To analyze and predict the mechanical behaviors of deep hard rocks,some key issues concerning rock fracturing mechanics for deep hard rock excavations are discussed.First,a series of apparatuses and methods have been ...To analyze and predict the mechanical behaviors of deep hard rocks,some key issues concerning rock fracturing mechanics for deep hard rock excavations are discussed.First,a series of apparatuses and methods have been developed to test the mechanical properties and fracturing behaviors of hard rocks under high true triaxial stress paths.Evolution mechanisms of stress-induced disasters in deep hard rock excavations,such as spalling,deep cracking,massive roof collapse,large deformation and rockbursts,have been recognized.The analytical theory for the fracturing process of hard rock masses,including the three-dimensional failure criterion,stress-induced mechanical model,fracturing degree index,energy release index and numerical method,has been established.The cracking-restraint method is developed for mitigating or controlling rock spalling,deep cracking and massive collapse of deep hard rocks.An energy-controlled method is also proposed for the prevention of rockbursts.Finally,two typical cases are used to illustrate the application of the proposed methodology in the Baihetan caverns and Bayu tunnels of China.展开更多
The objective of the study is the cytocidal and inhibitory effect of energy-controllable pulse on ovarian cancer cell line SKOV3. Ovarian cancer cell suspension were treated by electric pulse with different parameters...The objective of the study is the cytocidal and inhibitory effect of energy-controllable pulse on ovarian cancer cell line SKOV3. Ovarian cancer cell suspension were treated by electric pulse with different parameters. The inhibitory rate (IR) was assayed by modified colorimetric MTT methods, the growth curves of two test groups and one control group were also measured, and the ultrastructural changes were observed under electron microscopy (EM) and scan electron microscopy (SEM). It was found that the treated SKOV3 cell proliferated more slowly. IR was increased with the enhancement of pulse parameters. The ultrastructural study showed that morphological changes occurred obviously. Swollen mitochondria, fractured ridges, cyto-plasmic vacuoles and membrane holes appeared in most of the processed cells, and a part of bilayer membrane was ruptured. It is indicated that irreversible electric breakdown occurred in some of the treated cells, and the electric pulse could kill cancer cell and inhibit its recovery and growth.展开更多
基金financial support from the National Natural Science Foundation of China(Grant Nos.51839003 and 41827806)Liaoning Revitalization Talents Program of China(Grant No.XLYCYSZX1902)。
文摘To analyze and predict the mechanical behaviors of deep hard rocks,some key issues concerning rock fracturing mechanics for deep hard rock excavations are discussed.First,a series of apparatuses and methods have been developed to test the mechanical properties and fracturing behaviors of hard rocks under high true triaxial stress paths.Evolution mechanisms of stress-induced disasters in deep hard rock excavations,such as spalling,deep cracking,massive roof collapse,large deformation and rockbursts,have been recognized.The analytical theory for the fracturing process of hard rock masses,including the three-dimensional failure criterion,stress-induced mechanical model,fracturing degree index,energy release index and numerical method,has been established.The cracking-restraint method is developed for mitigating or controlling rock spalling,deep cracking and massive collapse of deep hard rocks.An energy-controlled method is also proposed for the prevention of rockbursts.Finally,two typical cases are used to illustrate the application of the proposed methodology in the Baihetan caverns and Bayu tunnels of China.
文摘The objective of the study is the cytocidal and inhibitory effect of energy-controllable pulse on ovarian cancer cell line SKOV3. Ovarian cancer cell suspension were treated by electric pulse with different parameters. The inhibitory rate (IR) was assayed by modified colorimetric MTT methods, the growth curves of two test groups and one control group were also measured, and the ultrastructural changes were observed under electron microscopy (EM) and scan electron microscopy (SEM). It was found that the treated SKOV3 cell proliferated more slowly. IR was increased with the enhancement of pulse parameters. The ultrastructural study showed that morphological changes occurred obviously. Swollen mitochondria, fractured ridges, cyto-plasmic vacuoles and membrane holes appeared in most of the processed cells, and a part of bilayer membrane was ruptured. It is indicated that irreversible electric breakdown occurred in some of the treated cells, and the electric pulse could kill cancer cell and inhibit its recovery and growth.
