The effect of the local hard zone (LHZ) distributed in the coarse grained HAZ (CGHAZ) has been analyzed by 2-dimensional FEM on a mechanical model of the weld CGHAZ. The existence of the LHZ elevates considerably the ...The effect of the local hard zone (LHZ) distributed in the coarse grained HAZ (CGHAZ) has been analyzed by 2-dimensional FEM on a mechanical model of the weld CGHAZ. The existence of the LHZ elevates considerably the stress in LHZ and causes the discontinuity of strain at the boundary between the LHZ and the matrix. The stress distribution in the LHZ is strongly affected by the shape of the LHZ. In a slender LHZ almost the whole region in the LHZ is exposed to elevated stress, whereas in the massive LHZ only the edge region sustains high stress. The longer the LHZ becomes, the more the highly stressed area, and the peak stress in the LHZ grows even under the same volume fraction of the LHZ. These results indicate that the slender LHZ brings about unstable fracture at a lower load level than the blocky LHZ. This tendency was confirmed by CTOD test results on the weld CGHAZ of a high-strength steel. The CGHAZ with elongated M-A constituents fractures at apparently lower critical CTOD than the CGHAZ with massive M-A constituents. In conclusion, the control of the shape of the M-A constituent has a striking effect on the toughness improvement of CGHAZ.展开更多
Objective: To evaluate the efficacy and safety of percutaneous microwave coagulation therapy (PMCT) for patients with primary and metastatic hepatic tumors.Methods: The enrolled 100 patients with 186 tumor nodules who...Objective: To evaluate the efficacy and safety of percutaneous microwave coagulation therapy (PMCT) for patients with primary and metastatic hepatic tumors.Methods: The enrolled 100 patients with 186 tumor nodules who underwent PMCT included 79 cases of primary or recurrent liver cancers and 21 cases of metastatic liver cancer. The tumors were divided into two groups according to the tumor size in diameter: group A, 0.5 cm?<3 cm; group B, ≥3 cm?<5 cm. Under local and/or epidural anesthesia, a single percutaneous microwave antenna (or two antennas array applicator) was inserted directly into the tumor in the liver for thermo-coagulation with the aid of ultrasound guidance.Results: Among the 186 lesions in 100 patients with primary and metastatic liver cancers, in group A, 123 (66%) were coagulated once. A Follow-up of 6–12 months demonstrated that 112 lesions (91%) showed no local recurrence by CT or MRI; In group B, of the 63 lesions (33.87%) coagulated twice, 31 (49%) showed no local recurrence by CT or MRI during a follow-up of 6 months. There were no serious clinical side effects or complications in all the PMCT patients.Conclusion: PMCT gives satisfactory curative effect on tumors with <3 cm in size. It is partly effective on lesions ≥3 cm?<5 cm in size. It is a minimally invasive and effective therapy, can be used safely in the field of percutaneous hepatis surgery, and carried out even in patients with poor liver function. Key words hepatocellular carcinoma - microwave - coagulation - therapy展开更多
A modified surface layer was formed on Ti-6Al-4V alloy by wet peening treatment. The variations of the residual stress,nano-hardness and microstructure of the modified layer with depth from surface were studied using ...A modified surface layer was formed on Ti-6Al-4V alloy by wet peening treatment. The variations of the residual stress,nano-hardness and microstructure of the modified layer with depth from surface were studied using X-ray diffraction analysis,nano-indentation analysis, scanning electron microscopy and transmission electron microscopy observations. The results show thatboth the compressive residual stress and hardness decrease with increasing depth, and the termination depths are 160 and 80 μm,respectively. The microstructure observation indicates that within 80 μm, the compressive residual stress and the hardness areenhanced by the co-action of the grain refinement strengthening and dislocation strengthening. Within 80–160 μm, the compressiveresidual stress mainly derives from the dislocation strengthening. The strengthened layer in Ti-6Al-4V alloy after wet peeningtreatment was quantitatively analyzed by a revised equation with respect to a relation between hardness and yield strength.展开更多
Desmoid tumor is a monoclonal, f ibroblastic proliferation arising in musculoaponeurotic structures. This connective tissue hyperplasia inf iltrates locally, recurs frequently after resection but does not metastasize....Desmoid tumor is a monoclonal, f ibroblastic proliferation arising in musculoaponeurotic structures. This connective tissue hyperplasia inf iltrates locally, recurs frequently after resection but does not metastasize. Abdominal desmoid occurs sporadically, in association with some familial syndromes and often represents a clinical dilemma for surgeons. The enigmatic biology and anatomical location of abdominal desmoids make treatment recommendations diff icult. This distinct pathological entity is reviewed with a specif ic focus on aetiology and management.展开更多
True-triaxial compression tests were carried out on cubic granite samples with a circular through hole using a true-triaxial testing system to investigate the influence of saturated water content(SWC) on the failure p...True-triaxial compression tests were carried out on cubic granite samples with a circular through hole using a true-triaxial testing system to investigate the influence of saturated water content(SWC) on the failure process and characteristics of a circular tunnel of surrounding rocks. The spalling failure under SWC can be divided into four periods: calm period, buckling deformation period, period of rock fragment gradual buckling and exfoliation, and period of formation of symmetrical V-shaped notches. When the horizontal axial and vertical stresses were constant, the spalling failure severity was reduced with the increase in lateral stress. Under natural water content, a strong rockburst with dynamic failure characteristics occurred on the circular hole sidewall. Under SWC, the failure severity was reduced and the circular hole sidewall experienced spalling failure, exhibiting progressive static failure characteristics.Therefore, water can reduce the failure severity of surrounding rocks in deep underground engineering, which has a certain guiding significance for the prevention and control of rockbursts.展开更多
Hepatic hydrothorax is a relatively infrequent but po- tentially serious complication of liver cirrhosis that often causes respiratory dysfunction. Several hypotheses for the development of hepatic hydrothorax have be...Hepatic hydrothorax is a relatively infrequent but po- tentially serious complication of liver cirrhosis that often causes respiratory dysfunction. Several hypotheses for the development of hepatic hydrothorax have been sug- gested to explain a transdiaphragmatic shift of ascitic fluid through small defects between the peritoneal cavity and the pleural space. However, the rapid development of hydrothorax within several hours is seldom encoun- tered. In addition, the causal factors for rapid passage of ascitic fluid into the pleural cavity are unknown. This report describes a patient with liver cirrhosis who suf- fered rapid development of a hydrothorax after manual compression of the abdomen.展开更多
文摘The effect of the local hard zone (LHZ) distributed in the coarse grained HAZ (CGHAZ) has been analyzed by 2-dimensional FEM on a mechanical model of the weld CGHAZ. The existence of the LHZ elevates considerably the stress in LHZ and causes the discontinuity of strain at the boundary between the LHZ and the matrix. The stress distribution in the LHZ is strongly affected by the shape of the LHZ. In a slender LHZ almost the whole region in the LHZ is exposed to elevated stress, whereas in the massive LHZ only the edge region sustains high stress. The longer the LHZ becomes, the more the highly stressed area, and the peak stress in the LHZ grows even under the same volume fraction of the LHZ. These results indicate that the slender LHZ brings about unstable fracture at a lower load level than the blocky LHZ. This tendency was confirmed by CTOD test results on the weld CGHAZ of a high-strength steel. The CGHAZ with elongated M-A constituents fractures at apparently lower critical CTOD than the CGHAZ with massive M-A constituents. In conclusion, the control of the shape of the M-A constituent has a striking effect on the toughness improvement of CGHAZ.
文摘Objective: To evaluate the efficacy and safety of percutaneous microwave coagulation therapy (PMCT) for patients with primary and metastatic hepatic tumors.Methods: The enrolled 100 patients with 186 tumor nodules who underwent PMCT included 79 cases of primary or recurrent liver cancers and 21 cases of metastatic liver cancer. The tumors were divided into two groups according to the tumor size in diameter: group A, 0.5 cm?<3 cm; group B, ≥3 cm?<5 cm. Under local and/or epidural anesthesia, a single percutaneous microwave antenna (or two antennas array applicator) was inserted directly into the tumor in the liver for thermo-coagulation with the aid of ultrasound guidance.Results: Among the 186 lesions in 100 patients with primary and metastatic liver cancers, in group A, 123 (66%) were coagulated once. A Follow-up of 6–12 months demonstrated that 112 lesions (91%) showed no local recurrence by CT or MRI; In group B, of the 63 lesions (33.87%) coagulated twice, 31 (49%) showed no local recurrence by CT or MRI during a follow-up of 6 months. There were no serious clinical side effects or complications in all the PMCT patients.Conclusion: PMCT gives satisfactory curative effect on tumors with <3 cm in size. It is partly effective on lesions ≥3 cm?<5 cm in size. It is a minimally invasive and effective therapy, can be used safely in the field of percutaneous hepatis surgery, and carried out even in patients with poor liver function. Key words hepatocellular carcinoma - microwave - coagulation - therapy
基金Project(51405059)supported by the National Natural Science Foundation of ChinaProject(2014M551074)supported by the China Postdoctoral Science FoundationProject(NCET-10-0278)supported by the Program for New Century Excellent Talents in University
文摘A modified surface layer was formed on Ti-6Al-4V alloy by wet peening treatment. The variations of the residual stress,nano-hardness and microstructure of the modified layer with depth from surface were studied using X-ray diffraction analysis,nano-indentation analysis, scanning electron microscopy and transmission electron microscopy observations. The results show thatboth the compressive residual stress and hardness decrease with increasing depth, and the termination depths are 160 and 80 μm,respectively. The microstructure observation indicates that within 80 μm, the compressive residual stress and the hardness areenhanced by the co-action of the grain refinement strengthening and dislocation strengthening. Within 80–160 μm, the compressiveresidual stress mainly derives from the dislocation strengthening. The strengthened layer in Ti-6Al-4V alloy after wet peeningtreatment was quantitatively analyzed by a revised equation with respect to a relation between hardness and yield strength.
文摘Desmoid tumor is a monoclonal, f ibroblastic proliferation arising in musculoaponeurotic structures. This connective tissue hyperplasia inf iltrates locally, recurs frequently after resection but does not metastasize. Abdominal desmoid occurs sporadically, in association with some familial syndromes and often represents a clinical dilemma for surgeons. The enigmatic biology and anatomical location of abdominal desmoids make treatment recommendations diff icult. This distinct pathological entity is reviewed with a specif ic focus on aetiology and management.
基金financial support from the National Natural Science Foundation of China (Nos.51904335,41630642)。
文摘True-triaxial compression tests were carried out on cubic granite samples with a circular through hole using a true-triaxial testing system to investigate the influence of saturated water content(SWC) on the failure process and characteristics of a circular tunnel of surrounding rocks. The spalling failure under SWC can be divided into four periods: calm period, buckling deformation period, period of rock fragment gradual buckling and exfoliation, and period of formation of symmetrical V-shaped notches. When the horizontal axial and vertical stresses were constant, the spalling failure severity was reduced with the increase in lateral stress. Under natural water content, a strong rockburst with dynamic failure characteristics occurred on the circular hole sidewall. Under SWC, the failure severity was reduced and the circular hole sidewall experienced spalling failure, exhibiting progressive static failure characteristics.Therefore, water can reduce the failure severity of surrounding rocks in deep underground engineering, which has a certain guiding significance for the prevention and control of rockbursts.
文摘Hepatic hydrothorax is a relatively infrequent but po- tentially serious complication of liver cirrhosis that often causes respiratory dysfunction. Several hypotheses for the development of hepatic hydrothorax have been sug- gested to explain a transdiaphragmatic shift of ascitic fluid through small defects between the peritoneal cavity and the pleural space. However, the rapid development of hydrothorax within several hours is seldom encoun- tered. In addition, the causal factors for rapid passage of ascitic fluid into the pleural cavity are unknown. This report describes a patient with liver cirrhosis who suf- fered rapid development of a hydrothorax after manual compression of the abdomen.
