Xiaohong Zhou

Urban drainage networks are critical infrastructure for modern cities, yet their complex and concealed nature makes real-time monitoring of abnormal events a persistent challenge. To address this, this work proposed a distributed optical fiber vibration sensing system based on phase-sensitive optical time-domain reflectometry (Φ-OTDR) for drainage pipeline monitoring. To accurately capture abnormal events from complex environmental noise, a two-tier intelligent processing architecture comprising localization and classification modules was developed. The localization module employed an enhanced You Only Look Once (YOLO) model integrating anchor-box optimization, a channel-attention module, and an additional small-target feature layer, achieving a mean average precision of 96.8% in laboratory tests. The classification module utilized a hybrid model combining convolutional neural network, bidirectional long short-term memory, and attention classifier, achieving an overall accuracy of 98.1% for five abnormal events. During two-week of continuous field monitoring, the system localized simulated events with errors below 2.60 m and distinguished internal leakage, knocking, and drilling from walking, running, and vehicle interference with precision and recall exceeding 99.6% for the tested classes. Notably, the system successfully detected and accurately localized an actual branch pipe leakage event, demonstrating its practical effectiveness under real-world operating conditions.

Increasing evidence suggests that the contribution of unregulated disinfection by-products (UR-DBPs) to the overall toxicity of disinfected water is underestimated. However, the molecular mechanisms by which they promote bladder carcinogenesis remain largely unexplored. Using the nontumorigenic human uroepithelial cell line SV-HUC-1, we sought to elucidate the potential genotoxic mechanisms underlying the bladder cancer risk associated with four classes of typical UR-DBPs: haloacetonitriles (HANs), haloacetamides (HAMs), halobenzoquinones (HBQs), and halobenzoquinone imines (HQCs). Genotoxicity was evaluated by the SOS/umu assay and the micronucleus assay. Only three of the eight UR-DBPs gave positive SOS/umu responses. However, all tested UR-DBPs showed clear cytotoxicity and micronucleus effects, with a consistent toxicity order: HANs > HAMs > HBQs and HQCs. Principal component analysis (PCA) of transcriptomic data indicated that the eight UR-DBPs may act through two distinct modes of action (MOAs). Gene set variation analysis (GSVA) further revealed that HANs and HAMs activated DNA repair pathways, including base excision repair (BER) and nonhomologous end-joining for double-strand break repair (DSBR-NHEJ), while HBQs and HQCs suppressed DNA damage repair pathways or the regulatory pathways involved in nucleotide excision repair (NER), mismatch repair (MMR), and double-strand break repair (DSBR). Western blotting confirmed that HBQs and HQCs significantly downregulated proteins critical for DNA damage repair regulation. This is possibly attributable to their stronger protein-binding capacities relative to other UR-DBPs. Collectively, these findings argue that the impairment of DNA repair regulation constitutes a distinct genotoxic mechanism that should be integrated into DBP risk evaluation alongside direct DNA damage.

Nearly one-third of the global population lacks access to safe drinking water, with the unavailability of simple and efficient disinfection devices being a key contributing factor. Mercury lamps are effective, safe, and reliable UV-based disinfection devices, whereas their application is limited to regions with a stable power supply. Here, we design a manually operated triboelectric-electromagnetic hybrid generator able to power a UV mercury lamp. Combining the advantages of a triboelectric nanogenerator and an electromagnetic generator, this unit exhibits electrical output of variable impedance characteristics, matching the power requirement of UV mercury lamps. Powered with cranking or pedaling, enabled by our tailor-designed transmission system, the device achieves 8-log pathogen removal from 2 L of water in 25 min with cranking or 10 L in 15 min with pedaling. The latter is sufficient to meet the daily drinking water needs of a family of four set by the World Health Organization. With a low capital cost, this grid-free UV disinfection system could potentially provide safe drinking water, at a levelized cost of 8.57 USD/(capita·yr) to ∼1.8 billion people in over 375 million households in underdeveloped countries/regions, substantially contributing to the United Nations Sustainable Development Goal 6.

Establishing a scientific, efficient surface water environmental monitoring system is fundamental to protecting water resources and enabling refined governance. This paper systematically reviewed monitoring frameworks in the European Union (EU) and the United States (US), focusing on the EU Water Framework Directive's surveillance, operational, and investigative monitoring, and on the US National Aquatic Resource Surveys, the National Water-Quality Assessment program, and state-level regulatory networks. Their management objectives, network designs, site-deployment logic, and operational mechanisms were compared to identify similarities, differences, and limitations. This review highlighted how tiered objectives, combined with fixed and probabilistic site selection, and coordinated federal–state responsibilities support both compliance and status assessment. Based on that comparative analysis, recommendations were proposed to optimize and modernize China's surface water monitoring system, including integrating routine status and baseline assessment, risk-graded rapid warning and diagnostic monitoring, and long-term ecological observation.

As a promising hydrogen carrier for low‐carbon energy cycling, ammonia also represents the most abundant alkaline gas in the atmosphere, impacting environmental quality through diverse geophysical and chemical processes. Hence, developing NH ₃ sensing materials with high sensitivity and stability under self‐powered operation is essential. A one‐step in situ polymerization method is demonstrated to synthesize zinc oxide/graphene oxide (ZnO/GO) nanocomposites, serving as a gas‐sensitive film for ammonia sensing and as high‐performance electrode materials in supercapacitors, simultaneously. For the supercapacitor, the specific capacitance of 131 F g ⁻¹ at 1 A g ⁻¹ is achieved. The ammonia sensor featured a low detection limit (0.1 ppm) and fast response/recovery time (17 s/26 s @ 10 ppm NH ₃ ), surpassing standards set by the US Occupational Safety and Health Administration (50 ppm), while outperforming commercial NH ₃ gas sensors. By integrating the sensor into a detection instrument for fixed‐point monitoring, the response relative standard deviation of below 1% over 210 days of continuous testing is achieved. In addition, a wearable contact‐separated TENG is developed to harvest mechanical energy from a contact‐separation setup that mimicked human footsteps, achieving a maximum output power of 4.1 mW to directly drive the ammonia gas sensor. The multi‐scenario applications enhanced the spatial coverage and operational flexibility of NH ₃ concentration monitoring.