83 research outputs found

    Enabling smartphone-based HD video chats by cooperative transmissions in CRNs

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    Smartphones have been equipped with the cameras that can shoot HD videos, and the video chat apps such as Skype are becoming popular. We can, therefore, intuitively predict the trend that users are expecting to enjoy HD video chats via utilizing their smartphones. Most of the current Internet services, however, cannot support the live HD video transmissions because of their low uplink rate. In order to overcome this limit, we propose to offload the uplink transmissions to cooperative users via cognitive radio networks. Specifically, we first divide the video stream into several substreams according to the H.264/SVC standard and the cooperative users’ uplink rates. Then, the cooperative users are selected by employing our proposed optimal multiple stopping method. Finally, the substreams are assigned to the selected cooperative users by a 0-1 Knapsack-based allocation algorithm. The simulation results demonstrate that our proposed scheme can successfully support 720P HD video chats

    Observation of Rydberg moir\'e excitons

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    Rydberg excitons, the solid-state counterparts of Rydberg atoms, have sparked considerable interest in harnessing their quantum application potentials, whereas a major challenge is realizing their spatial confinement and manipulation. Lately, the rise of two-dimensional moir\'e superlattices with highly tunable periodic potentials provides a possible pathway. Here, we experimentally demonstrate this capability through the observation of Rydberg moir\'e excitons (XRM), which are moir\'e trapped Rydberg excitons in monolayer semiconductor WSe2 adjacent to twisted bilayer graphene. In the strong coupling regime, the XRM manifest as multiple energy splittings, pronounced redshift, and narrowed linewidth in the reflectance spectra, highlighting their charge-transfer character where electron-hole separation is enforced by the strongly asymmetric interlayer Coulomb interactions. Our findings pave the way for pursuing novel physics and quantum technology exploitation based on the excitonic Rydberg states.Comment: 24 pages, including 4 figures and 6 supplementary figure

    Characterization of the response of IHEP-IME LGAD with shallow carbon to Gamma Irradiation

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    Low Gain Avalanche Detectors (LGAD), as part of High-Granularity Timing Detector (HGTD), is crucial to reducing pileup in the upgrading to HL-LHC. Many studies have been done on the bulk damages of the LGAD. However, there's no study about the surface radiation hardness of the LGAD sensors with carbon implanted. The IHEP-IME LGAD version 3 with the shallow carbon and different interpad separations were irradiated up to 2 MGy by gamma irradiation. The performance of the IHEP-IME LGAD version 3 before and after irradiation had been tested, such as the leakage current, break-down voltage, capacitance, Vgl_{gl}, and inter-pad resistance. The results showed that apart from minor fluctuations in some samples, no significant changes concerning inter-pad separation were observed before and after irradiation. Leakage current and break-down voltage increase after irradiation, which is considered due to surface passivation; the overall inter-pad resistance are larger than $10^9\ \Omegabeforeandafterirradiation;capacitanceisfoundtobelessthan4.5pFwithaslightdropinV before and after irradiation; capacitance is found to be less than 4.5 pF with a slight drop in V_{gl}$ after irradiation. All parameters meet the requirements of HGTD, and the results indicated that IHEP-IME LGAD v3 has excellent anti-irradiation performance

    Leakage current simulations of Low Gain Avalanche Diode with improved Radiation Damage Modeling

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    We report precise TCAD simulations of IHEP-IME-v1 Low Gain Avalanche Diode (LGAD) calibrated by secondary ion mass spectroscopy (SIMS). Our setup allows us to evaluate the leakage current, capacitance, and breakdown voltage of LGAD, which agree with measurements' results before irradiation. And we propose an improved LGAD Radiation Damage Model (LRDM) which combines local acceptor removal with global deep energy levels. The LRDM is applied to the IHEP-IME-v1 LGAD and able to predict the leakage current well at -30 ∘^{\circ}C after an irradiation fluence of Φeq=2.5×1015 neq/cm2 \Phi_{eq}=2.5 \times 10^{15} ~n_{eq}/cm^{2}. The charge collection efficiency (CCE) is under development

    Replication Data for: Effects of Lactobacillus reuteri on early feeding tolerance and infection prevention in preterm infants

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    Preterm infants have not well-developed organs, immature gastrointestinal tract, delayed colonization of intestinal flora and poor immunity. In this study, the effects of Lactobacillus reuteri DSM 17938 on daily reflux, the maximum feeding amount, weight gain, hospital stay, nosocomial infection and neonatal necrotizing enterocolitis were surveyed, and we elucidated its roles in early feeding tolerance, growth and infection prevention of preterm infants

    Anisotropic Picone identities and anisotropic Hardy inequalities

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    Abstract In this paper, we derive an anisotropic Picone identity for the anisotropic Laplacian, which contains some known Picone identities. As applications, a Sturmian comparison principle to the anisotropic elliptic equation and an anisotropic Hardy type inequality are shown
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