单卧轴全混日粮混合机的试验

阐述了单卧轴全混日粮混合机主要结构及工作原理.采用二次回归正交旋转组合试验设计对转子转速、混合时间和日粮含水率3个试验因素进行了以混合均匀度、日粮细粉率及单位质量功耗为评价指标的试验研究.得出了其参数的合理组合,即转子转速为55～65 r/min,混合时间为6～10min,日粮含水率为35%左右,充满系数大于0.4.在全混合日粮混合试验中,混合均匀度以变异系数进行评价,并以绿豆为示踪物进行了变异系数分析.试验结果证明该法可行.     

转轮式全混合日粮混合机试验设计与机理分析

为了揭示设计的转轮式全混合日粮混合机的混合机理,将其混合室在空间上平均划分为4个区,并结合高速摄像(1 200帧/s,4G)技术对其混合过程进行深入细致的研究,得出了其混合过程主要是剪切混合、对流混合和扩散混合交替进行的过程,且在混合过程中伴有物料的滑移运动、瀑布运动和涡流运动,并得出转子转速、混合叶板角度、混合时间和充满系数4个因素对混合质量影响较大,依据变异系数评价指标对上述因素进行了试验研究,确定其参数取值范围为:转子转速29~31 r/min,混合叶板角度16°~26°,混合时间10~12 min,充满系数48%~53%,在此范围内变异系数小于10%。     

双轴卧式日粮混合机加工质量影响因素试验

对影响双轴卧式全混合日粮混合机加工质量的主要结构与运动参数、物料特性及装料顺序等因素进行了试验研究.提出了评价全混合日粮混合加工质量的指标--日粮混合均匀度及粒度.通过试验得出了其结构与运动参数、物料的主要特性、物料装料顺序对全混合日粮混合加工质量的影响规律.结果表明,日粮含水率适宜范围为30%～60%,物料的合理装料顺序为作物秸秆、青贮、干草、精料.     

回转式日粮混合机混合机理分析与性能试验优化

针对我国日粮混合机机理研究及自主设计不足的问题,结合我国畜牧业发展的实际需要,设计了一种在筒体内壁安装抄板的回转式日粮混合机,实现日粮的均匀混合。为揭示其混合机理,利用回转式日粮混合试验装置,借助高速摄像技术对其混合过程进行了观察和分析,结果可知:按筒体内物料颗粒群运动特征可将物料分布区域划分为提料区、抛落区、回料区,其中抛落区是主混合区,其物料以剪切混合为主、以扩散与对流混合为辅,且各个区域的位置、大小、形状受结构和运行参数的影响很大;同时,以筒体转速、物料装载率、混合时间、抄板安装角和抄板高度为试验因素,以变异系数、净功耗为评价指标,采用五因素五水平(1/2部分实施)正交旋转组合试验方法进行了性能优化试验,并确定其最佳参数组合为:筒体转速23.5 r/min、物料装载率65%、混合时间4 min、抄板安装角11°、抄板高度109 mm,此时变异系数、净功耗分别为2.09%、33.734 kJ,比优化前分别降低了64.4%和15.1%。     

桨叶式日粮混合机机理分析与参数优化

为了促进全混合日粮(简称日粮)饲喂技术的推广应用,设计了一种桨叶式日粮混合机,并对该混合机进行了性能试验与参数优化。利用桨叶式日粮混合试验装置,对混合室内日粮的混合过程进行分析,将混合室内日粮分布区域划分为积料区、提料区、滑落区和塌落区,各区域混合方式为:积料区与提料区主要发生剪切混合与对流混合,滑落区与塌落区以较强剪切混合与扩散混合为主;以混合时间、转子转速和桨叶安装角为试验因素,以变异系数与净功耗为评价指标,采用三因素五水平二次回归正交旋转组合试验方法进行试验,获得了该机试验因素对混合均匀度及净功耗的影响规律。试验结果表明:在填充率为65%时,最优参数组合为:混合时间5. 3 min、转子转速8. 6 r/min、桨叶安装角34°,对应的变异系数为7. 01%、净功耗为51. 02 k J。该日粮混合机满足日粮的混合要求,性能较优。     

转筒与桨叶组合式日粮混合机设计与试验优化

根据我国推广日粮饲养技术的需要及日粮混合机自主创新研究少的现状,设计了一种由中空正十棱柱状转筒与其主轴上安装的桨叶组合而成的日粮混合机,实现日粮各组分的混合加工。为探究其混合性能,利用转筒与桨叶组合式日粮混合试验装置,以混合时间、填充率、转筒转速、桨叶回转半径为试验因素,以混合均匀度、净功耗为评价指标,采用二次回归正交旋转组合试验设计方法进行试验研究。运用Design-Expert软件建立并优化分析了试验因素与评价指标之间的回归数学模型,对优化结果进行了试验验证。结果表明:各试验因素对混合均匀度的影响由大到小依次为填充率、转筒转速、混合时间、桨叶回转半径;各试验因素对净功耗的影响由大到小依次为混合时间、转筒转速、填充率、桨叶回转半径;最佳参数组合方案为混合时间3.5 min、填充率66%、转筒转速29 r/min和桨叶回转半径236 mm,对应的混合均匀度为92.98%、净功耗为32.618 k J,比优化前分别降低了5.04%、3.31%。     

全混合日粮制备机优化及粗饲料粒度试验

对高效全混合日粮制备机主要部件进行优化设计。基于该样机采取二次正交旋转组合试验设计,以搅龙转速、混合时间、填充系数为影响因素,以粗饲料粒度为响应指标,运用Design-Expert软件对试验数据进行响应面分析和方差分析,得出对粗饲料粒度的影响程度由大到小为混合时间、搅龙转速、填充系数,在搅龙转速50.0 r/min、混合时间20.0 min、填充系数61.89%的条件下,粗饲料粒度可达70.1%。     

双轴卧式全混合日粮混合机的混合机理分析

根据我国畜牧业的实际需要,研究开发了双轴卧式全混合日粮混合机,介绍了该机的主要结构与工作原理。为了深入研究其混合机理,采用高速摄像机(1200帧/s,4G)进行了混合过程的摄像研究,并结合理论分析对双轴卧式全混合日粮混合机理进行了深入分析,得出了其主要的混合方式。     

国内TMR混合机研究现状分析

目前规模化养殖模式正逐渐替代传统养殖模式,成为我国未来养殖产业的主要模式。全混合日粮(TMR)饲养技术是保证规模化养殖健康发展的先进技术,其加工的主体设备是TMR混合机。本文重点介绍了国内目前TMR饲喂装备的研究现状,分析了当前研究成果的局限性,为后续TMR饲喂装备研发提供了指导建议。     

自走式全混合日粮制备机取料仿真与参数优化

针对国内自走式全混合日粮制备机缺乏取料机理和参数优化的现状,对自走式全混合日粮制备机的取料机构进行设计与分析,建立了取料作业的理论模型,并对螺旋叶片螺距、螺旋叶片直径、辊筒转速、前进速度、每刃进给量和取料刃长比等关键参数进行了计算和选取。采用EDEM对影响取料过程的前进速度、辊筒转速、螺旋叶片螺距、刀刃长比因素采用正交试验方案进行了仿真分析,并对仿真结果进行方差分析。分析表明,各因素对取料效率影响的主次顺序为：前进速度、螺旋叶片螺距、刀刃长比、辊筒转速,各因素对回流率影响的主次顺序为：螺旋叶片螺距、刀刃长比、辊筒转速、前进速度。综合考虑取料效率和回流率,最优参数组合为前进速度为4 m/min、螺旋叶片螺距230 mm、取料刀刃长比1.8、取料辊筒转速230 r/min。此时取料效率为82.6 m3/h,回流率为38.93%。采用最优参数组合进行试验,试验测得取料效率为77.02 m3/h,回流率为39.76%,与仿真分析基本一致。     

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。