层压复合工艺优化

文章采用正交组合实验,对复合织物的剥离强度、耐静水压、透湿和透气性能进行分析。利用灰色近优综合评定,得出最优工艺。     

Influence of Inactivation Treatment of Ship's Ballast Water on Corrosion Resistance of Ship Steel Plate

The effect of seawater after ultraviolet inactivation on corrosion of a shipbuilding steel plate was investigated by means of natural corrosion potential experiments and immersion corrosion test. The effects of natural seawater and treated seawater after ultraviolet inactivation on corrosion of the selected steel plate samples were compared with each other. The results showed that there was no obvious change in the chemical composition of treated seawater compared with natural seawater. The corrosion potential slightly increased by 10 mV, whereas the corrosion rate rose significantly by 20%. The experiments verified the naturally formed biofilm in the natural seawater for the inhibition of corrosion on the shipbuilding steel plate. The possible influences of ballast water treatment on biofilm by ultraviolet and electrolysis inactivation under the condition of practical usage were also investigated. And it was found that ballast water treatment methods with no continuous disinfection could protect original tank biofilm structure, reducing the intensity of tank corrosion.     

我国核电涂料发展概况

从我国核电涂料研究发展现状出发,分析总结了核电涂料的分类、技术标准、主要类型、产品应用,指出我国核电涂料的发展前景。     

α-Fe2O3/Pt hybrid nanorings and their enhanced photocatalytic activities

In this paper, α-Fe₂O₃ nanorings were synthesized and used as a support to further synthesize hybrid Pt/α-Fe₂O₃ nanorings. Transmission electron microscopy (TEM) analyses clearly suggest that Pt nanoparticles are deposited on the surface of α-Fe₂O₃ nanorings in a well-dispersed state. This metal–semiconductor hybrid system is expected to show high photocatalytic activity towards the degradation of environmental pollutants. Because of the Schottky contact between semiconductor and metal particles, the holes prefer to localize in energetically lower semiconductor, whereas the electrons can move through the heterointerface. This interfacial charge transfer and separation facilitate the redox reactions, results in a high photocatalytic activity. In our case, the as obtained α-Fe₂O₃/Pt hybrids exhibit enhanced photocatalytic performance with a degradation rate of 86.7% for methyl orange, which is much higher than that of pure α-Fe₂O₃ (33.2%).     

Effect of dysprosium doping on structural and vibrational properties of lead-free (Na0.7K0.3)0.5Bi0.5TiO3 ferroelectric ceramics

This study describes the effect of Dy³⁺ doping of lead-free ferroelectric sodium potassium bismuth titanate ((Na_0.7K_0.3)_0.5Bi_0.5TiO₃; NKBT) ceramics on their structural, optical, and vibrational properties. X-ray diffraction and Rietveld refinement analyses revealed that NKBT samples exhibited a rhombohedral perovskite structure belonging to the R3c space group, with the incorporation of Dy³⁺ resulting in structural parameter change and local atomic structure shift to tetragonal P4mm, as supported by the appearance of new Raman modes. Increased Dy³⁺ content decreased the NKBT band gap from 3.4 to 3.3 eV, which was ascribed to the introduction of Dy 4f levels between valence and conduction bands. Ferroelectric behavior studies combined with transport measurements explained the unexpected ferroelectric response weakening of Dy³⁺-modified NKBT by increased leakage current densities.     

Solution-processed ytterbium oxide dielectrics for low-voltage thin-film transistors and inverters

High permittivity (high k) metal-oxide thin films fabricated via solution processes have recently received much attention for the construction of low-operating voltage and high-performance thin-film transistors (TFTs). In this report, amorphous ytterbium oxide (Yb₂O₃) thin films were fabricated by spin coating and their applications in TFTs were explored. The physical properties of the solution-processed Yb₂O₃ thin films processed at different annealing temperatures were systematically investigated using various characterization techniques. To explore the feasibility of the Yb₂O₃ thin films as gate dielectrics for oxide TFTs, In₂O₃ TFTs based on Yb₂O₃ dielectrics were integrated. All the devices could be operated at 3 V, which is critical for the applications in portable, battery-driven, and low-power electronic devices. The optimized In₂O₃/Yb₂O₃ TFT exhibits high electrical performances, including field-effect mobility of 4.98 cm²/V s, on/off current ratio of ~ 10⁶, turn-on voltage around 0 V, and subthreshold swing of 70 mV/decade, respectively. To demonstrate the potential of In₂O₃/Yb₂O₃ TFT toward more complex logic application, the unipolar inverter was further constructed.     

Simulation of sacrificial anode protection for steel platform using boundary element method

In the present paper, an offshore platform model dealing with sacrificial anode protection was simulated using boundary element method. The potential and current density were calculated, and the distribution trend of the data was analyzed. To evaluate the computation results, proper physical model was built in a given dimension. The physical platform model was placed in a marine environment modeling tank that was designed to simulate the real marine environment with seawater, and the calculation data were compared with those from laboratory experimental work. This study showed that the boundary element method is a powerful tool for the sacrificial anode protection of marine structures.     

饰面材料对火灾冷热气层分界面的影响

采用ISO 9705标准全尺寸单室火灾实验方法,对3种常用的饰面装饰材料的单室火灾进行实验研究,实时测量地面辐射强度、室内和开口部位不同高度的温度随火灾变化的情况,分析装修材料对室内火灾的影响,测算轰燃时间以及冷热气层界面位置的变化,为火灾预防和扑救提供参考。     

A new solvent‐free super high build epoxy coating evaluated by marine corrosion simulation apparatus

Coal tar epoxy and epoxy asphalt coating have been widely used to protect marine constructions conventionally. However, their use is being restricted for increasing environmental concerns. Therefore, solvent‐free coating, i.e., coating without volatile organic compounds (VOCs) or hazardous air pollutant has become a new focus. Meanwhile, super high build (SHB) coating, having good anti‐corrosion performance and environment‐friendly feature, has become an important area of development in heavy‐duty protection to marine constructions. Herein, we combine the virtues of solvent‐free and SHB coating to introduce a new solvent‐free SHB heavy‐duty epoxy coating with no organic solvent and extremely low VOC content. Results show that the new coating is environment‐friendly, and has excellent physical properties and anti‐corrosion performance. The SHB coating performed much better than other three widely used coatings, especially in splash zone, the most dynamic area. The new solvent‐free SHB coating provides an ideal substitute to coal tar epoxy and epoxy asphalt coating and is expected to be widely used for anti‐corrosion of steel structures in splash, tidal, and immersed zones.     

Microstructure and mechanical properties of duplex stainless steel subjected to hydrostatic extrusion

The nanostructure and mechanical properties of ferritic-austenitic duplex stainless steel subjected to hydrostatic extrusion were examined. The refinement of the structure in the initial state and in the two deformation states (ε = 1.4 and ε = 3.8) was observed in an optical microscope (OM) and a transmission electron microscope (TEM). The results indicate that the structure evolved from microcrystalline with a grain size of about 4 μm to nanocrystalline with a grain size of about 150 nm in ferrite and 70 nm in austenite. The material was characterized mechanically by tensile tests performed in the two deformation states. The ultimate strength appeared to increase significantly compared to that in the initial deformation stages, which can be attributed to the grain refinement and plastic deformation. The heterogeneity observed in microregions results from the dual-phase structure of the steel. The results indicate that hydrostatic extrusion is a highly potential technology suitable for improving the properties of duplex steels.