Based on global initiatives such as the clean energy transition and the development of renewable energy,the pumped storage power station has become a new and significant way of energy storage and regulation,and its co...Based on global initiatives such as the clean energy transition and the development of renewable energy,the pumped storage power station has become a new and significant way of energy storage and regulation,and its construction environment is more complex than that of a traditional reservoir.In particular,the stability of the rock strata in the underground reservoirs is affected by the seepage pressure and rock stress,which presents some challenges in achieving engineering safety and stability.Using the advantages of the numerical simulation method in dealing deal with nonlinear problems in engineering stability,in this study,the stability of the underground reservoir of the Shidangshan(SDS)pumped storage power station was numerically calculated and quantitatively analyzed based on fluid-structure coupling theory,providing an important reference for the safe operation and management of the underground reservoir.First,using the COMSOL software,a suitablemechanicalmodel was created in accordance with the geological structure and project characteristics of the underground reservoir.Next,the characteristics of the stress field,displacement field,and seepage field after excavation of the underground reservoir were simulated in light of the seepage effect of groundwater on the nearby rock of the underground reservoir.Finally,based on the construction specifications and Molar-Coulomb criterion,a thorough evaluation of the stability of the underground reservoir was performed through simulation of the filling and discharge conditions and anti-seepage strengthening measures.The findings demonstrate that the numerical simulation results have a certain level of reliability and are in accordance with the stress measured in the project area.The underground reservoir excavation resulted in a maximum displacement value of the rock mass around the caverns of 3.56 mm in a typical section,and the safety coefficient of the parts,as determined using the Molar-Coulomb criterion,was higher than 1,indicating that the project as a whole is in a stable state.展开更多
At the China Spallation Neutron Source(CSNS), we have developed a custom gas-filling station, a glassblowing workshop, and a spin-exchange optical pumping(SEOP) system for producing high-quality ^(3)He-based neutron s...At the China Spallation Neutron Source(CSNS), we have developed a custom gas-filling station, a glassblowing workshop, and a spin-exchange optical pumping(SEOP) system for producing high-quality ^(3)He-based neutron spin filter(NSF) cells. The gas-filling station is capable of routinely filling ^(3)He cells made from GE180 glass of various dimensions, to be used as neutron polarizers and analyzers on beamlines at the CSNS. Performance tests on cells fabricated at our gas-filling station are conducted via neutron transmission and nuclear-magneticresonance measurements, revealing nominal filling pressures, and a saturated ~3He polarization in the region of 80%, with a lifetime of approximately 240 hours. These results demonstrate our ability to produce competitive NSF cells to meet the ever-increasing research needs of the polarized neutron research community.展开更多
The poor state of the environment,especially in urban areas,has become a major global issue,with developing countries such as Nigeria voicing growing concern.There is a scarcity of knowledge on the environmental impac...The poor state of the environment,especially in urban areas,has become a major global issue,with developing countries such as Nigeria voicing growing concern.There is a scarcity of knowledge on the environmental impact of PFSs as a result of the loss of life and property,as well as other serious socio-economic implications of non-compliance with PFSs siting criteria.The historical literature on the impact of residential buildings,the environment,and human health on PFSs in Nigeria,as well as the study’s gap,is examined in this research.It also outlines DPR compliance with PFSs location as well as established criteria for prohibiting PFS siting in Nigeria’s states.Relevant publications on PFSs-related topics were downloaded from Google Scholar.The goal of this study is to look back on a previous essay about PFSs in Nigeria and its impacts on the environment and human health.This study’s main purpose is to give a complete overview of Nigerian PFSs.According to the article analyzed,the majority of PFSs were located close to residents,with setbacks from the road and residential areas of less than 30 m in 90%of the filling stations.As a result,the landowners can band together to argue that a facility that is improperly sited cannot be built.A great deal of public participation is required.A campaign should be launched to raise awareness among filling station owners and other developers of the dangers of non-compliance with established norms.All violators of the established norms,as well as corrupt officials of enforcement agencies/bodies,should face open punishment so that others might learn their lessons.Finally,appropriate planning is required to allow future road expansion.展开更多
基金funded by the BeijingNatural Science Foundation of China(8222003)National Natural Science Foundation of China(41807180).
文摘Based on global initiatives such as the clean energy transition and the development of renewable energy,the pumped storage power station has become a new and significant way of energy storage and regulation,and its construction environment is more complex than that of a traditional reservoir.In particular,the stability of the rock strata in the underground reservoirs is affected by the seepage pressure and rock stress,which presents some challenges in achieving engineering safety and stability.Using the advantages of the numerical simulation method in dealing deal with nonlinear problems in engineering stability,in this study,the stability of the underground reservoir of the Shidangshan(SDS)pumped storage power station was numerically calculated and quantitatively analyzed based on fluid-structure coupling theory,providing an important reference for the safe operation and management of the underground reservoir.First,using the COMSOL software,a suitablemechanicalmodel was created in accordance with the geological structure and project characteristics of the underground reservoir.Next,the characteristics of the stress field,displacement field,and seepage field after excavation of the underground reservoir were simulated in light of the seepage effect of groundwater on the nearby rock of the underground reservoir.Finally,based on the construction specifications and Molar-Coulomb criterion,a thorough evaluation of the stability of the underground reservoir was performed through simulation of the filling and discharge conditions and anti-seepage strengthening measures.The findings demonstrate that the numerical simulation results have a certain level of reliability and are in accordance with the stress measured in the project area.The underground reservoir excavation resulted in a maximum displacement value of the rock mass around the caverns of 3.56 mm in a typical section,and the safety coefficient of the parts,as determined using the Molar-Coulomb criterion,was higher than 1,indicating that the project as a whole is in a stable state.
基金Supported by the National Key Research and Development Program of China (Grant No.2020YFA0406000)the Scientific Instrument Development Project of the Chinese Academy of Sciences (Grant No.284(2018))the National Natural Science Foundation of China (Grant No.11875265)。
文摘At the China Spallation Neutron Source(CSNS), we have developed a custom gas-filling station, a glassblowing workshop, and a spin-exchange optical pumping(SEOP) system for producing high-quality ^(3)He-based neutron spin filter(NSF) cells. The gas-filling station is capable of routinely filling ^(3)He cells made from GE180 glass of various dimensions, to be used as neutron polarizers and analyzers on beamlines at the CSNS. Performance tests on cells fabricated at our gas-filling station are conducted via neutron transmission and nuclear-magneticresonance measurements, revealing nominal filling pressures, and a saturated ~3He polarization in the region of 80%, with a lifetime of approximately 240 hours. These results demonstrate our ability to produce competitive NSF cells to meet the ever-increasing research needs of the polarized neutron research community.
文摘The poor state of the environment,especially in urban areas,has become a major global issue,with developing countries such as Nigeria voicing growing concern.There is a scarcity of knowledge on the environmental impact of PFSs as a result of the loss of life and property,as well as other serious socio-economic implications of non-compliance with PFSs siting criteria.The historical literature on the impact of residential buildings,the environment,and human health on PFSs in Nigeria,as well as the study’s gap,is examined in this research.It also outlines DPR compliance with PFSs location as well as established criteria for prohibiting PFS siting in Nigeria’s states.Relevant publications on PFSs-related topics were downloaded from Google Scholar.The goal of this study is to look back on a previous essay about PFSs in Nigeria and its impacts on the environment and human health.This study’s main purpose is to give a complete overview of Nigerian PFSs.According to the article analyzed,the majority of PFSs were located close to residents,with setbacks from the road and residential areas of less than 30 m in 90%of the filling stations.As a result,the landowners can band together to argue that a facility that is improperly sited cannot be built.A great deal of public participation is required.A campaign should be launched to raise awareness among filling station owners and other developers of the dangers of non-compliance with established norms.All violators of the established norms,as well as corrupt officials of enforcement agencies/bodies,should face open punishment so that others might learn their lessons.Finally,appropriate planning is required to allow future road expansion.
