- 标题
- 摘要
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- 实验方案
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Non-oxidation reduction strategy for highly selective detection of ascorbic acid with dual-ratio fluorescence and colorimetric signals
摘要： Ascorbic acid (AA), one of the most important vitamins, acts a critical role in various physiological reactions and is involved in many diseases. Thus, the development of highly selectivity methods for detecting AA level with the presence of different reducing substances is of great significance in complicated serum matrix. In this paper, a non-oxidation reduction regulation (NRR) strategy was designed to construct a novel dual-ratio fluorescence and colorimetric dual-readout assay for highly selective detection of AA. The strategy involves three processes: Ag+ oxidated o-phenylenediamine (OPD) to 2,3-diaminophenazine (OPDox), AA inhibited the generation of OPDox and the AA was oxidized to dehydroascorbic acid (DHAA). The specific performance of DHAA NRR, due to the condensation reaction between dicarbonyl group of DHAA and diamine group of OPD, that is confirmed by ESI-MS and 1H NMR spectra analysis, can remarkably enhance the selectivity of AA detection. Additionally, the proposed method based on NRR strategy not only provides a sensing platform for probing AA but also shows promising outlook in biomedical studies.
关键词： O-phenylenediamine,Non-oxidation reduction regulation,Ascorbic acid,Dual-ratio,Dual-readout
更新于2025-09-23 15:21:21
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Single-photon limit of dispersive readout of a qubit with a photodetector
摘要： We study the dispersive readout of a qubit in the ultimate limit of a single-photon probe. The use of a single-photon probe avoids the errors due to nonorthogonality of coherent states. A photodetector is used in the scheme we consider. The dynamics of the system is studied using the Heisenberg-Langevin equations. We treat the counter-rotating terms in the Hamiltonian perturbatively, which leads to the Bloch-Siegert shift in the resonator frequency. It is shown how the shift can improve the readout. The theory of photon transport through the qubit and the resonator it couples to is provided while taking the effect of the counter-rotating terms into account. To calculate the readout contrast, we use two approaches. The first one neglects the qubit relaxation and allows us to derive a compact expression for the contrast. Also, we obtain simple estimates for the system parameters to maximize the contrast. The second approach accounts for the qubit relaxation, which allows us to further improve the contrast. We demonstrate that for a readout time of 1 μs, a contrast of more than 75% can be achieved for an ideal detector and single-photon source.
关键词： Heisenberg-Langevin equations,qubit,dispersive readout,photon transport,Bloch-Siegert shift,readout contrast,photodetector,single-photon probe
更新于2025-09-23 15:21:01
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[IEEE 2019 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD) - Ottawa, ON, Canada (2019.7.8-2019.7.12)] 2019 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD) - Simulation of quantum light sources using the self-consistently coupled Schr??dinger-Poisson-Drift-Diffusion-Lindblad syste
摘要： A very-large-scale integration capable of extracting motion features from moving images in real time has been developed employing row-parallel and pixel-parallel architectures based on the digital pixel sensor technology. Directional edge filtering of input images is carried out in row-parallel processing to minimize the chip real estate. To achieve a real-time response of the system, a fully pixel-parallel architecture has been explored in adaptive binarization of filtered images for essential feature extraction as well as in their temporal integration and derivative operations. As a result, self-speed-adaptive motion feature extraction has been established. The chip was designed and fabricated in a 65-nm CMOS technology and used to build an object detection system. Motion-sensitive target image localization was demonstrated as an illustrative example.
关键词： parallel architecture,digital pixel sensor (DPS),Block-readout scheme,motion feature extraction (MFE),vision chip
更新于2025-09-23 15:21:01
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[IEEE 2020 IEEE 11th Latin American Symposium on Circuits & Systems (LASCAS) - San Jose, Costa Rica (2020.2.25-2020.2.28)] 2020 IEEE 11th Latin American Symposium on Circuits & Systems (LASCAS) - Advancing Uncooled Infrared Imagers Using An Open-Circuit Voltage Pixel
摘要： A topology leveraging a photodetector in the forward bias region generating an open-circuit voltage is proposed. Connecting the anode of the photodetector to the gate of a MOSFET device operating in the subthreshold region provides the basis for a new open-circuit voltage pixel (VocP). Theoretical analysis outlining the effective photodetector response and performance benefits is described. An integrated circuit (IC) with direct-injection pixels modified to support the VocP front-end and analog output readout fabricated in a CMOS 0.18 μm technology is also presented. The IC allows testing of mid-wave infrared (IR) photodiodes operating in both the photocurrent and VocP modes. The VocP pixel is compared to a traditional reverse bias current mode photodetector configuration. Simulation, modeling, and measurement show improved sensitivity and faster response time for the VocP over direct photocurrent detection.
关键词： model,ROIC,open-circuit voltage,readout,MWIR,Mid-wave,Voc
更新于2025-09-23 15:21:01
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A multi-channel PCI express readout board for fast readout of large pixel detectors
摘要： Recently the ATLAS Pixel Detector at CERN has been upgraded by inserting an additional layer of pixels, the Insertable B-Layer (IBL). In addition, the off-detector readout electronics of the other layers that composed the Pixel Detector (the B-Layer, the Layer 1, the Layer 2 and the Disks) were updated using the IBL readout boards. The system has been updated, one layer at a time, giving priority to the next critical layer as the luminosity and level-1 trigger frequency increased. Hence, after IBL, the first critical layer was the Layer 2, then the Layer 1 and finally the B-Layer and the Disks. Eventually, after the technical stop in 2018 the entire ATLAS Pixel Detector will share the same off-detector readout electronics. In parallel with the commissioning of the upgrade of the current ATLAS Pixel Detector we have designed and fabricated a new readout electronic board to address the requirements of the LHC Phase-2 upgrade. Two batches of prototypes of a Peripheral Component Interconnect Express (PCIe) Gen. 2 boards have been designed and fabricated, the second being a patched version of the first. The first batch was composed of two boards, called Pixel ReadOut Driver (Pixel_ROD) and the second batch was made of five cards called ??-LUP. All the boards feature many of the input–output ports and interfaces to address the requirements of the future front-end electronics being developed for the Large Hadron Collider (LHC) Phase-2 upgrade. Thus, the current VERSABUS Module Eurocard (VME) bus will be replaced with the PCIe bus to accommodate the huge increase of throughput (data to be transferred to the DAQ). In this new scenario, the GigaBit Transceiver (GBT) and Aurora protocols are compatible with our boards and the GBTx and RD53A chips will be the first components to be interfaced with. Some laboratory results and measurements are presented here.
关键词： FELIX,??-LUP,Readout system,Data acquisition circuits,ATLAS
更新于2025-09-23 15:21:01
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Detailed modeling of the video signal and optimal readout of charge-coupled devices
摘要： This article provides a practical design methodology to calculate an optimal filter for noise reduction in the readout of charge-coupled devices (CCDs) taking into account the charge transfer and feedthroughs due to capacitive coupling in the CCD. A detailed analysis of the dynamics of the video signal and charge transfer is presented, including the circuital modeling of the output stage of the CCD and the dynamics of the electronics in the video chain before the analog-to-digital (AD) converter. This model is used to compute an optimal filter that minimizes the variance of the pixel noise and uses the samples of the charge transfer, before the charge is fully settled. This is necessary to enhance the performance of previous results that also use optimal filters but do not use the transition samples, while also reducing the pixel readout time, resulting in faster readouts. As a proof of concept for the optimal filter, we present novel experimental results using a Skipper CCD, which has a floating sense node that allows to measure the charge packet an arbitrary number of times. However, this technique can be applied to any CCD that has a readout system that digitally samples the video signal.
关键词： CCD,optimal filter,minimum noise variance,readout,charge transfer
更新于2025-09-23 15:21:01
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LOCx2-130, a low-power, low-latency, 2 × 4.8-Gbps serializer ASIC for detector front-end readout
摘要： In this paper, we present the design and test results of LOCx2-130, a low-power, low-latency, dual-channel transmitter ASIC for detector front-end readout. LOCx2-130 has two channels of encoders and serializers, and each channel operates at 4.8 Gbps. LOCx2-130 can interface with three types of ADCs, an ASIC ADC and two COTS ADCs. LOCx2-130 is fabricated in a commercial 130-nm CMOS technology and is packaged in a 100-pin QFN package. LOCx2-130 consumes 440 mW and achieves a latency of less than 40.7 ns.
关键词： Trigger concepts and systems (hardware and software),Digital electronic circuits,Front-end electronics for detector readout
更新于2025-09-23 15:21:01
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New approach to raising the resolution of position sensitive detector with moving current-voltage characteristic
摘要： Position sensitive detectors (PSD) are widely applied for determining the coordinate of an optical signal and continuously tracking it. Currently, studies concerned with the possibility of further raising the spatial resolution of PSDs remain topical. In this paper, we present the results obtained in reaching an ultrahigh resolution for a device based on the PSD Multiscan with an integral operation principle which fundamentally differs from that of the lateral PSD. The PSD Multiscan design is based on an array of back-to-back photodiodes. Its optical signal coordinate read-out is formed via the moving current-voltage characteristic of the sensor directly on the PSD as an output potential proportional to the coordinate of the optical spot median. This measurement principle provides a continuous comparison of near-equal photocurrents, which maintains a high signal-to-noise ratio over the whole sensing area. The absence of computational operations in electronic circuits of the PSD Multiscan makes it possible to introduce a nonlinear amplifier element, which substantially improves the resolution of the device based on the sensor developed in the study (as good as 0.05 μm). It has been shown that the resolution remains high for detectors with different lengths and is independent of the position of the optical spot on the sensing area.
关键词： Analogue electronic circuits,Photon detectors for UV, visible and IR photons (solid-state) (PIN diodes, APDs, Si-PMTs, G-APDs, CCDs, EBCCDs, EMCCDs etc),Optical detector readout concepts
更新于2025-09-23 15:21:01
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Heavily Irradiated 65-nm Readout Chip With Asynchronous Channels for Future Pixel Detectors
摘要： This paper discusses the main results relevant to the characterization of an analog front-end processor designed in view of experiments with unprecedented particle rates and radiation levels at the high-luminosity Large Hadron Collider (HL-LHC). The front-end channel presented in this paper is part of the CHIPIX65-FE0 prototype, a readout application-speci?ed integrated circuit designed in a 65-nm CMOS technology in the frame of the CERN RD53 collaboration. The prototype integrates a 64 × 64 pixel matrix, divided into two 32 × 64 submatrices, featuring squared pixels with 50-μm pitch, embodying two analog front-end architectures based on synchronous and asynchronous hit discriminators. This paper is focused on the characterization of the array with asynchronous channels, before and after exposure to ionizing doses up to 630 Mrad(SiO2) of X-rays. The analog chain takes a per-channel area close to 1000 μm2, with a power dissipation of around 5 μW. The mean value of the equivalent noise charge, not signi?cantly affected by radiation, is close to 100 electrons with no sensor connected to the front end. The threshold dispersion before irradiation is 55 electrons, for a tuned threshold of 600 electrons, with a moderate increase after irradiation. In-pixel analog-to-digital conversion, based on the time-over-threshold technique, is not appreciably in?uenced by the radiation as well. The assessed performance guarantees sub-1000 electrons stable threshold operations, which is a mandatory feature for highly ef?cient readout chips at the HL-LHC.
关键词： pixel readout,Analog front ends,electronic noise,CMOS processes,ionizing radiation effects
更新于2025-09-23 15:21:01
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Quantum Dots via rf Reflectometry
摘要： Silicon spin qubits show great promise as a scalable qubit platform for fault-tolerant quantum computing. However, fast high-fidelity readout of charge and spin states, which is required for quantum error correction, has remained elusive. Radio-frequency reflectometry enables rapid high-fidelity readout of GaAs spin qubits, but the large capacitances between accumulation gates and the underlying two-dimensional electron gas in accumulation-mode Si quantum-dot devices, as well as the relatively low two-dimensional electron gas mobilities, have made radio-frequency reflectometry challenging in these platforms. In this work, we implement radio-frequency reflectometry in a Si/Si-Ge quantum-dot device with overlapping gates by making minor device-level changes that eliminate these challenges. We demonstrate charge-state readout with a fidelity above 99.9% in an integration time of 300 ns. We measure the singlet and triplet states of a double quantum dot via both conventional Pauli spin blockade and a charge latching mechanism, and we achieve maximum fidelities of 82.9 and 99.0% in 2.08- and 1.6-μs integration times, respectively. We also use radio-frequency reflectometry to perform single-shot readout of single-spin states via spin-selective tunneling in microsecond-scale integration times.
关键词： quantum computing,Silicon spin qubits,spin-state readout,charge-state readout,radio-frequency reflectometry
更新于2025-09-23 15:19:57