碳纤维复合材料传动轴临界转速分析

介绍了碳纤维增强的复合材料汽车传动轴临界转速的2种计算方法：理论公式法和有限元计算法。并将两者的结果进行比较,证明了有限元分析的可信性,为碳纤维在汽车中的应用提供了依据。     

基于营运数据的船舶能效分析及预测

为应对航运业日益严苛的温室气体减排要求,提出一种计算船舶实际营运性能的方法,并基于该方法实现对营运能效的分析和预测。以某大型集装箱船为研究对象,对其在2021年前2个月的营运数据进行分析。结果表明：该船的实际性能相比设计值降低约11.2%,通过采取坞修和调整船舶营运工况等措施能有效提高船舶的营运能效指数;通过对该船的营运能效进行预测,可给出提高船舶碳排放强度等级的具体措施,为船舶能效管理计划的制订提供参考。     

电动赛车轻量化材料车身设计及分析

为某电动赛车设计轻量化材料车身,通过对车身的三维建模,以及综合运用有限元模态分析技术,选用不同材料,优化车身结构,对整车车身的轻量化进行了较为深入的研究.通过文章的研究,对电动赛车车身在材料运用上提供了理论基础与技术支撑,与传统电动赛车的车身重量相比,车身重量大幅降低.     

Top-down effects and carbon flux in the ocean: A hypothesis

The close relationships between mesozooplankton, chlorophyll, and primary production normally observed across latitudes may be regarded as a bottom-up effect of increased productivity or, conversely, as a top-down effect of mesozooplankton on microzooplankton, releasing phytoplankton growth. The time-course of primary producers and mesozooplankton observed during the Late Winter Bloom in subtropical waters suggests a top-down effect, similar to the results found in lakes and mesocosm experiments. Two scenarios were observed during the development of the bloom in the Canary Island waters. The first was the increase in mesozooplankton as the effect of higher primary production due to mixing. The second scenario was the decrease in mesozooplankton due to the top-down effect of predation by diel vertical migrants upon epipelagic mesozooplankton. The structure of the food web in the euphotic zone was different depending on the presence or not of mesozooplankton, suggesting important consequences for the transport of carbon in those large areas of the ocean.     

碳减排背景下氢燃料电池船舶发展现状及监管建议

为实现碳减排目标,航运业必须寻找更为清洁环保的船舶替代燃料,而零碳排放的氢能源电池将发挥巨大潜力.在介绍氢燃料电池船舶国内应用现状和技术规范基础上,分析氢燃料电池船舶的优势和面临的挑战,最后从海事管理机构的角度提出了对氢燃料电池船舶的监管建议.     

Development of a corrected average speed model for calculating carbon dioxide emissions per link unit on urban roads

The purpose of our study is to develop a “corrected average emission model,” i.e., an improved average speed model that accurately calculates CO₂ emissions on the road. When emissions from the central roads of a city are calculated, the existing average speed model only reflects the driving behavior of a vehicle that accelerates and decelerates due to signals and traffic. Therefore, we verified the accuracy of the average speed model, analyzed the causes of errors based on the instantaneous model utilizing second-by-second data from driving in a city center, and then developed a corrected model that can improve the accuracy. We collected GPS data from probe vehicles, and calculated and analyzed the average emissions and instantaneous emissions per link unit. Our results showed that the average speed model underestimated CO₂ emissions with an increase in acceleration and idle time for a speed range of 20 km/h and below, which is the speed range for traffic congestion. Based on these results, we analyzed the relationship between average emissions and instantaneous emissions according to the average speed per link unit, and we developed a model that performed better with an improved accuracy of calculated CO₂ emissions for 20 km/h and below.     

碳纤维加固技术在旧厂房改建加固中的应用

碳纤维增强聚合物是一种新兴高强材料。以某旧厂房改建加固工程应用为例,介绍了碳纤维复合材料(CFRP)在结构加固中的计算方法和施工工艺。     

Air transportation in a carbon constrained world: Long-term dynamics of policies and strategies for mitigating the carbon footprint of commercial aviation

With increasing demand for air transportation worldwide and decreasing marginal fuel efficiency improvements, the contribution of aviation to climate change relative to other sectors is projected to increase in the future. As a result, growing public and political pressures are likely to further target air transportation to reduce its greenhouse gas emissions. The key challenges faced by policy makers and air transportation industry stakeholders is to reduce aviation greenhouse gas emissions while sustaining mobility for passengers and time-sensitive cargo as well as meeting future demand for air transportation in developing and emerging countries. This paper examines five generic policies for reducing the emissions of commercial aviation; (1) technological efficiency improvements, (2) operational efficiency improvements, (3) use of alternative fuels, (4) demand shift and (5) carbon pricing (i.e. market-based incentives). In order to evaluate the impacts of these policies on total emissions, air transport mobility, airfares and airline profitability, a system dynamics modeling approach was used. The Global Aviation Industry Dynamics (GAID) model captures the systemic interactions and the delayed feedbacks in the air transportation system and allows scenarios testing through simulations. For this analysis, a set of 34 scenarios with various levels of aggressiveness along the five generic policies were simulated and tested. It was found that no single policy can maintain emissions levels steady while increasing projected demand for air transportation. Simulation results suggest that a combination of the proposed policies does produce results that are close to a “weak” sustainability definition of increasing supply to meet new demand needs while maintaining constant or increasing slightly emissions levels. A combination of policies that includes aggressive levels of technological and operations efficiency improvements, use of biofuels along with moderate levels of carbon pricing and short-haul demand shifts efforts achieves a 140% increase in capacity in 2024 over 2004 while only increasing emissions by 20% over 2004. In addition, airline profitability is moderately impacted (10% reduction) compared to other scenarios where profitability is reduced by over 50% which pose a threat to necessary investments and the implementation of mitigating measures to reduce CO2 emissions. This study has shown that an approach based on a portfolio of mitigating measures and policies spanning across technology and operational improvements, use of biofuels, demand shift and carbon pricing is required to transition the air transportation industry close to an operating point of environmental and mobility sustainability.     

Competitive strategies for original equipment manufacturers considering carbon cap and trade

This paper considers an original equipment manufacturer (OEM) faces competition from an independent remanufacturer (IR) and they both are regulated by carbon cap and trade policy (CTP). We develop models to explore the OEM’s optimal competitive strategy in the face of IR’s competition and environmental regulation. We first investigate the impact of CTP on the OEM and IR. Then, we analyze three competitive strategies that the OEM may choose: remanufacturing, fixed-fee licensing, and royalty licensing. We investigate their optimal decisions under each strategy and identify the conditions under which these strategies can coordinate the OEM and IR. Finally, we explore conditions under which one strategy is superior to another. The results show that the OEM is worse off when competing with the IR under CTP if the carbon cap allocated to the OEM is small. Fixed-fee licensing and royalty licensing can coordinate the OEM and IR not only from an economic perspective but also from an environmental perspective. The OEM’s optimal competitive strategy is determined by thresholds of three critical parameters: the fixed cost of setting up a remanufacturing system, the fixed-fee, and the per-unit royalty. We provide specific guidance on strategy selection for the OEM.     

CFRP圆柱螺旋弹簧静刚度预测理论及仿真

针对实心结构形式的碳纤维复合材料圆柱螺旋弹簧进行了建模分析,明确了相关的设计参数,提出了一种碳纤维复合材料圆柱螺旋弹簧的静刚度预测理论,进行了算例分析,并将理论预测结果与仿真结果进行了比较.结果表明,理论预测值与仿真值相比误差较小,该预测理论可用于碳纤维复合材料圆柱螺旋弹簧的静刚度设计.