焦点和话题结构的音系-句法接口理论:阐释、反思与展望

近几年语言学接口理论的兴起,为焦点和话题结构的解读提供了一种新选择,这就是音系-句法接口的相关研究。从音系-句法接口来研究焦点和话题结构,可以为信息的语义突显以及表达提供新的解释,也印证了语言的信息交际功能离不开音系和句法的计算过程。本文旨在引入语言学的接口理论,尤其是最简方案以及优选论的音系制约条件等,启动并探索英汉语言表达和解释焦点和话题的不同方式,并最终为解释语言的信息结构寻求一种新的理论方法,从而打开焦点和话题结构研究的新视野。

有关克拉申输入假说理论的几点看法

本文就克拉申输入假说理论提出了几点看法：一是克拉申输入假说作为二语习得理论提出的停留于语言习得现象的陈述，并未对产生这种现象的机理做出的解释；二是在论证“无接口理论”时其反证和引文都有瑕疵；三是有关语言规则在语言习得中的作用的论述过于绝对，难以让人信服。

二语习得中显性和隐性知识与英语口语教学

显性和隐性知识是二语习得领域备受关注的话题。研究者们从不同的角度探讨了二者的关系及显性知识在隐性知识发展过程中的重要性。对它们关系的表述现今共有三种观点:无接口理论、强接口理论和弱接口理论。本文通过着重分析弱接口理论的应用,对如何采用该理论指导外语教学实践,提高学生的语言运用能力,促进EFL口语教学等问题进行了分析。

海军舰艇指挥控制决策支持系统设计

海军舰艇实时指挥控制决策支持系统是一个重要的研究课题 ,从舰艇的决策环境出发 ,分析了系统设计存在的问题 ,提出了基于模型框架的决策支持系统的设计思想 ,最后给出了一个舰船指挥控制决策支持系统(C2 -DSS)

Capacity models on expressway near a bus bay stop with an access

To determinate the expressway capacity near a bus bay stop with an access, capacity models on the expressway near a bus stop with an access were developed on the basis of gap acceptance theory and queuing theory. Depending on a bus stop position to an entrance or an exit ramp, the capacity models were developed for four cases. Bus bay stops with overflow and bus bay stops without overflow were considered. A comparison of simulation experiment and model calculation was carried out. Results show that the suggested models have high accuracy and reliability, at bus arrival rate below 60 vehicles per hour(veh/h) or vehicle volumes at the entrance and the exit below 200 passenger cars units per hour(pcu/h), and there are no significant difference in the capacities for four cases. When bus arrival rate is above 240 veh/h, the capacities of all four cases will decline rapidly. With berth number increasing, the increasing of the capacities is no obvious for four cases. As the bus arrival rate and vehicle volumes at the entrance and the exit increase, bus stops located downstream of an entrance and upstream of an exit have a remarkably effect on the capacities. The latter case is much heavier than the former. Those results can be used to traffic design and optimization on urban expressway near a bus stop with an access.

Microscopic dynamic simulation model for pedestrian at signalized intersection

Pedestrian's road-crossing model is the key part of micro-simulation for mixed traffic at signalized intersection.To reproduce the crossing behavior of pedestrians,the microscopic behaviors of the pedestrians passing through the crosswalk at signalized intersection were analyzed.A pedestrian's decision making model based on gap acceptance theory was proposed.Based on the field data at three typical intersections in Beijing,China,the critical gaps and lags of pedestrians were calibrated.In addition,considering pedestrian's required space,a modification of the social force model that consists of a self-deceleration mechanism prevents a simulated pedestrian from continuously pushing over other pedestrians,making the simulation more realistic.After the simple change,the modified social force model is able to reproduce the fundamental diagram of pedestrian flows for densities less than 3.5 m-2 as reported in the literature.

A New Fractal Model of Elastic,Elastoplastic and Plastic Normal Contact Stiffness for Slow Sliding Interface Considering Dynamic Friction and Strain Hardening

The deflection properties of elastic stage, elastoplastic stage and plastic stage of elastomer were analyzed. Taking account of the kinetic friction force in friction interface and strain hardening in slow sliding interface, the elastic, elastoplastic and plastic normal contact stiffness model for harsh surface was established, which revised the Majumdar-Bhushan fractal model and made it more perfect. In the combination of macro and micro perspective, the effects of coarse surface fractal variables, kinetic friction force in the friction interface, material characters of the friction couples on the contact status and contact property were discussed by the study of digital analysis. Results imply that the normal contact stiffness improves with the increasing real contact area and normal contact load, and reduces with the augment of kinetic friction coefficient. When the kinetic friction coefficient is smaller than 0.3, the normal contact stiffness comprises a linear decrease with the increment of kinetic friction coefficient. When the kinetic friction coefficient is bigger than 0.3, the normal contact stiffness has an exponential decrease with the increasing kinetic friction coefficient. © 2017, Shanghai Jiaotong University and Springer-Verlag GmbH Germany.

Superheating and melting behaviors of Ag clusters with Ni coating studied by molecular dynamics and experiments

Using molecular dynamics with embedded-atom-type interatomicpotentials, we simulated the melting behavior of a spherical Ag3055 cluster coated with Ni. The semi-coherent Ag/Ni interface formed at low temperatures acts as an effective barrier against the surface melting and leads to a substantial superheating of the Ag cluster. The melting point was found to be about 100 K above the equilibrium melting point of the bulk Ag crystal (1230 K±15 K) and about 290 K above that (1040 K) of the free Ag3055 cluster. A superheating of 70 K was observed in the high-temperature differential scanning calorimetry measurement for Ag particles with a mean size of 30 nm embedded in Ni matrix prepared by means of melt-spinning. Melting is initiated locally at the defective interfacial area and then propagates inwards, suggesting a heterogeneously nucleated melting event at the Ag/Ni interface.