In recent years, organic-inorganic halide perovskite solar cells have attracted widespread attention due to their tunable band gap, high optical absorption coefficient, and favorable structural stability. In this study, we employed first-principles calculations and density functional theory to investigate the electronic structure, mechanical properties, optical characteristics, and stability of ABI3 (A = MA, FA, NH4; B = Pb, Sn, Ge). We substituted Pb with its group counterparts Sn and Ge while retaining Pb at the B-site for comparative analysis. Through calculations of perovskite stability factors, precursor reaction energies, and ab initio molecular dynamics, we confirmed that lead-free perovskites exhibit favorable thermodynamic and structural stability under inert conditions, making them viable replacements for Pb. Our findings indicate that modifying the B-site element enables bandgap tuning, allowing for light absorption across different spectral ranges. Our theoretical research indicates that under hydrostatic pressure, the bandgap can be further modulated. NH4GeI3 demonstrates heightened sensitivity in both lattice parameters and bandgap values, exhibiting a bandgap reduction of 0.74 eV at 1.1 GPa. Its substantial pressure-bandgap response (S = 0.67 eV/GPa) suggests potential as a pressure-sensitive photodetector material. This study elucidates the property variations in Sn- and Ge-substituted perovskites, providing interesting insights for the further development and application of environmentally friendly lead-free organic-inorganic halide perovskites.

The search for 2D magnetic materials with high spin polarization, elevated Curie temperature, and strong magnetic anisotropy remains a pressing challenge in the field of spintronics. Considering that the magnetic design potential of Dion-Jacobson (DJ) phase 2D perovskites has not yet been fully explored, this study employs first-principles calculations to design and systematically investigate a novel DJ-phase 2D magnetic perovskite, MA2Mn2Cl8 (MA+ =CH3NH3+). The results of AIMD simulations, phonon spectrum, and structural parameter analyses confirm the excellent structural stability of this material. Its ground state is ferromagnetic, exhibiting a typical ferromagnetic half-metallic behavior characterized by 100 % spin polarization at the Fermi surface and a Fermi velocity of 2 x 105 m/s. This feature is verified to be robust across multiple computational approaches, including PBE, GGA + U, PBE + SOC, and HSE06 hybrid functional calculations. The estimated Curie temperature (TC) is approximately 245 K, which is significantly higher than that of conventional 2D ferromagnetic materials, and the magnetic anisotropy energy (MAE) reaches 2.3 meV. Overall, this material overcomes the performance limitations of traditional 2D magnetic systems, providing an ideal candidate for next-generation spintronic devices, and opens up new possibilities for the application of DJ-phase perovskites in the field of magnetic materials.

To meet the application demand for simultaneous structure inspection and elemental analysis, research on neutron imaging-driven prompt gamma activation analysis instrument is of great significance. Relying on the China Mianyang Research Reactor, the China Academy of Engineering Physics proposed the physical design of the PGAA -NT apparatus, carried out Monte Carlo simulations, signal commissioning and experimental tests, and successfully established an experimental facility that couples PGAA with neutron imaging. In terms of characterisation, the beam parameters, background features, Compton-suppression performance, wide-energy-range detection efficiency, and imaging spatial resolution of the instrument were accurately measured. The instrument exhibits the low background (full spectrum <200 cps at 1.5 x 108 ncm-2s-1), high energy resolution (2 keV at 1.332 MeV), high imaging spatial resolution ( <10 m) and millimetre-scale activated analysis volume. It provides a neutron measurement platform that combines three-dimensional structure detection with position-sensitive elemental analysis. This instrument fills the gap in China's PGAA-NT field, with performance reaching the international advanced level.

This paper focuses on the development of high-performance room-temperature low-noise amplifiers (LNAs) for radio astronomy aiming to compete with traditional cryogenic LNAs. The LNA, a core component of the radio telescope receiver, is essential for minimizing the system noise temperature and achieving high sensitivity. This paper details the design and measurement results of two LNAs: LNA1 (1 - 1.8 GHz) for the FAST core array and LNA2 (0.9 - 1.3 GHz) for the BINGO telescope. The results demonstrate that these room-temperature LNAs can match the performance of cryogenic LNAs to some extent, with significantly reduced noise temperatures, particularly when thermoelectric cooling is applied. These advancements provide a more reliable and cost-effective solution for receivers of telescope arrays and multi-beam receivers in radio astronomy.

Wide-spectral and polarization-sensitive photodetectors are vital for applications in imaging, communication, and intelligent sensing. Although two-dimensional (2D) materials have shown great promise in enhancing the performance of these devices, conventional methods for spectral discrimination often rely on complex designs, such as external filters or multisensor systems, increasing system cost and complexity. Developing simplified devices that integrate spectral and polarization detection remains a key challenge. Here, we demonstrated a 2D MoTe2/GeSe-based photodetector with wide-spectral photoresponse (400 to 1064 nm) and polarization sensitivity, achieving a responsivity of 1.35 A W−1 and a polarization ratio of 2.23 under 808 nm illumination. The device exhibited a unique 90° polarization reversal between green (532 nm) and red (808 nm), providing a novel mechanism for spectral discrimination. First-principles calculations reveal the polarization reversal phenomenon based on the heterostructure's optical anisotropy. Furthermore, integration with a convolutional neural network enables intelligent traffic signal recognition using polarization-sensitive images. This work highlights the potential of MoTe2/GeSe heterostructures for next-generation photodetectors, offering compact, multifunctional solutions with integrated spectral and polarization discrimination capabilities.

Neutron capture event imaging is a novel technique that has the potential to substantially enhance the resolution of existing imaging systems.This study provides a measurement method for neutron capture event distribution along with multiple reconstruction methods for super-resolution imaging.The proposed technology reduces the point-spread function of an imaging system through single-neutron detection and event reconstruction,thereby significantly improving imaging resolution.A single-neutron detection experiment was conducted using a highly practical and efficient 6 LiF-ZnS scintillation screen of a cold neutron imaging device in the research reactor.In milliseconds of exposure time,a large number of weak light clusters and their distribution in the scintillation screen were recorded frame by frame,to complete single-neutron detection.Several reconstruction algorithms were proposed for the calculations.The location of neutron capture was calculated using several processing methods such as noise removal,filtering,spot segmentation,contour analysis,and local positioning.The proposed algorithm achieved a higher imaging resolution and faster reconstruction speed,and single-neutron super-resolution imaging was realized by combining single-neutron detection experiments and reconstruction calculations.The results show that the resolution of the 100 μm thick 6 LiF-ZnS scintillation screen can be improved from 125 to 40 microns.This indicates that the proposed single-neutron detection and calculation method is effective and can significantly improve imaging resolution.

First-principles calculations and quantum transport simulations were performed to investigate the photogalvanic effect (PGE) in the high magnetic transition temperature ferromagnetic two-dimensional (2D) semiconductor MnNCl and the 2D lateral MnNI-MnNCl heterostructure. The MnNI-MnNCl heterostructure exhibits significantly enhanced non-centrosymmetric properties, resulting in increased PGE photocurrent and spin current around 0.4 eV. Compared to MnNCl, the photocurrent is amplified by 4-6 orders of magnitude and demonstrates excellent polarization sensitivity, with an extinction ratio reaching 83.92. These results underscore the potential of MnNClMnNI lateral heterostructures for use in self-powered, polarization-sensitive infrared detectors.

Taking advantage of the special reaction principle between neutrons and elements, the neutron imaging method is better suited to testing the structure and the defects of light materials that are covered by heavy materials. In contrast to thermal or cold neutron imaging, the fast neutrons are best suited to testing the large samples composed of various materials. Fission neutrons emitted from the reactor are more stable than those from other neutron sources. Based on the beamline for thermal neutron imaging at China Mianyang Research Reactor (CMRR), a combination of filters could increase the proportion of the fission neutrons. Various fission neutron collimators were calculated, designed and measured. The flux of fission neutrons was close to 3 x 105 cm-2 s- 1, when the collimation ratio was about 172. A fission neutron imaging system was built as well. The field of view (FOV) was as large as 400 mm x 400 mm, and the experimental spatial resolution was better than 0.5 mm. The fission neutron tomography was tested. The reconstruction results were comparable to the tomography performed in NECTAR at FRM-II. In addition, a serial time acquisition method was applied in the tomography to reduce the white noise. The ART reconstruction method may improve the quality of the reconstruction images.

The Laplace smoothing operator is used to constrain the relationship between the target grid and neighboring grids in the terrestrial water storage (TWS) inversion using global navigation satellite system (GNSS) observations. We propose an enhancement to the smoothing constraint matrix used in GNSS TWS inversion with prior spatial constraints from gravity recovery and climate experiment (GRACE) data and invert vertical GNSS displacement data for TWS changes in the Sichuan-Yunnan region. We focus on inverting multiyear seasonal TWS changes in the Sichuan-Yunnan region from January 2013 to June 2023, integrating GNSS, GRACE, and global land data assimilation system (GLDAS) data. Our findings demonstrate the consistency of spatiotemporal patterns between GNSS-inferred TWS and GRACE and GLDAS data. Comparing the estimated results with smoothing constraints, the proposed GNSS inversion utilizing the GRACE constraint enhances the capture of local TWS signals, improving spatial agreement with GRACE and GLDAS. The correlation coefficient with GRACE improves from 0.655 to 0.723, and with GLDAS, it improves from 0.730 to 0.779. We further integrate water balance equations for precipitation, runoff, and evapotranspiration in the Sichuan-Yunnan, validating our approach by aligning with established datasets and improving the spatial understanding of TWS dynamics. These enhancements underscore the effectiveness of our GNSS inversion strategy under the spatial constraint of GRACE and enable a more coherent and meaningful interpretation of GNSS-derived TWS changes.

Nuclear energy is a vital source of clean energy that will continue to play an essential role in global energy production for future generations. Nuclear fuel rods are core components of nuclear power plants, and their safe utilization is paramount. Due to its inherent high radioactivity, indirect neutron radiography (INR) is currently the only viable technology for irradiated nuclear fuel rods in the field of energy production. This study explores the experimental technique of indirect neutron computed tomography (INCT) for radioactive samples. This project includes the development of indium and dysprosium conversion screens of different thicknesses and conducts resolution tests to assess their performance. Moreover, pressurized water reactor (PWR) dummy nuclear fuel rods have been fabricated by self-developing substitute materials for cores and outsourcing of mechanical processing. Experimental research on the INR is performed using the developed dummy nuclear fuel rods. The sparse reconstruction technique is used to reconstruct the INR results of 120 pairs of dummy nuclear fuel rods at different angles, achieving a resolution of 0.8 mm for defect detection using INCT.

Recent observations of a contradictory impurity effect in the heavy-fermion superconductor CeCu2Si2 at ambient pressure have hindered the identification of its pairing symmetry. Here, we perform theoretical analyses with both intraband and interband impurity scatterings for the nodeless s +/--wave pairing, and report an anomalous nonmonotonic variation of its Tc suppression with the scattering strength. Our results reproduce the prominent reduction of Tc in good agreement with earlier experiments by atomic substitution and explains as well its robustness against electron irradiation. We ascribe the latter to the screening of the interband impurity potential in the strong scattering or unitary region. This resolves the seeming contradiction in different experimental probes and provides an important support to the nodeless s +/--wave scenario in CeCu2Si2 at ambient pressure. Our theory may be extended to other narrow-band systems such as twisted bilayer graphene and the recently discovered bilayer or trilayer nickelate superconductors, and provide a useful way to distinguish different pairing candidates thereof.

Chloroalkanes have long been a threat to environmental protection and human health, however, rapid and efficient detection of chloroalkanes remains challenging. Herein, 3-dimensional photonics crystals (3-D PCs) based on bimetallic materials of institute lavoisier frameworks-127 (MIL-127, Fe2M, M = Fe, Ni, Co, Zn) demonstrate the great potential of chloroalkanes sensing. Particularly, at temperature of 25 degrees C and dry conditions, the 3-D PC consisting of MIL-127 (Fe2Co) shows optimal selectivity and high concentration sensitivity of 0.0351 +/- 0.00007 nm ppm(-1) to carbon tetra-chloride (CCl4), and the limit of detection (LOD) can reach 2.85 +/- 0.01 ppm. Meanwhile, MIL-127 (Fe2Co) 3-D PC sensor presents a rapid response of 1 s and recovery time of 4.5 s for CCl4 vapor, and can maintain excellent sensing performance under heat-treatment of 200 degrees C or in the longterm storage (30 days). Mechanism studies indicated that the excellent sensing property derived from the doping of transition metals. Moreover, the moisture-enhanced adsorption of CCl4 for the MIL-127 (Fe2Co) 3-D PC sensor is also observed. H2O molecule can remarkably enhance the adsorption of MIL-127 (Fe2Co) to CCl4. The MIL-127 (Fe2Co) 3-D PC sensor shows the highest concentration sensitivity of 0.146 +/- 0.00082 nm ppm(-1) to CCl4 and the lowest limit of detection (LOD) of 685 +/- 4 ppb under the pre-adsorption of 75 ppm H2O. Our results provide an insight for a trace gas detection using metal-organic frameworks (MOFs) in the optical sensing field.

Increasing oxygen (O 2 ) content and down‐regulating the concentration of glutathione (GSH) in tumor microenvironment (TME) by multiple approaches remain critical factors for the promotion of phototherapeutic effect, especially for photodynamic therapy (PDT). Herein, indocyanine green (ICG) laden dendritic mesoporous manganese‐silicon nanocomposite (NC) is designed and subsequently managed with calcification through in situ growth of calcium phosphate (IDMMS@CaP NC). As specific response behavior of the mildly acidic and GSH overexpressed TME, the IDMMS@CaP NC can rapidly collapse when accumulated at the tumor site, liberate Mn 2+ , Ca 2+ , and ICG, simultaneously reduce the concentration of GSH. Mn 2+ can catalyze endogenous hydrogen peroxide to produce O 2 . Overloaded Ca 2+ induces mitochondrial injury, and reduces cellular metabolism and O 2 consumption. The photothermal effect from ICG with 808 nm laser irradiation can not only cause tumor cells necrosis but also accelerate blood flow to further improve the O 2 content at the tumor site. Consequently, owing to effective GSH depletion and multiple O 2 compensation, the PDT efficiency of ICG can be significantly increased. As proof of concept, the designed multifunctional nanocomposite will provide a general strategy for enhancing the role of phototherapy in cancer therapeutic area.

A novel non-destructive testing scanning system based on a large-size line array fast neutron detector and compact D-T neutron source has been constructed. The scanning range is up to 1000 mm, and the resolution is better than 1 mm. The fast neutron detection subsystem consists of a polypropylene zinc sulfide scintillator embedded with wavelength-shifting fibers, coupled with a light lens and a scientific CCD camera. With a new rotating tritium target, the lifetime of the compact D-T neutron source could achieve ten hours. The experimental results indicate that the scanning method based on line array fast neutron detector and D-T neutron source is feasible and enables the detection of slits on the order of 0.5 mm in width. Fast neutron tomography has been realized by this detection system too.

Enriching the application of multifunctional dendritic mesoporous organosilica (DMOS) is still challenging in anti-cancer research. Herein, manganese ions, iron ions, or cobalt ions and tetrasulfide bonds are co-incorporated into the framework of DMOS to yield multifunctional nanoparticles denoted as Mn-DMOS, Fe-DMOS, or Co-DMOS by directly doping metal ions during the synthetic process. Due to co-incorporation of metal ions and tetrasulfide bonds, these designed nanocarriers have more functions rather than only for cargo delivery. As proof of concept, the nanocomposite is established based on Mn-DMOS as an efficient nanocarrier for indocyanine green (ICG) delivery and modification with polyethylene glycol. In the tumor microenvironment, the generated hydrogen sulfide (H2 S) arising from the reaction between tetrasulfide bond and over-expressed glutathione (GSH) causes mitochondrial injury to reduce cellular respiration. The released Mn2+ from the rapidly decomposed nanocomposite catalyzes the endogenous hydrogen peroxide to produce oxygen (O2 ). The photothermal effect from the released ICG initiated by the near-infrared light induces cancer cells apoptosis and simultaneously enhances the content of blood O2 at tumor sites. Therefore, due to the GSH depletion and trimodal O2 compensation, the photodynamic therapy efficiency of ICG has significantly improved. In brief, these designed nanocarriers will play advanced roles in cancer therapy.

Recent observations of two nodeless gaps in superconducting CeCu$_2$Si$_2$ have raised intensive debates as to its exact gap structure of either sign-reversal ($s^{+-}$) or sign-preserving ($s^{++}$) pairing. Here we investigate the quasiparticle interference (QPI) using realistic Fermi surface topology for both weak and strong interband impurity scatterings. Our calculations of the QPI and integrated antisymmetrized local density of states reveal qualitative distinctions between $s^{+-}$ and $s^{++}$ pairing states, which include the intragap impurity resonance and a significant energy-dependence difference between two gap energies. Our predictions provide a guide for phase-sensitive QPI measurements to uncover decisively the true pairing symmetry in the heavy-fermion superconductor CeCu$_2$Si$_2$.

In this review, the research progress of MOF-based PC gas sensors from 1-D to 3-D PCs, which mainly include four aspects of sensing mechanism, material selection, structural optimization and sensing performances, is comprehensively summarized.

Nowadays, the therapeutic efficiency of tumor can be significantly influenced by the limitation of endogenous tumor microenvironment (TME). An ideal solution for improving therapeutic efficiency is constructing TME-responsive and multifunctional nanoreactor. Herein, a TME-responsive nanoreactor has been constructed using novel dendritic mesoporous silica nanoparticles (DMSNs) as the cornerstone, followed by anchoring platinum-(IV) prodrugs, loading photosensitizer indocyanine green (ICG), and decorating Cu2+ carboxylate MOFs. The prepared nanoreactor provides a high loading efficiency for Pt prodrugs and ICG, while the externally decorated MOFs can prevent premature leakage in neutral physiological environment at the same time. However, after accumulation at the tumor site, the outer MOFs can be rapidly decomposed in the TME to release Cu2+, which achieves efficient chemodynamic therapy (CDT) through Cu2+-triggered Fenton-like reaction and GSH depletion ability. At the same time, the released Pt drugs can achieve efficient chemotherapy. Moreover, the near-infrared (NIR) can activate the photodynamic and photothermal therapy (PDT&PTT) ability of ICG, resulting in PTT-enhanced CDT. Meanwhile, the nanoreactor can exhibit photothermal and magnetic resonance imaging (MRI) ability for highly specific diagnosis of tumor. Overall, this study provides a paradigm of TME-responsive nanoreactor for collaboratively multimodal enhanced tumor therapy.

The extensive use of hypochlorite (ClO- ) as oxidant and bleach has drawn serious concern due to their adverse environment and biological impact. Herein, a novel fluorescence probe composite material based on MAPbBr3@ZIF-8 was prepared by agitation method in room temperature, using lead bromide, armour ammonia bromine, 2-methylimidazole and zinc acetate as precursors. MAPbBr3@ZIF-8 composites exhibited remarkable stability in NaCl aqueous solution and UV lamp. Thus, the MAPbBr3@ZIF-8 composites were successfully used as a fluorescence probe for detection of ClO- via electron transfer and dynamic quenching mechanism. The fluorescence probe can detect ClO- in water with high selectivity even existed other anions (HCO3-, SO42- , Cl-, SiO32-, CO32-, NO3-, HSO3- ). Meanwhile, the response time of the MAPbBr3@ZIF-8 probe could be obtained to less than 40 s. The detection limit and quenching constant were calculated as 31.9 nM and 0.141 mu M-1. Furthermore, the fluorescence probe sensor showed excellent stability in natural environment with 94.6%100.6% recovery rates. The fluorescence probe based MAPbBr3@ZIF-8 composites in this study is promising for detecting ClO- anion in water.