条带式旋切后抛防堵装置设计与试验

针对我国华北平原一年两熟区玉米秸秆覆盖地小麦少免耕播种机易堵塞、动力防堵装置功耗大等问题,设计了一种条带式旋切后抛防堵装置。结合防堵装置工作原理,从秸秆流动、抛撒、防堵装置受力角度分析确定影响防堵性能和功耗的关键因素为:防堵装置与开沟器间距、旋切刀滑切角、刀轴转速;通过离散元模拟仿真与正交试验有限元仿真结合,以秸秆拥堵量和作业功耗为性能评价指标,对防堵单体和开沟器的组合装置进行参数优化,仿真结果表明,旋切刀滑切角为50°、刀轴转速为320 r/min、间距为100 mm时综合作业质量较优,防堵单体及开沟器功耗为2.8 k W,秸秆拥堵量为43根/dm,通过性能良好;对优选方案旋切刀进行有限元校核,其最大应力为1.387×108Pa,满足强度要求。在玉米秸秆覆盖地进行了小麦播种田间试验,结果表明,条带式旋切后抛防堵装置在3种秸秆覆盖量0.8、1.6、2.4 kg/m2和3种前进速度1、1.25、1.5 m/s作业条件下,通过性能均满足免耕施肥播种机国标要求,所设计旋切刀与传统旋耕刀相比,在通过性能基本一致的情况下,功耗减小13.83%,土壤扰动量减小37.5个百分点,沟深稳定性系数提高8.2个百分点。     

大垄玉米原茬地免耕播种机防堵装置设计与优化试验

为解决北方寒区玉米机收秸秆粉碎覆盖大垄原茬地免耕播种时易发生堵塞及地温回升较慢的问题,设计了一种大垄玉米原茬地免耕播种机的防堵装置。通过理论分析,设计了防堵装置关键部件,初步得到了该装置的结构和作业参数。应用三因素三水平正交试验方法和模糊综合评价分析法,以机组作业速度、清秸刀齿总成转速、清秸刀齿总成回转轴垂直面与机具前进方向的夹角为试验因素,以根茬清除率、秸秆清除率、防堵装置当量功耗为评价指标,对影响防堵装置性能的结构与作业参数进行了试验与优化研究。结果表明:在试验条件和试验因素水平范围内,影响多目标函数的参数优化组合为机组作业速度5.4 km/h、清秸刀齿总成转速440 r/min、清秸刀齿总成回转轴垂直面与机具前进方向的夹角20°,此时,根茬清除率为93.94%,秸秆清除率为95.39%,防堵装置当量功耗为4.36 k W,土壤扰动量为31.9%。     

滴灌区宽窄行玉米免耕播种带秸秆清理装置设计与试验

针对在滴灌区进行玉米免耕播种作业时,窄行内铺设的滴灌带与秸秆残茬易缠绕形成壅堵、影响播种机具通过性和作业质量等问题,提出适用于滴灌区宽窄行玉米免耕播种带的秸秆清理方法。设计了播种带秸秆残茬分区清理装置,该装置通过纵向错位布置拨草机构对播种带秸秆进行清理,对清理装置作业过程和秸秆抛撒轨迹进行了分析,确定了关键影响因素及参数取值范围;运用EDEM离散元仿真技术,以机具作业速度、入土深度和纵向间距为试验因素,以播种带秸秆清理率为评价指标进行了回归正交仿真试验,建立了响应面数学模型,并进行了参数优化和田间验证试验。结果表明,影响播种带秸秆清理率因素显著性由大到小依次为机具作业速度、纵向间距和入土深度;当作业速度为9km/h、纵向间距为1100mm、入土深度为45mm时,装置作业通过性良好,播种带秸秆残茬清理率均值为87.61%,比模型优化理论值低1.8个百分点,播种带清理宽度为508.0~540.4mm,满足滴灌区玉米免耕播种的农艺要求。     

2BMFJ-3型麦茬地免耕精播机防堵装置

针对黄淮海一年两熟地区小麦机收后地表残留的秸秆量大且根茬过高,致使免耕播种下茬作物时易发生堵塞的现象,设计了一种用于麦茬地免耕精播机的防堵装置。为确定该装置合理的结构与作业参数,采用三因素三水平正交试验方法进行了优化试验,得到最优参数组合:机组作业速度4.5 km/h、清秸覆秸刀齿排布4-3-4、刀轴转速400 r/min。田间试验结果表明,当清秸覆秸刀齿切茬深度为20～30 mm时,防堵装置土壤扰动量为63%～76%,防堵效果好,能够创造良好的种床,提高播种质量。     

螺旋切分式种带清理装置设计与试验

针对东北地区免耕播种时易出现秸秆堵塞等问题,本研究设计一种螺旋切分式种带清理装置。通过理论分析,确定了清茬刀的排布方式和清茬刀刃口曲线参数,并得到影响种带清理效果的主要因素：拖拉机前进速度、螺旋切分式种带清理装置转速和螺距。在离散元软件EDEM中建立螺旋切分式种带清理装置仿真模型,以种带清秸率为试验指标,以前进速度、转速和螺距为试验因素,进行了二次回归组合仿真试验,建立了种带清秸率的回归模型,结果表明,前进速度、转速和螺距对种带清秸率影响极显著(P<0.01),其中转速影响最为显著。利用Design-Expert软件对影响因素进行优化求解,得到最优参数组合为：前进速度2m/s、转速400r/min、螺距570mm,最佳组合下种带清秸率为92.55%。在最优参数下进行了田间验证试验,试验种带清洁率比仿真减少了约2.89个百分点,基本满足玉米免耕播种的要求。该研究为东北地区免耕播种机秸秆清理与防堵装置的研究提供了参考。     

少免耕播种机条带型行间侧抛清秸防堵装置研究

针对我国华北平原一年两熟区玉米秸秆覆盖地小麦少免耕播种机作业时存在易堵塞、种床清洁率低等问题,设计了一种条带型行间侧抛清秸防堵装置。对清秸防堵装置工作时秸秆抛撒特性进行理论分析,明确影响清秸效果的关键因素为侧倾刀弯折角、弯折线夹角和回转半径。以作业扭矩、抛土量和种床清洁率为指标,通过离散元仿真并结合旋转正交回归试验,确定了清秸防堵装置较优参数组合为侧倾刀弯折角25°、弯折线夹角30°、回转半径250mm,此时种床清洁率为80.5%、作业扭矩为47.2N·m、抛土率为15.8%。配合清秸防堵装置,分别设计了一沟双行种肥分施开沟器、V型土壤导流板等部件。其中种肥分施开沟器前方装有定刀,可与防堵装置形成动定刀切割,提高了防堵性能;V型土壤导流板夹角为130°,可将抛起的土壤颗粒反弹回种床,增加了回土量。田间播种试验表明,所设计的行间侧抛清秸防堵装置未发生堵〖JP3〗塞和缠草现象,种床清洁率为82.7%,作业扭矩为2982N·m,作业质量稳定,满足少免耕播种作业国标和农艺要求。     

前置式大垄原茬地种床整备装置设计与试验

为解决东北寒区部分播种机在秸秆重度覆盖还田地区无法正常播种作业问题,基于2BMFJ-DL4型原茬地免耕精量播种机侧向清秸覆秸原理,结合玉米大豆1.1m大垄轮作宽窄行种植模式,设计了一种前置式原茬地种床整备装置。通过理论分析和计算机仿真,设计了装置结构和液压系统,确定了其作业关键参数范围,液压系统分析结果表明,液压悬挂系统和液压驱动系统各执行元件的同步性能、转速和扭矩均满足作业技术要求。应用Design-Expert 8.0.6软件和三因素三水平正交试验方法,以作业速度、种床整备单元组刀轴转速和种床整备刀齿入土深度为试验因素,以清秸率、覆秸均匀度和每个种床整备单元组刀轴旋转功耗为评价指标,实施参数组合优化田间试验。结果表明,在参数组合为作业速度7.2km/h、种床整备单元组刀轴转速600r/min、种床整备刀齿入土深度30mm时,清秸率为91.03%,覆秸均匀度为92.61%,每个种床整备单元组刀轴旋转功耗为7.96kW,性能满足生产农艺技术要求;研究结果为提高播种机利用率和原茬地免耕覆秸播种机械化技术模式在玉米秸秆全量还田地区的推广应用提供了技术支持。     

免耕播种机浅旋清茬斜置式防堵装置设计与试验

针对黄淮海地区玉米免耕播种作业时,过量小麦秸秆残茬堵塞开沟器的问题,提出一种以拨离残茬和浅旋根茬形式实现苗床清整的斜置式防堵装置。通过理论分析对防堵装置结构参数进行设计,确定了各参数的范围和相互关系,并根据装置结构对耕刀拨茬入土和脱茬离土的过程进行受力分析,确定了影响工作性能的因素。运用离散元方法模拟防堵装置在田间作业过程,以秸秆清除率、土壤扰动系数和功耗为评价指标,对装置倾角、转速和前进速度进行回归分析和显著性检验,确定了各因素对评价指标的影响及主次顺序。通过对回归模型进行多目标函数优化求解,得到最优参数组合为：转速400r/min、前进速度6km/h、倾角18.5°,此时秸秆清除率为74.5%、土壤扰动系数为34.7%、功耗为1.36kW。以优化得到的参数对装置进行土槽试验,试验结果表明：转速为400r/min、前进速度6km/h、倾角18.5°时,秸秆清除率为92.5%、土壤扰动系数为29.6%、功耗为1.51kW,试验结果与仿真试验优化结果相吻合,满足设计要求。     

油菜精量联合直播机覆秸装置设计与试验

在长江中下游稻油轮作区,前茬水稻机收后秸秆全量留田,当接茬进行油菜精量联合直播作业时,浮秸易缠绕直播机触土部件,造成机具堵塞、种子落在秸秆上难以出苗等问题。为此,结合油菜覆草种植农艺措施,提出适于油菜直播水稻秸秆覆盖还田的机械化作业方案,设计了一种与油菜精量联合直播机配套的覆秸装置。通过理论分析,确定了覆秸装置关键环节工作部件的结构参数、安装位置与安装角及工作转速范围。控制秸秆喂入量分别为0.9、1.1、1.3kg/s,进行性能测试试验,验证了理论分析确定的各部件工作转速的适宜性和秸秆输送顺畅稳定性,结果表明,当播种覆秸作业机组配套69.9kW拖拉机、前进速度0.7m/s、捡拾装置滚筒转速80r/min、集秸装置螺旋输送器转速270r/min和链式提升装置转速270r/min时,机具作业顺畅,秸秆捡拾率达到90%以上。控制均匀铺放装置转速分别为210、240、270、300、330r/min,当转速为300r/min时,秸秆覆盖均匀率最高,超过92%。田间试验表明,覆秸直播机秸秆通过性能良好,各环节工作部件作业稳定,各项设计指标均满足技术标准要求,设计的覆秸装置与油菜精量联合直播机集成,一次作业可完成水稻浮秸的捡拾、堆集、输送、覆盖以及旋耕整地、开畦沟、施肥、油菜播种等工序,适宜在水稻机收后秸秆未作任何处理的稻茬田作业。     

全秸硬茬地碎秸行间集覆小麦播种机设计与试验

针对我国稻麦轮作区常规稻茬麦机械化播种时存在田间稻秸量大、耗工耗时和播期延误等问题,提出了全量碎秸行间集覆、洁区种带宽幅播种的技术思路,设计了一种全秸硬茬地碎秸行间集覆小麦播种机,该机能一次性完成碎秸清秸、行间覆秸、种带施肥旋耕、播种镇压等工序,适宜在稻收后未作任何秸秆移出及耕整地处理的全秸硬茬地作业。对秸秆粉碎装置、碎秸导流装置和种带旋耕装置等关键部件进行了理论分析,确定了相关结构与参数;为在种带内高质、顺畅、满播小麦,设计了播种及镇压装置;以粉碎刀辊转速、径向距离和作业速度为试验影响因素,以清秸率和种带宽度变异系数为评价指标,设计了三水平三因素正交试验。结果表明,工作参数为粉碎刀辊转速2200r/min、径向距离20mm、作业速度0.8m/s和旋耕刀辊转速300r/min时,对应田间试验的碎秸平均长度为110mm、平均碎秸合格率为91.47%、平均种带清秸率为92.58%、平均种带宽度变异系数为10.91%、平均播深为41mm、平均播深合格率为97.32%;长势跟踪及测产结果表明,与常规播种方式相比,未出现明显缺苗弱苗现象,两种播种方式的产量基本相同。     

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。