Crystallographic structure- and texture-dependent fracture behavior of polycrystalline lead zirconate titanate ceramics

Journal of Electroceramics - The effect of crystallographic structure and texture on the fracture behavior of lead zirconate titanate (PZT) ceramics was investigated. PZT ceramics with Zr/Ti ratio...     

Efficient photodegradation of phenol assisted by persulfate under visible light irradiation via a nitrogen-doped titanium-carbon composite

To realize the utilization of visible light and improve the photocatalytic efficiency of organic pollutant degradation in wastewater, a nitrogen-doped titanium-carbon composite (N-TiO₂/AC) prepared by sol-gel methods was applied in the photodegradation of phenol assisted by persulfate under visible light irradiation (named N-TiO₂/AC/PS/VIS). The results show that a synergistic effect exists between visible-light photocatalysis and persulfate activation. Compared with TiO₂/PS/VIS, the phenol degradation rate was found to be observably improved by 65% in the N-TiO₂/AC/PS/VIS system. This significant increase in degradation rate was mainly attributed to the following two factors: 1) The N and C doping can change the crystal structure of TiO₂, which extends the TiO₂ absorption wavelength range to the visible light region. 2) As an electron acceptor, PS can not only prevent electrons and holes from recombining with each other but can also generate strong oxidizing radicals such as ∙SO₄^– and ∙OH to accelerate the reaction dynamics. The process of phenol degradation was found to be consistent with the Langmuir pseudo-first-order kinetic model with an apparent rate constant k of 1.73 min^–1. The N-TiO₂/AC/PS/VIS process was proven to be a facile method for pollutant degradation with high pH adaptability, excellent visible-light utilization and good application prospects.     

One-step fabrication superhydrophobic sand filter for capillary-driven separation of water-in-oil emulsions

The efficient separation of water-in-oil emulsion is of significance in environment and energy filed, and it has become a world-wide challenge. Herein, we have presented a one-step, facile and low-cost approach to prepare superhydrophobic sands for efficient separation of water-in-oil emulsion. The as-prepared sand layers possessed a water contact angle higher than 151°, demonstrating their superior superhydrophobic property. Besides, the as-prepared sand layers could separate water-in-emulsions with separation efficiency up to 99.7%, which is superior to both traditional and superwettable filtration membranes. The effect of thickness of sand layer on separation performance was also investigated. The results showed that the filtration flux decreased with the increased of filtration thickness while the separation efficiency increased. The as-prepared sand layer proposed by this study is a processing candidate for separating water-in-oil emulsion in practical industry. Additionally,the as-prepared superhydrophobic sand fabrication method also provides an alternative for desert water storage.     

特高压直流电子式互感器阶跃特性智能化测试技术研究

通过对直流电流互感器阶跃特性测试技术和暂态特性建模的分析研究,提出了特高压直流电子式互感器阶跃特性智能化测试方案及现场测试解决方案,对改变目前直流输电工程中互感器选型、检测、运维的无序状态具有十分重要的意义,将为直流控制保护及监视系统的可靠运行提供技术保障,提高了直流输电工程的安全可靠运行水平.     

Toward Largely Enhanced Toughness and Balanced Strength in PA1012/EPDM Blends via Synergistic Effect of Sacrificial Bonds and Network Structure

Here, zinc-neutralized ethylene propylene diene monomer (EPDM) ionomers with different neutralization levels are prepared through melt blending, and are then incorporated with polyamide 1012 (PA1012) to fabricate PA1012/EPDM ionomer blends. Interestingly, complex crosslinking networks are formed in the blends due to the construction of sacrificial bonds (Zn²⁺-carboxyl, Zn²⁺-amide). The as-formed network structure and sacrificial bond endow the PA/EPDM blends with largely enhanced toughness (16 times higher than that of neat PA), as well as balanced strength and stiffness. Meanwhile, the rheological behaviors of PA1012/EPDM ionomer blends indicate their relative low melting viscosity, which can avoid the processing shortcomings of plastics toughened with rubber. Moreover, PA1012/EPDM ionomer blends show obvious gelation behavior, and a maximum notched Izod impact strength exhibited at the gel point, in which unique double network structure can be observed obviously, indicating that there is a corresponding correlation between the rheological and mechanical parameters. Furthermore, the supper-toughening mechanism of PA1012/EPDM ionomer blends at gel point is explored, which origins from the large deformation and cavitation of rubber particles and the destruction of special double network morphologies. This study provides a novel and effective strategy to fabricate PA materials with outstanding toughness and excellent strength simultaneously.     

N3-Kethoxal-Based Bioorthogonal Intracellular RNA Labeling

There is growing interest in developing intracellular RNA tools. Herein, we describe a strategy for N₃-kethoxal (N₃K)-based bioorthogonal intracellular RNA functionalization. With N₃K labeling followed by an in vivo click reaction with DBCO derivatives, RNA can be modified with fluorescent or phenol groups. This strategy provides a new way of labeling RNA inside cells.     

单,双向拉伸各性能指标间的相关性研究

采用９种板料进行了单拉及液压胀形（双向拉伸）试验，分别研究了双向拉伸各性能指标间及单、双向伸各性能指标间的相关关系，得到了一系列有意义的结果。     

Relating the molecular structure and crystallization behavior of polypropylene

The crystallization behavior of two polypropylene (PP) resins as used for biaxially oriented polypropylene (BOPP) and general injection mold applications, respectively, has been intensively investigated and compared by means of polarized light optical micrography (POM), differential scanning calorimetry (DSC), conventional transmission electron microscopy (TEM), and high resolution transmission electron microscopy (HRTEM). It is found that both molecular weight distribution and isotacticity of polypropylene strongly affect its crystallization characteristics, e.g., the number of crystal nuclei at the initial stage, crystallization dynamics, the morphology, size and perfection of crystals in the final product, and so on. The results indicate an appropriate molecular structure is vital in producing high‐quality BOPP film. Polym. Eng. Sci. 44:1749–1754, 2004. © 2004 Society of Plastics Engineers.     

超长余辉蓄能发光涂料的制备

通过选用透明度高、太阳能吸收率高的丙烯酸树脂和高亮度、长余辉时间的镝和铕稀土离子共掺杂的稀土硅酸盐光致发光粉末材料aCaO·bZnO·cBaO·dMgO·nSiO2:Eu,Dy,制备出了具有较强的蓄光能力和较长发光时间的夜光涂料,并论述了其制备方法和特性。