An automatic 3D wiring method for switchgear design is proposed in this paper. First, wiring constraints are created, and a corresponding evaluation model is proposed. Then, based on the structure of the cabinet, we p...An automatic 3D wiring method for switchgear design is proposed in this paper. First, wiring constraints are created, and a corresponding evaluation model is proposed. Then, based on the structure of the cabinet, we propose a contour expansion scheme to construct rough paths. Different wiring features of the switchgear are used to connect rough local paths. All the paths are represented in a uniform data structure and forma path network. Finally, an improved A* algorithm is used to search the wiring path between the components in the routing network; the evaluation model is considered as heuristic rules for path searching. The result can satisfy the practical requirements of switchgear design. Experimental results are also provided.展开更多
This paper introduces the necessity and superiority of auxiliary wiring WEBGIS, as well as system implementation difficulties and countermeasures. Then explained the general concept of auxiliary wiring systems, data i...This paper introduces the necessity and superiority of auxiliary wiring WEBGIS, as well as system implementation difficulties and countermeasures. Then explained the general concept of auxiliary wiring systems, data interface response, and finally introduced the system wiring switchover function, and gave an example.展开更多
Objectives: Atlantoaxial dislocation remains a rare and serious condition with a high preoperative and postoperative morbidity and mortality. Its successful surgical management is still challenging and gratifying for ...Objectives: Atlantoaxial dislocation remains a rare and serious condition with a high preoperative and postoperative morbidity and mortality. Its successful surgical management is still challenging and gratifying for neurosurgeons. Several technics have been described such as wiring, trans articular screwing, C1C2 screwing with plate and screw introduced by Goel et al., and modified by insertion of polyaxially screw and rod many years later by Harms. Unavailability and expensiveness of upper cervical spine instrumentation device led us to C1C2 Wiring resulting in a good outcome. Finally, a quadriplegic patient with a more comfortable financial condition had ordered devices from abroad and benefit for Goel and Harms screwing technique and improved dramatically from ASIA A to ASIA E. Material and methods: This is a retrospective study of patients managed in our department by a same neurosurgeon from January 2019 to April 2024. Results: We defined 6 men and 1 woman with an average age of 33 years. Unrestrained driver in a rollover motor vehicle accident was most common. Only one patient was neurologically intact on admission. Neurovegetative disorders were noticed in one patient. Dislocation was associated to a fracture of the dens in two patients. Three patients have been successfully operated with remarkable outcome, mostly from ASIA A to E. Conclusion: C1C2 dislocation is a serious condition and C1C2 Wiring represents an effective and cheaper technic. Therefore, this technic should deserve consideration above all in low incomes countries when screwing devices are not available. Seatbelt should be demanded for motor vehicle drivers and passengers.展开更多
Identifying each process and their constraint relations from the complex wiring harness drawings quickly and accurately is the basis for formulating process routes. According to the knowledge of automotive wiring harn...Identifying each process and their constraint relations from the complex wiring harness drawings quickly and accurately is the basis for formulating process routes. According to the knowledge of automotive wiring harness and the characteristics of wiring harness components, we established the model of wiring harness graph. Then we research the algorithm of identifying technology processes automatically, finally we describe the relationships between processes by introducing the constraint matrix, which is in or- der to lay a good foundation for harness process planning and production scheduling.展开更多
MASEGO Dibetle, an information and communications technology （ICT） student at Tshwane University of Technology in South Africa, looks utterly delighted. Over the last two weeks, the 20-year-old has met with world le...MASEGO Dibetle, an information and communications technology （ICT） student at Tshwane University of Technology in South Africa, looks utterly delighted. Over the last two weeks, the 20-year-old has met with world leading experts in her field of study and visited state-of-the-art laboratories during her first trip to China.展开更多
Purpose： Tension band wiring is commonly used for fixation of simple transverse fractures. The popular configuration is parallel Kirschner wires （K-wires） and a stainless steel wire loop placed in a vertically orie...Purpose： Tension band wiring is commonly used for fixation of simple transverse fractures. The popular configuration is parallel Kirschner wires （K-wires） and a stainless steel wire loop placed in a vertically oriented figure-of-8. Methods： We used a wooden model of a patella with a midway transverse fracture and compared four different types of fixation. The first construct had a vertical figure-of-8 with one twist of wire. The second contained a vertical figure-of-8 with two twists of wire. The third was a vertical figure-of-8 with two twists of wire placed at adjacent corners while the last one had a horizontal figure-of-8 with two twists of wire placed at adjacent corners, lnterfragmentary compression at the point of wire breakage was measured for each construct as well as permanent displacement on cyclic loading. Results： Placement of the figure-of-eight in a horizontal orientation with two wire twists at the corner improved interfragmentary compression by 63% （p 〈 0.05, Tukey post ]hoc test）. On cyclic loading, all the constructs with vertical figure-of-eight but none with a horizontal construct failed （p = 0.01; Fisher＇s exact test）. Permanent fracture displacement after cyclic loading was ,57% lower with horizontal figure- of-eight constructs （p 〈 0.05; t test）. Conclusion： Placing wire twists at the corner and a horizontal placement of figure-of-8 improves stability of the construct.展开更多
Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing addit...Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing additive-induced defects,and alleviating residual stress and deformation,all of which are critical for enhancing the mechanical performance of the manufactured parts.Integrating interlayer friction stir processing(FSP)into WAAM significantly enhances the quality of deposited materials.However,numerical simulation research focusing on elucidating the associated thermomechanical coupling mechanisms remains insufficient.A comprehensive numerical model was developed to simulate the thermomechanical coupling behavior in friction stir-assisted WAAM.The influence of post-deposition FSP on the coupled thermomechanical response of the WAAM process was analyzed quantitatively.Moreover,the residual stress distribution and deformation behavior under both single-layer and multilayer deposition conditions were investigated.Thermal analysis of different deposition layers in WAAM and friction stir-assisted WAAM was conducted.Results show that subsequent layer deposition induces partial remelting of the previously solidified layer,whereas FSP does not cause such remelting.Furthermore,thermal stress and deformation analysis confirm that interlayer FSP effectively mitigates residual stresses and distortion in WAAM components,thereby improving their structural integrity and mechanical properties.展开更多
This paper describes a built-in self-test (BIST) hardware overheadminimization technique used during a BIST synthesis process. The technique inserts a minimal amountof BIST resources into a digital system to make it f...This paper describes a built-in self-test (BIST) hardware overheadminimization technique used during a BIST synthesis process. The technique inserts a minimal amountof BIST resources into a digital system to make it fully testable. The BIST resource insertion isguided by the results of symbolic testability analysis. It takes into consideration both BISTregister cost and wiring overhead in order to obtain the minimal area designs. A Simulated Annealingalgorithm is used to solve the overhead minimization problem. Experiments show that consideringwiring area during BIST synthesis results in smaller final designs as compared to the cases when thewiring impact is ignored.展开更多
Mechanical waste-processing methods,whichcombine crushing and separation processes for therecovery of valuable materials,have been widely appliedin waste printed wiring board(PWB)treatment.However,both the high impact...Mechanical waste-processing methods,whichcombine crushing and separation processes for therecovery of valuable materials,have been widely appliedin waste printed wiring board(PWB)treatment.However,both the high impact toughness and the tensile and flexuralstrengths of whole PWB with a laminated structure resultin great energy consumption and severe abrasion of thecutters during multi-level crushing.In addition,the hightemperatures occurring in continual crushing probablycause the decomposition of the polymer matrix.A thermalcrackmethod using residual steam as the heating mediumhas been developed to pre-treat waste PWBs.Thistreatment reduces the mechanical strength in order toimprove the recovery rate of valuable materials insubsequent mechanical recycling.The changes of thePWBs’macro-mechanical properties were studied toevaluate thermal expansion impacts associated withchanges in temperature,and the dynamic dislocationmicro-structures were observed to identify the fracturemechanism.The results showed that thermal cracking withsteam at the temperature of 500 K can effectively attenuatethe mechanical properties of waste PWBs,by reducing theimpact,tensile and flexural strengths respectively,by59.2%,49.3%and 51.4%,compared to untreated PWB.Thermal expansion can also facilitate the separation ofcopper from glass fiber by reducing peel resistance by95.4%at 500 K.It was revealed that the flexural fracturewas a transverse cracking caused by concentrated stresswhen the heating temperature was less than 500 K,andshifted to a vertical cracking after exceeding 500 K.展开更多
Purpose:Intramedullary nailing is the preferred internal fixation technique for the treatment of subtrochanteric fractures because of its biomechanical advantages.However,no definitive conclusion has been reached rega...Purpose:Intramedullary nailing is the preferred internal fixation technique for the treatment of subtrochanteric fractures because of its biomechanical advantages.However,no definitive conclusion has been reached regarding whether combined cable cerclage is required during intramedullary nailing treatment.This study is performed to compare the clinical effects of intramedullary nailing with cerclage and non-cerclage wiring in the treatment of irreducible spiral subtrochanteric fractures.Methods:Patients with subtrochanteric fractures admitted to our center from January 2013 to December 2021 were retrospectively analyzed.The patients were enrolled in the case-control study according to the inclusion and exclusion criteria and divided into the non-cerclage group and the cerclage group.The patients'clinical data,including the operative time,intraoperative blood loss,hospital stay,reoperation rate,fracture union time,and Harris hip score,were compared between these 2 groups.Categorical variables were compared using Chi-square or Fisher's exact test.Continuous variables with normal distribution were presented as mean±standard deviation and analyzed with Student's t-test.Nonnormally distributed variables were expressed as median(Q_(1),Q_(3))and assessed using the Mann-Whitney test.A p<0.05 was considered significant.Results:In total,69 patients were included in the study(35 patients in the non-cerclage group and 34 patients in the cerclage group).The baseline data of the 2 groups were comparable.There were no significant difference in the length of hospital stay(z=-0.391,p=0.696),operative time(z=-1.289,p=0.197),or intraoperative blood loss(z=-1.321,p=0.186).However,compared with non-cerclage group,the fracture union time was shorter(z=-5.587,p<0.001),the rate of nonunion was lower(χ^(2)=6.030,p=0.03),the anatomical reduction rate was higher(χ^(2)=5.449,p=0.03),and the Harris hip score was higher(z=-2.99,p=0.003)in the cerclage group,all with statistically significant differences.Conclusions:Intramedullary nailing combined with cable cerclage wiring is a safe and reliable technique for the treatment of irreducible subtrochanteric fractures.This technique can improve the reduction effect,increase the stability of fracture fixation,shorten the fracture union time,reduce the occurrence of nonunion,and contribute to the recovery of hip joint function.展开更多
We present the first systematic experimental validation of return-current-driven cylindrical implosion scaling in micrometer-sized Cu and Al wires irradiated by J-class femtosecond laser pulses.Employing XFEL-based im...We present the first systematic experimental validation of return-current-driven cylindrical implosion scaling in micrometer-sized Cu and Al wires irradiated by J-class femtosecond laser pulses.Employing XFEL-based imaging with sub-micrometer spatial and femtosecond temporal resolution,supported by hydrodynamic and particle-in-cell simulations,we reveal how return current density depends precisely on wire diameter,material properties,and incident laser energy.We identify deviations from simple theoretical predictions due to geometrically influenced electron escape dynamics.These results refine and confirm the scaling laws essential for predictive modeling in high-energy-density physics and inertial fusion research.展开更多
In this study,multilayer lamination welding was employed to prepare graphene/copper(Gr/Cu)composite billets from graphene-coated copper foils,followed by multi-pass cold drawing to produce Φ1 mm Gr/Cu composite wires...In this study,multilayer lamination welding was employed to prepare graphene/copper(Gr/Cu)composite billets from graphene-coated copper foils,followed by multi-pass cold drawing to produce Φ1 mm Gr/Cu composite wires.Microstructure and property analyses in both the cold-drawn and annealed states show that the incorporation of graphene significantly improves the ductility and electrical conductivity of the copper wire.After annealing at 350℃ for 30 minutes,the composite wire demonstrates a tensile strength of 270 MPa and an electrical conductivity of 102.74%IACS,both superior to those of pure copper wire under identical conditions.At 150℃,the electrical conductivity of the annealed composite wire reaches 72.60%IACS,notably higher than the 68.19%IACS of pure copper.The results suggest that graphene is uniformly distributed within the composite wire,with minimal impact on conductivity,while effectively refining the copper grain structure to enhance ductility.Moreover,graphene suppresses copper lattice vibrations at elevated temperatures,reducing the rate of conductivity degradation.展开更多
Osmotic energy,existing between the seawater and river water,is a renewable energy source,which can be directly converted into electricity by ion-exchange membranes(IEM).In traditional IEMs,the ion transport channels ...Osmotic energy,existing between the seawater and river water,is a renewable energy source,which can be directly converted into electricity by ion-exchange membranes(IEM).In traditional IEMs,the ion transport channels are formed by nanophase separation of hydrophilic ion carriers and hydrophobic segments.It is difficult to realize high-density ion channels with controlled spatial arrangement and length scale of ion carriers.Herein,we construct high-density 1D ion wires as transmission channels.Through molecular design,hydrophilic imidazole groups and hydrophobic alkyl tails were introduced into the repeat units,which self-assembled into 1D ion transporting core and protecting shell along the main chains.The areal density of the ionic wire arrays is up to~10^(12)cm^(-2),which is the highest value.The ionic wires ensure both high ion flux transport and high selectivity,achieving an ultrahigh-power density of 40.5 W m^(-2)at a 500-fold salinity gradient.Besides,the ionic wire array membrane is well recyclable and antibacterial.The ionic wires provide novel concept for next generation of high-performance membranes.展开更多
Giant magnetoimpedance(GMI)sensors are increasingly employed in modern magnetic sensing technologies.However,improving the GMI performance of magnetic cores remains challenging due to intrinsic limitations in material...Giant magnetoimpedance(GMI)sensors are increasingly employed in modern magnetic sensing technologies.However,improving the GMI performance of magnetic cores remains challenging due to intrinsic limitations in material properties and structural stability.In this work,we explore the use of Joule heating to enhance the GMI response of Fe_(20)Ni_(80)/Cu composite wires.By applying a current of 1.8 A for 10 min,notable improvements in magnetic domain uniformity and a reduction in domain spacing are observed.Under these conditions,GMI ratios reach 1870% in the non-diagonal mode and1147%in the diagonal mode,respectively,highlighting their potential for applications in high-precision weak magnetic field sensing.展开更多
The fabrication of 304L stainless welding wires with a diameter 1.6 mm by using electrochemical cold drawing(ECD)of bars with a diameter of 5.6 mm was investigated,as well as that via traditional cold drawing(TCD)for ...The fabrication of 304L stainless welding wires with a diameter 1.6 mm by using electrochemical cold drawing(ECD)of bars with a diameter of 5.6 mm was investigated,as well as that via traditional cold drawing(TCD)for comparison.The results indicated that the dilute H_(2)SO_(4)aqueous solution was an appropriate electrolyte for ECD,and increasing the H_(2)SO_(4)concentration and current density within a range improved the corrosion rate and uniformity,leading to an easier and more coordinated deformation through uniformly distributing geometrically necessary dislocations and curved large-angle grain boundaries,and decreasing their density,and thus,an enhanced electrochemical plasticization(EP).Under the optimized electrochemical parameters(0.5 mol L^(-1)H_(2)SO_(4)electrolyte and current density of 12.2 mA cm^(-2)),the average cumulative reduction rate required for annealing was up to~34%,obviously higher than~20%of TCD due to the decreased work-hardening from the EP,so that the number of annealing was significantly reduced from 10 of TCD to 5,when the drawing pass was 23.In addition,the surface of the ECD wire was distinctly smoother and brighter than that of the TCD one.These findings confirm the large potential in engineering applications of the ECD technology based on the EP effect.展开更多
Inconel 625 alloy components were fabricated using hot wire laser metal deposition(HW-LMD)through process optimization,achieving a wire deposition rate of 1.72 kg/h.The microstructure and mechanical properties of the ...Inconel 625 alloy components were fabricated using hot wire laser metal deposition(HW-LMD)through process optimization,achieving a wire deposition rate of 1.72 kg/h.The microstructure and mechanical properties of the HW-LMD Inconel 625 alloys were systematically investigated.The results revealed that the microstructure of the HWLMD Inconel 625 alloys consisted of columnar dendrites,characterized by an average grain size of 12.5μm and a strong{100}〈001〉texture.The main phase identified wasγ-Ni,with the precipitation of Laves phase,measuring less than 1μm,observed in the inter-columnar dendritic regions.The average microhardness of the HW-LMD Inconel 625 alloys was HV1.0258.The yield strength and ultimate tensile strength were 493.5 and 837.4 MPa,respectively,with elongation exceeding 50%.Impact absorbing energies at 25 and-78℃were 223.08 and 200.24 J,respectively.Both the tensile and impact fracture surfaces exhibited dimples,indicating a ductile fracture mechanism during the deformation process.展开更多
Traditional dynamic analysis of mechanical structures,often limited to individual beams or plates,fails to fully capture their dynamic behaviors.In systems where space and mass are constrained,such as the battery supp...Traditional dynamic analysis of mechanical structures,often limited to individual beams or plates,fails to fully capture their dynamic behaviors.In systems where space and mass are constrained,such as the battery support structures in electric aircraft,conventional absorbers and isolators are insufficient for effective vibration control.This study simplifies the battery support structure of electric aircraft as an integrated composite beam consisting of three interconnected beams,and investigated its structural dynamics properties and nonlinear vibration control under thermal conditions caused by battery heat.The nonlinear vibration control is performed using the Nitinol steel wire ropes(Ni Ti-ST),with nonlinear damping properties.The natural frequencies of system are determined using the Rayleigh-Ritz technique.Theoretical results are validated through both Finite Element Method(FEM)and hammer tests.Moreover,the dynamic equations are derived using the Lagrange method and discretized via the Galerkin Truncation Method(GTM).The Harmonic Balance Method(HBM)is used to evaluate the vibration responses of the integrated model,with further verification through the Runge-Kutta Method(RKM).The experiments are conducted to corroborate the theoretical analysis.The results show that the system frequency changes in stages with the increase of the stiffness of the integrated composite beam connection.Especially in the case of varying environments,as the temperature increases,the frequency of system will first increase to a certain maximum value and then gradually decrease.Furthermore,the NiTi-ST effectively reduces vibration in the integrated composite beam,particularly under varying temperatures and external excitations.展开更多
基金Supported by National Key Technologies R&D Program of China(2015BAF23B03)National Nature Science Foundation of China(61672307)
文摘An automatic 3D wiring method for switchgear design is proposed in this paper. First, wiring constraints are created, and a corresponding evaluation model is proposed. Then, based on the structure of the cabinet, we propose a contour expansion scheme to construct rough paths. Different wiring features of the switchgear are used to connect rough local paths. All the paths are represented in a uniform data structure and forma path network. Finally, an improved A* algorithm is used to search the wiring path between the components in the routing network; the evaluation model is considered as heuristic rules for path searching. The result can satisfy the practical requirements of switchgear design. Experimental results are also provided.
文摘This paper introduces the necessity and superiority of auxiliary wiring WEBGIS, as well as system implementation difficulties and countermeasures. Then explained the general concept of auxiliary wiring systems, data interface response, and finally introduced the system wiring switchover function, and gave an example.
文摘Objectives: Atlantoaxial dislocation remains a rare and serious condition with a high preoperative and postoperative morbidity and mortality. Its successful surgical management is still challenging and gratifying for neurosurgeons. Several technics have been described such as wiring, trans articular screwing, C1C2 screwing with plate and screw introduced by Goel et al., and modified by insertion of polyaxially screw and rod many years later by Harms. Unavailability and expensiveness of upper cervical spine instrumentation device led us to C1C2 Wiring resulting in a good outcome. Finally, a quadriplegic patient with a more comfortable financial condition had ordered devices from abroad and benefit for Goel and Harms screwing technique and improved dramatically from ASIA A to ASIA E. Material and methods: This is a retrospective study of patients managed in our department by a same neurosurgeon from January 2019 to April 2024. Results: We defined 6 men and 1 woman with an average age of 33 years. Unrestrained driver in a rollover motor vehicle accident was most common. Only one patient was neurologically intact on admission. Neurovegetative disorders were noticed in one patient. Dislocation was associated to a fracture of the dens in two patients. Three patients have been successfully operated with remarkable outcome, mostly from ASIA A to E. Conclusion: C1C2 dislocation is a serious condition and C1C2 Wiring represents an effective and cheaper technic. Therefore, this technic should deserve consideration above all in low incomes countries when screwing devices are not available. Seatbelt should be demanded for motor vehicle drivers and passengers.
基金Supported by Chinese national Science Foundation (61070124)the Fundamental Research Funds for the Central Universities (2012HGBZ0195)
文摘Identifying each process and their constraint relations from the complex wiring harness drawings quickly and accurately is the basis for formulating process routes. According to the knowledge of automotive wiring harness and the characteristics of wiring harness components, we established the model of wiring harness graph. Then we research the algorithm of identifying technology processes automatically, finally we describe the relationships between processes by introducing the constraint matrix, which is in or- der to lay a good foundation for harness process planning and production scheduling.
文摘MASEGO Dibetle, an information and communications technology （ICT） student at Tshwane University of Technology in South Africa, looks utterly delighted. Over the last two weeks, the 20-year-old has met with world leading experts in her field of study and visited state-of-the-art laboratories during her first trip to China.
文摘Purpose： Tension band wiring is commonly used for fixation of simple transverse fractures. The popular configuration is parallel Kirschner wires （K-wires） and a stainless steel wire loop placed in a vertically oriented figure-of-8. Methods： We used a wooden model of a patella with a midway transverse fracture and compared four different types of fixation. The first construct had a vertical figure-of-8 with one twist of wire. The second contained a vertical figure-of-8 with two twists of wire. The third was a vertical figure-of-8 with two twists of wire placed at adjacent corners while the last one had a horizontal figure-of-8 with two twists of wire placed at adjacent corners, lnterfragmentary compression at the point of wire breakage was measured for each construct as well as permanent displacement on cyclic loading. Results： Placement of the figure-of-eight in a horizontal orientation with two wire twists at the corner improved interfragmentary compression by 63% （p 〈 0.05, Tukey post ]hoc test）. On cyclic loading, all the constructs with vertical figure-of-eight but none with a horizontal construct failed （p = 0.01; Fisher＇s exact test）. Permanent fracture displacement after cyclic loading was ,57% lower with horizontal figure- of-eight constructs （p 〈 0.05; t test）. Conclusion： Placing wire twists at the corner and a horizontal placement of figure-of-8 improves stability of the construct.
基金National Key Research and Development Program of China(2022YFB4600902)Shandong Provincial Science Foundation for Outstanding Young Scholars(ZR2024YQ020)。
文摘Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing additive-induced defects,and alleviating residual stress and deformation,all of which are critical for enhancing the mechanical performance of the manufactured parts.Integrating interlayer friction stir processing(FSP)into WAAM significantly enhances the quality of deposited materials.However,numerical simulation research focusing on elucidating the associated thermomechanical coupling mechanisms remains insufficient.A comprehensive numerical model was developed to simulate the thermomechanical coupling behavior in friction stir-assisted WAAM.The influence of post-deposition FSP on the coupled thermomechanical response of the WAAM process was analyzed quantitatively.Moreover,the residual stress distribution and deformation behavior under both single-layer and multilayer deposition conditions were investigated.Thermal analysis of different deposition layers in WAAM and friction stir-assisted WAAM was conducted.Results show that subsequent layer deposition induces partial remelting of the previously solidified layer,whereas FSP does not cause such remelting.Furthermore,thermal stress and deformation analysis confirm that interlayer FSP effectively mitigates residual stresses and distortion in WAAM components,thereby improving their structural integrity and mechanical properties.
文摘This paper describes a built-in self-test (BIST) hardware overheadminimization technique used during a BIST synthesis process. The technique inserts a minimal amountof BIST resources into a digital system to make it fully testable. The BIST resource insertion isguided by the results of symbolic testability analysis. It takes into consideration both BISTregister cost and wiring overhead in order to obtain the minimal area designs. A Simulated Annealingalgorithm is used to solve the overhead minimization problem. Experiments show that consideringwiring area during BIST synthesis results in smaller final designs as compared to the cases when thewiring impact is ignored.
基金This study was funded by the project from the National Natural Science Foundation of China(Grant No.20777043/B070204)the National Science and Technology Support Program(2006BAC02A18).
文摘Mechanical waste-processing methods,whichcombine crushing and separation processes for therecovery of valuable materials,have been widely appliedin waste printed wiring board(PWB)treatment.However,both the high impact toughness and the tensile and flexuralstrengths of whole PWB with a laminated structure resultin great energy consumption and severe abrasion of thecutters during multi-level crushing.In addition,the hightemperatures occurring in continual crushing probablycause the decomposition of the polymer matrix.A thermalcrackmethod using residual steam as the heating mediumhas been developed to pre-treat waste PWBs.Thistreatment reduces the mechanical strength in order toimprove the recovery rate of valuable materials insubsequent mechanical recycling.The changes of thePWBs’macro-mechanical properties were studied toevaluate thermal expansion impacts associated withchanges in temperature,and the dynamic dislocationmicro-structures were observed to identify the fracturemechanism.The results showed that thermal cracking withsteam at the temperature of 500 K can effectively attenuatethe mechanical properties of waste PWBs,by reducing theimpact,tensile and flexural strengths respectively,by59.2%,49.3%and 51.4%,compared to untreated PWB.Thermal expansion can also facilitate the separation ofcopper from glass fiber by reducing peel resistance by95.4%at 500 K.It was revealed that the flexural fracturewas a transverse cracking caused by concentrated stresswhen the heating temperature was less than 500 K,andshifted to a vertical cracking after exceeding 500 K.
文摘Purpose:Intramedullary nailing is the preferred internal fixation technique for the treatment of subtrochanteric fractures because of its biomechanical advantages.However,no definitive conclusion has been reached regarding whether combined cable cerclage is required during intramedullary nailing treatment.This study is performed to compare the clinical effects of intramedullary nailing with cerclage and non-cerclage wiring in the treatment of irreducible spiral subtrochanteric fractures.Methods:Patients with subtrochanteric fractures admitted to our center from January 2013 to December 2021 were retrospectively analyzed.The patients were enrolled in the case-control study according to the inclusion and exclusion criteria and divided into the non-cerclage group and the cerclage group.The patients'clinical data,including the operative time,intraoperative blood loss,hospital stay,reoperation rate,fracture union time,and Harris hip score,were compared between these 2 groups.Categorical variables were compared using Chi-square or Fisher's exact test.Continuous variables with normal distribution were presented as mean±standard deviation and analyzed with Student's t-test.Nonnormally distributed variables were expressed as median(Q_(1),Q_(3))and assessed using the Mann-Whitney test.A p<0.05 was considered significant.Results:In total,69 patients were included in the study(35 patients in the non-cerclage group and 34 patients in the cerclage group).The baseline data of the 2 groups were comparable.There were no significant difference in the length of hospital stay(z=-0.391,p=0.696),operative time(z=-1.289,p=0.197),or intraoperative blood loss(z=-1.321,p=0.186).However,compared with non-cerclage group,the fracture union time was shorter(z=-5.587,p<0.001),the rate of nonunion was lower(χ^(2)=6.030,p=0.03),the anatomical reduction rate was higher(χ^(2)=5.449,p=0.03),and the Harris hip score was higher(z=-2.99,p=0.003)in the cerclage group,all with statistically significant differences.Conclusions:Intramedullary nailing combined with cable cerclage wiring is a safe and reliable technique for the treatment of irreducible subtrochanteric fractures.This technique can improve the reduction effect,increase the stability of fracture fixation,shorten the fracture union time,reduce the occurrence of nonunion,and contribute to the recovery of hip joint function.
基金partially supported by the Center for Advanced Systems Understanding(CASUS)financed by Germany’s Federal Ministry of Education and Research(BMBF)+2 种基金the Saxon State Government out of the State Budget approved by the Saxon State Parliamentfunding from the European Union’s Just Transition Fund(JTF)within the project Röntgenlaser-Optimierung der Laserfusion(ROLF),Contract No.5086999001co-financed by the Saxon State Government out of the State Budget approved by the Saxon State Parliament.
文摘We present the first systematic experimental validation of return-current-driven cylindrical implosion scaling in micrometer-sized Cu and Al wires irradiated by J-class femtosecond laser pulses.Employing XFEL-based imaging with sub-micrometer spatial and femtosecond temporal resolution,supported by hydrodynamic and particle-in-cell simulations,we reveal how return current density depends precisely on wire diameter,material properties,and incident laser energy.We identify deviations from simple theoretical predictions due to geometrically influenced electron escape dynamics.These results refine and confirm the scaling laws essential for predictive modeling in high-energy-density physics and inertial fusion research.
基金Funded by Hunan Provincial Natural Science Foundation(No.2023JJ40074)Hunan Provincial Education Department Excellent Youth Project(No.21B0757)Hunan Provincial Engineering Technology Center(No.2022TP2036)。
文摘In this study,multilayer lamination welding was employed to prepare graphene/copper(Gr/Cu)composite billets from graphene-coated copper foils,followed by multi-pass cold drawing to produce Φ1 mm Gr/Cu composite wires.Microstructure and property analyses in both the cold-drawn and annealed states show that the incorporation of graphene significantly improves the ductility and electrical conductivity of the copper wire.After annealing at 350℃ for 30 minutes,the composite wire demonstrates a tensile strength of 270 MPa and an electrical conductivity of 102.74%IACS,both superior to those of pure copper wire under identical conditions.At 150℃,the electrical conductivity of the annealed composite wire reaches 72.60%IACS,notably higher than the 68.19%IACS of pure copper.The results suggest that graphene is uniformly distributed within the composite wire,with minimal impact on conductivity,while effectively refining the copper grain structure to enhance ductility.Moreover,graphene suppresses copper lattice vibrations at elevated temperatures,reducing the rate of conductivity degradation.
基金financially supported by the Key R&D Program of Shandong Province(2022SFGC0801)the National Natural Science Foundation of China(No.22005162 and 22175009)the Natural Science Foundation of Shandong Province(No.ZR2020QE093)。
文摘Osmotic energy,existing between the seawater and river water,is a renewable energy source,which can be directly converted into electricity by ion-exchange membranes(IEM).In traditional IEMs,the ion transport channels are formed by nanophase separation of hydrophilic ion carriers and hydrophobic segments.It is difficult to realize high-density ion channels with controlled spatial arrangement and length scale of ion carriers.Herein,we construct high-density 1D ion wires as transmission channels.Through molecular design,hydrophilic imidazole groups and hydrophobic alkyl tails were introduced into the repeat units,which self-assembled into 1D ion transporting core and protecting shell along the main chains.The areal density of the ionic wire arrays is up to~10^(12)cm^(-2),which is the highest value.The ionic wires ensure both high ion flux transport and high selectivity,achieving an ultrahigh-power density of 40.5 W m^(-2)at a 500-fold salinity gradient.Besides,the ionic wire array membrane is well recyclable and antibacterial.The ionic wires provide novel concept for next generation of high-performance membranes.
基金supported by the State Key Research and Development Program,Special Gravity Wave(Grant No.2023YFC2206003)the Gansu Provincial Science and Technology Program Funding(Grant No.24JRRA499)+1 种基金the Natural Science Foundation of Shandong Province(Grant No.ZR2024QB219)the Lanzhou City Science and Technology Program Project(Grant No.2025-2-47)。
文摘Giant magnetoimpedance(GMI)sensors are increasingly employed in modern magnetic sensing technologies.However,improving the GMI performance of magnetic cores remains challenging due to intrinsic limitations in material properties and structural stability.In this work,we explore the use of Joule heating to enhance the GMI response of Fe_(20)Ni_(80)/Cu composite wires.By applying a current of 1.8 A for 10 min,notable improvements in magnetic domain uniformity and a reduction in domain spacing are observed.Under these conditions,GMI ratios reach 1870% in the non-diagonal mode and1147%in the diagonal mode,respectively,highlighting their potential for applications in high-precision weak magnetic field sensing.
基金supported by Major Science and Technology Project of Gansu Province(Grant No.23ZDGA010)National Natural Science Foundation of China(Grant No.51971105).
文摘The fabrication of 304L stainless welding wires with a diameter 1.6 mm by using electrochemical cold drawing(ECD)of bars with a diameter of 5.6 mm was investigated,as well as that via traditional cold drawing(TCD)for comparison.The results indicated that the dilute H_(2)SO_(4)aqueous solution was an appropriate electrolyte for ECD,and increasing the H_(2)SO_(4)concentration and current density within a range improved the corrosion rate and uniformity,leading to an easier and more coordinated deformation through uniformly distributing geometrically necessary dislocations and curved large-angle grain boundaries,and decreasing their density,and thus,an enhanced electrochemical plasticization(EP).Under the optimized electrochemical parameters(0.5 mol L^(-1)H_(2)SO_(4)electrolyte and current density of 12.2 mA cm^(-2)),the average cumulative reduction rate required for annealing was up to~34%,obviously higher than~20%of TCD due to the decreased work-hardening from the EP,so that the number of annealing was significantly reduced from 10 of TCD to 5,when the drawing pass was 23.In addition,the surface of the ECD wire was distinctly smoother and brighter than that of the TCD one.These findings confirm the large potential in engineering applications of the ECD technology based on the EP effect.
基金supported by the Special Project of Gansu Province,China(Nos.23ZDGA010,22ZD6GA008)the Central Guiding Fund for Local Science and Technology Development Project,China(Nos.24ZYQA054,23ZYQA308)the Key Project of Research and Innovation in Universities,China(No.2024CXPT-06)。
文摘Inconel 625 alloy components were fabricated using hot wire laser metal deposition(HW-LMD)through process optimization,achieving a wire deposition rate of 1.72 kg/h.The microstructure and mechanical properties of the HW-LMD Inconel 625 alloys were systematically investigated.The results revealed that the microstructure of the HWLMD Inconel 625 alloys consisted of columnar dendrites,characterized by an average grain size of 12.5μm and a strong{100}〈001〉texture.The main phase identified wasγ-Ni,with the precipitation of Laves phase,measuring less than 1μm,observed in the inter-columnar dendritic regions.The average microhardness of the HW-LMD Inconel 625 alloys was HV1.0258.The yield strength and ultimate tensile strength were 493.5 and 837.4 MPa,respectively,with elongation exceeding 50%.Impact absorbing energies at 25 and-78℃were 223.08 and 200.24 J,respectively.Both the tensile and impact fracture surfaces exhibited dimples,indicating a ductile fracture mechanism during the deformation process.
基金supported by the National Natural Science Foundation of China(No.12272240)the Liaoning Revitalization Talents Program,China(No.XLYC2203197)。
文摘Traditional dynamic analysis of mechanical structures,often limited to individual beams or plates,fails to fully capture their dynamic behaviors.In systems where space and mass are constrained,such as the battery support structures in electric aircraft,conventional absorbers and isolators are insufficient for effective vibration control.This study simplifies the battery support structure of electric aircraft as an integrated composite beam consisting of three interconnected beams,and investigated its structural dynamics properties and nonlinear vibration control under thermal conditions caused by battery heat.The nonlinear vibration control is performed using the Nitinol steel wire ropes(Ni Ti-ST),with nonlinear damping properties.The natural frequencies of system are determined using the Rayleigh-Ritz technique.Theoretical results are validated through both Finite Element Method(FEM)and hammer tests.Moreover,the dynamic equations are derived using the Lagrange method and discretized via the Galerkin Truncation Method(GTM).The Harmonic Balance Method(HBM)is used to evaluate the vibration responses of the integrated model,with further verification through the Runge-Kutta Method(RKM).The experiments are conducted to corroborate the theoretical analysis.The results show that the system frequency changes in stages with the increase of the stiffness of the integrated composite beam connection.Especially in the case of varying environments,as the temperature increases,the frequency of system will first increase to a certain maximum value and then gradually decrease.Furthermore,the NiTi-ST effectively reduces vibration in the integrated composite beam,particularly under varying temperatures and external excitations.
