Notice of RetractionResearch on fuzzy comprehensive assessment for fire safety of regional buildings
The primary mission of fire safety assessment is seeks the change rule of system security, and entrusts with the certain quantity of the concept. Then according to the security condition and the degree of hazard of the system, take the essential measure to achieve the anticipated security goal. According to the characteristic, the origin of the buildings fire, the paper adopted the fire safety assessment method to research the preventing and controlling on buildings fire. The paper briefly introduced the fire safety assessment principle, the theory and the method, and adopted the fuzzy synthesis assessment method as the reasonable method for the fire safety evaluation of buildings. A fire safety assessment index system was founded firstly. Then, the calculation methods for the weight of evaluation indexes and fuzzy calculation were described. Finally, a comprehensive regional buildings fire evaluation and emergency response system was illustrated.
Application of Computational Simulation in Fire Science and Engineering Research
Computational simulation, especially field modeling, is highly developed in recent years. While it has been widely used in many fundamental research and engineering fields, few were applied to aspects of fire science and engineering research. In this paper, the developments and applications of computational simulation for fire dynamics arc firstly reviewed. The basic principles of large eddy simulation are described in detail, which involves turbulence modeling, combustion modeling, and thermal radiation modeling. An example of numerical experimental study of fire dynamics process for oil tank fire with large eddy simulation technology is provided and some fire provisions are approved with respect to the results. 
From the case, it is shown that field modeling has an extensive application future in fire safety science and engineering research. And it will become an effective means in fire management, fire risk evaluation, decision -making and supporting plan for severe disasters and so on.
A quantitative measure of nitrifying bacterial growth.
Nitrifying bacteria convert ammonia (NH3) to nitrate (NO3-) in a nitrification reaction. Methods to quantitatively separate the growth rate of these important bacterial populations from that of the dominant heterotrophic bacteria are important to our understanding of the nitrification process. The changing concentration of ammonia is often used as an indirect measure of nitrification but ammonification processes generate ammonia and confound this approach while heterotrophs remove nitrate via denitrification. Molecular probe methods can tell us what proportion of the microbial community is nitrifying bacteria but not their growth rate. The technique proposed here was able to quantify the growth rate of the nitrifying bacterial populations amidst complex ecological processes. The method incubates [methyl-3H] thymidine with water samples in the presence and absence of an inhibitor of nitrification-thiourea. The radioactively labeled DNA in the growing bacteria was extracted. The rate of incorporation of the label into the dividing bacterial DNA was used to determine bacterial growth rate. Total bacterial community growth rates in full-scale and pilot-scale fixed-film nitrifying reactors and an activated sludge reactor were 2.1 x 10(8), 4.1 x 10(8) and 0.4 x 10(8)cell ml(-1)d(-1), respectively; the growth rate of autotrophic-nitrifying bacteria was 0.7 x 10(8), 2.6 x 10(8) and 0.01 x 10(8)cell ml(-1)d(-1), respectively. Autotrophic-nitrifying bacteria contributed 30% and 60% of the total bacterial community growth rate in the nitrifying reactors whereas only 2% was observed in the activated sludge reactor that was not designed to nitrify. The rates of ammonia loss from the nitrifying reactors corresponded to the rate of growth of the nitrifying bacteria. This method has the potential to more often identify factors that enhance or limit nitrifying processes in both engineered and natural aquatic environments.