The high cycle fatigue（HCF） tests of modified 9 Cr-1 Mo dissimilarly welded joint were carried out at different elevated temperatures and the fracture mechanism was systematically revealed. The fatigue strength at 1...The high cycle fatigue（HCF） tests of modified 9 Cr-1 Mo dissimilarly welded joint were carried out at different elevated temperatures and the fracture mechanism was systematically revealed. The fatigue strength at 108 cycles based on S-N curve can be estimated as a half of weld joint＇s yield strength for all conducted temperatures, which can be a reliable criterion in predicting the fatigue life. The results show that the inter-critical heat affected zones（IC-HAZs） of both sides are the weak zones due to their low hardness and inferior fatigue resistance property. HAZ of COST-FB2（BM2） is the weakest zone at room temperature due to the existence of numerously distributed defects and the initiation of cracks, either in the surface or interior zone, impacting a crucial effect on the fatigue life of the joint. While at elevated temperatures, fatigue life was controlled mostly by the intrusion-extrusion mechanism at the specimen surface under high stress level and subsurface non-defect fatigue crack origin（SNDFCO） from the interior material under low stress amplitude. With increasing temperature, more and more fatigue failures began to occur at the HAZ of COST-E（BM1） due to its higher susceptibility of temperature. Besides, it is found that the-ferrite in the BM1 has no harm to the HCF behavior of the joint at the conducted temperatures.展开更多
Objective: to analyze the key points of nursing after ankle fracture surgery. Methods: 300 patients who underwent ankle fracture surgery in our hospital were selected and randomly divided into two groups with the same...Objective: to analyze the key points of nursing after ankle fracture surgery. Methods: 300 patients who underwent ankle fracture surgery in our hospital were selected and randomly divided into two groups with the same number in each group. At the same time, the patients' satisfaction degree of nursing and pain index were scored by questionnaire survey. Results: the pain score of the patients in the observation group was significantly lower than that of the conventional nursing, and the nursing satisfaction of the patients in the observation group was higher, the difference was statistically significant (P < 0.05). Conclusion: after the patients with ankle fractures undergo surgical treatment, pain nursing can effectively improve the patients' satisfaction with nursing and reduce the patients' pain score, which is worthy of promotion in clinical practice.展开更多
Gently dipping fractures subjected to river incision are widely distributed on rock slopes.In this paper,a rock slope on the Nujiang River(China)is investigated to study the role of gently dipping fractures in the roc...Gently dipping fractures subjected to river incision are widely distributed on rock slopes.In this paper,a rock slope on the Nujiang River(China)is investigated to study the role of gently dipping fractures in the rock slopes evolution.Detailed field surveys indicate that gentle fractures are concentrated in four main zones.Moreover,the kinematics of the fracture system suggest that the genesis of these fractures can be synthesized into a progressive evolution model.This model indicates that the joints begin with the formation of an array of en echelon cracks that are subjected to continued crack elongation and shearing before ultimately approaching one another and interacting to form a complex joint system.Geomechanical analysis is performed to reveal the mechanisms of this genesis,and three main fracture patterns are identified based on the slope stress and are classified with respect to the slope evolution.Based on the detail field investigations and the evolutionary history of the river valley,we propose that intermittent incision by the river was the main factor contributing to the concentrated distribution of gently dipping joints.展开更多
Objective: to explore the treatment of ankle fractures in the process of combining with the traditional Chinese medicine scheme. In this research, there are two kinds, namely, traditional Chinese medicine fumigation a...Objective: to explore the treatment of ankle fractures in the process of combining with the traditional Chinese medicine scheme. In this research, there are two kinds, namely, traditional Chinese medicine fumigation and manual reduction. During the treatment, summarize the implementation points of the scheme and improve the treatment effect. Methods: 100 patients with ankle fractures who were treated in our hospital from June 2019 to June 2021 were selected as the research object. They were divided into two groups according to the order before and after admission. The two groups of patients were recorded as the control group and the research group respectively. The treatment methods used by the two groups of patients were: open reduction and internal fixation surgery, traditional Chinese medicine fumigation and washing combined with manual reduction treatment. The clinical value of this treatment method was compared. Results: (1) the excellent and good rate was 98.00% in the study group and 74.00% in the control group (p < 0.05);(2) in terms of VAS score and kofoed score, before treatment, the scores of the two groups of patients were basically the same (p< 0.05). after treatment, the patients in the research group had higher kofoed score and the patients in the control group had higher VAS score (p < 0.05);(3) after treatment, there was no significant difference in ankle pain, swelling and ankle function score between the two groups (p< 0.05). Conclusion: for patients with ankle fractures, the use of traditional Chinese medicine fumigation and manual reduction for treatment is more effective and can reduce the pain of patients. It is of great significance to promote the recovery of joint function of patients and can be widely used in clinical practice.展开更多
A complete rock failure process usually involves opening/sliding of preexisting discontinuities as well as frac- turing in intact rock bridges to form persistent failure sur- faces and subsequent motions of the genera...A complete rock failure process usually involves opening/sliding of preexisting discontinuities as well as frac- turing in intact rock bridges to form persistent failure sur- faces and subsequent motions of the generated rock blocks. The recently developed numerical manifold method （NMM） has potential for modelling such a complete failure process. However, the NMM suffers one limitation, i.e., unexpected material domain area change occurs in rotation modelling. This problem can not be easily solved because the rigid body rotation is not represented explicitly in the NMM. The discontinuous deformation analysis （DDA） is specially de- veloped for modelling discrete block systems. The rotation- induced material area change in the DDA modelling can be avoided conveniently because the rigid body rotation is represented in an explicit form. In this paper, a transition technique is proposed and implemented to convert a NMMmodelling to a DDA modelling so as to simulate a complete rock failure process entirely by means of the two methods, in which the NMM is adopted to model the early fracturing as well as the transition from continua to discontinua, while the DDA is adopted to model the subsequent motion of the generated rock blocks. Such a numerical approach also im- proves the simulation efficiency greatly as compared with a complete NMM modelling approach. The fracturing of a rock slab with pre-existing non-persistent joints located on a slope crest and the induced rockfall process are simulated. The validity of the modelling transition from the NMM to the DDA is verified and the applicability of the proposed nu- merical approach is investigated.展开更多
Double fracture-dislocations of the thumb are rare. Only a single case report of a simultaneous extraarticular fracture of the base of the first metacarpal and dislocation of the metacarpophalangeal joint has been pre...Double fracture-dislocations of the thumb are rare. Only a single case report of a simultaneous extraarticular fracture of the base of the first metacarpal and dislocation of the metacarpophalangeal joint has been previously reported. We report the second case report of this injury in a 20-year-old man. The patient had an excellent outcome after treatment.展开更多
Ni-P alloy was chemically plated on Al2O3 ceramics to produce uniform alloy coatings at tem- peratures below 70℃. Cu metal was electroplated onto the Ni-P coating to facilitate the soldering and shorten the chemica...Ni-P alloy was chemically plated on Al2O3 ceramics to produce uniform alloy coatings at tem- peratures below 70℃. Cu metal was electroplated onto the Ni-P coating to facilitate the soldering and shorten the chemical plating time. Then, the electroplated ceramic specimens were soldered with 60 wt.% Sn-40 wt.% Pb solder in active colophony. The highest shear strength was acquired after the heat treatment at 170℃ for 15 min. The joint fractures mostly propagated along the interface between the ceramics and the Ni-P coating, with some fracture in both the ceramics and the Ni-P coating near the interface and some along the interface between the Cu and Ni-P coatings. The results show that ceramic surface roughness and the chemical plating parameters influence the coating quality, and that suitable heat treatment before the soldering also improves the adhesion between the ceramics and Ni-P coatings, thus strengthening the joints.展开更多
文摘The high cycle fatigue（HCF） tests of modified 9 Cr-1 Mo dissimilarly welded joint were carried out at different elevated temperatures and the fracture mechanism was systematically revealed. The fatigue strength at 108 cycles based on S-N curve can be estimated as a half of weld joint＇s yield strength for all conducted temperatures, which can be a reliable criterion in predicting the fatigue life. The results show that the inter-critical heat affected zones（IC-HAZs） of both sides are the weak zones due to their low hardness and inferior fatigue resistance property. HAZ of COST-FB2（BM2） is the weakest zone at room temperature due to the existence of numerously distributed defects and the initiation of cracks, either in the surface or interior zone, impacting a crucial effect on the fatigue life of the joint. While at elevated temperatures, fatigue life was controlled mostly by the intrusion-extrusion mechanism at the specimen surface under high stress level and subsurface non-defect fatigue crack origin（SNDFCO） from the interior material under low stress amplitude. With increasing temperature, more and more fatigue failures began to occur at the HAZ of COST-E（BM1） due to its higher susceptibility of temperature. Besides, it is found that the-ferrite in the BM1 has no harm to the HCF behavior of the joint at the conducted temperatures.
文摘Objective: to analyze the key points of nursing after ankle fracture surgery. Methods: 300 patients who underwent ankle fracture surgery in our hospital were selected and randomly divided into two groups with the same number in each group. At the same time, the patients' satisfaction degree of nursing and pain index were scored by questionnaire survey. Results: the pain score of the patients in the observation group was significantly lower than that of the conventional nursing, and the nursing satisfaction of the patients in the observation group was higher, the difference was statistically significant (P < 0.05). Conclusion: after the patients with ankle fractures undergo surgical treatment, pain nursing can effectively improve the patients' satisfaction with nursing and reduce the patients' pain score, which is worthy of promotion in clinical practice.
基金financially supported by the National Natural Science Foundation of China (Grant No. 41521002 41130745+2 种基金 41272330)State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Independent Research Project (Grant No. SKLGP2016Z015)supported by the Funding of Science and Technology Office of Sichuan Province (Grant Nos. 2015JQ0020)
文摘Gently dipping fractures subjected to river incision are widely distributed on rock slopes.In this paper,a rock slope on the Nujiang River(China)is investigated to study the role of gently dipping fractures in the rock slopes evolution.Detailed field surveys indicate that gentle fractures are concentrated in four main zones.Moreover,the kinematics of the fracture system suggest that the genesis of these fractures can be synthesized into a progressive evolution model.This model indicates that the joints begin with the formation of an array of en echelon cracks that are subjected to continued crack elongation and shearing before ultimately approaching one another and interacting to form a complex joint system.Geomechanical analysis is performed to reveal the mechanisms of this genesis,and three main fracture patterns are identified based on the slope stress and are classified with respect to the slope evolution.Based on the detail field investigations and the evolutionary history of the river valley,we propose that intermittent incision by the river was the main factor contributing to the concentrated distribution of gently dipping joints.
文摘Objective: to explore the treatment of ankle fractures in the process of combining with the traditional Chinese medicine scheme. In this research, there are two kinds, namely, traditional Chinese medicine fumigation and manual reduction. During the treatment, summarize the implementation points of the scheme and improve the treatment effect. Methods: 100 patients with ankle fractures who were treated in our hospital from June 2019 to June 2021 were selected as the research object. They were divided into two groups according to the order before and after admission. The two groups of patients were recorded as the control group and the research group respectively. The treatment methods used by the two groups of patients were: open reduction and internal fixation surgery, traditional Chinese medicine fumigation and washing combined with manual reduction treatment. The clinical value of this treatment method was compared. Results: (1) the excellent and good rate was 98.00% in the study group and 74.00% in the control group (p < 0.05);(2) in terms of VAS score and kofoed score, before treatment, the scores of the two groups of patients were basically the same (p< 0.05). after treatment, the patients in the research group had higher kofoed score and the patients in the control group had higher VAS score (p < 0.05);(3) after treatment, there was no significant difference in ankle pain, swelling and ankle function score between the two groups (p< 0.05). Conclusion: for patients with ankle fractures, the use of traditional Chinese medicine fumigation and manual reduction for treatment is more effective and can reduce the pain of patients. It is of great significance to promote the recovery of joint function of patients and can be widely used in clinical practice.
基金supported by the Research Fund for the Doctoral Program of Higher Education of China (20090101120057)the Scientific Research Fund of Zhejiang Provincial Education Department (Y200909163)
文摘A complete rock failure process usually involves opening/sliding of preexisting discontinuities as well as frac- turing in intact rock bridges to form persistent failure sur- faces and subsequent motions of the generated rock blocks. The recently developed numerical manifold method （NMM） has potential for modelling such a complete failure process. However, the NMM suffers one limitation, i.e., unexpected material domain area change occurs in rotation modelling. This problem can not be easily solved because the rigid body rotation is not represented explicitly in the NMM. The discontinuous deformation analysis （DDA） is specially de- veloped for modelling discrete block systems. The rotation- induced material area change in the DDA modelling can be avoided conveniently because the rigid body rotation is represented in an explicit form. In this paper, a transition technique is proposed and implemented to convert a NMMmodelling to a DDA modelling so as to simulate a complete rock failure process entirely by means of the two methods, in which the NMM is adopted to model the early fracturing as well as the transition from continua to discontinua, while the DDA is adopted to model the subsequent motion of the generated rock blocks. Such a numerical approach also im- proves the simulation efficiency greatly as compared with a complete NMM modelling approach. The fracturing of a rock slab with pre-existing non-persistent joints located on a slope crest and the induced rockfall process are simulated. The validity of the modelling transition from the NMM to the DDA is verified and the applicability of the proposed nu- merical approach is investigated.
文摘Double fracture-dislocations of the thumb are rare. Only a single case report of a simultaneous extraarticular fracture of the base of the first metacarpal and dislocation of the metacarpophalangeal joint has been previously reported. We report the second case report of this injury in a 20-year-old man. The patient had an excellent outcome after treatment.
基金Supported by the Innovation Foundation of Aerospace Science and Technology of China and the Young Teacher Foundation of the Department of Mechanical Engineering and the Key Laboratory Open Fund of Tsinghua University
文摘Ni-P alloy was chemically plated on Al2O3 ceramics to produce uniform alloy coatings at tem- peratures below 70℃. Cu metal was electroplated onto the Ni-P coating to facilitate the soldering and shorten the chemical plating time. Then, the electroplated ceramic specimens were soldered with 60 wt.% Sn-40 wt.% Pb solder in active colophony. The highest shear strength was acquired after the heat treatment at 170℃ for 15 min. The joint fractures mostly propagated along the interface between the ceramics and the Ni-P coating, with some fracture in both the ceramics and the Ni-P coating near the interface and some along the interface between the Cu and Ni-P coatings. The results show that ceramic surface roughness and the chemical plating parameters influence the coating quality, and that suitable heat treatment before the soldering also improves the adhesion between the ceramics and Ni-P coatings, thus strengthening the joints.
