Investigation of battery end-of-life conditions for plug-in hybrid electric vehicles

Plug-in hybrid electric vehicles (PHEVs) capable of drawing tractive energy from the electric grid represent an energy efficient alternative to conventional vehicles. After several thousand charge depleting cycles, PHEV traction batteries can be subject to energy and power degradation which has the potential to affect vehicle performance and efficiency. This study seeks to understand the effect of battery degradation and the need for battery replacement in PHEVs through the experimental measurement of lithium ion battery lifetime under PHEV-type driving and charging conditions. The dynamic characteristics of the battery performance over its lifetime are then input into a vehicle performance and fuel consumption simulation to understand these effects as a function of battery degradation state, and as a function of vehicle control strategy. The results of this study show that active management of PHEV battery degradation by the vehicle control system can improve PHEV performance and fuel consumption relative to a more passive baseline. Simulation of the performance of the PHEV throughout its battery lifetime shows that battery replacement will be neither economically incentivized nor necessary to maintain performance in PHEVs. These results have important implications for techno-economic evaluations of PHEVs which have treated battery replacement and its costs with inconsistency.     

Hydrothermal synthesis of Pt/MWCNTs nanocomposite electrocatalysts for proton exchange membrane fuel cell systems

A hydrothermal method for preparation of size-controlled Pt nanoparticles dispersed highly on multiwalled carbon nanotubes (Pt/MWCNTs) has been studied to optimize the effective parameters (temperature, time, pH and stirring rate) using Taguchi method. The synthesized Pt/MWCNTs nanocomposite samples were characterized through X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray fluorescence (XRF) analyses to identify mean Pt nanoparticles size and Pt content. The analysis of the primary experimental data and demonstration of the main effect trend of each parameter showed that a reaction temperature of about 140 °C, a reaction period of 5 h, a slightly basic reaction pH (∼9) and a stirring rate of 500 rpm are the optimum process conditions which give a low mean Pt nanoparticles size (2.8 nm) and a high Pt content (19.4 wt.%) simultaneously. Cyclic voltammetry (CV) analysis showed that under optimum conditions the synthesized sample gives a specific surface area of 99 m² g⁻¹. Obtaining the polarization curves for the two fabricated membrane electrode assemblies (MEAs) using the optimized catalyst and a commercial Pt/C catalyst (10 wt.%, Aldrich) with Pt loading of 0.4 mg cm⁻² demonstrated that the catalyst prepared under optimum conditions shows a considerably better performance.     

Fabrication of highly ordered and vertically oriented TiO2 nanotube arrays for ordered heterojunction polymer/inorganic hybrid solar cell

Highly ordered and vertically oriented TiO₂ nanotube arrays with a length of 250 nm and a diameter of 70 nm were prepared by atomic layer deposition (ALD) coupled with anodic aluminum oxide (AAO) template. An ordered heterojunction (OHJ) polymer/inorganic hybrid solar cell was fabricated by successful infiltration of P3HT into the nanotube arrays. Structural features of the nanotube arrays enabling the interdigitated structure of the OHJ were discussed and the performance of the solar cell was characterized to be the power conversion efficiency of 0.50%.     

空气-水复合平板型太阳能集热器

提出了一种适用于太阳能供热采暖工程的新型太阳能空气-水复合平板集热器。该集热器可以单独使用空气、水或同时以空气和水作为集热工质。测试显示,该集热器空气循环集热效率为55%～65%,水循环集热效率为32%～34%,能够满足太阳能供热采暖工程的要求。该集热器成本不高,适用于在我国北方广大农村地区推广使用。     

车辆混合动力传动技术发展现状与展望

概述了混合动力汽车两种主要传动机构：电动和静液传动混合动力系统的特点并对其进行了比较。总结了国外各研究机构对于混合动力传动这一问题的研究和成果,对控制策略的研究现状进行了介绍。最后指出了混合动力汽车传动机构目前需要进行的主要研究工作。     

直通式上成形器：高档文化纸纸机改造的有效途径

介绍了直通式上成形器的结构，性能及使用。其主要优点是：两面差小，成形质量好，两面脱水易调，适应车速低，结构简单，造价低。     

MASS BALANCE CALCULATIONS FOR DIFFERENT MODELS OF HYDROCARBON MIGRATION IN THE JEANNE D'ARC BASIN,OFFSHORE NEWFOUNDLAND

Basin and petroleum systems modelling is a powerful tool in petroleum exploration, but uncertainties remain in terms of the evaluation of a petroleum accumulation's size and quality, even when the petroleum system is well known and the latest modelling technology is applied. In order to interpret the results of a modelling exercise, it is necessary to understand the advantages and disadvantages of the various possible approaches used to assess petroleum migration and accumulation. This paper attempts to compare the influence of different migration modelling techniques – the flowpath, Darcy “hybrid” and invasion percolation approaches – on basin‐wide mass balance calculations for a temperature‐ and pressure‐calibrated, numerical four‐dimensional basin model. The study was performed using PetroMod® software. The study area is the well‐known Jeanne d'Arc Basin located offshore Newfoundland, eastern Canada. Model predictions were verified against pre‐existing data including the quantity and quality of discovered hydrocarbons in the basin. Modelling results showed that the Darcy method produced substantially different results compared to the other migration techniques and this was due to the high accumulation efficiency. The flowpath method, and a combination of flowpath and Darcy methods (referred to as the “hybrid” method) yielded similar results; furthermore, the hybrid method predicted the petroleum composition quite accurately. The invasion percolation method gave similar results to the hybrid approach, but little or no variation in API and GOR across the basin was predicted. The adsorption model initially applied did not adequately reproduce the natural behaviour of source rocks with respect to petroleum expulsion efficiency. Therefore a revised model was implemented in which the adsorption capacity was reduced with increasing maturity. This revised adsorption model led to more realistic volumes of hydrocarbons being retained within the source rock. The application of this approach had only a minor impact on the volume and quality of the petroleum present in the reservoir units.     

利用遗传-粒子群优化混合算法求取剩余静校正量

剩余静校正是一个具有多参数、多极值的全局优化问题,当大量未知参数存在时,常规的遗传算法（GA）几乎无法避免早熟现象,难以保证收敛于全局最优。结合粒子群优化算法（PSO）和遗传算法的优势,提出了一种新颖的粒子群优化-遗传混合算法。混合算法利用了粒子群优化算法的速度和位置的更新规则,并引入遗传算法里的交叉变异思想。用混合算法和遗传算法分别对两个理论模型进行试处理,处理结果表明,混合算法比遗传算法具有更好的性能,是一种求取复杂地形条件下剩余静校正量的实用方法。     

聚(苯乙烯-b-丙烯酰胺)/有机蒙脱土纳米复合材料的合成及表征

 采用可逆加成-断裂链转移(RAFT)聚合法合成两亲性聚(苯乙烯-b-丙烯酰胺)(P(St-b-Am))的过程中，为改善嵌段聚合物的热稳定性能，添加有机蒙脱土(O-MMT)，成功制备了两亲性纳米复合材料P(St-b-Am)/O-MMT。通过GPC、IR、XRD、TEM、TG测试表明，采用RAFT法能有效控制PSt/O-MMT大分子链转移剂中聚苯乙烯(PSt)的相对分子质量及其分布，其聚合分散度PDI<1.3；由于蒙脱土片层以纳米级分散在两亲性聚合物基体中形成了纳米复合材料，从而有效提高了P(St-b-Am)/O-MMT的热稳定性能。     

混合地震反演技术及其在水合物勘探中的应用

在没有钻井资料的勘探地区，人们期望能快速准确地反演出各种属性参数。虽然叠后反演简单易行，但仅能反演出波阻抗信息；而叠前反演能够提供较多的属性参数，但运算量巨大。为将叠前和叠后的优势有机地结合起来，人们提出了混合反演的方法。混合反演法的基本原理是：首先采用基因遗传算法，在叠前数据上根据勘探要求任意选择控制点进行波形反演，建立弹性模型；然后利用AVO处理方法得到P波和伪s波剖面；最后，在P波和伪S波数据体上，以弹性模型作为低频背景趋势，进行叠后约束稀疏脉冲反演，得到P波阻抗和S波阻抗剖面以及纵横波速度比、泊松比和拉梅参数等地震属性参数。利用混合反演法对我国南海北部的0101线进行了反演，得到了品质较高的多种属性剖面，并对水合物的赋存情况进行了分析。