The nitrate ion (NO₃⁻) is a typical pollutant in environmental samples, posing a threat to the aquatic ecosystem and human health. Therefore, rapid and accurate detection of NO₃⁻ is crucial for both the aquatic sciences and government regulations. Here we report the fabrication of an amino-functionalized, vertically ordered mesoporous silica film (NH₂-VMSF) confining localized copper nanoparticles (CuNPs) for the electrochemical detection of NO₃⁻. NH₂-VMSF-carrying amino groups possess an ordered perpendicular nanochannel structure and ultrasmall nanopores, enabling the confined growth of CuNPs through the electrodeposition method. The resulting CuNPs/NH₂-VMSF-modified indium tin oxide (ITO) electrode (CuNPs/NH₂-VMSF/ITO) combines the electrocatalytic reduction ability of CuNPs and the electrostatic attraction capacity of NH₂-VMSF towards NO₃⁻. Thus, it is a rapid and sensitive electrochemical method for the determination of NO₃⁻ with a wide linear detection range of 5.0–1000 μM and a low detection limit of 2.3 μM. Direct electrochemical detection of NO₃⁻ in water samples (tap water, lake water, seawater, and rainwater) with acceptable recoveries ranging from 97.8% to 109% was performed, demonstrating that the proposed CuNPs/NH₂-VMSF/ITO sensor has excellent reproducibility, regeneration, and anti-interference abilities.

The brittle failure of ceramic coatings limits their application in many fields. To address this issue, a novel armoured ceramic coating was developed to suppress brittle failure. First, an interconnected frame microstructure was micromachined onto the surface of a mild steel substrate using a nanosecond laser. Subsequently, a polymer-derived ceramic slurry was sprayed and sintered to obtain an armoured ceramic coating. The laser-micromachined burr-like microstructure of the substrate facilitated adhesion between the coating and the substrate. The results of the mechanical properties test showed that the armoured coating could withstand more than 20 cycles of water-cooled thermal shock at 600 °C, and the peeling area of the armoured coating was approximately three times less than that of the unarmoured coating under a normal load of 1471 N. The laboratory and field corrosion test results indicated that at high temperatures, the corrosion resistance of the armoured coating was comparable with that of the unarmoured coating and was approximately 10 times higher than that of the uncoated sample. The proposed method will aid in suppressing the brittle failure of ceramic coatings and broaden their scope of application in different fields.

Adding fillers to polysilazane (PSZ)-derived ceramic coating is one of the main methods used to reduce PSZ porosity. In this study, we designed a sinter visualization device for understanding the effect of fillers on coating porosity and observed pore evolution within the coating sintering process using different filler ratios. When there was no filler in the coating, gas evolution occurred at the initial sintering stage due to a PSZ pyrolysis reaction. In the final stage, numerous cracks appeared because of volume shrinkage. It was determined that such coatings cannot provide good protection. Although the cracks disappeared after adding glass powder, many bubbles appeared. After adding ZrO₂, the bubbles in the coating significantly reduced. When the volume ratio of PSZ/glass powder/ZrO₂ was 1:2:1, the coating porosity after sintering was the lowest. Based on our visualization experimental results, we concluded that the glass powder’s healing effect and the ZrO₂ skeleton effect were the main reasons for the reduced coating porosity. In addition, the sinter visualization device can be used to observe the surface morphology of other similar coatings during the sintering processes.

多孔介质内气泡的Ostwald熟化行为广泛存在于CO₂地质封存、多孔材料制备、燃料电池等领域。为探究孔隙尺度下多孔介质内气泡的熟化特性，本文建立了基于浓度耦合计算的三维孔隙网络模型，该模型考虑了气泡形态、多孔介质结构以及气液之间的传质，通过求解三维孔隙网络内各孔体的气相浓度，得到各气泡的演化过程，并采用四孔隙结构微流体芯片可视化实验验证了模型的可靠性。为分析多孔介质非均质性对气泡熟化过程影响，构建了两种不同孔隙尺寸的三维孔网结构，对两个区域内的气泡熟化过程进行了数值模拟，结果表明：气泡初始分布会对熟化过程产生影响，当气泡非均匀分布时，气泡从小孔隙区域传输至大孔隙区域的同时，也会各自向自身区域的大气泡区域传质；气泡初始尺寸的差异，会加速熟化进程，使熟化时间明显短于均匀分布状态。孔隙数的选取对平均毛细力、饱和度等连续尺度等效参数具有显著影响，孔隙数增加时毛细力与饱和度呈现更具规律性的非线性变化。该模型的建立可以预测地质封存过程中CO₂的演化过程，为CO₂长期封存过程中非均质性的影响机制研究提供指导。

Slag formation on the heating surface in solid fuel-fired boilers is a common problem. In this paper, with polysilazane used as the precursor, three different ceramic coatings were prepared by adding hexagonal boron nitride (h-BN), ZrO₂, and Al₂O₃ inert fillers. The coatings were applied to a TP347 substrate by the Czochralski method. The spreading and solidification experiments of the molten ash were performed and matched with numerical simulation. The results show that compared with the steel sheet, the molten ash has a large contact angle on the coating, a small spreading coefficient and the same spreading time, indicating that the coating has the slagging resistance property. The coating with the addition of h-BN has better slagging resistance properties than the other two coatings. The numerical simulation results are consistent with the experimental results.