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Coupling evaluation for material removal and thermal control on precision milling machine tools

《机械工程前沿(英文)》 2022年 第17卷 第1期   页码 12-12 doi: 10.1007/s11465-021-0668-9

摘要: Machine tools are one of the most representative machining systems in manufacturing. The energy consumption of machine tools has been a research hotspot and frontier for green low-carbon manufacturing. However, previous research merely regarded the material removal (MR) energy as useful energy consumption and ignored the useful energy consumed by thermal control (TC) for maintaining internal thermal stability and machining accuracy. In pursuit of energy-efficient, high-precision machining, more attention should be paid to the energy consumption of TC and the coupling relationship between MR and TC. Hence, the cutting energy efficiency model considering the coupling relationship is established based on the law of conservation of energy. An index of energy consumption ratio of TC is proposed to characterize its effect on total energy usage. Furthermore, the heat characteristics are analyzed, which can be adopted to represent machining accuracy. Experimental study indicates that TC is the main energy-consuming process of the precision milling machine tool, which overwhelms the energy consumption of MR. The forced cooling mode of TC results in a 7% reduction in cutting energy efficiency. Regression analysis shows that heat dissipation positively contributes 54.1% to machining accuracy, whereas heat generation negatively contributes 45.9%. This paper reveals the coupling effect of MR and TC on energy efficiency and machining accuracy. It can provide a foundation for energy-efficient, high-precision machining of machine tools.

关键词: machine tools     cutting energy efficiency     thermal stability     machining accuracy     coupling evaluation    

并联机床后置处理器的开发及实验研究

李铁民,叶佩青,汪劲松

《中国工程科学》 2003年 第5卷 第12期   页码 80-86

摘要:

以六自由度6-TPS型并联机床为模型,阐述了机床控制数据的生成原理和流程;以此为基础,规划了后置处理器的功能和整体结构。对若干关键技术进行了研究和探讨,包括基于参数化二进制格式的内部数据传输,基于刀轴矢量的笛卡儿空间粗插补算法,三维和二维刀具半径补偿,刀位文件的预处理以及加工代码的词法和语法检查等。最后介绍了利用本系统进行的切削实验,验证了系统的工程实用性。

关键词: 并联机床     后置处理算法     后置处理器    

数控机床精度评价新方法

赵万华,张 俊,刘 辉,杨晓君

《中国工程科学》 2013年 第15卷 第1期   页码 93-98

摘要:

传统的定位精度与重复定位精度等指标是在准静态下评价数控机床(CNC)性能的,无法反映数控机床在运动和加工过程中的精度。首先从数控机床的数控、伺服、机械等环节在服役态下所表现出来的性能出发,提出一种对数控机床更有针对性的,以运动精度为指标的机床精度评价新方法,通过数控指令与运动轴实际位移的符合程度即运动精度来评价机床精度,然后给出了具体的评价指标,并提出了评价指标的测量方法。分析表明,这种新的机床运动精度描述评价方法能够系统、全面地评价数控机床关键性能的优劣。最后从数控、伺服和机械角度分别阐述了影响运动精度的因素。

关键词: 数控机床     运动精度     评价指标     影响因素    

point selection in large-scale FBG temperature sensors for thermal error modeling of heavy-duty CNC machinetools

Jianmin HU, Zude ZHOU, Quan LIU, Ping LOU, Junwei YAN, Ruiya LI

《机械工程前沿(英文)》 2019年 第14卷 第4期   页码 442-451 doi: 10.1007/s11465-019-0543-0

摘要: Thermal error is one of the main factors that influence the machining accuracy of computer numerical control (CNC) machine tools. It is usually reduced by thermal error compensation. Temperature field monitoring and key temperature measurement point (TMP) selection are the bases of thermal error modeling and compensation for CNC machine tools. Compared with small- and medium-sized CNC machine tools, heavy-duty CNC machine tools require the use of more temperature sensors to measure their temperature comprehensively because of their larger size and more complex heat sources. However, the presence of many TMPs counteracts the movement of CNC machine tools due to sensor cables, and too many temperature variables may adversely influence thermal error modeling. Novel temperature sensors based on fiber Bragg grating (FBG) are developed in this study. A total of 128 FBG temperature sensors that are connected in series through a thin optical fiber are mounted on a heavy-duty CNC machine tool to monitor its temperature field. Key TMPs are selected using these large-scale FBG temperature sensors by using the density-based spatial clustering of applications with noise algorithm to reduce the calculation workload and avoid problems in the coupling of TMPs for thermal error modeling. Back propagation neural network thermal error prediction models are established to verify the performance of the proposed TMP selection method. Results show that the number of TMPs is reduced from 128 to 5, and the developed model demonstrates good prediction effects and strong robustness under different working conditions of the heavy-duty CNC machine tool.

关键词: thermal error     heavy-duty CNC machine tools     FBG     key TMPs     prediction model    

高速高精度机床热分析与热设计技术

高建民,史晓军,许艾明,赵博选

《中国工程科学》 2013年 第15卷 第1期   页码 28-33

摘要:

随着机床高速高精度的技术发展,热问题已成为影响机床特性的重要因素。从提高机床的固有热性能出发,系统介绍了机床热特性分析、热结构优化及其冷却技术的理论和方法,以及国内外研究现状,并探讨了机床“热设计”理论与技术的最新进展和未来研究重点及趋势。

关键词: 高速高精度机床     热特性分析     热结构优化     冷却技术    

Phylogenetic diversity of NO reductases, new tools for monitoring, and insights into NO production in

《环境科学与工程前沿(英文)》 2022年 第16卷 第10期 doi: 10.1007/s11783-022-1562-3

摘要:

● 548 representative nor genes were collected to create complete phylogenetic trees.

关键词: N2O     Greenhouse gas     NO reductase     NO dismutase     Primer     Crystal structure    

Design and analysis of a class of redundant collaborative manipulators with 2-dimension large rotational angles

Xiaodong JIN, Yuefa FANG, Dan ZHANG, Xueling LUO

《机械工程前沿(英文)》 2020年 第15卷 第1期   页码 66-80 doi: 10.1007/s11465-019-0570-x

摘要: The parallel spindle heads with high rotational capability are demanded in the area of multi-axis machine tools and 3D printers. This paper focuses on designing a class of 2R1T (R: Rotation; T: Translation) parallel spindle heads and the corresponding collaborative 5-axis manipulators with 2-dimension (2D) large rotational angles. In order to construct 2D rotational degrees of freedom (DOF), a platform with 2-dimension revolute joints is proposed first. Based on the constraint screw theory, the feasible limbs that can be connected in the platform are synthesized. In order to provide constant rotational axis for the platform, a class of redundant limbs are designed. A class of redundant 2R1T parallel spindle heads is obtained by connecting the redundant limbs with the platform and the redundant characteristics are verified by the modified Grübler-Kutzbach criterion. The corresponding 5-axis collaborative manipulators are presented by constructing a 2-DOF series translational bottom moving platform. The inverse kinematics and the orientation workspace as well as the decoupling characteristics of this type of 2R1T parallel spindle heads are analyzed. The results show that these manipulators have large 2D rotational angles than the traditional A3/Z3 heads and can be potentially used in the application of multi-axis machine tools and the 3D printers.

关键词: parallel mechanism     redundant mechanism     large rotational angles     machine tools     2R1T spindle head     collaborative manipulator    

Edge preparation methods for cutting tools: a review

《机械工程前沿(英文)》 2023年 第18卷 第4期 doi: 10.1007/s11465-023-0766-y

摘要: Edge preparation can remove cutting edge defects, such as burrs, chippings, and grinding marks, generated in the grinding process and improve the cutting performance and service life of tools. Various edge preparation methods have been proposed for different tool matrix materials, geometries, and application requirements. This study presents a scientific and systematic review of the development of tool edge preparation technology and provides ideas for its future development. First, typical edge characterization methods, which associate the microgeometric characteristics of the cutting edge with cutting performance, are briefly introduced. Then, edge preparation methods for cutting tools, in which materials at the cutting edge area are removed to decrease defects and obtain a suitable microgeometry of the cutting edge for machining, are discussed. New edge preparation methods are explored on the basis of existing processing technologies, and the principles, advantages, and limitations of these methods are systematically summarized and analyzed. Edge preparation methods are classified into two categories: mechanical processing methods and nontraditional processing methods. These methods are compared from the aspects of edge consistency, surface quality, efficiency, processing difficulty, machining cost, and general availability. In this manner, a more intuitive understanding of the characteristics can be gained. Finally, the future development direction of tool edge preparation technology is prospected.

关键词: edge preparation method     preparation principle     cutting edge geometry     edge characterization     tool performance    

Operando modeling and measurements: Powerful tools for revealing the mechanism of alkali carbonate-based

《能源前沿(英文)》 2023年 第17卷 第3期   页码 380-389 doi: 10.1007/s11708-023-0872-x

摘要: Alkali carbonate-based sorbents (ACSs), including Na2CO3- and K2CO3-based sorbents, are promising for CO2 capture. However, the complex sorbent components and operation conditions lead to the versatile kinetics of CO2 sorption on these sorbents. This paper proposed that operando modeling and measurements are powerful tools to understand the mechanism of sorbents in real operating conditions, facilitating the sorbent development, reactor design, and operation parameter optimization. It reviewed the theoretical simulation achievements during the development of ACSs. It elucidated the findings obtained by utilizing density functional theory (DFT) calculations, ab initio molecular dynamics (AIMD) simulations, and classical molecular dynamics (CMD) simulations as well. The hygroscopicity of sorbent and the humidity of gas flow are crucial to shifting the carbonation reaction from the gas−solid mode to the gas−liquid mode, boosting the kinetics. Moreover, it briefly introduced a machine learning (ML) approach as a promising method to aid sorbent design. Furthermore, it demonstrated a conceptual compact operando measurement system in order to understand the behavior of ACSs in the real operation process. The proposed measurement system includes a micro fluidized-bed (MFB) reactor for kinetic analysis, a multi-camera sub-system for 3D particle movement tracking, and a combined Raman and IR sub-system for solid/gas components and temperature monitoring. It is believed that this system is useful to evaluate the real-time sorbent performance, validating the theoretical prediction and promoting the industrial scale-up of ACSs for CO2 capture.

关键词: CO2 capture     carbonation     theoretical modeling     operando techniques     reaction visualization    

PathogenTrack and Yeskit: tools for identifying intracellular pathogens from single-cell RNA-sequencing

《医学前沿(英文)》 2022年 第16卷 第2期   页码 251-262 doi: 10.1007/s11684-021-0915-9

摘要: Pathogenic microbes can induce cellular dysfunction, immune response, and cause infectious disease and other diseases including cancers. However, the cellular distributions of pathogens and their impact on host cells remain rarely explored due to the limited methods. Taking advantage of single-cell RNA-sequencing (scRNA-seq) analysis, we can assess the transcriptomic features at the single-cell level. Still, the tools used to interpret pathogens (such as viruses, bacteria, and fungi) at the single-cell level remain to be explored. Here, we introduced PathogenTrack, a python-based computational pipeline that uses unmapped scRNA-seq data to identify intracellular pathogens at the single-cell level. In addition, we established an R package named Yeskit to import, integrate, analyze, and interpret pathogen abundance and transcriptomic features in host cells. Robustness of these tools has been tested on various real and simulated scRNA-seq datasets. PathogenTrack is competitive to the state-of-the-art tools such as Viral-Track, and the first tools for identifying bacteria at the single-cell level. Using the raw data of bronchoalveolar lavage fluid samples (BALF) from COVID-19 patients in the SRA database, we found the SARS-CoV-2 virus exists in multiple cell types including epithelial cells and macrophages. SARS-CoV-2-positive neutrophils showed increased expression of genes related to type I interferon pathway and antigen presenting module. Additionally, we observed the Haemophilus parahaemolyticus in some macrophage and epithelial cells, indicating a co-infection of the bacterium in some severe cases of COVID-19. The PathogenTrack pipeline and the Yeskit package are publicly available at GitHub.

关键词: scRNA-seq     intracellular pathogen     microbe     COVID-19     SARS-CoV-2    

美国联邦政府机构技术预测工具应用态势分析

孙棕檀,李云,李浩悦,特日格乐

《中国工程科学》 2017年 第19卷 第5期   页码 92-96 doi: 10.15302/J-SSCAE-2017.05.016

摘要:

美国国防分析研究所发布的《美国联邦政府技术预测工具应用现状与潜在应用》研究报告对美国联邦政府机构技术预测工作开展现状进行了梳理,对联邦政府机构期望拥有的技术预测工具能力进行了分析。本文在此基础上,对联邦政府机构技术预测工具的应用态势进行了总结,为我国开发相应技术预测工具提供参考与借鉴。

关键词: 美国联邦政府机构     技术预测工具     自动化    

战略性新兴产业国外经典政策工具分析——政府采购与补贴政策

许冠南,王秀芹,潘美娟,周源

《中国工程科学》 2016年 第18卷 第4期   页码 113-120 doi: 10.15302/J-SSCAE-2016.04.017

摘要:

当前,战略性新兴产业已经成为一国产业结构升级和抢占世界经济发展制高点的关键,世界各国纷纷将新兴产业的发展提升到国家战略高度,应用各种政策工具大力推动新兴产业加速发展。研究国外为促进新兴产业发展做出的重要举措对我国制定相应政策具有重要的借鉴作用。本文重点分析了发达国家为了推进新兴产业发展所采用的政府采购与政府补贴两种经典政策工具,以期为我国培育发展战略性新兴产业提供参考。

关键词: 新兴产业     政策工具     政府采购     政府补贴     产业政策分析    

Challenges of human–machine collaboration in risky decision-making

《工程管理前沿(英文)》 2022年 第9卷 第1期   页码 89-103 doi: 10.1007/s42524-021-0182-0

摘要: The purpose of this paper is to delineate the research challenges of human–machine collaboration in risky decision-making. Technological advances in machine intelligence have enabled a growing number of applications in human–machine collaborative decision-making. Therefore, it is desirable to achieve superior performance by fully leveraging human and machine capabilities. In risky decision-making, a human decision-maker is vulnerable to cognitive biases when judging the possible outcomes of a risky event, whereas a machine decision-maker cannot handle new and dynamic contexts with incomplete information well. We first summarize features of risky decision-making and possible biases of human decision-makers therein. Then, we argue the necessity and urgency of advancing human–machine collaboration in risky decision-making. Afterward, we review the literature on human–machine collaboration in a general decision context, from the perspectives of human–machine organization, relationship, and collaboration. Lastly, we propose challenges of enhancing human–machine communication and teamwork in risky decision-making, followed by future research avenues.

关键词: human–machine collaboration     risky decision-making     human–machine team and interaction     task allocation     human–machine relationship    

Spatial prediction of soil contamination based on machine learning: a review

《环境科学与工程前沿(英文)》 2023年 第17卷 第8期 doi: 10.1007/s11783-023-1693-1

摘要:

● A review of machine learning (ML) for spatial prediction of soil contamination.

关键词: Soil contamination     Machine learning     Prediction     Spatial distribution    

大埋深富水砂卵石地层泥水盾构带压换刀及动火焊接技术

程明亮,何峰,吕传田

《中国工程科学》 2010年 第12卷 第12期   页码 46-50

摘要:

通过北京铁路地下直径线工程盾构施工实践经验,总结了大埋深富水砂卵石地层泥水盾构施工中带压换刀技术以及特殊情况下的带压动火焊接技术。带压换刀的技术主要有两个方面:一是选择合理换刀地点及进舱工作压力,保证掌子面土体的稳定;二是进行开挖舱高浓度泥浆的置换和中盾高浓度泥浆的注入,有效地防止了气体的逃逸。在施工中成功实现了带压进舱250余次,工作压力从0.9 bar (1 bar=100 kPa)增加到2.8 bar,未发生任何安全事故。

关键词: 泥水盾构     砂卵石地层     富水地层     带压换刀     焊接    

标题 作者 时间 类型 操作

Coupling evaluation for material removal and thermal control on precision milling machine tools

期刊论文

并联机床后置处理器的开发及实验研究

李铁民,叶佩青,汪劲松

期刊论文

数控机床精度评价新方法

赵万华,张 俊,刘 辉,杨晓君

期刊论文

point selection in large-scale FBG temperature sensors for thermal error modeling of heavy-duty CNC machinetools

Jianmin HU, Zude ZHOU, Quan LIU, Ping LOU, Junwei YAN, Ruiya LI

期刊论文

高速高精度机床热分析与热设计技术

高建民,史晓军,许艾明,赵博选

期刊论文

Phylogenetic diversity of NO reductases, new tools for monitoring, and insights into NO production in

期刊论文

Design and analysis of a class of redundant collaborative manipulators with 2-dimension large rotational angles

Xiaodong JIN, Yuefa FANG, Dan ZHANG, Xueling LUO

期刊论文

Edge preparation methods for cutting tools: a review

期刊论文

Operando modeling and measurements: Powerful tools for revealing the mechanism of alkali carbonate-based

期刊论文

PathogenTrack and Yeskit: tools for identifying intracellular pathogens from single-cell RNA-sequencing

期刊论文

美国联邦政府机构技术预测工具应用态势分析

孙棕檀,李云,李浩悦,特日格乐

期刊论文

战略性新兴产业国外经典政策工具分析——政府采购与补贴政策

许冠南,王秀芹,潘美娟,周源

期刊论文

Challenges of human–machine collaboration in risky decision-making

期刊论文

Spatial prediction of soil contamination based on machine learning: a review

期刊论文

大埋深富水砂卵石地层泥水盾构带压换刀及动火焊接技术

程明亮,何峰,吕传田

期刊论文