基于Abaqus的耦合式玉米秸秆皮穰分离仿真与试验

为提高玉米秸秆皮穰分离率、推进秸秆高值化利用进程,采用Abaqus/Explicit动力学显式求解器和中心差分求解法对异向碾压和异向碾压锤切2种耦合式皮穰分离方法进行模拟分析,确定最佳耦合分离方式为异向碾压锤切耦合作用进而试制秸秆异向碾压锤切皮穰分离试验台,并确定最佳工作与结构参数。以刀盘转速、碾压揭皮辊转速和刀片滑切角为试验因素,以秸秆皮穰分离率为试验指标,通过三元二次正交回归组合试验对分离试验台进行参数优化利用Design-Expert进行数据分析建立因素与指标间数学模型。试验表明:在刀盘转速为449 r/min、碾压揭皮辊转速为226 r/min、刀片滑切角为46°的最优工作参数组合下,皮穰分离率为88%,分离后的皮穰呈段状,满足实际生产需求。     

螺旋齿辊式秸秆调质装置性能试验

利用所研制的螺旋齿辊式秸秆调质装置试验台,采用调质齿辊差速转动方式对摘穗后玉米秸秆进行压裂、破节的连续调质正交试验,分析了调质齿辊工作间隙、调质齿辊转速及秸秆喂入速度对秸秆调质性能的影响.试验结果表明,调质齿辊工作间隙对秸秆调质作业性能影响显著,最优参数组合为调质齿辊工作间隙2 mm,调质齿辊转速65 r/min,秸秆喂入速度4 km/h.     

玉米秸秆皮穰分离机剥叶机构的试验研究

为提高玉米秸秆的利用价值,进行玉米秸秆皮、穰、叶分离加工非常有必要。为此,对茎叶分离的关键机构—剥叶机构进行了试验研究。依据自行设计的剥叶试验装置,选取影响剥叶效果的主要因素喂入速度、剥叶辊转速、剥叶板间隙、剥叶板夹角为试验因素,以剥叶率为试验评价指标,采用四因子二次回归正交旋转组合设计方法,建立了4个试验因素对剥叶率的影响规律模型。综合考虑各影响因素,确定最佳参数组合为:喂入速度1 m/s、剥叶辊转速1 000 r/min、剥叶板间隙24 mm、剥叶板夹角15°。     

玉米秸秆皮瓤叶分离机械皮瓤分离机理研究

为了研究玉米秸杆皮瓤叶分离机械的皮瓤分离机构的工作过程和工作原理,利用自行设计的皮瓤叶分离机械实验台,对玉米秸杆皮瓤叶分离过程中的皮瓤分离机理进行了研究。研究的内容主要包括皮瓤分离过程分析、皮瓤分离过程的受力分析和皮瓤分离过程的运动分析。通过研究,确定玉米秸秆皮瓤分离全过程为3个阶段,即展压阶段、接触剥瓤阶段和抛瓤阶段。由受力分析可知,当剖瓤辊转速增加时,切刀对秸瓤的作用力增加;由运动分析可知,剖瓤辊旋转1周,每把切刀对秸秆的作用距离与切刀和支持底板的距离有关。以上结论为研制高效的玉米秸秆皮瓤叶分离机械奠定了理论基础。     

玉米秸秆皮颗粒燃料耐久性能试验与工艺优化

为研究原料特性和设备关键机构运动因素对生物质颗粒燃料耐久性能的影响规律及其最佳因素参数组合,以玉米秸秆皮为原料,利用平模成型机对其进行压缩成型试验。以含水率、模辊间隙、主轴转速为试验因素,以抗破碎性为评价指标,采用Box-Benhnken法进行三因素三水平响应面试验设计;借助Design—Expert 8.0.6软件进行回归分析和响应面分析,建立并分析了各试验因素与抗破碎性之间的数学模型。结果表明,对抗破碎性影响程度的大小顺序为:含水率主轴转速模辊间隙;在含水率为15%、模辊间隙为0.3mm、主轴转速为196r/min条件下,玉米秸秆皮颗粒燃料的抗破碎性为94.9%。     

青贮玉米饲料籽粒破碎试验台设计与试验

为研究青贮玉米籽粒破碎机理,采用理论计算、三维建模和性能试验相结合的方法,设计喂入速度、破碎辊转速和对辊间隙等参数可调的青贮玉米饲料籽粒破碎试验台,主要工作部件包括喂入碾压机构、切碎滚筒装置和对辊式籽粒破碎装置,可对全株青贮玉米一次性完成秸秆传送、喂入压平、切碎抛送和籽粒破碎等工作流程。试验结果表明:当喂入速度为2 m/s、上破碎辊主轴转速为2 600 r/min时,秸秆切碎长度为21.79 mm,切碎长度合格率为95.9%,籽粒破碎率为96.3%,各项指标均符合国家标准和行业标准要求,可为籽粒破碎装置的设计提供理论依据和技术参考。     

卧辊式玉米秸秆调质装置调质功耗试验

为研究卧辊式玉米秸秆调质装置作业参数影响功耗的规律,利用自主研制的秸秆调质装置试验台和功率测控系统,基于电功率差值法对摘穗后玉米秸秆进行压裂、破节的连续调质正交试验,分析了调质辊工作间隙、调质辊转速及秸秆喂入速度对秸秆调质功耗的影响.结果表明:调质间隙对秸秆调质功耗影响显著;参数组合为调质间隙2.5mm、调质辊转速88～95 r/min、秸秆喂入速度3.3 ～ 4.0 km/h时,满足秸秆调质性能和降低功耗的要求.     

籽瓜破碎取籽分离机的试验研究

为满足籽瓜加工生产线对预处理加工的要求,对自主研制的QW-QZ-2型籽瓜破碎取籽分离机的破碎分离效果进行了试验研究。以喂入量、破碎辊转速、皮瓤分离辊转速、籽瓤分离辊转速为试验因素,以瓜籽含杂率、瓜籽破损率、瓜籽损失率和皮中含瓤率为试验指标,进行单因素试验。试验结果表明:适宜的工作参数范围为:喂入量25～30 kg/min、破碎辊转速120～135 r/min、皮瓤分离辊转速90～105 r/min、籽瓤分离辊转速105～120 r/min;影响瓜籽含杂率的主次因素依次为:皮瓤分离辊转速、籽瓤分离辊转速、破碎辊转速和喂入量;影响瓜籽破损率的主次因素依次为:皮瓤分离辊转速、籽瓤分离辊转速、喂入量和破碎辊转速;影响瓜籽损失率和皮中含瓤率的主次因素依次为:皮瓤分离辊转速、破碎辊转速和喂入量。该研究可为籽瓜破碎取籽分离机的设计和工作参数的优化提供理论依据。     

纵轴流辊式组合玉米柔性脱粒分离装置设计与试验

为满足黄淮海地区较高含水率玉米籽粒直收作业要求,解决现有籽粒收获机籽粒破碎率和未脱净率高、玉米芯轴苞叶易堵塞凹板等问题,在分析现有脱粒装置结构特点的基础上,设计了一种“柔性钉齿+双扭簧压力短纹杆”组合式脱粒元件和“六棱孔网格筛+鱼鳞式脱粒橡胶辊”组合式脱粒凹板相配合的柔性脱粒分离装置。对关键部件进行理论分析,确定了影响脱粒性能的主要因素,利用搭建的纵轴流辊式组合玉米柔性脱粒试验台进行单因素试验,得到脱粒性能较好时滚筒转速、辊筒传动比以及脱粒间隙的变化范围。以滚筒转速、辊筒传动比和脱粒间隙为试验因素,以籽粒破碎率、未脱净率为指标进行三因素三水平正交试验。结果表明,对籽粒破碎率和未脱净率影响由大到小均为滚筒转速、辊筒传动比、脱粒间隙;最优参数组合为滚筒转速475r/min、辊筒传动比1.5、脱粒间隙45mm,此时籽粒破碎率为3.76%,未脱净率为0.52%。对该组合进行试验验证,各指标符合国家相关标准要求。     

甘蔗收获机切段装置设计与试验

针对甘蔗收获机切段装置存在的切段机理理论缺乏、切段损失大、对切段装置要求多样化等现状,对比分析了切段装置前置式、中置式、后置式3种形式的收获流程,并基于对前置切段式结构的理论分析,推导前置切段式切段长度的经验公式,设计了切段装置试验台和切段装置前置式收获机割台。进行了切段过程高速摄影试验,获知蔗段在切段过程中的运动规律、蔗叶与蔗茎的分离形式、断口糖分损失的主要形式及原因,通过田间正交试验确定了影响蔗段合格率因素主次顺序为:交错深度、行驶速度、切段辊转速,当交错深度为4 mm,行驶速度为2 km/h,切段辊转速为300 r/min时,割台蔗茎合格率达到93%。通过统计学分析计算,得出了长度系数为0.7,其长度分布近似符合正态分布规律。     

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。