119 research outputs found
A new crack diagnosis method on box structure based on empirical mode decomposition
A new crack diagnosis method on a two-story box structure based on empirical mode decomposition is proposed in this paper. According to the simulation analysis, it turns out that the model of the structure can be barely influenced by the crack. Response signals of swept sine vibration test are empirical mode decomposed into a set of intrinsic mode functions, from which tag vectors are constructed, then tag angles are defined to dignose the failure of the board. Combined with the load direction to the structure, the position and direction of the crack can be deduced using tag angles
Rotational symmetry breaking in superconducting nickelate Nd0.8Sr0.2NiO2 films
The infinite-layer nickelates, isostructural to the high-Tc superconductor
cuprates, have risen as a promising platform to host unconventional
superconductivity and stimulated growing interests in the condensed matter
community. Despite numerous researches, the superconducting pairing symmetry of
the nickelate superconductors, the fundamental characteristic of a
superconducting state, is still under debate. Moreover, the strong electronic
correlation in the nickelates may give rise to a rich phase diagram, where the
underlying interplay between the superconductivity and other emerging quantum
states with broken symmetry is awaiting exploration. Here, we study the angular
dependence of the transport properties on the infinite-layer nickelate
Nd0.8Sr0.2NiO2 superconducting films with Corbino-disk configuration. The
azimuthal angular dependence of the magnetoresistance (R({\phi})) manifests the
rotational symmetry breaking from isotropy to four-fold (C4) anisotropy with
increasing magnetic field, revealing a symmetry breaking phase transition.
Approaching the low temperature and large magnetic field regime, an additional
two-fold (C2) symmetric component in the R({\phi}) curves and an anomalous
upturn of the temperature-dependent critical field are observed simultaneously,
suggesting the emergence of an exotic electronic phase. Our work uncovers the
evolution of the quantum states with different rotational symmetries and
provides deep insight into the global phase diagram of the nickelate
superconductors
Quantum Griffiths singularity in three-dimensional superconductor to Anderson critical insulator transition
Disorder is ubiquitous in real materials and can have dramatic effects on
quantum phase transitions. Originating from the disorder enhanced quantum
fluctuation, quantum Griffiths singularity (QGS) has been revealed as a
universal phenomenon in quantum criticality of low-dimensional superconductors.
However, due to the weak fluctuation effect, QGS is very challenging to detect
experimentally in three-dimensional (3D) superconducting systems. Here we
report the discovery of QGS associated with the quantum phase transition from
3D superconductor to Anderson critical insulator in a spinel oxide MgTi2O4
(MTO). Under both perpendicular and parallel magnetic field, the dynamical
critical exponent diverges when approaching the quantum critical point,
demonstrating the existence of 3D QGS. Among 3D superconductors, MTO shows
relatively strong fluctuation effect featured as a wide superconducting
transition region. The enhanced fluctuation, which may arise from the mobility
edge of Anderson localization, finally leads to the occurrence of 3D quantum
phase transition and QGS. Our findings offer a new perspective to understand
quantum phase transitions in strongly disordered 3D systems
Rotational Symmetry Breaking in Superconducting Nickelate Nd0.8Sr0.2NiO2 Films
The infinite-layer nickelates, isostructural to the high-Tc cuprate superconductors, have emerged as a promising platform to host unconventional superconductivity and stimulated growing interest in the condensed matter community. Despite considerable attention, the superconducting pairing symmetry of the nickelate superconductors, the fundamental characteristic of a superconducting state, is still under debate. Moreover, the strong electronic correlation in the nickelates may give rise to a rich phase diagram, where the underlying interplay between the superconductivity and other emerging quantum states with broken symmetry is awaiting exploration. Here, we study the angular dependence of the transport properties of the infinite-layer nickelate Nd0.8Sr0.2NiO2 superconducting films with Corbino-disk configuration. The azimuthal angular dependence of the magnetoresistance (R(φ)) manifests the rotational symmetry breaking from isotropy to four-fold (C4) anisotropy with increasing magnetic field, revealing a symmetry-breaking phase transition. Approaching the low-temperature and large-magnetic-field regime, an additional two-fold (C2) symmetric component in the R(φ) curves and an anomalous upturn of the temperature-dependent critical field are observed simultaneously, suggesting the emergence of an exotic electronic phase. Our work uncovers the evolution of the quantum states with different rotational symmetries in nickelate superconductors and provides deep insight into their global phase diagram
Incremental prognostic value of ADC histogram analysis in patients with high-risk prostate cancer receiving adjuvant hormonal therapy after radical prostatectomy
PurposeTo investigate the incremental prognostic value of preoperative apparent diffusion coefficient (ADC) histogram analysis in patients with high-risk prostate cancer (PCa) who received adjuvant hormonal therapy (AHT) after radical prostatectomy (RP).MethodsSixty-two PCa patients in line with the criteria were enrolled in this study. The 10th, 50th, and 90th percentiles of ADC (ADC10, ADC50, ADC90), the mean value of ADC (ADCmean), kurtosis, and skewness were obtained from the whole-lesion ADC histogram. The Kaplan–Meier method and Cox regression analysis were used to analyze the relationship between biochemical recurrence-free survival (BCR-fs) and ADC parameters and other clinicopathological factors. Prognostic models were constructed with and without ADC parameters.ResultsThe median follow-up time was 53.4 months (range, 41.1-79.3 months). BCR was found in 19 (30.6%) patients. Kaplan−Meier curves showed that lower ADCmean, ADC10, ADC50, and ADC90 and higher kurtosis could predict poorer BCR-fs (all p<0.05). After adjusting for clinical parameters, ADC50 and kurtosis remained independent prognostic factors for BCR-fs (HR: 0.172, 95% CI: 0.055-0.541, p=0.003; HR: 7.058, 95% CI: 2.288-21.773, p=0.001, respectively). By adding ADC parameters to the clinical model, the C index and diagnostic accuracy for the 24- and 36-month BCR-fs were improved.ConclusionADC histogram analysis has incremental prognostic value in patients with high-risk PCa who received AHT after RP. Combining ADC50, kurtosis and clinical parameters can improve the accuracy of BCR-fs prediction
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