Formation mechanism and characterization of black silicon surface by a single-step wet-chemical process.

We report a simple single-step etching method for formation of black surface on silicon wafer by using HAuCl4-HF-H2O2 etching solution, in which catalytic Au particles were deposited in situ. The black surface suppresses the reflectivity in a wide spectral region. The formation mechanism involved has been discussed.

Metalorganic chemical vapor deposition growth of InAs/GaSb type II superlattices with controllable AsxSb1-x interfaces.

InAs/GaSb type II superlattices were grown on (100) GaSb substrates by metalorganic chemical vapor deposition (MOCVD). A plane of mixed As and Sb atoms connecting the InAs and GaSb layers was introduced to compensate the tensile strain created by the InAs layer in the SL. Characterizations of the samples by atomic force microscopy and high-resolution X-ray diffraction demonstrate flat surface morphology and good crystalline quality.

Improper motorcycle helmet use in provincial areas of a developing country.

Motorcycle helmet wearing rates remain low in smaller cities in developing countries. We therefore examined the knowledge, attitudes, and behavior of motorcyclists towards helmet use in two mid-sized cities in China. The methods included roadside observation and interview.

Motorcycle helmet use in Southern China: an observational study.

Objective: In China, despite national motorcycle helmet legislation and the known safety benefits of helmets, helmet use remains low. The aim of this study was to determine the rate of motorcycle helmet use and attitudes towards helmet use among drivers and passengers in two cities in Southern China to provide baseline data and scientific evidence for the formulation of an intervention aimed at strengthening road safety law enforcement.

Methods: Observational sites were randomly selected from three road types (national roads, main streets, and subordinate streets).