EFFect of Mn--(2+) and La--(3+) on enhancing the thermal stability and combustion activity of hexaaluminate

催化燃烧是提高效率,降低热nO_X污染的有效方法,要求活性组分及其载体具有良好的抗烧结性。这可通过在Al_2O_3中引入碱土金属离子组成层状结构的六铝酸盐来实现。以lA--(3+)取代部分碱土离子(如bA--(2+)等),能更容易获取纯净的六铝酸盐,而以Mn--(2+)取代部分Al--(3+),既可提高甲烷完全燃烧的活性,又增进了催化剂的高温热稳定性,再结合制备方法的改进,氧化铝载体及其活性组分的高温性能会得到显著改善。Catalytic combustion is an eFFective method to increase combustion eFFiciency and reduce NOx thermal pollution.It demands that the active constituents and their supports have excellent sintering resistance, which can be achieved by introducing alkaline-earth metal ions (Ba2+, Sr2+ etc.) into A12O3 to Form hexaaluminate with layer structure.When alkaline earth metal ions are partially substituted with La3+ , it is easier to obtain pure such as Ba2+ hexaaluminate , but when A13+ are partially substituted with Mn2+,it will enhance not only the catalyst's activity For methane combustion, but also its thermal stability.IF it is combined with an improvement on the manuFacturing method,the high temperature perFormance of the alumina support and the active constituents will be considerably improved.国家自然科学基金资助项

The Syntheses of the New Plant Growth Retardant Uniconazole

含钐的锆基萤石型复氧化物与镧系钙钛矿型化合物一样，表现出良好的促进甲烷完全燃烧的催化活性.无论从单位质量、单位表面积的甲烷转化率或是起燃温度上比较，前者都不逊色，且有良好的高温性能.这种新材料的催化活性与其制备法密切相关，其中碳酸盐共沉淀法，有机酸的化学混合法可以得到很好的结果，而氢氧化物共沉淀法却差得多.α Triazolylpinacolone reacted with 4 chlorophenylacetaldehyde to produce 92% vinyltriazolyl ketone 3 with E/Z=0.77; the 3 was isomerized by Br 2/MeSO 3H to produce 94% E Vinyltriazolyl ketone 3a, the 3a was reduced by KBH 4 at 0 ℃ to produced 95% Uniconazole 4, with purity in 98% and E/Z≥99/1.Uniconazole was used For an eFFective plant growth retardant and Fungicide.福建省自然科学基

PREPARATION of La_2O-3-ZrO_2 OXIDE COMBUSTIONAL CATALYST WITH DEFECTIVE FLUORITE STRUCTURE

缺陷萤石型lA_2Q_3-zrO_2固溶体的催化燃烧活性受制备条件的影响,本文通过对其共沉淀前体的表面结构和热分解过程的分析,发现共沸蒸馏的办法可以有效地控制前体表面羟基的缩合过程,减少团聚,保持前体中金属离子均匀分散,为生成缺陷有序的烧绿石型的lA_2zr_2O_7复氧化物提供了可能,复合氧化物固溶体的表面阳离子配置情况与样品的催化氧化性能密切相关,软团聚前体的烧结产物对甲烷燃烧反应具有更高的催化活性。One of the most important factors which affect the catalytic performances of complex oxide used in catalytic combustion is the preparative process of samples.Combined with several spectrum techniques, the study on the thermal decomposing procedure of the coprecipated precursors illustrates that the catalytic activity of La2O3-ZrO2 composite oxide solid solution is intimately concerned with drying condition, due to the different crystallization therein.The codistillation involved n-butanol could keep the uniform distribution of metal cations in precursor intact, and facilitates acquiring the well-crystallized sample by following thermal treatment.These crystalline with regular lattice will supply more anion defects on the surface, which act as the active sites for the complete oxidation of hydrocarbon

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^