This paper outlines the results obtained from real time microseismic monitoring of an opencast coal mine in South India.The objective of the study is to investigate the stress changes within the rockmass along the slo...This paper outlines the results obtained from real time microseismic monitoring of an opencast coal mine in South India.The objective of the study is to investigate the stress changes within the rockmass along the slope due to underground mine development operation and their impact on the stability of the highwall slope.The installed microseismic systems recorded the seismic triggerings down toà2 moment magnitude.In general,most of the events recorded during the monitoring period are weak in seismic energy.The study adopts a simple and more reliable tool to characterize the seismically active zone for assessing the stability of the highwall in real time.The impact of underground working on the slope is studied on the basis of the seismic event impact contours and seismic clusters.During the monitoring period,it is observed that the intensity of the overall microseismic activity along the slope due to the mine development operations did not cause any adverse impact on the highwall stability.展开更多
Classification systems such as Slope Mass Rating(SMR) are currently being used to undertake slope stability analysis. In SMR classification system, data is allocated to certain classes based on linguistic and experien...Classification systems such as Slope Mass Rating(SMR) are currently being used to undertake slope stability analysis. In SMR classification system, data is allocated to certain classes based on linguistic and experience-based criteria. In order to eliminate linguistic criteria resulted from experience-based judgments and account for uncertainties in determining class boundaries developed by SMR system,the system classification results were corrected using two clustering algorithms, namely K-means and fuzzy c-means(FCM), for the ratings obtained via continuous and discrete functions. By applying clustering algorithms in SMR classification system, no in-advance experience-based judgment was made on the number of extracted classes in this system, and it was only after all steps of the clustering algorithms were accomplished that new classification scheme was proposed for SMR system under different failure modes based on the ratings obtained via continuous and discrete functions. The results of this study showed that, engineers can achieve more reliable and objective evaluations over slope stability by using SMR system based on the ratings calculated via continuous and discrete functions.展开更多
The comparative study of charge effect on the size-dependence stabilities of gold clusters Aun^z (n = 2-12, z = 0/±1) in gas phase is performed at the M06-L/Lanl2dz level. The lowest-energy structures charged b...The comparative study of charge effect on the size-dependence stabilities of gold clusters Aun^z (n = 2-12, z = 0/±1) in gas phase is performed at the M06-L/Lanl2dz level. The lowest-energy structures charged by -1, 0 and +1 are optimized. The result shows that the geo- metries of the clusters with over 7 atoms tend to be cake-like. From the two- to three-dimensional geometries, the oscillatory behaviors are exhibited in the structural and electronic properties with the most pronounced in energy gap. The amplitude for the positive clusters is bigger than both the neutral and negative clusters. The neutral clusters with even number of even-coordinated atoms are more stable than the neighbors with odd number of even-coordinated atoms, as is completely reversed for the charged clusters. The oscillatory behaviors for the charged clusters are opposite to that for the neutral clusters, as is attributed to the electron-paired effect.展开更多
Based on the density functional theory with generalized gradient approximation, the stable geometrical structures of one or more CO molecules adsorbed on the Al6Si cluster are investigated and the corresponding adsorp...Based on the density functional theory with generalized gradient approximation, the stable geometrical structures of one or more CO molecules adsorbed on the Al6Si cluster are investigated and the corresponding adsorption energies are also calculated. It is found that the cluster Al6Si can adsorb six CO molecules. The thermal stability of the(CO)6@Al6Si complexes is examined using the atom centered density matrix propagation molecular dynamics calculations at 373 K. The results show that two isomers of Al6Si cluster can solidly adsorb six CO molecules, and the other isomer adsorbs four ones. Therefore, the Al6Si cluster is a promising candidate for eliminating CO effectively.展开更多
基金the S&T project ‘‘High resolution microseismic monitoring for early detection and analysis of slope failure in opencast mines’’ funded by inistry of Coal,Government of IndiaThe Singareni Collieries Co Ltd (SCCL),Andhra Pradesh
文摘This paper outlines the results obtained from real time microseismic monitoring of an opencast coal mine in South India.The objective of the study is to investigate the stress changes within the rockmass along the slope due to underground mine development operation and their impact on the stability of the highwall slope.The installed microseismic systems recorded the seismic triggerings down toà2 moment magnitude.In general,most of the events recorded during the monitoring period are weak in seismic energy.The study adopts a simple and more reliable tool to characterize the seismically active zone for assessing the stability of the highwall in real time.The impact of underground working on the slope is studied on the basis of the seismic event impact contours and seismic clusters.During the monitoring period,it is observed that the intensity of the overall microseismic activity along the slope due to the mine development operations did not cause any adverse impact on the highwall stability.
文摘Classification systems such as Slope Mass Rating(SMR) are currently being used to undertake slope stability analysis. In SMR classification system, data is allocated to certain classes based on linguistic and experience-based criteria. In order to eliminate linguistic criteria resulted from experience-based judgments and account for uncertainties in determining class boundaries developed by SMR system,the system classification results were corrected using two clustering algorithms, namely K-means and fuzzy c-means(FCM), for the ratings obtained via continuous and discrete functions. By applying clustering algorithms in SMR classification system, no in-advance experience-based judgment was made on the number of extracted classes in this system, and it was only after all steps of the clustering algorithms were accomplished that new classification scheme was proposed for SMR system under different failure modes based on the ratings obtained via continuous and discrete functions. The results of this study showed that, engineers can achieve more reliable and objective evaluations over slope stability by using SMR system based on the ratings calculated via continuous and discrete functions.
基金supported by the National Natural Science Foundation of China(21063009)the Natural Science Foundation of Inner Mongolia(2012MS0218)+1 种基金the Natural Science Foundation of Inner Mongolia(No.2014BS0206)the Graduate Student Innovation Foundation of Inner Mongulia Normal University(CXJJS13045)
文摘The comparative study of charge effect on the size-dependence stabilities of gold clusters Aun^z (n = 2-12, z = 0/±1) in gas phase is performed at the M06-L/Lanl2dz level. The lowest-energy structures charged by -1, 0 and +1 are optimized. The result shows that the geo- metries of the clusters with over 7 atoms tend to be cake-like. From the two- to three-dimensional geometries, the oscillatory behaviors are exhibited in the structural and electronic properties with the most pronounced in energy gap. The amplitude for the positive clusters is bigger than both the neutral and negative clusters. The neutral clusters with even number of even-coordinated atoms are more stable than the neighbors with odd number of even-coordinated atoms, as is completely reversed for the charged clusters. The oscillatory behaviors for the charged clusters are opposite to that for the neutral clusters, as is attributed to the electron-paired effect.
基金supported by the National Natural Science Foundation of China(Nos.NSFC-11574125 and NSFC-11374132)the Taishan Scholar Project of Shandong Province(ts201511055)
文摘Based on the density functional theory with generalized gradient approximation, the stable geometrical structures of one or more CO molecules adsorbed on the Al6Si cluster are investigated and the corresponding adsorption energies are also calculated. It is found that the cluster Al6Si can adsorb six CO molecules. The thermal stability of the(CO)6@Al6Si complexes is examined using the atom centered density matrix propagation molecular dynamics calculations at 373 K. The results show that two isomers of Al6Si cluster can solidly adsorb six CO molecules, and the other isomer adsorbs four ones. Therefore, the Al6Si cluster is a promising candidate for eliminating CO effectively.