The emission positions of kHz QPOs and Kerr spacetime influence

Based the Alfven wave oscillation model (AWOM) and relativistic precession model (RPM) for twin kHz QPOs, we estimate the emission positions of most detected kHz QPOs to be at r=18+-3 km (R/15km) except Cir X-1 at r = 30\+-5 km (R/15km). For the proposed Keplerian frequency as an upper limit to kHz QPO, the spin effects in Kerr Spacetime are discussed, which have about a 5% (2%) modification for that of the Schwarzchild case for the spin frequency of 1000 (400) Hz.The application to the four typical QPO sources, Cir X-1, Sco X-1, SAX J1808.4-3658 and XTE 1807-294, is mentioned.Comment: Science China, Physics, Mechanics & Astronomy, 2010, 53, NO.

Dense matter with eXTP

In this White Paper we present the potential of the Enhanced X-ray Timing and Polarimetry (eXTP) mission for determining the nature of dense matter; neutron star cores host an extreme density regime which cannot be replicated in a terrestrial laboratory. The tightest statistical constraints on the dense matter equation of state will come from pulse profile modelling of accretion-powered pulsars, burst oscillation sources, and rotation-powered pulsars. Additional constraints will derive from spin measurements, burst spectra, and properties of the accretion flows in the vicinity of the neutron star. Under development by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Science, the eXTP mission is expected to be launched in the mid 2020s.Comment: Accepted for publication on Sci. China Phys. Mech. Astron. (2019

Dynamic interaction of soil and end-bearing piles in sloping ground: Numerical simulation and analytical solution

peer reviewe

Vertical dynamic interaction and group efficiency factor for floating pile group in layered soil

peer reviewedThis paper theoretically estimates the dynamic pile–soil interaction and the group efficiency factor for pile group in layered soil through energy-based method. The vertical dynamic interaction of partially embedded single piles and their surrounding layered soil is analytically deduced from Hamilton's principle. Combined with a series of numerical simulations, the soil attenuation factor from energy method is modified for adapting to the wave speed variation in various layers. Then, the pile-to-pile interaction factor is directly solved with the help of the transfer-matrix method. The dynamic governing equation of pile group with an elevated rigid cap is established by superposing the pile-to-pile interaction factors. Finally, the dynamic impedance of pile group is obtained and derived into a group efficiency factor. Compared with the plane strain method, this present method can produce a more suitable soil attenuation factor and a dynamic interaction factor at low frequency range, which is exploited for practical engineering design. The effects of subsoil layer, subsoil layer, and unembedded pile segment on group efficiency factor are investigated. The results show that the real part of group efficiency factor decreases at high frequency range for a small pile spacing, which may be detriment to the pile group capacity. Besides that, the combined effects of unembedded segment and weak surface soil on group efficiency factor are highlighted

Orientin Ameliorates LPS-Induced Inflammatory Responses through the Inhibitory of the NF- κ

Inflammation is a complex response to diverse pathological conditions, resulting in negative rather than protective effects when uncontrolled. Orientin (Ori), a flavonoid component isolated from natural plants, possesses abundant properties. Thus, we aimed to discover the potential therapeutic effects of orientin on lipopolysaccharide- (LPS-) induced inflammation in RAW 264.7 cells and the underlying mechanisms. In our studies, we evaluated the effects of Ori on proinflammatory mediator production stimulated by LPS, including tumor necrosis factor- (TNF-) α, interleukin- (IL-) 6, IL-18, and IL-1β, along with prostaglandin E2 (PGE2) and NO. Our data indicated that orientin dramatically inhibited the levels of these mediators. Consistent with these results, the expression levels of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) were also reduced. Further study demonstrated that such inhibitory effects of Ori were due to suppression of the nuclear factor-kappa B (NF-κB) pathway and nucleotide-binding domain- (NOD-) like receptor protein 3 (NLRP3) inflammasome activation, which may contribute to its anti-inflammatory effects. Together, these findings show that Ori may be an effective candidate for ameliorating LPS-induced inflammatory responses