The calculated results of the overall safety factors of the arch dam by the strength reserve method,the water-level overcharge method,and the water specific gravity overcharge method are 3.0-3.5,1.5-1.6,and 2.0-2.3,respectively.
Fuzzy comprehensive evaluation method was used to calculate the safety degrees corresponding to management and to the human-machine-environment system composed of flight,support and maintenance subsystems.
A group of scientists conducted a comprehensive investigation on ecological safety and water and soil erosion in the Northwest Loess Plateau, Northwest China.
Therefore, the extension scale of converting cropland to forest could be enlarged properly in the reservoir area, while it should be limited in the non-reservoir area due to the issues of higher population density and food safety.
Ericerus pela Chavannes, the insect producing white wax,belongs to Coccidae,Homoptera. The female adult lays eggs while the male larva produces wax, whichis a well-known product from Southwest China. The wax secreted by the malelarvae may be boiled and extracted to result in something known as white wax.Its boiling point reaches above 82-83℃. It has manifold uses. Before WorldWar Ⅱ, besides the consumption at home, th greater part of this product wasexported abroad. The supply of the female adults of this w...
In this paper the conditions for the application of thioacetamide in inorganic qualitative analysis are investigated, such as the sensitivity of formation of bismuth sulfide, its hydrolysis in aqueous solution and factors affecting its reaction in acid solution. Thioacetamide is proved to be a satisfactory substitute for H_2S in the analytical laboratory, owing to its simplicity in manipulation, safety, odourlessness and economy. In addition, its sulfide precipitates are easy to filter or centrifuge.
The present paper attempts to review the current state of the problem of structural safety by means of the probability and statistical approach, based on the important papers published in Russia, America, and other European countries. At the end of the paper some possible directions of further developments needed in our country are mentioned.