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Tomography of the dynamic stress coefficient for stress wave prediction in sedimentary rock layer under the mining additional stress 被引量:7
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作者 Wenlong Shen Guocang Shi +3 位作者 Yungang Wang Jianbiao Bai Ruifeng Zhang Xiangyu Wang 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2021年第4期653-663,共11页
In this study,the tomography of dynamic stress coefficient(TDSC)was established based on a mechanical model of stress wave propagation in bedding planes and a mathematical model of the stress wave attenuation in rock ... In this study,the tomography of dynamic stress coefficient(TDSC)was established based on a mechanical model of stress wave propagation in bedding planes and a mathematical model of the stress wave attenuation in rock masses.The reliability of the TDSC was verified by a linear bedding plane model and field monitoring.Generally,the TDSC in the dynamic stress propagation of bedding planes increases with the following conditions:(1)the increase of the normal stiffness of the bedding plane,(2)the increase of the incident angle of the stress wave,(3)the decrease of the incident frequency of the stress wave,or(4)the growth of three ratios(the ratios of rock densities,elastic moduli,and the Poisson’s ratios)of rocks on either side of bedding planes.The additional stress weakens TDSC linearly and slowly during the stress wave propagation in bedding planes,and the weakening effect increases with the growth of the three ratios.Besides,the TDSC decreases exponentially in the rock mass as propagation distance increases.In a field case,the TDSC decreases significantly as vertical and horizontal distances increase and its wave range increases as vertical distance increases in the sedimentary rock layers. 展开更多
关键词 Tomography of the dynamic stress COEFFICIENT stress wave attenuation Mining additional stress Sedimentary rock layer
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Attenuation of endoplasmic reticulum stress as a treatment strategy against ischemia/reperfusion injury 被引量:5
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作者 Chih-Li Lin 《Neural Regeneration Research》 SCIE CAS CSCD 2015年第12期1930-1931,共2页
Brain ischemic stroke is the leading cause of long-lasting injury,disability,and death in adults.Although the brain represents only about 2%of the total body mass,it consumes almost 20%of the body's oxygen.As a resul... Brain ischemic stroke is the leading cause of long-lasting injury,disability,and death in adults.Although the brain represents only about 2%of the total body mass,it consumes almost 20%of the body's oxygen.As a result,brain cells are extremely sensitive to hypoxia.Once cerebral ischemia occurs. 展开更多
关键词 Attenuation of endoplasmic reticulum stress as a treatment strategy against ischemia/reperfusion injury AKT ER UPR
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Research on the Dynamic Compressibility of Polyurethane Microcellular Elastomer and its Application for Impact Resistance
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作者 Zhi-Ying Zhao Hao Jiang +3 位作者 Xiao-Dong Li Xu-Dong Zhang Xing Su Mei-Shuai Zou 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2024年第8期1185-1197,共13页
The packaging materials with cushioning performance are used to prevent the internal contents from being damaged by the impact and vibration of external forces.The polyurethane microcellular elastomers(PUMEs)can absor... The packaging materials with cushioning performance are used to prevent the internal contents from being damaged by the impact and vibration of external forces.The polyurethane microcellular elastomers(PUMEs)can absorb energy through cell collapse and molecular chain creep.In this study,PUMEs with different densities were investigated by scanning electron microscopy,dynamic mechanical analysis and dynamic compression tests.PUMEs exhibited significant im pact resistance and the maximum peak stress attenuation ratio reached 73.33%.The protective equipment was made by PUME with the optimal density of 600 kg/m^(3),and then the acceleration sensing device installed with the same protective equipment fell from a height of 3,5 and 10 m to evaluate the energy-absorbing property and reusability of PUMEs.The results showed that PUMEs equipment reduced the peak acceleration of the device by 93.84%,with a maximum deviation of 9%between actual test and simulation,and shortened the impact time of first landing by 57.39%.In addition,the equipment PUMEs equipment could effectively reduce the stress on the protected items. 展开更多
关键词 Polyurethane microcellular elastomer Impact velocity stress attenuation ratio Impact resistance
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Blast damage zone strength reduction method for deep cavern excavation and its application
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作者 Tianzhi YAO Zuguo MO +5 位作者 Li QIAN Yunpeng GAO Jianhai ZHANG Xianglin XING Enlong LIU Ru ZHANG 《Frontiers of Structural and Civil Engineering》 SCIE EI CSCD 2024年第2期236-251,共16页
The drill and blast(D&B)method is widely used to excavate underground spaces,but explosions generally cause damage to the rock.Still,no blast simulation method can provide computational accuracy and efficiency.In ... The drill and blast(D&B)method is widely used to excavate underground spaces,but explosions generally cause damage to the rock.Still,no blast simulation method can provide computational accuracy and efficiency.In this paper,a blast equivalent simulation method called the blast damage zone strength reduction(BDZSR)method is proposed.This method first calculates the range of the blast-induced damage zone(BDZ)by formulae,then reduces the strength and deformation parameters of the rock within the BDZ ahead of excavation,and finally calculates the excavation damage zone(EDZ)for the D&B method by numerical simulation.This method combines stress wave attenuation,rock damage criteria and stress path variation to derive the BDZ depth calculation formulae.The formulae consider the initial geo-stress,and the reliability is verified by numerical simulations.The calculation of BDZ depth with these formulae allows the corresponding numerical simulation to avoid the time-consuming dynamic calculation process,thus greatly enhancing the calculation efficiency.The method was applied to the excavation in Jinping Class II hydropower station to verify its feasibility.The results show that the BDZSR method can be applied to blast simulation of underground caverns and provide a new way to study blast-induced damage. 展开更多
关键词 attenuation of stress wave deep-buried underground building drill and blast in situ stress
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