In order to get rid of the dependence on high-precision centrifuges in accelerometer nonlinear coefficients calibration,this paper proposes a system-level calibration method for field condition.Firstly,a 42-dimension ...In order to get rid of the dependence on high-precision centrifuges in accelerometer nonlinear coefficients calibration,this paper proposes a system-level calibration method for field condition.Firstly,a 42-dimension Kalman filter is constructed to reduce impact brought by turntable.Then,a biaxial rotation path is designed based on the accelerometer output model,including orthogonal 22 positions and tilt 12 positions,which enhances gravity excitation on nonlinear coefficients of accelerometer.Finally,sampling is carried out for calibration and further experiments.The results of static inertial navigation experiments lasting 4000 s show that compared with the traditional method,the proposed method reduces the position error by about 390 m.展开更多
Underground energy and resource development,deep underground energy storage and other projects involve the global stability of multiple interconnected cavern groups under internal and external dynamic disturbances.An ...Underground energy and resource development,deep underground energy storage and other projects involve the global stability of multiple interconnected cavern groups under internal and external dynamic disturbances.An evaluation method of the global stability coefficient of underground caverns based on static overload and dynamic overload was proposed.Firstly,the global failure criterion for caverns was defined based on its band connection of plastic-strain between multi-caverns.Then,overloading calculation of the boundary geostress and seismic intensity on the caverns model was carried out,and the critical unstable state of multi-caverns can be identified,if the plastic-strain band appeared between caverns during these overloading processes.Thus,the global stability coefficient for the multi-caverns under static loading and earthquake was obtained based on the corresponding overloading coefficient.Practical analysis for the Yingliangbao(YLB)hydraulic caverns indicated that this method can not only effectively obtain the global stability coefficient of caverns under static and dynamic earthquake conditions,but also identify the caverns’high-risk zone of local instability through localized plastic strain of surrounding rock.This study can provide some reference for the layout design and seismic optimization of underground cavern group.展开更多
国际原子能机构(IAEA)目前已经按2008年制定的长期结构(Long Term Structure)自上而下建立了由145项标准组成的安全标准体系,同时计划在2026年制定一个着眼于未来10~15年的新长期结构,以适应人工智能、气候变化、新型反应堆等带来的新...国际原子能机构(IAEA)目前已经按2008年制定的长期结构(Long Term Structure)自上而下建立了由145项标准组成的安全标准体系,同时计划在2026年制定一个着眼于未来10~15年的新长期结构,以适应人工智能、气候变化、新型反应堆等带来的新需求。本文介绍了IAEA辐射安全标准委员会(RASSC)的主要工作,并讨论了RASSC近期关注的辐射安全问题:针对现存照射辨识和管理方面的挑战,RASSC正在新制定一项关于现存照射的综合性安全导则;虽然国际放射防护委员会(ICRP)已经更新了职业人员内照射剂量系数,RASSC不会立即修订与之相关的安全标准,同时会持续关注成员国经验反馈;随着新型放疗技术的应用,RASSC近期还关注放射性核素治疗中的辐射防护、放疗患者的第二原发癌的风险。展开更多
基金supported by the National Natural Science Foundation of China(42276199).
文摘In order to get rid of the dependence on high-precision centrifuges in accelerometer nonlinear coefficients calibration,this paper proposes a system-level calibration method for field condition.Firstly,a 42-dimension Kalman filter is constructed to reduce impact brought by turntable.Then,a biaxial rotation path is designed based on the accelerometer output model,including orthogonal 22 positions and tilt 12 positions,which enhances gravity excitation on nonlinear coefficients of accelerometer.Finally,sampling is carried out for calibration and further experiments.The results of static inertial navigation experiments lasting 4000 s show that compared with the traditional method,the proposed method reduces the position error by about 390 m.
基金Project(2023YFC2907204)supported by the National Key Research and Development Program of ChinaProject(52325905)supported by the National Natural Science Foundation of ChinaProject(DJ-HXGG-2023-16)supported by the Key Technology Research Projects of Power China。
文摘Underground energy and resource development,deep underground energy storage and other projects involve the global stability of multiple interconnected cavern groups under internal and external dynamic disturbances.An evaluation method of the global stability coefficient of underground caverns based on static overload and dynamic overload was proposed.Firstly,the global failure criterion for caverns was defined based on its band connection of plastic-strain between multi-caverns.Then,overloading calculation of the boundary geostress and seismic intensity on the caverns model was carried out,and the critical unstable state of multi-caverns can be identified,if the plastic-strain band appeared between caverns during these overloading processes.Thus,the global stability coefficient for the multi-caverns under static loading and earthquake was obtained based on the corresponding overloading coefficient.Practical analysis for the Yingliangbao(YLB)hydraulic caverns indicated that this method can not only effectively obtain the global stability coefficient of caverns under static and dynamic earthquake conditions,but also identify the caverns’high-risk zone of local instability through localized plastic strain of surrounding rock.This study can provide some reference for the layout design and seismic optimization of underground cavern group.
文摘国际原子能机构(IAEA)目前已经按2008年制定的长期结构(Long Term Structure)自上而下建立了由145项标准组成的安全标准体系,同时计划在2026年制定一个着眼于未来10~15年的新长期结构,以适应人工智能、气候变化、新型反应堆等带来的新需求。本文介绍了IAEA辐射安全标准委员会(RASSC)的主要工作,并讨论了RASSC近期关注的辐射安全问题:针对现存照射辨识和管理方面的挑战,RASSC正在新制定一项关于现存照射的综合性安全导则;虽然国际放射防护委员会(ICRP)已经更新了职业人员内照射剂量系数,RASSC不会立即修订与之相关的安全标准,同时会持续关注成员国经验反馈;随着新型放疗技术的应用,RASSC近期还关注放射性核素治疗中的辐射防护、放疗患者的第二原发癌的风险。
