Steel jacket-type platforms are the common kind of the offshore structures and health monitoring is an important issue in their safety assessment. In the present study, a new damage detection method is adopted for thi...Steel jacket-type platforms are the common kind of the offshore structures and health monitoring is an important issue in their safety assessment. In the present study, a new damage detection method is adopted for this kind of structures and inspected experimentally by use of a laboratory model. The method is investigated for developing the robust damage detection technique which is less sensitive to both measurement and analytical model uncertainties. For this purpose, incorporation of the artificial immune system with weighted attributes （AISWA） method into finite element （FE） model updating is proposed and compared with other methods for exploring its effectiveness in damage identification. Based on mimicking immune recognition, noise simulation and attributes weighting, the method offers important advantages and has high success rates. Therefore, it is proposed as a suitable method for the detection of the failures in the large civil engineering structures with complicated structural geometry, such as the considered case study.展开更多
The aldol reaction of the silyl enol ether of cyclopent-2-enone with aldehydes is mediated by various Lewis acids.Threo isomers are the major diastereoisomers formed in most cases.A reverse diastereoselectivity was ob...The aldol reaction of the silyl enol ether of cyclopent-2-enone with aldehydes is mediated by various Lewis acids.Threo isomers are the major diastereoisomers formed in most cases.A reverse diastereoselectivity was observed when the reaction was mediated by TBAF.The results have been discussed in detail by structure and transition state analysis.展开更多
文摘Steel jacket-type platforms are the common kind of the offshore structures and health monitoring is an important issue in their safety assessment. In the present study, a new damage detection method is adopted for this kind of structures and inspected experimentally by use of a laboratory model. The method is investigated for developing the robust damage detection technique which is less sensitive to both measurement and analytical model uncertainties. For this purpose, incorporation of the artificial immune system with weighted attributes （AISWA） method into finite element （FE） model updating is proposed and compared with other methods for exploring its effectiveness in damage identification. Based on mimicking immune recognition, noise simulation and attributes weighting, the method offers important advantages and has high success rates. Therefore, it is proposed as a suitable method for the detection of the failures in the large civil engineering structures with complicated structural geometry, such as the considered case study.
文摘The aldol reaction of the silyl enol ether of cyclopent-2-enone with aldehydes is mediated by various Lewis acids.Threo isomers are the major diastereoisomers formed in most cases.A reverse diastereoselectivity was observed when the reaction was mediated by TBAF.The results have been discussed in detail by structure and transition state analysis.
