University of Macau

About: University of Macau is a education organization based out in Macao, Macau, China. It is known for research contribution in the topics: Population & Control theory. The organization has 6636 authors who have published 18324 publications receiving 327384 citations. The organization is also known as: UM & UMAC.

The Effect of Earnings–Announcement Timing on Earnings Management

Abstract: This paper examines whether firms which delay earnings announcements engage in earnings management. The cross–sectional version of the modified Jones 1995 model is used to estimate ‘normal’ accruals. Prior research has documented that, on average, delayed earnings announcements are associated with negative earnings surprises. Our evidence suggests that the market anticipates unfavorable earnings news when it observes reporting delays. As a consequence, late reporters appear to make the most of a bad situation by employing income–decreasing accruals in big–bath–type earnings management and in contractual renegotiations. We find that the magnitude of income–reducing abnormal accruals is related to the reporting lag.

Microstructure of SnO2.

Abstract: The microstructure of ${\mathrm{SnO}}_{2}$, prepared by the sol-gel method, was studied by scanning electron microscopy, transmission electron microscopy, high-resolution electron microscopy, and x-ray diffraction. A nanosponge structure was observed. There is much surface and interface structure. The interfaces vary in type from amorphous to crystalline. The high density of defects greatly influences the physical and chemical properties of this material.

Metal halide perovskites: stability and sensing-ability

Abstract: Metal halide perovskites have been intensively studied over the past years due to their attractive electronic, optical and optoelectronic properties In spite of the phenomenally high solar-conversion efficiency achieved with perovskites, their adverse instability remains the key obstacle restricting their wider applications These ionic crystals can be affected by many factors, such as varied temperatures, humid air, polar solvents, and electron-withdrawing/donating gases However, under certain controlled conditions, changes in perovskite structures/compositions via, for example, phase transitions, hydration/dehydration, gas adsorption/desorption, and ion intercalation/decalation, can all be reversed, suggesting their great potential for sensing applications In this contribution, we first overview recent investigations and mechanistic studies on the stability of metal halide perovskites under various environmental conditions Then, we highlight the recent attempts to apply perovskites for the detection of temperature change, humidity, gases, solvents and ions Finally, we discuss current challenges and future opportunities for developing sensing systems based on metal halide perovskites