手推式蔬菜种子播种机的设计

随着棚室蔬菜种植业的发展壮大,以人工为主的种植模式已经远远不能满足发展需要,存在种植效率低、播种精度低、浪费种子和株距不均等诸多问题。针对这种情况研发设计一种适合棚室作业的手推式蔬菜种子播种机。该机具采用了高精度排种器,使播种精度、播种效率、株距以及粒距等远远好于人工播种;用户可根据需要随意更换不同的排种轮,一台机具可实现播种不同株距的不同蔬菜种子;整个机具结构简单、设计巧妙、占地面积小。该机具投入使用后将大大减轻农民的劳动强度,使棚室内的种植环境保持清洁、无污染,填补了国内棚室蔬菜种子播种机械的空白。     

动态规划法在日光温室青椒灌溉制度优化设计中的应用

基于Jensen水分生产函数模型,利用动态规划方法对日光温室青椒的灌溉制度进行优化。求解程序采用C#语言编写,分析计算中分别采用格点法和逐次逼近法。结果表明,逐次逼近法的优化效果好。     

基于MSP430的温室大棚温度远程监控系统

研制了一种温室大棚的温度远程监控系统,系统以MSP430F149为控制终端的核心控制器,采用DS18B20作为温度传感器,利用GSM通信网络传输温度、故障等信息至农户手机或监控中心上位机。同时,详细阐述了系统温度采集、控制终端系统、GSM短信息系统和上位机监控系统等硬件设计思想。试验样机在某农户的蔬菜大棚中进行了试验,结果表明:系统能很好地完成温度控制、故障报警、GSM短信息传输功能,具有操作简单、智能化和人机界面友好等特点,在农业领域有良好的推广价值和应用前景。     

基于模糊推理的坝上地区温室杂草识别专家系统的开发

适用于我国坝上地区实际特点的温室杂草识别专家系统目前尚未解决杂草识别过程中的模糊性问题。为此,针对坝上温室杂草识别专家系统知识描述的不确定性,对其中的不确定因素采用模糊逻辑与产生式规则相结合的方法,引入多维模糊推理算法,结合杂草的形态特征进行识别,开发了基于模糊推理的坝上地区温室杂草识别的专家系统。     

设施番茄土壤温室气体排放对水氮管理的响应

[目的]探讨不同水、氮管理设施番茄产量和土壤温室气体排放的相互关系,构建最适水、氮组合模式,以期达到"节水、减氮、高产"的目的.[方法]设置4种氮肥梯度(F0:0 kg/hm2、F1:150 kg/hm2、F2:300 kg/hm2、F3:450 kg/hm2)与3种灌水定额(W1:0.5 Epan、W2:0.7Epa...     

论设施农业的创新与发展

设施农业是在人为可控环境保护设施下进行的高效农业生产方式,具有经济、社会和生态综合效益.在我国大力发展设施农业,对于调整农业产业结构、促进农业增效、农民增收和推动农业可持续发展具有重要意义.为此,阐述了设施农业的内涵与特征,总结分析了我国设施农业发展取得的成就和存在的问题,并在此基础上从加强政府宏观调控、进行科技创新、有效组织、科学管理、完善服务体系、积极开拓市场以及改善环境等方面初步探讨了促进我国设施农业创新发展的对策.     

利用微机对温室培育温度进行控制的研究

随着社会的发展和农业的进步,人们在各个季节都能吃上新鲜的蔬菜和水果.单片机和微型计算机在农业的发展中也起到了非常重要的作用.为此,以MCS51单片机温度控制系统对果蔬的培育环境进行温度控制为例,结合国内外先进温度控制系统的设计,对整个温控系统设计的硬件进行了阐述,说明了具体的调试步骤.     

植物检疫隔离温室的研究与开发

针对我国进出口植物快速增长而植物检疫隔离设施总体水平落后、环境控制功能弱的现状,在多年设计、推广温室设施的基础上,根据国情进行了植物检疫隔离温室的研究与开发。该温室根据植物生理学特性及生长特性进行设计,确保了植物检疫的准确性和有效性。其主要用于进出口植物的检疫,也可用于一些对环境要求极为苛刻植物的种植,对保障我国农产品优质、安全生产及工厂化高效农业的健康发展具有重要意义.     

Simulation of transpiration, drainage, N uptake, nitrate leaching, and N uptake concentration in tomato grown in open substrate

Free-drainage or “open” substrate system used for vegetable production in greenhouses is associated with appreciable NO₃⁻ leaching losses and drainage volumes. Simulation models of crop N uptake, N leaching, water use and drainage of crops in these systems will be useful for crop and water resource management, and environmental assessment. This work (i) modified the TOMGRO model to simulate N uptake for tomato grown in greenhouses in SE Spain, (ii) modified the PrHo model to simulate transpiration of tomato grown in substrate and (iii) developed an aggregated model combining TOMGRO and PrHo to calculate N uptake concentrations and drainage NO₃⁻ concentration. The component models simulate NO₃⁻-N leached by subtracting simulated N uptake from measured applied N, and drainage by subtracting simulated transpiration from measured irrigation. Three tomato crops grown sequentially in free-draining rock wool in a plastic greenhouse were used for calibration and validation. Measured daily transpiration was determined by the water balance method from daily measurements of irrigation and drainage. Measured N uptake was determined by N balance, using data of volumes and of concentrations of NO₃⁻ and NH₄⁺ in applied nutrient solution and drainage. Accuracy of the two modified component models and aggregated model was assessed by comparing simulated to measured values using linear regression analysis, comparison of slope and intercept values of regression equations, and root mean squared error (RMSE) values. For the three crops, the modified TOMGRO provided accurate simulations of cumulative crop N uptake, (RMSE = 6.4, 1.9 and 2.6% of total N uptake) and NO₃⁻-N leached (RMSE = 11.0, 10.3, and 6.1% of total NO₃⁻-N leached). The modified PrHo provided accurate simulation of cumulative transpiration (RMSE = 4.3, 1.7 and 2.4% of total transpiration) and cumulative drainage (RMSE = 13.8, 6.9, 7.4% of total drainage). For the four cumulative parameters, slopes and intercepts of the linear regressions were mostly not statistically significant (P < 0.05) from one and zero, respectively, and coefficient of determination (r²) values were 0.96-0.98. Simulated values of total drainage volumes for the three crops were +21, +1 and −13% of measured total drainage volumes. The aggregated TOMGRO-PrHo model generally provided accurate simulation of crop N uptake concentration after 30-40 days of transplanting, with an average RMSE of approximately 2 mmol L⁻¹. Simulated values of average NO₃⁻ concentration in drainage, obtained with the aggregated model, were −7, +18 and +31% of measured values.     

行星齿轮架孔系加工的车床夹具设计

以一典型零件为例,介绍一种使用专用工艺装备加工孔系的加工方法及工艺装备设计.同时分析了加工过程中误差产生的原因及解决措施.对于中小企业和非专业厂家来说.能利用现有设备资源进行挖潜改造不失为一种投资省、见效快而且切实可行的有效途径.