氯和几个烷烃反应的立体动力学研究

介绍了在扩展的London-Eyring-Polanyi-Sato(LEPS)势能面基础上,利用准经典轨线法计算了Cl+CH4、Cl+C2H6、Cl+C3H8反应的产物极化分布,并分析了在质心系计算得到四个广义极化微分反应截面(PD-DCS)(2π/σ)(dσ00/dωt)(2π/σ)(dσ20/dωt)(2π/σ)(dσ22+/dωt)(2π/σ)(dσ21-/dωt)和k-k′-j′三矢量相关的极角分布P(φr)、k′-j′两矢量相关的p(rθ)分布以及用rθ和r表示的产物转动角动量的空间分布.     

Science Letters:Filament geometrical model and nozzle trajectory analysis in the fused deposition modeling process

The geometrical model of the filament during the fused deposition modeling (FDM) process was firstly proposed based on three different models, tractrix, parabola, and catenary. Comparing with the actual measured filament curves on the Stratasys 1600 FDM machine, it is indicated that the tractrix model had the best agreement with the actual measured curves. With the analytical simulation, the nozzle trajectories in the straight-line deposition road, circle road, and arbitrary continuous curve road were deduced, according to the traxtric based geometrical model of the filament.     

Antecedents and trajectories of AMT adoption: The case of Greek manufacturing SMEs

This study examines antecedents and trajectories of advanced manufacturing technology (AMT) adoption in three categories: stand-alone, intermediate, and integrated technologies. Antecedents of adoption include prior investments in AMT, developments in firms’ manufacturing capabilities, technology strategy, absorptive capacity, and environmental pressures. Based on a sample of 87 Greek manufacturing SMEs, we find that AMT adoption follows an incremental, piecemeal progression from the least complicated through intermediate to integrated technologies. It is found that an increase in the firms’ quality and flexibility capabilities induces them to adopt further AMT, whereas advances in low-cost, innovation, and delivery capabilities appear negatively related to further AMT adoption. Absorptive capacity, technology strategy and environmental pressures play a central role in decisions for additional investments in AMT. In the context of a catching-up economy, these results support the notion of a ‘stepwise’ technology accumulation process as well as ‘satisficing’ technological change.     

工业机器人关节空间的插值轨迹规划

首先介绍了工业机器人轨迹规划的概念及涉及到的问题,并改进关节空间的三次多项式插值轨迹规划,提出五次多项式插值轨迹规划,最后重点分析了含多个途经点的插值轨迹规划、抛物线过渡轨迹规划,并进一步完善这两种情况同时存在时的轨迹规划.     

Trajectories in teacher education: Recognising prior learning in practice

This article analyses the trajectories into teacher education of a group of child minders who are studying to become pre-school teachers. The specific focus is what impact their prior experiences and learning from pre-school have on their trajectories, and how these experiences and learning are recognised in the first year of teacher education. A situated learning perspective is applied, with a focus on participation and trajectories in the two communities of practice in which teacher education is situated – the university and the pre-school. The data consist of transcribed interviews with ten student teachers, and additional data are gathered from stakeholders in the program. The results show that prior experiences and learning are given implicit and indirect recognition. In the practice of the pre-school, the trajectory means a shift in identity, from child minder to student teacher and pre-school teacher. In the practice of the university, prior experiences and learning help students in their trajectories from peripheral to fuller participation.     

Numerical simulation of pollutant transport and accumulation areas in the Hangzhou Bay

Based on the COHERENS model (a coupled hydrodynamic ecological model for regional and shelf seas), a numerical hydrodynamic model of the Hangzhou Bay, influenced by tide, regional winds and freshwater from the Yangtze River and the Qiantangjiang River was established. The Lagrangian particle tracking was simulated to provide tracer trajectories. For convenience, the modeling area was divided into 8 subdomains and the modeling focused on March (dry season) and July (wet season). Numerical simulation and analysis indicate that the tracer trajectories originated in different subdomains are quite different. Most particles released in the mouth of the bay move outside the bay quickly and reach the farthest place at 122.5°E; while particles released in the inner part of the bay mostly remain in the same subdomain, with only minor migrations in two opposite directions along the shore. The tracer experiments also indicate that the northwest region of the bay is an area where pollutant can easily accumulate in both wet and dry seasons, and that the southeast region of the bay is another area for pollutant to accumulate in dry season because it is the main path for the contaminant.     

工业机器人时间最优轨迹规划仿真研究

为了使工业机器人在某个轨迹下执行焊接任务的时间最短,采用改进的模拟退火算法作为优化方法,对工业机器人关节轨迹进行时间最优规划。仿真结果表明,与其它同约束条件下的轨迹规划算法相比,采用新型算法后,机器人焊接时间缩短了1.24s,从而验证了该算法的有效性。     

后发国家产业技术追赶模式研究

技术是促进经济发展的关键因素,后发国家经济追赶战略的实现也应以技术追赶为基础.在回顾已有技术追赶理论研究的基础上,重点研究后发国家产业技术追赶的模式,将后发国家的产业技术追赶划分为同轨道跟随型、同轨道差异型、异轨道崛起型及后轨道创造型四种模式,深入分析了这四种模式的特征.     

新创高新技术企业的集群化与国际化成长

本文认为高新技术企业潜在的成长路径并不是唯一的,论文探讨了新创高新技术企业的集群化成长与国际化成长,并就不同成长路径的作用过程与机制进行了研究,在此基础上对新创高新技术企业成长路径的选择进行了分析。     

数控服装裁剪机控制系统设计

设计了一种由计算机控制的服装裁剪机数控系统,该系统具有裁剪参数读入与修改、裁剪过程控制、裁剪刀偏移智能补偿、裁剪刀自动刃磨、裁剪参数轨迹模拟以及裁剪过程路径同步模拟等功能,样机试验结果验证了所设计控制系统的有效性。