为准确表征转子系统不同运行状态,提出一种改进的变分模态分解(Modified Variational Mode Decomposition,MVMD)与瞬时能量分布排列熵(Instantaneous Energy Distribution Permutation Entropy,IEDPE)结合的转子故障特征量化提取方法。...为准确表征转子系统不同运行状态,提出一种改进的变分模态分解(Modified Variational Mode Decomposition,MVMD)与瞬时能量分布排列熵(Instantaneous Energy Distribution Permutation Entropy,IEDPE)结合的转子故障特征量化提取方法。利用相关性阈值策略确定变分模态分解(Variational Mode Decomposition,VMD)分解层参数并设计MVMD算法;然后,将采集到的振动信号输入MVMD中进行分解,计算各模态分量的瞬时能量分布;最后,提取各模态分量IEDPE作为故障量化特征。与MVMD+PE、EMD+IEDPE、EEMD+IEDPE进行对比,结果表明,提取的故障特征可更有效地表征转子故障状态之间的显著差别,使故障类别更准确识别。展开更多
Understanding the strength characteristics and deformation behaviour of the tunnel surrounding rock in a fault zone is significant for tunnel stability evaluation.In this study,a series of unconfined compression tests...Understanding the strength characteristics and deformation behaviour of the tunnel surrounding rock in a fault zone is significant for tunnel stability evaluation.In this study,a series of unconfined compression tests were conducted to investigate the mechanical characteristics and failure behaviour of completely weathered granite(CWG)from a fault zone,considering with height-diameter(h/d)ratio,dry densities(ρd)and moisture contents(ω).Based on the experimental results,a regression mathematical model of unconfined compressive strength(UCS)for CWG was developed using the Multiple Nonlinear Regression method(MNLR).The research results indicated that the UCS of the specimen with a h/d ratio of 0.6 decreased with the increase ofω.When the h/d ratio increased to 1.0,the UCS increasedωwith up to 10.5%and then decreased.Increasingρd is conducive to the improvement of the UCS at anyω.The deformation and rupture process as well as final failure modes of the specimen are controlled by h/d ratio,ρd andω,and the h/d ratio is the dominant factor affecting the final failure mode,followed byωandρd.The specimens with different h/d ratio exhibited completely different fracture mode,i.e.,typical splitting failure(h/d=0.6)and shear failure(h/d=1.0).By comparing the experimental results,this regression model for predicting UCS is accurate and reliable,and the h/d ratio is the dominant factor affecting the UCS of CWG,followed byρd and thenω.These findings provide important references for maintenance of the tunnel crossing other fault fractured zones,especially at low confining pressure or unconfined condition.展开更多
目的探讨修复锁骨原发恶性肿瘤整块切除术后锁骨区巨大骨与软组织缺损的方法及肩关节功能疗效。方法回顾性分析2018年1月至2021年12月收治的3例锁骨原发恶性肿瘤行肿瘤整块切除(全锁骨或次全锁骨切除)及个体化修复锁骨区骨与软组织缺损...目的探讨修复锁骨原发恶性肿瘤整块切除术后锁骨区巨大骨与软组织缺损的方法及肩关节功能疗效。方法回顾性分析2018年1月至2021年12月收治的3例锁骨原发恶性肿瘤行肿瘤整块切除(全锁骨或次全锁骨切除)及个体化修复锁骨区骨与软组织缺损的患者资料,均为女性,年龄分别为48、57、14岁。肿瘤类型为骨肉瘤、孤立性浆细胞瘤、多形性未分化肉瘤。术后辅助化疗及肩关节康复锻炼,评估肿瘤转归及肩关节活动,功能评分采用骨与软组织肿瘤功能评分(Musculoskeletal Tumor Society score,MSTS)、Constant-Murley评分及美国加州大学(University of California,Los Angeles,UCLA)肩关节评分系统。结果3例均获得随访,随访时间分别为33、23、8个月,至末次随访均未见肿瘤复发及转移。在肿瘤切除后,1例骨肉瘤及1例多形性未分化肉瘤患者行锁骨钢板联合先进人工韧带加强系统(ligament advanced reinforcement system,LARS)重建,1例孤立性浆细胞瘤患者行LARS韧带重建,末次随访MSTS分别为28、30、28分,Constant-Murley评分分别为80、90、84分,UCLA评分分别为29、33、30分。围手术期及随访期间内无并发症发生。结论锁骨原发恶性肿瘤整块切除后重建锁骨及周围重要韧带对术后肩关节活动功能恢复意义重大,锁骨及胸锁关节重建后可获得较满意的稳定性及良好的肩关节功能。展开更多
文摘为准确表征转子系统不同运行状态,提出一种改进的变分模态分解(Modified Variational Mode Decomposition,MVMD)与瞬时能量分布排列熵(Instantaneous Energy Distribution Permutation Entropy,IEDPE)结合的转子故障特征量化提取方法。利用相关性阈值策略确定变分模态分解(Variational Mode Decomposition,VMD)分解层参数并设计MVMD算法;然后,将采集到的振动信号输入MVMD中进行分解,计算各模态分量的瞬时能量分布;最后,提取各模态分量IEDPE作为故障量化特征。与MVMD+PE、EMD+IEDPE、EEMD+IEDPE进行对比,结果表明,提取的故障特征可更有效地表征转子故障状态之间的显著差别,使故障类别更准确识别。
基金supported by the National Natural Science Foundation of China,NSFC(No.42202318).
文摘Understanding the strength characteristics and deformation behaviour of the tunnel surrounding rock in a fault zone is significant for tunnel stability evaluation.In this study,a series of unconfined compression tests were conducted to investigate the mechanical characteristics and failure behaviour of completely weathered granite(CWG)from a fault zone,considering with height-diameter(h/d)ratio,dry densities(ρd)and moisture contents(ω).Based on the experimental results,a regression mathematical model of unconfined compressive strength(UCS)for CWG was developed using the Multiple Nonlinear Regression method(MNLR).The research results indicated that the UCS of the specimen with a h/d ratio of 0.6 decreased with the increase ofω.When the h/d ratio increased to 1.0,the UCS increasedωwith up to 10.5%and then decreased.Increasingρd is conducive to the improvement of the UCS at anyω.The deformation and rupture process as well as final failure modes of the specimen are controlled by h/d ratio,ρd andω,and the h/d ratio is the dominant factor affecting the final failure mode,followed byωandρd.The specimens with different h/d ratio exhibited completely different fracture mode,i.e.,typical splitting failure(h/d=0.6)and shear failure(h/d=1.0).By comparing the experimental results,this regression model for predicting UCS is accurate and reliable,and the h/d ratio is the dominant factor affecting the UCS of CWG,followed byρd and thenω.These findings provide important references for maintenance of the tunnel crossing other fault fractured zones,especially at low confining pressure or unconfined condition.
文摘目的探讨修复锁骨原发恶性肿瘤整块切除术后锁骨区巨大骨与软组织缺损的方法及肩关节功能疗效。方法回顾性分析2018年1月至2021年12月收治的3例锁骨原发恶性肿瘤行肿瘤整块切除(全锁骨或次全锁骨切除)及个体化修复锁骨区骨与软组织缺损的患者资料,均为女性,年龄分别为48、57、14岁。肿瘤类型为骨肉瘤、孤立性浆细胞瘤、多形性未分化肉瘤。术后辅助化疗及肩关节康复锻炼,评估肿瘤转归及肩关节活动,功能评分采用骨与软组织肿瘤功能评分(Musculoskeletal Tumor Society score,MSTS)、Constant-Murley评分及美国加州大学(University of California,Los Angeles,UCLA)肩关节评分系统。结果3例均获得随访,随访时间分别为33、23、8个月,至末次随访均未见肿瘤复发及转移。在肿瘤切除后,1例骨肉瘤及1例多形性未分化肉瘤患者行锁骨钢板联合先进人工韧带加强系统(ligament advanced reinforcement system,LARS)重建,1例孤立性浆细胞瘤患者行LARS韧带重建,末次随访MSTS分别为28、30、28分,Constant-Murley评分分别为80、90、84分,UCLA评分分别为29、33、30分。围手术期及随访期间内无并发症发生。结论锁骨原发恶性肿瘤整块切除后重建锁骨及周围重要韧带对术后肩关节活动功能恢复意义重大,锁骨及胸锁关节重建后可获得较满意的稳定性及良好的肩关节功能。
