Analysis and Testing Centre

To clarify the influence of mining rates on the fracturing of hard roofs in thick coal seams and the patterns of microseismic activity, a comprehensive approach combining field investigations, numerical simulations, and on-site validation was adopted. This study revealed the stress and energy evolution laws of hard roofs in mining faces under different mining rate effects, elucidated the spatiotemporal distribution characteristics of microseismic events under varying mining rates, and subsequently optimized the mining rates for different rock burst risk zones in the working face to ensure safe and efficient mining operations. Furthermore, the study optimized the mining rates for different rock burst hazard zones in the working face. The results indicate that as the mining rate of the working face increases, the peak abutment pressure ahead of the coal wall shifts closer to the exposed surface, leading to an increase in the accumulated elastic energy in the roof, which raises the likelihood of inducing rock bursts. Under low-speed mining, microseismic events are predominantly distributed ahead of the coal wall, while under high-speed mining, they are primarily concentrated behind it. On-site validation demonstrated that controlling the mining rates for moderate and low rock burst hazard zones at 6.4 m/d and 4.8 m/d, respectively, resulted in both the frequency and energy of microseismic events remaining at relatively low levels, thereby achieving the objective of ensuring safe and efficient mining operations.

ABSTRACT Efficient heat dissipation is vital for emerging high‐power electronic systems, where interfacial thermal resistance remains one of the primary limitations to reliable operation. Here, we report a mechanically perforated, vertically aligned graphene paper/epoxy composite produced through an integrated perforation–stacking–cutting process. The perforation strategy not only suppresses graphene restacking but also creates interlayer phonon bridges, thereby establishing continuous through‐plane heat conduction pathways while simultaneously strengthening matrix–filler interfacial coupling. By optimizing the filler volume fraction, the composite delivers an ultrahigh through‐plane thermal conductivity of 456 W m −1 K −1 combined with a low compressive modulus of 4.8 MPa, ensuring excellent conformability and reduced interfacial resistance. The PGPE 28 sample exhibits a total thermal resistance of 0.23 K cm 2 W −1 and outstanding reliability, maintaining structural and thermal stability after 10 000 thermal‐shock cycles and 8 h of continuous operation at 60 W. When deployed at the device level, PGPE 28 markedly lowers the steady‐state temperature of LED and CPU modules compared with commercial thermal interface materials (HD90000 and Shin‐Etsu 7921) and retains robust performance under fan‐failure conditions. This work provides a scalable route for manufacturing graphene‐based TIMs that simultaneously achieve high thermal conductivity and mechanical compliance, offering a promising solution for thermal management.

This study systematically investigates the interfacial assembly and photoswitching behavior of the photoresponsive molecule AZO-C1 at the air/water interface by integrating surface tension measurements, second harmonic generation (SHG), sum frequency generation (SFG) vibrational spectroscopy, and quantum chemical calculations. The results demonstrate that the AZO-C1 monolayer exhibits stable and reversible surface tension switching (between ∼57 and ∼63 mN/m) under alternating UV and visible light irradiation. SHG experiments reveal reversible changes in the second-order nonlinear optical response, primarily attributed to interfacial molecular reorganization and variations in the effective number density of responsive molecules induced by azobenzene photoisomerization, rather than uniform molecular reorientation. SFG spectra further confirm a significant enhancement of the N═N stretching vibration signal (∼1516 cm–1) upon UV exposure, characteristic of the cis-isomer, while the C–H vibration signals of the alkyl chains remain unchanged. This indicates a decoupled reorganization mechanism: the azobenzene headgroup undergoes reversible conformational and polarity changes, while the hydrophobic alkyl chains maintain a stable conformation, preserving the structural integrity of the interfacial assembly. The multiscale analysis bridges macroscopic interfacial properties with molecular-level conformational changes, providing a rational strategy for designing robust, fast-switching, and reversible photocontrolled interfacial materials based on a domain-decoupling design principle.

Altered metabolism has been recognized as a core feature of cancer; however, spatiotemporal tracking of metabolic pathway-specific imaging in cancer cells remains a challenging task. Here we have successfully developed a photochromic fluorescent probe CM generated by coupling coumarin fluorophore and spiropyran (SP) to precisely monitor Cysteine (Cys) metabolic processes by remote light control. Cys was endogenously metabolized to produce SO2, equilibrating with sulfites (SO32–)/bisulfites (HSO3–). The dynamic dual-fluorescence signal was released only after endogenous production of SO2 by Cys and the light-triggered. Consequently, a novel strategy employing light-triggered, synchronized dual-fluorescence blinking was successfully used as a “double-check” assay for Cys metabolism, and the unique response of the probe to Cys/HSO3– in the different spectral behaviors were theoretically characterized using ultraviolet (UV)–visible (vis), fluorescence, density functional theory (DFT) calculations and 1H NMR. What more, the fluorescent imaging of using CM was achieved through the integrated mechanisms of the Forster resonance energy transfer (FRET) and intramolecular charge transfer (ICT). We further show that the in situ UV-activation strategy will significantly reduce interference from false-positive signals during probe transport within cells, thereby offering practical potential for accurate early cancer diagnosis.

Abstract Vertical transmission of plant pathogenic viruses is an important component of viral persistence, survival, and spread in agricultural production systems. This type of transmission is of considerable economic significance as it can cause major crop losses by serving as the initial focus of infection for future epidemics. Vertical transmission occurs when a virus is passed on to offspring either by direct invasion of the developing seed embryo from infected mother plants or through infected pollen grains after fertilization. We have recently demonstrated by high throughput sequencing that mature seeds of the agriculturally important forage crop alfalfa ( Medicago sativa L.) are associated with a broad range of viruses some of which could potentially spread over long distances via seed. Aside from alfalfa mosaic virus, little is currently known about viral transmission via alfalfa pollen and its role in the epidemiology in this crop. This research was conducted to screen the pollen obtained from unique alfalfa genotypes for the presence of pathogenic viruses and their potential for dissemination. The plants from which the pollen was collected were alfalfa genotypes selected for fungal plant disease resistance and agronomic performance in a USDA ARS pre-breeding program in Prosser, WA.

Atomic catalytic pairs (CPs) have shown great promise in driving multi-step catalytic transformations, yet the influence of spatial arrangement and coordination asymmetry on homonuclear CPs remain poorly understood. Herein, we construct atomically dispersed homonuclear Pt1-Pt1 CPs with asymmetric Pt1C3-Pt1O1C3 coordination anchored on reduced graphene oxide. By precisely tuning the spacing between the adjacent Pt1C3-Pt1O1C3 CPs to approximately 5.3 Å, the catalyst achieves an exceptional turnover frequency of 27,218 h-1 for transfer hydrogenation of azobenzene via ammonia-borane hydrolysis, surpassing benchmarking catalysts by more than an order of magnitude. The Pt1C3-Pt1O1C3 CPs separated by 5.3 Å can facilitate co-adsorption of sterically hindered intermediates and at the same time the asymmetric Pt1C3-Pt1O1C3 coordination enables facile hydrogen shuttling and barrier-suppressed hydrogenation. These synergistic effects enhance the overall azobenzene hydrogenation efficiency. Our findings uncover a fundamental spatial design principle for atomically precise homonuclear asymmetric CPs, offering new opportunities for sustainable and efficient fine chemical synthesis.

The advancement of IoT technology presents new opportunities for environmental monitoring systems. This paper designs an IoT-based intelligent environmental monitoring system that employs multisource sensor collaborative sensing technology for environmental data acquisition. It utilizes a dual-mode communication network to ensure reliable data transmission and integrates deep learning algorithms to construct an environmental quality assessment model, thereby achieving real-time monitoring, intelligent analysis, and early warning of environmental data. System testing and validation demonstrate that this solution holds significant practical value and broader applicability.