The flux cored wires with different amounts of rare earth （RE） oxides additions for hardfacing （harden-face-welding） the workpieces of high chromium cast iron were studied in this work.The morphology of carbides i...The flux cored wires with different amounts of rare earth （RE） oxides additions for hardfacing （harden-face-welding） the workpieces of high chromium cast iron were studied in this work.The morphology of carbides in hardfacing metal was observed,and the type of the carbides was determined by optical microscopy,scanning electron microscopy （SEM）,energy dispersive spectrometer （EDS） and X-ray diffraction （XRD）.Based on the data of effect of RE on carbides morphology,the refined reason for carbide by RE oxide was discussed with the misfit theory.The results showed that,the microstructure of hardfacing metal was composed of martensite,residual austenite and M7C3 carbides.With the increasing amount of RE oxide additions,the volume fraction and roundness of the carbides were increased,however,the area and perimeter of carbides were decreased.It indicated that carbides in hardfacing metal could be refined and spheroidized by adding RE oxides in flux cored wires.展开更多
Objective:To comparatively study complete dislo cation of acromioclavicular joint treated with three different methods. Methods:A total of 96 patients (81 males and 15 females, aged 16-59 years, mean=45 years) with co...Objective:To comparatively study complete dislo cation of acromioclavicular joint treated with three different methods. Methods:A total of 96 patients (81 males and 15 females, aged 16-59 years, mean=45 years) with complete dislocation of acromioclavicular join t were treated with Dewars operation (Group A, n=32), internal fixation with K irschner tension band wires (Group B, n=44), or internal fixation with Wolter pl ates (Group C, n=20), respectively, in this study. Eighty-five patients suffere d from acute dislocations and eleven from chronic dislocations. Results:The patients were followed up for 50 months on an aver age. According to Karlssons standard, in Group A, 26 patients were assessed as good, 5 as fair and 1 as poor. In Group B, 20 patients were assessed as good, 1 3 as fair and 11 as poor. In Group C, 15 patients were assessed as good, 4 as fa ir and 1 as poor. The good and fair rates were significantly different between G roup A and Group B, and between Group C and Group B, but no statistical differen ce was found between Group A and Group C. The operating time was ( 52.36 ± 7 .24 ) minutes, ( 67.43 ± 8.11 ) minutes and ( 69.73 ± 8.04 ) minutes in Groups A, B and C, respectively. And the hospitalizing fees were ( 2 400 ± 270) yuan, ( 2 100 ±190) yuan and ( 8 450 ±360) yuan in Groups A, B and C, respectively. Conclusions:Dewars operation is a good and safe method with shorter operating time and lower hospitalizing fee for treating complete disloca tion of acromioclavicular joint. The method is simple without the need of a seco nd operation to remove the implants and with few complications.展开更多
Objective： To assess the therapeutic results of open reduction and internal fixation with crossed K-wires via lateral approach for displaced supracondvlar fractures of the humerus in children. Methods： We prospecti...Objective： To assess the therapeutic results of open reduction and internal fixation with crossed K-wires via lateral approach for displaced supracondvlar fractures of the humerus in children. Methods： We prospectively followed 52 children who presented with Gartland type 3 displaced supraeondylar fractures of the humerus and were managed by open reduction and internal fixation with crossed K-wires via lateral approach.There were 37 male and 15 female patients; average age was 7.39 years. The most common mechanism of trauma was fall while playing （n=23）, followed by fall from height （n=20）, road traffic accidents （n-5） and fall from standing height （n=2）. In 2 cases, mode of injury was not available. The mean follow-up was 12 months and patients were assessed according to Flynn＇s criteria. Results： Lateral approach provided an excellent view of the lateral column between two nervous planes and enabled an anatomical reduction in all cases. Immobilizing the elbow at 90 degrees or more of flexion was not needed after cross K-wire fixation. Majority of patients regained full range of motion within 6 weeks of pin removal. Two patients had postoperative ulnar nerve injuries that resolved after pin removal. The common late complication of cubitus varus was not seen in any patient. Delayed presentation to the emergency department, repeated manipulations by bone setters and massage with edible oil were responsible for stiffness in 5 patients. Superficial pin tract infection was noted in 5 patients that resolved with dressings and antibiotics. No deep infection occurred. A detailed clinical examination and radiographic analysis was done at final follow-up. They included measurement of carrying angle and range of movements of both operated and normal sides, and radiographs of both upper limbs for comparison. According to Flynn＇s criteria, 90.4% patients showed satisfactory results. Conclusion： Lateral approach for open reduction and internal fixation of the widely-displaced supracondylar fract展开更多
The deformation microstructure evolution of single crystal copper wires produced by OCC method has been studied with the help of TEM, EBSD; OM. The results show that there are a small number of dendrites; twins in the...The deformation microstructure evolution of single crystal copper wires produced by OCC method has been studied with the help of TEM, EBSD; OM. The results show that there are a small number of dendrites; twins in the undeformed single crystal copper wires. However, it is difficult to observe these dendrites in deformed single crystal copper wires. The structure evolution of deformed single crystal copper wires during drawing process can be divided into three stages. When the true strain is lower than 0.94, macroscopic subdivision of grains is not evident,; the microscopic evolution of deformed structure is that the cells are formed; elongated in drawn direction. When the true strain is between 0.94; 1.96, macroscopic subdivision of grains takes place,; the number of microbands located on {111}; cell blocks is much more than that with the true strain lower than 0.94. When the true strain is larger than 1.96, the macroscopic subdivision of grains becomes more evident than that with the true strain between 0.94; 1.96,; S-bands structure; lamellar boundaries will be formed. From EBSD analysis, it is found that part of 100 texture resulting from solidifying is transformed into 111; 112 due to shear deformation, but 100 texture component is still kept in majority. When the true strain is 0.94, the misorientation angle of dislocation boundaries resulting from deformation is lower than 14°. However, when the true strain arrives at 1.96, the misorientation angle of some boundaries will be greater than 50°,; the peak of misorientation angle distribution produced by texture evolution is located in the range between 25°; 30°.展开更多
The weather system, meteorological conditions, and microphysics of cloud, fog, and rain droplets are studied during the formation, growth, maintenance, and shedding periods of ice accretion on wires in Enshi, Hubei Pr...The weather system, meteorological conditions, and microphysics of cloud, fog, and rain droplets are studied during the formation, growth, maintenance, and shedding periods of ice accretion on wires in Enshi, Hubei Province in China using 2008/2009 and 2009/2010 winter observations. The comprehensive observations include data of visibility, microphysics of fog and rain droplets, and ice thickness, as well as data from an automated weather station and other routinely recorded meteorological data. The results show that icing occurred during the passage of a cold front, with a high-pressure system and a cold temperature trough at 850 hPa, and a southeasterly at 500 hPa that provided abundant moisture. Ice formation usually started in the evening or early morning, and ice shed around noon the following day when the temperature was -1℃ to 0℃. The averaged liquid water content of the fog droplet was distinctly greater during the growth period than during the other three periods, and there was precipitation during the growth period in each case of ice accretion. The growth rate of the ice thickness was clearly correlated with the liquid water content, with a correlation coefficient of 0.62. Simulations using empirical equations were carried out, and the simulated ice thickness agreed with observations fairly well.展开更多
Building on a new model proposed recently for calculating constant electro-magnetic field values, the present article explores the electro-magnetic field configuration generated by parallel electrical wires. This impo...Building on a new model proposed recently for calculating constant electro-magnetic field values, the present article explores the electro-magnetic field configuration generated by parallel electrical wires. This imposes a reevaluation of the drawing procedure for constructing field curves with a constant field values around multiple parallel electrical conducting wires. To achieve this, we employ methods akin to those used for creating contours on topographical maps, ensuring a consistent numerical field value along the entire length of the field curves. Subsequent calculations will be conducted for scenarios where wires are not parallel.展开更多
A stranded wires helical spring is formed of a multilayer and coaxial strand of several wires twisted together with the same direction of spiral. Compared with the conventional single wire spring, the stranded wires h...A stranded wires helical spring is formed of a multilayer and coaxial strand of several wires twisted together with the same direction of spiral. Compared with the conventional single wire spring, the stranded wires helical spring has the notable predominance in strength, damping and vibration reduction, which is usually used in aircraft engines, automatic weapons, etc. However, due to its complicated structure, the precise computation of its strength and rigidity need be a correct mathematical model, which then will be imported to finite element analysis software for solutions. Equations on solving geometric parameters, such as external diameters of strands and screw pitches of wires, are put forward in the paper. It also proposes a novel methodology on solving geometric parameters and establishing entity models of the stranded wires helical spring, which provides foundation of computing mechanical parameters by FEA. Then mathematical models on the centre line of the strand and the surface curve of each wire, after closing two ends in a spring, are proposed. Finally, geometric parameters are solved in a case study, and a 3D entity model of a spring with 3 layers and 16 wires is established, which has validated the accuracy of the proposed methodology and the 3D entity mathematical model. The method provides a new way to design stranded wire helical spring.展开更多
The texture evolution of cold drawing copper wires produced by continuous casting was measured by X-ray diffractometry and electron back-scatter diffractometry,and was simulated using Taylor model.The results show tha...The texture evolution of cold drawing copper wires produced by continuous casting was measured by X-ray diffractometry and electron back-scatter diffractometry,and was simulated using Taylor model.The results show that in the drawn poly-crystal copper wires produced by traditional continuous casting,111 and 100 duplex fiber texture forms,and with increasing strain,the intensities of 111 and 100 increase.In the drawn single-crystal copper wires produced by Ohno continuous casting,100 rotates to 111,and there is inhomogeneous distribution of fiber texture along radial direction of the wires,which is caused by the distribution of shear deformation.Compared with 100,111 fiber texture is more stable in the drawn copper wires.Comparison of the experimental results with the simulated results shows that the simulation by Taylor model can analyze the texture evolution of drawn copper wires.展开更多
In order to obtain the Al wires with good mechanical properties and high electrical conductivities, conductive wires of Al-0.16 Zr, Al-0.16 Sc, Al-0.12Sc-0.04Zr（mass fraction, %） and pure Al（99.996%） were produced...In order to obtain the Al wires with good mechanical properties and high electrical conductivities, conductive wires of Al-0.16 Zr, Al-0.16 Sc, Al-0.12Sc-0.04Zr（mass fraction, %） and pure Al（99.996%） were produced with the diameter of 9.5 mm by continuous rheo-extrusion technology, and the extruded materials were heat treated and analyzed. The results show that the separate additions of 0.16% Sc and 0.16% Zr to pure Al improve the ultimate tensile strength but reduce the electrical conductivity, and the similar trend is found in the Al-0.12Sc-0.04 Zr alloy. After the subsequent heat treatment, the wire with the optimum comprehensive properties is Al-0.12Sc-0.04 Zr alloy, of which the ultimate tensile strength and electrical conductivity reach 160 MPa and 64.03%（IACS）, respectively.展开更多
Purpose:Supracondylar fractures of the humerus cause significant morbidity in children.Nerve damage and loss of fracture reduction are common recognised complications in patients with this injury.Uncertainty surrounds...Purpose:Supracondylar fractures of the humerus cause significant morbidity in children.Nerve damage and loss of fracture reduction are common recognised complications in patients with this injury.Uncertainty surrounds the optimal Kirschner wire configuration and diameter for closed reduction and pinning of these fractures.This study describes current practice and examined the association between wire configuration or diameter and outcomes(clinical and radiological)in the operative management of paediatric supracondylar fractures.Methods:Children presenting w让h GartlandⅡorⅢsupracondylar fractures at five hospitals in southwest England were eligible for inclusion.Collaborators scrutinised paper and electronic case notes.Outcome measures were maintenance of reduction and iatrogenic nerve injury.Results:Altogether 209 patients were eligible for inclusion:15.7%had a documented neurological deficit at presentation;3.9%who were neurologically intact at presentation sustained a new deficit caused by treatment and 13.4%experienced a clinically significant loss of reduction following fixation.Maintenance of reduction was significantly better in patients treated specifically with crossed×3 Kirschner wire configuration compared to all other configurations.The incidence of iatrogenic nerve injury was not significantly different between groups treated with different wire configurations.Conclusion:We present a large multicentre cohort study showing that crossed×3 Kirschner wires are associated with better maintenance of reduction than crossed×2 or lateral entry wires.Greater numbers would be required to properly investigate nerve injury relating to operative management of supracondylar fractures.We found significant variations in practice and compliance w让h the British Orthopaedic Association Standard for Trauma(BOAST)11 guidelines.展开更多
This article is based on a recent model specifically defining magnetic field values around electrical wires. With this model, calculations of field around parallel wires were obtained. Now, this model is extended with...This article is based on a recent model specifically defining magnetic field values around electrical wires. With this model, calculations of field around parallel wires were obtained. Now, this model is extended with the new concept of magnetic equipotential surface to magnetic field curves around crossing wires. Cases of single, double, and triple wires are described. Subsequent article will be conducted for more general scenarios where wires are neither infinite nor parallel.展开更多
（Fes3Ga17）98Cr2 wires each with a diameter of 0.7 mm are prepared by hot swaging and warm drawing from the casting rods directly, because the ductility of Fes3Ga17alloy is improved by adding Cr element. The Wiedeman...（Fes3Ga17）98Cr2 wires each with a diameter of 0.7 mm are prepared by hot swaging and warm drawing from the casting rods directly, because the ductility of Fes3Ga17alloy is improved by adding Cr element. The Wiedemann twists and dependences on magnetostrictions of Fe83Ga17 and （Fe83Ga17）98Cr2 wires are investigated. The largest observed Wiedemann twists of 245 s.cm-1 and 182 s.cm-1 are detected in the annealed Fes3Ga17 and （Fe83Ga17）98Cr2 wires, respectively. The magnetostrictions of the annealed Fes3Ga17 and （Fes3Ga17）98Cr2 wires are 160 ppm and 107 ppm, respectively. The maximum of the Wiedemann twist increases with magnetostriction increasing. However the magnetostriction is just one important factor that affects the Wiedemann effect of alloy wire, and the relationship between magnetostriction and Wiedemann effect is a complex function rather than a simple function.展开更多
In this study, we present a 2-step deposition method via sputtering and electroplating that uses carbon nanotube(CNT) wires synthesized from a wet-spinning technique to produce high-performance CNT/Au/Cu composite wir...In this study, we present a 2-step deposition method via sputtering and electroplating that uses carbon nanotube(CNT) wires synthesized from a wet-spinning technique to produce high-performance CNT/Au/Cu composite wires. After the Au sputtering pre-treatment, the deposition of Cu on the CNT wires was found to be much more homogeneous due to improved wettability and reactivity of the wire surface. At different electrodeposition time, the mechanical strength of the CNT/Au/Cu composite wires could be as high as 0.74 GPa(~2 times stronger than metal wires) while their electrical conductivity could reach 4.65 × 10~5 S/cm(~80% of that for copper). More importantly, the CNT/Au/Cu composite wires with high CNT volume fraction are expected to be lightweight(up to 42% lower than Cu mass density), suggesting that our high-performance composite wires are a promising candidate to substitute conventional heavy metal wires in the future applications.展开更多
Objective： To evaluate the feasibility and therapeutic effect of treating sternoclavicular joint dislocation by K-wire and tension band wire fixation, and to improve the safety and stability of this technique.Methods...Objective： To evaluate the feasibility and therapeutic effect of treating sternoclavicular joint dislocation by K-wire and tension band wire fixation, and to improve the safety and stability of this technique.Methods： This study consisted of 9 cases, 6 males and 3 females with the mean age of 25 years （range, 9-62 years）.The causes were traffic accident in 7 cases, falling in 1 case and fight in 1 case. The duration from injury to operation was 2 hours to 7 days. There were 5 left dislocations and 4right dislocations; 8 anterior dislocations and 1 posterior dislocation, including one combined with left scapular fracture and one with left olecranon fracture. Open reduction and internal fixation using K-wires and tension band wires were performed to treat dislocations.Results： All patients were followed up for 6 to 24months, 10 months on average. According to Rockwood＇s rating scale on postoperative sternoclavicular joint, 8 cases achieved excellent outcomes with an average score of 13.88,and the rest case achieved a good outcome with the score of 12. Anatomical reduction was obtained in all cases. There were no such postoperative complications as severe infection, injury to blood vessel and nerve, failure of fixation,etc. Patients were all satisfied with the anatomical reduction and functional recovery.Conclusions： The technique of K-wire and tension band wire fixation is safe, simple, effective, less invasive and has been successfully used in orthopedic surgery. It is effective in treating sternoclavicular joint dislocation though it has some disadvantages.展开更多
基金Project supported by One Hundred Excellent Talents of Hebei Province of China and Key Project of Science and Technology of Hebei Province (09215106D)
文摘The flux cored wires with different amounts of rare earth （RE） oxides additions for hardfacing （harden-face-welding） the workpieces of high chromium cast iron were studied in this work.The morphology of carbides in hardfacing metal was observed,and the type of the carbides was determined by optical microscopy,scanning electron microscopy （SEM）,energy dispersive spectrometer （EDS） and X-ray diffraction （XRD）.Based on the data of effect of RE on carbides morphology,the refined reason for carbide by RE oxide was discussed with the misfit theory.The results showed that,the microstructure of hardfacing metal was composed of martensite,residual austenite and M7C3 carbides.With the increasing amount of RE oxide additions,the volume fraction and roundness of the carbides were increased,however,the area and perimeter of carbides were decreased.It indicated that carbides in hardfacing metal could be refined and spheroidized by adding RE oxides in flux cored wires.
文摘Objective:To comparatively study complete dislo cation of acromioclavicular joint treated with three different methods. Methods:A total of 96 patients (81 males and 15 females, aged 16-59 years, mean=45 years) with complete dislocation of acromioclavicular join t were treated with Dewars operation (Group A, n=32), internal fixation with K irschner tension band wires (Group B, n=44), or internal fixation with Wolter pl ates (Group C, n=20), respectively, in this study. Eighty-five patients suffere d from acute dislocations and eleven from chronic dislocations. Results:The patients were followed up for 50 months on an aver age. According to Karlssons standard, in Group A, 26 patients were assessed as good, 5 as fair and 1 as poor. In Group B, 20 patients were assessed as good, 1 3 as fair and 11 as poor. In Group C, 15 patients were assessed as good, 4 as fa ir and 1 as poor. The good and fair rates were significantly different between G roup A and Group B, and between Group C and Group B, but no statistical differen ce was found between Group A and Group C. The operating time was ( 52.36 ± 7 .24 ) minutes, ( 67.43 ± 8.11 ) minutes and ( 69.73 ± 8.04 ) minutes in Groups A, B and C, respectively. And the hospitalizing fees were ( 2 400 ± 270) yuan, ( 2 100 ±190) yuan and ( 8 450 ±360) yuan in Groups A, B and C, respectively. Conclusions:Dewars operation is a good and safe method with shorter operating time and lower hospitalizing fee for treating complete disloca tion of acromioclavicular joint. The method is simple without the need of a seco nd operation to remove the implants and with few complications.
文摘Objective： To assess the therapeutic results of open reduction and internal fixation with crossed K-wires via lateral approach for displaced supracondvlar fractures of the humerus in children. Methods： We prospectively followed 52 children who presented with Gartland type 3 displaced supraeondylar fractures of the humerus and were managed by open reduction and internal fixation with crossed K-wires via lateral approach.There were 37 male and 15 female patients; average age was 7.39 years. The most common mechanism of trauma was fall while playing （n=23）, followed by fall from height （n=20）, road traffic accidents （n-5） and fall from standing height （n=2）. In 2 cases, mode of injury was not available. The mean follow-up was 12 months and patients were assessed according to Flynn＇s criteria. Results： Lateral approach provided an excellent view of the lateral column between two nervous planes and enabled an anatomical reduction in all cases. Immobilizing the elbow at 90 degrees or more of flexion was not needed after cross K-wire fixation. Majority of patients regained full range of motion within 6 weeks of pin removal. Two patients had postoperative ulnar nerve injuries that resolved after pin removal. The common late complication of cubitus varus was not seen in any patient. Delayed presentation to the emergency department, repeated manipulations by bone setters and massage with edible oil were responsible for stiffness in 5 patients. Superficial pin tract infection was noted in 5 patients that resolved with dressings and antibiotics. No deep infection occurred. A detailed clinical examination and radiographic analysis was done at final follow-up. They included measurement of carrying angle and range of movements of both operated and normal sides, and radiographs of both upper limbs for comparison. According to Flynn＇s criteria, 90.4% patients showed satisfactory results. Conclusion： Lateral approach for open reduction and internal fixation of the widely-displaced supracondylar fract
基金Supported by the National Natural Science Foundation of China (Grant Nos. 50471098 and 59971033)the Natural Science Foundation of Shaanxi Province, China (Grant No. 2003E101)the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institution of MOE, China
文摘The deformation microstructure evolution of single crystal copper wires produced by OCC method has been studied with the help of TEM, EBSD; OM. The results show that there are a small number of dendrites; twins in the undeformed single crystal copper wires. However, it is difficult to observe these dendrites in deformed single crystal copper wires. The structure evolution of deformed single crystal copper wires during drawing process can be divided into three stages. When the true strain is lower than 0.94, macroscopic subdivision of grains is not evident,; the microscopic evolution of deformed structure is that the cells are formed; elongated in drawn direction. When the true strain is between 0.94; 1.96, macroscopic subdivision of grains takes place,; the number of microbands located on {111}; cell blocks is much more than that with the true strain lower than 0.94. When the true strain is larger than 1.96, the macroscopic subdivision of grains becomes more evident than that with the true strain between 0.94; 1.96,; S-bands structure; lamellar boundaries will be formed. From EBSD analysis, it is found that part of 100 texture resulting from solidifying is transformed into 111; 112 due to shear deformation, but 100 texture component is still kept in majority. When the true strain is 0.94, the misorientation angle of dislocation boundaries resulting from deformation is lower than 14°. However, when the true strain arrives at 1.96, the misorientation angle of some boundaries will be greater than 50°,; the peak of misorientation angle distribution produced by texture evolution is located in the range between 25°; 30°.
基金supported by National Key Technology R&D Program of China (Grant No. 2008BAC48B01)National Natural Science Foundation of China (Grant No. 40775012)+1 种基金the Jiangsu Province Qinglan Project for Cloud Fog Precipitation and the Aerosol Research Groupa project funded by the Priority Acadenic Program Development of Jiangsu Higher Education Institutions
文摘The weather system, meteorological conditions, and microphysics of cloud, fog, and rain droplets are studied during the formation, growth, maintenance, and shedding periods of ice accretion on wires in Enshi, Hubei Province in China using 2008/2009 and 2009/2010 winter observations. The comprehensive observations include data of visibility, microphysics of fog and rain droplets, and ice thickness, as well as data from an automated weather station and other routinely recorded meteorological data. The results show that icing occurred during the passage of a cold front, with a high-pressure system and a cold temperature trough at 850 hPa, and a southeasterly at 500 hPa that provided abundant moisture. Ice formation usually started in the evening or early morning, and ice shed around noon the following day when the temperature was -1℃ to 0℃. The averaged liquid water content of the fog droplet was distinctly greater during the growth period than during the other three periods, and there was precipitation during the growth period in each case of ice accretion. The growth rate of the ice thickness was clearly correlated with the liquid water content, with a correlation coefficient of 0.62. Simulations using empirical equations were carried out, and the simulated ice thickness agreed with observations fairly well.
文摘Building on a new model proposed recently for calculating constant electro-magnetic field values, the present article explores the electro-magnetic field configuration generated by parallel electrical wires. This imposes a reevaluation of the drawing procedure for constructing field curves with a constant field values around multiple parallel electrical conducting wires. To achieve this, we employ methods akin to those used for creating contours on topographical maps, ensuring a consistent numerical field value along the entire length of the field curves. Subsequent calculations will be conducted for scenarios where wires are not parallel.
基金supported by National Natural Science Foundation for Distinguished Young Scholar of China (Grant No. 50925518)National Natural Science Foundation of China (Grant No. 50775226)+1 种基金Key Project of Ministry of Education of China(Grant No. 109129)Chongqing Municipal Key Scientific and Technological Project of China (Grant No. CSTC2009AC3049)
文摘A stranded wires helical spring is formed of a multilayer and coaxial strand of several wires twisted together with the same direction of spiral. Compared with the conventional single wire spring, the stranded wires helical spring has the notable predominance in strength, damping and vibration reduction, which is usually used in aircraft engines, automatic weapons, etc. However, due to its complicated structure, the precise computation of its strength and rigidity need be a correct mathematical model, which then will be imported to finite element analysis software for solutions. Equations on solving geometric parameters, such as external diameters of strands and screw pitches of wires, are put forward in the paper. It also proposes a novel methodology on solving geometric parameters and establishing entity models of the stranded wires helical spring, which provides foundation of computing mechanical parameters by FEA. Then mathematical models on the centre line of the strand and the surface curve of each wire, after closing two ends in a spring, are proposed. Finally, geometric parameters are solved in a case study, and a 3D entity model of a spring with 3 layers and 16 wires is established, which has validated the accuracy of the proposed methodology and the 3D entity mathematical model. The method provides a new way to design stranded wire helical spring.
基金Projects(50771076,50901055)supported by the National Natural Science Foundation of ChinaProject(07JK274)supported by the Education Department Foundation of Shaanxi Province,China
文摘The texture evolution of cold drawing copper wires produced by continuous casting was measured by X-ray diffractometry and electron back-scatter diffractometry,and was simulated using Taylor model.The results show that in the drawn poly-crystal copper wires produced by traditional continuous casting,111 and 100 duplex fiber texture forms,and with increasing strain,the intensities of 111 and 100 increase.In the drawn single-crystal copper wires produced by Ohno continuous casting,100 rotates to 111,and there is inhomogeneous distribution of fiber texture along radial direction of the wires,which is caused by the distribution of shear deformation.Compared with 100,111 fiber texture is more stable in the drawn copper wires.Comparison of the experimental results with the simulated results shows that the simulation by Taylor model can analyze the texture evolution of drawn copper wires.
基金Project(51222405)supported by the National Natural Science Foundation for Outstanding Young Scholars of ChinaProject(51034002)supported by the National Natural Science Foundation of ChinaProject(120502001)supported by the Fundamental Research Funds for the Central Universities of China
文摘In order to obtain the Al wires with good mechanical properties and high electrical conductivities, conductive wires of Al-0.16 Zr, Al-0.16 Sc, Al-0.12Sc-0.04Zr（mass fraction, %） and pure Al（99.996%） were produced with the diameter of 9.5 mm by continuous rheo-extrusion technology, and the extruded materials were heat treated and analyzed. The results show that the separate additions of 0.16% Sc and 0.16% Zr to pure Al improve the ultimate tensile strength but reduce the electrical conductivity, and the similar trend is found in the Al-0.12Sc-0.04 Zr alloy. After the subsequent heat treatment, the wire with the optimum comprehensive properties is Al-0.12Sc-0.04 Zr alloy, of which the ultimate tensile strength and electrical conductivity reach 160 MPa and 64.03%（IACS）, respectively.
文摘Purpose:Supracondylar fractures of the humerus cause significant morbidity in children.Nerve damage and loss of fracture reduction are common recognised complications in patients with this injury.Uncertainty surrounds the optimal Kirschner wire configuration and diameter for closed reduction and pinning of these fractures.This study describes current practice and examined the association between wire configuration or diameter and outcomes(clinical and radiological)in the operative management of paediatric supracondylar fractures.Methods:Children presenting w让h GartlandⅡorⅢsupracondylar fractures at five hospitals in southwest England were eligible for inclusion.Collaborators scrutinised paper and electronic case notes.Outcome measures were maintenance of reduction and iatrogenic nerve injury.Results:Altogether 209 patients were eligible for inclusion:15.7%had a documented neurological deficit at presentation;3.9%who were neurologically intact at presentation sustained a new deficit caused by treatment and 13.4%experienced a clinically significant loss of reduction following fixation.Maintenance of reduction was significantly better in patients treated specifically with crossed×3 Kirschner wire configuration compared to all other configurations.The incidence of iatrogenic nerve injury was not significantly different between groups treated with different wire configurations.Conclusion:We present a large multicentre cohort study showing that crossed×3 Kirschner wires are associated with better maintenance of reduction than crossed×2 or lateral entry wires.Greater numbers would be required to properly investigate nerve injury relating to operative management of supracondylar fractures.We found significant variations in practice and compliance w让h the British Orthopaedic Association Standard for Trauma(BOAST)11 guidelines.
文摘This article is based on a recent model specifically defining magnetic field values around electrical wires. With this model, calculations of field around parallel wires were obtained. Now, this model is extended with the new concept of magnetic equipotential surface to magnetic field curves around crossing wires. Cases of single, double, and triple wires are described. Subsequent article will be conducted for more general scenarios where wires are neither infinite nor parallel.
基金Project supported by the State Key Development Program for Basic Research of China (Grant No. 2011CB606304)the National Natural Science Foundation for Postdoctoral Scientists of China (Grant No. 2011M500229)the Program for New Century Excellent Talents in University,China (Grant No. NCET-09-02120)
文摘（Fes3Ga17）98Cr2 wires each with a diameter of 0.7 mm are prepared by hot swaging and warm drawing from the casting rods directly, because the ductility of Fes3Ga17alloy is improved by adding Cr element. The Wiedemann twists and dependences on magnetostrictions of Fe83Ga17 and （Fe83Ga17）98Cr2 wires are investigated. The largest observed Wiedemann twists of 245 s.cm-1 and 182 s.cm-1 are detected in the annealed Fes3Ga17 and （Fe83Ga17）98Cr2 wires, respectively. The magnetostrictions of the annealed Fes3Ga17 and （Fes3Ga17）98Cr2 wires are 160 ppm and 107 ppm, respectively. The maximum of the Wiedemann twist increases with magnetostriction increasing. However the magnetostriction is just one important factor that affects the Wiedemann effect of alloy wire, and the relationship between magnetostriction and Wiedemann effect is a complex function rather than a simple function.
基金supported financially by the Lloyd’s Register Foundation (No.R-265-000-553-597).
文摘In this study, we present a 2-step deposition method via sputtering and electroplating that uses carbon nanotube(CNT) wires synthesized from a wet-spinning technique to produce high-performance CNT/Au/Cu composite wires. After the Au sputtering pre-treatment, the deposition of Cu on the CNT wires was found to be much more homogeneous due to improved wettability and reactivity of the wire surface. At different electrodeposition time, the mechanical strength of the CNT/Au/Cu composite wires could be as high as 0.74 GPa(~2 times stronger than metal wires) while their electrical conductivity could reach 4.65 × 10~5 S/cm(~80% of that for copper). More importantly, the CNT/Au/Cu composite wires with high CNT volume fraction are expected to be lightweight(up to 42% lower than Cu mass density), suggesting that our high-performance composite wires are a promising candidate to substitute conventional heavy metal wires in the future applications.
文摘Objective： To evaluate the feasibility and therapeutic effect of treating sternoclavicular joint dislocation by K-wire and tension band wire fixation, and to improve the safety and stability of this technique.Methods： This study consisted of 9 cases, 6 males and 3 females with the mean age of 25 years （range, 9-62 years）.The causes were traffic accident in 7 cases, falling in 1 case and fight in 1 case. The duration from injury to operation was 2 hours to 7 days. There were 5 left dislocations and 4right dislocations; 8 anterior dislocations and 1 posterior dislocation, including one combined with left scapular fracture and one with left olecranon fracture. Open reduction and internal fixation using K-wires and tension band wires were performed to treat dislocations.Results： All patients were followed up for 6 to 24months, 10 months on average. According to Rockwood＇s rating scale on postoperative sternoclavicular joint, 8 cases achieved excellent outcomes with an average score of 13.88,and the rest case achieved a good outcome with the score of 12. Anatomical reduction was obtained in all cases. There were no such postoperative complications as severe infection, injury to blood vessel and nerve, failure of fixation,etc. Patients were all satisfied with the anatomical reduction and functional recovery.Conclusions： The technique of K-wire and tension band wire fixation is safe, simple, effective, less invasive and has been successfully used in orthopedic surgery. It is effective in treating sternoclavicular joint dislocation though it has some disadvantages.
