铁路机车空调电源标准探讨

简述铁路机车空调电源产品开发历程,探讨制定行业标准,分析技术参数、质量指标、检验规则以及按企业标准生产运用状况,以期加快标准制定速度。     

Does the pedestrian environment affect the utility of walking? A case of path choice in downtown Boston

There is a lack of consensus as to whether the relationship between the built environment and travel is causal and, if it is, the extent of this causality. This problem is largely caused by inappropriate research designs adopted in many studies. This paper proposes a new method (based on path choice) to investigate the causal effect of the pedestrian environment on the utility of walking. Specifically, the paper examines how the pedestrian environment affects subway commuters’ egress path choice from a station to their workplaces in downtown Boston. The path-based measure is sensitive enough to capture minor differences in the environment experienced by pedestrians. More importantly, path choice is less likely to correlate with job and housing location choices, and therefore largely avoids the self-selection problem. The results suggest that the pedestrian environment can significantly affect a person’s walking experience and the utility of walking along a path.     

快速启动电控陀螺罗经的仿人智能控制

快速启动陀螺罗经,对提高罗经的工作性能及改善舰船战术性能具有重要意义。本文提出将多模态仿人智能控制应用于陀螺罗经的启动过程。仿真试验表明,该控制算法可有效地缩短陀螺罗经的启动时间。     

A review of the effect of a／W ratio on fracture toughness （Ⅰ）—experimental investigation in EPFM

Many experimental investigations have previously been performed and recently done on different shipbuilding structural steels where the specimens size and crack depth/specimen width (a/W) were varied. A series of interesting results have been gained. It is worthwhile to have a review on the effect of a/W ratio on fracture toughness, and further theoretical analysis is necessary. In this paper, experimental work in elasticplastic fracture mechanics (EPFM) was discussed. Tests had been carried out on 10 kinds of strength steels. Results showed that J _i and δ₁ values increased with decreasing a/W when a/W<0.3 for three-point bend specimens and that shallow crack specimens which have less constrained flow field give markedly higher values of toughness than deeply notched specimens. However, for a/W>0.3, the toughness was found to be independent of a/W. Slip line field analysis shows that for shallow cracks, the hydrostatic stress is lower than that from standard deeply cracked bend specimen which develops a high level of crack tip constraint, provides a lower bound estimate of toughness, and will ensure an unduly conservative approach when applied to structure defects especially if initiation values of COD/J-integral are used.     

办公自动化系统安全问题和解决途径

随着交通系统办公自动化系统推广应用,系统的安全问题也日益严重。本文介绍了所采用的安全策略,重点介绍了全省交通CA认证管理系统组成结构。通过这些措施,办公自动化系统的安全性得到了有效提高。     

新发现的韩国《雁行图》所表现的中朝关系

韩国学者朴泰根教授最新发现的明代<雁行图>,以图文并茂的形式,展现了明天启年间,中朝关系的实际情况,真实地反映了中朝相互来往的海上和国内路线,具有很高的史学价值.     

南京地铁桩基试验研究

介绍了南京地铁试桩概况、自平衡试桩法的工作原理,及其在南京地铁一期工程中成功应用。结果表明,该法具有较好的精度,适应各种条件,可为设计单位提供依据,显示了其在桩基测试中优越性。     

加入WTO后我国铁路货物运输对策

我国加入世界贸易组织,经济发展环境发生巨大变化,铁路运输业迎来新的发展机遇,同时,我国政府承诺逐步开放铁路货物运输市场,又使铁路运输业面临严峻的挑战。铁路部门如何利用这一机遇,积极迎接挑战,对铁路运输业的未来影响深远。本文在分析加入世界贸易组织对我国铁路运输业影响的基础上,重点论述了我国铁路在货物运输方面应采取的对策。     

音乐审美教育

二十一世纪的音乐教育应以突出音乐美育为主。音乐美育的核心内容是美感教育,重在培养人的审美意识和审美能力,以审美的态度来对待一切音乐活动,以此淡化音乐教育中的实用功利性。     

美国海军导弹防御系统的发展分析

介绍美国海军导弹防御系统的发展历程以及装备的研制、改进情况，指出在现代战争中发展美国海车导弹防御系统的优势和重要性，重点探讨几种导弹防御系统的性能及其特点，最后论述美国海军导弹防御系统的发展分析。