Rosariocurrin5205

s from accurately acquired coincidence events. In conclusion complementary to CCP, DCP can provide high count-rate capability, simplified algorithm for implementation, and potentially a practical solution for online acquisition of a PET with a larger number of detector pairs or for ultrahigh-throughput imaging.Upconversion micro/nanolasers are promising in fundamental physics research and practical applications. However, due to the limitation of gain medium and cavity quality, such lasers still suffer from a high lasing threshold (P th). Herein, upconverted whispering-gallery-mode lasing by two-photon absorption is achieved from CdS microplatelets with single-mode emission and low threshold (∼1.2 mJ cm-2). The threshold is three times lower than the best reported value in previous CdS upconversion lasers. Moreover, wavelength-tunable upconverted single-mode lasing is demonstrated from 510.4 to 518.9 nm with narrow linewidths around 0.85 nm, which is further verified through numerical simulations. In addition, the size-dependent lasing behavior is realized from single-mode to multimode oscillation; the corresponding lasing threshold decreases with increasing cavity edge length (L), following a P th ∝ 1/L 2 relationship. These results underscore the promise of CdS microplatelets for developing chip-level frequency upconversion lasers.

Brain-machine interfaces (BMIs) seek to restore lost motor functions in individuals with neurological disorders by enabling them to control external devices directly with their thoughts. This work aims to improve robustness and decoding accuracy that currently become major challenges in the clinical translation of intracortical BMIs.

We propose entire spiking activity (ESA) -an envelope of spiking activity that can be extracted by a simple, threshold-less, and automated technique- as the input signal. We couple ESA with deep learning-based decoding algorithm that uses quasi-recurrent neural network (QRNN) architecture. We evaluate comprehensively the performance of ESA-driven QRNN decoder for decoding hand kinematics from neural signals chronically recorded from the primary motor cortex area of three non-human primates performing different tasks.

Our proposed method yields consistently higher decoding performance than any other combinations of the input signal and decoding algorithm previously reported across long term recording sessions. It can sustain high decoding performance even when removing spikes from the raw signals, when using the different number of channels, and when using a smaller amount of training data.

Overall results demonstrate exceptionally high decoding accuracy and chronic robustness, which is highly desirable given it is an unresolved challenge in BMIs.

Overall results demonstrate exceptionally high decoding accuracy and chronic robustness, which is highly desirable given it is an unresolved challenge in BMIs.Quantum dots (QDs) are promising materials used for room temperature mid-infrared (MIR) photodetector due to their solution processing, compatibility with silicon and tunability of band structure. Up to now, HgTe QDs is the most widely studied material for MIR detection. However, photodetectors assembled with HgTe QDs usually work under cryogenic cooling to improve photoelectric performance, greatly limiting their application at room temperature. Here, less-toxic SnTe QDs were controllably synthesized with high crystallinity and uniformity. Through proper ligand exchange and annealing treatment, the photoconductive device assembled with SnTe QDs demonstrated ultralow dark current and broadband photo-electric response from visible light to 2 μm at room temperature. In addition, the visible and near infrared photo-electric performance of the SnTe QDs device were well maintained even standing 15 d in air. This excellent performance was due to the effective protection of the ligand on surface of the QDs and the effective transport of photo-carriers between the SnTe interparticles. Selleck Navitoclax It would provide a new idea for environmentally friendly mid-IR photodetectors working at room temperature.Black phosphorus (BP) is a promising material for photodetectors due to its excellent and broadband photoresponse. To realize a wide application of BP in photodetection, there is a continuous eagerness for new approaches to tailor photoresponse of BP for a specific purpose, such as high sensitivity and switching of negative/positive responses. Here, we demonstrate that the ion irradiation with controllable conditions can enhance the photoresponsivity of BP for two orders compared to the pristine one, and can select the positive/negative photoresponse of the BP. The range of the tailored photoresponse covers the whole optical spectrum, ranging from the visible (532 nm) to the mid-infrared (10 μm). This work shows a pathway to modulate the photoresponse of BP, which opens new possibilities for potential photonic applications.Electrical scanning probe microscopies (SPM) use ultrasharp metallic tips to obtain nanometer spatial resolution and are a key tool for characterizing nanoscale semiconducting materials and systems. However, these tips are not passive probes; their high work functions can induce local band bending whose effects depend sensitively on the local geometry and material properties and thus are inherently difficult to quantify. We use sequential finite element simulations to first explore the magnitude and spatial distribution of charge reorganization due to tip-induced band bending (TIBB) for planar and nanostructured geometries. We demonstrate that tip-induced depletion and accumulation of carriers can be significantly modified in confined geometries such as nanowires compared to a bulk planar response. This charge reorganization is due to finite size effects that arise as the nanostructure size approaches the Debye length, with significant implications for a range of SPM techniques. We then use the reorganized charge distribution from our model to describe experimentally measured quantities, using in operando scanning microwave impedance microscopy measurements on axial p-i-n silicon nanowire devices as a specific example. By incorporating TIBB, we reveal that our experimentally observed enhancement (absence) of contrast at the p-i (i-n) junction is explained by the tip-induced accumulation (depletion) of carriers at the interface. Our results demonstrate that the inclusion of TIBB is critical for an accurate interpretation of electrical SPM measurements, and is especially important for weakly screening or low-doped materials, as well as the complex doping patterns and confined geometries commonly encountered in nanoscale systems.