功能性小麦品种的概念、类别和发展前景（网络首发、推荐阅读）

结合全球倡导的营养导向型农业和功能性食品的内容，首次提出“功能性小麦品种”的概念，将其定义为“含有对人体健康有益的活性成分，可调节人体有益代谢，能给人体健康带来某种益处或满足特定人群的特殊需求，同时可以作为日常食物的口感正常、无毒副作用的小麦品种类型”；结合疫情警示和我国进入后工业时代后，人们需求必将由“吃得饱”、“吃得好”向“吃得健康”转变，因而提出继高产品种、优质品种之后培育“功能性小麦品种”的育种目标。根据多年关于小麦淀粉、蛋白、酯类和其他成分的功能研究结果，介绍新育成的“麦黄酮”、“高色素”、“高抗性淀粉”、“富锌”、“低醇溶蛋白”和“低植酸”等功能性小麦新品种（系）的营养特性和农艺产量状况；根据“健康中国2030”规划等国家战略，进行“功能性品种培育是解决我国功能性食品‘卡脖子’的关键基础，一种功能性品种可以形成一类功能性食品，多种功能性品种可以形成我国功能性面制品产业，推动我国整个食品工业的发展”的前景展望；根据功能性品种及其食品的稳定性和可靠性是产品和市场的“生命线”，从对消费者负责的高度，提出关于“功能性农作物品种审定导向和组建功能性成分检测机构；编制有关功能性品种和食品的国家或行业标准，设立功能性食品和功能性农作物品种的商业标志，保证我国功能性农作物品种及其食品健康发展”等方面的具体建议。     

Synthesis and slurry spray coating of barium strontium alumino silicate on SiC substrate

Barium strontium alumino silicate (BSAS); (Ba_0.6Sr_0.4Al₂Si₂O₈) was synthesized through solid state reaction between BaCO₃, SrCO₃, Al₂O₃ and SiO₂ subjected to wet milling in isopropanol for about 24 h. The sequence of the solid state reaction was studied by subjecting to DG/DTG from room temperature to 1550 °C. The crystallographic phase evolution was confirmed by X-ray diffraction of the powders calcined in the range 1000 to 1300 °C for 2 h. The monoclinic celsian phase obtained at 1300 °C, pelletized through uniaxial pressing was sinterable to 67 to 78% density in the temperature range of 1300 to 1500 °C. The density improved to 75 to 94% after ball milling for 76 h, while ZrO₂ addition further improved the density by 2%. The celcian phase of BSAS was dispersed in isopropyl alcohol, milled for about 24 h and spray coated on to plain SiC and mullite precoated SiC substrates. Sintering of coated samples and characterization for weight gain/loss, microstructure, scratch test prove that mullite + BSAS coating is more effective than single layer coating of BSAS on SiC substrates.     

杂化包覆玄武岩鳞片/环氧涂料制备与性能

本文在环氧涂料中添加玄武岩鳞片，提高其防腐蚀性能。针对玄武岩鳞片的团聚问题，通过机械力化学改性工艺，采用正硅酸四乙酯、HY-311型钛酸酯偶联剂、E-44型环氧树脂对玄武岩鳞片进行杂化包覆，结果表明，杂化包覆后玄武岩鳞片的沉降时间从2h提高至96 h。杂化包覆玄武岩鳞片添加量为20%涂层的性能最优，附着力为13.40 MPa，耐盐雾时间为2000 h，在3.5%NaCl溶液中浸泡2000 h后，0.01 Hz的阻抗模值仍然有5.15×109 Ω·cm2。     

Water vapor volatilization and oxidation induced surface cracking of environmental barrier coating systems: A numerical approach

A numerical model is developed for surface crack propagation in brittle ceramic coatings, aiming at the intrinsic failure of rare-earth silicate environmental barrier coating systems (EBCs) under combustion conditions in advanced gas turbines. The main features of progressive degradation of EBCs in such conditions are captured, including selective silica vaporization in the top coat due to exposure to water vapor, diffusion path-dependent bond coat oxidation, as well as crack propagation during cyclic thermal loading. In light of these features, user-defined subroutines are implemented in finite element analysis, where surface crack growth is simulated by node separation. Numerical results are validated by existing experimental data, in terms of monosilicate layer thickening, thermal oxide growth, and fracture behaviors. The experimentally observed quasi-linear oxidation in the early stage is also elucidated. Furthermore, it is suggested that surface crack undergoes rapid propagation in the late stage of extended thermal cycling in water vapor and leads to catastrophic failure, driven by both thermal mismatch and oxide growth stresses. The latter is identified as the dominant mechanism of penetration. Based on detailed analyses of failure mechanisms, the optimization strategy of EBCs composition is proposed, balancing the trade-off between mechanical compliance and erosion resistance.     

Inhibited intracrystalline cracks and enhanced electrochemical properties of NCM811 cathode materials coated by EPS

The formation of micro-cracks in Ni-rich LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) cathode particles is an extremely important factor affecting the electrochemical characteristics after long-term cycling. Generally, cracks can be divided into intergranular crack and intracrystalline crack according to their positions. Coating has been confirmed as a highly effective strategy to relieve intergranular cracks. However, the intracrystalline cracks of primary-like particles have rarely been studied. In this work, ethoxy functional polysiloxane (EPS) was directly coated on the surface of original NCM811 by tetraethyl orthosilicate (TEOS) hydrolytic polycondensation method without any additives. Then, the microstructure, micromorphology, surface state and electrochemical properties were investigated in detail by XRD, SEM, TEM, CV and EIS. The results displayed that the micro-cracks of primary-like particles were effectively suppressed under appropriate EPS coating. Accordingly, excellent capacity retention of 95.6% (100 cycles, 1C) and rate performance (144.6 mA h/g, 5C) were obtained. These improved mechanical and electrochemical properties are considered to be related to the EPS stress buffer layer, suppressed oxygen vacancies, inhibited phase transition and reduced volume change.     

Self-healing capacity of Mullite-Yb2SiO5 environmental barrier coating material with embedded Ti2AlC MAX phase particles

Repetitive heating and cooling cycles inevitably cause crack damage of hot gas components of gas turbine engines, such as blades and vanes. In this study the self-healing capacity is investigated of mullite + ytterbium monosilicate (Yb₂SiO₅) as EBC material with Ti₂AlC MAX phase particles embedded as a crack-healing agent. The effect of Ti₂AlC in the EBC was compared with the self-healing ability of the mullite + Yb₂SiO₅ material. After introducing cracks by Vickers indentation on the surface of each sample, crack healing was realized by controlling the temperature and time during the post-heat-treatment process. For the mullite + Yb₂SiO₅ composite with Ti₂AlC particles, crack healing occurred at 1000 °C, while in the case of the mullite + Yb₂SiO₅ composite without Ti₂AlC, a sustained temperature of 1300 °C or higher was required. Compared with the healing of the mullite + Yb₂SiO₅ composite by the formation of a eutectic phase, the addition of Ti₂AlC promoted healing via the oxidation of Ti and Al. Notably, the surface formation of a ternary oxide of Ti–Yb–O was confirmed, which completely covered the damage area. Consequently, the addition of a Ti₂AlC MAX phase to the EBC composite resulted in a complete strength recovery, while the mullite + Yb₂SiO₅ composite without Ti₂AlC showed a strength recovery of about 80%. Furthermore, by analyzing the indentation load–displacement curve to indicate the role of Ti₂AlC, the addition of Ti₂AlC improved both the hardness and stiffness of the composite.     

Development and characterisation of a Y2Ti2O7-based glass-ceramic as a potential oxidation protective coating for titanium suboxide (TiOx)

A silica-based glass-ceramic, with Y₂Ti₂O₇ as the major crystalline phase, is designed, characterised and tested as an oxidation-protective coating for a titanium suboxide (TiO_x) thermoelectric material at temperatures of up to 600 °C. The optimised sinter-crystallisation treatment temperatures are found to be 1300 °C and 855 °C for a duration of 30 min, and this treatment leads to a glass-ceramic with cubic Y₂Ti₂O₇ and CaAl₂Si₂O₈ as crystalline phases. An increase of ~270 °C in the dilatometric softening temperature is observed after devitrification of the parent glass, thus further extending its working temperature range.Excellent adhesion of the glass-ceramic coating to the thermoelectric material is maintained after exposure to a temperature of 600 °C for 120 h under oxidising conditions, thus confirming the effectiveness of the T1 glass-ceramic in protecting the TiO_x material.     

Hydrogen sulfide gas detection by Au-decorated ZnO nanotube: a computational study and comparison to experimental observations

Based on the experimental reports, Au-decoration on the ZnO nanostructures dramatically increases the electronic sensitivity to H₂S gas. In the current study, we computationally scrutinized the mechanism of Au-decoration on a ZnO nanotube (ZON) and the influence on its sensing behavior toward H₂S gas. The intrinsic ZON weakly interacted with the H₂S gas with an adsorption energy of ?11.2 kcal/mol. The interaction showed no effect on the HOMO–LUMO gap and conductivity of ZON. The predicted response of intrinsic ZON toward H₂S gas is 6.3, which increases to 78.1 by the Au-decoration at 298 K. The corresponding experimental values are about 5.0 and 80.0, indicating excellent agreement with our findings. We showed that the Au atom catalyzes the reaction 3O₂?+?2H₂S?→?2SO₂?+?2H₂O. Our calculated energy barrier (at 298 K) is about 12.3 kcal/mol for this reaction. The gap and electrical conductance Au-ZON largely changed by this reaction are attributed to the electron donation and back-donation processes. The obtained recovery time is about 1.35 ms for desorption of generated gases from the surface of the Au-ZON sensor.     

Symmetric and asymmetric membranes based on La0.5Sr0.5Fe0.7Ga0.3O3-δ perovskite with high oxygen semipermeation flux performances and identification of the rate-determining step of oxygen transport

This work focuses on identifying the rate-determining step of oxygen transport through La_0.5Sr_0.5Fe_0.7Ga_0.3O_3-δ membranes with symmetric and asymmetric architectures. The best oxygen semipermeation fluxes are 3.4 10⁻³ mol. m^-2.s^-1 and 6.3 10⁻³ mol. m^-2.s^-1 at 900 °C for the symmetric membrane and asymmetric membrane with a modified surface. The asymmetric membrane with a modified surface leads to an increase of approximately 7 times the oxygen flux compared to that obtained with the La_0.5Sr_0.5Fe_0.7Ga_0.3O_3-δ dense membrane without surface modification. This work also shows that the oxygen flux is mainly governed by gaseous oxygen diffusion through the porous support of asymmetric La_0.5Sr_0.5Fe_0.7Ga_0.3O_3-δ membranes.     

Surface modification of cellulose nanocrystals towards new materials development

Cellulose nanocrystals (CNCs) are a kind of sustainable nanoparticle from biomass, which are widely used as reinforcing filler and assembly building block for high-performance composites and function materials including biomaterial, optics, and so forth. Here, their unique advantages in material applications were reviewed based on their rod-like morphology, crystalline structure, dimension-related effects, and multi-level order structure. Then, we focused on the molecular engineering of CNCs, including the structure and physicochemical properties of their surface, along with surface modification methods and steric effects. We further discussed the performance-improvement and functionalization methods based on multi-component complex systems, together with the effects of surface molecular engineering on the performance and functions. Meanwhile, methods of optimizing orientation in uniaxial arrays were discussed along with those of enhancing photoluminescence efficiency via surface chemical modification and substance coordination. In the end, we prospected the design, development, and construction methods of new CNCs materials.