并联混合动力汽车怠速停机控制策略研究

怠速停机是混合动力汽车主要节能途径之一,本文以并联式混合动力客车为研究平台,建立了怠速停机控制策略,在CRUISE环境下对发动机怠速时间、怠速转速与燃油经济性的关系进行了深入的研究,基于国内典型城市公交循环工况的仿真结果表明:采用怠速停机控制策略后,燃油经济性比原车得到显著改善。     

混联混合动力车辆能量管理控制策略优化

在分析混联式混合动力车动力总成结构及超级电容的动态特性的基础上,提出了基于规则的混联混合动力车的整车分层式控制系统.对整车驾驶员意图识别、模式判断和驱动力分配策略进行研究,并通过实车试验对其进行验证与评价.以中国典型城市公交工况为目标循环工况,进行实车测试,测试结果表明整车动力总成燃油经济性提升10%.     

单行星排客车混动系统控制策略对比

为了提高混合动力汽车的燃油经济性及降低汽车的尾气排放,从中国城市典型工况的动力需求出发,以单行星排10.5 m城市公交客车为研究对象,采用MATLAB软件建立整车经济性计算模型;然后,对比分析客车在单一目标控制策略和双层筛选全局优化控制策略下的节油效果.研究结果表明:在中国城市典型工况下,客车采用双层筛选全局优化控制策略比采用单一目标控制策略节油效果更为显著,节油率高达4.4%.     

网联混合动力汽车跟驰场景的预测能量管理控制

针对网联混合动力汽车跟驰场景下能量管理控制中燃油经济性和驾驶安全性综合优化问题，利用车-车及车-路通信，设计了一种基于前车速度预测-本车速度规划的预测能量管理控制策略。前车速度预测器由长短时记忆神经网络构建，神经网络内部超参数通过粒子群优化算法离线优化确定；基于预测的前车速度，求解以跟车距离、车速度、加速度及直接影响驾驶舒适性的车辆冲击度为成本函数的优化问题获得预测域内本车的速度规划；进一步利用序列二次规划算法求解车辆燃油经济性和驾驶安全性综合优化的能量管理控制问题，得到最优功率分配控制策略。多种驾驶工况下的仿真验证了所提出的预测控制策略的有效性及车辆安全跟驰下较好的燃油经济性。     

单轴并联式混合动力城市客车再生制动挡位决策

设计一种串并混联式复合制动踏板方案,并针对该方案制订再生制动阶跃式制动力分配曲线.分析了影响再生制动效率的多种因素,提出运用序列二次规划(SQP)算法优化挡位决策和电机输出扭矩以解决再生制动中回收效率与制动力分配曲线和电机转速的矛盾.在Cruise和Matlab/Simulink联合仿真平台下,建立了单轴并联式混合动力传动系统整车模型,基于欧洲公交客车循环工况(UDC)进行了仿真研究.结果表明,电池荷电状态(SOC)比采用传统双参数换挡规律提高了近1.5%.进行了三种典型制动工况下实车试验,取得了与仿真结果相吻合的试验结果,其中正常制动工况下的能量回收率比传统双参数换挡策略提高了近11.00%.     

基于循环工况的重型车辆换挡序列优化

针对自动变速车辆换挡策略优化问题,以燃油经济性和车辆行驶性能综合最优为目标,利用动态规划(DP)方法,计算并分析了配备自动机械变速器(AMT)的重型车辆在C-WTVC循环工况下换挡序列的最优决策。建立了循环工况下车辆换挡优化问题的动态规划模型;以功率储备作为评价车辆行驶性能的参数指标,建立了包含经济性、行驶性能的多参数指标函数。考虑了AMT换挡期间存在动力中断的特点,对DP方法进行改进,获得了一系列的挡位序列。研究结果显示,与原有两参数换挡规律对比,DP方法得到的挡位序列使车辆总油耗降低了6.4%,行驶性能指标提高了3.5%。研究表明使用DP方法和多参数指标函数可以得到车辆在循环工况下综合性能最优的换挡序列,对AMT重型车辆的自动控制具有指导意义。     

基于模糊在线识别的并联混合动力客车自适应控制策略

针对一款并联混合动力客车提出了一种基于模糊在线识别的自适应控制策略.基于自主研发的混合动力车数据采集监控系统构建符合本地车辆实际行驶道路特点的典型工况,设计模糊工况识别算法对车辆实际行驶的工况类型进行在线识别.根据最小等效燃油消耗控制算法和电池电量平衡控制方法,结合工况识别的结果调用相应最优控制参数,对发动机和电池的功率分配进行实时优化计算,实现对整车的控制.实验结果表明,所设计的模糊识别方法能够较好地完成行驶工况类型的识别.基于此所提出的自适应控制方法能够在满足车辆需求功率和电池SOC维持在有效工作区间内的前提下完成发动机和电池的最优功率分配,显著提高整车的燃油经济性.      

基于循环工况统计规律的混联式混合动力客车参数匹配与性能仿真

参考中国城市公交城区循环工况的整车动力性及经济性要求,对混联式动力系统运行模式进行分析,根据其结构特点设计基于发动机最佳工作效率曲线的控制策略,应用Matlab/Simulink建立整车仿真模型,进行了基于循环工况统计规律的功率匹配,并对该混合动力客车的动力性及经济性进行仿真实验验证。结果表明,所匹配的客车参数能够满足整车性能目标,整车的燃油经济性相比于传统客车提高30%,同时,能够很好地维持SOC电池荷电状态保持在一定范围内,发动机的工作点基本在高效区域内运行。     

多源信息融合的车速预测方法及整车能量管理

为了进一步挖掘功率分流混合动力汽车的节能潜力,提出了一种融合驾驶意图、车间运动特征及工况历程特征信息的车速预测方法。在此基础上,以燃油经济性最优为目标,建立了基于模型预测控制的整车能量管理优化模型,并采用动态规划算法在有限时域内进行求解,实现了各动力源转矩的实时最优分配。通过MATLAB/simulink软件平台仿真验证表明:在城市道路循环工况下,车速预测精度在不同预测时域都得到了进一步的提升。相比于参数优化后的规则策略,该整车能量管理策略在3种典型工况下,燃油消耗量分别降低了28.53%、23.40%和26.42%,从而验证了该车速预测方法和整车能量管理策略的有效性。     

增程式纯电驱动城市客车能量管理策略对比研究(英文)

针对一辆12m 增程式城市客车,对比研究了几种常见的能量管理算法.该城市客车由锂离子电池驱动,并配有一个功率辅助单元(auxiliary power unit,APU)作为里程延长器.功率辅助单元由发动机和发电机组成,可以将燃料中的化学能转化为电能,补充动力电池的电量.首先,建立了该动力系统的动态模型.基于该模型,定义了一个以日行驶燃油消耗量最小为目标的全局优化问题.采用动态规划方法(dynamicprogramming,DP)进行求解;其次,对比分析了动态规划策略、耗尽-维持(charge depleting and chargesustaining)策略、混合(blended)策略等几种常见的能量管理方法.仿真结果表明,对于本文所研究的特定动力系统,采用全局最优策略,日行驶工况下燃油经济性为26.1L/100km;采用混合策略,日行驶工况下燃油经济性为29.1L/100km;采用耗尽-维持策略,日行驶工况下燃油经济性为28.2L/100km.由于全局优化策略无法投入使用,相较于混合策略,耗尽-维持策略可降低油耗3%.将耗尽-维持策略应用于实际车辆.道路实验表明,空载状况下实际油耗为23.6L/100km,满载情况下为24.9L/100km.相较于传统车平均 30L/100km 的水平,满载情况下耗尽-维持策略可降低油耗17%.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-