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Learning to hear again with alternating cochlear frequency allocations
Superselective embolic particle guidance in vessel networks via shape-adaptive acoustic manipulation
Interleaved quartic high gain DC–DC converter
Abstract This research paper presents a high-gain DC–DC converter with ultra-step-up voltage gain capability. The proposed converter is synthesized from a two-phase interleaved boost converter (IBC), and its voltage gain is doubled by adopting a voltage lift capacitor. To enhance its voltage gain capability, a floating capacitor-based gain extension cell is adopted subsequently. This cell yields a voltage gain that is cubed times the output voltage obtained from a classical boost converter (CBC). By cascading the two stages, the voltage gain of the proposed converter is enhanced to quartic times (4th power) that of the CBC. The proposed gain extension concept is validated by conducting practical experiments on a 16 V to 400 V, 150 W prototype version. Practically, the prototype converter delivers 150 W to the load and operates at a full-load efficiency of 92.7% when its switches are operated at safe duty ratio values. Under dynamic conditions, the proposed converter regulates the output voltage to 400 V quickly over a wide range of input voltage and load current variations; the overshoots and undershoots are also negligible. The maximum voltage gain of the proposed converter momentarily increases to 37 when the input voltage is drastically reduced to 10.8 V while the switches are still operated at safe duty ratio values. The voltage stress on the semiconductor devices is only a fraction of the output voltage due to the hybrid voltage gain extension technique. The input current is also ripple-free as the switches in the IBC structure are always operated at a duty ratio of 50%, and only the third switch is controlled to meet the required voltage gain. The salient features of the proposed converter are clearly highlighted by comparing it with several converters that possess quadratic, cubic, and quartic voltage gain functions. The common-ground connection between the source and the load in the proposed converter is an added preferable feature for PV applications.
Removal of microplastics by algal biomass from aqueous solutions: performance, optimization, and modeling
Association of body mass index with clinicopathological features among patients with clear cell renal cell carcinoma treated with surgery: a retrospective study
Structural and electronic features enabling delocalized charge-carriers in CuSbSe2
AbstractInorganic semiconductors based on heavy pnictogen cations (Sb3+ and Bi3+) have gained significant attention as potential nontoxic and stable alternatives to lead-halide perovskites for solar cell applications. A limitation of these novel materials, which is being increasingly commonly found, is carrier localization, which substantially reduces mobilities and diffusion lengths. Herein, CuSbSe2 is investigated and discovered to have delocalized free carriers, as shown through optical pump terahertz probe spectroscopy and temperature-dependent mobility measurements. Using a combination of theory and experiment, the critical enabling factors are found to be: 1) having a layered structure, which allows distortions to the unit cell during the propagation of an acoustic wave to be relaxed in the interlayer gaps, with minimal changes in bond length, thus limiting deformation potentials; 2) favourable quasi-bonding interactions across the interlayer gap giving rise to higher electronic dimensionality; 3) Born effective charges not being anomalously high, which, combined with the small bandgap ($$\le$$ ≤ 1.2 eV), result in a low ionic contribution to the dielectric constant compared to the electronic contribution, thus reducing the strength of Fröhlich coupling. These insights can drive forward the rational discovery of perovskite-inspired materials that can avoid carrier localization.
A improved group quantum key distribution protocol with multi-party collaboration
NH3 release during the snow evaporation process in typical cities in Northeast China
Biological and residual activity of candidate larvicide formulation, SumiLarv 2MR, against an exotic invasive mosquito Anopheles stephensi Liston, 1901 (Diptera: Culicidae) in Ethiopia
Single-neuron spiking variability in hippocampus dynamically tracks sensory content during memory formation in humans
AbstractDuring memory formation, the hippocampus is presumed to represent the content of stimuli, but how it does so is unknown. Using computational modelling and human single-neuron recordings, we show that the more precisely hippocampal spiking variability tracks the composite features of each individual stimulus, the better those stimuli are later remembered. We propose that moment-to-moment spiking variability may provide a new window into how the hippocampus constructs memories from the building blocks of our sensory world.