An electrical potential difference emerges between the central and edge regions of the p-region in focal plane arrays (FPAs), particularly pronounced in HgCdTe FPAs, characterized by a higher potential in the center and a lower potential at the edges. This may lead to an uneven spatial distribution of the pixel current. In order to analyze this phenomenon, one-dimensional and two-dimensional models were established in this paper, and the Newton-Raphson method was employed to calculate. A simplified relationship between the center-edge potential difference and the array size as well as the current was derived. The elevation of the potential at the center of the array is attributed to the current loop within the array, which becomes more pronounced with increased FPA format. The FPAs current was calculated under conditions of non-uniform diode characteristics across pixels, and the simulation results agree well with the measured data. Finally, three methods were discussed to reduce the impact of this potential difference. Among them, increasing the bias voltage and introducing threaded electrodes have been verified to yield certain improvements.

Linear-mode HgCdTe avalanche photodiodes (APDs) have attracted significant attention due to their exceptionally low excess noise, operational bias ranging from-12 to 0 V, and linearly tunable gain. These characteristics suggest promising future applications in optical observations. The design of the multiplication region based on the PIN structure is critical, as it directly influences the photoelectric properties of the device, including gain and excess noise. This paper primarily investigates the effect of implanted areas on the multiplication region and examines area-related gain and noise characteristics of mid-wavelength infrared (MWIR) HgCdTe APDs at a temperature of 80 K. Studies conducted on diodes with varying implanted areas indicate that those with larger implanted areas create a wider multiplication region, which leads to lower gain and higher excess noise factors. Finally, 30 mu m pitch 640 x 512 array HgCdTe APDs for cut-off wavelengths 4.8 mu m at 80 K corresponding to compositions xCd = 0.31 were fabricated. The number of noise bad pixels and the band-to-band tunneling (BBT) current have been significantly reduced due to the optimized the multiplication region width. Consequently, high-definition imaging under short integration times has been successfully achieved.

Silicon detectors play a crucial role in high energy physics experiments. In future high energy physics experiments, silicon detectors will be exposed to extremely high fluence environment, which can significantly affect their performance. It is important to understand the electrical behavior of detectors after irradiation. In this study, an irradiation simulation framework is constructed in RAdiation SEmiconductoR (RASER) to simulate leakage current and charge collection effciency. The defect parameters are obtained from the Hamburg penta trap model (HPTM). Based on this work, we predict the silicon inner tracker which under a ten-year Circular Electron Positron Collider (CEPC) Higgs mode run can still maintain over 90% charge collection efficiency.

The miniaturization of light-emitting diodes (LEDs) is pivotal in ultrahigh-resolution displays. Metal-halide perovskites promise efficient light emission, long-range carrier transport and scalable manufacturing for bright microscale LED (micro-LED) displays. However, thin-film perovskites with inhomogeneous spatial distribution of light emission and unstable surface under lithography are incompatible with the micro-LED devices. Continuous single-crystalline perovskite films with eliminated grain boundaries, stable surfaces and optical homogeneity are highly demanded for micro-LEDs, but their growth and device integration remain challenging. Here we realize the remote-epitaxy growth of crystalline perovskite films, enabling their seamless integration into micro-LEDs with a pixel size down to 4 μm. By incorporating a subnanometre graphene interlayer, we enable remote epitaxy and transfer of perovskites with relaxed strain. These micro-LEDs exhibit a high electroluminescence efficiency of 16.7

An RF-driven ion source has been put into commissioning on the China Spallation Neutron Source (CSNS) accelerator since September 2021. In the last two run cycles, the ion source has operated for 310 and 323 days respectively, with an availability of almost 100%. To fully meet the requirements of the CSNS project Phase-II (CSNS-II), the beam intensity from the linac should be enhanced to above 40mA, and the transverse emittance should be minimized to suppress beam loss during acceleration and transportation. A new test bench consisting of an ion source and a LEBT has been constructed to carry out these optimization and research. The featured functions of the LEBT are associated with proton elimination and electrostatic beam chopping. This report covers the operation status and development of the RF-driven H- source and the new LEBT.

A high-precision beam monitor system based on silicon carbide PIN sensor is designed for the 1.6 GeV proton beam of China Spallation Neutron Source. The conceptual design of the beam monitor system is composed of front-end electronics with SiC PIN sensor and readout system. The charge collection efficiency of the SiC PIN sensor after proton radiation is studied with 80 MeV proton beam. 98 % in the beam monitor system. The results reveal that the beam monitor system can be used for the 1.6 GeV proton beam of China Spallation Neutron Source.

A unique large-span cable-net structure, as the key unit of the active reflector system of FAST, is specially introduced. The cable-net structure contains a huge cable mesh and thousands of down-tied cables driven by hydraulic actuators. The mesh is normally prestressed to form a 500m-aperture base sphere, but some part may further change its shape to form paraboloid for the purpose of good illumination during FAST works. Such shape change or deformation requires that hundreds of hydraulic actuators drive coordinately. Therefore deformation strategy is necessary to be discussed in details on how much each actuator should stretch out or draw back to paraboloid. Its simulation based on finite element method is further given for demonstration. The regular strategy works well if the illumination area can be limited within the cable mesh. Otherwise, it may induce such structural dangers as slack cable, over-stressed cable or fatigue failure. A new strategy is then developed to crack such problem. It first follows the regular strategy, then checks and finds out all the potentially dangerous cables. The stresses of these dangerous cables are controlled in the safe range via adjusting the related down-tied cables. A comparative simulation result with the measurement on site verifies its effectiveness.

Three-dimensional (3D) cell cultures have contributed to a variety of biological research fields by filling the gap between monolayers and animal models. The modern optical sectioning microscopic methods make it possible to probe the complexity of 3D cell cultures but are limited by the inherent opaqueness. While tissue optical clearing methods have emerged as powerful tools for investigating whole-mount tissues in 3D, they often have limitations, such as being too harsh for fragile 3D cell cultures, requiring complex handling protocols, or inducing tissue deformation with shrinkage or expansion. To address this issue, we proposed a modified optical clearing method for 3D cell cultures, called MACS-W, which is simple, highly efficient, and morphology-preserving. In our evaluation of MACS-W, we found that it exhibits excellent clearing capability in just 10[Formula: see text]min, with minimal deformation, and helps drug evaluation on tumor spheroids. In summary, MACS-W is a fast, minimally-deformative and fluorescence compatible clearing method that has the potential to be widely used in the studies of 3D cell cultures.

Chiral two-dimensional (2D) perovskites offer numerous attractive features for optoelectronics owing to their soft, deformable lattices and a high degree of chemical tunability. While tremendous advances have been made in perovskite-based direct circularly polarized light (CPL) detection, the low circular polarization anisotropy factor and sensitivity of those photodetectors arising from large lattice distortion still limit practical applications. Herein, chiral 2D perovskite-based single-crystalline microwire arrays with enhanced circular dichroism (CD) absorption are fabricated with the synergy of the capillary-bridge-confined assembly method and chlorine-substituted phenethylamine (Cl-MBA). Compared with phenethylamine (MBA)-inserted perovskites, the smaller lattice distortion and increased halogen–halogen interaction within Cl–MBA-inserted perovskites strengthen lattice rigidity and weaken electron-phonon coupling to improve carrier transport and thermal stability, resulting in high-performance CPL photodetectors with an anisotropy factor of 0.25, responsivity exceeding 95.7±9.3 A W −1 and detectivity exceeding (3.05±0.30)×10 13 Jones. This work opens a new perspective to modulate circular polarization sensitivity and will be helpful to realize promising implementations in quantum computation and communication.

The Space Advanced Technology demonstration satellite (SATech-01), a mission for low-cost space science and new technology experiments, organized by Chinese Academy of Sciences (CAS), was successfully launched into a Sun-synchronous orbit at an altitude of ∼500 km on July 27, 2022, from the Jiuquan Satellite Launch Centre. Serving as an experimental platform for space science exploration and the demonstration of advanced common technologies in orbit, SATech-01 is equipped with 16 experimental payloads, including the solar upper transition region imager (SUTRI), the lobster eye imager for astronomy (LEIA), the high energy burst searcher (HEBS), and a High Precision Magnetic Field Measurement System based on a CPT Magnetometer (CPT). It also incorporates an imager with freeform optics, an integrated thermal imaging sensor, and a multi-functional integrated imager, etc. This paper provides an overview of SATech-01, including a technical description of the satellite and its scientific payloads, along with their on-orbit performance.

Infrared photon detection technology usually works in the passive sensing mode and contains the advantages of long acting-distance, good anti-interference, excellent penetration of smoke and haze, and all-day operation, which has been widely used in space remote sensing, military equipment, astronomical detection and other aspects. So far, the second-generation and the third-generation infrared photon detectors have been deployed widely. The high-end third-generation infrared photon detectors have been gradually promoted to practical application. The fourth generation and more forward-looking research including new concept, new technology, and new device has been proposed. This paper focuses on the research status of infrared technology at home and abroad, emphatically introducing the hotspots and development trends of infrared photon detectors. Firstly, the concept of SWaP(3) is introduced due to tactical ubiquity and strategic high performance. Secondly, the high-end third-generation infrared photon detectors with ultra-high spatial resolution, ultra-high energy resolution, ultra-high time resolution and ultra-high spectral resolution are reviewed. Technical characteristics and implementation methods of ultimate-performance infrared detectors are analyzed. Then, the fourth-generation infrared photon detector based on the artificial micro-structure is discussed. The realization approaches and technical challenges of multi-dimensional information fusion such as polarization, spectrum and phase are mainly introduced. Lastly, highly innovative trends of future detectors are discussed according to upgradation from on-chip digitization to on-chip intelligence.

Hierarchical heterostructures fabricated from several optoelectronic materials with different physical properties are the basis for the integration of multifunctional and high-performing micro/nanodevices. Compared with one-component systems, heterostructures with programmable geometries can effectively control device performance, integrate multiple functions, and generate specific applications. However, patterning high-quality hierarchical heterostructures still faces difficulties in regard to solution processing, such as the dissolution of prepared structures during multiple processes and the uncontrollable assembly behaviors of different materials. Here, we report a universal method for fabricating cross-stacked P3HT/MAPbBr3 heterostructure arrays with a large area, homogeneous size, precise position, long-range order, and pure crystallographic orientation. The controlled hierarchical dewetting processes are confined by capillary bridges in the sandwich-structured assembly system, yielding bilayer heterostructure arrays with programmable geometries and tunable positional relationships. Our strategy provides a new perspective for the fabrication of high-throughput and high-efficiency hierarchical heterostructures toward integrated optoelectronics.

High current beam is required for CSNS update in future. Over 50 mA H− will be designed to deliver to the linac in CSNS II. For the present state of CSNS ion source, the beam emittance cannot satisfy the requirement of RFQ entrance at the 50 mA H− beam. In order to improve the beam quality, CSNS ion source is required further improvement. Simulation shows emittance growth due to the space charge force in the intense H− beam when the beam transports through the analyzing magnet. After considering the neutralization of space charge, the emittance growth could be suppressed. The analyzing magnet thus is considered to removed, which might destroy the neutralization of space charge. The beam emittance is measured at the revised CSNS ion source. Measured results show that beam emittance without the analyzing magnet becomes smaller than that of CSNS ion source. At the requirement of 0.2 πmm mrad, beam current is larger than 30 mA. It reveals that analyzing magnet could destroy space charge neutralization and result in the significant increase of emittance. Although the results presented are preliminary, it is important to improve the beam quality. This paper details the ion source improvement and measurement process.

ABSTRACT The Five-hundred-meter Aperture Spherical radio Telescope (FAST), the largest single-dish radio telescope in the world, has implemented an innovative technology for its huge reflector, which changes the shape of the primary reflector from spherical to that of a paraboloid of 300-m aperture. Here, we explore how the current FAST sensitivity can potentially be further improved by increasing the illuminated area (i.e. the aperture of the paraboloid embedded in the spherical surface). Alternatively, the maximum zenith angle can be increased to give greater sky coverage by decreasing the illuminated aperture. Different parabolic apertures within the FAST capability are analyzed in terms of how far the spherical surface would have to move to approximate a paraboloid. The sensitivity of FAST can be improved by approximately 10 per cent if the aperture of the paraboloid is increased from 300 to 315 m. The parabolic aperture lies within the main spherical surface and does not extend beyond its edge. The maximum zenith angle can be increased to approximately 35º from $26{_{.}^{\circ}}4$, if we decrease the aperture of the paraboloid to 220 m. This would still give a sensitivity similar to the Arecibo 305-m radio telescope. Radial deviations between paraboloids of different apertures and the spherical surfaces of differing radii are also investigated. Maximum zenith angles corresponding to different apertures of the paraboloid are further derived. A spherical surface with a different radius can provide a reference baseline for shape-changing applied through active reflector technology to FAST-like telescopes.

Noise equivalent temperature difference (NETD) is an important figure of merit for infrared detectors. Lower NETD means that the detector can realize smaller temperature resolution and longer range recognition. In this work, we investigate the device performance, especially the NETD characteristics of a long-wavelength infrared (LWIR) photodetector based on InAs/GaSb type-II superlattice (T2SL). To achieve mK-level temperature-sensitivity, the effect of detector's intrinsic and extrinsic factors on NETD performance has been discussed. Through a series of efforts, a NETD value of 7 mK was realized for a T2SL detector with a 100% cutoff wavelength of 11.4 μm at 77 K.

The precise measurement of weak magnetic fields by using high-sensitivity magnetometers is not only widely used, but also promotes the development of many research fields. The magnetic field measurement capability of the magnetometer determines the potential and scope of its application, which means that research on its magnetic field measurement capability is essential.In this work, we develop a rubidium-xenon vapor cell atomic magnetometer. The cell filled with 5-torr 129Xe, 250-torr N2 and a droplet of enriched 87Rb is placed in the center of a five-layer magnetic shield with four sets of inner coils to control the internal magnetic field environment. In the cell, 129Xe is polarized by spin exchange collisions with 87Rb atoms, which are pumped with a circularly polarized laser beam at the D1 transition. If magnetic fields or pulses are applied to the cell, the polarization state of 87Rb and 129Xe will change and evolve, whose evolution process can be described by a pair of Bloch equations. The analysis of the Bloch equations indicates that the rubidium-xenon vapor cell atomic magnetometer can measure magnetic fields by two different methods. The magnetic field measurement capabilities of the two methods are experimentally calibrated respectively. The first method is to measure the alternating current (AC) magnetic fields by measuring the influence of the external magnetic fields on the polarization of the 87Rb atoms. The experimental results show that the sensitivity of the AC magnetic field measurement is about \begin{document}$1.5\;{{{\rm{pT}}} / {\sqrt {{\rm{Hz}}} }} $\end{document} in a frequency range of 2100 Hz, and the bandwidth is about 2.8 kHz. The second method is to measure the static magnetic fields by measuring the Larmor frequency of the hyperpolarized 129Xe in the cell. Considering that its measurement accuracy is limited by the relaxation of the hyperpolarized 129Xe, the transverse and longitudinal relaxation time are measured to be about 20.6 s and 21.5 s, respectively. Then, the experimental calibration results indicate that the static magnetic field measurement precision is about 9.4 pT and the measurement range exceeds 50 μT, which prove that the static magnetic field measurement can still be performed under geomagnetic field (50 μT). The rubidium-xenon vapor cell atomic magnetometer enables the measurement of AC magnetic fields and static magnetic fields in the same system. Compared with the spin exchange relaxation free (SERF) atomic magnetometer, the rubidium-xenon vapor cell atomic magnetometer has some unique advantages. For AC magnetic field measurement, it has a wider frequency range. For static magnetic field measurement, it can be performed under geomagnetic field and can give the magnetic field measurement value without using the calibration parameters of the system. These characteristics make the rubidium-xenon vapor cell atomic magnetometer have broad application prospects. It is expected to be applied to geomagnetic surveys, basic physics and other aspects of research.

Methods : Permanent vHBP was attempted in 30 patients (50% men, age 64 ± 15 years) with symptomatic bradycardia and indicated for pacemaker.implantation. The TVA revealed by right ventriculography was used as an anatomic landmark for localizing the site for vHBP under the TVA. Procedural feasibility, vHBP pacing parameters, the effect of vHBP lead on tricuspid valve function, and procedure-related complications were evaluated.

OBJECTIVE:To compare the effects of transcatheter arterial chemoembolization (TACE) with transcatheter arterial embolization (TAE) on liver function, hepatic damage, and hepatic fibrogenesis in a rabbit tumor model.MATERIALS AND METHODS:Thirty-nine New Zealand white rabbits implanted with VX2 tumors in the left liver lobes were randomly divided into three groups: TAE, TACE, and control group. In the TAE group (n = 15), polyvinyl alcohol particles (PVAs) were used for left hepatic artery embolization. In the TACE group (n = 15), the tumors were treated with left hepatic arterial infusions of a suspension of 10-hydroxycamptothecin and lipiodol, followed by embolization with PVAs. In the control group (n = 9), the animals received sham treatment with distilled water. Serum and liver samples were collected at 6 hours, 3 days and 7 days after treatment. Liver damage was measured using a liver function test and histological analyses. Liver fibrogenesis and hepatic stellate cell (HSC) activation were evaluated using Sirius Red and anti-alpha-smooth muscle actin (α-SMA) immunohistochemical stains.RESULTS:TACE caused liver injury with greater increases in serum alanine aminotransferase and aspartate aminotransferase levels on day 3 (P<0.05). Histological analyses revealed increased hepatic necrosis in adjacent non-tumorous liver tissue from day 3 compared to the TAE group (Suzuki score of 2.33±1.29 versus 1.13±1.18, P = 0.001). HSC activation and proliferation were significantly increased in the TACE group compared to the control group at 3 and 7 days after treatment (0.074±0.014 vs. 0.010±0.006, and 0.088±0.023 vs. 0.017±0.009, P<0.05). Sirius Red staining demonstrated a statistically significant increase in collagen deposition in the livers in the TACE group 7 days after embolization compared to the control group (0.118±0.012 vs. 0.060±0.017, P = 0.05).CONCLUSION:The results of this animal study revealed that TACE induced prominent hepatocellular damage and hepatic fibrogenesis, which compromised liver function and may be responsible for chronic liver decompensation.