3,182 research outputs found
Biodegradable Polylactic Acid (PLA) Microstructures for Scaffold Applications
In this research, we present a simple and cost effective soft lithographic
process to fabricate PLA scaffolds for tissue engineering. In which, the
negative photoresist JSR THB-120N was spun on a glass subtract followed by
conventional UV lithographic processes to fabricate the master to cast the PDMS
elastomeric mold. A thin poly(vinyl alcohol) (PVA) layer was used as a mode
release such that the PLA scaffold can be easily peeled off. The PLA precursor
solution was then cast onto the PDMS mold to form the PLA microstructures.
After evaporating the solvent, the PLA microstructures can be easily peeled off
from the PDMS mold. Experimental results show that the desired microvessels
scaffold can be successfully transferred to the biodegradable polymer PLA.Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/EDA-Publishing
Equilibrium vortex formation in ultrarapidly rotating two-component Bose-Einstein condensates
Equilibrium vortex formation in rotating binary Bose gases with a rotating
frequency higher than the harmonic trapping frequency is investigated
theoretically. We consider the system being evaporatively cooled to form
condensates and a combined numerical scheme is applied to ensure the binary
system being in an authentic equilibrium state. To keep the system stable
against the large centrifugal force of ultrafast rotation, a quartic trapping
potential is added to the existing harmonic part. Using the Thomas-Fermi
approximation, a critical rotating frequency \Omega_c is derived, which
characterizes the structure with or without a central density hole. Vortex
structures are studied in detail with rotation frequency both above and below
?\Omega_c and with respect to the miscible, symmetrically separated, and
asymmetrically separated phases in their nonrotating ground-state counterparts.Comment: 7 pages, 7 figure
Dynamical Linear Response of TDDFT with LDA+U Functional: strongly hybridized Frenkel excitons in NiO
Within the framework of time-dependent density-functional theory (TDDFT), we
derive the dynamical linear response of LDA+U functional and benchmark it on
NiO, a prototypical Mott insulator. Formulated using real-space Wannier
functions, our computationally inexpensive framework gives detailed insights
into the formation of tightly bound Frenkel excitons with reasonable accuracy.
Specifically, a strong hybridization of multiple excitons is found to
significantly modify the exciton properties. Furthermore, our study exposes a
significant generic limitation of adiabatic approximation in TDDFT with hybrid
functionals and in existing Bethe-Salpeter-equation approaches, advocating the
necessity of strongly energy-dependent kernels in future development.Comment: 5 pages, 2 figure
Compression mechanisms in the anisotropically bonded elements Se and Te
[[abstract]]The compression mechanisms of the elements selenium and tellurium (which exhibit highly anisotropic bonding under ambient conditions) are explored. A combination of experiments and ab initio simulation (including generalized gradient corrections) is used to examine the structural and dynamic properties of these elements in detail. The effect of pressure on both these systems is to enhance the weak interchain bonding at the expense of the stronger intrachain covalent interactions. This is manifested by a pronounced mode softening of the intrachain vibrational modes under pressure as found from both Raman spectroscopy and simulation. A corresponding increase of the rigid-chain rotation mode is also revealed by the calculations. We also investigate pressure-induced polymorphism in these materials in order to resolve controversy concerning the high-pressure crystallographic structures.[[notice]]補正完畢[[booktype]]紙本[[countrycodes]]US
Charmed Baryon Weak Decays with SU(3) Flavor Symmetry
We study the semileptonic and non-leptonic charmed baryon decays with
flavor symmetry, where the charmed baryons can be , , , or . With denoted as the baryon
octet (decuplet), we find that the
decays are forbidden, while the ,
, and decays are the only existing Cabibbo-allowed modes
for , , and , respectively. We predict the rarely studied
decays, such as and . For the observation, the doubly and triply charmed baryon decays of
, ,
, and are the favored Cabibbo-allowed decays,
which are accessible to the BESIII and LHCb experiments.Comment: 29 pages, no figure, a typo in the table correcte
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