资源类型

期刊论文 983

会议视频 112

会议信息 2

会议专题 2

年份

2024 1

2023 65

2022 87

2021 121

2020 72

2019 47

2018 65

2017 60

2016 43

2015 40

2014 34

2013 39

2012 33

2011 33

2010 58

2009 48

2008 28

2007 34

2006 12

2005 21

展开 ︾

关键词

颠覆性技术 22

关键技术 17

智能制造 16

信息技术 14

技术 14

农业科学 11

技术预见 11

发展趋势 8

工程科技 8

三峡工程 7

战略研究 7

施工技术 7

碳中和 7

能源 7

2035年 6

技术创新 6

2035 5

发展战略 5

城镇建设 5

展开 ︾

检索范围:

排序: 展示方式:

Product lifecycle-oriented virtual assembly technology

LIU Jian-hua, NING Ru-xin, YAO Jun, WAN Bi-le

《机械工程前沿(英文)》 2006年 第1卷 第4期   页码 388-395 doi: 10.1007/s11465-006-0045-8

摘要: VA (virtual assembly) provides a more efficient, intuitive and convenient method for assembly process modeling, simulation and analysis. Previous researches about VA are almost isolated and dispersive, and have not established the understanding and definition of VA from a macroscopical and integrated view. Based on the analysis of the connotations of VA, a PLO-VATA (product lifecycle-oriented virtual assembly technology architecture) is proposed, in this architecture, VA is decomposed into four basic elements: principles and methodology of DFA (design for assembly), assembly analysis and evaluation, virtual assembly model and virtual assembly toolkits. Immersion, concurrence, integration and collaboration are the four main characteristics of VA being put forward. The key techniques of VA including virtual assembly model, virtual assembly analysis and evaluation, and virtual assembly process planning are discussed. Finally, a prototype system is built to validate the feasibility of the proposed method.

关键词: integrated     concurrence     feasibility     dispersive     assembly technology    

Assembly of biosynthetic pathways in

Lidan Ye,Xiaomei Lv,Hongwei Yu

《化学科学与工程前沿(英文)》 2017年 第11卷 第1期   页码 126-132 doi: 10.1007/s11705-016-1597-8

摘要: A robust and versatile tool for multigene pathway assembly is a key to the biosynthesis of high-value chemicals. Here we report the rapid construction of biosynthetic pathways in using a marker recyclable integrative toolbox (pUMRI) developed in our research group, which has features of ready-to-use, convenient marker recycling, arbitrary element replacement, shuttle plasmid, auxotrophic marker independence, GAL regulation, and decentralized assembly. Functional isoprenoid biosynthesis pathways containing 4–11 genes with lengths ranging from ~10 to ~22 kb were assembled using this toolbox within 1–5 rounds of reiterative recombination. In combination with GAL-regulated metabolic engineering, high production of isoprenoids (e.g., 16.3 mg?g dcw carotenoids) was achieved. These results demonstrate the wide range of application and the efficiency of the pUMRI toolbox in multigene pathway construction of .

关键词: pathway assembly     toolbox     reiterative recombination     S. cerevisiae     biosynthesis    

A novel task-oriented framework for dual-arm robotic assembly task

《机械工程前沿(英文)》 2021年 第16卷 第3期   页码 528-545 doi: 10.1007/s11465-021-0638-2

摘要: In industrial manufacturing, the deployment of dual-arm robots in assembly tasks has become a trend. However, making the dual-arm robots more intelligent in such applications is still an open, challenging issue. This paper proposes a novel framework that combines task-oriented motion planning with visual perception to facilitate robot deployment from perception to execution and finish assembly problems by using dual-arm robots. In this framework, visual perception is first employed to track the effects of the robot behaviors and observe states of the workpieces, where the performance of tasks can be abstracted as a high-level state for intelligent reasoning. The assembly task and manipulation sequences can be obtained by analyzing and reasoning the state transition trajectory of the environment as well as the workpieces. Next, the corresponding assembly manipulation can be generated and parameterized according to the differences between adjacent states by combining with the prebuilt knowledge of the scenarios. Experiments are set up with a dual-arm robotic system (ABB YuMi and an RGB-D camera) to validate the proposed framework. Experimental results demonstrate the effectiveness of the proposed framework and the promising value of its practical application.

关键词: dual-arm assembly     AI reasoning     intelligent system     task-oriented motion planning     visual perception    

Pareto lexicographic α-robust approach and its application in robust multi objective assembly line balancing

null

《机械工程前沿(英文)》 2014年 第9卷 第3期   页码 257-264 doi: 10.1007/s11465-014-0294-x

摘要:

Robustness in most of the literature is associated with min-max or min-max regret criteria. However, these criteria of robustness are conservative and therefore recently new criteria called, lexicographic α-robust method has been introduced in literature which defines the robust solution as a set of solutions whose quality or jth largest cost is not worse than the best possible jth largest cost in all scenarios. These criteria might be significant for robust optimization of single objective optimization problems. However, in real optimization problems, two or more than two conflicting objectives are desired to optimize concurrently and solution of multi objective optimization problems exists in the form of a set of solutions called Pareto solutions and from these solutions it might be difficult to decide which Pareto solution can satisfy min-max, min-max regret or lexicographic α-robust criteria by considering multiple objectives simultaneously. Therefore, lexicographic α-robust method which is a recently introduced method in literature is extended in the current research for Pareto solutions. The proposed method called Pareto lexicographic α-robust approach can define Pareto lexicographic α-robust solutions from different scenarios by considering multiple objectives simultaneously. A simple example and an application of the proposed method on a simple problem of multi objective optimization of simple assembly line balancing problem with task time uncertainty is presented to get their robust solutions. The presented method can be significant to implement on different multi objective robust optimization problems containing uncertainty.

关键词: Pareto     lexicographic α-robust     assembly line balancing    

Wheat research and breeding in the new era of a high-quality reference genome

Rudi APPELS

《农业科学与工程前沿(英文)》 2019年 第6卷 第3期   页码 225-232 doi: 10.15302/J-FASE-2019265

摘要:

The publications of the International Wheat Genome Sequencing Consortium (IWGSC) released in August 2018 are reviewed and placed into the context of developments arising from the availability of the high-quality wheat genome assembly.

关键词: assembly technology     molecular markers     polyploidy     transcript networks     wheat genome    

钢塔节段水平预拼装关键技术研究

张永利,顾碧峰

《中国工程科学》 2010年 第12卷 第4期   页码 48-52

摘要:

通过对泰州长江公路大桥钢塔柱预拼装方案的选择和关键工艺的研究,提出结构形式复杂的钢塔节段预拼装工艺选择原则。在研究了钢塔节段预拼环境的影响、支撑条件、金属接触率等水平预拼装关键工艺控制项点后,成功地解决了泰州桥钢塔节段水平预拼装中的技术难题。钢塔节段水平预拼装填补了我国钢塔制造的技术空白,为后续复杂钢塔节段水平预拼装方案选择提供了有力基础。

关键词: 钢塔     水平预拼装     支撑控制     水平力施加    

Assembly design system based on engineering connection

Wensheng YIN

《机械工程前沿(英文)》 2016年 第11卷 第4期   页码 423-432 doi: 10.1007/s11465-016-0382-1

摘要:

An assembly design system is an important part of computer-aided design systems, which are important tools for realizing product concept design. The traditional assembly design system does not record the connection information of production on the engineering layer; consequently, the upstream design idea cannot be fully used in the downstream design. An assembly design model based on the relationship of engineering connection is presented. In this model, all nodes are divided into two categories: The component and the connection. Moreover, the product is constructed on the basis of the connection relationship of the components. The model is an And/Or graph and has the ability to record all assembly schemes. This model records only the connection information that has engineering application value in the product design. In addition, this model can significantly reduce the number of combinations, and is very favorable for the assembly sequence planning in the downstream. The system contains a connection knowledge system that can be mapped to the connection node, and the connection knowledge obtained in practice can be returned to the knowledge system. Finally, VC++6.0 is used to develop a prototype system called Connect-based Assembly Planning (CAP). The relationship between the CAP system and the commercial assembly design system is also established.

关键词: product design     assembly design     engineering connection     assembly sequence planning    

Enzyme-instructed self-assembly of peptides containing phosphoserine to form supramolecular hydrogels

Jie Zhou, Xuewen Du, Jiaqing Wang, Natsuko Yamagata, Bing Xu

《化学科学与工程前沿(英文)》 2017年 第11卷 第4期   页码 509-515 doi: 10.1007/s11705-017-1613-7

摘要: Enzyme-instructed self-assembly (EISA) offers a facile approach to explore the supramolecular assemblies of small molecules in cellular milieu for a variety of biomedical applications. One of the commonly used enzymes is phosphatase, but the study of the substrates of phosphatases mainly focuses on the phosphotyrosine containing peptides. In this work, we examine the EISA of phosphoserine containing small peptides for the first time by designing and synthesizing a series of precursors containing only phosphoserine or both phosphoserine and phosphotyrosine. Conjugating a phosphoserine to the -terminal of a well-established self-assembling peptide backbone, (naphthalene-2-ly)-acetyl-diphenylalanine (NapFF), affords a novel hydrogelation precursor for EISA. The incorporation of phosphotyrosine, another substrate of phosphatase, into the resulting precursor, provides one more enzymatic trigger on a single molecule, and meanwhile increases the precursors’ propensity to aggregate after being fully dephosphorylated. Exchanging the positions of phosphorylated serine and tyrosine in the peptide backbone provides insights on how the specific molecular structures influence self-assembling behaviors of small peptides and the subsequent cellular responses. Moreover, the utilization of D-amino acids largely enhances the biostability of the peptides, thus providing a unique soft material for potential biomedical applications.

关键词: enzyme-instructed self-assembly     phosphoserine     phosphatase     supramolecular hydrogel    

Distinct community assembly processes underlie significant spatiotemporal dynamics of abundant and rare

《环境科学与工程前沿(英文)》 2022年 第16卷 第6期 doi: 10.1007/s11783-021-1513-4

摘要:

• Season and landform influenced spatiotemporal patterns of abundant and rare taxa.

关键词: Rare taxa     Biogeography     Community assembly     Bacterioplankton     The Yangtze River    

Research on constraint-based virtual assembly technologies

YANG Rundang, WU Dianliang, FAN Xiumin, YAN Juanqi

《机械工程前沿(英文)》 2007年 第2卷 第2期   页码 243-249 doi: 10.1007/s11465-007-0043-5

摘要: To realize a constraint-based virtual assembly operation, the unified representations of the assembly constraint, the equivalent relation between the constraint and the degree of freedom (DOF), and the movement DOF reduction in a virtual environment are proposed. Several algorithms about the constraint treatment are submitted. First, the automatic recognition algorithm based on the assembly relation is used to determine the position and orientation relation between two geometry elements of constraint whether they meet the given errors. Second, to satisfy the new constraint, according to the positing solving algorithm, the position and orientation of an active part are modified with minimal adjustment after the part has satisfied the affirmed constraints. Finally, the algorithm of movement navigation based on the generalized coordinate system is put forward, and the part movement is guided. These algorithms have been applied to the integrated virtual assembly environment (IVAE) system. Experiments have indicated that these algorithms have well supported constraint treatments in the IVAE and realized the closer combination of the virtual and the real assembly processes.

关键词: movement DOF     recognition algorithm     assembly     orientation     combination    

The construction of pseudo-Janus silica/surfactant assembly and their application to stabilize Pickering

《化学科学与工程前沿(英文)》 2022年 第16卷 第7期   页码 1101-1113 doi: 10.1007/s11705-021-2095-1

摘要: Nanoparticles with high surface energy and chemical activity have drawn substantial attention in petroleum industry. Recently, Janus nanoparticles exhibited tremendous potential in enhanced oil recovery (EOR) due to their asymmetric structures and properties. In this study, a series of amphiphilic pseudo-Janus@OTAB (PJ@C18) nanoparticles with different concentrations of stearyltrimethylammoium bromide (OTAB) were successfully fabricated. The structures and properties of PJ@C18 were characterized by Fourier transform infrared spectroscopy and ζ-potential measurements. Based on the emulsification experimental results, the interaction models and the self-assembly behavior between hydrophilic nanoparticles (SiO2@NH2) and OTAB molecules at the oil/water interface were proposed, which was further confirmed via the measurements of the contact angle and dynamic interfacial tension. Interestingly, it was found that the change of pH value from 7.5 to 4.0 caused the type reversal of the PJ@C18-1000 stabilized Pickering emulsions. Furthermore, the PJ@C18-1000 stabilized Pickering emulsion system with excellent salt and temperature tolerances (10000 mg∙L–1, 90 °C) significantly improved the oil recovery in the single-tube (more than 17%) and double-tube (more than 25%) sand pack model flooding tests. The findings of this study could help to better understand the construction mechanism of pseudo-Janus silica/surfactant assembly and the potential application of PJ@C18-1000 stabilized Pickering emulsions for EOR.

关键词: Janus nanoparticles     surfactant     double phase inversion     self-assembly     enhanced oil recovery    

A survey on assembly lines and its types

Ullah SAIF,Zailin GUAN,Baoxi WANG,Jahanzeb MIRZA,Shiyang HUANG

《机械工程前沿(英文)》 2014年 第9卷 第2期   页码 95-105 doi: 10.1007/s11465-014-0302-1

摘要:

Assembly lines are useful for mass production of standard as well as customized products. Line balancing is an important issue, in this regard an optimal or near optimal balance can provide a fruitful savings in the initial cost and also in the running cost of such production systems. A survey of different problems in different types of assembly lines and some of the critical and on going research areas are highlighted here. The provided research information is momentous for the research community in assembly line area to proceed further in the presented issues of assembly lines.

关键词: assembly lines     line balancing     survey    

Differences in distributions, assembly mechanisms, and putative interactions of AOB and NOB at a large

《环境科学与工程前沿(英文)》 2023年 第17卷 第10期 doi: 10.1007/s11783-023-1722-0

摘要:

● Nitrifiers in WWTP were investigated at large spatial scale.

关键词: Activated sludge     Spatial distributions     Microbial assembly     Co-occurrence patterns     Nitrifying bacteria    

Cusp points and assembly changing motions in the PRR-PR-PRR planar parallel manipulator

《机械工程前沿(英文)》 2023年 第18卷 第2期 doi: 10.1007/s11465-022-0743-x

摘要: Most parallel manipulators have multiple solutions to the direct kinematic problem. The ability to perform assembly changing motions has received the attention of a few researchers. Cusp points play an important role in the kinematic behavior. This study investigates the cusp points and assembly changing motions in a two degrees of freedom planar parallel manipulator. The direct kinematic problem of the manipulator yields a quartic polynomial equation. Each root in the equation determines the assembly configuration, and four solutions are obtained for a given set of actuated joint coordinates. By regarding the discriminant of the repeated roots of the quartic equation as an implicit function of two actuated joint coordinates, the direct kinematic singularity loci in the joint space are determined by the implicit function. Cusp points are then obtained by the intersection of a quadratic curve and a cubic curve. Two assembly changing motions by encircling different cusp points are highlighted, for each pair of solutions with the same sign of the determinants of the direct Jacobian matrices.

关键词: planar parallel manipulator     assembly changing motions     cusp points     quartic polynomial     discriminant of repeated roots    

Ant colony optimization for assembly sequence planning based on parameters optimization

Zunpu HAN, Yong WANG, De TIAN

《机械工程前沿(英文)》 2021年 第16卷 第2期   页码 393-409 doi: 10.1007/s11465-020-0613-3

摘要: As an important part of product design and manufacturing, assembly sequence planning (ASP) has a considerable impact on product quality and manufacturing costs. ASP is a typical NP-complete problem that requires effective methods to find the optimal or near-optimal assembly sequence. First, multiple assembly constraints and rules are incorporated into an assembly model. The assembly constraints and rules guarantee to obtain a reasonable assembly sequence. Second, an algorithm called SOS-ACO that combines symbiotic organisms search (SOS) and ant colony optimization (ACO) is proposed to calculate the optimal or near-optimal assembly sequence. Several of the ACO parameter values are given, and the remaining ones are adaptively optimized by SOS. Thus, the complexity of ACO parameter assignment is greatly reduced. Compared with the ACO algorithm, the hybrid SOS-ACO algorithm finds optimal or near-optimal assembly sequences in fewer iterations. SOS-ACO is also robust in identifying the best assembly sequence in nearly every experiment. Lastly, the performance of SOS-ACO when the given ACO parameters are changed is analyzed through experiments. Experimental results reveal that SOS-ACO has good adaptive capability to various values of given parameters and can achieve competitive solutions.

关键词: assembly sequence planning     ant colony optimization     symbiotic organisms search     parameter optimization    

标题 作者 时间 类型 操作

Product lifecycle-oriented virtual assembly technology

LIU Jian-hua, NING Ru-xin, YAO Jun, WAN Bi-le

期刊论文

Assembly of biosynthetic pathways in

Lidan Ye,Xiaomei Lv,Hongwei Yu

期刊论文

A novel task-oriented framework for dual-arm robotic assembly task

期刊论文

Pareto lexicographic α-robust approach and its application in robust multi objective assembly line balancing

null

期刊论文

Wheat research and breeding in the new era of a high-quality reference genome

Rudi APPELS

期刊论文

钢塔节段水平预拼装关键技术研究

张永利,顾碧峰

期刊论文

Assembly design system based on engineering connection

Wensheng YIN

期刊论文

Enzyme-instructed self-assembly of peptides containing phosphoserine to form supramolecular hydrogels

Jie Zhou, Xuewen Du, Jiaqing Wang, Natsuko Yamagata, Bing Xu

期刊论文

Distinct community assembly processes underlie significant spatiotemporal dynamics of abundant and rare

期刊论文

Research on constraint-based virtual assembly technologies

YANG Rundang, WU Dianliang, FAN Xiumin, YAN Juanqi

期刊论文

The construction of pseudo-Janus silica/surfactant assembly and their application to stabilize Pickering

期刊论文

A survey on assembly lines and its types

Ullah SAIF,Zailin GUAN,Baoxi WANG,Jahanzeb MIRZA,Shiyang HUANG

期刊论文

Differences in distributions, assembly mechanisms, and putative interactions of AOB and NOB at a large

期刊论文

Cusp points and assembly changing motions in the PRR-PR-PRR planar parallel manipulator

期刊论文

Ant colony optimization for assembly sequence planning based on parameters optimization

Zunpu HAN, Yong WANG, De TIAN

期刊论文