Radiation doses to patients in diagnostics and interventional radiology need to be optimized to comply with the principles of radiation protection in medical practice. This involves using specific detectors with respe...Radiation doses to patients in diagnostics and interventional radiology need to be optimized to comply with the principles of radiation protection in medical practice. This involves using specific detectors with respective diagnostic beams to carry out quality control/quality assurance tests needed to optimize patient doses in the hospital. Semiconductor detectors are used in dosimetry to verify the equipment performance and dose to patients. This work aims to assess the performance, energy dependence, and response of five commercially available semiconductor detectors in RQR, RQR-M, RQA, and RQT at Secondary Standard Dosimetry for clinical applications. The diagnostic beams were generated using Exradin A4 reference ion chamber and PTW electrometer. The ambient temperature and pressure were noted for KTP correction. The detectors designed for RQR showed good performance in RQT beams and vice versa. The detectors designed for RQR-M displayed high energy dependency in other diagnostic beams. The type of diagnostic beam quality determines the response of semiconductor detectors. Therefore, a detector should be calibrated according to the beam qualities to be measured.展开更多
A mathematical model integrating both vaccination and treatment strategies for childhood pneumonia is developed to assess conditions for effective dis-ease control.Special attention is given to individuals who do not ...A mathematical model integrating both vaccination and treatment strategies for childhood pneumonia is developed to assess conditions for effective dis-ease control.Special attention is given to individuals who do not respond to the vaccine,and their role in pneumonia transmission dynamics is analyzed.The effective reproduction number is derived,and conditions for the asymp-totic stability of both the disease-free and endemic equilibria are established.An optimal control analysis is conducted to determine the most effective strate-gies for minimizing pneumonia cases.Three time-dependent control measures are considered:1)pneumonia prevention,2)identification and treatment of carriers,and 3)enhanced treatment of infected individuals.Numerical simu-lations and sensitivity analysis reveal that while vaccination and treatment sig-nificantly reduce pneumonia prevalence,the presence of vaccine-unrespon-sive serotypes poses a challenge to disease eradication.Additionally,results indicate that implementing multiple control strategies is more effective than relying on a single intervention.A combination of all three measures yields the best outcomes in reducing both infection and carriage rates.展开更多
Over the past decade,China has undertaken substation intellectualization of more than 2000 substation operations in three stages.Much experience has been achieved during this developmental period.In this paper,the sta...Over the past decade,China has undertaken substation intellectualization of more than 2000 substation operations in three stages.Much experience has been achieved during this developmental period.In this paper,the status of smart substation development in China is systematically presented,as well as future directions of the smart substation,such as adoption of the hierarchical protection and control system.展开更多
文摘Radiation doses to patients in diagnostics and interventional radiology need to be optimized to comply with the principles of radiation protection in medical practice. This involves using specific detectors with respective diagnostic beams to carry out quality control/quality assurance tests needed to optimize patient doses in the hospital. Semiconductor detectors are used in dosimetry to verify the equipment performance and dose to patients. This work aims to assess the performance, energy dependence, and response of five commercially available semiconductor detectors in RQR, RQR-M, RQA, and RQT at Secondary Standard Dosimetry for clinical applications. The diagnostic beams were generated using Exradin A4 reference ion chamber and PTW electrometer. The ambient temperature and pressure were noted for KTP correction. The detectors designed for RQR showed good performance in RQT beams and vice versa. The detectors designed for RQR-M displayed high energy dependency in other diagnostic beams. The type of diagnostic beam quality determines the response of semiconductor detectors. Therefore, a detector should be calibrated according to the beam qualities to be measured.
文摘A mathematical model integrating both vaccination and treatment strategies for childhood pneumonia is developed to assess conditions for effective dis-ease control.Special attention is given to individuals who do not respond to the vaccine,and their role in pneumonia transmission dynamics is analyzed.The effective reproduction number is derived,and conditions for the asymp-totic stability of both the disease-free and endemic equilibria are established.An optimal control analysis is conducted to determine the most effective strate-gies for minimizing pneumonia cases.Three time-dependent control measures are considered:1)pneumonia prevention,2)identification and treatment of carriers,and 3)enhanced treatment of infected individuals.Numerical simu-lations and sensitivity analysis reveal that while vaccination and treatment sig-nificantly reduce pneumonia prevalence,the presence of vaccine-unrespon-sive serotypes poses a challenge to disease eradication.Additionally,results indicate that implementing multiple control strategies is more effective than relying on a single intervention.A combination of all three measures yields the best outcomes in reducing both infection and carriage rates.
基金National Natural Science Foundation of China under Grant 51120175001Key Project of Smart Grid Technology and Equipment of National Key Research and Development Plan of China under Grant 2016YFB0900600Science and Technology Project of State Grid Corporation of China under Grant GWKJ2013-005.
文摘Over the past decade,China has undertaken substation intellectualization of more than 2000 substation operations in three stages.Much experience has been achieved during this developmental period.In this paper,the status of smart substation development in China is systematically presented,as well as future directions of the smart substation,such as adoption of the hierarchical protection and control system.
