基于LabVIEW的蟹苗培育监控系统研究

中华绒螯蟹的蟹苗对其培育过程中的水质环境要求较高。为提高蟹苗成活率,实现精细化养殖,提高蟹苗质量,本文设计了室内中华绒螯蟹苗的培育生长环境监控系统。该控制系统以pH传感器、溶解氧传感器、温度传感器等水质参数作为输入,以各种进、出水电磁阀及继电器作为执行机构,采用基于LabVIEW的虚拟仪器技术实现蟹苗培育过程水质的监测和自动控制。     

黄牛在松软地面行走步态的逆向动力学分析

采用高速摄像技术,对黄牛在春耕前的水稻田上行走时肢体的运动形态进行了分析,得到了黄牛的步态参数。利用逆向动力学方法,建立了黄牛在水稻田上行走时的运动学方程。结合实例计算结果,分析了黄牛质心的位移、速度、加速度和土壤作用力的变化,讨论了黄牛在水稻田上行走时的运动特性。该方法为研究和设计松软地面步行机械的运动方式和步法协调提供一定的理论基础。     

仿生步行足沙地力学特性研究

基于螃蟹对滩涂、沙地、湿地等有很强的运动适应性,参照中华绒螯蟹步行足指节的结构,设计了4种仿生步行足:圆锥、圆锥沟纹、棱锥和圆柱沟纹步行足,并与圆柱足对照。通过土槽试验,考察在多种试验条件下,不同步行足对入土力、支承力、推进力和出土力的影响,并采用正交试验分析影响推进力的主要因素。与圆柱足的对比试验结果表明:仿生足有良好的沙地力学特性,锥形仿生足入土力减小64.71%~95.43%;圆柱沟纹仿生足使支承力增加9.48%~24.31%,推进力提高3.84%;仿生足出土力降低13.26%~89.83%,有效减少能耗。研究成果为松软路面步行机构触土部件的设计与优化提供了基础依据。     

基于遗传算法的双足机器人足踝蹬地参数优化

为提高双足机器人步态的经济性,研究了足踝蹬地扭矩和蹬地时机对行走速度和能耗的影响。基于Matlab/Simulink建立了双足机器人仿真模型并搭建了控制程序,以行走速度为目标函数,利用遗传算法对不同步长下足踝蹬地扭矩和蹬地时机进行优化,以两腿间夹角确定步长。利用无量纲速度和无量纲能耗作为评价双足机器人运动性能指标,仿真结果表明,随着步长由40°增加到60°,机器人行走速度和能耗均随之增加。当步长为60°,蹬地扭矩为41N·m,蹬地时机为整个步态周期的43.82%时,双足机器人行走速度最大为0.48,对应能耗为2.97。以速度能耗比作为评价机器人步态经济性指标,仿真结果表明,双足机器人在步长50°,蹬地扭矩为35N·m,蹬地时机为步态周期的45.18%时,机器人步态的经济性更高,对应速度和能耗分别为0.43和2.26。机器人足底地反力出现3个波峰,当步长为50°和60°时,随着足踝蹬地阶段的出现,足底地反力出现第3个波峰,峰值分别为245.45N和281.23N。本研究可为双足机器人在特定步长下选取合适的蹬地参数提供重要参考依据。     

丘陵地区林果作业人机交互助力器研制

利用人体运动学及步态分析基本理论,研制一种人机交互助力器,用于减轻丘陵山地林果农负重爬坡作业的劳动强度和体力消耗,并进行现场实验验证。该助力器分为四部分:固定结构、测试系统、控制系统及动力系统;通过分析人体爬坡时的运动学特征形成步态规划,检测人体运动学参数并判断运动状态,控制舵机动作,带动柔索对人体腿部提供助力,结合弹性机构储存弹性势能原理,从而达到在人体行走、负重爬坡时的助力作用;通过人体运动力学理论分析,实现关键部件选型并进行现场实验,助力效果良好。     

六腿机器人的典型步态研究

本文从稳定性、速度、负重3个角度对六腿机器人在同样占空比下的3中静态稳定性周期步态进行比较。对六腿仿生机器人的静态典型步态运动原理进行了分析,探讨了仿生六腿机器人的典型三脚步态行走规划,并对六腿机器人三角步态稳定性简要分析。本文的研究工作为六腿机器人在非平坦地面自由步态规划提供一定参考意义。     

仿生地面行走机构的步态研究现状与进展

步态是一种生物特征,是研究地面行走机构的基础.为此,对双足人、四足动物、六足昆虫的行走方式和躯体形态以及它们在步态、体态方面的差别进行了综合论述,进而对不同行走方式的机器人的步态策略进行了论述,并对行走机构足数与性能进行了定性评价,展望了动物步态和仿生步行机器人研究的发展前景.     

基于支撑多边形的四足步行机动平台静步态分析

静步态是步行机动平台的基本步态,静步态研究是进行其它步态研究的基础。阐述了静步态的参数和步态稳定性的影响因素。基于足底支撑多边形,分析了间歇静步态不同迈腿顺序下重心的最小调整次数,选择了一种适用于复杂环境行走的间歇静步态。同时,分析了协调静步态各腿的初始位置,选择了一种适用于平坦路面的协调静步态,并计算了稳定裕度。     

茭白田套养河蟹技术

为了进一步推进农业结构战略性调整 ,使农业高产、农民增收 ,扬中市八桥镇农技站在创新村外八圩杂草丛生的抛荒地上进行复垦围埂 ,搞茭白田套养河蟹。茭白品种选用苏州地方品种“小蜡台” ,河蟹选用长江系列“中华绒敖蟹 (当年仔蟹 )。具体试验如下 :一、开沟围埂 :在田的四周筑一条高 1ｍ、宽 1 5ｍ田埂 ,坡度 1∶2 ,筑好后田内四周形成一条围沟 ,占总田面积的 30 %左右。二、围网暂养 :仔蟹进塘时 ,由于个体小、行动慢、食量小、管理难等问题 ,要采用集中围网培育 ,以提高成活率。同时便于网外的小草幼苗早期生长 ,免受幼蟹吃食 ,人工控制…     

步行式挖掘机坡度横向行走稳定性分析

针对步行式挖掘机坡度横向行走时的稳定性问题,建立了包含底盘机构和作业装置多自由度系统的*步行式挖掘机静力学模型,并考虑了作业装置回转运动时附加惯性力矩,构造了步行式挖掘机横向行走时稳定性分析的多目标优化模型.利用效用函数法对多目标优化模型进行求解,对横向行走的最大坡度、底盘和作业装置的状态参数进行了优化分析.结果表明,该方法简单、可靠,为确定步行式挖掘机坡度横向行走时的步行机构状态参数和安全控制提供了理论依据.     

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。