迫导向转向架低锥度失稳问题的研究

本文深入探讨了迫导向转向架所具有的低锥度失稳问题。以三轴、二轴迫导向转向架为对象建立数学模型,分析运动学失稳和动力学失稳两种模式。得到不同导向刚度下产生失稳的临界踏面锥度和不同锥度下的临界速度值。研究发现,通过参数的合理匹配,可使临界锥度降至常见最小锥度以下,从而可以避免低锥度失稳,为迫导向转向架的参数设计提出了一个新的准则。     

AN EXPERIMENTAL STUDY ON REMOVAL OF NOx IN FLUE GAS AT THENONEQUILIBRIUM PLASMA

Removal of nitrogen oxides (NOx) in flue gas by means of nonequilibrium plasma technology is a very prospect and attractive method. As the nonequilibrium plasma micro discharges can generate a powerful energy flux, imparted to the flue gas, the molecules and atoms of pollutants are motivated and decomposed, and then NOx in the flue gas are decomposed and conversed in the particular conditions. Based on nonequilibrium plasma in combination with catalytic principle, an experimental investigation on NOx decomposition and conversion with AI2 03 catalysts was carriedout and the NOx removal rate up to 95% was obtained. The NOx decomposition and conversion principle with AI2O3 catalysts was also discussed.     

EFFECTS OF TOTAL SAPONINS OF PANAX NOTOGINSENG AND LIGUSTRAZINE ON THE PROLIFERATION OF CEREBRAL MICROVASCULAR ENDOTHELIAL CELLS OF RATS

Ｅｎｄｏｔｈｅｌｉａｌｃｅｌｌｓ (ＥＣｓ)ｆｕｎｃｔｉｏｎａｓｔｈｅｂａｒｒｉｅｒｏｆｔｈｅｂｒａｉｎａｎｄｒｅｌａｔｅｔｏｔｈｅｓｅｃｒｅｔｉｏｎｏｆｓｏｍｅｅｎｄｏ ｃｒｉｎｅｓ.Ｔｈｅｉｒｄｙｓｆｕｎｃｔｉｏｎｉｓｃｌｏｓｅｌｙｒｅｌａｔｅｄｔｏｔｈｅｏｃｃｕｒｒｅｎｃｅａｎｄｄｅｖｅｌｏｐｍｅｎｔｏｆｃｅｒｅｂｒａｌｖａｓｃｕｌａｒｄｉｓｅａｓｅｓ[1] .ＤａｍａｇｅｔｏＥＣｓｉｓｔｈｅｆｉｒｓｔｓｉｇｎａｎｄａｂａ ｓｉｃｆａｃｔｏｒｏｆｃｅｒｅｂｒａｌｉｓｃｈｅｍｉａ .Ｔｈｅｒｅｆｏｒｅ ,…     

用社会主义核心价值体系教育和引导当代大学生

分析了对大学生开展社会主义核心价值体系教育的意义,指出了高校社会主义核心价值体系教育的主要内容,提出了高等学校开展社会主义核心价值体系教育的保障措施。     

诊断冷却系统的过热问题 你将获益多多

为客户检查和确定发动机过热的原因,往往会成为你手中一个＂烫手的山芋＂。不过,如果你知道该向客户询问哪些问题,并且已经向他们提问时,那么你也正逐步走向成功。     

复杂悬跨条件下的管线涡激振动分析(英文)

Spans occur when a pipeline is laid on a rough undulating seabed or when upheaval buckling occurs due to constrained thermal expansion. This not only results in static and dynamic loads on the flowline at span sections, but also generates vortex induced vibration (VIV), which can lead to fatigue issues. The phenomenon, if not predicted and controlled properly, will negatively affect pipeline integrity, leading to expensive remediation and intervention work. Span analysis can be complicated by: long span lengths, a large number of spans caused by a rough seabed, and multi-span interactions. In addition, the complexity can be more onerous and challenging when soil uncertainty, concrete degradation and unknown residual lay tension are considered in the analysis. This paper describes the latest developments and a .state-of-the-art. finite element analysis program that has been developed to simulate the span response of a flowline under complex boundary and loading conditions. Both VIV and direct wave loading are captured in the analysis and the results are sequentially used for the ultimate limit state (ULS) check and fatigue life calculation.     

混合动力汽车是通往零排放梦想的桥梁

全球各大汽车制造商如今都面临着巨大挑战，就是如何为传统燃油发动机寻找一种可持续发展的可替代能源。虽然几十年来，人们已经探索出了很多种可行的方法，但至今为止，还没有一种可投入大规模生产，并与传统内燃机相抗衡的解决途径。在全球温室效应加剧和油价飙高的压力下，汽车制造商责无旁贷，那么混合动力是否是一种有效的解决方案呢？     

What do commuters think travel time reliability is worth? Calculating economic value of reducing the frequency and extent of unexpected delays

The measurement of transportation system reliability has become one of the central topics of travel demand studies. A growing literature concerns the measurement of value of travel time reliability which provides a monetary cost of avoiding unpredictable travel time. The goal of this study is to measure commuters’ sensitivities to travel time reliability and their willingness to pay (WTP) to avoid unreliable routes. The preferences are elicited through a pivoted stated preference survey technique. To circumvent the issue of presenting numerical distributions and statistical terms to day-to-day commuters, we use the frequency of delay days as a means of measuring traveler’s sensitivities to travel time reliability. The advantage of using simplified measures to elicit traveler preferences for travel time reliability is that these methods simply compare days with high delay to days with usual travel time. It was found that travelers are not only averse to the amount of unexpected delay but also to the frequency of days with unexpected delays. The paper presents WTP findings for three measures: travel time, frequency embedded travel time, and travel time reliability. The ‘reliability’ increase in WTP for travel time is found to be nearly proportional to the frequency of experiencing unexpected delays. For example, the WTP for mean travel time is calculated at $6.98/h; however, reliability adds $3.27 (about 50 % of $6.98) to avoid unexpected delays ‘5 out of 10 days’. The results of the study would provide valuable inputs to cost-benefit analyses and traffic and revenue studies required for road tolling investment projects.     

Comparison analysis for subjective and objective weights of financial positions of container shipping companies

This paper explores the positions of financial ratios identified utilizing both subjective and objective weighting methods—the consistent fuzzy preference relation (CFPR) and entropy—based on questionnaires collected from experts and the financial statements of major shipping companies in Taiwan and Korea. The comparison of perceptions of financial ratios by country and by expert group illuminates some financial aspects that experts may have ignored or not paid close attention to during the business operating process, especially in today’s turbulent world shipping market. The major results of this paper show that experts in the two countries have different perceptions of the debt-to-equity ratio and that by combining the results of objective and subjective weights, categorization of financial ratios by quadrant can help decision-makers find business options and strategies to improve the financial performance of their companies. This research approach may be applied to other business entities, improving on the direct rating method used in previous studies.     

公路交通与经济发展适应性评价研究

公路交通与经济发展密切相关,不同经济发展阶段对公路交通发展水平的要求不同。基于公路交通与经济发展的适应性内涵分析,从公路交通基础设施、运输服务、管理水平与信息化、发展环境与可持续性5个方面,建立了其适应性评价指标体系;科学定位所处公路交通发展环境,界定了评价指标标准,对评价指标进行量纲一体化;提出基于AHP的非线性加权...