We study the evolution of the temporal properties of MAXIJ1820+070 during the 2018 outburst in its hard state from MJD58,190 to 58,289 with Insight-HXMT in a broad energy band 1-150 keV. We find different behaviors of the hardness ratio, the fractional rms and time lag before and after MJD58,257, suggesting a transition occurred around this point. The observed time lags between the soft photons in the 1-5 keV band and the hard photons in higher energy bands, up to 150 keV, are frequency-dependent: the time lags in the low-frequency range, 2-10mHz, are both soft and hard lags with a timescale of dozens of seconds but without a clear trend along the outburst; the time lags in the high-frequency range, 1-10Hz, are only hard lags with a timescale of tens of milliseconds; they first increase until around MJD58,257 and decrease after this date. The high-frequency time lags are significantly correlated to the photon index derived from the fit to the quasi-simultaneous NICER spectrum in the 1-10 keV band. This result is qualitatively consistent with a model in which the high-frequency time lags are produced by Comptonization in a jet.Unified Astronomy Thesaurus concepts: Black holes (162); Compact objects (288); Low-mass x-ray binary stars (939)

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This work applies a constrained coincidence site lattice/constrained complete pattern shift lattice (CCSL/ CDSCL) model and secondary O-lattice model to simulate the interfacial structure in the major side interface of Mg 17 Al 12 /Mg. The result shows that, at the orientation relationship (OR) with a small deviation (ϳ0.5 deg) from the Burgers OR, the secondary misfit in the interface normal to the parallel ⌬g vectors can be completely accommodated by the steps. The secondary dislocation networks in the habit plane and major side facet have been calculated.

We consider periodic good matching bands (which are centered at the O-lines) as the characteristic feature of the structures in irrational singular interfaces in the primary preferred state. This feature is shared by various structures described by different models for irrational singular interfaces, and it can be used to consolidate different descriptions. We have made a quantitative analysis on the distribution of good matching zones (GMZs) in a relationship with plane matching geometry. This analysis emphasizes that matching of one set of principal planes does not represent good lattice matching. Good lattice matching is possible only at the locations of 0-d intersections, where three sets of nonlinearly related Moiré planes intersect. Matching of one or more sets of principal planes in an interface usually implies the possible presence of periodic GMZs in the interface. The analysis also explains why and in what condition a dislocation configuration can be described by the traces of Moiré planes. The distribution of exact 0-d intersections can be determined based on the O-lattice theory. The approximate 0-d intersections can be used for determining a possible interfacial structure when periodic O-elements do not exist.

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