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The confocal Raman spectra of mixed phthalic acid/ammonium sulfate (AS) droplets deposited on a polytetrafluoroethylene (PTFE) substrate and a hydrophilic glass substrate are collected. The evolution of the physical state of the mixed droplet deposited on the PTFE substrate at various relative humidities consists of three states: well-mixed liquid state, liquid-liquid phase-separated state, and crystalline state. When the mixed droplets exist in liquid-liquid phase-separated state, the morphologies of the droplets on a PTFE substrate and on a glass slide are totally reverse, that is, an aqueous AS inner phase surrounded by an organic outer phase and an organic inner phase surrounded by an AS outer phase, respectively. We propose that the salting-out effect may induce the diffusion and formation of the organic phase, thus leading to the generation of liquid-liquid phase separation. The surface tension and hydrophobicity/hydrophilicity of substrates influence the spatial distribution of mixed aerosols. The understanding about the evolution of the physical state of mixed droplets and the effect of the substrates are important for probing the formation of atmospheric aerosols' morphology in the dehumidifying process.

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Due to the complexity of impact-induced reaction, it is difficult to predict and evaluate the ignition and safety of explosives under low velocity impact. Plastic deformation is very important to explosive ignition under impact loading. At low strain rates, plastic deformation can be treated as an isothermal process. The deformation under high-strain-rate is usually seen as an adiabatic process, and the deformation work is transformed into heat with the attendant temperature increase of the explosive. In this paper, we proposed an ignition criterion in terms of effective plastic work and specific plastic power to predict the ignition of explosives under low velocity impact. The plastic work begins to accumulate, when the specific plastic power (i.e., the plastic strain rate) in a local region meets a threshold value; and when the plastic work is sufficient enough, the ignition occurs. The criterion parameters are determined by numerical simulation using LS-DYNA. Numerical simulation is compared with experimental data in order to calibrate the numerical model. The threshold values of this ignition criterion for different configurations are determined. In order to evaluate the validity of the criterion, the predictions of the ignition time, ignition zone, threshold velocities in Steven test with different PBX size designs and various projectiles, as well as the ignition threshold conditions in a modified drop weight test, Susan test, and Spigot test, are carried out. The predicted results show a good agreement with experimental results, and the errors of the ignition threshold are less than 15% for all the experimental configurations.

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Employing systematic experiments and comparing the CO2 absorption amount, absorption rate and CO2 loading of various amines and their mixtures, the optimal formula of blended amine solution is investigated. The results demonstrate the absorption characteristics of diethylenetriamine are the best, followed by monoethanolamine and methyldiethanolamine, while diethanolamine has no competitive advantage, neither in terms of the absorption amount and rate nor loading of CO2. The amine concentration has a significant influence on CO2 absorption, followed by formula and ratio, while the temperature and pressure affect little. The optimal formula of blended amine solution with the highest rate constant and activation energy of CO2 absorption was determined.