48 research outputs found
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
COVID‐19 in Tuberculosis patients: a report of three cases
The clinical features and treatment of pulmonary tuberculosis patients with COVID‐19 is unclear and understudied. Here, three pulmonary tuberculosis patients with COVID‐19 infection were prospectively followed from hospital admission to discharge. We provide information and experience with treatment of pulmonary tuberculosis cases with confirmed COVID‐19 infection
Thermochemical non-equilibrium flow characteristics of high Mach number inlet in a wide operation range
The high-temperature non-equilibrium effect is a novel and significant issue in the flows over a high Mach number (above Mach 8) air-breathing vehicle. Thus, this study attempts to inves-tigate the high-temperature non-equilibrium flows of a curved compression two-dimensional scram -jet inlet at Mach 8 to 12 utilizing the two-dimensional non-equilibrium RANS calculations. Notably, the thermochemical non-equilibrium gas model can predict the actual high-temperature flows, and the numerical results of the other four thermochemical gas models are only used for com-parative analysis. Firstly, the thermochemical non-equilibrium flow fields and work performance of the inlet at Mach 8 to 12 are analyzed. Then, the influences of high-temperature non-equilibrium effects on the starting characteristics of the inlet are investigated. The results reveal that a large sep-aration bubble caused by the cowl shock/lower wall boundary layer interaction appears upstream of the shoulder, at Mach 8. The separation zone size is smaller, and its location is closer to the down-stream area while the thermal process changes from frozen to non-equilibrium and then to equilib-rium. With the increase of inflow Mach number, the thermochemical non-equilibrium effects in the whole inlet flow field gradually strengthen, so their influences on the overall work performance of the high Mach number inlet are more obvious. The vibrational relaxation or thermal non -equilibrium effects can yield more visible influences on the inlet performance than the chemical non-equilibrium reactions. The inlet in the thermochemical non-equilibrium flow can restart more easily than that in the thermochemical frozen flow. This work should provide a basis for the design and starting ability prediction of the high Mach number inlet in the wide operation range. (c) 2023 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/)
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