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We studied the 9th grade science achievements, focusing on Biology, of Lao students in Vientiane capital, Lao People's Democratic Republic (Lao PDR, or Laos). Our survey-using selected questions on Biology from Trends in International Mathematics and Science Study (TIMSS) 2011-was conducted in February 2015 on a total of 388 9th grade students from 3 lower secondary schools (3 districts in Vientiane capital). We analyzed the average correctness of Lao students, and compared them with Japanese and average of all OECD countries. We found that a school with less ideal educational condition in the Outskirts Zone of the Vientiane Capital scored lower points comparing to the Urban schools. Also, it seems that science education in Laos focuses more on Reasoning skills than Knowledge or Application skills.

The H2SO4–H2O2–H2O system, typically a solution with five parts H2SO4, one part H2O2 and one part H2O in volume ratio, is currently used for chemical polishing of a GaAs crystal to obtain microscopically smooth surfaces. However, the etching of the (111)Ga surface in this etchant leads to the formation of etch pits. In this study, the etching behavior of the (111)Ga surface in various compositions of the H2SO4–H2O2–H2O system at temperatures of 0–70°C is mainly re-examined. It is found that a microscopically smooth {111} surface can be obtained by etching in the solutions with 78+x parts H2SO4, two parts H2O2 and 20-x parts H2O (x=0–4) at 70°C. In contrast, dark and light pits are formed on the (111)Ga surface etched in a solution with two parts H2SO4, one part H2O2 and seven parts H2O at 0°C. Their origin is predicted on the basis of double-etching test results.