Concentration Phase Separation of Substitution-Doped Atoms in TMDCs Monolayer

The density and spatial distribution of substituted dopants affect the transition metal dichalcogenides (TMDCs) materials properties. Previous studies have demonstrated that the density of dopants in TMDCs increases with the amount of doping, and the phenomenon of doping concentration difference between the nucleation center and the edge is observed, but the spatial distribution law of doping atoms has not been carefully studied. Here, it is demonstrated that the spatial distribution of dopants changes at high doping concentrations. The spontaneous formation of an interface with a steep doping concentration change is named concentration phase separation (CPS). The difference in the spatial distribution of dopants on both sides of the interface can be identified by an optical microscope. This is consistent with the results of spectral analysis and microstructure characterization of scanning transmission electron microscope. According to the calculation results of density functional theory, the chemical potential has two relatively stable energies as the doping concentration increases, which leads to the spontaneous formation of CPS. Understanding the abnormal phenomena is important for the design of TMDCs devices. This work has great significance in the establishment and improvement of the doping theory and the design of the doping process for 2D materials.     

形变热处理对2A12铝合金微观组织、织构及性能的影响

利用扫描电镜显微观察（含能谱分析）和电子背散射衍射技术（Electron Backscatter Diffraction， EBSD）等分析方法研究了不同形变热处理制度对2A12铝合金板材的微观组织、织构及性能的影响。结果表明：2A12铝合金经形变热处理后，晶粒沿轧制方向拉长，晶粒尺寸减小。随着形变热处理反复次数的增加，亚晶界比例降低，2°?15°的小角度晶界比例提高，大角度晶界比例先增后减，此时的退火过程由回复多边化主导转变为再结晶主导，再结晶程度提高。单步形变热处理样品因形变量较小，大小晶界和亚晶界比例较为接近。与退火制度相同的小变形样品相比，大形变热处理样品亚晶减少，大角度和小角度晶界增加，再结晶程度提高。形变量较大时，将存在Brass→R-Cu和m-Brass→Goss→R-Goss→Cube、T和P_0°→Near rotated Cube和｛102｝<201>的织构演变路径。单步小变形退火时，路径将改变为：R-Cu和m-Brass→Goss→R-Cube。随着变形量的增加，2A12铝合金的强度和硬度增加，韧性和塑性降低。     

微波复热对竹笋鸡汤品质的影响

目的 探究微波复热对竹笋鸡汤品质的影响。方法 采用不同微波功率(300、500和700 W)对竹笋鸡汤进行复热处理，分析竹笋鸡汤水溶性蛋白质、脂肪、游离氨基酸含量和挥发性风味物质，探究微波复热后竹笋鸡汤间品质差异。结果 随着微波功率增加，700 W处理下水溶性蛋白质含量和脂肪含量最高。300 W组的总游离氨基酸含量和鲜味氨基酸显著高于700 W和500 W，且其谷氨酸和丙氨酸味觉活度值(Taste Active Value, TAV)最大。随着微波功率的增加，竹笋鸡汤中挥发性风味物质总量和醛类总量呈现逐渐下降趋势；醇类和酮类物质总量先增加后下降，在500 W功率时达到最高值。结论 综合各项指标，采用300 W微波复热后的竹笋鸡汤品质更佳。该研究为预制汤品的复热工艺提供了理论指导。     

Effect of Variables on Ignition Delays of hydrazone/nitric acid systems

The effect of relative amounts of fuel and oxidizer, composition of the oxidizer and compactness of the fuel on ignition delays of hydrazones with nitric acid has been studied. Several of the hydrazones give minimum ignition delays at the mixture ratio close to the stoichiometric ratio. Ignition delays of phenyl- and dimethylhydrazones are greatly influenced by the acid composition. Longer ignition delays are observed with the acids having higher concentrations of NO₂. A reaction mechanism leading to hypergolic ignition has been proposed for phenylhydrazones/nitric acid systems. Longer ignition delays are observed when the fuels are taken in compacted forms.