2,013 research outputs found
Effects of Aromatic Ammoniums on Methyl Ammonium Lead Iodide Hybrid Perovskite Materials
The introduction of bulky ammoniums into methyl ammonium lead iodide hybrid perovskites (MAPbI3) has emerged as a promising strategy to improve the properties of these materials. In the present work, we studied the effects of several aromatic ammoniums onto the structural, electronic, and optical properties of MAPbI3. Although powder XRD data suggest that the bulky cations are not involved in the bulk phase of the MAPbI3, a surprisingly large effect of the bulky cations onto the photoluminescence properties was observed
Charm Quarks Are More Hydrodynamic Than Light Quarks in Final-State Elliptic Flow
We study the charm quark elliptic flow () in heavy ion as well as
small system collisions by tracking the evolution history of quarks of
different flavors within a multi-phase transport model. The charm quark
is studied as a function of the number of collisions the charm quark suffers
with other quarks and then compared to the of lighter quarks. We find
that the common escape mechanism is at work for both the charm and light quark
. However, contrary to the naive expectation, the hydrodynamics-type
flow is found to contribute more to the final state charm than light
quark . This could be explained by the smaller average deflection angle
the heavier charm quark undergoes in each collision, so that heavy quarks need
more scatterings to accumulate a significant , while lighter quarks can
more easily change directions with scatterings with their coming more
from the escape mechanism. Our finding thus suggests that the charm is
a better probe for studying the hydrodynamic properties of the quark-gluon
plasma.Comment: 10 pages, 4 figure
Ant-behavior inspired intelligent nanonet for targeted drug delivery in cancer therapy
Targeted drug delivery system is believed as one of the most promising solutions for cancer treatment due to its low-dose requirement and less side effects. However, both passive targeting and active targeting rely on systemic blood circulation and diffusion, which is actually not the real βactiveβ drug delivery. In this paper, an ant-behavior inspired nanonetwork composing of intelligent nanomachines is proposed. A big intelligent nanomachine take small intelligent nanomachines and drugs to the vicinity of of the tumor area. The small intelligent nanomachines can coordinate with each other to find the most effective path to the tumor cell for drug transportation. The framework and mechanism of this cooperative network are proposed. The route finding algorithm is presented. The convergence performance is analytically analyzed where the influence of the factors such as molecule degradation rate, home-destination distance, number of small nanomachines to the convergence is presented. Finally the simulation results validate the effectiveness of the proposed mechanism and analytical analysi
Large Eddy Simulation analysis on confined swirling flows in a gas turbine swirl burner
This paper describes a Large Eddy Simulation (LES) investigation into flow fields in a model gas turbine combustor equipped with a swirl burner. A probability density function was used to describe the interaction physics of chemical reaction and turbulent flow as liquid fuel was directly injected into the combustion chamber and rapidly mixed with the swirling air. Simulation results showed that heat release during combustion accelerated the axial velocity motion and made the recirculation zone more compact. As the combustion was taking place under lean burn conditions, NO emissions was less than 10 ppm. Finally, the effects of outlet contraction on swirling flows and combustion instability were investigated. Results suggest that contracted outlet can enhance the generation of a Central Vortex Core (CVC) flow structure. As peak RMS of velocity fluctuation profiles at center-line suggested the turbulent instability can be enhanced by CVC motion, the Power Spectrum Density (PSD) amplitude also explained that the oscillation at CVC position was greater than other places. Both evidences demonstrated that outlet contraction can increase the instability of the central field.
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Re-examining the premise of isobaric collisions and a novel method to measure the chiral magnetic effect
In these proceedings we show that the premise of the isobaric and collisions to search for the chiral magnetic effect (CME) may not hold as originally anticipated due to large uncertainties in the isobaric nuclear structures. We demonstrate this using Woods-Saxon densities and the proton and neutron densities calculated by the density functional theory. Furthermore, a novel method is proposed to gauge background and possible CME contributions in the same system, intrinsically better than the isobaric collisions of two different systems. We illustrate the method with Monte Carlo Glauber and AMPT (A Multi-Phase Transport) simulations
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Tonal symmetry induces fluency and sense of well-formedness
Fluency influences grammaticality judgments of visually presented strings in artificial grammar learning (AGL). Of many potential sources that engender fluency, symmetry is considered to be an important factor. However, symmetry may function differently for visual and auditory stimuli, which present computationally different problems. Thus, the current study aimed to examine whether objectively manipulating fluency by speeding up perception (i.e. manipulating the inter-stimulus interval, ISI, between each syllable of a string) influenced judgments of tonal strings; and thus how symmetry-based fluency might influence judgments. In experiment 1, with only a test phase, participants were required to give their preference ratings of tonal strings as a measurement of fluency. In experiment 2, participants were instructed to make grammaticality judgments after being incidentally trained on tonal symmetry. Results of experiment 1 showed that tonal strings with shorter ISI were liked more than those with longer ISI while such difference was not found between symmetric and asymmetric strings without training. Additionally, experiment 2 found both main effects of symmetry and ISI as well as an interaction. In particular, only asymmetric strings were more likely to be judged as grammatical when they were presented at a shorter ISI. Taken together, participants were sensitive to the fluency induced by the manipulation of ISI and sensitive to symmetry only after training. In sum, we conclude that objective speed influenced grammaticality judgments, implicit learning of tonal symmetry resulted in enhanced fluency, and that fluency may serve as a basis for grammaticality judgments
Design and Analysis of a Through-Body Signal Transmission System Based on Human Oxygen Saturation Detection
For a long time, people have carried out various studies on molecular communication (MC) and the Internet of Bio-Nanothings (IoBNT) in order to realize biomedical applications inside the human body. However, how to realize the communication between these applications and the outside body has become a new problem. In general, different components in the blood have different light absorption rates. Based on this, we propose a new through-body communication method. The nanomachine in the blood vessel transmits signals by releasing certain substances that can influence blood oxygen saturation. The change in blood oxygen saturation can be detected by an outside body device measuring the attenuation of the light through the blood. The framework of the entire communication system is proposed and mathematically modeled. Its error performance is discussed and evaluated. The mutual information (MI) of the designed communication system is also derived and calculated. This research will contribute to the realization of the connection of the IoBNT inside the human body to the outside device
Heavy quark flow as better probes of QGP properties
In earlier studies we have proposed that most parton v2 comes from the anisotropic escape of partons, not from the hydrodynamic flow, even for semi-central Au+Au collisions at SNN = 200 GeV. Here we study the flavor dependence of this escape mechanism with a multi-phase transport model. In contrast to naive expectations, we find that the charm v2 is much more sensitive to the hydrodynamic flow than the lighter quark v2, and the fraction of v2 from the escape mechanism decreases strongly with the quark mass for large collision systems. We also find that the light quark collective flow is essential for the charm quark v2. Our finding thus suggests that heavy quark flows are better probes of the quark-gluon-plasma properties than light quark flows
Origin of the Mass Splitting of Elliptic Anisotropy in a Multiphase Transport Model
The mass splitting of elliptic anisotropy () at low transverse momentum
is considered as a hallmark of hydrodynamic collective flow. We investigate a
multiphase transport (AMPT) model where the is mainly generated by an
anisotropic escape mechanism, not of the hydrodynamic flow nature, and where
mass splitting is also observed. We demonstrate that the mass splitting
in AMPT is small right after hadronization (especially when resonance decays
are included); the mass splitting mainly comes from hadronic rescatterings,
even though their contribution to the overall charged hadron is small.
These findings are qualitatively the same as those from hybrid models that
combine hydrodynamics with a hadron cascade. We further show that there is no
qualitative difference between heavy ion collisions and small system
collisions. Our results indicate that the mass splitting is not a unique
signature of hydrodynamic collective flow and thus cannot distinguish whether
the elliptic flow is generated mainly from hydrodynamics or the anisotropic
parton escape.Comment: 5 pages, 4 figure
Origin of the mass splitting of azimuthal anisotropies in a multiphase transport model
Both hydrodynamics-based models and a multi-phase transport (AMPT) model can
reproduce the mass splitting of azimuthal anisotropy () at low transverse
momentum () as observed in heavy ion collisions. In the AMPT model,
however, is mainly generated by the parton escape mechanism, not by the
hydrodynamic flow. In this study we provide detailed results on the mass
splitting of in this transport model, including and of
various hadron species in d+Au and Au+Au collisions at the Relativistic Heavy
Ion Collider and p+Pb collisions at the Large Hadron Collider. We show that the
mass splitting of hadron and in AMPT first arises from the
kinematics in the quark coalescence hadronization process, and then, more
dominantly, comes from hadronic rescatterings, even though the contribution
from the latter to the overall charged hadron is small. We further show
that there is no qualitative difference between heavy ion collisions and
small-system collisions or between elliptic () and triangular ()
anisotropies. Our studies thus demonstrate that the mass splitting of and
at low- is not a unique signature of hydrodynamic collective
flow but can be the interplay of several physics effects.Comment: 11 pages, 12 figures. Followup long paper to H. Li et al. Phys. Rev.
C 93 (2016) 051901(R) (2016) [arXiv:1601.05390]; changes from v1 to v2: added
phi-meson results in Fig.2 and Fig.11; v3: published versio
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