On bivariate time-varying price staleness

Price staleness refers to the extent of zero returns in price dynamics. Bandi et al. (2020c) introduce two types of staleness: systematic and idiosyncratic staleness. In this study, we allow price staleness to be time-varying and study the statistical inference for idiosyncratic and common price staleness between two assets. We propose consistent estimators for both time-varying idiosyncratic and systematic price staleness and derive their asymptotic theory. Moreover, we develop a feasible nonparametric test for the simultaneous constancy of idiosyncratic and common price staleness. Our inference is based on infill asymptotics. Finally, we conduct simulation studies under various scenarios to assess the finite sample performance of the proposed approaches and provide an empirical application of the proposed theory.</p

Identification results of selected rock specimens under a polarizing microscope.

Identification results of selected rock specimens under a polarizing microscope.</p

Inductively coupled plasma mass spectrometry (ICP-MS) analysis results of element contents of samples from the KNG.

Inductively coupled plasma mass spectrometry (ICP-MS) analysis results of element contents of samples from the KNG.</p

Photographs of lithological differences and morphologies of rock samples after rock failure.

(a) Cretaceous strata lithology, (b) Triassic strata lithology, and (c) Permian strata lithology. Post-rock failure morphology of (d) the Cretaceous rock sample from Hudiedong Cave, (e) the Triassic rock sample form Mt. Elephant, and (f) the Permian rock sample from Mt. Taitongshan.</p

XRD patterns of rock samples from Hudiedong cave.

Qtz = quartz, Cal = calcite, An = ankerite, and Dol = dolomite. Fig 6 is excluded from this article's CC-BY license. See the accompanying retraction notice for more information.</p

Impacts of rock properties on Danxia landform formation based on lithological experiments at Kongtongshan National Geopark, northwest China

As an erosional landform, the formation processes of Danxia landform are controlled by internal and external forces as well as lithologic properties. Using field data, we studied the role of lithologic properties on the formation of Danxia landform in Kongtongshan National Geopark, northwest China, through a series of experiments, including uniaxial compressive strength, identification analysis under polarizing microscope, X-ray diffraction analysis, inductively coupled plasma-mass spectrometry analysis, and scanning electron microscopy. The results show that the diagenesis degree, mineral composition, cement composition, degree of cementation, geochemical composition and element contents, and micro-structure influenced the structure and anti-weathering and anti-erosion abilities of the Danxia rock mass. Differential weathering of rock in different environments was an important force shaping the different types of Danxia landform. Weathering failure of the Danxia rock mass was the result of multiple combined factors; as well as lithology, other factors, such as those induced during tectonic uplift (i.e., faulting, jointing, and fracturing) and climate, cannot be neglected. Therefore, lithology played an important role in the structural development of Danxia landform, and different lithologies influenced its weathering rate and formation processes. Our findings can provide a reference for revealing the microscopic development of Danxia landform in arid and semi-arid areas.</div

Photographs of main laboratory equipment.

(a) The YAW-42061 microcomputer controlled electro-hydraulic servo pressure testing machine. (b) Polarizing microscope (BX51-P). (c) Inductively coupled plasma mass spectrometer (iCAP Qc). (d) PANalytical Empyrean X-ray Diffractometer. (e) Philips Quanta 400 FE Environment Scanning Electron Microscope.</p

Location of Kongtongshan National Geopark in China.

Location of Kongtongshan National Geopark in China.</p

Sketch of the stress field distribution around the pillar in Hudiedong Cave (denser red lines indicate a higher stress magnitude).

Sketch of the stress field distribution around the pillar in Hudiedong Cave (denser red lines indicate a higher stress magnitude).</p

Geomorphic features of Danxia landform in the KNG.

(a) Candle Peak, (b) Mt. Elephant, (c) an unconformable contact at Wendaogong, (d) caverns at Yanzhixia, (e) V-shaped valley at Yehu bridge, (f) narrow gorge (A Thread of Sky), (g) vertical joints at Five-finger Peak, (h) escarpment at Nantai, and (i) colluvial rock block in Yanzhi River (Erlang stone). Fig 4C and 4D panels are excluded from this article's CC-BY license. See the accompanying retraction notice for more information.</p