Phase equilibria studies in the CaO–SiO2–Al2O3–MgO system with CaO/SiO2 ratio of 0.9

Phase equilibria and liquidus temperatures in the CaO–SiO₂–Al₂O₃–MgO system at a CaO/SiO₂ weight ratio of 0.9 in the liquid phase have been experimentally determined employing high-temperature equilibration and quenching technique followed by electron probe X-ray microanalysis. Isotherms at 1573, 1623, 1673, and 1773 K were determined and the primary phase fields of wollastonite, melilite, olivine, periclase, spinel, and corundum have been located. Compositions of the olivine and melilite solid solutions were analyzed and discussed. Comparisons between the newly constructed diagram, existing data, and FactSage predicted phase diagrams were performed and differences were discussed. The present study will be useful for guidance of industrial practices and further development of thermodynamic modeling.     

Efficient MOF- derived V–Ni3S2 nanosheet arrays for electrocatalytic overall water splitting in alkali

The synergistic achievement of low-cost earth-abundant electrocatalysts and high efficiency to meet renewable energy need is highly desirable yet challenging. Here, we developed a simple Ni foam self -templating route for V-doped Ni₃S₂ nanosheet arrays through in situ formation of metal-organic frameworks (MOFs) combined with subsequent conversion. The as-prepared MOF-V-Ni₃S₂/NF catalyst delivers outstanding electrocatalytic performance in the alkaline solution, which requires low overpotentials of 118.1 mV @10 mA cm^?2 and 268 mV @10 mA cm^?2 for hydrogen evolution reaction and oxygen evolution reaction, respectively. The V-doping and MOF-derived 3D hieratical nanostructure play a vital role in the catalytic process, which provides efficient active sites and large surface areas. Furthermore, an alkaline electrolyzer was assembled with two pieces of MOF-V-Ni₃S₂/NF, which achieves efficient water splitting at 1.58 V @10 mA cm^?2. This strategy opens up new channels to synthesize MOF-based bifunctional electrocatalysts toward overall water spitting.     

An innovative process for synthesis of superfine nanostructured Li2TiO3 tritium breeder ceramic pebbles via TBOT hydrolysis – solvothermal method

In this paper, a method combining hydrolysis of tetrabutyl orthotitanate (TBOT) and solvothermal reaction was first used to fabricate nanostructured Li₂TiO₃ tritium breeder ceramic pebbles. Initially, superfine nanostructured Li₂TiO₃ powders were synthesized with average particle size of about 10?nm, according to TEM. The surface area of precursor particles synthesized via this method was found to be 115.85?m²/g by BET analysis, which is much larger than that of the product obtained using traditional methods. The results showed that precursor particles had high sintering activity. XRD pattern revealed that the phase transition temperature for monoclinic phase Li₂TiO₃ prepared by this method was nearly 450?°C, which was the lowest phase transition temperature reported among all wet chemical methods to date. Subsequently, investigation of ceramic sintering demonstrated that Li₂TiO₃ ceramic pebbles with desired nano-crystalline sizes (27.98 ~ 55.03?nm) were obtained by sintering at 500 ~ 600?°C for 4?h. The possible mechanisms were proposed based on the reaction processes of TBOT hydrolysis, solvothermal reaction and sintering.     

An effective approach for reliability-based robust design optimization of uncertain powertrain mounting systems involving imprecise information

The uncertain parameters of automotive powertrain mounting systems (PMSs) may involve imprecise information (e.g., incomplete, different and conflicting information) in engineering practice. An effective approach is proposed for the reliability-based robust design optimization (RBRDO) of uncertain PMSs involving imprecise information. In the proposed approach, the imprecise information of uncertain parameters is firstly addressed and combined based on evidence theory, and the uncertain parameters are treated as evidence variables. Then, an uncertainty analysis method named evidence perturbation-central difference method (EPCDM) is derived to fast estimate the mean intervals, standard deviation intervals, and the belief and plausibility measures related to system inherent characteristics. A reference method named evidence-Monte Carlo method (EMCM) is developed to verify the effectiveness of EPCDM. Next, to conduct robustness design, the weighted sum of the lower bounds of means and the upper bounds of standard deviations of system inherent characteristics are taken to construct optimization objective; while to perform reliability design, the belief measures related to system inherent characteristics are used to create reliability constraints. Afterwards, a nested RBRDO model is established to explore the optimum design of the PMS, which considers both reliability and robustness simultaneously. The nested PBRDO can be effectively simplified based on EPCDM. The effectiveness of the proposed approach is finally demonstrated by the application example.

     

水性抗菌羟基丙烯酸树脂的制备及性能

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)、丙烯酸(AA)、丙烯酸羟丙酯(HPA)为单体,过氧化二苯甲酰(BPO)为引发剂,乙醇为助溶剂,采用半连续溶液聚合法合成得到了水性羟基丙烯酸树脂(hs-WA),再用三乙胺(TEA)中和,最后引入季铵盐抗菌剂3-(甲氧基硅烷基)丙基二甲基十八烷基氯化铵(TSA),合成得到了水性抗菌羟基丙烯酸树脂(hs-WAT)。利用FTIR、1HNMR、接触角、SEM、TG和DSC对样品进行了分析,并采用菌落计数法和抑菌圈法对样品进行了抗菌测试。结果表明:引入TSA反应后,树脂的表面形貌没有改变;水接触角从78.5?增大至87.5?;样品的分解温度范围为299～456℃,热稳定性提高;聚合物链柔韧性增强(Tg=8.3℃)。抗菌性能分析表明:当引入TSA的质量分数为4%(以树脂的固含量计)时,hs-WAT膜对大肠杆菌(革兰氏阴性菌)以及金黄色葡萄球菌(革兰氏阳性菌)的杀灭率达99.9%以上,TSA未发生迁移,合成的聚合物为水性非渗透性接触型抗菌材料。     

Enhanced voltage endurance capability of Ba(Zr0.2Ti0.8)O3 thin films induced by atomic-layer-deposited Al2O3 intercalations and the application in electrostatic energy storage

Ultrathin Al₂O₃ insulating intercalations with different thicknesses and numbers, prepared by atomic layer deposition technology, were introduced into Ba(Zr_0.2Ti_0.8)O₃ (BZT) relaxor ferroelectric films as the dielectric for electrostatic energy storage capacitors. The phase structure, microstructure and electrical properties were investigated in detail. Due to the insertion of insulating layers, the films show less leakage current and enhanced voltage endurance capability when the thickness of single Al₂O₃ intercalation exceeds a threshold (0.45–0.9 nm). The voltage endurance capability can be more enhanced by increasing the number of Al₂O₃ intercalations. For energy storage applications, the energy storage density and efficiency obtained from the polarization-electric field loops are significantly improved owing to the suppressed leakage and enhanced voltage endurance ability. The results promote the application of BZT-based films in electrostatic energy storage. It is demonstrated that the introduction of atomic-layer-deposited insulating intercalations with controllable thickness, such as those fabricated by ALD method, is an effective way to improve the electrical performance of devices based on composite materials.