In order to eliminate noise interference of metal magnetic memory signal in early diagnosis of stress concentration zones and metal defects, the empirical mode decomposition method combined with the magnetic field gra...In order to eliminate noise interference of metal magnetic memory signal in early diagnosis of stress concentration zones and metal defects, the empirical mode decomposition method combined with the magnetic field gradient characteristic was proposed. A compressive force periodically acting upon a casing pipe led to appreciable deformation, and magnetic signals were measured by a magnetic indicator TSC-1M-4. The raw magnetic memory signal was first decomposed into different intrinsic mode functions and a residue, and the magnetic field gradient distribution of the subsequent reconstructed signal was obtained. The experimental results show that the gradient around 350 mm represents the maximum value ignoring the marginal effect, and there is a good correlation between the real maximum field gradient and the stress concentration zone. The wavelet transform associated with envelop analysis also exhibits this gradient characteristic, indicating that the proposed method is effective for early identifying critical zones.展开更多
Intra-articular coronal fractures （Hoffas fractures） of distal femur are rare. Although bicondylar involvement in these fractures has been reported in the literature in association with high velocity traumata, the o...Intra-articular coronal fractures （Hoffas fractures） of distal femur are rare. Although bicondylar involvement in these fractures has been reported in the literature in association with high velocity traumata, the occurrence of these fractures involving extensor mechanism rupture and avulsion ofipsilateral tibial spine is extremely rare. To our acquaintance, such a fracture pattern has not yet been reported in the literature so far. In this article, we report one such case and discuss the importance of early diagnosis and prompt internal fixation in the management of such cases.We believe that these rare combinations of injuries should be treated aggressively by early open reduction and anatomic rigid internal fixation in order to achieve good recovery of function.展开更多
基金Project(10772061) supported by the National Natural Science Foundation of ChinaProject(A200907) supported by the Natural Science Foundation of Heilongjiang Province, China Project(20092322120001) supported by the PhD Programs Foundations of Ministry of Education of China
文摘In order to eliminate noise interference of metal magnetic memory signal in early diagnosis of stress concentration zones and metal defects, the empirical mode decomposition method combined with the magnetic field gradient characteristic was proposed. A compressive force periodically acting upon a casing pipe led to appreciable deformation, and magnetic signals were measured by a magnetic indicator TSC-1M-4. The raw magnetic memory signal was first decomposed into different intrinsic mode functions and a residue, and the magnetic field gradient distribution of the subsequent reconstructed signal was obtained. The experimental results show that the gradient around 350 mm represents the maximum value ignoring the marginal effect, and there is a good correlation between the real maximum field gradient and the stress concentration zone. The wavelet transform associated with envelop analysis also exhibits this gradient characteristic, indicating that the proposed method is effective for early identifying critical zones.
文摘Intra-articular coronal fractures （Hoffas fractures） of distal femur are rare. Although bicondylar involvement in these fractures has been reported in the literature in association with high velocity traumata, the occurrence of these fractures involving extensor mechanism rupture and avulsion ofipsilateral tibial spine is extremely rare. To our acquaintance, such a fracture pattern has not yet been reported in the literature so far. In this article, we report one such case and discuss the importance of early diagnosis and prompt internal fixation in the management of such cases.We believe that these rare combinations of injuries should be treated aggressively by early open reduction and anatomic rigid internal fixation in order to achieve good recovery of function.
