Gastrointestinal(GI)cancers remain a leading cause of cancer-related morbidity and mortality worldwide.Artificial intelligence(AI),particularly machine learning and deep learning(DL),has shown promise in enhancing can...Gastrointestinal(GI)cancers remain a leading cause of cancer-related morbidity and mortality worldwide.Artificial intelligence(AI),particularly machine learning and deep learning(DL),has shown promise in enhancing cancer detection,diagnosis,and prognostication.A narrative review of literature published from January 2015 to march 2025 was conducted using PubMed,Web of Science,and Scopus.Search terms included"gastrointestinal cancer","artificial intelligence","machine learning","deep learning","radiomics","multimodal detection"and"predictive modeling".Studies were included if they focused on clinically relevant AI applications in GI oncology.AI algorithms for GI cancer detection have achieved high performance across imaging modalities,with endoscopic DL systems reporting accuracies of 85%-97%for polyp detection and segmentation.Radiomics-based models have predicted molecular biomarkers such as programmed cell death ligand 2 expression with area under the curves up to 0.92.Large language models applied to radiology reports demonstrated diagnostic accuracy comparable to junior radiologists(78.9%vs 80.0%),though without incremental value when combined with human interpretation.Multimodal AI approaches integrating imaging,pathology,and clinical data show emerging potential for precision oncology.AI in GI oncology has reached clinically relevant accuracy levels in multiple diagnostic tasks,with multimodal approaches and predictive biomarker modeling offering new opportunities for personalized care.However,broader validation,integration into clinical workflows,and attention to ethical,legal,and social implications remain critical for widespread adoption.展开更多
The gears of new energy vehicles are required to withstand higher rotational speeds and greater loads,which puts forward higher precision essentials for gear manufacturing.However,machining process parameters can caus...The gears of new energy vehicles are required to withstand higher rotational speeds and greater loads,which puts forward higher precision essentials for gear manufacturing.However,machining process parameters can cause changes in cutting force/heat,resulting in affecting gear machining precision.Therefore,this paper studies the effect of different process parameters on gear machining precision.A multi-objective optimization model is established for the relationship between process parameters and tooth surface deviations,tooth profile deviations,and tooth lead deviations through the cutting speed,feed rate,and cutting depth of the worm wheel gear grinding machine.The response surface method(RSM)is used for experimental design,and the corresponding experimental results and optimal process parameters are obtained.Subsequently,gray relational analysis-principal component analysis(GRA-PCA),particle swarm optimization(PSO),and genetic algorithm-particle swarm optimization(GA-PSO)methods are used to analyze the experimental results and obtain different optimal process parameters.The results show that optimal process parameters obtained by the GRA-PCA,PSO,and GA-PSO methods improve the gear machining precision.Moreover,the gear machining precision obtained by GA-PSO is superior to other methods.展开更多
Micro-grinding has been widely used in aerospace and other industry.However,the small diameter of the micro-grinding tool has limited its machining performance and efficiency.In order to solve the above problems,micro...Micro-grinding has been widely used in aerospace and other industry.However,the small diameter of the micro-grinding tool has limited its machining performance and efficiency.In order to solve the above problems,micro-structure has been applied on the micro-grinding tool.A morphology modeling has been established in this study to characterize the surface of microstructured micro-grinding tool,and the grinding performance of micro-structured micro-grinding tool has been analyzed through undeformed chip thickness,abrasive edge width,and effective distance between abrasives.Then deviation analysis,path optimization and parameter optimization of microchannel array precision grinding have been finished to improve processing quality and efficiency,and the deflection angle has the most obvious effects on the rectangular slot depth,micro-structured micro-grinding tool could reduce 10%surface roughness and 20%grinding force compared to original micro-grinding tool.Finally,the microchannel array has been machined with a size deviation of 2μm and surface roughness of 0.2μm.展开更多
Based on the theory of elastic mechanics and material mechanics, the orientation precision of the hohl schaft kegel（HSK） tooling system in static and dynamic states is theoretically and experimentally studied. The r...Based on the theory of elastic mechanics and material mechanics, the orientation precision of the hohl schaft kegel（HSK） tooling system in static and dynamic states is theoretically and experimentally studied. The relation between the clamping force and the shank taper is obtained. And a proper clamping force is found to be essential to assure the axial and radial orientation precisions of the HSK tooling system in high speed machining （HSM）. Analytical results show that the reason why the HSK tooling system can keep high precision at the high rotational speed is that the actual axial clamping force keeps the two surfaces of the shank and the spindle in contact all the time.展开更多
Artificial intelligence(AI)and machine learning(ML)are transforming spine care by addressing diagnostics,treatment planning,and rehabilitation challenges.This study highlights advancements in precision medicine for sp...Artificial intelligence(AI)and machine learning(ML)are transforming spine care by addressing diagnostics,treatment planning,and rehabilitation challenges.This study highlights advancements in precision medicine for spinal pathologies,leveraging AI and ML to enhance diagnostic accuracy through deep learning algorithms,enabling faster and more accurate detection of abnormalities.AIpowered robotics and surgical navigation systems improve implant placement precision and reduce complications in complex spine surgeries.Wearable devices and virtual platforms,designed with AI,offer personalized,adaptive therapies that improve treatment adherence and recovery outcomes.AI also enables preventive interventions by assessing spine condition risks early.Despite progress,challenges remain,including limited healthcare datasets,algorithmic biases,ethical concerns,and integration into existing systems.Interdisciplinary collaboration and explainable AI frameworks are essential to unlock AI’s full potential in spine care.Future developments include multimodal AI systems integrating imaging,clinical,and genetic data for holistic treatment approaches.AI and ML promise significant improvements in diagnostic accuracy,treatment personalization,service accessibility,and cost efficiency,paving the way for more streamlined and effective spine care,ultimately enhancing patient outcomes.展开更多
The investigation was carried out on the technical problems of finishing the inner surface of elbow parts and the action mechanism of particles in elbow precision machining by abrasive flow.This work was analyzed and ...The investigation was carried out on the technical problems of finishing the inner surface of elbow parts and the action mechanism of particles in elbow precision machining by abrasive flow.This work was analyzed and researched by combining theory,numerical and experimental methods.The direct simulation Monte Carlo(DSMC)method and the finite element analysis method were combined to reveal the random collision of particles during the precision machining of abrasive flow.Under different inlet velocity,volume fraction and abrasive particle size,the dynamic pressure and turbulence flow energy of abrasive flow in elbow were analyzed,and the machining mechanism of particles on the wall and the influence of different machining parameters on the precision machining quality of abrasive flow were obtained.The test results show the order of the influence of different parameters on the quality of abrasive flow precision machining and establish the optimal process parameters.The results of the surface morphology before and after the precision machining of the inner surface of the elbow are discussed,and the surface roughness Ra value is reduced from 1.125μm to 0.295μm after the precision machining of the abrasive flow.The application of DSMC method provides special insights for the development of abrasive flow technology.展开更多
Preparation method of magnetic nanoparticles with core-shell structure was introduced,especially focusing on the preparation principle of sol-gel method,microemulsion method,and self-assembly technique.The application...Preparation method of magnetic nanoparticles with core-shell structure was introduced,especially focusing on the preparation principle of sol-gel method,microemulsion method,and self-assembly technique.The application of core-shell nanoparticles in precision machining was discussed.The Fe_(3)O_(4)@SiO_(2)composite particles were prepared by sol-gel method and were applied to the magnetorheological polishing of titanium alloy plates.Results show that core-shell nanoparticles with higher surface quality can be obtained after processing,compared with those after conventional abrasives.After polishing for 20 min,the surface roughness of the workpiece reaches 23 nm and the scratches are effectively reduced.Finally,the preparation and application of coreshell nanoparticles are summarized and prospected to provide a reference for further research on core-shell nanoparticles.展开更多
A new idea for designing wheel patterns is presented so as to solve theproblems about machining accuracy of workpiece and wear of honing wheel in ultra-precision planehoning. The influence factors on motion principle ...A new idea for designing wheel patterns is presented so as to solve theproblems about machining accuracy of workpiece and wear of honing wheel in ultra-precision planehoning. The influence factors on motion principle and pattern structures are analyzed andoptimization machining parameters are obtained. By calculating effective cutting length on thesurface of workpiece cut by wheel's abrasive and the orbit of one point on the surface of workpiececontacting with wheel, the wear coefficient of different kinds of wheels and accuracy coefficient ofworkpiece machined by corresponding wheels are obtained. Furthermore, the simulation results showthat the optimal pattern structure of wheel turns out to have lower wheel wear and higher machiningaccuracy.展开更多
During ultra-precision machining, machining accuracy is determined by many factors and interaction of these factors. Error sources are systematically analyzed for ultra-precision machine tools, and the influencing deg...During ultra-precision machining, machining accuracy is determined by many factors and interaction of these factors. Error sources are systematically analyzed for ultra-precision machine tools, and the influencing degree of each factor is presented to provide orientation for error reduction and error compensation.展开更多
There have been various theoretical attempts by researchers worldwide to link up different scales of plasticity studies from the nano-, micro- and macro-scale of observation, based on molecular dynamics, crystal plast...There have been various theoretical attempts by researchers worldwide to link up different scales of plasticity studies from the nano-, micro- and macro-scale of observation, based on molecular dynamics, crystal plasticity and continuum mechanics. Very few attempts, however, have been reported in ultra-precision machining studies. A mesoplasticity approach advocated by Lee and Yang is adopted by the authors and is successfully applied to studies of the micro-cutting mechanisms in ultra-precision machining. Traditionally, the shear angle in metal cutting, as well as the cutting force variation, can only be determined from cutting tests. In the pioneering work of the authors, the use of mesoplasticity theory enables prediction of the fluctuation of the shear angle and micro-cutting force, shear band formation, chip morphology in diamond turning and size effect in nano-indentation. These findings are verified by experiments. The mesoplasticity formulation opens up a new direction of studies to enable how the plastic behaviour of materials and their constitutive representations in deformation processing, such as machining can be predicted, assessed and deduced from the basic properties of the materials measurable at the microscale.展开更多
To meet the demands for highly advanced components with ultra precise contour accuracy and optical surface quality arising in the fields of photonics and optics, automotive, medical applications and biotechnology, con...To meet the demands for highly advanced components with ultra precise contour accuracy and optical surface quality arising in the fields of photonics and optics, automotive, medical applications and biotechnology, consumer electronics and renewable energy, more advanced production machines and processes have to be developed. As the complexity of machine tools rises steadily, the automation of manufacture increases rapidly, processes become more integrated and cycle times have to be reduced significantly, challenges of engineering efficient machine tools with respect to these demands expand every day. Especially the manufacture of freeform geometries with non-continuous and asymmetric surfaces requires advanced diamond machining strategies involving highly dynamic axes movements with a high bandwidth and position accuracy. Ultra precision lathes additionally equipped with Slow Tool and Fast Tool systems can be regarded as state-of-the-art machines achieving the objectives of high quality optical components. The mechanical design of such ultra precision machine tools as well as the mechanical integration of additional highly dynamic axes are very well understood today. In contrast to that, neither advanced control strategies for ultra precision machining nor the control integration of additional Fast Tool systems have been sufficiently developed yet. Considering a complex machine setup as a mechatronic system, it becomes obvious that enhancements to further increase the achievable form accuracy and surface quality and at the same time decrease cycle times and error sensitivity can only be accomplished by innovative, integrated control systems. At the Fraunhofer Institute for Production Technology IPT a novel, fully integrated control approach has been developed to overcome the drawbacks of state-of-the-art machine controls for ultra precision processes. Current control systems are often realized as decentralized solutions consisting of various computational hardware components for setpoint generation, machine control, HMI （human machine interface）, Slow Tool control and Fast Tool control. While implementing such a distributed control strategy, many disadvantages arise in terms of complex communication interfaces, discontinuous safety structures, synchronization of cycle times and the machining accuracy as a whole. The novel control approach has been developed as a fully integrated machine control including standard CNC （computer numerical control） and PLC （programmable logic controller） functionality, advanced setpoint generation methods, an extended HMI as well as an FPGA （field programmable gate array）-based controller for a voice coil driven Slow Tool and a piezo driven Fast Tool axis. As the new control system has been implemented as a fully integrated platform using digital communication via EtherCAT, a continuous safety strategy could be realized, the error sensitivity and EMC susceptibility could be significantly decreased and the overall process accuracy from setpoint generation over path interpolation to axes movements could be enhanced. The novel control at the same time offers additional possibilities of automation, process integration, online data acquisition and evaluation as well as error compensation methods.展开更多
With the continuous collaborative innovation and development of Internet technology and mechanical manufacturing technology, the realization of precision machining process has become the leading innovative technology ...With the continuous collaborative innovation and development of Internet technology and mechanical manufacturing technology, the realization of precision machining process has become the leading innovative technology in the manufacturing industry. China is a big industrial country, and industry is one of the important industrial forms to promote economic development. The machinery manufacturing industry accounts for half of the construction work of industrial engineering projects. However, in order to transform China from an industrial power to an industrial power, the mechanical manufacturing industry needs to be improved from the material, structure, technology and other aspects, combined with advanced information technology means, using scientific and normative principles to complete the mechanical manufacturing content. Next, the article discusses the application of modern mechanical manufacturing technology and precision machining technology.展开更多
This paper presents a terahertz（THz）band-pass filter using ultra-precision machining technology based on Chebyshev filter prototype.This iris inductive window coupled waveguide filter was designed by using 8 resonan...This paper presents a terahertz（THz）band-pass filter using ultra-precision machining technology based on Chebyshev filter prototype.This iris inductive window coupled waveguide filter was designed by using 8 resonant cavities with a center frequency of 345 GHz and a 7% bandwidth.The final design fulfills the desired specifications and presents the minimum insertion loss of 1.55 d B and the return loss of less than 15 d B at 345 GHz.The stop-band rejection is50 d B off the center frequency about 30 GHz,which means it has a good performance of high stop-band suppression.Compared with the recent development of THz filters,this filter possesses the characteristic of simple structure and is easy to machining.展开更多
As the technical content of promoting industrial development in the industrial field, the in-depth study of modern mechanical manufacturing technology and precision machining technology is not only conducive to improv...As the technical content of promoting industrial development in the industrial field, the in-depth study of modern mechanical manufacturing technology and precision machining technology is not only conducive to improving the development level of China's manufacturing industry, but also of great significance to industrial enterprises. However, due to the late development of advanced technology in China, the development of mechanical manufacturing technology and precision machining technology is not perfect, and there are still some problems, such as insufficient degree of automation, inadequate application of machining technology and so on. Relevant enterprises should carry out analysis and research, understand the characteristics and advantages of modern machinery manufacturing and the application mode of precision machining technology, select the integrated application of technology according to different product characteristics and requirements, improve the quality of machinery manufacturing and service quality, promote the accelerated development of China’s machinery manufacturing industry and contribute to China’s economic construction.展开更多
In the process of machining, it is difficult to eliminate the errors due to various factors, which will affect the final product quality. In order to actively control the errors in mechanical processing, it is necessa...In the process of machining, it is difficult to eliminate the errors due to various factors, which will affect the final product quality. In order to actively control the errors in mechanical processing, it is necessary to effectively apply modern mechanical processing technology and actively adopt precision processing technology to ensure the product quality and meet the increasing demand of users. Precision machining technology and mechanical design and manufacturing technology are complementary relations. They are interrelated and promote each other. This benign relationship greatly promotes the development of China's economy and industry.展开更多
Modern mechanical manufacturing technology and precision machining technology have a positive role in promoting the whole industrial production. However, with the development of modern science and technology, the actu...Modern mechanical manufacturing technology and precision machining technology have a positive role in promoting the whole industrial production. However, with the development of modern science and technology, the actual requirements of modern mechanical manufacturing technology and precision machining technology are gradually improving, forcing the current enterprises to make appropriate adjustments in combination with the actual requirements of modern industrial production. Therefore, under the requirements of current production management, this paper makes a comprehensive analysis and exploration of the relationship between modern mechanical manufacturing technology and precision processing technology, further combs out the practical problems existing in the whole industrial production of modern mechanical manufacturing technology and precision processing technology, and judges the relevant contents involved in the modern mechanical manufacturing and processing technology, in order to promote the transformation of industrial production mode and improve the overall quality of industrial production management in our country.展开更多
A dynamical dq model is proposed for a linear flux-switching permanent magnet（LFSPM） machine which is suitable for high-precision control applications.The operation principle of the prototype machine is analyzed usi...A dynamical dq model is proposed for a linear flux-switching permanent magnet（LFSPM） machine which is suitable for high-precision control applications.The operation principle of the prototype machine is analyzed using the finite element method（FEM）,and the parameters,such as the back electromotive force（EMF） and the phase flux linkage,are calculated.The calculated and measured results reveal that the back EMF and the flux linkage are essentially sinusoidal,and the variation of the phase flux linkage profile of the LFSPM machine is similar to that of the linear surface permanent magnet（LSPM） machine.Based on this,a dynamical dq model and a simulation control model are proposed.The simulation results are compared with the test results obtained from a DSP-based control platform,which verifies that the model is correct and effective.Moreover,the model can be used for design optimization and control development.展开更多
Machine tool thermal error is an important reason for poor machining accuracy. Thermal error compensation is a primary technology in accuracy control. To build thermal error model, temperature variables are needed to ...Machine tool thermal error is an important reason for poor machining accuracy. Thermal error compensation is a primary technology in accuracy control. To build thermal error model, temperature variables are needed to be divided into several groups on an appropriate threshold. Currently, group threshold value is mainly determined by researchers experience. Few studies focus on group threshold in temperature variable grouping. Since the threshold is important in error compensation, this paper arms to find out an optimal threshold to realize temperature variable optimization in thermal error modeling. Firstly, correlation coefficient is used to express membership grade of temperature variables, and the theory of fuzzy transitive closure is applied to obtain relational matrix of temperature variables. Concepts as compact degree and separable degree are introduced. Then evaluation model of temperature variable clustering is built. The optimal threshold and the best temperature variable clustering can be obtained by setting the maximum value of evaluation model as the objective. Finally, correlation coefficients between temperature variables and thermal error are calculated in order to find out optimum temperature variables for thermal error modeling. An experiment is conducted on a precise horizontal machining center. In experiment, three displacement sensors are used to measure spindle thermal error and twenty-nine temperature sensors are utilized to detect the machining center temperature. Experimental result shows that the new method of temperature variable optimization on optimal threshold successfully worked out a best threshold value interval and chose seven temperature variables from twenty-nine temperature measuring points. The model residual of z direction is within 3 μm. Obviously, the proposed new variable optimization method has simple computing process and good modeling accuracy, which is quite fit for thermal error compensation.展开更多
Digitization precision analysis is an important tool to ensure the design precision of machine tool currently. The correlative research about precision modeling and analysis mainly focuses on the geometry precision an...Digitization precision analysis is an important tool to ensure the design precision of machine tool currently. The correlative research about precision modeling and analysis mainly focuses on the geometry precision and motion precision of machine tool, and the forming motion precision of workpiece surface. For the machine tool with complex forming motion, there is not accurate corresponding relationship between the existing criterion on precision design and the machining precision of workpiece. Therefore, a design scheme on machine tool precision based on error prediction is proposed, which is divided into two-stage digitization precision analysis crucially. The first stage aims at the technology system to complete the precision distribution and inspection from the workpiece to various component parts of technology system and achieve the total output precision of machine tool under the specified machining precision; the second stage aims at the machine tool system to complete the precision distribution and inspection from the output precision of machine tool to the machine tool components. This article serves YK3610 gear hobber as the example to describe the error model of two systems and basic application method, and the practical cutting precision of this machine tool achieves to 5-4-4 grade. The proposed method can provide reliable guidance to the precision design of machine tool with complex forming motion.展开更多
文摘Gastrointestinal(GI)cancers remain a leading cause of cancer-related morbidity and mortality worldwide.Artificial intelligence(AI),particularly machine learning and deep learning(DL),has shown promise in enhancing cancer detection,diagnosis,and prognostication.A narrative review of literature published from January 2015 to march 2025 was conducted using PubMed,Web of Science,and Scopus.Search terms included"gastrointestinal cancer","artificial intelligence","machine learning","deep learning","radiomics","multimodal detection"and"predictive modeling".Studies were included if they focused on clinically relevant AI applications in GI oncology.AI algorithms for GI cancer detection have achieved high performance across imaging modalities,with endoscopic DL systems reporting accuracies of 85%-97%for polyp detection and segmentation.Radiomics-based models have predicted molecular biomarkers such as programmed cell death ligand 2 expression with area under the curves up to 0.92.Large language models applied to radiology reports demonstrated diagnostic accuracy comparable to junior radiologists(78.9%vs 80.0%),though without incremental value when combined with human interpretation.Multimodal AI approaches integrating imaging,pathology,and clinical data show emerging potential for precision oncology.AI in GI oncology has reached clinically relevant accuracy levels in multiple diagnostic tasks,with multimodal approaches and predictive biomarker modeling offering new opportunities for personalized care.However,broader validation,integration into clinical workflows,and attention to ethical,legal,and social implications remain critical for widespread adoption.
基金Projects(U22B2084,52275483,52075142)supported by the National Natural Science Foundation of ChinaProject(2023ZY01050)supported by the Ministry of Industry and Information Technology High Quality Development,China。
文摘The gears of new energy vehicles are required to withstand higher rotational speeds and greater loads,which puts forward higher precision essentials for gear manufacturing.However,machining process parameters can cause changes in cutting force/heat,resulting in affecting gear machining precision.Therefore,this paper studies the effect of different process parameters on gear machining precision.A multi-objective optimization model is established for the relationship between process parameters and tooth surface deviations,tooth profile deviations,and tooth lead deviations through the cutting speed,feed rate,and cutting depth of the worm wheel gear grinding machine.The response surface method(RSM)is used for experimental design,and the corresponding experimental results and optimal process parameters are obtained.Subsequently,gray relational analysis-principal component analysis(GRA-PCA),particle swarm optimization(PSO),and genetic algorithm-particle swarm optimization(GA-PSO)methods are used to analyze the experimental results and obtain different optimal process parameters.The results show that optimal process parameters obtained by the GRA-PCA,PSO,and GA-PSO methods improve the gear machining precision.Moreover,the gear machining precision obtained by GA-PSO is superior to other methods.
基金co-supported by the Enterprise Innovation and Development Joint Program of the National Natural Science Foundation of China(No.U20B2032)Open Project Funding of State Key Laboratory for High Performance Tools(GXNGJSKL-2024-08)+1 种基金Open Foundation of the State Key Laboratory of Intelligent Manufacturing Equipment and Technology(IMETKF2023005)Introduced Innovative Scientific Research Team Project of Zhongshan(the tenth batch)(CXTD2023008)。
文摘Micro-grinding has been widely used in aerospace and other industry.However,the small diameter of the micro-grinding tool has limited its machining performance and efficiency.In order to solve the above problems,micro-structure has been applied on the micro-grinding tool.A morphology modeling has been established in this study to characterize the surface of microstructured micro-grinding tool,and the grinding performance of micro-structured micro-grinding tool has been analyzed through undeformed chip thickness,abrasive edge width,and effective distance between abrasives.Then deviation analysis,path optimization and parameter optimization of microchannel array precision grinding have been finished to improve processing quality and efficiency,and the deflection angle has the most obvious effects on the rectangular slot depth,micro-structured micro-grinding tool could reduce 10%surface roughness and 20%grinding force compared to original micro-grinding tool.Finally,the microchannel array has been machined with a size deviation of 2μm and surface roughness of 0.2μm.
文摘Based on the theory of elastic mechanics and material mechanics, the orientation precision of the hohl schaft kegel（HSK） tooling system in static and dynamic states is theoretically and experimentally studied. The relation between the clamping force and the shank taper is obtained. And a proper clamping force is found to be essential to assure the axial and radial orientation precisions of the HSK tooling system in high speed machining （HSM）. Analytical results show that the reason why the HSK tooling system can keep high precision at the high rotational speed is that the actual axial clamping force keeps the two surfaces of the shank and the spindle in contact all the time.
文摘Artificial intelligence(AI)and machine learning(ML)are transforming spine care by addressing diagnostics,treatment planning,and rehabilitation challenges.This study highlights advancements in precision medicine for spinal pathologies,leveraging AI and ML to enhance diagnostic accuracy through deep learning algorithms,enabling faster and more accurate detection of abnormalities.AIpowered robotics and surgical navigation systems improve implant placement precision and reduce complications in complex spine surgeries.Wearable devices and virtual platforms,designed with AI,offer personalized,adaptive therapies that improve treatment adherence and recovery outcomes.AI also enables preventive interventions by assessing spine condition risks early.Despite progress,challenges remain,including limited healthcare datasets,algorithmic biases,ethical concerns,and integration into existing systems.Interdisciplinary collaboration and explainable AI frameworks are essential to unlock AI’s full potential in spine care.Future developments include multimodal AI systems integrating imaging,clinical,and genetic data for holistic treatment approaches.AI and ML promise significant improvements in diagnostic accuracy,treatment personalization,service accessibility,and cost efficiency,paving the way for more streamlined and effective spine care,ultimately enhancing patient outcomes.
基金Projects(51206011,U1937201)supported by the National Natural Science Foundation of ChinaProject(20200301040RQ)supported by the Science and Technology Development Program of Jilin Province,China+1 种基金Project(JJKH20190541KJ)supported by the Education Department of Jilin Province,ChinaProject(18DY017)supported by Changchun Science and Technology Program of Changchun City,China。
文摘The investigation was carried out on the technical problems of finishing the inner surface of elbow parts and the action mechanism of particles in elbow precision machining by abrasive flow.This work was analyzed and researched by combining theory,numerical and experimental methods.The direct simulation Monte Carlo(DSMC)method and the finite element analysis method were combined to reveal the random collision of particles during the precision machining of abrasive flow.Under different inlet velocity,volume fraction and abrasive particle size,the dynamic pressure and turbulence flow energy of abrasive flow in elbow were analyzed,and the machining mechanism of particles on the wall and the influence of different machining parameters on the precision machining quality of abrasive flow were obtained.The test results show the order of the influence of different parameters on the quality of abrasive flow precision machining and establish the optimal process parameters.The results of the surface morphology before and after the precision machining of the inner surface of the elbow are discussed,and the surface roughness Ra value is reduced from 1.125μm to 0.295μm after the precision machining of the abrasive flow.The application of DSMC method provides special insights for the development of abrasive flow technology.
基金National Natural Science Foundation of China(52265056)Lanzhou Youth Talent Project(2023-QN-38)Hongliu Youth Fund of Lanzhou University of Technology(07/062004)。
文摘Preparation method of magnetic nanoparticles with core-shell structure was introduced,especially focusing on the preparation principle of sol-gel method,microemulsion method,and self-assembly technique.The application of core-shell nanoparticles in precision machining was discussed.The Fe_(3)O_(4)@SiO_(2)composite particles were prepared by sol-gel method and were applied to the magnetorheological polishing of titanium alloy plates.Results show that core-shell nanoparticles with higher surface quality can be obtained after processing,compared with those after conventional abrasives.After polishing for 20 min,the surface roughness of the workpiece reaches 23 nm and the scratches are effectively reduced.Finally,the preparation and application of coreshell nanoparticles are summarized and prospected to provide a reference for further research on core-shell nanoparticles.
基金This project is supported by Foundation of Xiamen Univer sity of China for Scholars Return from Abroad (No.08003).
文摘A new idea for designing wheel patterns is presented so as to solve theproblems about machining accuracy of workpiece and wear of honing wheel in ultra-precision planehoning. The influence factors on motion principle and pattern structures are analyzed andoptimization machining parameters are obtained. By calculating effective cutting length on thesurface of workpiece cut by wheel's abrasive and the orbit of one point on the surface of workpiececontacting with wheel, the wear coefficient of different kinds of wheels and accuracy coefficient ofworkpiece machined by corresponding wheels are obtained. Furthermore, the simulation results showthat the optimal pattern structure of wheel turns out to have lower wheel wear and higher machiningaccuracy.
文摘During ultra-precision machining, machining accuracy is determined by many factors and interaction of these factors. Error sources are systematically analyzed for ultra-precision machine tools, and the influencing degree of each factor is presented to provide orientation for error reduction and error compensation.
基金the Research Committee of The Hong Kong Polytechnic University and the Innovation Technology Commission of The Hong Kong SAR Government for their financial support of the Hong Kong Partner State Key Laboratory of Ultra-Precision Machining Technology
文摘There have been various theoretical attempts by researchers worldwide to link up different scales of plasticity studies from the nano-, micro- and macro-scale of observation, based on molecular dynamics, crystal plasticity and continuum mechanics. Very few attempts, however, have been reported in ultra-precision machining studies. A mesoplasticity approach advocated by Lee and Yang is adopted by the authors and is successfully applied to studies of the micro-cutting mechanisms in ultra-precision machining. Traditionally, the shear angle in metal cutting, as well as the cutting force variation, can only be determined from cutting tests. In the pioneering work of the authors, the use of mesoplasticity theory enables prediction of the fluctuation of the shear angle and micro-cutting force, shear band formation, chip morphology in diamond turning and size effect in nano-indentation. These findings are verified by experiments. The mesoplasticity formulation opens up a new direction of studies to enable how the plastic behaviour of materials and their constitutive representations in deformation processing, such as machining can be predicted, assessed and deduced from the basic properties of the materials measurable at the microscale.
文摘To meet the demands for highly advanced components with ultra precise contour accuracy and optical surface quality arising in the fields of photonics and optics, automotive, medical applications and biotechnology, consumer electronics and renewable energy, more advanced production machines and processes have to be developed. As the complexity of machine tools rises steadily, the automation of manufacture increases rapidly, processes become more integrated and cycle times have to be reduced significantly, challenges of engineering efficient machine tools with respect to these demands expand every day. Especially the manufacture of freeform geometries with non-continuous and asymmetric surfaces requires advanced diamond machining strategies involving highly dynamic axes movements with a high bandwidth and position accuracy. Ultra precision lathes additionally equipped with Slow Tool and Fast Tool systems can be regarded as state-of-the-art machines achieving the objectives of high quality optical components. The mechanical design of such ultra precision machine tools as well as the mechanical integration of additional highly dynamic axes are very well understood today. In contrast to that, neither advanced control strategies for ultra precision machining nor the control integration of additional Fast Tool systems have been sufficiently developed yet. Considering a complex machine setup as a mechatronic system, it becomes obvious that enhancements to further increase the achievable form accuracy and surface quality and at the same time decrease cycle times and error sensitivity can only be accomplished by innovative, integrated control systems. At the Fraunhofer Institute for Production Technology IPT a novel, fully integrated control approach has been developed to overcome the drawbacks of state-of-the-art machine controls for ultra precision processes. Current control systems are often realized as decentralized solutions consisting of various computational hardware components for setpoint generation, machine control, HMI （human machine interface）, Slow Tool control and Fast Tool control. While implementing such a distributed control strategy, many disadvantages arise in terms of complex communication interfaces, discontinuous safety structures, synchronization of cycle times and the machining accuracy as a whole. The novel control approach has been developed as a fully integrated machine control including standard CNC （computer numerical control） and PLC （programmable logic controller） functionality, advanced setpoint generation methods, an extended HMI as well as an FPGA （field programmable gate array）-based controller for a voice coil driven Slow Tool and a piezo driven Fast Tool axis. As the new control system has been implemented as a fully integrated platform using digital communication via EtherCAT, a continuous safety strategy could be realized, the error sensitivity and EMC susceptibility could be significantly decreased and the overall process accuracy from setpoint generation over path interpolation to axes movements could be enhanced. The novel control at the same time offers additional possibilities of automation, process integration, online data acquisition and evaluation as well as error compensation methods.
文摘With the continuous collaborative innovation and development of Internet technology and mechanical manufacturing technology, the realization of precision machining process has become the leading innovative technology in the manufacturing industry. China is a big industrial country, and industry is one of the important industrial forms to promote economic development. The machinery manufacturing industry accounts for half of the construction work of industrial engineering projects. However, in order to transform China from an industrial power to an industrial power, the mechanical manufacturing industry needs to be improved from the material, structure, technology and other aspects, combined with advanced information technology means, using scientific and normative principles to complete the mechanical manufacturing content. Next, the article discusses the application of modern mechanical manufacturing technology and precision machining technology.
基金supported by the National Natural Science Foundation of China under Grant No.61434006
文摘This paper presents a terahertz（THz）band-pass filter using ultra-precision machining technology based on Chebyshev filter prototype.This iris inductive window coupled waveguide filter was designed by using 8 resonant cavities with a center frequency of 345 GHz and a 7% bandwidth.The final design fulfills the desired specifications and presents the minimum insertion loss of 1.55 d B and the return loss of less than 15 d B at 345 GHz.The stop-band rejection is50 d B off the center frequency about 30 GHz,which means it has a good performance of high stop-band suppression.Compared with the recent development of THz filters,this filter possesses the characteristic of simple structure and is easy to machining.
文摘As the technical content of promoting industrial development in the industrial field, the in-depth study of modern mechanical manufacturing technology and precision machining technology is not only conducive to improving the development level of China's manufacturing industry, but also of great significance to industrial enterprises. However, due to the late development of advanced technology in China, the development of mechanical manufacturing technology and precision machining technology is not perfect, and there are still some problems, such as insufficient degree of automation, inadequate application of machining technology and so on. Relevant enterprises should carry out analysis and research, understand the characteristics and advantages of modern machinery manufacturing and the application mode of precision machining technology, select the integrated application of technology according to different product characteristics and requirements, improve the quality of machinery manufacturing and service quality, promote the accelerated development of China’s machinery manufacturing industry and contribute to China’s economic construction.
文摘In the process of machining, it is difficult to eliminate the errors due to various factors, which will affect the final product quality. In order to actively control the errors in mechanical processing, it is necessary to effectively apply modern mechanical processing technology and actively adopt precision processing technology to ensure the product quality and meet the increasing demand of users. Precision machining technology and mechanical design and manufacturing technology are complementary relations. They are interrelated and promote each other. This benign relationship greatly promotes the development of China's economy and industry.
文摘Modern mechanical manufacturing technology and precision machining technology have a positive role in promoting the whole industrial production. However, with the development of modern science and technology, the actual requirements of modern mechanical manufacturing technology and precision machining technology are gradually improving, forcing the current enterprises to make appropriate adjustments in combination with the actual requirements of modern industrial production. Therefore, under the requirements of current production management, this paper makes a comprehensive analysis and exploration of the relationship between modern mechanical manufacturing technology and precision processing technology, further combs out the practical problems existing in the whole industrial production of modern mechanical manufacturing technology and precision processing technology, and judges the relevant contents involved in the modern mechanical manufacturing and processing technology, in order to promote the transformation of industrial production mode and improve the overall quality of industrial production management in our country.
基金The National Natural Science Foundation of China (No.41076054)
文摘A dynamical dq model is proposed for a linear flux-switching permanent magnet（LFSPM） machine which is suitable for high-precision control applications.The operation principle of the prototype machine is analyzed using the finite element method（FEM）,and the parameters,such as the back electromotive force（EMF） and the phase flux linkage,are calculated.The calculated and measured results reveal that the back EMF and the flux linkage are essentially sinusoidal,and the variation of the phase flux linkage profile of the LFSPM machine is similar to that of the linear surface permanent magnet（LSPM） machine.Based on this,a dynamical dq model and a simulation control model are proposed.The simulation results are compared with the test results obtained from a DSP-based control platform,which verifies that the model is correct and effective.Moreover,the model can be used for design optimization and control development.
基金supported by Jiangsu Provincial Prospective Joint Research Foundation for Industry-University-Research of China (Grant No. BY2009102)Henan Provincial Major Scientific and Technological Projects of China (Grant No. 102102210050)
文摘Machine tool thermal error is an important reason for poor machining accuracy. Thermal error compensation is a primary technology in accuracy control. To build thermal error model, temperature variables are needed to be divided into several groups on an appropriate threshold. Currently, group threshold value is mainly determined by researchers experience. Few studies focus on group threshold in temperature variable grouping. Since the threshold is important in error compensation, this paper arms to find out an optimal threshold to realize temperature variable optimization in thermal error modeling. Firstly, correlation coefficient is used to express membership grade of temperature variables, and the theory of fuzzy transitive closure is applied to obtain relational matrix of temperature variables. Concepts as compact degree and separable degree are introduced. Then evaluation model of temperature variable clustering is built. The optimal threshold and the best temperature variable clustering can be obtained by setting the maximum value of evaluation model as the objective. Finally, correlation coefficients between temperature variables and thermal error are calculated in order to find out optimum temperature variables for thermal error modeling. An experiment is conducted on a precise horizontal machining center. In experiment, three displacement sensors are used to measure spindle thermal error and twenty-nine temperature sensors are utilized to detect the machining center temperature. Experimental result shows that the new method of temperature variable optimization on optimal threshold successfully worked out a best threshold value interval and chose seven temperature variables from twenty-nine temperature measuring points. The model residual of z direction is within 3 μm. Obviously, the proposed new variable optimization method has simple computing process and good modeling accuracy, which is quite fit for thermal error compensation.
基金supported by National Natural Science Foundation of China (Grant No. 51075419)Chongqing Municipal Natural Science Foundation of China (Grant No. CSTC,2009BB3234)
文摘Digitization precision analysis is an important tool to ensure the design precision of machine tool currently. The correlative research about precision modeling and analysis mainly focuses on the geometry precision and motion precision of machine tool, and the forming motion precision of workpiece surface. For the machine tool with complex forming motion, there is not accurate corresponding relationship between the existing criterion on precision design and the machining precision of workpiece. Therefore, a design scheme on machine tool precision based on error prediction is proposed, which is divided into two-stage digitization precision analysis crucially. The first stage aims at the technology system to complete the precision distribution and inspection from the workpiece to various component parts of technology system and achieve the total output precision of machine tool under the specified machining precision; the second stage aims at the machine tool system to complete the precision distribution and inspection from the output precision of machine tool to the machine tool components. This article serves YK3610 gear hobber as the example to describe the error model of two systems and basic application method, and the practical cutting precision of this machine tool achieves to 5-4-4 grade. The proposed method can provide reliable guidance to the precision design of machine tool with complex forming motion.
