18,642 research outputs found
Momentum-resolved radio-frequency spectroscopy of a spin-orbit coupled atomic Fermi gas near a Feshbach resonance in harmonic traps
We theoretically investigate the momentum-resolved radio-frequency
spectroscopy of a harmonically trapped atomic Fermi gas near a Feshbach
resonance in the presence of equal Rashba and Dresselhaus spin-orbit coupling.
The system is qualitatively modeled as an ideal gas mixture of atoms and
molecules, in which the properties of molecules, such as the wavefunction,
binding energy and effective mass, are determined from the two-particle
solution of two-interacting atoms. We calculate separately the radio-frequency
response from atoms and molecules at finite temperatures by using the standard
Fermi golden rule, and take into account the effect of harmonic traps within
local density approximation. The total radio-frequency spectroscopy is
discussed, as functions of temperature and spin-orbit coupling strength. Our
results give a qualitative picture of radio-frequency spectroscopy of a
resonantly interacting spin-orbit coupled Fermi gas and can be directly tested
in atomic Fermi gases of K40 atoms at Shanxi University and of Li6 atoms at
MIT.Comment: 11 pages, 9 Figure
Two-channel model description of confinement-induced Feshbach molecules
Using a two-channel model, we investigate theoretically the binding energy of
confinement-induced Feshbach molecules in two- and one-dimensional ultracold
atomic systems, near a Feshbach resonance. We show that the two-channel
prediction will evidently deviate from the simple single-channel theory as the
width of Feshbach resonances decreases. For one-dimensional system, we perform
a full two-channel calculation, with the inclusion of bare interatomic
interactions in the open channel. Away from the resonance, we find a sizable
correction to the binding energy, if we neglect incorrectly the bare
interatomic interactions as in the previous work [Dickerscheid and Stoof, Phys.
Rev. A 72, 053625 (2005)]. We compare our theoretical results with existing
experimental data and present predictions for narrow Feshbach resonances that
could be tested in future experiments.Comment: 8 pages, 5 figure
S4Net: Single Stage Salient-Instance Segmentation
We consider an interesting problem-salient instance segmentation in this
paper. Other than producing bounding boxes, our network also outputs
high-quality instance-level segments. Taking into account the
category-independent property of each target, we design a single stage salient
instance segmentation framework, with a novel segmentation branch. Our new
branch regards not only local context inside each detection window but also its
surrounding context, enabling us to distinguish the instances in the same scope
even with obstruction. Our network is end-to-end trainable and runs at a fast
speed (40 fps when processing an image with resolution 320x320). We evaluate
our approach on a publicly available benchmark and show that it outperforms
other alternative solutions. We also provide a thorough analysis of the design
choices to help readers better understand the functions of each part of our
network. The source code can be found at
\url{https://github.com/RuochenFan/S4Net}
Fluorescence sensing technologies for ophthalmic diagnosis
Personalized and point-of-care (POC) diagnoses are critical for ocular physiology and disease diagnosis. Real-time monitoring and continuous sampling abilities of tear fluid and user-friendliness have become the key characteristics for the applied ophthalmic techniques. Fluorescence technologies, as one of the most popular methods that can fulfill the requirements of clinical ophthalmic applications for optical sensing, have been raised and applied for tear sensing and diagnostic platforms in recent decades. Wearable sensors in this case have been increasingly developed for ocular diagnosis. Contact lenses, as one of the commercialized and popular tools for ocular dysfunction, have been developed as a platform for fluorescence sensing in tears diagnostics and real-time monitoring. Numbers of biochemical analytes have been examined through developed fluorescent contact lens sensors, including pH values, electrolytes, glucose, and enzymes. These sensors have been proven for monitoring ocular conditions, enhancing and detecting medical treatments, and tracking efficiency of related ophthalmic surgeries at POC settings. This review summarizes the applied ophthalmic fluorescence sensing technologies in tears for ocular diagnosis and monitoring. In addition, the cooperation of fabricated fluorescent sensor with mobile phone readout devices for diagnosing ocular diseases with specific biomarkers continuously is also discussed. Further perspectives for the developments and applications of fluorescent ocular sensing and diagnosing technologies are also provided
Optimal Vibration Control for Half-Car Suspension on In-Vehicle Networks in Delta Domain
The paper explores the optimal vibration control design problem for a half-car suspension working on in-vehicle networks in delta domain. First, the original suspension system with ECU-actuator delay and sensor-ECU delay is modeled. By using delta operators, the original system is transformed into an associated sampled-data system with time delays in delta domain. After model transformation, the sampled-data system equation is reduced to one without actuator delays and convenient to calculate the states with nonintegral time delay. Therefore, the sampled-data optimal vibration control law can be easily obtained deriving from a Riccati equation and a Stein equation of delta domain. The feedforward control term and the control memory terms designed in the control law ensure the compensation for the effects produced by disturbance and actuator delay, respectively. Moreover, an observer is constructed to implement the physical realizability of the feedforward term and solve the immeasurability problem of some state variables. A half-car suspension model with delays is applied to simulate the responses through the designed controller. Simulation results illustrate the effectiveness of the proposed controller and the simplicity of the designing approach
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