Design of a super-hydrophilic/super-oleophobic g-C3N4/Ti(OH)4/PFOA nanocomposite coated mesh as a smart nanofilter with robust anti-fouling properties for separation of oil and water emulsions

The design and development of efficient approaches for water–oil separation have had widespread interest. This study aimed to synthesize nanocomposites based on Ti(OH)₄ and g-C₃N₄ nanosheets (CN-NS) to show experimentally that the inclusion of Ti(OH)₄ nanoparticles of 9.2 nm size into CN-NS leads to an improved oil-water separation efficiency and anti-fouling performance. So, a novel, reusable, and recyclable super-hydrophilic/underwater super-oleophobic CN-NS/Ti(OH)₄ nanocomposite-coated stainless steel mesh was developed to separate oil-in-water emulsions. Super-wettability was obtained in the CN-NS/Ti(OH)₄ nanocomposite with WCA = 0° and UOCA = 154°, respectively, showing significant super-hydrophilicity and underwater super-oleophobicity. Surface hydrophilicity increased after anchoring Ti(OH)₄ on the CN-NS surface, resulting from oxygen-containing functional groups and consequently making defects on the mesh surface. Enhanced underwater oleophobicity of nanocomposite coated mesh is attributed to its higher surface roughness, which is a result of its micro-nano meter and mesoporous hierarchical structure. Moreover, the self-cleaning property of the as-prepared mesh was demonstrated by visible light irradiation on the contaminated mesh. In addition, perfluorooctanoic acid (PFOA) reduced energy in CN-NS/Ti(OH)₄/PFOA mesh, resulting in a super-hydrophilic/super-oleophobic mesh. The CN-NS/Ti(OH)₄/PFOA nanocomposite-coated filter was observed to separate water from a 1 wt% water-in-oil emulsion at 0.2 bar pressure with a filtration flux of 317.2 L m⁻² h⁻¹ and 95% separation efficiency.     

Synthesis and performance of tetragonal BaTiO3 fine powders via a facile tartaric acid assisted method

A facile tartaric acid assisted method using metatitanic acid, barium hydroxide and tartaric acid as starting materials is proposed to prepare tetragonal BaTiO₃ fine powders. Owing to the ultrafine character of the as-formed BaCO₃ with high chemical activity, and its arrangement coating the surface of intermediate TiO₂ nanoscale needles, pure cubic phase BaTiO₃ homogeneous powders with size of about 50 nm was obtained via calcining treatment at 650 ℃, which subsequently transformed as tetragonal BaTiO₃ uniform powders with size of about 240 nm and high tetragonality (c/a=1.0095) after calcining treatment at 1050 ℃. The BaTiO₃ ceramic prepared from the BaTiO₃ uniform powders displayed much improvement performances with high permittivity of about 5980 and low dielectric loss of about 0.014 at room temperature in comparison to the BaTiO₃ ceramic prepared respectively from the BaTiO₃ synthesized via a traditional solid-state method, and commercial BaTiO₃, suggesting it’s compatible in application of MLCCs with high performance.     

A novel approach to sintering (Ba,Ca)(Ti,Zr)O3 multilayer ceramic capacitors with Ni electrodes

In this study, a novel sintering technique combining rapid heating and constrained sintering was adopted to fire multilayer ceramic capacitors (MLCCs). It was demonstrated that chamber development can be significantly minimized, leading to a small internal residual stress in MLCCs when they were fired by the novel sintering technique instead of free sintering. The magnitude of tensile stress was closely related to the heating rate and the thickness of the constraining layer. The presence of in-plane tensile stress resulted from the constrained sintering in the x–y plane of the MLCCs, which then modified both the densification rate of the dielectric materials and the inner electrode. The thin inner electrode (<1 μm) with high continuity (>98%) and the fine grain size (1.5 μm) with narrow distribution (±0.10 μm) of BCTZ-based MLCC with a concave-free morphology can be attained by using such a rapid constrained sintering technique when BT is used as a constraining layer laminated on both sides of the multilayer BCTZ-based MLCC.     

初探CBE模式在高职化工专业有机化学教学中的应用

从教材、教学手段、实训设施、课程改革及双师型教师五个方面,分析研究了目前有机化学教学中存在的问题与不足,结合本人的教学经验,探讨了CBE模式下高职化工专业有机化学教学的创新及具体的教学过程。CBE模式的引入,能提高学生学习兴趣,提升学生职业技能水平。     

2个Smarandache LCM函数的混合均值估计

研究了Smarandache LCM函数SL(n)与r角形数函数ur(n)和vr(n)的混合均值问题.利用初等方法和解析方法,给出了2个有趣的渐近公式,发展了F.Smarandache教授在《Only Problems,Not Solution》中涉及的相关研究工作.     

Hydrogen accommodation in Zr second phase particles: Implications for H pick-up and hydriding of Zircaloy-2 and Zircaloy-4

Ab-initio computer simulations have been used to predict the energies associated with the accommodation of H atoms at interstitial sites in α, β-Zr and Zr–M intermetallics formed with common alloying additions (M = Cr, Fe, Ni). Intermetallics that relate to the Zr₂(Ni,Fe) second phase particles (SPPs) found in Zircaloy-2 exhibit favourable solution enthalpies for H. The intermetallic phases that relate to the Zr(Cr,Fe)₂ SPPs, found predominantly in Zircaloy-4, do not offer favourable sites for interstitial H. It is proposed that Zr(Cr,Fe)₂ particles may act as bridges for the migration of H through the oxide layer, whilst the Zr₂(Ni,Fe)-type particles will trap the migrating H until these are dissolved or fully oxidised.     

电化学处理高浓度有机废水的研究进展

随着现代工业的迅速发展,工业废水的排放量日益增加。这给人们的生活和生产带来了极大的危害。尤其是工业高浓度有机废水,其毒性高,对环境污染大,因而其废水的处理技术受到了广泛的关注。电化学方法具有容易控制,容易建立密闭循环且无二次污染等优点,在处理有机废水方面受到广泛关注,应用很广。文章介绍了高浓度有机废水的各种电化学处理方法的机理及研究进展,并指出了今后的研究发展     

Applicability assessment of a real-time PCR assay for the specific detection of bovine,ovine and caprine material in feedstuffs

A TaqMan real-time polymerase chain reaction (PCR) method was developed for specific detection of bovine, ovine and caprine processed animal protein (PAP) in industrial feedstuffs. The method uses species-specific primers and probes targeting short mitochondrial D-loop sequences, and a positive amplification control based on 18S rRNA gene. The applicability of the real-time PCR protocol was assessed through analysis of 126 industrial feed samples that were manufactured to reproduce rendering processes of commercial feeds destined for farmed animals. The assay successfully classified samples as positive or negative according to the ruminant composition, enabling qualitative detection of banned material in feeds at levels as low as 0.1%. Although the method provides quantitative potential, results suggest that the real quantitative capability of the assay is limited by the existing variability in terms of composition and processing treatments of the feeds, which affect the amount and quality of amplifiable DNA.     

生物医用钛及钛合金的研制、生产和应用

简介了新型生物医用功能材料用钛及钛合金的研制历史、生产、标准和应用。     

Fundamental electrochemical and Raman spectroscopic investigations of the flotation behaviour of PtAs2

Platinum arsenide minerals are important platinum carriers in altered platinum reserves such as the Great Dyke of Zimbabwe and the Platreef (in the Bushveld Complex of South Africa). Industrial mineralogical investigations suggest these minerals to be poorly recovered during froth flotation and are believed to be slow floating. In this work, electrochemical investigations, electrochemical contact angle measurements and Raman spectroscopy have been employed to investigate the interaction of ethyl xanthate with synthetic PtAs₂. The electrochemical investigations suggest a strong interaction of the xanthate with the mineral at potentials higher than the reversible potential of the xanthate–dixanthogen couple. Raman spectroscopy has confirmed the presence of dixanthogen on the mineral surface when the surfaces are anodically polarized. Contact angle investigations indicated the surface to be hydrophobic; possible mechanisms of the slow floating behaviour are discussed.