Based on the upper bound theorem of limit analysis,the factor of safety for shallow tunnel in saturated soil is calculated in conjunction with the strength reduction technique.To analyze the influence of the pore pres...Based on the upper bound theorem of limit analysis,the factor of safety for shallow tunnel in saturated soil is calculated in conjunction with the strength reduction technique.To analyze the influence of the pore pressure on the factor of safety for shallow tunnel,the power of pore pressure is regarded as a power of external force in the energy calculation.Using the rigid multiple-block failure mechanism,the objective function for the factor of safety is constructed and the optimal solutions are derived by employing the sequential quadratic programming.According to the results of optimization calculation,the factor of safety of shallow tunnel for different pore pressure coefficients and variational groundwater tables are obtained.The parameter analysis shows that the pore pressure coefficient and the location of the groundwater table have significant influence on the factor of safety for shallow tunnel.展开更多
To study the quasispecies diversity of porcine reproductive and respiratory syndrome virus (PRRSV), open reading frame 5 (ORF5) of strain SD0612 was amplified and cloned. Sixty clones of ORF5 were sequenced and analyz...To study the quasispecies diversity of porcine reproductive and respiratory syndrome virus (PRRSV), open reading frame 5 (ORF5) of strain SD0612 was amplified and cloned. Sixty clones of ORF5 were sequenced and analyzed with DNAStar software. Nucleic acid sequence homology was 97.7%-100%, with 78 mutations observed. Among these 60 clones, the sequences of 17 clones were identical and recognized as the dominant quasispecies of strain SD0612. Evolution of SD0612 quasispecies diversity under antibody selective pressure was also studied. SD0612 was passed continuously in the Marc-145 cell line over 40 passages in 6 independent lineages. SD0612 antiserum was not added to lineage A, B, and C cultures; however, antiserum was added to culture medium for lineages D, E, and F. PRRSV ORF5 was then amplified, cloned, and sequenced from each of the 6 lineages, designated as A40-F40. F40 was further passed in Marc-145 cells using 6 independent lineages with or without F40 antiserum for another 40 passages. ORF5 from the 6 newly-derived virus lineages, which we designated as a40-f40, were amplified, cloned and sequenced. The proportion of dominant quasispecies increased with passage number in cell cultures supplemented with antibodies, but decreased when antibodies were lacking. Our work has demonstrated a diversity of quasispecies for ORF5 in PRRSV SD0612. Antibody selective pressure was able to significantly influence quasispecies diversity and promote a dominant quasispecies that was able to evade immune reactions.展开更多
The furnace process is very important in boiler operation,and furnace pressure works as an important parameter in furnace process.Therefore,there is a need to analyze and monitor the pressure signal in furnace.However...The furnace process is very important in boiler operation,and furnace pressure works as an important parameter in furnace process.Therefore,there is a need to analyze and monitor the pressure signal in furnace.However,little work has been conducted on the relationship with the pressure sequence and boiler’s load under different working conditions.Since pressure sequence contains complex information,it demands feature extraction methods from multi-aspect consideration.In this paper,fuzzy c-means analysis method based on weighted validity index(VFCM)has been proposed for the working condition classification based on feature extraction.To deal with the fluctuating and time-varying pressure sequence,feature extraction is taken as nonlinear analysis based on entropy theory.Three kinds of entropy values,extracted from pressure sequence in time-frequency domain,are studied as the clustering objects for work condition classification.Weighted validity index,taking the close and separation degree into consideration,is calculated on the base of Silhouette index and Krzanowski-Lai index to obtain the optimal clustering number.Each time FCM runs,the weighted validity index evaluates the clustering result and the optimal clustering number will be obtained when it reaches the maximum value.Four datasets from UCI Machine Learning Repository are presented to certify the effectiveness in VFCM.Pressure sequences got from a 300 MW boiler are then taken for case study.The result of the pressure sequence case study with an error rate of 0.5332%shows the valuable information on boiler’s load and pressure sequence in furnace.The relationship between boiler’s load and entropy values extracted from pressure sequence is proposed.Moreover,the method can be considered to be a reference method for data mining in other fluctuating and time-varying sequences.展开更多
基金Project(51178468) supported by the National Natural Science Foundation of ChinaProject(2010bsxt07) supported by the Doctoral Dissertation Innovation Fund of Central South University,China
文摘Based on the upper bound theorem of limit analysis,the factor of safety for shallow tunnel in saturated soil is calculated in conjunction with the strength reduction technique.To analyze the influence of the pore pressure on the factor of safety for shallow tunnel,the power of pore pressure is regarded as a power of external force in the energy calculation.Using the rigid multiple-block failure mechanism,the objective function for the factor of safety is constructed and the optimal solutions are derived by employing the sequential quadratic programming.According to the results of optimization calculation,the factor of safety of shallow tunnel for different pore pressure coefficients and variational groundwater tables are obtained.The parameter analysis shows that the pore pressure coefficient and the location of the groundwater table have significant influence on the factor of safety for shallow tunnel.
文摘To study the quasispecies diversity of porcine reproductive and respiratory syndrome virus (PRRSV), open reading frame 5 (ORF5) of strain SD0612 was amplified and cloned. Sixty clones of ORF5 were sequenced and analyzed with DNAStar software. Nucleic acid sequence homology was 97.7%-100%, with 78 mutations observed. Among these 60 clones, the sequences of 17 clones were identical and recognized as the dominant quasispecies of strain SD0612. Evolution of SD0612 quasispecies diversity under antibody selective pressure was also studied. SD0612 was passed continuously in the Marc-145 cell line over 40 passages in 6 independent lineages. SD0612 antiserum was not added to lineage A, B, and C cultures; however, antiserum was added to culture medium for lineages D, E, and F. PRRSV ORF5 was then amplified, cloned, and sequenced from each of the 6 lineages, designated as A40-F40. F40 was further passed in Marc-145 cells using 6 independent lineages with or without F40 antiserum for another 40 passages. ORF5 from the 6 newly-derived virus lineages, which we designated as a40-f40, were amplified, cloned and sequenced. The proportion of dominant quasispecies increased with passage number in cell cultures supplemented with antibodies, but decreased when antibodies were lacking. Our work has demonstrated a diversity of quasispecies for ORF5 in PRRSV SD0612. Antibody selective pressure was able to significantly influence quasispecies diversity and promote a dominant quasispecies that was able to evade immune reactions.
基金supported by the National Natural Science Foundation of China(Grant No.51176030)Jiangsu Science and Technology Department(Grant No.BY2015070-17)
文摘The furnace process is very important in boiler operation,and furnace pressure works as an important parameter in furnace process.Therefore,there is a need to analyze and monitor the pressure signal in furnace.However,little work has been conducted on the relationship with the pressure sequence and boiler’s load under different working conditions.Since pressure sequence contains complex information,it demands feature extraction methods from multi-aspect consideration.In this paper,fuzzy c-means analysis method based on weighted validity index(VFCM)has been proposed for the working condition classification based on feature extraction.To deal with the fluctuating and time-varying pressure sequence,feature extraction is taken as nonlinear analysis based on entropy theory.Three kinds of entropy values,extracted from pressure sequence in time-frequency domain,are studied as the clustering objects for work condition classification.Weighted validity index,taking the close and separation degree into consideration,is calculated on the base of Silhouette index and Krzanowski-Lai index to obtain the optimal clustering number.Each time FCM runs,the weighted validity index evaluates the clustering result and the optimal clustering number will be obtained when it reaches the maximum value.Four datasets from UCI Machine Learning Repository are presented to certify the effectiveness in VFCM.Pressure sequences got from a 300 MW boiler are then taken for case study.The result of the pressure sequence case study with an error rate of 0.5332%shows the valuable information on boiler’s load and pressure sequence in furnace.The relationship between boiler’s load and entropy values extracted from pressure sequence is proposed.Moreover,the method can be considered to be a reference method for data mining in other fluctuating and time-varying sequences.
