145 research outputs found
Study of , Decays with QCD Factorization
The , decays are studied in
the scheme of the QCD factorization approach. The branching ratios are
calculated with the asymptotic distribution amplitude of the pion. The charm
quark mass effect is considered. We find that the mass effect on the branching
ratios is small.Comment: 20 pages, 3 figures, 3 table
A Wideband MIMO Channel Model for Aerial Intelligent Reflecting Surface-Assisted Wireless Communications
Compared to traditional intelligent reflecting surfaces(IRS), aerial IRS
(AIRS) has unique advantages, such as more flexible deployment and wider
service coverage. However, modeling AIRS in the channel presents new challenges
due to their mobility. In this paper, a three-dimensional (3D) wideband channel
model for AIRS and IRS joint-assisted multiple-input multiple-output (MIMO)
communication system is proposed, where considering the rotational degrees of
freedom in three directions and the motion angles of AIRS in space. Based on
the proposed model, the channel impulse response (CIR), correlation function,
and channel capacity are derived, and several feasible joint phase shifts
schemes for AIRS and IRS units are proposed. Simulation results show that the
proposed model can capture the channel characteristics accurately, and the
proposed phase shifts methods can effectively improve the channel statistical
characteristics and increase the system capacity. Additionally, we observe that
in certain scenarios, the paths involving the IRS and the line-of-sight (LoS)
paths exhibit similar characteristics. These findings provide valuable insights
for the future development of intelligent communication systems.Comment: 6 pages, 7 figure
Coherent Compensation based ISAC Signal Processing for Long-range Sensing
Integrated sensing and communication (ISAC) will greatly enhance the
efficiency of physical resource utilization. The design of ISAC signal based on
the orthogonal frequency division multiplex (OFDM) signal is the mainstream.
However, when detecting the long-range target, the delay of echo signal exceeds
CP duration, which will result in inter-symbol interference (ISI) and
inter-carrier interference (ICI), limiting the sensing range. Facing the above
problem, we propose to increase useful signal power through coherent
compensation and improve the signal to interference plus noise power ratio
(SINR) of each OFDM block. Compared with the traditional 2D-FFT algorithm, the
improvement of SINR of range-doppler map (RDM) is verified by simulation, which
will expand the sensing range
Gene Expression from the ORF50/K8 Region of Kaposi's Sarcoma-Associated Herpesvirus
The ORF50 gene of Kaposi's sarcoma (KS)-associated herpesvirus, or human herpesvirus 8 (KSHV), activates viral replication and is weakly homologous to the herpesvirus family of R transactivators; therefore, the transcription and translation events from this region of KSHV are key events in viral reactivation. We demonstrate that ORF50 is expressed in a bicistronic message after induction of the viral lytic cycle. ORF50 migrated as a series of polypeptides: the major ones as 119 and 101 kDa, respectively. Using 3' rapid amplification of cDNA ends, RT-PCR, and cDNA library screening, we demonstrate that the major ORF50 transcript also encodes K8. The ORF50/K8 transcript was resistant to cyclohexamide, whereas the K8 transcript was only partially resistant to cyclohexamide at early timepoints. Both transcripts showed partial resistance after 12 h of phorbol ester induction. Using a GAL4-ORF50 fusion protein expression vector, we demonstrate that the transactivation domain of ORF50 resides within a 160-amino-acid region of the carboxyl portion of the ORF. Upstream regions of both ORF50 and K8 have basal promoter activity in KSHV-infected cells. K8, which had sequence homology to Bzip proteins, did not activate either promoter. However, both promoters were activated after cotransfection of ORF50 in BCBL-1 cells
A Sparsity-Based InSAR Phase Denoising Algorithm Using Nonlocal Wavelet Shrinkage
An interferometric synthetic aperture radar (InSAR) phase denoising algorithm using the local sparsity of wavelet coefficients and nonlocal similarity of grouped blocks was developed. From the Bayesian perspective, the double-l1 norm regularization model that enforces the local and nonlocal sparsity constraints was used. Taking advantages of coefficients of the nonlocal similarity between group blocks for the wavelet shrinkage, the proposed algorithm effectively filtered the phase noise. Applying the method to simulated and acquired InSAR data, we obtained satisfactory results. In comparison, the algorithm outperformed several widely-used InSAR phase denoising approaches in terms of the number of residues, root-mean-square errors and other edge preservation indexes
Research on mechanical properties of high-performance cable-in-conduit conductors with different design
The China Fusion Engineering Test Reactor (CFETR) is a new tokamak fusion reactor under preliminary design, where the toroidal field (TF) coil has been designed to create a magnetic field of over 14.3 T. The TF conductors need to operate stably at 14.3 T, requiring the exclusion of conductor performance degradation from thermal and electromagnetic loading as much as possible. The maximum Lorentz force will reach about 1200 kN m-1, which is much higher than that of ITER conductors. In previous research, performance degradation was found during electromagnetic cycles and warm-up-cool-down cycles. A correlation was found between a conductor's degradation and its mechanical properties. According to the analysis, a conductor with a short twist pitch (STP) scheme or a copper wound superconducting strand (CWS) design has large stiffness, which enables significant performance improvement in terms of the electromagnetic and thermal load cycling. The cable stiffness is closely related to the number of inter-strand contact points inside the conductor. Based on this concept, four types of prototype cable-in-conduit conductor samples with STP and CWS design were manufactured. The number of inter-strand contact points was analyzed, and mechanical transverse load testing was performed at 77 K. The results show that the conductors with more contact points per unit length exhibit a higher stiffness. However, the cable designed with high cable stiffness caused strand indentation, which was also investigated. In this paper, the conductor design and experimental results are discussed and compared with ITER TF and central solenoid conductors.</p
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Battery-free, fully implantable optofluidic cuff system for wireless optogenetic and pharmacological neuromodulation of peripheral nerves
Studies of the peripheral nervous system rely on controlled manipulation of neuronal function with pharmacologic and/or optogenetic techniques. Traditional hardware for these purposes can cause notable damage to fragile nerve tissues, create irritation at the biotic/abiotic interface, and alter the natural behaviors of animals. Here, we present a wireless, battery-free device that integrates a microscale inorganic light-emitting diode and an ultralow-power microfluidic system with an electrochemical pumping mechanism in a soft platform that can be mounted onto target peripheral nerves for programmed delivery of light and/or pharmacological agents in freely moving animals. Biocompliant designs lead to minimal effects on overall nerve health and function, even with chronic use in vivo. The small size and light weight construction allow for deployment as fully implantable devices in mice. These features create opportunities for studies of the peripheral nervous system outside of the scope of those possible with existing technologies.NIH Director's Transformative Research [TR01 NS081707]; NIH SPARC Award via the NIBIB of the NIH [U18EB021793, R01 NS42595]; NIMH of the NIH [R41MH116525]; NRSA [F32 DK115122]; McDonnell Center for Cellular and Molecular Neurobiology Postdoctoral Fellowship [T32 DA007261]; Medical Scientist Training Program (MSTP) [T32 GM07200]; University of Missouri-Columbia start-up fund; NINDS NRSA [F31 NS103472]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
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