1,874 research outputs found
Ferroelectricity of Ice Nanotubes inside Carbon Nanotubes
We report that ice nanotubes with odd number of side faces inside carbon
nanotubes exhibit spontaneous electric polarization along its axes direction by
using molecular dynamics simulations. The mechanism of this nanoscale
quasi-one-dimensional ferroelectricity is due to low dimensional confinement
and the orientational order of hydrogen bonds. These ferroelectric fiber
structural materials are different from traditional perovskite structural bulk
materials.Comment: 4 pages and 4 figure
A New Two-Dimensional Functional Material with Desirable Bandgap and Ultrahigh Carrier Mobility
Two-dimensional (2D) semiconductors with direct and modest bandgap and
ultrahigh carrier mobility are highly desired functional materials for
nanoelectronic applications. Herein, we predict that monolayer CaP3 is a new 2D
functional material that possesses not only a direct bandgap of 1.15 eV (based
on HSE06 computation), and also a very high electron mobility up to 19930 cm2
V-1 s-1, comparable to that of monolayer phosphorene. More remarkably, contrary
to the bilayer phosphorene which possesses dramatically reduced carrier
mobility compared to its monolayer counterpart, CaP3 bilayer possesses even
higher electron mobility (22380 cm2 V-1 s-1) than its monolayer counterpart.
The bandgap of 2D CaP3 can be tuned over a wide range from 1.15 to 0.37 eV
(HSE06 values) through controlling the number of stacked CaP3 layers. Besides
novel electronic properties, 2D CaP3 also exhibits optical absorption over the
entire visible-light range. The combined novel electronic, charge mobility, and
optical properties render 2D CaP3 an exciting functional material for future
nanoelectronic and optoelectronic applications
Onsite data processing and monitoring for the Daya Bay Experiment
The Daya Bay Reactor Neutrino Experiment started running on September 23,
2011. The offline computing environment, consisting of 11 servers at Daya Bay,
was built to process onsite data. With current computing ability, onsite data
processing is running smoothly. The Performance Quality Monitoring system (PQM)
has been developed to monitor the detector performance and data quality. Its
main feature is the ability to efficiently process multi-data-stream from three
experimental halls. The PQM processes raw data files from the Daya Bay data
acquisition system, generates and publishes histograms via a graphical web
interface by executing the user-defined algorithm modules, and saves the
histograms for permanent storage. The fact that the whole process takes only
around 40 minutes makes it valuable for the shift crew to monitor the running
status of all the sub-detectors and the data quality
Pengaruh Penerapan Strategi Concept Mapping terhadap Hasil Belajar Siswa di Sekolah Dasar
This study aimed to analyze the influence of concept mapping strategy towards the learning result students in social science study on the V B grade of SD Negeri 17 Pontianak Kota. This study used an experimental method with Pre-Experimental design form using One-Group Pretest-Posttest Design. The population in this research were 68 students. The samples in this research was V B as a research class. Based on the t-test, the calculation result obtained t test (7,29) > t table (1,699) with significance level α = 5% means a significant influence using concept mapping strategy. The value of effect size (ES) is 0.39 with moderate category. It means that concept mapping strategy give a moderate effect to the learning result students in social science study on the V B grade of SD Negeri 17 Pontianak Kota
CG-fusion CAM: Online segmentation of laser-induced damage on large-aperture optics
Online segmentation of laser-induced damage on large-aperture optics in
high-power laser facilities is challenged by complicated damage morphology,
uneven illumination and stray light interference. Fully supervised semantic
segmentation algorithms have achieved state-of-the-art performance, but rely on
plenty of pixel-level labels, which are time-consuming and labor-consuming to
produce. LayerCAM, an advanced weakly supervised semantic segmentation
algorithm, can generate pixel-accurate results using only image-level labels,
but its scattered and partially under-activated class activation regions
degrade segmentation performance. In this paper, we propose a weakly supervised
semantic segmentation method with Continuous Gradient CAM and its nonlinear
multi-scale fusion (CG-fusion CAM). The method redesigns the way of
back-propagating gradients and non-linearly activates the multi-scale fused
heatmaps to generate more fine-grained class activation maps with appropriate
activation degree for different sizes of damage sites. Experiments on our
dataset show that the proposed method can achieve segmentation performance
comparable to that of fully supervised algorithms
Metal-free cross-coupling reaction of aldehydes with disulfides by using DTBP as an oxidant under solvent-free conditions
Metal-free sp(3) C-H functionalization: a novel approach for the syntheses of selenide ethers and thioesters from methyl arenes
A DTBP-promoted metal-free and solvent-free formation of C-Se and C-S bonds through sp(3) C-H functionalization of methyl arenes with diselenides and disulfides is described
- …