Surgical meshes have been employed in the management of a variety of pathological conditions including hernia,pelvic floor dysfunctions,periodontal guided bone regeneration,wound healing and more recently for breast p...Surgical meshes have been employed in the management of a variety of pathological conditions including hernia,pelvic floor dysfunctions,periodontal guided bone regeneration,wound healing and more recently for breast plastic surgery after mastectomy.These common pathologies affect a wide portion of the worldwide population;therefore,an effective and enhanced treatment is crucial to ameliorate patients’living conditions both from medical and aesthetic points of view.At present,non-absorbable synthetic polymers are the most widely used class of biomaterials for the manufacturing of mesh implants for hernia,pelvic floor dysfunctions and guided bone regeneration,with polypropylene and poly tetrafluoroethylene being the most common.Biological prostheses,such as surgical grafts,have been employed mainly for breast plastic surgery and wound healing applications.Despite the advantages of mesh implants to the treatment of these conditions,there are still many drawbacks,mainly related to the arising of a huge number of post-operative complications,among which infections are the most common.Developing a mesh that could appropriately integrate with the native tissue,promote its healing and constructive remodelling,is the key aim of ongoing research in the area of surgical mesh implants.To this end,the adoption of new biomaterials including absorbable and natural polymers,the use of drugs and advanced manufacturing technologies,such as 3D printing and electrospinning,are under investigation to address the previously mentioned challenges and improve the outcomes of future clinical practice.The aim of this work is to review the key advantages and disadvantages related to the use of surgical meshes,the main issues characterizing each clinical procedure and the future directions in terms of both novel manufacturing technologies and latest regulatory considerations.展开更多
Industry 4.0 as referred to a fourth industrial revolution has endorsed in several national manufacturing development plans such as in Germany, the UK, and China. A set of important pervasive and secondary technologie...Industry 4.0 as referred to a fourth industrial revolution has endorsed in several national manufacturing development plans such as in Germany, the UK, and China. A set of important pervasive and secondary technologies for future manufacturing activities have been identified such as additive manufacturing, sensor technology, big data analytics, Internet of things, robotics, cloud computing, and nanotechnology.展开更多
As a subversive manufacturing technology, additive manufacturing technology has many technical advantages such as high freedom of design and not limited by complex structure of parts. The application of additive manuf...As a subversive manufacturing technology, additive manufacturing technology has many technical advantages such as high freedom of design and not limited by complex structure of parts. The application of additive manufacturing technology to the charge molding of energetic materials will subvert the traditional manufacturing concept of energetic materials, realize the advanced charge design concept, shorten the research and development time of weapons and equipment, and improve the comprehensive performance of weapons and equipment, which is of great significance for the rapid development of high-tech weapons and equipment. This paper analyzes the research progress of additive manufacturing technology in the field of energetic materials at home and abroad and puts forward some suggestions for future research of this technology. .展开更多
Based on the traditional re-entrant honeycomb,a novel re-entrant octagon honeycomb(ROH)is proposed.The deformation mode of the honeycomb under quasi-static compression is analyzed by numerical simulation,and the resul...Based on the traditional re-entrant honeycomb,a novel re-entrant octagon honeycomb(ROH)is proposed.The deformation mode of the honeycomb under quasi-static compression is analyzed by numerical simulation,and the results are in good agreement with the experimental ones.The deformation modes,mechanical properties,and energy absorption characteristics of ROH along the impact and perpendicular directions gradient design are investigated under different velocities.The results indicated that the deformation mode of ROH is affected by gradient design along the direction of impact and impact speed.In addition,gradient design along the direction of impact can increase the initial peak stress of ROH and accelerate its densification phase.Gradient design perpendicular to the impact direction can enhance the energy absorption performance of ROH,especially for ROH,with wall thickness increasing from the inside outwards.Compared to ROH with uniform wall thickness at the same relative density,ROH with a gradient design can increase the plateau stress by over half.With the elevation of impact velocity,the plateau stress and specific energy absorption exhibit an upward trend,aligning with the dynamic performance pattern observed in conventional honeycombs.The results can be used as a reference for the design and application of honeycomb and provide a new idea for developing more efficient and reliable energy-absorbing materials.展开更多
An effect of unequal deformation in development of advanced plasticprocessing technologies is researched by studying an in-plane bending process of strip metal underunequal compressing. The research results show the f...An effect of unequal deformation in development of advanced plasticprocessing technologies is researched by studying an in-plane bending process of strip metal underunequal compressing. The research results show the following: If appropriately controlled, unequalplastic deformation can play an important role not only in the improvement of quality of partsobtained by plastic processing technologies, but also in the development of new processes foradvanced plastic working technologies. A coordinated growth of unequal plastic deformation candevelop the deformation potentiality of material to the fall. The degree of unequal plasticdeformation can be used as bases for optimization design of processes and dies of plastic forming.展开更多
Synchronous rolling-casting freeform manufacturing for Metal(SRCFMM) means that the refined liquid metal is continuously pressed out from the bottom of crucible. There is a horizontal movable plate beneath the outlet....Synchronous rolling-casting freeform manufacturing for Metal(SRCFMM) means that the refined liquid metal is continuously pressed out from the bottom of crucible. There is a horizontal movable plate beneath the outlet. The clearance between the outlet and the plate is about several hundred micrometers. SRCFMM, similar to additive manufacturing, implies layer by layer shaping and consolidation of feedstock to arbitrary configurations, normally using a computer controlled movable plate. The primary dendritic crystal is easily crushed by movement of substrate in the rolling-casting area. ZL104 was used as the test materials, determining the control temperature by differential scanning thermal analysis(DSC), preparing a kind of samples by SR CFMM, then analyzing microstructures and mechanical property of the samples. Characteristics and distribution of the primary particles were assessed by optical microscopy(OM), scanning electron microscopy(SEM), energy dispersive spectrum(EDS) and image analysis software. Mechanical property of the samples was assessed by vickers hardness. The results show that the samples fabricated by SRCFMM have uniform structures and good performances with the velocity of the substrate controlled about 10 cm/s and temperature at about 580 ℃.展开更多
By vermicularizing agent containing RE (REFeSi), austempered vermicular graphite cast iron (AVGCI) with RE can be produced with austempered treatment. The process of austenitization of vermicular graphite cast iron (V...By vermicularizing agent containing RE (REFeSi), austempered vermicular graphite cast iron (AVGCI) with RE can be produced with austempered treatment. The process of austenitization of vermicular graphite cast iron (VGCI) with RE and the transformation of AVGCI with RE with temperature increasing were studied by SEM with heating device. Properties of AVGCI with RE, such as tensile strength, elongation, impact toughness, hardness, thermal fatigue resistance, thermal expansive coefficient and weight increasing by oxidation were measured by electron universal testing machine with heating device. Experimental results indicate that AVGCI with RE possesses good comprehensive properties at room and elevated temperatures.展开更多
In order to realize the optimal design of the industrial robot arm structure,an optimization method of the industrial robot arm structure based on green manufacturing technology is proposed.The stability of arm struct...In order to realize the optimal design of the industrial robot arm structure,an optimization method of the industrial robot arm structure based on green manufacturing technology is proposed.The stability of arm structure parameter acquisition can be controlled.The quantitative adjustment model of structural optimization parameters is constructed.The differential fusion control of the arm structure is realized.This paper analyzes the structure parameter law of the robot arm.We use dynamic parameter prediction and output torque parameter compensation method to control the arm structure.According to the adaptive iterative processing results,the arm structure parameter identification is realized.According to the identification results,the cutting parameter optimization method is adopted for the analytical control of the arm structure,and finally the optimized design of the industrial robot arm structure is realized through the green manufacturing technology.The simulation test results show that for the accuracy of the industrial robot arm structure design,this method is better,the output stability is higher,and the arm motion trajectory has a low deviation from the actual motion trajectory,which improves the optimization control and design capabilities of the industrial robot arm structure.展开更多
Manufacturing of a product is constituted of the va ri ous attributes such as quality, cost, performance, and time to market. Manufactu ring can also be understood as the entire product realization process, from spec ...Manufacturing of a product is constituted of the va ri ous attributes such as quality, cost, performance, and time to market. Manufactu ring can also be understood as the entire product realization process, from spec ification through design and production to marketing and distribution. The induc tion of Information Technology (IT) in manufacturing includes the hardware that computes and communicates, the software that provides data, knowledge, and infor mation while at the same time controlling the hardware, and the interfaces betwe en computers and the tools and machines on the shop floor. The manufacturing pro cess utilizes IT in the design of products and processes, production, and manufa cturing-related business practices. IT applications applied to manufacturing helps in rapid shifts in production fro m one product to another, faster implementation of new concepts in products, fas ter delivery of products to customers, full utilization of capital and human res ources, streamlining of operations to focus on essential business needs, and eli mination of unnecessary or wasteful activities. IT can be used to meet a range of needs of manufacturing decision makers. It can be said that IT is an enabler and facilitator of radical change to culture of manufacturing which is highly co nservative for many good reasons. With increasing global competition, applications of global information technolog y is giving manufacturing unit an opportunity to increase control and enhance co ordination, while opening doors to new global markets and businesses. In some st udies conducted it ahs been shown that how information technology can produce pr oductivity gains and job losses in specific areas, whereas dynamic stability was also achieved through IT in some cases. In a study of an industry the IT has cu t manufacturers cost from eProcurement to web based supply chain management and after sales service. IT has certainly revolutionized the manufacturing and the i ndustries have completely redefined their business by switching over to World Wi de Web. This paper, attempts to review the significant advances and practical applicatio ns of information technology in the field of manufacturing.展开更多
This paper reviews the development of manufacturing technology and the progress that has so far been made in this field.It points out that manufacturing technology is not only the pillar of material civilization and t...This paper reviews the development of manufacturing technology and the progress that has so far been made in this field.It points out that manufacturing technology is not only the pillar of material civilization and the base of spiritual civilization of man,but also the foundation of a country's competitivendess.The paper also attempts to review the future of manufacturing technology through the description of the new pattern of manufacturing market,new features of manufactured products,new characteristics of technologies as well as the emerging trends of manufacturing enterprises and man-agement in the 21 st cetury.展开更多
As a typical representative and main technicalmeans of advanced manufacturing technology,robotic technology plays an important role in raisingan enterpse’s engineering level, improving its prod-uct quality and produc...As a typical representative and main technicalmeans of advanced manufacturing technology,robotic technology plays an important role in raisingan enterpse’s engineering level, improving its prod-uct quality and productivity, and realizing civilizedproduction. Currently, there are nearly one millionrobots of various kinds, which are employed widelyin different fields of manufacturing industry. Robot-ics is now one of the high technologies, which arecompetitively developed by the developed coun-展开更多
An abstract model and representation method for manufacturing environment is presented based on analysis of process planning tasks and factory configuration capable of handling the process plans. This model has been p...An abstract model and representation method for manufacturing environment is presented based on analysis of process planning tasks and factory configuration capable of handling the process plans. This model has been proved to be applicable to the generative process planning and to shopflow control information integration. A general manufacturing environment modelling tool has been developed under the X-window support to verity the mentioned model and modelling technology.展开更多
Entangled porous metallic wire material(EPMWM)has the potential as a thermal insulation material in defence and engineering.In order to optimize its thermophysical properties at the design stage,it is of great signifi...Entangled porous metallic wire material(EPMWM)has the potential as a thermal insulation material in defence and engineering.In order to optimize its thermophysical properties at the design stage,it is of great significance to reveal the thermal response mechanism of EPMWM based on its complex structural effects.In the present work,virtual manufacturing technology(VMT)was developed to restore the physics-based 3D model of EPMWM.On this basis,the transient thermal analysis is carried out to explore the contact-relevant thermal behavior of EPMWM,and then the spiral unit containing unique structural information are further extracted and counted.In particular,the thermal resistance network is numerically constructed based on the spiral unit through the thermoelectric analogy method to accurately predict the effective thermal conductivity(ETC)of EPMWM.Finally,the thermal diffusivity and specific heat of the samples were obtained by the laser thermal analyzer to calculate the ETC and thermal insulation factor of interest.The results show that the ETC of EPMWM increases with increasing temperature or reducing density under the experimental conditions.The numerical prediction is consistent with the experimental result and the average error is less than 4%.展开更多
With unique manufacturing technology,the additive manufacturing technology divides the three-dimensional object into countless two-dimensional laminates.Compared with the traditional material reduction manufacturing m...With unique manufacturing technology,the additive manufacturing technology divides the three-dimensional object into countless two-dimensional laminates.Compared with the traditional material reduction manufacturing method,it has the characteristics of saving materials,being fast,and especially suitable for single and small batch parts and the rapid manufacturing of parts with complex shapes and internal structures.In this paper,various methods of additive manufacturing technology are reviewed.This paper introduces the characteristics of selective laser melting technology and its forming equipment system.On this basis,the technical defects of selective laser melting technology are analyzed,and the status of controlling defects in SLM technology is explained.In the end,the prospects of additive manufacturing technology are described.展开更多
At present, the most common micro/nano-scale fabri ca tion processes include the plane silicon process based on IC technology, stereo silicon process, LIGA, quasi-LIGA based on near ultra violet deep lithography, MEMS...At present, the most common micro/nano-scale fabri ca tion processes include the plane silicon process based on IC technology, stereo silicon process, LIGA, quasi-LIGA based on near ultra violet deep lithography, MEMS, energy beam etching and micro/nano-machining, etc. A common problem for t hese processes is the difficulty to fabricate arbitrary form for 3-dimensional micro/nano-parts, devices or mechanisms. To develop advanced MEMS manufacturin g technology, and to achieve fabrication of true 3-dimensional parts, devices or mechanisms, this paper proposes a nanofabrication technology for rapid proto typing of 3-dimensional parts, using plasma chemical vapor deposition (PCVD). This process can be describes as follows: A laser beam is produced by a low power, quasi molecule laser. It enters the vac uum chamber through a window, and is focused on with the substrate surface. A ga s in the chamber is ionized by the laser beam to produce PCVD on the substrate s urface, and forms a particle of the size of Ф100 nm (its thickness is about 100 nm). When the laser beam moves along X-axis, many particles form a line. Then the laser beam moves one step in Y-axis to form a new line. A plane is complete d by many lines. Then the substrate moves in Z-axis to form new plane. Eventu ally, many planes form a 3-dimensional component. Using available CAD/CAM softw are with this process, rapid prototyping of complex components can be achieved. A nanometer precision linear motor, such as that described in Chinese national p atent (patent No. ZL 98 2 16753.9), can be used to obtain the nanometer precisio n movements in the process. The process does not require mask, can be used for v arious rapid prototyping materials, to obtain high fabrication precision (its sc ale precision is 15 nm), and larger ratio of height to width of micro/nano-stru cture. It can find widespread applications in the fabrication of micro-mechani sm, trimming IC, and fabricating minilens, etc.展开更多
The kind of micro-/nano-meter precision actuator in cludes a piezoelectric one, an electric deformation one, a magnetic deformation one, a mechanical one, and a mechanical and electrical one. This paper puts forw ard ...The kind of micro-/nano-meter precision actuator in cludes a piezoelectric one, an electric deformation one, a magnetic deformation one, a mechanical one, and a mechanical and electrical one. This paper puts forw ard a mechanical and electrical step actuator of nanometer precision, which cons ists of a step motor of large fine-dividing number of step angle, shaft couplin gs, a decelerator of large decelerating ratio, a screw mechanism and a pole of U shape, and has the minimum step displacement of 10 nm, the step displac ement precision of 1 nm, the step frequency of 4 kHz, the maximum loadability of 20 kg. In order to achieve the nano displacement of nano precision by this actu ator, the theoretical analysis of stress and strain must be made on the transmit ting course of nano displacement of the actuator, and their numerical simulation is done by computer. The paper establishes the constitutive equation of 3-D stress and the strain co ordinate equation of the composing system of the nanometer precision actuator. A s a result, the theoretical relation among stress and strain and displacement is set up. The torque of the step motor produces a thrust to transmit the displace ment of the above system of the parts and assemblies to output the needed nano d isplacement. In the case of concrete analysis and calculating, the comparing met hod of film-roof is applied to analyze and calculate the motor axis, decelerato r axes, the screw pole and the nut. The analysis method of plane stress and stra in is used to analyze and calculate the shaft couplings and gears. The analysis method of beam stress and strain is used to do the pole of U shape. These calcul ation is belong to the physical non-linear problem. Under the condition of smal l deformation, the analysis way of the finite element can be combined with the a bove analyses and calculations. The elementary analysis results show that the na nometer precision actuator can be applied in STM nanofabrication.展开更多
Three dimension free curves find wide applications in engineering. There is no problem to express them exactly mathematically, but th e reportage has not been done on the investigation of precision analysis of thre e-...Three dimension free curves find wide applications in engineering. There is no problem to express them exactly mathematically, but th e reportage has not been done on the investigation of precision analysis of thre e-dimension free curves nanofabrication. Nanofabrication Precision includes the geometrical precision and the precision of driving system (below simply cal led the system precision). This paper submits the precision analysis method of c urve normal vector to analyze geometrical precision. Take an aspherical surf ace for example, it can be fitted and constructed by tensor product parameter cu rves, such as linear drawing curves, straight veins curves, rotating curves, swe eping curves, DUCT curves and Geomap curves. Then the curves of the aspherical s urface is iterated and modified to select the best fitted curves of the aspheric al surface. Finally, the geometrical precision of perfect approximate aspherical surface fitting has been sought. This kind of geometrical fitting construction is very important. Another is the system precision, which contains axial position precision, line p recision, and twisting and swinging precision, etc. The paper adopts the theory of precision optimum match (Prof. Wang Er-qi first put forward in 19 83) to allocate precision optimumly. The minimum cost is used as an objective fu nction, and weight method matches the precision. To obtain the optimum match combination of the minimum cost design parameters and every composing element t olerance, the precision is iterated and sought optimumly to design the system op timumly. The theoretical analysis shows that it’s feasible to control three dim ension free curves nanofabrication within nanometer scale precision.展开更多
Perovskite materials show exciting potential for light-emitting diodes(LEDs)owing to their intrinsically high photoluminescence efficiency and color purity.The research focusing on perovskite light-emitting diodes(PeL...Perovskite materials show exciting potential for light-emitting diodes(LEDs)owing to their intrinsically high photoluminescence efficiency and color purity.The research focusing on perovskite light-emitting diodes(PeLEDs)has experienced an exponential growth in the past six years.The maximum external quantum efficiency of red,green,and blue PeLEDs has surpassed 20%,20%,and 10%,respectively.Nevertheless,the current PeLEDs are still in the laboratory stage,and the key for further development of PeLEDs is large-area fabrication.In this paper,we briefly discuss the similarities and differences between manufacturing high-quality and large-area PeLEDs and perovskite solar cells.Especially,the general technologies for fabricating large-area perovskite films are also introduced.The effect of charge transport layers and electrodes on large-area devices are discussed as well.Most importantly,we summarize the advances of large-area(active area≥30 mm^(2))PeLEDs reported since 2017,and describe the methods for optimizing large-area PeLEDs reported in the literature.Finally,the development perspective of PeLEDs is presented for the goal of highly efficient and large-area PeLED fabrication.It is of great significance for the application of PeLEDs in future display and lighting.展开更多
文摘Surgical meshes have been employed in the management of a variety of pathological conditions including hernia,pelvic floor dysfunctions,periodontal guided bone regeneration,wound healing and more recently for breast plastic surgery after mastectomy.These common pathologies affect a wide portion of the worldwide population;therefore,an effective and enhanced treatment is crucial to ameliorate patients’living conditions both from medical and aesthetic points of view.At present,non-absorbable synthetic polymers are the most widely used class of biomaterials for the manufacturing of mesh implants for hernia,pelvic floor dysfunctions and guided bone regeneration,with polypropylene and poly tetrafluoroethylene being the most common.Biological prostheses,such as surgical grafts,have been employed mainly for breast plastic surgery and wound healing applications.Despite the advantages of mesh implants to the treatment of these conditions,there are still many drawbacks,mainly related to the arising of a huge number of post-operative complications,among which infections are the most common.Developing a mesh that could appropriately integrate with the native tissue,promote its healing and constructive remodelling,is the key aim of ongoing research in the area of surgical mesh implants.To this end,the adoption of new biomaterials including absorbable and natural polymers,the use of drugs and advanced manufacturing technologies,such as 3D printing and electrospinning,are under investigation to address the previously mentioned challenges and improve the outcomes of future clinical practice.The aim of this work is to review the key advantages and disadvantages related to the use of surgical meshes,the main issues characterizing each clinical procedure and the future directions in terms of both novel manufacturing technologies and latest regulatory considerations.
文摘Industry 4.0 as referred to a fourth industrial revolution has endorsed in several national manufacturing development plans such as in Germany, the UK, and China. A set of important pervasive and secondary technologies for future manufacturing activities have been identified such as additive manufacturing, sensor technology, big data analytics, Internet of things, robotics, cloud computing, and nanotechnology.
文摘As a subversive manufacturing technology, additive manufacturing technology has many technical advantages such as high freedom of design and not limited by complex structure of parts. The application of additive manufacturing technology to the charge molding of energetic materials will subvert the traditional manufacturing concept of energetic materials, realize the advanced charge design concept, shorten the research and development time of weapons and equipment, and improve the comprehensive performance of weapons and equipment, which is of great significance for the rapid development of high-tech weapons and equipment. This paper analyzes the research progress of additive manufacturing technology in the field of energetic materials at home and abroad and puts forward some suggestions for future research of this technology. .
基金This work is supported by the National Natural Science Foundation of China(No.11902232).
文摘Based on the traditional re-entrant honeycomb,a novel re-entrant octagon honeycomb(ROH)is proposed.The deformation mode of the honeycomb under quasi-static compression is analyzed by numerical simulation,and the results are in good agreement with the experimental ones.The deformation modes,mechanical properties,and energy absorption characteristics of ROH along the impact and perpendicular directions gradient design are investigated under different velocities.The results indicated that the deformation mode of ROH is affected by gradient design along the direction of impact and impact speed.In addition,gradient design along the direction of impact can increase the initial peak stress of ROH and accelerate its densification phase.Gradient design perpendicular to the impact direction can enhance the energy absorption performance of ROH,especially for ROH,with wall thickness increasing from the inside outwards.Compared to ROH with uniform wall thickness at the same relative density,ROH with a gradient design can increase the plateau stress by over half.With the elevation of impact velocity,the plateau stress and specific energy absorption exhibit an upward trend,aligning with the dynamic performance pattern observed in conventional honeycombs.The results can be used as a reference for the design and application of honeycomb and provide a new idea for developing more efficient and reliable energy-absorbing materials.
基金National Natural Science Foundation of China (No.59475059) and the Aeronautical Science Foundation of China (No.94G53111).
文摘An effect of unequal deformation in development of advanced plasticprocessing technologies is researched by studying an in-plane bending process of strip metal underunequal compressing. The research results show the following: If appropriately controlled, unequalplastic deformation can play an important role not only in the improvement of quality of partsobtained by plastic processing technologies, but also in the development of new processes foradvanced plastic working technologies. A coordinated growth of unequal plastic deformation candevelop the deformation potentiality of material to the fall. The degree of unequal plasticdeformation can be used as bases for optimization design of processes and dies of plastic forming.
基金Funded by the National Natural Science Foundation of China(No.51341009)
文摘Synchronous rolling-casting freeform manufacturing for Metal(SRCFMM) means that the refined liquid metal is continuously pressed out from the bottom of crucible. There is a horizontal movable plate beneath the outlet. The clearance between the outlet and the plate is about several hundred micrometers. SRCFMM, similar to additive manufacturing, implies layer by layer shaping and consolidation of feedstock to arbitrary configurations, normally using a computer controlled movable plate. The primary dendritic crystal is easily crushed by movement of substrate in the rolling-casting area. ZL104 was used as the test materials, determining the control temperature by differential scanning thermal analysis(DSC), preparing a kind of samples by SR CFMM, then analyzing microstructures and mechanical property of the samples. Characteristics and distribution of the primary particles were assessed by optical microscopy(OM), scanning electron microscopy(SEM), energy dispersive spectrum(EDS) and image analysis software. Mechanical property of the samples was assessed by vickers hardness. The results show that the samples fabricated by SRCFMM have uniform structures and good performances with the velocity of the substrate controlled about 10 cm/s and temperature at about 580 ℃.
文摘By vermicularizing agent containing RE (REFeSi), austempered vermicular graphite cast iron (AVGCI) with RE can be produced with austempered treatment. The process of austenitization of vermicular graphite cast iron (VGCI) with RE and the transformation of AVGCI with RE with temperature increasing were studied by SEM with heating device. Properties of AVGCI with RE, such as tensile strength, elongation, impact toughness, hardness, thermal fatigue resistance, thermal expansive coefficient and weight increasing by oxidation were measured by electron universal testing machine with heating device. Experimental results indicate that AVGCI with RE possesses good comprehensive properties at room and elevated temperatures.
基金the Research Fund of Faculty of Engineering,University of Malaya(Grant No.GPF052A-2018)
文摘In order to realize the optimal design of the industrial robot arm structure,an optimization method of the industrial robot arm structure based on green manufacturing technology is proposed.The stability of arm structure parameter acquisition can be controlled.The quantitative adjustment model of structural optimization parameters is constructed.The differential fusion control of the arm structure is realized.This paper analyzes the structure parameter law of the robot arm.We use dynamic parameter prediction and output torque parameter compensation method to control the arm structure.According to the adaptive iterative processing results,the arm structure parameter identification is realized.According to the identification results,the cutting parameter optimization method is adopted for the analytical control of the arm structure,and finally the optimized design of the industrial robot arm structure is realized through the green manufacturing technology.The simulation test results show that for the accuracy of the industrial robot arm structure design,this method is better,the output stability is higher,and the arm motion trajectory has a low deviation from the actual motion trajectory,which improves the optimization control and design capabilities of the industrial robot arm structure.
文摘Manufacturing of a product is constituted of the va ri ous attributes such as quality, cost, performance, and time to market. Manufactu ring can also be understood as the entire product realization process, from spec ification through design and production to marketing and distribution. The induc tion of Information Technology (IT) in manufacturing includes the hardware that computes and communicates, the software that provides data, knowledge, and infor mation while at the same time controlling the hardware, and the interfaces betwe en computers and the tools and machines on the shop floor. The manufacturing pro cess utilizes IT in the design of products and processes, production, and manufa cturing-related business practices. IT applications applied to manufacturing helps in rapid shifts in production fro m one product to another, faster implementation of new concepts in products, fas ter delivery of products to customers, full utilization of capital and human res ources, streamlining of operations to focus on essential business needs, and eli mination of unnecessary or wasteful activities. IT can be used to meet a range of needs of manufacturing decision makers. It can be said that IT is an enabler and facilitator of radical change to culture of manufacturing which is highly co nservative for many good reasons. With increasing global competition, applications of global information technolog y is giving manufacturing unit an opportunity to increase control and enhance co ordination, while opening doors to new global markets and businesses. In some st udies conducted it ahs been shown that how information technology can produce pr oductivity gains and job losses in specific areas, whereas dynamic stability was also achieved through IT in some cases. In a study of an industry the IT has cu t manufacturers cost from eProcurement to web based supply chain management and after sales service. IT has certainly revolutionized the manufacturing and the i ndustries have completely redefined their business by switching over to World Wi de Web. This paper, attempts to review the significant advances and practical applicatio ns of information technology in the field of manufacturing.
文摘This paper reviews the development of manufacturing technology and the progress that has so far been made in this field.It points out that manufacturing technology is not only the pillar of material civilization and the base of spiritual civilization of man,but also the foundation of a country's competitivendess.The paper also attempts to review the future of manufacturing technology through the description of the new pattern of manufacturing market,new features of manufactured products,new characteristics of technologies as well as the emerging trends of manufacturing enterprises and man-agement in the 21 st cetury.
文摘As a typical representative and main technicalmeans of advanced manufacturing technology,robotic technology plays an important role in raisingan enterpse’s engineering level, improving its prod-uct quality and productivity, and realizing civilizedproduction. Currently, there are nearly one millionrobots of various kinds, which are employed widelyin different fields of manufacturing industry. Robot-ics is now one of the high technologies, which arecompetitively developed by the developed coun-
文摘An abstract model and representation method for manufacturing environment is presented based on analysis of process planning tasks and factory configuration capable of handling the process plans. This model has been proved to be applicable to the generative process planning and to shopflow control information integration. A general manufacturing environment modelling tool has been developed under the X-window support to verity the mentioned model and modelling technology.
基金National Natural Science Foundation of China(Grant Nos.52175162,51805086 and 51975123)Natural Science Foundation of Fujian Province,China(Grant No.2019J01210)Health Education Joint Project of Fujian Province,China(Grant No.2019-WJ-01).
文摘Entangled porous metallic wire material(EPMWM)has the potential as a thermal insulation material in defence and engineering.In order to optimize its thermophysical properties at the design stage,it is of great significance to reveal the thermal response mechanism of EPMWM based on its complex structural effects.In the present work,virtual manufacturing technology(VMT)was developed to restore the physics-based 3D model of EPMWM.On this basis,the transient thermal analysis is carried out to explore the contact-relevant thermal behavior of EPMWM,and then the spiral unit containing unique structural information are further extracted and counted.In particular,the thermal resistance network is numerically constructed based on the spiral unit through the thermoelectric analogy method to accurately predict the effective thermal conductivity(ETC)of EPMWM.Finally,the thermal diffusivity and specific heat of the samples were obtained by the laser thermal analyzer to calculate the ETC and thermal insulation factor of interest.The results show that the ETC of EPMWM increases with increasing temperature or reducing density under the experimental conditions.The numerical prediction is consistent with the experimental result and the average error is less than 4%.
基金Sailing Plan in Guangdong Province(Grant No.2015YT02G090)Development of Additive Manufacturing Powder Materials and Preparation Technology(Grant No.2018002)+1 种基金Yangjiang High Power Laser Application Laboratory Construction(Grant No.2018057)Yangjiang High Power Laser Application Laboratory Co.,Ltd.supports the Construction of New R&D Institutions in the East and Northwest of Guangdong Province(Grant No.20180902).
文摘With unique manufacturing technology,the additive manufacturing technology divides the three-dimensional object into countless two-dimensional laminates.Compared with the traditional material reduction manufacturing method,it has the characteristics of saving materials,being fast,and especially suitable for single and small batch parts and the rapid manufacturing of parts with complex shapes and internal structures.In this paper,various methods of additive manufacturing technology are reviewed.This paper introduces the characteristics of selective laser melting technology and its forming equipment system.On this basis,the technical defects of selective laser melting technology are analyzed,and the status of controlling defects in SLM technology is explained.In the end,the prospects of additive manufacturing technology are described.
文摘At present, the most common micro/nano-scale fabri ca tion processes include the plane silicon process based on IC technology, stereo silicon process, LIGA, quasi-LIGA based on near ultra violet deep lithography, MEMS, energy beam etching and micro/nano-machining, etc. A common problem for t hese processes is the difficulty to fabricate arbitrary form for 3-dimensional micro/nano-parts, devices or mechanisms. To develop advanced MEMS manufacturin g technology, and to achieve fabrication of true 3-dimensional parts, devices or mechanisms, this paper proposes a nanofabrication technology for rapid proto typing of 3-dimensional parts, using plasma chemical vapor deposition (PCVD). This process can be describes as follows: A laser beam is produced by a low power, quasi molecule laser. It enters the vac uum chamber through a window, and is focused on with the substrate surface. A ga s in the chamber is ionized by the laser beam to produce PCVD on the substrate s urface, and forms a particle of the size of Ф100 nm (its thickness is about 100 nm). When the laser beam moves along X-axis, many particles form a line. Then the laser beam moves one step in Y-axis to form a new line. A plane is complete d by many lines. Then the substrate moves in Z-axis to form new plane. Eventu ally, many planes form a 3-dimensional component. Using available CAD/CAM softw are with this process, rapid prototyping of complex components can be achieved. A nanometer precision linear motor, such as that described in Chinese national p atent (patent No. ZL 98 2 16753.9), can be used to obtain the nanometer precisio n movements in the process. The process does not require mask, can be used for v arious rapid prototyping materials, to obtain high fabrication precision (its sc ale precision is 15 nm), and larger ratio of height to width of micro/nano-stru cture. It can find widespread applications in the fabrication of micro-mechani sm, trimming IC, and fabricating minilens, etc.
文摘The kind of micro-/nano-meter precision actuator in cludes a piezoelectric one, an electric deformation one, a magnetic deformation one, a mechanical one, and a mechanical and electrical one. This paper puts forw ard a mechanical and electrical step actuator of nanometer precision, which cons ists of a step motor of large fine-dividing number of step angle, shaft couplin gs, a decelerator of large decelerating ratio, a screw mechanism and a pole of U shape, and has the minimum step displacement of 10 nm, the step displac ement precision of 1 nm, the step frequency of 4 kHz, the maximum loadability of 20 kg. In order to achieve the nano displacement of nano precision by this actu ator, the theoretical analysis of stress and strain must be made on the transmit ting course of nano displacement of the actuator, and their numerical simulation is done by computer. The paper establishes the constitutive equation of 3-D stress and the strain co ordinate equation of the composing system of the nanometer precision actuator. A s a result, the theoretical relation among stress and strain and displacement is set up. The torque of the step motor produces a thrust to transmit the displace ment of the above system of the parts and assemblies to output the needed nano d isplacement. In the case of concrete analysis and calculating, the comparing met hod of film-roof is applied to analyze and calculate the motor axis, decelerato r axes, the screw pole and the nut. The analysis method of plane stress and stra in is used to analyze and calculate the shaft couplings and gears. The analysis method of beam stress and strain is used to do the pole of U shape. These calcul ation is belong to the physical non-linear problem. Under the condition of smal l deformation, the analysis way of the finite element can be combined with the a bove analyses and calculations. The elementary analysis results show that the na nometer precision actuator can be applied in STM nanofabrication.
文摘Three dimension free curves find wide applications in engineering. There is no problem to express them exactly mathematically, but th e reportage has not been done on the investigation of precision analysis of thre e-dimension free curves nanofabrication. Nanofabrication Precision includes the geometrical precision and the precision of driving system (below simply cal led the system precision). This paper submits the precision analysis method of c urve normal vector to analyze geometrical precision. Take an aspherical surf ace for example, it can be fitted and constructed by tensor product parameter cu rves, such as linear drawing curves, straight veins curves, rotating curves, swe eping curves, DUCT curves and Geomap curves. Then the curves of the aspherical s urface is iterated and modified to select the best fitted curves of the aspheric al surface. Finally, the geometrical precision of perfect approximate aspherical surface fitting has been sought. This kind of geometrical fitting construction is very important. Another is the system precision, which contains axial position precision, line p recision, and twisting and swinging precision, etc. The paper adopts the theory of precision optimum match (Prof. Wang Er-qi first put forward in 19 83) to allocate precision optimumly. The minimum cost is used as an objective fu nction, and weight method matches the precision. To obtain the optimum match combination of the minimum cost design parameters and every composing element t olerance, the precision is iterated and sought optimumly to design the system op timumly. The theoretical analysis shows that it’s feasible to control three dim ension free curves nanofabrication within nanometer scale precision.
基金Project supported by the Ningxia Key Project of Research and Development Plan(Grant No.2020BDE03013).
文摘Perovskite materials show exciting potential for light-emitting diodes(LEDs)owing to their intrinsically high photoluminescence efficiency and color purity.The research focusing on perovskite light-emitting diodes(PeLEDs)has experienced an exponential growth in the past six years.The maximum external quantum efficiency of red,green,and blue PeLEDs has surpassed 20%,20%,and 10%,respectively.Nevertheless,the current PeLEDs are still in the laboratory stage,and the key for further development of PeLEDs is large-area fabrication.In this paper,we briefly discuss the similarities and differences between manufacturing high-quality and large-area PeLEDs and perovskite solar cells.Especially,the general technologies for fabricating large-area perovskite films are also introduced.The effect of charge transport layers and electrodes on large-area devices are discussed as well.Most importantly,we summarize the advances of large-area(active area≥30 mm^(2))PeLEDs reported since 2017,and describe the methods for optimizing large-area PeLEDs reported in the literature.Finally,the development perspective of PeLEDs is presented for the goal of highly efficient and large-area PeLED fabrication.It is of great significance for the application of PeLEDs in future display and lighting.