汽车维修管理中存在的问题及完善对策

随着国民经济的飞速发展,汽车逐步进入家家户户。在如今,汽车成了交通发达的标志,而且汽车在我国的生活中显得越来越重要。汽车进入寻常百姓家,是国家经济繁荣,社会富强昌盛的标志,但是汽车在使用的过程中,需要时刻的进行保养,只有将汽车保养好才能更好地增强其使用的安全性和延长汽车的使用寿命。汽车的维修和保养是十分必要的,但是在现实生活中,却少有人在意汽车的维修,从而给汽车的使用带来了一些不好的影响。基于此,本文主要根据对实践生活的了解,对汽车在维修管理中存在的问题进行分析,然后提出一些行之有效的措施加以解决,使其能够更好地推动汽车行业的发展和保障驾驶员的安全。除此之外,希望能够通过对一些措施的提出,来给众多的驾驶者和研究者提供一些经验借鉴。     

An eco-routing model considering microscopic vehicle operating conditions

The eco-routing problem concerned in this paper addresses the optimal route choice of eco-drivers who aim to meet an emission standard imposed by regulators, while trying to find the path with the minimum total operating cost, which consists of both travel time and fuel costs. The paper first develops fuel consumption and greenhouse gas emissions estimation models that link emission rates to a vehicle’s physical and operational properties. Unlike most studies in the literature, the emission model developed in this paper retains as many microscopic characteristics as feasible in the context of route planning. Specifically, it is able to approximate the impacts of major acceleration events associated with link changes and intersection idling, and yet does not require detailed acceleration data as inputs. The proposed eco-routing model also explicitly captures delays at intersections and the emissions associated with them. Using a simple probabilistic model, the impacts of different turning movements on eco-routing are incorporated. The proposed model is formulated as a constrained shortest path problem and solved by off-the-shelf solvers. Numerical experiments confirm that vehicle characteristics, especially weight and engine displacement, may influence eco-routing. The results also suggest that ignoring the effects of turning movements and acceleration may lead to sub-optimal routes for eco-drivers.     

桥梁伸缩缝施工质量控制策略

桥梁伸缩缝大致分五类。桥梁伸缩缝施工主要存在三个方面的问题。桥梁伸缩缝施工质量要从施工准备、开槽、缝体安装、混凝土浇注和养生进行控制。     

大客车除霜器安装使用方面的问题分析与探讨

简要介绍大客车用除霜器的结构、原理及用途，根据在安装使用中出现的一些问题进行分析和探讨。     

我国服务型校长成长的现状、问题与策略研究

文中首先从校长自身的认知和环境因素对我国服务型校长发展现状进行了分析，在此基础上对我国服务型校长成长的问题进行了剖析，并就此提出了如何推动我国服务型校长成长的相关建议。     

工程建设领域突出问题治理探讨

文章阐述了交通运输系统工程建设领域突出问题的现状和主要表现形式,分析了问题产生的原因,并从教育、制度、监管和惩处等方面提出了治理工程建设领域突出问题的思路与对策。     

Hydrodynamics of a body floating in a two-layer fluid of finite depth. Part 1. Radiation problem

A linearized 2-D radiation problem was considered for a general floating body in a two-layer fluid of finite depth. A boundary integral-equation method was developed for directly computing the velocity potential on the wetted surface of a body which is immersed in both the upper and lower layers as a general case. To do this, appropriate time-harmonic Greens functions were derived, and an efficient numerical method of evaluating those functions is proposed. Based on Greens theorem, hydrodynamic relations such as the energy-conservation principle were derived theoretically for a case of finite depth, and we confirm that those relations are satisfied numerically with very good accuracy. Experiments were also carried out using water and isoparaffin oil as the two fluids and a Lewis-form body. Measured results for the added mass, the damping coefficient, and the amplitude of the generated waves are compared with the computed results, and a favorable agreement is found.     

Variational principle for determining the unknown wetted surface of a planing ship

A variational principle is presented to solve the problem of determining the unknown wetted surface of a planing ship on still water under gravity. The functional associated with the variational principle is expressed by the unknown wetted length distribution, the vortex line function, and the circulation distribution around the longitudinal sections, not by the bottom pressure distribution. In addition, the variational principle is adjoined with pseudoflow, here called reverse flow. The extremal of the functional satisfy the hull boundary integral equation in a similar way to that of lifting-surface theory and the elevated water surface condition along the spray root line. Both are sufficient to determine the wetted surface. A method of high aspect ratio approximation is also investigated. A simple relation is obtained between the wetted surface when moving and at standstill. The calculated shapes of the wetted surface of a planing plate agreed well with experimental results. Received for publication on Nov. 11, 1999; accepted on April 4, 2000     

南宁市渍水现状及治理对策研究

分析南宁市渍水成因、现状及问题 ,提出治理对策。     

路面接触非线性特性研究

考虑荷载作用下,沥青路面面层之间以及面层与基层之间,实际上可能处于接触状态。本文采用有限元技术对路面的接触非线性特性进行分析,结合高速公路的现场试验,比较表明,接触模型比层状体系模型更适合描述路面的力学特性。