In this paper, a novel interferometric method with a wide range of sensitivities, called holography quasi projection moire, is proposed. It combines the features of the variated double projection moire method and the ...In this paper, a novel interferometric method with a wide range of sensitivities, called holography quasi projection moire, is proposed. It combines the features of the variated double projection moire method and the holographic interferometry method. This technique is used to study the failure modes of microelectronic packaging modules.展开更多
Background: The prognostic values of staging parameters require continual re?assessment amid changes in diag?nostic and therapeutic methods. This study aimed to identify the prognostic factors and failure patterns of ...Background: The prognostic values of staging parameters require continual re?assessment amid changes in diag?nostic and therapeutic methods. This study aimed to identify the prognostic factors and failure patterns of non?meta?static nasopharyngeal carcinoma(NPC) in the intensity?modulated radiotherapy(IMRT) era.Methods: We reviewed the data from 749 patients with newly diagnosed, biopsy?proven, non?metastatic NPC in our cancer center(South China, an NPC endemic area) between January 2003 and December 2007. All patients under?went magnetic resonance imaging(MRI) before receiving IMRT. The actuarial survival rates were estimated using the Kaplan–Meier method, and survival curves were compared using the log?rank test. Multivariate analyses with the Cox proportional hazards model were used to test for the independent prognostic factors by backward eliminating insigniicant explanatory variables.Results: The 5?year occurrence rates of local failure, regional failure, locoregional failure, and distant failure were 5.4, 3.0, 7.4, and 17.4%, respectively. The 5?year survival rates were as follows: local relapse?free survival, 94.6%; nodal relapse?free survival, 97.0%; distant metastasis?free survival, 82.6%; disease?free survival, 75.1%; and overall survival, 82.0%. Multivariate Cox regression analysis revealed that orbit involvement was the only signiicant prognostic fac?tor for local failure(P = 0.011). Parapharyngeal tumor extension, retropharyngeal lymph node involvement, and the laterality, longest diameter, and Ho's location of the cervical lymph nodes were signiicant prognostic factors for both distant failure and disease failure(all P < 0.05). Intracranial extension had signiicant prognostic value for distant failure(P = 0.040).Conclusions: The key failure pattern for NPC was distant metastasis in the IMRT era. With changes in diagnostic and therapeutic technologies as well as treatment modalities, the signiicant prognostic parameters for local control have also been altered substantially.展开更多
To investigate the effect of different states of charge(SOC)on the thermal runaway(TR)propagation behaviors within lithium-ion-batteries based energy storage modules,an experimental setup was developed to conduct fail...To investigate the effect of different states of charge(SOC)on the thermal runaway(TR)propagation behaviors within lithium-ion-batteries based energy storage modules,an experimental setup was developed to conduct failure propagation tests on battery modules at an SOC of 97%,85%,and 50%.The result indicates that an increase in the SOC of batteries can decrease the TR trigger temperature,making batteries trigger TR earlier and reducing the average failure propagation time between two adjacent cells.In addition,the failure propagation tests reveal that at higher SOCs,the TR reaction becomes more violent,the maximal reaction temperature is also much higher,and the damage to the battery module is severe.Compared to the battery module with 97%SOC,the TR trigger time of the battery module with 50%SOC was postponed by approximately 57.8%.Meanwhile,the average failure propagation time got prolonged by approximately 36.0%.Thus,this study can provide references for the thermal safety design of energy-storage battery modules.展开更多
模块间接地故障是H桥级联型电池储能系统(cascaded H bridge based battery energy storage system,CHB-BESS)的易发故障,快速诊断故障位置对减少故障损失至关重要。模块间接地故障的故障特征主要体现在零序电流上,会受到接地过渡电阻...模块间接地故障是H桥级联型电池储能系统(cascaded H bridge based battery energy storage system,CHB-BESS)的易发故障,快速诊断故障位置对减少故障损失至关重要。模块间接地故障的故障特征主要体现在零序电流上,会受到接地过渡电阻的影响。为实现接地过渡电阻不确定情况下,故障模块位置的快速准确鲁棒定位,本工作提出了一种基于损失特征矩阵的快速故障诊断方法。首先,本工作建立了零序等效电路模型;然后,将零序电流模型离散化;接着,提出基于损失特征矩阵的定位方法,该方法使用拓扑矩阵描述故障位置和过渡电阻的遍历信息,基于离散化模型来遍历计算零序电流,将计算结果与测量结果的偏差记录在损失特征矩阵中,通过偏差最优解确定故障位置;其次,本工作证实了故障定位问题作为最优化问题具有最优解唯一性,偏差最优解在接地过渡电阻不确定的情况下可获得准确的故障发生位置;最终,基于最优解唯一性提出了最优化计算的加速方法。实测表明,所提方法的平均定位误差仅为0.2个子模块,在接地过渡电阻较大范围不确定的情况下实现了准确定位,并且所提加速方法显著提高诊断速度。展开更多
针对雷达电源组件因长期处于振动应力作用下易导致振动疲劳而出现失效,进而影响雷达可靠性的问题,提出了一种基于振动故障物理(physics of failure,PoF)和蒙特卡洛的雷达电源组件故障预计方法。首先根据雷达电源组件的硬件结构、产品材...针对雷达电源组件因长期处于振动应力作用下易导致振动疲劳而出现失效,进而影响雷达可靠性的问题,提出了一种基于振动故障物理(physics of failure,PoF)和蒙特卡洛的雷达电源组件故障预计方法。首先根据雷达电源组件的硬件结构、产品材料等参数建立雷达电源组件有限元分析(finite element analysis,FEA)数字样机模型,然后施加雷达电源组件的振动边界载荷,进行振动应力分析,对比模态实验结果,验证了振动应力分析的合理性;最后考虑雷达电源组件元器件参数的不确定性,结合PoF和蒙特卡洛抽样进行故障预计,得到雷达电源各组件潜在故障的寿命分布。结果表明,在振动应力下,16块电源板的预计寿命最短。与实际故障预计结果对比,验证了所提算法的合理性。该方法在对雷达电源组件进行故障预计方面有很好的应用前景,促进了基于PoF模型的故障预计技术发展。展开更多
基金The project supported by the National Natural Science Foundation of China
文摘In this paper, a novel interferometric method with a wide range of sensitivities, called holography quasi projection moire, is proposed. It combines the features of the variated double projection moire method and the holographic interferometry method. This technique is used to study the failure modes of microelectronic packaging modules.
基金supported by grants from the Key Laboratory Construction Project of Guangzhou City,China (121800085)the Health & Medical Collaborative Innovation Project of Guangzhou City,China (201400000001)+2 种基金the National Science & Technology Pillar Program during the Twelfth Five-year Plan Period (2014BAI09B10)the National Natural Science Foundation of China (81201746)the Planned Science and Technology Project of Guangdong Province,China (2013B020400004)
文摘Background: The prognostic values of staging parameters require continual re?assessment amid changes in diag?nostic and therapeutic methods. This study aimed to identify the prognostic factors and failure patterns of non?meta?static nasopharyngeal carcinoma(NPC) in the intensity?modulated radiotherapy(IMRT) era.Methods: We reviewed the data from 749 patients with newly diagnosed, biopsy?proven, non?metastatic NPC in our cancer center(South China, an NPC endemic area) between January 2003 and December 2007. All patients under?went magnetic resonance imaging(MRI) before receiving IMRT. The actuarial survival rates were estimated using the Kaplan–Meier method, and survival curves were compared using the log?rank test. Multivariate analyses with the Cox proportional hazards model were used to test for the independent prognostic factors by backward eliminating insigniicant explanatory variables.Results: The 5?year occurrence rates of local failure, regional failure, locoregional failure, and distant failure were 5.4, 3.0, 7.4, and 17.4%, respectively. The 5?year survival rates were as follows: local relapse?free survival, 94.6%; nodal relapse?free survival, 97.0%; distant metastasis?free survival, 82.6%; disease?free survival, 75.1%; and overall survival, 82.0%. Multivariate Cox regression analysis revealed that orbit involvement was the only signiicant prognostic fac?tor for local failure(P = 0.011). Parapharyngeal tumor extension, retropharyngeal lymph node involvement, and the laterality, longest diameter, and Ho's location of the cervical lymph nodes were signiicant prognostic factors for both distant failure and disease failure(all P < 0.05). Intracranial extension had signiicant prognostic value for distant failure(P = 0.040).Conclusions: The key failure pattern for NPC was distant metastasis in the IMRT era. With changes in diagnostic and therapeutic technologies as well as treatment modalities, the signiicant prognostic parameters for local control have also been altered substantially.
基金Supported by the Ministry of Science and Technology of China (Grant No.2022YFB2404803)the National Natural Science Foundation of China (Grant No.52207241)the International Joint Mission on Climate Change and Carbon Neutrality。
文摘To investigate the effect of different states of charge(SOC)on the thermal runaway(TR)propagation behaviors within lithium-ion-batteries based energy storage modules,an experimental setup was developed to conduct failure propagation tests on battery modules at an SOC of 97%,85%,and 50%.The result indicates that an increase in the SOC of batteries can decrease the TR trigger temperature,making batteries trigger TR earlier and reducing the average failure propagation time between two adjacent cells.In addition,the failure propagation tests reveal that at higher SOCs,the TR reaction becomes more violent,the maximal reaction temperature is also much higher,and the damage to the battery module is severe.Compared to the battery module with 97%SOC,the TR trigger time of the battery module with 50%SOC was postponed by approximately 57.8%.Meanwhile,the average failure propagation time got prolonged by approximately 36.0%.Thus,this study can provide references for the thermal safety design of energy-storage battery modules.
文摘模块间接地故障是H桥级联型电池储能系统(cascaded H bridge based battery energy storage system,CHB-BESS)的易发故障,快速诊断故障位置对减少故障损失至关重要。模块间接地故障的故障特征主要体现在零序电流上,会受到接地过渡电阻的影响。为实现接地过渡电阻不确定情况下,故障模块位置的快速准确鲁棒定位,本工作提出了一种基于损失特征矩阵的快速故障诊断方法。首先,本工作建立了零序等效电路模型;然后,将零序电流模型离散化;接着,提出基于损失特征矩阵的定位方法,该方法使用拓扑矩阵描述故障位置和过渡电阻的遍历信息,基于离散化模型来遍历计算零序电流,将计算结果与测量结果的偏差记录在损失特征矩阵中,通过偏差最优解确定故障位置;其次,本工作证实了故障定位问题作为最优化问题具有最优解唯一性,偏差最优解在接地过渡电阻不确定的情况下可获得准确的故障发生位置;最终,基于最优解唯一性提出了最优化计算的加速方法。实测表明,所提方法的平均定位误差仅为0.2个子模块,在接地过渡电阻较大范围不确定的情况下实现了准确定位,并且所提加速方法显著提高诊断速度。
文摘针对雷达电源组件因长期处于振动应力作用下易导致振动疲劳而出现失效,进而影响雷达可靠性的问题,提出了一种基于振动故障物理(physics of failure,PoF)和蒙特卡洛的雷达电源组件故障预计方法。首先根据雷达电源组件的硬件结构、产品材料等参数建立雷达电源组件有限元分析(finite element analysis,FEA)数字样机模型,然后施加雷达电源组件的振动边界载荷,进行振动应力分析,对比模态实验结果,验证了振动应力分析的合理性;最后考虑雷达电源组件元器件参数的不确定性,结合PoF和蒙特卡洛抽样进行故障预计,得到雷达电源各组件潜在故障的寿命分布。结果表明,在振动应力下,16块电源板的预计寿命最短。与实际故障预计结果对比,验证了所提算法的合理性。该方法在对雷达电源组件进行故障预计方面有很好的应用前景,促进了基于PoF模型的故障预计技术发展。
