柴油机微粒生成及控制技术

在总结柴油机微粒排放的生成机理的基础上,分析了影响柴油机微粒生成的各种因素。通过对柴油机微粒各种净化方式的比较,总结指出了柴油机微粒处理的发展趋势。     

沥青路面高温稳定性影响因素分析

对沥青路面的高温稳定性从内因和外因方面进行了定性分析,并采用有限元分析的方法对几种路面结构变形进行了定量分析,找出车辙产生的原因,为工程设计、施工、管理中如何减少车辙的发生提供必要的参考。     

Vehicle energy efficiency evaluation from well-to-wheel lifecycle perspective

Given a fundamental role of automobiles in human society, evaluation of vehicle energy efficiency is of utmost importance. Various reports have been published hitherto concerning well-to-wheel (WTW) fuel consumption at the vehicle operation phase. On the other hand, WTW energy consumption at other lifecycle phases has been scarcely integrated in the assessment of vehicle energy efficiency. Particularly, WTW energy consumption for material structure is significantly associated with fuel economy. As such, this paper firstly analyzes the lifecycle WTW vehicle energy efficiency from the perspective of both material structures at the manufacture phase and fuel consumption at the operation phase for conventional vehicle (CV), electric vehicle (EV), hybrid vehicle (HV) and fuel cell vehicle (FCV). Then, an expected transition of vehicle weight and energy consumption arising from material structural shift through the replacement of steel with aluminum is evaluated. Finally, the overall vehicle energy efficiency in Japan in 2020–2050 is projected. It is discovered that the inclusion of energy consumption for material structure has a significant impact on the determination of the vehicle energy efficiency, particularly for new generation vehicles. WTW analysis at the multiple lifecycle phases may be of use in establishing more comprehensive principles of vehicle energy efficiency.     

信息集成环境下船舶制造企业材料成本控制研究

材料成本在整个造船成本中占有约70%的份额,所以控制造船成本的关键是要控制材料成本。本文从设计、计划、采购、入库、领用、核算等材料成本形成的全过程梳理材料管理的职能、过程、活动,找出材料成本控制的关键环节,建立材料成本控制体系,并以项目为主线,详细阐述在信息集成环境下每个环节材料成本控制的实现方法,使材料成本管理和控制有效统一。     

韶钢物流运作的分析及增加铁路运量的对策

通过对韶关钢铁集团公司物流运作情况的分析,以及各种运输方式优劣性的比较,考虑到铁路运输能力不断增强和韶钢产量不断增加的有利条件,提出了增加铁路运量的对策。     

简述摩托车气缸材料及表面处理

摩托车气缸常用的合金铸铁材料包括高磷铸铁、硼铸铁和铬钼铜铸铁。目前常常用的表面处理方法有表面淬火、软氮化和等离子CVD等。铝合金气缸体在减小质量、提高散热能力方面是最理想的,但为提高其耐磨性要进行表面处理。含Si量低的亚共晶铝合金可通过材料强化法及表面改性法改善其耐磨性、耐热性、强度及刚性。此外还有过共晶铝合金气缸材料。     

Material transport from the nearshore to the basinal environment in the southern Baltic Sea: I. Processes and mass estimates

Processes involved in erosion, transport and deposition of cohesive materials are studied in a transect from shallow (16 m) to deep (47 m) water of the SW Baltic Sea. The wave- and current-induced energy input to the seabed in shallow water is high with strong variability and suspended matter concentrations may double within a few hours. Primary settling fluxes (from sedimentation traps) are less than 10 g m⁻² day⁻¹, whereas resuspension fluxes (evaluated from sedimentation flux gradients) are 15–20 times higher and the residence time for suspended matter in the water column is 1–2 days. Settling velocities of aggregates are on average six times higher than for individual particles resulting in an enhanced downward transport of organic matter. Wave-induced resuspension (four to six times per month) takes place with higher shear stresses on the bottom than current-induced resuspension (three to five times per month). The short residence time in the water column and the frequent resuspension events provide a fast operating benthic–pelagic coupling. Due to the high-energy input, the shallow water areas are nondepositional on time scales longer than 1–2 weeks. The sediment is sand partly covered by a thin fluff layer during low-energy periods. The presence of the fluff layer keeps the resuspension threshold very low (<0.023 N m⁻²) throughout the year. Evaluated from 3-D sediment transport modeling, transport from shallow to deep water is episodic. The net main directions are towards the Arkona Basin (5.5×10⁵ t per year) and the Bornholm Basin (3.7×10⁵ t per year). Energy input to the bottom in deep water is low and takes place much less frequently. Wave-induced resuspension occurs on average once per month. Residence time of particles (based on radioactive isotopes) in the water column is half a year and the sediment accumulation rate is 2.2 mm year⁻¹ in the Arkona Basin.     

甲供材料费用计算方法的探讨

在工程施工招标公布的招标价中，不少工程不合甲供材料费，但这些甲供材料同样需要施工单位进行施工和安装，那么如何合理而准确的计算施工单位完成的甲供材料的费用和界定其归属，是承发包双方特别关注的问题。此文针对甲供材料费用现行计算方法存在的问题进行分析，通过分析提出改进后的计算方法。并通过某新建铁路接触网工程实例，采用2种计算方法分别计算甲供材料的费用，通过比较，确实存在差异。本应属于施工单位的费用，却因现行计算方法的硬性规定，归甲方所有。     

乘用车制动盘黑色印记问题研究

车辆在行驶一段里程之后,会在车辆制动盘表面形成一圈可变的黑色印记。随着里程的变化,黑色印记位置和宽度会发生随机变化。该黑色印记用手触摸无明显触感,仅仅是不美观,但会给用户造成不安感,认为制动系统存在问题。针对该现象,进行了大量的台架和整车试验分析,结果表明制动盘的机加工工艺和制动衬块的材料是引起问题的主要原因。通过更改制动盘机加工工艺及制动衬块材料,可以解决制动盘黑色印记问题。     

汽车造型设计实物验证模型材料选择应用研究

汽车造型设计实物验证是汽车开发流程中重要的内容。文章概述了目前汽车造型设计实物验证模型制作过程中的材料应用情况,分析了应用在实物验证模型中各主流材料的加工特性及其在具体模型制作过程中的优缺点,阐述了如何针对不同开发阶段汽车造型验证模型制作的要求和特点,合理选择正确的材料应用于验证模型和样件的制作,以最低的成本和最环保的方式获得最佳的效果。