8,693 research outputs found
Twin Cogenesis
We investigate a cogenesis scenario within the twin Higgs setup which can
naturally explain the nature of dark matter, the cosmic coincidence puzzle,
little hierarchy problem, leptogenesis and the tiny neutrino masses. Three
heavy Majorana neutrinos are introduced to the standard model sector and the
twin sector respectively, which explain the tiny neutrino masses and generate
the lepton asymmetry and the twin lepton asymmetry at the same time. The twin
cogenesis scenario is general and applies to any viable twin Higgs model
without hard breaking and evading the
constraint. We demonstrate twin cogenesis in two models: fraternal twin Higgs
model, and neutrino-philic twin two Higgs doublet model, a newly proposed model
to lift the twin neutrino masses with spontaneous breaking. The
MeV scale dark photon ensures the energy in the twin sector as well as the
symmetric component of twin sector particles can be depleted. The lightest twin
baryons are the dark matter candidates with masses approximately 5.5~GeV, which
explain naturally the amount of dark matter and visible matter in the Universe
are of the same order.Comment: 28 pages, 1 figure. Revised version with updated references and minor
revisio
Custodial Symmetry Violation in Scalar Extensions of the Standard Model
The new measurement of the W boson mass from the CDF collaboration shows a
significant tension with the Standard Model prediction, which evidences
violation of custodial symmetry in the scalar sector. We study the scalar
extensions of the Standard Model, which can be categorized into two classes,
scalar sector with custodial symmetry (Georgi-Machacek model and its
generalizations) and scalar sector without custodial symmetry, and explore how
these extensions fit to the electroweak precision data and the CDF new .
The favored oblique parameters are coming from either the large mass splitting
in the multiplet via the loop contribution or the large vacuum expectation
value which breaks custodial symmetry at the tree level. In particular, we find
that GeV new particles are allowed in the scalar extension
scenarios.Comment: 24 pages, 4 figure
One-step implementation of multi-qubit conditional phase gating with nitrogen-vacancy centers coupled to a high-Q silica microsphere cavity
The diamond nitrogen-vacancy (NV) center is an excellent candidate for
quantum information processing, whereas entangling separate NV centers is still
of great experimental challenge. We propose an one-step conditional phase flip
with three NV centers coupled to a whispering-gallery mode cavity by virtue of
the Raman transition and smart qubit encoding. As decoherence is much
suppressed, our scheme could work for more qubits. The experimental feasibility
is justified.Comment: 3 pages, 2 figures, Accepted by Appl. Phys. Let
Fuzzing mechanism and fibre fatigue of wool knit
The fibre fatigue fibrillation and even fracture of knitted wool fabric under the rubbing force have been studied using scanning electron microscopy. The fatigue fracture sections, involved in the process of abrasion, show that loop hairs predominantly participate in fuzzing and the free ends exist in either pills formation or wearing-off. The major form of failure consists of the bend fatigue which is about 70 - 80% of the total failure and cracks. Fibrils occur in torsional fatigue (10 - 18%) and fibrillation head-ends comprise both bending and twisting
Epoxy Interlocking: A Novel Approach to Enhance FRP-to-concrete Bond Behavior
This paper presents a novel approach which can enhance the interfacial bond behavior between fiber reinforced polymer (FRP) composite material and concrete. Epoxy ribs are formed by grooving on the concrete surface before epoxy is applied. The dowel action from the epoxy ribs leads to an “epoxy interlocking” effect. The mechanism of the proposed epoxy interlocking approach was analyzed in this paper from both adhesion and interlocking aspects. Furthermore, the partial interaction of the epoxy interlocking was quantified and calibrated by experimental results. The epoxy interlocking in the tested specimens led to an 88.8% increase in bond strength on average. An analytical approach was proposed to quantify the average partial interaction for the individual epoxy ribs. The load-slip relationship for individual epoxy ribs was found to be related to concrete compression behavior. A parametric study was conducted analytically on the effects of groove depth and spacing, concrete strength and epoxy rib location. The reasonable results in the parametric study further verify the efficiency of the epoxy interlocking to enhance the bond performance between FRP and concrete
Anisotropic elastic constants calculation of stainless steel cladded layers of pressure vessel steel plate
Cladding stainless steel layer on the inner surface of ferrite pressure vessel is a common method to improve the corrosion resistance and save the economic cost. However, the movement of heat source and temperature gradient in the process of cladded welding will lead to the anisotropy of cladded layer material. When measuring the residual stress of pressure vessel steel plate with stainless steel cladded layers (SSCL) by contour method, it is necessary to know the elastic mechanical properties of stainless steel cladded layers accurately. The assumption of transversely isotropy (TI) was employed, and the relationship between the material compliance matrix and the elastic modulus of transversely isotropic material was utilized. Based on the elastic modulus of each cladded layer and the whole steel plate from the longitudinal direction (0°) until the transverse direction (90°) measured by the experiment, the independent constants S11, S13, S33 and S44 in the compliance matrix of each cladded layer and the whole steel plate were obtained by regression analysis method. Furthermore, by using the relationship between the independent constants of the stiffness matrix of the transversely isotropic material and the single crystal material, the independent constant S12 in the compliance matrix of each stainless steel cladded layer and the whole steel plate were obtained. And then the independent constants of the stiffness matrix of each cladded layer and the whole steel plate were acquired. Hence, a method for calculating the anisotropic elastic constants of the stainless steel cladded layer and the whole steel plate was proposed. The results will provide material data support for measuring residual stress of pressure vessel steel plate with stainless steel cladded layers by contour method
Inhibitory effect of tetramethylpyrazine combined with propranolol on murine hemangioma endothelial cells
Purpose: To study the inhibitory effect of different doses of tetramethylpyrazine (TMP) combined with the beta-blocker, propranolol (Pro) on hemangioma endothelial (EOMA) cells.
Methods: EOMA cells were cultured in vitro with varying doses of TMP and Pro (5, 10, 20 and 40 uM). The effect of treatments on cell proliferation was assessed by MTT assay, while cell apoptosis was assayed by flow cytometry. The expressions of Bcl-2, Bax, p-mTOR), total-mammalian target of rapamycin (t-mTOR, p-p70S6) and total-p70 ribosomal protein S6 (t-p70S6) proteins were determined using Western blot.
Results: MTT data showed that when used alone, TMP had no significant inhibitory effect on EOMA cells (p > 0.05). However, when TMP was combined with propranolol, there was significant inhibition of EOMA cells, and that the inhibition is dependent on TMP dose. Flow cytometry results showed that the combination of TMP and Pro induced EOMA cell apoptosis dose-dependently (p < 0.05). Moreover, TMP dose-dependently inhibited the phosphorylation of mTOR and p70S6 in EOMA cells, and enhanced Bax expression, but downregulated Bcl-2 (p < 0.05).
Conclusion: These results suggest that TMP enhances the inhibitory influence of Pro p-mTOR and pp-70S6 in EOMA cells in a dose-dependent manner. Thus, TMP may enhance Pro-induced inhibition of the growth of endothelial cells, and promote apoptosis through suppression of activation of PI3K/AKT signal route. These findings provide a theoretical basis for the clinical application of TMP/Pro combination for the treatment of hemangioma
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