沙漠路基风积沙特性和压实机理研究

风积沙广泛分布于沙漠地区,储量非常丰富、取材十分方便,成为修筑路基的主要材料.风积沙颗粒松散无黏性,具有颗粒细、天然含水率小、保水性差等特性.其整体强度与稳定性对通车后使用寿命将起到关键作用,但其压实一直是施工中的难题,风积沙的压实控制成为修筑沙漠公路之关键所在.文中以榆佳高速公路路基实体工程为对象,通过研究分析,探讨出较为合理地碾压控制方法.     

轿车后副车架多轴疲劳分析

以某轿车五连杆独立后悬架的副车架为研究对象,根据台架试验方法建立了后悬架系统有限元模型,利用虚拟应变片技术和焊缝寿命预测技术,通过CAE分析与台架试验测试相结合,通过改进结构降低裂纹位置的疲劳损伤值,解决了该后副车架在台架试验中焊接位置出现裂纹的问题.改进结构一次性通过了8通道耐久性台架试验,表明有限元分析与台架试验相结合的方法可有效预测副车架焊缝疲劳寿命.     

EGR率对柴油机富氢EGR燃烧过程的影响

在一台柴油机可视化实验台上,用高速摄像机拍摄下柴油机富氢EGR燃烧过程的火焰照片,应用三基色法计算了燃烧温度场,结合示功图和放热率曲线分析了EGR率对富氢EGR燃烧过程的影响.结果表明:当掺氢比为2％时,随着EGR率的增加,着火时刻呈现推迟的趋势,燃烧持续时间先延长后缩短;缸内最大爆发压力减小,达到峰值压力的时间推迟;放热率峰值下降,放热率曲线整体推后;缸内最高温度和平均温度随之降低.     

应用于小型发动机市场的怠速空气控制阀

面对发展中国家越来越严峻的空气污染状况,正在积极制定、颁布更加严厉的小型发动机排放法规和标准。目前,怠速空气控制阀（IACV）与电子燃油喷射（EFI）组合已被广泛应用于大型发动机汽车市场的尾气排放中,这种组合同样也被认为是有助于降低小型发动机尾气排放的最有效的解决方案。     

The determinants of maritime policy

The paper is to explore the relation between national economic development and the formulation of maritime policy. It collects and examines data from 30 maritime nations, and shows that maritime policy is determined by economic circumstance rather than the result of rational decision of policy makers. A general solution is produced for an optimum maritime policy under a given economic condition. The general solution can serve as a benchmark for future maritime policy making and research in general.     

Mature hub ports in the free trade environment,the way forward from a global supply chain perspective: an Asian case

Asia-Pacific countries with divergent economic and political backgrounds developed a regime of bilateral free trade agreements in response to globalization. Challenged by the 1997 and 2008 financial crises, this Asian trade regime has remained intact, although the most powerful stakeholders have changed positions, as indicated by the strong emergence of China in the past decade. Efforts of key trading partners to tackle non-tariff barriers (e.g., rule of origin and customs formalities) in the region have yielded little progress thus far. Instead of aiming at a regional consensus on non-tariff barriers by all member states, a global supply chain (GSC) approach is recommended. Mature hub ports at strategic locations with advanced institutional measures could set up international trade facilitation centers co-locating multinational customs formalities. This GSC approach may also be adopted to construct a GSC hub development model that explains the transformation of hub ports.     

船厂门机变幅系统的优化设计

门机在修造船厂应用十分广泛,本文以D2545型门机为研究对象,从影响整机使用性能和成本的变幅系统入手,分别计算和比较水平性、不平衡力矩、臂架结构和变幅机构功率这几个关键技术参数,说明优化方案对成本和使用性能的影响。     

电子浆料用超细银粉的制备

本文以AgNO3为原料,胺类作为还原剂,有机酸类为分散剂,采用化学还原法制备超细银粉。通过扫描电镜、激光粒度分析仪分析银粉的形貌和粒度,并制成浆料用在压敏陶瓷上。研究了AgNO3浓度对银粉分散性和粒度的影响,并且将银粉制备成电子浆料,研究其对压敏陶瓷通流性能的影响。结果表明,当CAgNO3低于1.0mol·l-1时,能够获得粒度较小、粒径集中优良的银粉,而CAgNO3为0.75mol·l-1和1.0mol·l-1时,制备的银粉用于电子浆料更适合于压敏电阻器。     

压电陶瓷扬声器内电极用银钯浆料的研制

制备了钯银比为5/95的银钯粉,采用乙基纤维素和醇酸树脂混合体系作为有机载体,加入少量玻璃粉制得了性能优良的内电极银钯浆料,可在压电陶瓷扬声器上使用。     

Evaluating competitiveness using fuzzy analytic hierarchy process—A case study of Chinese airlines

With the development of a national market economy, the Chinese aviation industry is now confronted with international competition. Therefore, it is necessary to research the competitive status of Chinese national aviation, as well as advice on how to enhance the competitiveness of the Chinese aviation industry. The main objective of this paper is to propose FAHP as an effective solution for resolving the uncertainty and imprecision in the evaluation of airlines' competitiveness. In this paper, we review the research of industrial international aviation competitiveness at both home and abroad, discuss a theoretical framework for the study of aviation competitiveness, establish an index system with five first‐order indicators and 17 second‐order indicators, set up a Chinese aviation competitiveness model based on simple fuzzy numbers from the fuzzy analytic hierarchy process, and evaluate the competitiveness of five major Chinese airlines. The results showed that this model and these indicators are scientific and practical, with a wide range of application prospects for the purpose of improving and increasing Chinese airline competitiveness in the international market. The effective approach presented in this paper is especially applicable when subjective judgments on performance ratings and attribute weights are not accessible or reliable, or when suitable decision makers are not available. Copyright © 2011 John Wiley & Sons, Ltd.