Ming Li

Increasing planting density is crucial for global food security, yet accurately characterizing the 3D spatiotemporal heterogeneity of the canopy microenvironment remains a critical bottleneck. Existing monitoring technologies are hindered by single-point measurements, high costs, and the lack of capabilities for synchronous multi-parameter and multi-layer data acquisition. To address this, this study developed a novel 3D canopy microenvironment measurement instrument integrating 10 adjustable PAR-temperature-relative humidity probes with a 1 Hz maximum sampling frequency. Field calibration demonstrated exceptional accuracy (PAR R² > 0.99, cosine response error < 0.48% at 0°–37.5°) and robust long-term stability, exhibiting only a 0.05% relative error drift over months of continuous high-humidity operation. This instrument was applied to continuously monitor winter wheat under nine planting densities from jointing to maturity. This application enabled the first synchronous characterization of the microenvironment's 3D co-evolution. Key findings revealed that clear-sky conditions produced static light gaps and wind-induced dynamic sunflecks, whereas overcast conditions yielded uniform light transmittance. Furthermore, canopy thermal structures exhibited inversion shifts, with nocturnal cooling surfaces migrating upward during crop development. High-density canopies created effective moisture-retention buffers, while low-density treatments suffered rapid moisture loss during grain-filling. Agronomic analysis highlighted a yield-quality trade-off: increasing density enhanced grain yield but decreased protein and wet gluten contents. Ultimately, this high-spatiotemporal-resolution tool offers broad prospects for crop functional-structural modeling and precision smart agriculture IoT deployment.

Building-integrated photovoltaics (BIPVs) are promising for sustainable urban energy systems but remain constrained by coupled trade-offs among aesthetics, power output, thermal management, and cost. Conventional pigment- or dye-based coloring often reduces power conversion efficiency (PCE) and durability, whereas many structurally colored photovoltaic strategies rely on complex, difficult-to-scale nanostructures. Here, we report a scalable colored photovoltaic strategy based on color-selective polymer multilayer films (PMF-C) derived from a PEN/PMMA platform compatible with continuous coextrusion and layer multiplication. PMF-C generates vivid structural coloration through a selective high-reflection stopband in the visible range while maintaining high transmission over the remaining photovoltaic-relevant spectrum. This spectral selectivity enables color generation and passive thermal regulation by reducing solar heat gain. Integrated with an infrared-emissive EVA encapsulation architecture, PMF-GPV achieves an operating-temperature reduction of up to ∼8.65 °C while retaining ∼74% of the baseline PCE. Beyond experimental demonstration, we establish a data-driven opto-thermo-electrical framework that predicts color, efficiency, and operating temperature prior to fabrication across a broad PMF-C material and structural design space. Parametric sweeps and Pareto analysis identify refractive-index combinations for efficiency-priority, temperature-priority, and balanced designs; notably, under an idealized uniform-thickness design, the PEN/PMMA pair is predicted to retain 86.9% of the reference-cell PCE while reducing the operating temperature by 5.17 K. A machine-learning-assisted inverse-design workflow rapidly maps target colors to feasible PMF-C structural parameters. This work provides both a scalable material platform and a predictive design framework for colored BIPVs with jointly engineered appearance, efficiency, and passive thermal-management performance.

Vertical agrivoltaic (V-APV) systems can help enhance the dual productivity of land by integrating food crop cultivation between rows of vertical solar panels. However, conventional V-APV systems suffer from excessive light shading and uneven spatiotemporal distributions of solar radiation. To address these limitations, this study proposes and validates a novel uniform-light vertical agrivoltaic system (U-VPV) that integrates an even-sunlight plate (ESP) to reshape the in-field solar irradiance distribution and microclimate. Field experiments demonstrate that the U-VPV significantly enhances light uniformity and regulates microclimates. The coefficient of variation of morning canopy photosynthetically active radiation is reduced, and the potential evaporation is reduced by approximately 16.5%. Consequently, the system exhibits only a minor fresh weight reduction of 13.2%, showing no significant difference from the unshaded open-field control. Furthermore, the per-module power generation efficiency improved by 10.16% compares to the conventional V-APV system, with the land equivalent ratio (LER) reaching 1.603. By incorporating the commercial and industrial time-of-use electricity pricing mechanism, the comprehensive economic return per unit land area exceeds that of the standard optimal-tilt photovoltaic system by 15.8%. The proposed U-VPV provides a highly feasible engineering pathway for the large-scale deployment and intensive land use of V-APV systems.

Building-integrated photovoltaics (BIPVs) are promising for sustainable urban energy systems but remain challenged by the trade-off among aesthetics, power output, thermal management, and cost. Conventional pigment- or dye-based coloring often reduces power conversion efficiency (PCE) and durability, whereas many structurally colored photovoltaic strategies rely on complex nanostructures that are difficult to scale. Here, we develop a scalable colored photovoltaic approach based on a polymer multilayer film (PMF) fabricated from a PEN/PMMA refractive-index pair by continuous co-extrusion with layer multiplication, enabling vivid structural coloration through selective visible reflection. When integrated with a mid-infrared-emissive encapsulation layer, the PMF simultaneously provides passive radiative cooling, lowering the operating temperature by up to ~8.65 °C, while the demonstrated device retains ~74% of the baseline PCE. To move beyond this representative implementation, we further establish a data-driven opto-thermo-electrical framework that predicts color, efficiency, and operating temperature prior to fabrication across a broad PMF material and structural design space. Large-scale parametric sweeps generate response maps and Pareto frontiers that identify refractive-index combinations best suited to different application scenarios by balancing optical selectivity, electrical performance, and thermal regulation, while a machine-learning-assisted inverse design workflow rapidly maps target colors to feasible PMF structural parameters. This approach provides both a scalable material strategy and a predictive design framework for colored BIPVs with jointly optimized appearance, efficiency, and thermal stability.

Agrivoltaic (AV) systems have emerged as a transformative solution to global challenges in food–energy–water security, climate resilience, and sustainable land use. The purpose of this study is to analyze trends, influences, intellectual structures, and future research directions in AV systems research from 2011 to 2023. Using a bibliometric approach guided by the PRISMA framework, 477 documents from the Scopus database were analyzed through performance analysis and science mapping with Bibliometrix and VOSviewer. Key findings reveal exponential growth in research output, with the United States, France, and Germany leading in publications, citations, and international collaboration. Eight thematic clusters were identified, including dual productivity of land use, renewable energy integration, policy implications, and climate adaptation. Influential contributors, such as Joshua M. Pearce, and leading journals, including Applied Energy, shape the field. Emerging areas focus on advanced photovoltaic materials and integrated resource management strategies. This study provides a comprehensive roadmap for advancing AV systems research by identifying critical trends, proposing innovative solutions, and fostering interdisciplinary collaborations. Despite limitations, such as database dependency, this analysis highlights AV systems’ transformative potential to achieve global sustainability goals.