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货车对高速公路安全的影响与对策 总被引：3，自引：0，他引：3
严世同 《重庆职业技术学院学报》2006,15(3):134-136
本文就国内外交通事故的严重现状进行了分析,通过事故分析说明货车占高速公路交通事故的权重,通过事故数据说明货车在高速公路上产生交通事故的原因,并由此提出减少货车在高速公路上的交通事故措施。 相似文献
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为了探究轻型高速公路路线纵断面设计关键参数,基于Carsim/Trucksim软件搭建了人-车-路耦合系统,根据普遍性和不利性原则,选取轿车、面包车和轻型货车作为轻型车辆的代表性车型,开展了代表性车型在直坡路段和弯坡组合路段的行驶仿真。根据轻型车辆在纵断面和弯坡组合路段运行特征,确定了轻型高速公路的控制车型以及路线纵断面的坡度、坡长参数。结果表明：轻型高速公路纵断面设计参数应以轻型货车和面包车作为控制车型;高速行驶下,车辆在弯坡组合路段的速度衰减比在单纵坡路段更为剧烈;根据速度衰减特性和允许速度降幅,轻型高速公路设计速度为100 km/h时,若允许轻型货车通行,应以比功率为25 W/kg的轻型货车作为控制车辆,路线纵断面最大纵坡为5%,最大坡长为750 m,若不允许轻型货车通行,路线纵断面最大纵坡为6%,可不限制最大坡长;设计速度为120 km/h和140 km/h时,应以比功率为35 W/kg的面包车作为控制车辆,路线纵断面最大纵坡分别为6%和5%,对应的最大坡长均为1 200 m。 相似文献
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谈模拟教学在汽车实训教学中的作用 总被引：1，自引：0，他引：1
汽车的电控化已成为当代社会的现实，我国目前在轿车上已经全部电控化，货车也将逐步电控化。现代汽车的电子化、多媒体化和智能化，使得汽车已不仅是一个代步工具，它同时具有了交通、娱乐、办公和通信的多种功能。 相似文献
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随着人们对具有中国文化特色的轿车需求的不断增加,中国元素正越来越多的被应用到国产轿车的造型设计中.本文从设计要素、美学特征等方面对中国元素在轿车造型设计中的应用进行总结归纳,从设计的角度,结合民族文化和消费者的需求,提出中国轿车造型设计应从民族性和现代性两个方面着手"双管齐下"的设计思路. 相似文献
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赵建宁 《河北职业技术学院学报》2014,(1):39-42
轿车车门是轿车车身重要的组成部分,它的设计质量直接影响整车的安全性、造型效果、空气动力学特性、密封性及噪声等。轿车车门动态特性分析是基于车门有限元分析模型的建立,对轿车车门在自由状态下进行模态分析。文章在四种工况下对轿车车门的扭转刚度、下垂刚度进行分析。通过分析,为轿车车门结构设计选择及结构优化提供了理论依据。 相似文献
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《东南大学学报》2017,(3)
使用轨迹数据评价4种不同跟驰类型(类型1~4分别为小汽车跟随小汽车、小汽车跟随货车、货车跟随小汽车、货车跟随货车)对高速公路交织区追尾事故风险的影响.介绍了碰撞时间,并将其作为判断追尾事故风险的替代性安全指标,然后使用高速公路交织区的轨迹数据进行病例对照分析,在不同碰撞时间阈值下建立了3个logistic回归模型用于定量评价不同跟驰类型的影响,并对解释变量进行分析以期研究导致回归模型结果的可能原因.结果表明,当碰撞时间阈值等于2 s时,第3种跟驰类型的追尾事故风险比第1种跟驰类型高3.167倍,而第2种类型和第4种类型的优势比都小于1,该结果代表更安全的状态.对解释变量的分析显示第3种类型拥有最大的速度差和最小的净距,这与交织区车辆运行特征相一致,也是更大追尾事故风险的原因.该研究揭示了高速公路交织区不同跟驰类型追尾事故风险的机理. 相似文献
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朱辉 《中学生数理化(高中版)》2006,(10):59-63
一、选择题1.某弹簧振子简谐运动图象如图1所示，则下列说法正确的是(). A.质点在105内走过的路程为乙tom，位移为零B.t一。75时·质点的位移为正，且正在向平衡位置运动C.t一1.25时，质点的速度方向与加速度方向都和、轴正方向相反D.在1.25到1.55时间内质点的动能在增大，弹簧的弹力对质点做正功2.公路巡警开车在高速公路上以100 km/h的恒定速度巡查，在同一车道上巡警车向前方的一辆轿车发出一个已知频率的电磁波，如果该电磁波被那辆轿车反射回来时，巡警车收到的电磁波频率比发出时的低.说明那辆轿车的车速(). A.大于功Okm/h B.小于1… 相似文献
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An NCME Instructional Module on Booklet Designs in Large-Scale Assessments of Student Achievement: Theory and Practice 总被引：2，自引：0，他引：2
In most large-scale assessments of student achievement, several broad content domains are tested. Because more items are needed to cover the content domains than can be presented in the limited testing time to each individual student, multiple test forms or booklets are utilized to distribute the items to the students. The construction of an appropriate booklet design is a complex and challenging endeavor that has far-reaching implications for data calibration and score reporting. This module describes the construction of booklet designs as the task of allocating items to booklets under context-specific constraints. Several types of experimental designs are presented that can be used as booklet designs. The theoretical properties and construction principles for each type of design are discussed and illustrated with examples. Finally, the evaluation of booklet designs is described and future directions for researching, teaching, and reporting on booklet designs for large-scale assessments of student achievement are identified. 相似文献
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Helen C. Purchase 《Assessment & Evaluation in Higher Education》2000,25(4):341-352
Peer assessment is recognised as a useful learning activity, not merely as a means by which assignments can be marked. In a design subject such as Human-computer Interaction, peer-assessment offers a unique opportunity for students to be exposed to a wide range of different designs in an environment that ensures that they reflect on these designs. However, it is important that the marking criteria are well specified and unambiguous. This paper reports on the use of peer-assessment as an effective learning activity for revealing the wide range of design issues and dimensions in interface design, where formal marking is based on clear, functional criteria. Subjective consideration of the interfaces is encouraged through a ranking system and the subsequent elicitation of interface design principles. The successful implementation of this scheme demonstrates its benefits both as a learning activity and as an opportunity for student reflection. 相似文献
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刘丽平 《乐山师范学院学报》2014,(7):116-120
教学设计是教师课前教学的预设和计划,决定着教师的课堂教学行为,关系着师生的课堂教学效能。当前,高中英语教师对课堂教学设计有着不同的认识和理解,不同程度地存在忽视和费时低效的现象,已经引起了学界和教师的关注和思考。文章依据高中英语新课程理念,基于学习理论、系统理论、设计理论和传播理论,从微观视角探讨课堂教学设计分析与维度以及完善与反思。 相似文献
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Learning environment designs at the boundary of school and work can be characterised as integrative because they integrate features from the contexts of school and work. Many different manifestations of such integrative learning environments are found in current vocational education, both in senior secondary education and higher professional education. However, limited research has focused on how to design these learning environments and not much is known about their designable elements (i.e. the epistemic, spatial, instrumental, temporal and social elements that constitute the learning environments). The purpose of this study was to examine manifestations of two categories of integrative learning environment designs: designs based on incorporation; and designs based on hybridisation. Cross-case analysis of six cases in senior secondary vocational education and higher professional education in the Netherlands led to insights into the designable elements of both categories of designs. We report findings about the epistemic, spatial, instrumental, temporal and social elements of the studied cases. Specific characteristics of designs based on incorporation and designs based on hybridisation were identified and links between the designable elements became apparent, thus contributing to a deeper understanding of the design of learning environments that aim to connect the contexts of school and work.
相似文献16.
Gary R. Morrison Steven M. Ross Charles W. Schultz Jacqueline K. O'Dell 《Educational technology research and development : ETR & D》1989,37(3):53-60
Learner preferences for varying screen density levels were examined using multiple screen designs (high external validity)
and single screen designs (high internal validity). When viewing multiple screens for each design in Study 1, subjects indicated
the highest preference for medium-density screens while tending to select higher-density over lower density screens in individual
comparisons. When viewing only the first screen of each density level in Study 2, subjects again expressed preferences for
higher-density over lower-density designs. Suggestions are provided concerning the use of realistic and nonrealistic content
for the stimulus materials as well as implications of using externally and internally valid screen designs for future research
on computer-based instruction screen design. 相似文献
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Although educational research and practice has found many benefits of long-term and complex design activities, an issue of growing concern is that students might lose sight of science learning while diverting their attention to design aesthetics, collaborative management, and technology. A question is whether or not science is actually separate from these aspects; it may be that science permeates the design environment and is thus contexted within these other activities. To investigate this possibility we followed a classroom of 33 students, divided into 7 teams, and we examined their science discussions as they planned for creating instructional software designs. Specifically, we investigated which conversational contexts gave rise to science talk. We found that a focus on the fine-grained details of the instructional science designs themselves and the contributions of more design-experienced students played an important role in the sophistication of the science content in the planning discussions. In examining less productive contexts for science talk, we found that a conversational focus in planning discussions on collaboration and software issues, as well as the science focus of the software designs, impacted the quality of science integration. In our discussion, we address the issue of which design contexts afford opportunities for richer discourse and the implications for other project-based design activities. 相似文献
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巫文鸿 《新疆教育学院学报》2008,24(1):133-135
简洁美是现代平面设计的基本要求,也是现代信息传递的基本要求。那么如何将简洁美的设计理念贯穿于现代平面设计中,正确充分地传达信息,是现代平面设计所面临的一个新的问题。 相似文献
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李润 《兰州石化职业技术学院学报》2012,12(2):9-11
自顶向下的设计模式符合产品的设计思路,Pro/E软件在组件模式下的骨架模型设计是自顶向下设计的方法之一。该法可以使设计信息在整个组件中顺利地传达,保证了产品设计合理性和装配的准确性,从而确保稳妥的设计。结合Pro/E参数化建模思路,在组件模式下设计了曲柄摇杆机构的参数化骨架模型,并通过该骨架模型创建了机构零件,通过改变机构骨架模型参数,实现了曲柄摇杆机构的参数化和系列化设计。 相似文献