锤击式破碎机的结构及主要参数设计

锤击式破碎机是一种粉碎设备,适用于农作物的秸秆、根茎、饲料用的骨头、贝壳以及焦渣等硬度物料的破碎,并可调节破碎粒度,具有生产效率高、能耗小、使用安全、维修方便等优点,在农业、畜牧业等行业应用广泛.为了使锤击式破碎机在标准化、通用化、系列化方面更趋完善,对影响锤击式破碎机性能和加工质量等方面的因素进行了分析、研究和探讨,使其不但在结构和功能上合理,且有利于环境保护.     

面向黑水虻转化的厨余垃圾破碎机设计与模态分析

针对厨余垃圾急剧增加的问题,无害化、资源化处理的垃圾处理方法成为研究的热点。黑水虻转化是一种高效绿色的厨余垃圾处理方式,传统厨余垃圾破碎机的破碎效果不能满足黑水虻幼虫进食粒径的要求。因此,文章针对黑水虻幼虫养殖饲料破碎粒径的需求,设计了一款单电机驱动的双齿辊破碎机,并对其关键零部件进行模态分析,证明其结构可靠。     

土壤破碎机的设计与有限元分析

针对用于烟苗种植的破膜覆土机,设计开发一款小型土壤破碎机。对小型破碎机的最大破碎能力进行计算同时对破碎齿进行受力分析,验证其满足各项工作要求。使用ANSYS Workbench软件对整个破碎辊进行静力学和模态分析,证明其结构满足各项要求,可应用于生产实践,对破膜覆土机的整机研发提供参考。     

立轴冲击式破碎机主抛料头载荷研究

转子是立轴冲击式破碎机的主要工作部件,而主抛料头是转子上磨损最为严重的零部件,通过分析立轴冲击式破碎机结构和工作原理的基础上,进行了转子的Solid Works三维建模.通过将模型导入ADAMS中进行动力学仿真,模拟破碎机在运转中物料的抛出过程,得到了转子上主抛料头随转速的不同变化所受最大冲击力和平均冲击力.仿真分析表明,转速是影响立轴冲击破碎机破碎质量和效率的重要因素,但破碎效果不总是随着转速的提高而提高.还会加剧主抛料头的磨损;1400-1500r/min以及1600-1750r/min是主抛料头受力均衡,转子能获得平稳运转的转速区间;此外,为了全面兼顾破碎机的破碎质量、效率以及使用寿命,降低最大冲击力的值和频率是至关重要的,因此既需要考虑转子结构及相关参数的优化,还要分析进料粒度均匀性的影响.     

八爪式株间机械除草装置虚拟设计与运动仿

设计了一种适合作物株间作业的八爪式机械除草装置,采用Pro/E进行了虚拟样机设计,建立了除草装置的装配模型,利用ADAMS软件对该装置进行运动学仿真,得出在不同速比下的除草铲齿运动轨迹,通过计算得到除草铲齿与土壤接触部分的面积,并对每个铲齿的覆盖区域以及相邻铲齿覆盖的重合区域进行分析,确定的合理速比为λ=0.754,优化了装置的结构和运动参数.     

大豆播种机破碎式仿生覆土装置设计与试验

受东方蝼蛄刺状挖掘足能够高效挖掘土壤的启发,设计了大豆播种机破碎式覆土装置,以提高其碎土性能。对东方蝼蛄前足的趾爪趾长、趾尖角、趾间距、侧面的楔角进行测量,以此为依据设计了仿生碎土圆盘。破碎式仿生覆土装置由大小碎土圆盘、折弯法兰、固定机架、旋转副、减震弹簧和悬挂架组成。本覆土装置专为双行种子沟设计,可实现对大豆沟槽双侧进行覆土。对仿生碎土圆盘碎土齿进行了受力分析,并利用Ansys及Ls-Dyna软件对所设计部件进行仿真优化分析,得到碎土圆盘切削受力情况土壤的等效应力分布以及覆土过程中种子横向位移。田间试验结果表明破碎式仿生覆土装置完成了覆土功能要求,破碎率达到92.2%,平均覆土厚度为2.4 cm,平均种子行间距为10.1 cm。     

新型板齿式双纵轴流脱粒滚筒在籽粒收获机上的应用

本文介绍了新型板齿式双纵轴流脱粒滚筒装置的结构组成、技术特点以及在牧神籽粒收获机上的应用及试验情况。     

水稻不同脱粒装置脱粒性能的对比试验研究

为了提高水稻联合收获机的工作效率,降低功耗,减轻清选负荷,自行研制了板齿和杆齿作为水稻脱粒的主要元件,分别与栅格凹板组成不同的脱粒分离装置,并对这两种脱粒分离装置进行了脱粒对比台架试验.试验结果表明,杆齿-栅格凹板脱粒分离装置在脱粒水稻时对茎秆的破碎程度轻、功耗低、脱出混合物中轻杂物含量少,能够有效地减轻清选负荷.     

高速精量播种机阿基米德螺线型弧面双齿盘覆土装置设计与试验

针对现有重型精量播种机在高速作业时存在覆土装置影响播种均匀性、种沟内种子被“架空”等问题,基于阿基米德螺线切刃曲线与挤压式覆土原理相结合的思路,设计了一种阿基米德螺线型弧面双齿盘覆土装置,实现了覆土厚度适宜且均匀一致,降低覆土作业对播种均匀性影响的目的。本研究对覆土装置的结构参数、覆土量进行分析,确定了影响覆土效果的主要参数取值范围;利用EDEM离散元仿真技术建立了覆土装置-种子-土壤间的离散元模型,对关键参数进行仿真优化,确定弧面双齿盘的最优参数组合;通过田间试验对该装置的作业性能进行了验证。研究结果表明：影响弧面双齿盘作业性能的主要结构参数为阿基米德螺线型弧面双齿盘的中心间距、安装倾角、入土深度。当弧面双齿盘的中心间距为142.6mm、安装倾角为20°、入土深度为55mm时,该装置通过性能良好,覆土厚度均匀一致,平均厚度为47mm,合格粒距标准差、变异系数与空白对照组分别相差0.22mm、1.81个百分点,对播种均匀性影响小,满足精量播种的农艺要求。     

双曲柄外齿环板减速传动的研究

针对目前环式减速传动在使用过程中存在振动大、噪声高等问题,提出一种由一级渐开线传动和一级N型少齿差外环式传动组合而成的双曲柄外齿环板减速传动,不仅保留了现有环式传动的优点,还具有体积更小、传动比更大、刚度更高等特点.本文对双曲柄外齿环板减速传动的结构形式、传动原理进行了分析,对其传动比进行了计算,研究了该传动的功率流,推导出各构件角速度关系和力矩平衡方程,计算了该传动的传动效率可达91.9%.     

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。