新能源汽车推广补贴政策效果分析

为加快新能源汽车产业发展,推进节能减排,促进大气污染治理,我国自2009年开展节能与新能源汽车示范推广工作,与之对应的财税补贴政策不断更新出台。为评估新能源汽车推广政策的实施效果,支持相关政策制定,文中根据2013年发布的《关于继续开展新能源汽车推广应用工作的通知》,对符合该政策补助条件的各类车型的推广实施情况进行了细致分析。分析结果表明,我国新能源汽车有了长足的发展,未来仍具备较大的发展潜力。     

Traffic signal timing problems with environmental and equity considerations

Traffic signal timings in a road network can not only affect total user travel time and total amount of traffic emissions in the network but also create an inequity problem in terms of the change in travel costs of users traveling between different locations. This paper proposes a multi‐objective bi‐level programming model for design of sustainable and equitable traffic signal timings for a congested signal‐controlled road network. The upper level of the proposed model is a multi‐objective programming problem with an equity constraint that maximizes the reserve capacity of the network and minimizes the total amount of traffic emissions. The lower level is a deterministic network user equilibrium problem that considers the vehicle delays at signalized intersections of the network. To solve the proposed model, an approach for normalizing incommensurable objective functions is presented, and a heuristic solution algorithm that combines a penalty function approach and a simulated annealing method is developed. Two numerical examples are presented to show the effects of reserve capacity improvement and green time proportion on network flow distribution and transportation system performance and the importance of incorporating environmental and equity objectives in the traffic signal timing problems. Copyright © 2013 John Wiley & Sons, Ltd.     

港口大宗散货码头带式输送机减电机节能技术分析

鉴于港口煤炭、矿石等大宗散货码头用长距离带式输送机经常在轻载状态下运行,输送机所需要的传动功率较低,出现严重的＂大马拉小车＂现象,导致输送机能耗较高,系统功率因数较低的情况,分析了带式输送机减电机节能运行的可行性和关键技术,开发了输送机减电机运行计算软件,给出了散货码头带式输送机减电机运行的合理建议。     

基于多元化投资的高速公路养护管理模式研究

针对高速公路建设多元化投资模式,阐述了高速公路养护管理模式,比较分析了高速公路自主养护模式和市场化养护模式各自的优缺点,提出了市场化养护模式是高速公路养护管理的发展趋势。     

Central pattern generator based gait control for planar quadruped robots

In this paper, a gait control scheme is presented for planar quadruped robots based on a biologic concept, namely central pattern generator （CPG）. A CPG is modeled as a group of the coupled nonlinear oscillators with an interaction weighting matrix which determines the gait patterns. The CPG model, mapping functions and a proportional-differential （PD） joint controller compose the basic gait generator. By using the duty factor of gait patterns as a tonic signal, the activity of the CPG model can be modulated, and as a result, a smooth transition between different gait patterns is achieved. Moreover, by tuning the parameters of the CPG model and mapping functions, the proposed basic gait generator can realize adaptive workspace trajectories for the robot to suit different terrains. Simulation results illustrate and validate the effectiveness of the proposed gait controllers.     

Simulation platform for the underwater snake-like robot swimming based on Kane’s dynamic model and central pattern generator

A systematic method for swimming control of the underwater snake-like robot is still lacking. We construct a simulation platform of the underwater snake-like robot swimming based on Kane＇s dynamic model and central pattern generator （CPG）. The partial velocity is deduced. The forces which contribute to dynamics are determined by Kane＇s approach. Hydrodynamic coefficients are determined by experiments. Then, we design a CPG-based control architecture implemented as the system of coupled nonlinear oscillators. The CPG, like its biological counterpart, can produce coordinated patterns of rhythmic activity while being modulated by simple control parameters. The relations between the CPG parameters and the speed of the underwater snake-like robot swimming are investigated. Swimming in a straight line, turning, and switching between swimming modes are implemented in our simulation platform to prove the feasibility of the proposed simulation platform. The results show that the simulation platform can imitate different swimming modes of the underwater snake-like robot.     

西安地铁深基坑施工过程中的变形规律研究

针对西安地铁#4线某站深基坑施工,采用摩尔-库伦弹塑性理论,运用FLAC3D软件建立有限元分析模型,对不同工况下的围护结构水平位移及地表沉降进行模拟,将不同工况下的围护结构的水平位移和地表沉降的模拟值与其实测值比较分析,得出基坑开挖对周围地表沉降的影响距离为1.5倍的开挖深度;距离围护桩顶2/3桩长的位置是最容易出现危险的地方,且模拟值大多小于实测值,究其原因是没有考虑黄土的湿陷性、雨季施工及车辆动荷载等因素。     

船舶签证制度改革后的海事监管研究

文中从船舶签证规则制度的形成开始。梳理了船舶签证这一具体行政行为所承载的权利和义务,最后提出取消船舶签证后的一些海事监管建议。     

京沪高速公路改扩建岩质高边坡病害诱因分析

为研究高速公路改扩建沿线高边坡病害诱因,本文依托京沪高速改扩建工程,采用理论分析和现场调研分析了边坡形态、地层岩性、地质构造等工程地质条件、降雨、地震、地应力等自然因素特征以及机械开挖、爆破开挖、植被破坏、人工堆载等人类工程活动等病害诱因对边坡稳定性的影响。并以此为基础,提出边坡施工开挖过程中相应的施工建议。