11,093 research outputs found
Research on Anti-flutter Processing of Aeroengine Casing
Due to the thin and rigid wall of aeroengine casing, it is easy to reduce the machining accuracy for the vibration of machine tools and cutting tools. Therefore, this paper designed an auxiliary fixture that can suppress such vibration. According to the vibration absorption principle of the tuned mass damper, this fixture is designed to transfer the vibration energy of the casing to the auxiliary fixture so as to reduce the vibration of the casing itself. According to Ansy’s work bench analysis, this fixture can significantly reduce the vibration of the casing. The results show that the maximum vibration amplitude of the casing is reduced by 60%, and the average vibration amplitude is also significantly reduced. The auxiliary fixture has many advantages such as simple installation, simple disassembly and installation, strong expansibility and so on
Atomic resolution imaging at 2.5 GHz using near-field microwave microscopy
Atomic resolution imaging is demonstrated using a hybrid scanning
tunneling/near-field microwave microscope (microwave-STM). The microwave
channels of the microscope correspond to the resonant frequency and quality
factor of a coaxial microwave resonator, which is built in to the STM scan head
and coupled to the probe tip. We find that when the tip-sample distance is
within the tunneling regime, we obtain atomic resolution images using the
microwave channels of the microwave-STM. We attribute the atomic contrast in
the microwave channels to GHz frequency current through the tip-sample tunnel
junction. Images of the surfaces of HOPG and Au(111) are presented.Comment: 9 pages, 5 figures, submitted to Applied Physics Letter
ADNet: Lane Shape Prediction via Anchor Decomposition
In this paper, we revisit the limitations of anchor-based lane detection
methods, which have predominantly focused on fixed anchors that stem from the
edges of the image, disregarding their versatility and quality. To overcome the
inflexibility of anchors, we decompose them into learning the heat map of
starting points and their associated directions. This decomposition removes the
limitations on the starting point of anchors, making our algorithm adaptable to
different lane types in various datasets. To enhance the quality of anchors, we
introduce the Large Kernel Attention (LKA) for Feature Pyramid Network (FPN).
This significantly increases the receptive field, which is crucial in capturing
the sufficient context as lane lines typically run throughout the entire image.
We have named our proposed system the Anchor Decomposition Network (ADNet).
Additionally, we propose the General Lane IoU (GLIoU) loss, which significantly
improves the performance of ADNet in complex scenarios. Experimental results on
three widely used lane detection benchmarks, VIL-100, CULane, and TuSimple,
demonstrate that our approach outperforms the state-of-the-art methods on
VIL-100 and exhibits competitive accuracy on CULane and TuSimple. Code and
models will be released on https://github.com/ Sephirex-X/ADNet.Comment: ICCV2023 accepte
Observational constraint on Dark Energy from Quantum Uncertainty
We explore the theoretical possibility that dark energy density is derived
from massless scalar bosons in vacuum and present a physical model for dark
energy. By assuming massless scalar bosons fall into the horizon boundary of
the cosmos with the expansion of the universe, we can deduce the uncertainty in
the relative position of scalar bosons based on the quantum fluctuation of
space-time and the assumption that scalar bosons satisfy P-symmetry under the
parity transformation , which can be used
to estimate scalar bosons and dark energy density. Furthermore, we attempt to
explain the origin of negative pressure from the increasing entropy density of
the Boltzmann system and derive the equation for the state parameter, which is
consistent with the specific equations of state for dark energy. Finally, we
employ the SNIa Pantheon sample and Planck 2018 CMB angular power spectra to
constrain the models and orovide statistical results for the cosmology
parameters
Tentative evidence of spatially extended GeV emission from SS433/W50
We analyze 10 years of Fermi-LAT data towards the SS433/W50 region. With the
latest source catalog and diffuse background models, the gamma-ray excess from
SS433/W50 is detected with a significance of 6{\sigma} in the photon energy
range of 500 MeV - 10 GeV. Our analysis indicates that an extended flat disk
morphology is preferred over a point-source description, suggesting that the
GeV emission region is much larger than that of the TeV emission detected by
HAWC. The size of the GeV emission is instead consistent with the extent of the
radio nebula W50, a supernova remnant being distorted by the jets, so we
suggest that the GeV emission may originate from this supernova remnant. The
spectral result of the GeV emission is also consistent with an supernova
remnant origin. We also derive the GeV flux upper limits on the TeV emission
region, which put moderate constrains on the leptonic models to explain the
multiwavelength data.Comment: 7 pages, 4 figures, accepted for publication in A&
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