In order to realize simultaneous quantitative detection of various enteroviruses from water samples, a real-time reverse transcriptionpolymerase chain reaction （real-time RT-PCR） method was developed with universal ...In order to realize simultaneous quantitative detection of various enteroviruses from water samples, a real-time reverse transcriptionpolymerase chain reaction （real-time RT-PCR） method was developed with universal primer pairs designed based on the highly conserved non-coding region sequences of genome targeting poliovirus, coxsackievirus and enterovirus 71. The recombinant plasmid was constructed as enterovirus DNA standard by cloning poliovirus cDNA into a pMD18-T vector. The real-time RT-PCR method utilizing SYBR Green I was optimized. As a result of a series of examinations, the detection limit of the method was found to be 2.31 genome equivalent copy （GEC）/μL, the intraand inter-assay variations were lower than 2% and 5%, respectively, and enteroviruses were well distinguished from other microorganisms. There was a good linear relationship （r 2 = 0.997） between the logarithm of viral density and cycle threshold in a wide range of 2.31 × 10 0 to 2.31 × 10 9 GEC/μL. The validity of the method was further proved by its application for the detection of enteroviruses from various practical water samples.展开更多
Steel shear wall(SSW) was properly determined using numerical and experimental approaches.The properties of SSW and LYP(low yield point) steel shear wall(LSSW) were measured.It is revealed that LSSW exhibits higher pr...Steel shear wall(SSW) was properly determined using numerical and experimental approaches.The properties of SSW and LYP(low yield point) steel shear wall(LSSW) were measured.It is revealed that LSSW exhibits higher properties compared to SSW in both elastic and inelastic zones.It is also concluded that the addition of CFRP(carbon fiber reinforced polymers) enhances the seismic parameters of LSSW(stiffness,energy absorption,shear capacity,over strength values).Also,stress values applied to boundary frames are lower due to post buckling forces.The effect of fiber angle was also studied and presented as a mathematical equation.展开更多
This paper aimed to examine the site dependence and evaluate the methods for site analysis of far-source ground motions. This was achieved through the examination of frequency content estimated by different methods ba...This paper aimed to examine the site dependence and evaluate the methods for site analysis of far-source ground motions. This was achieved through the examination of frequency content estimated by different methods based on strong ground motions recorded at twelve far-source stations in Shandong province during the Wenchuan earthquake. The stations were located in sites with soil profiles ranging from code classes Ⅰ to Ⅲ. Approaches used included the Fourier amplitude spectrum （FAS）, the earthquake response spectrum （ERS）, the spectral ratio between the horizontal and the vertical components （H/V）, the spectral ratio between the spectra at the site and at a reference site （SRRS）, and coda wave analysis （CWA）. Results showed that major periods of these ground motions obtained by FAS, ERS and H/V ratio methods were all evidently larger than site dominant periods; the periods were also different from each other and mainly reflected the frequency content of long period components. Prominent periods obtained by the SRRS approach neither illuminated the long period aspect nor efficiently determined site features of the motions. The CWA resulted in a period close to site period for stations with good quality recordings. The results obtained in this study will be useful for the evaluation of far-source effect in constructing seismic design spectra and in selecting methods for ground motion site analysis.展开更多
This study proposes an approach that considers mitigation strategies in predicting landslide susceptibility through machine learning(ML)and geographic information system(GIS)techniques.ML models,such as random forest(...This study proposes an approach that considers mitigation strategies in predicting landslide susceptibility through machine learning(ML)and geographic information system(GIS)techniques.ML models,such as random forest(RF),logistic regression(LR),and support vector classification(SVC)are incorporated into GIS to predict landslide susceptibilities in Hong Kong.To consider the effect of mitigation strategies on landslide susceptibility,non-landslide samples were produced in the upgraded area and added to randomly created samples to serve as ML models in training datasets.Two scenarios were created to compare and demonstrate the efficiency of the proposed approach;Scenario I does not considering landslide control while Scenario II considers mitigation strategies for landslide control.The largest landslide susceptibilities are 0.967(from RF),followed by 0.936(from LR)and 0.902(from SVC)in Scenario II;in Scenario I,they are 0.986(from RF),0.955(from LR)and 0.947(from SVC).This proves that the ML models considering mitigation strategies can decrease the current landslide susceptibilities.The comparison between the different ML models shows that RF performed better than LR and SVC,and provides the best prediction of the spatial distribution of landslide susceptibilities.展开更多
基金supported by the National Natural Sci-ence Foundation of China (No. 50908185)the National Program of Water Pollution Control (No. 2008ZX07317-004)+2 种基金the Basic Research Foundation of Xi’an University of Architecture and Technology (No. JC0910)the Research Foundation for Talented Scholars of Xi’an University of Architecture and Technology (No. RC0824)the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT0853)
文摘In order to realize simultaneous quantitative detection of various enteroviruses from water samples, a real-time reverse transcriptionpolymerase chain reaction （real-time RT-PCR） method was developed with universal primer pairs designed based on the highly conserved non-coding region sequences of genome targeting poliovirus, coxsackievirus and enterovirus 71. The recombinant plasmid was constructed as enterovirus DNA standard by cloning poliovirus cDNA into a pMD18-T vector. The real-time RT-PCR method utilizing SYBR Green I was optimized. As a result of a series of examinations, the detection limit of the method was found to be 2.31 genome equivalent copy （GEC）/μL, the intraand inter-assay variations were lower than 2% and 5%, respectively, and enteroviruses were well distinguished from other microorganisms. There was a good linear relationship （r 2 = 0.997） between the logarithm of viral density and cycle threshold in a wide range of 2.31 × 10 0 to 2.31 × 10 9 GEC/μL. The validity of the method was further proved by its application for the detection of enteroviruses from various practical water samples.
文摘Steel shear wall(SSW) was properly determined using numerical and experimental approaches.The properties of SSW and LYP(low yield point) steel shear wall(LSSW) were measured.It is revealed that LSSW exhibits higher properties compared to SSW in both elastic and inelastic zones.It is also concluded that the addition of CFRP(carbon fiber reinforced polymers) enhances the seismic parameters of LSSW(stiffness,energy absorption,shear capacity,over strength values).Also,stress values applied to boundary frames are lower due to post buckling forces.The effect of fiber angle was also studied and presented as a mathematical equation.
基金funded by National Natural Science Foundation of China (50808168)Ministry of Science and Technology of Weihai (2008087)Foundation of Harbin Institute of Technology at Weihai (HIT(Y)200801)
文摘This paper aimed to examine the site dependence and evaluate the methods for site analysis of far-source ground motions. This was achieved through the examination of frequency content estimated by different methods based on strong ground motions recorded at twelve far-source stations in Shandong province during the Wenchuan earthquake. The stations were located in sites with soil profiles ranging from code classes Ⅰ to Ⅲ. Approaches used included the Fourier amplitude spectrum （FAS）, the earthquake response spectrum （ERS）, the spectral ratio between the horizontal and the vertical components （H/V）, the spectral ratio between the spectra at the site and at a reference site （SRRS）, and coda wave analysis （CWA）. Results showed that major periods of these ground motions obtained by FAS, ERS and H/V ratio methods were all evidently larger than site dominant periods; the periods were also different from each other and mainly reflected the frequency content of long period components. Prominent periods obtained by the SRRS approach neither illuminated the long period aspect nor efficiently determined site features of the motions. The CWA resulted in a period close to site period for stations with good quality recordings. The results obtained in this study will be useful for the evaluation of far-source effect in constructing seismic design spectra and in selecting methods for ground motion site analysis.
基金funding by the National Natural Science Foundation of China(Grant No.42007416)the Hong Kong Polytechnic University Strategic Importance Fund(ZE2T)and Project of Research Institute of Land and Space(CD78).
文摘This study proposes an approach that considers mitigation strategies in predicting landslide susceptibility through machine learning(ML)and geographic information system(GIS)techniques.ML models,such as random forest(RF),logistic regression(LR),and support vector classification(SVC)are incorporated into GIS to predict landslide susceptibilities in Hong Kong.To consider the effect of mitigation strategies on landslide susceptibility,non-landslide samples were produced in the upgraded area and added to randomly created samples to serve as ML models in training datasets.Two scenarios were created to compare and demonstrate the efficiency of the proposed approach;Scenario I does not considering landslide control while Scenario II considers mitigation strategies for landslide control.The largest landslide susceptibilities are 0.967(from RF),followed by 0.936(from LR)and 0.902(from SVC)in Scenario II;in Scenario I,they are 0.986(from RF),0.955(from LR)and 0.947(from SVC).This proves that the ML models considering mitigation strategies can decrease the current landslide susceptibilities.The comparison between the different ML models shows that RF performed better than LR and SVC,and provides the best prediction of the spatial distribution of landslide susceptibilities.
