547 research outputs found
Electrical and optical properties of fluid iron from compressed to expanded regime
Using quantum molecular dynamics simulations, we show that the electrical and
optical properties of fluid iron change drastically from compressed to expanded
regime. The simulation results reproduce the main trends of the electrical
resistivity along isochores and are found to be in good agreement with
experimental data. The transition of expanded fluid iron into a nonmetallic
state takes place close to the density at which the constant volume derivative
of the electrical resistivity on internal energy becomes negative. The study of
the optical conductivity, absorption coefficient, and Rosseland mean opacity
shows that, quantum molecular dynamics combined with the Kubo-Greenwood
formulation provides a powerful tool to calculate and benchmark the electrical
and optical properties of iron from expanded fluid to warm dense region
A Natural Language Model of Computing with Words in Web Pages
PACLIC 20 / Wuhan, China / 1-3 November, 200
A refined numerical investigation of a large equivalent shallow-depth underwater explosion
The large equivalent shallow-depth explosion problem is very significant in
the field of naval architecture and ocean engineering, as such explosions can
be used to attack and demolish ships and anti-ship missiles. In the current
work, a refined numerical study of the flow-field characteristics of a large
equivalent shallow-depth explosion is carried out using a self-developed
Eulerian finite element solver. Firstly, the numerical model is validated
against theoretical results and a small equivalent explosion test in a tank.
The numerical results are found to agree well with the theoretical and
experimental results. In the next step, the cavitation cut-off effect is added
to the underwater explosion model, and the cavitation phenomenon is
quantitatively analyzed through the flow-field pressure. In addition, the
dynamic characteristics of the bubble and water hump under various initial
conditions for different stand-off parameters are analyzed. The effect of
gravity on these physical processes is also discussed. The bubble pulsation
period, taking into account the free surface effect, is then quantitatively
studied and compared with Cole's experimental formula for an underwater
explosion. Overall, when the stand-off parameter > 2, the influence of the free
surface on the empirical period of the bubble is not significant. Our
investigation provides broad insights into shallow-depth underwater explosions
from theoretical, experimental, and numerical perspectives
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Cdk1‐interacting protein Cip1 is regulated by the S phase checkpoint in response to genotoxic stress
In eukaryotic cells, a surveillance mechanism, the S phase checkpoint, detects and responds to insults that challenge chromosomal replication, arresting cell cycle progression and triggering appropriate events to prevent genomic instability. In the budding yeast Saccharomyces cerevisiae, Mec1/ATM/ATR, and its downstream kinase, Rad53/Chk2, mediate the response to genotoxic stress. In this study, we place Cip1, a recently identified Cdk1 inhibitor (CKI), under the regulation of Mec1 and Rad53 in response to genotoxic stress. Cip1 accumulates dramatically in a Mec1- and Rad53-dependent manner upon replication stress. This increase requires the activity of MBF, but not the transcriptional activator kinase Dun1. At the protein level, stabilization of replication stress-induced Cip1 requires continued de novo protein synthesis. In addition, Cip1 is phosphorylated at an S/TQ motif in a Mec1-dependent manner. Deletion of Cip1 affects proliferation in hydroxyurea-containing plates. Significantly, the sensitivity is increased when the dosage of the G1 cyclin CLN2 is increased, compatible to a role of Cip1 as a G1-cyclin-dependent kinase inhibitor. In all, our results place Cip1 under the S phase checkpoint response to genotoxic stress. Furthermore, Cip1 plays a significant role to preserve viability in response to insults that threaten chromosome replication
Design and Distortion Analysis of Passive Sensor Probes for the Measurements in Electric Fields
The sensor probes deployed in the electric fields will cause the distortion in the vicinities, therefore it may significantly affect the accuracy of the measurements in the electric fields. In this paper, we propose a novel approach to separate the electric field distortion due to the spherical sensor probes in a uniform electric field. Moreover, we also investigate the impacts of the spherical sensor probes to the original electric field distortion in terms of the size of sensor probes, the electrode materials, the coupling between the polar electrodes in the design of sensor probes. Our simulation results show that a passive electric field sensor system with the bands from 5 Hz to 200 kHz, and a 20 nF capacitance, combining with our new electric field distortion correction scheme, can surprise meet the requirements of the practical engineering. Moreover, our simulation results also show that the electric field sensor probe system we suggested only has 0.16 % nonlinear errors compared with the corresponding original system measurements. We hope our work will stimulate the future research in the design of the sensor probe systems for monitoring of the electric field
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