110 research outputs found
Plasma-Assisted Synthesis of Carbon Nanotubes
The application of plasma-enhanced chemical vapour deposition (PECVD) in the production and modification of carbon nanotubes (CNTs) will be reviewed. The challenges of PECVD methods to grow CNTs include low temperature synthesis, ion bombardment effects and directional growth of CNT within the plasma sheath. New strategies have been developed for low temperature synthesis of single-walled CNTs based the understanding of plasma chemistry and modelling. The modification of CNT surface properties and synthesis of CNT hybrid materials are possible with the utilization of plasma
Single channel based interference-free and self-powered human-machine interactive interface using eigenfrequency-dominant mechanism
The recent development of wearable devices is revolutionizing the way of
human-machine interaction (HMI). Nowadays, an interactive interface that
carries more embedded information is desired to fulfil the increasing demand in
era of Internet of Things. However, present approach normally relies on sensor
arrays for memory expansion, which inevitably brings the concern of wiring
complexity, signal differentiation, power consumption, and miniaturization.
Herein, a one-channel based self-powered HMI interface, which uses the
eigenfrequency of magnetized micropillar (MMP) as identification mechanism, is
reported. When manually vibrated, the inherent recovery of the MMP caused a
damped oscillation that generates current signals because of Faraday's Law of
induction. The time-to-frequency conversion explores the MMP-related
eigenfrequency, which provides a specific solution to allocate diverse commands
in an interference-free behavior even with one electric channel. A cylindrical
cantilever model was built to regulate the MMP eigenfrequencies via precisely
designing the dimensional parameters and material properties. We show that
using one device and two electrodes, high-capacity HMI interface can be
realized when the MMPs with different eigenfrequencies have been integrated.
This study provides the reference value to design the future HMI system
especially for situations that require a more intuitive and intelligent
communication experience with high-memory demand.Comment: 35 pages, 6 figure
Graphene/silicon heterojunction for reconfigurable phase-relevant activation function in coherent optical neural networks
Optical neural networks (ONNs) herald a new era in information and
communication technologies and have implemented various intelligent
applications. In an ONN, the activation function (AF) is a crucial component
determining the network performances and on-chip AF devices are still in
development. Here, we first demonstrate on-chip reconfigurable AF devices with
phase activation fulfilled by dual-functional graphene/silicon (Gra/Si)
heterojunctions. With optical modulation and detection in one device, time
delays are shorter, energy consumption is lower, reconfigurability is higher
and the device footprint is smaller than other on-chip AF strategies. The
experimental modulation voltage (power) of our Gra/Si heterojunction achieves
as low as 1 V (0.5 mW), superior to many pure silicon counterparts. In the
photodetection aspect, a high responsivity of over 200 mA/W is realized.
Special nonlinear functions generated are fed into a complex-valued ONN to
challenge handwritten letters and image recognition tasks, showing improved
accuracy and potential of high-efficient, all-component-integration on-chip
ONN. Our results offer new insights for on-chip ONN devices and pave the way to
high-performance integrated optoelectronic computing circuits
Real-time Monitoring for the Next Core-Collapse Supernova in JUNO
Core-collapse supernova (CCSN) is one of the most energetic astrophysical
events in the Universe. The early and prompt detection of neutrinos before
(pre-SN) and during the SN burst is a unique opportunity to realize the
multi-messenger observation of the CCSN events. In this work, we describe the
monitoring concept and present the sensitivity of the system to the pre-SN and
SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is
a 20 kton liquid scintillator detector under construction in South China. The
real-time monitoring system is designed with both the prompt monitors on the
electronic board and online monitors at the data acquisition stage, in order to
ensure both the alert speed and alert coverage of progenitor stars. By assuming
a false alert rate of 1 per year, this monitoring system can be sensitive to
the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos
up to about 370 (360) kpc for a progenitor mass of 30 for the case
of normal (inverted) mass ordering. The pointing ability of the CCSN is
evaluated by using the accumulated event anisotropy of the inverse beta decay
interactions from pre-SN or SN neutrinos, which, along with the early alert,
can play important roles for the followup multi-messenger observations of the
next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure
Method for alkali hydride formation and materials for hydrogen storage
US20030113252A1Published Applicatio
Study on Productivity Numerical Simulation of Highly Deviated and Fractured Wells in Deep Oil and Gas Reservoirs
This paper establishes the model of sandstone, porosity and permeability on single well in allusion to 10 highly deviated and fractured wells in deep oil and gas reservoirs of Jidong Oilfield, which forms a numerical simulation method of highly deviated and fractured wells in deep oil and gas reservoirs of Jidong Oilfield. The numerical simulation results of highly deviated and fractured wells productivity in deep oil and gas reservoirs are given out under different layers (layer ES1, layer ES3, layer ED2,and layer ED3), different deviation angles(60° and 75°), different fracture parameters and producing pressure drops. Through the comparison with testing data getting from exploration wells, we know that the calculation results of numerical simulation are consistent with practical testing results
Study on Productivity Numerical Simulation of Highly Deviated and Fractured Wells in Deep Oil and Gas Reservoirs
This paper establishes the model of sandstone, porosity and permeability on single well in allusion to 10 highly deviated and fractured wells in deep oil and gas reservoirs of Jidong Oilfield, which forms a numerical simulation method of highly deviated and fractured wells in deep oil and gas reservoirs of Jidong Oilfield. The numerical simulation results of highly deviated and fractured wells productivity in deep oil and gas reservoirs are given out under different layers (layer ES1, layer ES3, layer ED2,and layer ED3), different deviation angles(60° and 75°), different fracture parameters and producing pressure drops. Through the comparison with testing data getting from exploration wells, we know that the calculation results of numerical simulation are consistent with practical testing results
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