1,980 research outputs found
Studies on Rheological Behaviors of Bismaleimide Resin System for Resin Transfer Molding
AbstractThe rheological behavior of bismaleimide resin for resin transfer molding(RTM) was studied with DSC analysis and viscosity experiments. A rheological model based on the dual-Arrhenius equation was established and used to simulate the rheological behavior of the resin. The model predictions determined from the dual-Arrhenius equation were in good agreement with experimental data. The processing window of the resin system can be well determined based on the developed model. The rheological model is important for processing simulation and quality control of RTM processing for high performance composites
The strong vertices of charmed mesons , and charmonia ,
In this work, the strong form factors and coupling constants of the vertices
, , , ,
are calculated within the framework of the QCD sum rule.
For each vertex, we analyze the form factor considering all possible off-shell
cases and the contributions of the vacuum condensate terms
, ,
, and
. Then, the form
factors are fitted into analytical functions and are extrapolated into
time-like regions to get the strong coupling constants. Finally, the strong
coupling constants are obtained by using on-shell cases of the intermediate
mesons(). The results are as follows,
,
GeV,
,
and
GeV
Intrinsically stretchable and transparent thin-film transistors based on printable silver nanowires, carbon nanotubes and an elastomeric dielectric.
Thin-film field-effect transistor is a fundamental component behind various mordern electronics. The development of stretchable electronics poses fundamental challenges in developing new electronic materials for stretchable thin-film transistors that are mechanically compliant and solution processable. Here we report the fabrication of transparent thin-film transistors that behave like an elastomer film. The entire fabrication is carried out by solution-based techniques, and the resulting devices exhibit a mobility of ∼30 cm(2) V(-1) s(-1), on/off ratio of 10(3)-10(4), switching current >100 μA, transconductance >50 μS and relative low operating voltages. The devices can be stretched by up to 50% strain and subjected to 500 cycles of repeated stretching to 20% strain without significant loss in electrical property. The thin-film transistors are also used to drive organic light-emitting diodes. The approach and results represent an important progress toward the development of stretchable active-matrix displays
The strong vertices of bottom mesons , and bottomonia ,
In this article, the strong coupling constants of vertices ,
, , and
are analyzed in the framework of QCD sum rules. In this
work, all possible off-shell cases and the contributions of vacuum condensate
terms including , , , and
are considered. The
momentum dependent strong coupling constants are first calculated and then are
fitted into analytical functions which are used to extrapolate into
time-like regions to obtain the final values of strong coupling constants. The
final results are ,
GeV,
,
and
GeV. These strong
coupling constants are important input parameters which reflect the dynamic
properties of the interactions among the mesons and quarkonia
Analysis of the strong vertices of and in QCD sum rules
In this work, we analyze the strong vertices and
using the three-point QCD sum rules under the tensor
structures ,
and . We firstly calculate the momentum
dependent strong coupling constants by considering contributions of
the perturbative part and the condensate terms ,
, and
. By fitting these coupling constants into
analytical functions and extrapolating them into time-like regions, we then
obtain the on-shell values of strong coupling constants for these vertices. The
results are GeV,
GeV,
GeV,
GeV,
GeV and
GeV. These strong
coupling constants are important parameters which can help us to understand the
strong decay behaviors of hadrons
Structural Determinants for Ligand-Receptor Conformational Selection in a Peptide G Protein-coupled Receptor
G protein coupled receptors (GPCRs) modulate the majority of physiological processes through specific intermolecular interactions with structurally diverse ligands and activation of differential intracellular signaling. A key issue yet to be resolved is how GPCRs developed selectivity and diversity of ligand binding and intracellular signaling during evolution. We have explored the structural basis of selectivity of naturally occurring gonadotropin-releasing hormones (GnRHs) from different species in the single functional human GnRH receptor. We found that the highly variable amino acids in position 8 of the naturally occurring isoforms of GnRH play a discriminating role in selecting receptor conformational states. The human GnRH receptor has a higher affinity for the cognate GnRH I but a lower affinity for GnRH II and GnRHs from other species possessing substitutions for Arg(8). The latter were partial agonists in the human GnRH receptor. Mutation of Asn(7.45) in transmembrane domain (TM) 7 had no effect on GnRH I affinity but specifically increased affinity for other GnRHs and converted them to full agonists. Using molecular modeling and site-directed mutagenesis, we demonstrated that the highly conserved Asn(7.45) makes intramolecular interactions with a highly conserved Cys(6.47) in TM 6, suggesting that disruption of this intramolecular interaction induces a receptor conformational change which allosterically alters ligand specific binding sites and changes ligand selectivity and signaling efficacy. These results reveal GnRH ligand and receptor structural elements for conformational selection, and support co-evolution of GnRH ligand and receptor conformations
The - and -wave fully charmed tetraquark states and their radial excitations
Inspired by recent progresses in observations of the fully charmed tetraquark
states by LHCb, CMS, and ATLAS Collaborations, we perform a systematic study of
the ground states and the first radial excitations of the - and -wave
system. Their mass spectra, root
mean square(r.m.s.) radii and radial density distributions are studied with the
relativized quark model. The calculations show that there is no stable bound
states for the full-charmed tetraquark states, and the r.m.s. radii of these
tetraquark states are smaller than 1 fm. Our results support assigning X(6600)
structure, MeV, as one of the (1) and
(1) states or their mixtures. Another structure also named as
X(6600) by CMS Collaboration, GeV,
may arise from the lowest 1 states with =, , and
. The possible assignments for X(6900) include the (2),
(2) states, and the highest 1 state with . As for
X(7200), it can be interpreted as one of the highest 2 states with
, , and , and the 3 states can not be
completely excluded from the candidates.Comment: to be published in European Physical Journal
Strong decay properties of single heavy baryons , and
Motivated by recent progresses in experiments in searching for the
baryons, we systematically analyze the strong decay behaviors of
single heavy baryons , and . The two-body
strong decay properties of -wave, -wave and some -wave states are
studied with the model. The results support assigning the recently
observed and as the 2S()
and 1D() states, respectively. In addition, the quantum
numbers of many other experimentally observed baryons are also suggested
according to their strong decays. Finally, some baryons which have good
potentials to be observed in experiments are predicted and the possible decay
channels for searching for these predicted states are also suggested.Comment: arXiv admin note: substantial text overlap with arXiv:2206.0812
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