Using earth satellite observation means, remote sensing information distilled technique and regional research production, we have roundly analyzed and made an integrated evaluation about the Lop Nur nuclear test field...Using earth satellite observation means, remote sensing information distilled technique and regional research production, we have roundly analyzed and made an integrated evaluation about the Lop Nur nuclear test field in western China. This product reveals the rarely-known nuke explosion effect and response events of geology conditions. It also offers us legible and practical first-hand materials about human extreme effects, important engineering environment and intimidating influence process. By excavating and appraising the materials gradually on the natural environment factors changing in the test field through macroscopic elimination and typical filtration, it can supply basic scientific data for security of national nuclear usage, appraising the nuclear environment synthetically and developing nuclear strategy expediently.展开更多
Results are reported on a research for the radioactive level in the investigation region and the control region around the Xinjiang Nuclear Testing Site from 1982 to 1987. There are no significant differences on the l...Results are reported on a research for the radioactive level in the investigation region and the control region around the Xinjiang Nuclear Testing Site from 1982 to 1987. There are no significant differences on the land γ radiation level, nor in the radioactive level in the soil, food and water between the two regions. The distribution and transfer of 90Sr, 137Cs and Pu in various kinds of soil are also discussed. It is estimated that the effective dose equivalent of radiation, undergone by the residents around the Testing Site is only 2.9% of that of natural radiation taken yearly by people in normal areas.展开更多
The goal of this study was to examine the danger of six North Korean underground nuclear tests to the regional safety associated with deadly earthquakes and volcanoes. Geological instabilities at Cretaceous granites w...The goal of this study was to examine the danger of six North Korean underground nuclear tests to the regional safety associated with deadly earthquakes and volcanoes. Geological instabilities at Cretaceous granites were triggered by North Korean nuclear tests to induce the enhanced seismic impacts on earthquakes in China, Russia, Japan, Taiwan (China), South Korea, USA, Ecuador, Vanuatu, Indonesia, and Mexico after lag times between the nuclear test site and individual epicenters. It is urgent to prohibit North Korean nuclear tests for the regional stability of surrounding countries with Cretaceous granites.展开更多
Current sway test platforms for marine nuclear equipment face challenges in meeting the GJB 150.23A requirements.This is primarily because of the performance limitations of conventional actuators under extreme marine ...Current sway test platforms for marine nuclear equipment face challenges in meeting the GJB 150.23A requirements.This is primarily because of the performance limitations of conventional actuators under extreme marine conditions.This study aimed to overcome these constraints using an innovative parallel mechanism design.We developed a novel 6-PUS parallel platform featuring six kinematic chains with hybrid series-parallel actuators.Each chain combines(1)force-speed adaptive transmission,(2)redundant motor-driven dual-screw actuation,and(3)passive load-balancing mechanisms.Comprehensive kinematic/dynamic modeling and experimental validation were conducted.Tests demonstrated the capability of the platform to achieve cyclic speeds of±45°/7 s and±30°/3 s while supporting 10-ton loads.Successful sway tests on nuclear components(reactor pressurizer and control rod drive mechanism)confirmed the operational reliability.This work presented three key innovations:(1)a new parallel-platform architecture that overcomes the limitations of conventional actuators;(2)integrated hybrid actuation with adaptive transmission;and(3)high-speed,heavy-load performance that meets stringent marine testing standards.This solution significantly advances nuclear equipment qualification testing technology.展开更多
BACKGROUND Elderly patients awaiting moderate to high-risk surgery may undergo nuclear stress testing(NST)in order to evaluate their cardiovascular risk.The prognostic utility of such testing in the very elderly(≥85 ...BACKGROUND Elderly patients awaiting moderate to high-risk surgery may undergo nuclear stress testing(NST)in order to evaluate their cardiovascular risk.The prognostic utility of such testing in the very elderly(≥85 years)has yet to be fully evaluated.Octogenarians and nonogenarians frequently have a number of concurrent conditions including a high rate of coronary disease,and therefore the prognostic value of NST for their preoperative risk assessment has been questioned.Our evaluation assesses the ability of nuclear stress testing to predict peri-operative cardiac outcomes in this patient population.AIM To investigate the ability of NST to predict peri-operative cardiac outcomes in elderly patients awaiting moderate to high-risk surgery.METHODS Patients≥85 years undergoing pre-operative NST were retrospectively evaluated.Patients undergoing low-risk surgery were excluded.Major adverse cardiac events(MACE)were considered any adverse event that occurred prior to discharge and included acute heart failure,arrhythmia,acute myocardial infarction,unstable angina,or death.Associations between patient risk factors,MACE,and the obtained results of the pre-operative stress testing,ejection fraction(<40%or≥40%),summed stress score(≤8,≥9),and the summed difference score(≤0,>0)were analyzed.RESULTS A total of 69 patients(mean age 88±2.6 years,31 males)underwent nuclear stress testing prior to surgery.There were 41(60%)patients found to have an abnormal NST.Sixteen(23%)patients were noted to experience post-operative MACE.No significant associations between risk factors and MACE were noted.Patients with an abnormal NST and/or a summed stress score≥9 weresignificantly(P<0.01)more likely to develop peri-operative MACE.CONCLUSION Indicated preoperative NST is useful to assess pre-operative risk in elderly patients≥85 years undergoing moderate to high-risk surgery.展开更多
On February 25, the Unit 1 of Ling’ao Nuclear Power Plant phase II underwent a 41-day-long hot functional test successfully with its major systems satisfying the requirements for
Objectives: The study compared cardiac scintigraphy stress scanning practices applied in a National Maltese Nuclear Medicine centre and in international centres. This was achieved through the design of an online surve...Objectives: The study compared cardiac scintigraphy stress scanning practices applied in a National Maltese Nuclear Medicine centre and in international centres. This was achieved through the design of an online survey which investigated participant knowledge of stress testing, and current procedural practice. Methods: An online survey comprising 12 questions was prepared using Survey Monkey. Professional Nuclear Medicine groups such as the Medical-Physics-Engineering community and Virtual Radiopharmacy were targeted. Access to the survey remained open for eight months during which a periodic reminder was sent to optimise the response rate. Forty-three members responded from across Europe and Australasia. Chi-square tests and comparisons between multiple responses using IBM SPSS 20 were used to evaluate the results. Information related to Maltese practice was collated separately for review and comparative purposes. Results: The online survey participants comprised United Kingdom [72%], other European countries [18%] and Australasia [9%]. The majority of respondents [n = 39] reported pharmacological stress testing as being performed either alone or in conjunction with exercise stress testing as the preferred option. Most participants [60%] were aware of local stress test protocols but had limited knowledge in relation to guidelines designed for cases where patients were not suitable for pharmacological stress testing. Conclusion: The survey provided information about procedures within participating centres for scintigraphic cardiac stress scanning. Differences were identified with regards to the preferred radiopharmaceutical tracers and procedural protocols. Further investigation of examination techniques is warranted, with the aim of increasing standardisation of protocol compliance and the application of more suitable practice.展开更多
基金The State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chi-nese Academy of Sciences, the open fund item (No. SKLLQG0701) to subsidizedthe constructprogram of the key discipline in Hunan Province, China, the fund item (No. D2007001) the State Key Labo-ratories of Continental Dynamics,Northwest University, the open fund item (No. DL2006001) to combine subsi-dized.
文摘Using earth satellite observation means, remote sensing information distilled technique and regional research production, we have roundly analyzed and made an integrated evaluation about the Lop Nur nuclear test field in western China. This product reveals the rarely-known nuke explosion effect and response events of geology conditions. It also offers us legible and practical first-hand materials about human extreme effects, important engineering environment and intimidating influence process. By excavating and appraising the materials gradually on the natural environment factors changing in the test field through macroscopic elimination and typical filtration, it can supply basic scientific data for security of national nuclear usage, appraising the nuclear environment synthetically and developing nuclear strategy expediently.
文摘Results are reported on a research for the radioactive level in the investigation region and the control region around the Xinjiang Nuclear Testing Site from 1982 to 1987. There are no significant differences on the land γ radiation level, nor in the radioactive level in the soil, food and water between the two regions. The distribution and transfer of 90Sr, 137Cs and Pu in various kinds of soil are also discussed. It is estimated that the effective dose equivalent of radiation, undergone by the residents around the Testing Site is only 2.9% of that of natural radiation taken yearly by people in normal areas.
文摘The goal of this study was to examine the danger of six North Korean underground nuclear tests to the regional safety associated with deadly earthquakes and volcanoes. Geological instabilities at Cretaceous granites were triggered by North Korean nuclear tests to induce the enhanced seismic impacts on earthquakes in China, Russia, Japan, Taiwan (China), South Korea, USA, Ecuador, Vanuatu, Indonesia, and Mexico after lag times between the nuclear test site and individual epicenters. It is urgent to prohibit North Korean nuclear tests for the regional stability of surrounding countries with Cretaceous granites.
基金Supported by Shanghai Nuclear Engineering Research&Design Institute Co.,Ltd.
文摘Current sway test platforms for marine nuclear equipment face challenges in meeting the GJB 150.23A requirements.This is primarily because of the performance limitations of conventional actuators under extreme marine conditions.This study aimed to overcome these constraints using an innovative parallel mechanism design.We developed a novel 6-PUS parallel platform featuring six kinematic chains with hybrid series-parallel actuators.Each chain combines(1)force-speed adaptive transmission,(2)redundant motor-driven dual-screw actuation,and(3)passive load-balancing mechanisms.Comprehensive kinematic/dynamic modeling and experimental validation were conducted.Tests demonstrated the capability of the platform to achieve cyclic speeds of±45°/7 s and±30°/3 s while supporting 10-ton loads.Successful sway tests on nuclear components(reactor pressurizer and control rod drive mechanism)confirmed the operational reliability.This work presented three key innovations:(1)a new parallel-platform architecture that overcomes the limitations of conventional actuators;(2)integrated hybrid actuation with adaptive transmission;and(3)high-speed,heavy-load performance that meets stringent marine testing standards.This solution significantly advances nuclear equipment qualification testing technology.
文摘BACKGROUND Elderly patients awaiting moderate to high-risk surgery may undergo nuclear stress testing(NST)in order to evaluate their cardiovascular risk.The prognostic utility of such testing in the very elderly(≥85 years)has yet to be fully evaluated.Octogenarians and nonogenarians frequently have a number of concurrent conditions including a high rate of coronary disease,and therefore the prognostic value of NST for their preoperative risk assessment has been questioned.Our evaluation assesses the ability of nuclear stress testing to predict peri-operative cardiac outcomes in this patient population.AIM To investigate the ability of NST to predict peri-operative cardiac outcomes in elderly patients awaiting moderate to high-risk surgery.METHODS Patients≥85 years undergoing pre-operative NST were retrospectively evaluated.Patients undergoing low-risk surgery were excluded.Major adverse cardiac events(MACE)were considered any adverse event that occurred prior to discharge and included acute heart failure,arrhythmia,acute myocardial infarction,unstable angina,or death.Associations between patient risk factors,MACE,and the obtained results of the pre-operative stress testing,ejection fraction(<40%or≥40%),summed stress score(≤8,≥9),and the summed difference score(≤0,>0)were analyzed.RESULTS A total of 69 patients(mean age 88±2.6 years,31 males)underwent nuclear stress testing prior to surgery.There were 41(60%)patients found to have an abnormal NST.Sixteen(23%)patients were noted to experience post-operative MACE.No significant associations between risk factors and MACE were noted.Patients with an abnormal NST and/or a summed stress score≥9 weresignificantly(P<0.01)more likely to develop peri-operative MACE.CONCLUSION Indicated preoperative NST is useful to assess pre-operative risk in elderly patients≥85 years undergoing moderate to high-risk surgery.
文摘On February 25, the Unit 1 of Ling’ao Nuclear Power Plant phase II underwent a 41-day-long hot functional test successfully with its major systems satisfying the requirements for
文摘Objectives: The study compared cardiac scintigraphy stress scanning practices applied in a National Maltese Nuclear Medicine centre and in international centres. This was achieved through the design of an online survey which investigated participant knowledge of stress testing, and current procedural practice. Methods: An online survey comprising 12 questions was prepared using Survey Monkey. Professional Nuclear Medicine groups such as the Medical-Physics-Engineering community and Virtual Radiopharmacy were targeted. Access to the survey remained open for eight months during which a periodic reminder was sent to optimise the response rate. Forty-three members responded from across Europe and Australasia. Chi-square tests and comparisons between multiple responses using IBM SPSS 20 were used to evaluate the results. Information related to Maltese practice was collated separately for review and comparative purposes. Results: The online survey participants comprised United Kingdom [72%], other European countries [18%] and Australasia [9%]. The majority of respondents [n = 39] reported pharmacological stress testing as being performed either alone or in conjunction with exercise stress testing as the preferred option. Most participants [60%] were aware of local stress test protocols but had limited knowledge in relation to guidelines designed for cases where patients were not suitable for pharmacological stress testing. Conclusion: The survey provided information about procedures within participating centres for scintigraphic cardiac stress scanning. Differences were identified with regards to the preferred radiopharmaceutical tracers and procedural protocols. Further investigation of examination techniques is warranted, with the aim of increasing standardisation of protocol compliance and the application of more suitable practice.
