins in condensed
matter systems guides the development of novel devices where spin-polarized
current is generated and manipulated. Recent attention on a set of previously
overlooked symmetry operations in magnetic materials leads to the emergence of
a new type of spin splitting besides the well-studied Zeeman, Rashba and
Dresselhaus effects, enabling giant and momentum dependent spin polarization of
energy bands on selected antiferromagnets independent of relativistic
spin-orbit interaction. Despite the ever-growing theoretical predictions, the
direct spectroscopic proof of such spin splitting is still lacking. Here, we
provide solid spectroscopic and computational evidence for the existence of
such materials. In the noncoplanar antiferromagnet MnTe, the in-plane
components of spin are found to be antisymmetric about the high-symmetry planes
of the Brillouin zone, comprising a plaid-like spin texture in the
antiferromagnetic ground state. Such an unconventional spin pattern, further
found to diminish at the high-temperature paramagnetic state, stems from the
intrinsic antiferromagnetic order instead of the relativistic spin-orbit
coupling. Our finding demonstrates a new type of spin-momentum locking with a
nonrelativistic origin, placing antiferromagnetic spintronics on a firm basis
and paving the way for studying exotic quantum phenomena in related materials.Comment: Version 2, 30 pages, 4 main figures and 8 supporting figure
Rationale and design of a multi‐center, prospective randomized controlled trial on the effects of sacubitril–valsartan versus enalapril on left ventricular remodeling in ST ‐elevation myocardial infarction: The PERI‐STEMI study
Background
Angiotensin receptor neprilysin inhibitor (ARNI) sacubitril-valsartan has been recommended as one of the first-line therapies in heart failure with reduced ejection fraction. However, whether ARNI could benefit patients with ST-segment elevation myocardial infarction (STEMI) by improving left ventricular (LV) remodeling remains unknown. The primary objective of the PERI-STEMI trial is to assess whether sacubitril-valsartan is more effective in preventing adverse LV remodeling for patients with STEMI than enalapril.
Hypothesis
We hypothesize that sacubitril/valsartan is superior to enalapril in preventing adverse LV remodeling evaluated by cardiovascular magnetic resonance imaging at the 6-month follow-up.
Methods
PERI-STEMI is an investigator-initiated, prospective, multi-center, randomized, open-label, superiority trial with blinded evaluation of outcomes. A total of 376 first-time STEMI patients with primary percutaneous coronary intervention (PPCI) within 12 h after symptom onset will be randomized to sacubitril-valsartan or enalapril treatment. All the patients will receive a baseline cardiovascular magnetic resonance (CMR) examination at 4–7 days post-PPCI. The primary endpoint is the change of indexed LV mass at the 6-month follow-up CMR.
Results
Enrollment of the first patient is planned in November 2021. Recruitment is anticipated to last for 12–18 months and patients will be followed for 5 years after randomization. The study is expected to complete in June 2027.
Conclusions
The results of the PERI-STEMI trial are expected to provide CMR evidence on whether ARNI could benefit patients with STEMI, so as to facilitate the strategy of CMR-based risk stratification and therapy selection for these patients. PERI-STEMI is registered at ClinicalTrials.gov (NCT04912167)
The index set problem for Boolean (or nonnegative) matrices
AbstractThe index set problem for a class of Boolean (or nonnegative) matrices is a generalization of the exponent set problem for n × n primitive matrices. We survey the recent advances on the index set problem for various classes of Boolean matrices. Some related research problems are suggested
Nonlinear Dynamics Analysis of Disc Brake Frictional Vibration
The brake system is a key component to ensuring the safe driving and riding comfort of the vehicle, and the friction between the brake disc and the friction plate is the main source of vibration and noise. Therefore, in order to improve the stability of the braking system and reduce the generation of vibration, a six-degree-of-freedom nonlinear dynamics model was established, and using the Stribeck friction model and related parameters, the dynamic equation was solved by the Runge-Kutta method. The bifurcation diagram, Lyapunov diagram, time domain diagram, frequency spectrum diagram, and phase plane diagram of the brake pad and brake disc during friction braking were obtained, and the vibration characteristics of both under different braking pressure, braking speed, brake pad support stiffness, and brake disc support stiffness were analyzed. The results show that brake pressure is an important factor in triggering nonlinear vibration; increasing the braking speed will increase the amplitude of vibration, but will shorten the time to enter the stable motion state, and increasing the support stiffness brake pad and disc will reduce the amplitude of system vibration
Nonlinear Dynamics Analysis of Disc Brake Frictional Vibration
The brake system is a key component to ensuring the safe driving and riding comfort of the vehicle, and the friction between the brake disc and the friction plate is the main source of vibration and noise. Therefore, in order to improve the stability of the braking system and reduce the generation of vibration, a six-degree-of-freedom nonlinear dynamics model was established, and using the Stribeck friction model and related parameters, the dynamic equation was solved by the Runge-Kutta method. The bifurcation diagram, Lyapunov diagram, time domain diagram, frequency spectrum diagram, and phase plane diagram of the brake pad and brake disc during friction braking were obtained, and the vibration characteristics of both under different braking pressure, braking speed, brake pad support stiffness, and brake disc support stiffness were analyzed. The results show that brake pressure is an important factor in triggering nonlinear vibration; increasing the braking speed will increase the amplitude of vibration, but will shorten the time to enter the stable motion state, and increasing the support stiffness brake pad and disc will reduce the amplitude of system vibration
- …