35 research outputs found
Bending behavior test and assessment for full-scale PC box girder reinforced by prestressed CFRP plate
This paper focuses on behavior of full scale prestressed concrete (PC) box girder with difference degrees of damage derived from service stage. According to typical structural damage, strengthening measures are proposed, including gluing steel plate, gluing prestressed CFRP plate and so on. In order to testify the effectiveness of reinforced method, bending behavior test are conducted for full scale PC box girder both before and after strengthening. After the test, the bending behaviors of test girder are comparatively analyzed, and the failure mechanism of test girder reinforced by prestressed CFRP plate is studied. What’s more, the strengthening method of gluing prestressed CFRP plate is applied in in-situ prestressed concrete box girder bridge with obvious damage. The static and dynamic testing of this reinforced bridge shows the feasibility and effectiveness of gluing prestressed CFRP plate strengthening method. Studies in this paper provide reliable guidance for engineering application
Fermionic zero modes in self-dual vortex background
We study fermionic zero modes in the background of self-dual vortex on a
two-dimensional non-compact extra space in 5+1 dimensions. In the Abelian Higgs
model, we present an unified description of the topological and non-topological
self-dual vortex on the extra two dimensions. Based on it, we study
localization of bulk fermions on a brane with inclusion of Yang-Mills and
gravity backgrounds in six dimensions. Through two simple cases, it is shown
that the vortex background contributes a phase shift to the fermionic zero
mode, this phase is actually origin from the Aharonov-Bohm effect.Comment: 11 pages, no figures, to appear in MPL
Fermionic zero modes in gauge and gravity backgrounds On
In this note we study fermionic zero modes in gauge and gravity backgrounds
taking a two dimensional compact manifold as extra dimensions. The result
is that there exist massless Dirac fermions which have normalizable zero modes
under quite general assumptions about these backgrounds on the bulk. Several
special cases of gauge background on the torus are discussed and some simple
fermionic zero modes are obtained.Comment: 8 pages, no figures, v2: more references, accepted by Mod.Phys.Lett.
Hopf bifurcation analysis in a neutral predator-prey model with age structure in prey
We show a detailed study on the dynamics of a neutral delay differential population model with age structure in the prey species. By selecting the mature delay as a bifurcation parameter, we obtain the stability and Hopf bifurcations of the coexistence equilibrium. Moreover, by computing the normal form on the center manifold, we give the formulas determining the stability of periodic solutions and the direction of Hopf bifurcation. Finally, we give some numerical simulations to support and strengthen the theoretical results
Hopf bifurcation analysis in a neutral predator–prey model with age structure in prey
We show a detailed study on the dynamics of a neutral delay differential population model with age structure in the prey species. By selecting the mature delay as a bifurcation parameter, we obtain the stability and Hopf bifurcations of the coexistence equilibrium. Moreover, by computing the normal form on the center manifold, we give the formulas determining the stability of periodic solutions and the direction of Hopf bifurcation. Finally, we give some numerical simulations to support and strengthen the theoretical results
Knotted Solitons in a Charged Two-Condensate Bose System
By making use of the decomposition of U(1) gauge potential theory and the
\phi mapping method, we propose that a charged two-condensate Bose system
possesses vortex lines and two classes of knotted solitons. The topological
charges of the vortex lines are characterized by the Hopf indices and the
Brower degrees of \phi-mapping, and the knotted solitons are described by the
nontrivial Hopf invariant and the BF action, respectively.Comment: 12 pages,0 figure
Biodegradable Silk Fibroin Nanocarriers to Modulate Hypoxia Tumor Microenvironment Favoring Enhanced Chemotherapy
Biopolymer silk fibroin (SF) is a great candidate for drug carriers characterized by its tunable biodegradability, and excellent biocompatibility properties. Recently, we have constructed SF-based nano-enabled drug delivery carriers, in which doxorubicin (Dox) and atovaquone (Ato) were encapsulated with Arg-Gly-Asp-SF-Polylactic Acid (RSA) to form micellar-like nanoparticles (RSA-Dox-Ato NPs). The RGD peptide was decorated on micellar-like nanoparticles, promoting tumor accumulation of the drug. Meanwhile, Ato, as a mitochondrial complex III inhibitor inhibiting mitochondrial respiration, would reverse the hypoxia microenvironment and enhance chemotherapy in the tumor. In vitro, the biopolymer alone showed extremely low cytotoxicity to 4T1 cell lines, while the RSA-Dox-Ato demonstrated a higher inhibition rate than other groups. Most significantly, the ROS levels in cells were obviously improved after being treated with RSA-Dox-Ato, indicating that the hypoxic microenvironment was alleviated. Eventually, SF-based targeted drug carrier provides biocompatibility to reverse hypoxia microenvironment in vivo for enhancing chemotherapy, strikingly suppressing tumor development, and thereby suggesting a promising candidate for drug delivery system