秸秆粉碎机工艺参数对粉碎效果影响研究

为提高秸秆粉碎机的生产效率,探究秸秆粉碎机工艺参数对粉碎效果的影响规律,以玉米秸秆(含水率1 4%)为原料,采用二次旋转组合试验,研究秸秆粉碎机的转速、动定刀间隙及动刀间距对粉碎效率及能耗的影响规律,并用Design-Expert软件处理试验数据,建立了各工艺参数对粉碎效果影响规律的数学模型,经检验效果显著。结果表明:优化的参数组合为转速500r/min、动定刀间隙17mm、动刀间距20mm,在此参数条件下粉碎合格率达90%,度电产量达到37.12kg。     

揉碎机轴向喂入性能试验研究

在9R-40型秸秆揉碎机的基础上设计安装轴向喂入装置,通过改变揉碎机主轴转速进行了样机性能对比试验.试验结果表明:主轴转速为2980～2750r/min时,原机比轴向喂入样机生产率高;主轴转速为2515～2280r/min时,轴向喂入样机比原机生产率高.主轴转速为2980～2750r/min时,度电产量差别不大;主轴转速为2515～2280r/min时,轴向样机比原机度电产量高.原机揉碎度高于轴向样机揉碎度.主轴转速对轴向喂入样机的生产率和度电产量影响有明显差异:生产率在主轴转速为2980r/min时最高,为661 87kg/h;度电产量在主轴转速为2280r/min时最高,为160.49kg/kW·h.     

盘刀式铡草机抛送性能试验研究

针对盘刀式铡草机存在的生产率低、功耗大、易堵塞等问题,以玉米秸秆为试验材料,选取不同的主轴转速、叶片倾角和秸秆含水率作为试验因素进行抛送性能试验研究。试验结果表明:各因素对抛送过程生产率影响的主次顺序为主轴转速>叶片倾角>秸秆含水率;对抛送过程功耗影响的主次顺序为主轴转速>秸秆含水率>叶片倾角。当叶片倾角为7°、主轴转速为650r/min、秸秆含水率为22.1%时,抛送过程生产率最高;当叶片倾角为11°、铡草机主轴转速为510r/min、秸秆含水率为27.3%时,抛送过程功率消耗最低;同时,得到了可用于预测铡草机抛送过程生产率和功率消耗的线性回归模型。     

盘刀式铡草机切割性能仿真分析与试验研究

针对盘刀式铡草机存在生产率低、功耗高的问题,对铡草机切割器的切割性能进行仿真与试验研究。以铡草机的主轴转速、动定刀间隙、秸秆含水率及动刀圆弧度作为试验因素,切割功耗为评价指标进行切割性能研究。利用ANSYS LS-DYNA仿真软件对铡草机切割玉米秸秆过程进行动态仿真试验分析,并结合物理试验验证模型的准确性。通过单因素仿真试验得出含水率、动定刀间隙和主轴转速为影响铡草机切割功耗的主要因素。在此基础上,通过Box-Behnken试验得出各因素对切割功耗影响的主次顺序为含水率>动定刀间隙>主轴转速。对回归方程寻优求解得到玉米秸秆切割过程中功耗最低的较优参数组合,即主轴转速600r/min、动定刀间隙1.5mm、含水率53.5%。研究结果可为研究铡草机的整机功耗提供数据支持,进而为实现铡草机性能改进提供依据。     

梯形筛片对锤片式粉碎机性能影响的试验研究

锤片式粉碎机虽然在饲料加工业和食品行业等被广泛应用,但其普遍存在功耗高、度电产量低等问题。为了提高锤片式粉碎机的生产率和度电产量,设计了一种新型筛片—梯形筛片来替代环形平筛,从而破坏粉碎室内环流层,增大筛理面积,并进行了4因素6水平均匀设计试验。试验结果表明,使用梯形筛片可以改善锤片式粉碎机的性能;当筛片参数组合为梯形底角为70°、高度7mm、下底长80m和间距10mm时,锤片式粉碎机生产率和度电产量最高。     

锤片式粉碎机工作参数优化试验研究

为解决锤片式粉碎机工作效率低、能耗高等问题,对其工作参数进行响应面优化设计。首先进行粉碎机最佳工作参数组合的优化试验,分析主轴速度、回料管直径、喂料速率、筛网孔径及物料含水率对生产率、电耗和粒度的影响规律。然后对试验数据进行响应面设计分析,求解出最优组合并进行试验验证。试验结果表明,粉碎机的最优工作参数组合为：主轴转速2 700 r/min、回料管直径57 mm、喂料速率0.25 kg/s、物料含水率10%和筛网孔径6 mm。对比单因素最优的评价指标,生产率提高4.36%,电耗下降3.23%,粒度减小23.21%。     

无线局域网络技术在田间秸秆粉碎功耗测试中的应用

将无线局域网络技术引入玉米秸秆粉碎机的田间粉碎测试中,实现了对玉米秸秆田间粉碎功耗的无线遥测,田间测试试验证明该无线局域网络测试系统安全方便.同时通过回归正交试验方法获得当机车前进速度为2.9 km/h,刀辊转速为597 r/min时.秸秆粉碎性能最佳工作指标为粉碎功耗2.98 kW,粉碎合格率90.017%.     

农作物秸秆多功能粉碎机的试验研究

在分析多功能秸秆粉碎机技术原理的基础上,利用稻草、麦秸、油菜秆、花生壳、玉米秸秆等原料,分别对秸秆原料粉碎前后的含水率、原料和成品容重、空载转速、空载功率、负荷转速、生产率、吨料电耗等技术性能进行了试验研究,通过研究得知,多功能秸秆粉碎机性能好,适应性广,吨料能耗低,生产率稳定,是用于农作物秸秆粉碎的理想机械。     

新型棉秸秆揉丝粉碎机的结构设计及优化

棉秸秆的综合利用越来越得到人们的重视。棉秸秆利用的重要一个环节就是粉碎。目前锤片式秸秆粉碎机是应用较为广泛的一种秸秆粉碎机,但是影响秸秆粉碎机的参数很多,其中刀轴的转速及锤片的数量等对其性能有很大影响。为此在理论设计分析的基础上,通过场地粉碎试验两者相结合,得到棉秸秆粉碎机的最优参数组合,为棉秸秆揉丝粉碎机的设计提供理论基础,为棉秸秆的综合利用奠定基础。     

玉米秸秆机械化粉碎还田影响因素研究

以玉米秸秆含水率与秸秆力学特性相互关系为基础,采用正交试验法,研究了秸秆含水率、还田机刀型、刀轴转速对玉米秸秆粉碎特性的影响。结果表明:随秸秆含水率的增加,秸秆抗剪强度减小,当含水率大于30%时,抗剪强度随含水率的增加变化不显著;秸秆含水率为20%是秸秆抗拉强度拐点,大于20%时抗拉强度随秸秆含水率增加而增大,低于20%时抗拉强度受秸秆含水率影响不显著;秸秆含水率、还田机刀型、刀轴转速对秸秆粉碎长度合格率均有显著性影响,秸秆含水率和刀轴转速大于刀型;秸秆含水率、还田机刀型、刀轴转速对机具功耗均有显著性影响,刀轴转速刀型秸秆含水率。在实际生产中,建议在玉米收获后尽早进行粉碎,还田机刀型应优先选择Y型或L型,刀轴转速选择1 800r/min左右最优。本研究为选择合理的秸秆粉碎模式提供了理论基础     

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。