On-surface photochemistry provides a non-thermal strategy that can circumvent the side reactions and structural defects associated with thermal activation, enabling enhanced control over surface reactions. Among these, Ullmann coupling serves as a representative on-surface reaction for fundamental studies of reaction mechanisms and controllability. However, how the aromatic core of molecular precursors governs photoinduced C-Br activation on metal surfaces remains insufficiently understood. In this work, we investigated photoinduced Ullmann coupling on Au(111) using three dibromo molecular precursors with distinct aromatic cores. The three precursors show markedly different photoreactivities under 405 and 532 nm irradiation. Time-dependent density functional theory calculations reveal a photoinduced surface-to-molecule charge-transfer process. Combined with calculations of potential energy surfaces for C-Br bond dissociations, these results provide a qualitative rationale for comparing the relative tendency of photo-triggered C-Br cleavage at the surface. The results establish a direct correlation between photo-selectivity and the molecular aromatic core, providing mechanistic insight into light-controlled on-surface synthesis and offering design principles for tailoring light-responsive precursors toward desired carbon nanostructures.

The pursuit of autonomous chemical transformations with single-bond precision represents a central challenge in molecular nanoscience. While scanning tunneling microscopy (STM) enables site-specific reactions by directly engaging individual atoms and bonds, conventional approaches rely on expert intervention and lack reproducibility and scalability. Here we introduce a deep learning-based strategy that autonomously executes multi-step, bond-selective transformations. Our system integrates computer vision for molecular recognition, neural networks for bond-state classification, and deep reinforcement learning for closed-loop optimization of activation parameters. As a proof of concept, we demonstrate the selective dissociation of C-Br bonds in a tetra-brominated porphyrin on Au(111). Importantly, the approach extends beyond single-bond events, enabling programmed multi-step sequences including four distinct pathways with high fidelity. By advancing from isolated, human-directed manipulations to fully autonomous, data-driven reaction control, this platform establishes a paradigm for intelligent single-molecule chemistry. It provides a generalizable framework for on-surface synthesis, where adaptive agents orchestrate molecular transformations with a level of precision and scalability unattainable by manual approaches.

Surface-confined metal-organic frameworks have emerged as versatile structures with a broad spectrum of applications such as nanoelectronics, catalysis, sensing, and molecular storage, owing to their unique structural and electronic properties. However, the exploration and optimization of molecular networks typically involve resource-intensive trial-and-error experiments. The complexity comes from factors like metal nodes, organic ligands, substrates, and the preparation conditions. To address this challenge, high-throughput methodologies have been used in materials exploration. In this work, we explored a high-throughput method for preparing sub-monolayer metals with continuous coverage spread on metal surfaces. By employing a physical mask during metal deposition under ultra-high vacuum conditions, we achieved sample libraries with copper (Cu) and silver (Ag) adatoms on the metal substrates, and constructed surface-supported metal-organic frameworks with varying metal-to-molecule stoichiometric ratios. This approach facilitates the exploration of surface-confined metal-organic frameworks, particularly in terms of varying metal-to-ligand stoichiometric ratios, offering an efficient pathway to unlock the potential of these intricate two-dimensional networks.

Photochemical reactions offer several advantages such as external control through manipulation of the light source and independence from temperature. These features enable precise control over reaction pathways on demand through photochemistry. In this work, we explore photoinduced on-surface debrominated coupling. The reaction is triggered by photoirradiation using wavelengths ranging from 254 to 850 nm at room temperature. The multiple photoreaction processes were further elucidated by comparing the responses of the reaction outcomes to the electronic structure of the adsorbates. Notably, the charge transfer process facilitates chemical reactions in the near-infrared region. We also identify the direct intramolecular excitation under UV radiation, which exhibits the highest photoactivity. The proposed reaction mechanisms are further validated by our theoretical calculations. Finally, we demonstrate selective debrominated coupling on Au(111) using photochemistry. This study establishes a foundation for understanding photochemistry on metal surfaces and its applications in surface chemistry.

X-ray imaging requires effective light transmission through scintillation screens. However, solid or solution-based scintillators suffer from photon scattering and attenuation. While prior efforts have focused on improving light extraction in solid-state scintillators through nanostructuring or optical engineering, challenges remain in mitigating internal scattering losses. Here, we report a liquid scintillator-based strategy that eliminates light scattering by exploiting in-situ coordination between lanthanide ions and ionic liquid ligands. This coordination chemistry ensures high structural homogeneity and optical transparency. Combined with self-absorption-free lanthanides, this approach achieves over 93% scintillation light transmittance, boosting X-ray imaging spatial resolution to 26 lp mm-1 within a 1 mm scintillation screen. Our scintillators exhibit long-term stability and environmental compatibility, leveraging the inherent properties of ionic liquids for sustained and biocompatible X-ray imaging. Their fluidic and shape-adaptive nature enables the development of convex and zoom scintillation lenses, facilitating uniform omni-angle X-ray detection and in-situ zoom X-ray imaging.

The efficient production of high-quality scintillators with long radioluminescence afterglow is crucial for high-performance X-ray luminescence extension imaging. However, scaling-up the synthesis of ligand-free scintillators to fabricate large-area X-ray imaging screens for industrial applications remains a challenge. In this study, we report an efficient method to synthesize ligand-free, lanthanide-doped microscintillators by a one-pot reaction via the concentrated hydrothermal method. The as-synthesized microscintillators exhibit prolonged persistent radioluminescence for up to 30 days after X-ray exposure and remain high stability in air or water for more than 18 months without deterioration. Monte Carlo simulations indicate that the size effect is responsible for the excellent afterglow performance of the microscintillators. We employ these high-quality lanthanide-doped microscintillators to fabricate a large-area X-ray imaging detector using a blade-coating method, a spatial resolution of 24.9 lp/mm for X-ray imaging. Our study offers a solution for scaling-up the synthesis of low-cost microscintillators for practical applications.

Long-lasting radioluminescence scintillators have recently attracted substantial attention from both research and industrial communities, primarily due to their distinctive capabilities of converting and storing X-ray energy. However, determination of energy-conversion kinetics in these nanocrystals remains unexplored. Here we present a strategy to probe and unveil energy-funneling kinetics in NaLuF 4 :Mn 2+ /Gd 3+ nanocrystal sublattices through Gd 3+ -driven microenvironment engineering and Mn 2+ -mediated radioluminescence profiling. Our photophysical studies reveal effective control of energy-funneling kinetics and demonstrate the tunability of electron trap depth ranging from 0.66 to 0.96 eV, with the corresponding trap density varying between 2.38×10 5 and 1.34×10 7  cm −3 . This enables controlled release of captured electrons over durations spanning from seconds to 30 days. It allows tailorable emission wavelength within the range of 520–580 nm and fine-tuning of thermally-stimulated temperature between 313–403 K. We further utilize these scintillators to fabricate high-density, large-area scintillation screens that exhibit a 6-fold improvement in X-ray sensitivity, 22 lp/mm high-resolution X-ray imaging, and a 30-day-long optical memory. This enables high-contrast imaging of injured mice through fast thermally-stimulated radioluminescence readout. These findings offer new insights into the correlation of radioluminescence dynamics with energy-funneling kinetics, thereby contributing to the advancement of high-energy nanophotonic applications.

We synthesized a fluorescence ratiometric probe by combining coumarin and rhodamine B with ethylenediamine to sense Fe3+ and measure ionizing radiation doses. The presence of Fe3+ caused rhodamine to transition from a closed helical structure to an open-ring structure. Additionally, fluorescence resonance energy transfer (FRET) occurred between coumarin and rhodamine B. As a result, the fluorescence intensity at 405 nm (I405) due to coumarin was decreased, whereas that at 585 nm (I585) derived from open-ring structure rhodamine B was increased. The ratio of I585 and I405 (I585/I405) linearly increased as the Fe3+ concentration increased. The probe sensed Fe3+ in a 0-110 μM range, with a lower limit of detection (LOD) of 0.226 μM. Inspired by Fricke dosimeters, we extended the probe to measure X-ray doses using the fluorescence methodology. The probe measured X-ray doses in a 0-30 Gy range with a lower LOD of 0.5 Gy. Additionally, the dosing capability was independent of the dosing rates. Our probe showed potential for detecting Fe3+ and measuring ionizing radiation doses.

Non-invasive phototherapy has been emerging as an ambitious tactic for suppression of amyloid-β (Aβ) self-assembly against Alzheimer's disease (AD). However, it remains a daunting challenge to develop efficient photosensitizers for Aβ oxygenation that are activatable in a deep brain tissue through the scalp and skull, while reducing side effects on normal tissues. Here, we report an Aβ targeted, low-dose X-ray-excitable long-afterglow scintillator (ScNPs@RB/Ab) for efficient deep-brain phototherapy. We demonstrate that the as-synthesized ScNPs@RB/Ab is capable of converting X-rays into visible light to activate the photosensitizers of rose bengal (RB) for Aβ oxygenation through the scalp and skull. We show that the ScNPs@RB/Ab persistently emitting visible luminescence can substantially minimize the risk of excessive X-ray exposure dosage. Importantly, peptide KLVFFAED-functionalized ScNPs@RB/Ab shows a blood-brain barrier permeability. In vivo experimental results validated that ScNPs@RB/Ab alleviated Aβ burden and slowed cognitive decline in triple-transgenic AD model mice at extremely low X-ray doses without side effects. Our study paves a new pathway to develop high-efficiency transcranial AD phototherapy. STATEMENT OF SIGNIFICANCE: Non-invasive phototherapy has been emerging as an ambitious tactic for suppression of amyloid-β (Aβ) self-assembly against Alzheimer's disease (AD). However, it remains a daunting challenge to develop efficient photosensitizers for Aβ oxygenation that are activatable in a deep brain tissue through the scalp and skull, while reducing side effects on normal tissues. Herein, we report an Aβ targeted, low-dose X-ray-excitable long-afterglow scintillators (ScNPs@RB/Ab) for efficient deep-brain phototherapy. In vivo experimental results validated that ScNPs@RB/Ab alleviated Aβ burden and slowed cognitive decline in triple-transgenic AD model mice at extremely low X-ray doses without side effects.

Radio frequency identification (RFID) tags are widely used in various electronic devices due to their low cost, simple structure, and convenient data reading. This topic aims to study the key technologies of ultra-high frequency (UHF) RFID tags and high-precision temperature sensors, and how to reduce the power consumption of the temperature sensor and the overall circuits while maintaining minimal loss of performance. Combined with the biomedicine, an innovative high-precision human UHF RFID chip for body temperature monitoring is designed. In this study, a ring oscillator whose output frequency is linearly related to temperature is designed and proposed as a temperature-sensing circuit by innovatively combining auxiliary calibration technology. Then, a binary counter is used to count the pulses, and the temperature is ultimately calculated. This topic designed a relaxation oscillator independent of voltage and current. The various types of resistors were used to offset the temperature deviation. A current mirror array calibration circuit is used to calibrate the process corner deviation of the clock circuit with a self-calibration algorithm. This study mainly contributes to reducing power consumption and improving accuracy. The total power consumption of the RF/analog front-end and temperature sensor is $7.65\mu \text{W}$ . The measurement error of the temperature sensor in the range of 0 to 60°C is less than ±0.1%, and the accuracy of the output frequency of the clock circuit is ±2.5%.

Solution-processed scintillators hold great promise in fabrication of low-cost X-ray detectors. However, state of the art of these scintillators is still challenging in their environmental toxicity and instability. In this study, we develop a class of tetradecagonal CuI microcrystals as highly stable, eco-friendly, and low-cost scintillators that exhibit intense radioluminescence under X-ray irradiation. The red broadband emission is attributed to the recombination of self-trapped excitons in CuI microcrystals. We demonstrate the incorporation of such CuI microscintillator into a flexible polymer to fabricate an X-ray detector for high-resolution imaging with a spatial resolution up to 20 line pairs per millimeter (lp mm−1), which enables sharp image effects by attaching the flexible imaging detectors onto curved object surfaces.

Colloidal nanocrystal scintillators hold great potential in fabricating large-area, flexible X-ray detectors for high-resolution X-ray imaging of highly curved, irregularly shaped objects. The synthesis of high-efficiency, high-stability nanoscintillators is of great importance for the development of X-ray imaging detectors. In this study, we develop a class of cerium (Ce3+)-sensitized core-shell nanoscintillators that are suitable for achieving flexible X-ray luminescence imaging. We demonstrate that an epitaxial growth of NaGdF4:Ce(60%) on the surface of NaGdF4:Eu(15%) nanoscintillators as a sensitization layer allows for enhancing X-ray-induced radioluminescence. We reveal that the enhancement of X-ray luminescence in nanoscintillators could be attributed to the synergistic effect of high-Z composition-induced X-ray absorption, Ce3+ sensitization, and surface passivation to relieve energy quenching. By incorporating the nanoscintillators into a flexible elastomer of polydimethylsiloxane (PDMS), we demonstrate its utility in high-resolution flexible X-ray luminescence imaging.

现有便携式心电采集系统需要低功耗高分辨率的模拟数字转换模块,虽然基于脉冲宽度调制的模拟信息转换器(AIC)可以有效降低系统的采样速率,但是该系统量化部分的转化时钟与量化精度成正比,因此存在功耗过高的问题.依据心电信号的能量不均衡特性,提出一种基于功率熵的精度可调时间-数字转换模块(TDC)设计方法.以能量最大化作为设计准则的基本思想,通过分析ECG信号的功率谱熵,确定系统观测向量所需的最小量化精度,实现AIC时间编码系统的优化设计.测试结果表明,该设计方法能够在压缩比为4,重构信噪比为38.91 dB,重构精度为0.36％的情况下,在采样心电信号的同时减少了 80％的TDC内部时钟动态翻转,从而有效降低功耗.

Power efficiency and stability are critical for wearable ECG application. The paper presents a Pulse-Width-Modulation (PWM) voltage type DC-DC converter, which has a small area of 0.32 mm2 on active chip, output voltage range of 0.8V to 3.5V, output power up to 7.5 mW, and peak efficiency of 95.8%. The simulation results show that the output voltage of the system is 1.8V, the output current is 4mA, the ripple voltage is 13mV and the efficiency is 86.1%, which meets the requirements of a presented system. The circuit will be fabricated by the SMIC in the near future with 0.18 μm Bipolar-CMOS-DMOS (BCD) process.

A series of red emitting phosphors Eu3+:NaY(WO4)2 were successfully synthesized through conventional hydrothermal reactions. Meanwhile, the photoluminescence characteristics of Eu3+:NaY(WO4)2 microparticles were detailedly discussed. The XRD measurements demonstrate that all products exhibited pure phase as NaY(WO4)2 and doping Eu3+ ions did evoke change the crystal parameters of matrix material. The SEM and TEM images show that the particle morphology was quasi-cubes with uniform appearance and the size was about 3–4 µm. Microparticles of Eu3+:NaY(WO4)2 can observe emissions located at 594 nm and 618 nm while excited by near-UV (249 nm) and near-IR (797 nm). And the energy transfer mechanism between Eu3+ was proved to be electric dipole–dipole (d–d) interaction as well as the critical distance was calculated to be 9.936 Å. What’s more, the phonon sideband spectra of Eu3+ ions was used to calculated Huang-Rays factor and analyze the phonon energy. Subsequently, for self-generated quenching process of Eu3+ occurs was well explained according to Auzel’s theoretical model. Besides, the CIE color coordinates of Eu3+:NaY(WO4)2 phosphors exhibited the ideal red chromaticity.