基于层次化的智能协同制造平台框架

为了满足企业灵活组织内部资源,快速响应个性化定制的需求,自底向上分析企业制造资源生产组织方式,构建了基于层次化的智能协同制造平台框架。框架从硬件物联、数据贯通、云端协同三个层面分析制造资源,并提出框架的三个子平台,即基于工业物联的硬件协同平台、基于PLM的生产制造协同平台和基于工业云的价值链协同平台。从协同框架和架构内容两方面分别对框架子平台进行描述,探讨了平台涉及到的核心关键技术。三个层次内部横向集成,层间纵向贯通,从而构成基于层次化的智能协同制造平台框架。     

无人机模块化设计与自组织优化研究

传统四轴无人机部件拆装困难，难以满足多种载荷挂载需求。本文针对性地提出了一种模块化设计方案，可有效克服传统四轴无人机的不足，并通过受力分析验证了方案的可行性。同时，在模块化设计方案的基础上分析了无人机集群内部个体间的相互作用，建立了可使特定范围内无人机自组织飞行的数学模型。最后，在具体应用方面，提出了两种可解决无人机集群自组织避障问题的应对策略，有效提升了模块化自组织无人机对复杂环境的适应能力。     

制造商主导的多主体智能协同运维服务新模式

为解决设备制造商(OEM)、服务商、供应商和用户等多主体间自主、协同、可信的服务配置，决策和运行管控等智能运维服务问题，以智能制造核心OEM企业为主导，提出面向复杂装备的多主体服务型智能协同运维服务新模式。在该模式中，明晰了主体协同交互运行生态，构建了系统体系架构，揭示了服务运作逻辑，探索了服务集成配置、关键运维要素辨识、协同维修决策及数据/知识可信运行共享四项关键使能技术。结合原型系统应用验证，为OEM及第三方企业实现智能协同运维服务转型升级提供理论技术指导及实践应用借鉴。     

电子技术及通信工程的协同发展探析

分别就电子技术、通信工程作出分析,并从两者间的相互作用着手,就电子技术与通信工程的协同发展进行探讨。     

一种协同生产管理实现模式

对敏捷制造环境进行分析,提出协同生产管理概念;借助Ｉｎｔｅｒ－ｎｅｔ／Ｉｎｔｒａｎｅｔ构造了一个协同生产管理实施框架;运用层次分析法与效用相结合的方法,建立协同生产资源选择与评价算法;应用多智能体技术,设计出一种多智能体自组织协同生产实施方案。     

自组织制造网格及其任务调度算法

通过分析制造系统自组织的特征，以及网格技术在制造业应用的理论基础和系统框架，提出了自组织制造网格的概念，指出资源动态管理和调度是自组织制造网格中建立虚拟组织、实现资源共享和协同工作的瓶颈点，提出基于T，Q，C，S的多层次、多目标整数规划调度算法。同时，结合自组织制造网格的应用实例和一个具体的加工任务，验证了自组织制造网格理论的合理性和调度算法的可行性。     

基于多组件Agent的协同设计系统

提出了适合协同设计的、基于多层有限状态机的组件Agent理论模型。通过对产品模型建立过程中应具备的中性交换、重用、远程更改、知识工程及自管理等方面的需求分析，提出了包含三类基本数据（功能数据、结构数据和管理数据）和外围更改数据的面向协同设计的产品数据模型。提出了将组件Agent理论模型和产品模型相结合的产品组件Agent模型框架，详细论述了实现过程中的几个关键问题：环境模型的建立、策略集组织、基于分布式组件技术的软件重用、程序与数据的封装。实际应用表明，该系统能有效地提高相关企业的产品协同设计能力。     

复杂零件网络协同制造平台研究

为了实现网络制造环境下制造资源共享与优化配置，提出了面向复杂零件的协同制造链的概念，分析了协同制造链的组织与运行模式；创建了一个基于语义Web的网络协同制造平台，对其主要功能、体系结构、工作流程进行了研究，指出网络协同制造平台在协同制造链构建与运行过程中居于核心地位。     

跨组织业务过程协同并行建模

为确保组织之间通信、交互和协作实施的正确性和一致性,对业务过程进行建模和验证,并关注形式验证的效率,根据应用需求获取参与协同的业务过程单元;基于协作点的语义对业务过程单元间存在的协作关系进行划分,应用等价划分的思想对跨组织业务过程协同进行并行建模,得到跨组织业务过程协同模型;通过对协同制造中供应链内的采购订单进行并行建模,与现有的、具有代表性的方法进行对比并进行了理论分析。结果表明,跨组织业务过程协同模型能够提高模型的形式验证效率、减少形式验证时间。     

基于客户／服务器结构的CIMS协同控制结构研究

对ＣＩＭＳ的基于客户／服务器的协同控制结构进行研究分析，特别是对制造系统部分各设备的分布式自组织协同控制及其实现进行深入的探讨。各设备在协同控制器的作用下，通过在线实时竞争协商，灵活机动地完成整个生产任务。     

Analytical modeling of multiple particle impacts on brittle materials

The progression of material removal from glass plates through multiple collisions with glass beads is described analytically in terms of erosion pit nucleation and growth. Ring fractures are responsible for the initiation of erosion damage. A criterion for pit nucleation is established based on ring fracture interactions.     

Evaluation of crack nucleation site and mechanical properties for friction stir welded butt joint in 2024-T3 aluminum alloy

In this paper, metallographic observations, hardness measurement, and static and fatigue tests were conducted to investigate the discontinuity states which become crack nucleation sites in friction stir welded butt joints in 2-mm-thick 2024-T3 aluminum alloy and static and fatigue properties of the joint. Because different types of surface finish can be used depending on the application of the joint, several types of surface conditions were tested to evaluate their effect on crack nucleation sites and static and fatigue life. Indentation hardness tests revealed that typical hardness reduction is not necessarily observed on the section of the welding line. Based on fatigue test results, it was confirmed that there are several types of crack nucleation sites for friction stir welding (FSW) joints depending on the surface finish, and the features of the fracture surface also differ depending on the site. Furthermore, the type of discontinuity state affects the fatigue life of the FSW joint.     

采用Cellular Automaton法模拟铝合金的微观组织

采用Cellular Automaton微观模型，并与宏观的传热计算相结合，对砂型铸造铝合金铸件的凝固组织形成进行了模拟。在模拟过程中，采用连续形核的方法处理液态金属的异质形核现象。通过高斯分布函数描述表核质点密度随温度的分布关系，在给定过冷度时对分布函数求积分可得该时刻的形核密度。晶粒生长模型则考虑枝晶尖端生长动力学和择优生长方向（100）晶向，模拟计算结果表明，在冷却速度不变的情况下，随着形核分布参数△TN增加，所得到的晶粒尺寸增大。从数学角度对模拟结果进行了分析。     

The absolute metastable limit of liquids under tension—A review

A quest for obtaining the absolute metastable limit of liquids has been attempted by many researchers using various methods. The absolute limit obtained was the case having the maximum nucleation rate with one molecule critical cluster from a nucleation theory based on molecular interactions. In this study, the tensile strengths measured by various techniques were compared to the theoretical absolute metastable limit. The tensile strength of water, measured in microscopic inclusions, is close to the absolute metastable limit of 160 MPa while the tensile strength values measured by the centrifugal and acoustic methods is only about 15% of the absolute metastable limit. It has been found that the tensile strength values depend on the experimental conditions which determine the nucleation rate values. Problems related to predicting the absolute metastable limit by the classical bubble nucleation theory were also discussed.     

A Freon-filled bubble chamber for neutron detection in inertial confinement fusion experiments

Neutron imaging is one of the main methods used in inertial confinement fusion experiments to measure the core symmetry of target implosions. Previous studies have shown that bubble chambers have the potential to obtain higher resolution images of the targets for a shorter source-to-target distance than typical scintillator arrays. A bubble chamber for neutron imaging with Freon 115 as the active medium was designed and built for the OMEGA laser system. Bubbles resulting from spontaneous nucleation were recorded. Bubbles resulting from neutron-Freon interactions were observed at neutron yields of 10(13) emitted from deuterium-tritium target implosions on OMEGA. The measured column bubble density was too low for neutron imaging on OMEGA but agreed with the model of bubble formation. The recorded data suggest that neutron bubble detectors are a promising technology for the higher neutron yields expected at National Ignition Facility.     

C2H2 interaction with Ni nanocrystals: towards a better understanding of carbon nanotubes nucleation in CVD synthesis

We present a study of the early stages of carbon nanotubes nucleation in CVD synthesis by combining field ion/electron emission microscopy (FIM/FEM) and atom-probe investigation (AP) of the nickel-carbon interaction. Acetylene decomposition on Ni tips at 873K is observed to induce additional step formation on an initially facetted (polyhedral) crystal. Carbon-enriched steps are then observed to act as preferential nucleation centers of graphene sheets formation. Atom-probe experiments reveal C(2) and C(3) species and frequency dependent studies demonstrate that the origin of these species is different from C(1). Experiments provide clear evidence for the crucial role of carbon-enriched steps as nucleation sites of graphene sheets on the Ni surface.     

低合金高强度钢药芯焊丝焊缝中夹杂物诱导针状铁素体形核的作用

测量了HSLA钢药芯焊丝焊缝中夹杂物尺寸大小,分布状况,用透射电镜和能谱仪观测了焊缝中夹杂物的形态和化学成分,系统研究了焊缝中AF的形核机理。在药芯焊丝焊缝中,适量的Ni、Mn和Mo有利于提高焊缝显微组织中的AF质量分数,Ni、Mn和Mo的质量分数和焊接线能量对夹杂物的尺寸大小、化学成分影响不大,诱导AF形核、长大的夹杂物是Ti、Mn、Si、Al、Cu形成的氧硫复合物。夹杂物有高能惰性界面,以及夹杂物附近存在很高的应变能,两者共同作用诱导药芯焊丝焊缝中AF的形核。     

Morphology and Nanomechanical Properties of ZDDP Antiwear Films as a Function of Tribological Contact Time

We have employed scanning force microscopy (SFM) and nanoindentation analysis to track the evolution of tribologically generated antiwear films derived from zinc dialkyldithiophosphate (ZDDP) as a function of rubbing time. The SFM images reveal that film morphology evolves with time through a growth mechanism consisting of three stages. In the first stage nucleation on active sites at the steel surface leads to the growth of distinct segregated islands. In the second stage the islands coalesce causing the film to spread over a larger fraction of the surface. In the final stage continuous rubbing induces the large islands to divide into smaller, densely packed structures. In contrast to the observed morphological changes, rubbing time does not strongly influence the nanomechanical properties of the films. This highlights the importance of film morphology in determining the effectiveness of ZDDP antiwear films. We also observe large variation in both the morphology and nanomechanical properties that are likely due to the heterogeneity in contact pressure at the pin-sample interface of the wear rig.     

Imaging of collagen type III in fluid by atomic force microscopy

Type III collagen is a component of the basement membrane of endothelial cells, and may play a role in the interaction between hemostatic system proteins and the basement membrane of blood vessels. To begin to investigate these structural interactions, we have imaged type III collagen in solution by atomic force microscopy. A 20 microg/ml solution of type III collagen in bicarbonate buffer (pH 9.5) from calf skin was deposited onto a freshly cleaved mica substrate. Atomic force microscopy images were acquired using a fluid cell and tapping mode with oxide-sharpened silicon nitride probes 2, 3, and 4 hours after deposition of the collagen onto the mica. Two-hour preparations displayed fibrillar networks with well-defined sites of nucleation and lateral growth. At 3 and 4 hour polymerizations, more mature fibrils of increasing lengths, diameters, and complexity were observed. Fibrils appeared to be aligning and twisting (helical formation) to form a mature fibril with a higher mass per unit area. Interestingly, the mature fibrils appeared larger centrally with tapered ends displaying declining slopes. These observations compare favorably with those previously published on collagen type I assembly [Gale et al. (1995) Biophys. J. 68:2124-2128]. High resolution atomic force microscopy images of type III collagen in solution should provide a template for observation of the interactions between basement membrane components and hemostatic system proteins present in cardiovascular disease.     

Numerical estimation of non-equilibrium condensation of steam in supersonic nozzles

Condensation phase change during the expansion of steam is an inevitable phenomenon encountered in several engineering applications. Under supersonic flow conditions, the expansion rate of flow will be very steep so that, steam continues to expand even after local pressure crosses the saturation curve. Steam gets supersaturated rapidly and the condensation departs far away from equilibrium state. By complicated sequences of spontaneous nucleation, several nucleation sites will be formed in the flow field. Water droplets may form at this sites by mass addition due to condensation. The latent heat liberated during phase change results in the formation of a condensation shock wave across which flow velocity gets reduced. Precise knowledge of this process is important since the presence of water droplets in steam can lead to erosion and subsequent reduction of performance. Non-equilibrium condensation can be numerically modeled using additional transport equations which solve for the mass fraction of condensate generated from the phase change process. In the present work, a five-equation non-equilibrium condensation model available in ANSYS FLUENT is studied and used. The methodology is validated against case studies reported in the literature. Later, parametric studies were conducted to investigate the effect of inlet saturation ratio of steam on the flow characteristic in two well-known steam nozzles.