A 2.5D analysis is presented of the vibration reduction of buildings alongside the railway by open or infilled trenches. Assuming the soil-structure system to be uniform along the railway direction, ...the 2D profile is used for obtaining the 3D response of the system by the 2.5D approach. Unlike most previous studies, the effect of self oscillation frequencies of the train due to wheel-rail interaction associated with rail irregularity is duly taken into account, in addition to the train and trench parameters. Focus is placed on the difference between the 2D and 2.5D results and on the mechanism of isolation of for the building. Contrary to the 2D analysis, the 2.5D response for the floor is found to be higher than the ceiling, implying that the wave transmission effect along the railway direction is greater than the amplification effect of the building structure. In addition, the 2.5D results are generally smaller than the 2D ones due to confinement of energy on the 2D plane. Both open and in-filled trenches are good for reducing building vibrations induced by trains, especially by those with higher self-oscillation frequencies when moving over irregular railways.
•First use of 2.5D approach to analyze the vibration of railway-side buildings mitigated by trenches.•First inclusion of train’s self oscillation frequencies due to wheel-rail interaction in the presence of rail irregularity.•Physical interpretation of the difference in the responses obtained by the 2.5D and 2D approaches.•Unveiling the mechanism of isolation by trenches with regard to excitation by moving trains for various physical parameters.•Conclusions crucial to the design of trenches are drawn for practical applications.
Cadmium (Cd) is the major component of polluted environment, which has numerous undesirable effects on health. Cd could induce apoptosis of HEK293 cells, and the mitochondria may play a key role. ...However, the mode of action is unclear. In the present study, we aimed to evaluate the ability of the Cd to induce dysfunction of mitochondria. We examined the effect of cadmium chloride (1, 5 and 10 μM) on mitochondrial membrane permeability and potential as well as oxidative stress markers in mitochondria isolated from HEK293 cells. We found that Cd could directly increase in permeability and decrease in membrane potential of mitochondria, even resulted in mitochondrial swelling, and that Cd could inhibit the activities of ATPase, lactate dehydrogenase (LDH), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), enhanced the levels of reactive oxygen species (ROS) and lipid peroxidation (LPO). On the whole, the results show that Cd can directly lead to mitochondrial dysfunction of HEK293 cells, including increased permeability, inhibiting respiration and evoking oxidative stress. Thus, for the first time, this paper makes an overall analysis of Cd-induced changes of structure and function of isolated mitochondria. Our findings may also have general implications in Cd-induced apoptosis by mitochondria pathway.
In the first part of a two-paper sequence, the phase distortion caused by inhomogeneous radomes is studied to reveal the boresight error (BSE) characteristics, and a method is proposed to estimate ...the insertion phase delay distribution and the BSE. In this second part, the bandwidth performance and the effect of radome coating, thickness errors, and layer number are further analyzed to acquire an overall understanding of the performance of inhomogeneous radomes through the comparison with variable thickness radomes (VTRs). Transmission loss and BSE, the two most important EM characteristics of airborne radomes, are considered. The bandwidth performance of VTRs is, from the authors' best knowledge, for the first time optimized, and corresponding conclusions are drawn. Results indicate that inhomogeneous radomes have superiorities over VTRs, which makes this kind of radome a potentially popular choice in modern airborne applications.
In this paper, the spin and parity of the Zc(3900)± state are determined to be JP = 1+ with a statistical significance larger than 7σ over other quantum numbers in a partial wave analysis of the ...process e+e- → π+π-J/Ψ. We use a data sample of 1.92 fb-1 accumulated at $ \sqrt{s}=4.23 $ and 4.26 GeV with the BESIII experiment. When parametrizing the Zc(3900)± with a Flatté-like formula, we determine its pole mass Mpole = (3881.2±4.2stat ±52.7syst) MeV/c2 and pole width Γpole = (51.8± 4.6stat ± 36.0syst) MeV. Finally, we also measure cross sections for the process e+e- → Zc(3900)+π- + c.c. → J/Ψπ+π- and determine an upper limit at the 90% confidence level for the process e+e- → Zc(4020)+π- + c.c. → J/Ψ π+π-.
The 2.5D dynamic response of a half-space to an internal point load moving at sub- and super-critical speeds is studied in Cartesian coordinates both analytically and numerically. Firstly, the ...partial differential equations of waves are converted to the ordinary differential equations by the Fourier transformation. Then, a multiplying factor is derived and added to the stiffness matrix to account for the dissipation of the load moving at different velocities, with or without self-frequency. Finally, the displacements of the half-space induced by the waves propagating upward and downward are obtained analytically for the specified boundary conditions. For comparison, the half-space is also analyzed by the 2.5D finite/infinite element method. The findings of the paper include: (1) the 2.5D solutions for a point load moving extremely fast are same as those for the line load by the 2D approach, (2) the dissipation of the moving load can be considered by adjusting the multiplying factor, (3) the attenuation of the half-space above the load level is reduced by the dissipation of the moving load, and (4) the displacement of the half-space increases with the self-frequency of the moving load.
•2.5D response of half-space to an internal point load moving is studied analytically and numerically.•Both sub- and super-critical velocities of the load relative to Rayleigh's wave velocity are considered.•Dissipation of the moving load is considered by adjusting the multiplying factor.•2.5D solutions for a point load moving extremely fast are same as those for 2D solutions for a line load.•Attenuation of half-space above the load level is reduced by dissipation of the load.
Aim To present the neuroradiological and clinical characteristics of Ewing's sarcoma family of tumours (ESFTs) and to increase awareness of this neoplasm. Materials and methods The magnetic resonance ...imaging (MRI) features and clinical presentations of seven patients with pathologically documented ESFTs were retrospectively analysed. The tumour location, morphological features, signal intensity, contrast enhancement characteristics, involvement of the paraspinal soft tissues, and adjacent bony structures were assessed. Results Most of the ESFTs in young adults were well-circumscribed. The present study demonstrated that ESFTs often have a hypo- or iso-intense signal on T1-weighted imaging and an iso-intense signal on T2-weighted imaging. Spinal ESFTs tended to present homogeneous signal intensity and diffuse enhancement. ESFTs are more likely to occur in the thoracic spine and later to infiltrate into the paraspinal area or vertebral bone. A broad dural attachment is another common feature in the cases presented here. Conclusions ESFT is a rare neoplasm that can have significant overlap in imaging appearance compared with other spinal neoplasms. A well-demarcated extradural mass invading the paraspinal soft or vertebral bones, with iso-intense on T2 weighted imaging and homogeneous enhancement could facilitate the diagnosis of spinal ESFT.
Abstract
Topological superconductors have long been predicted to host Majorana zero modes which obey non-Abelian statistics and have potential for realizing non-decoherence topological quantum ...computation. However, material realization of topological superconductors is still a challenge in condensed matter physics. Utilizing high-resolution angle-resolved photoemission spectroscopy and first-principles calculations, we predict and then unveil the coexistence of topological Dirac semimetal and topological insulator states in the vicinity of Fermi energy (
E
F
) in the titanium-based oxypnictide superconductor BaTi
2
Sb
2
O. Further spin-resolved measurements confirm its spin-helical surface states around
E
F
, which are topologically protected and give an opportunity for realization of Majorana zero modes and Majorana flat bands in one material. Hosting dual topological states, the intrinsic superconductor BaTi
2
Sb
2
O is expected to be a promising platform for further investigation of topological superconductivity.
Abstract Using (27.12 ± 0.14) × 108 ψ(3686) events collected with the BESIII detector at BEPCII, the decay of ψ(3686) → Ω − K + Ξ ¯ 0 $$ {\varOmega}^{-}{K}^{+}{\overline{\Xi}}^0 $$ + c.c. is observed ...for the first time. The branching fraction of this decay is measured to be B ψ 3686 → Ω − K + Ξ ¯ 0 + c . c . $$ {\mathcal{B}}_{\psi (3686)\to {\varOmega}^{-}{K}^{+}{\overline{\Xi}}^0+\textrm{c}.\textrm{c}.} $$ = (2.78 ± 0.40 ± 0.18) × 10 −6, where the first uncertainty is statistical and the second is systematic. Possible baryon excited states are searched for in this decay, but no evident intermediate state is observed with the current sample size.
By introducing the interval process model, a non-random vibration analysis method is proposed in this paper to calculate the dynamic displacement response bounds of elastic beams under uncertain ...excitations. Firstly, based on the interval process model, a conception of spatial-time interval field is proposed to describe the uncertainty of excitations in spatial and time domain. Secondly, the middle point function and the radius function of displacement response of the elastic beam are deduced by combining the spatial-time interval field and the traditional mode superposition method, based on which an analytical formulation of the upper and lower displacement response bound functions of the elastic beam are obtained. In addition, the displacement response bound functions of a simply supported beam structure under two types of external excitations, namely the concentrated load and the sinusoidal distributed load, are given. Finally, several numerical examples are investigated to demonstrate the effectiveness of the proposed method.
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