Research on double-yield surface model with considering time effect and its application in vibration engineering

In order to accurately study the dynamic characteristics of soft clay under vibrating loads, the classical double-yield surface model is improved in this paper, and it is introduced time effect which is proposed by Borja to build a constitutive model. The constitutive model considers creep and is suitable for analysis on dynamic characteristics of soft clay. Next, GDS dynamic triaxial experiment is carried out in the indoor, and validation analysis is conducted by means of the experimental data. In order to verify its actual effect, the improved model is applied to settlement calculation of soft clay during subway operation under vibrating loads, and then the calculation result is compared with the experimental data. It shows that the improved double-yield surface model which considers time effect can describe the dynamic deformation characteristics of soft clay more reasonably. And the proposed model is suitable for analysis on settlement of soft clay under vibrating loads of subway

Multifunctional photonic integrated circuit for diverse microwave signal generation, transmission and processing

Microwave photonics (MWP) studies the interaction between microwave and optical waves for the generation, transmission and processing of microwave signals (i.e., three key domains), taking advantages of broad bandwidth and low loss offered by modern photonics. Integrated MWP using photonic integrated circuits (PICs) can reach a compact, reliable and green implementation. Most PICs, however, are recently developed to perform one or more functions restricted inside a single domain. In this paper, as highly desired, a multifunctional PIC is proposed to cover the three key domains. The PIC is fabricated on InP platform by monolithically integrating four laser diodes and two modulators. Using the multifunctional PIC, seven fundamental functions across microwave signal generation, transmission and processing are demonstrated experimentally. Outdoor field trials for electromagnetic environment surveillance along an in-service high-speed railway are also performed. The success to such a PIC marks a key step forward for practical and massive MWP implementations.Comment: 17 page

Evidence of Hadronic Emission from the brightest-of-all-time GRB 221009A

Acceleration of hadrons in relativistic shocks has been long expected and invoked to model GRB high-energy photon and neutrino emissions. However, so far there has been no direct observational evidence of hadronic emission from GRBs. The B.O.A.T. ("brightest of all time") gamma-ray burst (GRB) 221009A had extreme energies (with an isotropic energy exceeding $10^{55}$ erg) and was detected in broad-band including the very-high-energy (VHE, $>100\,\rm GeV$) band up to $>10$ TeV. Here we perform a comprehensive spectral analysis of the GRB from keV to TeV energy range and perform detailed spectral and light curve modelings considering both the traditional synchrotron self-Compton process and the electromagnetic (EM) cascade process initiated by hadronic interactions by accelerated cosmic rays in the external shock. We find that the leptonic scenario alone is not adequate to account for the observations, whereas the proposed scenario with the combination of hadronic and leptonic components can well reproduce the multi-wavelength spectra and the light curve. This result reveals the existence of the accelerated hadronic component in the early afterglow of this extreme burst. According to this scenario, the observed TeV light curve should contain imprints of the prompt MeV emission.Comment: 15 pages, 4 figures, 3 tables. originally submitted version for Nature Astronom

Calculation of earth pressure on rigid retaining walls with considerations to the seismic load and soil stress-deflection

At present, the calculation of active earth pressure behind retaining walls is mainly based on the hypothesis that the fracture surface of rolling earth behind retaining walls is straight-running through wall heels. However, most experiments have proven that this hypothesis is false. In this study, active earth pressure behind retaining walls under seismic loading was discussed from the perspective of stress deflection. Stress on soil layer behind the vertical retaining wall was analyzed by quasi-static method. Then, the expression of seismic angle of rupture was proposed by referring to the balance of horizontal forces and changes with wall height. On this basis, the calculation formulas of active earth pressure, seismic active earth force, total moment at the wall and the point of application of active thrust from the base of wall were acquired by solving this balance equation. Calculated results were compared with test data and results of other methods. The rationality of the proposed method was verified. Thus, the proposed method is applicable to multi-layered filling behind the retaining wall

Search for serum biomarkers in patients with bipolar disorder and major depressive disorder using metabolome analysis

ObjectiveBipolar disorder (BD) and major depressive disorder (MDD) are two common psychiatric disorders. Due to the overlapping clinical symptoms and the lack of objective diagnostic biomarkers, bipolar disorder (BD) is easily misdiagnosed as major depressive disorder (MDD), which in turn affects treatment decisions and prognosis. This study aimed to investigate biomarkers that could be used to differentiate BD from MDD.MethodsNuclear magnetic resonance (NMR) spectroscopy was performed to assess serum metabolic profiles in depressed patients with BD (n = 59), patients with MDD (n = 14), and healthy controls (n = 10). Data was analyzed using partial least squares discriminant analysis, orthogonal partial least squares discriminant analysis and t-tests. Different metabolites (VIP > 1 and p < 0.05) were identified and further analyzed using Metabo Analyst 5.0 to identify relevant metabolic pathways.ResultsThe metabolic phenotypes of the BD and MDD groups were significantly different from those of the healthy controls, and there were different metabolite differences between them. In the BD group, the levels of 3-hydroxybutyric acid, n-acetyl glycoprotein, β-glucose, pantothenic acid, mannose, glycerol, and lipids were significantly higher than those in the healthy control group, and the levels of lactate and acetoacetate were significantly lower than those in the healthy control group. In the MDD group, the levels of 3-hydroxybutyric acid, n-acetyl glycoprotein, pyruvate, choline, acetoacetic acid, and lipids were significantly higher than those of healthy controls, and the levels of acetic acid and glycerol were significantly lower than those of healthy controls.ConclusionGlycerolipid metabolism is significantly involved in BD and MDD. Pyruvate metabolism is significantly involved in MDD. Pyruvate, choline, and acetate may be potential biomarkers for MDD to distinguish from BD, and pantothenic acid may be a potential biomarker for BD to distinguish from MDD