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To expand the field of view and obtain a full-scale image of a debris cloud, a large-field pulsed digital in-line holography (DIH) system is developed to study the three-dimensional (3D) positions and shapes of debris clouds generated by hypervelocity impact. A general model for the large-field pulsed DIH system is introduced. Derived from strict theoretical analysis, it suggests that the hologram recorded by a large-field pulsed DIH system can be described by an equivalent lensless system. At the Hypervelocity Impact Research Centre of the China Aerodynamics Research and Development Centre, based on hypervelocity impact equipment with a 7.6 mm bore, experiments on a 3 mm aluminium sphere impacting a 1 mm thick aluminium target plate with a velocity of 3.58 km/s were carried out. Ensuring the successful capture of the transient state of debris clouds, the large-field pulsed DIH system is synchronised with the impact event and the combination of the neutral density filter and the bandpass filter is proposed, to eliminate the plasma radiation and enhance the signal-to-noise ratio of the hologram. The experimental results show that the holographic fringes are clearly recorded and the detailed shapes and structures of both large and small aluminium fragments are observed after reconstruction. The structure of debris clouds can be divided into three parts: front, core and shell, agreeing well with results measured by laser shadowgraph. The study demonstrates the feasibility of a large-field pulsed DIH system for accurate measurements of ultrafast debris clouds and shows great potential in the diagnostics of hypervelocity impacts.

Solid–liquid phase equilibrium and solubility data for quaternary system of terephthalic acid + isophthalic acid + phthalic acid + N-methyl-2-pyrrolidone at 303.15 K and 313.15 K were determined by Schreinemakers’ method of wet residue under atmosphere pressure. Based on the measured solubility, the quaternary phase diagrams were constructed at the two studied temperatures according to the Janeck method. At each temperature, the quaternary phase diagram includes three crystallization regions of pure solid, three co-saturated curves and one eutectic point. The three pure solids are phthalic acid, adduct of isophthalic acid with N-methyl-2-pyrrolidone (the mole ratio of isophthalic acid to N-methyl-2-pyrrolidone is 1:2), adduct of terephthalic acid with N-methyl-2-pyrrolidone (the mole ratio of terephthalic acid to N-methyl-2-pyrrolidone is 1:2), which are confirmed by the method of Schreinemakers’ wet residue. The crystallization region of adduct of terephthalic acid with N-methyl-2-pyrrolidone is larger than those of phthalic acid and adduct of isophthalic acid with N-methyl-2-pyrrolidone. Furthermore, the quaternary solid–liquid phase equilibrium were predicted by NRTL model. The calculated quaternary phase diagrams agreed well with experimental data.

The isobaric vapor–liquid equilibrium data for binary systems of 1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2) and 3-chloroaniline (1) + 3,5-dichloroaniline (2) were measured experimentally under pressures of 20.00, 60.00 and 101.20 kPa using an inclined ebulliometer. Thermodynamic consistency of the vapor–liquid equilibrium data was tested by means of the Herington semiempirical method, and the isobaric vapor–liquid equilibrium data were correlated with three activity coefficient models, which were Wilson, NRTL and UNIQUAC. The energy interaction parameters were acquired by a nonlinear least-squares regression method for the three thermodynamic models. Results indicate that all the three activity coefficient models can describe the measured isobaric vapor–liquid data acceptably. The isobaric vapor–liquid equilibrium data determined in the present work are important in the design and operation for purification of 3,5-dichloroaniline by distillation.