噪声发电在船舶机舱中的应用

船舶机舱的巨大噪音一直是改善船舶机舱环境的一个重要难题,这严重影响了船舶机舱工作人员的身体健康及工作环境。本文利用一种声电转换材料,将船舶机舱中的机器噪声能量收集起来转换为电能加以利用,这不仅减少噪声污染,改善机舱环境,而且能够产生电能,从而达到节能环保的作用。     

基于PTC材料加热的柴油喷油器模拟

文章选用居里温度为60℃的陶瓷基PTC材料作为加热元件,利用流体力学计算软件Fluent模拟了两种不同燃油流量下用PTC材料加热柴油的温度场变化。仿真结果表明,利用PTC材料加热可有效提高燃油温度,改善冷启动性能,且随着燃油流量的增加,喷油器出口温度呈下降趋势。     

激光加工复合材料电池盒夹具的设计方法

由于复合材料电池盒的易变形性和制造误差特征,复合材料电池盒加工夹具设计显著区别于普通机械加工工件定位夹具。本文首先介绍了复合材料加工技术的发展,给出了随着加工技术的发展带来了夹具的简化;最后,重点阐述了面向复合材料电池盒夹具设计的定位原理和夹具的优化设计方法。     

基于形貌特征的CO2腐蚀速率预测方法

针对CO2腐蚀过程复杂，难以利用实测数据有效预测腐蚀速率问题，文中以腐蚀形貌图像为对象，利用支持向量机（SVM）构建预测模型，实现对CO2腐蚀速率的预测。对N80钢的CO2腐蚀图像进行灰度处理、灰度增强及二值化处理，提取蚀孔数目和孔蚀面积。经计算获得孔蚀密度及孔蚀率，结合工作温度及CO2分压作为腐蚀速率预测的四维特征向量。以SVM构建预测模型，经测试，可准确预测CO2腐蚀速率，并与神经网络预测结果进行对比，验证了该方法的优越性。     

切头飞剪起制动过程动力学参数分析

切头飞剪是用于切断金属材料的一种机械设备，采用飞剪来剪切轧件，使轧钢车间的生产连续化，生产率大大提高，对双滚筒切头飞剪在剪切过程中的动能及起动、制动过程中的惯性力进行了定性的分析，并绘出了力能参数脉动图。     

新能源汽车续驶里程焦虑及维修技术研究

续驶里程焦虑是新能源汽车售后市场抱怨最多的问题。文章从售后角度分析了导致续驶里程焦虑的原因及维修排查技术,提出了一些建议性措施。旨在为售后相关人员提供一定的理论指导,从而推动售后市场更好的发展。     

浅谈水闸工程中的消能防冲计算

消能防冲计算是水闸工程设计中的重要环节,消力池、海漫段、防冲槽等消能防冲设施的结构尺寸都需要通过计算确定.水闸设计规范给出了相应的消能防冲计算公式.结合工程实例,从计算水位组合的选取、河道不冲流速及允许流量的计算、闸门开度及过闸流量的确定、消能防冲计算过程、消能防冲设施布置等几个方面对水闸工程中的消能防冲计算及消能防冲设施设计进行了简要介绍.     

高职新能源汽车技术专业课程体系的探索——全国87所院校的调研报告

随着国家节能减排政策的不断深化,新能源汽车技术专业逐渐成为近年来各高职院校的热门专业,经过几年的发展,各学校的新能源汽车专业都办出了自己的特色,很多都值得我们学习,笔者面向全国开办有新能源汽车技术专业的院校,针对其专业课程体系做了调研,并将调研结论进行分析,为课程体系的构建提出建设性的意见。     

Comparing Fisher Interviews,Logbooks, and Catch Landings Estimates of Extraction Rates in a Small-Scale Fishery

Researchers are turning to alternative data sources (e.g., resource user knowledge) to provide information required for wildlife management. Little is known about the reliability of data elicited from resource users relative to data obtained from user-independent approaches (e.g., observations of fish catches). We test for consensus among three methods that quantify past (1996 to 2007) seahorse catch-per-unit-effort (CPUE) for a small-scale, data-poor fishery in the Philippines: interviews with fishers about good, bad, and typical catch; fisher logbooks; and observations of catch landings. Interviews and logbooks indicated no trends in CPUE through time, consistent with results from the fisher-independent metric, catch landings. Although interview estimates of “typical” CPUE greatly exceeded “typical” observed catches and logbook estimates, interview estimates of “bad” CPUE were comparable. Catch landings estimates for a fisher in a particular year were uncorrelated to what he reported during retrospective interviews. Interviews should be used cautiously to inform specific catch targets (e.g., total allowable catches), although including interview questions about a range of catch experiences (e.g., good, bad and typical), may improve interview-derived data. Logbooks are particularly useful for capturing information about fishing expeditions that produce no fish, which are largely missed by other methods.     

Performance evaluation of the inside intersection median-turn lane markings on the mobility and safety performance of signalized intersections in the Philippines and Japan

Signalized intersections are one of the key elements that play a vital role at road networks. The efficiency and safety levels of intersections can affect the operational performance of the whole system. In general, turning traffic, especially median-turning, has always been considered as the most problematic movement in the operation of intersections. This becomes more critical with high turning demand where exclusive turning lanes (single or double) can be assigned to provide larger capacities for these movements and to reduce conflicts with through traffic. However, improper treatment of median-turn lanes could create cross-maneuvering behavior which may limit the expected increase in capacity and create safety issues. Median-turning lane markings are commonly provided at intersections in Japan to guide drivers while turning which is expected to reduce the conflicts among turning traffic. Meanwhile, in the Philippines, exclusive median-turn lanes are installed at intersections without proper treatment which may contribute to the low mobility and safety levels. Therefore, this study evaluated the impact of inside intersection lane markings on the operation of median-turn lanes in terms of mobility and safety. The vehicle maneuver, speed and interactions between the turning traffic were utilized as essential components for the assessment. The empirical analysis shows that conflicting trajectories were present on double turn lanes without median-turn lane markings in the Philippines, which resulted to serious conflicts among the turning vehicles and negatively influenced the turning speed and saturation flow rate of the turn lanes. On the other hand, the turn lane markings in Japan, provided a positive impact to mobility and safety of the turning lanes. Moreover, it was also found that the geometric characteristics and traffic signal phasing scheme highly affects the capacity and safety condition of signalized intersections.