严寒地区高速铁路混凝土基床聚氨酯保温特性试验研究

基于严寒区京沈客专朝阳试验段路基基床的温度监测资料分析,研究不同厚度聚氨酯保温板对高速铁路路基混凝土基床温度变化特性影响.测试结果表明:①铺设聚氨酯保温板能够有效阻断严寒区环境与路基基床间的热量传递,保温效果与板厚相关;②地温大多数时间呈阳高阴低现象,同时阴、阳坡路基温差波动幅度随埋深逐渐减小;③基床表层阴、阳面各测点的温度变化起始时间一致,而阴面的冻结时间比阳面晚一个月.由此表明,保温板能够有效降低环境与混凝土道床之间的热交换,但是对路基阴、阳坡的影响存在差异.建议在严寒地区高速铁路路基阳、阴坡可以采取不同厚度的聚氨酯保温板,减小阴阳坡地温差异,保持季冻土路基温度变化稳定.     

基于动态冲击试验的通勤类飞机座椅符合性验证技术

国产某型民用通勤类飞机为了取得欧洲航空安全局(EASA)型号合格证,机上座椅需进行设计更改并补充进行应急着陆情况下的动态要求符合性验证.通过对适航条款及相应标准的解读,研究了基于动态试验的航空座椅动态要求适航验证技术,其主要包括座椅动态性能基本要求、试验构型及工况筛选、试验规划、合格判据和试验结果分析等内容.结果表明,该型机旅客座椅满足适航规章对座椅的动态性能要求.该项旅客座椅动态性能试验的成功为型号取得EASA型号合格证奠定了良好的基础,该型飞机也即将成为第一个取得欧洲型号合格证的国产飞机.     

铁路运输客货管理机制的探讨

随着我国加入WTO和铁路全面参与运输市场竞争,必须尽快构建适应市场需求的铁路客货管理的动力机制和运作机制,以激发企业和员工搞好营销的内在活力,同时要构建铁路客运和货运的服务质量评价指标,以及相应的质量监督和考核管理办法,做到各项管理活而不乱、管而不死,使铁路客货运输服务质量不断提高,以满足不断增长的经济和社会发展需要。     

新财务清算政策下提高铁路城际列车效益的思考

近年来,铁路短途城际客运得到了很大的发展,开行城际列车已成为铁路运输企业新的经济增长点。新财务清算政策实施后,开行城际列车的效益受到一定程度的影响,针对存在的问题,就如何提高其效益水平进行了讨论。提出了完善开行结构、增加营业收入、减少客运付费、降低成本支出等建议措施。     

人才强国,关键在于培养和使用好人才

我国是一个人口大国，如何将我国的人口负担转化为人才资源优势，这是党和国家建设事业的关键问题。笔者认为人才强国战略的实施，关键在于培养和使用好人才，在于快出人才，多出人才和出好人才。为此，文章提出了一些人才使用的策略。     

The European high-speed train network: Predicted effects on accessibility patterns

The principal aim of this paper is to evaluate the impact of the future European high-speed train network on accessibility, by reducing time distance between places and modifying their relative location. We compare the current situation with that foreseen for the year 2010, according to the Outline Plan of the European High-Speed Train Network, in order to analyse which areas will most benefit from construction and improvement of the infrastructure. It is hypothesized that the high-speed train will certainly bring the peripheral regions closer to the central ones, but will also increase imbalances between the main cities and their hinterlands. A weighted average distance indicator is applied for this purpose. This measure identifies the spatial distribution of accessibility in the area of study, emphasizing the infrastructure effects, and locates accessibility changes at the European level. A Geographic Information System (GIS) has been used to carry out this study.     

拓宽专业口径,优化课程体系,培养新世纪合格人才

在实施科教兴国战略的过程中 ,作为知识创新、传播与应用和培养创新精神和创新人才摇篮的高等学校 ,面对新世纪对人才的需求 ,拓宽专业口径 ,改革人才培养模式 ,探索宽口径专业下培养适应社会需求的高质量人才 ,全面推进素质教育 ,增强学生未来工作的适应性是摆在高等学校面前的重要课题     

海洋环境管制的供需矛盾分析

本文从我国海洋环境问题的现实出发，重点分析了海洋环境管制的供求现状和矛盾，指出我国海洋环境管制的必要性和紧迫性。同时，结合我国海洋环境管制的现实，探讨了我国海洋环境管制的发展，提出我国在加强海洋环境管制的同时应拓宽思路，促进海洋环境管制的有效供给。     

基于灰色系统理论的旅游客源预测模型--以中国入境旅游客源为例

本文基于灰色系统理论,以中国1978年以来入境客源为例,建构了旅游客源预测的灰色模型,并与常用的线性模型的预测精度进行了定量对比。所得基本结论为:①旅游系统是灰色系统,灰色系统理论是研究旅游现象的有力工具;②中国入境客源灰色GM(1,1)模型的预测精度高于线性模型;③就灰色预测而言,如果原始数据列较长(例如21年),对原始数据进行平滑处理所得预测模型精度较高,而对原始数据进行取自然对数的处理所得模型预测精度较低;如果原始数据列较短(例如5年),对原始数据进行取自然对数的预处理所得模型预测精度较高。本文所得结论对其他旅游序列预测应该具有一定的借鉴与参考价值。     

Ratio-based design hour determination for airport passenger terminal facilities

To avoid both over-design and under-sizing of airport passenger terminal facilities such as security checkpoints, the infrastructure is designed for a specifically determined design load. As such, the design load is considered for a short period of time, usually an hour of operation, during which peak, though not necessarily maximum, demand occurs. For strategic planning applications, future design loads can be determined by either fictitious flight schedules or ratio-based models which forecast the relationship between design load and annual demand. This study presents two ratio-based methods which allow the direct determination of design hour loads (DHL) for passenger terminal facilities. The unsaturated DHL model considers the relationship between observed passenger flows in the terminal and aggregated annual demand data. The saturated DHL model includes several operational constraints which limit the actual DHL, such as limitations in the runway system or the fleet mix operating at an airport. Both models are applied to two real-world airports, for which the DHL of the security checkpoint facilities is estimated from large datasets covering multiple years. Results are significant at the 5 % level and suggest that the proposed ratio-based methods are appropriate for airport strategic planning applications.