基于AMESim-Simulink的混联式液压混合动力垃圾车建模与仿真

针对城市垃圾车的动力系统结构和控制策略,提出一种适用于城市垃圾车工况的混联式液压混合动力系统。介绍了混联式液压混合动力系统的结构与工作原理,基于AMESim与Simulink/Stateflow软件,建立垃圾车混联式液压混合动力系统的联合仿真模型,分析其燃油经济性。仿真结果表明,在只考虑垃圾车行驶工况下,采用混合动力垃圾车的燃油经济性比传统动力垃圾车提高了37.2%。     

内燃式机械-液压双元动力系统方案

提出了一种内燃式机械液压双元动力系统(MHBPS),该系统集成了内燃机与柱塞泵技术,可以同时输出机械液压双元动力,或变换地输出机械、液压两种动力之一,特别适用于工程机械等具有多作业功能的车辆及负荷率严重不合理、制动能浪费严重的城市车辆。针对3种典型的MHBPS,着重论述了系统方案和工作特点。对MHBPS的3种典型应用进行了分析。     

影响柴油机伞帘喷雾燃烧系统性能的几个因素

研究了单缸柴油机喷嘴端伸出量、喷孔参数、启喷压力、供油提前角、燃烧室结构和工况对伞帘喷雾燃烧系统性能的影响。结果表明,喷嘴端伸出量明显影响燃油消耗率和烟度,最佳喷嘴端伸出量随喷孔锥角同向变化;启喷压力、供油提前角、中心喷孔直径和燃烧室凸缘高度存在最佳值;伞帘喷雾燃烧系统的最佳供油提前角比传统燃烧系统小得多;在低负荷下,喷嘴带中心喷孔时的烟度稍高些,但燃油消耗率不恶化。     

插电式混合动力农业运输车驱动工况控制及仿真

在建立了插电式混合动力农业运输车发动机、电机和电池的数学模型基础上，设计了插电式混合动力农业运输车驱动工况的控制策略，该控制策略采用基于规则的逻辑门限值控制策略，以汽车需求转矩和蓄电池荷电状态SOC为基本控制参数；利用MATLAB/Simulink和Stateflow软件对插电式混合动力农业运输车燃油经济性进行仿真分析。结果显示与相同类型的传统内燃机农业运输车相比，其燃油消耗明显降低，说明所设计的插电式混合动力农业运输车驱动工况的控制策略是有效的，同时分析了整车参数对汽车燃油消耗的影响。     

博世开发乘用车液压混合动力系统

继成功开发电力轴驱混合动力系统,并将其应用于雪铁龙柴油车型之后,博世计划与标致雪铁龙集团再度携手,共同开发乘用车液压混合动力系统。通过为系统引入两套液压单元和储能器组件,液压混合动力系统可提供三种车辆驱动方式——传统机械驱动、液压驱动、机械与液压共同驱动。在低负荷时,系统可使内燃机以更经济的状态运行;制动时,系统可回收动能并将之转换为液     

两冲程HCCI自由活塞式内燃发电机仿

综合利用Matlab/Simulink、Chemkin、电磁场有限元法对HCCI自由活塞式内燃发电机建立了仿真模型。分析了系统的运动特征,阐明了它与传统内燃机运动规律的差异。讨论了变负荷、燃空当量比下自由活塞式内燃机的变压缩比特性。仿真结果表明,自由活塞式内燃发电机能够根据外部参数调节压缩比,当工作在高压缩比下时,有利于提高燃烧效率、降低内燃机排放。     

两冲程HCCI自由活塞式内燃发电机仿真

综合利用Matlab/Simulink、Chemkin、电磁场有限元法对HCCI自由活塞式内燃发电机建立了仿真模型.分析了系统的运动特征,阐明了它与传统内燃机运动规律的差异.讨论了变负荷、燃空当量比下自由活塞式内燃机的变压缩比特性.仿真结果表明,自由活塞式内燃发电机能够根据外部参数调节压缩比,当工作在高压缩比下时,有利于提高燃烧效率、降低内燃机排放.     

混联型混合动力汽车能量管理策略优

对一种混联型混合动力系统运行工况进行了分析.基于发动机、电机和蓄电池的效率图,建立了混联型混合动力汽车充电工况和放电工况的系统效率模型.放电工况以系统放电效率最大为优化目标,充电工况根据蓄电池荷电状态不同,分别以系统充电效率最大、系统充电效率与充电功率乘积最大为优化目标,对混合动力系统能量管理策略进行了优化研究,获得了汽车在不同运行条件下的发动机、电动机和发电机的最优控制转矩及转速.燃油经济性仿真结果显示,该混合动力系统在NEDC循环工况下的整车燃油消耗降低36.95%.     

汽油机程控可变工作气缸系统的试验研究

车用发动机一般多工作在中小负荷区，而这一部分区域的燃油消耗率比最低燃油消耗率高出许多，为了降低发动机中小负荷的燃油消耗，在汽油机原结构基本不变的基础上，设计了一种通过特制的摇臂组件，采用电磁铁控制滑键来控制气门开启与关闭的装置，对于发动机不同的使用工况，通过控制工作缸数使之处于最佳的节油状态，台架试验结果表明，使用该装置可降低发动机部分负荷燃油消耗率和排放，并可降低怠速排放。     

直喷式柴油机电控涡流进气系统的研究

根据进气涡流对直喷式柴油机燃烧过程和性能的影响规律 ,对直喷式柴油机进气涡流的优化问题进行了研究。利用 80 98单片机、传感器、电磁阀、气缸式控制阀等组成了一个电控涡流进气系统 ,并在 1 1 0 0直喷式柴油机上进行了性能试验 ,结果表明 :采用电控涡流进气系统可使柴油机在每一工况下涡流比均能达到最佳值 ,既能降低NOx排放 ,又能降低燃油消耗率     

Overland water and salt flows in a set of rice paddies

Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m⁻¹) and an infiltration rate of 5.8 mm day⁻¹. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day⁻¹), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day⁻¹ was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration.     

瓦房店市水果生产标准化发展研究

瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。     

金谷子耐旱TG118引种试种及推广应用

对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。     

对《种子法》存在问题的探讨

《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。     

Review of the Egyptian experience in implementing land drainage projects

About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered.     

和谐社会理论建设的几点哲学思考

在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。     

A European irrigation map for spatially distributed agricultural modelling

We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications.     

粉质仪和拉伸仪在面粉生产中的应用

在介绍粉质仪和拉伸仪结构和原理的基础上,探讨了粉质曲线中吸水率、形成时间、稳定时间、弱化度和评价值等指标与面粉品质的关系,以及如何根据拉伸曲线中面团最大拉伸阻力、延伸度和拉伸曲线面积等指标来评价面团品质,并结合生产实际,概述了粉质仪和拉伸仪在面粉生产中的作用。     

农村信息化服务的现状及建设措施

分析当前我国农村信息化服务的现状,提出加强农村信息化服务的新举措。     

车辆ABS控制算法的研究及探讨

对现代汽车的ABS控制算法作了一些简单的介绍,同时指出了它们的一些缺陷,相应地提出了几种对ABS的其它控制方法并加以探讨,其中着重论述了ABS门限值控制算法中参考车速的确定方法和基于附着系数的控制算法。